From nobody Wed Apr 8 06:22:54 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 345D6C32772 for ; Tue, 23 Aug 2022 18:02:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233273AbiHWSCx (ORCPT ); Tue, 23 Aug 2022 14:02:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55104 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229530AbiHWSBC (ORCPT ); Tue, 23 Aug 2022 14:01:02 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id AD5DADCFCA; Tue, 23 Aug 2022 09:07:10 -0700 (PDT) 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 BB94411FB; Tue, 23 Aug 2022 09:07:13 -0700 (PDT) Received: from e121896.arm.com (unknown [10.57.14.228]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id DE3553F718; Tue, 23 Aug 2022 09:07:07 -0700 (PDT) From: James Clark To: suzuki.poulose@arm.com, coresight@lists.linaro.org, mathieu.poirier@linaro.org Cc: mike.leach@linaro.org, leo.yan@linaro.org, linux-kernel@vger.kernel.org, german.gomez@arm.com, James Clark , Jonathan Corbet , Catalin Marinas , Will Deacon , Alexander Shishkin , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org Subject: [PATCH v3 1/2] coresight: etm4x: Expose default timestamp source in sysfs Date: Tue, 23 Aug 2022 17:06:49 +0100 Message-Id: <20220823160650.455823-2-james.clark@arm.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20220823160650.455823-1-james.clark@arm.com> References: <20220823160650.455823-1-james.clark@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: German Gomez Add a new sysfs interface in /sys/bus/coresight/devices/etm/ts_source indicating the configured timestamp source when the ETM device driver was probed. The perf tool will use this information to detect if the trace data timestamp matches the kernel time, enabling correlation of CoreSight trace with perf events. Suggested-by: Suzuki K Poulose Signed-off-by: German Gomez Reviewed-by: Leo Yan Signed-off-by: James Clark --- arch/arm64/include/asm/sysreg.h | 1 + .../coresight/coresight-etm4x-sysfs.c | 29 +++++++++++++++++++ 2 files changed, 30 insertions(+) diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysre= g.h index 7c71358d44c4..7a518a011669 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -1021,6 +1021,7 @@ #define SYS_MPIDR_SAFE_VAL (BIT(31)) =20 #define TRFCR_ELx_TS_SHIFT 5 +#define TRFCR_ELx_TS_MASK ((0x3UL) << TRFCR_ELx_TS_SHIFT) #define TRFCR_ELx_TS_VIRTUAL ((0x1UL) << TRFCR_ELx_TS_SHIFT) #define TRFCR_ELx_TS_GUEST_PHYSICAL ((0x2UL) << TRFCR_ELx_TS_SHIFT) #define TRFCR_ELx_TS_PHYSICAL ((0x3UL) << TRFCR_ELx_TS_SHIFT) diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/= hwtracing/coresight/coresight-etm4x-sysfs.c index 6ea8181816fc..9cac848cffaf 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c @@ -2306,6 +2306,34 @@ static ssize_t cpu_show(struct device *dev, } static DEVICE_ATTR_RO(cpu); =20 +static ssize_t ts_source_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + int val; + struct etmv4_drvdata *drvdata =3D dev_get_drvdata(dev->parent); + + if (!drvdata->trfcr) { + val =3D -1; + goto out; + } + + switch (drvdata->trfcr & TRFCR_ELx_TS_MASK) { + case TRFCR_ELx_TS_VIRTUAL: + case TRFCR_ELx_TS_GUEST_PHYSICAL: + case TRFCR_ELx_TS_PHYSICAL: + val =3D FIELD_GET(TRFCR_ELx_TS_MASK, drvdata->trfcr); + break; + default: + val =3D -1; + break; + } + +out: + return sysfs_emit(buf, "%d\n", val); +} +static DEVICE_ATTR_RO(ts_source); + static struct attribute *coresight_etmv4_attrs[] =3D { &dev_attr_nr_pe_cmp.attr, &dev_attr_nr_addr_cmp.attr, @@ -2360,6 +2388,7 @@ static struct attribute *coresight_etmv4_attrs[] =3D { &dev_attr_vmid_val.attr, &dev_attr_vmid_masks.attr, &dev_attr_cpu.attr, + &dev_attr_ts_source.attr, NULL, }; =20 --=20 2.28.0