ia64: Validate online cpus in irq_set_affinity() callbacks

The [user space] interface does not filter out offline cpus. It merily
guarantees that the mask contains at least one online cpu.

So the selector in the irq chip implementation needs to make sure to
pick only an online cpu because otherwise:

     Offline Core 1
     Set affinity to 0xe (is valid due to online mask 0xd)
     cpumask_first will pick core 1, which is offline

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: ia64 <linux-ia64@vger.kernel.org>
Link: http://lkml.kernel.org/r/20140304203100.650414633@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

2 files changed, 3 insertions, 3 deletions

diff --git a/arch/ia64/sn/kernel/irq.c b/arch/ia64/sn/kernel/irq.c
index 62cf4dde6a04..85d095154902 100644
--- a/arch/ia64/sn/kernel/irq.c
+++ b/arch/ia64/sn/kernel/irq.c
@@ -209,8 +209,8 @@ static int sn_set_affinity_irq(struct irq_data *data,
         nasid_t nasid;
         int slice;
 
-        nasid = cpuid_to_nasid(cpumask_first(mask));
-        slice = cpuid_to_slice(cpumask_first(mask));
+        nasid = cpuid_to_nasid(cpumask_first_and(mask, cpu_online_mask));
+        slice = cpuid_to_slice(cpumask_first_and(mask, cpu_online_mask));
 
         list_for_each_entry_safe(sn_irq_info, sn_irq_info_safe,
                                  sn_irq_lh[irq], list)
diff --git a/arch/ia64/sn/kernel/msi_sn.c b/arch/ia64/sn/kernel/msi_sn.c
index 2b98b9e088de..afc58d2799ad 100644
--- a/arch/ia64/sn/kernel/msi_sn.c
+++ b/arch/ia64/sn/kernel/msi_sn.c
@@ -166,7 +166,7 @@ static int sn_set_msi_irq_affinity(struct irq_data *data,
         struct sn_pcibus_provider *provider;
         unsigned int cpu, irq = data->irq;
 
-        cpu = cpumask_first(cpu_mask);
+        cpu = cpumask_first_and(cpu_mask, cpu_online_mask);
         sn_irq_info = sn_msi_info[irq].sn_irq_info;
         if (sn_irq_info == NULL || sn_irq_info->irq_int_bit >= 0)
                 return -1;