linux-kernel - [PATCH 6/7] perf: apple_m1: Don't disable counter in m1_pmu_enable

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20250107-arm-pmu-cleanups-v1-v1-6-313951346a25@kernel.org>
Date: Tue, 07 Jan 2025 11:57:24 -0600
From: "Rob Herring (Arm)" <robh@...nel.org>
To: Will Deacon <will@...nel.org>, Mark Rutland <mark.rutland@....com>
Cc: Marc Zyngier <maz@...nel.org>, linux-arm-kernel@...ts.infradead.org, 
 linux-kernel@...r.kernel.org
Subject: [PATCH 6/7] perf: apple_m1: Don't disable counter in
 m1_pmu_enable_event()

Currently m1_pmu_enable_event() starts by disabling the event counter
it has been asked to enable. This should not be necessary as the
counter (and the PMU as a whole) should not be active when
m1_pmu_enable_event() is called.

Cc: Marc Zyngier <maz@...nel.org>
Signed-off-by: Rob Herring (Arm) <robh@...nel.org>
---
 drivers/perf/apple_m1_cpu_pmu.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/drivers/perf/apple_m1_cpu_pmu.c b/drivers/perf/apple_m1_cpu_pmu.c
index 1d4d01e1275e05c9dc656502d22de5bb2fc46b11..6a7071f0298d3d15f0c6f2fbc49789d669aa02e6 100644
--- a/drivers/perf/apple_m1_cpu_pmu.c
+++ b/drivers/perf/apple_m1_cpu_pmu.c
@@ -394,10 +394,6 @@ static void m1_pmu_enable_event(struct perf_event *event)
 	user = event->hw.config_base & M1_PMU_CFG_COUNT_USER;
 	kernel = event->hw.config_base & M1_PMU_CFG_COUNT_KERNEL;
 
-	m1_pmu_disable_counter_interrupt(event->hw.idx);
-	m1_pmu_disable_counter(event->hw.idx);
-	isb();
-
 	m1_pmu_configure_counter(event->hw.idx, evt, user, kernel);
 	m1_pmu_enable_counter(event->hw.idx);
 	m1_pmu_enable_counter_interrupt(event->hw.idx);

-- 
2.45.2