From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 896AA3C9EF6; Sun, 2 Aug 2026 16:53:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785689622; cv=none; b=TX4L95Yhx7V7WaK0q+lVu+NwPJtK3vW6ZhCf51wLEhO0dfvniKU8vxotsGYXDh7DJEJ/9/PRO9hupT3QH1PS1zrZpapa0XBf3sU+V02uBtnkRFA40jn1Bf/J9E3ByzZWBp/1mCTbHd0qyPC/vH65MxXEgW+AwCVVg4Sh0RwMfqg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785689622; c=relaxed/simple; bh=b/VNPkwPUumPkXZC0NVwXxj5iEweX9a5MwCOIgyy3CY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Aj8Jmm9H7kXB18J/x8XK+aGweEJxwLVMtvVqUo6qCOwKbZPFD6ojnR6XmQl2ucYGbpuTdPcbHw+tl3lWct5gEuJ5euWojVY4IjDmSG/QQnhbhLlpXbVDKJ8Oz+a0KkUzbzIqi3g/zGeu56shntutP3I5AxA439Mb0yFrp/7csd0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ma03lMFj; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ma03lMFj" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 512C21F00A3A; Sun, 2 Aug 2026 16:53:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785689621; bh=DebX7evhEtlgthyyjGu18FUeYtqUAeNC8V77aBBdbns=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=ma03lMFjEIGpCCK44yCD73/RZdEU9x93nIEs2F3en0qOqsY0FmfYB3vaNfwB+Ltxl wL+bii+DHKGgsy2WfccmrkYxZeg4hW6q+hrl8W4DYjitINoxZSDus4nsmMPNJmCyYx naZzIQgzp+D4UwvnQGHeWHVhIMsSeZ5rfCjPATc+2SDLX0c0ulpHmhuHwsgSW2sNXz KzK64QI9AA3L1ciSS3yVze7La95ayIWUhVOQQtXgdJp8m7WLy3ynD7FJHyMKONfPmV BcmoPM44zc0wlYBry3D+sikoWFM9+EYRl0HGoSqXMJ73jfJZpYf9YT84PVWU9HgjUn lGMfvgdUzYCdA== Received: from sofa.misterjones.org ([185.219.108.64] helo=valley-girl.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.98.2) (envelope-from ) id 1wqZRT-0000000BVIZ-10vj; Sun, 02 Aug 2026 16:53:39 +0000 From: Marc Zyngier To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: Catalin Marinas , Will Deacon , Mark Rutland , Thomas Gleixner , Ben Horgan , Daniel Lezcano , stable@vger.kernel.org Subject: [PATCH v3 1/8] clocksource/drivers/arm_arch_timer: Add read_sched_clock_is_arch_counter() predicate Date: Sun, 2 Aug 2026 17:53:20 +0100 Message-ID: <20260802165327.385217-2-maz@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260802165327.385217-1-maz@kernel.org> References: <20260802165327.385217-1-maz@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, catalin.marinas@arm.com, will@kernel.org, mark.rutland@arm.com, tglx@kernel.org, ben.horgan@arm.com, daniel.lezcano@linaro.org, stable@vger.kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false The PMUv3 driver really wants to know whether sched_clock() is backed by the architected timer. However, updates to the timer driver have broken the check, as there is more than a single accessor for the counters, depending on the level of brokenness of the HW. Add a predicate that checks for those accessors, and update the PMUv3 driver to DTRT. Fixes: 24ee7607b286b ("arm64/arch_timer: Provide noinstr sched_clock_read() functions") Signed-off-by: Marc Zyngier Cc: stable@vger.kernel.org --- drivers/clocksource/arm_arch_timer.c | 10 ++++++++++ drivers/perf/arm_pmuv3.c | 2 +- include/clocksource/arm_arch_timer.h | 8 +++++++- 3 files changed, 18 insertions(+), 2 deletions(-) diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index 4adf756423de9..c02e97f9b7af5 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -951,6 +951,16 @@ static void __init arch_counter_register(void) sched_clock_register(scr, width, arch_timer_rate); } +bool read_sched_clock_is_arch_counter(const struct clock_read_data *crd) +{ + u64 (*rd)(void) = crd->read_sched_clock; + + return (rd == raw_counter_get_cntvct_stable || + rd == raw_counter_get_cntpct_stable || + rd == arch_counter_get_cntvct || + rd == arch_counter_get_cntpct); +} + static void arch_timer_stop(struct clock_event_device *clk) { pr_debug("disable IRQ%d cpu #%d\n", clk->irq, smp_processor_id()); diff --git a/drivers/perf/arm_pmuv3.c b/drivers/perf/arm_pmuv3.c index 8014ff766cff5..ed880145d41b3 100644 --- a/drivers/perf/arm_pmuv3.c +++ b/drivers/perf/arm_pmuv3.c @@ -1624,7 +1624,7 @@ void arch_perf_update_userpage(struct perf_event *event, do { rd = sched_clock_read_begin(&seq); - if (rd->read_sched_clock != arch_timer_read_counter) + if (!read_sched_clock_is_arch_counter(rd)) return; userpg->time_mult = rd->mult; diff --git a/include/clocksource/arm_arch_timer.h b/include/clocksource/arm_arch_timer.h index 2eda895f19f54..84cdbaffcfb5e 100644 --- a/include/clocksource/arm_arch_timer.h +++ b/include/clocksource/arm_arch_timer.h @@ -84,13 +84,15 @@ struct arch_timer_mem { struct arch_timer_mem_frame frame[ARCH_TIMER_MEM_MAX_FRAMES]; }; +struct clock_read_data; + #ifdef CONFIG_ARM_ARCH_TIMER extern u32 arch_timer_get_rate(void); extern u64 (*arch_timer_read_counter)(void); extern struct arch_timer_kvm_info *arch_timer_get_kvm_info(void); extern bool arch_timer_evtstrm_available(void); - +extern bool read_sched_clock_is_arch_counter(const struct clock_read_data *); #else static inline u32 arch_timer_get_rate(void) @@ -108,6 +110,10 @@ static inline bool arch_timer_evtstrm_available(void) return false; } +static bool read_sched_clock_is_arch_counter(const struct clock_read_data *crd) +{ + return false; +} #endif #endif -- 2.47.3