x86/perf/amd: Remove tracing from perf_lopwr_cb()

The perf_lopwr_cb() function is called from the idle routines; there
is no RCU there, we must not enter tracing.

Use __always_inline, noidle annotations and existing no-trace methods.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Tony Lindgren <tony@atomide.com>
Tested-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230112195539.392862891@infradead.org

arch/x86/events/amd/brs.c

@@ -41,18 +41,15 @@ static inline unsigned int brs_to(int idx)
 	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)
@@ -405,7 +402,7 @@ void amd_pmu_brs_sched_task(struct perf_event_pmu_context *pmu_ctx, bool sched_i
  * 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;

arch/x86/include/asm/perf_event.h

@@ -578,7 +578,7 @@ 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 __always_inline void perf_lopwr_cb(bool lopwr_in)
 {
 	static_call_mod(perf_lopwr_cb)(lopwr_in);
 }