[PATCH] ARM: smp: Formalize an IPI for wakeup

From: Stephen Boyd
Date: Mon Sep 10 2012 - 18:24:23 EST


Remove the offset from ipi_msg_type and assume that SGI0 is the
wakeup interrupt now that all WFI hotplug users call
gic_raise_softirq() with 0 instead of 1. This allows us to
track how many wakeup interrupts are sent and also removes the
unknown IPI printk message for WFI hotplug based systems.

Reviewed-by: Nicolas Pitre <nico@xxxxxxxxxx>
Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
---
arch/arm/include/asm/hardirq.h | 2 +-
arch/arm/kernel/smp.c | 13 +++++++++----
2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/arch/arm/include/asm/hardirq.h b/arch/arm/include/asm/hardirq.h
index 436e60b..2740c2a2 100644
--- a/arch/arm/include/asm/hardirq.h
+++ b/arch/arm/include/asm/hardirq.h
@@ -5,7 +5,7 @@
#include <linux/threads.h>
#include <asm/irq.h>

-#define NR_IPI 5
+#define NR_IPI 6

typedef struct {
unsigned int __softirq_pending;
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index ebd8ad2..d98c37e 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -51,7 +51,8 @@
struct secondary_data secondary_data;

enum ipi_msg_type {
- IPI_TIMER = 2,
+ IPI_WAKEUP,
+ IPI_TIMER,
IPI_RESCHEDULE,
IPI_CALL_FUNC,
IPI_CALL_FUNC_SINGLE,
@@ -347,7 +348,8 @@ void arch_send_call_function_single_ipi(int cpu)
}

static const char *ipi_types[NR_IPI] = {
-#define S(x,s) [x - IPI_TIMER] = s
+#define S(x,s) [x] = s
+ S(IPI_WAKEUP, "CPU wakeup interrupts"),
S(IPI_TIMER, "Timer broadcast interrupts"),
S(IPI_RESCHEDULE, "Rescheduling interrupts"),
S(IPI_CALL_FUNC, "Function call interrupts"),
@@ -500,10 +502,13 @@ void handle_IPI(int ipinr, struct pt_regs *regs)
unsigned int cpu = smp_processor_id();
struct pt_regs *old_regs = set_irq_regs(regs);

- if (ipinr >= IPI_TIMER && ipinr < IPI_TIMER + NR_IPI)
- __inc_irq_stat(cpu, ipi_irqs[ipinr - IPI_TIMER]);
+ if (ipinr < NR_IPI)
+ __inc_irq_stat(cpu, ipi_irqs[ipinr]);

switch (ipinr) {
+ case IPI_WAKEUP:
+ break;
+
case IPI_TIMER:
irq_enter();
ipi_timer();
--
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