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 419A01C549A for ; Fri, 20 Dec 2024 10:45:31 +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=1734691533; cv=none; b=IJXeEmPXunKGmLRX5H0NRhkkzS/0R9qai97gEpBXeZzkdNozz8mVyFhWplH/5jZQNnilHm/oJufntVWg0zIISo+Gwo0YvdJ8W6r+aIvA4OwslQ2A1s2l+HdIEdarrSLQ7nvjbw0VB0J2RT6U4z2y4OILcdUJEnORv3CMlzSMpE8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734691533; c=relaxed/simple; bh=RIe/5ZaCtNLHo29qreZI0j1qk+lpe9VGGmd6j6rEDJ4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=CsIelu7jGH9unEcwEGLnTKtyE5oLN6X2j35jGRlBI2uRT+XG5PMBwJ5TulWac5uUkcrPIGVskGQAsJxGGZG80aHqYTHLLd6qYBSev/xx9WE+7zRghZK8QWwtocIMfatdWKRGZBaBrOxL/AwR0TDp+P3nbv02vNcSyEMhZhR2f6M= 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; 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 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 B10321480; Fri, 20 Dec 2024 02:45:58 -0800 (PST) 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 90A2D3F720; Fri, 20 Dec 2024 02:45:28 -0800 (PST) From: Yeoreum Yun To: suzuki.poulose@arm.com, james.clark@linaro.org, alexander.shishkin@linux.intel.com, bigeasy@linutronix.de, clrkwllms@kernel.org, rostedt@goodmis.org, mike.leach@linaro.org Cc: coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-rt-devel@lists.linux.dev, Yeoreum Yun Subject: [PATCH v4 1/1] coresight/ultrasoc: change smb_drv_data spinlock's type to raw_spinlock_t Date: Fri, 20 Dec 2024 10:45:13 +0000 Message-Id: <20241220104521.809071-3-yeoreum.yun@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20241220104521.809071-1-yeoreum.yun@arm.com> References: <20241220104521.809071-1-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 In ultrasoc-smb drivers, smb_drv_data->spinlock can be held during __schedule() by perf_event_task_sched_out()/in(). Since smb__drv_data->spinlock type is spinlock_t and perf_event_task_sched_out()/in() is called after acquiring rq_lock, which is raw_spinlock_t (an unsleepable lock), this poses an issue in PREEMPT_RT kernel where spinlock_t is sleepable. To address this, change type smb_drv_data->spinlock in ultrasoc-smb drivers, which can be called by perf_event_task_sched_out()/in(), from spinlock_t to raw_spinlock_t. Reviewed-by: James Clark Signed-off-by: Yeoreum Yun --- drivers/hwtracing/coresight/ultrasoc-smb.c | 12 ++++++------ drivers/hwtracing/coresight/ultrasoc-smb.h | 2 +- 2 files changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/hwtracing/coresight/ultrasoc-smb.c b/drivers/hwtracing/coresight/ultrasoc-smb.c index dc3c9504dd7c..26cfc939e5bd 100644 --- a/drivers/hwtracing/coresight/ultrasoc-smb.c +++ b/drivers/hwtracing/coresight/ultrasoc-smb.c @@ -98,7 +98,7 @@ static int smb_open(struct inode *inode, struct file *file) struct smb_drv_data *drvdata = container_of(file->private_data, struct smb_drv_data, miscdev); - guard(spinlock)(&drvdata->spinlock); + guard(raw_spinlock)(&drvdata->spinlock); if (drvdata->reading) return -EBUSY; @@ -152,7 +152,7 @@ static int smb_release(struct inode *inode, struct file *file) struct smb_drv_data *drvdata = container_of(file->private_data, struct smb_drv_data, miscdev); - guard(spinlock)(&drvdata->spinlock); + guard(raw_spinlock)(&drvdata->spinlock); drvdata->reading = false; return 0; @@ -245,7 +245,7 @@ static int smb_enable(struct coresight_device *csdev, enum cs_mode mode, struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent); int ret = 0; - guard(spinlock)(&drvdata->spinlock); + guard(raw_spinlock)(&drvdata->spinlock); /* Do nothing, the trace data is reading by other interface now */ if (drvdata->reading) @@ -280,7 +280,7 @@ static int smb_disable(struct coresight_device *csdev) { struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent); - guard(spinlock)(&drvdata->spinlock); + guard(raw_spinlock)(&drvdata->spinlock); if (drvdata->reading) return -EBUSY; @@ -378,7 +378,7 @@ static unsigned long smb_update_buffer(struct coresight_device *csdev, if (!buf) return 0; - guard(spinlock)(&drvdata->spinlock); + guard(raw_spinlock)(&drvdata->spinlock); /* Don't do anything if another tracer is using this sink. */ if (csdev->refcnt != 1) @@ -563,7 +563,7 @@ static int smb_probe(struct platform_device *pdev) smb_reset_buffer(drvdata); platform_set_drvdata(pdev, drvdata); - spin_lock_init(&drvdata->spinlock); + raw_spin_lock_init(&drvdata->spinlock); drvdata->pid = -1; ret = smb_register_sink(pdev, drvdata); diff --git a/drivers/hwtracing/coresight/ultrasoc-smb.h b/drivers/hwtracing/coresight/ultrasoc-smb.h index a91d39cfccb8..c4c111275627 100644 --- a/drivers/hwtracing/coresight/ultrasoc-smb.h +++ b/drivers/hwtracing/coresight/ultrasoc-smb.h @@ -115,7 +115,7 @@ struct smb_drv_data { struct coresight_device *csdev; struct smb_data_buffer sdb; struct miscdevice miscdev; - spinlock_t spinlock; + raw_spinlock_t spinlock; bool reading; pid_t pid; }; -- LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}