From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 6C4B72DC76A for ; Sun, 12 Apr 2026 17:55:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776016522; cv=none; b=lKU3BoyOV3qdjorY+n57Mt6g2llAWGxuSTmBSWPDvC8SP84yLn/HNE5zucg4BGhdzjxWa96mZ0YtmU4lXqIQJCxIVA6JwU3gmA2cLKDdcU6A+e290bijrUONiOKr52YN3AmjfbyA+xciUDQzB7fQP5LeFz/xg3EXlm6X/RzIEvQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776016522; c=relaxed/simple; bh=mKawjLnXNWYlIwgbwkDtV+GuxhWy+F6OTu66yyuoBXQ=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=L5Ql9vBt+OYFhFRMzlWL3QoUvZXG2lygMlsmtdKaMAcGnBASJ2q2xFL+5P2g/HWK3Sihw+Q6ITWu6xJGSJaV8R40xOkSRU8mh+ZYMbo60o/qwvQhoe23jRJ0ywNDQgXIXbWRS+pX4goGJXJyGe2GvdAK1f4pI+bMWMXuj3gxZ70= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=bEt1G7qL; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="bEt1G7qL" Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 3B3C832FA; Sun, 12 Apr 2026 10:55:14 -0700 (PDT) Received: from e129823.cambridge.arm.com (e129823.arm.com [10.1.197.6]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 68AD43F7B4; Sun, 12 Apr 2026 10:55:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1776016519; bh=mKawjLnXNWYlIwgbwkDtV+GuxhWy+F6OTu66yyuoBXQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bEt1G7qL8bX2GHo1LJv7EPRTleftY8FaFRgMRHk60gozbhAHAqVuryNPxALHLGzpE fzlr81KIUa9RY6cQchnUD9ZLEShjRIgefmqDLxFE7Dk6bPFWqVDKmQwmHknyiqGS4q 2wKptTxBgrjGRS+ByZbfec+AJJR+ZEbU/3bhQgJU= From: Yeoreum Yun To: coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: suzuki.poulose@arm.com, mike.leach@arm.com, james.clark@linaro.org, alexander.shishkin@linux.intel.com, leo.yan@arm.com, jie.gan@oss.qualcomm.com, Yeoreum Yun Subject: [PATCH v3 5/5] coresight: etm3x: fix inconsistencies with sysfs configration Date: Sun, 12 Apr 2026 18:55:06 +0100 Message-Id: <20260412175506.412301-6-yeoreum.yun@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260412175506.412301-1-yeoreum.yun@arm.com> References: <20260412175506.412301-1-yeoreum.yun@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The current ETM3x configuration via sysfs can lead to the following inconsistencies: - If a configuration is modified via sysfs while a perf session is active, the running configuration may differ between before a sched-out and after a subsequent sched-in. To resolve these inconsistencies, the configuration should be separated into: - active_config, which is applied configuration for the current session - config, which stores the settings configured via sysfs. and apply configuration after taking a mode. Signed-off-by: Yeoreum Yun --- drivers/hwtracing/coresight/coresight-etm.h | 2 ++ .../coresight/coresight-etm3x-core.c | 20 ++++++++++++------- 2 files changed, 15 insertions(+), 7 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-etm.h b/drivers/hwtracing/coresight/coresight-etm.h index 2ffe477c0c12..85ede334c9d0 100644 --- a/drivers/hwtracing/coresight/coresight-etm.h +++ b/drivers/hwtracing/coresight/coresight-etm.h @@ -243,6 +243,7 @@ struct etm_config { * @boot_enable:true if we should start tracing at boot time. * @os_unlock: true if access to management registers is allowed. * @traceid: value of the current ID for this component. + * @active_config: structure holding current running configuration parameters. * @config: structure holding configuration parameters. */ struct etm_drvdata { @@ -258,6 +259,7 @@ struct etm_drvdata { bool boot_enable; bool os_unlock; u32 traceid; + struct etm_config active_config; struct etm_config config; }; diff --git a/drivers/hwtracing/coresight/coresight-etm3x-core.c b/drivers/hwtracing/coresight/coresight-etm3x-core.c index f669eeeef538..efed6b8a7d72 100644 --- a/drivers/hwtracing/coresight/coresight-etm3x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm3x-core.c @@ -309,7 +309,7 @@ static int etm_parse_event_config(struct etm_drvdata *drvdata, struct perf_event *event) { const struct etm_caps *caps = &drvdata->caps; - struct etm_config *config = &drvdata->config; + struct etm_config *config = &drvdata->active_config; struct perf_event_attr *attr = &event->attr; u8 ts_level; @@ -368,7 +368,7 @@ static int etm_enable_hw(struct etm_drvdata *drvdata) int i, rc; u32 etmcr; const struct etm_caps *caps = &drvdata->caps; - struct etm_config *config = &drvdata->config; + struct etm_config *config = &drvdata->active_config; struct coresight_device *csdev = drvdata->csdev; CS_UNLOCK(drvdata->csa.base); @@ -442,24 +442,30 @@ static int etm_enable_hw(struct etm_drvdata *drvdata) struct etm_enable_arg { struct etm_drvdata *drvdata; + u32 traceid; int rc; }; static void etm_enable_sysfs_smp_call(void *info) { struct etm_enable_arg *arg = info; + struct etm_drvdata *drvdata; struct coresight_device *csdev; if (WARN_ON(!arg)) return; - csdev = arg->drvdata->csdev; + drvdata = arg->drvdata; + csdev = drvdata->csdev; if (!coresight_take_mode(csdev, CS_MODE_SYSFS)) { /* Someone is already using the tracer */ arg->rc = -EBUSY; return; } + drvdata->active_config = drvdata->config; + drvdata->traceid = arg->traceid; + arg->rc = etm_enable_hw(arg->drvdata); /* The tracer didn't start */ @@ -514,14 +520,13 @@ static int etm_enable_sysfs(struct coresight_device *csdev, struct coresight_pat spin_lock(&drvdata->spinlock); - drvdata->traceid = path->trace_id; - /* * Configure the ETM only if the CPU is online. If it isn't online * hw configuration will take place on the local CPU during bring up. */ if (cpu_online(drvdata->cpu)) { arg.drvdata = drvdata; + arg.traceid = path->trace_id; ret = smp_call_function_single(drvdata->cpu, etm_enable_sysfs_smp_call, &arg, 1); if (!ret) @@ -565,7 +570,7 @@ static void etm_disable_hw(struct etm_drvdata *drvdata) { int i; const struct etm_caps *caps = &drvdata->caps; - struct etm_config *config = &drvdata->config; + struct etm_config *config = &drvdata->active_config; struct coresight_device *csdev = drvdata->csdev; CS_UNLOCK(drvdata->csa.base); @@ -884,7 +889,8 @@ static int etm_probe(struct amba_device *adev, const struct amba_id *id) if (etm_arch_supported(drvdata->arch) == false) return -EINVAL; - etm_set_default(&drvdata->config); + etm_set_default(&drvdata->active_config); + drvdata->config = drvdata->active_config; pdata = coresight_get_platform_data(dev); if (IS_ERR(pdata)) -- LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}