[patch 17/66] powerpc: perf: Convert book3s notifier to state machine callbacks

From: Anna-Maria Gleixner
Date: Mon Jul 11 2016 - 08:43:28 EST


From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

Install the callbacks via the state machine and let the core invoke
the callbacks on the already online CPUs.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
Signed-off-by: Anna-Maria Gleixner <anna-maria@xxxxxxxxxxxxx>
---
arch/powerpc/perf/core-book3s.c | 30 +++++++-----------------------
include/linux/cpuhotplug.h | 1 +
2 files changed, 8 insertions(+), 23 deletions(-)

--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -2158,31 +2158,15 @@ static void perf_event_interrupt(struct
irq_exit();
}

-static void power_pmu_setup(int cpu)
+int power_pmu_prepare_cpu(unsigned int cpu)
{
struct cpu_hw_events *cpuhw = &per_cpu(cpu_hw_events, cpu);

- if (!ppmu)
- return;
- memset(cpuhw, 0, sizeof(*cpuhw));
- cpuhw->mmcr[0] = MMCR0_FC;
-}
-
-static int
-power_pmu_notifier(struct notifier_block *self, unsigned long action, void *hcpu)
-{
- unsigned int cpu = (long)hcpu;
-
- switch (action & ~CPU_TASKS_FROZEN) {
- case CPU_UP_PREPARE:
- power_pmu_setup(cpu);
- break;
-
- default:
- break;
+ if (ppmu) {
+ memset(cpuhw, 0, sizeof(*cpuhw));
+ cpuhw->mmcr[0] = MMCR0_FC;
}
-
- return NOTIFY_OK;
+ return 0;
}

int register_power_pmu(struct power_pmu *pmu)
@@ -2205,7 +2189,7 @@ int register_power_pmu(struct power_pmu
#endif /* CONFIG_PPC64 */

perf_pmu_register(&power_pmu, "cpu", PERF_TYPE_RAW);
- perf_cpu_notifier(power_pmu_notifier);
-
+ cpuhp_setup_state(CPUHP_PERF_POWER, "PERF_POWER",
+ power_pmu_prepare_cpu, NULL);
return 0;
}
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -10,6 +10,7 @@ enum cpuhp_state {
CPUHP_PERF_X86_AMD_UNCORE_PREP,
CPUHP_PERF_X86_RAPL_PREP,
CPUHP_PERF_BFIN,
+ CPUHP_PERF_POWER,
CPUHP_NOTIFY_PREPARE,
CPUHP_BRINGUP_CPU,
CPUHP_AP_IDLE_DEAD,