x86_64: make /proc/interrupts work with dyn irq_desc

loop with irq_desc list

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 24 insertions, 7 deletions

diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c
index 5d5976e0311a..7bd841a9c640 100644
--- a/arch/x86/kernel/irq_64.c
+++ b/arch/x86/kernel/irq_64.c
@@ -70,9 +70,27 @@ static inline void stack_overflow_check(struct pt_regs *regs)
 
 int show_interrupts(struct seq_file *p, void *v)
 {
-        int i = *(loff_t *) v, j;
+        int i, 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, "           ");
@@ -81,12 +99,8 @@ 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);
-
-                if (!desc)
-                        return 0;
 
                 spin_lock_irqsave(&desc->lock, flags);
 #ifndef CONFIG_SMP
@@ -116,7 +130,9 @@ 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 ", cpu_pda(j)->__nmi_count);
@@ -155,6 +171,7 @@ skip:
                 seq_printf(p, "  Spurious interrupts\n");
                 seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
         }
+
         return 0;
 }