[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, 12 insertions, 48 deletions

diff --git a/arch/mips/sibyte/bcm1480/irq.c b/arch/mips/sibyte/bcm1480/irq.c
index 8b1f4148492..2e8f6b2e242 100644
--- a/arch/mips/sibyte/bcm1480/irq.c
+++ b/arch/mips/sibyte/bcm1480/irq.c
@@ -45,11 +45,9 @@
  */
 
 
-#define shutdown_bcm1480_irq	disable_bcm1480_irq
 static void end_bcm1480_irq(unsigned int irq);
 static void enable_bcm1480_irq(unsigned int irq);
 static void disable_bcm1480_irq(unsigned int irq);
-static unsigned int startup_bcm1480_irq(unsigned int irq);
 static void ack_bcm1480_irq(unsigned int irq);
 #ifdef CONFIG_SMP
 static void bcm1480_set_affinity(unsigned int irq, cpumask_t mask);
@@ -85,11 +83,10 @@ extern char sb1250_duart_present[];
 
 static struct irq_chip bcm1480_irq_type = {
 	.typename = "BCM1480-IMR",
-	.startup = startup_bcm1480_irq,
-	.shutdown = shutdown_bcm1480_irq,
-	.enable = enable_bcm1480_irq,
-	.disable = disable_bcm1480_irq,
 	.ack = ack_bcm1480_irq,
+	.mask = disable_bcm1480_irq,
+	.mask_ack = ack_bcm1480_irq,
+	.unmask = enable_bcm1480_irq,
 	.end = end_bcm1480_irq,
 #ifdef CONFIG_SMP
 	.set_affinity = bcm1480_set_affinity
@@ -188,14 +185,6 @@ static void bcm1480_set_affinity(unsigned int irq, cpumask_t mask)
 
 /*****************************************************************************/
 
-static unsigned int startup_bcm1480_irq(unsigned int irq)
-{
-	bcm1480_unmask_irq(bcm1480_irq_owner[irq], irq);
-
-	return 0;		/* never anything pending */
-}
-
-
 static void disable_bcm1480_irq(unsigned int irq)
 {
 	bcm1480_mask_irq(bcm1480_irq_owner[irq], irq);
@@ -270,16 +259,9 @@ void __init init_bcm1480_irqs(void)
 {
 	int i;
 
-	for (i = 0; i < NR_IRQS; i++) {
-		irq_desc[i].status = IRQ_DISABLED;
-		irq_desc[i].action = 0;
-		irq_desc[i].depth = 1;
-		if (i < BCM1480_NR_IRQS) {
-			irq_desc[i].chip = &bcm1480_irq_type;
-			bcm1480_irq_owner[i] = 0;
-		} else {
-			irq_desc[i].chip = &no_irq_chip;
-		}
+	for (i = 0; i < BCM1480_NR_IRQS; i++) {
+		set_irq_chip(i, &bcm1480_irq_type);
+		bcm1480_irq_owner[i] = 0;
 	}
 }
 
diff --git a/arch/mips/sibyte/sb1250/irq.c b/arch/mips/sibyte/sb1250/irq.c
index d5d26770daf..82ce7533053 100644
--- a/arch/mips/sibyte/sb1250/irq.c
+++ b/arch/mips/sibyte/sb1250/irq.c
@@ -44,11 +44,9 @@
  */
 
 
-#define shutdown_sb1250_irq	disable_sb1250_irq
 static void end_sb1250_irq(unsigned int irq);
 static void enable_sb1250_irq(unsigned int irq);
 static void disable_sb1250_irq(unsigned int irq);
-static unsigned int startup_sb1250_irq(unsigned int irq);
 static void ack_sb1250_irq(unsigned int irq);
 #ifdef CONFIG_SMP
 static void sb1250_set_affinity(unsigned int irq, cpumask_t mask);
@@ -70,11 +68,10 @@ extern char sb1250_duart_present[];
 
 static struct irq_chip sb1250_irq_type = {
 	.typename = "SB1250-IMR",
-	.startup = startup_sb1250_irq,
-	.shutdown = shutdown_sb1250_irq,
-	.enable = enable_sb1250_irq,
-	.disable = disable_sb1250_irq,
 	.ack = ack_sb1250_irq,
+	.mask = disable_sb1250_irq,
+	.mask_ack = ack_sb1250_irq,
+	.unmask = enable_sb1250_irq,
 	.end = end_sb1250_irq,
 #ifdef CONFIG_SMP
 	.set_affinity = sb1250_set_affinity
@@ -163,14 +160,6 @@ static void sb1250_set_affinity(unsigned int irq, cpumask_t mask)
 
 /*****************************************************************************/
 
-static unsigned int startup_sb1250_irq(unsigned int irq)
-{
-	sb1250_unmask_irq(sb1250_irq_owner[irq], irq);
-
-	return 0;		/* never anything pending */
-}
-
-
 static void disable_sb1250_irq(unsigned int irq)
 {
 	sb1250_mask_irq(sb1250_irq_owner[irq], irq);
@@ -239,16 +228,9 @@ void __init init_sb1250_irqs(void)
 {
 	int i;
 
-	for (i = 0; i < NR_IRQS; i++) {
-		irq_desc[i].status = IRQ_DISABLED;
-		irq_desc[i].action = 0;
-		irq_desc[i].depth = 1;
-		if (i < SB1250_NR_IRQS) {
-			irq_desc[i].chip = &sb1250_irq_type;
-			sb1250_irq_owner[i] = 0;
-		} else {
-			irq_desc[i].chip = &no_irq_chip;
-		}
+	for (i = 0; i < SB1250_NR_IRQS; i++) {
+		set_irq_chip(i, &sb1250_irq_type);
+		sb1250_irq_owner[i] = 0;
 	}
 }