[RESEND PATCH V5 1/8] powerpc: Free up the slot ofPPC_MSG_CALL_FUNC_SINGLE IPI message

From: Preeti U Murthy
Date: Wed Jan 22 2014 - 02:11:48 EST


From: Srivatsa S. Bhat <srivatsa.bhat@xxxxxxxxxxxxxxxxxx>

The IPI handlers for both PPC_MSG_CALL_FUNC and PPC_MSG_CALL_FUNC_SINGLE map
to a common implementation - generic_smp_call_function_single_interrupt(). So,
we can consolidate them and save one of the IPI message slots, (which are
precious on powerpc, since only 4 of those slots are available).

So, implement the functionality of PPC_MSG_CALL_FUNC_SINGLE using
PPC_MSG_CALL_FUNC itself and release its IPI message slot, so that it can be
used for something else in the future, if desired.

Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Preeti U. Murthy <preeti@xxxxxxxxxxxxxxxxxx>
Acked-by: Geoff Levand <geoff@xxxxxxxxxxxxx> [For the PS3 part]
---

arch/powerpc/include/asm/smp.h | 2 +-
arch/powerpc/kernel/smp.c | 12 +++++-------
arch/powerpc/platforms/cell/interrupt.c | 2 +-
arch/powerpc/platforms/ps3/smp.c | 2 +-
4 files changed, 8 insertions(+), 10 deletions(-)

diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h
index 084e080..9f7356b 100644
--- a/arch/powerpc/include/asm/smp.h
+++ b/arch/powerpc/include/asm/smp.h
@@ -120,7 +120,7 @@ extern int cpu_to_core_id(int cpu);
* in /proc/interrupts will be wrong!!! --Troy */
#define PPC_MSG_CALL_FUNCTION 0
#define PPC_MSG_RESCHEDULE 1
-#define PPC_MSG_CALL_FUNC_SINGLE 2
+#define PPC_MSG_UNUSED 2
#define PPC_MSG_DEBUGGER_BREAK 3

/* for irq controllers that have dedicated ipis per message (4) */
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index ac2621a..ee7d76b 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -145,9 +145,9 @@ static irqreturn_t reschedule_action(int irq, void *data)
return IRQ_HANDLED;
}

-static irqreturn_t call_function_single_action(int irq, void *data)
+static irqreturn_t unused_action(int irq, void *data)
{
- generic_smp_call_function_single_interrupt();
+ /* This slot is unused and hence available for use, if needed */
return IRQ_HANDLED;
}

@@ -168,14 +168,14 @@ static irqreturn_t debug_ipi_action(int irq, void *data)
static irq_handler_t smp_ipi_action[] = {
[PPC_MSG_CALL_FUNCTION] = call_function_action,
[PPC_MSG_RESCHEDULE] = reschedule_action,
- [PPC_MSG_CALL_FUNC_SINGLE] = call_function_single_action,
+ [PPC_MSG_UNUSED] = unused_action,
[PPC_MSG_DEBUGGER_BREAK] = debug_ipi_action,
};

const char *smp_ipi_name[] = {
[PPC_MSG_CALL_FUNCTION] = "ipi call function",
[PPC_MSG_RESCHEDULE] = "ipi reschedule",
- [PPC_MSG_CALL_FUNC_SINGLE] = "ipi call function single",
+ [PPC_MSG_UNUSED] = "ipi unused",
[PPC_MSG_DEBUGGER_BREAK] = "ipi debugger",
};

@@ -251,8 +251,6 @@ irqreturn_t smp_ipi_demux(void)
generic_smp_call_function_interrupt();
if (all & IPI_MESSAGE(PPC_MSG_RESCHEDULE))
scheduler_ipi();
- if (all & IPI_MESSAGE(PPC_MSG_CALL_FUNC_SINGLE))
- generic_smp_call_function_single_interrupt();
if (all & IPI_MESSAGE(PPC_MSG_DEBUGGER_BREAK))
debug_ipi_action(0, NULL);
} while (info->messages);
@@ -280,7 +278,7 @@ EXPORT_SYMBOL_GPL(smp_send_reschedule);

void arch_send_call_function_single_ipi(int cpu)
{
- do_message_pass(cpu, PPC_MSG_CALL_FUNC_SINGLE);
+ do_message_pass(cpu, PPC_MSG_CALL_FUNCTION);
}

void arch_send_call_function_ipi_mask(const struct cpumask *mask)
diff --git a/arch/powerpc/platforms/cell/interrupt.c b/arch/powerpc/platforms/cell/interrupt.c
index 2d42f3b..adf3726 100644
--- a/arch/powerpc/platforms/cell/interrupt.c
+++ b/arch/powerpc/platforms/cell/interrupt.c
@@ -215,7 +215,7 @@ void iic_request_IPIs(void)
{
iic_request_ipi(PPC_MSG_CALL_FUNCTION);
iic_request_ipi(PPC_MSG_RESCHEDULE);
- iic_request_ipi(PPC_MSG_CALL_FUNC_SINGLE);
+ iic_request_ipi(PPC_MSG_UNUSED);
iic_request_ipi(PPC_MSG_DEBUGGER_BREAK);
}

diff --git a/arch/powerpc/platforms/ps3/smp.c b/arch/powerpc/platforms/ps3/smp.c
index 4b35166..00d1a7c 100644
--- a/arch/powerpc/platforms/ps3/smp.c
+++ b/arch/powerpc/platforms/ps3/smp.c
@@ -76,7 +76,7 @@ static int __init ps3_smp_probe(void)

BUILD_BUG_ON(PPC_MSG_CALL_FUNCTION != 0);
BUILD_BUG_ON(PPC_MSG_RESCHEDULE != 1);
- BUILD_BUG_ON(PPC_MSG_CALL_FUNC_SINGLE != 2);
+ BUILD_BUG_ON(PPC_MSG_UNUSED != 2);
BUILD_BUG_ON(PPC_MSG_DEBUGGER_BREAK != 3);

for (i = 0; i < MSG_COUNT; i++) {

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