From nobody Fri Dec 19 07:33:06 2025 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 75B941AC442 for ; Fri, 14 Jun 2024 15:02:46 +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=1718377367; cv=none; b=bqW5CEnmpYr9zBqfRA4p635sBYdMK43T9frFQt5VdPIcV7wDb0z4e82nbgFDOhqLAwLxzm2qFG0fY4tU9nbNy2RHxWsNJu1KTkVzkBV8hMxSmGZH+OS6aTNfoNdd0GUoMwv8sqZxYw5e5QZ67uY1dgpLgemWoXzQaNeZ1m40YMI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718377367; c=relaxed/simple; bh=XzyY1VYxH0Tt/pg7qvgDUvhr+hjVQGV0sJ/Tk5PDMEM=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=QyhWbc3nxPsY8DH1EtrMdxaO7/zW7kesUxMumySnIGqWuLA2g5C63ib+Y0LPD8dtbRLe7B9bGb2+IxfNeTvd52nWJK+6U756+zUZB4cfk3hz62S9RyKg88MM1K5wXiJot8l1Ub3tf8h8rXbs5WPeELJVHS4mti2xtcVGD/U41Vs= 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 9C3B31BCA; Fri, 14 Jun 2024 08:03:10 -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 EA4223F5A1; Fri, 14 Jun 2024 08:02:42 -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 , Shaopeng Tan Subject: [PATCH v3 29/38] x86/resctrl: Describe resctrl's bitmap size assumptions Date: Fri, 14 Jun 2024 15:00:24 +0000 Message-Id: <20240614150033.10454-30-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20240614150033.10454-1-james.morse@arm.com> References: <20240614150033.10454-1-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 Tested-by: Peter Newman Tested-by: Shaopeng Tan --- include/linux/resctrl.h | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index d67225f95ee1..3fc5f760e041 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 + /** * enum resctrl_conf_type - The type of configuration. * @CDP_NONE: No prioritisation, both code and data are controlled or moni= tored. --=20 2.39.2