diff options
| -rw-r--r-- | arch/x86/events/amd/brs.c | 33 | ||||
| -rw-r--r-- | arch/x86/events/amd/core.c | 4 | ||||
| -rw-r--r-- | arch/x86/events/perf_event.h | 1 | ||||
| -rw-r--r-- | arch/x86/include/asm/perf_event.h | 23 |
4 files changed, 61 insertions, 0 deletions
diff --git a/arch/x86/events/amd/brs.c b/arch/x86/events/amd/brs.c index 40461c3ce714..895c82165d85 100644 --- a/arch/x86/events/amd/brs.c +++ b/arch/x86/events/amd/brs.c @@ -7,6 +7,7 @@ * Contributed by Stephane Eranian <eranian@google.com> */ #include <linux/kernel.h> +#include <linux/jump_label.h> #include <asm/msr.h> #include <asm/cpufeature.h> @@ -329,3 +330,35 @@ void amd_pmu_brs_sched_task(struct perf_event_context *ctx, bool sched_in) if (sched_in) amd_brs_poison_buffer(); } + +/* + * called from ACPI processor_idle.c or acpi_pad.c + * with interrupts disabled + */ +void perf_amd_brs_lopwr_cb(bool lopwr_in) +{ + struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events); + union amd_debug_extn_cfg cfg; + + /* + * on mwait in, we may end up in non C0 state. + * we must disable branch sampling to avoid holding the NMI + * for too long. We disable it in hardware but we + * keep the state in cpuc, so we can re-enable. + * + * The hardware will deliver the NMI if needed when brsmen cleared + */ + if (cpuc->brs_active) { + cfg.val = get_debug_extn_cfg(); + cfg.brsmen = !lopwr_in; + set_debug_extn_cfg(cfg.val); + } +} + +DEFINE_STATIC_CALL_NULL(perf_lopwr_cb, perf_amd_brs_lopwr_cb); +EXPORT_STATIC_CALL_TRAMP_GPL(perf_lopwr_cb); + +void __init amd_brs_lopwr_init(void) +{ + static_call_update(perf_lopwr_cb, perf_amd_brs_lopwr_cb); +} diff --git a/arch/x86/events/amd/core.c b/arch/x86/events/amd/core.c index f7bce8364fe4..8e1e818f8195 100644 --- a/arch/x86/events/amd/core.c +++ b/arch/x86/events/amd/core.c @@ -1,5 +1,6 @@ // SPDX-License-Identifier: GPL-2.0-only #include <linux/perf_event.h> +#include <linux/jump_label.h> #include <linux/export.h> #include <linux/types.h> #include <linux/init.h> @@ -1225,6 +1226,9 @@ static int __init amd_core_pmu_init(void) /* * put_event_constraints callback same as Fam17h, set above */ + + /* branch sampling must be stopped when entering low power */ + amd_brs_lopwr_init(); } x86_pmu.attr_update = amd_attr_update; diff --git a/arch/x86/events/perf_event.h b/arch/x86/events/perf_event.h index ef27aee04b13..3b0324584da3 100644 --- a/arch/x86/events/perf_event.h +++ b/arch/x86/events/perf_event.h @@ -1226,6 +1226,7 @@ void amd_brs_enable(void); void amd_brs_enable_all(void); void amd_brs_disable_all(void); void amd_brs_drain(void); +void amd_brs_lopwr_init(void); void amd_brs_disable_all(void); int amd_brs_setup_filter(struct perf_event *event); void amd_brs_reset(void); diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h index 58d9e4b1fa0a..8199fc5a37ea 100644 --- a/arch/x86/include/asm/perf_event.h +++ b/arch/x86/include/asm/perf_event.h @@ -2,6 +2,8 @@ #ifndef _ASM_X86_PERF_EVENT_H #define _ASM_X86_PERF_EVENT_H +#include <linux/static_call.h> + /* * Performance event hw details: */ @@ -513,6 +515,27 @@ static inline void intel_pt_handle_vmx(int on) #if defined(CONFIG_PERF_EVENTS) && defined(CONFIG_CPU_SUP_AMD) extern void amd_pmu_enable_virt(void); extern void amd_pmu_disable_virt(void); + +#if defined(CONFIG_PERF_EVENTS_AMD_BRS) + +#define PERF_NEEDS_LOPWR_CB 1 + +/* + * architectural low power callback impacts + * drivers/acpi/processor_idle.c + * drivers/acpi/acpi_pad.c + */ +extern void perf_amd_brs_lopwr_cb(bool lopwr_in); + +DECLARE_STATIC_CALL(perf_lopwr_cb, perf_amd_brs_lopwr_cb); + +static inline void perf_lopwr_cb(bool lopwr_in) +{ + static_call_mod(perf_lopwr_cb)(lopwr_in); +} + +#endif /* PERF_NEEDS_LOPWR_CB */ + #else static inline void amd_pmu_enable_virt(void) { } static inline void amd_pmu_disable_virt(void) { } |