[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 0d18ed4..a1a9af6 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 af51889..8e2074b 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 */