From mboxrd@z Thu Jan 1 00:00:00 1970 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 9A6AFCA0FED for ; Wed, 10 Sep 2025 20:46:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=30qEGjfaWEKH77Cx930i6qWs2wzCYvPK4HMfDWDXukI=; b=ueM6CZZ++yqFjepIv2qmA00PrR sTsxb1jDep6Q71Diy/Ub08NGjJnHEY7R+WgUl0Qj8gC/0wWQ8W0daV3UqcY9ySHHb3yP/GpS8lv5p RGkrKbEdk9168RKzxLOuQg1ftnAXyfZbLoPhjArVFZOacLXLXuB8zTMTiRuS5n053gZEJVXXZ2GtI evwGsVF/PgXnquAcZ+t5J/Y4jmmU7MMyVQJ9kzv5z0Iu7Q1ASFCLYg311x+1in+NM2VIwCu090LIw HyOSppz7ow34UYEgRGy1BSvJ20UpPWeSm5Wvp3iwEPEPIstiNorcgTrQc4iUrH1tqOniquFL+gGUq +ZGc7r8g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uwRhU-0000000Gf2U-0H8C; Wed, 10 Sep 2025 20:45:56 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uwRhL-0000000Gesj-1mos for linux-arm-kernel@lists.infradead.org; Wed, 10 Sep 2025 20:45:54 +0000 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 31A9D153B; Wed, 10 Sep 2025 13:45:38 -0700 (PDT) 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 DD01E3F63F; Wed, 10 Sep 2025 13:45:41 -0700 (PDT) From: James Morse To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org Cc: James Morse , 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 , Dave Martin , Koba Ko , Shanker Donthineni , fenghuay@nvidia.com, baisheng.gao@unisoc.com, Jonathan Cameron , Rob Herring , Rohit Mathew , Rafael Wysocki , Len Brown , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , Greg Kroah-Hartman , Danilo Krummrich Subject: [PATCH v2 27/29] arm_mpam: Add helper to reset saved mbwu state Date: Wed, 10 Sep 2025 20:43:07 +0000 Message-Id: <20250910204309.20751-28-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20250910204309.20751-1-james.morse@arm.com> References: <20250910204309.20751-1-james.morse@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250910_134547_584206_6A3E3FED X-CRM114-Status: GOOD ( 19.28 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org resctrl expects to reset the bandwidth counters when the filesystem is mounted. To allow this, add a helper that clears the saved mbwu state. Instead of cross calling to each CPU that can access the component MSC to write to the counter, set a flag that causes it to be zero'd on the the next read. This is easily done by forcing a configuration update. Signed-off-by: James Morse --- drivers/resctrl/mpam_devices.c | 47 +++++++++++++++++++++++++++++++-- drivers/resctrl/mpam_internal.h | 5 +++- 2 files changed, 49 insertions(+), 3 deletions(-) diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index 3080a81f0845..8254d6190ca2 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -1088,9 +1088,11 @@ static u64 mpam_msmon_overflow_val(struct mpam_msc_ris *ris) static void __ris_msmon_read(void *arg) { bool nrdy = false; + bool config_mismatch; struct mon_read *m = arg; u64 now, overflow_val = 0; struct mon_cfg *ctx = m->ctx; + bool reset_on_next_read = false; struct mpam_msc_ris *ris = m->ris; struct msmon_mbwu_state *mbwu_state; struct mpam_props *rprops = &ris->props; @@ -1105,6 +1107,14 @@ static void __ris_msmon_read(void *arg) FIELD_PREP(MSMON_CFG_MON_SEL_RIS, ris->ris_idx); mpam_write_monsel_reg(msc, CFG_MON_SEL, mon_sel); + if (m->type == mpam_feat_msmon_mbwu) { + mbwu_state = &ris->mbwu_state[ctx->mon]; + if (mbwu_state) { + reset_on_next_read = mbwu_state->reset_on_next_read; + mbwu_state->reset_on_next_read = false; + } + } + /* * Read the existing configuration to avoid re-writing the same values. * This saves waiting for 'nrdy' on subsequent reads. @@ -1112,7 +1122,10 @@ static void __ris_msmon_read(void *arg) read_msmon_ctl_flt_vals(m, &cur_ctl, &cur_flt); clean_msmon_ctl_val(&cur_ctl); gen_msmon_ctl_flt_vals(m, &ctl_val, &flt_val); - if (cur_flt != flt_val || cur_ctl != (ctl_val | MSMON_CFG_x_CTL_EN)) + config_mismatch = cur_flt != flt_val || + cur_ctl != (ctl_val | MSMON_CFG_x_CTL_EN); + + if (config_mismatch || reset_on_next_read) write_msmon_ctl_flt_vals(m, ctl_val, flt_val); switch (m->type) { @@ -1145,7 +1158,6 @@ static void __ris_msmon_read(void *arg) if (nrdy) break; - mbwu_state = &ris->mbwu_state[ctx->mon]; if (!mbwu_state) break; @@ -1245,6 +1257,37 @@ int mpam_msmon_read(struct mpam_component *comp, struct mon_cfg *ctx, return err; } +void mpam_msmon_reset_mbwu(struct mpam_component *comp, struct mon_cfg *ctx) +{ + int idx; + struct mpam_msc *msc; + struct mpam_vmsc *vmsc; + struct mpam_msc_ris *ris; + + if (!mpam_is_enabled()) + return; + + idx = srcu_read_lock(&mpam_srcu); + list_for_each_entry_rcu(vmsc, &comp->vmsc, comp_list) { + if (!mpam_has_feature(mpam_feat_msmon_mbwu, &vmsc->props)) + continue; + + msc = vmsc->msc; + list_for_each_entry_rcu(ris, &vmsc->ris, vmsc_list) { + if (!mpam_has_feature(mpam_feat_msmon_mbwu, &ris->props)) + continue; + + if (WARN_ON_ONCE(!mpam_mon_sel_lock(msc))) + continue; + + ris->mbwu_state[ctx->mon].correction = 0; + ris->mbwu_state[ctx->mon].reset_on_next_read = true; + mpam_mon_sel_unlock(msc); + } + } + srcu_read_unlock(&mpam_srcu, idx); +} + static void mpam_reset_msc_bitmap(struct mpam_msc *msc, u16 reg, u16 wd) { u32 num_words, msb; diff --git a/drivers/resctrl/mpam_internal.h b/drivers/resctrl/mpam_internal.h index c190826dfbda..7cbcafe8294a 100644 --- a/drivers/resctrl/mpam_internal.h +++ b/drivers/resctrl/mpam_internal.h @@ -223,10 +223,12 @@ struct mon_cfg { /* * Changes to enabled and cfg are protected by the msc->lock. - * Changes to prev_val and correction are protected by the msc's mon_sel_lock. + * Changes to reset_on_next_read, prev_val and correction are protected by the + * msc's mon_sel_lock. */ struct msmon_mbwu_state { bool enabled; + bool reset_on_next_read; struct mon_cfg cfg; /* The value last read from the hardware. Used to detect overflow. */ @@ -393,6 +395,7 @@ int mpam_apply_config(struct mpam_component *comp, u16 partid, int mpam_msmon_read(struct mpam_component *comp, struct mon_cfg *ctx, enum mpam_device_features, u64 *val); +void mpam_msmon_reset_mbwu(struct mpam_component *comp, struct mon_cfg *ctx); int mpam_get_cpumask_from_cache_id(unsigned long cache_id, u32 cache_level, cpumask_t *affinity); -- 2.39.5