[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>

7 files changed, 47 insertions, 260 deletions

diff --git a/arch/mips/kernel/i8259.c b/arch/mips/kernel/i8259.c
index 48e3418c217b..2526c0ca4d81 100644
--- a/arch/mips/kernel/i8259.c
+++ b/arch/mips/kernel/i8259.c
@@ -40,21 +40,10 @@ static void end_8259A_irq (unsigned int irq)
                 enable_8259A_irq(irq);
 }
 
-#define shutdown_8259A_irq      disable_8259A_irq
-
 void mask_and_ack_8259A(unsigned int);
 
-static unsigned int startup_8259A_irq(unsigned int irq)
-{
-        enable_8259A_irq(irq);
-
-        return 0; /* never anything pending */
-}
-
 static struct irq_chip i8259A_irq_type = {
         .typename = "XT-PIC",
-        .startup = startup_8259A_irq,
-        .shutdown = shutdown_8259A_irq,
         .enable = enable_8259A_irq,
         .disable = disable_8259A_irq,
         .ack = mask_and_ack_8259A,
@@ -120,7 +109,7 @@ int i8259A_irq_pending(unsigned int irq)
 void make_8259A_irq(unsigned int irq)
 {
         disable_irq_nosync(irq);
-        irq_desc[irq].chip = &i8259A_irq_type;
+        set_irq_chip(irq, &i8259A_irq_type);
         enable_irq(irq);
 }
 
@@ -323,12 +312,8 @@ void __init init_i8259_irqs (void)
 
         init_8259A(0);
 
-        for (i = 0; i < 16; i++) {
-                irq_desc[i].status = IRQ_DISABLED;
-                irq_desc[i].action = NULL;
-                irq_desc[i].depth = 1;
-                irq_desc[i].chip = &i8259A_irq_type;
-        }
+        for (i = 0; i < 16; i++)
+                set_irq_chip(i, &i8259A_irq_type);
 
         setup_irq(2, &irq2);
 }
diff --git a/arch/mips/kernel/irq-msc01.c b/arch/mips/kernel/irq-msc01.c
index 650a80ca3741..e1880b27381b 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
diff --git a/arch/mips/kernel/irq-mv6434x.c b/arch/mips/kernel/irq-mv6434x.c
index 37d106202b83..5012b9df1b5a 100644
--- a/arch/mips/kernel/irq-mv6434x.c
+++ b/arch/mips/kernel/irq-mv6434x.c
@@ -67,39 +67,6 @@ static inline void unmask_mv64340_irq(unsigned int irq)
 }
 
 /*
- * Enables the IRQ on Marvell Chip
- */
-static void enable_mv64340_irq(unsigned int irq)
-{
-        unmask_mv64340_irq(irq);
-}
-
-/*
- * Initialize the IRQ on Marvell Chip
- */
-static unsigned int startup_mv64340_irq(unsigned int irq)
-{
-        unmask_mv64340_irq(irq);
-        return 0;
-}
-
-/*
- * Disables the IRQ on Marvell Chip
- */
-static void disable_mv64340_irq(unsigned int irq)
-{
-        mask_mv64340_irq(irq);
-}
-
-/*
- * Masks and ACKs an IRQ
- */
-static void mask_and_ack_mv64340_irq(unsigned int irq)
-{
-        mask_mv64340_irq(irq);
-}
-
-/*
  * End IRQ processing
  */
 static void end_mv64340_irq(unsigned int irq)
@@ -133,15 +100,12 @@ void ll_mv64340_irq(void)
                 do_IRQ(ls1bit32(irq_src_high) + irq_base + 32);
 }
 
-#define shutdown_mv64340_irq    disable_mv64340_irq
-
 struct irq_chip mv64340_irq_type = {
         .typename = "MV-64340",
-        .startup = startup_mv64340_irq,
-        .shutdown = shutdown_mv64340_irq,
-        .enable = enable_mv64340_irq,
-        .disable = disable_mv64340_irq,
-        .ack = mask_and_ack_mv64340_irq,
+        .ack = mask_mv64340_irq,
+        .mask = mask_mv64340_irq,
+        .mask_ack = mask_mv64340_irq,
+        .unmask = unmask_mv64340_irq,
         .end = end_mv64340_irq,
 };
 
@@ -149,13 +113,8 @@ void __init mv64340_irq_init(unsigned int base)
 {
         int i;
 
-        /* Reset irq handlers pointers to NULL */
-        for (i = base; i < base + 64; i++) {
-                irq_desc[i].status = IRQ_DISABLED;
-                irq_desc[i].action = 0;
-                irq_desc[i].depth = 2;
-                irq_desc[i].chip = &mv64340_irq_type;
-        }
+        for (i = base; i < base + 64; i++)
+                set_irq_chip(i, &mv64340_irq_type);
 
         irq_base = base;
 }
diff --git a/arch/mips/kernel/irq-rm7000.c b/arch/mips/kernel/irq-rm7000.c
index 6b54c7109e2e..6a297e3b8899 100644
--- a/arch/mips/kernel/irq-rm7000.c
+++ b/arch/mips/kernel/irq-rm7000.c
@@ -29,42 +29,6 @@ static inline void mask_rm7k_irq(unsigned int irq)
         clear_c0_intcontrol(0x100 << (irq - irq_base));
 }
 
-static inline void rm7k_cpu_irq_enable(unsigned int irq)
-{
-        unsigned long flags;
-
-        local_irq_save(flags);
-        unmask_rm7k_irq(irq);
-        local_irq_restore(flags);
-}
-
-static void rm7k_cpu_irq_disable(unsigned int irq)
-{
-        unsigned long flags;
-
-        local_irq_save(flags);
-        mask_rm7k_irq(irq);
-        local_irq_restore(flags);
-}
-
-static unsigned int rm7k_cpu_irq_startup(unsigned int irq)
-{
-        rm7k_cpu_irq_enable(irq);
-
-        return 0;
-}
-
-#define rm7k_cpu_irq_shutdown   rm7k_cpu_irq_disable
-
-/*
- * While we ack the interrupt interrupts are disabled and thus we don't need
- * to deal with concurrency issues.  Same for rm7k_cpu_irq_end.
- */
-static void rm7k_cpu_irq_ack(unsigned int irq)
-{
-        mask_rm7k_irq(irq);
-}
-
 static void rm7k_cpu_irq_end(unsigned int irq)
 {
         if (!(irq_desc[irq].status & (IRQ_DISABLED | IRQ_INPROGRESS)))
@@ -73,11 +37,10 @@ static void rm7k_cpu_irq_end(unsigned int irq)
 
 static struct irq_chip rm7k_irq_controller = {
         .typename = "RM7000",
-        .startup = rm7k_cpu_irq_startup,
-        .shutdown = rm7k_cpu_irq_shutdown,
-        .enable = rm7k_cpu_irq_enable,
-        .disable = rm7k_cpu_irq_disable,
-        .ack = rm7k_cpu_irq_ack,
+        .ack = mask_rm7k_irq,
+        .mask = mask_rm7k_irq,
+        .mask_ack = mask_rm7k_irq,
+        .unmask = unmask_rm7k_irq,
         .end = rm7k_cpu_irq_end,
 };
 
@@ -87,12 +50,8 @@ void __init rm7k_cpu_irq_init(int base)
 
         clear_c0_intcontrol(0x00000f00);                /* Mask all */
 
-        for (i = base; i < base + 4; i++) {
-                irq_desc[i].status = IRQ_DISABLED;
-                irq_desc[i].action = NULL;
-                irq_desc[i].depth = 1;
-                irq_desc[i].chip = &rm7k_irq_controller;
-        }
+        for (i = base; i < base + 4; i++)
+                set_irq_chip(i, &rm7k_irq_controller);
 
         irq_base = base;
 }
diff --git a/arch/mips/kernel/irq-rm9000.c b/arch/mips/kernel/irq-rm9000.c
index 62f011ba97a2..977538445cf3 100644
--- a/arch/mips/kernel/irq-rm9000.c
+++ b/arch/mips/kernel/irq-rm9000.c
@@ -48,15 +48,6 @@ static void rm9k_cpu_irq_disable(unsigned int irq)
         local_irq_restore(flags);
 }
 
-static unsigned int rm9k_cpu_irq_startup(unsigned int irq)
-{
-        rm9k_cpu_irq_enable(irq);
-
-        return 0;
-}
-
-#define rm9k_cpu_irq_shutdown   rm9k_cpu_irq_disable
-
 /*
  * Performance counter interrupts are global on all processors.
  */
@@ -89,16 +80,6 @@ static void rm9k_perfcounter_irq_shutdown(unsigned int irq)
         on_each_cpu(local_rm9k_perfcounter_irq_shutdown, (void *) irq, 0, 1);
 }
 
-
-/*
- * While we ack the interrupt interrupts are disabled and thus we don't need
- * to deal with concurrency issues.  Same for rm9k_cpu_irq_end.
- */
-static void rm9k_cpu_irq_ack(unsigned int irq)
-{
-        mask_rm9k_irq(irq);
-}
-
 static void rm9k_cpu_irq_end(unsigned int irq)
 {
         if (!(irq_desc[irq].status & (IRQ_DISABLED | IRQ_INPROGRESS)))
@@ -107,11 +88,10 @@ static void rm9k_cpu_irq_end(unsigned int irq)
 
 static struct irq_chip rm9k_irq_controller = {
         .typename = "RM9000",
-        .startup = rm9k_cpu_irq_startup,
-        .shutdown = rm9k_cpu_irq_shutdown,
-        .enable = rm9k_cpu_irq_enable,
-        .disable = rm9k_cpu_irq_disable,
-        .ack = rm9k_cpu_irq_ack,
+        .ack = mask_rm9k_irq,
+        .mask = mask_rm9k_irq,
+        .mask_ack = mask_rm9k_irq,
+        .unmask = unmask_rm9k_irq,
         .end = rm9k_cpu_irq_end,
 };
 
@@ -119,9 +99,10 @@ static struct irq_chip rm9k_perfcounter_irq = {
         .typename = "RM9000",
         .startup = rm9k_perfcounter_irq_startup,
         .shutdown = rm9k_perfcounter_irq_shutdown,
-        .enable = rm9k_cpu_irq_enable,
-        .disable = rm9k_cpu_irq_disable,
-        .ack = rm9k_cpu_irq_ack,
+        .ack = mask_rm9k_irq,
+        .mask = mask_rm9k_irq,
+        .mask_ack = mask_rm9k_irq,
+        .unmask = unmask_rm9k_irq,
         .end = rm9k_cpu_irq_end,
 };
 
@@ -135,15 +116,11 @@ void __init rm9k_cpu_irq_init(int base)
 
         clear_c0_intcontrol(0x0000f000);                /* Mask all */
 
-        for (i = base; i < base + 4; i++) {
-                irq_desc[i].status = IRQ_DISABLED;
-                irq_desc[i].action = NULL;
-                irq_desc[i].depth = 1;
-                irq_desc[i].chip = &rm9k_irq_controller;
-        }
+        for (i = base; i < base + 4; i++)
+                set_irq_chip(i, &rm9k_irq_controller);
 
         rm9000_perfcount_irq = base + 1;
-        irq_desc[rm9000_perfcount_irq].chip = &rm9k_perfcounter_irq;
+        set_irq_chip(rm9000_perfcount_irq, &rm9k_perfcounter_irq);
 
         irq_base = base;
 }
diff --git a/arch/mips/kernel/irq.c b/arch/mips/kernel/irq.c
index 9b0e49d63d7b..e997c9454f47 100644
--- a/arch/mips/kernel/irq.c
+++ b/arch/mips/kernel/irq.c
@@ -172,19 +172,6 @@ __setup("nokgdb", nokgdb);
 
 void __init init_IRQ(void)
 {
-        int i;
-
-        for (i = 0; i < NR_IRQS; i++) {
-                irq_desc[i].status  = IRQ_DISABLED;
-                irq_desc[i].action  = NULL;
-                irq_desc[i].depth   = 1;
-                irq_desc[i].chip = &no_irq_chip;
-                spin_lock_init(&irq_desc[i].lock);
-#ifdef CONFIG_MIPS_MT_SMTC
-                irq_hwmask[i] = 0;
-#endif /* CONFIG_MIPS_MT_SMTC */
-        }
-
         arch_init_irq();
 
 #ifdef CONFIG_KGDB
diff --git a/arch/mips/kernel/irq_cpu.c b/arch/mips/kernel/irq_cpu.c
index 9bb21c7f2149..3b7cfa407e87 100644
--- a/arch/mips/kernel/irq_cpu.c
+++ b/arch/mips/kernel/irq_cpu.c
@@ -50,44 +50,6 @@ static inline void mask_mips_irq(unsigned int irq)
         irq_disable_hazard();
 }
 
-static inline void mips_cpu_irq_enable(unsigned int irq)
-{
-        unsigned long flags;
-
-        local_irq_save(flags);
-        unmask_mips_irq(irq);
-        back_to_back_c0_hazard();
-        local_irq_restore(flags);
-}
-
-static void mips_cpu_irq_disable(unsigned int irq)
-{
-        unsigned long flags;
-
-        local_irq_save(flags);
-        mask_mips_irq(irq);
-        back_to_back_c0_hazard();
-        local_irq_restore(flags);
-}
-
-static unsigned int mips_cpu_irq_startup(unsigned int irq)
-{
-        mips_cpu_irq_enable(irq);
-
-        return 0;
-}
-
-#define mips_cpu_irq_shutdown           mips_cpu_irq_disable
-
-/*
- * While we ack the interrupt interrupts are disabled and thus we don't need
- * to deal with concurrency issues.  Same for mips_cpu_irq_end.
- */
-static void mips_cpu_irq_ack(unsigned int irq)
-{
-        mask_mips_irq(irq);
-}
-
 static void mips_cpu_irq_end(unsigned int irq)
 {
         if (!(irq_desc[irq].status & (IRQ_DISABLED | IRQ_INPROGRESS)))
@@ -96,11 +58,10 @@ static void mips_cpu_irq_end(unsigned int irq)
 
 static struct irq_chip mips_cpu_irq_controller = {
         .typename       = "MIPS",
-        .startup        = mips_cpu_irq_startup,
-        .shutdown       = mips_cpu_irq_shutdown,
-        .enable         = mips_cpu_irq_enable,
-        .disable        = mips_cpu_irq_disable,
-        .ack            = mips_cpu_irq_ack,
+        .ack            = mask_mips_irq,
+        .mask           = mask_mips_irq,
+        .mask_ack       = mask_mips_irq,
+        .unmask         = unmask_mips_irq,
         .end            = mips_cpu_irq_end,
 };
 
@@ -110,8 +71,6 @@ static struct irq_chip mips_cpu_irq_controller = {
 
 #define unmask_mips_mt_irq      unmask_mips_irq
 #define mask_mips_mt_irq        mask_mips_irq
-#define mips_mt_cpu_irq_enable  mips_cpu_irq_enable
-#define mips_mt_cpu_irq_disable mips_cpu_irq_disable
 
 static unsigned int mips_mt_cpu_irq_startup(unsigned int irq)
 {
@@ -119,13 +78,11 @@ static unsigned int mips_mt_cpu_irq_startup(unsigned int irq)
 
         clear_c0_cause(0x100 << (irq - mips_cpu_irq_base));
         evpe(vpflags);
-        mips_mt_cpu_irq_enable(irq);
+        unmask_mips_mt_irq(irq);
 
         return 0;
 }
 
-#define mips_mt_cpu_irq_shutdown        mips_mt_cpu_irq_disable
-
 /*
  * While we ack the interrupt interrupts are disabled and thus we don't need
  * to deal with concurrency issues.  Same for mips_cpu_irq_end.
@@ -143,10 +100,10 @@ static void mips_mt_cpu_irq_ack(unsigned int irq)
 static struct irq_chip mips_mt_cpu_irq_controller = {
         .typename       = "MIPS",
         .startup        = mips_mt_cpu_irq_startup,
-        .shutdown       = mips_mt_cpu_irq_shutdown,
-        .enable         = mips_mt_cpu_irq_enable,
-        .disable        = mips_mt_cpu_irq_disable,
         .ack            = mips_mt_cpu_irq_ack,
+        .mask           = mask_mips_mt_irq,
+        .mask_ack       = mips_mt_cpu_irq_ack,
+        .unmask         = unmask_mips_mt_irq,
         .end            = mips_mt_cpu_irq_end,
 };
 
@@ -163,19 +120,11 @@ void __init mips_cpu_irq_init(int irq_base)
          * leave them uninitialized for other processors.
          */
         if (cpu_has_mipsmt)
-                for (i = irq_base; i < irq_base + 2; i++) {
-                        irq_desc[i].status = IRQ_DISABLED;
-                        irq_desc[i].action = NULL;
-                        irq_desc[i].depth = 1;
-                        irq_desc[i].chip = &mips_mt_cpu_irq_controller;
-                }
-
-        for (i = irq_base + 2; i < irq_base + 8; i++) {
-                irq_desc[i].status = IRQ_DISABLED;
-                irq_desc[i].action = NULL;
-                irq_desc[i].depth = 1;
-                irq_desc[i].chip = &mips_cpu_irq_controller;
-        }
+                for (i = irq_base; i < irq_base + 2; i++)
+                        set_irq_chip(i, &mips_mt_cpu_irq_controller);
+
+        for (i = irq_base + 2; i < irq_base + 8; i++)
+                set_irq_chip(i, &mips_cpu_irq_controller);
 
         mips_cpu_irq_base = irq_base;
 }