From 2a606a18cd672a16343d146a126721b34cc6adbd Mon Sep 17 00:00:00 2001 From: Stephane Eranian Date: Tue, 22 Mar 2022 15:15:12 -0700 Subject: ACPI: Add perf low power callback Add an optional callback needed by some PMU features, e.g., AMD BRS, to give a chance to the perf_events code to change its state before a CPU goes to low power and after it comes back. The callback is void when the PERF_NEEDS_LOPWR_CB flag is not set. This flag must be set in arch specific perf_event.h header whenever needed. When not set, there is no impact on the ACPI code. Signed-off-by: Stephane Eranian [peterz: build fix] Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20220322221517.2510440-9-eranian@google.com --- drivers/acpi/acpi_pad.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'drivers/acpi/acpi_pad.c') diff --git a/drivers/acpi/acpi_pad.c b/drivers/acpi/acpi_pad.c index f45979aa2d64..ec0e22a1e25d 100644 --- a/drivers/acpi/acpi_pad.c +++ b/drivers/acpi/acpi_pad.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include @@ -164,6 +165,9 @@ static int power_saving_thread(void *data) tsc_marked_unstable = 1; } local_irq_disable(); + + perf_lopwr_cb(true); + tick_broadcast_enable(); tick_broadcast_enter(); stop_critical_timings(); @@ -172,6 +176,9 @@ static int power_saving_thread(void *data) start_critical_timings(); tick_broadcast_exit(); + + perf_lopwr_cb(false); + local_irq_enable(); if (time_before(expire_time, jiffies)) { -- cgit v1.2.3