[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, 6 insertions, 47 deletions

diff --git a/arch/mips/kernel/irq-mv6434x.c b/arch/mips/kernel/irq-mv6434x.c
index 37d106202b83..5012b9df1b5a 100644
--- a/arch/mips/kernel/irq-mv6434x.c
+++ b/arch/mips/kernel/irq-mv6434x.c
@@ -67,39 +67,6 @@ static inline void unmask_mv64340_irq(unsigned int irq)
 }
 
 /*
- * Enables the IRQ on Marvell Chip
- */
-static void enable_mv64340_irq(unsigned int irq)
-{
-        unmask_mv64340_irq(irq);
-}
-
-/*
- * Initialize the IRQ on Marvell Chip
- */
-static unsigned int startup_mv64340_irq(unsigned int irq)
-{
-        unmask_mv64340_irq(irq);
-        return 0;
-}
-
-/*
- * Disables the IRQ on Marvell Chip
- */
-static void disable_mv64340_irq(unsigned int irq)
-{
-        mask_mv64340_irq(irq);
-}
-
-/*
- * Masks and ACKs an IRQ
- */
-static void mask_and_ack_mv64340_irq(unsigned int irq)
-{
-        mask_mv64340_irq(irq);
-}
-
-/*
  * End IRQ processing
  */
 static void end_mv64340_irq(unsigned int irq)
@@ -133,15 +100,12 @@ void ll_mv64340_irq(void)
                 do_IRQ(ls1bit32(irq_src_high) + irq_base + 32);
 }
 
-#define shutdown_mv64340_irq    disable_mv64340_irq
-
 struct irq_chip mv64340_irq_type = {
         .typename = "MV-64340",
-        .startup = startup_mv64340_irq,
-        .shutdown = shutdown_mv64340_irq,
-        .enable = enable_mv64340_irq,
-        .disable = disable_mv64340_irq,
-        .ack = mask_and_ack_mv64340_irq,
+        .ack = mask_mv64340_irq,
+        .mask = mask_mv64340_irq,
+        .mask_ack = mask_mv64340_irq,
+        .unmask = unmask_mv64340_irq,
         .end = end_mv64340_irq,
 };
 
@@ -149,13 +113,8 @@ void __init mv64340_irq_init(unsigned int base)
 {
         int i;
 
-        /* Reset irq handlers pointers to NULL */
-        for (i = base; i < base + 64; i++) {
-                irq_desc[i].status = IRQ_DISABLED;
-                irq_desc[i].action = 0;
-                irq_desc[i].depth = 2;
-                irq_desc[i].chip = &mv64340_irq_type;
-        }
+        for (i = base; i < base + 64; i++)
+                set_irq_chip(i, &mv64340_irq_type);
 
         irq_base = base;
 }