From patchwork Fri Dec 20 10:45:18 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yeoreum Yun X-Patchwork-Id: 13916564 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 715D8E77188 for ; Fri, 20 Dec 2024 11:13:43 +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:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=ljL7AFcI7IIjYI5958YETZOH6G0XYmGGzbsx1CoOEYo=; b=gy4JKcADmJq+FaJDuog0uAgE+P OtYngudhJvbunUoWdGpxFNdk3xekYeZut0ajUNiv6qX+I3ST4FBK9amDtQKC1/vff/4+Uf0HjmoQr iBtrLE8gk0O31v/Mc18of3a4AhY9keaOk4sOnfRx27I4+Bkqyw/ezOuUjBsu7HlEbHEGIHgtSSS5n O6XBK2zJLlNUSvpquY1CCSTx4ZOYrnyxzwRzRKIy+FwXo9CL2p6/BRupXn7lyvv20IgP3oxJVrvTz vNxjp9Qk34hoxNstlQIMf+fyOroIztJBis+aSdeDxR36D1gzErTv5RO2860o/wdTNtvH8DPkNSMly QvtqjqLQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tOawa-00000004hQv-43qE; Fri, 20 Dec 2024 11:13:20 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tOaVq-00000004d76-3pDT for linux-arm-kernel@lists.infradead.org; Fri, 20 Dec 2024 10:45:44 +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 A16801480; Fri, 20 Dec 2024 02:46:10 -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 82AB93F720; Fri, 20 Dec 2024 02:45:40 -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 6/9] coresight-funnel: change funnel_drvdata spinlock's type to raw_spinlock_t Date: Fri, 20 Dec 2024 10:45:18 +0000 Message-Id: <20241220104521.809071-8-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> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241220_024543_033422_ED4F254E X-CRM114-Status: GOOD ( 10.25 ) 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 In coresight-funnel drivers, cti_drvdata->spinlock can be held during __schedule() by perf_event_task_sched_out()/in(). Since funnel_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 funnel_drvdata->spinlock in coresight-funnel drivers, 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-funnel.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-funnel.c b/drivers/hwtracing/coresight/coresight-funnel.c index 33efe1acbef7..a566c8854327 100644 --- a/drivers/hwtracing/coresight/coresight-funnel.c +++ b/drivers/hwtracing/coresight/coresight-funnel.c @@ -47,7 +47,7 @@ struct funnel_drvdata { struct clk *pclk; struct coresight_device *csdev; unsigned long priority; - spinlock_t spinlock; + raw_spinlock_t spinlock; }; static int dynamic_funnel_enable_hw(struct funnel_drvdata *drvdata, int port) @@ -85,7 +85,7 @@ static int funnel_enable(struct coresight_device *csdev, unsigned long flags; bool first_enable = false; - spin_lock_irqsave(&drvdata->spinlock, flags); + raw_spin_lock_irqsave(&drvdata->spinlock, flags); if (atomic_read(&in->dest_refcnt) == 0) { if (drvdata->base) rc = dynamic_funnel_enable_hw(drvdata, in->dest_port); @@ -94,7 +94,7 @@ static int funnel_enable(struct coresight_device *csdev, } if (!rc) atomic_inc(&in->dest_refcnt); - spin_unlock_irqrestore(&drvdata->spinlock, flags); + raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); if (first_enable) dev_dbg(&csdev->dev, "FUNNEL inport %d enabled\n", @@ -129,13 +129,13 @@ static void funnel_disable(struct coresight_device *csdev, unsigned long flags; bool last_disable = false; - spin_lock_irqsave(&drvdata->spinlock, flags); + raw_spin_lock_irqsave(&drvdata->spinlock, flags); if (atomic_dec_return(&in->dest_refcnt) == 0) { if (drvdata->base) dynamic_funnel_disable_hw(drvdata, in->dest_port); last_disable = true; } - spin_unlock_irqrestore(&drvdata->spinlock, flags); + raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); if (last_disable) dev_dbg(&csdev->dev, "FUNNEL inport %d disabled\n", @@ -266,7 +266,7 @@ static int funnel_probe(struct device *dev, struct resource *res) } dev->platform_data = pdata; - spin_lock_init(&drvdata->spinlock); + raw_spin_lock_init(&drvdata->spinlock); desc.type = CORESIGHT_DEV_TYPE_LINK; desc.subtype.link_subtype = CORESIGHT_DEV_SUBTYPE_LINK_MERG; desc.ops = &funnel_cs_ops;