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 9C55A41F5D7; Sun, 6 Sep 2026 10:08:15 +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=1788689297; cv=none; b=pwT1LACdJlXVi7K3nUdCa5f/dpaVCBaypSyGgYJUfCAmBLh6jsFYJ8Te/5jMxbFbw+eBSS1I1amy2YGChLN87NtZwuRqLYKKq+u0ZroaV3sCqeE5hr+PfYPR1W70ZjAXMQuF97oD6DRWnQotnMNtgpaljwLMXMFiKg1eawH2dkU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788689297; c=relaxed/simple; bh=F8Y91aWTSj5i8Wz6utcS18Q4WyoXG6zyxASn9PHvNSQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=s6sayuO965YFV5ynXHoPky6juBpuPRekUUPIQfHIgD8DG8sED4O5O7R6CWf0AZ7ChIQ2TkVZZnk3kFRIu3fthOOpYzvipaDYkVPL0k5PlzjrsN5RD+rDfojaz7zEP6pSm0zwt9j/S8t2fuZGINVtiu75owxyuzvp3n0VU/2T1Y0= 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=XRypduSd; 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="XRypduSd" 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 1D80E1BC0; Sun, 6 Sep 2026 03:08:11 -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 022B73F7D8; Sun, 6 Sep 2026 03:08:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1788689294; bh=F8Y91aWTSj5i8Wz6utcS18Q4WyoXG6zyxASn9PHvNSQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XRypduSdOnLqnn2I6vdnWppDMfUoI8cxqTc4LmiCP7HixtRWWP5gjd5ni0t7tQi4Y pcGUG76Mc+9t/qx4dEbsT/14aGovn5P3WFJeLJW8oblYp36x+ImwbONfO3+TGv8po6 8rRrN3brmt+X4+hk1lwKGkJMqTkkcjXKaFGJjGgQ= 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 15/25] firmware: arm_scmi: Add common per-protocol debugfs support Date: Sun, 6 Sep 2026 11:06:13 +0100 Message-ID: <20260906100623.3488327-16-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 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 --- v8 --> v9 - avoid NULL deref on DBG cleanup path v5 --> v6 - bail out of dentry_get helper when SCMI debug susbsytem failed to init - remove stale SCMI protocol operations - add a preoper clean up of debugfs when protocol init fails --- drivers/firmware/arm_scmi/Kconfig | 14 +++++++++++ drivers/firmware/arm_scmi/common.h | 2 ++ drivers/firmware/arm_scmi/driver.c | 35 +++++++++++++++++++++++++-- drivers/firmware/arm_scmi/protocols.h | 6 +++++ include/linux/scmi_protocol.h | 1 - 5 files changed, 55 insertions(+), 3 deletions(-) diff --git a/drivers/firmware/arm_scmi/Kconfig b/drivers/firmware/arm_scmi/Kconfig index 783c24a20e29..f506c4d1d96a 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 1d9e6af09672..8c0e49748c32 100644 --- a/drivers/firmware/arm_scmi/common.h +++ b/drivers/firmware/arm_scmi/common.h @@ -324,6 +324,7 @@ 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 @@ -331,6 +332,7 @@ 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 408fa4cb83a6..e8d93690ecc2 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 @@ -102,6 +103,8 @@ 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. @@ -116,6 +119,7 @@ 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) @@ -2094,6 +2098,25 @@ 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) || !info->dbg) + 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, @@ -2104,6 +2127,7 @@ 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, }; /** @@ -2289,12 +2313,12 @@ scmi_alloc_init_protocol_instance(struct scmi_info *info, /* proto->init is assured NON NULL by scmi_protocol_register */ ret = pi->proto->instance_init(&pi->ph); if (ret) - goto clean; + goto clean_dbg; ret = idr_alloc(&info->protocols, pi, proto->id, proto->id + 1, GFP_KERNEL); if (ret != proto->id) - goto clean; + goto clean_dbg; /* * Warn but ignore events registration errors since we do not want @@ -2315,6 +2339,8 @@ scmi_alloc_init_protocol_instance(struct scmi_info *info, return pi; +clean_dbg: + debugfs_remove_recursive(pi->dbg); clean: /* Take care to put the protocol module's owner before releasing all */ scmi_protocol_put(proto); @@ -2430,6 +2456,8 @@ 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); @@ -3169,6 +3197,9 @@ 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 1f9925b8f495..04e196a9fbf4 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 @@ -284,6 +285,9 @@ 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, @@ -307,6 +311,8 @@ 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 83ab8edc0b13..037b486dc873 100644 --- a/include/linux/scmi_protocol.h +++ b/include/linux/scmi_protocol.h @@ -1156,7 +1156,6 @@ 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); - const struct scmi_notify_ops *notify_ops; }; -- 2.54.0