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 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 1B9B8E9904A for ; Fri, 10 Apr 2026 07:43:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=ERalPOaOMt4fPERtwlxx+rJur6eXFfz83mMWYHRcMnE=; b=mgAPGAgvZvOZ/E6pSNGJdEl9/P fLmpCxWHlDzQ9HSbTt8j6uIGDiHmnHazurWS+TFDCviFJyH7oLd31BE9shrmdBU7SaAWqGkxKUU2n POCdP6yyHq5O5nmFa1CKdhktFWyPGKJf1r2pu8M718GsHlPFYQp/2J2TZlLie8kWdF3YjSq6C+hG5 XK0cR937+pe0T2+PjqB9XcC6gKug2TXYhiDjftcQMyC72IcJi+TWxy1IxSsAdfZqfb7tZ3Lh0HDt0 5Pi/MQeUK1jB4L+QTaE8B9vjs6dLq/LDLy4SBJlaIeOY8RmT3KzSx+QXc7Q2G8QSXvrEENCAwJNec +A+r4buQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1wB6WZ-0000000BmNj-0MjR; Fri, 10 Apr 2026 07:43:31 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1wB6WT-0000000BmJs-1C2q for linux-arm-kernel@lists.infradead.org; Fri, 10 Apr 2026 07:43:26 +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 E57B41CE2; Fri, 10 Apr 2026 00:43:18 -0700 (PDT) Received: from e129823.cambridge.arm.com (e129823.arm.com [10.1.197.6]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 466793FAF5; Fri, 10 Apr 2026 00:43:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1775807004; bh=YlQRdmCKqr+jttj2wP/iKipfMEKEUIRYNoKwk+EAlPA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QzKDB2LY+Viwdv93JQXtzizmzZpEcOa5uvV+e+MNWcBnjDuDpxDerzRSxH9mQ6IqI HcGkM8KwhzUvvcQUnpMqxG+D8ZZxL2WxK3mZrW9wdbzHggJIux4zn2Ds8ojDU2mknN IC3qi+NbrDeobm+/+G2jtB0sdzHP6zze/Ge2cC8w= From: Yeoreum Yun To: coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: suzuki.poulose@arm.com, mike.leach@arm.com, james.clark@linaro.org, alexander.shishkin@linux.intel.com, leo.yan@arm.com, Yeoreum Yun Subject: [PATCH v2 3/5] coresight: etm4x: fix inconsistencies with sysfs configration Date: Fri, 10 Apr 2026 08:43:08 +0100 Message-Id: <20260410074310.2693385-4-yeoreum.yun@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260410074310.2693385-1-yeoreum.yun@arm.com> References: <20260410074310.2693385-1-yeoreum.yun@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260410_004325_413647_FB65A780 X-CRM114-Status: GOOD ( 25.06 ) 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 The current ETM4x configuration via sysfs can lead to the following inconsistencies: - If a configuration is modified via sysfs while a perf session is active, the running configuration may differ between before a sched-out and after a subsequent sched-in. - If a perf session and sysfs session tries to enable concurrently, configuration from configfs could be corrupted. - There is chance to corrupt drvdata->config if perf session tries to enabled among handling cscfg_csdev_disable_active_config() in etm4_disable_sysfs(). To resolve these inconsistencies, the configuration should be separated into: - active_config, which is applied configuration for the current session - config, which stores the settings configured via sysfs. and apply configuration from configfs after taking a mode. Signed-off-by: Yeoreum Yun --- .../hwtracing/coresight/coresight-etm4x-cfg.c | 2 +- .../coresight/coresight-etm4x-core.c | 74 ++++++++++++------- drivers/hwtracing/coresight/coresight-etm4x.h | 2 + 3 files changed, 49 insertions(+), 29 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-etm4x-cfg.c b/drivers/hwtracing/coresight/coresight-etm4x-cfg.c index d14d7c8a23e5..0553771d04e7 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-cfg.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-cfg.c @@ -47,7 +47,7 @@ static int etm4_cfg_map_reg_offset(struct etmv4_drvdata *drvdata, struct cscfg_regval_csdev *reg_csdev, u32 offset) { int err = -EINVAL, idx; - struct etmv4_config *drvcfg = &drvdata->config; + struct etmv4_config *drvcfg = &drvdata->active_config; u32 off_mask; if (((offset >= TRCEVENTCTL0R) && (offset <= TRCVIPCSSCTLR)) || diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c index b7abb171f523..c7b4a0b85106 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c @@ -245,6 +245,9 @@ void etm4_release_trace_id(struct etmv4_drvdata *drvdata) struct etm4_enable_arg { struct etmv4_drvdata *drvdata; + unsigned long cfg_hash; + int preset; + u8 trace_id; int rc; }; @@ -270,10 +273,11 @@ static void etm4x_prohibit_trace(struct etmv4_drvdata *drvdata) static u64 etm4x_get_kern_user_filter(struct etmv4_drvdata *drvdata) { u64 trfcr = drvdata->trfcr; + struct etmv4_config *config = &drvdata->active_config; - if (drvdata->config.mode & ETM_MODE_EXCL_KERN) + if (config->mode & ETM_MODE_EXCL_KERN) trfcr &= ~TRFCR_EL1_ExTRE; - if (drvdata->config.mode & ETM_MODE_EXCL_USER) + if (config->mode & ETM_MODE_EXCL_USER) trfcr &= ~TRFCR_EL1_E0TRE; return trfcr; @@ -281,7 +285,7 @@ static u64 etm4x_get_kern_user_filter(struct etmv4_drvdata *drvdata) /* * etm4x_allow_trace - Allow CPU tracing in the respective ELs, - * as configured by the drvdata->config.mode for the current + * as configured by the drvdata->active_config.mode for the current * session. Even though we have TRCVICTLR bits to filter the * trace in the ELs, it doesn't prevent the ETM from generating * a packet (e.g, TraceInfo) that might contain the addresses from @@ -292,12 +296,13 @@ static u64 etm4x_get_kern_user_filter(struct etmv4_drvdata *drvdata) static void etm4x_allow_trace(struct etmv4_drvdata *drvdata) { u64 trfcr, guest_trfcr; + struct etmv4_config *config = &drvdata->active_config; /* If the CPU doesn't support FEAT_TRF, nothing to do */ if (!drvdata->trfcr) return; - if (drvdata->config.mode & ETM_MODE_EXCL_HOST) + if (config->mode & ETM_MODE_EXCL_HOST) trfcr = drvdata->trfcr & ~(TRFCR_EL1_ExTRE | TRFCR_EL1_E0TRE); else trfcr = etm4x_get_kern_user_filter(drvdata); @@ -305,7 +310,7 @@ static void etm4x_allow_trace(struct etmv4_drvdata *drvdata) write_trfcr(trfcr); /* Set filters for guests and pass to KVM */ - if (drvdata->config.mode & ETM_MODE_EXCL_GUEST) + if (config->mode & ETM_MODE_EXCL_GUEST) guest_trfcr = drvdata->trfcr & ~(TRFCR_EL1_ExTRE | TRFCR_EL1_E0TRE); else guest_trfcr = etm4x_get_kern_user_filter(drvdata); @@ -499,7 +504,7 @@ static int etm4_enable_hw(struct etmv4_drvdata *drvdata) { int i, rc; const struct etmv4_caps *caps = &drvdata->caps; - struct etmv4_config *config = &drvdata->config; + struct etmv4_config *config = &drvdata->active_config; struct coresight_device *csdev = drvdata->csdev; struct device *etm_dev = &csdev->dev; struct csdev_access *csa = &csdev->access; @@ -616,19 +621,36 @@ static int etm4_enable_hw(struct etmv4_drvdata *drvdata) static void etm4_enable_sysfs_smp_call(void *info) { struct etm4_enable_arg *arg = info; + struct etmv4_drvdata *drvdata; struct coresight_device *csdev; if (WARN_ON(!arg)) return; - csdev = arg->drvdata->csdev; + drvdata = arg->drvdata; + csdev = drvdata->csdev; if (!coresight_take_mode(csdev, CS_MODE_SYSFS)) { /* Someone is already using the tracer */ arg->rc = -EBUSY; return; } - arg->rc = etm4_enable_hw(arg->drvdata); + drvdata->active_config = drvdata->config; + + if (arg->cfg_hash) { + arg->rc = cscfg_csdev_enable_active_config(csdev, + arg->cfg_hash, + arg->preset); + if (arg->rc) + return; + } + + drvdata->trcid = arg->trace_id; + + /* Tracer will never be paused in sysfs mode */ + drvdata->paused = false; + + arg->rc = etm4_enable_hw(drvdata); /* The tracer didn't start */ if (arg->rc) @@ -670,7 +692,7 @@ static int etm4_config_timestamp_event(struct etmv4_drvdata *drvdata, int ctridx; int rselector; const struct etmv4_caps *caps = &drvdata->caps; - struct etmv4_config *config = &drvdata->config; + struct etmv4_config *config = &drvdata->active_config; /* No point in trying if we don't have at least one counter */ if (!caps->nr_cntr) @@ -754,7 +776,7 @@ static int etm4_parse_event_config(struct coresight_device *csdev, int ret = 0; struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); const struct etmv4_caps *caps = &drvdata->caps; - struct etmv4_config *config = &drvdata->config; + struct etmv4_config *config = &drvdata->active_config; struct perf_event_attr max_timestamp = { .ATTR_CFG_FLD_timestamp_CFG = U64_MAX, }; @@ -916,24 +938,18 @@ static int etm4_enable_sysfs(struct coresight_device *csdev, struct coresight_pa /* enable any config activated by configfs */ cscfg_config_sysfs_get_active_cfg(&cfg_hash, &preset); - if (cfg_hash) { - ret = cscfg_csdev_enable_active_config(csdev, cfg_hash, preset); - if (ret) - return ret; - } raw_spin_lock(&drvdata->spinlock); - drvdata->trcid = path->trace_id; - - /* Tracer will never be paused in sysfs mode */ - drvdata->paused = false; - /* * Executing etm4_enable_hw on the cpu whose ETM is being enabled * ensures that register writes occur when cpu is powered. */ arg.drvdata = drvdata; + arg.cfg_hash = cfg_hash; + arg.preset = preset; + arg.trace_id = path->trace_id; + ret = smp_call_function_single(drvdata->cpu, etm4_enable_sysfs_smp_call, &arg, 1); if (!ret) @@ -1034,7 +1050,7 @@ static void etm4_disable_hw(struct etmv4_drvdata *drvdata) { u32 control; const struct etmv4_caps *caps = &drvdata->caps; - struct etmv4_config *config = &drvdata->config; + struct etmv4_config *config = &drvdata->active_config; struct coresight_device *csdev = drvdata->csdev; struct csdev_access *csa = &csdev->access; int i; @@ -1070,6 +1086,8 @@ static void etm4_disable_sysfs_smp_call(void *info) etm4_disable_hw(drvdata); + cscfg_csdev_disable_active_config(drvdata->csdev); + coresight_set_mode(drvdata->csdev, CS_MODE_DISABLED); } @@ -1130,9 +1148,6 @@ static void etm4_disable_sysfs(struct coresight_device *csdev) drvdata, 1); raw_spin_unlock(&drvdata->spinlock); - - cscfg_csdev_disable_active_config(csdev); - cpus_read_unlock(); /* @@ -1375,6 +1390,7 @@ static void etm4_init_arch_data(void *info) struct etm4_init_arg *init_arg = info; struct etmv4_drvdata *drvdata; struct etmv4_caps *caps; + struct etmv4_config *config; struct csdev_access *csa; struct device *dev = init_arg->dev; int i; @@ -1382,6 +1398,7 @@ static void etm4_init_arch_data(void *info) drvdata = dev_get_drvdata(init_arg->dev); caps = &drvdata->caps; csa = init_arg->csa; + config = &drvdata->active_config; /* * If we are unable to detect the access mechanism, @@ -1442,7 +1459,7 @@ static void etm4_init_arch_data(void *info) /* EXLEVEL_S, bits[19:16] Secure state instruction tracing */ caps->s_ex_level = FIELD_GET(TRCIDR3_EXLEVEL_S_MASK, etmidr3); - drvdata->config.s_ex_level = caps->s_ex_level; + config->s_ex_level = caps->s_ex_level; /* EXLEVEL_NS, bits[23:20] Non-secure state instruction tracing */ caps->ns_ex_level = FIELD_GET(TRCIDR3_EXLEVEL_NS_MASK, etmidr3); /* @@ -1687,7 +1704,7 @@ static void etm4_set_default(struct etmv4_config *config) static int etm4_get_next_comparator(struct etmv4_drvdata *drvdata, u32 type) { int nr_comparator, index = 0; - struct etmv4_config *config = &drvdata->config; + struct etmv4_config *config = &drvdata->active_config; /* * nr_addr_cmp holds the number of comparator _pair_, so time 2 @@ -1728,7 +1745,7 @@ static int etm4_set_event_filters(struct etmv4_drvdata *drvdata, { int i, comparator, ret = 0; u64 address; - struct etmv4_config *config = &drvdata->config; + struct etmv4_config *config = &drvdata->active_config; struct etm_filters *filters = event->hw.addr_filters; if (!filters) @@ -2250,7 +2267,8 @@ static int etm4_add_coresight_dev(struct etm4_init_arg *init_arg) if (!desc.name) return -ENOMEM; - etm4_set_default(&drvdata->config); + etm4_set_default(&drvdata->active_config); + drvdata->config = drvdata->active_config; pdata = coresight_get_platform_data(dev); if (IS_ERR(pdata)) diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h index 57508d301327..33a4f68dd0cb 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x.h +++ b/drivers/hwtracing/coresight/coresight-etm4x.h @@ -1069,6 +1069,7 @@ struct etmv4_save_state { * allows tracing at all ELs. We don't want to compute this * at runtime, due to the additional setting of TRFCR_CX when * in EL2. Otherwise, 0. + * @active_config: structure holding current applied configuration parameters. * @config: structure holding configuration parameters. * @save_state: State to be preserved across power loss * @paused: Indicates if the trace unit is paused. @@ -1089,6 +1090,7 @@ struct etmv4_drvdata { bool os_unlock : 1; bool paused : 1; u64 trfcr; + struct etmv4_config active_config; struct etmv4_config config; struct etmv4_save_state *save_state; DECLARE_BITMAP(arch_features, ETM4_IMPDEF_FEATURE_MAX); -- LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}