From: Dapeng Mi <dapeng1.mi@linux.intel.com>
To: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Namhyung Kim <namhyung@kernel.org>,
Ian Rogers <irogers@google.com>,
Adrian Hunter <adrian.hunter@intel.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Andi Kleen <ak@linux.intel.com>,
Eranian Stephane <eranian@google.com>
Cc: linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org,
Dapeng Mi <dapeng1.mi@intel.com>, Zide Chen <zide.chen@intel.com>,
Falcon Thomas <thomas.falcon@intel.com>,
Xudong Hao <xudong.hao@intel.com>,
Dapeng Mi <dapeng1.mi@linux.intel.com>
Subject: [Patch v3 6/7] perf/x86: Use macros to replace magic numbers in attr_rdpmc
Date: Wed, 14 Jan 2026 09:17:49 +0800 [thread overview]
Message-ID: <20260114011750.350569-7-dapeng1.mi@linux.intel.com> (raw)
In-Reply-To: <20260114011750.350569-1-dapeng1.mi@linux.intel.com>
Replace magic numbers in attr_rdpmc with macros to improve readability
and make their meanings clearer for users.
Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
---
arch/x86/events/core.c | 7 ++++---
arch/x86/events/intel/p6.c | 2 +-
arch/x86/events/perf_event.h | 7 +++++++
3 files changed, 12 insertions(+), 4 deletions(-)
diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index 0ecac9495d74..c2717cb5034f 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -2163,7 +2163,8 @@ static int __init init_hw_perf_events(void)
pr_cont("%s PMU driver.\n", x86_pmu.name);
- x86_pmu.attr_rdpmc = 1; /* enable userspace RDPMC usage by default */
+ /* enable userspace RDPMC usage by default */
+ x86_pmu.attr_rdpmc = X86_USER_RDPMC_CONDITIONAL_ENABLE;
for (quirk = x86_pmu.quirks; quirk; quirk = quirk->next)
quirk->func();
@@ -2643,12 +2644,12 @@ static ssize_t set_attr_rdpmc(struct device *cdev,
*/
if (val == 0)
static_branch_inc(&rdpmc_never_available_key);
- else if (x86_pmu.attr_rdpmc == 0)
+ else if (x86_pmu.attr_rdpmc == X86_USER_RDPMC_NEVER_ENABLE)
static_branch_dec(&rdpmc_never_available_key);
if (val == 2)
static_branch_inc(&rdpmc_always_available_key);
- else if (x86_pmu.attr_rdpmc == 2)
+ else if (x86_pmu.attr_rdpmc == X86_USER_RDPMC_ALWAYS_ENABLE)
static_branch_dec(&rdpmc_always_available_key);
on_each_cpu(cr4_update_pce, NULL, 1);
diff --git a/arch/x86/events/intel/p6.c b/arch/x86/events/intel/p6.c
index 6e41de355bd8..fb991e0ac614 100644
--- a/arch/x86/events/intel/p6.c
+++ b/arch/x86/events/intel/p6.c
@@ -243,7 +243,7 @@ static __init void p6_pmu_rdpmc_quirk(void)
*/
pr_warn("Userspace RDPMC support disabled due to a CPU erratum\n");
x86_pmu.attr_rdpmc_broken = 1;
- x86_pmu.attr_rdpmc = 0;
+ x86_pmu.attr_rdpmc = X86_USER_RDPMC_NEVER_ENABLE;
}
}
diff --git a/arch/x86/events/perf_event.h b/arch/x86/events/perf_event.h
index f7caabc5d487..24a81d2916e9 100644
--- a/arch/x86/events/perf_event.h
+++ b/arch/x86/events/perf_event.h
@@ -187,6 +187,13 @@ struct amd_nb {
(1ULL << PERF_REG_X86_R14) | \
(1ULL << PERF_REG_X86_R15))
+/* user space rdpmc control values */
+enum {
+ X86_USER_RDPMC_NEVER_ENABLE = 0,
+ X86_USER_RDPMC_CONDITIONAL_ENABLE = 1,
+ X86_USER_RDPMC_ALWAYS_ENABLE = 2,
+};
+
/*
* Per register state.
*/
--
2.34.1
next prev parent reply other threads:[~2026-01-14 1:22 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-14 1:17 [Patch v3 0/7] Enable core PMU for DMR and NVL Dapeng Mi
2026-01-14 1:17 ` [Patch v3 1/7] perf/x86/intel: Support the 4 new OMR MSRs introduced in " Dapeng Mi
2026-01-14 1:17 ` [Patch v3 2/7] perf/x86/intel: Add support for PEBS memory auxiliary info field in DMR Dapeng Mi
2026-01-14 1:17 ` [Patch v3 3/7] perf/x86/intel: Add core PMU support for DMR Dapeng Mi
2026-01-14 1:17 ` [Patch v3 4/7] perf/x86/intel: Add support for PEBS memory auxiliary info field in NVL Dapeng Mi
2026-01-14 1:17 ` [Patch v3 5/7] perf/x86/intel: Add core PMU support for Novalake Dapeng Mi
2026-01-14 1:17 ` Dapeng Mi [this message]
2026-03-09 23:56 ` [Patch v3 6/7] perf/x86: Use macros to replace magic numbers in attr_rdpmc Ian Rogers
2026-03-10 3:14 ` Mi, Dapeng
2026-01-14 1:17 ` [Patch v3 7/7] perf/x86/intel: Add support for rdpmc user disable feature Dapeng Mi
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