From nobody Mon Feb 9 03:46:02 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id C6A74277817 for ; Fri, 28 Feb 2025 20:00:06 +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=1740772809; cv=none; b=G0s8z0W0B6EC8dr0IFOLrCF0kb5fL/bNJphMVK/gneB8OK5643/eEpgyFyaq1jtABlxdtwpOuLALPGGOGY2zshtTlo4B8iwf0uwT4ZE5b7uhzii9b9qn/ySYXY98GkxlJWw+6Zl68ZlWhomEpJ/twqM37/I6IB+nARzgkvFrW/g= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740772809; c=relaxed/simple; bh=ptdGh11RcLHvtCc7fCukUsnKRpj/T2i3Dq6Wj823gps=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=WOnVpSUpneoR1DuE694QgOSlfYuwDOD87bSpoNAZX+mUyTC8KaCk1mwVmiNHN94KUcdc7Yv6X+LKnvIQZ4c2Q/nGbWJHqBhxr4BhwzUqFeVr+HE97bucRYKUyjE4W+hDa/gugpfv5i1LAfqKn0K8incQc0yKYtlRqbRDRRmhgJU= 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 3C73B176C; Fri, 28 Feb 2025 12:00:21 -0800 (PST) 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 72B2E3F5A1; Fri, 28 Feb 2025 12:00:02 -0800 (PST) From: James Morse To: x86@kernel.org, linux-kernel@vger.kernel.org Cc: 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 , Koba Ko , Shanker Donthineni , fenghuay@nvidia.com, Dave Martin , Shaopeng Tan , Tony Luck Subject: [PATCH v7 02/49] x86/resctrl: Add a helper to avoid reaching into the arch code resource list Date: Fri, 28 Feb 2025 19:58:26 +0000 Message-Id: <20250228195913.24895-3-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20250228195913.24895-1-james.morse@arm.com> References: <20250228195913.24895-1-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 occasionally wants to know something about a specific resource, in these cases it reaches into the arch code's rdt_resources_all[] array. Once the filesystem parts of resctrl are moved to /fs/, this means it will need visibility of the architecture specific struct rdt_hw_resource definition, and the array of all resources. All architectures would also need a r_resctrl member in this struct. Instead, abstract this via a helper to allow architectures to do different things here. Move the level enum to the resctrl header and add a helper to retrieve the struct rdt_resource by 'rid'. resctrl_arch_get_resource() should not return NULL for any value in the enum, it may instead return a dummy resource that is !alloc_enabled && !mon_enabled. Co-developed-by: Dave Martin Signed-off-by: Dave Martin Signed-off-by: James Morse Tested-by: Peter Newman Tested-by: Carl Worth # arm64 Tested-by: Shaopeng Tan Reviewed-by: Shaopeng Tan Reviewed-by: Reinette Chatre Reviewed-by: Tony Luck Reviewed-by: Fenghua Yu --- Change since v5: * Ensure rdt_resources_all[] is always padded to RDT_NUM_RESOURCES Changes since v1: * Backed out non-functional renaming of "r" to "l3" in rdt_get_tree(), and unhoisted the assignment of r (as now is) back into the if () where it started out. There seem to be no uses of this variable outside this if(). * [Commit message only] Typo fix: s/resctrl_hw_resource/rdt_hw_resource/g --- arch/x86/kernel/cpu/resctrl/core.c | 12 ++++++++++-- arch/x86/kernel/cpu/resctrl/ctrlmondata.c | 2 +- arch/x86/kernel/cpu/resctrl/internal.h | 10 ---------- arch/x86/kernel/cpu/resctrl/monitor.c | 8 ++++---- arch/x86/kernel/cpu/resctrl/rdtgroup.c | 14 +++++++------- include/linux/resctrl.h | 17 +++++++++++++++++ 6 files changed, 39 insertions(+), 24 deletions(-) diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resct= rl/core.c index 3d1735ed8d1f..12b41316d8f7 100644 --- a/arch/x86/kernel/cpu/resctrl/core.c +++ b/arch/x86/kernel/cpu/resctrl/core.c @@ -62,7 +62,7 @@ static void mba_wrmsr_amd(struct msr_param *m); #define ctrl_domain_init(id) LIST_HEAD_INIT(rdt_resources_all[id].r_resctr= l.ctrl_domains) #define mon_domain_init(id) LIST_HEAD_INIT(rdt_resources_all[id].r_resctrl= .mon_domains) =20 -struct rdt_hw_resource rdt_resources_all[] =3D { +struct rdt_hw_resource rdt_resources_all[RDT_NUM_RESOURCES] =3D { [RDT_RESOURCE_L3] =3D { .r_resctrl =3D { @@ -127,6 +127,14 @@ u32 resctrl_arch_system_num_rmid_idx(void) return r->num_rmid; } =20 +struct rdt_resource *resctrl_arch_get_resource(enum resctrl_res_level l) +{ + if (l >=3D RDT_NUM_RESOURCES) + return NULL; + + return &rdt_resources_all[l].r_resctrl; +} + /* * cache_alloc_hsw_probe() - Have to probe for Intel haswell server CPUs * as they do not have CPUID enumeration support for Cache allocation. @@ -174,7 +182,7 @@ static inline void cache_alloc_hsw_probe(void) bool is_mba_sc(struct rdt_resource *r) { if (!r) - return rdt_resources_all[RDT_RESOURCE_MBA].r_resctrl.membw.mba_sc; + r =3D resctrl_arch_get_resource(RDT_RESOURCE_MBA); =20 /* * The software controller support is only applicable to MBA resource. diff --git a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c b/arch/x86/kernel/cp= u/resctrl/ctrlmondata.c index 536351159cc2..4af27ef5a8a1 100644 --- a/arch/x86/kernel/cpu/resctrl/ctrlmondata.c +++ b/arch/x86/kernel/cpu/resctrl/ctrlmondata.c @@ -649,7 +649,7 @@ int rdtgroup_mondata_show(struct seq_file *m, void *arg) resid =3D md.u.rid; domid =3D md.u.domid; evtid =3D md.u.evtid; - r =3D &rdt_resources_all[resid].r_resctrl; + r =3D resctrl_arch_get_resource(resid); =20 if (md.u.sum) { /* diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/r= esctrl/internal.h index 20c898f09b7e..75252a7e1ebc 100644 --- a/arch/x86/kernel/cpu/resctrl/internal.h +++ b/arch/x86/kernel/cpu/resctrl/internal.h @@ -512,16 +512,6 @@ extern struct rdtgroup rdtgroup_default; extern struct dentry *debugfs_resctrl; extern enum resctrl_event_id mba_mbps_default_event; =20 -enum resctrl_res_level { - RDT_RESOURCE_L3, - RDT_RESOURCE_L2, - RDT_RESOURCE_MBA, - RDT_RESOURCE_SMBA, - - /* Must be the last */ - RDT_NUM_RESOURCES, -}; - static inline struct rdt_resource *resctrl_inc(struct rdt_resource *res) { struct rdt_hw_resource *hw_res =3D resctrl_to_arch_res(res); diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/re= sctrl/monitor.c index 94a1d9780461..58b5b21349a8 100644 --- a/arch/x86/kernel/cpu/resctrl/monitor.c +++ b/arch/x86/kernel/cpu/resctrl/monitor.c @@ -365,7 +365,7 @@ static void limbo_release_entry(struct rmid_entry *entr= y) */ void __check_limbo(struct rdt_mon_domain *d, bool force_free) { - struct rdt_resource *r =3D &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl; + struct rdt_resource *r =3D resctrl_arch_get_resource(RDT_RESOURCE_L3); u32 idx_limit =3D resctrl_arch_system_num_rmid_idx(); struct rmid_entry *entry; u32 idx, cur_idx =3D 1; @@ -521,7 +521,7 @@ int alloc_rmid(u32 closid) =20 static void add_rmid_to_limbo(struct rmid_entry *entry) { - struct rdt_resource *r =3D &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl; + struct rdt_resource *r =3D resctrl_arch_get_resource(RDT_RESOURCE_L3); struct rdt_mon_domain *d; u32 idx; =20 @@ -761,7 +761,7 @@ static void update_mba_bw(struct rdtgroup *rgrp, struct= rdt_mon_domain *dom_mbm) struct rdtgroup *entry; u32 cur_bw, user_bw; =20 - r_mba =3D &rdt_resources_all[RDT_RESOURCE_MBA].r_resctrl; + r_mba =3D resctrl_arch_get_resource(RDT_RESOURCE_MBA); evt_id =3D rgrp->mba_mbps_event; =20 closid =3D rgrp->closid; @@ -925,7 +925,7 @@ void mbm_handle_overflow(struct work_struct *work) if (!resctrl_mounted || !resctrl_arch_mon_capable()) goto out_unlock; =20 - r =3D &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl; + r =3D resctrl_arch_get_resource(RDT_RESOURCE_L3); d =3D container_of(work, struct rdt_mon_domain, mbm_over.work); =20 list_for_each_entry(prgrp, &rdt_all_groups, rdtgroup_list) { diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/r= esctrl/rdtgroup.c index 04b653d613e8..45093b9e8e63 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -2256,7 +2256,7 @@ static void l2_qos_cfg_update(void *arg) =20 static inline bool is_mba_linear(void) { - return rdt_resources_all[RDT_RESOURCE_MBA].r_resctrl.membw.delay_linear; + return resctrl_arch_get_resource(RDT_RESOURCE_MBA)->membw.delay_linear; } =20 static int set_cache_qos_cfg(int level, bool enable) @@ -2346,8 +2346,8 @@ static void mba_sc_domain_destroy(struct rdt_resource= *r, */ static bool supports_mba_mbps(void) { - struct rdt_resource *rmbm =3D &rdt_resources_all[RDT_RESOURCE_L3].r_resct= rl; - struct rdt_resource *r =3D &rdt_resources_all[RDT_RESOURCE_MBA].r_resctrl; + struct rdt_resource *rmbm =3D resctrl_arch_get_resource(RDT_RESOURCE_L3); + struct rdt_resource *r =3D resctrl_arch_get_resource(RDT_RESOURCE_MBA); =20 return (is_mbm_enabled() && r->alloc_capable && is_mba_linear() && @@ -2360,7 +2360,7 @@ static bool supports_mba_mbps(void) */ static int set_mba_sc(bool mba_sc) { - struct rdt_resource *r =3D &rdt_resources_all[RDT_RESOURCE_MBA].r_resctrl; + struct rdt_resource *r =3D resctrl_arch_get_resource(RDT_RESOURCE_MBA); u32 num_closid =3D resctrl_arch_get_num_closid(r); struct rdt_ctrl_domain *d; unsigned long fflags; @@ -2714,7 +2714,7 @@ static int rdt_get_tree(struct fs_context *fc) resctrl_mounted =3D true; =20 if (is_mbm_enabled()) { - r =3D &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl; + r =3D resctrl_arch_get_resource(RDT_RESOURCE_L3); list_for_each_entry(dom, &r->mon_domains, hdr.list) mbm_setup_overflow_handler(dom, MBM_OVERFLOW_INTERVAL, RESCTRL_PICK_ANY_CPU); @@ -3951,7 +3951,7 @@ static int rdtgroup_show_options(struct seq_file *seq= , struct kernfs_root *kf) if (resctrl_arch_get_cdp_enabled(RDT_RESOURCE_L2)) seq_puts(seq, ",cdpl2"); =20 - if (is_mba_sc(&rdt_resources_all[RDT_RESOURCE_MBA].r_resctrl)) + if (is_mba_sc(resctrl_arch_get_resource(RDT_RESOURCE_MBA))) seq_puts(seq, ",mba_MBps"); =20 if (resctrl_debug) @@ -4151,7 +4151,7 @@ static void clear_childcpus(struct rdtgroup *r, unsig= ned int cpu) =20 void resctrl_offline_cpu(unsigned int cpu) { - struct rdt_resource *l3 =3D &rdt_resources_all[RDT_RESOURCE_L3].r_resctrl; + struct rdt_resource *l3 =3D resctrl_arch_get_resource(RDT_RESOURCE_L3); struct rdt_mon_domain *d; struct rdtgroup *rdtgrp; =20 diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h index d94abba1c716..37279e2a89da 100644 --- a/include/linux/resctrl.h +++ b/include/linux/resctrl.h @@ -37,6 +37,16 @@ enum resctrl_conf_type { CDP_DATA, }; =20 +enum resctrl_res_level { + RDT_RESOURCE_L3, + RDT_RESOURCE_L2, + RDT_RESOURCE_MBA, + RDT_RESOURCE_SMBA, + + /* Must be the last */ + RDT_NUM_RESOURCES, +}; + #define CDP_NUM_TYPES (CDP_DATA + 1) =20 /* @@ -226,6 +236,13 @@ struct rdt_resource { bool cdp_capable; }; =20 +/* + * Get the resource that exists at this level. If the level is not support= ed + * a dummy/not-capable resource can be returned. Levels >=3D RDT_NUM_RESOU= RCES + * will return NULL. + */ +struct rdt_resource *resctrl_arch_get_resource(enum resctrl_res_level l); + /** * struct resctrl_schema - configuration abilities of a resource presented= to * user-space --=20 2.39.5