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 F0AB04AF9E9 for ; Thu, 24 Sep 2026 17:34:16 +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=1790271258; cv=none; b=o4zhMuCvIZNywCaGf2EiRSLvajhZi3HHkv4s7qdzr0CJ4QB2u+22++inR0r30Iv9cgOeOSS5r4NTcsrTR+1W7xb/m5jFKwJMiLCN+5XrfXXdi7is2yHcyOxT47RXddunmrdzMuZOJhkSKPXvYN01nb2jK5q2O5xZiBm7mkjBJ0o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790271258; c=relaxed/simple; bh=53Q5rj/7x+pKv27XfPvPIecPjq6QeuKQwbgS+7MBKw0=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=McKnTyiyPur8FUktaTW6xpPzR/34RCc+bgFvpBBEqE5gE0H3g3Q+9vYD0kSpx19yy2HxYxBCaN4muHWf7wJmQq6XQVFMVWWvWRl8VAP+hSOlYsLFADCoY20siM/iAyclKB304jllAgp+hXf9K+/ZZCFrwVFjWNEf6LOjteYcnX8= 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=J6v1g7Zk; 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="J6v1g7Zk" 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 DB2741E5E; Thu, 24 Sep 2026 10:34:12 -0700 (PDT) Received: from e129823.arm.com (e129823.arm.com [10.2.213.3]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 11BDE3F86F; Thu, 24 Sep 2026 10:34:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1790271256; bh=53Q5rj/7x+pKv27XfPvPIecPjq6QeuKQwbgS+7MBKw0=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=J6v1g7ZksczunscKjuZNMJU2izJgyhiTRoDKt1PNFXdwdd1F5zPsDhsnXzAOCxgAZ L8Y+74TmzGGMToqz9MioidUn6mf39WMzSdTeZDFXXU4J/tZR6k7WIReyJ1p+TWHh4o lFO7lKLJ5iLZ0kXLNvxNhIwQwJb1Sy37oeAdNr0I= From: Yeoreum Yun Date: Thu, 24 Sep 2026 18:33:39 +0100 Subject: [PATCH v12 01/14] coresight: etm4x: read-back TRCSEQSTR at disabling and prohibit modifying seq_state while enabling. Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260924-separate_etm_cfg_v2-v12-1-a2b41d2f7c2b@arm.com> References: <20260924-separate_etm_cfg_v2-v12-0-a2b41d2f7c2b@arm.com> In-Reply-To: <20260924-separate_etm_cfg_v2-v12-0-a2b41d2f7c2b@arm.com> To: Mike Leach , James Clark , Leo Yan , Greg Kroah-Hartman , Mathieu Poirier , coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-rt-devel@lists.linux.dev Cc: Suzuki K Poulose , Alexander Shishkin , Sebastian Andrzej Siewior , Clark Williams , Steven Rostedt , Yeoreum Yun X-Mailer: b4 0.13.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1933; i=yeoreum.yun@arm.com; h=from:subject:message-id; bh=53Q5rj/7x+pKv27XfPvPIecPjq6QeuKQwbgS+7MBKw0=; b=owEB7QES/pANAwAKAW3Vw9FaxTEzAcsmYgBqtV8L2TzE38V3muYAysfVSoimlW95GWmvvUhPA jy2pl3LNLqJAbMEAAEKAB0WIQQtg+CS3QUzuFh1pJ1t1cPRWsUxMwUCarVfCwAKCRBt1cPRWsUx M9CwC/91iDVFdb41gcvWs14pPQ2nxw1scsI/e/7l3QCUOA8VSEtsrnfuboDUqT7t3/yTnehA/py 0MBfFIeRMnYMzPfEkq3YKKF6V53CGuIIqG1D7OYvwwu48RbsItOI6fl+1pS/YlmNjWVLZTpJFsP KNgZltaLulip3XWdkBV7uMFW+57ljVlOjuFlIcYbHbmAcPfFyu9QHHISxiiPPpdxYy5B3db+L6w pTPU2BXFVbu78HQdup6KnsS9Cqf8qllB3+Wn4Q1I8z5H5wqP6Miqm1iJe5gWVJKC/BXW7lo+mMx vjKvYfi6VBAxwQkozgcmemjvEUhfi8GbECTiu1Bh1wcedLAoAo4fcQDHk7LDlvQxuja8c/9TDN5 ul11CxCho0HMOKc1JWuIgo0IgLkHsloqM1du/zCcfEkc/Y59aFh4Cwa9XMT5DVy5NePuw+BS0Ba KVA7u+Mn7rBmHAymuw05tWSqQBeD+4xmveW/E+fpODle25CCicgvc8peRr1L2SzMsug/I= X-Developer-Key: i=yeoreum.yun@arm.com; a=openpgp; fpr=2D83E092DD0533B85875A49D6DD5C3D15AC53133 TRCSEQSTR can be changed by the ETM while a session is active. Its value therefore needs to be preserved when a sysfs session is disabled so that users can read the current sequence state after the session ends. This means that any changes made to TRCSEQSTR while the sysfs-session is active would be lost when the session is disabled. Copy the TRCSEQSTR value when disabling a sysfs session, and prohibit modifying seq_state while the session is active. Suggested-by: Mike Leach Signed-off-by: Yeoreum Yun --- drivers/hwtracing/coresight/coresight-etm4x-core.c | 4 ++++ drivers/hwtracing/coresight/coresight-etm4x-sysfs.c | 2 ++ 2 files changed, 6 insertions(+) diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c index 2247ad55d444..9ca03a5913a3 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c @@ -1073,6 +1073,10 @@ static void etm4_disable_hw(struct etmv4_drvdata *drvdata) etm4x_relaxed_read32(csa, TRCCNTVRn(i)); } + /* read back the sequence state */ + if (drvdata->nrseqstate) + config->seq_state = etm4x_relaxed_read32(csa, TRCSEQSTR); + coresight_disclaim_device_unlocked(csdev); etm4_cs_lock(drvdata, csa); diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c index cc6cdd3ae29d..db3cf4ad6806 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c @@ -1437,6 +1437,8 @@ static ssize_t seq_state_store(struct device *dev, return -EINVAL; if (val >= drvdata->nrseqstate) return -EINVAL; + if (IS_ERR_OR_NULL(drvdata) || coresight_get_mode(drvdata->csdev)) + return -EBUSY; config->seq_state = val; return size; -- 2.43.0