From mboxrd@z Thu Jan 1 00:00:00 1970 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=ham 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 8FA28C2BB40 for ; Mon, 14 Dec 2020 17:39:30 +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 32AE221534 for ; Mon, 14 Dec 2020 17:39:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 32AE221534 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=/5DZkN1yfPE8QWWEWlF0eSgxgf3rgXU22EY9G+s5QSY=; b=m4m1aDuBR8uVDGHvG012U1VWt 51k08Awvx68pWFwMP3HtkFTfDBoD7yo4vEh1wDn9ZGTJTXb3jwM4cHoDMKOURiv62hBJJhozAN0bj v6qUgRJza2rJ2bwQ1HhWHRIpfpSoFOu2KnA+s8FR5BTgkh2ZgPbSOfwobqX13xdiKenGOY6+frMZ4 G5eNoDhxKbTsmQBoJ8TBBLmC3eNicW2hLi+nTn3v0a55D6onBnyApsBzESA44BMkgHbrdBpg37KqD lVxmGxHYyA1NWsKFxXXEOlf4UxRRsX8b9sySg1ThhyVr3AHH4pIO4bBQVreIRRK6PTjEr9AEuGKn1 OtRVvnybA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kornK-0005Dd-GE; Mon, 14 Dec 2020 17:37:58 +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 1korn9-0005AO-F9 for linux-arm-kernel@lists.infradead.org; Mon, 14 Dec 2020 17:37:48 +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 57939D6E; Mon, 14 Dec 2020 09:37:45 -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 D747C3F66E; Mon, 14 Dec 2020 09:37:43 -0800 (PST) From: Suzuki K Poulose To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v5 02/25] coresight: etm4x: Skip accessing TRCPDCR in save/restore Date: Mon, 14 Dec 2020 17:37:08 +0000 Message-Id: <20201214173731.302520-3-suzuki.poulose@arm.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20201214173731.302520-1-suzuki.poulose@arm.com> References: <20201214173731.302520-1-suzuki.poulose@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201214_123747_571571_793962EF X-CRM114-Status: GOOD ( 13.00 ) 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, Suzuki K Poulose , catalin.marinas@arm.com, linux-kernel@vger.kernel.org, Tingwei Zhang , leo.yan@linaro.org, jonathan.zhouwen@huawei.com, mike.leach@linaro.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit 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: 02510a5aa78df45 ("coresight: etm4x: Add support to skip trace unit power up") Cc: Mathieu Poirier Cc: Mike Leach Cc: Sai Prakash Ranjan Cc: Tingwei Zhang Reviewed-by: Sai Prakash Ranjan Tested-by: Sai Prakash Ranjan 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 eb56fba1f7c0..20136722011e 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; -- 2.24.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel