[PATCH v3 01/51] x86/perf/amd: Remove tracing from perf_lopwr_cb()
From: Peter Zijlstra <peterz@infradead.org>
Date: 2023-01-12 20:04:10
Also in:
linux-acpi, linux-alpha, linux-arch, linux-arm-msm, linux-clk, linux-m68k, linux-mips, linux-mm, linux-omap, linux-perf-users, linux-pm, linux-riscv, linux-s390, linux-samsung-soc, linux-sh, linux-tegra, linux-um, linuxppc-dev, lkml, loongarch, sparclinux, virtualization
The perf_lopwr_cb() is called from the idle routines; there is no RCU there, we must not enter tracing. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Rafael J. Wysocki <redacted> Acked-by: Frederic Weisbecker <frederic@kernel.org> Tested-by: Tony Lindgren <tony@atomide.com> Tested-by: Ulf Hansson <redacted> --- arch/x86/events/amd/brs.c | 13 +++++-------- arch/x86/include/asm/perf_event.h | 2 +- 2 files changed, 6 insertions(+), 9 deletions(-)
--- a/arch/x86/events/amd/brs.c
+++ b/arch/x86/events/amd/brs.c@@ -41,18 +41,15 @@ static inline unsigned int brs_to(int id return MSR_AMD_SAMP_BR_FROM + 2 * idx + 1; } -static inline void set_debug_extn_cfg(u64 val) +static __always_inline void set_debug_extn_cfg(u64 val) { /* bits[4:3] must always be set to 11b */ - wrmsrl(MSR_AMD_DBG_EXTN_CFG, val | 3ULL << 3); + __wrmsr(MSR_AMD_DBG_EXTN_CFG, val | 3ULL << 3, val >> 32); } -static inline u64 get_debug_extn_cfg(void) +static __always_inline u64 get_debug_extn_cfg(void) { - u64 val; - - rdmsrl(MSR_AMD_DBG_EXTN_CFG, val); - return val; + return __rdmsr(MSR_AMD_DBG_EXTN_CFG); } static bool __init amd_brs_detect(void)
@@ -338,7 +335,7 @@ void amd_pmu_brs_sched_task(struct perf_ * called from ACPI processor_idle.c or acpi_pad.c * with interrupts disabled */ -void perf_amd_brs_lopwr_cb(bool lopwr_in) +void noinstr 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; --- a/arch/x86/include/asm/perf_event.h +++ b/arch/x86/include/asm/perf_event.h
@@ -554,7 +554,7 @@ extern void perf_amd_brs_lopwr_cb(bool l DECLARE_STATIC_CALL(perf_lopwr_cb, perf_amd_brs_lopwr_cb); -static inline void perf_lopwr_cb(bool lopwr_in) +static __always_inline void perf_lopwr_cb(bool lopwr_in) { static_call_mod(perf_lopwr_cb)(lopwr_in); }