[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, 13 insertions, 64 deletions

diff --git a/arch/mips/kernel/irq_cpu.c b/arch/mips/kernel/irq_cpu.c
index 9bb21c7f2149..3b7cfa407e87 100644
--- a/arch/mips/kernel/irq_cpu.c
+++ b/arch/mips/kernel/irq_cpu.c
@@ -50,44 +50,6 @@ static inline void mask_mips_irq(unsigned int irq)
         irq_disable_hazard();
 }
 
-static inline void mips_cpu_irq_enable(unsigned int irq)
-{
-        unsigned long flags;
-
-        local_irq_save(flags);
-        unmask_mips_irq(irq);
-        back_to_back_c0_hazard();
-        local_irq_restore(flags);
-}
-
-static void mips_cpu_irq_disable(unsigned int irq)
-{
-        unsigned long flags;
-
-        local_irq_save(flags);
-        mask_mips_irq(irq);
-        back_to_back_c0_hazard();
-        local_irq_restore(flags);
-}
-
-static unsigned int mips_cpu_irq_startup(unsigned int irq)
-{
-        mips_cpu_irq_enable(irq);
-
-        return 0;
-}
-
-#define mips_cpu_irq_shutdown           mips_cpu_irq_disable
-
-/*
- * While we ack the interrupt interrupts are disabled and thus we don't need
- * to deal with concurrency issues.  Same for mips_cpu_irq_end.
- */
-static void mips_cpu_irq_ack(unsigned int irq)
-{
-        mask_mips_irq(irq);
-}
-
 static void mips_cpu_irq_end(unsigned int irq)
 {
         if (!(irq_desc[irq].status & (IRQ_DISABLED | IRQ_INPROGRESS)))
@@ -96,11 +58,10 @@ static void mips_cpu_irq_end(unsigned int irq)
 
 static struct irq_chip mips_cpu_irq_controller = {
         .typename       = "MIPS",
-        .startup        = mips_cpu_irq_startup,
-        .shutdown       = mips_cpu_irq_shutdown,
-        .enable         = mips_cpu_irq_enable,
-        .disable        = mips_cpu_irq_disable,
-        .ack            = mips_cpu_irq_ack,
+        .ack            = mask_mips_irq,
+        .mask           = mask_mips_irq,
+        .mask_ack       = mask_mips_irq,
+        .unmask         = unmask_mips_irq,
         .end            = mips_cpu_irq_end,
 };
 
@@ -110,8 +71,6 @@ static struct irq_chip mips_cpu_irq_controller = {
 
 #define unmask_mips_mt_irq      unmask_mips_irq
 #define mask_mips_mt_irq        mask_mips_irq
-#define mips_mt_cpu_irq_enable  mips_cpu_irq_enable
-#define mips_mt_cpu_irq_disable mips_cpu_irq_disable
 
 static unsigned int mips_mt_cpu_irq_startup(unsigned int irq)
 {
@@ -119,13 +78,11 @@ static unsigned int mips_mt_cpu_irq_startup(unsigned int irq)
 
         clear_c0_cause(0x100 << (irq - mips_cpu_irq_base));
         evpe(vpflags);
-        mips_mt_cpu_irq_enable(irq);
+        unmask_mips_mt_irq(irq);
 
         return 0;
 }
 
-#define mips_mt_cpu_irq_shutdown        mips_mt_cpu_irq_disable
-
 /*
  * While we ack the interrupt interrupts are disabled and thus we don't need
  * to deal with concurrency issues.  Same for mips_cpu_irq_end.
@@ -143,10 +100,10 @@ static void mips_mt_cpu_irq_ack(unsigned int irq)
 static struct irq_chip mips_mt_cpu_irq_controller = {
         .typename       = "MIPS",
         .startup        = mips_mt_cpu_irq_startup,
-        .shutdown       = mips_mt_cpu_irq_shutdown,
-        .enable         = mips_mt_cpu_irq_enable,
-        .disable        = mips_mt_cpu_irq_disable,
         .ack            = mips_mt_cpu_irq_ack,
+        .mask           = mask_mips_mt_irq,
+        .mask_ack       = mips_mt_cpu_irq_ack,
+        .unmask         = unmask_mips_mt_irq,
         .end            = mips_mt_cpu_irq_end,
 };
 
@@ -163,19 +120,11 @@ void __init mips_cpu_irq_init(int irq_base)
          * leave them uninitialized for other processors.
          */
         if (cpu_has_mipsmt)
-                for (i = irq_base; i < irq_base + 2; i++) {
-                        irq_desc[i].status = IRQ_DISABLED;
-                        irq_desc[i].action = NULL;
-                        irq_desc[i].depth = 1;
-                        irq_desc[i].chip = &mips_mt_cpu_irq_controller;
-                }
-
-        for (i = irq_base + 2; i < irq_base + 8; i++) {
-                irq_desc[i].status = IRQ_DISABLED;
-                irq_desc[i].action = NULL;
-                irq_desc[i].depth = 1;
-                irq_desc[i].chip = &mips_cpu_irq_controller;
-        }
+                for (i = irq_base; i < irq_base + 2; i++)
+                        set_irq_chip(i, &mips_mt_cpu_irq_controller);
+
+        for (i = irq_base + 2; i < irq_base + 8; i++)
+                set_irq_chip(i, &mips_cpu_irq_controller);
 
         mips_cpu_irq_base = irq_base;
 }