[ARM] 4108/2: Allow multiple GIC interrupt controllers in a system
The current implementation only assumes one GIC to be present in the
system. However, there are platforms with more than one cascaded interrupt
controllers (RealView/EB MPCore for example).
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/common/gic.c b/arch/arm/common/gic.c
index 09b9d1b..4deece5 100644
--- a/arch/arm/common/gic.c
+++ b/arch/arm/common/gic.c
@@ -14,7 +14,9 @@
*
* o There is one CPU Interface per CPU, which sends interrupts sent
* by the Distributor, and interrupts generated locally, to the
- * associated CPU.
+ * associated CPU. The base address of the CPU interface is usually
+ * aliased so that the same address points to different chips depending
+ * on the CPU it is accessed from.
*
* Note that IRQs 0-31 are special - they are local to each CPU.
* As such, the enable set/clear, pending set/clear and active bit
@@ -31,10 +33,38 @@
#include <asm/mach/irq.h>
#include <asm/hardware/gic.h>
-static void __iomem *gic_dist_base;
-static void __iomem *gic_cpu_base;
static DEFINE_SPINLOCK(irq_controller_lock);
+struct gic_chip_data {
+ unsigned int irq_offset;
+ void __iomem *dist_base;
+ void __iomem *cpu_base;
+};
+
+#ifndef MAX_GIC_NR
+#define MAX_GIC_NR 1
+#endif
+
+static struct gic_chip_data gic_data[MAX_GIC_NR];
+
+static inline void __iomem *gic_dist_base(unsigned int irq)
+{
+ struct gic_chip_data *gic_data = get_irq_chip_data(irq);
+ return gic_data->dist_base;
+}
+
+static inline void __iomem *gic_cpu_base(unsigned int irq)
+{
+ struct gic_chip_data *gic_data = get_irq_chip_data(irq);
+ return gic_data->cpu_base;
+}
+
+static inline unsigned int gic_irq(unsigned int irq)
+{
+ struct gic_chip_data *gic_data = get_irq_chip_data(irq);
+ return irq - gic_data->irq_offset;
+}
+
/*
* Routines to acknowledge, disable and enable interrupts
*
@@ -55,8 +85,8 @@
u32 mask = 1 << (irq % 32);
spin_lock(&irq_controller_lock);
- writel(mask, gic_dist_base + GIC_DIST_ENABLE_CLEAR + (irq / 32) * 4);
- writel(irq, gic_cpu_base + GIC_CPU_EOI);
+ writel(mask, gic_dist_base(irq) + GIC_DIST_ENABLE_CLEAR + (gic_irq(irq) / 32) * 4);
+ writel(gic_irq(irq), gic_cpu_base(irq) + GIC_CPU_EOI);
spin_unlock(&irq_controller_lock);
}
@@ -65,7 +95,7 @@
u32 mask = 1 << (irq % 32);
spin_lock(&irq_controller_lock);
- writel(mask, gic_dist_base + GIC_DIST_ENABLE_CLEAR + (irq / 32) * 4);
+ writel(mask, gic_dist_base(irq) + GIC_DIST_ENABLE_CLEAR + (gic_irq(irq) / 32) * 4);
spin_unlock(&irq_controller_lock);
}
@@ -74,14 +104,14 @@
u32 mask = 1 << (irq % 32);
spin_lock(&irq_controller_lock);
- writel(mask, gic_dist_base + GIC_DIST_ENABLE_SET + (irq / 32) * 4);
+ writel(mask, gic_dist_base(irq) + GIC_DIST_ENABLE_SET + (gic_irq(irq) / 32) * 4);
spin_unlock(&irq_controller_lock);
}
#ifdef CONFIG_SMP
static void gic_set_cpu(unsigned int irq, cpumask_t mask_val)
{
- void __iomem *reg = gic_dist_base + GIC_DIST_TARGET + (irq & ~3);
+ void __iomem *reg = gic_dist_base(irq) + GIC_DIST_TARGET + (gic_irq(irq) & ~3);
unsigned int shift = (irq % 4) * 8;
unsigned int cpu = first_cpu(mask_val);
u32 val;
@@ -95,6 +125,37 @@
}
#endif
+static void fastcall gic_handle_cascade_irq(unsigned int irq,
+ struct irq_desc *desc)
+{
+ struct gic_chip_data *chip_data = get_irq_data(irq);
+ struct irq_chip *chip = get_irq_chip(irq);
+ unsigned int cascade_irq;
+ unsigned long status;
+
+ /* primary controller ack'ing */
+ chip->ack(irq);
+
+ spin_lock(&irq_controller_lock);
+ status = readl(chip_data->cpu_base + GIC_CPU_INTACK);
+ spin_unlock(&irq_controller_lock);
+
+ cascade_irq = (status & 0x3ff);
+ if (cascade_irq > 1020)
+ goto out;
+ if (cascade_irq < 32 || cascade_irq >= NR_IRQS) {
+ do_bad_IRQ(cascade_irq, desc);
+ goto out;
+ }
+
+ cascade_irq += chip_data->irq_offset;
+ generic_handle_irq(cascade_irq);
+
+ out:
+ /* primary controller unmasking */
+ chip->unmask(irq);
+}
+
static struct irq_chip gic_chip = {
.name = "GIC",
.ack = gic_ack_irq,
@@ -105,15 +166,29 @@
#endif
};
-void __init gic_dist_init(void __iomem *base)
+void __init gic_cascade_irq(unsigned int gic_nr, unsigned int irq)
+{
+ if (gic_nr >= MAX_GIC_NR)
+ BUG();
+ if (set_irq_data(irq, &gic_data[gic_nr]) != 0)
+ BUG();
+ set_irq_chained_handler(irq, gic_handle_cascade_irq);
+}
+
+void __init gic_dist_init(unsigned int gic_nr, void __iomem *base,
+ unsigned int irq_start)
{
unsigned int max_irq, i;
u32 cpumask = 1 << smp_processor_id();
+ if (gic_nr >= MAX_GIC_NR)
+ BUG();
+
cpumask |= cpumask << 8;
cpumask |= cpumask << 16;
- gic_dist_base = base;
+ gic_data[gic_nr].dist_base = base;
+ gic_data[gic_nr].irq_offset = (irq_start - 1) & ~31;
writel(0, base + GIC_DIST_CTRL);
@@ -158,8 +233,9 @@
/*
* Setup the Linux IRQ subsystem.
*/
- for (i = 29; i < max_irq; i++) {
+ for (i = irq_start; i < gic_data[gic_nr].irq_offset + max_irq; i++) {
set_irq_chip(i, &gic_chip);
+ set_irq_chip_data(i, &gic_data[gic_nr]);
set_irq_handler(i, handle_level_irq);
set_irq_flags(i, IRQF_VALID | IRQF_PROBE);
}
@@ -167,9 +243,13 @@
writel(1, base + GIC_DIST_CTRL);
}
-void __cpuinit gic_cpu_init(void __iomem *base)
+void __cpuinit gic_cpu_init(unsigned int gic_nr, void __iomem *base)
{
- gic_cpu_base = base;
+ if (gic_nr >= MAX_GIC_NR)
+ BUG();
+
+ gic_data[gic_nr].cpu_base = base;
+
writel(0xf0, base + GIC_CPU_PRIMASK);
writel(1, base + GIC_CPU_CTRL);
}
@@ -179,6 +259,7 @@
{
unsigned long map = *cpus_addr(cpumask);
- writel(map << 16 | irq, gic_dist_base + GIC_DIST_SOFTINT);
+ /* this always happens on GIC0 */
+ writel(map << 16 | irq, gic_data[0].dist_base + GIC_DIST_SOFTINT);
}
#endif