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 39A38CD4F54 for ; Thu, 28 May 2026 14:10:03 +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:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=5Y1C7MDY7j9PI7+t+t5jiHK4PQnwFdSn0Ob2ceSujCc=; b=D7FQ4OBa8lIsBC3bEeS1Pj58Ko gTcPQiCwOo3Ps6Sf+v9yZsRD7NFRV1vyVrwjOhNJzyN5bnUV6uV4CCpyv4utApAa0cbS7tJ4vMOuD OD1E7KHFW1cLPiEHLI84O8SYLChB+uaiNJH7594iUQCQ4l0Hw7moehSh6i9y3VV1vms4cmzO4Qj2K /UCL8DBGYPUqgs8e5zNChJogP1mqNqizG8Y6/GrBp6T/MfCDpbR+W5VdNTZTWUeaixvsvzfYq2EAE uS+o2ZVtMhpY9KOzyxnrCCabX5vqpgE0ymmhYEe8NS/YCPEsq6eMPr0NGp1PsfEeoS02wTaccPZJ/ /8i5aHIA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wSbQl-00000005pC1-34Lu; Thu, 28 May 2026 14:09:51 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wSbQi-00000005pBT-1RAl for linux-arm-kernel@lists.infradead.org; Thu, 28 May 2026 14:09:50 +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 7A28544A7; Thu, 28 May 2026 07:09:41 -0700 (PDT) Received: from localhost (e132581.arm.com [10.1.196.87]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0B0553F905; Thu, 28 May 2026 07:09:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1779977386; bh=QWziwUfKTB0cDn2oehq+pIi1Op0UjVJR7vsqGSPxdDM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=DfLtYe7XQHXtlE+20SyBgVTOGZtO+C+/fYYaudyLcaIFC7Y9QQ7ECM5pC8dZeL80S 6QPQRZcsHs6WY7lYDm95XBs4YgGp4UtkkV1tQPG3m+GyFEAsMn1SO59528n/DIWtRr engvFChW6GoJy6NTkBtlTeylQiHVTIawhuPeeu+g= Date: Thu, 28 May 2026 15:09:43 +0100 From: Leo Yan To: Yeoreum Yun Cc: coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, suzuki.poulose@arm.com, mike.leach@arm.com, james.clark@linaro.org, alexander.shishkin@linux.intel.com, jie.gan@oss.qualcomm.com Subject: Re: [PATCH v7 08/13] coresight: etm4x: fix inconsistencies with sysfs configuration Message-ID: <20260528140943.GE101133@e132581.arm.com> References: <20260519154812.254884-1-yeoreum.yun@arm.com> <20260519154812.254884-9-yeoreum.yun@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260519154812.254884-9-yeoreum.yun@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260528_070948_470619_1A038BD0 X-CRM114-Status: GOOD ( 30.65 ) 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 On Tue, May 19, 2026 at 04:48:07PM +0100, Yeoreum Yun wrote: [...] > --- 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; Wouldn't it make more sense to keep using drvdata->config for cfgfs? This would avoid cfgfs updating the active configuration while a session is enabled. My understanding is after refactoring cfgfs, we will never expose active_config or config anymore so this should not an issue. Before that, maybe we just keep to use config so can avoid mess. > 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 9b477b36b432..f0a9f2ef4b27 100644 > --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c > +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c > @@ -243,6 +243,7 @@ void etm4_release_trace_id(struct etmv4_drvdata *drvdata) > struct etm4_enable_arg { > struct etmv4_drvdata *drvdata; > struct coresight_path *path; > + struct etmv4_config config; > int rc; > }; > > @@ -268,10 +269,11 @@ 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; > @@ -279,7 +281,7 @@ 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 > @@ -290,12 +292,13 @@ 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); > @@ -303,7 +306,7 @@ 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); > @@ -497,7 +500,7 @@ 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; > @@ -618,27 +621,53 @@ 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; > + unsigned long cfg_hash; > + int preset; > > 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); > + /* enable any config activated by configfs */ > + cscfg_config_sysfs_get_active_cfg(&cfg_hash, &preset); > > - /* The tracer didn't start */ > + drvdata->active_config = arg->config; Can move this down to just before drvdata->trcid assignment so cscfg operations can be put together? > + > + if (cfg_hash) { > + arg->rc = cscfg_csdev_enable_active_config(csdev, > + cfg_hash, > + preset); > + if (arg->rc) > + goto err; > + } > + > + drvdata->trcid = arg->path->trace_id; > + > + /* Tracer will never be paused in sysfs mode */ > + drvdata->paused = false; > + > + arg->rc = etm4_enable_hw(drvdata); > if (arg->rc) { > - coresight_set_mode(csdev, CS_MODE_DISABLED); > - return; > + cscfg_csdev_disable_active_config(csdev); > + goto err; Add a new goto tag (like err_enable_hw) for the disable_active_config rollback? > } > > + drvdata->sticky_enable = true; > csdev->path = arg->path; > + > + return; > +err: > + /* The tracer didn't start */ > + coresight_set_mode(csdev, CS_MODE_DISABLED); > } > > /* > @@ -676,7 +705,7 @@ 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) > @@ -760,7 +789,7 @@ 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, > }; > @@ -922,25 +951,7 @@ static int etm4_enable_sysfs(struct coresight_device *csdev, struct coresight_pa > { > struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent); > struct etm4_enable_arg arg = { }; > - unsigned long cfg_hash; > - int ret, preset; > - > - /* 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) { > - etm4_release_trace_id(drvdata); > - return ret; > - } > - } > - > - raw_spin_lock(&drvdata->spinlock); > - > - drvdata->trcid = path->trace_id; > - > - /* Tracer will never be paused in sysfs mode */ > - drvdata->paused = false; > + int ret; > > /* > * Executing etm4_enable_hw on the cpu whose ETM is being enabled > @@ -948,20 +959,20 @@ static int etm4_enable_sysfs(struct coresight_device *csdev, struct coresight_pa > */ > arg.drvdata = drvdata; > arg.path = path; > + > + raw_spin_lock(&drvdata->spinlock); > + arg.config = drvdata->config; > + raw_spin_unlock(&drvdata->spinlock); > + > ret = smp_call_function_single(drvdata->cpu, > etm4_enable_sysfs_smp_call, &arg, 1); > if (!ret) > ret = arg.rc; > if (!ret) > - drvdata->sticky_enable = true; > - > - if (ret) > + dev_dbg(&csdev->dev, "ETM tracing enabled\n"); > + else > etm4_release_trace_id(drvdata); > > - raw_spin_unlock(&drvdata->spinlock); > - > - if (!ret) > - dev_dbg(&csdev->dev, "ETM tracing enabled\n"); > return ret; > } > > @@ -1048,7 +1059,7 @@ 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; > @@ -1091,6 +1102,8 @@ static void etm4_disable_sysfs_smp_call(void *info) > etm4_disable_hw(drvdata); > > drvdata->csdev->path = NULL; > + cscfg_csdev_disable_active_config(drvdata->csdev); Move cscfg_csdev_disable_active_config() just after etm4_disable_hw() so the sequence is consistent with perf mode. [...] > @@ -1449,7 +1458,7 @@ 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; config->s_ex_level is redundant and not really a configuration item. We should use caps->s_ex_level instead of config->s_ex_level wherever it is used. Thanks, Leo