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 E85291A34A0 for ; Fri, 2 Aug 2024 17:31:36 +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=1722619898; cv=none; b=YkNEgZ222Hpc4vE6IymcTad1oVbEKx2EAhtUnpmVfgsjSAFBxcwvav0QF3NW26grYhI2dDVG9LzzKiF5I7zEhQkj0o0Gu56vt1zKGmRvgMEbXki8X9+Lq0KIlFaau31BxDLzgow/AOopBZG+GplYPDh/VpKdrciXgxqHI9o3fYw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722619898; c=relaxed/simple; bh=jVVbBkHgu6EbzAdE0+KawabwZeijzPi0OVSAEju0ZWI=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=c2hgpW596ORe77EIm/k6ijz9Unm0WfKJGd2yO9VRiUNK9erNtYA7HLxe/kj+b39Hm95DezNrNFKyLlx6rCU/bDIQk+iYJNAg+Wc/ezIjJaripQ2+TFrDNB7S+x0ad9knAVBLQsGDFfgu06jsM68X7tHVK/H4+IlE71NjY6Y3mJM= 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 4421C165C; Fri, 2 Aug 2024 10:32:02 -0700 (PDT) Received: from merodach.members.linode.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 9A1DC3F64C; Fri, 2 Aug 2024 10:31:33 -0700 (PDT) From: James Morse To: x86@kernel.org, linux-kernel@vger.kernel.org Cc: Fenghua Yu , Reinette Chatre , Thomas Gleixner , Ingo Molnar , Borislav Petkov , H Peter Anvin , Babu Moger , James Morse , shameerali.kolothum.thodi@huawei.com, D Scott Phillips OS , carl@os.amperecomputing.com, 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 Subject: [PATCH v4 29/39] x86/resctrl: Describe resctrl's bitmap size assumptions Date: Fri, 2 Aug 2024 17:28:43 +0000 Message-Id: <20240802172853.22529-30-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20240802172853.22529-1-james.morse@arm.com> References: <20240802172853.22529-1-james.morse@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit resctrl operates on configuration bitmaps and a bitmap of allocated CLOSID, both are stored in a u32. MPAM supports configuration/portion bitmaps and PARTIDs larger than will fit in a u32. Add some preprocessor values that make it clear why MPAM clamps some of these values. This will make it easier to find code related to these values if this resctrl behaviour ever changes. Signed-off-by: James Morse Tested-by: Carl Worth # arm64 --- include/linux/resctrl.h | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index 31a28151193d..1ebf705ec3c5 100644 --- a/include/linux/resctrl.h +++ b/include/linux/resctrl.h @@ -27,6 +27,17 @@ int proc_resctrl_show(struct seq_file *m, /* max value for struct rdt_domain's mbps_val */ #define MBA_MAX_MBPS U32_MAX +/* + * Resctrl uses a u32 as a closid bitmap. The maximum closid is 32. + */ +#define RESCTRL_MAX_CLOSID 32 + +/* + * Resctrl uses u32 to hold the user-space config. The maximum bitmap size is + * 32. + */ +#define RESCTRL_MAX_CBM 32 + /* Walk all possible resources, with variants for only controls or monitors. */ #define for_each_rdt_resource(_r) \ for ((_r) = resctrl_arch_get_resource(0); \ -- 2.39.2