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 79D0BFED9FD for ; Tue, 17 Mar 2026 18:17:23 +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=cirOdyXIHXzGhSSQIhihmhZnNRfKsePG26a0OFJMGi4=; b=d6k2Uj8bwjAlmCafWufncyaaP2 oJ3t0xvsm5fs9h8Y+Eh87bZAB1+OdBt7Xoro/sH/DlMTFvp2ldcC1WJxqZAbBFGOzNbbfGexGWFbX QzqwYXNXGeNI7xgBed1mB0BT/uuP/5S4n7zBTTnxUCknFhkJsZhEMnetC4TGVINDSneP+yVys1C4S V6/WiMHwzBAuZO9nb/DIem2dC+rxAWA+Ei9+OIrb2N6fN+lergKwVGBAod0aL24Lz8S9trS0b4ztY 1FlnzOzKSvXrjAwgiV9wNb8jowZzbk2i5pHwqjb9ehglM7sAz69lYAusIpnY3/4FYJ45ST+5mRhW8 0JQGFTrw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1w2Yyl-000000072Oq-0WUN; Tue, 17 Mar 2026 18:17:19 +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 1w2Yye-000000072N3-42ke for linux-arm-kernel@lists.infradead.org; Tue, 17 Mar 2026 18:17:14 +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 90D7516F2; Tue, 17 Mar 2026 11:17:05 -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 8A2403F7BD; Tue, 17 Mar 2026 11:17:10 -0700 (PDT) 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@linaro.org, james.clark@linaro.org, alexander.shishkin@linux.intel.com, leo.yan@arm.com, Yeoreum Yun Subject: [PATCH 1/2] coresight: etm4x: fix inconsistencies with sysfs configration Date: Tue, 17 Mar 2026 18:17:04 +0000 Message-Id: <20260317181705.2456271-2-yeoreum.yun@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260317181705.2456271-1-yeoreum.yun@arm.com> References: <20260317181705.2456271-1-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-20260317_111713_189207_B5540395 X-CRM114-Status: GOOD ( 22.80 ) 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. - Once a perf session is enabled, some read-only register fields (e.g., TRCSSCSR) may not be reported correctly, because drvdata->config is cleared while enabling with perf mode, even though the information was previously read via etm4_init_arch_data(). To resolve these inconsistencies, the configuration should be separated into: - active_config, which represents the currently applied configuration - config, which stores the settings configured via sysfs. Signed-off-by: Yeoreum Yun --- .../hwtracing/coresight/coresight-etm4x-cfg.c | 2 +- .../coresight/coresight-etm4x-core.c | 45 +++++++++++-------- drivers/hwtracing/coresight/coresight-etm4x.h | 2 + 3 files changed, 30 insertions(+), 19 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-etm4x-cfg.c b/drivers/hwtracing/coresight/coresight-etm4x-cfg.c index c302072b293a..84213d40d1ae 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 d565a73f0042..c552129c4a0c 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c @@ -88,9 +88,11 @@ static int etm4_probe_cpu(unsigned int cpu); */ static bool etm4x_sspcicrn_present(struct etmv4_drvdata *drvdata, int n) { + struct etmv4_config *config = &drvdata->active_config; + return (n < drvdata->nr_ss_cmp) && drvdata->nr_pe && - (drvdata->config.ss_status[n] & TRCSSCSRn_PC); + (config->ss_status[n] & TRCSSCSRn_PC); } u64 etm4x_sysreg_read(u32 offset, bool _relaxed, bool _64bit) @@ -266,10 +268,11 @@ 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; @@ -277,7 +280,7 @@ 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 @@ -288,12 +291,13 @@ 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); @@ -301,7 +305,7 @@ 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); @@ -494,7 +498,7 @@ static int etm4_enable_trace_unit(struct etmv4_drvdata *drvdata) static int etm4_enable_hw(struct etmv4_drvdata *drvdata) { int i, rc; - 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; @@ -666,7 +670,7 @@ static int etm4_config_timestamp_event(struct etmv4_drvdata *drvdata, { int ctridx; int rselector; - 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 (!drvdata->nr_cntr) @@ -749,7 +753,7 @@ static int etm4_parse_event_config(struct coresight_device *csdev, { int ret = 0; struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); - 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, }; @@ -911,14 +915,17 @@ 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); + + raw_spin_lock(&drvdata->spinlock); + + drvdata->active_config = drvdata->config; + 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 */ @@ -1028,7 +1035,7 @@ static void etm4_disable_trace_unit(struct etmv4_drvdata *drvdata) static void etm4_disable_hw(struct etmv4_drvdata *drvdata) { u32 control; - 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; @@ -1374,12 +1381,14 @@ static void etm4_init_arch_data(void *info) u32 etmidr5; struct etm4_init_arg *init_arg = info; struct etmv4_drvdata *drvdata; + struct etmv4_config *config; struct csdev_access *csa; struct device *dev = init_arg->dev; int i; drvdata = dev_get_drvdata(init_arg->dev); csa = init_arg->csa; + config = &drvdata->active_config; /* * If we are unable to detect the access mechanism, @@ -1440,7 +1449,7 @@ static void etm4_init_arch_data(void *info) /* EXLEVEL_S, bits[19:16] Secure state instruction tracing */ drvdata->s_ex_level = FIELD_GET(TRCIDR3_EXLEVEL_S_MASK, etmidr3); - drvdata->config.s_ex_level = drvdata->s_ex_level; + config->s_ex_level = drvdata->s_ex_level; /* EXLEVEL_NS, bits[23:20] Non-secure state instruction tracing */ drvdata->ns_ex_level = FIELD_GET(TRCIDR3_EXLEVEL_NS_MASK, etmidr3); /* @@ -1491,8 +1500,7 @@ static void etm4_init_arch_data(void *info) */ drvdata->nr_ss_cmp = FIELD_GET(TRCIDR4_NUMSSCC_MASK, etmidr4); for (i = 0; i < drvdata->nr_ss_cmp; i++) { - drvdata->config.ss_status[i] = - etm4x_relaxed_read32(csa, TRCSSCSRn(i)); + config->ss_status[i] = etm4x_relaxed_read32(csa, TRCSSCSRn(i)); } /* NUMCIDC, bits[27:24] number of Context ID comparators for tracing */ drvdata->numcidc = FIELD_GET(TRCIDR4_NUMCIDC_MASK, etmidr4); @@ -1685,7 +1693,7 @@ 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 @@ -1726,7 +1734,7 @@ 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) @@ -2246,7 +2254,8 @@ 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 89d81ce4e04e..76beb896f188 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x.h +++ b/drivers/hwtracing/coresight/coresight-etm4x.h @@ -1022,6 +1022,7 @@ 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 * @skip_power_up: Indicates if an implementation can skip powering up @@ -1079,6 +1080,7 @@ struct etmv4_drvdata { bool skip_power_up : 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}