[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, 8 insertions, 25 deletions

diff --git a/arch/mips/sgi-ip22/ip22-eisa.c b/arch/mips/sgi-ip22/ip22-eisa.c
index 0d18ed47c47a..a1a9af6da7bf 100644
--- a/arch/mips/sgi-ip22/ip22-eisa.c
+++ b/arch/mips/sgi-ip22/ip22-eisa.c
@@ -95,16 +95,11 @@ static irqreturn_t ip22_eisa_intr(int irq, void *dev_id)
 
 static void enable_eisa1_irq(unsigned int irq)
 {
-        unsigned long flags;
         u8 mask;
 
-        local_irq_save(flags);
-
         mask = inb(EISA_INT1_MASK);
         mask &= ~((u8) (1 << irq));
         outb(mask, EISA_INT1_MASK);
-
-        local_irq_restore(flags);
 }
 
 static unsigned int startup_eisa1_irq(unsigned int irq)
@@ -130,8 +125,6 @@ static void disable_eisa1_irq(unsigned int irq)
         outb(mask, EISA_INT1_MASK);
 }
 
-#define shutdown_eisa1_irq      disable_eisa1_irq
-
 static void mask_and_ack_eisa1_irq(unsigned int irq)
 {
         disable_eisa1_irq(irq);
@@ -148,25 +141,20 @@ static void end_eisa1_irq(unsigned int irq)
 static struct irq_chip ip22_eisa1_irq_type = {
         .typename       = "IP22 EISA",
         .startup        = startup_eisa1_irq,
-        .shutdown       = shutdown_eisa1_irq,
-        .enable         = enable_eisa1_irq,
-        .disable        = disable_eisa1_irq,
         .ack            = mask_and_ack_eisa1_irq,
+        .mask           = disable_eisa1_irq,
+        .mask_ack       = mask_and_ack_eisa1_irq,
+        .unmask         = enable_eisa1_irq,
         .end            = end_eisa1_irq,
 };
 
 static void enable_eisa2_irq(unsigned int irq)
 {
-        unsigned long flags;
         u8 mask;
 
-        local_irq_save(flags);
-
         mask = inb(EISA_INT2_MASK);
         mask &= ~((u8) (1 << (irq - 8)));
         outb(mask, EISA_INT2_MASK);
-
-        local_irq_restore(flags);
 }
 
 static unsigned int startup_eisa2_irq(unsigned int irq)
@@ -192,8 +180,6 @@ static void disable_eisa2_irq(unsigned int irq)
         outb(mask, EISA_INT2_MASK);
 }
 
-#define shutdown_eisa2_irq      disable_eisa2_irq
-
 static void mask_and_ack_eisa2_irq(unsigned int irq)
 {
         disable_eisa2_irq(irq);
@@ -210,10 +196,10 @@ static void end_eisa2_irq(unsigned int irq)
 static struct irq_chip ip22_eisa2_irq_type = {
         .typename       = "IP22 EISA",
         .startup        = startup_eisa2_irq,
-        .shutdown       = shutdown_eisa2_irq,
-        .enable         = enable_eisa2_irq,
-        .disable        = disable_eisa2_irq,
         .ack            = mask_and_ack_eisa2_irq,
+        .mask           = disable_eisa2_irq,
+        .mask_ack       = mask_and_ack_eisa2_irq,
+        .unmask         = enable_eisa2_irq,
         .end            = end_eisa2_irq,
 };
 
@@ -275,13 +261,10 @@ int __init ip22_eisa_init(void)
         outb(0, EISA_DMA2_WRITE_SINGLE);
 
         for (i = SGINT_EISA; i < (SGINT_EISA + EISA_MAX_IRQ); i++) {
-                irq_desc[i].status = IRQ_DISABLED;
-                irq_desc[i].action = 0;
-                irq_desc[i].depth = 1;
                 if (i < (SGINT_EISA + 8))
-                        irq_desc[i].chip = &ip22_eisa1_irq_type;
+                        set_irq_chip(i, &ip22_eisa1_irq_type);
                 else
-                        irq_desc[i].chip = &ip22_eisa2_irq_type;
+                        set_irq_chip(i, &ip22_eisa2_irq_type);
         }
 
         /* Cannot use request_irq because of kmalloc not being ready at such