From nobody Thu Apr 2 14:47:32 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 2F077ECAAD5 for ; Fri, 2 Sep 2022 15:57:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237758AbiIBP5d (ORCPT ); Fri, 2 Sep 2022 11:57:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40524 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237601AbiIBPzq (ORCPT ); Fri, 2 Sep 2022 11:55:46 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 04A38CD788 for ; Fri, 2 Sep 2022 08:49:39 -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 EB8301596; Fri, 2 Sep 2022 08:49:44 -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 666F53F766; Fri, 2 Sep 2022 08:49:36 -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 17/21] x86/resctrl: Move mbm_overflow_count() into resctrl_arch_rmid_read() Date: Fri, 2 Sep 2022 15:48:25 +0000 Message-Id: <20220902154829.30399-18-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" resctrl_arch_rmid_read() is intended as the function that an architecture agnostic resctrl filesystem driver can use to read a value in bytes from a counter. Currently the function returns the MBM values in chunks directly from hardware. When reading a bandwidth counter, mbm_overflow_count() must be used to correct for any possible overflow. mbm_overflow_count() is architecture specific, its behaviour should be part of resctrl_arch_rmid_read(). Move the mbm_overflow_count() calls into resctrl_arch_rmid_read(). This allows the resctrl filesystems's prev_msr to be removed in favour of the architecture private version. 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 --- arch/x86/kernel/cpu/resctrl/internal.h | 2 -- arch/x86/kernel/cpu/resctrl/monitor.c | 35 +++++++++++++++----------- 2 files changed, 20 insertions(+), 17 deletions(-) diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/r= esctrl/internal.h index 1d2e7bd6305f..8039e8aba7de 100644 --- a/arch/x86/kernel/cpu/resctrl/internal.h +++ b/arch/x86/kernel/cpu/resctrl/internal.h @@ -281,7 +281,6 @@ struct rftype { /** * struct mbm_state - status for each MBM counter in each domain * @chunks: Total data moved (multiply by rdt_group.mon_scale to get bytes) - * @prev_msr: Value of IA32_QM_CTR for this RMID last time we read it * @prev_bw_chunks: Previous chunks value read for bandwidth calculation * @prev_bw: The most recent bandwidth in MBps * @delta_bw: Difference between the current and previous bandwidth @@ -289,7 +288,6 @@ struct rftype { */ struct mbm_state { u64 chunks; - u64 prev_msr; u64 prev_bw_chunks; u32 prev_bw; u32 delta_bw; diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/re= sctrl/monitor.c index 262141bf4264..862a4462ed60 100644 --- a/arch/x86/kernel/cpu/resctrl/monitor.c +++ b/arch/x86/kernel/cpu/resctrl/monitor.c @@ -167,9 +167,20 @@ void resctrl_arch_reset_rmid(struct rdt_resource *r, s= truct rdt_domain *d, memset(am, 0, sizeof(*am)); } =20 +static u64 mbm_overflow_count(u64 prev_msr, u64 cur_msr, unsigned int widt= h) +{ + u64 shift =3D 64 - width, chunks; + + chunks =3D (cur_msr << shift) - (prev_msr << shift); + return chunks >> shift; +} + int resctrl_arch_rmid_read(struct rdt_resource *r, struct rdt_domain *d, u32 rmid, enum resctrl_event_id eventid, u64 *val) { + struct rdt_hw_resource *hw_res =3D resctrl_to_arch_res(r); + struct rdt_hw_domain *hw_dom =3D resctrl_to_arch_dom(d); + struct arch_mbm_state *am; u64 msr_val; =20 if (!cpumask_test_cpu(smp_processor_id(), &d->cpu_mask)) @@ -191,7 +202,13 @@ int resctrl_arch_rmid_read(struct rdt_resource *r, str= uct rdt_domain *d, if (msr_val & RMID_VAL_UNAVAIL) return -EINVAL; =20 - *val =3D msr_val; + am =3D get_arch_mbm_state(hw_dom, rmid, eventid); + if (am) { + *val =3D mbm_overflow_count(am->prev_msr, msr_val, hw_res->mbm_width); + am->prev_msr =3D msr_val; + } else { + *val =3D msr_val; + } =20 return 0; } @@ -322,19 +339,10 @@ void free_rmid(u32 rmid) list_add_tail(&entry->list, &rmid_free_lru); } =20 -static u64 mbm_overflow_count(u64 prev_msr, u64 cur_msr, unsigned int widt= h) -{ - u64 shift =3D 64 - width, chunks; - - chunks =3D (cur_msr << shift) - (prev_msr << shift); - return chunks >> shift; -} - static int __mon_event_count(u32 rmid, struct rmid_read *rr) { - struct rdt_hw_resource *hw_res =3D resctrl_to_arch_res(rr->r); struct mbm_state *m; - u64 chunks, tval =3D 0; + u64 tval =3D 0; =20 if (rr->first) resctrl_arch_reset_rmid(rr->r, rr->d, rmid, rr->evtid); @@ -363,13 +371,10 @@ static int __mon_event_count(u32 rmid, struct rmid_re= ad *rr) =20 if (rr->first) { memset(m, 0, sizeof(struct mbm_state)); - m->prev_msr =3D tval; return 0; } =20 - chunks =3D mbm_overflow_count(m->prev_msr, tval, hw_res->mbm_width); - m->chunks +=3D chunks; - m->prev_msr =3D tval; + m->chunks +=3D tval; =20 rr->val +=3D get_corrected_mbm_count(rmid, m->chunks); =20 --=20 2.30.2