[MIPS] IRQ cleanups

This is a big irq cleanup patch.

* Use set_irq_chip() to register irq_chip.
* Initialize .mask, .unmask, .mask_ack field.  Functions for these
  method are already exist in most case.
* Do not initialize .startup, .shutdown, .enable, .disable fields if
  default routines provided by irq_chip_set_defaults() were suitable.
* Remove redundant irq_desc initializations.
* Remove unnecessary local_irq_save/local_irq_restore, spin_lock.

With this cleanup, it would be easy to switch to slightly lightwait
irq flow handlers (handle_level_irq(), etc.) instead of __do_IRQ().

Though whole this patch is quite large, changes in each irq_chip are
not quite simple.  Please review and test on your platform.  Thanks.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 0 insertions, 13 deletions

diff --git a/arch/mips/kernel/irq.c b/arch/mips/kernel/irq.c
index 9b0e49d63d7b..e997c9454f47 100644
--- a/arch/mips/kernel/irq.c
+++ b/arch/mips/kernel/irq.c
@@ -172,19 +172,6 @@ __setup("nokgdb", nokgdb);
 
 void __init init_IRQ(void)
 {
-        int i;
-
-        for (i = 0; i < NR_IRQS; i++) {
-                irq_desc[i].status  = IRQ_DISABLED;
-                irq_desc[i].action  = NULL;
-                irq_desc[i].depth   = 1;
-                irq_desc[i].chip = &no_irq_chip;
-                spin_lock_init(&irq_desc[i].lock);
-#ifdef CONFIG_MIPS_MT_SMTC
-                irq_hwmask[i] = 0;
-#endif /* CONFIG_MIPS_MT_SMTC */
-        }
-
         arch_init_irq();
 
 #ifdef CONFIG_KGDB