[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>

2 files changed, 25 insertions, 117 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
diff --git a/arch/mips/sgi-ip22/ip22-int.c b/arch/mips/sgi-ip22/ip22-int.c
index af518898eaa1..8e2074b4ce43 100644
--- a/arch/mips/sgi-ip22/ip22-int.c
+++ b/arch/mips/sgi-ip22/ip22-int.c
@@ -40,34 +40,17 @@ extern int ip22_eisa_init(void);
 
 static void enable_local0_irq(unsigned int irq)
 {
-        unsigned long flags;
-
-        local_irq_save(flags);
         /* don't allow mappable interrupt to be enabled from setup_irq,
          * we have our own way to do so */
         if (irq != SGI_MAP_0_IRQ)
                 sgint->imask0 |= (1 << (irq - SGINT_LOCAL0));
-        local_irq_restore(flags);
-}
-
-static unsigned int startup_local0_irq(unsigned int irq)
-{
-        enable_local0_irq(irq);
-        return 0;               /* Never anything pending  */
 }
 
 static void disable_local0_irq(unsigned int irq)
 {
-        unsigned long flags;
-
-        local_irq_save(flags);
         sgint->imask0 &= ~(1 << (irq - SGINT_LOCAL0));
-        local_irq_restore(flags);
 }
 
-#define shutdown_local0_irq     disable_local0_irq
-#define mask_and_ack_local0_irq disable_local0_irq
-
 static void end_local0_irq (unsigned int irq)
 {
         if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
@@ -76,44 +59,26 @@ static void end_local0_irq (unsigned int irq)
 
 static struct irq_chip ip22_local0_irq_type = {
         .typename       = "IP22 local 0",
-        .startup        = startup_local0_irq,
-        .shutdown       = shutdown_local0_irq,
-        .enable         = enable_local0_irq,
-        .disable        = disable_local0_irq,
-        .ack            = mask_and_ack_local0_irq,
+        .ack            = disable_local0_irq,
+        .mask           = disable_local0_irq,
+        .mask_ack       = disable_local0_irq,
+        .unmask         = enable_local0_irq,
         .end            = end_local0_irq,
 };
 
 static void enable_local1_irq(unsigned int irq)
 {
-        unsigned long flags;
-
-        local_irq_save(flags);
         /* don't allow mappable interrupt to be enabled from setup_irq,
          * we have our own way to do so */
         if (irq != SGI_MAP_1_IRQ)
                 sgint->imask1 |= (1 << (irq - SGINT_LOCAL1));
-        local_irq_restore(flags);
-}
-
-static unsigned int startup_local1_irq(unsigned int irq)
-{
-        enable_local1_irq(irq);
-        return 0;               /* Never anything pending  */
 }
 
 void disable_local1_irq(unsigned int irq)
 {
-        unsigned long flags;
-
-        local_irq_save(flags);
         sgint->imask1 &= ~(1 << (irq - SGINT_LOCAL1));
-        local_irq_restore(flags);
 }
 
-#define shutdown_local1_irq     disable_local1_irq
-#define mask_and_ack_local1_irq disable_local1_irq
-
 static void end_local1_irq (unsigned int irq)
 {
         if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
@@ -122,44 +87,26 @@ static void end_local1_irq (unsigned int irq)
 
 static struct irq_chip ip22_local1_irq_type = {
         .typename       = "IP22 local 1",
-        .startup        = startup_local1_irq,
-        .shutdown       = shutdown_local1_irq,
-        .enable         = enable_local1_irq,
-        .disable        = disable_local1_irq,
-        .ack            = mask_and_ack_local1_irq,
+        .ack            = disable_local1_irq,
+        .mask           = disable_local1_irq,
+        .mask_ack       = disable_local1_irq,
+        .unmask         = enable_local1_irq,
         .end            = end_local1_irq,
 };
 
 static void enable_local2_irq(unsigned int irq)
 {
-        unsigned long flags;
-
-        local_irq_save(flags);
         sgint->imask0 |= (1 << (SGI_MAP_0_IRQ - SGINT_LOCAL0));
         sgint->cmeimask0 |= (1 << (irq - SGINT_LOCAL2));
-        local_irq_restore(flags);
-}
-
-static unsigned int startup_local2_irq(unsigned int irq)
-{
-        enable_local2_irq(irq);
-        return 0;               /* Never anything pending  */
 }
 
 void disable_local2_irq(unsigned int irq)
 {
-        unsigned long flags;
-
-        local_irq_save(flags);
         sgint->cmeimask0 &= ~(1 << (irq - SGINT_LOCAL2));
         if (!sgint->cmeimask0)
                 sgint->imask0 &= ~(1 << (SGI_MAP_0_IRQ - SGINT_LOCAL0));
-        local_irq_restore(flags);
 }
 
-#define shutdown_local2_irq disable_local2_irq
-#define mask_and_ack_local2_irq disable_local2_irq
-
 static void end_local2_irq (unsigned int irq)
 {
         if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
@@ -168,44 +115,26 @@ static void end_local2_irq (unsigned int irq)
 
 static struct irq_chip ip22_local2_irq_type = {
         .typename       = "IP22 local 2",
-        .startup        = startup_local2_irq,
-        .shutdown       = shutdown_local2_irq,
-        .enable         = enable_local2_irq,
-        .disable        = disable_local2_irq,
-        .ack            = mask_and_ack_local2_irq,
+        .ack            = disable_local2_irq,
+        .mask           = disable_local2_irq,
+        .mask_ack       = disable_local2_irq,
+        .unmask         = enable_local2_irq,
         .end            = end_local2_irq,
 };
 
 static void enable_local3_irq(unsigned int irq)
 {
-        unsigned long flags;
-
-        local_irq_save(flags);
         sgint->imask1 |= (1 << (SGI_MAP_1_IRQ - SGINT_LOCAL1));
         sgint->cmeimask1 |= (1 << (irq - SGINT_LOCAL3));
-        local_irq_restore(flags);
-}
-
-static unsigned int startup_local3_irq(unsigned int irq)
-{
-        enable_local3_irq(irq);
-        return 0;               /* Never anything pending  */
 }
 
 void disable_local3_irq(unsigned int irq)
 {
-        unsigned long flags;
-
-        local_irq_save(flags);
         sgint->cmeimask1 &= ~(1 << (irq - SGINT_LOCAL3));
         if (!sgint->cmeimask1)
                 sgint->imask1 &= ~(1 << (SGI_MAP_1_IRQ - SGINT_LOCAL1));
-        local_irq_restore(flags);
 }
 
-#define shutdown_local3_irq disable_local3_irq
-#define mask_and_ack_local3_irq disable_local3_irq
-
 static void end_local3_irq (unsigned int irq)
 {
         if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
@@ -214,11 +143,10 @@ static void end_local3_irq (unsigned int irq)
 
 static struct irq_chip ip22_local3_irq_type = {
         .typename       = "IP22 local 3",
-        .startup        = startup_local3_irq,
-        .shutdown       = shutdown_local3_irq,
-        .enable         = enable_local3_irq,
-        .disable        = disable_local3_irq,
-        .ack            = mask_and_ack_local3_irq,
+        .ack            = disable_local3_irq,
+        .mask           = disable_local3_irq,
+        .mask_ack       = disable_local3_irq,
+        .unmask         = enable_local3_irq,
         .end            = end_local3_irq,
 };
 
@@ -430,10 +358,7 @@ void __init arch_init_irq(void)
                 else
                         handler         = &ip22_local3_irq_type;
 
-                irq_desc[i].status      = IRQ_DISABLED;
-                irq_desc[i].action      = 0;
-                irq_desc[i].depth       = 1;
-                irq_desc[i].chip        = handler;
+                set_irq_chip(i, handler);
         }
 
         /* vector handler. this register the IRQ as non-sharable */