On parisc, we have the issue that function call pointers are hugely
expensive, so we'd like to minimise their use in the interrupts.
Unfortunately, this involves directly calling the ack/eoi functions
instead of indirecting.  To permit this without losing the advantages of
centrally managed irq code, I introduced template builders for irq
handlers.  This allows us to construct special handlers on parisc that
don't indirect through function call pointers.

Signed-off-by: James Bottomley <[EMAIL PROTECTED]>

Some fixes by Andrew Morton and Matthew Wilcox due to rapid code flux
in this area.

Signed-off-by: Matthew Wilcox <[EMAIL PROTECTED]>
---
 kernel/irq/chip.c |  163 ++++++++++++++++++++++++++++++++++-------------------
 1 files changed, 104 insertions(+), 59 deletions(-)

diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index ebfd24a..1b18c5c 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -17,6 +17,87 @@
 
 #include "internals.h"
 
+/* Helpers for constructing IRQ handlers */
+
+#ifdef CONFIG_SMP
+#define HANDLE_PERCPU_IRQ(NAME, ACK, EOI)                              \
+void fastcall                                                          \
+handle_percpu_irq##NAME(unsigned int irq, struct irq_desc *desc)       \
+{                                                                      \
+       irqreturn_t action_ret;                                         \
+                                                                       \
+       kstat_this_cpu.irqs[irq]++;                                     \
+                                                                       \
+       ACK(desc, irq);                                                 \
+                                                                       \
+       action_ret = handle_IRQ_event(irq, desc->action);               \
+       if (!noirqdebug)                                                \
+               note_interrupt(irq, desc, action_ret);                  \
+                                                                       \
+       EOI(desc,irq);                                                  \
+}
+#else
+#define HANDLE_PERCPU_IRQ(NAME, ACK, END)
+#endif /* CONFIG_SMP */
+
+#define HANDLE_LEVEL_IRQ(NAME, MASK, UNMASK)                           \
+void fastcall                                                          \
+handle_level_irq##NAME(unsigned int irq, struct irq_desc *desc)                
\
+{                                                                      \
+       unsigned int cpu = smp_processor_id();                          \
+       struct irqaction *action;                                       \
+       irqreturn_t action_ret;                                         \
+                                                                       \
+       spin_lock(&desc->lock);                                         \
+       MASK(desc, irq);                                                \
+                                                                       \
+       if (unlikely(desc->status & IRQ_INPROGRESS))                    \
+               goto out_unlock;                                        \
+       desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);                    \
+       kstat_cpu(cpu).irqs[irq]++;                                     \
+                                                                       \
+       /*                                                              \
+        * If its disabled or no action available                       \
+        * keep it masked and get out of here                           \
+        */                                                             \
+       action = desc->action;                                          \
+       if (unlikely(!action || (desc->status & IRQ_DISABLED))) {       \
+               desc->status |= IRQ_PENDING;                            \
+               goto out_unlock;                                        \
+       }                                                               \
+                                                                       \
+       desc->status |= IRQ_INPROGRESS;                                 \
+       desc->status &= ~IRQ_PENDING;                                   \
+       spin_unlock(&desc->lock);                                       \
+                                                                       \
+       action_ret = handle_IRQ_event(irq, action);                     \
+       if (!noirqdebug)                                                \
+               note_interrupt(irq, desc, action_ret);                  \
+                                                                       \
+       spin_lock(&desc->lock);                                         \
+       desc->status &= ~IRQ_INPROGRESS;                                \
+       UNMASK(desc,irq);                                               \
+out_unlock:                                                            \
+       spin_unlock(&desc->lock);                                       \
+}
+
+#define HANDLE_SPECIFIC_IRQ(NAME, ACK, EOI, HANDLER)                   \
+void fastcall                                                          \
+handle_specific_irq##NAME(unsigned int irq, struct irq_desc *desc)     \
+{                                                                      \
+       irqreturn_t action_ret;                                         \
+                                                                       \
+       kstat_this_cpu.irqs[irq]++;                                     \
+                                                                       \
+       ACK(desc, irq);                                                 \
+                                                                       \
+       action_ret = HANDLER(irq, desc->action->dev_id);                \
+       if (!noirqdebug)                                                \
+               note_interrupt(irq, desc, action_ret);                  \
+                                                                       \
+       EOI(desc,irq);                                                  \
+}
+
 /**
  *     dynamic_irq_init - initialize a dynamically allocated irq
  *     @irq:   irq number to initialize
@@ -247,6 +328,24 @@ static inline void mask_ack_irq(struct i
        }
 }
 
+static inline void unmask_enabled_irq(struct irq_desc *desc, int irq)
+{
+       if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask)
+               desc->chip->unmask(irq);
+}
+
+static inline void ack_irq(struct irq_desc *desc, int irq)
+{
+       if (desc->chip->ack)
+               desc->chip->ack(irq);
+}
+
+static inline void eoi_irq(struct irq_desc *desc, int irq)
+{
+       if (desc->chip->eoi)
+               desc->chip->eoi(irq);
+}
+
 /**
  *     handle_simple_irq - Simple and software-decoded IRQs.
  *     @irq:   the interrupt number
@@ -300,46 +399,7 @@ out_unlock:
  *     it after the associated handler has acknowledged the device, so the
  *     interrupt line is back to inactive.
  */
-void fastcall
-handle_level_irq(unsigned int irq, struct irq_desc *desc)
-{
-       unsigned int cpu = smp_processor_id();
-       struct irqaction *action;
-       irqreturn_t action_ret;
-
-       spin_lock(&desc->lock);
-       mask_ack_irq(desc, irq);
-
-       if (unlikely(desc->status & IRQ_INPROGRESS))
-               goto out_unlock;
-       desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
-       kstat_cpu(cpu).irqs[irq]++;
-
-       /*
-        * If its disabled or no action available
-        * keep it masked and get out of here
-        */
-       action = desc->action;
-       if (unlikely(!action || (desc->status & IRQ_DISABLED))) {
-               desc->status |= IRQ_PENDING;
-               goto out_unlock;
-       }
-
-       desc->status |= IRQ_INPROGRESS;
-       desc->status &= ~IRQ_PENDING;
-       spin_unlock(&desc->lock);
-
-       action_ret = handle_IRQ_event(irq, action);
-       if (!noirqdebug)
-               note_interrupt(irq, desc, action_ret);
-
-       spin_lock(&desc->lock);
-       desc->status &= ~IRQ_INPROGRESS;
-       if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask)
-               desc->chip->unmask(irq);
-out_unlock:
-       spin_unlock(&desc->lock);
-}
+HANDLE_LEVEL_IRQ(, mask_ack_irq, unmask_enabled_irq)
 
 /**
  *     handle_fasteoi_irq - irq handler for transparent controllers
@@ -472,7 +532,6 @@ out_unlock:
        spin_unlock(&desc->lock);
 }
 
-#ifdef CONFIG_SMP
 /**
  *     handle_percpu_IRQ - Per CPU local irq handler
  *     @irq:   the interrupt number
@@ -480,25 +539,11 @@ out_unlock:
  *
  *     Per CPU interrupts on SMP machines without locking requirements
  */
-void fastcall
-handle_percpu_irq(unsigned int irq, struct irq_desc *desc)
-{
-       irqreturn_t action_ret;
-
-       kstat_this_cpu.irqs[irq]++;
-
-       if (desc->chip->ack)
-               desc->chip->ack(irq);
+HANDLE_PERCPU_IRQ(, ack_irq, eoi_irq)
 
-       action_ret = handle_IRQ_event(irq, desc->action);
-       if (!noirqdebug)
-               note_interrupt(irq, desc, action_ret);
-
-       if (desc->chip->eoi)
-               desc->chip->eoi(irq);
-}
-
-#endif /* CONFIG_SMP */
+#ifdef ARCH_HAS_IRQ_HANDLERS
+#include <asm/irq-handlers.h>
+#endif
 
 void
 __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained,
-- 
1.4.3.3

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