On IA64, the timer interrupt is not (always?) zero as it is on x86 platforms. Also, the timer interrupt is CPU-local. Two things need to be changed to make the irqpoll option make also working on IA64:
o Call note_interrupt() also on CPU-local interrupts in __do_IRQ().
o Set a variable timer_irq to the value of the timer interrupt
after the timer interrupt has been registered and assigned.
That requires changes in Linux-generic files. The default of timer_irq is 0, so
the patch doesn't break i386/x86_64. However, other platforms also may also
have a timer interrupt non-equal to zero, so they can also use the new
set_timer_interrupt() function.
The patch is against 2.6.21-rc4. Please give me your input how to improve
the way it's done if you don't like the way I did the change. irqpoll is
required to work with kdump in some situations and that's why I discovered
that kdump doesn't work on that platform (HP rx2660).
Signed-off-by: Bernhard Walle <[EMAIL PROTECTED]>
---
arch/ia64/kernel/irq_ia64.c | 6 +++++-
arch/ia64/kernel/time.c | 6 +++++-
include/asm-ia64/hw_irq.h | 2 +-
include/linux/irq.h | 3 +++
kernel/irq/handle.c | 2 ++
kernel/irq/spurious.c | 10 +++++++++-
6 files changed, 25 insertions(+), 4 deletions(-)
Index: mainline-msi-init/arch/ia64/kernel/irq_ia64.c
===================================================================
--- mainline-msi-init.orig/arch/ia64/kernel/irq_ia64.c
+++ mainline-msi-init/arch/ia64/kernel/irq_ia64.c
@@ -280,11 +280,12 @@ static struct irqaction resched_irqactio
};
#endif
-void
+int
register_percpu_irq (ia64_vector vec, struct irqaction *action)
{
irq_desc_t *desc;
unsigned int irq;
+ int first_match = -1;
for (irq = 0; irq < NR_IRQS; ++irq)
if (irq_to_vector(irq) == vec) {
@@ -293,7 +294,10 @@ register_percpu_irq (ia64_vector vec, st
desc->chip = &irq_type_ia64_lsapic;
if (action)
setup_irq(irq, action);
+ first_match = irq;
}
+
+ return first_match;
}
void __init
Index: mainline-msi-init/arch/ia64/kernel/time.c
===================================================================
--- mainline-msi-init.orig/arch/ia64/kernel/time.c
+++ mainline-msi-init/arch/ia64/kernel/time.c
@@ -247,7 +247,11 @@ void __devinit ia64_disable_timer(void)
void __init
time_init (void)
{
- register_percpu_irq(IA64_TIMER_VECTOR, &timer_irqaction);
+ int timer_irq;
+
+ timer_irq = register_percpu_irq(IA64_TIMER_VECTOR, &timer_irqaction);
+ set_timer_interrupt(timer_irq);
+
efi_gettimeofday(&xtime);
ia64_init_itm();
Index: mainline-msi-init/include/linux/irq.h
===================================================================
--- mainline-msi-init.orig/include/linux/irq.h
+++ mainline-msi-init/include/linux/irq.h
@@ -272,6 +272,9 @@ static inline int irq_balancing_disabled
/* Handle irq action chains: */
extern int handle_IRQ_event(unsigned int irq, struct irqaction *action);
+/* sets the timer interrupt number for irqpoll handling
(kernel/irq/spurious.c) */
+extern void set_timer_interrupt(unsigned int irq);
+
/*
* Built-in IRQ handlers for various IRQ types,
* callable via desc->chip->handle_irq()
Index: mainline-msi-init/kernel/irq/spurious.c
===================================================================
--- mainline-msi-init.orig/kernel/irq/spurious.c
+++ mainline-msi-init/kernel/irq/spurious.c
@@ -12,6 +12,7 @@
#include <linux/interrupt.h>
static int irqfixup __read_mostly;
+static unsigned int timer_irq __read_mostly;
/*
* Recovery handler for misrouted interrupts.
@@ -146,7 +147,7 @@ void note_interrupt(unsigned int irq, st
if (unlikely(irqfixup)) {
/* Don't punish working computers */
- if ((irqfixup == 2 && irq == 0) || action_ret == IRQ_NONE) {
+ if ((irqfixup == 2 && irq == timer_irq) || action_ret ==
IRQ_NONE) {
int ok = misrouted_irq(irq);
if (action_ret == IRQ_NONE)
desc->irqs_unhandled -= ok;
@@ -174,6 +175,13 @@ void note_interrupt(unsigned int irq, st
desc->irqs_unhandled = 0;
}
+
+void set_timer_interrupt(unsigned int irq)
+{
+ timer_irq = irq;
+}
+EXPORT_SYMBOL_GPL(set_timer_interrupt);
+
int noirqdebug __read_mostly;
int noirqdebug_setup(char *str)
Index: mainline-msi-init/include/asm-ia64/hw_irq.h
===================================================================
--- mainline-msi-init.orig/include/asm-ia64/hw_irq.h
+++ mainline-msi-init/include/asm-ia64/hw_irq.h
@@ -95,7 +95,7 @@ extern int assign_irq_vector (int irq);
extern void free_irq_vector (int vector);
extern int reserve_irq_vector (int vector);
extern void ia64_send_ipi (int cpu, int vector, int delivery_mode, int
redirect);
-extern void register_percpu_irq (ia64_vector vec, struct irqaction *action);
+extern int register_percpu_irq (ia64_vector vec, struct irqaction *action);
static inline void ia64_resend_irq(unsigned int vector)
{
Index: mainline-msi-init/kernel/irq/handle.c
===================================================================
--- mainline-msi-init.orig/kernel/irq/handle.c
+++ mainline-msi-init/kernel/irq/handle.c
@@ -180,6 +180,8 @@ fastcall unsigned int __do_IRQ(unsigned
if (desc->chip->ack)
desc->chip->ack(irq);
action_ret = handle_IRQ_event(irq, desc->action);
+ if (!noirqdebug)
+ note_interrupt(irq, desc, action_ret);
desc->chip->end(irq);
return 1;
}
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