From patchwork Thu Nov 19 16:45:24 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Suzuki K Poulose X-Patchwork-Id: 11918293 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 19782C56201 for ; Thu, 19 Nov 2020 16:47:40 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 924B42222A for ; Thu, 19 Nov 2020 16:47:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="ged9fGvg" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 924B42222A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:Message-Id:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=HfCmq7jEJx6oXd5gPHuTxpJWPwi99fB7ZDWNNyohccI=; b=ged9fGvgPrUX+1I4qlJssr7ez n7pXrFHH1oXGn0Ge3Uo7J3gAVGWYtmsYdXxz2kBef7WM1gcOIXNs6lpD+lu2ilXmzEivkEHTlU3O4 2CSAQSHv5UjmiuZ92dU0JXc//rdRa4r91n4krFwMxwdsIxgQZViI30sOBJeoG3WqgToyr9YikFJqI 2GVTT7wnH86ZUCicFUrWnaIhKVwk4V2actYmE16rW/61PMIYrss9UuUQJwaM7rWw9Z1yHCpz6humH wO8hIflMtRjmhji6cAWPO3LIeRS/amfFGMdF7DN7h6g/XE8WQRzAzxl1pIpHHwHjY7rZte/nWSDh8 i12gpe3Pg==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kfn5P-0001KN-DB; Thu, 19 Nov 2020 16:47:07 +0000 Received: from foss.arm.com ([217.140.110.172]) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kfn4U-0000yz-GF for linux-arm-kernel@lists.infradead.org; Thu, 19 Nov 2020 16:46:20 +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 5875615AD; Thu, 19 Nov 2020 08:46:04 -0800 (PST) Received: from ewhatever.cambridge.arm.com (ewhatever.cambridge.arm.com [10.1.197.1]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 078303F719; Thu, 19 Nov 2020 08:46:02 -0800 (PST) From: Suzuki K Poulose To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v4 02/25] coresight: etm4x: Skip accessing TRCPDCR in save/restore Date: Thu, 19 Nov 2020 16:45:24 +0000 Message-Id: <20201119164547.2982871-3-suzuki.poulose@arm.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20201119164547.2982871-1-suzuki.poulose@arm.com> References: <20201119164547.2982871-1-suzuki.poulose@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201119_114610_893711_6183E6BA X-CRM114-Status: GOOD ( 13.10 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Sai Prakash Ranjan , mathieu.poirier@linaro.org, anshuman.khandual@arm.com, coresight@lists.linaro.org, Suzuki K Poulose , linux-kernel@vger.kernel.org, Tingwei Zhang , jonathan.zhouwen@huawei.com, mike.leach@linaro.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org When the ETM is affected by Qualcomm errata, modifying the TRCPDCR could cause the system hang. Even though this is taken care of during enable/disable ETM, the ETM state save/restore could still access the TRCPDCR. Make sure we skip the access during the save/restore. Found by code inspection. Fixes: commit 02510a5aa78df45 ("coresight: etm4x: Add support to skip trace unit power up") Cc: Mathieu Poirier Cc: Mike Leach Cc: Sai Prakash Ranjan Cc: Tingwei Zhang Signed-off-by: Suzuki K Poulose --- drivers/hwtracing/coresight/coresight-etm4x-core.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c index 59a4a166adf4..ea2e317ddb7d 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c @@ -1277,7 +1277,8 @@ static int etm4_cpu_save(struct etmv4_drvdata *drvdata) state->trcclaimset = readl(drvdata->base + TRCCLAIMCLR); - state->trcpdcr = readl(drvdata->base + TRCPDCR); + if (!drvdata->skip_power_up) + state->trcpdcr = readl(drvdata->base + TRCPDCR); /* wait for TRCSTATR.IDLE to go up */ if (coresight_timeout(drvdata->base, TRCSTATR, TRCSTATR_IDLE_BIT, 1)) { @@ -1295,9 +1296,9 @@ static int etm4_cpu_save(struct etmv4_drvdata *drvdata) * potentially save power on systems that respect the TRCPDCR_PU * despite requesting software to save/restore state. */ - writel_relaxed((state->trcpdcr & ~TRCPDCR_PU), - drvdata->base + TRCPDCR); - + if (!drvdata->skip_power_up) + writel_relaxed((state->trcpdcr & ~TRCPDCR_PU), + drvdata->base + TRCPDCR); out: CS_LOCK(drvdata->base); return ret; @@ -1392,7 +1393,8 @@ static void etm4_cpu_restore(struct etmv4_drvdata *drvdata) writel_relaxed(state->trcclaimset, drvdata->base + TRCCLAIMSET); - writel_relaxed(state->trcpdcr, drvdata->base + TRCPDCR); + if (!drvdata->skip_power_up) + writel_relaxed(state->trcpdcr, drvdata->base + TRCPDCR); drvdata->state_needs_restore = false;