1 files changed, 62 insertions, 6 deletions

diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c
index 8e3478c995e..1890fb085cd 100644
--- a/arch/powerpc/sysdev/mpic.c
+++ b/arch/powerpc/sysdev/mpic.c
@@ -563,6 +563,51 @@ static void __init mpic_scan_ht_pics(struct mpic *mpic)
 
 #endif /* CONFIG_MPIC_U3_HT_IRQS */
 
+#ifdef CONFIG_SMP
+static int irq_choose_cpu(unsigned int virt_irq)
+{
+	cpumask_t mask = irq_desc[virt_irq].affinity;
+	int cpuid;
+
+	if (cpus_equal(mask, CPU_MASK_ALL)) {
+		static int irq_rover;
+		static DEFINE_SPINLOCK(irq_rover_lock);
+		unsigned long flags;
+
+		/* Round-robin distribution... */
+	do_round_robin:
+		spin_lock_irqsave(&irq_rover_lock, flags);
+
+		while (!cpu_online(irq_rover)) {
+			if (++irq_rover >= NR_CPUS)
+				irq_rover = 0;
+		}
+		cpuid = irq_rover;
+		do {
+			if (++irq_rover >= NR_CPUS)
+				irq_rover = 0;
+		} while (!cpu_online(irq_rover));
+
+		spin_unlock_irqrestore(&irq_rover_lock, flags);
+	} else {
+		cpumask_t tmp;
+
+		cpus_and(tmp, cpu_online_map, mask);
+
+		if (cpus_empty(tmp))
+			goto do_round_robin;
+
+		cpuid = first_cpu(tmp);
+	}
+
+	return get_hard_smp_processor_id(cpuid);
+}
+#else
+static int irq_choose_cpu(unsigned int virt_irq)
+{
+	return hard_smp_processor_id();
+}
+#endif
 
 #define mpic_irq_to_hw(virq)	((unsigned int)irq_map[virq].hwirq)
 
@@ -777,12 +822,18 @@ void mpic_set_affinity(unsigned int irq, cpumask_t cpumask)
 	struct mpic *mpic = mpic_from_irq(irq);
 	unsigned int src = mpic_irq_to_hw(irq);
 
-	cpumask_t tmp;
+	if (mpic->flags & MPIC_SINGLE_DEST_CPU) {
+		int cpuid = irq_choose_cpu(irq);
+
+		mpic_irq_write(src, MPIC_INFO(IRQ_DESTINATION), 1 << cpuid);
+	} else {
+		cpumask_t tmp;
 
-	cpus_and(tmp, cpumask, cpu_online_map);
+		cpus_and(tmp, cpumask, cpu_online_map);
 
-	mpic_irq_write(src, MPIC_INFO(IRQ_DESTINATION),
-		       mpic_physmask(cpus_addr(tmp)[0]));	
+		mpic_irq_write(src, MPIC_INFO(IRQ_DESTINATION),
+			       mpic_physmask(cpus_addr(tmp)[0]));
+	}
 }
 
 static unsigned int mpic_type_to_vecpri(struct mpic *mpic, unsigned int type)
@@ -1220,6 +1271,7 @@ void __init mpic_set_default_senses(struct mpic *mpic, u8 *senses, int count)
 void __init mpic_init(struct mpic *mpic)
 {
 	int i;
+	int cpu;
 
 	BUG_ON(mpic->num_sources == 0);
 
@@ -1262,6 +1314,11 @@ void __init mpic_init(struct mpic *mpic)
 
 	mpic_pasemi_msi_init(mpic);
 
+	if (mpic->flags & MPIC_PRIMARY)
+		cpu = hard_smp_processor_id();
+	else
+		cpu = 0;
+
 	for (i = 0; i < mpic->num_sources; i++) {
 		/* start with vector = source number, and masked */
 		u32 vecpri = MPIC_VECPRI_MASK | i |
@@ -1272,8 +1329,7 @@ void __init mpic_init(struct mpic *mpic)
 			continue;
 		/* init hw */
 		mpic_irq_write(i, MPIC_INFO(IRQ_VECTOR_PRI), vecpri);
-		mpic_irq_write(i, MPIC_INFO(IRQ_DESTINATION),
-			       1 << hard_smp_processor_id());
+		mpic_irq_write(i, MPIC_INFO(IRQ_DESTINATION), 1 << cpu);
 	}
 	
 	/* Init spurious vector */