[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, 37 deletions

diff --git a/arch/mips/kernel/irq-msc01.c b/arch/mips/kernel/irq-msc01.c
index 650a80ca374..e1880b27381 100644
--- a/arch/mips/kernel/irq-msc01.c
+++ b/arch/mips/kernel/irq-msc01.c
@@ -45,31 +45,6 @@ static inline void unmask_msc_irq(unsigned int irq)
 }
 
 /*
- * Enables the IRQ on SOC-it
- */
-static void enable_msc_irq(unsigned int irq)
-{
-	unmask_msc_irq(irq);
-}
-
-/*
- * Initialize the IRQ on SOC-it
- */
-static unsigned int startup_msc_irq(unsigned int irq)
-{
-	unmask_msc_irq(irq);
-	return 0;
-}
-
-/*
- * Disables the IRQ on SOC-it
- */
-static void disable_msc_irq(unsigned int irq)
-{
-	mask_msc_irq(irq);
-}
-
-/*
  * Masks and ACKs an IRQ
  */
 static void level_mask_and_ack_msc_irq(unsigned int irq)
@@ -136,25 +111,21 @@ msc_bind_eic_interrupt (unsigned int irq, unsigned int set)
 		    (irq<<MSC01_IC_RAMW_ADDR_SHF) | (set<<MSC01_IC_RAMW_DATA_SHF));
 }
 
-#define shutdown_msc_irq	disable_msc_irq
-
 struct irq_chip msc_levelirq_type = {
 	.typename = "SOC-it-Level",
-	.startup = startup_msc_irq,
-	.shutdown = shutdown_msc_irq,
-	.enable = enable_msc_irq,
-	.disable = disable_msc_irq,
 	.ack = level_mask_and_ack_msc_irq,
+	.mask = mask_msc_irq,
+	.mask_ack = level_mask_and_ack_msc_irq,
+	.unmask = unmask_msc_irq,
 	.end = end_msc_irq,
 };
 
 struct irq_chip msc_edgeirq_type = {
 	.typename = "SOC-it-Edge",
-	.startup =startup_msc_irq,
-	.shutdown = shutdown_msc_irq,
-	.enable = enable_msc_irq,
-	.disable = disable_msc_irq,
 	.ack = edge_mask_and_ack_msc_irq,
+	.mask = mask_msc_irq,
+	.mask_ack = edge_mask_and_ack_msc_irq,
+	.unmask = unmask_msc_irq,
 	.end = end_msc_irq,
 };
 
@@ -175,14 +146,14 @@ void __init init_msc_irqs(unsigned int base, msc_irqmap_t *imp, int nirq)
 
 		switch (imp->im_type) {
 		case MSC01_IRQ_EDGE:
-			irq_desc[base+n].chip = &msc_edgeirq_type;
+			set_irq_chip(base+n, &msc_edgeirq_type);
 			if (cpu_has_veic)
 				MSCIC_WRITE(MSC01_IC_SUP+n*8, MSC01_IC_SUP_EDGE_BIT);
 			else
 				MSCIC_WRITE(MSC01_IC_SUP+n*8, MSC01_IC_SUP_EDGE_BIT | imp->im_lvl);
 			break;
 		case MSC01_IRQ_LEVEL:
-			irq_desc[base+n].chip = &msc_levelirq_type;
+			set_irq_chip(base+n, &msc_levelirq_type);
 			if (cpu_has_veic)
 				MSCIC_WRITE(MSC01_IC_SUP+n*8, 0);
 			else