irq: replace loop with nr_irqs with for_each_irq_desc

There are a handful of loops that go from 0 to nr_irqs and use
get_irq_desc() on them. These would allocate all the irq_desc
entries, regardless of the need for them.

Use the smarter for_each_irq_desc() iterator that will only iterate
over the present ones.

v2: make sure arch without GENERIC_HARDIRQS work too

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

3 files changed, 8 insertions, 8 deletions

diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h
index 422dd00c8bd3..c9767e641980 100644
--- a/kernel/irq/internals.h
+++ b/kernel/irq/internals.h
@@ -14,11 +14,11 @@ extern int __irq_set_trigger(struct irq_desc *desc, unsigned int irq,
                 unsigned long flags);
 
 #ifdef CONFIG_PROC_FS
-extern void register_irq_proc(unsigned int irq);
+extern void register_irq_proc(unsigned int irq, struct irq_desc *desc);
 extern void register_handler_proc(unsigned int irq, struct irqaction *action);
 extern void unregister_handler_proc(unsigned int irq, struct irqaction *action);
 #else
-static inline void register_irq_proc(unsigned int irq) { }
+static inline void register_irq_proc(unsigned int irq, struct irq_desc *desc) { }
 static inline void register_handler_proc(unsigned int irq,
                                          struct irqaction *action) { }
 static inline void unregister_handler_proc(unsigned int irq,
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index b5943e9f95aa..5070f55fdc16 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -478,7 +478,7 @@ int setup_irq(unsigned int irq, struct irqaction *new)
         spin_unlock_irqrestore(&desc->lock, flags);
 
         new->irq = irq;
-        register_irq_proc(irq);
+        register_irq_proc(irq, desc);
         new->dir = NULL;
         register_handler_proc(irq, new);
 
diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
index c2f356c808f6..bc0993d86c8b 100644
--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -182,11 +182,10 @@ void register_handler_proc(unsigned int irq, struct irqaction *action)
 
 #define MAX_NAMELEN 10
 
-void register_irq_proc(unsigned int irq)
+void register_irq_proc(unsigned int irq, struct irq_desc *desc)
 {
         char name [MAX_NAMELEN];
         struct proc_dir_entry *entry;
-        struct irq_desc *desc = irq_to_desc(irq);
 
         if (!root_irq_dir || (desc->chip == &no_irq_chip) || desc->dir)
                 return;
@@ -230,7 +229,8 @@ void register_default_affinity_proc(void)
 
 void init_irq_proc(void)
 {
-        int i;
+        unsigned int irq;
+        struct irq_desc *desc;
 
         /* create /proc/irq */
         root_irq_dir = proc_mkdir("irq", NULL);
@@ -242,7 +242,7 @@ void init_irq_proc(void)
         /*
          * Create entries for all existing IRQs.
          */
-        for (i = 0; i < nr_irqs; i++)
-                register_irq_proc(i);
+        for_each_irq_desc(irq, desc)
+                register_irq_proc(irq, desc);
 }