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 EC3B522FF2D for ; Fri, 8 Aug 2025 07:20:36 +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=1754637639; cv=none; b=eP7r6wbqs3JmkMZLM981UzaByK0keloinLjS7Q0/3TbQWk4e4R7btOSzvJICztZDLhz2GySBNjxwQF/ThFIkRIlhlHjACozJKRZsmQM69mWhnGnOF+NnJA74eS5jhA3uWnouLYDUQxBeMjiznp7nGlljfjyNLBz8Yp2QWLbygOg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754637639; c=relaxed/simple; bh=IkCAf5t6UkYyC1UKhTiX+pCqKezVhF7+B1DJtNHte7w=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=uICyQukspboeAg5CnaXNAI/Oo6eDwSeacVKZOXOPgNAyPa14SilqejcInnzf92mJeZFYLsgyMTwGL0TEQqUw5Kv6UjZ4/hKEFZW/1h/Gt163tVJrDwf3n+7o3NEpT7DCIqOzZUVWkjaCu532Gr7BOUw/v6seIOvGJN1Z2swc4rc= 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; 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 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 2171122EA; Fri, 8 Aug 2025 00:20:28 -0700 (PDT) Received: from [10.57.5.99] (unknown [10.57.5.99]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 2F9B33F673; Fri, 8 Aug 2025 00:20:31 -0700 (PDT) Message-ID: <99531c99-0430-4248-960a-a55fcdba79da@arm.com> Date: Fri, 8 Aug 2025 08:20:28 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH 20/36] arm_mpam: Probe the hardware features resctrl supports To: Ben Horgan , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Rob Herring , Rohit Mathew , Shanker Donthineni , Zeng Heng , Lecopzer Chen , Carl Worth , shameerali.kolothum.thodi@huawei.com, D Scott Phillips OS , lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, baolin.wang@linux.alibaba.com, Jamie Iles , Xin Hao , peternewman@google.com, dfustini@baylibre.com, amitsinght@marvell.com, David Hildenbrand , Rex Nie , Dave Martin , Koba Ko References: <20250711183648.30766-1-james.morse@arm.com> <20250711183648.30766-21-james.morse@arm.com> <46e49e66-1da3-433c-bdad-9468133c78a2@arm.com> Content-Language: en-US From: James Morse In-Reply-To: <46e49e66-1da3-433c-bdad-9468133c78a2@arm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Hi Ben, On 28/07/2025 09:56, Ben Horgan wrote: > On 7/11/25 19:36, James Morse wrote: >> Expand the probing support with the control and monitor types >> we can use with resctrl. >> diff --git a/drivers/platform/arm64/mpam/mpam_internal.h b/drivers/platform/arm64/mpam/ >> mpam_internal.h >> index 42a454d5f914..ae6fd1f62cc4 100644 >> --- a/drivers/platform/arm64/mpam/mpam_internal.h >> +++ b/drivers/platform/arm64/mpam/mpam_internal.h >> @@ -136,6 +136,55 @@ static inline void mpam_mon_sel_lock_held(struct mpam_msc *msc) >> lockdep_assert_preemption_enabled(); >> } >> +/* >> + * When we compact the supported features, we don't care what they are. >> + * Storing them as a bitmap makes life easy. >> + */ >> +typedef u16 mpam_features_t; >> + >> +/* Bits for mpam_features_t */ >> +enum mpam_device_features { >> + mpam_feat_ccap_part = 0, >> + mpam_feat_cpor_part, >> + mpam_feat_mbw_part, >> + mpam_feat_mbw_min, >> + mpam_feat_mbw_max, >> + mpam_feat_mbw_prop, >> + mpam_feat_msmon, >> + mpam_feat_msmon_csu, >> + mpam_feat_msmon_csu_capture, >> + mpam_feat_msmon_csu_hw_nrdy, >> + mpam_feat_msmon_mbwu, >> + mpam_feat_msmon_mbwu_capture, >> + mpam_feat_msmon_mbwu_rwbw, >> + mpam_feat_msmon_mbwu_hw_nrdy, >> + mpam_feat_msmon_capt, >> + MPAM_FEATURE_LAST, >> +}; >> +#define MPAM_ALL_FEATURES ((1 << MPAM_FEATURE_LAST) - 1) > > Consider a static assert to check the type is big enough. > > static_assert(BITS_PER_TYPE(mpam_features_t) >= MPAM_FEATURE_LAST); Fancy. There used to be an uglier one - not sure what happened to it! Thanks, James