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| author | Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> | 2013-09-04 10:55:17 +0100 |
|---|---|---|
| committer | Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> | 2013-12-16 17:17:35 +0000 |
| commit | 1f85008e74768a88e1ddb96cc1fe45bb2378166c (patch) | |
| tree | 7ef3e417c838d91b73ead8f7c0e2f83e6e79739b /arch/arm64/kernel/smp.c | |
| parent | 60fc6942f6ac124503ed7f8506736a8f56b4ca7e (diff) | |
| download | blackbird-obmc-linux-1f85008e74768a88e1ddb96cc1fe45bb2378166c.tar.gz blackbird-obmc-linux-1f85008e74768a88e1ddb96cc1fe45bb2378166c.zip | |
arm64: enable generic clockevent broadcast
On platforms with power management capabilities, timers that are shut
down when a CPU enters deep C-states must be emulated using an always-on
timer and a timer IPI to relay the timer IRQ to target CPUs on an SMP
system.
This patch enables the generic clockevents broadcast infrastructure for
arm64, by providing the required Kconfig entries and adding the timer
IPI infrastructure.
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Diffstat (limited to 'arch/arm64/kernel/smp.c')
| -rw-r--r-- | arch/arm64/kernel/smp.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index a0c2ca602cf8..0b8c859e744f 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -61,6 +61,7 @@ enum ipi_msg_type { IPI_CALL_FUNC, IPI_CALL_FUNC_SINGLE, IPI_CPU_STOP, + IPI_TIMER, }; /* @@ -447,6 +448,7 @@ static const char *ipi_types[NR_IPI] = { S(IPI_CALL_FUNC, "Function call interrupts"), S(IPI_CALL_FUNC_SINGLE, "Single function call interrupts"), S(IPI_CPU_STOP, "CPU stop interrupts"), + S(IPI_TIMER, "Timer broadcast interrupts"), }; void show_ipi_list(struct seq_file *p, int prec) @@ -532,6 +534,14 @@ void handle_IPI(int ipinr, struct pt_regs *regs) irq_exit(); break; +#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST + case IPI_TIMER: + irq_enter(); + tick_receive_broadcast(); + irq_exit(); + break; +#endif + default: pr_crit("CPU%u: Unknown IPI message 0x%x\n", cpu, ipinr); break; @@ -544,6 +554,13 @@ void smp_send_reschedule(int cpu) smp_cross_call(cpumask_of(cpu), IPI_RESCHEDULE); } +#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST +void tick_broadcast(const struct cpumask *mask) +{ + smp_cross_call(mask, IPI_TIMER); +} +#endif + void smp_send_stop(void) { unsigned long timeout; |
