From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id B7C28C9830E for ; Thu, 24 Sep 2026 17:34:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Cc:To:In-Reply-To:References :Message-Id:Content-Transfer-Encoding:Content-Type:MIME-Version:Subject:Date: From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=KWaP8T8LNQZ3oLSL9ltW/te9G7B8TmnAjDxKMwhtkVs=; b=XPzedURXEAvEpSpk5NnO0uW9FX 1UDOhHsJPQ1YGT6zOPucLE67HAjPdQf9Q61VUBt8XZEXnCrtleTfGxQUhpEEFGjlbXAWHJnnZxbUS +AXTg3KUVl/KnptIh2QG48mStcwKrZh3bTs15utGG48Tspgjvp+heQgRYieXERRSJYu0vAAe6rXCV czmXcnZy8X8OO49pOIU/5VtKV3tHtYl1aYJHJ10R4MGGdHpcWzovwnd0u/FLTiIJCUIbarLVatcV8 Gwj76AYhOLSoOjq88M1D/TheWDYB0+pYN1msaMhzVbkZABjf0XAXqNlKUy++en7gggOVzZLEFFNHT /Dc6U2Ng==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x9nKu-0000000Bm8v-2LQQ; Thu, 24 Sep 2026 17:34:20 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x9nKr-0000000Bm7t-1e2V for linux-arm-kernel@lists.infradead.org; Thu, 24 Sep 2026 17:34:18 +0000 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. 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260924_103417_678398_EF17A4F0 X-CRM114-Status: GOOD ( 13.63 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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