From nobody Wed Dec 17 13:06:29 2025 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 CA8B1C07545 for ; Wed, 25 Oct 2023 18:06:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343552AbjJYSGp (ORCPT ); Wed, 25 Oct 2023 14:06:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41352 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235008AbjJYSGM (ORCPT ); Wed, 25 Oct 2023 14:06:12 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 516171994 for ; Wed, 25 Oct 2023 11:05:50 -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 98CF2C15; Wed, 25 Oct 2023 11:06:31 -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 1C6C63F738; Wed, 25 Oct 2023 11:05:45 -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 Subject: [PATCH v7 18/24] x86/resctrl: Make rdt_enable_key the arch's decision to switch Date: Wed, 25 Oct 2023 18:03:39 +0000 Message-Id: <20231025180345.28061-19-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20231025180345.28061-1-james.morse@arm.com> References: <20231025180345.28061-1-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" rdt_enable_key is switched when resctrl is mounted. It was also previously used to prevent a second mount of the filesystem. Any other architecture that wants to support resctrl has to provide identical static keys. Now that there are helpers for enabling and disabling the alloc/mon keys, resctrl doesn't need to switch this extra key, it can be done by the arch code. Use the static-key increment and decrement helpers, and change resctrl to ensure the calls are balanced. Tested-by: Shaopeng Tan Tested-by: Peter Newman Reviewed-by: Shaopeng Tan Reviewed-by: Reinette Chatre Signed-off-by: James Morse Reviewed-by: Babu Moger --- No changes since v6 arch/x86/include/asm/resctrl.h | 4 ++++ arch/x86/kernel/cpu/resctrl/rdtgroup.c | 11 +++++------ 2 files changed, 9 insertions(+), 6 deletions(-) diff --git a/arch/x86/include/asm/resctrl.h b/arch/x86/include/asm/resctrl.h index 3c9137b6ad4f..b74aa34dc9e8 100644 --- a/arch/x86/include/asm/resctrl.h +++ b/arch/x86/include/asm/resctrl.h @@ -45,21 +45,25 @@ DECLARE_STATIC_KEY_FALSE(rdt_mon_enable_key); static inline void resctrl_arch_enable_alloc(void) { static_branch_enable_cpuslocked(&rdt_alloc_enable_key); + static_branch_inc_cpuslocked(&rdt_enable_key); } =20 static inline void resctrl_arch_disable_alloc(void) { static_branch_disable_cpuslocked(&rdt_alloc_enable_key); + static_branch_dec_cpuslocked(&rdt_enable_key); } =20 static inline void resctrl_arch_enable_mon(void) { static_branch_enable_cpuslocked(&rdt_mon_enable_key); + static_branch_inc_cpuslocked(&rdt_enable_key); } =20 static inline void resctrl_arch_disable_mon(void) { static_branch_disable_cpuslocked(&rdt_mon_enable_key); + static_branch_dec_cpuslocked(&rdt_enable_key); } =20 /* diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/r= esctrl/rdtgroup.c index 48418857b685..edfb37680046 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -2677,10 +2677,8 @@ static int rdt_get_tree(struct fs_context *fc) if (rdt_mon_capable) resctrl_arch_enable_mon(); =20 - if (rdt_alloc_capable || rdt_mon_capable) { - static_branch_enable_cpuslocked(&rdt_enable_key); + if (rdt_alloc_capable || rdt_mon_capable) resctrl_mounted =3D true; - } =20 if (is_mbm_enabled()) { r =3D &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl; @@ -2951,9 +2949,10 @@ static void rdt_kill_sb(struct super_block *sb) rdtgroup_default.mode =3D RDT_MODE_SHAREABLE; schemata_list_destroy(); rdtgroup_destroy_root(); - resctrl_arch_disable_alloc(); - resctrl_arch_disable_mon(); - static_branch_disable_cpuslocked(&rdt_enable_key); + if (rdt_alloc_capable) + resctrl_arch_disable_alloc(); + if (rdt_mon_capable) + resctrl_arch_disable_mon(); resctrl_mounted =3D false; kernfs_kill_sb(sb); mutex_unlock(&rdtgroup_mutex); --=20 2.39.2