From nobody Wed Dec 17 21:39:44 2025 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 8DE81204C06 for ; Mon, 16 Dec 2024 11:50:13 +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=1734349815; cv=none; b=IqS7qD8L5BgYyj/V6JhxD0iP+btEkzv/lrFvtCubG1csKJTtTOjTqC/v5/a21hkpqBvwtk6DBt74e6yFKOGvqAaujWqFz3cGmTK2k3M/+8RgCUnTbdrH+CIurv3aCxJedi/aCF26U9TJDeVTcmx3c1u5CCPNqU0hpOQQA1E3bmM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734349815; c=relaxed/simple; bh=Bb++mKdq8inl0cVkR5vxQ17falPfsDPqL3TOjRCxl2c=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=aZ02aPscKowjh/pwtnQMbBIMuGHuWmRoJlgpyj4SAOYtoDFBE0Dd8QRGmzPZgx2N0cajd3tF96FQQyyH5fh4qX2iMmGbwYI5Nv2V8LuLcp4RUhR8FNP6nSGOofuiMYkfFypu5OIGdxgr1Bs/t+Cggxfngoo31oeGsyP1jbyYrds= 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 276F611FB; Mon, 16 Dec 2024 03:50:41 -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 0D2893F58B; Mon, 16 Dec 2024 03:50:10 -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 v3 1/9] coresight: change coresight_device lock type to raw_spinlock_t Date: Mon, 16 Dec 2024 11:49:58 +0000 Message-Id: <20241216115006.415861-2-yeoreum.yun@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20241216115006.415861-1-yeoreum.yun@arm.com> References: <20241216115006.415861-1-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" coresight_device->cscfg_csdev_lock can be held during __schedule() by perf_event_task_sched_out()/in(). Since coresight->cscfg_csdev_lock 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 of coresight_device->cscfg_csdev_lock from spinlock_t to raw_spinlock_t. Signed-off-by: Yeoreum Yun Reviewed-by: Mike Leach --- .../hwtracing/coresight/coresight-syscfg.c | 26 +++++++++---------- include/linux/coresight.h | 2 +- 2 files changed, 14 insertions(+), 14 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-syscfg.c b/drivers/hwtra= cing/coresight/coresight-syscfg.c index 11138a9762b0..a70c1454b410 100644 --- a/drivers/hwtracing/coresight/coresight-syscfg.c +++ b/drivers/hwtracing/coresight/coresight-syscfg.c @@ -89,9 +89,9 @@ static int cscfg_add_csdev_cfg(struct coresight_device *c= sdev, } /* if matched features, add config to device.*/ if (config_csdev) { - spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags); + raw_spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags); list_add(&config_csdev->node, &csdev->config_csdev_list); - spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags); + raw_spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags); } =20 return 0; @@ -194,9 +194,9 @@ static int cscfg_load_feat_csdev(struct coresight_devic= e *csdev, =20 /* add to internal csdev feature list & initialise using reset call */ cscfg_reset_feat(feat_csdev); - spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags); + raw_spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags); list_add(&feat_csdev->node, &csdev->feature_csdev_list); - spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags); + raw_spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags); =20 return 0; } @@ -765,7 +765,7 @@ static int cscfg_list_add_csdev(struct coresight_device= *csdev, =20 INIT_LIST_HEAD(&csdev->feature_csdev_list); INIT_LIST_HEAD(&csdev->config_csdev_list); - spin_lock_init(&csdev->cscfg_csdev_lock); + raw_spin_lock_init(&csdev->cscfg_csdev_lock); =20 return 0; } @@ -855,7 +855,7 @@ void cscfg_csdev_reset_feats(struct coresight_device *c= sdev) struct cscfg_feature_csdev *feat_csdev; unsigned long flags; =20 - spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags); + raw_spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags); if (list_empty(&csdev->feature_csdev_list)) goto unlock_exit; =20 @@ -863,7 +863,7 @@ void cscfg_csdev_reset_feats(struct coresight_device *c= sdev) cscfg_reset_feat(feat_csdev); =20 unlock_exit: - spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags); + raw_spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags); } EXPORT_SYMBOL_GPL(cscfg_csdev_reset_feats); =20 @@ -1059,7 +1059,7 @@ int cscfg_csdev_enable_active_config(struct coresight= _device *csdev, * Look for matching configuration - set the active configuration * context if found. */ - spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags); + raw_spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags); list_for_each_entry(config_csdev_item, &csdev->config_csdev_list, node) { config_desc =3D config_csdev_item->config_desc; if ((atomic_read(&config_desc->active_cnt)) && @@ -1069,7 +1069,7 @@ int cscfg_csdev_enable_active_config(struct coresight= _device *csdev, break; } } - spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags); + raw_spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags); =20 /* * If found, attempt to enable @@ -1090,12 +1090,12 @@ int cscfg_csdev_enable_active_config(struct coresig= ht_device *csdev, * * Set enabled if OK, err if not. */ - spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags); + raw_spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags); if (csdev->active_cscfg_ctxt) config_csdev_active->enabled =3D true; else err =3D -EBUSY; - spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags); + raw_spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags); } } return err; @@ -1124,7 +1124,7 @@ void cscfg_csdev_disable_active_config(struct coresig= ht_device *csdev) * If it was not enabled, we have no work to do, otherwise mark as disabl= ed. * Clear the active config pointer. */ - spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags); + raw_spin_lock_irqsave(&csdev->cscfg_csdev_lock, flags); config_csdev =3D (struct cscfg_config_csdev *)csdev->active_cscfg_ctxt; if (config_csdev) { if (!config_csdev->enabled) @@ -1133,7 +1133,7 @@ void cscfg_csdev_disable_active_config(struct coresig= ht_device *csdev) config_csdev->enabled =3D false; } csdev->active_cscfg_ctxt =3D NULL; - spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags); + raw_spin_unlock_irqrestore(&csdev->cscfg_csdev_lock, flags); =20 /* true if there was an enabled active config */ if (config_csdev) diff --git a/include/linux/coresight.h b/include/linux/coresight.h index c13342594278..924b58c343b3 100644 --- a/include/linux/coresight.h +++ b/include/linux/coresight.h @@ -296,7 +296,7 @@ struct coresight_device { /* system configuration and feature lists */ struct list_head feature_csdev_list; struct list_head config_csdev_list; - spinlock_t cscfg_csdev_lock; + raw_spinlock_t cscfg_csdev_lock; void *active_cscfg_ctxt; }; =20 --=20 LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}