1 files changed, 28 insertions, 9 deletions

diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c
index 576c5df6cad8..0a57e39159a8 100644
--- a/arch/x86/kernel/irq_32.c
+++ b/arch/x86/kernel/irq_32.c
@@ -224,9 +224,10 @@ unsigned int do_IRQ(struct pt_regs *regs)
         struct pt_regs *old_regs;
         /* high bit used in ret_from_ code */
         int overflow, irq = ~regs->orig_ax;
-        struct irq_desc *desc = irq_to_desc(irq);
+        struct irq_desc *desc;
 
-        if (unlikely((unsigned)irq >= nr_irqs)) {
+        desc = irq_to_desc(irq);
+        if (unlikely(!desc)) {
                 printk(KERN_EMERG "%s: cannot handle IRQ %d\n",
                                         __func__, irq);
                 BUG();
@@ -263,6 +264,24 @@ int show_interrupts(struct seq_file *p, void *v)
         int i = *(loff_t *) v, j;
         struct irqaction * action;
         unsigned long flags;
+        unsigned int entries;
+        struct irq_desc *desc;
+        int tail = 0;
+
+#ifdef CONFIG_HAVE_SPARSE_IRQ
+        desc = (struct irq_desc *)v;
+        entries = -1U;
+        i = desc->irq;
+        if (!desc->next)
+                tail = 1;
+#else
+        entries = nr_irqs - 1;
+        i = *(loff_t *) v;
+        if (i == nr_irqs)
+                tail = 1;
+        else
+                desc = irq_to_desc(i);
+#endif
 
         if (i == 0) {
                 seq_printf(p, "           ");
@@ -271,9 +290,8 @@ int show_interrupts(struct seq_file *p, void *v)
                 seq_putc(p, '\n');
         }
 
-        if (i < nr_irqs) {
+        if (i <= entries) {
                 unsigned any_count = 0;
-                struct irq_desc *desc = irq_to_desc(i);
 
                 spin_lock_irqsave(&desc->lock, flags);
 #ifndef CONFIG_SMP
@@ -285,7 +303,7 @@ int show_interrupts(struct seq_file *p, void *v)
                 action = desc->action;
                 if (!action && !any_count)
                         goto skip;
-                seq_printf(p, "%3d: ",i);
+                seq_printf(p, "%#x: ",i);
 #ifndef CONFIG_SMP
                 seq_printf(p, "%10u ", kstat_irqs(i));
 #else
@@ -304,7 +322,9 @@ int show_interrupts(struct seq_file *p, void *v)
                 seq_putc(p, '\n');
 skip:
                 spin_unlock_irqrestore(&desc->lock, flags);
-        } else if (i == nr_irqs) {
+        }
+
+        if (tail) {
                 seq_printf(p, "NMI: ");
                 for_each_online_cpu(j)
                         seq_printf(p, "%10u ", nmi_count(j));
@@ -396,15 +416,14 @@ void fixup_irqs(cpumask_t map)
 {
         unsigned int irq;
         static int warned;
+        struct irq_desc *desc;
 
-        for (irq = 0; irq < nr_irqs; irq++) {
+        for_each_irq_desc(irq, desc) {
                 cpumask_t mask;
-                struct irq_desc *desc;
 
                 if (irq == 2)
                         continue;
 
-                desc = irq_to_desc(irq);
                 cpus_and(mask, desc->affinity, map);
                 if (any_online_cpu(mask) == NR_CPUS) {
                         printk("Breaking affinity for irq %i\n", irq);