From nobody Mon Feb 9 06:25:06 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 2CB2B142621 for ; Thu, 21 Mar 2024 16:52:54 +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=1711039975; cv=none; b=Gn/p4kHmXlBU+tfdeq+zEXMn7a+bk9higeRga/X2K9Ks1tu7045IfxjAKJogqVm09Q9nspy8kWgOwIDlDmlx2mKDvttHZ3tZmTWE1nxHLfjppzTFGDXGyKxEx/0nXTiasLuKSN1pd2FbRwJfIgQvcIYLAzldEnN4n15iE+PtufA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711039975; c=relaxed/simple; bh=vE8ObtSbNXXuQbtQiG9u6MeSrab/F7HqkgTUdTMXcBI=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=GbsXkv46qpnBuhSC5pCnDjTD/NwPTlM8OLJLWlQ0CLonFUCtNfgak1IPqn0ihx1rUgNjB28ESFJjzJ4tA8iz/icHhBIXAMh3qieNNHLbOU2t77VQGSmrAvCuh9EsfdcecTaKkYSaIQEB7hlLpyZ7cXN604kIFzfPLG/MuzbPOFE= 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 18508168F; Thu, 21 Mar 2024 09:53:28 -0700 (PDT) Received: from merodach.members.linode.com (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id CEF593F67D; Thu, 21 Mar 2024 09:52:50 -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 v1 26/31] x86/resctrl: Describe resctrl's bitmap size assumptions Date: Thu, 21 Mar 2024 16:51:01 +0000 Message-Id: <20240321165106.31602-27-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20240321165106.31602-1-james.morse@arm.com> References: <20240321165106.31602-1-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: quoted-printable Content-Type: text/plain; charset="utf-8" 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 --- include/linux/resctrl.h | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index 84420253dc05..f463fb949677 100644 --- a/include/linux/resctrl.h +++ b/include/linux/resctrl.h @@ -26,6 +26,17 @@ int proc_resctrl_show(struct seq_file *m, /* max value for struct rdt_domain's mbps_val */ #define MBA_MAX_MBPS U32_MAX =20 +/* + * 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 + /** * struct pseudo_lock_region - pseudo-lock region information * @s: Resctrl schema for the resource to which this --=20 2.39.2