powerpc: Remove get_irq_desc()

get_irq_desc() is a powerpc-specific version of irq_to_desc(). That
is reason enough to remove it, but it also doesn't know about sparse
irq_desc support which irq_to_desc() does (when we enable it).

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c
index 30c44e6..4fd57ab 100644
--- a/arch/powerpc/sysdev/mpic.c
+++ b/arch/powerpc/sysdev/mpic.c
@@ -572,7 +572,7 @@
 	cpumask_t mask;
 	int cpuid;
 
-	cpumask_copy(&mask, irq_desc[virt_irq].affinity);
+	cpumask_copy(&mask, irq_to_desc(virt_irq)->affinity);
 	if (cpus_equal(mask, CPU_MASK_ALL)) {
 		static int irq_rover;
 		static DEFINE_SPINLOCK(irq_rover_lock);
@@ -621,7 +621,7 @@
 	if (irq < NUM_ISA_INTERRUPTS)
 		return NULL;
 
-	return irq_desc[irq].chip_data;
+	return irq_to_desc(irq)->chip_data;
 }
 
 /* Determine if the linux irq is an IPI */
@@ -648,14 +648,14 @@
 /* Get the mpic structure from the IPI number */
 static inline struct mpic * mpic_from_ipi(unsigned int ipi)
 {
-	return irq_desc[ipi].chip_data;
+	return irq_to_desc(ipi)->chip_data;
 }
 #endif
 
 /* Get the mpic structure from the irq number */
 static inline struct mpic * mpic_from_irq(unsigned int irq)
 {
-	return irq_desc[irq].chip_data;
+	return irq_to_desc(irq)->chip_data;
 }
 
 /* Send an EOI */
@@ -735,7 +735,7 @@
 
 	mpic_unmask_irq(irq);
 
-	if (irq_desc[irq].status & IRQ_LEVEL)
+	if (irq_to_desc(irq)->status & IRQ_LEVEL)
 		mpic_ht_end_irq(mpic, src);
 }
 
@@ -745,7 +745,7 @@
 	unsigned int src = mpic_irq_to_hw(irq);
 
 	mpic_unmask_irq(irq);
-	mpic_startup_ht_interrupt(mpic, src, irq_desc[irq].status);
+	mpic_startup_ht_interrupt(mpic, src, irq_to_desc(irq)->status);
 
 	return 0;
 }
@@ -755,7 +755,7 @@
 	struct mpic *mpic = mpic_from_irq(irq);
 	unsigned int src = mpic_irq_to_hw(irq);
 
-	mpic_shutdown_ht_interrupt(mpic, src, irq_desc[irq].status);
+	mpic_shutdown_ht_interrupt(mpic, src, irq_to_desc(irq)->status);
 	mpic_mask_irq(irq);
 }
 
@@ -772,7 +772,7 @@
 	 * latched another edge interrupt coming in anyway
 	 */
 
-	if (irq_desc[irq].status & IRQ_LEVEL)
+	if (irq_to_desc(irq)->status & IRQ_LEVEL)
 		mpic_ht_end_irq(mpic, src);
 	mpic_eoi(mpic);
 }
@@ -856,7 +856,7 @@
 {
 	struct mpic *mpic = mpic_from_irq(virq);
 	unsigned int src = mpic_irq_to_hw(virq);
-	struct irq_desc *desc = get_irq_desc(virq);
+	struct irq_desc *desc = irq_to_desc(virq);
 	unsigned int vecpri, vold, vnew;
 
 	DBG("mpic: set_irq_type(mpic:@%p,virq:%d,src:0x%x,type:0x%x)\n",