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 739844229BA; Sun, 6 Sep 2026 10:08:19 +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=1788689301; cv=none; b=GpyhJMDCCHP7/59fyBRqyKXsUOyzed7Anrq66XkLNUbK7n/EFtdkSJv7NsdFFs5Uf0fZhoelKeKPI/hqCc9kBc4Gkgo5ZZ8RevhEPEI4I8sCY3A9PezSPIs4pqNky6X8wMBC1PWVSeztSK7fFCb5AmWocUcBFyH22RfK0CX5QjA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788689301; c=relaxed/simple; bh=0Y4LEA4BzzG08Ro08S5p/a1MdXKRtlEow14s+KS2lkE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=geBV6fILXwMnXEZt77oJ2geww5+peJKLrsbZ733sp6Q2nvJ+bCIr7eANYWe04YsC6hTdgd/en7p4u1lNJ24171ksynnYJvuvuqqCBuD8YOpk94WOwdHWSe3VzzOMBhdSRjhvKTow6fi19w8jZpTAa0vm1GhYb1CK6yEKAQRfOlc= 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; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=am9dp+Ot; 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 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="am9dp+Ot" 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 4B2351713; Sun, 6 Sep 2026 03:08:15 -0700 (PDT) Received: from pluto (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 2F3E93F7D8; Sun, 6 Sep 2026 03:08:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1788689299; bh=0Y4LEA4BzzG08Ro08S5p/a1MdXKRtlEow14s+KS2lkE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=am9dp+OttuQiY40OUXEUmkLZhpvPhywU4e0bHtQI7ho5MFFrSkfgfr1FvmuIE0hs7 TLUCga5tzPS43hzQCb/lB1QEhbTFs8HSyINmEloTd99ib4uwQD5g4g2lxYoacf5fhS D1AJ/IjXS8/KITQVD7wdc7pEPK11XOQgHFmHt3xk= From: Cristian Marussi To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, arm-scmi@vger.kernel.org, linux-doc@vger.kernel.org Cc: sudeep.holla@kernel.org, james.quinlan@broadcom.com, f.fainelli@gmail.com, vincent.guittot@linaro.org, etienne.carriere@st.com, peng.fan@oss.nxp.com, michal.simek@amd.com, d-gole@ti.com, jic23@kernel.org, elif.topuz@arm.com, lukasz.luba@arm.com, philip.radford@arm.com, david@kernel.org, souvik.chakravarty@arm.com, leitao@kernel.org, kas@kernel.org, puranjay@kernel.org, usama.arif@linux.dev, kernel-team@meta.com, Cristian Marussi Subject: [PATCH v11 16/25] firmware: arm_scmi: Add Telemetry debugfs SHMTI dump support Date: Sun, 6 Sep 2026 11:06:14 +0100 Message-ID: <20260906100623.3488327-17-cristian.marussi@arm.com> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260906100623.3488327-1-cristian.marussi@arm.com> References: <20260906100623.3488327-1-cristian.marussi@arm.com> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Expose one debugfs entry for each discovered SHMTI that can be used to dump the related SHMTI in binary form from TBGN up to TEND markers. No processing is done kernel side, beside using proper accessors for device memory. Signed-off-by: Cristian Marussi --- v8 --> v9 - use kvzalloc/kfree - use file_update_time to update debugfs file ts v5 --> v6 - added mutex to protect binary dump buffer during reads (Sashiko) - using debugfs_create_file_size() (Sashiko) --- drivers/firmware/arm_scmi/telemetry.c | 95 +++++++++++++++++++++++++++ 1 file changed, 95 insertions(+) diff --git a/drivers/firmware/arm_scmi/telemetry.c b/drivers/firmware/arm_scmi/telemetry.c index 26bd05295df7..3df6cb44dc32 100644 --- a/drivers/firmware/arm_scmi/telemetry.c +++ b/drivers/firmware/arm_scmi/telemetry.c @@ -11,8 +11,11 @@ #include #include #include +#include +#include #include #include +#include #include #include #include @@ -402,6 +405,14 @@ struct telemetry_shmti { struct scmi_telemetry_shmti_info info; }; +struct scmi_telemetry_dbg_shmti { + struct telemetry_shmti *shmti; + size_t buf_sz; + void *buf; + /* Protect this descriptor from concurrent readers using it */ + struct mutex mtx; +}; + #define SHMTI_EPLG(s) \ ({ \ struct telemetry_shmti *_s = (s); \ @@ -1475,6 +1486,87 @@ scmi_telemetry_enumerate_common_intervals(struct telemetry_info *ti) ti->info.intervals); } +static int scmi_telemetry_dbg_shmti_open(struct inode *inode, struct file *filp) +{ + struct scmi_telemetry_dbg_shmti *sblob; + struct telemetry_shmti *shmti; + + if (!inode->i_private) + return -ENODEV; + + shmti = inode->i_private; + sblob = kzalloc_obj(*sblob); + if (!sblob) + return -ENOMEM; + + sblob->shmti = shmti; + sblob->buf = kvzalloc(shmti->info.len, GFP_KERNEL); + if (!sblob->buf) { + kfree(sblob); + return -ENOMEM; + } + + mutex_init(&sblob->mtx); + + filp->private_data = sblob; + + return 0; +} + +static ssize_t scmi_telemetry_dbg_shmti_read(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + struct scmi_telemetry_dbg_shmti *sblob = filp->private_data; + + /* Dump on first read and again after each rewind to start pos */ + guard(mutex)(&sblob->mtx); + if (!sblob->buf_sz || *ppos == 0) { + memcpy_fromio(sblob->buf, sblob->shmti->base, + sblob->shmti->info.len); + sblob->buf_sz = sblob->shmti->info.len; + /* update inode timestamps */ + file_update_time(filp); + } + + return simple_read_from_buffer(buf, count, ppos, sblob->buf, sblob->buf_sz); +} + +static int scmi_telemetry_dbg_shmti_release(struct inode *inode, struct file *filp) +{ + struct scmi_telemetry_dbg_shmti *sblob = filp->private_data; + + kvfree(sblob->buf); + kfree(sblob); + + return 0; +} + +static const struct file_operations scmi_telemetry_dbg_shmti_fops = { + .open = scmi_telemetry_dbg_shmti_open, + .release = scmi_telemetry_dbg_shmti_release, + .read = scmi_telemetry_dbg_shmti_read, + .llseek = generic_file_llseek, + .owner = THIS_MODULE, +}; + +static void scmi_telemetry_debugfs_initialize(struct telemetry_info *ti) +{ + const struct scmi_protocol_handle *ph = ti->ph; + struct dentry *top, *shmti_top; + + top = ph->hops->debugfs_proto_dentry_get(ph); + shmti_top = debugfs_create_dir("shmtis", top); + + for (unsigned int i = 0; i < ti->num_shmti; i++) { + char id[16]; + + snprintf(id, 16, "%u", i); + debugfs_create_file_size(id, 0444, shmti_top, &ti->shmti[i], + &scmi_telemetry_dbg_shmti_fops, + ti->shmti[i].info.len); + } +} + static int iter_shmti_update_state(struct scmi_iterator_state *st, const void *response, void *priv) { @@ -3970,6 +4062,9 @@ static int scmi_telemetry_protocol_init(const struct scmi_protocol_handle *ph) } } + if (IS_ENABLED(CONFIG_ARM_SCMI_DEBUG_PROTOCOLS)) + scmi_telemetry_debugfs_initialize(ti); + return 0; } -- 2.54.0