From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 036711D5147; Mon, 19 Jan 2026 11:43:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.176.79.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768823031; cv=none; b=FgbooRxpqYSsYSMf+DINXkiK6kBWOZiwiHQ0NuBojyUZAiPqs6xhBe5YUQjyuV0Dqdq2TuAoecpHZzOGmIjlneFxxGbCAyKGNHRAyR3XtUjAZnfvTj39H6UD2ZwG9LTsqcJZyUxeq6W2Ejt23JpO8R/2QhwRkBbFI8vz6Gk5egg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768823031; c=relaxed/simple; bh=5sgE+g7Rv8h6aCm4guVJSiih+b9y4imi8KIOT18FKeo=; h=Date:From:To:CC:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=OjNX9yqy2SNUHzq7FlvJu+FkAVmHFEYeMdSGsGHhOT/czVbsYBou1oSYlVnyBu+xUijv0d/l3HN+legATtMXtjA05AY8DzaHyJp2SnE6VI4QmVnQMP6xKKSRnqx8iSnC4CMMh7ZThDldez2nBRSZGTH+aDQ40if02DEAG2pM6aw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=185.176.79.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.18.224.83]) by frasgout.his.huawei.com (SkyGuard) with ESMTPS id 4dvpVz2PSvzJ46mQ; Mon, 19 Jan 2026 19:43:23 +0800 (CST) Received: from dubpeml500005.china.huawei.com (unknown [7.214.145.207]) by mail.maildlp.com (Postfix) with ESMTPS id 1719340569; Mon, 19 Jan 2026 19:43:46 +0800 (CST) Received: from localhost (10.203.177.15) by dubpeml500005.china.huawei.com (7.214.145.207) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Mon, 19 Jan 2026 11:43:45 +0000 Date: Mon, 19 Jan 2026 11:43:43 +0000 From: Jonathan Cameron To: Cristian Marussi CC: , , , , , , , , , , , , , , , , Subject: Re: [PATCH v2 04/17] uapi: Add ARM SCMI definitions Message-ID: <20260119114343.00003f07@huawei.com> In-Reply-To: <20260114114638.2290765-5-cristian.marussi@arm.com> References: <20260114114638.2290765-1-cristian.marussi@arm.com> <20260114114638.2290765-5-cristian.marussi@arm.com> X-Mailer: Claws Mail 4.3.0 (GTK 3.24.42; x86_64-w64-mingw32) Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: lhrpeml100009.china.huawei.com (7.191.174.83) To dubpeml500005.china.huawei.com (7.214.145.207) On Wed, 14 Jan 2026 11:46:08 +0000 Cristian Marussi wrote: > Add a number of structures and ioctls definitions used by the ARM > SCMI Telemetry protocol. > > Signed-off-by: Cristian Marussi A few drive by comments. > diff --git a/include/uapi/linux/scmi.h b/include/uapi/linux/scmi.h > new file mode 100644 > index 000000000000..e4e9939a1bf8 > --- /dev/null > +++ b/include/uapi/linux/scmi.h > @@ -0,0 +1,287 @@ > +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ > +/* > + * Copyright (C) 2026 ARM Ltd. > + */ > +#ifndef _UAPI_LINUX_SCMI_H > +#define _UAPI_LINUX_SCMI_H > + > +/* > + * Userspace interface SCMI Telemetry > + */ > + > +#include > +#include > +/** > + * scmi_tlm_intervals - Update intervals descriptor > + * > + * @discrete: Flag to indicate the nature of the intervals described in > + * @update_intervals. > + * When 'false' @update_intervals is a triplet: min/max/step > + * @pad: Padding fields to enforce alignment. > + * @num: Number of entries of @update_intervals > + * @update_intervals: A variably-sized array containing the update intervals > + * > + * Used by: > + * RW - SCMI_TLM_GET_INTRVS > + * > + * Supported by: > + * control/ > + * groups//control > + */ > +struct scmi_tlm_intervals { > + __u8 discrete; > + __u8 pad[3]; > + __u32 num; Trivial but this seems a little inconsistent. In other 'num' entries (e.g. num_des) below a more specific name is used. > +#define SCMI_TLM_UPDATE_INTVL_SEGMENT_LOW 0 > +#define SCMI_TLM_UPDATE_INTVL_SEGMENT_HIGH 1 > +#define SCMI_TLM_UPDATE_INTVL_SEGMENT_STEP 2 > + __u32 update_intervals[] __counted_by(num); > +}; > + > +/** > + * scmi_tlm_des_list - List of all defined DEs > + * > + * @num_des: Number of entries in @des > + * @des: An array containing descriptors for all defined DEs > + * > + * Used by: > + * RW - SCMI_TLM_GET_DE_LIST > + * > + * Supported by: > + * control/ > + */ > +struct scmi_tlm_des_list { > + __u32 num_des; > + struct scmi_tlm_de_info des[] __counted_by(num_des); > +}; > + > +/** > + * scmi_tlm_de_sample - A DE reading > + * > + * @id: DE identifier > + * @tstamp: DE reading timestamp (equal 0 is NOT supported) > + * @val: Reading of the DE data value > + * > + * Used by: > + * RW - SCMI_TLM_GET_DE_VALUE > + * > + * Supported by: > + * control/ > + */ > +struct scmi_tlm_de_sample { > + __u32 id; Packing issues maybe if this ever ends up on 32 bit machines. Even more so once it's in an array below. > + __u64 tstamp; > + __u64 val; > +}; > + > +/** > + * scmi_tlm_data_read - Bulk read of multiple DEs > + * > + * @num_samples: Number of entries returned in @samples > + * @samples: An array of samples containing an entry for each DE that was > + * enabled when the single sample read request was issued. > + * > + * Used by: > + * RW - SCMI_TLM_SINGLE_SAMPLE > + * RW - SCMI_TLM_BULK_READ > + * > + * Supported by: > + * control/ > + * groups//control > + */ > +struct scmi_tlm_data_read { > + __u32 num_samples; > + struct scmi_tlm_de_sample samples[] __counted_by(num_samples); > +};