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>

2 files changed, 48 insertions, 11 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;
 }
 
diff --git a/fs/proc/proc_misc.c b/fs/proc/proc_misc.c
index c3cbabe8b38e..72dd739a7f8a 100644
--- a/fs/proc/proc_misc.c
+++ b/fs/proc/proc_misc.c
@@ -645,15 +645,36 @@ static const struct file_operations proc_stat_operations = {
  */
 static void *int_seq_start(struct seq_file *f, loff_t *pos)
 {
+#ifdef CONFIG_HAVE_SPARSE_IRQ
+        struct irq_desc *desc;
+        int irq;
+        int count = *pos;
+
+        for_each_irq_desc(irq, desc) {
+                if (count-- == 0)
+                        return desc;
+        }
+
+        return NULL;
+#else
         return (*pos <= nr_irqs) ? pos : NULL;
+#endif
 }
 
+
 static void *int_seq_next(struct seq_file *f, void *v, loff_t *pos)
 {
+#ifdef CONFIG_HAVE_SPARSE_IRQ
+        struct irq_desc *desc;
+
+        desc = ((struct irq_desc *)v)->next;
         (*pos)++;
-        if (*pos > nr_irqs)
-                return NULL;
-        return pos;
+
+        return desc;
+#else
+        (*pos)++;
+        return (*pos <= nr_irqs) ? pos : NULL;
+#endif
 }
 
 static void int_seq_stop(struct seq_file *f, void *v)
@@ -661,7 +682,6 @@ static void int_seq_stop(struct seq_file *f, void *v)
         /* Nothing to do */
 }
 
-
 static const struct seq_operations int_seq_ops = {
         .start = int_seq_start,
         .next  = int_seq_next,