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=-16.7 required=3.0 tests=BAYES_00, 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 8B156C2BB40 for ; Mon, 14 Dec 2020 18:04:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 49F3A22286 for ; Mon, 14 Dec 2020 18:04:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728810AbgLNSDd (ORCPT ); Mon, 14 Dec 2020 13:03:33 -0500 Received: from foss.arm.com ([217.140.110.172]:50528 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2408640AbgLNRjp (ORCPT ); Mon, 14 Dec 2020 12:39:45 -0500 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 087AF1500; Mon, 14 Dec 2020 09:38:12 -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 C40333F66E; Mon, 14 Dec 2020 09:38:10 -0800 (PST) From: Suzuki K Poulose To: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org, catalin.marinas@arm.com, mathieu.poirier@linaro.org, mike.leach@linaro.org, leo.yan@linaro.org, jonathan.zhouwen@huawei.com, Suzuki K Poulose Subject: [PATCH v5 20/25] coresight: etm4x: Detect system instructions support Date: Mon, 14 Dec 2020 17:37:26 +0000 Message-Id: <20201214173731.302520-21-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 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org ETM v4.4 onwards adds support for system instruction access to the ETM. Detect the support on an ETM and switch to using the mode when available. Cc: Mike Leach Reviewed-by: Mathieu Poirier Signed-off-by: Suzuki K Poulose --- .../coresight/coresight-etm4x-core.c | 39 +++++++++++++++++++ 1 file changed, 39 insertions(+) diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c index 366fae810b55..25eb42c95527 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c @@ -684,6 +684,37 @@ static const struct coresight_ops etm4_cs_ops = { .source_ops = &etm4_source_ops, }; +static inline bool cpu_supports_sysreg_trace(void) +{ + u64 dfr0 = read_sysreg_s(SYS_ID_AA64DFR0_EL1); + + return ((dfr0 >> ID_AA64DFR0_TRACEVER_SHIFT) & 0xfUL) > 0; +} + +static bool etm4_init_sysreg_access(struct etmv4_drvdata *drvdata, + struct csdev_access *csa) +{ + u32 devarch; + + if (!cpu_supports_sysreg_trace()) + return false; + + /* + * ETMs implementing sysreg access must implement TRCDEVARCH. + */ + devarch = read_etm4x_sysreg_const_offset(TRCDEVARCH); + if ((devarch & ETM_DEVARCH_ID_MASK) != ETM_DEVARCH_ETMv4x_ARCH) + return false; + *csa = (struct csdev_access) { + .io_mem = false, + .read = etm4x_sysreg_read, + .write = etm4x_sysreg_write, + }; + + drvdata->arch = etm_devarch_to_arch(devarch); + return true; +} + static bool etm4_init_iomem_access(struct etmv4_drvdata *drvdata, struct csdev_access *csa) { @@ -714,9 +745,17 @@ static bool etm4_init_iomem_access(struct etmv4_drvdata *drvdata, static bool etm4_init_csdev_access(struct etmv4_drvdata *drvdata, struct csdev_access *csa) { + /* + * Always choose the memory mapped io, if there is + * a memory map to prevent sysreg access on broken + * systems. + */ if (drvdata->base) return etm4_init_iomem_access(drvdata, csa); + if (etm4_init_sysreg_access(drvdata, csa)) + return true; + return false; } -- 2.24.1