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 0B3F43F44E9; Sun, 6 Sep 2026 10:08:06 +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=1788689289; cv=none; b=uFO8l7I2lox91PxX0J9Fp/ENgFabhuKbPNB9ClynsZo977nRptbm7kNUEXtP2F+GEbewyKXi+UdBP+EiR5fYhT3DNuUJ9WjMclc8TCKy4LAnEe9KyYFuygaxt4Ng3QrQdcA8nfHDv7lhrUPvpQmUYQtD6/w/trBDTNEA09w+Rcc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788689289; c=relaxed/simple; bh=G9SuWb3lueFiHj7U9yi9Tetqys69QORzlzraY9D96X0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=VlwIQrvfwZ5YNUzIT/vRatni08IizOuakP/faShK0m56r6jakkjCHHWrKWQFg/0keREXacDhWvYaGoDJ6eE1WATHXXi1vxWRcmdDKXjG9YnbgD/vPtpOCqBXHJjxVxuse4VC/kk8+HIvy+aYv+Ns9k1nYrhLNyvqlCA7TScjPlQ= 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=Rjq6DwRe; 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="Rjq6DwRe" 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 9C69E1AED; Sun, 6 Sep 2026 03:08:02 -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 717743F7D8; Sun, 6 Sep 2026 03:08:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1788689286; bh=G9SuWb3lueFiHj7U9yi9Tetqys69QORzlzraY9D96X0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Rjq6DwRemvhczaZRug8Cw/2qtViJrLX146WeozhltfF5zazgstIdsTwbx3VlFzQ0D YPhSezhc0gelEEfD8CAm8646EP8R53LW7aRH5zMe/MbV3YXuh/c1OXY/kHJordfW4Z IysAxC4UnBcz4AZcU9whUBAfFPCLhR/w5AhUWqJ0= 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 13/25] firmware: arm-scmi: Add telemetry generic event support Date: Sun, 6 Sep 2026 11:06:11 +0100 Message-ID: <20260906100623.3488327-14-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 Add support to allow SCMI driver users to subscribe/unsubscribe to specific Telemetry abstract (non protocol) events. This enables SCMI drivers to subscribe to available events by registering an eventfd context that the core SCMI stack will use as a signalling mechanisms. Signed-off-by: Cristian Marussi --- v10 --> v11 - move events cleanup into resource_free v8 --> v9 - add a TLM_EVT_DUMMY placeholder (waiting for more events later on..) --- drivers/firmware/arm_scmi/telemetry.c | 97 +++++++++++++++++++++++++++ include/linux/scmi_protocol.h | 16 +++++ 2 files changed, 113 insertions(+) diff --git a/drivers/firmware/arm_scmi/telemetry.c b/drivers/firmware/arm_scmi/telemetry.c index 6409ee727158..4bb2010c89b5 100644 --- a/drivers/firmware/arm_scmi/telemetry.c +++ b/drivers/firmware/arm_scmi/telemetry.c @@ -12,6 +12,7 @@ #include #include #include +#include #include #include #include @@ -479,6 +480,11 @@ enum de_state { ENA_MAX }; +struct telemetry_event { + struct eventfd_ctx *ctx; + struct list_head item; +}; + struct telemetry_info { bool streaming_mode; unsigned int num_shmti; @@ -505,6 +511,9 @@ struct telemetry_info { struct list_head free_des; struct list_head fcs_des; struct scmi_telemetry_info info; + /* Mutex to protect access to @events */ + struct mutex events_mtx; + struct list_head events[SCMI_TLM_EVT_MAX]; struct notifier_block telemetry_nb; atomic_t rinfo_initializing; struct completion rinfo_initdone; @@ -524,6 +533,21 @@ static int scmi_telemetry_shmti_scan(struct telemetry_info *ti, static inline void scmi_telemetry_uuid_link(struct telemetry_de *tde, struct telemetry_uuid *uuid); +static int scmi_telemetry_event_signal(struct telemetry_info *ti, + enum scmi_telemetry_event type) +{ + struct telemetry_event *evt; + + if (type >= SCMI_TLM_EVT_MAX) + return -EINVAL; + + guard(mutex)(&ti->events_mtx); + list_for_each_entry(evt, &ti->events[type], item) + eventfd_signal(evt->ctx); + + return 0; +} + static inline void scmi_telemetry_de_state_update(struct telemetry_info *ti, enum de_state state, bool *current_state, const bool next_state) @@ -3330,6 +3354,54 @@ static int scmi_telemetry_reset(const struct scmi_protocol_handle *ph) return ret; } +static int scmi_telemetry_event_subscribe(const struct scmi_protocol_handle *ph, + enum scmi_telemetry_event type, + struct eventfd_ctx *ctx) +{ + struct telemetry_info *ti = ph->get_priv(ph); + struct telemetry_event *evt; + + if (type >= SCMI_TLM_EVT_MAX) + return -EINVAL; + + evt = kzalloc_obj(*evt); + if (!evt) + return -ENOMEM; + + evt->ctx = ctx; + guard(mutex)(&ti->events_mtx); + list_add(&evt->item, &ti->events[type]); + + trace_scmi_tlm_access(0, "TLM_EVT_SUBS", 0, 0); + + return 0; +} + +static int scmi_telemetry_event_unsubscribe(const struct scmi_protocol_handle *ph, + enum scmi_telemetry_event type, + struct eventfd_ctx *ctx) +{ + struct telemetry_info *ti = ph->get_priv(ph); + struct telemetry_event *evt, *n; + + if (type >= SCMI_TLM_EVT_MAX) + return -EINVAL; + + guard(mutex)(&ti->events_mtx); + list_for_each_entry_safe(evt, n, &ti->events[type], item) { + if (evt->ctx == ctx) { + list_del(&evt->item); + kfree(evt); + + trace_scmi_tlm_access(0, "TLM_EVT_UNSUBS", 0, 0); + + break; + } + } + + return 0; +} + static const struct scmi_telemetry_proto_ops tlm_proto_ops = { .info_get = scmi_telemetry_info_get, .de_lookup = scmi_telemetry_de_lookup, @@ -3341,6 +3413,8 @@ static const struct scmi_telemetry_proto_ops tlm_proto_ops = { .des_bulk_read = scmi_telemetry_des_bulk_read, .des_sample_get = scmi_telemetry_des_sample_get, .reset = scmi_telemetry_reset, + .event_subscribe = scmi_telemetry_event_subscribe, + .event_unsubscribe = scmi_telemetry_event_unsubscribe, }; static bool @@ -3555,6 +3629,23 @@ __scmi_telemetry_resources_get(struct telemetry_info *ti) return smp_load_acquire(&ti->rinfo); } +static void scmi_telemetry_event_cleanup(struct telemetry_info *ti) +{ + guard(mutex)(&ti->events_mtx); + /* Clear any residual events */ + for (int type = 0; type < SCMI_TLM_EVT_MAX; type++) { + struct telemetry_event *evt, *n; + + list_for_each_entry_safe(evt, n, &ti->events[type], item) { + dev_warn(ti->ph->dev, + "Found UN-SUBSCRIBED event type %d!\n", type); + list_del(&evt->item); + eventfd_ctx_put(evt->ctx); + kfree(evt); + } + } +} + static void scmi_telemetry_resources_free(void *arg) { struct scmi_telemetry_res_info *rinfo; @@ -3595,6 +3686,9 @@ static void scmi_telemetry_resources_free(void *arg) scmi_telemetry_line_put(line); xa_destroy(&ti->xa_lines); + /* Cleanup any still registered event */ + scmi_telemetry_event_cleanup(ti); + kfree(ti->tdes); kfree(rinfo->des); kfree(rinfo->dei_store); @@ -3750,6 +3844,9 @@ static int scmi_telemetry_instance_init(struct telemetry_info *ti) if (ret) return ret; + for (int i = 0; i < SCMI_TLM_EVT_MAX; i++) + INIT_LIST_HEAD(&ti->events[i]); + mutex_init(&ti->events_mtx); atomic_set(&ti->des_enabled[ENA_STATE], 0); atomic_set(&ti->des_enabled[ENA_TSTAMP], 0); mutex_init(&ti->des_enabled_mtx); diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h index 2d571c78613b..06591b27f365 100644 --- a/include/linux/scmi_protocol.h +++ b/include/linux/scmi_protocol.h @@ -11,6 +11,7 @@ #include #include #include +#include #include #include #include @@ -994,6 +995,11 @@ struct scmi_telemetry_de_sample { unsigned long long val; }; +enum scmi_telemetry_event { + SCMI_TLM_EVT_DUMMY, + SCMI_TLM_EVT_MAX, +}; + /** * struct scmi_telemetry_proto_ops - represents the various operations provided * by SCMI Telemetry Protocol @@ -1017,6 +1023,10 @@ struct scmi_telemetry_de_sample { * This causes an immediate update platform-side of all the * enabled DEs. * @reset: reset configuration and telemetry data. + * @event_subscribe: subscribe to the specified event @type using the provided + * @eventfd_ctx. + * @event_unsubscribe: unsubscribe to the specified event @type the previously + * registered @eventfd_ctx. */ struct scmi_telemetry_proto_ops { const struct scmi_telemetry_info __must_check *(*info_get) @@ -1044,6 +1054,12 @@ struct scmi_telemetry_proto_ops { int __must_check (*des_sample_get)(const struct scmi_protocol_handle *ph, int grp_id, int *num_samples, struct scmi_telemetry_de_sample *samples); + int (*event_subscribe)(const struct scmi_protocol_handle *ph, + enum scmi_telemetry_event type, + struct eventfd_ctx *ctx); + int (*event_unsubscribe)(const struct scmi_protocol_handle *ph, + enum scmi_telemetry_event type, + struct eventfd_ctx *ctx); int (*reset)(const struct scmi_protocol_handle *ph); }; -- 2.54.0