From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 1CA6EC44501 for ; Fri, 3 Jul 2026 12:37:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=8TNXx4BZW/2HTPAb4MOc8Mwcj1HGhSz6eggvcyJPZd8=; b=Qr8UjhM6hWXEp7TT3YdhEhWVc7 X6ipQ2Rps3Ks9Bb3jSzfMAzlT63nhQPqs+n+DMU2yhCREHdtaUKBpLJ6gpAHn5wjvWeT6x4oHtuiT 2oroImmZq/TYTljpQqvbKKpbxdZrhLHK4gFkq/f4yawQvhYbq5vnLQLjG2rDdmhbJd7Nhs+YPVBRa x/12IxgD9raz7McIj371YTA3jjIr1lL8Xxs/IQCIADCjpw6iv5RIuNqOS9QLZ8m2HhQ/JX4CA67Xb Uj7EXCZPV2lmttlCx9eeDejHsvIKtLfGj1oz4+0mKVuJCQIlaNco+93ELIqqiRhUZ3bsKtdyYLSTl hH+L+knA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wfd96-00000006xZv-3W5U; Fri, 03 Jul 2026 12:37:28 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wfd8L-00000006xE1-1YkU for linux-arm-kernel@lists.infradead.org; Fri, 03 Jul 2026 12:37:27 +0000 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 41D144649; Fri, 3 Jul 2026 05:36:36 -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 20F2E3F905; Fri, 3 Jul 2026 05:36:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1783082200; bh=rh6cUwBsUU5OKWxIPR8KSzs0KEvY2omC8yMBDv/pEbk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=d/G3xEjqeRZqo8hctQSEXTygfRNl7PY05jA1ojzae5h224S/PtPGj1ZFwSwud9RjD CM8Hi2r5+Pai6Fe1KBuo95ct07ep90pDO7N+2gaVO0L0AOtVr2D5CGx3tlXeqR3KDv Q7n10LQufHmt6x3aznvwJp2zOMm1htG0YA3ZcXqk= 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 03/23] firmware: arm_scmi: Allow registration of unknown-size events/reports Date: Fri, 3 Jul 2026 13:35:41 +0100 Message-ID: <20260703123601.381275-4-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> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260703_053641_497753_1C104FB5 X-CRM114-Status: GOOD ( 17.28 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Allow protocols to register events with build-time unknown sizes: such events can be declared zero-sized and let the core SCMI stack perform the needed safe-net boundary checks based on the configured transport size. Signed-off-by: Cristian Marussi --- v2 --> v3 - split out of previous patch on protocol notifier - use max() instead of max_t() --- drivers/firmware/arm_scmi/notify.c | 24 +++++++++++++++++++----- drivers/firmware/arm_scmi/notify.h | 8 ++++++-- 2 files changed, 25 insertions(+), 7 deletions(-) diff --git a/drivers/firmware/arm_scmi/notify.c b/drivers/firmware/arm_scmi/notify.c index 40ec184eedae..3e4c97ab7b61 100644 --- a/drivers/firmware/arm_scmi/notify.c +++ b/drivers/firmware/arm_scmi/notify.c @@ -595,7 +595,13 @@ int scmi_notify(const struct scmi_handle *handle, u8 proto_id, u8 evt_id, if (!r_evt) return -EINVAL; - if (len > r_evt->evt->max_payld_sz) { + /* + * Events with a zero max_payld_sz are sized to be of the maximum + * size allowed by the transport: no need to be size-checked here + * since the transport layer would have already dropped such + * over-sized messages. + */ + if (r_evt->evt->max_payld_sz && len > r_evt->evt->max_payld_sz) { dev_err(handle->dev, "discard badly sized message\n"); return -EINVAL; } @@ -754,7 +760,7 @@ int scmi_register_protocol_events(const struct scmi_handle *handle, u8 proto_id, const struct scmi_protocol_handle *ph, const struct scmi_protocol_events *ee) { - int i; + int i, max_msg_sz; unsigned int num_sources; size_t payld_sz = 0; struct scmi_registered_events_desc *pd; @@ -769,6 +775,8 @@ int scmi_register_protocol_events(const struct scmi_handle *handle, u8 proto_id, if (!ni) return -ENOMEM; + max_msg_sz = ph->hops->get_max_msg_size(ph); + /* num_sources cannot be <= 0 */ if (ee->num_sources) { num_sources = ee->num_sources; @@ -781,8 +789,13 @@ int scmi_register_protocol_events(const struct scmi_handle *handle, u8 proto_id, } evt = ee->evts; - for (i = 0; i < ee->num_events; i++) - payld_sz = max_t(size_t, payld_sz, evt[i].max_payld_sz); + for (i = 0; i < ee->num_events; i++) { + if (evt[i].max_payld_sz == 0) { + payld_sz = max_msg_sz; + break; + } + payld_sz = max(payld_sz, evt[i].max_payld_sz); + } payld_sz += sizeof(struct scmi_event_header); pd = scmi_allocate_registered_events_desc(ni, proto_id, ee->queue_sz, @@ -811,7 +824,8 @@ int scmi_register_protocol_events(const struct scmi_handle *handle, u8 proto_id, mutex_init(&r_evt->sources_mtx); r_evt->report = devm_kzalloc(ni->handle->dev, - evt->max_report_sz, GFP_KERNEL); + evt->max_report_sz ?: max_msg_sz, + GFP_KERNEL); if (!r_evt->report) return -ENOMEM; diff --git a/drivers/firmware/arm_scmi/notify.h b/drivers/firmware/arm_scmi/notify.h index 76758a736cf4..ecfa4b746487 100644 --- a/drivers/firmware/arm_scmi/notify.h +++ b/drivers/firmware/arm_scmi/notify.h @@ -18,8 +18,12 @@ /** * struct scmi_event - Describes an event to be supported * @id: Event ID - * @max_payld_sz: Max possible size for the payload of a notification message - * @max_report_sz: Max possible size for the report of a notification message + * @max_payld_sz: Max possible size for the payload of a notification message. + * Set to zero to use the maximum payload size allowed by the + * transport. + * @max_report_sz: Max possible size for the report of a notification message. + * Set to zero to use the maximum payload size allowed by the + * transport. * * Each SCMI protocol, during its initialization phase, can describe the events * it wishes to support in a few struct scmi_event and pass them to the core -- 2.54.0