[014/107] powerpc/mpic: Fix problem that affinity is not updated

[Greg KH]

2.6.32-longterm review patch.  If anyone has any objections, please let us know.

------------------

From: Yang Li <leoli@xxxxxxxxxxxxx>

commit 38e1313fc753482b93aa6c6f11cfbd43a5bcd963 upstream.

Since commit 57b150cce8e004ddd36330490a68bfb59b7271e9, desc->affinity
of an irq is changed after calling desc->chip->set_affinity.
Therefore we need to fix the irq_choose_cpu() not to depend on the
desc->affinity for new mask.

Signed-off-by: Jiajun Wu <b06378@xxxxxxxxxxxxx>
Signed-off-by: Li Yang <leoli@xxxxxxxxxxxxx>
Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 arch/powerpc/sysdev/mpic.c |   17 +++++------------
 1 file changed, 5 insertions(+), 12 deletions(-)

--- a/arch/powerpc/sysdev/mpic.c
+++ b/arch/powerpc/sysdev/mpic.c
@@ -567,12 +567,10 @@ static void __init mpic_scan_ht_pics(str
 #endif /* CONFIG_MPIC_U3_HT_IRQS */
 
 #ifdef CONFIG_SMP
-static int irq_choose_cpu(unsigned int virt_irq)
+static int irq_choose_cpu(const cpumask_t *mask)
 {
-	cpumask_t mask;
 	int cpuid;
 
-	cpumask_copy(&mask, irq_desc[virt_irq].affinity);
 	if (cpus_equal(mask, CPU_MASK_ALL)) {
 		static int irq_rover;
 		static DEFINE_SPINLOCK(irq_rover_lock);
@@ -594,20 +592,15 @@ static int irq_choose_cpu(unsigned int v
 
 		spin_unlock_irqrestore(&irq_rover_lock, flags);
 	} else {
-		cpumask_t tmp;
-
-		cpus_and(tmp, cpu_online_map, mask);
-
-		if (cpus_empty(tmp))
+		cpuid = cpumask_first_and(mask, cpu_online_mask);
+		if (cpuid >= nr_cpu_ids)
 			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)
+static int irq_choose_cpu(const cpumask_t *mask)
 {
 	return hard_smp_processor_id();
 }
@@ -816,7 +809,7 @@ int mpic_set_affinity(unsigned int irq,
 	unsigned int src = mpic_irq_to_hw(irq);
 
 	if (mpic->flags & MPIC_SINGLE_DEST_CPU) {
-		int cpuid = irq_choose_cpu(irq);
+		int cpuid = irq_choose_cpu(cpumask);
 
 		mpic_irq_write(src, MPIC_INFO(IRQ_DESTINATION), 1 << cpuid);
 	} else {


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