[PATCH 6.1.y] perf/x86/intel: Remove anythread_deprecated bit from perf_capabilities

From: Dapeng Mi <redacted>

[ Upstream commit 8767b4d73018bd3143f4c55b672064fad292f11b ]

AnyThread mode deprecation is enumerated by CPUID.0AH:EDX[15] instead of
PERF_CAPABILITIES MSR. It's not a good practice to define a bit to
represent "anythread deprecation" in perf_capabilities. It leads to the
anythread_deprecated bit could be overwritten by the real value of
PERF_CAPABILITIES MSR, just like the below code in update_pmu_cap() does.

if (!intel_pmu_broken_perf_cap()) {
	/* Perf Metric (Bit 15) and PEBS via PT (Bit 16) are hybrid enumeration */
	rdmsrq(MSR_IA32_PERF_CAPABILITIES, hybrid(pmu, intel_cap).capabilities);
}

It leads to the anythread_deprecated bit is cleared to 0 and the "any"
attribute is incorrectly shown in the /sys/devices/cpu/format/ folder on
these support Perfmon v6 platforms, like Clearwater Forest.

$ grep . /sys/devices/cpu/format/*
/sys/devices/cpu/format/acr_mask:config2:0-63
/sys/devices/cpu/format/any:config:21
/sys/devices/cpu/format/cmask:config:24-31

So remove the anythread_deprecated bit from perf_capabilities structure
and directly depends on CPUID.0AH:EDX[15] to judge if anythread is
deprecated.

Fixes: cadbaa039b99 ("perf/x86/intel: Make anythread filter support conditional")
Reported-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Dapeng Mi <redacted>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Zide Chen <redacted>
Reviewed-by: Thomas Falcon <redacted>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260616044654.3468742-2-dapeng1.mi@linux.intel.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/x86/events/intel/core.c | 10 +++-------
 arch/x86/events/perf_event.h |  2 +-
 2 files changed, 4 insertions(+), 8 deletions(-)

diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index b1bc81bef4083..4b2b17d8d89d2 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c

@@ -5971,12 +5971,6 @@ __init int intel_pmu_init(void)
 
 	x86_add_quirk(intel_arch_events_quirk); /* Install first, so it runs last */
 
-	if (version >= 5) {
-		x86_pmu.intel_cap.anythread_deprecated = edx.split.anythread_deprecated;
-		if (x86_pmu.intel_cap.anythread_deprecated)
-			pr_cont(" AnyThread deprecated, ");
-	}
-
 	/*
 	 * Install the hw-cache-events table:
 	 */

@@ -6715,8 +6709,10 @@ __init int intel_pmu_init(void)
 				     (u64)fixed_mask);
 
 	/* AnyThread may be deprecated on arch perfmon v5 or later */
-	if (x86_pmu.intel_cap.anythread_deprecated)
+	if (version >= 5 && edx.split.anythread_deprecated) {
 		x86_pmu.format_attrs = intel_arch_formats_attr;
+		pr_cont("AnyThread deprecated, ");
+	}
 
 	intel_pmu_check_event_constraints(x86_pmu.event_constraints,
 					  x86_pmu.num_counters,

diff --git a/arch/x86/events/perf_event.h b/arch/x86/events/perf_event.h
index b95cab9846dd7..5f93316c60216 100644
--- a/arch/x86/events/perf_event.h
+++ b/arch/x86/events/perf_event.h

@@ -606,7 +606,7 @@ union perf_capabilities {
 		u64     pebs_baseline:1;
 		u64	perf_metrics:1;
 		u64	pebs_output_pt_available:1;
-		u64	anythread_deprecated:1;
+		u64	__reserved:1;
 	};
 	u64	capabilities;
 };

-- 
2.53.0