From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 6E1BF373BF2; Tue, 17 Mar 2026 11:01:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773745282; cv=none; b=fepgPAapp+SpcxfN20tbMH6PkkgsIDnsRQXJUyIX5svMyEnvfL2YC42vJMineFZrDHXsPu+53XlgpHYc6Zp1VIUpz+5UfCgUSD/x3vgnD9Ug9jUH+/si/gVBmebixGWTpjerMGOwIEexuaaNB2Bv9DmYSzuBj+VhkBEbFa2MBQ4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773745282; c=relaxed/simple; bh=0Y6usg7zBh1OvQlKFbecGoWf3gNBs6KQNaYhOeFm6EQ=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=rdVpVxqd/bb9djdz8MPxZHpOYoZt4oKfeshOvtEtBp0glrObmY8EY3Zeo3Cqu8MjDgEYJxLuV+0pQwqV1IHsJEJ+GrQ0nmTCrJb2PWDuR1fV+AIt+i3IxQemrdXIyVYGY97EU6/sVLU6IN3ip74HJLdB9qnERdFKrngOwZZBaU0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com 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 CE7D61756; Tue, 17 Mar 2026 04:01:13 -0700 (PDT) Received: from [10.57.19.134] (unknown [10.57.19.134]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 1D33D3F7BD; Tue, 17 Mar 2026 04:01:18 -0700 (PDT) Message-ID: <1c4ab892-6f01-40ff-83e2-9060aa69616f@arm.com> Date: Tue, 17 Mar 2026 11:01:16 +0000 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v15 2/7] coresight: tmc: add create/clean functions for etr_buf_list Content-Language: en-GB To: Jie Gan , Mike Leach , James Clark , Alexander Shishkin , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Tingwei Zhang , Bjorn Andersson , Konrad Dybcio Cc: coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org References: <20260313-enable-byte-cntr-for-ctcu-v15-0-1777f14ed319@oss.qualcomm.com> <20260313-enable-byte-cntr-for-ctcu-v15-2-1777f14ed319@oss.qualcomm.com> From: Suzuki K Poulose In-Reply-To: <20260313-enable-byte-cntr-for-ctcu-v15-2-1777f14ed319@oss.qualcomm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 13/03/2026 09:02, Jie Gan wrote: > Introduce functions for creating and inserting or removing the > etr_buf_node to/from the etr_buf_list. > > The byte-cntr functionality requires two etr_buf to receive trace data. > The active etr_buf collects the trace data from source device, while the > byte-cntr reading function accesses the deactivated etr_buf after is > has been filled and synced, transferring data to the userspace. > > Reviewed-by: Mike Leach > Signed-off-by: Jie Gan > --- > drivers/hwtracing/coresight/coresight-tmc-core.c | 1 + > drivers/hwtracing/coresight/coresight-tmc-etr.c | 108 +++++++++++++++++++++++ > drivers/hwtracing/coresight/coresight-tmc.h | 17 ++++ > 3 files changed, 126 insertions(+) > > diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c > index c89fe996af23..bac3278ef4dd 100644 > --- a/drivers/hwtracing/coresight/coresight-tmc-core.c > +++ b/drivers/hwtracing/coresight/coresight-tmc-core.c > @@ -835,6 +835,7 @@ static int __tmc_probe(struct device *dev, struct resource *res) > idr_init(&drvdata->idr); > mutex_init(&drvdata->idr_mutex); > dev_list = "tmc_etr"; > + INIT_LIST_HEAD(&drvdata->etr_buf_list); > break; > case TMC_CONFIG_TYPE_ETF: > desc.groups = coresight_etf_groups; > diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c > index 4dc1defe27a5..fdf23e1c932f 100644 > --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c > +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c > @@ -1918,6 +1918,114 @@ const struct coresight_ops tmc_etr_cs_ops = { > .panic_ops = &tmc_etr_sync_ops, > }; > > +/** > + * tmc_clean_etr_buf_list - clean the etr_buf_list. > + * @drvdata: driver data of the TMC device. > + * > + * Remove unused buffers from @drvdata->etr_buf_list and free them. > + */ > +void tmc_clean_etr_buf_list(struct tmc_drvdata *drvdata) > +{ > + struct etr_buf_node *nd, *next; > + unsigned long flags; > + > + lockdep_assert_held(&drvdata->spinlock); > + list_for_each_entry_safe(nd, next, &drvdata->etr_buf_list, link) { > + if (nd->sysfs_buf == drvdata->sysfs_buf) { > + if (coresight_get_mode(drvdata->csdev) != CS_MODE_DISABLED) { > + /* > + * Dont free the sysfs_buf, just remove it from list. > + * drvdata->sysfs_buf will hold the buffer and free it later. > + */ > + nd->sysfs_buf = NULL; > + list_del(&nd->link); > + kfree(nd); > + continue; > + } > + } > + /* Free allocated buffers which are not utilized by ETR */ > + raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); This is dangerous ! Restoring the irqflags to an uninitialised value from a different function thant where it was locked. Please clean this up Suzuki > + tmc_etr_free_sysfs_buf(nd->sysfs_buf); > + raw_spin_lock_irqsave(&drvdata->spinlock, flags); > + drvdata->sysfs_buf = NULL; > + nd->sysfs_buf = NULL; > + list_del(&nd->link); > + kfree(nd); > + } > +} > +EXPORT_SYMBOL_GPL(tmc_clean_etr_buf_list); > + > +/** > + * tmc_create_etr_buf_list - create a list to manage the etr_buf_node. > + * @drvdata: driver data of the TMC device. > + * @num_nodes: number of nodes want to create with the list. > + * > + * Return 0 upon success and return the error number if fail. > + */ > +int tmc_create_etr_buf_list(struct tmc_drvdata *drvdata, int num_nodes) > +{ > + struct etr_buf_node *new_node; > + struct etr_buf *sysfs_buf; > + unsigned long flags; > + int i = 0, ret = 0; > + > + lockdep_assert_held(&drvdata->spinlock); > + /* We dont need a list if there is only one node */ > + if (num_nodes < 2) > + return -EINVAL; > + > + /* We expect that sysfs_buf in drvdata has already been allocated. */ > + if (drvdata->sysfs_buf) { > + raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); > + /* Directly insert the allocated sysfs_buf into the list first */ > + new_node = kzalloc_obj(*new_node, GFP_KERNEL); > + if (IS_ERR(new_node)) > + return PTR_ERR(new_node); > + > + raw_spin_lock_irqsave(&drvdata->spinlock, flags); > + new_node->sysfs_buf = drvdata->sysfs_buf; > + new_node->is_free = false; > + list_add(&new_node->link, &drvdata->etr_buf_list); > + i++; > + } > + > + raw_spin_unlock_irqrestore(&drvdata->spinlock, flags); > + while (i < num_nodes) { > + new_node = kzalloc_obj(*new_node, GFP_KERNEL); > + if (IS_ERR(new_node)) { > + ret = PTR_ERR(new_node); > + break; > + } > + > + sysfs_buf = tmc_alloc_etr_buf(drvdata, drvdata->size, 0, cpu_to_node(0), NULL); > + if (IS_ERR(sysfs_buf)) { > + kfree(new_node); > + ret = PTR_ERR(sysfs_buf); > + break; > + } > + > + /* We dont have a available sysfs_buf in drvdata, setup one */ > + if (!drvdata->sysfs_buf) { > + drvdata->sysfs_buf = sysfs_buf; > + new_node->is_free = false; > + } else > + new_node->is_free = true; > + > + new_node->sysfs_buf = sysfs_buf; > + list_add(&new_node->link, &drvdata->etr_buf_list); > + i++; > + } > + > + /* Clean the list if there is an error */ > + if (ret) > + tmc_clean_etr_buf_list(drvdata); > + > + raw_spin_lock_irqsave(&drvdata->spinlock, flags); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(tmc_create_etr_buf_list); > + > int tmc_read_prepare_etr(struct tmc_drvdata *drvdata) > { > int ret = 0; > diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h > index 319a354ede9f..81237944b986 100644 > --- a/drivers/hwtracing/coresight/coresight-tmc.h > +++ b/drivers/hwtracing/coresight/coresight-tmc.h > @@ -208,6 +208,19 @@ struct tmc_resrv_buf { > s64 len; > }; > > +/** > + * @sysfs_buf: Allocated sysfs_buf. > + * @is_free: Indicates whether the buffer is free to choose. > + * @pos: Position of the buffer. > + * @link: list_head of the node. > + */ > +struct etr_buf_node { > + struct etr_buf *sysfs_buf; > + bool is_free; > + loff_t pos; > + struct list_head link; > +}; > + > /** > * struct tmc_drvdata - specifics associated to an TMC component > * @atclk: optional clock for the core parts of the TMC. > @@ -245,6 +258,7 @@ struct tmc_resrv_buf { > * (after crash) by default. > * @crash_mdata: Reserved memory for storing tmc crash metadata. > * Used by ETR/ETF. > + * @etr_buf_list: List that is used to manage allocated etr_buf. > */ > struct tmc_drvdata { > struct clk *atclk; > @@ -275,6 +289,7 @@ struct tmc_drvdata { > struct etr_buf *perf_buf; > struct tmc_resrv_buf resrv_buf; > struct tmc_resrv_buf crash_mdata; > + struct list_head etr_buf_list; > }; > > struct etr_buf_operations { > @@ -447,5 +462,7 @@ struct etr_buf *tmc_etr_get_buffer(struct coresight_device *csdev, > enum cs_mode mode, > struct coresight_path *path); > extern const struct attribute_group coresight_etr_group; > +void tmc_clean_etr_buf_list(struct tmc_drvdata *drvdata); > +int tmc_create_etr_buf_list(struct tmc_drvdata *drvdata, int num_nodes); > > #endif >