linux-kernel - [tip: perf/core] perf/x86/intel: Decouple BTS initialization from PEBS initialization

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Message-ID: <174489488800.31282.11319373754198048027.tip-bot2@tip-bot2>
Date: Thu, 17 Apr 2025 13:01:28 -0000
From: "tip-bot2 for Dapeng Mi" <tip-bot2@...utronix.de>
To: linux-tip-commits@...r.kernel.org
Cc: Dapeng Mi <dapeng1.mi@...ux.intel.com>,
 "Peter Zijlstra (Intel)" <peterz@...radead.org>,
 Ingo Molnar <mingo@...nel.org>, x86@...nel.org, linux-kernel@...r.kernel.org
Subject: [tip: perf/core] perf/x86/intel: Decouple BTS initialization from
 PEBS initialization

The following commit has been merged into the perf/core branch of tip:

Commit-ID:     d971342d38bf228ea4c137249501eb5be38ee958
Gitweb:        https://git.kernel.org/tip/d971342d38bf228ea4c137249501eb5be38ee958
Author:        Dapeng Mi <dapeng1.mi@...ux.intel.com>
AuthorDate:    Tue, 15 Apr 2025 11:44:10 
Committer:     Ingo Molnar <mingo@...nel.org>
CommitterDate: Thu, 17 Apr 2025 14:21:24 +02:00

perf/x86/intel: Decouple BTS initialization from PEBS initialization

Move x86_pmu.bts flag initialization into bts_init() from
intel_ds_init() and rename intel_ds_init() to intel_pebs_init() since it
fully initializes PEBS now after removing the x86_pmu.bts
initialization.

It's safe to move x86_pmu.bts into bts_init() since all x86_pmu.bts flag
are called after bts_init() execution.

Signed-off-by: Dapeng Mi <dapeng1.mi@...ux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Signed-off-by: Ingo Molnar <mingo@...nel.org>
Link: https://lkml.kernel.org/r/20250415114428.341182-5-dapeng1.mi@linux.intel.com
---
 arch/x86/events/intel/bts.c  | 6 +++++-
 arch/x86/events/intel/core.c | 2 +-
 arch/x86/events/intel/ds.c   | 5 ++---
 arch/x86/events/perf_event.h | 2 +-
 4 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/arch/x86/events/intel/bts.c b/arch/x86/events/intel/bts.c
index 16bc89c..9560f69 100644
--- a/arch/x86/events/intel/bts.c
+++ b/arch/x86/events/intel/bts.c
@@ -599,7 +599,11 @@ static void bts_event_read(struct perf_event *event)
 
 static __init int bts_init(void)
 {
-	if (!boot_cpu_has(X86_FEATURE_DTES64) || !x86_pmu.bts)
+	if (!boot_cpu_has(X86_FEATURE_DTES64))
+		return -ENODEV;
+
+	x86_pmu.bts = boot_cpu_has(X86_FEATURE_BTS);
+	if (!x86_pmu.bts)
 		return -ENODEV;
 
 	if (boot_cpu_has(X86_FEATURE_PTI)) {
diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index c7937b8..16049ba 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -6928,7 +6928,7 @@ __init int intel_pmu_init(void)
 	if (boot_cpu_has(X86_FEATURE_ARCH_LBR))
 		intel_pmu_arch_lbr_init();
 
-	intel_ds_init();
+	intel_pebs_init();
 
 	x86_add_quirk(intel_arch_events_quirk); /* Install first, so it runs last */
 
diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c
index fcf9c5b..d894cf3 100644
--- a/arch/x86/events/intel/ds.c
+++ b/arch/x86/events/intel/ds.c
@@ -2651,10 +2651,10 @@ static void intel_pmu_drain_pebs_icl(struct pt_regs *iregs, struct perf_sample_d
 }
 
 /*
- * BTS, PEBS probe and setup
+ * PEBS probe and setup
  */
 
-void __init intel_ds_init(void)
+void __init intel_pebs_init(void)
 {
 	/*
 	 * No support for 32bit formats
@@ -2662,7 +2662,6 @@ void __init intel_ds_init(void)
 	if (!boot_cpu_has(X86_FEATURE_DTES64))
 		return;
 
-	x86_pmu.bts  = boot_cpu_has(X86_FEATURE_BTS);
 	x86_pmu.pebs = boot_cpu_has(X86_FEATURE_PEBS);
 	x86_pmu.pebs_buffer_size = PEBS_BUFFER_SIZE;
 	if (x86_pmu.version <= 4)
diff --git a/arch/x86/events/perf_event.h b/arch/x86/events/perf_event.h
index 46bbb50..ac6743e 100644
--- a/arch/x86/events/perf_event.h
+++ b/arch/x86/events/perf_event.h
@@ -1673,7 +1673,7 @@ void intel_pmu_drain_pebs_buffer(void);
 
 void intel_pmu_store_pebs_lbrs(struct lbr_entry *lbr);
 
-void intel_ds_init(void);
+void intel_pebs_init(void);
 
 void intel_pmu_lbr_save_brstack(struct perf_sample_data *data,
 				struct cpu_hw_events *cpuc,