From nobody Wed Dec 17 11:48:13 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 B992FC7618E for ; Thu, 20 Apr 2023 22:06:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232912AbjDTWGw (ORCPT ); Thu, 20 Apr 2023 18:06:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38178 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229736AbjDTWGt (ORCPT ); Thu, 20 Apr 2023 18:06:49 -0400 Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4757F270C for ; Thu, 20 Apr 2023 15:06:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1682028407; x=1713564407; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=TX3utSJkvuG87gr/i0jCm7n2nnIrYB4p9WSinKZRLsI=; b=N1EzTJuu92cE7L979Zhqxd68LQQQ+ZId+6J9f3DFK8okBe9W7tUWnQof Sg8ENeCs5pl0h0YQeJZy9jzbVJyum3kf8nvSSS4SuoCA6UZ+rQ0H8vjGL liJnGmGb/nzN553Mo23N1P1GElEvTgt2mXg18PQ6QtvPmta+YOJ0A75ru QnwRvMbxuAeZ3QvKjYiwqh6cAays6HjVlVHLHRggUZl4zgXFxkVjj+iJO /szTx1OFdSxtUWmYqyIVgxEit/Z0keCWoKtBvXsUYS0nro8yMTK/XeGpl b8VBcM5nulXGNJaj5BLqijJD0k0UcIsqRDXoapUPPhHOHT1NWgwsYWTMh Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10686"; a="348650896" X-IronPort-AV: E=Sophos;i="5.99,213,1677571200"; d="scan'208";a="348650896" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Apr 2023 15:06:44 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10686"; a="724583749" X-IronPort-AV: E=Sophos;i="5.99,213,1677571200"; d="scan'208";a="724583749" Received: from agluck-desk3.sc.intel.com ([172.25.222.78]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Apr 2023 15:06:44 -0700 From: Tony Luck To: Fenghua Yu , Reinette Chatre , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , Shaopeng Tan , Jamie Iles , James Morse , Babu Moger Cc: x86@kernel.org, linux-kernel@vger.kernel.org, Tony Luck Subject: [RFC PATCH 1/7] x86/resctrl: Add register/unregister functions for driver to hook into resctrl Date: Thu, 20 Apr 2023 15:06:30 -0700 Message-Id: <20230420220636.53527-2-tony.luck@intel.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230420220636.53527-1-tony.luck@intel.com> References: <20230420220636.53527-1-tony.luck@intel.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" Just one callback at the point for the driver to be notified when the resctrl filesystem is mounted or unmounted. Virtually all drivers will need this hook to enable/disable their feature(s) as part of mount/unmount. Signed-off-by: Tony Luck --- include/linux/resctrl.h | 13 +++++++ arch/x86/kernel/cpu/resctrl/rdtgroup.c | 50 ++++++++++++++++++++++++++ 2 files changed, 63 insertions(+) diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index 8334eeacfec5..78513edddca0 100644 --- a/include/linux/resctrl.h +++ b/include/linux/resctrl.h @@ -204,6 +204,19 @@ struct resctrl_schema { u32 num_closid; }; =20 +/** + * struct resctrl_driver - interface for driver to attach to resctrl + * @list: List of registered drivers + * @mount: Callback for mount/unmount + */ +struct resctrl_driver { + struct list_head list; + void (*mount)(bool mount); +}; + +int resctrl_register_driver(struct resctrl_driver *d); +void resctrl_unregister_driver(struct resctrl_driver *d); + /* The number of closid supported by this resource regardless of CDP */ u32 resctrl_arch_get_num_closid(struct rdt_resource *r); int resctrl_arch_update_domains(struct rdt_resource *r, u32 closid); diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/r= esctrl/rdtgroup.c index 6ad33f355861..3e6778bde427 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -51,6 +51,9 @@ static struct kernfs_node *kn_mongrp; /* Kernel fs node for "mon_data" directory under root */ static struct kernfs_node *kn_mondata; =20 +static LIST_HEAD(drivers); +static bool resctrl_is_mounted; + static struct seq_buf last_cmd_status; static char last_cmd_status_buf[512]; =20 @@ -2437,6 +2440,42 @@ static int schemata_list_create(void) return ret; } =20 +static void driver_up(struct resctrl_driver *d) +{ + if (d->mount) + d->mount(true); +} + +static void driver_down(struct resctrl_driver *d) +{ + if (d->mount) + d->mount(false); +} + +int resctrl_register_driver(struct resctrl_driver *d) +{ + mutex_lock(&rdtgroup_mutex); + list_add(&d->list, &drivers); + + if (resctrl_is_mounted) + driver_up(d); + mutex_unlock(&rdtgroup_mutex); + + return 0; +} +EXPORT_SYMBOL_GPL(resctrl_register_driver); + +void resctrl_unregister_driver(struct resctrl_driver *d) +{ + mutex_lock(&rdtgroup_mutex); + list_del(&d->list); + + if (resctrl_is_mounted) + driver_down(d); + mutex_unlock(&rdtgroup_mutex); +} +EXPORT_SYMBOL_GPL(resctrl_unregister_driver); + static void schemata_list_destroy(void) { struct resctrl_schema *s, *tmp; @@ -2450,6 +2489,7 @@ static void schemata_list_destroy(void) static int rdt_get_tree(struct fs_context *fc) { struct rdt_fs_context *ctx =3D rdt_fc2context(fc); + struct resctrl_driver *d; struct rdt_domain *dom; struct rdt_resource *r; int ret; @@ -2516,6 +2556,10 @@ static int rdt_get_tree(struct fs_context *fc) mbm_setup_overflow_handler(dom, MBM_OVERFLOW_INTERVAL); } =20 + list_for_each_entry(d, &drivers, list) + driver_up(d); + resctrl_is_mounted =3D true; + goto out; =20 out_psl: @@ -2761,6 +2805,7 @@ static void rmdir_all_sub(void) =20 static void rdt_kill_sb(struct super_block *sb) { + struct resctrl_driver *d; struct rdt_resource *r; =20 cpus_read_lock(); @@ -2780,6 +2825,11 @@ static void rdt_kill_sb(struct super_block *sb) static_branch_disable_cpuslocked(&rdt_mon_enable_key); static_branch_disable_cpuslocked(&rdt_enable_key); kernfs_kill_sb(sb); + + list_for_each_entry(d, &drivers, list) + driver_down(d); + resctrl_is_mounted =3D false; + mutex_unlock(&rdtgroup_mutex); cpus_read_unlock(); } --=20 2.39.2