Merge branch 'irqdomain/next' of git://git.secretlab.ca/git/linux-2.6 into for_3.4/dt_irq_domain2
diff --git a/Documentation/IRQ-domain.txt b/Documentation/IRQ-domain.txt
new file mode 100644
index 0000000..27dcaab
--- /dev/null
+++ b/Documentation/IRQ-domain.txt
@@ -0,0 +1,117 @@
+irq_domain interrupt number mapping library
+
+The current design of the Linux kernel uses a single large number
+space where each separate IRQ source is assigned a different number.
+This is simple when there is only one interrupt controller, but in
+systems with multiple interrupt controllers the kernel must ensure
+that each one gets assigned non-overlapping allocations of Linux
+IRQ numbers.
+
+The irq_alloc_desc*() and irq_free_desc*() APIs provide allocation of
+irq numbers, but they don't provide any support for reverse mapping of
+the controller-local IRQ (hwirq) number into the Linux IRQ number
+space.
+
+The irq_domain library adds mapping between hwirq and IRQ numbers on
+top of the irq_alloc_desc*() API.  An irq_domain to manage mapping is
+preferred over interrupt controller drivers open coding their own
+reverse mapping scheme.
+
+irq_domain also implements translation from Device Tree interrupt
+specifiers to hwirq numbers, and can be easily extended to support
+other IRQ topology data sources.
+
+=== irq_domain usage ===
+An interrupt controller driver creates and registers an irq_domain by
+calling one of the irq_domain_add_*() functions (each mapping method
+has a different allocator function, more on that later).  The function
+will return a pointer to the irq_domain on success.  The caller must
+provide the allocator function with an irq_domain_ops structure with
+the .map callback populated as a minimum.
+
+In most cases, the irq_domain will begin empty without any mappings
+between hwirq and IRQ numbers.  Mappings are added to the irq_domain
+by calling irq_create_mapping() which accepts the irq_domain and a
+hwirq number as arguments.  If a mapping for the hwirq doesn't already
+exist then it will allocate a new Linux irq_desc, associate it with
+the hwirq, and call the .map() callback so the driver can perform any
+required hardware setup.
+
+When an interrupt is received, irq_find_mapping() function should
+be used to find the Linux IRQ number from the hwirq number.
+
+If the driver has the Linux IRQ number or the irq_data pointer, and
+needs to know the associated hwirq number (such as in the irq_chip
+callbacks) then it can be directly obtained from irq_data->hwirq.
+
+=== Types of irq_domain mappings ===
+There are several mechanisms available for reverse mapping from hwirq
+to Linux irq, and each mechanism uses a different allocation function.
+Which reverse map type should be used depends on the use case.  Each
+of the reverse map types are described below:
+
+==== Linear ====
+irq_domain_add_linear()
+
+The linear reverse map maintains a fixed size table indexed by the
+hwirq number.  When a hwirq is mapped, an irq_desc is allocated for
+the hwirq, and the IRQ number is stored in the table.
+
+The Linear map is a good choice when the maximum number of hwirqs is
+fixed and a relatively small number (~ < 256).  The advantages of this
+map are fixed time lookup for IRQ numbers, and irq_descs are only
+allocated for in-use IRQs.  The disadvantage is that the table must be
+as large as the largest possible hwirq number.
+
+The majority of drivers should use the linear map.
+
+==== Tree ====
+irq_domain_add_tree()
+
+The irq_domain maintains a radix tree map from hwirq numbers to Linux
+IRQs.  When an hwirq is mapped, an irq_desc is allocated and the
+hwirq is used as the lookup key for the radix tree.
+
+The tree map is a good choice if the hwirq number can be very large
+since it doesn't need to allocate a table as large as the largest
+hwirq number.  The disadvantage is that hwirq to IRQ number lookup is
+dependent on how many entries are in the table.
+
+Very few drivers should need this mapping.  At the moment, powerpc
+iseries is the only user.
+
+==== No Map ===-
+irq_domain_add_nomap()
+
+The No Map mapping is to be used when the hwirq number is
+programmable in the hardware.  In this case it is best to program the
+Linux IRQ number into the hardware itself so that no mapping is
+required.  Calling irq_create_direct_mapping() will allocate a Linux
+IRQ number and call the .map() callback so that driver can program the
+Linux IRQ number into the hardware.
+
+Most drivers cannot use this mapping.
+
+==== Legacy ====
+irq_domain_add_legacy()
+irq_domain_add_legacy_isa()
+
+The Legacy mapping is a special case for drivers that already have a
+range of irq_descs allocated for the hwirqs.  It is used when the
+driver cannot be immediately converted to use the linear mapping.  For
+example, many embedded system board support files use a set of #defines
+for IRQ numbers that are passed to struct device registrations.  In that
+case the Linux IRQ numbers cannot be dynamically assigned and the legacy
+mapping should be used.
+
+The legacy map assumes a contiguous range of IRQ numbers has already
+been allocated for the controller and that the IRQ number can be
+calculated by adding a fixed offset to the hwirq number, and
+visa-versa.  The disadvantage is that it requires the interrupt
+controller to manage IRQ allocations and it requires an irq_desc to be
+allocated for every hwirq, even if it is unused.
+
+The legacy map should only be used if fixed IRQ mappings must be
+supported.  For example, ISA controllers would use the legacy map for
+mapping Linux IRQs 0-15 so that existing ISA drivers get the correct IRQ
+numbers.
diff --git a/MAINTAINERS b/MAINTAINERS
index 9a648eb..57dd0f5 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3640,6 +3640,15 @@
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git irq/core
 F:	kernel/irq/
 
+IRQ DOMAINS (IRQ NUMBER MAPPING LIBRARY)
+M:	Benjamin Herrenschmidt <benh@kernel.crashing.org>
+M:	Grant Likely <grant.likely@secretlab.ca>
+T:	git git://git.secretlab.ca/git/linux-2.6.git irqdomain/next
+S:	Maintained
+F:	Documentation/IRQ-domain.txt
+F:	include/linux/irqdomain.h
+F:	kernel/irq/irqdomain.c
+
 ISAPNP
 M:	Jaroslav Kysela <perex@perex.cz>
 S:	Maintained
diff --git a/arch/arm/common/gic.c b/arch/arm/common/gic.c
index c47d619..f0783be 100644
--- a/arch/arm/common/gic.c
+++ b/arch/arm/common/gic.c
@@ -51,7 +51,6 @@
 };
 
 struct gic_chip_data {
-	unsigned int irq_offset;
 	union gic_base dist_base;
 	union gic_base cpu_base;
 #ifdef CONFIG_CPU_PM
@@ -61,9 +60,7 @@
 	u32 __percpu *saved_ppi_enable;
 	u32 __percpu *saved_ppi_conf;
 #endif
-#ifdef CONFIG_IRQ_DOMAIN
-	struct irq_domain domain;
-#endif
+	struct irq_domain *domain;
 	unsigned int gic_irqs;
 #ifdef CONFIG_GIC_NON_BANKED
 	void __iomem *(*get_base)(union gic_base *);
@@ -282,7 +279,7 @@
 		irqnr = irqstat & ~0x1c00;
 
 		if (likely(irqnr > 15 && irqnr < 1021)) {
-			irqnr = irq_domain_to_irq(&gic->domain, irqnr);
+			irqnr = irq_find_mapping(gic->domain, irqnr);
 			handle_IRQ(irqnr, regs);
 			continue;
 		}
@@ -314,8 +311,8 @@
 	if (gic_irq == 1023)
 		goto out;
 
-	cascade_irq = irq_domain_to_irq(&chip_data->domain, gic_irq);
-	if (unlikely(gic_irq < 32 || gic_irq > 1020 || cascade_irq >= NR_IRQS))
+	cascade_irq = irq_find_mapping(chip_data->domain, gic_irq);
+	if (unlikely(gic_irq < 32 || gic_irq > 1020))
 		do_bad_IRQ(cascade_irq, desc);
 	else
 		generic_handle_irq(cascade_irq);
@@ -348,10 +345,9 @@
 
 static void __init gic_dist_init(struct gic_chip_data *gic)
 {
-	unsigned int i, irq;
+	unsigned int i;
 	u32 cpumask;
 	unsigned int gic_irqs = gic->gic_irqs;
-	struct irq_domain *domain = &gic->domain;
 	void __iomem *base = gic_data_dist_base(gic);
 	u32 cpu = cpu_logical_map(smp_processor_id());
 
@@ -386,23 +382,6 @@
 	for (i = 32; i < gic_irqs; i += 32)
 		writel_relaxed(0xffffffff, base + GIC_DIST_ENABLE_CLEAR + i * 4 / 32);
 
-	/*
-	 * Setup the Linux IRQ subsystem.
-	 */
-	irq_domain_for_each_irq(domain, i, irq) {
-		if (i < 32) {
-			irq_set_percpu_devid(irq);
-			irq_set_chip_and_handler(irq, &gic_chip,
-						 handle_percpu_devid_irq);
-			set_irq_flags(irq, IRQF_VALID | IRQF_NOAUTOEN);
-		} else {
-			irq_set_chip_and_handler(irq, &gic_chip,
-						 handle_fasteoi_irq);
-			set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
-		}
-		irq_set_chip_data(irq, gic);
-	}
-
 	writel_relaxed(1, base + GIC_DIST_CTRL);
 }
 
@@ -618,11 +597,27 @@
 }
 #endif
 
-#ifdef CONFIG_OF
-static int gic_irq_domain_dt_translate(struct irq_domain *d,
-				       struct device_node *controller,
-				       const u32 *intspec, unsigned int intsize,
-				       unsigned long *out_hwirq, unsigned int *out_type)
+static int gic_irq_domain_map(struct irq_domain *d, unsigned int irq,
+				irq_hw_number_t hw)
+{
+	if (hw < 32) {
+		irq_set_percpu_devid(irq);
+		irq_set_chip_and_handler(irq, &gic_chip,
+					 handle_percpu_devid_irq);
+		set_irq_flags(irq, IRQF_VALID | IRQF_NOAUTOEN);
+	} else {
+		irq_set_chip_and_handler(irq, &gic_chip,
+					 handle_fasteoi_irq);
+		set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
+	}
+	irq_set_chip_data(irq, d->host_data);
+	return 0;
+}
+
+static int gic_irq_domain_xlate(struct irq_domain *d,
+				struct device_node *controller,
+				const u32 *intspec, unsigned int intsize,
+				unsigned long *out_hwirq, unsigned int *out_type)
 {
 	if (d->of_node != controller)
 		return -EINVAL;
@@ -639,26 +634,23 @@
 	*out_type = intspec[2] & IRQ_TYPE_SENSE_MASK;
 	return 0;
 }
-#endif
 
 const struct irq_domain_ops gic_irq_domain_ops = {
-#ifdef CONFIG_OF
-	.dt_translate = gic_irq_domain_dt_translate,
-#endif
+	.map = gic_irq_domain_map,
+	.xlate = gic_irq_domain_xlate,
 };
 
 void __init gic_init_bases(unsigned int gic_nr, int irq_start,
 			   void __iomem *dist_base, void __iomem *cpu_base,
-			   u32 percpu_offset)
+			   u32 percpu_offset, struct device_node *node)
 {
+	irq_hw_number_t hwirq_base;
 	struct gic_chip_data *gic;
-	struct irq_domain *domain;
-	int gic_irqs;
+	int gic_irqs, irq_base;
 
 	BUG_ON(gic_nr >= MAX_GIC_NR);
 
 	gic = &gic_data[gic_nr];
-	domain = &gic->domain;
 #ifdef CONFIG_GIC_NON_BANKED
 	if (percpu_offset) { /* Frankein-GIC without banked registers... */
 		unsigned int cpu;
@@ -694,10 +686,10 @@
 	 * For primary GICs, skip over SGIs.
 	 * For secondary GICs, skip over PPIs, too.
 	 */
-	domain->hwirq_base = 32;
+	hwirq_base = 32;
 	if (gic_nr == 0) {
 		if ((irq_start & 31) > 0) {
-			domain->hwirq_base = 16;
+			hwirq_base = 16;
 			if (irq_start != -1)
 				irq_start = (irq_start & ~31) + 16;
 		}
@@ -713,17 +705,17 @@
 		gic_irqs = 1020;
 	gic->gic_irqs = gic_irqs;
 
-	domain->nr_irq = gic_irqs - domain->hwirq_base;
-	domain->irq_base = irq_alloc_descs(irq_start, 16, domain->nr_irq,
-					   numa_node_id());
-	if (IS_ERR_VALUE(domain->irq_base)) {
+	gic_irqs -= hwirq_base; /* calculate # of irqs to allocate */
+	irq_base = irq_alloc_descs(irq_start, 16, gic_irqs, numa_node_id());
+	if (IS_ERR_VALUE(irq_base)) {
 		WARN(1, "Cannot allocate irq_descs @ IRQ%d, assuming pre-allocated\n",
 		     irq_start);
-		domain->irq_base = irq_start;
+		irq_base = irq_start;
 	}
-	domain->priv = gic;
-	domain->ops = &gic_irq_domain_ops;
-	irq_domain_add(domain);
+	gic->domain = irq_domain_add_legacy(node, gic_irqs, irq_base,
+				    hwirq_base, &gic_irq_domain_ops, gic);
+	if (WARN_ON(!gic->domain))
+		return;
 
 	gic_chip.flags |= gic_arch_extn.flags;
 	gic_dist_init(gic);
@@ -768,7 +760,6 @@
 	void __iomem *dist_base;
 	u32 percpu_offset;
 	int irq;
-	struct irq_domain *domain = &gic_data[gic_cnt].domain;
 
 	if (WARN_ON(!node))
 		return -ENODEV;
@@ -782,9 +773,7 @@
 	if (of_property_read_u32(node, "cpu-offset", &percpu_offset))
 		percpu_offset = 0;
 
-	domain->of_node = of_node_get(node);
-
-	gic_init_bases(gic_cnt, -1, dist_base, cpu_base, percpu_offset);
+	gic_init_bases(gic_cnt, -1, dist_base, cpu_base, percpu_offset, node);
 
 	if (parent) {
 		irq = irq_of_parse_and_map(node, 0);
diff --git a/arch/arm/common/vic.c b/arch/arm/common/vic.c
index dcb004a..7a66311 100644
--- a/arch/arm/common/vic.c
+++ b/arch/arm/common/vic.c
@@ -56,7 +56,7 @@
 	u32		int_enable;
 	u32		soft_int;
 	u32		protect;
-	struct irq_domain domain;
+	struct irq_domain *domain;
 };
 
 /* we cannot allocate memory when VICs are initially registered */
@@ -192,14 +192,8 @@
 	v->resume_sources = resume_sources;
 	v->irq = irq;
 	vic_id++;
-
-	v->domain.irq_base = irq;
-	v->domain.nr_irq = 32;
-#ifdef CONFIG_OF_IRQ
-	v->domain.of_node = of_node_get(node);
-#endif /* CONFIG_OF */
-	v->domain.ops = &irq_domain_simple_ops;
-	irq_domain_add(&v->domain);
+	v->domain = irq_domain_add_legacy(node, 32, irq, 0,
+					  &irq_domain_simple_ops, v);
 }
 
 static void vic_ack_irq(struct irq_data *d)
@@ -348,7 +342,7 @@
 	vic_register(base, irq_start, 0, node);
 }
 
-static void __init __vic_init(void __iomem *base, unsigned int irq_start,
+void __init __vic_init(void __iomem *base, unsigned int irq_start,
 			      u32 vic_sources, u32 resume_sources,
 			      struct device_node *node)
 {
@@ -444,7 +438,7 @@
 	stat = readl_relaxed(vic->base + VIC_IRQ_STATUS);
 	while (stat) {
 		irq = ffs(stat) - 1;
-		handle_IRQ(irq_domain_to_irq(&vic->domain, irq), regs);
+		handle_IRQ(irq_find_mapping(vic->domain, irq), regs);
 		stat &= ~(1 << irq);
 		handled = 1;
 	}
diff --git a/arch/arm/include/asm/hardware/gic.h b/arch/arm/include/asm/hardware/gic.h
index 4bdfe00..4b1ce6c 100644
--- a/arch/arm/include/asm/hardware/gic.h
+++ b/arch/arm/include/asm/hardware/gic.h
@@ -39,7 +39,7 @@
 extern struct irq_chip gic_arch_extn;
 
 void gic_init_bases(unsigned int, int, void __iomem *, void __iomem *,
-		    u32 offset);
+		    u32 offset, struct device_node *);
 int gic_of_init(struct device_node *node, struct device_node *parent);
 void gic_secondary_init(unsigned int);
 void gic_handle_irq(struct pt_regs *regs);
@@ -49,7 +49,7 @@
 static inline void gic_init(unsigned int nr, int start,
 			    void __iomem *dist , void __iomem *cpu)
 {
-	gic_init_bases(nr, start, dist, cpu, 0);
+	gic_init_bases(nr, start, dist, cpu, 0, NULL);
 }
 
 #endif
diff --git a/arch/arm/include/asm/hardware/vic.h b/arch/arm/include/asm/hardware/vic.h
index f42ebd6..e14af1a 100644
--- a/arch/arm/include/asm/hardware/vic.h
+++ b/arch/arm/include/asm/hardware/vic.h
@@ -47,6 +47,8 @@
 struct device_node;
 struct pt_regs;
 
+void __vic_init(void __iomem *base, unsigned int irq_start, u32 vic_sources,
+		u32 resume_sources, struct device_node *node);
 void vic_init(void __iomem *base, unsigned int irq_start, u32 vic_sources, u32 resume_sources);
 int vic_of_init(struct device_node *node, struct device_node *parent);
 void vic_handle_irq(struct pt_regs *regs);
diff --git a/arch/arm/mach-exynos/common.c b/arch/arm/mach-exynos/common.c
index c59e188..6de298c 100644
--- a/arch/arm/mach-exynos/common.c
+++ b/arch/arm/mach-exynos/common.c
@@ -402,7 +402,7 @@
 	gic_bank_offset = soc_is_exynos4412() ? 0x4000 : 0x8000;
 
 	if (!of_have_populated_dt())
-		gic_init_bases(0, IRQ_PPI(0), S5P_VA_GIC_DIST, S5P_VA_GIC_CPU, gic_bank_offset);
+		gic_init_bases(0, IRQ_PPI(0), S5P_VA_GIC_DIST, S5P_VA_GIC_CPU, gic_bank_offset, NULL);
 #ifdef CONFIG_OF
 	else
 		of_irq_init(exynos4_dt_irq_match);
diff --git a/arch/arm/mach-imx/imx51-dt.c b/arch/arm/mach-imx/imx51-dt.c
index e6bad17..1e03ef4 100644
--- a/arch/arm/mach-imx/imx51-dt.c
+++ b/arch/arm/mach-imx/imx51-dt.c
@@ -47,7 +47,7 @@
 static int __init imx51_tzic_add_irq_domain(struct device_node *np,
 				struct device_node *interrupt_parent)
 {
-	irq_domain_add_simple(np, 0);
+	irq_domain_add_legacy(np, 128, 0, 0, &irq_domain_simple_ops, NULL);
 	return 0;
 }
 
@@ -57,7 +57,7 @@
 	static int gpio_irq_base = MXC_GPIO_IRQ_START + ARCH_NR_GPIOS;
 
 	gpio_irq_base -= 32;
-	irq_domain_add_simple(np, gpio_irq_base);
+	irq_domain_add_legacy(np, 32, gpio_irq_base, 0, &irq_domain_simple_ops, NULL);
 
 	return 0;
 }
diff --git a/arch/arm/mach-imx/imx53-dt.c b/arch/arm/mach-imx/imx53-dt.c
index 05ebb3e..fd5be0f2 100644
--- a/arch/arm/mach-imx/imx53-dt.c
+++ b/arch/arm/mach-imx/imx53-dt.c
@@ -51,7 +51,7 @@
 static int __init imx53_tzic_add_irq_domain(struct device_node *np,
 				struct device_node *interrupt_parent)
 {
-	irq_domain_add_simple(np, 0);
+	irq_domain_add_legacy(np, 128, 0, 0, &irq_domain_simple_ops, NULL);
 	return 0;
 }
 
@@ -61,7 +61,7 @@
 	static int gpio_irq_base = MXC_GPIO_IRQ_START + ARCH_NR_GPIOS;
 
 	gpio_irq_base -= 32;
-	irq_domain_add_simple(np, gpio_irq_base);
+	irq_domain_add_legacy(np, 32, gpio_irq_base, 0, &irq_domain_simple_ops, NULL);
 
 	return 0;
 }
diff --git a/arch/arm/mach-imx/mach-imx6q.c b/arch/arm/mach-imx/mach-imx6q.c
index c257281..6075d4d 100644
--- a/arch/arm/mach-imx/mach-imx6q.c
+++ b/arch/arm/mach-imx/mach-imx6q.c
@@ -97,7 +97,8 @@
 	static int gpio_irq_base = MXC_GPIO_IRQ_START + ARCH_NR_GPIOS;
 
 	gpio_irq_base -= 32;
-	irq_domain_add_simple(np, gpio_irq_base);
+	irq_domain_add_legacy(np, 32, gpio_irq_base, 0, &irq_domain_simple_ops,
+			      NULL);
 
 	return 0;
 }
diff --git a/arch/arm/mach-msm/board-msm8x60.c b/arch/arm/mach-msm/board-msm8x60.c
index 0a11342..962e711 100644
--- a/arch/arm/mach-msm/board-msm8x60.c
+++ b/arch/arm/mach-msm/board-msm8x60.c
@@ -80,12 +80,8 @@
 
 static void __init msm8x60_dt_init(void)
 {
-	struct device_node *node;
-
-	node = of_find_matching_node_by_address(NULL, msm_dt_gic_match,
-			MSM8X60_QGIC_DIST_PHYS);
-	if (node)
-		irq_domain_add_simple(node, GIC_SPI_START);
+	irq_domain_generate_simple(msm_dt_gic_match, MSM8X60_QGIC_DIST_PHYS,
+				GIC_SPI_START);
 
 	if (of_machine_is_compatible("qcom,msm8660-surf")) {
 		printk(KERN_INFO "Init surf UART registers\n");
diff --git a/arch/arm/mach-omap2/board-generic.c b/arch/arm/mach-omap2/board-generic.c
index d32b593..02d7e82 100644
--- a/arch/arm/mach-omap2/board-generic.c
+++ b/arch/arm/mach-omap2/board-generic.c
@@ -68,7 +68,7 @@
 {
 	struct device_node *node = of_find_matching_node(NULL, intc_match);
 	if (node)
-		irq_domain_add_simple(node, 0);
+		irq_domain_add_legacy(node, 32, 0, 0, &irq_domain_simple_ops, NULL);
 
 	omap_sdrc_init(NULL, NULL);
 
diff --git a/arch/arm/mach-prima2/irq.c b/arch/arm/mach-prima2/irq.c
index d93ceef..37c2de9 100644
--- a/arch/arm/mach-prima2/irq.c
+++ b/arch/arm/mach-prima2/irq.c
@@ -68,7 +68,7 @@
 	if (!sirfsoc_intc_base)
 		panic("unable to map intc cpu registers\n");
 
-	irq_domain_add_simple(np, 0);
+	irq_domain_add_legacy(np, 32, 0, 0, &irq_domain_simple_ops, NULL);
 
 	of_node_put(np);
 
diff --git a/arch/arm/mach-versatile/core.c b/arch/arm/mach-versatile/core.c
index 02b7b93..008ce22 100644
--- a/arch/arm/mach-versatile/core.c
+++ b/arch/arm/mach-versatile/core.c
@@ -98,8 +98,11 @@
 
 void __init versatile_init_irq(void)
 {
-	vic_init(VA_VIC_BASE, IRQ_VIC_START, ~0, 0);
-	irq_domain_generate_simple(vic_of_match, VERSATILE_VIC_BASE, IRQ_VIC_START);
+	struct device_node *np;
+
+	np = of_find_matching_node_by_address(NULL, vic_of_match,
+					      VERSATILE_VIC_BASE);
+	__vic_init(VA_VIC_BASE, IRQ_VIC_START, ~0, 0, np);
 
 	writel(~0, VA_SIC_BASE + SIC_IRQ_ENABLE_CLEAR);
 
diff --git a/arch/c6x/Kconfig b/arch/c6x/Kconfig
index 26e67f0..3c64b28 100644
--- a/arch/c6x/Kconfig
+++ b/arch/c6x/Kconfig
@@ -12,6 +12,7 @@
 	select HAVE_GENERIC_HARDIRQS
 	select HAVE_MEMBLOCK
 	select HAVE_SPARSE_IRQ
+	select IRQ_DOMAIN
 	select OF
 	select OF_EARLY_FLATTREE
 
diff --git a/arch/c6x/include/asm/irq.h b/arch/c6x/include/asm/irq.h
index a6ae3c9..f13b78d 100644
--- a/arch/c6x/include/asm/irq.h
+++ b/arch/c6x/include/asm/irq.h
@@ -13,6 +13,7 @@
 #ifndef _ASM_C6X_IRQ_H
 #define _ASM_C6X_IRQ_H
 
+#include <linux/irqdomain.h>
 #include <linux/threads.h>
 #include <linux/list.h>
 #include <linux/radix-tree.h>
@@ -41,253 +42,9 @@
 /* This number is used when no interrupt has been assigned */
 #define NO_IRQ		0
 
-/* This type is the placeholder for a hardware interrupt number. It has to
- * be big enough to enclose whatever representation is used by a given
- * platform.
- */
-typedef unsigned long irq_hw_number_t;
-
-/* Interrupt controller "host" data structure. This could be defined as a
- * irq domain controller. That is, it handles the mapping between hardware
- * and virtual interrupt numbers for a given interrupt domain. The host
- * structure is generally created by the PIC code for a given PIC instance
- * (though a host can cover more than one PIC if they have a flat number
- * model). It's the host callbacks that are responsible for setting the
- * irq_chip on a given irq_desc after it's been mapped.
- *
- * The host code and data structures are fairly agnostic to the fact that
- * we use an open firmware device-tree. We do have references to struct
- * device_node in two places: in irq_find_host() to find the host matching
- * a given interrupt controller node, and of course as an argument to its
- * counterpart host->ops->match() callback. However, those are treated as
- * generic pointers by the core and the fact that it's actually a device-node
- * pointer is purely a convention between callers and implementation. This
- * code could thus be used on other architectures by replacing those two
- * by some sort of arch-specific void * "token" used to identify interrupt
- * controllers.
- */
-struct irq_host;
-struct radix_tree_root;
-struct device_node;
-
-/* Functions below are provided by the host and called whenever a new mapping
- * is created or an old mapping is disposed. The host can then proceed to
- * whatever internal data structures management is required. It also needs
- * to setup the irq_desc when returning from map().
- */
-struct irq_host_ops {
-	/* Match an interrupt controller device node to a host, returns
-	 * 1 on a match
-	 */
-	int (*match)(struct irq_host *h, struct device_node *node);
-
-	/* Create or update a mapping between a virtual irq number and a hw
-	 * irq number. This is called only once for a given mapping.
-	 */
-	int (*map)(struct irq_host *h, unsigned int virq, irq_hw_number_t hw);
-
-	/* Dispose of such a mapping */
-	void (*unmap)(struct irq_host *h, unsigned int virq);
-
-	/* Translate device-tree interrupt specifier from raw format coming
-	 * from the firmware to a irq_hw_number_t (interrupt line number) and
-	 * type (sense) that can be passed to set_irq_type(). In the absence
-	 * of this callback, irq_create_of_mapping() and irq_of_parse_and_map()
-	 * will return the hw number in the first cell and IRQ_TYPE_NONE for
-	 * the type (which amount to keeping whatever default value the
-	 * interrupt controller has for that line)
-	 */
-	int (*xlate)(struct irq_host *h, struct device_node *ctrler,
-		     const u32 *intspec, unsigned int intsize,
-		     irq_hw_number_t *out_hwirq, unsigned int *out_type);
-};
-
-struct irq_host {
-	struct list_head	link;
-
-	/* type of reverse mapping technique */
-	unsigned int		revmap_type;
-#define IRQ_HOST_MAP_PRIORITY   0 /* core priority irqs, get irqs 1..15 */
-#define IRQ_HOST_MAP_NOMAP	1 /* no fast reverse mapping */
-#define IRQ_HOST_MAP_LINEAR	2 /* linear map of interrupts */
-#define IRQ_HOST_MAP_TREE	3 /* radix tree */
-	union {
-		struct {
-			unsigned int size;
-			unsigned int *revmap;
-		} linear;
-		struct radix_tree_root tree;
-	} revmap_data;
-	struct irq_host_ops	*ops;
-	void			*host_data;
-	irq_hw_number_t		inval_irq;
-
-	/* Optional device node pointer */
-	struct device_node	*of_node;
-};
-
 struct irq_data;
 extern irq_hw_number_t irqd_to_hwirq(struct irq_data *d);
 extern irq_hw_number_t virq_to_hw(unsigned int virq);
-extern bool virq_is_host(unsigned int virq, struct irq_host *host);
-
-/**
- * irq_alloc_host - Allocate a new irq_host data structure
- * @of_node: optional device-tree node of the interrupt controller
- * @revmap_type: type of reverse mapping to use
- * @revmap_arg: for IRQ_HOST_MAP_LINEAR linear only: size of the map
- * @ops: map/unmap host callbacks
- * @inval_irq: provide a hw number in that host space that is always invalid
- *
- * Allocates and initialize and irq_host structure. Note that in the case of
- * IRQ_HOST_MAP_LEGACY, the map() callback will be called before this returns
- * for all legacy interrupts except 0 (which is always the invalid irq for
- * a legacy controller). For a IRQ_HOST_MAP_LINEAR, the map is allocated by
- * this call as well. For a IRQ_HOST_MAP_TREE, the radix tree will be allocated
- * later during boot automatically (the reverse mapping will use the slow path
- * until that happens).
- */
-extern struct irq_host *irq_alloc_host(struct device_node *of_node,
-				       unsigned int revmap_type,
-				       unsigned int revmap_arg,
-				       struct irq_host_ops *ops,
-				       irq_hw_number_t inval_irq);
-
-
-/**
- * irq_find_host - Locates a host for a given device node
- * @node: device-tree node of the interrupt controller
- */
-extern struct irq_host *irq_find_host(struct device_node *node);
-
-
-/**
- * irq_set_default_host - Set a "default" host
- * @host: default host pointer
- *
- * For convenience, it's possible to set a "default" host that will be used
- * whenever NULL is passed to irq_create_mapping(). It makes life easier for
- * platforms that want to manipulate a few hard coded interrupt numbers that
- * aren't properly represented in the device-tree.
- */
-extern void irq_set_default_host(struct irq_host *host);
-
-
-/**
- * irq_set_virq_count - Set the maximum number of virt irqs
- * @count: number of linux virtual irqs, capped with NR_IRQS
- *
- * This is mainly for use by platforms like iSeries who want to program
- * the virtual irq number in the controller to avoid the reverse mapping
- */
-extern void irq_set_virq_count(unsigned int count);
-
-
-/**
- * irq_create_mapping - Map a hardware interrupt into linux virq space
- * @host: host owning this hardware interrupt or NULL for default host
- * @hwirq: hardware irq number in that host space
- *
- * Only one mapping per hardware interrupt is permitted. Returns a linux
- * virq number.
- * If the sense/trigger is to be specified, set_irq_type() should be called
- * on the number returned from that call.
- */
-extern unsigned int irq_create_mapping(struct irq_host *host,
-				       irq_hw_number_t hwirq);
-
-
-/**
- * irq_dispose_mapping - Unmap an interrupt
- * @virq: linux virq number of the interrupt to unmap
- */
-extern void irq_dispose_mapping(unsigned int virq);
-
-/**
- * irq_find_mapping - Find a linux virq from an hw irq number.
- * @host: host owning this hardware interrupt
- * @hwirq: hardware irq number in that host space
- *
- * This is a slow path, for use by generic code. It's expected that an
- * irq controller implementation directly calls the appropriate low level
- * mapping function.
- */
-extern unsigned int irq_find_mapping(struct irq_host *host,
-				     irq_hw_number_t hwirq);
-
-/**
- * irq_create_direct_mapping - Allocate a virq for direct mapping
- * @host: host to allocate the virq for or NULL for default host
- *
- * This routine is used for irq controllers which can choose the hardware
- * interrupt numbers they generate. In such a case it's simplest to use
- * the linux virq as the hardware interrupt number.
- */
-extern unsigned int irq_create_direct_mapping(struct irq_host *host);
-
-/**
- * irq_radix_revmap_insert - Insert a hw irq to linux virq number mapping.
- * @host: host owning this hardware interrupt
- * @virq: linux irq number
- * @hwirq: hardware irq number in that host space
- *
- * This is for use by irq controllers that use a radix tree reverse
- * mapping for fast lookup.
- */
-extern void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq,
-				    irq_hw_number_t hwirq);
-
-/**
- * irq_radix_revmap_lookup - Find a linux virq from a hw irq number.
- * @host: host owning this hardware interrupt
- * @hwirq: hardware irq number in that host space
- *
- * This is a fast path, for use by irq controller code that uses radix tree
- * revmaps
- */
-extern unsigned int irq_radix_revmap_lookup(struct irq_host *host,
-					    irq_hw_number_t hwirq);
-
-/**
- * irq_linear_revmap - Find a linux virq from a hw irq number.
- * @host: host owning this hardware interrupt
- * @hwirq: hardware irq number in that host space
- *
- * This is a fast path, for use by irq controller code that uses linear
- * revmaps. It does fallback to the slow path if the revmap doesn't exist
- * yet and will create the revmap entry with appropriate locking
- */
-
-extern unsigned int irq_linear_revmap(struct irq_host *host,
-				      irq_hw_number_t hwirq);
-
-
-
-/**
- * irq_alloc_virt - Allocate virtual irq numbers
- * @host: host owning these new virtual irqs
- * @count: number of consecutive numbers to allocate
- * @hint: pass a hint number, the allocator will try to use a 1:1 mapping
- *
- * This is a low level function that is used internally by irq_create_mapping()
- * and that can be used by some irq controllers implementations for things
- * like allocating ranges of numbers for MSIs. The revmaps are left untouched.
- */
-extern unsigned int irq_alloc_virt(struct irq_host *host,
-				   unsigned int count,
-				   unsigned int hint);
-
-/**
- * irq_free_virt - Free virtual irq numbers
- * @virq: virtual irq number of the first interrupt to free
- * @count: number of interrupts to free
- *
- * This function is the opposite of irq_alloc_virt. It will not clear reverse
- * maps, this should be done previously by unmap'ing the interrupt. In fact,
- * all interrupts covered by the range being freed should have been unmapped
- * prior to calling this.
- */
-extern void irq_free_virt(unsigned int virq, unsigned int count);
 
 extern void __init init_pic_c64xplus(void);
 
diff --git a/arch/c6x/kernel/irq.c b/arch/c6x/kernel/irq.c
index 0929e4b..d77bcfd 100644
--- a/arch/c6x/kernel/irq.c
+++ b/arch/c6x/kernel/irq.c
@@ -73,10 +73,10 @@
 	set_irq_regs(old_regs);
 }
 
-static struct irq_host *core_host;
+static struct irq_domain *core_domain;
 
-static int core_host_map(struct irq_host *h, unsigned int virq,
-			 irq_hw_number_t hw)
+static int core_domain_map(struct irq_domain *h, unsigned int virq,
+			   irq_hw_number_t hw)
 {
 	if (hw < 4 || hw >= NR_PRIORITY_IRQS)
 		return -EINVAL;
@@ -86,8 +86,9 @@
 	return 0;
 }
 
-static struct irq_host_ops core_host_ops = {
-	.map = core_host_map,
+static const struct irq_domain_ops core_domain_ops = {
+	.map = core_domain_map,
+	.xlate = irq_domain_xlate_onecell,
 };
 
 void __init init_IRQ(void)
@@ -100,10 +101,11 @@
 	np = of_find_compatible_node(NULL, NULL, "ti,c64x+core-pic");
 	if (np != NULL) {
 		/* create the core host */
-		core_host = irq_alloc_host(np, IRQ_HOST_MAP_PRIORITY, 0,
-					   &core_host_ops, 0);
-		if (core_host)
-			irq_set_default_host(core_host);
+		core_domain = irq_domain_add_legacy(np, NR_PRIORITY_IRQS,
+						    0, 0, &core_domain_ops,
+						    NULL);
+		if (core_domain)
+			irq_set_default_host(core_domain);
 		of_node_put(np);
 	}
 
@@ -128,601 +130,15 @@
 	return 0;
 }
 
-/*
- * IRQ controller and virtual interrupts
- */
-
-/* The main irq map itself is an array of NR_IRQ entries containing the
- * associate host and irq number. An entry with a host of NULL is free.
- * An entry can be allocated if it's free, the allocator always then sets
- * hwirq first to the host's invalid irq number and then fills ops.
- */
-struct irq_map_entry {
-	irq_hw_number_t	hwirq;
-	struct irq_host	*host;
-};
-
-static LIST_HEAD(irq_hosts);
-static DEFINE_RAW_SPINLOCK(irq_big_lock);
-static DEFINE_MUTEX(revmap_trees_mutex);
-static struct irq_map_entry irq_map[NR_IRQS];
-static unsigned int irq_virq_count = NR_IRQS;
-static struct irq_host *irq_default_host;
-
 irq_hw_number_t irqd_to_hwirq(struct irq_data *d)
 {
-	return irq_map[d->irq].hwirq;
+	return d->hwirq;
 }
 EXPORT_SYMBOL_GPL(irqd_to_hwirq);
 
 irq_hw_number_t virq_to_hw(unsigned int virq)
 {
-	return irq_map[virq].hwirq;
+	struct irq_data *irq_data = irq_get_irq_data(virq);
+	return WARN_ON(!irq_data) ? 0 : irq_data->hwirq;
 }
 EXPORT_SYMBOL_GPL(virq_to_hw);
-
-bool virq_is_host(unsigned int virq, struct irq_host *host)
-{
-	return irq_map[virq].host == host;
-}
-EXPORT_SYMBOL_GPL(virq_is_host);
-
-static int default_irq_host_match(struct irq_host *h, struct device_node *np)
-{
-	return h->of_node != NULL && h->of_node == np;
-}
-
-struct irq_host *irq_alloc_host(struct device_node *of_node,
-				unsigned int revmap_type,
-				unsigned int revmap_arg,
-				struct irq_host_ops *ops,
-				irq_hw_number_t inval_irq)
-{
-	struct irq_host *host;
-	unsigned int size = sizeof(struct irq_host);
-	unsigned int i;
-	unsigned int *rmap;
-	unsigned long flags;
-
-	/* Allocate structure and revmap table if using linear mapping */
-	if (revmap_type == IRQ_HOST_MAP_LINEAR)
-		size += revmap_arg * sizeof(unsigned int);
-	host = kzalloc(size, GFP_KERNEL);
-	if (host == NULL)
-		return NULL;
-
-	/* Fill structure */
-	host->revmap_type = revmap_type;
-	host->inval_irq = inval_irq;
-	host->ops = ops;
-	host->of_node = of_node_get(of_node);
-
-	if (host->ops->match == NULL)
-		host->ops->match = default_irq_host_match;
-
-	raw_spin_lock_irqsave(&irq_big_lock, flags);
-
-	/* Check for the priority controller. */
-	if (revmap_type == IRQ_HOST_MAP_PRIORITY) {
-		if (irq_map[0].host != NULL) {
-			raw_spin_unlock_irqrestore(&irq_big_lock, flags);
-			of_node_put(host->of_node);
-			kfree(host);
-			return NULL;
-		}
-		irq_map[0].host = host;
-	}
-
-	list_add(&host->link, &irq_hosts);
-	raw_spin_unlock_irqrestore(&irq_big_lock, flags);
-
-	/* Additional setups per revmap type */
-	switch (revmap_type) {
-	case IRQ_HOST_MAP_PRIORITY:
-		/* 0 is always the invalid number for priority */
-		host->inval_irq = 0;
-		/* setup us as the host for all priority interrupts */
-		for (i = 1; i < NR_PRIORITY_IRQS; i++) {
-			irq_map[i].hwirq = i;
-			smp_wmb();
-			irq_map[i].host = host;
-			smp_wmb();
-
-			ops->map(host, i, i);
-		}
-		break;
-	case IRQ_HOST_MAP_LINEAR:
-		rmap = (unsigned int *)(host + 1);
-		for (i = 0; i < revmap_arg; i++)
-			rmap[i] = NO_IRQ;
-		host->revmap_data.linear.size = revmap_arg;
-		smp_wmb();
-		host->revmap_data.linear.revmap = rmap;
-		break;
-	case IRQ_HOST_MAP_TREE:
-		INIT_RADIX_TREE(&host->revmap_data.tree, GFP_KERNEL);
-		break;
-	default:
-		break;
-	}
-
-	pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
-
-	return host;
-}
-
-struct irq_host *irq_find_host(struct device_node *node)
-{
-	struct irq_host *h, *found = NULL;
-	unsigned long flags;
-
-	/* We might want to match the legacy controller last since
-	 * it might potentially be set to match all interrupts in
-	 * the absence of a device node. This isn't a problem so far
-	 * yet though...
-	 */
-	raw_spin_lock_irqsave(&irq_big_lock, flags);
-	list_for_each_entry(h, &irq_hosts, link)
-		if (h->ops->match(h, node)) {
-			found = h;
-			break;
-		}
-	raw_spin_unlock_irqrestore(&irq_big_lock, flags);
-	return found;
-}
-EXPORT_SYMBOL_GPL(irq_find_host);
-
-void irq_set_default_host(struct irq_host *host)
-{
-	pr_debug("irq: Default host set to @0x%p\n", host);
-
-	irq_default_host = host;
-}
-
-void irq_set_virq_count(unsigned int count)
-{
-	pr_debug("irq: Trying to set virq count to %d\n", count);
-
-	BUG_ON(count < NR_PRIORITY_IRQS);
-	if (count < NR_IRQS)
-		irq_virq_count = count;
-}
-
-static int irq_setup_virq(struct irq_host *host, unsigned int virq,
-			    irq_hw_number_t hwirq)
-{
-	int res;
-
-	res = irq_alloc_desc_at(virq, 0);
-	if (res != virq) {
-		pr_debug("irq: -> allocating desc failed\n");
-		goto error;
-	}
-
-	/* map it */
-	smp_wmb();
-	irq_map[virq].hwirq = hwirq;
-	smp_mb();
-
-	if (host->ops->map(host, virq, hwirq)) {
-		pr_debug("irq: -> mapping failed, freeing\n");
-		goto errdesc;
-	}
-
-	irq_clear_status_flags(virq, IRQ_NOREQUEST);
-
-	return 0;
-
-errdesc:
-	irq_free_descs(virq, 1);
-error:
-	irq_free_virt(virq, 1);
-	return -1;
-}
-
-unsigned int irq_create_direct_mapping(struct irq_host *host)
-{
-	unsigned int virq;
-
-	if (host == NULL)
-		host = irq_default_host;
-
-	BUG_ON(host == NULL);
-	WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
-
-	virq = irq_alloc_virt(host, 1, 0);
-	if (virq == NO_IRQ) {
-		pr_debug("irq: create_direct virq allocation failed\n");
-		return NO_IRQ;
-	}
-
-	pr_debug("irq: create_direct obtained virq %d\n", virq);
-
-	if (irq_setup_virq(host, virq, virq))
-		return NO_IRQ;
-
-	return virq;
-}
-
-unsigned int irq_create_mapping(struct irq_host *host,
-				irq_hw_number_t hwirq)
-{
-	unsigned int virq, hint;
-
-	pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
-
-	/* Look for default host if nececssary */
-	if (host == NULL)
-		host = irq_default_host;
-	if (host == NULL) {
-		printk(KERN_WARNING "irq_create_mapping called for"
-		       " NULL host, hwirq=%lx\n", hwirq);
-		WARN_ON(1);
-		return NO_IRQ;
-	}
-	pr_debug("irq: -> using host @%p\n", host);
-
-	/* Check if mapping already exists */
-	virq = irq_find_mapping(host, hwirq);
-	if (virq != NO_IRQ) {
-		pr_debug("irq: -> existing mapping on virq %d\n", virq);
-		return virq;
-	}
-
-	/* Allocate a virtual interrupt number */
-	hint = hwirq % irq_virq_count;
-	virq = irq_alloc_virt(host, 1, hint);
-	if (virq == NO_IRQ) {
-		pr_debug("irq: -> virq allocation failed\n");
-		return NO_IRQ;
-	}
-
-	if (irq_setup_virq(host, virq, hwirq))
-		return NO_IRQ;
-
-	pr_debug("irq: irq %lu on host %s mapped to virtual irq %u\n",
-		hwirq, host->of_node ? host->of_node->full_name : "null", virq);
-
-	return virq;
-}
-EXPORT_SYMBOL_GPL(irq_create_mapping);
-
-unsigned int irq_create_of_mapping(struct device_node *controller,
-				   const u32 *intspec, unsigned int intsize)
-{
-	struct irq_host *host;
-	irq_hw_number_t hwirq;
-	unsigned int type = IRQ_TYPE_NONE;
-	unsigned int virq;
-
-	if (controller == NULL)
-		host = irq_default_host;
-	else
-		host = irq_find_host(controller);
-	if (host == NULL) {
-		printk(KERN_WARNING "irq: no irq host found for %s !\n",
-		       controller->full_name);
-		return NO_IRQ;
-	}
-
-	/* If host has no translation, then we assume interrupt line */
-	if (host->ops->xlate == NULL)
-		hwirq = intspec[0];
-	else {
-		if (host->ops->xlate(host, controller, intspec, intsize,
-				     &hwirq, &type))
-			return NO_IRQ;
-	}
-
-	/* Create mapping */
-	virq = irq_create_mapping(host, hwirq);
-	if (virq == NO_IRQ)
-		return virq;
-
-	/* Set type if specified and different than the current one */
-	if (type != IRQ_TYPE_NONE &&
-	    type != (irqd_get_trigger_type(irq_get_irq_data(virq))))
-		irq_set_irq_type(virq, type);
-	return virq;
-}
-EXPORT_SYMBOL_GPL(irq_create_of_mapping);
-
-void irq_dispose_mapping(unsigned int virq)
-{
-	struct irq_host *host;
-	irq_hw_number_t hwirq;
-
-	if (virq == NO_IRQ)
-		return;
-
-	/* Never unmap priority interrupts */
-	if (virq < NR_PRIORITY_IRQS)
-		return;
-
-	host = irq_map[virq].host;
-	if (WARN_ON(host == NULL))
-		return;
-
-	irq_set_status_flags(virq, IRQ_NOREQUEST);
-
-	/* remove chip and handler */
-	irq_set_chip_and_handler(virq, NULL, NULL);
-
-	/* Make sure it's completed */
-	synchronize_irq(virq);
-
-	/* Tell the PIC about it */
-	if (host->ops->unmap)
-		host->ops->unmap(host, virq);
-	smp_mb();
-
-	/* Clear reverse map */
-	hwirq = irq_map[virq].hwirq;
-	switch (host->revmap_type) {
-	case IRQ_HOST_MAP_LINEAR:
-		if (hwirq < host->revmap_data.linear.size)
-			host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
-		break;
-	case IRQ_HOST_MAP_TREE:
-		mutex_lock(&revmap_trees_mutex);
-		radix_tree_delete(&host->revmap_data.tree, hwirq);
-		mutex_unlock(&revmap_trees_mutex);
-		break;
-	}
-
-	/* Destroy map */
-	smp_mb();
-	irq_map[virq].hwirq = host->inval_irq;
-
-	irq_free_descs(virq, 1);
-	/* Free it */
-	irq_free_virt(virq, 1);
-}
-EXPORT_SYMBOL_GPL(irq_dispose_mapping);
-
-unsigned int irq_find_mapping(struct irq_host *host,
-			      irq_hw_number_t hwirq)
-{
-	unsigned int i;
-	unsigned int hint = hwirq % irq_virq_count;
-
-	/* Look for default host if nececssary */
-	if (host == NULL)
-		host = irq_default_host;
-	if (host == NULL)
-		return NO_IRQ;
-
-	/* Slow path does a linear search of the map */
-	i = hint;
-	do  {
-		if (irq_map[i].host == host &&
-		    irq_map[i].hwirq == hwirq)
-			return i;
-		i++;
-		if (i >= irq_virq_count)
-			i = 4;
-	} while (i != hint);
-	return NO_IRQ;
-}
-EXPORT_SYMBOL_GPL(irq_find_mapping);
-
-unsigned int irq_radix_revmap_lookup(struct irq_host *host,
-				     irq_hw_number_t hwirq)
-{
-	struct irq_map_entry *ptr;
-	unsigned int virq;
-
-	if (WARN_ON_ONCE(host->revmap_type != IRQ_HOST_MAP_TREE))
-		return irq_find_mapping(host, hwirq);
-
-	/*
-	 * The ptr returned references the static global irq_map.
-	 * but freeing an irq can delete nodes along the path to
-	 * do the lookup via call_rcu.
-	 */
-	rcu_read_lock();
-	ptr = radix_tree_lookup(&host->revmap_data.tree, hwirq);
-	rcu_read_unlock();
-
-	/*
-	 * If found in radix tree, then fine.
-	 * Else fallback to linear lookup - this should not happen in practice
-	 * as it means that we failed to insert the node in the radix tree.
-	 */
-	if (ptr)
-		virq = ptr - irq_map;
-	else
-		virq = irq_find_mapping(host, hwirq);
-
-	return virq;
-}
-
-void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq,
-			     irq_hw_number_t hwirq)
-{
-	if (WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE))
-		return;
-
-	if (virq != NO_IRQ) {
-		mutex_lock(&revmap_trees_mutex);
-		radix_tree_insert(&host->revmap_data.tree, hwirq,
-				  &irq_map[virq]);
-		mutex_unlock(&revmap_trees_mutex);
-	}
-}
-
-unsigned int irq_linear_revmap(struct irq_host *host,
-			       irq_hw_number_t hwirq)
-{
-	unsigned int *revmap;
-
-	if (WARN_ON_ONCE(host->revmap_type != IRQ_HOST_MAP_LINEAR))
-		return irq_find_mapping(host, hwirq);
-
-	/* Check revmap bounds */
-	if (unlikely(hwirq >= host->revmap_data.linear.size))
-		return irq_find_mapping(host, hwirq);
-
-	/* Check if revmap was allocated */
-	revmap = host->revmap_data.linear.revmap;
-	if (unlikely(revmap == NULL))
-		return irq_find_mapping(host, hwirq);
-
-	/* Fill up revmap with slow path if no mapping found */
-	if (unlikely(revmap[hwirq] == NO_IRQ))
-		revmap[hwirq] = irq_find_mapping(host, hwirq);
-
-	return revmap[hwirq];
-}
-
-unsigned int irq_alloc_virt(struct irq_host *host,
-			    unsigned int count,
-			    unsigned int hint)
-{
-	unsigned long flags;
-	unsigned int i, j, found = NO_IRQ;
-
-	if (count == 0 || count > (irq_virq_count - NR_PRIORITY_IRQS))
-		return NO_IRQ;
-
-	raw_spin_lock_irqsave(&irq_big_lock, flags);
-
-	/* Use hint for 1 interrupt if any */
-	if (count == 1 && hint >= NR_PRIORITY_IRQS &&
-	    hint < irq_virq_count && irq_map[hint].host == NULL) {
-		found = hint;
-		goto hint_found;
-	}
-
-	/* Look for count consecutive numbers in the allocatable
-	 * (non-legacy) space
-	 */
-	for (i = NR_PRIORITY_IRQS, j = 0; i < irq_virq_count; i++) {
-		if (irq_map[i].host != NULL)
-			j = 0;
-		else
-			j++;
-
-		if (j == count) {
-			found = i - count + 1;
-			break;
-		}
-	}
-	if (found == NO_IRQ) {
-		raw_spin_unlock_irqrestore(&irq_big_lock, flags);
-		return NO_IRQ;
-	}
- hint_found:
-	for (i = found; i < (found + count); i++) {
-		irq_map[i].hwirq = host->inval_irq;
-		smp_wmb();
-		irq_map[i].host = host;
-	}
-	raw_spin_unlock_irqrestore(&irq_big_lock, flags);
-	return found;
-}
-
-void irq_free_virt(unsigned int virq, unsigned int count)
-{
-	unsigned long flags;
-	unsigned int i;
-
-	WARN_ON(virq < NR_PRIORITY_IRQS);
-	WARN_ON(count == 0 || (virq + count) > irq_virq_count);
-
-	if (virq < NR_PRIORITY_IRQS) {
-		if (virq + count < NR_PRIORITY_IRQS)
-			return;
-		count  -= NR_PRIORITY_IRQS - virq;
-		virq = NR_PRIORITY_IRQS;
-	}
-
-	if (count > irq_virq_count || virq > irq_virq_count - count) {
-		if (virq > irq_virq_count)
-			return;
-		count = irq_virq_count - virq;
-	}
-
-	raw_spin_lock_irqsave(&irq_big_lock, flags);
-	for (i = virq; i < (virq + count); i++) {
-		struct irq_host *host;
-
-		host = irq_map[i].host;
-		irq_map[i].hwirq = host->inval_irq;
-		smp_wmb();
-		irq_map[i].host = NULL;
-	}
-	raw_spin_unlock_irqrestore(&irq_big_lock, flags);
-}
-
-#ifdef CONFIG_VIRQ_DEBUG
-static int virq_debug_show(struct seq_file *m, void *private)
-{
-	unsigned long flags;
-	struct irq_desc *desc;
-	const char *p;
-	static const char none[] = "none";
-	void *data;
-	int i;
-
-	seq_printf(m, "%-5s  %-7s  %-15s  %-18s  %s\n", "virq", "hwirq",
-		      "chip name", "chip data", "host name");
-
-	for (i = 1; i < nr_irqs; i++) {
-		desc = irq_to_desc(i);
-		if (!desc)
-			continue;
-
-		raw_spin_lock_irqsave(&desc->lock, flags);
-
-		if (desc->action && desc->action->handler) {
-			struct irq_chip *chip;
-
-			seq_printf(m, "%5d  ", i);
-			seq_printf(m, "0x%05lx  ", irq_map[i].hwirq);
-
-			chip = irq_desc_get_chip(desc);
-			if (chip && chip->name)
-				p = chip->name;
-			else
-				p = none;
-			seq_printf(m, "%-15s  ", p);
-
-			data = irq_desc_get_chip_data(desc);
-			seq_printf(m, "0x%16p  ", data);
-
-			if (irq_map[i].host && irq_map[i].host->of_node)
-				p = irq_map[i].host->of_node->full_name;
-			else
-				p = none;
-			seq_printf(m, "%s\n", p);
-		}
-
-		raw_spin_unlock_irqrestore(&desc->lock, flags);
-	}
-
-	return 0;
-}
-
-static int virq_debug_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, virq_debug_show, inode->i_private);
-}
-
-static const struct file_operations virq_debug_fops = {
-	.open = virq_debug_open,
-	.read = seq_read,
-	.llseek = seq_lseek,
-	.release = single_release,
-};
-
-static int __init irq_debugfs_init(void)
-{
-	if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
-				 NULL, &virq_debug_fops) == NULL)
-		return -ENOMEM;
-
-	return 0;
-}
-device_initcall(irq_debugfs_init);
-#endif /* CONFIG_VIRQ_DEBUG */
diff --git a/arch/c6x/platforms/megamod-pic.c b/arch/c6x/platforms/megamod-pic.c
index 7c37a94..c1c4e2a 100644
--- a/arch/c6x/platforms/megamod-pic.c
+++ b/arch/c6x/platforms/megamod-pic.c
@@ -48,7 +48,7 @@
 };
 
 struct megamod_pic {
-	struct irq_host	*irqhost;
+	struct irq_domain *irqhost;
 	struct megamod_regs __iomem *regs;
 	raw_spinlock_t lock;
 
@@ -116,7 +116,7 @@
 	}
 }
 
-static int megamod_map(struct irq_host *h, unsigned int virq,
+static int megamod_map(struct irq_domain *h, unsigned int virq,
 		       irq_hw_number_t hw)
 {
 	struct megamod_pic *pic = h->host_data;
@@ -136,21 +136,9 @@
 	return 0;
 }
 
-static int megamod_xlate(struct irq_host *h, struct device_node *ct,
-			 const u32 *intspec, unsigned int intsize,
-			 irq_hw_number_t *out_hwirq, unsigned int *out_type)
-
-{
-	/* megamod intspecs must have 1 cell */
-	BUG_ON(intsize != 1);
-	*out_hwirq = intspec[0];
-	*out_type = IRQ_TYPE_NONE;
-	return 0;
-}
-
-static struct irq_host_ops megamod_host_ops = {
+static const struct irq_domain_ops megamod_domain_ops = {
 	.map	= megamod_map,
-	.xlate	= megamod_xlate,
+	.xlate	= irq_domain_xlate_onecell,
 };
 
 static void __init set_megamod_mux(struct megamod_pic *pic, int src, int output)
@@ -223,9 +211,8 @@
 		return NULL;
 	}
 
-	pic->irqhost = irq_alloc_host(np, IRQ_HOST_MAP_LINEAR,
-				      NR_COMBINERS * 32, &megamod_host_ops,
-				      IRQ_UNMAPPED);
+	pic->irqhost = irq_domain_add_linear(np, NR_COMBINERS * 32,
+					     &megamod_domain_ops, pic);
 	if (!pic->irqhost) {
 		pr_err("%s: Could not alloc host.\n", np->full_name);
 		goto error_free;
diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
index c8d6efb..11060fa 100644
--- a/arch/microblaze/Kconfig
+++ b/arch/microblaze/Kconfig
@@ -14,6 +14,7 @@
 	select TRACING_SUPPORT
 	select OF
 	select OF_EARLY_FLATTREE
+	select IRQ_DOMAIN
 	select HAVE_GENERIC_HARDIRQS
 	select GENERIC_IRQ_PROBE
 	select GENERIC_IRQ_SHOW
diff --git a/arch/microblaze/include/asm/hardirq.h b/arch/microblaze/include/asm/hardirq.h
index cd1ac9a..fb3c05a 100644
--- a/arch/microblaze/include/asm/hardirq.h
+++ b/arch/microblaze/include/asm/hardirq.h
@@ -1,17 +1 @@
-/*
- * Copyright (C) 2006 Atmark Techno, Inc.
- *
- * This file is subject to the terms and conditions of the GNU General Public
- * License. See the file "COPYING" in the main directory of this archive
- * for more details.
- */
-
-#ifndef _ASM_MICROBLAZE_HARDIRQ_H
-#define _ASM_MICROBLAZE_HARDIRQ_H
-
-/* should be defined in each interrupt controller driver */
-extern unsigned int get_irq(struct pt_regs *regs);
-
 #include <asm-generic/hardirq.h>
-
-#endif /* _ASM_MICROBLAZE_HARDIRQ_H */
diff --git a/arch/microblaze/include/asm/irq.h b/arch/microblaze/include/asm/irq.h
index a175132..bab3b13 100644
--- a/arch/microblaze/include/asm/irq.h
+++ b/arch/microblaze/include/asm/irq.h
@@ -9,49 +9,13 @@
 #ifndef _ASM_MICROBLAZE_IRQ_H
 #define _ASM_MICROBLAZE_IRQ_H
 
-
-/*
- * Linux IRQ# is currently offset by one to map to the hardware
- * irq number. So hardware IRQ0 maps to Linux irq 1.
- */
-#define NO_IRQ_OFFSET	1
-#define IRQ_OFFSET	NO_IRQ_OFFSET
-#define NR_IRQS		(32 + IRQ_OFFSET)
+#define NR_IRQS		(32 + 1)
 #include <asm-generic/irq.h>
 
-/* This type is the placeholder for a hardware interrupt number. It has to
- * be big enough to enclose whatever representation is used by a given
- * platform.
- */
-typedef unsigned long irq_hw_number_t;
-
-extern unsigned int nr_irq;
-
 struct pt_regs;
 extern void do_IRQ(struct pt_regs *regs);
 
-/** FIXME - not implement
- * irq_dispose_mapping - Unmap an interrupt
- * @virq: linux virq number of the interrupt to unmap
- */
-static inline void irq_dispose_mapping(unsigned int virq)
-{
-	return;
-}
-
-struct irq_host;
-
-/**
- * irq_create_mapping - Map a hardware interrupt into linux virq space
- * @host: host owning this hardware interrupt or NULL for default host
- * @hwirq: hardware irq number in that host space
- *
- * Only one mapping per hardware interrupt is permitted. Returns a linux
- * virq number.
- * If the sense/trigger is to be specified, set_irq_type() should be called
- * on the number returned from that call.
- */
-extern unsigned int irq_create_mapping(struct irq_host *host,
-					irq_hw_number_t hwirq);
+/* should be defined in each interrupt controller driver */
+extern unsigned int get_irq(void);
 
 #endif /* _ASM_MICROBLAZE_IRQ_H */
diff --git a/arch/microblaze/kernel/intc.c b/arch/microblaze/kernel/intc.c
index 44b177e..ad12067 100644
--- a/arch/microblaze/kernel/intc.c
+++ b/arch/microblaze/kernel/intc.c
@@ -9,6 +9,7 @@
  */
 
 #include <linux/init.h>
+#include <linux/irqdomain.h>
 #include <linux/irq.h>
 #include <asm/page.h>
 #include <linux/io.h>
@@ -25,8 +26,6 @@
 #define INTC_BASE	intc_baseaddr
 #endif
 
-unsigned int nr_irq;
-
 /* No one else should require these constants, so define them locally here. */
 #define ISR 0x00			/* Interrupt Status Register */
 #define IPR 0x04			/* Interrupt Pending Register */
@@ -84,24 +83,45 @@
 	.irq_mask_ack = intc_mask_ack,
 };
 
-unsigned int get_irq(struct pt_regs *regs)
-{
-	int irq;
+static struct irq_domain *root_domain;
 
-	/*
-	 * NOTE: This function is the one that needs to be improved in
-	 * order to handle multiple interrupt controllers. It currently
-	 * is hardcoded to check for interrupts only on the first INTC.
-	 */
-	irq = in_be32(INTC_BASE + IVR) + NO_IRQ_OFFSET;
-	pr_debug("get_irq: %d\n", irq);
+unsigned int get_irq(void)
+{
+	unsigned int hwirq, irq = -1;
+
+	hwirq = in_be32(INTC_BASE + IVR);
+	if (hwirq != -1U)
+		irq = irq_find_mapping(root_domain, hwirq);
+
+	pr_debug("get_irq: hwirq=%d, irq=%d\n", hwirq, irq);
 
 	return irq;
 }
 
+int xintc_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw)
+{
+	u32 intr_mask = (u32)d->host_data;
+
+	if (intr_mask & (1 << hw)) {
+		irq_set_chip_and_handler_name(irq, &intc_dev,
+						handle_edge_irq, "edge");
+		irq_clear_status_flags(irq, IRQ_LEVEL);
+	} else {
+		irq_set_chip_and_handler_name(irq, &intc_dev,
+						handle_level_irq, "level");
+		irq_set_status_flags(irq, IRQ_LEVEL);
+	}
+	return 0;
+}
+
+static const struct irq_domain_ops xintc_irq_domain_ops = {
+	.xlate = irq_domain_xlate_onetwocell,
+	.map = xintc_map,
+};
+
 void __init init_IRQ(void)
 {
-	u32 i, intr_mask;
+	u32 nr_irq, intr_mask;
 	struct device_node *intc = NULL;
 #ifdef CONFIG_SELFMOD_INTC
 	unsigned int intc_baseaddr = 0;
@@ -146,16 +166,9 @@
 	/* Turn on the Master Enable. */
 	out_be32(intc_baseaddr + MER, MER_HIE | MER_ME);
 
-	for (i = IRQ_OFFSET; i < (nr_irq + IRQ_OFFSET); ++i) {
-		if (intr_mask & (0x00000001 << (i - IRQ_OFFSET))) {
-			irq_set_chip_and_handler_name(i, &intc_dev,
-				handle_edge_irq, "edge");
-			irq_clear_status_flags(i, IRQ_LEVEL);
-		} else {
-			irq_set_chip_and_handler_name(i, &intc_dev,
-				handle_level_irq, "level");
-			irq_set_status_flags(i, IRQ_LEVEL);
-		}
-		irq_get_irq_data(i)->hwirq = i - IRQ_OFFSET;
-	}
+	/* Yeah, okay, casting the intr_mask to a void* is butt-ugly, but I'm
+	 * lazy and Michal can clean it up to something nicer when he tests
+	 * and commits this patch.  ~~gcl */
+	root_domain = irq_domain_add_linear(intc, nr_irq, &xintc_irq_domain_ops,
+							(void *)intr_mask);
 }
diff --git a/arch/microblaze/kernel/irq.c b/arch/microblaze/kernel/irq.c
index bbebcae..ace700a 100644
--- a/arch/microblaze/kernel/irq.c
+++ b/arch/microblaze/kernel/irq.c
@@ -31,14 +31,13 @@
 	trace_hardirqs_off();
 
 	irq_enter();
-	irq = get_irq(regs);
+	irq = get_irq();
 next_irq:
 	BUG_ON(!irq);
-	/* Substract 1 because of get_irq */
-	generic_handle_irq(irq + IRQ_OFFSET - NO_IRQ_OFFSET);
+	generic_handle_irq(irq);
 
-	irq = get_irq(regs);
-	if (irq) {
+	irq = get_irq();
+	if (irq != -1U) {
 		pr_debug("next irq: %d\n", irq);
 		++concurrent_irq;
 		goto next_irq;
@@ -48,18 +47,3 @@
 	set_irq_regs(old_regs);
 	trace_hardirqs_on();
 }
-
-/* MS: There is no any advance mapping mechanism. We are using simple 32bit
-  intc without any cascades or any connection that's why mapping is 1:1 */
-unsigned int irq_create_mapping(struct irq_host *host, irq_hw_number_t hwirq)
-{
-	return hwirq + IRQ_OFFSET;
-}
-EXPORT_SYMBOL_GPL(irq_create_mapping);
-
-unsigned int irq_create_of_mapping(struct device_node *controller,
-				   const u32 *intspec, unsigned int intsize)
-{
-	return intspec[0] + IRQ_OFFSET;
-}
-EXPORT_SYMBOL_GPL(irq_create_of_mapping);
diff --git a/arch/microblaze/kernel/setup.c b/arch/microblaze/kernel/setup.c
index 604cd9d..70e6d0b 100644
--- a/arch/microblaze/kernel/setup.c
+++ b/arch/microblaze/kernel/setup.c
@@ -51,8 +51,6 @@
 
 	unflatten_device_tree();
 
-	/* NOTE I think that this function is not necessary to call */
-	/* irq_early_init(); */
 	setup_cpuinfo();
 
 	microblaze_cache_init();
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 5ab6e89..edbbae1 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -2327,6 +2327,7 @@
 	bool "Flattened Device Tree support"
 	select OF
 	select OF_EARLY_FLATTREE
+	select IRQ_DOMAIN
 	help
 	  Include support for flattened device tree machine descriptions.
 
diff --git a/arch/mips/include/asm/irq.h b/arch/mips/include/asm/irq.h
index 2354c87..fb698dc 100644
--- a/arch/mips/include/asm/irq.h
+++ b/arch/mips/include/asm/irq.h
@@ -11,15 +11,12 @@
 
 #include <linux/linkage.h>
 #include <linux/smp.h>
+#include <linux/irqdomain.h>
 
 #include <asm/mipsmtregs.h>
 
 #include <irq.h>
 
-static inline void irq_dispose_mapping(unsigned int virq)
-{
-}
-
 #ifdef CONFIG_I8259
 static inline int irq_canonicalize(int irq)
 {
diff --git a/arch/mips/kernel/prom.c b/arch/mips/kernel/prom.c
index 6b8b420..558b539 100644
--- a/arch/mips/kernel/prom.c
+++ b/arch/mips/kernel/prom.c
@@ -60,20 +60,6 @@
 }
 #endif
 
-/*
- * irq_create_of_mapping - Hook to resolve OF irq specifier into a Linux irq#
- *
- * Currently the mapping mechanism is trivial; simple flat hwirq numbers are
- * mapped 1:1 onto Linux irq numbers.  Cascaded irq controllers are not
- * supported.
- */
-unsigned int irq_create_of_mapping(struct device_node *controller,
-				   const u32 *intspec, unsigned int intsize)
-{
-	return intspec[0];
-}
-EXPORT_SYMBOL_GPL(irq_create_of_mapping);
-
 void __init early_init_devtree(void *params)
 {
 	/* Setup flat device-tree pointer */
diff --git a/arch/openrisc/include/asm/prom.h b/arch/openrisc/include/asm/prom.h
index e1f3fe2..bbb34e5 100644
--- a/arch/openrisc/include/asm/prom.h
+++ b/arch/openrisc/include/asm/prom.h
@@ -24,6 +24,7 @@
 
 #include <linux/types.h>
 #include <asm/irq.h>
+#include <linux/irqdomain.h>
 #include <linux/atomic.h>
 #include <linux/of_irq.h>
 #include <linux/of_fdt.h>
@@ -63,15 +64,6 @@
 struct pci_dev;
 extern int of_irq_map_pci(struct pci_dev *pdev, struct of_irq *out_irq);
 
-/* This routine is here to provide compatibility with how powerpc
- * handles IRQ mapping for OF device nodes.  We precompute and permanently
- * register them in the platform_device objects, whereas powerpc computes them
- * on request.
- */
-static inline void irq_dispose_mapping(unsigned int virq)
-{
-}
-
 #endif /* __ASSEMBLY__ */
 #endif /* __KERNEL__ */
 #endif /* _ASM_OPENRISC_PROM_H */
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 1919634..303703d 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -135,6 +135,7 @@
 	select HAVE_GENERIC_HARDIRQS
 	select HAVE_SPARSE_IRQ
 	select IRQ_PER_CPU
+	select IRQ_DOMAIN
 	select GENERIC_IRQ_SHOW
 	select GENERIC_IRQ_SHOW_LEVEL
 	select IRQ_FORCED_THREADING
diff --git a/arch/powerpc/include/asm/ehv_pic.h b/arch/powerpc/include/asm/ehv_pic.h
index a9e1f4f..dc7d48e 100644
--- a/arch/powerpc/include/asm/ehv_pic.h
+++ b/arch/powerpc/include/asm/ehv_pic.h
@@ -25,7 +25,7 @@
 
 struct ehv_pic {
 	/* The remapper for this EHV_PIC */
-	struct irq_host	*irqhost;
+	struct irq_domain	*irqhost;
 
 	/* The "linux" controller struct */
 	struct irq_chip	hc_irq;
diff --git a/arch/powerpc/include/asm/i8259.h b/arch/powerpc/include/asm/i8259.h
index 105ade2..c3fdfbd 100644
--- a/arch/powerpc/include/asm/i8259.h
+++ b/arch/powerpc/include/asm/i8259.h
@@ -6,7 +6,7 @@
 
 extern void i8259_init(struct device_node *node, unsigned long intack_addr);
 extern unsigned int i8259_irq(void);
-extern struct irq_host *i8259_get_host(void);
+extern struct irq_domain *i8259_get_host(void);
 
 #endif /* __KERNEL__ */
 #endif /* _ASM_POWERPC_I8259_H */
diff --git a/arch/powerpc/include/asm/irq.h b/arch/powerpc/include/asm/irq.h
index c0e1bc3..fe0b09d 100644
--- a/arch/powerpc/include/asm/irq.h
+++ b/arch/powerpc/include/asm/irq.h
@@ -9,6 +9,7 @@
  * 2 of the License, or (at your option) any later version.
  */
 
+#include <linux/irqdomain.h>
 #include <linux/threads.h>
 #include <linux/list.h>
 #include <linux/radix-tree.h>
@@ -35,258 +36,12 @@
 /* Total number of virq in the platform */
 #define NR_IRQS		CONFIG_NR_IRQS
 
-/* Number of irqs reserved for the legacy controller */
-#define NUM_ISA_INTERRUPTS	16
-
 /* Same thing, used by the generic IRQ code */
 #define NR_IRQS_LEGACY		NUM_ISA_INTERRUPTS
 
-/* This type is the placeholder for a hardware interrupt number. It has to
- * be big enough to enclose whatever representation is used by a given
- * platform.
- */
-typedef unsigned long irq_hw_number_t;
-
-/* Interrupt controller "host" data structure. This could be defined as a
- * irq domain controller. That is, it handles the mapping between hardware
- * and virtual interrupt numbers for a given interrupt domain. The host
- * structure is generally created by the PIC code for a given PIC instance
- * (though a host can cover more than one PIC if they have a flat number
- * model). It's the host callbacks that are responsible for setting the
- * irq_chip on a given irq_desc after it's been mapped.
- *
- * The host code and data structures are fairly agnostic to the fact that
- * we use an open firmware device-tree. We do have references to struct
- * device_node in two places: in irq_find_host() to find the host matching
- * a given interrupt controller node, and of course as an argument to its
- * counterpart host->ops->match() callback. However, those are treated as
- * generic pointers by the core and the fact that it's actually a device-node
- * pointer is purely a convention between callers and implementation. This
- * code could thus be used on other architectures by replacing those two
- * by some sort of arch-specific void * "token" used to identify interrupt
- * controllers.
- */
-struct irq_host;
-struct radix_tree_root;
-
-/* Functions below are provided by the host and called whenever a new mapping
- * is created or an old mapping is disposed. The host can then proceed to
- * whatever internal data structures management is required. It also needs
- * to setup the irq_desc when returning from map().
- */
-struct irq_host_ops {
-	/* Match an interrupt controller device node to a host, returns
-	 * 1 on a match
-	 */
-	int (*match)(struct irq_host *h, struct device_node *node);
-
-	/* Create or update a mapping between a virtual irq number and a hw
-	 * irq number. This is called only once for a given mapping.
-	 */
-	int (*map)(struct irq_host *h, unsigned int virq, irq_hw_number_t hw);
-
-	/* Dispose of such a mapping */
-	void (*unmap)(struct irq_host *h, unsigned int virq);
-
-	/* Translate device-tree interrupt specifier from raw format coming
-	 * from the firmware to a irq_hw_number_t (interrupt line number) and
-	 * type (sense) that can be passed to set_irq_type(). In the absence
-	 * of this callback, irq_create_of_mapping() and irq_of_parse_and_map()
-	 * will return the hw number in the first cell and IRQ_TYPE_NONE for
-	 * the type (which amount to keeping whatever default value the
-	 * interrupt controller has for that line)
-	 */
-	int (*xlate)(struct irq_host *h, struct device_node *ctrler,
-		     const u32 *intspec, unsigned int intsize,
-		     irq_hw_number_t *out_hwirq, unsigned int *out_type);
-};
-
-struct irq_host {
-	struct list_head	link;
-
-	/* type of reverse mapping technique */
-	unsigned int		revmap_type;
-#define IRQ_HOST_MAP_LEGACY     0 /* legacy 8259, gets irqs 1..15 */
-#define IRQ_HOST_MAP_NOMAP	1 /* no fast reverse mapping */
-#define IRQ_HOST_MAP_LINEAR	2 /* linear map of interrupts */
-#define IRQ_HOST_MAP_TREE	3 /* radix tree */
-	union {
-		struct {
-			unsigned int size;
-			unsigned int *revmap;
-		} linear;
-		struct radix_tree_root tree;
-	} revmap_data;
-	struct irq_host_ops	*ops;
-	void			*host_data;
-	irq_hw_number_t		inval_irq;
-
-	/* Optional device node pointer */
-	struct device_node	*of_node;
-};
-
 struct irq_data;
 extern irq_hw_number_t irqd_to_hwirq(struct irq_data *d);
 extern irq_hw_number_t virq_to_hw(unsigned int virq);
-extern bool virq_is_host(unsigned int virq, struct irq_host *host);
-
-/**
- * irq_alloc_host - Allocate a new irq_host data structure
- * @of_node: optional device-tree node of the interrupt controller
- * @revmap_type: type of reverse mapping to use
- * @revmap_arg: for IRQ_HOST_MAP_LINEAR linear only: size of the map
- * @ops: map/unmap host callbacks
- * @inval_irq: provide a hw number in that host space that is always invalid
- *
- * Allocates and initialize and irq_host structure. Note that in the case of
- * IRQ_HOST_MAP_LEGACY, the map() callback will be called before this returns
- * for all legacy interrupts except 0 (which is always the invalid irq for
- * a legacy controller). For a IRQ_HOST_MAP_LINEAR, the map is allocated by
- * this call as well. For a IRQ_HOST_MAP_TREE, the radix tree will be allocated
- * later during boot automatically (the reverse mapping will use the slow path
- * until that happens).
- */
-extern struct irq_host *irq_alloc_host(struct device_node *of_node,
-				       unsigned int revmap_type,
-				       unsigned int revmap_arg,
-				       struct irq_host_ops *ops,
-				       irq_hw_number_t inval_irq);
-
-
-/**
- * irq_find_host - Locates a host for a given device node
- * @node: device-tree node of the interrupt controller
- */
-extern struct irq_host *irq_find_host(struct device_node *node);
-
-
-/**
- * irq_set_default_host - Set a "default" host
- * @host: default host pointer
- *
- * For convenience, it's possible to set a "default" host that will be used
- * whenever NULL is passed to irq_create_mapping(). It makes life easier for
- * platforms that want to manipulate a few hard coded interrupt numbers that
- * aren't properly represented in the device-tree.
- */
-extern void irq_set_default_host(struct irq_host *host);
-
-
-/**
- * irq_set_virq_count - Set the maximum number of virt irqs
- * @count: number of linux virtual irqs, capped with NR_IRQS
- *
- * This is mainly for use by platforms like iSeries who want to program
- * the virtual irq number in the controller to avoid the reverse mapping
- */
-extern void irq_set_virq_count(unsigned int count);
-
-
-/**
- * irq_create_mapping - Map a hardware interrupt into linux virq space
- * @host: host owning this hardware interrupt or NULL for default host
- * @hwirq: hardware irq number in that host space
- *
- * Only one mapping per hardware interrupt is permitted. Returns a linux
- * virq number.
- * If the sense/trigger is to be specified, set_irq_type() should be called
- * on the number returned from that call.
- */
-extern unsigned int irq_create_mapping(struct irq_host *host,
-				       irq_hw_number_t hwirq);
-
-
-/**
- * irq_dispose_mapping - Unmap an interrupt
- * @virq: linux virq number of the interrupt to unmap
- */
-extern void irq_dispose_mapping(unsigned int virq);
-
-/**
- * irq_find_mapping - Find a linux virq from an hw irq number.
- * @host: host owning this hardware interrupt
- * @hwirq: hardware irq number in that host space
- *
- * This is a slow path, for use by generic code. It's expected that an
- * irq controller implementation directly calls the appropriate low level
- * mapping function.
- */
-extern unsigned int irq_find_mapping(struct irq_host *host,
-				     irq_hw_number_t hwirq);
-
-/**
- * irq_create_direct_mapping - Allocate a virq for direct mapping
- * @host: host to allocate the virq for or NULL for default host
- *
- * This routine is used for irq controllers which can choose the hardware
- * interrupt numbers they generate. In such a case it's simplest to use
- * the linux virq as the hardware interrupt number.
- */
-extern unsigned int irq_create_direct_mapping(struct irq_host *host);
-
-/**
- * irq_radix_revmap_insert - Insert a hw irq to linux virq number mapping.
- * @host: host owning this hardware interrupt
- * @virq: linux irq number
- * @hwirq: hardware irq number in that host space
- *
- * This is for use by irq controllers that use a radix tree reverse
- * mapping for fast lookup.
- */
-extern void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq,
-				    irq_hw_number_t hwirq);
-
-/**
- * irq_radix_revmap_lookup - Find a linux virq from a hw irq number.
- * @host: host owning this hardware interrupt
- * @hwirq: hardware irq number in that host space
- *
- * This is a fast path, for use by irq controller code that uses radix tree
- * revmaps
- */
-extern unsigned int irq_radix_revmap_lookup(struct irq_host *host,
-					    irq_hw_number_t hwirq);
-
-/**
- * irq_linear_revmap - Find a linux virq from a hw irq number.
- * @host: host owning this hardware interrupt
- * @hwirq: hardware irq number in that host space
- *
- * This is a fast path, for use by irq controller code that uses linear
- * revmaps. It does fallback to the slow path if the revmap doesn't exist
- * yet and will create the revmap entry with appropriate locking
- */
-
-extern unsigned int irq_linear_revmap(struct irq_host *host,
-				      irq_hw_number_t hwirq);
-
-
-
-/**
- * irq_alloc_virt - Allocate virtual irq numbers
- * @host: host owning these new virtual irqs
- * @count: number of consecutive numbers to allocate
- * @hint: pass a hint number, the allocator will try to use a 1:1 mapping
- *
- * This is a low level function that is used internally by irq_create_mapping()
- * and that can be used by some irq controllers implementations for things
- * like allocating ranges of numbers for MSIs. The revmaps are left untouched.
- */
-extern unsigned int irq_alloc_virt(struct irq_host *host,
-				   unsigned int count,
-				   unsigned int hint);
-
-/**
- * irq_free_virt - Free virtual irq numbers
- * @virq: virtual irq number of the first interrupt to free
- * @count: number of interrupts to free
- *
- * This function is the opposite of irq_alloc_virt. It will not clear reverse
- * maps, this should be done previously by unmap'ing the interrupt. In fact,
- * all interrupts covered by the range being freed should have been unmapped
- * prior to calling this.
- */
-extern void irq_free_virt(unsigned int virq, unsigned int count);
 
 /**
  * irq_early_init - Init irq remapping subsystem
diff --git a/arch/powerpc/include/asm/mpic.h b/arch/powerpc/include/asm/mpic.h
index 67b4d98..a5b7c56 100644
--- a/arch/powerpc/include/asm/mpic.h
+++ b/arch/powerpc/include/asm/mpic.h
@@ -255,7 +255,7 @@
 	struct device_node *node;
 
 	/* The remapper for this MPIC */
-	struct irq_host		*irqhost;
+	struct irq_domain	*irqhost;
 
 	/* The "linux" controller struct */
 	struct irq_chip		hc_irq;
diff --git a/arch/powerpc/include/asm/xics.h b/arch/powerpc/include/asm/xics.h
index c48de98..4ae9a09 100644
--- a/arch/powerpc/include/asm/xics.h
+++ b/arch/powerpc/include/asm/xics.h
@@ -86,7 +86,7 @@
 extern unsigned int xics_default_server;
 extern unsigned int xics_default_distrib_server;
 extern unsigned int xics_interrupt_server_size;
-extern struct irq_host *xics_host;
+extern struct irq_domain *xics_host;
 
 struct xics_cppr {
 	unsigned char stack[MAX_NUM_PRIORITIES];
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 01e2877..bdfb3eee 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -490,409 +490,19 @@
 	local_irq_restore(flags);
 }
 
-
-/*
- * IRQ controller and virtual interrupts
- */
-
-/* The main irq map itself is an array of NR_IRQ entries containing the
- * associate host and irq number. An entry with a host of NULL is free.
- * An entry can be allocated if it's free, the allocator always then sets
- * hwirq first to the host's invalid irq number and then fills ops.
- */
-struct irq_map_entry {
-	irq_hw_number_t	hwirq;
-	struct irq_host	*host;
-};
-
-static LIST_HEAD(irq_hosts);
-static DEFINE_RAW_SPINLOCK(irq_big_lock);
-static DEFINE_MUTEX(revmap_trees_mutex);
-static struct irq_map_entry irq_map[NR_IRQS];
-static unsigned int irq_virq_count = NR_IRQS;
-static struct irq_host *irq_default_host;
-
 irq_hw_number_t irqd_to_hwirq(struct irq_data *d)
 {
-	return irq_map[d->irq].hwirq;
+	return d->hwirq;
 }
 EXPORT_SYMBOL_GPL(irqd_to_hwirq);
 
 irq_hw_number_t virq_to_hw(unsigned int virq)
 {
-	return irq_map[virq].hwirq;
+	struct irq_data *irq_data = irq_get_irq_data(virq);
+	return WARN_ON(!irq_data) ? 0 : irq_data->hwirq;
 }
 EXPORT_SYMBOL_GPL(virq_to_hw);
 
-bool virq_is_host(unsigned int virq, struct irq_host *host)
-{
-	return irq_map[virq].host == host;
-}
-EXPORT_SYMBOL_GPL(virq_is_host);
-
-static int default_irq_host_match(struct irq_host *h, struct device_node *np)
-{
-	return h->of_node != NULL && h->of_node == np;
-}
-
-struct irq_host *irq_alloc_host(struct device_node *of_node,
-				unsigned int revmap_type,
-				unsigned int revmap_arg,
-				struct irq_host_ops *ops,
-				irq_hw_number_t inval_irq)
-{
-	struct irq_host *host;
-	unsigned int size = sizeof(struct irq_host);
-	unsigned int i;
-	unsigned int *rmap;
-	unsigned long flags;
-
-	/* Allocate structure and revmap table if using linear mapping */
-	if (revmap_type == IRQ_HOST_MAP_LINEAR)
-		size += revmap_arg * sizeof(unsigned int);
-	host = kzalloc(size, GFP_KERNEL);
-	if (host == NULL)
-		return NULL;
-
-	/* Fill structure */
-	host->revmap_type = revmap_type;
-	host->inval_irq = inval_irq;
-	host->ops = ops;
-	host->of_node = of_node_get(of_node);
-
-	if (host->ops->match == NULL)
-		host->ops->match = default_irq_host_match;
-
-	raw_spin_lock_irqsave(&irq_big_lock, flags);
-
-	/* If it's a legacy controller, check for duplicates and
-	 * mark it as allocated (we use irq 0 host pointer for that
-	 */
-	if (revmap_type == IRQ_HOST_MAP_LEGACY) {
-		if (irq_map[0].host != NULL) {
-			raw_spin_unlock_irqrestore(&irq_big_lock, flags);
-			of_node_put(host->of_node);
-			kfree(host);
-			return NULL;
-		}
-		irq_map[0].host = host;
-	}
-
-	list_add(&host->link, &irq_hosts);
-	raw_spin_unlock_irqrestore(&irq_big_lock, flags);
-
-	/* Additional setups per revmap type */
-	switch(revmap_type) {
-	case IRQ_HOST_MAP_LEGACY:
-		/* 0 is always the invalid number for legacy */
-		host->inval_irq = 0;
-		/* setup us as the host for all legacy interrupts */
-		for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
-			irq_map[i].hwirq = i;
-			smp_wmb();
-			irq_map[i].host = host;
-			smp_wmb();
-
-			/* Legacy flags are left to default at this point,
-			 * one can then use irq_create_mapping() to
-			 * explicitly change them
-			 */
-			ops->map(host, i, i);
-
-			/* Clear norequest flags */
-			irq_clear_status_flags(i, IRQ_NOREQUEST);
-		}
-		break;
-	case IRQ_HOST_MAP_LINEAR:
-		rmap = (unsigned int *)(host + 1);
-		for (i = 0; i < revmap_arg; i++)
-			rmap[i] = NO_IRQ;
-		host->revmap_data.linear.size = revmap_arg;
-		smp_wmb();
-		host->revmap_data.linear.revmap = rmap;
-		break;
-	case IRQ_HOST_MAP_TREE:
-		INIT_RADIX_TREE(&host->revmap_data.tree, GFP_KERNEL);
-		break;
-	default:
-		break;
-	}
-
-	pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
-
-	return host;
-}
-
-struct irq_host *irq_find_host(struct device_node *node)
-{
-	struct irq_host *h, *found = NULL;
-	unsigned long flags;
-
-	/* We might want to match the legacy controller last since
-	 * it might potentially be set to match all interrupts in
-	 * the absence of a device node. This isn't a problem so far
-	 * yet though...
-	 */
-	raw_spin_lock_irqsave(&irq_big_lock, flags);
-	list_for_each_entry(h, &irq_hosts, link)
-		if (h->ops->match(h, node)) {
-			found = h;
-			break;
-		}
-	raw_spin_unlock_irqrestore(&irq_big_lock, flags);
-	return found;
-}
-EXPORT_SYMBOL_GPL(irq_find_host);
-
-void irq_set_default_host(struct irq_host *host)
-{
-	pr_debug("irq: Default host set to @0x%p\n", host);
-
-	irq_default_host = host;
-}
-
-void irq_set_virq_count(unsigned int count)
-{
-	pr_debug("irq: Trying to set virq count to %d\n", count);
-
-	BUG_ON(count < NUM_ISA_INTERRUPTS);
-	if (count < NR_IRQS)
-		irq_virq_count = count;
-}
-
-static int irq_setup_virq(struct irq_host *host, unsigned int virq,
-			    irq_hw_number_t hwirq)
-{
-	int res;
-
-	res = irq_alloc_desc_at(virq, 0);
-	if (res != virq) {
-		pr_debug("irq: -> allocating desc failed\n");
-		goto error;
-	}
-
-	/* map it */
-	smp_wmb();
-	irq_map[virq].hwirq = hwirq;
-	smp_mb();
-
-	if (host->ops->map(host, virq, hwirq)) {
-		pr_debug("irq: -> mapping failed, freeing\n");
-		goto errdesc;
-	}
-
-	irq_clear_status_flags(virq, IRQ_NOREQUEST);
-
-	return 0;
-
-errdesc:
-	irq_free_descs(virq, 1);
-error:
-	irq_free_virt(virq, 1);
-	return -1;
-}
-
-unsigned int irq_create_direct_mapping(struct irq_host *host)
-{
-	unsigned int virq;
-
-	if (host == NULL)
-		host = irq_default_host;
-
-	BUG_ON(host == NULL);
-	WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
-
-	virq = irq_alloc_virt(host, 1, 0);
-	if (virq == NO_IRQ) {
-		pr_debug("irq: create_direct virq allocation failed\n");
-		return NO_IRQ;
-	}
-
-	pr_debug("irq: create_direct obtained virq %d\n", virq);
-
-	if (irq_setup_virq(host, virq, virq))
-		return NO_IRQ;
-
-	return virq;
-}
-
-unsigned int irq_create_mapping(struct irq_host *host,
-				irq_hw_number_t hwirq)
-{
-	unsigned int virq, hint;
-
-	pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
-
-	/* Look for default host if nececssary */
-	if (host == NULL)
-		host = irq_default_host;
-	if (host == NULL) {
-		printk(KERN_WARNING "irq_create_mapping called for"
-		       " NULL host, hwirq=%lx\n", hwirq);
-		WARN_ON(1);
-		return NO_IRQ;
-	}
-	pr_debug("irq: -> using host @%p\n", host);
-
-	/* Check if mapping already exists */
-	virq = irq_find_mapping(host, hwirq);
-	if (virq != NO_IRQ) {
-		pr_debug("irq: -> existing mapping on virq %d\n", virq);
-		return virq;
-	}
-
-	/* Get a virtual interrupt number */
-	if (host->revmap_type == IRQ_HOST_MAP_LEGACY) {
-		/* Handle legacy */
-		virq = (unsigned int)hwirq;
-		if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
-			return NO_IRQ;
-		return virq;
-	} else {
-		/* Allocate a virtual interrupt number */
-		hint = hwirq % irq_virq_count;
-		virq = irq_alloc_virt(host, 1, hint);
-		if (virq == NO_IRQ) {
-			pr_debug("irq: -> virq allocation failed\n");
-			return NO_IRQ;
-		}
-	}
-
-	if (irq_setup_virq(host, virq, hwirq))
-		return NO_IRQ;
-
-	pr_debug("irq: irq %lu on host %s mapped to virtual irq %u\n",
-		hwirq, host->of_node ? host->of_node->full_name : "null", virq);
-
-	return virq;
-}
-EXPORT_SYMBOL_GPL(irq_create_mapping);
-
-unsigned int irq_create_of_mapping(struct device_node *controller,
-				   const u32 *intspec, unsigned int intsize)
-{
-	struct irq_host *host;
-	irq_hw_number_t hwirq;
-	unsigned int type = IRQ_TYPE_NONE;
-	unsigned int virq;
-
-	if (controller == NULL)
-		host = irq_default_host;
-	else
-		host = irq_find_host(controller);
-	if (host == NULL) {
-		printk(KERN_WARNING "irq: no irq host found for %s !\n",
-		       controller->full_name);
-		return NO_IRQ;
-	}
-
-	/* If host has no translation, then we assume interrupt line */
-	if (host->ops->xlate == NULL)
-		hwirq = intspec[0];
-	else {
-		if (host->ops->xlate(host, controller, intspec, intsize,
-				     &hwirq, &type))
-			return NO_IRQ;
-	}
-
-	/* Create mapping */
-	virq = irq_create_mapping(host, hwirq);
-	if (virq == NO_IRQ)
-		return virq;
-
-	/* Set type if specified and different than the current one */
-	if (type != IRQ_TYPE_NONE &&
-	    type != (irqd_get_trigger_type(irq_get_irq_data(virq))))
-		irq_set_irq_type(virq, type);
-	return virq;
-}
-EXPORT_SYMBOL_GPL(irq_create_of_mapping);
-
-void irq_dispose_mapping(unsigned int virq)
-{
-	struct irq_host *host;
-	irq_hw_number_t hwirq;
-
-	if (virq == NO_IRQ)
-		return;
-
-	host = irq_map[virq].host;
-	if (WARN_ON(host == NULL))
-		return;
-
-	/* Never unmap legacy interrupts */
-	if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
-		return;
-
-	irq_set_status_flags(virq, IRQ_NOREQUEST);
-
-	/* remove chip and handler */
-	irq_set_chip_and_handler(virq, NULL, NULL);
-
-	/* Make sure it's completed */
-	synchronize_irq(virq);
-
-	/* Tell the PIC about it */
-	if (host->ops->unmap)
-		host->ops->unmap(host, virq);
-	smp_mb();
-
-	/* Clear reverse map */
-	hwirq = irq_map[virq].hwirq;
-	switch(host->revmap_type) {
-	case IRQ_HOST_MAP_LINEAR:
-		if (hwirq < host->revmap_data.linear.size)
-			host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
-		break;
-	case IRQ_HOST_MAP_TREE:
-		mutex_lock(&revmap_trees_mutex);
-		radix_tree_delete(&host->revmap_data.tree, hwirq);
-		mutex_unlock(&revmap_trees_mutex);
-		break;
-	}
-
-	/* Destroy map */
-	smp_mb();
-	irq_map[virq].hwirq = host->inval_irq;
-
-	irq_free_descs(virq, 1);
-	/* Free it */
-	irq_free_virt(virq, 1);
-}
-EXPORT_SYMBOL_GPL(irq_dispose_mapping);
-
-unsigned int irq_find_mapping(struct irq_host *host,
-			      irq_hw_number_t hwirq)
-{
-	unsigned int i;
-	unsigned int hint = hwirq % irq_virq_count;
-
-	/* Look for default host if nececssary */
-	if (host == NULL)
-		host = irq_default_host;
-	if (host == NULL)
-		return NO_IRQ;
-
-	/* legacy -> bail early */
-	if (host->revmap_type == IRQ_HOST_MAP_LEGACY)
-		return hwirq;
-
-	/* Slow path does a linear search of the map */
-	if (hint < NUM_ISA_INTERRUPTS)
-		hint = NUM_ISA_INTERRUPTS;
-	i = hint;
-	do  {
-		if (irq_map[i].host == host &&
-		    irq_map[i].hwirq == hwirq)
-			return i;
-		i++;
-		if (i >= irq_virq_count)
-			i = NUM_ISA_INTERRUPTS;
-	} while(i != hint);
-	return NO_IRQ;
-}
-EXPORT_SYMBOL_GPL(irq_find_mapping);
-
 #ifdef CONFIG_SMP
 int irq_choose_cpu(const struct cpumask *mask)
 {
@@ -929,232 +539,11 @@
 }
 #endif
 
-unsigned int irq_radix_revmap_lookup(struct irq_host *host,
-				     irq_hw_number_t hwirq)
-{
-	struct irq_map_entry *ptr;
-	unsigned int virq;
-
-	if (WARN_ON_ONCE(host->revmap_type != IRQ_HOST_MAP_TREE))
-		return irq_find_mapping(host, hwirq);
-
-	/*
-	 * The ptr returned references the static global irq_map.
-	 * but freeing an irq can delete nodes along the path to
-	 * do the lookup via call_rcu.
-	 */
-	rcu_read_lock();
-	ptr = radix_tree_lookup(&host->revmap_data.tree, hwirq);
-	rcu_read_unlock();
-
-	/*
-	 * If found in radix tree, then fine.
-	 * Else fallback to linear lookup - this should not happen in practice
-	 * as it means that we failed to insert the node in the radix tree.
-	 */
-	if (ptr)
-		virq = ptr - irq_map;
-	else
-		virq = irq_find_mapping(host, hwirq);
-
-	return virq;
-}
-
-void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq,
-			     irq_hw_number_t hwirq)
-{
-	if (WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE))
-		return;
-
-	if (virq != NO_IRQ) {
-		mutex_lock(&revmap_trees_mutex);
-		radix_tree_insert(&host->revmap_data.tree, hwirq,
-				  &irq_map[virq]);
-		mutex_unlock(&revmap_trees_mutex);
-	}
-}
-
-unsigned int irq_linear_revmap(struct irq_host *host,
-			       irq_hw_number_t hwirq)
-{
-	unsigned int *revmap;
-
-	if (WARN_ON_ONCE(host->revmap_type != IRQ_HOST_MAP_LINEAR))
-		return irq_find_mapping(host, hwirq);
-
-	/* Check revmap bounds */
-	if (unlikely(hwirq >= host->revmap_data.linear.size))
-		return irq_find_mapping(host, hwirq);
-
-	/* Check if revmap was allocated */
-	revmap = host->revmap_data.linear.revmap;
-	if (unlikely(revmap == NULL))
-		return irq_find_mapping(host, hwirq);
-
-	/* Fill up revmap with slow path if no mapping found */
-	if (unlikely(revmap[hwirq] == NO_IRQ))
-		revmap[hwirq] = irq_find_mapping(host, hwirq);
-
-	return revmap[hwirq];
-}
-
-unsigned int irq_alloc_virt(struct irq_host *host,
-			    unsigned int count,
-			    unsigned int hint)
-{
-	unsigned long flags;
-	unsigned int i, j, found = NO_IRQ;
-
-	if (count == 0 || count > (irq_virq_count - NUM_ISA_INTERRUPTS))
-		return NO_IRQ;
-
-	raw_spin_lock_irqsave(&irq_big_lock, flags);
-
-	/* Use hint for 1 interrupt if any */
-	if (count == 1 && hint >= NUM_ISA_INTERRUPTS &&
-	    hint < irq_virq_count && irq_map[hint].host == NULL) {
-		found = hint;
-		goto hint_found;
-	}
-
-	/* Look for count consecutive numbers in the allocatable
-	 * (non-legacy) space
-	 */
-	for (i = NUM_ISA_INTERRUPTS, j = 0; i < irq_virq_count; i++) {
-		if (irq_map[i].host != NULL)
-			j = 0;
-		else
-			j++;
-
-		if (j == count) {
-			found = i - count + 1;
-			break;
-		}
-	}
-	if (found == NO_IRQ) {
-		raw_spin_unlock_irqrestore(&irq_big_lock, flags);
-		return NO_IRQ;
-	}
- hint_found:
-	for (i = found; i < (found + count); i++) {
-		irq_map[i].hwirq = host->inval_irq;
-		smp_wmb();
-		irq_map[i].host = host;
-	}
-	raw_spin_unlock_irqrestore(&irq_big_lock, flags);
-	return found;
-}
-
-void irq_free_virt(unsigned int virq, unsigned int count)
-{
-	unsigned long flags;
-	unsigned int i;
-
-	WARN_ON (virq < NUM_ISA_INTERRUPTS);
-	WARN_ON (count == 0 || (virq + count) > irq_virq_count);
-
-	if (virq < NUM_ISA_INTERRUPTS) {
-		if (virq + count < NUM_ISA_INTERRUPTS)
-			return;
-		count  =- NUM_ISA_INTERRUPTS - virq;
-		virq = NUM_ISA_INTERRUPTS;
-	}
-
-	if (count > irq_virq_count || virq > irq_virq_count - count) {
-		if (virq > irq_virq_count)
-			return;
-		count = irq_virq_count - virq;
-	}
-
-	raw_spin_lock_irqsave(&irq_big_lock, flags);
-	for (i = virq; i < (virq + count); i++) {
-		struct irq_host *host;
-
-		host = irq_map[i].host;
-		irq_map[i].hwirq = host->inval_irq;
-		smp_wmb();
-		irq_map[i].host = NULL;
-	}
-	raw_spin_unlock_irqrestore(&irq_big_lock, flags);
-}
-
 int arch_early_irq_init(void)
 {
 	return 0;
 }
 
-#ifdef CONFIG_VIRQ_DEBUG
-static int virq_debug_show(struct seq_file *m, void *private)
-{
-	unsigned long flags;
-	struct irq_desc *desc;
-	const char *p;
-	static const char none[] = "none";
-	void *data;
-	int i;
-
-	seq_printf(m, "%-5s  %-7s  %-15s  %-18s  %s\n", "virq", "hwirq",
-		      "chip name", "chip data", "host name");
-
-	for (i = 1; i < nr_irqs; i++) {
-		desc = irq_to_desc(i);
-		if (!desc)
-			continue;
-
-		raw_spin_lock_irqsave(&desc->lock, flags);
-
-		if (desc->action && desc->action->handler) {
-			struct irq_chip *chip;
-
-			seq_printf(m, "%5d  ", i);
-			seq_printf(m, "0x%05lx  ", irq_map[i].hwirq);
-
-			chip = irq_desc_get_chip(desc);
-			if (chip && chip->name)
-				p = chip->name;
-			else
-				p = none;
-			seq_printf(m, "%-15s  ", p);
-
-			data = irq_desc_get_chip_data(desc);
-			seq_printf(m, "0x%16p  ", data);
-
-			if (irq_map[i].host && irq_map[i].host->of_node)
-				p = irq_map[i].host->of_node->full_name;
-			else
-				p = none;
-			seq_printf(m, "%s\n", p);
-		}
-
-		raw_spin_unlock_irqrestore(&desc->lock, flags);
-	}
-
-	return 0;
-}
-
-static int virq_debug_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, virq_debug_show, inode->i_private);
-}
-
-static const struct file_operations virq_debug_fops = {
-	.open = virq_debug_open,
-	.read = seq_read,
-	.llseek = seq_lseek,
-	.release = single_release,
-};
-
-static int __init irq_debugfs_init(void)
-{
-	if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
-				 NULL, &virq_debug_fops) == NULL)
-		return -ENOMEM;
-
-	return 0;
-}
-__initcall(irq_debugfs_init);
-#endif /* CONFIG_VIRQ_DEBUG */
-
 #ifdef CONFIG_PPC64
 static int __init setup_noirqdistrib(char *str)
 {
diff --git a/arch/powerpc/platforms/512x/mpc5121_ads_cpld.c b/arch/powerpc/platforms/512x/mpc5121_ads_cpld.c
index 9f09319..ca3a062 100644
--- a/arch/powerpc/platforms/512x/mpc5121_ads_cpld.c
+++ b/arch/powerpc/platforms/512x/mpc5121_ads_cpld.c
@@ -21,7 +21,7 @@
 #include <asm/prom.h>
 
 static struct device_node *cpld_pic_node;
-static struct irq_host *cpld_pic_host;
+static struct irq_domain *cpld_pic_host;
 
 /*
  * Bits to ignore in the misc_status register
@@ -123,13 +123,13 @@
 }
 
 static int
-cpld_pic_host_match(struct irq_host *h, struct device_node *node)
+cpld_pic_host_match(struct irq_domain *h, struct device_node *node)
 {
 	return cpld_pic_node == node;
 }
 
 static int
-cpld_pic_host_map(struct irq_host *h, unsigned int virq,
+cpld_pic_host_map(struct irq_domain *h, unsigned int virq,
 			     irq_hw_number_t hw)
 {
 	irq_set_status_flags(virq, IRQ_LEVEL);
@@ -137,8 +137,7 @@
 	return 0;
 }
 
-static struct
-irq_host_ops cpld_pic_host_ops = {
+static const struct irq_domain_ops cpld_pic_host_ops = {
 	.match = cpld_pic_host_match,
 	.map = cpld_pic_host_map,
 };
@@ -191,8 +190,7 @@
 
 	cpld_pic_node = of_node_get(np);
 
-	cpld_pic_host =
-	    irq_alloc_host(np, IRQ_HOST_MAP_LINEAR, 16, &cpld_pic_host_ops, 16);
+	cpld_pic_host = irq_domain_add_linear(np, 16, &cpld_pic_host_ops, NULL);
 	if (!cpld_pic_host) {
 		printk(KERN_ERR "CPLD PIC: failed to allocate irq host!\n");
 		goto end;
diff --git a/arch/powerpc/platforms/52xx/media5200.c b/arch/powerpc/platforms/52xx/media5200.c
index 96f85e5..17d91b7 100644
--- a/arch/powerpc/platforms/52xx/media5200.c
+++ b/arch/powerpc/platforms/52xx/media5200.c
@@ -45,7 +45,7 @@
 struct media5200_irq {
 	void __iomem *regs;
 	spinlock_t lock;
-	struct irq_host *irqhost;
+	struct irq_domain *irqhost;
 };
 struct media5200_irq media5200_irq;
 
@@ -112,7 +112,7 @@
 	raw_spin_unlock(&desc->lock);
 }
 
-static int media5200_irq_map(struct irq_host *h, unsigned int virq,
+static int media5200_irq_map(struct irq_domain *h, unsigned int virq,
 			     irq_hw_number_t hw)
 {
 	pr_debug("%s: h=%p, virq=%i, hwirq=%i\n", __func__, h, virq, (int)hw);
@@ -122,7 +122,7 @@
 	return 0;
 }
 
-static int media5200_irq_xlate(struct irq_host *h, struct device_node *ct,
+static int media5200_irq_xlate(struct irq_domain *h, struct device_node *ct,
 				 const u32 *intspec, unsigned int intsize,
 				 irq_hw_number_t *out_hwirq,
 				 unsigned int *out_flags)
@@ -136,7 +136,7 @@
 	return 0;
 }
 
-static struct irq_host_ops media5200_irq_ops = {
+static const struct irq_domain_ops media5200_irq_ops = {
 	.map = media5200_irq_map,
 	.xlate = media5200_irq_xlate,
 };
@@ -173,15 +173,12 @@
 
 	spin_lock_init(&media5200_irq.lock);
 
-	media5200_irq.irqhost = irq_alloc_host(fpga_np, IRQ_HOST_MAP_LINEAR,
-					       MEDIA5200_NUM_IRQS,
-					       &media5200_irq_ops, -1);
+	media5200_irq.irqhost = irq_domain_add_linear(fpga_np,
+			MEDIA5200_NUM_IRQS, &media5200_irq_ops, &media5200_irq);
 	if (!media5200_irq.irqhost)
 		goto out;
 	pr_debug("%s: allocated irqhost\n", __func__);
 
-	media5200_irq.irqhost->host_data = &media5200_irq;
-
 	irq_set_handler_data(cascade_virq, &media5200_irq);
 	irq_set_chained_handler(cascade_virq, media5200_irq_cascade);
 
diff --git a/arch/powerpc/platforms/52xx/mpc52xx_gpt.c b/arch/powerpc/platforms/52xx/mpc52xx_gpt.c
index f94f06e..028470b 100644
--- a/arch/powerpc/platforms/52xx/mpc52xx_gpt.c
+++ b/arch/powerpc/platforms/52xx/mpc52xx_gpt.c
@@ -81,7 +81,7 @@
  * @regs: virtual address of GPT registers
  * @lock: spinlock to coordinate between different functions.
  * @gc: gpio_chip instance structure; used when GPIO is enabled
- * @irqhost: Pointer to irq_host instance; used when IRQ mode is supported
+ * @irqhost: Pointer to irq_domain instance; used when IRQ mode is supported
  * @wdt_mode: only relevant for gpt0: bit 0 (MPC52xx_GPT_CAN_WDT) indicates
  *   if the gpt may be used as wdt, bit 1 (MPC52xx_GPT_IS_WDT) indicates
  *   if the timer is actively used as wdt which blocks gpt functions
@@ -91,7 +91,7 @@
 	struct device *dev;
 	struct mpc52xx_gpt __iomem *regs;
 	spinlock_t lock;
-	struct irq_host *irqhost;
+	struct irq_domain *irqhost;
 	u32 ipb_freq;
 	u8 wdt_mode;
 
@@ -204,7 +204,7 @@
 	}
 }
 
-static int mpc52xx_gpt_irq_map(struct irq_host *h, unsigned int virq,
+static int mpc52xx_gpt_irq_map(struct irq_domain *h, unsigned int virq,
 			       irq_hw_number_t hw)
 {
 	struct mpc52xx_gpt_priv *gpt = h->host_data;
@@ -216,7 +216,7 @@
 	return 0;
 }
 
-static int mpc52xx_gpt_irq_xlate(struct irq_host *h, struct device_node *ct,
+static int mpc52xx_gpt_irq_xlate(struct irq_domain *h, struct device_node *ct,
 				 const u32 *intspec, unsigned int intsize,
 				 irq_hw_number_t *out_hwirq,
 				 unsigned int *out_flags)
@@ -236,7 +236,7 @@
 	return 0;
 }
 
-static struct irq_host_ops mpc52xx_gpt_irq_ops = {
+static const struct irq_domain_ops mpc52xx_gpt_irq_ops = {
 	.map = mpc52xx_gpt_irq_map,
 	.xlate = mpc52xx_gpt_irq_xlate,
 };
@@ -252,14 +252,12 @@
 	if (!cascade_virq)
 		return;
 
-	gpt->irqhost = irq_alloc_host(node, IRQ_HOST_MAP_LINEAR, 1,
-				      &mpc52xx_gpt_irq_ops, -1);
+	gpt->irqhost = irq_domain_add_linear(node, 1, &mpc52xx_gpt_irq_ops, gpt);
 	if (!gpt->irqhost) {
-		dev_err(gpt->dev, "irq_alloc_host() failed\n");
+		dev_err(gpt->dev, "irq_domain_add_linear() failed\n");
 		return;
 	}
 
-	gpt->irqhost->host_data = gpt;
 	irq_set_handler_data(cascade_virq, gpt);
 	irq_set_chained_handler(cascade_virq, mpc52xx_gpt_irq_cascade);
 
diff --git a/arch/powerpc/platforms/52xx/mpc52xx_pic.c b/arch/powerpc/platforms/52xx/mpc52xx_pic.c
index 1a9a495..8520b58 100644
--- a/arch/powerpc/platforms/52xx/mpc52xx_pic.c
+++ b/arch/powerpc/platforms/52xx/mpc52xx_pic.c
@@ -132,7 +132,7 @@
 
 static struct mpc52xx_intr __iomem *intr;
 static struct mpc52xx_sdma __iomem *sdma;
-static struct irq_host *mpc52xx_irqhost = NULL;
+static struct irq_domain *mpc52xx_irqhost = NULL;
 
 static unsigned char mpc52xx_map_senses[4] = {
 	IRQ_TYPE_LEVEL_HIGH,
@@ -301,7 +301,7 @@
 /**
  * mpc52xx_irqhost_xlate - translate virq# from device tree interrupts property
  */
-static int mpc52xx_irqhost_xlate(struct irq_host *h, struct device_node *ct,
+static int mpc52xx_irqhost_xlate(struct irq_domain *h, struct device_node *ct,
 				 const u32 *intspec, unsigned int intsize,
 				 irq_hw_number_t *out_hwirq,
 				 unsigned int *out_flags)
@@ -335,7 +335,7 @@
 /**
  * mpc52xx_irqhost_map - Hook to map from virq to an irq_chip structure
  */
-static int mpc52xx_irqhost_map(struct irq_host *h, unsigned int virq,
+static int mpc52xx_irqhost_map(struct irq_domain *h, unsigned int virq,
 			       irq_hw_number_t irq)
 {
 	int l1irq;
@@ -384,7 +384,7 @@
 	return 0;
 }
 
-static struct irq_host_ops mpc52xx_irqhost_ops = {
+static const struct irq_domain_ops mpc52xx_irqhost_ops = {
 	.xlate = mpc52xx_irqhost_xlate,
 	.map = mpc52xx_irqhost_map,
 };
@@ -444,9 +444,9 @@
 	 * As last step, add an irq host to translate the real
 	 * hw irq information provided by the ofw to linux virq
 	 */
-	mpc52xx_irqhost = irq_alloc_host(picnode, IRQ_HOST_MAP_LINEAR,
+	mpc52xx_irqhost = irq_domain_add_linear(picnode,
 	                                 MPC52xx_IRQ_HIGHTESTHWIRQ,
-	                                 &mpc52xx_irqhost_ops, -1);
+	                                 &mpc52xx_irqhost_ops, NULL);
 
 	if (!mpc52xx_irqhost)
 		panic(__FILE__ ": Cannot allocate the IRQ host\n");
diff --git a/arch/powerpc/platforms/82xx/pq2ads-pci-pic.c b/arch/powerpc/platforms/82xx/pq2ads-pci-pic.c
index 8ccf9ed..328d221 100644
--- a/arch/powerpc/platforms/82xx/pq2ads-pci-pic.c
+++ b/arch/powerpc/platforms/82xx/pq2ads-pci-pic.c
@@ -29,7 +29,7 @@
 
 struct pq2ads_pci_pic {
 	struct device_node *node;
-	struct irq_host *host;
+	struct irq_domain *host;
 
 	struct {
 		u32 stat;
@@ -103,7 +103,7 @@
 	}
 }
 
-static int pci_pic_host_map(struct irq_host *h, unsigned int virq,
+static int pci_pic_host_map(struct irq_domain *h, unsigned int virq,
 			    irq_hw_number_t hw)
 {
 	irq_set_status_flags(virq, IRQ_LEVEL);
@@ -112,14 +112,14 @@
 	return 0;
 }
 
-static struct irq_host_ops pci_pic_host_ops = {
+static const struct irq_domain_ops pci_pic_host_ops = {
 	.map = pci_pic_host_map,
 };
 
 int __init pq2ads_pci_init_irq(void)
 {
 	struct pq2ads_pci_pic *priv;
-	struct irq_host *host;
+	struct irq_domain *host;
 	struct device_node *np;
 	int ret = -ENODEV;
 	int irq;
@@ -156,17 +156,13 @@
 	out_be32(&priv->regs->mask, ~0);
 	mb();
 
-	host = irq_alloc_host(np, IRQ_HOST_MAP_LINEAR, NUM_IRQS,
-	                      &pci_pic_host_ops, NUM_IRQS);
+	host = irq_domain_add_linear(np, NUM_IRQS, &pci_pic_host_ops, priv);
 	if (!host) {
 		ret = -ENOMEM;
 		goto out_unmap_regs;
 	}
 
-	host->host_data = priv;
-
 	priv->host = host;
-	host->host_data = priv;
 	irq_set_handler_data(irq, priv);
 	irq_set_chained_handler(irq, pq2ads_pci_irq_demux);
 
diff --git a/arch/powerpc/platforms/85xx/socrates_fpga_pic.c b/arch/powerpc/platforms/85xx/socrates_fpga_pic.c
index 12cb9bb..3bbbf74 100644
--- a/arch/powerpc/platforms/85xx/socrates_fpga_pic.c
+++ b/arch/powerpc/platforms/85xx/socrates_fpga_pic.c
@@ -51,7 +51,7 @@
 static DEFINE_RAW_SPINLOCK(socrates_fpga_pic_lock);
 
 static void __iomem *socrates_fpga_pic_iobase;
-static struct irq_host *socrates_fpga_pic_irq_host;
+static struct irq_domain *socrates_fpga_pic_irq_host;
 static unsigned int socrates_fpga_irqs[3];
 
 static inline uint32_t socrates_fpga_pic_read(int reg)
@@ -227,7 +227,7 @@
 	.irq_set_type	= socrates_fpga_pic_set_type,
 };
 
-static int socrates_fpga_pic_host_map(struct irq_host *h, unsigned int virq,
+static int socrates_fpga_pic_host_map(struct irq_domain *h, unsigned int virq,
 		irq_hw_number_t hwirq)
 {
 	/* All interrupts are LEVEL sensitive */
@@ -238,7 +238,7 @@
 	return 0;
 }
 
-static int socrates_fpga_pic_host_xlate(struct irq_host *h,
+static int socrates_fpga_pic_host_xlate(struct irq_domain *h,
 		struct device_node *ct,	const u32 *intspec, unsigned int intsize,
 		irq_hw_number_t *out_hwirq, unsigned int *out_flags)
 {
@@ -269,7 +269,7 @@
 	return 0;
 }
 
-static struct irq_host_ops socrates_fpga_pic_host_ops = {
+static const struct irq_domain_ops socrates_fpga_pic_host_ops = {
 	.map    = socrates_fpga_pic_host_map,
 	.xlate  = socrates_fpga_pic_host_xlate,
 };
@@ -279,10 +279,9 @@
 	unsigned long flags;
 	int i;
 
-	/* Setup an irq_host structure */
-	socrates_fpga_pic_irq_host = irq_alloc_host(pic, IRQ_HOST_MAP_LINEAR,
-			SOCRATES_FPGA_NUM_IRQS,	&socrates_fpga_pic_host_ops,
-			SOCRATES_FPGA_NUM_IRQS);
+	/* Setup an irq_domain structure */
+	socrates_fpga_pic_irq_host = irq_domain_add_linear(pic,
+		    SOCRATES_FPGA_NUM_IRQS, &socrates_fpga_pic_host_ops, NULL);
 	if (socrates_fpga_pic_irq_host == NULL) {
 		pr_err("FPGA PIC: Unable to allocate host\n");
 		return;
diff --git a/arch/powerpc/platforms/86xx/gef_pic.c b/arch/powerpc/platforms/86xx/gef_pic.c
index 94594e5..af3fd69 100644
--- a/arch/powerpc/platforms/86xx/gef_pic.c
+++ b/arch/powerpc/platforms/86xx/gef_pic.c
@@ -50,7 +50,7 @@
 static DEFINE_RAW_SPINLOCK(gef_pic_lock);
 
 static void __iomem *gef_pic_irq_reg_base;
-static struct irq_host *gef_pic_irq_host;
+static struct irq_domain *gef_pic_irq_host;
 static int gef_pic_cascade_irq;
 
 /*
@@ -153,7 +153,7 @@
 /* When an interrupt is being configured, this call allows some flexibilty
  * in deciding which irq_chip structure is used
  */
-static int gef_pic_host_map(struct irq_host *h, unsigned int virq,
+static int gef_pic_host_map(struct irq_domain *h, unsigned int virq,
 			  irq_hw_number_t hwirq)
 {
 	/* All interrupts are LEVEL sensitive */
@@ -163,7 +163,7 @@
 	return 0;
 }
 
-static int gef_pic_host_xlate(struct irq_host *h, struct device_node *ct,
+static int gef_pic_host_xlate(struct irq_domain *h, struct device_node *ct,
 			    const u32 *intspec, unsigned int intsize,
 			    irq_hw_number_t *out_hwirq, unsigned int *out_flags)
 {
@@ -177,7 +177,7 @@
 	return 0;
 }
 
-static struct irq_host_ops gef_pic_host_ops = {
+static const struct irq_domain_ops gef_pic_host_ops = {
 	.map	= gef_pic_host_map,
 	.xlate	= gef_pic_host_xlate,
 };
@@ -211,10 +211,9 @@
 		return;
 	}
 
-	/* Setup an irq_host structure */
-	gef_pic_irq_host = irq_alloc_host(np, IRQ_HOST_MAP_LINEAR,
-					  GEF_PIC_NUM_IRQS,
-					  &gef_pic_host_ops, NO_IRQ);
+	/* Setup an irq_domain structure */
+	gef_pic_irq_host = irq_domain_add_linear(np, GEF_PIC_NUM_IRQS,
+					  &gef_pic_host_ops, NULL);
 	if (gef_pic_irq_host == NULL)
 		return;
 
diff --git a/arch/powerpc/platforms/cell/axon_msi.c b/arch/powerpc/platforms/cell/axon_msi.c
index 40a6e34..db360fc 100644
--- a/arch/powerpc/platforms/cell/axon_msi.c
+++ b/arch/powerpc/platforms/cell/axon_msi.c
@@ -67,7 +67,7 @@
 
 
 struct axon_msic {
-	struct irq_host *irq_host;
+	struct irq_domain *irq_domain;
 	__le32 *fifo_virt;
 	dma_addr_t fifo_phys;
 	dcr_host_t dcr_host;
@@ -152,7 +152,7 @@
 
 static struct axon_msic *find_msi_translator(struct pci_dev *dev)
 {
-	struct irq_host *irq_host;
+	struct irq_domain *irq_domain;
 	struct device_node *dn, *tmp;
 	const phandle *ph;
 	struct axon_msic *msic = NULL;
@@ -184,14 +184,14 @@
 		goto out_error;
 	}
 
-	irq_host = irq_find_host(dn);
-	if (!irq_host) {
-		dev_dbg(&dev->dev, "axon_msi: no irq_host found for node %s\n",
+	irq_domain = irq_find_host(dn);
+	if (!irq_domain) {
+		dev_dbg(&dev->dev, "axon_msi: no irq_domain found for node %s\n",
 			dn->full_name);
 		goto out_error;
 	}
 
-	msic = irq_host->host_data;
+	msic = irq_domain->host_data;
 
 out_error:
 	of_node_put(dn);
@@ -280,7 +280,7 @@
 	BUILD_BUG_ON(NR_IRQS > 65536);
 
 	list_for_each_entry(entry, &dev->msi_list, list) {
-		virq = irq_create_direct_mapping(msic->irq_host);
+		virq = irq_create_direct_mapping(msic->irq_domain);
 		if (virq == NO_IRQ) {
 			dev_warn(&dev->dev,
 				 "axon_msi: virq allocation failed!\n");
@@ -318,7 +318,7 @@
 	.name		= "AXON-MSI",
 };
 
-static int msic_host_map(struct irq_host *h, unsigned int virq,
+static int msic_host_map(struct irq_domain *h, unsigned int virq,
 			 irq_hw_number_t hw)
 {
 	irq_set_chip_data(virq, h->host_data);
@@ -327,7 +327,7 @@
 	return 0;
 }
 
-static struct irq_host_ops msic_host_ops = {
+static const struct irq_domain_ops msic_host_ops = {
 	.map	= msic_host_map,
 };
 
@@ -337,7 +337,7 @@
 	u32 tmp;
 
 	pr_devel("axon_msi: disabling %s\n",
-		  msic->irq_host->of_node->full_name);
+		  msic->irq_domain->of_node->full_name);
 	tmp  = dcr_read(msic->dcr_host, MSIC_CTRL_REG);
 	tmp &= ~MSIC_CTRL_ENABLE & ~MSIC_CTRL_IRQ_ENABLE;
 	msic_dcr_write(msic, MSIC_CTRL_REG, tmp);
@@ -392,16 +392,13 @@
 	}
 	memset(msic->fifo_virt, 0xff, MSIC_FIFO_SIZE_BYTES);
 
-	msic->irq_host = irq_alloc_host(dn, IRQ_HOST_MAP_NOMAP,
-					NR_IRQS, &msic_host_ops, 0);
-	if (!msic->irq_host) {
-		printk(KERN_ERR "axon_msi: couldn't allocate irq_host for %s\n",
+	msic->irq_domain = irq_domain_add_nomap(dn, &msic_host_ops, msic);
+	if (!msic->irq_domain) {
+		printk(KERN_ERR "axon_msi: couldn't allocate irq_domain for %s\n",
 		       dn->full_name);
 		goto out_free_fifo;
 	}
 
-	msic->irq_host->host_data = msic;
-
 	irq_set_handler_data(virq, msic);
 	irq_set_chained_handler(virq, axon_msi_cascade);
 	pr_devel("axon_msi: irq 0x%x setup for axon_msi\n", virq);
diff --git a/arch/powerpc/platforms/cell/beat_interrupt.c b/arch/powerpc/platforms/cell/beat_interrupt.c
index 55015e1..e5c3a2c 100644
--- a/arch/powerpc/platforms/cell/beat_interrupt.c
+++ b/arch/powerpc/platforms/cell/beat_interrupt.c
@@ -34,7 +34,7 @@
 static uint64_t	beatic_irq_mask_enable[(MAX_IRQS+255)/64];
 static uint64_t	beatic_irq_mask_ack[(MAX_IRQS+255)/64];
 
-static struct irq_host *beatic_host;
+static struct irq_domain *beatic_host;
 
 /*
  * In this implementation, "virq" == "IRQ plug number",
@@ -122,7 +122,7 @@
  *
  * Note that the number (virq) is already assigned at upper layer.
  */
-static void beatic_pic_host_unmap(struct irq_host *h, unsigned int virq)
+static void beatic_pic_host_unmap(struct irq_domain *h, unsigned int virq)
 {
 	beat_destruct_irq_plug(virq);
 }
@@ -133,7 +133,7 @@
  *
  * Note that the number (virq) is already assigned at upper layer.
  */
-static int beatic_pic_host_map(struct irq_host *h, unsigned int virq,
+static int beatic_pic_host_map(struct irq_domain *h, unsigned int virq,
 			       irq_hw_number_t hw)
 {
 	int64_t	err;
@@ -154,7 +154,7 @@
  * Called from irq_create_of_mapping() only.
  * Note: We have only 1 entry to translate.
  */
-static int beatic_pic_host_xlate(struct irq_host *h, struct device_node *ct,
+static int beatic_pic_host_xlate(struct irq_domain *h, struct device_node *ct,
 				 const u32 *intspec, unsigned int intsize,
 				 irq_hw_number_t *out_hwirq,
 				 unsigned int *out_flags)
@@ -166,13 +166,13 @@
 	return 0;
 }
 
-static int beatic_pic_host_match(struct irq_host *h, struct device_node *np)
+static int beatic_pic_host_match(struct irq_domain *h, struct device_node *np)
 {
 	/* Match all */
 	return 1;
 }
 
-static struct irq_host_ops beatic_pic_host_ops = {
+static const struct irq_domain_ops beatic_pic_host_ops = {
 	.map = beatic_pic_host_map,
 	.unmap = beatic_pic_host_unmap,
 	.xlate = beatic_pic_host_xlate,
@@ -239,9 +239,7 @@
 	ppc_md.get_irq = beatic_get_irq;
 
 	/* Allocate an irq host */
-	beatic_host = irq_alloc_host(NULL, IRQ_HOST_MAP_NOMAP, 0,
-				     &beatic_pic_host_ops,
-					 0);
+	beatic_host = irq_domain_add_nomap(NULL, &beatic_pic_host_ops, NULL);
 	BUG_ON(beatic_host == NULL);
 	irq_set_default_host(beatic_host);
 }
diff --git a/arch/powerpc/platforms/cell/interrupt.c b/arch/powerpc/platforms/cell/interrupt.c
index 96a433d..2d42f3b 100644
--- a/arch/powerpc/platforms/cell/interrupt.c
+++ b/arch/powerpc/platforms/cell/interrupt.c
@@ -56,7 +56,7 @@
 
 static DEFINE_PER_CPU(struct iic, cpu_iic);
 #define IIC_NODE_COUNT	2
-static struct irq_host *iic_host;
+static struct irq_domain *iic_host;
 
 /* Convert between "pending" bits and hw irq number */
 static irq_hw_number_t iic_pending_to_hwnum(struct cbe_iic_pending_bits bits)
@@ -186,7 +186,7 @@
 	out_be64(&per_cpu(cpu_iic, cpu).regs->generate, (0xf - msg) << 4);
 }
 
-struct irq_host *iic_get_irq_host(int node)
+struct irq_domain *iic_get_irq_host(int node)
 {
 	return iic_host;
 }
@@ -222,13 +222,13 @@
 #endif /* CONFIG_SMP */
 
 
-static int iic_host_match(struct irq_host *h, struct device_node *node)
+static int iic_host_match(struct irq_domain *h, struct device_node *node)
 {
 	return of_device_is_compatible(node,
 				    "IBM,CBEA-Internal-Interrupt-Controller");
 }
 
-static int iic_host_map(struct irq_host *h, unsigned int virq,
+static int iic_host_map(struct irq_domain *h, unsigned int virq,
 			irq_hw_number_t hw)
 {
 	switch (hw & IIC_IRQ_TYPE_MASK) {
@@ -245,7 +245,7 @@
 	return 0;
 }
 
-static int iic_host_xlate(struct irq_host *h, struct device_node *ct,
+static int iic_host_xlate(struct irq_domain *h, struct device_node *ct,
 			   const u32 *intspec, unsigned int intsize,
 			   irq_hw_number_t *out_hwirq, unsigned int *out_flags)
 
@@ -285,7 +285,7 @@
 	return 0;
 }
 
-static struct irq_host_ops iic_host_ops = {
+static const struct irq_domain_ops iic_host_ops = {
 	.match = iic_host_match,
 	.map = iic_host_map,
 	.xlate = iic_host_xlate,
@@ -378,8 +378,8 @@
 void __init iic_init_IRQ(void)
 {
 	/* Setup an irq host data structure */
-	iic_host = irq_alloc_host(NULL, IRQ_HOST_MAP_LINEAR, IIC_SOURCE_COUNT,
-				  &iic_host_ops, IIC_IRQ_INVALID);
+	iic_host = irq_domain_add_linear(NULL, IIC_SOURCE_COUNT, &iic_host_ops,
+					 NULL);
 	BUG_ON(iic_host == NULL);
 	irq_set_default_host(iic_host);
 
diff --git a/arch/powerpc/platforms/cell/spider-pic.c b/arch/powerpc/platforms/cell/spider-pic.c
index 442c28c..d8b7cc8 100644
--- a/arch/powerpc/platforms/cell/spider-pic.c
+++ b/arch/powerpc/platforms/cell/spider-pic.c
@@ -62,7 +62,7 @@
 #define SPIDER_IRQ_INVALID	63
 
 struct spider_pic {
-	struct irq_host		*host;
+	struct irq_domain		*host;
 	void __iomem		*regs;
 	unsigned int		node_id;
 };
@@ -168,7 +168,7 @@
 	.irq_set_type = spider_set_irq_type,
 };
 
-static int spider_host_map(struct irq_host *h, unsigned int virq,
+static int spider_host_map(struct irq_domain *h, unsigned int virq,
 			irq_hw_number_t hw)
 {
 	irq_set_chip_data(virq, h->host_data);
@@ -180,7 +180,7 @@
 	return 0;
 }
 
-static int spider_host_xlate(struct irq_host *h, struct device_node *ct,
+static int spider_host_xlate(struct irq_domain *h, struct device_node *ct,
 			   const u32 *intspec, unsigned int intsize,
 			   irq_hw_number_t *out_hwirq, unsigned int *out_flags)
 
@@ -194,7 +194,7 @@
 	return 0;
 }
 
-static struct irq_host_ops spider_host_ops = {
+static const struct irq_domain_ops spider_host_ops = {
 	.map = spider_host_map,
 	.xlate = spider_host_xlate,
 };
@@ -299,12 +299,10 @@
 		panic("spider_pic: can't map registers !");
 
 	/* Allocate a host */
-	pic->host = irq_alloc_host(of_node, IRQ_HOST_MAP_LINEAR,
-				   SPIDER_SRC_COUNT, &spider_host_ops,
-				   SPIDER_IRQ_INVALID);
+	pic->host = irq_domain_add_linear(of_node, SPIDER_SRC_COUNT,
+					  &spider_host_ops, pic);
 	if (pic->host == NULL)
 		panic("spider_pic: can't allocate irq host !");
-	pic->host->host_data = pic;
 
 	/* Go through all sources and disable them */
 	for (i = 0; i < SPIDER_SRC_COUNT; i++) {
diff --git a/arch/powerpc/platforms/embedded6xx/flipper-pic.c b/arch/powerpc/platforms/embedded6xx/flipper-pic.c
index f61a2dd..53d6eee0 100644
--- a/arch/powerpc/platforms/embedded6xx/flipper-pic.c
+++ b/arch/powerpc/platforms/embedded6xx/flipper-pic.c
@@ -96,9 +96,9 @@
  *
  */
 
-static struct irq_host *flipper_irq_host;
+static struct irq_domain *flipper_irq_host;
 
-static int flipper_pic_map(struct irq_host *h, unsigned int virq,
+static int flipper_pic_map(struct irq_domain *h, unsigned int virq,
 			   irq_hw_number_t hwirq)
 {
 	irq_set_chip_data(virq, h->host_data);
@@ -107,13 +107,13 @@
 	return 0;
 }
 
-static int flipper_pic_match(struct irq_host *h, struct device_node *np)
+static int flipper_pic_match(struct irq_domain *h, struct device_node *np)
 {
 	return 1;
 }
 
 
-static struct irq_host_ops flipper_irq_host_ops = {
+static const struct irq_domain_ops flipper_irq_domain_ops = {
 	.map = flipper_pic_map,
 	.match = flipper_pic_match,
 };
@@ -130,10 +130,10 @@
 	out_be32(io_base + FLIPPER_ICR, 0xffffffff);
 }
 
-struct irq_host * __init flipper_pic_init(struct device_node *np)
+struct irq_domain * __init flipper_pic_init(struct device_node *np)
 {
 	struct device_node *pi;
-	struct irq_host *irq_host = NULL;
+	struct irq_domain *irq_domain = NULL;
 	struct resource res;
 	void __iomem *io_base;
 	int retval;
@@ -159,17 +159,15 @@
 
 	__flipper_quiesce(io_base);
 
-	irq_host = irq_alloc_host(np, IRQ_HOST_MAP_LINEAR, FLIPPER_NR_IRQS,
-				  &flipper_irq_host_ops, -1);
-	if (!irq_host) {
-		pr_err("failed to allocate irq_host\n");
+	irq_domain = irq_domain_add_linear(np, FLIPPER_NR_IRQS,
+				  &flipper_irq_domain_ops, io_base);
+	if (!irq_domain) {
+		pr_err("failed to allocate irq_domain\n");
 		return NULL;
 	}
 
-	irq_host->host_data = io_base;
-
 out:
-	return irq_host;
+	return irq_domain;
 }
 
 unsigned int flipper_pic_get_irq(void)
diff --git a/arch/powerpc/platforms/embedded6xx/hlwd-pic.c b/arch/powerpc/platforms/embedded6xx/hlwd-pic.c
index e491917..3006b51 100644
--- a/arch/powerpc/platforms/embedded6xx/hlwd-pic.c
+++ b/arch/powerpc/platforms/embedded6xx/hlwd-pic.c
@@ -89,9 +89,9 @@
  *
  */
 
-static struct irq_host *hlwd_irq_host;
+static struct irq_domain *hlwd_irq_host;
 
-static int hlwd_pic_map(struct irq_host *h, unsigned int virq,
+static int hlwd_pic_map(struct irq_domain *h, unsigned int virq,
 			   irq_hw_number_t hwirq)
 {
 	irq_set_chip_data(virq, h->host_data);
@@ -100,11 +100,11 @@
 	return 0;
 }
 
-static struct irq_host_ops hlwd_irq_host_ops = {
+static const struct irq_domain_ops hlwd_irq_domain_ops = {
 	.map = hlwd_pic_map,
 };
 
-static unsigned int __hlwd_pic_get_irq(struct irq_host *h)
+static unsigned int __hlwd_pic_get_irq(struct irq_domain *h)
 {
 	void __iomem *io_base = h->host_data;
 	int irq;
@@ -123,14 +123,14 @@
 				      struct irq_desc *desc)
 {
 	struct irq_chip *chip = irq_desc_get_chip(desc);
-	struct irq_host *irq_host = irq_get_handler_data(cascade_virq);
+	struct irq_domain *irq_domain = irq_get_handler_data(cascade_virq);
 	unsigned int virq;
 
 	raw_spin_lock(&desc->lock);
 	chip->irq_mask(&desc->irq_data); /* IRQ_LEVEL */
 	raw_spin_unlock(&desc->lock);
 
-	virq = __hlwd_pic_get_irq(irq_host);
+	virq = __hlwd_pic_get_irq(irq_domain);
 	if (virq != NO_IRQ)
 		generic_handle_irq(virq);
 	else
@@ -155,9 +155,9 @@
 	out_be32(io_base + HW_BROADWAY_ICR, 0xffffffff);
 }
 
-struct irq_host *hlwd_pic_init(struct device_node *np)
+struct irq_domain *hlwd_pic_init(struct device_node *np)
 {
-	struct irq_host *irq_host;
+	struct irq_domain *irq_domain;
 	struct resource res;
 	void __iomem *io_base;
 	int retval;
@@ -177,15 +177,14 @@
 
 	__hlwd_quiesce(io_base);
 
-	irq_host = irq_alloc_host(np, IRQ_HOST_MAP_LINEAR, HLWD_NR_IRQS,
-				  &hlwd_irq_host_ops, -1);
-	if (!irq_host) {
-		pr_err("failed to allocate irq_host\n");
+	irq_domain = irq_domain_add_linear(np, HLWD_NR_IRQS,
+					   &hlwd_irq_domain_ops, io_base);
+	if (!irq_domain) {
+		pr_err("failed to allocate irq_domain\n");
 		return NULL;
 	}
-	irq_host->host_data = io_base;
 
-	return irq_host;
+	return irq_domain;
 }
 
 unsigned int hlwd_pic_get_irq(void)
@@ -200,7 +199,7 @@
 
 void hlwd_pic_probe(void)
 {
-	struct irq_host *host;
+	struct irq_domain *host;
 	struct device_node *np;
 	const u32 *interrupts;
 	int cascade_virq;
diff --git a/arch/powerpc/platforms/iseries/irq.c b/arch/powerpc/platforms/iseries/irq.c
index b210345..05ce516 100644
--- a/arch/powerpc/platforms/iseries/irq.c
+++ b/arch/powerpc/platforms/iseries/irq.c
@@ -342,7 +342,7 @@
 
 #ifdef CONFIG_PCI
 
-static int iseries_irq_host_map(struct irq_host *h, unsigned int virq,
+static int iseries_irq_host_map(struct irq_domain *h, unsigned int virq,
 				irq_hw_number_t hw)
 {
 	irq_set_chip_and_handler(virq, &iseries_pic, handle_fasteoi_irq);
@@ -350,13 +350,13 @@
 	return 0;
 }
 
-static int iseries_irq_host_match(struct irq_host *h, struct device_node *np)
+static int iseries_irq_host_match(struct irq_domain *h, struct device_node *np)
 {
 	/* Match all */
 	return 1;
 }
 
-static struct irq_host_ops iseries_irq_host_ops = {
+static const struct irq_domain_ops iseries_irq_domain_ops = {
 	.map = iseries_irq_host_map,
 	.match = iseries_irq_host_match,
 };
@@ -368,7 +368,7 @@
 void __init iSeries_init_IRQ(void)
 {
 	/* Register PCI event handler and open an event path */
-	struct irq_host *host;
+	struct irq_domain *host;
 	int ret;
 
 	/*
@@ -380,8 +380,7 @@
 	/* Create irq host. No need for a revmap since HV will give us
 	 * back our virtual irq number
 	 */
-	host = irq_alloc_host(NULL, IRQ_HOST_MAP_NOMAP, 0,
-			      &iseries_irq_host_ops, 0);
+	host = irq_domain_add_nomap(NULL, &iseries_irq_domain_ops, NULL);
 	BUG_ON(host == NULL);
 	irq_set_default_host(host);
 
diff --git a/arch/powerpc/platforms/powermac/pic.c b/arch/powerpc/platforms/powermac/pic.c
index 7761aab..92afc38 100644
--- a/arch/powerpc/platforms/powermac/pic.c
+++ b/arch/powerpc/platforms/powermac/pic.c
@@ -61,7 +61,7 @@
 static unsigned long ppc_lost_interrupts[NR_MASK_WORDS];
 static unsigned long ppc_cached_irq_mask[NR_MASK_WORDS];
 static int pmac_irq_cascade = -1;
-static struct irq_host *pmac_pic_host;
+static struct irq_domain *pmac_pic_host;
 
 static void __pmac_retrigger(unsigned int irq_nr)
 {
@@ -268,13 +268,13 @@
 	.name		= "cascade",
 };
 
-static int pmac_pic_host_match(struct irq_host *h, struct device_node *node)
+static int pmac_pic_host_match(struct irq_domain *h, struct device_node *node)
 {
 	/* We match all, we don't always have a node anyway */
 	return 1;
 }
 
-static int pmac_pic_host_map(struct irq_host *h, unsigned int virq,
+static int pmac_pic_host_map(struct irq_domain *h, unsigned int virq,
 			     irq_hw_number_t hw)
 {
 	if (hw >= max_irqs)
@@ -288,21 +288,10 @@
 	return 0;
 }
 
-static int pmac_pic_host_xlate(struct irq_host *h, struct device_node *ct,
-			       const u32 *intspec, unsigned int intsize,
-			       irq_hw_number_t *out_hwirq,
-			       unsigned int *out_flags)
-
-{
-	*out_flags = IRQ_TYPE_NONE;
-	*out_hwirq = *intspec;
-	return 0;
-}
-
-static struct irq_host_ops pmac_pic_host_ops = {
+static const struct irq_domain_ops pmac_pic_host_ops = {
 	.match = pmac_pic_host_match,
 	.map = pmac_pic_host_map,
-	.xlate = pmac_pic_host_xlate,
+	.xlate = irq_domain_xlate_onecell,
 };
 
 static void __init pmac_pic_probe_oldstyle(void)
@@ -352,9 +341,8 @@
 	/*
 	 * Allocate an irq host
 	 */
-	pmac_pic_host = irq_alloc_host(master, IRQ_HOST_MAP_LINEAR, max_irqs,
-				       &pmac_pic_host_ops,
-				       max_irqs);
+	pmac_pic_host = irq_domain_add_linear(master, max_irqs,
+					      &pmac_pic_host_ops, NULL);
 	BUG_ON(pmac_pic_host == NULL);
 	irq_set_default_host(pmac_pic_host);
 
diff --git a/arch/powerpc/platforms/powermac/smp.c b/arch/powerpc/platforms/powermac/smp.c
index 44d7692..a81e5a8 100644
--- a/arch/powerpc/platforms/powermac/smp.c
+++ b/arch/powerpc/platforms/powermac/smp.c
@@ -125,7 +125,7 @@
 static int psurge_type = PSURGE_NONE;
 
 /* irq for secondary cpus to report */
-static struct irq_host *psurge_host;
+static struct irq_domain *psurge_host;
 int psurge_secondary_virq;
 
 /*
@@ -176,7 +176,7 @@
 	psurge_set_ipi(cpu);
 }
 
-static int psurge_host_map(struct irq_host *h, unsigned int virq,
+static int psurge_host_map(struct irq_domain *h, unsigned int virq,
 			 irq_hw_number_t hw)
 {
 	irq_set_chip_and_handler(virq, &dummy_irq_chip, handle_percpu_irq);
@@ -184,7 +184,7 @@
 	return 0;
 }
 
-struct irq_host_ops psurge_host_ops = {
+static const struct irq_domain_ops psurge_host_ops = {
 	.map	= psurge_host_map,
 };
 
@@ -192,8 +192,7 @@
 {
 	int rc = -ENOMEM;
 
-	psurge_host = irq_alloc_host(NULL, IRQ_HOST_MAP_NOMAP, 0,
-		&psurge_host_ops, 0);
+	psurge_host = irq_domain_add_nomap(NULL, &psurge_host_ops, NULL);
 
 	if (psurge_host)
 		psurge_secondary_virq = irq_create_direct_mapping(psurge_host);
diff --git a/arch/powerpc/platforms/ps3/interrupt.c b/arch/powerpc/platforms/ps3/interrupt.c
index 617efa1..2a4ff86 100644
--- a/arch/powerpc/platforms/ps3/interrupt.c
+++ b/arch/powerpc/platforms/ps3/interrupt.c
@@ -667,7 +667,7 @@
 static void dump_bmp(struct ps3_private* pd) {};
 #endif /* defined(DEBUG) */
 
-static int ps3_host_map(struct irq_host *h, unsigned int virq,
+static int ps3_host_map(struct irq_domain *h, unsigned int virq,
 	irq_hw_number_t hwirq)
 {
 	DBG("%s:%d: hwirq %lu, virq %u\n", __func__, __LINE__, hwirq,
@@ -678,13 +678,13 @@
 	return 0;
 }
 
-static int ps3_host_match(struct irq_host *h, struct device_node *np)
+static int ps3_host_match(struct irq_domain *h, struct device_node *np)
 {
 	/* Match all */
 	return 1;
 }
 
-static struct irq_host_ops ps3_host_ops = {
+static const struct irq_domain_ops ps3_host_ops = {
 	.map = ps3_host_map,
 	.match = ps3_host_match,
 };
@@ -751,10 +751,9 @@
 {
 	int result;
 	unsigned cpu;
-	struct irq_host *host;
+	struct irq_domain *host;
 
-	host = irq_alloc_host(NULL, IRQ_HOST_MAP_NOMAP, 0, &ps3_host_ops,
-		PS3_INVALID_OUTLET);
+	host = irq_domain_add_nomap(NULL, &ps3_host_ops, NULL);
 	irq_set_default_host(host);
 	irq_set_virq_count(PS3_PLUG_MAX + 1);
 
diff --git a/arch/powerpc/platforms/wsp/opb_pic.c b/arch/powerpc/platforms/wsp/opb_pic.c
index 19f353d..cb565bf 100644
--- a/arch/powerpc/platforms/wsp/opb_pic.c
+++ b/arch/powerpc/platforms/wsp/opb_pic.c
@@ -30,7 +30,7 @@
 static int opb_index = 0;
 
 struct opb_pic {
-	struct irq_host *host;
+	struct irq_domain *host;
 	void *regs;
 	int index;
 	spinlock_t lock;
@@ -179,7 +179,7 @@
 	.irq_set_type	= opb_set_irq_type
 };
 
-static int opb_host_map(struct irq_host *host, unsigned int virq,
+static int opb_host_map(struct irq_domain *host, unsigned int virq,
 		irq_hw_number_t hwirq)
 {
 	struct opb_pic *opb;
@@ -196,20 +196,9 @@
 	return 0;
 }
 
-static int opb_host_xlate(struct irq_host *host, struct device_node *dn,
-		const u32 *intspec, unsigned int intsize,
-		irq_hw_number_t *out_hwirq, unsigned int *out_type)
-{
-	/* Interrupt size must == 2 */
-	BUG_ON(intsize != 2);
-	*out_hwirq = intspec[0];
-	*out_type = intspec[1];
-	return 0;
-}
-
-static struct irq_host_ops opb_host_ops = {
+static const struct irq_domain_ops opb_host_ops = {
 	.map = opb_host_map,
-	.xlate = opb_host_xlate,
+	.xlate = irq_domain_xlate_twocell,
 };
 
 irqreturn_t opb_irq_handler(int irq, void *private)
@@ -263,13 +252,11 @@
 		goto free_opb;
 	}
 
-	/* Allocate an irq host so that Linux knows that despite only
+	/* Allocate an irq domain so that Linux knows that despite only
 	 * having one interrupt to issue, we're the controller for multiple
 	 * hardware IRQs, so later we can lookup their virtual IRQs. */
 
-	opb->host = irq_alloc_host(dn, IRQ_HOST_MAP_LINEAR,
-			OPB_NR_IRQS, &opb_host_ops, -1);
-
+	opb->host = irq_domain_add_linear(dn, OPB_NR_IRQS, &opb_host_ops, opb);
 	if (!opb->host) {
 		printk(KERN_ERR "opb: Failed to allocate IRQ host!\n");
 		goto free_regs;
@@ -277,7 +264,6 @@
 
 	opb->index = opb_index++;
 	spin_lock_init(&opb->lock);
-	opb->host->host_data = opb;
 
 	/* Disable all interrupts by default */
 	opb_out(opb, OPB_MLSASIER, 0);
diff --git a/arch/powerpc/sysdev/cpm1.c b/arch/powerpc/sysdev/cpm1.c
index 5d7d59a..d4fa03f 100644
--- a/arch/powerpc/sysdev/cpm1.c
+++ b/arch/powerpc/sysdev/cpm1.c
@@ -54,7 +54,7 @@
 immap_t __iomem *mpc8xx_immr;
 static cpic8xx_t __iomem *cpic_reg;
 
-static struct irq_host *cpm_pic_host;
+static struct irq_domain *cpm_pic_host;
 
 static void cpm_mask_irq(struct irq_data *d)
 {
@@ -98,7 +98,7 @@
 	return irq_linear_revmap(cpm_pic_host, cpm_vec);
 }
 
-static int cpm_pic_host_map(struct irq_host *h, unsigned int virq,
+static int cpm_pic_host_map(struct irq_domain *h, unsigned int virq,
 			  irq_hw_number_t hw)
 {
 	pr_debug("cpm_pic_host_map(%d, 0x%lx)\n", virq, hw);
@@ -123,7 +123,7 @@
 	.name = "error",
 };
 
-static struct irq_host_ops cpm_pic_host_ops = {
+static const struct irq_domain_ops cpm_pic_host_ops = {
 	.map = cpm_pic_host_map,
 };
 
@@ -164,8 +164,7 @@
 
 	out_be32(&cpic_reg->cpic_cimr, 0);
 
-	cpm_pic_host = irq_alloc_host(np, IRQ_HOST_MAP_LINEAR,
-				      64, &cpm_pic_host_ops, 64);
+	cpm_pic_host = irq_domain_add_linear(np, 64, &cpm_pic_host_ops, NULL);
 	if (cpm_pic_host == NULL) {
 		printk(KERN_ERR "CPM2 PIC: failed to allocate irq host!\n");
 		sirq = NO_IRQ;
diff --git a/arch/powerpc/sysdev/cpm2_pic.c b/arch/powerpc/sysdev/cpm2_pic.c
index bcab50e..d3be961 100644
--- a/arch/powerpc/sysdev/cpm2_pic.c
+++ b/arch/powerpc/sysdev/cpm2_pic.c
@@ -50,7 +50,7 @@
 
 static intctl_cpm2_t __iomem *cpm2_intctl;
 
-static struct irq_host *cpm2_pic_host;
+static struct irq_domain *cpm2_pic_host;
 #define NR_MASK_WORDS   ((NR_IRQS + 31) / 32)
 static unsigned long ppc_cached_irq_mask[NR_MASK_WORDS];
 
@@ -214,7 +214,7 @@
 	return irq_linear_revmap(cpm2_pic_host, irq);
 }
 
-static int cpm2_pic_host_map(struct irq_host *h, unsigned int virq,
+static int cpm2_pic_host_map(struct irq_domain *h, unsigned int virq,
 			  irq_hw_number_t hw)
 {
 	pr_debug("cpm2_pic_host_map(%d, 0x%lx)\n", virq, hw);
@@ -224,21 +224,9 @@
 	return 0;
 }
 
-static int cpm2_pic_host_xlate(struct irq_host *h, struct device_node *ct,
-			    const u32 *intspec, unsigned int intsize,
-			    irq_hw_number_t *out_hwirq, unsigned int *out_flags)
-{
-	*out_hwirq = intspec[0];
-	if (intsize > 1)
-		*out_flags = intspec[1];
-	else
-		*out_flags = IRQ_TYPE_NONE;
-	return 0;
-}
-
-static struct irq_host_ops cpm2_pic_host_ops = {
+static const struct irq_domain_ops cpm2_pic_host_ops = {
 	.map = cpm2_pic_host_map,
-	.xlate = cpm2_pic_host_xlate,
+	.xlate = irq_domain_xlate_onetwocell,
 };
 
 void cpm2_pic_init(struct device_node *node)
@@ -275,8 +263,7 @@
 	out_be32(&cpm2_intctl->ic_scprrl, 0x05309770);
 
 	/* create a legacy host */
-	cpm2_pic_host = irq_alloc_host(node, IRQ_HOST_MAP_LINEAR,
-				       64, &cpm2_pic_host_ops, 64);
+	cpm2_pic_host = irq_domain_add_linear(node, 64, &cpm2_pic_host_ops, NULL);
 	if (cpm2_pic_host == NULL) {
 		printk(KERN_ERR "CPM2 PIC: failed to allocate irq host!\n");
 		return;
diff --git a/arch/powerpc/sysdev/ehv_pic.c b/arch/powerpc/sysdev/ehv_pic.c
index b6731e4..6e0e100 100644
--- a/arch/powerpc/sysdev/ehv_pic.c
+++ b/arch/powerpc/sysdev/ehv_pic.c
@@ -182,13 +182,13 @@
 	return irq_linear_revmap(global_ehv_pic->irqhost, irq);
 }
 
-static int ehv_pic_host_match(struct irq_host *h, struct device_node *node)
+static int ehv_pic_host_match(struct irq_domain *h, struct device_node *node)
 {
 	/* Exact match, unless ehv_pic node is NULL */
 	return h->of_node == NULL || h->of_node == node;
 }
 
-static int ehv_pic_host_map(struct irq_host *h, unsigned int virq,
+static int ehv_pic_host_map(struct irq_domain *h, unsigned int virq,
 			 irq_hw_number_t hw)
 {
 	struct ehv_pic *ehv_pic = h->host_data;
@@ -217,7 +217,7 @@
 	return 0;
 }
 
-static int ehv_pic_host_xlate(struct irq_host *h, struct device_node *ct,
+static int ehv_pic_host_xlate(struct irq_domain *h, struct device_node *ct,
 			   const u32 *intspec, unsigned int intsize,
 			   irq_hw_number_t *out_hwirq, unsigned int *out_flags)
 
@@ -248,7 +248,7 @@
 	return 0;
 }
 
-static struct irq_host_ops ehv_pic_host_ops = {
+static const struct irq_domain_ops ehv_pic_host_ops = {
 	.match = ehv_pic_host_match,
 	.map = ehv_pic_host_map,
 	.xlate = ehv_pic_host_xlate,
@@ -275,9 +275,8 @@
 		return;
 	}
 
-	ehv_pic->irqhost = irq_alloc_host(np, IRQ_HOST_MAP_LINEAR,
-		NR_EHV_PIC_INTS, &ehv_pic_host_ops, 0);
-
+	ehv_pic->irqhost = irq_domain_add_linear(np, NR_EHV_PIC_INTS,
+						 &ehv_pic_host_ops, ehv_pic);
 	if (!ehv_pic->irqhost) {
 		of_node_put(np);
 		kfree(ehv_pic);
@@ -293,7 +292,6 @@
 		of_node_put(np2);
 	}
 
-	ehv_pic->irqhost->host_data = ehv_pic;
 	ehv_pic->hc_irq = ehv_pic_irq_chip;
 	ehv_pic->hc_irq.irq_set_affinity = ehv_pic_set_affinity;
 	ehv_pic->coreint_flag = coreint_flag;
diff --git a/arch/powerpc/sysdev/fsl_msi.c b/arch/powerpc/sysdev/fsl_msi.c
index ecb5c19..0c01deb 100644
--- a/arch/powerpc/sysdev/fsl_msi.c
+++ b/arch/powerpc/sysdev/fsl_msi.c
@@ -60,7 +60,7 @@
 	.name		= "FSL-MSI",
 };
 
-static int fsl_msi_host_map(struct irq_host *h, unsigned int virq,
+static int fsl_msi_host_map(struct irq_domain *h, unsigned int virq,
 				irq_hw_number_t hw)
 {
 	struct fsl_msi *msi_data = h->host_data;
@@ -74,7 +74,7 @@
 	return 0;
 }
 
-static struct irq_host_ops fsl_msi_host_ops = {
+static const struct irq_domain_ops fsl_msi_host_ops = {
 	.map = fsl_msi_host_map,
 };
 
@@ -387,8 +387,8 @@
 	}
 	platform_set_drvdata(dev, msi);
 
-	msi->irqhost = irq_alloc_host(dev->dev.of_node, IRQ_HOST_MAP_LINEAR,
-				      NR_MSI_IRQS, &fsl_msi_host_ops, 0);
+	msi->irqhost = irq_domain_add_linear(dev->dev.of_node,
+				      NR_MSI_IRQS, &fsl_msi_host_ops, msi);
 
 	if (msi->irqhost == NULL) {
 		dev_err(&dev->dev, "No memory for MSI irqhost\n");
@@ -420,8 +420,6 @@
 
 	msi->feature = features->fsl_pic_ip;
 
-	msi->irqhost->host_data = msi;
-
 	/*
 	 * Remember the phandle, so that we can match with any PCI nodes
 	 * that have an "fsl,msi" property.
diff --git a/arch/powerpc/sysdev/fsl_msi.h b/arch/powerpc/sysdev/fsl_msi.h
index f6c646a..8225f86 100644
--- a/arch/powerpc/sysdev/fsl_msi.h
+++ b/arch/powerpc/sysdev/fsl_msi.h
@@ -26,7 +26,7 @@
 #define FSL_PIC_IP_VMPIC  0x00000003
 
 struct fsl_msi {
-	struct irq_host *irqhost;
+	struct irq_domain *irqhost;
 
 	unsigned long cascade_irq;
 
diff --git a/arch/powerpc/sysdev/i8259.c b/arch/powerpc/sysdev/i8259.c
index d18bb27..997df6a 100644
--- a/arch/powerpc/sysdev/i8259.c
+++ b/arch/powerpc/sysdev/i8259.c
@@ -25,7 +25,7 @@
 
 static DEFINE_RAW_SPINLOCK(i8259_lock);
 
-static struct irq_host *i8259_host;
+static struct irq_domain *i8259_host;
 
 /*
  * Acknowledge the IRQ using either the PCI host bridge's interrupt
@@ -163,12 +163,12 @@
 	.flags = IORESOURCE_BUSY,
 };
 
-static int i8259_host_match(struct irq_host *h, struct device_node *node)
+static int i8259_host_match(struct irq_domain *h, struct device_node *node)
 {
 	return h->of_node == NULL || h->of_node == node;
 }
 
-static int i8259_host_map(struct irq_host *h, unsigned int virq,
+static int i8259_host_map(struct irq_domain *h, unsigned int virq,
 			  irq_hw_number_t hw)
 {
 	pr_debug("i8259_host_map(%d, 0x%lx)\n", virq, hw);
@@ -185,7 +185,7 @@
 	return 0;
 }
 
-static int i8259_host_xlate(struct irq_host *h, struct device_node *ct,
+static int i8259_host_xlate(struct irq_domain *h, struct device_node *ct,
 			    const u32 *intspec, unsigned int intsize,
 			    irq_hw_number_t *out_hwirq, unsigned int *out_flags)
 {
@@ -205,13 +205,13 @@
 	return 0;
 }
 
-static struct irq_host_ops i8259_host_ops = {
+static struct irq_domain_ops i8259_host_ops = {
 	.match = i8259_host_match,
 	.map = i8259_host_map,
 	.xlate = i8259_host_xlate,
 };
 
-struct irq_host *i8259_get_host(void)
+struct irq_domain *i8259_get_host(void)
 {
 	return i8259_host;
 }
@@ -263,8 +263,7 @@
 	raw_spin_unlock_irqrestore(&i8259_lock, flags);
 
 	/* create a legacy host */
-	i8259_host = irq_alloc_host(node, IRQ_HOST_MAP_LEGACY,
-				    0, &i8259_host_ops, 0);
+	i8259_host = irq_domain_add_legacy_isa(node, &i8259_host_ops, NULL);
 	if (i8259_host == NULL) {
 		printk(KERN_ERR "i8259: failed to allocate irq host !\n");
 		return;
diff --git a/arch/powerpc/sysdev/ipic.c b/arch/powerpc/sysdev/ipic.c
index 95da897..b50f978 100644
--- a/arch/powerpc/sysdev/ipic.c
+++ b/arch/powerpc/sysdev/ipic.c
@@ -672,13 +672,13 @@
 	.irq_set_type	= ipic_set_irq_type,
 };
 
-static int ipic_host_match(struct irq_host *h, struct device_node *node)
+static int ipic_host_match(struct irq_domain *h, struct device_node *node)
 {
 	/* Exact match, unless ipic node is NULL */
 	return h->of_node == NULL || h->of_node == node;
 }
 
-static int ipic_host_map(struct irq_host *h, unsigned int virq,
+static int ipic_host_map(struct irq_domain *h, unsigned int virq,
 			 irq_hw_number_t hw)
 {
 	struct ipic *ipic = h->host_data;
@@ -692,26 +692,10 @@
 	return 0;
 }
 
-static int ipic_host_xlate(struct irq_host *h, struct device_node *ct,
-			   const u32 *intspec, unsigned int intsize,
-			   irq_hw_number_t *out_hwirq, unsigned int *out_flags)
-
-{
-	/* interrupt sense values coming from the device tree equal either
-	 * LEVEL_LOW (low assertion) or EDGE_FALLING (high-to-low change)
-	 */
-	*out_hwirq = intspec[0];
-	if (intsize > 1)
-		*out_flags = intspec[1];
-	else
-		*out_flags = IRQ_TYPE_NONE;
-	return 0;
-}
-
-static struct irq_host_ops ipic_host_ops = {
+static struct irq_domain_ops ipic_host_ops = {
 	.match	= ipic_host_match,
 	.map	= ipic_host_map,
-	.xlate	= ipic_host_xlate,
+	.xlate	= irq_domain_xlate_onetwocell,
 };
 
 struct ipic * __init ipic_init(struct device_node *node, unsigned int flags)
@@ -728,9 +712,8 @@
 	if (ipic == NULL)
 		return NULL;
 
-	ipic->irqhost = irq_alloc_host(node, IRQ_HOST_MAP_LINEAR,
-				       NR_IPIC_INTS,
-				       &ipic_host_ops, 0);
+	ipic->irqhost = irq_domain_add_linear(node, NR_IPIC_INTS,
+					      &ipic_host_ops, ipic);
 	if (ipic->irqhost == NULL) {
 		kfree(ipic);
 		return NULL;
@@ -738,8 +721,6 @@
 
 	ipic->regs = ioremap(res.start, resource_size(&res));
 
-	ipic->irqhost->host_data = ipic;
-
 	/* init hw */
 	ipic_write(ipic->regs, IPIC_SICNR, 0x0);
 
diff --git a/arch/powerpc/sysdev/ipic.h b/arch/powerpc/sysdev/ipic.h
index 9391c57..90031d1 100644
--- a/arch/powerpc/sysdev/ipic.h
+++ b/arch/powerpc/sysdev/ipic.h
@@ -43,7 +43,7 @@
 	volatile u32 __iomem	*regs;
 
 	/* The remapper for this IPIC */
-	struct irq_host		*irqhost;
+	struct irq_domain		*irqhost;
 };
 
 struct ipic_info {
diff --git a/arch/powerpc/sysdev/mpc8xx_pic.c b/arch/powerpc/sysdev/mpc8xx_pic.c
index 2ca0a85..d5f5416 100644
--- a/arch/powerpc/sysdev/mpc8xx_pic.c
+++ b/arch/powerpc/sysdev/mpc8xx_pic.c
@@ -17,7 +17,7 @@
 
 extern int cpm_get_irq(struct pt_regs *regs);
 
-static struct irq_host *mpc8xx_pic_host;
+static struct irq_domain *mpc8xx_pic_host;
 #define NR_MASK_WORDS   ((NR_IRQS + 31) / 32)
 static unsigned long ppc_cached_irq_mask[NR_MASK_WORDS];
 static sysconf8xx_t __iomem *siu_reg;
@@ -110,7 +110,7 @@
 
 }
 
-static int mpc8xx_pic_host_map(struct irq_host *h, unsigned int virq,
+static int mpc8xx_pic_host_map(struct irq_domain *h, unsigned int virq,
 			  irq_hw_number_t hw)
 {
 	pr_debug("mpc8xx_pic_host_map(%d, 0x%lx)\n", virq, hw);
@@ -121,7 +121,7 @@
 }
 
 
-static int mpc8xx_pic_host_xlate(struct irq_host *h, struct device_node *ct,
+static int mpc8xx_pic_host_xlate(struct irq_domain *h, struct device_node *ct,
 			    const u32 *intspec, unsigned int intsize,
 			    irq_hw_number_t *out_hwirq, unsigned int *out_flags)
 {
@@ -142,7 +142,7 @@
 }
 
 
-static struct irq_host_ops mpc8xx_pic_host_ops = {
+static struct irq_domain_ops mpc8xx_pic_host_ops = {
 	.map = mpc8xx_pic_host_map,
 	.xlate = mpc8xx_pic_host_xlate,
 };
@@ -171,8 +171,7 @@
 		goto out;
 	}
 
-	mpc8xx_pic_host = irq_alloc_host(np, IRQ_HOST_MAP_LINEAR,
-					 64, &mpc8xx_pic_host_ops, 64);
+	mpc8xx_pic_host = irq_domain_add_linear(np, 64, &mpc8xx_pic_host_ops, NULL);
 	if (mpc8xx_pic_host == NULL) {
 		printk(KERN_ERR "MPC8xx PIC: failed to allocate irq host!\n");
 		ret = -ENOMEM;
diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c
index 4e9ccb1..c83a512 100644
--- a/arch/powerpc/sysdev/mpic.c
+++ b/arch/powerpc/sysdev/mpic.c
@@ -965,13 +965,13 @@
 #endif /* CONFIG_MPIC_U3_HT_IRQS */
 
 
-static int mpic_host_match(struct irq_host *h, struct device_node *node)
+static int mpic_host_match(struct irq_domain *h, struct device_node *node)
 {
 	/* Exact match, unless mpic node is NULL */
 	return h->of_node == NULL || h->of_node == node;
 }
 
-static int mpic_host_map(struct irq_host *h, unsigned int virq,
+static int mpic_host_map(struct irq_domain *h, unsigned int virq,
 			 irq_hw_number_t hw)
 {
 	struct mpic *mpic = h->host_data;
@@ -1041,7 +1041,7 @@
 	return 0;
 }
 
-static int mpic_host_xlate(struct irq_host *h, struct device_node *ct,
+static int mpic_host_xlate(struct irq_domain *h, struct device_node *ct,
 			   const u32 *intspec, unsigned int intsize,
 			   irq_hw_number_t *out_hwirq, unsigned int *out_flags)
 
@@ -1121,13 +1121,13 @@
 	BUG_ON(!(mpic->flags & MPIC_SECONDARY));
 
 	virq = mpic_get_one_irq(mpic);
-	if (virq != NO_IRQ)
+	if (virq)
 		generic_handle_irq(virq);
 
 	chip->irq_eoi(&desc->irq_data);
 }
 
-static struct irq_host_ops mpic_host_ops = {
+static struct irq_domain_ops mpic_host_ops = {
 	.match = mpic_host_match,
 	.map = mpic_host_map,
 	.xlate = mpic_host_xlate,
@@ -1345,10 +1345,9 @@
 	mpic->isu_shift = 1 + __ilog2(mpic->isu_size - 1);
 	mpic->isu_mask = (1 << mpic->isu_shift) - 1;
 
-	mpic->irqhost = irq_alloc_host(mpic->node, IRQ_HOST_MAP_LINEAR,
+	mpic->irqhost = irq_domain_add_linear(mpic->node,
 				       isu_size ? isu_size : mpic->num_sources,
-				       &mpic_host_ops,
-				       flags & MPIC_LARGE_VECTORS ? 2048 : 256);
+				       &mpic_host_ops, mpic);
 
 	/*
 	 * FIXME: The code leaks the MPIC object and mappings here; this
@@ -1357,8 +1356,6 @@
 	if (mpic->irqhost == NULL)
 		return NULL;
 
-	mpic->irqhost->host_data = mpic;
-
 	/* Display version */
 	switch (greg_feature & MPIC_GREG_FEATURE_VERSION_MASK) {
 	case 1:
diff --git a/arch/powerpc/sysdev/mpic_msi.c b/arch/powerpc/sysdev/mpic_msi.c
index 0f67cd7..0622aa9 100644
--- a/arch/powerpc/sysdev/mpic_msi.c
+++ b/arch/powerpc/sysdev/mpic_msi.c
@@ -32,7 +32,7 @@
 static int mpic_msi_reserve_u3_hwirqs(struct mpic *mpic)
 {
 	irq_hw_number_t hwirq;
-	struct irq_host_ops *ops = mpic->irqhost->ops;
+	const struct irq_domain_ops *ops = mpic->irqhost->ops;
 	struct device_node *np;
 	int flags, index, i;
 	struct of_irq oirq;
diff --git a/arch/powerpc/sysdev/mv64x60_pic.c b/arch/powerpc/sysdev/mv64x60_pic.c
index 14d1302..8848e99 100644
--- a/arch/powerpc/sysdev/mv64x60_pic.c
+++ b/arch/powerpc/sysdev/mv64x60_pic.c
@@ -70,7 +70,7 @@
 static u32 mv64x60_cached_high_mask = MV64X60_HIGH_GPP_GROUPS;
 static u32 mv64x60_cached_gpp_mask;
 
-static struct irq_host *mv64x60_irq_host;
+static struct irq_domain *mv64x60_irq_host;
 
 /*
  * mv64x60_chip_low functions
@@ -208,7 +208,7 @@
 	[MV64x60_LEVEL1_GPP]  = &mv64x60_chip_gpp,
 };
 
-static int mv64x60_host_map(struct irq_host *h, unsigned int virq,
+static int mv64x60_host_map(struct irq_domain *h, unsigned int virq,
 			  irq_hw_number_t hwirq)
 {
 	int level1;
@@ -223,7 +223,7 @@
 	return 0;
 }
 
-static struct irq_host_ops mv64x60_host_ops = {
+static struct irq_domain_ops mv64x60_host_ops = {
 	.map   = mv64x60_host_map,
 };
 
@@ -250,9 +250,8 @@
 	paddr = of_translate_address(np, reg);
 	mv64x60_irq_reg_base = ioremap(paddr, reg[1]);
 
-	mv64x60_irq_host = irq_alloc_host(np, IRQ_HOST_MAP_LINEAR,
-					  MV64x60_NUM_IRQS,
-					  &mv64x60_host_ops, MV64x60_NUM_IRQS);
+	mv64x60_irq_host = irq_domain_add_linear(np, MV64x60_NUM_IRQS,
+					  &mv64x60_host_ops, NULL);
 
 	spin_lock_irqsave(&mv64x60_lock, flags);
 	out_le32(mv64x60_gpp_reg_base + MV64x60_GPP_INTR_MASK,
diff --git a/arch/powerpc/sysdev/qe_lib/qe_ic.c b/arch/powerpc/sysdev/qe_lib/qe_ic.c
index 73034bd..2fba6ef2 100644
--- a/arch/powerpc/sysdev/qe_lib/qe_ic.c
+++ b/arch/powerpc/sysdev/qe_lib/qe_ic.c
@@ -245,13 +245,13 @@
 	.irq_mask_ack = qe_ic_mask_irq,
 };
 
-static int qe_ic_host_match(struct irq_host *h, struct device_node *node)
+static int qe_ic_host_match(struct irq_domain *h, struct device_node *node)
 {
 	/* Exact match, unless qe_ic node is NULL */
 	return h->of_node == NULL || h->of_node == node;
 }
 
-static int qe_ic_host_map(struct irq_host *h, unsigned int virq,
+static int qe_ic_host_map(struct irq_domain *h, unsigned int virq,
 			  irq_hw_number_t hw)
 {
 	struct qe_ic *qe_ic = h->host_data;
@@ -272,23 +272,10 @@
 	return 0;
 }
 
-static int qe_ic_host_xlate(struct irq_host *h, struct device_node *ct,
-			    const u32 * intspec, unsigned int intsize,
-			    irq_hw_number_t * out_hwirq,
-			    unsigned int *out_flags)
-{
-	*out_hwirq = intspec[0];
-	if (intsize > 1)
-		*out_flags = intspec[1];
-	else
-		*out_flags = IRQ_TYPE_NONE;
-	return 0;
-}
-
-static struct irq_host_ops qe_ic_host_ops = {
+static struct irq_domain_ops qe_ic_host_ops = {
 	.match = qe_ic_host_match,
 	.map = qe_ic_host_map,
-	.xlate = qe_ic_host_xlate,
+	.xlate = irq_domain_xlate_onetwocell,
 };
 
 /* Return an interrupt vector or NO_IRQ if no interrupt is pending. */
@@ -339,8 +326,8 @@
 	if (qe_ic == NULL)
 		return;
 
-	qe_ic->irqhost = irq_alloc_host(node, IRQ_HOST_MAP_LINEAR,
-					NR_QE_IC_INTS, &qe_ic_host_ops, 0);
+	qe_ic->irqhost = irq_domain_add_linear(node, NR_QE_IC_INTS,
+					       &qe_ic_host_ops, qe_ic);
 	if (qe_ic->irqhost == NULL) {
 		kfree(qe_ic);
 		return;
@@ -348,7 +335,6 @@
 
 	qe_ic->regs = ioremap(res.start, resource_size(&res));
 
-	qe_ic->irqhost->host_data = qe_ic;
 	qe_ic->hc_irq = qe_ic_irq_chip;
 
 	qe_ic->virq_high = irq_of_parse_and_map(node, 0);
diff --git a/arch/powerpc/sysdev/qe_lib/qe_ic.h b/arch/powerpc/sysdev/qe_lib/qe_ic.h
index c1361d0..c327872 100644
--- a/arch/powerpc/sysdev/qe_lib/qe_ic.h
+++ b/arch/powerpc/sysdev/qe_lib/qe_ic.h
@@ -79,7 +79,7 @@
 	volatile u32 __iomem *regs;
 
 	/* The remapper for this QEIC */
-	struct irq_host *irqhost;
+	struct irq_domain *irqhost;
 
 	/* The "linux" controller struct */
 	struct irq_chip hc_irq;
diff --git a/arch/powerpc/sysdev/tsi108_pci.c b/arch/powerpc/sysdev/tsi108_pci.c
index 4d18658..188012c 100644
--- a/arch/powerpc/sysdev/tsi108_pci.c
+++ b/arch/powerpc/sysdev/tsi108_pci.c
@@ -51,7 +51,7 @@
 u32 tsi108_pci_cfg_base;
 static u32 tsi108_pci_cfg_phys;
 u32 tsi108_csr_vir_base;
-static struct irq_host *pci_irq_host;
+static struct irq_domain *pci_irq_host;
 
 extern u32 get_vir_csrbase(void);
 extern u32 tsi108_read_reg(u32 reg_offset);
@@ -376,7 +376,7 @@
 	.irq_unmask = tsi108_pci_irq_unmask,
 };
 
-static int pci_irq_host_xlate(struct irq_host *h, struct device_node *ct,
+static int pci_irq_host_xlate(struct irq_domain *h, struct device_node *ct,
 			    const u32 *intspec, unsigned int intsize,
 			    irq_hw_number_t *out_hwirq, unsigned int *out_flags)
 {
@@ -385,7 +385,7 @@
 	return 0;
 }
 
-static int pci_irq_host_map(struct irq_host *h, unsigned int virq,
+static int pci_irq_host_map(struct irq_domain *h, unsigned int virq,
 			  irq_hw_number_t hw)
 {	unsigned int irq;
 	DBG("%s(%d, 0x%lx)\n", __func__, virq, hw);
@@ -397,7 +397,7 @@
 	return 0;
 }
 
-static struct irq_host_ops pci_irq_host_ops = {
+static struct irq_domain_ops pci_irq_domain_ops = {
 	.map = pci_irq_host_map,
 	.xlate = pci_irq_host_xlate,
 };
@@ -419,10 +419,9 @@
 {
 	DBG("Tsi108_pci_int_init: initializing PCI interrupts\n");
 
-	pci_irq_host = irq_alloc_host(node, IRQ_HOST_MAP_LEGACY,
-				      0, &pci_irq_host_ops, 0);
+	pci_irq_host = irq_domain_add_legacy_isa(node, &pci_irq_domain_ops, NULL);
 	if (pci_irq_host == NULL) {
-		printk(KERN_ERR "pci_irq_host: failed to allocate irq host !\n");
+		printk(KERN_ERR "pci_irq_host: failed to allocate irq domain!\n");
 		return;
 	}
 
diff --git a/arch/powerpc/sysdev/uic.c b/arch/powerpc/sysdev/uic.c
index 063c901..9203393 100644
--- a/arch/powerpc/sysdev/uic.c
+++ b/arch/powerpc/sysdev/uic.c
@@ -49,7 +49,7 @@
 	raw_spinlock_t lock;
 
 	/* The remapper for this UIC */
-	struct irq_host	*irqhost;
+	struct irq_domain	*irqhost;
 };
 
 static void uic_unmask_irq(struct irq_data *d)
@@ -174,7 +174,7 @@
 	.irq_set_type	= uic_set_irq_type,
 };
 
-static int uic_host_map(struct irq_host *h, unsigned int virq,
+static int uic_host_map(struct irq_domain *h, unsigned int virq,
 			irq_hw_number_t hw)
 {
 	struct uic *uic = h->host_data;
@@ -190,21 +190,9 @@
 	return 0;
 }
 
-static int uic_host_xlate(struct irq_host *h, struct device_node *ct,
-			  const u32 *intspec, unsigned int intsize,
-			  irq_hw_number_t *out_hwirq, unsigned int *out_type)
-
-{
-	/* UIC intspecs must have 2 cells */
-	BUG_ON(intsize != 2);
-	*out_hwirq = intspec[0];
-	*out_type = intspec[1];
-	return 0;
-}
-
-static struct irq_host_ops uic_host_ops = {
+static struct irq_domain_ops uic_host_ops = {
 	.map	= uic_host_map,
-	.xlate	= uic_host_xlate,
+	.xlate	= irq_domain_xlate_twocell,
 };
 
 void uic_irq_cascade(unsigned int virq, struct irq_desc *desc)
@@ -270,13 +258,11 @@
 	}
 	uic->dcrbase = *dcrreg;
 
-	uic->irqhost = irq_alloc_host(node, IRQ_HOST_MAP_LINEAR,
-				      NR_UIC_INTS, &uic_host_ops, -1);
+	uic->irqhost = irq_domain_add_linear(node, NR_UIC_INTS, &uic_host_ops,
+					     uic);
 	if (! uic->irqhost)
 		return NULL; /* FIXME: panic? */
 
-	uic->irqhost->host_data = uic;
-
 	/* Start with all interrupts disabled, level and non-critical */
 	mtdcr(uic->dcrbase + UIC_ER, 0);
 	mtdcr(uic->dcrbase + UIC_CR, 0);
diff --git a/arch/powerpc/sysdev/xics/xics-common.c b/arch/powerpc/sysdev/xics/xics-common.c
index d72eda6..ea5e204 100644
--- a/arch/powerpc/sysdev/xics/xics-common.c
+++ b/arch/powerpc/sysdev/xics/xics-common.c
@@ -40,7 +40,7 @@
 
 DEFINE_PER_CPU(struct xics_cppr, xics_cppr);
 
-struct irq_host *xics_host;
+struct irq_domain *xics_host;
 
 static LIST_HEAD(ics_list);
 
@@ -212,16 +212,16 @@
 		/* We can't set affinity on ISA interrupts */
 		if (virq < NUM_ISA_INTERRUPTS)
 			continue;
-		if (!virq_is_host(virq, xics_host))
-			continue;
-		irq = (unsigned int)virq_to_hw(virq);
-		/* We need to get IPIs still. */
-		if (irq == XICS_IPI || irq == XICS_IRQ_SPURIOUS)
-			continue;
 		desc = irq_to_desc(virq);
 		/* We only need to migrate enabled IRQS */
 		if (!desc || !desc->action)
 			continue;
+		if (desc->irq_data.domain != xics_host)
+			continue;
+		irq = desc->irq_data.hwirq;
+		/* We need to get IPIs still. */
+		if (irq == XICS_IPI || irq == XICS_IRQ_SPURIOUS)
+			continue;
 		chip = irq_desc_get_chip(desc);
 		if (!chip || !chip->irq_set_affinity)
 			continue;
@@ -301,7 +301,7 @@
 }
 #endif /* CONFIG_SMP */
 
-static int xics_host_match(struct irq_host *h, struct device_node *node)
+static int xics_host_match(struct irq_domain *h, struct device_node *node)
 {
 	struct ics *ics;
 
@@ -323,7 +323,7 @@
 	.irq_unmask = xics_ipi_unmask,
 };
 
-static int xics_host_map(struct irq_host *h, unsigned int virq,
+static int xics_host_map(struct irq_domain *h, unsigned int virq,
 			 irq_hw_number_t hw)
 {
 	struct ics *ics;
@@ -351,7 +351,7 @@
 	return -EINVAL;
 }
 
-static int xics_host_xlate(struct irq_host *h, struct device_node *ct,
+static int xics_host_xlate(struct irq_domain *h, struct device_node *ct,
 			   const u32 *intspec, unsigned int intsize,
 			   irq_hw_number_t *out_hwirq, unsigned int *out_flags)
 
@@ -366,7 +366,7 @@
 	return 0;
 }
 
-static struct irq_host_ops xics_host_ops = {
+static struct irq_domain_ops xics_host_ops = {
 	.match = xics_host_match,
 	.map = xics_host_map,
 	.xlate = xics_host_xlate,
@@ -374,8 +374,7 @@
 
 static void __init xics_init_host(void)
 {
-	xics_host = irq_alloc_host(NULL, IRQ_HOST_MAP_TREE, 0, &xics_host_ops,
-				   XICS_IRQ_SPURIOUS);
+	xics_host = irq_domain_add_tree(NULL, &xics_host_ops, NULL);
 	BUG_ON(xics_host == NULL);
 	irq_set_default_host(xics_host);
 }
diff --git a/arch/powerpc/sysdev/xilinx_intc.c b/arch/powerpc/sysdev/xilinx_intc.c
index 6183799..8d73c3c 100644
--- a/arch/powerpc/sysdev/xilinx_intc.c
+++ b/arch/powerpc/sysdev/xilinx_intc.c
@@ -40,7 +40,7 @@
 #define XINTC_IVR	24	/* Interrupt Vector */
 #define XINTC_MER	28	/* Master Enable */
 
-static struct irq_host *master_irqhost;
+static struct irq_domain *master_irqhost;
 
 #define XILINX_INTC_MAXIRQS	(32)
 
@@ -141,7 +141,7 @@
 /**
  * xilinx_intc_xlate - translate virq# from device tree interrupts property
  */
-static int xilinx_intc_xlate(struct irq_host *h, struct device_node *ct,
+static int xilinx_intc_xlate(struct irq_domain *h, struct device_node *ct,
 				const u32 *intspec, unsigned int intsize,
 				irq_hw_number_t *out_hwirq,
 				unsigned int *out_flags)
@@ -161,7 +161,7 @@
 
 	return 0;
 }
-static int xilinx_intc_map(struct irq_host *h, unsigned int virq,
+static int xilinx_intc_map(struct irq_domain *h, unsigned int virq,
 				  irq_hw_number_t irq)
 {
 	irq_set_chip_data(virq, h->host_data);
@@ -177,15 +177,15 @@
 	return 0;
 }
 
-static struct irq_host_ops xilinx_intc_ops = {
+static struct irq_domain_ops xilinx_intc_ops = {
 	.map = xilinx_intc_map,
 	.xlate = xilinx_intc_xlate,
 };
 
-struct irq_host * __init
+struct irq_domain * __init
 xilinx_intc_init(struct device_node *np)
 {
-	struct irq_host * irq;
+	struct irq_domain * irq;
 	void * regs;
 
 	/* Find and map the intc registers */
@@ -200,12 +200,11 @@
 	out_be32(regs + XINTC_IAR, ~(u32) 0); /* Acknowledge pending irqs */
 	out_be32(regs + XINTC_MER, 0x3UL); /* Turn on the Master Enable. */
 
-	/* Allocate and initialize an irq_host structure. */
-	irq = irq_alloc_host(np, IRQ_HOST_MAP_LINEAR, XILINX_INTC_MAXIRQS,
-			     &xilinx_intc_ops, -1);
+	/* Allocate and initialize an irq_domain structure. */
+	irq = irq_domain_add_linear(np, XILINX_INTC_MAXIRQS, &xilinx_intc_ops,
+				    regs);
 	if (!irq)
 		panic(__FILE__ ": Cannot allocate IRQ host\n");
-	irq->host_data = regs;
 
 	return irq;
 }
diff --git a/arch/sparc/include/asm/prom.h b/arch/sparc/include/asm/prom.h
index edd3d3cde..c287651 100644
--- a/arch/sparc/include/asm/prom.h
+++ b/arch/sparc/include/asm/prom.h
@@ -22,6 +22,7 @@
 #include <linux/proc_fs.h>
 #include <linux/mutex.h>
 #include <linux/atomic.h>
+#include <linux/irqdomain.h>
 
 #define OF_ROOT_NODE_ADDR_CELLS_DEFAULT	2
 #define OF_ROOT_NODE_SIZE_CELLS_DEFAULT	1
@@ -55,15 +56,6 @@
 extern void __iomem *of_ioremap(struct resource *res, unsigned long offset, unsigned long size, char *name);
 extern void of_iounmap(struct resource *res, void __iomem *base, unsigned long size);
 
-/* These routines are here to provide compatibility with how powerpc
- * handles IRQ mapping for OF device nodes.  We precompute and permanently
- * register them in the platform_device objects, whereas powerpc computes them
- * on request.
- */
-static inline void irq_dispose_mapping(unsigned int virq)
-{
-}
-
 extern struct device_node *of_console_device;
 extern char *of_console_path;
 extern char *of_console_options;
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 5bed94e1..e0829a6 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -398,6 +398,7 @@
 	select X86_REBOOTFIXUPS
 	select OF
 	select OF_EARLY_FLATTREE
+	select IRQ_DOMAIN
 	---help---
 	  Select for the Intel CE media processor (CE4100) SOC.
 	  This option compiles in support for the CE4100 SOC for settop
@@ -2076,6 +2077,7 @@
 	select GPIOLIB
 	select OF
 	select OF_PROMTREE
+	select IRQ_DOMAIN
 	---help---
 	  Add support for detecting the unique features of the OLPC
 	  XO hardware.
diff --git a/arch/x86/include/asm/irq_controller.h b/arch/x86/include/asm/irq_controller.h
deleted file mode 100644
index 423bbbd..0000000
--- a/arch/x86/include/asm/irq_controller.h
+++ /dev/null
@@ -1,12 +0,0 @@
-#ifndef __IRQ_CONTROLLER__
-#define __IRQ_CONTROLLER__
-
-struct irq_domain {
-	int (*xlate)(struct irq_domain *h, const u32 *intspec, u32 intsize,
-			u32 *out_hwirq, u32 *out_type);
-	void *priv;
-	struct device_node *controller;
-	struct list_head l;
-};
-
-#endif
diff --git a/arch/x86/include/asm/prom.h b/arch/x86/include/asm/prom.h
index 644dd885..60bef66 100644
--- a/arch/x86/include/asm/prom.h
+++ b/arch/x86/include/asm/prom.h
@@ -21,7 +21,6 @@
 #include <asm/irq.h>
 #include <linux/atomic.h>
 #include <asm/setup.h>
-#include <asm/irq_controller.h>
 
 #ifdef CONFIG_OF
 extern int of_ioapic;
@@ -43,15 +42,6 @@
 #define pci_address_to_pio pci_address_to_pio
 unsigned long pci_address_to_pio(phys_addr_t addr);
 
-/**
- * irq_dispose_mapping - Unmap an interrupt
- * @virq: linux virq number of the interrupt to unmap
- *
- * FIXME: We really should implement proper virq handling like power,
- * but that's going to be major surgery.
- */
-static inline void irq_dispose_mapping(unsigned int virq) { }
-
 #define HAVE_ARCH_DEVTREE_FIXUPS
 
 #endif /* __ASSEMBLY__ */
diff --git a/arch/x86/kernel/devicetree.c b/arch/x86/kernel/devicetree.c
index 5282179..3ae2ced 100644
--- a/arch/x86/kernel/devicetree.c
+++ b/arch/x86/kernel/devicetree.c
@@ -4,6 +4,7 @@
 #include <linux/bootmem.h>
 #include <linux/export.h>
 #include <linux/io.h>
+#include <linux/irqdomain.h>
 #include <linux/interrupt.h>
 #include <linux/list.h>
 #include <linux/of.h>
@@ -17,64 +18,14 @@
 #include <linux/initrd.h>
 
 #include <asm/hpet.h>
-#include <asm/irq_controller.h>
 #include <asm/apic.h>
 #include <asm/pci_x86.h>
 
 __initdata u64 initial_dtb;
 char __initdata cmd_line[COMMAND_LINE_SIZE];
-static LIST_HEAD(irq_domains);
-static DEFINE_RAW_SPINLOCK(big_irq_lock);
 
 int __initdata of_ioapic;
 
-#ifdef CONFIG_X86_IO_APIC
-static void add_interrupt_host(struct irq_domain *ih)
-{
-	unsigned long flags;
-
-	raw_spin_lock_irqsave(&big_irq_lock, flags);
-	list_add(&ih->l, &irq_domains);
-	raw_spin_unlock_irqrestore(&big_irq_lock, flags);
-}
-#endif
-
-static struct irq_domain *get_ih_from_node(struct device_node *controller)
-{
-	struct irq_domain *ih, *found = NULL;
-	unsigned long flags;
-
-	raw_spin_lock_irqsave(&big_irq_lock, flags);
-	list_for_each_entry(ih, &irq_domains, l) {
-		if (ih->controller ==  controller) {
-			found = ih;
-			break;
-		}
-	}
-	raw_spin_unlock_irqrestore(&big_irq_lock, flags);
-	return found;
-}
-
-unsigned int irq_create_of_mapping(struct device_node *controller,
-				   const u32 *intspec, unsigned int intsize)
-{
-	struct irq_domain *ih;
-	u32 virq, type;
-	int ret;
-
-	ih = get_ih_from_node(controller);
-	if (!ih)
-		return 0;
-	ret = ih->xlate(ih, intspec, intsize, &virq, &type);
-	if (ret)
-		return 0;
-	if (type == IRQ_TYPE_NONE)
-		return virq;
-	irq_set_irq_type(virq, type);
-	return virq;
-}
-EXPORT_SYMBOL_GPL(irq_create_of_mapping);
-
 unsigned long pci_address_to_pio(phys_addr_t address)
 {
 	/*
@@ -354,36 +305,43 @@
 	},
 };
 
-static int ioapic_xlate(struct irq_domain *id, const u32 *intspec, u32 intsize,
-			u32 *out_hwirq, u32 *out_type)
+static int ioapic_xlate(struct irq_domain *domain,
+			struct device_node *controller,
+			const u32 *intspec, u32 intsize,
+			irq_hw_number_t *out_hwirq, u32 *out_type)
 {
-	struct mp_ioapic_gsi *gsi_cfg;
 	struct io_apic_irq_attr attr;
 	struct of_ioapic_type *it;
-	u32 line, idx, type;
+	u32 line, idx;
+	int rc;
 
-	if (intsize < 2)
+	if (WARN_ON(intsize < 2))
 		return -EINVAL;
 
-	line = *intspec;
-	idx = (u32) id->priv;
-	gsi_cfg = mp_ioapic_gsi_routing(idx);
-	*out_hwirq = line + gsi_cfg->gsi_base;
+	line = intspec[0];
 
-	intspec++;
-	type = *intspec;
-
-	if (type >= ARRAY_SIZE(of_ioapic_type))
+	if (intspec[1] >= ARRAY_SIZE(of_ioapic_type))
 		return -EINVAL;
 
-	it = of_ioapic_type + type;
-	*out_type = it->out_type;
+	it = &of_ioapic_type[intspec[1]];
 
+	idx = (u32) domain->host_data;
 	set_io_apic_irq_attr(&attr, idx, line, it->trigger, it->polarity);
 
-	return io_apic_setup_irq_pin_once(*out_hwirq, cpu_to_node(0), &attr);
+	rc = io_apic_setup_irq_pin_once(irq_find_mapping(domain, line),
+					cpu_to_node(0), &attr);
+	if (rc)
+		return rc;
+
+	*out_hwirq = line;
+	*out_type = it->out_type;
+	return 0;
 }
 
+const struct irq_domain_ops ioapic_irq_domain_ops = {
+	.xlate = ioapic_xlate,
+};
+
 static void __init ioapic_add_ofnode(struct device_node *np)
 {
 	struct resource r;
@@ -399,13 +357,14 @@
 	for (i = 0; i < nr_ioapics; i++) {
 		if (r.start == mpc_ioapic_addr(i)) {
 			struct irq_domain *id;
+			struct mp_ioapic_gsi *gsi_cfg;
 
-			id = kzalloc(sizeof(*id), GFP_KERNEL);
+			gsi_cfg = mp_ioapic_gsi_routing(i);
+
+			id = irq_domain_add_legacy(np, 32, gsi_cfg->gsi_base, 0,
+						   &ioapic_irq_domain_ops,
+						   (void*)i);
 			BUG_ON(!id);
-			id->controller = np;
-			id->xlate = ioapic_xlate;
-			id->priv = (void *)i;
-			add_interrupt_host(id);
 			return;
 		}
 	}
diff --git a/drivers/gpio/gpio-mpc8xxx.c b/drivers/gpio/gpio-mpc8xxx.c
index 5cd04b6..e6568c1 100644
--- a/drivers/gpio/gpio-mpc8xxx.c
+++ b/drivers/gpio/gpio-mpc8xxx.c
@@ -37,7 +37,7 @@
 	 * open drain mode safely
 	 */
 	u32 data;
-	struct irq_host *irq;
+	struct irq_domain *irq;
 	void *of_dev_id_data;
 };
 
@@ -281,7 +281,7 @@
 	.irq_set_type	= mpc8xxx_irq_set_type,
 };
 
-static int mpc8xxx_gpio_irq_map(struct irq_host *h, unsigned int virq,
+static int mpc8xxx_gpio_irq_map(struct irq_domain *h, unsigned int virq,
 				irq_hw_number_t hw)
 {
 	struct mpc8xxx_gpio_chip *mpc8xxx_gc = h->host_data;
@@ -296,24 +296,9 @@
 	return 0;
 }
 
-static int mpc8xxx_gpio_irq_xlate(struct irq_host *h, struct device_node *ct,
-				  const u32 *intspec, unsigned int intsize,
-				  irq_hw_number_t *out_hwirq,
-				  unsigned int *out_flags)
-
-{
-	/* interrupt sense values coming from the device tree equal either
-	 * EDGE_FALLING or EDGE_BOTH
-	 */
-	*out_hwirq = intspec[0];
-	*out_flags = intspec[1];
-
-	return 0;
-}
-
-static struct irq_host_ops mpc8xxx_gpio_irq_ops = {
+static struct irq_domain_ops mpc8xxx_gpio_irq_ops = {
 	.map	= mpc8xxx_gpio_irq_map,
-	.xlate	= mpc8xxx_gpio_irq_xlate,
+	.xlate	= irq_domain_xlate_twocell,
 };
 
 static struct of_device_id mpc8xxx_gpio_ids[] __initdata = {
@@ -364,9 +349,8 @@
 	if (hwirq == NO_IRQ)
 		goto skip_irq;
 
-	mpc8xxx_gc->irq =
-		irq_alloc_host(np, IRQ_HOST_MAP_LINEAR, MPC8XXX_GPIO_PINS,
-			       &mpc8xxx_gpio_irq_ops, MPC8XXX_GPIO_PINS);
+	mpc8xxx_gc->irq = irq_domain_add_linear(np, MPC8XXX_GPIO_PINS,
+					&mpc8xxx_gpio_irq_ops, mpc8xxx_gc);
 	if (!mpc8xxx_gc->irq)
 		goto skip_irq;
 
@@ -374,8 +358,6 @@
 	if (id)
 		mpc8xxx_gc->of_dev_id_data = id->data;
 
-	mpc8xxx_gc->irq->host_data = mpc8xxx_gc;
-
 	/* ack and mask all irqs */
 	out_be32(mm_gc->regs + GPIO_IER, 0xffffffff);
 	out_be32(mm_gc->regs + GPIO_IMR, 0);
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index f147395..1489c35 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -201,6 +201,7 @@
 config TWL4030_CORE
 	bool "Texas Instruments TWL4030/TWL5030/TWL6030/TPS659x0 Support"
 	depends on I2C=y && GENERIC_HARDIRQS
+	select IRQ_DOMAIN
 	help
 	  Say yes here if you have TWL4030 / TWL6030 family chip on your board.
 	  This core driver provides register access and IRQ handling
diff --git a/drivers/mfd/twl-core.c b/drivers/mfd/twl-core.c
index 8ce3959..4970d43 100644
--- a/drivers/mfd/twl-core.c
+++ b/drivers/mfd/twl-core.c
@@ -149,7 +149,7 @@
 
 #define TWL_MODULE_LAST TWL4030_MODULE_LAST
 
-#define TWL4030_NR_IRQS    8
+#define TWL4030_NR_IRQS    34 /* core:8, power:8, gpio: 18 */
 #define TWL6030_NR_IRQS    20
 
 /* Base Address defns for twl4030_map[] */
@@ -263,10 +263,6 @@
 
 static struct twl_client twl_modules[TWL_NUM_SLAVES];
 
-#ifdef CONFIG_IRQ_DOMAIN
-static struct irq_domain domain;
-#endif
-
 /* mapping the module id to slave id and base address */
 struct twl_mapping {
 	unsigned char sid;	/* Slave ID */
@@ -1227,14 +1223,8 @@
 
 	pdata->irq_base = status;
 	pdata->irq_end = pdata->irq_base + nr_irqs;
-
-#ifdef CONFIG_IRQ_DOMAIN
-	domain.irq_base = pdata->irq_base;
-	domain.nr_irq = nr_irqs;
-	domain.of_node = of_node_get(node);
-	domain.ops = &irq_domain_simple_ops;
-	irq_domain_add(&domain);
-#endif
+	irq_domain_add_legacy(node, nr_irqs, pdata->irq_base, 0,
+			      &irq_domain_simple_ops, NULL);
 
 	if (i2c_check_functionality(client->adapter, I2C_FUNC_I2C) == 0) {
 		dev_dbg(&client->dev, "can't talk I2C?\n");
@@ -1315,11 +1305,10 @@
 		twl_i2c_write_u8(TWL4030_MODULE_INTBR, temp, REG_GPPUPDCTR1);
 	}
 
-#ifdef CONFIG_OF_DEVICE
+	status = -ENODEV;
 	if (node)
 		status = of_platform_populate(node, NULL, NULL, &client->dev);
-	else
-#endif
+	if (status)
 		status = add_children(pdata, id->driver_data);
 
 fail:
diff --git a/drivers/net/phy/mdio-gpio.c b/drivers/net/phy/mdio-gpio.c
index 50e8e5e..7189adf 100644
--- a/drivers/net/phy/mdio-gpio.c
+++ b/drivers/net/phy/mdio-gpio.c
@@ -255,13 +255,13 @@
 	return platform_driver_register(&mdio_ofgpio_driver);
 }
 
-static inline void __exit mdio_ofgpio_exit(void)
+static inline void mdio_ofgpio_exit(void)
 {
 	platform_driver_unregister(&mdio_ofgpio_driver);
 }
 #else
 static inline int __init mdio_ofgpio_init(void) { return 0; }
-static inline void __exit mdio_ofgpio_exit(void) { }
+static inline void mdio_ofgpio_exit(void) { }
 #endif /* CONFIG_OF_GPIO */
 
 static struct platform_driver mdio_gpio_driver = {
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 63b3ec4..20fbebd 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -55,7 +55,7 @@
 #include <asm/dcr.h>
 #endif
 
-#if !defined(CONFIG_SPARC)
+#ifdef CONFIG_OF_ADDRESS
 /*
  * The following routines scan a subtree and registers a device for
  * each applicable node.
@@ -462,4 +462,4 @@
 	of_node_put(root);
 	return rc;
 }
-#endif /* !CONFIG_SPARC */
+#endif /* CONFIG_OF_ADDRESS */
diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
index bd4272b..ead4a42 100644
--- a/include/linux/irqdomain.h
+++ b/include/linux/irqdomain.h
@@ -9,99 +9,182 @@
  * representation into a hardware irq number that can be mapped back to a
  * Linux irq number without any extra platform support code.
  *
- * irq_domain is expected to be embedded in an interrupt controller's private
- * data structure.
+ * Interrupt controller "domain" data structure. This could be defined as a
+ * irq domain controller. That is, it handles the mapping between hardware
+ * and virtual interrupt numbers for a given interrupt domain. The domain
+ * structure is generally created by the PIC code for a given PIC instance
+ * (though a domain can cover more than one PIC if they have a flat number
+ * model). It's the domain callbacks that are responsible for setting the
+ * irq_chip on a given irq_desc after it's been mapped.
+ *
+ * The host code and data structures are agnostic to whether or not
+ * we use an open firmware device-tree. We do have references to struct
+ * device_node in two places: in irq_find_host() to find the host matching
+ * a given interrupt controller node, and of course as an argument to its
+ * counterpart domain->ops->match() callback. However, those are treated as
+ * generic pointers by the core and the fact that it's actually a device-node
+ * pointer is purely a convention between callers and implementation. This
+ * code could thus be used on other architectures by replacing those two
+ * by some sort of arch-specific void * "token" used to identify interrupt
+ * controllers.
  */
+
 #ifndef _LINUX_IRQDOMAIN_H
 #define _LINUX_IRQDOMAIN_H
 
-#include <linux/irq.h>
-#include <linux/mod_devicetable.h>
+#include <linux/types.h>
+#include <linux/radix-tree.h>
 
-#ifdef CONFIG_IRQ_DOMAIN
 struct device_node;
 struct irq_domain;
+struct of_device_id;
+
+/* Number of irqs reserved for a legacy isa controller */
+#define NUM_ISA_INTERRUPTS	16
+
+/* This type is the placeholder for a hardware interrupt number. It has to
+ * be big enough to enclose whatever representation is used by a given
+ * platform.
+ */
+typedef unsigned long irq_hw_number_t;
 
 /**
  * struct irq_domain_ops - Methods for irq_domain objects
- * @to_irq: (optional) given a local hardware irq number, return the linux
- *          irq number.  If to_irq is not implemented, then the irq_domain
- *          will use this translation: irq = (domain->irq_base + hwirq)
- * @dt_translate: Given a device tree node and interrupt specifier, decode
- *                the hardware irq number and linux irq type value.
+ * @match: Match an interrupt controller device node to a host, returns
+ *         1 on a match
+ * @map: Create or update a mapping between a virtual irq number and a hw
+ *       irq number. This is called only once for a given mapping.
+ * @unmap: Dispose of such a mapping
+ * @xlate: Given a device tree node and interrupt specifier, decode
+ *         the hardware irq number and linux irq type value.
+ *
+ * Functions below are provided by the driver and called whenever a new mapping
+ * is created or an old mapping is disposed. The driver can then proceed to
+ * whatever internal data structures management is required. It also needs
+ * to setup the irq_desc when returning from map().
  */
 struct irq_domain_ops {
-	unsigned int (*to_irq)(struct irq_domain *d, unsigned long hwirq);
-
-#ifdef CONFIG_OF
-	int (*dt_translate)(struct irq_domain *d, struct device_node *node,
-			    const u32 *intspec, unsigned int intsize,
-			    unsigned long *out_hwirq, unsigned int *out_type);
-#endif /* CONFIG_OF */
+	int (*match)(struct irq_domain *d, struct device_node *node);
+	int (*map)(struct irq_domain *d, unsigned int virq, irq_hw_number_t hw);
+	void (*unmap)(struct irq_domain *d, unsigned int virq);
+	int (*xlate)(struct irq_domain *d, struct device_node *node,
+		     const u32 *intspec, unsigned int intsize,
+		     unsigned long *out_hwirq, unsigned int *out_type);
 };
 
 /**
  * struct irq_domain - Hardware interrupt number translation object
- * @list: Element in global irq_domain list.
+ * @link: Element in global irq_domain list.
+ * @revmap_type: Method used for reverse mapping hwirq numbers to linux irq. This
+ *               will be one of the IRQ_DOMAIN_MAP_* values.
+ * @revmap_data: Revmap method specific data.
+ * @ops: pointer to irq_domain methods
+ * @host_data: private data pointer for use by owner.  Not touched by irq_domain
+ *             core code.
  * @irq_base: Start of irq_desc range assigned to the irq_domain.  The creator
  *            of the irq_domain is responsible for allocating the array of
  *            irq_desc structures.
  * @nr_irq: Number of irqs managed by the irq domain
  * @hwirq_base: Starting number for hwirqs managed by the irq domain
- * @ops: pointer to irq_domain methods
- * @priv: private data pointer for use by owner.  Not touched by irq_domain
- *        core code.
  * @of_node: (optional) Pointer to device tree nodes associated with the
  *           irq_domain.  Used when decoding device tree interrupt specifiers.
  */
 struct irq_domain {
-	struct list_head list;
-	unsigned int irq_base;
-	unsigned int nr_irq;
-	unsigned int hwirq_base;
+	struct list_head link;
+
+	/* type of reverse mapping_technique */
+	unsigned int revmap_type;
+	union {
+		struct {
+			unsigned int size;
+			unsigned int first_irq;
+			irq_hw_number_t first_hwirq;
+		} legacy;
+		struct {
+			unsigned int size;
+			unsigned int *revmap;
+		} linear;
+		struct radix_tree_root tree;
+	} revmap_data;
 	const struct irq_domain_ops *ops;
-	void *priv;
+	void *host_data;
+	irq_hw_number_t inval_irq;
+
+	/* Optional device node pointer */
 	struct device_node *of_node;
 };
 
-/**
- * irq_domain_to_irq() - Translate from a hardware irq to a linux irq number
- *
- * Returns the linux irq number associated with a hardware irq.  By default,
- * the mapping is irq == domain->irq_base + hwirq, but this mapping can
- * be overridden if the irq_domain implements a .to_irq() hook.
- */
-static inline unsigned int irq_domain_to_irq(struct irq_domain *d,
-					     unsigned long hwirq)
+#ifdef CONFIG_IRQ_DOMAIN
+struct irq_domain *irq_domain_add_legacy(struct device_node *of_node,
+					 unsigned int size,
+					 unsigned int first_irq,
+					 irq_hw_number_t first_hwirq,
+					 const struct irq_domain_ops *ops,
+					 void *host_data);
+struct irq_domain *irq_domain_add_linear(struct device_node *of_node,
+					 unsigned int size,
+					 const struct irq_domain_ops *ops,
+					 void *host_data);
+struct irq_domain *irq_domain_add_nomap(struct device_node *of_node,
+					 const struct irq_domain_ops *ops,
+					 void *host_data);
+struct irq_domain *irq_domain_add_tree(struct device_node *of_node,
+					 const struct irq_domain_ops *ops,
+					 void *host_data);
+
+extern struct irq_domain *irq_find_host(struct device_node *node);
+extern void irq_set_default_host(struct irq_domain *host);
+extern void irq_set_virq_count(unsigned int count);
+
+static inline struct irq_domain *irq_domain_add_legacy_isa(
+				struct device_node *of_node,
+				const struct irq_domain_ops *ops,
+				void *host_data)
 {
-	if (d->ops->to_irq)
-		return d->ops->to_irq(d, hwirq);
-	if (WARN_ON(hwirq < d->hwirq_base))
-		return 0;
-	return d->irq_base + hwirq - d->hwirq_base;
+	return irq_domain_add_legacy(of_node, NUM_ISA_INTERRUPTS, 0, 0, ops,
+				     host_data);
 }
+extern struct irq_domain *irq_find_host(struct device_node *node);
+extern void irq_set_default_host(struct irq_domain *host);
+extern void irq_set_virq_count(unsigned int count);
 
-#define irq_domain_for_each_hwirq(d, hw) \
-	for (hw = d->hwirq_base; hw < d->hwirq_base + d->nr_irq; hw++)
 
-#define irq_domain_for_each_irq(d, hw, irq) \
-	for (hw = d->hwirq_base, irq = irq_domain_to_irq(d, hw); \
-	     hw < d->hwirq_base + d->nr_irq; \
-	     hw++, irq = irq_domain_to_irq(d, hw))
+extern unsigned int irq_create_mapping(struct irq_domain *host,
+				       irq_hw_number_t hwirq);
+extern void irq_dispose_mapping(unsigned int virq);
+extern unsigned int irq_find_mapping(struct irq_domain *host,
+				     irq_hw_number_t hwirq);
+extern unsigned int irq_create_direct_mapping(struct irq_domain *host);
+extern void irq_radix_revmap_insert(struct irq_domain *host, unsigned int virq,
+				    irq_hw_number_t hwirq);
+extern unsigned int irq_radix_revmap_lookup(struct irq_domain *host,
+					    irq_hw_number_t hwirq);
+extern unsigned int irq_linear_revmap(struct irq_domain *host,
+				      irq_hw_number_t hwirq);
 
-extern void irq_domain_add(struct irq_domain *domain);
-extern void irq_domain_del(struct irq_domain *domain);
+extern const struct irq_domain_ops irq_domain_simple_ops;
 
-extern struct irq_domain_ops irq_domain_simple_ops;
-#endif /* CONFIG_IRQ_DOMAIN */
+/* stock xlate functions */
+int irq_domain_xlate_onecell(struct irq_domain *d, struct device_node *ctrlr,
+			const u32 *intspec, unsigned int intsize,
+			irq_hw_number_t *out_hwirq, unsigned int *out_type);
+int irq_domain_xlate_twocell(struct irq_domain *d, struct device_node *ctrlr,
+			const u32 *intspec, unsigned int intsize,
+			irq_hw_number_t *out_hwirq, unsigned int *out_type);
+int irq_domain_xlate_onetwocell(struct irq_domain *d, struct device_node *ctrlr,
+			const u32 *intspec, unsigned int intsize,
+			irq_hw_number_t *out_hwirq, unsigned int *out_type);
 
-#if defined(CONFIG_IRQ_DOMAIN) && defined(CONFIG_OF_IRQ)
-extern void irq_domain_add_simple(struct device_node *controller, int irq_base);
+#if defined(CONFIG_OF_IRQ)
 extern void irq_domain_generate_simple(const struct of_device_id *match,
 					u64 phys_base, unsigned int irq_start);
-#else /* CONFIG_IRQ_DOMAIN && CONFIG_OF_IRQ */
+#else /* CONFIG_OF_IRQ */
 static inline void irq_domain_generate_simple(const struct of_device_id *match,
 					u64 phys_base, unsigned int irq_start) { }
-#endif /* CONFIG_IRQ_DOMAIN && CONFIG_OF_IRQ */
+#endif /* !CONFIG_OF_IRQ */
+
+#else /* CONFIG_IRQ_DOMAIN */
+static inline void irq_dispose_mapping(unsigned int virq) { }
+#endif /* !CONFIG_IRQ_DOMAIN */
 
 #endif /* _LINUX_IRQDOMAIN_H */
diff --git a/include/linux/of_address.h b/include/linux/of_address.h
index 3118623..01b925a 100644
--- a/include/linux/of_address.h
+++ b/include/linux/of_address.h
@@ -4,6 +4,7 @@
 #include <linux/errno.h>
 #include <linux/of.h>
 
+#ifdef CONFIG_OF_ADDRESS
 extern u64 of_translate_address(struct device_node *np, const __be32 *addr);
 extern int of_address_to_resource(struct device_node *dev, int index,
 				  struct resource *r);
@@ -25,12 +26,37 @@
 #define pci_address_to_pio pci_address_to_pio
 #endif
 
-#ifdef CONFIG_PCI
+#else /* CONFIG_OF_ADDRESS */
+static inline int of_address_to_resource(struct device_node *dev, int index,
+					 struct resource *r)
+{
+	return -EINVAL;
+}
+static inline struct device_node *of_find_matching_node_by_address(
+					struct device_node *from,
+					const struct of_device_id *matches,
+					u64 base_address)
+{
+	return NULL;
+}
+static inline void __iomem *of_iomap(struct device_node *device, int index)
+{
+	return NULL;
+}
+static inline const u32 *of_get_address(struct device_node *dev, int index,
+					u64 *size, unsigned int *flags)
+{
+	return NULL;
+}
+#endif /* CONFIG_OF_ADDRESS */
+
+
+#if defined(CONFIG_OF_ADDRESS) && defined(CONFIG_PCI)
 extern const __be32 *of_get_pci_address(struct device_node *dev, int bar_no,
 			       u64 *size, unsigned int *flags);
 extern int of_pci_address_to_resource(struct device_node *dev, int bar,
 				      struct resource *r);
-#else /* CONFIG_PCI */
+#else /* CONFIG_OF_ADDRESS && CONFIG_PCI */
 static inline int of_pci_address_to_resource(struct device_node *dev, int bar,
 				             struct resource *r)
 {
@@ -42,8 +68,7 @@
 {
 	return NULL;
 }
-#endif /* CONFIG_PCI */
-
+#endif /* CONFIG_OF_ADDRESS && CONFIG_PCI */
 
 #endif /* __OF_ADDRESS_H */
 
diff --git a/include/linux/of_irq.h b/include/linux/of_irq.h
index d0307ee..d229ad3 100644
--- a/include/linux/of_irq.h
+++ b/include/linux/of_irq.h
@@ -6,6 +6,7 @@
 #include <linux/types.h>
 #include <linux/errno.h>
 #include <linux/irq.h>
+#include <linux/irqdomain.h>
 #include <linux/ioport.h>
 #include <linux/of.h>
 
@@ -65,9 +66,6 @@
 extern unsigned int irq_create_of_mapping(struct device_node *controller,
 					  const u32 *intspec,
 					  unsigned int intsize);
-#ifdef CONFIG_IRQ_DOMAIN
-extern void irq_dispose_mapping(unsigned int irq);
-#endif
 extern int of_irq_to_resource(struct device_node *dev, int index,
 			      struct resource *r);
 extern int of_irq_count(struct device_node *dev);
diff --git a/include/linux/of_platform.h b/include/linux/of_platform.h
index 040ce2f..242fa35 100644
--- a/include/linux/of_platform.h
+++ b/include/linux/of_platform.h
@@ -81,7 +81,7 @@
 					 struct device *parent);
 extern struct platform_device *of_find_device_by_node(struct device_node *np);
 
-#if !defined(CONFIG_SPARC) /* SPARC has its own device registration method */
+#ifdef CONFIG_OF_ADDRESS /* device reg helpers depend on OF_ADDRESS */
 /* Platform devices and busses creation */
 extern struct platform_device *of_platform_device_create(struct device_node *np,
 						   const char *bus_id,
@@ -94,7 +94,15 @@
 				const struct of_device_id *matches,
 				const struct of_dev_auxdata *lookup,
 				struct device *parent);
-#endif /* !CONFIG_SPARC */
+#else
+static inline int of_platform_populate(struct device_node *root,
+					const struct of_device_id *matches,
+					const struct of_dev_auxdata *lookup,
+					struct device *parent)
+{
+	return -ENODEV;
+}
+#endif /* !CONFIG_OF_ADDRESS */
 
 #endif /* CONFIG_OF_DEVICE */
 
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 1f9e265..af48e59 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -1,189 +1,793 @@
+#include <linux/debugfs.h>
+#include <linux/hardirq.h>
+#include <linux/interrupt.h>
 #include <linux/irq.h>
+#include <linux/irqdesc.h>
 #include <linux/irqdomain.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
+#include <linux/seq_file.h>
 #include <linux/slab.h>
+#include <linux/smp.h>
+#include <linux/fs.h>
+
+#define IRQ_DOMAIN_MAP_LEGACY 0 /* driver allocated fixed range of irqs.
+				 * ie. legacy 8259, gets irqs 1..15 */
+#define IRQ_DOMAIN_MAP_NOMAP 1 /* no fast reverse mapping */
+#define IRQ_DOMAIN_MAP_LINEAR 2 /* linear map of interrupts */
+#define IRQ_DOMAIN_MAP_TREE 3 /* radix tree */
 
 static LIST_HEAD(irq_domain_list);
 static DEFINE_MUTEX(irq_domain_mutex);
 
+static DEFINE_MUTEX(revmap_trees_mutex);
+static unsigned int irq_virq_count = NR_IRQS;
+static struct irq_domain *irq_default_domain;
+
 /**
- * irq_domain_add() - Register an irq_domain
- * @domain: ptr to initialized irq_domain structure
+ * irq_domain_alloc() - Allocate a new irq_domain data structure
+ * @of_node: optional device-tree node of the interrupt controller
+ * @revmap_type: type of reverse mapping to use
+ * @ops: map/unmap domain callbacks
+ * @host_data: Controller private data pointer
  *
- * Registers an irq_domain structure.  The irq_domain must at a minimum be
- * initialized with an ops structure pointer, and either a ->to_irq hook or
- * a valid irq_base value.  Everything else is optional.
+ * Allocates and initialize and irq_domain structure.  Caller is expected to
+ * register allocated irq_domain with irq_domain_register().  Returns pointer
+ * to IRQ domain, or NULL on failure.
  */
-void irq_domain_add(struct irq_domain *domain)
-{
-	struct irq_data *d;
-	int hwirq, irq;
-
-	/*
-	 * This assumes that the irq_domain owner has already allocated
-	 * the irq_descs.  This block will be removed when support for dynamic
-	 * allocation of irq_descs is added to irq_domain.
-	 */
-	irq_domain_for_each_irq(domain, hwirq, irq) {
-		d = irq_get_irq_data(irq);
-		if (!d) {
-			WARN(1, "error: assigning domain to non existant irq_desc");
-			return;
-		}
-		if (d->domain) {
-			/* things are broken; just report, don't clean up */
-			WARN(1, "error: irq_desc already assigned to a domain");
-			return;
-		}
-		d->domain = domain;
-		d->hwirq = hwirq;
-	}
-
-	mutex_lock(&irq_domain_mutex);
-	list_add(&domain->list, &irq_domain_list);
-	mutex_unlock(&irq_domain_mutex);
-}
-
-/**
- * irq_domain_del() - Unregister an irq_domain
- * @domain: ptr to registered irq_domain.
- */
-void irq_domain_del(struct irq_domain *domain)
-{
-	struct irq_data *d;
-	int hwirq, irq;
-
-	mutex_lock(&irq_domain_mutex);
-	list_del(&domain->list);
-	mutex_unlock(&irq_domain_mutex);
-
-	/* Clear the irq_domain assignments */
-	irq_domain_for_each_irq(domain, hwirq, irq) {
-		d = irq_get_irq_data(irq);
-		d->domain = NULL;
-	}
-}
-
-#if defined(CONFIG_OF_IRQ)
-/**
- * irq_create_of_mapping() - Map a linux irq number from a DT interrupt spec
- *
- * Used by the device tree interrupt mapping code to translate a device tree
- * interrupt specifier to a valid linux irq number.  Returns either a valid
- * linux IRQ number or 0.
- *
- * When the caller no longer need the irq number returned by this function it
- * should arrange to call irq_dispose_mapping().
- */
-unsigned int irq_create_of_mapping(struct device_node *controller,
-				   const u32 *intspec, unsigned int intsize)
-{
-	struct irq_domain *domain;
-	unsigned long hwirq;
-	unsigned int irq, type;
-	int rc = -EINVAL;
-
-	/* Find a domain which can translate the irq spec */
-	mutex_lock(&irq_domain_mutex);
-	list_for_each_entry(domain, &irq_domain_list, list) {
-		if (!domain->ops->dt_translate)
-			continue;
-		rc = domain->ops->dt_translate(domain, controller,
-					intspec, intsize, &hwirq, &type);
-		if (rc == 0)
-			break;
-	}
-	mutex_unlock(&irq_domain_mutex);
-
-	if (rc != 0)
-		return 0;
-
-	irq = irq_domain_to_irq(domain, hwirq);
-	if (type != IRQ_TYPE_NONE)
-		irq_set_irq_type(irq, type);
-	pr_debug("%s: mapped hwirq=%i to irq=%i, flags=%x\n",
-		 controller->full_name, (int)hwirq, irq, type);
-	return irq;
-}
-EXPORT_SYMBOL_GPL(irq_create_of_mapping);
-
-/**
- * irq_dispose_mapping() - Discard a mapping created by irq_create_of_mapping()
- * @irq: linux irq number to be discarded
- *
- * Calling this function indicates the caller no longer needs a reference to
- * the linux irq number returned by a prior call to irq_create_of_mapping().
- */
-void irq_dispose_mapping(unsigned int irq)
-{
-	/*
-	 * nothing yet; will be filled when support for dynamic allocation of
-	 * irq_descs is added to irq_domain
-	 */
-}
-EXPORT_SYMBOL_GPL(irq_dispose_mapping);
-
-int irq_domain_simple_dt_translate(struct irq_domain *d,
-			    struct device_node *controller,
-			    const u32 *intspec, unsigned int intsize,
-			    unsigned long *out_hwirq, unsigned int *out_type)
-{
-	if (d->of_node != controller)
-		return -EINVAL;
-	if (intsize < 1)
-		return -EINVAL;
-	if (d->nr_irq && ((intspec[0] < d->hwirq_base) ||
-	    (intspec[0] >= d->hwirq_base + d->nr_irq)))
-		return -EINVAL;
-
-	*out_hwirq = intspec[0];
-	*out_type = IRQ_TYPE_NONE;
-	if (intsize > 1)
-		*out_type = intspec[1] & IRQ_TYPE_SENSE_MASK;
-	return 0;
-}
-
-/**
- * irq_domain_create_simple() - Set up a 'simple' translation range
- */
-void irq_domain_add_simple(struct device_node *controller, int irq_base)
+static struct irq_domain *irq_domain_alloc(struct device_node *of_node,
+					   unsigned int revmap_type,
+					   const struct irq_domain_ops *ops,
+					   void *host_data)
 {
 	struct irq_domain *domain;
 
 	domain = kzalloc(sizeof(*domain), GFP_KERNEL);
-	if (!domain) {
-		WARN_ON(1);
-		return;
+	if (WARN_ON(!domain))
+		return NULL;
+
+	/* Fill structure */
+	domain->revmap_type = revmap_type;
+	domain->ops = ops;
+	domain->host_data = host_data;
+	domain->of_node = of_node_get(of_node);
+
+	return domain;
+}
+
+static void irq_domain_add(struct irq_domain *domain)
+{
+	mutex_lock(&irq_domain_mutex);
+	list_add(&domain->link, &irq_domain_list);
+	mutex_unlock(&irq_domain_mutex);
+	pr_debug("irq: Allocated domain of type %d @0x%p\n",
+		 domain->revmap_type, domain);
+}
+
+static unsigned int irq_domain_legacy_revmap(struct irq_domain *domain,
+					     irq_hw_number_t hwirq)
+{
+	irq_hw_number_t first_hwirq = domain->revmap_data.legacy.first_hwirq;
+	int size = domain->revmap_data.legacy.size;
+
+	if (WARN_ON(hwirq < first_hwirq || hwirq >= first_hwirq + size))
+		return 0;
+	return hwirq - first_hwirq + domain->revmap_data.legacy.first_irq;
+}
+
+/**
+ * irq_domain_add_legacy() - Allocate and register a legacy revmap irq_domain.
+ * @of_node: pointer to interrupt controller's device tree node.
+ * @size: total number of irqs in legacy mapping
+ * @first_irq: first number of irq block assigned to the domain
+ * @first_hwirq: first hwirq number to use for the translation. Should normally
+ *               be '0', but a positive integer can be used if the effective
+ *               hwirqs numbering does not begin at zero.
+ * @ops: map/unmap domain callbacks
+ * @host_data: Controller private data pointer
+ *
+ * Note: the map() callback will be called before this function returns
+ * for all legacy interrupts except 0 (which is always the invalid irq for
+ * a legacy controller).
+ */
+struct irq_domain *irq_domain_add_legacy(struct device_node *of_node,
+					 unsigned int size,
+					 unsigned int first_irq,
+					 irq_hw_number_t first_hwirq,
+					 const struct irq_domain_ops *ops,
+					 void *host_data)
+{
+	struct irq_domain *domain;
+	unsigned int i;
+
+	domain = irq_domain_alloc(of_node, IRQ_DOMAIN_MAP_LEGACY, ops, host_data);
+	if (!domain)
+		return NULL;
+
+	domain->revmap_data.legacy.first_irq = first_irq;
+	domain->revmap_data.legacy.first_hwirq = first_hwirq;
+	domain->revmap_data.legacy.size = size;
+
+	mutex_lock(&irq_domain_mutex);
+	/* Verify that all the irqs are available */
+	for (i = 0; i < size; i++) {
+		int irq = first_irq + i;
+		struct irq_data *irq_data = irq_get_irq_data(irq);
+
+		if (WARN_ON(!irq_data || irq_data->domain)) {
+			mutex_unlock(&irq_domain_mutex);
+			of_node_put(domain->of_node);
+			kfree(domain);
+			return NULL;
+		}
 	}
 
-	domain->irq_base = irq_base;
-	domain->of_node = of_node_get(controller);
-	domain->ops = &irq_domain_simple_ops;
-	irq_domain_add(domain);
-}
-EXPORT_SYMBOL_GPL(irq_domain_add_simple);
+	/* Claim all of the irqs before registering a legacy domain */
+	for (i = 0; i < size; i++) {
+		struct irq_data *irq_data = irq_get_irq_data(first_irq + i);
+		irq_data->hwirq = first_hwirq + i;
+		irq_data->domain = domain;
+	}
+	mutex_unlock(&irq_domain_mutex);
 
+	for (i = 0; i < size; i++) {
+		int irq = first_irq + i;
+		int hwirq = first_hwirq + i;
+
+		/* IRQ0 gets ignored */
+		if (!irq)
+			continue;
+
+		/* Legacy flags are left to default at this point,
+		 * one can then use irq_create_mapping() to
+		 * explicitly change them
+		 */
+		ops->map(domain, irq, hwirq);
+
+		/* Clear norequest flags */
+		irq_clear_status_flags(irq, IRQ_NOREQUEST);
+	}
+
+	irq_domain_add(domain);
+	return domain;
+}
+
+/**
+ * irq_domain_add_linear() - Allocate and register a legacy revmap irq_domain.
+ * @of_node: pointer to interrupt controller's device tree node.
+ * @ops: map/unmap domain callbacks
+ * @host_data: Controller private data pointer
+ */
+struct irq_domain *irq_domain_add_linear(struct device_node *of_node,
+					 unsigned int size,
+					 const struct irq_domain_ops *ops,
+					 void *host_data)
+{
+	struct irq_domain *domain;
+	unsigned int *revmap;
+
+	revmap = kzalloc(sizeof(*revmap) * size, GFP_KERNEL);
+	if (WARN_ON(!revmap))
+		return NULL;
+
+	domain = irq_domain_alloc(of_node, IRQ_DOMAIN_MAP_LINEAR, ops, host_data);
+	if (!domain) {
+		kfree(revmap);
+		return NULL;
+	}
+	domain->revmap_data.linear.size = size;
+	domain->revmap_data.linear.revmap = revmap;
+	irq_domain_add(domain);
+	return domain;
+}
+
+struct irq_domain *irq_domain_add_nomap(struct device_node *of_node,
+					 const struct irq_domain_ops *ops,
+					 void *host_data)
+{
+	struct irq_domain *domain = irq_domain_alloc(of_node,
+					IRQ_DOMAIN_MAP_NOMAP, ops, host_data);
+	if (domain)
+		irq_domain_add(domain);
+	return domain;
+}
+
+/**
+ * irq_domain_add_tree()
+ * @of_node: pointer to interrupt controller's device tree node.
+ * @ops: map/unmap domain callbacks
+ *
+ * Note: The radix tree will be allocated later during boot automatically
+ * (the reverse mapping will use the slow path until that happens).
+ */
+struct irq_domain *irq_domain_add_tree(struct device_node *of_node,
+					 const struct irq_domain_ops *ops,
+					 void *host_data)
+{
+	struct irq_domain *domain = irq_domain_alloc(of_node,
+					IRQ_DOMAIN_MAP_TREE, ops, host_data);
+	if (domain) {
+		INIT_RADIX_TREE(&domain->revmap_data.tree, GFP_KERNEL);
+		irq_domain_add(domain);
+	}
+	return domain;
+}
+
+/**
+ * irq_find_host() - Locates a domain for a given device node
+ * @node: device-tree node of the interrupt controller
+ */
+struct irq_domain *irq_find_host(struct device_node *node)
+{
+	struct irq_domain *h, *found = NULL;
+	int rc;
+
+	/* We might want to match the legacy controller last since
+	 * it might potentially be set to match all interrupts in
+	 * the absence of a device node. This isn't a problem so far
+	 * yet though...
+	 */
+	mutex_lock(&irq_domain_mutex);
+	list_for_each_entry(h, &irq_domain_list, link) {
+		if (h->ops->match)
+			rc = h->ops->match(h, node);
+		else
+			rc = (h->of_node != NULL) && (h->of_node == node);
+
+		if (rc) {
+			found = h;
+			break;
+		}
+	}
+	mutex_unlock(&irq_domain_mutex);
+	return found;
+}
+EXPORT_SYMBOL_GPL(irq_find_host);
+
+/**
+ * irq_set_default_host() - Set a "default" irq domain
+ * @domain: default domain pointer
+ *
+ * For convenience, it's possible to set a "default" domain that will be used
+ * whenever NULL is passed to irq_create_mapping(). It makes life easier for
+ * platforms that want to manipulate a few hard coded interrupt numbers that
+ * aren't properly represented in the device-tree.
+ */
+void irq_set_default_host(struct irq_domain *domain)
+{
+	pr_debug("irq: Default domain set to @0x%p\n", domain);
+
+	irq_default_domain = domain;
+}
+
+/**
+ * irq_set_virq_count() - Set the maximum number of linux irqs
+ * @count: number of linux irqs, capped with NR_IRQS
+ *
+ * This is mainly for use by platforms like iSeries who want to program
+ * the virtual irq number in the controller to avoid the reverse mapping
+ */
+void irq_set_virq_count(unsigned int count)
+{
+	pr_debug("irq: Trying to set virq count to %d\n", count);
+
+	BUG_ON(count < NUM_ISA_INTERRUPTS);
+	if (count < NR_IRQS)
+		irq_virq_count = count;
+}
+
+static int irq_setup_virq(struct irq_domain *domain, unsigned int virq,
+			    irq_hw_number_t hwirq)
+{
+	struct irq_data *irq_data = irq_get_irq_data(virq);
+
+	irq_data->hwirq = hwirq;
+	irq_data->domain = domain;
+	if (domain->ops->map(domain, virq, hwirq)) {
+		pr_debug("irq: -> mapping failed, freeing\n");
+		irq_data->domain = NULL;
+		irq_data->hwirq = 0;
+		return -1;
+	}
+
+	irq_clear_status_flags(virq, IRQ_NOREQUEST);
+
+	return 0;
+}
+
+/**
+ * irq_create_direct_mapping() - Allocate an irq for direct mapping
+ * @domain: domain to allocate the irq for or NULL for default domain
+ *
+ * This routine is used for irq controllers which can choose the hardware
+ * interrupt numbers they generate. In such a case it's simplest to use
+ * the linux irq as the hardware interrupt number.
+ */
+unsigned int irq_create_direct_mapping(struct irq_domain *domain)
+{
+	unsigned int virq;
+
+	if (domain == NULL)
+		domain = irq_default_domain;
+
+	BUG_ON(domain == NULL);
+	WARN_ON(domain->revmap_type != IRQ_DOMAIN_MAP_NOMAP);
+
+	virq = irq_alloc_desc_from(1, 0);
+	if (!virq) {
+		pr_debug("irq: create_direct virq allocation failed\n");
+		return 0;
+	}
+	if (virq >= irq_virq_count) {
+		pr_err("ERROR: no free irqs available below %i maximum\n",
+			irq_virq_count);
+		irq_free_desc(virq);
+		return 0;
+	}
+
+	pr_debug("irq: create_direct obtained virq %d\n", virq);
+
+	if (irq_setup_virq(domain, virq, virq)) {
+		irq_free_desc(virq);
+		return 0;
+	}
+
+	return virq;
+}
+
+/**
+ * irq_create_mapping() - Map a hardware interrupt into linux irq space
+ * @domain: domain owning this hardware interrupt or NULL for default domain
+ * @hwirq: hardware irq number in that domain space
+ *
+ * Only one mapping per hardware interrupt is permitted. Returns a linux
+ * irq number.
+ * If the sense/trigger is to be specified, set_irq_type() should be called
+ * on the number returned from that call.
+ */
+unsigned int irq_create_mapping(struct irq_domain *domain,
+				irq_hw_number_t hwirq)
+{
+	unsigned int virq, hint;
+
+	pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", domain, hwirq);
+
+	/* Look for default domain if nececssary */
+	if (domain == NULL)
+		domain = irq_default_domain;
+	if (domain == NULL) {
+		printk(KERN_WARNING "irq_create_mapping called for"
+		       " NULL domain, hwirq=%lx\n", hwirq);
+		WARN_ON(1);
+		return 0;
+	}
+	pr_debug("irq: -> using domain @%p\n", domain);
+
+	/* Check if mapping already exists */
+	virq = irq_find_mapping(domain, hwirq);
+	if (virq) {
+		pr_debug("irq: -> existing mapping on virq %d\n", virq);
+		return virq;
+	}
+
+	/* Get a virtual interrupt number */
+	if (domain->revmap_type == IRQ_DOMAIN_MAP_LEGACY)
+		return irq_domain_legacy_revmap(domain, hwirq);
+
+	/* Allocate a virtual interrupt number */
+	hint = hwirq % irq_virq_count;
+	if (hint == 0)
+		hint++;
+	virq = irq_alloc_desc_from(hint, 0);
+	if (!virq)
+		virq = irq_alloc_desc_from(1, 0);
+	if (!virq) {
+		pr_debug("irq: -> virq allocation failed\n");
+		return 0;
+	}
+
+	if (irq_setup_virq(domain, virq, hwirq)) {
+		if (domain->revmap_type != IRQ_DOMAIN_MAP_LEGACY)
+			irq_free_desc(virq);
+		return 0;
+	}
+
+	pr_debug("irq: irq %lu on domain %s mapped to virtual irq %u\n",
+		hwirq, domain->of_node ? domain->of_node->full_name : "null", virq);
+
+	return virq;
+}
+EXPORT_SYMBOL_GPL(irq_create_mapping);
+
+unsigned int irq_create_of_mapping(struct device_node *controller,
+				   const u32 *intspec, unsigned int intsize)
+{
+	struct irq_domain *domain;
+	irq_hw_number_t hwirq;
+	unsigned int type = IRQ_TYPE_NONE;
+	unsigned int virq;
+
+	domain = controller ? irq_find_host(controller) : irq_default_domain;
+	if (!domain) {
+#ifdef CONFIG_MIPS
+		/*
+		 * Workaround to avoid breaking interrupt controller drivers
+		 * that don't yet register an irq_domain.  This is temporary
+		 * code. ~~~gcl, Feb 24, 2012
+		 *
+		 * Scheduled for removal in Linux v3.6.  That should be enough
+		 * time.
+		 */
+		if (intsize > 0)
+			return intspec[0];
+#endif
+		printk(KERN_WARNING "irq: no irq domain found for %s !\n",
+		       controller->full_name);
+		return 0;
+	}
+
+	/* If domain has no translation, then we assume interrupt line */
+	if (domain->ops->xlate == NULL)
+		hwirq = intspec[0];
+	else {
+		if (domain->ops->xlate(domain, controller, intspec, intsize,
+				     &hwirq, &type))
+			return 0;
+	}
+
+	/* Create mapping */
+	virq = irq_create_mapping(domain, hwirq);
+	if (!virq)
+		return virq;
+
+	/* Set type if specified and different than the current one */
+	if (type != IRQ_TYPE_NONE &&
+	    type != (irqd_get_trigger_type(irq_get_irq_data(virq))))
+		irq_set_irq_type(virq, type);
+	return virq;
+}
+EXPORT_SYMBOL_GPL(irq_create_of_mapping);
+
+/**
+ * irq_dispose_mapping() - Unmap an interrupt
+ * @virq: linux irq number of the interrupt to unmap
+ */
+void irq_dispose_mapping(unsigned int virq)
+{
+	struct irq_data *irq_data = irq_get_irq_data(virq);
+	struct irq_domain *domain;
+	irq_hw_number_t hwirq;
+
+	if (!virq || !irq_data)
+		return;
+
+	domain = irq_data->domain;
+	if (WARN_ON(domain == NULL))
+		return;
+
+	/* Never unmap legacy interrupts */
+	if (domain->revmap_type == IRQ_DOMAIN_MAP_LEGACY)
+		return;
+
+	irq_set_status_flags(virq, IRQ_NOREQUEST);
+
+	/* remove chip and handler */
+	irq_set_chip_and_handler(virq, NULL, NULL);
+
+	/* Make sure it's completed */
+	synchronize_irq(virq);
+
+	/* Tell the PIC about it */
+	if (domain->ops->unmap)
+		domain->ops->unmap(domain, virq);
+	smp_mb();
+
+	/* Clear reverse map */
+	hwirq = irq_data->hwirq;
+	switch(domain->revmap_type) {
+	case IRQ_DOMAIN_MAP_LINEAR:
+		if (hwirq < domain->revmap_data.linear.size)
+			domain->revmap_data.linear.revmap[hwirq] = 0;
+		break;
+	case IRQ_DOMAIN_MAP_TREE:
+		mutex_lock(&revmap_trees_mutex);
+		radix_tree_delete(&domain->revmap_data.tree, hwirq);
+		mutex_unlock(&revmap_trees_mutex);
+		break;
+	}
+
+	irq_free_desc(virq);
+}
+EXPORT_SYMBOL_GPL(irq_dispose_mapping);
+
+/**
+ * irq_find_mapping() - Find a linux irq from an hw irq number.
+ * @domain: domain owning this hardware interrupt
+ * @hwirq: hardware irq number in that domain space
+ *
+ * This is a slow path, for use by generic code. It's expected that an
+ * irq controller implementation directly calls the appropriate low level
+ * mapping function.
+ */
+unsigned int irq_find_mapping(struct irq_domain *domain,
+			      irq_hw_number_t hwirq)
+{
+	unsigned int i;
+	unsigned int hint = hwirq % irq_virq_count;
+
+	/* Look for default domain if nececssary */
+	if (domain == NULL)
+		domain = irq_default_domain;
+	if (domain == NULL)
+		return 0;
+
+	/* legacy -> bail early */
+	if (domain->revmap_type == IRQ_DOMAIN_MAP_LEGACY)
+		return irq_domain_legacy_revmap(domain, hwirq);
+
+	/* Slow path does a linear search of the map */
+	if (hint == 0)
+		hint = 1;
+	i = hint;
+	do {
+		struct irq_data *data = irq_get_irq_data(i);
+		if (data && (data->domain == domain) && (data->hwirq == hwirq))
+			return i;
+		i++;
+		if (i >= irq_virq_count)
+			i = 1;
+	} while(i != hint);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(irq_find_mapping);
+
+/**
+ * irq_radix_revmap_lookup() - Find a linux irq from a hw irq number.
+ * @domain: domain owning this hardware interrupt
+ * @hwirq: hardware irq number in that domain space
+ *
+ * This is a fast path, for use by irq controller code that uses radix tree
+ * revmaps
+ */
+unsigned int irq_radix_revmap_lookup(struct irq_domain *domain,
+				     irq_hw_number_t hwirq)
+{
+	struct irq_data *irq_data;
+
+	if (WARN_ON_ONCE(domain->revmap_type != IRQ_DOMAIN_MAP_TREE))
+		return irq_find_mapping(domain, hwirq);
+
+	/*
+	 * Freeing an irq can delete nodes along the path to
+	 * do the lookup via call_rcu.
+	 */
+	rcu_read_lock();
+	irq_data = radix_tree_lookup(&domain->revmap_data.tree, hwirq);
+	rcu_read_unlock();
+
+	/*
+	 * If found in radix tree, then fine.
+	 * Else fallback to linear lookup - this should not happen in practice
+	 * as it means that we failed to insert the node in the radix tree.
+	 */
+	return irq_data ? irq_data->irq : irq_find_mapping(domain, hwirq);
+}
+
+/**
+ * irq_radix_revmap_insert() - Insert a hw irq to linux irq number mapping.
+ * @domain: domain owning this hardware interrupt
+ * @virq: linux irq number
+ * @hwirq: hardware irq number in that domain space
+ *
+ * This is for use by irq controllers that use a radix tree reverse
+ * mapping for fast lookup.
+ */
+void irq_radix_revmap_insert(struct irq_domain *domain, unsigned int virq,
+			     irq_hw_number_t hwirq)
+{
+	struct irq_data *irq_data = irq_get_irq_data(virq);
+
+	if (WARN_ON(domain->revmap_type != IRQ_DOMAIN_MAP_TREE))
+		return;
+
+	if (virq) {
+		mutex_lock(&revmap_trees_mutex);
+		radix_tree_insert(&domain->revmap_data.tree, hwirq, irq_data);
+		mutex_unlock(&revmap_trees_mutex);
+	}
+}
+
+/**
+ * irq_linear_revmap() - Find a linux irq from a hw irq number.
+ * @domain: domain owning this hardware interrupt
+ * @hwirq: hardware irq number in that domain space
+ *
+ * This is a fast path, for use by irq controller code that uses linear
+ * revmaps. It does fallback to the slow path if the revmap doesn't exist
+ * yet and will create the revmap entry with appropriate locking
+ */
+unsigned int irq_linear_revmap(struct irq_domain *domain,
+			       irq_hw_number_t hwirq)
+{
+	unsigned int *revmap;
+
+	if (WARN_ON_ONCE(domain->revmap_type != IRQ_DOMAIN_MAP_LINEAR))
+		return irq_find_mapping(domain, hwirq);
+
+	/* Check revmap bounds */
+	if (unlikely(hwirq >= domain->revmap_data.linear.size))
+		return irq_find_mapping(domain, hwirq);
+
+	/* Check if revmap was allocated */
+	revmap = domain->revmap_data.linear.revmap;
+	if (unlikely(revmap == NULL))
+		return irq_find_mapping(domain, hwirq);
+
+	/* Fill up revmap with slow path if no mapping found */
+	if (unlikely(!revmap[hwirq]))
+		revmap[hwirq] = irq_find_mapping(domain, hwirq);
+
+	return revmap[hwirq];
+}
+
+#ifdef CONFIG_VIRQ_DEBUG
+static int virq_debug_show(struct seq_file *m, void *private)
+{
+	unsigned long flags;
+	struct irq_desc *desc;
+	const char *p;
+	static const char none[] = "none";
+	void *data;
+	int i;
+
+	seq_printf(m, "%-5s  %-7s  %-15s  %-18s  %s\n", "virq", "hwirq",
+		      "chip name", "chip data", "domain name");
+
+	for (i = 1; i < nr_irqs; i++) {
+		desc = irq_to_desc(i);
+		if (!desc)
+			continue;
+
+		raw_spin_lock_irqsave(&desc->lock, flags);
+
+		if (desc->action && desc->action->handler) {
+			struct irq_chip *chip;
+
+			seq_printf(m, "%5d  ", i);
+			seq_printf(m, "0x%05lx  ", desc->irq_data.hwirq);
+
+			chip = irq_desc_get_chip(desc);
+			if (chip && chip->name)
+				p = chip->name;
+			else
+				p = none;
+			seq_printf(m, "%-15s  ", p);
+
+			data = irq_desc_get_chip_data(desc);
+			seq_printf(m, "0x%16p  ", data);
+
+			if (desc->irq_data.domain->of_node)
+				p = desc->irq_data.domain->of_node->full_name;
+			else
+				p = none;
+			seq_printf(m, "%s\n", p);
+		}
+
+		raw_spin_unlock_irqrestore(&desc->lock, flags);
+	}
+
+	return 0;
+}
+
+static int virq_debug_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, virq_debug_show, inode->i_private);
+}
+
+static const struct file_operations virq_debug_fops = {
+	.open = virq_debug_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+};
+
+static int __init irq_debugfs_init(void)
+{
+	if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
+				 NULL, &virq_debug_fops) == NULL)
+		return -ENOMEM;
+
+	return 0;
+}
+__initcall(irq_debugfs_init);
+#endif /* CONFIG_VIRQ_DEBUG */
+
+int irq_domain_simple_map(struct irq_domain *d, unsigned int irq,
+			  irq_hw_number_t hwirq)
+{
+	return 0;
+}
+
+/**
+ * irq_domain_xlate_onecell() - Generic xlate for direct one cell bindings
+ *
+ * Device Tree IRQ specifier translation function which works with one cell
+ * bindings where the cell value maps directly to the hwirq number.
+ */
+int irq_domain_xlate_onecell(struct irq_domain *d, struct device_node *ctrlr,
+			     const u32 *intspec, unsigned int intsize,
+			     unsigned long *out_hwirq, unsigned int *out_type)
+{
+	if (WARN_ON(intsize < 1))
+		return -EINVAL;
+	*out_hwirq = intspec[0];
+	*out_type = IRQ_TYPE_NONE;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(irq_domain_xlate_onecell);
+
+/**
+ * irq_domain_xlate_twocell() - Generic xlate for direct two cell bindings
+ *
+ * Device Tree IRQ specifier translation function which works with two cell
+ * bindings where the cell values map directly to the hwirq number
+ * and linux irq flags.
+ */
+int irq_domain_xlate_twocell(struct irq_domain *d, struct device_node *ctrlr,
+			const u32 *intspec, unsigned int intsize,
+			irq_hw_number_t *out_hwirq, unsigned int *out_type)
+{
+	if (WARN_ON(intsize < 2))
+		return -EINVAL;
+	*out_hwirq = intspec[0];
+	*out_type = intspec[1] & IRQ_TYPE_SENSE_MASK;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(irq_domain_xlate_twocell);
+
+/**
+ * irq_domain_xlate_onetwocell() - Generic xlate for one or two cell bindings
+ *
+ * Device Tree IRQ specifier translation function which works with either one
+ * or two cell bindings where the cell values map directly to the hwirq number
+ * and linux irq flags.
+ *
+ * Note: don't use this function unless your interrupt controller explicitly
+ * supports both one and two cell bindings.  For the majority of controllers
+ * the _onecell() or _twocell() variants above should be used.
+ */
+int irq_domain_xlate_onetwocell(struct irq_domain *d,
+				struct device_node *ctrlr,
+				const u32 *intspec, unsigned int intsize,
+				unsigned long *out_hwirq, unsigned int *out_type)
+{
+	if (WARN_ON(intsize < 1))
+		return -EINVAL;
+	*out_hwirq = intspec[0];
+	*out_type = (intsize > 1) ? intspec[1] : IRQ_TYPE_NONE;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(irq_domain_xlate_onetwocell);
+
+const struct irq_domain_ops irq_domain_simple_ops = {
+	.map = irq_domain_simple_map,
+	.xlate = irq_domain_xlate_onetwocell,
+};
+EXPORT_SYMBOL_GPL(irq_domain_simple_ops);
+
+#ifdef CONFIG_OF_IRQ
 void irq_domain_generate_simple(const struct of_device_id *match,
 				u64 phys_base, unsigned int irq_start)
 {
 	struct device_node *node;
-	pr_info("looking for phys_base=%llx, irq_start=%i\n",
+	pr_debug("looking for phys_base=%llx, irq_start=%i\n",
 		(unsigned long long) phys_base, (int) irq_start);
 	node = of_find_matching_node_by_address(NULL, match, phys_base);
 	if (node)
-		irq_domain_add_simple(node, irq_start);
-	else
-		pr_info("no node found\n");
+		irq_domain_add_legacy(node, 32, irq_start, 0,
+				      &irq_domain_simple_ops, NULL);
 }
 EXPORT_SYMBOL_GPL(irq_domain_generate_simple);
-#endif /* CONFIG_OF_IRQ */
-
-struct irq_domain_ops irq_domain_simple_ops = {
-#ifdef CONFIG_OF_IRQ
-	.dt_translate = irq_domain_simple_dt_translate,
-#endif /* CONFIG_OF_IRQ */
-};
-EXPORT_SYMBOL_GPL(irq_domain_simple_ops);
+#endif