From 402d9a1e02f7215628f13b7c80ff3e98c3a0cadc Mon Sep 17 00:00:00 2001 From: "Srivatsa S. Bhat" Date: Wed, 26 Feb 2014 05:37:29 +0530 Subject: powerpc: Free up the slot of PPC_MSG_CALL_FUNC_SINGLE IPI message 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 Signed-off-by: Preeti U. Murthy Acked-by: Geoff Levand [For the PS3 part] Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/platforms/ps3/smp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/powerpc/platforms/ps3') diff --git a/arch/powerpc/platforms/ps3/smp.c b/arch/powerpc/platforms/ps3/smp.c index 4b35166229fe..00d1a7c2a5a4 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++) { -- cgit v1.2.3 From 1b67bee129a36c22c17186cc2a9981678e9323ee Mon Sep 17 00:00:00 2001 From: "Srivatsa S. Bhat" Date: Wed, 26 Feb 2014 05:37:43 +0530 Subject: powerpc: Implement tick broadcast IPI as a fixed IPI message For scalability and performance reasons, we want the tick broadcast IPIs to be handled as efficiently as possible. Fixed IPI messages are one of the most efficient mechanisms available - they are faster than the smp_call_function mechanism because the IPI handlers are fixed and hence they don't involve costly operations such as adding IPI handlers to the target CPU's function queue, acquiring locks for synchronization etc. Luckily we have an unused IPI message slot, so use that to implement tick broadcast IPIs efficiently. Signed-off-by: Srivatsa S. Bhat [Functions renamed to tick_broadcast* and Changelog modified by Preeti U. Murthy] Signed-off-by: Preeti U. Murthy Acked-by: Geoff Levand [For the PS3 part] Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/include/asm/smp.h | 2 +- arch/powerpc/include/asm/time.h | 1 + arch/powerpc/kernel/smp.c | 21 +++++++++++++++++---- arch/powerpc/kernel/time.c | 5 +++++ arch/powerpc/platforms/cell/interrupt.c | 2 +- arch/powerpc/platforms/ps3/smp.c | 2 +- 6 files changed, 26 insertions(+), 7 deletions(-) (limited to 'arch/powerpc/platforms/ps3') diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h index 9f7356bf6482..ff51046b6466 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_UNUSED 2 +#define PPC_MSG_TICK_BROADCAST 2 #define PPC_MSG_DEBUGGER_BREAK 3 /* for irq controllers that have dedicated ipis per message (4) */ diff --git a/arch/powerpc/include/asm/time.h b/arch/powerpc/include/asm/time.h index c1f267694acb..1d428e6007ca 100644 --- a/arch/powerpc/include/asm/time.h +++ b/arch/powerpc/include/asm/time.h @@ -28,6 +28,7 @@ extern struct clock_event_device decrementer_clockevent; struct rtc_time; extern void to_tm(int tim, struct rtc_time * tm); extern void GregorianDay(struct rtc_time *tm); +extern void tick_broadcast_ipi_handler(void); extern void generic_calibrate_decr(void); diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index ee7d76bfcb4c..e2a4232c5871 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -35,6 +35,7 @@ #include #include #include +#include #include #include #include @@ -145,9 +146,9 @@ static irqreturn_t reschedule_action(int irq, void *data) return IRQ_HANDLED; } -static irqreturn_t unused_action(int irq, void *data) +static irqreturn_t tick_broadcast_ipi_action(int irq, void *data) { - /* This slot is unused and hence available for use, if needed */ + tick_broadcast_ipi_handler(); return IRQ_HANDLED; } @@ -168,14 +169,14 @@ 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_UNUSED] = unused_action, + [PPC_MSG_TICK_BROADCAST] = tick_broadcast_ipi_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_UNUSED] = "ipi unused", + [PPC_MSG_TICK_BROADCAST] = "ipi tick-broadcast", [PPC_MSG_DEBUGGER_BREAK] = "ipi debugger", }; @@ -251,6 +252,8 @@ 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_TICK_BROADCAST)) + tick_broadcast_ipi_handler(); if (all & IPI_MESSAGE(PPC_MSG_DEBUGGER_BREAK)) debug_ipi_action(0, NULL); } while (info->messages); @@ -289,6 +292,16 @@ void arch_send_call_function_ipi_mask(const struct cpumask *mask) do_message_pass(cpu, PPC_MSG_CALL_FUNCTION); } +#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST +void tick_broadcast(const struct cpumask *mask) +{ + unsigned int cpu; + + for_each_cpu(cpu, mask) + do_message_pass(cpu, PPC_MSG_TICK_BROADCAST); +} +#endif + #if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC) void smp_send_debugger_break(void) { diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c index b3dab20acf34..3ff97dbb35be 100644 --- a/arch/powerpc/kernel/time.c +++ b/arch/powerpc/kernel/time.c @@ -825,6 +825,11 @@ static void decrementer_set_mode(enum clock_event_mode mode, decrementer_set_next_event(DECREMENTER_MAX, dev); } +/* Interrupt handler for the timer broadcast IPI */ +void tick_broadcast_ipi_handler(void) +{ +} + static void register_decrementer_clockevent(int cpu) { struct clock_event_device *dec = &per_cpu(decrementers, cpu); diff --git a/arch/powerpc/platforms/cell/interrupt.c b/arch/powerpc/platforms/cell/interrupt.c index adf372606a1c..8a106b4172e0 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_UNUSED); + iic_request_ipi(PPC_MSG_TICK_BROADCAST); iic_request_ipi(PPC_MSG_DEBUGGER_BREAK); } diff --git a/arch/powerpc/platforms/ps3/smp.c b/arch/powerpc/platforms/ps3/smp.c index 00d1a7c2a5a4..b358bec6c8cb 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_UNUSED != 2); + BUILD_BUG_ON(PPC_MSG_TICK_BROADCAST != 2); BUILD_BUG_ON(PPC_MSG_DEBUGGER_BREAK != 3); for (i = 0; i < MSG_COUNT; i++) { -- cgit v1.2.3