From nobody Mon Apr 6 13:10:12 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 26E34C001B5 for ; Fri, 2 Sep 2022 15:55:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237599AbiIBPzp (ORCPT ); Fri, 2 Sep 2022 11:55:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40956 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237344AbiIBPye (ORCPT ); Fri, 2 Sep 2022 11:54:34 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 716C5DF36 for ; Fri, 2 Sep 2022 08:49:13 -0700 (PDT) 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 E75C915A1; Fri, 2 Sep 2022 08:49:18 -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 62D1E3F766; Fri, 2 Sep 2022 08:49:10 -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 , lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, Jamie Iles , Cristian Marussi , Xin Hao , xingxin.hx@openanolis.org, baolin.wang@linux.alibaba.com Subject: [PATCH v6 07/21] x86/resctrl: Abstract and use supports_mba_mbps() Date: Fri, 2 Sep 2022 15:48:15 +0000 Message-Id: <20220902154829.30399-8-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20220902154829.30399-1-james.morse@arm.com> References: <20220902154829.30399-1-james.morse@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" To determine whether the mba_MBps option to resctrl should be supported, resctrl tests the boot CPUs' x86_vendor. This isn't portable, and needs abstracting behind a helper so this check can be part of the filesystem code that moves to /fs/. Re-use the tests set_mba_sc() does to determine if the mba_sc is supported on this system. An 'alloc_capable' test is added so that support for the controls isn't implied by the 'delay_linear' property, which is always true for MPAM. Because mbm_update() only update mba_sc if the mbm_local counters are enabled, supports_mba_mbps() checks is_mbm_local_enabled(). (instead of using is_mbm_enabled(), which checks both) Reviewed-by: Jamie Iles Tested-by: Xin Hao Reviewed-by: Shaopeng Tan Tested-by: Shaopeng Tan Tested-by: Cristian Marussi Reviewed-by: Reinette Chatre Signed-off-by: James Morse --- Changes since v5: * Changed supports_mba_mbps() to use is_mbm_local_enabled() Changes since v3: * Added use in resctrl_online_domain() Changes since v1: * Capitalisation * Added MPAM example in commit message * Fixed supports_mba_mbps() logic error in rdt_parse_param() --- arch/x86/kernel/cpu/resctrl/rdtgroup.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/r= esctrl/rdtgroup.c index b32ceff8325a..4ee26264ecfc 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -1890,17 +1890,26 @@ void rdt_domain_reconfigure_cdp(struct rdt_resource= *r) } =20 /* - * Enable or disable the MBA software controller - * which helps user specify bandwidth in MBps. * MBA software controller is supported only if * MBM is supported and MBA is in linear scale. */ +static bool supports_mba_mbps(void) +{ + struct rdt_resource *r =3D &rdt_resources_all[RDT_RESOURCE_MBA].r_resctrl; + + return (is_mbm_local_enabled() && + r->alloc_capable && is_mba_linear()); +} + +/* + * Enable or disable the MBA software controller + * which helps user specify bandwidth in MBps. + */ static int set_mba_sc(bool mba_sc) { struct rdt_resource *r =3D &rdt_resources_all[RDT_RESOURCE_MBA].r_resctrl; =20 - if (!is_mbm_enabled() || !is_mba_linear() || - mba_sc =3D=3D is_mba_sc(r)) + if (!supports_mba_mbps() || mba_sc =3D=3D is_mba_sc(r)) return -EINVAL; =20 r->membw.mba_sc =3D mba_sc; @@ -2255,7 +2264,7 @@ static int rdt_parse_param(struct fs_context *fc, str= uct fs_parameter *param) ctx->enable_cdpl2 =3D true; return 0; case Opt_mba_mbps: - if (boot_cpu_data.x86_vendor !=3D X86_VENDOR_INTEL) + if (!supports_mba_mbps()) return -EINVAL; ctx->enable_mba_mbps =3D true; return 0; --=20 2.30.2