From nobody Thu Apr 9 03:30:23 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 E44B5C4332F for ; Tue, 1 Nov 2022 16:31:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230471AbiKAQb5 (ORCPT ); Tue, 1 Nov 2022 12:31:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33926 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229890AbiKAQbb (ORCPT ); Tue, 1 Nov 2022 12:31:31 -0400 Received: from mail-wm1-x332.google.com (mail-wm1-x332.google.com [IPv6:2a00:1450:4864:20::332]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 654B31CFFC for ; Tue, 1 Nov 2022 09:31:29 -0700 (PDT) Received: by mail-wm1-x332.google.com with SMTP id ay14-20020a05600c1e0e00b003cf6ab34b61so3768344wmb.2 for ; Tue, 01 Nov 2022 09:31:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=references:in-reply-to:message-id:date:subject:cc:to:from:from:to :cc:subject:date:message-id:reply-to; bh=fdNBgmLA0ARtvmJ0vN5Z/w6aKfYyu8s0U0URVnDv14o=; b=GmBttxW57q4eTxB+S/I89JTXG96fqaGKEX3+vysn28FpPRqw9ol3jkXM4Xe5wINmTf IGcsWtkLLUIXPUNEVtiqiq2ZFUJ2v5pvNs9aZzXdg88hYWdjrvDFSjN26E2pHza6T986 +elzQiNRNdXLay3Jig/5ard3PSZzzYRo74dnyrDS8441jJLnH61N3aPVHLDTf+rTW7GU VzcNPftF3plhDka6AHNmZJmHmntfsZNjyDy+6hlK4L18eENgEkBXMy2kU5MgkSxuRTxI RQSSUfGwMQhe3JJF4kVbdnFhr3ZFAIvKdy9+69eQvdCeNsaFMK9PmtsGXQ9zdHUu8vI8 HISQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=references:in-reply-to:message-id:date:subject:cc:to:from :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=fdNBgmLA0ARtvmJ0vN5Z/w6aKfYyu8s0U0URVnDv14o=; b=GqxobomcOgxWMdrM0NTbeXieB4skMqA/8DRKNZjWHlS8KBJkw5KxWiJ2ljVhgl1WND ggntT2+/SjwyL/CY5CtI7L/aGTmUCewqc45PUsrEYUdiuMF1rJ9MpoUppdUx2PmlQMhp fPAQqsjtQunikLH2u3SxhqMtWTShqPxAzxHZgjo4bZetK5umPF5VWIPTznXFKWmE2Smb 0k0dQhqu5PWSkdZd0iC7y4TFgUJ94PULVUcxSvtqwKS41x8NpROBHAyghFahVIT+wDRX WS/4FOTaqAz5b2cNrKhtIqkXcU+7IsjfXMZaGAmPTWSi91RVftdsIW0qLHPYpynzOaOc jF5Q== X-Gm-Message-State: ACrzQf1Iv0uUUaV8WlI+IrsVeCl5LwGKgoQWp0cFH5tL3GYRZR5REevK dsn9PC9ngvMbBCbNUo8ICTAQvg== X-Google-Smtp-Source: AMsMyM5TSEWjTx8x+xRblm1eFpK1faSNEwZCU48u8GG46iWu6Y9mu8PLqBH9P6FaCw59yn8vvjSygQ== X-Received: by 2002:a05:600c:230d:b0:3c4:2975:321a with SMTP id 13-20020a05600c230d00b003c42975321amr22606104wmo.155.1667320287924; Tue, 01 Nov 2022 09:31:27 -0700 (PDT) Received: from linaro.org ([2a00:23c5:6809:2201:e844:18b6:fc5:bbc9]) by smtp.gmail.com with ESMTPSA id bu15-20020a056000078f00b0022ac1be009esm8339844wrb.16.2022.11.01.09.31.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 01 Nov 2022 09:31:27 -0700 (PDT) From: Mike Leach To: coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: mathieu.poirier@linaro.org, suzuki.poulose@arm.com, peterz@infradead.org, mingo@redhat.com, acme@kernel.org, linux-perf-users@vger.kernel.org, leo.yan@linaro.org, quic_jinlmao@quicinc.com, Mike Leach Subject: [PATCH v5 06/14] coresight: etm3x: Update ETM3 driver to use Trace ID API Date: Tue, 1 Nov 2022 16:30:55 +0000 Message-Id: <20221101163103.17921-7-mike.leach@linaro.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20221101163103.17921-1-mike.leach@linaro.org> References: <20221101163103.17921-1-mike.leach@linaro.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Use the TraceID API to allocate ETM trace IDs dynamically. As with the etm4x we allocate on enable / disable for perf, allocate on enable / reset for sysfs. Additionally we allocate on sysfs file read as both perf and sysfs can read the ID before enabling the hardware. Remove sysfs option to write trace ID - which is inconsistent with both the dynamic allocation method and the fixed allocation method previously used. Signed-off-by: Mike Leach Reviewed-by: Suzuki K Poulose --- drivers/hwtracing/coresight/coresight-etm.h | 2 + .../coresight/coresight-etm3x-core.c | 69 +++++++++++++++++-- .../coresight/coresight-etm3x-sysfs.c | 27 ++------ 3 files changed, 72 insertions(+), 26 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-etm.h b/drivers/hwtracin= g/coresight/coresight-etm.h index f3ab96eaf44e..3667428d38b6 100644 --- a/drivers/hwtracing/coresight/coresight-etm.h +++ b/drivers/hwtracing/coresight/coresight-etm.h @@ -287,4 +287,6 @@ int etm_get_trace_id(struct etm_drvdata *drvdata); void etm_set_default(struct etm_config *config); void etm_config_trace_mode(struct etm_config *config); struct etm_config *get_etm_config(struct etm_drvdata *drvdata); +int etm_read_alloc_trace_id(struct etm_drvdata *drvdata); +void etm_release_trace_id(struct etm_drvdata *drvdata); #endif diff --git a/drivers/hwtracing/coresight/coresight-etm3x-core.c b/drivers/h= wtracing/coresight/coresight-etm3x-core.c index d0ab9933472b..9a7a9e974d41 100644 --- a/drivers/hwtracing/coresight/coresight-etm3x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm3x-core.c @@ -32,6 +32,7 @@ =20 #include "coresight-etm.h" #include "coresight-etm-perf.h" +#include "coresight-trace-id.h" =20 /* * Not really modular but using module_param is the easiest way to @@ -490,16 +491,59 @@ static int etm_trace_id(struct coresight_device *csde= v) return etm_get_trace_id(drvdata); } =20 +int etm_read_alloc_trace_id(struct etm_drvdata *drvdata) +{ + int trace_id; + + /* + * This will allocate a trace ID to the cpu, + * or return the one currently allocated. + * + * trace id function has its own lock + */ + trace_id =3D coresight_trace_id_get_cpu_id(drvdata->cpu); + if (IS_VALID_ID(trace_id)) + drvdata->traceid =3D (u8)trace_id; + else + dev_err(&drvdata->csdev->dev, + "Failed to allocate trace ID for %s on CPU%d\n", + dev_name(&drvdata->csdev->dev), drvdata->cpu); + return trace_id; +} + +void etm_release_trace_id(struct etm_drvdata *drvdata) +{ + coresight_trace_id_put_cpu_id(drvdata->cpu); +} + static int etm_enable_perf(struct coresight_device *csdev, struct perf_event *event) { struct etm_drvdata *drvdata =3D dev_get_drvdata(csdev->dev.parent); + int trace_id; =20 if (WARN_ON_ONCE(drvdata->cpu !=3D smp_processor_id())) return -EINVAL; =20 /* Configure the tracer based on the session's specifics */ etm_parse_event_config(drvdata, event); + + /* + * perf allocates cpu ids as part of _setup_aux() - device needs to use + * the allocated ID. This reads the current version without allocation. + * + * This does not use the trace id lock to prevent lock_dep issues + * with perf locks - we know the ID cannot change until perf shuts down + * the session + */ + trace_id =3D coresight_trace_id_read_cpu_id(drvdata->cpu); + if (!IS_VALID_ID(trace_id)) { + dev_err(&drvdata->csdev->dev, "Failed to set trace ID for %s on CPU%d\n", + dev_name(&drvdata->csdev->dev), drvdata->cpu); + return -EINVAL; + } + drvdata->traceid =3D (u8)trace_id; + /* And enable it */ return etm_enable_hw(drvdata); } @@ -512,6 +556,11 @@ static int etm_enable_sysfs(struct coresight_device *c= sdev) =20 spin_lock(&drvdata->spinlock); =20 + /* sysfs needs to allocate and set a trace ID */ + ret =3D etm_read_alloc_trace_id(drvdata); + if (ret < 0) + goto unlock_enable_sysfs; + /* * Configure the ETM only if the CPU is online. If it isn't online * hw configuration will take place on the local CPU during bring up. @@ -528,6 +577,10 @@ static int etm_enable_sysfs(struct coresight_device *c= sdev) ret =3D -ENODEV; } =20 + if (ret) + etm_release_trace_id(drvdata); + +unlock_enable_sysfs: spin_unlock(&drvdata->spinlock); =20 if (!ret) @@ -611,6 +664,9 @@ static void etm_disable_perf(struct coresight_device *c= sdev) coresight_disclaim_device_unlocked(csdev); =20 CS_LOCK(drvdata->base); + + /* perf will release trace ids when _free_aux() is called at the end of t= he session */ + } =20 static void etm_disable_sysfs(struct coresight_device *csdev) @@ -635,6 +691,13 @@ static void etm_disable_sysfs(struct coresight_device = *csdev) spin_unlock(&drvdata->spinlock); cpus_read_unlock(); =20 + /* + * we only release trace IDs when resetting sysfs. + * This permits sysfs users to read the trace ID after the trace + * session has completed. This maintains operational behaviour with + * prior trace id allocation method + */ + dev_dbg(&csdev->dev, "ETM tracing disabled\n"); } =20 @@ -781,11 +844,6 @@ static void etm_init_arch_data(void *info) CS_LOCK(drvdata->base); } =20 -static void etm_init_trace_id(struct etm_drvdata *drvdata) -{ - drvdata->traceid =3D coresight_get_trace_id(drvdata->cpu); -} - static int __init etm_hp_setup(void) { int ret; @@ -871,7 +929,6 @@ static int etm_probe(struct amba_device *adev, const st= ruct amba_id *id) if (etm_arch_supported(drvdata->arch) =3D=3D false) return -EINVAL; =20 - etm_init_trace_id(drvdata); etm_set_default(&drvdata->config); =20 pdata =3D coresight_get_platform_data(dev); diff --git a/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c b/drivers/= hwtracing/coresight/coresight-etm3x-sysfs.c index fd81eca3ec18..2f271b7fb048 100644 --- a/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c +++ b/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c @@ -85,6 +85,7 @@ static ssize_t reset_store(struct device *dev, } =20 etm_set_default(config); + etm_release_trace_id(drvdata); spin_unlock(&drvdata->spinlock); } =20 @@ -1189,30 +1190,16 @@ static DEVICE_ATTR_RO(cpu); static ssize_t traceid_show(struct device *dev, struct device_attribute *attr, char *buf) { - unsigned long val; - struct etm_drvdata *drvdata =3D dev_get_drvdata(dev->parent); - - val =3D etm_get_trace_id(drvdata); - - return sprintf(buf, "%#lx\n", val); -} - -static ssize_t traceid_store(struct device *dev, - struct device_attribute *attr, - const char *buf, size_t size) -{ - int ret; - unsigned long val; + int trace_id; struct etm_drvdata *drvdata =3D dev_get_drvdata(dev->parent); =20 - ret =3D kstrtoul(buf, 16, &val); - if (ret) - return ret; + trace_id =3D etm_read_alloc_trace_id(drvdata); + if (trace_id < 0) + return trace_id; =20 - drvdata->traceid =3D val & ETM_TRACEID_MASK; - return size; + return sysfs_emit(buf, "%#x\n", trace_id); } -static DEVICE_ATTR_RW(traceid); +static DEVICE_ATTR_RO(traceid); =20 static struct attribute *coresight_etm_attrs[] =3D { &dev_attr_nr_addr_cmp.attr, --=20 2.17.1