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=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 DAE8CC4332B for ; Tue, 2 Mar 2021 04:08:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A954764DDD for ; Tue, 2 Mar 2021 04:08:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241526AbhCBCIM (ORCPT ); Mon, 1 Mar 2021 21:08:12 -0500 Received: from mail.kernel.org ([198.145.29.99]:50712 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242084AbhCATfJ (ORCPT ); Mon, 1 Mar 2021 14:35:09 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 49E8765214; Mon, 1 Mar 2021 17:22:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1614619341; bh=PxZaXedl2P6bCaHX0ljUgUVN2TbxqyrvQcDboCvNTKA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dRT65EWFcTqT+9emsiIKLyaAvIQfjbjegW6MhV4yDj0DZEhn0rerN2LpkAAHjE37U JLM4k4sfUkOs52rcpeSRAlu0PF8ZPET1abqeYOsvILHww+50FsikhLmkdbeCSTxX/5 1FraVLL4ioM/0qmnZIcc9296YZCBN3nmmQd7qQCc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mathieu Poirier , Mike Leach , Sai Prakash Ranjan , Tingwei Zhang , Suzuki K Poulose , Sasha Levin Subject: [PATCH 5.10 419/663] coresight: etm4x: Skip accessing TRCPDCR in save/restore Date: Mon, 1 Mar 2021 17:11:07 +0100 Message-Id: <20210301161202.606107908@linuxfoundation.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210301161141.760350206@linuxfoundation.org> References: <20210301161141.760350206@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Suzuki K Poulose [ Upstream commit df81b43802f43c0954a55e5d513e8750a1ab4d31 ] 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. Link: https://lore.kernel.org/r/20210110224850.1880240-3-suzuki.poulose@arm.com Fixes: 02510a5aa78d ("coresight: etm4x: Add support to skip trace unit power up") Cc: Mathieu Poirier Cc: Mike Leach Cc: Sai Prakash Ranjan Cc: Tingwei Zhang Tested-by: Sai Prakash Ranjan Reviewed-by: Sai Prakash Ranjan Signed-off-by: Suzuki K Poulose Signed-off-by: Mathieu Poirier Link: https://lore.kernel.org/r/20210201181351.1475223-5-mathieu.poirier@linaro.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- 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 95b54b0a36252..8b6666e6fddbf 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c @@ -1254,7 +1254,8 @@ 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)) { @@ -1272,9 +1273,9 @@ 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; @@ -1368,7 +1369,8 @@ 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; -- 2.27.0