3 files changed, 24 insertions, 0 deletions

diff --git a/arch/ia64/kernel/irq.c b/arch/ia64/kernel/irq.c
index ce49c85c928f..b4c239685d2e 100644
--- a/arch/ia64/kernel/irq.c
+++ b/arch/ia64/kernel/irq.c
@@ -104,6 +104,17 @@ void set_irq_affinity_info (unsigned int irq, int hwid, int redir)
                 irq_redir[irq] = (char) (redir & 0xff);
         }
 }
+
+bool is_affinity_mask_valid(cpumask_t cpumask)
+{
+        if (ia64_platform_is("sn2")) {
+                /* Only allow one CPU to be specified in the smp_affinity mask */
+                if (cpus_weight(cpumask) != 1)
+                        return false;
+        }
+        return true;
+}
+
 #endif /* CONFIG_SMP */
 
 #ifdef CONFIG_HOTPLUG_CPU
diff --git a/include/asm-ia64/irq.h b/include/asm-ia64/irq.h
index 79479e2c6966..67221615e317 100644
--- a/include/asm-ia64/irq.h
+++ b/include/asm-ia64/irq.h
@@ -11,6 +11,9 @@
  * 02/29/00     D.Mosberger     moved most things into hw_irq.h
  */
 
+#include <linux/types.h>
+#include <linux/cpumask.h>
+
 #define NR_IRQS         256
 #define NR_IRQ_VECTORS  NR_IRQS
 
@@ -29,5 +32,8 @@ extern void disable_irq (unsigned int);
 extern void disable_irq_nosync (unsigned int);
 extern void enable_irq (unsigned int);
 extern void set_irq_affinity_info (unsigned int irq, int dest, int redir);
+bool is_affinity_mask_valid(cpumask_t cpumask);
+
+#define is_affinity_mask_valid is_affinity_mask_valid
 
 #endif /* _ASM_IA64_IRQ_H */
diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
index ddde0ef9ccdc..b4f1674fca79 100644
--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -27,6 +27,10 @@ static int irq_affinity_read_proc(char *page, char **start, off_t off,
         return len;
 }
 
+#ifndef is_affinity_mask_valid
+#define is_affinity_mask_valid(val) 1
+#endif
+
 int no_irq_affinity;
 static int irq_affinity_write_proc(struct file *file, const char __user *buffer,
                                    unsigned long count, void *data)
@@ -42,6 +46,9 @@ static int irq_affinity_write_proc(struct file *file, const char __user *buffer,
         if (err)
                 return err;
 
+        if (!is_affinity_mask_valid(new_value))
+                return -EINVAL;
+
         /*
          * Do not allow disabling IRQs completely - it's a too easy
          * way to make the system unusable accidentally :-) At least