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 54D393D47A6; Fri, 3 Jul 2026 12:37:29 +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=1783082251; cv=none; b=TKT0SXL+PcP5Qkb2/eEnFBMn6l5HwVKBU3/QgYeC5wNkV9Oqt2kgOmgsnRo1tGdKMTUKHlli2bXJesgIlzyk/WF9+cXf6esD93BDVxQT6+Mjm6l0d1z0Ls7amwdK96+ezh/gjSU0fm+Q27Xjai3cLM41WJJ7Xol8aKliBfStGI8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783082251; c=relaxed/simple; bh=+g8iNsr3diBgnLCTy6PLZDZrMvospiQB6qob2wscLQ8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=EB+zFEaZwQW1GY0fLgt6q+GYUs1b17p9tw1PImlIZPqO6XIBTogf8sVX8egKNYw8v3m6lB2maLqYunDn73AcnlL8LtiqKgFpfrBLrxoX86fjU387K9QaoC5GLnCVk0ZvbSWzqFYKBUqw9tyA2Hh/HTT8K30GedbsbMxwzv4v8Rc= 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=X2hX5hZC; 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="X2hX5hZC" 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 EF1B21F60; Fri, 3 Jul 2026 05:37:22 -0700 (PDT) Received: from pluto.fritz.box (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 255EC3F905; Fri, 3 Jul 2026 05:37:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1783082246; bh=+g8iNsr3diBgnLCTy6PLZDZrMvospiQB6qob2wscLQ8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=X2hX5hZCFWvCO9VHTccn9hX+cWDFS0U9YCdNDcxA12U0oi05TCNtZhcZAsjewBlrL uPPKQwqJpcC8NhVOOT/XfWv88pTboj+eg3tAU7w5KTZ7ufATu7fFx9Z8wx6KYtQqBq fvOsNmtiVg1xJanjffgpeaTdFgGc4zMMJiOBo5+M= 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, brauner@kernel.org, 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 v5 15/23] firmware: arm_scmi: Add common per-protocol debugfs support Date: Fri, 3 Jul 2026 13:35:53 +0100 Message-ID: <20260703123601.381275-16-cristian.marussi@arm.com> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260703123601.381275-1-cristian.marussi@arm.com> References: <20260703123601.381275-1-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 Allow interested SCMI protocols to register their own specific debugfs entries under a common per-instance and per-protocol subtree rooted at /sys/kernel/debug/scmi//protocols// Expose a helper to enable protocol initialization code to get access to such per-protocol/per-instance dentries in order to be able to install their own dedicated debugfs entries. Per-protocol debugfs support is configurable and default off. Signed-off-by: Cristian Marussi --- drivers/firmware/arm_scmi/Kconfig | 14 +++++++++++++ drivers/firmware/arm_scmi/common.h | 2 ++ drivers/firmware/arm_scmi/driver.c | 29 +++++++++++++++++++++++++++ drivers/firmware/arm_scmi/protocols.h | 6 ++++++ include/linux/scmi_protocol.h | 12 ++++++++++- 5 files changed, 62 insertions(+), 1 deletion(-) diff --git a/drivers/firmware/arm_scmi/Kconfig b/drivers/firmware/arm_scmi/Kconfig index e3fb36825978..06d2319420a0 100644 --- a/drivers/firmware/arm_scmi/Kconfig +++ b/drivers/firmware/arm_scmi/Kconfig @@ -69,6 +69,20 @@ config ARM_SCMI_DEBUG_COUNTERS such useful debug counters. This can be helpful for debugging and SCMI monitoring. +config ARM_SCMI_DEBUG_PROTOCOLS + bool "Enable SCMI protocols debug" + select ARM_SCMI_NEED_DEBUGFS + depends on DEBUG_FS + default n + help + Enables per-protocol specific debug features, where available. + When provided, such per-protocol debugfs entries are grouped + inside a common a subtree named by the protocol number and rooted + under a per-instance 'protocols' directory. + + Such per-protocol entries subtree structure is freely defined + within the related protocol code. + config ARM_SCMI_QUIRKS bool "Enable SCMI Quirks framework" depends on JUMP_LABEL || COMPILE_TEST diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h index b9cd542302fb..8582e56ec488 100644 --- a/drivers/firmware/arm_scmi/common.h +++ b/drivers/firmware/arm_scmi/common.h @@ -322,6 +322,7 @@ enum debug_counters { /** * struct scmi_debug_info - Debug common info * @top_dentry: A reference to the top debugfs dentry + * @protos: A reference to the top debugfs protocols subdirectory * @name: Name of this SCMI instance * @type: Type of this SCMI instance * @is_atomic: Flag to state if the transport of this instance is atomic @@ -329,6 +330,7 @@ enum debug_counters { */ struct scmi_debug_info { struct dentry *top_dentry; + struct dentry *protos; const char *name; const char *type; bool is_atomic; diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index f933b8b9e29c..d54d155e69a8 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -18,6 +18,7 @@ #include #include +#include #include #include #include @@ -99,6 +100,8 @@ struct scmi_xfers_info { * has completed. * @ph: An embedded protocol handle that will be passed down to protocol * initialization code to identify this instance. + * @dbg: An optional reference to this protocol top debugfs directory; it will + * be automatically recursively removed on protocol de-initialization. * * Each protocol is initialized independently once for each SCMI platform in * which is defined by DT and implemented by the SCMI server fw. @@ -112,6 +115,7 @@ struct scmi_protocol_instance { unsigned int version; unsigned int negotiated_version; struct scmi_protocol_handle ph; + struct dentry *dbg; }; #define ph_to_pi(h) container_of(h, struct scmi_protocol_instance, ph) @@ -2085,6 +2089,25 @@ static void scmi_common_fastchannel_db_ring(struct scmi_fc_db_info *db) SCMI_PROTO_FC_RING_DB(64); } +static struct dentry * +scmi_debugfs_proto_dentry_get(const struct scmi_protocol_handle *ph) +{ + struct scmi_protocol_instance *pi = ph_to_pi(ph); + struct scmi_info *info = handle_to_scmi_info(pi->handle); + + if (!IS_ENABLED(CONFIG_ARM_SCMI_DEBUG_PROTOCOLS)) + return ERR_PTR(-ENODEV); + + if (!pi->dbg) { + char proto_dir[8]; + + snprintf(proto_dir, 8, "0x%02X", pi->proto->id); + pi->dbg = debugfs_create_dir(proto_dir, info->dbg->protos); + } + + return pi->dbg; +} + static const struct scmi_proto_helpers_ops helpers_ops = { .extended_name_get = scmi_common_extended_name_get, .get_max_msg_size = scmi_common_get_max_msg_size, @@ -2095,6 +2118,7 @@ static const struct scmi_proto_helpers_ops helpers_ops = { .protocol_msg_check = scmi_protocol_msg_check, .fastchannel_init = scmi_common_fastchannel_init, .fastchannel_db_ring = scmi_common_fastchannel_db_ring, + .debugfs_proto_dentry_get = scmi_debugfs_proto_dentry_get, }; /** @@ -2389,6 +2413,8 @@ void scmi_protocol_release(const struct scmi_handle *handle, u8 protocol_id) if (refcount_dec_and_test(&pi->users)) { void *gid = pi->gid; + debugfs_remove_recursive(pi->dbg); + if (pi->proto->events) scmi_deregister_protocol_events(handle, protocol_id); @@ -3111,6 +3137,9 @@ static struct scmi_debug_info *scmi_debugfs_common_setup(struct scmi_info *info) if (IS_ENABLED(CONFIG_ARM_SCMI_DEBUG_COUNTERS)) scmi_debugfs_counters_setup(dbg, trans); + if (IS_ENABLED(CONFIG_ARM_SCMI_DEBUG_PROTOCOLS)) + dbg->protos = debugfs_create_dir("protocols", top_dentry); + dbg->top_dentry = top_dentry; if (devm_add_action_or_reset(info->dev, diff --git a/drivers/firmware/arm_scmi/protocols.h b/drivers/firmware/arm_scmi/protocols.h index cc67e512fb6a..29dc6f14ee6d 100644 --- a/drivers/firmware/arm_scmi/protocols.h +++ b/drivers/firmware/arm_scmi/protocols.h @@ -11,6 +11,7 @@ #include #include +#include #include #include #include @@ -280,6 +281,9 @@ struct scmi_fc_info { * gathering FC descriptions from the SCMI platform server. * @fastchannel_db_ring: A common helper to ring a FC doorbell. * @get_max_msg_size: A common helper to get the maximum message size. + * @debugfs_proto_dentry_get: A common helper to get a per-protocol debugfs top + * directory to use as a root. It will be + * recursively removed on protocol de-initialization. */ struct scmi_proto_helpers_ops { int (*extended_name_get)(const struct scmi_protocol_handle *ph, @@ -303,6 +307,8 @@ struct scmi_proto_helpers_ops { u32 *rate_limit); void (*fastchannel_db_ring)(struct scmi_fc_db_info *db); int (*get_max_msg_size)(const struct scmi_protocol_handle *ph); + struct dentry *(*debugfs_proto_dentry_get) + (const struct scmi_protocol_handle *ph); }; /** diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h index de6b3c7cc959..c932390b9a09 100644 --- a/include/linux/scmi_protocol.h +++ b/include/linux/scmi_protocol.h @@ -1126,6 +1126,12 @@ struct scmi_notify_ops { * never sleep and act accordingly. * An optional atomic threshold value could be returned * where configured. + * @debugfs_entry_get: method to get, and possibly create, a debugfs dentry + * rooted under the top debugfs directory for the SCMI + * instance referred by handle. + * @debugfs_entry_put: method to put, and possibly destroy, a debugfs dentry + * rooted under the top debugfs directory for the SCMI + * instance referred by handle. * @notify_ops: pointer to set of notifications related operations */ struct scmi_handle { @@ -1140,7 +1146,11 @@ struct scmi_handle { void (*devm_protocol_put)(struct scmi_device *sdev, u8 proto); bool (*is_transport_atomic)(const struct scmi_handle *handle, unsigned int *atomic_threshold); - + struct dentry __must_check * + (*debugfs_entry_get)(const struct scmi_handle *handle, + const char *name); + void (*debugfs_entry_put)(const struct scmi_handle *handle, + struct dentry *dentry); const struct scmi_notify_ops *notify_ops; }; -- 2.54.0