From nobody Wed Dec 17 21:28:08 2025 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 63E2820B800 for ; Thu, 6 Mar 2025 09:48:15 +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=1741254498; cv=none; b=nec/+HRJrEyrGWVKYMi44ydsbpeRyIkjAQPnQZfm6WwwKVmq3X4+TNjqoQakOV0AibBq9ugG3Ilk9W9ikvunc4IriCaFciRT7WBWeiseJMYBDI63k4T95h/SzUsvz6sUDSCSWreCmI1cTgGcAyb3aLdFUiuebsr7lX9yAkrTsXQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741254498; c=relaxed/simple; bh=I778jcywmJL+J7FNP5OapM64WVgu/Fj+5Q1WpIy1tjY=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=KKZFp7hXRRcUsNKH2ahOlqzCH9nloAaPF9vD/aox2KdWeILjMnc+HFdTLqJLo6Ol65DKkeq/zm5cNqyuYbvBP7lOo867rPxKk+Re/WE0Qe3ydrSzfP40giaILcEzVWAJ6EBrgR9JJ+aAmuC7EZFCrGMWE5xqT9KOlRr5qfUMPGI= 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 AB5781007; Thu, 6 Mar 2025 01:48:27 -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 E879A3F673; Thu, 6 Mar 2025 01:48:12 -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 5/9] coresight-etb10: change etb_drvdata spinlock's type to raw_spinlock_t Date: Thu, 6 Mar 2025 09:47:56 +0000 Message-Id: <20250306094800.1082950-6-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 coresight-etb10 drivers, etb_drvdata->spinlock can be held during __schedule() by perf_event_task_sched_out()/in(). Since etb_drvdata->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 etb_drvdata->spinlock in coresight-etb10 drive= rs, which can be called by perf_event_task_sched_out()/in(), from spinlock_t to raw_spinlock_t. Reviewed-by: James Clark Reviewed-by: Mike Leach Signed-off-by: Yeoreum Yun --- drivers/hwtracing/coresight/coresight-etb10.c | 26 +++++++++---------- 1 file changed, 13 insertions(+), 13 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtrac= ing/coresight/coresight-etb10.c index aea9ac9c4bd0..7948597d483d 100644 --- a/drivers/hwtracing/coresight/coresight-etb10.c +++ b/drivers/hwtracing/coresight/coresight-etb10.c @@ -84,7 +84,7 @@ struct etb_drvdata { struct clk *atclk; struct coresight_device *csdev; struct miscdevice miscdev; - spinlock_t spinlock; + raw_spinlock_t spinlock; local_t reading; pid_t pid; u8 *buf; @@ -145,7 +145,7 @@ static int etb_enable_sysfs(struct coresight_device *cs= dev) unsigned long flags; struct etb_drvdata *drvdata =3D dev_get_drvdata(csdev->dev.parent); =20 - spin_lock_irqsave(&drvdata->spinlock, flags); + raw_spin_lock_irqsave(&drvdata->spinlock, flags); =20 /* Don't messup with perf sessions. */ if (coresight_get_mode(csdev) =3D=3D CS_MODE_PERF) { @@ -163,7 +163,7 @@ static int etb_enable_sysfs(struct coresight_device *cs= dev) =20 csdev->refcnt++; out: - spin_unlock_irqrestore(&drvdata->spinlock, flags); + raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); return ret; } =20 @@ -176,7 +176,7 @@ static int etb_enable_perf(struct coresight_device *csd= ev, void *data) struct perf_output_handle *handle =3D data; struct cs_buffers *buf =3D etm_perf_sink_config(handle); =20 - spin_lock_irqsave(&drvdata->spinlock, flags); + raw_spin_lock_irqsave(&drvdata->spinlock, flags); =20 /* No need to continue if the component is already in used by sysFS. */ if (coresight_get_mode(drvdata->csdev) =3D=3D CS_MODE_SYSFS) { @@ -219,7 +219,7 @@ static int etb_enable_perf(struct coresight_device *csd= ev, void *data) } =20 out: - spin_unlock_irqrestore(&drvdata->spinlock, flags); + raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); return ret; } =20 @@ -352,11 +352,11 @@ static int etb_disable(struct coresight_device *csdev) struct etb_drvdata *drvdata =3D dev_get_drvdata(csdev->dev.parent); unsigned long flags; =20 - spin_lock_irqsave(&drvdata->spinlock, flags); + raw_spin_lock_irqsave(&drvdata->spinlock, flags); =20 csdev->refcnt--; if (csdev->refcnt) { - spin_unlock_irqrestore(&drvdata->spinlock, flags); + raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); return -EBUSY; } =20 @@ -366,7 +366,7 @@ static int etb_disable(struct coresight_device *csdev) /* Dissociate from monitored process. */ drvdata->pid =3D -1; coresight_set_mode(csdev, CS_MODE_DISABLED); - spin_unlock_irqrestore(&drvdata->spinlock, flags); + raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); =20 dev_dbg(&csdev->dev, "ETB disabled\n"); return 0; @@ -443,7 +443,7 @@ static unsigned long etb_update_buffer(struct coresight= _device *csdev, =20 capacity =3D drvdata->buffer_depth * ETB_FRAME_SIZE_WORDS; =20 - spin_lock_irqsave(&drvdata->spinlock, flags); + raw_spin_lock_irqsave(&drvdata->spinlock, flags); =20 /* Don't do anything if another tracer is using this sink */ if (csdev->refcnt !=3D 1) @@ -566,7 +566,7 @@ static unsigned long etb_update_buffer(struct coresight= _device *csdev, __etb_enable_hw(drvdata); CS_LOCK(drvdata->base); out: - spin_unlock_irqrestore(&drvdata->spinlock, flags); + raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); =20 return to_read; } @@ -587,13 +587,13 @@ static void etb_dump(struct etb_drvdata *drvdata) { unsigned long flags; =20 - spin_lock_irqsave(&drvdata->spinlock, flags); + raw_spin_lock_irqsave(&drvdata->spinlock, flags); if (coresight_get_mode(drvdata->csdev) =3D=3D CS_MODE_SYSFS) { __etb_disable_hw(drvdata); etb_dump_hw(drvdata); __etb_enable_hw(drvdata); } - spin_unlock_irqrestore(&drvdata->spinlock, flags); + raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); =20 dev_dbg(&drvdata->csdev->dev, "ETB dumped\n"); } @@ -746,7 +746,7 @@ static int etb_probe(struct amba_device *adev, const st= ruct amba_id *id) drvdata->base =3D base; desc.access =3D CSDEV_ACCESS_IOMEM(base); =20 - spin_lock_init(&drvdata->spinlock); + raw_spin_lock_init(&drvdata->spinlock); =20 drvdata->buffer_depth =3D etb_get_buffer_depth(drvdata); =20 --=20 LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}