From patchwork Wed May 11 14:45:58 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Clark X-Patchwork-Id: 12846276 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 934B5C433EF for ; Wed, 11 May 2022 14:47:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=3JeloJeGKQNZQUfjRVRFSL5Q7MtPDOcNiOh2pwSDPhE=; b=rPluG5v/q2X50y pLCp9Nl9rZyN6iko9I7rAYwzmnzRApZ05NS3s6XeZ+UnjvEJ2i7mQlK0gWffRx3TBYsIlKhDcYKpU 1Ij666YesbHrDq1VzhQChGXMsMNXNQwLMM/mX+kbzdI3K/+jEUx3dp6g0YLVgJDh3/nK2ZU/F3+NT IHxg+t449cBczs3srXeQv4wub5FwpmsHBb8EEkBaq9x+2y6/IbtwEX1oPX3bgBG59qx9TacRDQg8A j4EDVR3Uednuvu91LcOcu9blM7l0FC4uh899LnKRavseMXo6Dx1GmJWGoqizOS/ZWXvC0T1okTTE4 92dAw53+bbBkagIfhJ0g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nonbZ-007ISE-AT; Wed, 11 May 2022 14:46:21 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nonbO-007IN8-A9 for linux-arm-kernel@lists.infradead.org; Wed, 11 May 2022 14:46:11 +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 A56431042; Wed, 11 May 2022 07:46:09 -0700 (PDT) Received: from e121896.arm.com (unknown [10.57.2.55]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id EC4933F66F; Wed, 11 May 2022 07:46:07 -0700 (PDT) From: James Clark To: suzuki.poulose@arm.com, mathieu.poirier@linaro.org, coresight@lists.linaro.org, mike.leach@linaro.org Cc: leo.yan@linaro.com, James Clark , Leo Yan , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 1/4] coresight: Add config flag to enable branch broadcast Date: Wed, 11 May 2022 15:45:58 +0100 Message-Id: <20220511144601.2257870-2-james.clark@arm.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20220511144601.2257870-1-james.clark@arm.com> References: <20220511144601.2257870-1-james.clark@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220511_074610_480686_1BAF2D3B X-CRM114-Status: GOOD ( 16.62 ) 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 When enabled, all taken branch addresses are output, even if the branch was because of a direct branch instruction. This enables reconstruction of the program flow without having access to the memory image of the code being executed. Use bit 8 for the config option which would be the correct bit for programming ETMv3. Although branch broadcast can't be enabled on ETMv3 because it's not in the define ETM3X_SUPPORTED_OPTIONS, using the correct bit might help prevent future collisions or allow it to be enabled if needed. Signed-off-by: James Clark Reviewed-by: Mike Leach --- drivers/hwtracing/coresight/coresight-etm-perf.c | 2 ++ drivers/hwtracing/coresight/coresight-etm4x-core.c | 14 ++++++++++++++ include/linux/coresight-pmu.h | 2 ++ 3 files changed, 18 insertions(+) diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c index c039b6ae206f..43bbd5dc3d3b 100644 --- a/drivers/hwtracing/coresight/coresight-etm-perf.c +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c @@ -52,6 +52,7 @@ static DEFINE_PER_CPU(struct coresight_device *, csdev_src); * The PMU formats were orignally for ETMv3.5/PTM's ETMCR 'config'; * now take them as general formats and apply on all ETMs. */ +PMU_FORMAT_ATTR(branch_broadcast, "config:"__stringify(ETM_OPT_BRANCH_BROADCAST)); PMU_FORMAT_ATTR(cycacc, "config:" __stringify(ETM_OPT_CYCACC)); /* contextid1 enables tracing CONTEXTIDR_EL1 for ETMv4 */ PMU_FORMAT_ATTR(contextid1, "config:" __stringify(ETM_OPT_CTXTID)); @@ -97,6 +98,7 @@ static struct attribute *etm_config_formats_attr[] = { &format_attr_sinkid.attr, &format_attr_preset.attr, &format_attr_configid.attr, + &format_attr_branch_broadcast.attr, NULL, }; diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c index 87299e99dabb..cf249ecad5a5 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c @@ -696,6 +696,20 @@ static int etm4_parse_event_config(struct coresight_device *csdev, ret = cscfg_csdev_enable_active_config(csdev, cfg_hash, preset); } + /* branch broadcast - enable if selected and supported */ + if (attr->config & BIT(ETM_OPT_BRANCH_BROADCAST)) { + if (!drvdata->trcbb) { + /* + * Missing BB support could cause silent decode errors + * so fail to open if it's not supported. + */ + ret = -EINVAL; + goto out; + } else { + config->cfg |= BIT(ETM4_CFG_BIT_BB); + } + } + out: return ret; } diff --git a/include/linux/coresight-pmu.h b/include/linux/coresight-pmu.h index 4ac5c081af93..6c2fd6cc5a98 100644 --- a/include/linux/coresight-pmu.h +++ b/include/linux/coresight-pmu.h @@ -18,6 +18,7 @@ * ETMv3.5/PTM doesn't define ETMCR config bits with prefix "ETM3_" and * directly use below macros as config bits. */ +#define ETM_OPT_BRANCH_BROADCAST 8 #define ETM_OPT_CYCACC 12 #define ETM_OPT_CTXTID 14 #define ETM_OPT_CTXTID2 15 @@ -25,6 +26,7 @@ #define ETM_OPT_RETSTK 29 /* ETMv4 CONFIGR programming bits for the ETM OPTs */ +#define ETM4_CFG_BIT_BB 3 #define ETM4_CFG_BIT_CYCACC 4 #define ETM4_CFG_BIT_CTXTID 6 #define ETM4_CFG_BIT_VMID 7