From nobody Wed Dec 17 21:27:06 2025 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 56DC720CCF0 for ; Thu, 6 Mar 2025 09:48:23 +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=1741254504; cv=none; b=Uft5ngQxRnZEJhI4hQnsWLpPB7tcgJJoMwrZXyvBFwZUf4DRKf3qgh7QfioN5e8v6id1qX8DUM2NSclHJ+21F0m1j4WKauS6l0znonfwTaglQwDWASazIebBIg5PRxqxUzAWTP1u7jKHAmTx2fbwwzUjeeNsW4UFix4B9moBVjM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741254504; c=relaxed/simple; bh=RIe/5ZaCtNLHo29qreZI0j1qk+lpe9VGGmd6j6rEDJ4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=R8tD1u3kcKLK+4fYaYgeeFBvGG/fzqYEu89xNTXk2Z91UCSAyZuOnsO3xwZxQ+0YRx9sipCpLg7vSJeUybdE3Ml7zQlN2f4nQAS9U1UOFuBnDmr2Ouz2hNkiA+8ql1s3AhLBfhq5SI7cpWl5dxRTiBJGipRj/xkwJ8vfRE5Nzlw= 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 DE2A21007; Thu, 6 Mar 2025 01:48:35 -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 0DD043F673; Thu, 6 Mar 2025 01:48:20 -0800 (PST) From: Yeoreum Yun To: suzuki.poulose@arm.com, mike.leach@linaro.org, james.clark@linaro.org, alexander.shishkin@linux.intel.com, bigeasy@linutronix.de, clrkwllms@kernel.org, rostedt@goodmis.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 v5 9/9] coresight/ultrasoc: change smb_drv_data spinlock's type to raw_spinlock_t Date: Thu, 6 Mar 2025 09:48:00 +0000 Message-Id: <20250306094800.1082950-10-yeoreum.yun@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20250306094800.1082950-1-yeoreum.yun@arm.com> References: <20250306094800.1082950-1-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: quoted-printable Content-Type: text/plain; charset="utf-8" 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 *fil= e) struct smb_drv_data *drvdata =3D container_of(file->private_data, struct smb_drv_data, miscdev); =20 - guard(spinlock)(&drvdata->spinlock); + guard(raw_spinlock)(&drvdata->spinlock); =20 if (drvdata->reading) return -EBUSY; @@ -152,7 +152,7 @@ static int smb_release(struct inode *inode, struct file= *file) struct smb_drv_data *drvdata =3D container_of(file->private_data, struct smb_drv_data, miscdev); =20 - guard(spinlock)(&drvdata->spinlock); + guard(raw_spinlock)(&drvdata->spinlock); drvdata->reading =3D false; =20 return 0; @@ -245,7 +245,7 @@ static int smb_enable(struct coresight_device *csdev, e= num cs_mode mode, struct smb_drv_data *drvdata =3D dev_get_drvdata(csdev->dev.parent); int ret =3D 0; =20 - guard(spinlock)(&drvdata->spinlock); + guard(raw_spinlock)(&drvdata->spinlock); =20 /* 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 =3D dev_get_drvdata(csdev->dev.parent); =20 - guard(spinlock)(&drvdata->spinlock); + guard(raw_spinlock)(&drvdata->spinlock); =20 if (drvdata->reading) return -EBUSY; @@ -378,7 +378,7 @@ static unsigned long smb_update_buffer(struct coresight= _device *csdev, if (!buf) return 0; =20 - guard(spinlock)(&drvdata->spinlock); + guard(raw_spinlock)(&drvdata->spinlock); =20 /* Don't do anything if another tracer is using this sink. */ if (csdev->refcnt !=3D 1) @@ -563,7 +563,7 @@ static int smb_probe(struct platform_device *pdev) =20 smb_reset_buffer(drvdata); platform_set_drvdata(pdev, drvdata); - spin_lock_init(&drvdata->spinlock); + raw_spin_lock_init(&drvdata->spinlock); drvdata->pid =3D -1; =20 ret =3D 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; }; --=20 LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}