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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