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 578113E558A; Sun, 20 Sep 2026 09:21:10 +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=1789896076; cv=none; b=IVdIUy2RJKHt/UDqTjT6DRDK/oOvpUPcuZRfUS8xlnSsaa6T83QPDod+xZeXJqZgqTx4iDIsr36rxV605qNLWloZFuHIE6Hi8Qv41290CAAQTUZMVEQp9ThebYdlmC7VVRHMFMxB1F/r7iAvaA3crJpzN8ot4NSus6UvL1dULmk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789896076; c=relaxed/simple; bh=t9wyyeFMtxTXqDtnieZJaEnVceYHrygP7s5U8LrdN4U=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=cH/KzKDFfwI55ADm5chpYhTlmzC3A///clUZgXEznOBvCPcGPfgIjmEUMfHeq54eed/hdCsSHDWR8fFOPyn0UWudg9+N2kJw9SXL52TIETjMcK50KqzArXusFWptnh3d348YsgRVBgZFYkfjro4BSV7gu0bP9ktvpzVrNSGNY8A= 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=LAfe+EYK; 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="LAfe+EYK" 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 C20B71650; Sun, 20 Sep 2026 02:21:06 -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 6F4F13F59E; Sun, 20 Sep 2026 02:21:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1789896070; bh=t9wyyeFMtxTXqDtnieZJaEnVceYHrygP7s5U8LrdN4U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LAfe+EYKuJjFImL9E5GNvvtEJzJICNNETd3BtNGHQ996sgFy8dWc/5pNwTQ4HmSU2 E6DePx9z6IdxoYs2IjUl5thX3i5XIKGbvrwG7xqc+r+PtYZlRBZ4kT082CwW4uhfnV +LSMaNSWiRGW24wvu23rzgCXgSJTd3iQs+oKN+jM= 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 v12 14/25] firmware: arm_scmi: Add Telemetry generation counter event Date: Sun, 20 Sep 2026 10:19:17 +0100 Message-ID: <20260920091928.2014972-15-cristian.marussi@arm.com> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260920091928.2014972-1-cristian.marussi@arm.com> References: <20260920091928.2014972-1-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 a per-instance generation counter to track configuration changes which uses the common telemetry events framework. Signed-off-by: Cristian Marussi --- v11 -->v12 - reviewed generation counter update logic v6 --> v7 - use new Generic event mechanism based on EventFD instead of WaitQ v5 --> v6 - add relese semantic to the atomic set of the generation counter - use new eventfd_ctx common event logic --- drivers/firmware/arm_scmi/telemetry.c | 48 ++++++++++++++++++++++++++- include/linux/scmi_protocol.h | 6 ++-- 2 files changed, 51 insertions(+), 3 deletions(-) diff --git a/drivers/firmware/arm_scmi/telemetry.c b/drivers/firmware/arm_scmi/telemetry.c index c76409083160..ada4838d2351 100644 --- a/drivers/firmware/arm_scmi/telemetry.c +++ b/drivers/firmware/arm_scmi/telemetry.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include #include @@ -26,6 +27,7 @@ #include #include #include +#include #include "protocols.h" #include "notify.h" @@ -35,6 +37,7 @@ /* Updated only after ALL the mandatory features for that version are merged */ #define SCMI_PROTOCOL_SUPPORTED_VERSION 0x10000 +#define SCMI_TLM_GENERATION_ONE (SCMI_TLM_GENERATION_INVALID + 1U) #define SCMI_TLM_TDCF_MAX_RETRIES 5 #define SCMI_TLM_DE_IMPL_NUM_DWORDS 4 @@ -719,6 +722,37 @@ scmi_telemetry_tde_cache_lookup(struct telemetry_de *tde, return 0; } +static inline void __scmi_telemetry_generation_set(struct telemetry_info *ti, + unsigned int new) +{ + int ret; + + atomic_set_release(&ti->info.generation, new); + + ret = scmi_telemetry_event_signal(ti, SCMI_TLM_EVT_GENERATION); + if (ret) + dev_warn_once(ti->ph->dev, + "Could NOT signal telemetry event %d\n", + SCMI_TLM_EVT_GENERATION); +} + +static inline void scmi_telemetry_generation_update(struct telemetry_info *ti) +{ + unsigned int next; + + lockdep_assert_held(&ti->config_mtx); + + /* Wrap around skipping invalid generation 0 */ + next = (atomic_read(&ti->info.generation) + 1) ?: SCMI_TLM_GENERATION_ONE; + + __scmi_telemetry_generation_set(ti, next); +} + +static inline void scmi_telemetry_generation_reset(struct telemetry_info *ti) +{ + __scmi_telemetry_generation_set(ti, SCMI_TLM_GENERATION_ONE); +} + struct scmi_tlm_de_priv { struct telemetry_info *ti; void *next; @@ -2734,6 +2768,8 @@ static int __scmi_telemetry_state_set(const struct scmi_protocol_handle *ph, tstamp_enabled_state, *tstamp); + /* A local change can have an impact anyway */ + scmi_telemetry_generation_update(ti); return 0; } @@ -2766,11 +2802,13 @@ static int __scmi_telemetry_state_set(const struct scmi_protocol_handle *ph, ret = ph->xops->do_xfer(ph, t); if (!ret) { ret = scmi_telemetry_state_set_resp_process(ti, obj, resp, is_group); - if (!ret) + if (!ret) { /* Update cached state on success */ scmi_telemetry_state_cache_update(ti, enable, enabled_state, tstamp, tstamp_enabled_state, grp, de); + scmi_telemetry_generation_update(ti); + } } ph->xops->xfer_put(ph, t); @@ -2959,6 +2997,9 @@ scmi_telemetry_collection_configure(const struct scmi_protocol_handle *ph, ph->xops->xfer_put(ph, t); + if (!ret) + scmi_telemetry_generation_update(ti); + return ret; } @@ -3473,6 +3514,9 @@ static int scmi_telemetry_reset(const struct scmi_protocol_handle *ph) struct telemetry_info *ti = ph->get_priv(ph); scmi_telemetry_local_resources_reset(ti); + /* Reset generation now that server has been reset */ + scmi_telemetry_generation_reset(ti); + /* NO need to lookup the initial state we have just reset all */ } @@ -3994,6 +4038,8 @@ static int scmi_telemetry_instance_init(struct telemetry_info *ti) for (int i = 0; i < SCMI_TLM_EVT_MAX; i++) INIT_LIST_HEAD(&ti->events[i]); mutex_init(&ti->events_mtx); + /* Generation counter init */ + atomic_set(&ti->info.generation, SCMI_TLM_GENERATION_ONE); 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 b4b3e95547ba..56b098bc472d 100644 --- a/include/linux/scmi_protocol.h +++ b/include/linux/scmi_protocol.h @@ -891,6 +891,7 @@ enum scmi_telemetry_collection { SCMI_TLM_SINGLE_READ, }; +#define SCMI_TLM_GENERATION_INVALID 0U #define SCMI_TLM_GRP_INVALID 0xFFFFFFFF struct scmi_telemetry_intervals { @@ -986,6 +987,7 @@ struct scmi_telemetry_info { bool enabled; bool notif_enabled; enum scmi_telemetry_collection current_mode; + atomic_t generation; }; struct scmi_telemetry_de_sample { @@ -996,7 +998,7 @@ struct scmi_telemetry_de_sample { }; enum scmi_telemetry_event { - SCMI_TLM_EVT_DUMMY, + SCMI_TLM_EVT_GENERATION, SCMI_TLM_EVT_MAX, }; @@ -1022,11 +1024,11 @@ enum scmi_telemetry_event { * the ones belonging to a specific group when provided. * 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. + * @reset: reset configuration and telemetry data. */ struct scmi_telemetry_proto_ops { const struct scmi_telemetry_info __must_check *(*info_get) -- 2.54.0