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 9D9D1CF31B7 for ; Wed, 19 Nov 2025 12:26:19 +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=dkHBn+aGya+xx8ltNeEaD3h3NWDsISUIctgXOPvq+NY=; b=SNuWyYtzKrXArqkkB3FCzmm5cu +7bZQnwEw8xqUwPkeB/dsl+hn7ZKNU3Ozq2TM5ADufZPHqhfyUG9AVS/Vz++Kb6SBy5zK5FurkfTH 5pR+SV63bO7U5FlsYGZsg748S/jbldB1vh9Tq3eEs2edTPuxXU3VCiyMimcX4n6XWevH1ssqT+BP3 262EUqO12SAKBWsltG5oW0HbCRCf+rKsKo0YmrYYek1Srd1h0EJawalIW/lj5gsF/6LGNeecTjq6g Ot/ZAZP5971aRALtGdxjQOgtF5QREzIf6+kTeKcn/EQ0jwPzsrlVr3t2GPPGYBeXfyzAGmU2iWWTO VbpYpNhA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vLhGA-000000038jq-3RP7; Wed, 19 Nov 2025 12:26:07 +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 1vLhG2-000000038b5-08O7 for linux-arm-kernel@lists.infradead.org; Wed, 19 Nov 2025 12:26:04 +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 88DD719F0; Wed, 19 Nov 2025 04:25:49 -0800 (PST) Received: from e134344.cambridge.arm.com (e134344.arm.com [10.1.196.46]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id E823A3F740; Wed, 19 Nov 2025 04:25:51 -0800 (PST) From: Ben Horgan To: james.morse@arm.com Cc: amitsinght@marvell.com, baisheng.gao@unisoc.com, baolin.wang@linux.alibaba.com, bobo.shaobowang@huawei.com, carl@os.amperecomputing.com, catalin.marinas@arm.com, dakr@kernel.org, dave.martin@arm.com, david@redhat.com, dfustini@baylibre.com, fenghuay@nvidia.com, gregkh@linuxfoundation.org, gshan@redhat.com, guohanjun@huawei.com, jeremy.linton@arm.com, jonathan.cameron@huawei.com, kobak@nvidia.com, lcherian@marvell.com, lenb@kernel.org, linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, lpieralisi@kernel.org, peternewman@google.com, quic_jiles@quicinc.com, rafael@kernel.org, robh@kernel.org, rohit.mathew@arm.com, scott@os.amperecomputing.com, sdonthineni@nvidia.com, sudeep.holla@arm.com, tan.shaopeng@fujitsu.com, will@kernel.org, xhao@linux.alibaba.com, reinette.chatre@intel.com, Zeng Heng , Shaopeng Tan , Ben Horgan Subject: [PATCH v6 27/34] arm_mpam: Track bandwidth counter state for power management Date: Wed, 19 Nov 2025 12:22:57 +0000 Message-ID: <20251119122305.302149-28-ben.horgan@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20251119122305.302149-1-ben.horgan@arm.com> References: <20251119122305.302149-1-ben.horgan@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-20251119_042558_199025_D951C074 X-CRM114-Status: GOOD ( 22.34 ) 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 From: James Morse Bandwidth counters need to run continuously to correctly reflect the bandwidth. Save the counter state when the hardware is reset due to CPU hotplug. Add struct mbwu_state to track the bandwidth counter. Support for tracking overflow with the same structure will be added in a subsequent commit. Cc: Zeng Heng Reviewed-by: Gavin Shan Reviewed-by: Zeng Heng Reviewed-by: Jonathan Cameron Reviewed-by: Shaopeng Tan Reviewed-by: Fenghua Yu Tested-by: Carl Worth Tested-by: Gavin Shan Tested-by: Zeng Heng Tested-by: Shaopeng Tan Tested-by: Hanjun Guo Signed-off-by: James Morse Signed-off-by: Ben Horgan --- Changes since v3: Drop tags Fix correction accounting Split out overflow checking --- drivers/resctrl/mpam_devices.c | 126 +++++++++++++++++++++++++++++++- drivers/resctrl/mpam_internal.h | 21 +++++- 2 files changed, 145 insertions(+), 2 deletions(-) diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index 4859c8b096c3..c8ea37558f69 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -993,6 +993,7 @@ static void __ris_msmon_read(void *arg) struct mon_read *m = arg; struct mon_cfg *ctx = m->ctx; struct mpam_msc_ris *ris = m->ris; + struct msmon_mbwu_state *mbwu_state; struct mpam_props *rprops = &ris->props; struct mpam_msc *msc = m->ris->vmsc->msc; u32 mon_sel, ctl_val, flt_val, cur_ctl, cur_flt; @@ -1023,11 +1024,21 @@ static void __ris_msmon_read(void *arg) now = mpam_read_monsel_reg(msc, CSU); if (mpam_has_feature(mpam_feat_msmon_csu_hw_nrdy, rprops)) nrdy = now & MSMON___NRDY; + now = FIELD_GET(MSMON___VALUE, now); break; case mpam_feat_msmon_mbwu: now = mpam_read_monsel_reg(msc, MBWU); if (mpam_has_feature(mpam_feat_msmon_mbwu_hw_nrdy, rprops)) nrdy = now & MSMON___NRDY; + now = FIELD_GET(MSMON___VALUE, now); + + if (nrdy) + break; + + mbwu_state = &ris->mbwu_state[ctx->mon]; + + /* Include bandwidth consumed before the last hardware reset */ + now += mbwu_state->correction; break; default: m->err = -EINVAL; @@ -1039,7 +1050,6 @@ static void __ris_msmon_read(void *arg) return; } - now = FIELD_GET(MSMON___VALUE, now); *m->val += now; } @@ -1235,6 +1245,67 @@ static void mpam_reprogram_ris_partid(struct mpam_msc_ris *ris, u16 partid, mutex_unlock(&msc->part_sel_lock); } +/* Call with msc cfg_lock held */ +static int mpam_restore_mbwu_state(void *_ris) +{ + int i; + struct mon_read mwbu_arg; + struct mpam_msc_ris *ris = _ris; + + for (i = 0; i < ris->props.num_mbwu_mon; i++) { + if (ris->mbwu_state[i].enabled) { + mwbu_arg.ris = ris; + mwbu_arg.ctx = &ris->mbwu_state[i].cfg; + mwbu_arg.type = mpam_feat_msmon_mbwu; + + __ris_msmon_read(&mwbu_arg); + } + } + + return 0; +} + +/* Call with MSC cfg_lock held */ +static int mpam_save_mbwu_state(void *arg) +{ + int i; + u64 val; + struct mon_cfg *cfg; + u32 cur_flt, cur_ctl, mon_sel; + struct mpam_msc_ris *ris = arg; + struct msmon_mbwu_state *mbwu_state; + struct mpam_msc *msc = ris->vmsc->msc; + + for (i = 0; i < ris->props.num_mbwu_mon; i++) { + mbwu_state = &ris->mbwu_state[i]; + cfg = &mbwu_state->cfg; + + if (WARN_ON_ONCE(!mpam_mon_sel_lock(msc))) + return -EIO; + + mon_sel = FIELD_PREP(MSMON_CFG_MON_SEL_MON_SEL, i) | + FIELD_PREP(MSMON_CFG_MON_SEL_RIS, ris->ris_idx); + mpam_write_monsel_reg(msc, CFG_MON_SEL, mon_sel); + + cur_flt = mpam_read_monsel_reg(msc, CFG_MBWU_FLT); + cur_ctl = mpam_read_monsel_reg(msc, CFG_MBWU_CTL); + mpam_write_monsel_reg(msc, CFG_MBWU_CTL, 0); + + val = mpam_read_monsel_reg(msc, MBWU); + mpam_write_monsel_reg(msc, MBWU, 0); + + cfg->mon = i; + cfg->pmg = FIELD_GET(MSMON_CFG_x_FLT_PMG, cur_flt); + cfg->match_pmg = FIELD_GET(MSMON_CFG_x_CTL_MATCH_PMG, cur_ctl); + cfg->partid = FIELD_GET(MSMON_CFG_x_FLT_PARTID, cur_flt); + mbwu_state->correction += val; + mbwu_state->enabled = FIELD_GET(MSMON_CFG_x_CTL_EN, cur_ctl); + mpam_mon_sel_unlock(msc); + } + + return 0; +} + static void mpam_init_reset_cfg(struct mpam_config *reset_cfg) { *reset_cfg = (struct mpam_config) { @@ -1343,6 +1414,9 @@ static void mpam_reprogram_msc(struct mpam_msc *msc) mpam_touch_msc(msc, __write_config, &arg); } ris->in_reset_state = reset; + + if (mpam_has_feature(mpam_feat_msmon_mbwu, &ris->props)) + mpam_touch_msc(msc, &mpam_restore_mbwu_state, ris); } mutex_unlock(&msc->cfg_lock); } @@ -1436,6 +1510,9 @@ static int mpam_cpu_offline(unsigned int cpu) * lost while the CPUs are offline. */ ris->in_reset_state = false; + + if (mpam_is_enabled()) + mpam_touch_msc(msc, &mpam_save_mbwu_state, ris); } mutex_unlock(&msc->cfg_lock); } @@ -2109,7 +2186,22 @@ static void mpam_unregister_irqs(void) static void __destroy_component_cfg(struct mpam_component *comp) { + struct mpam_msc *msc; + struct mpam_vmsc *vmsc; + struct mpam_msc_ris *ris; + + lockdep_assert_held(&mpam_list_lock); + add_to_garbage(comp->cfg); + list_for_each_entry(vmsc, &comp->vmsc, comp_list) { + msc = vmsc->msc; + + if (mpam_mon_sel_lock(msc)) { + list_for_each_entry(ris, &vmsc->ris, vmsc_list) + add_to_garbage(ris->mbwu_state); + mpam_mon_sel_unlock(msc); + } + } } static void mpam_reset_component_cfg(struct mpam_component *comp) @@ -2135,6 +2227,8 @@ static void mpam_reset_component_cfg(struct mpam_component *comp) static int __allocate_component_cfg(struct mpam_component *comp) { + struct mpam_vmsc *vmsc; + mpam_assert_partid_sizes_fixed(); if (comp->cfg) @@ -2152,6 +2246,36 @@ static int __allocate_component_cfg(struct mpam_component *comp) mpam_reset_component_cfg(comp); + list_for_each_entry(vmsc, &comp->vmsc, comp_list) { + struct mpam_msc *msc; + struct mpam_msc_ris *ris; + struct msmon_mbwu_state *mbwu_state; + + if (!vmsc->props.num_mbwu_mon) + continue; + + msc = vmsc->msc; + list_for_each_entry(ris, &vmsc->ris, vmsc_list) { + if (!ris->props.num_mbwu_mon) + continue; + + mbwu_state = kcalloc(ris->props.num_mbwu_mon, + sizeof(*ris->mbwu_state), + GFP_KERNEL); + if (!mbwu_state) { + __destroy_component_cfg(comp); + return -ENOMEM; + } + + init_garbage(&mbwu_state[0].garbage); + + if (mpam_mon_sel_lock(msc)) { + ris->mbwu_state = mbwu_state; + mpam_mon_sel_unlock(msc); + } + } + } + return 0; } diff --git a/drivers/resctrl/mpam_internal.h b/drivers/resctrl/mpam_internal.h index 12f0a5b7f39e..12ce80bc7ff7 100644 --- a/drivers/resctrl/mpam_internal.h +++ b/drivers/resctrl/mpam_internal.h @@ -91,7 +91,10 @@ struct mpam_msc { */ struct mutex part_sel_lock; - /* cfg_lock protects the msc configuration. */ + /* + * cfg_lock protects the msc configuration and guards against mbwu_state + * save and restore racing. + */ struct mutex cfg_lock; /* @@ -202,6 +205,19 @@ struct mon_cfg { enum mon_filter_options opts; }; +/* Changes to msmon_mbwu_state are protected by the msc's mon_sel_lock. */ +struct msmon_mbwu_state { + bool enabled; + struct mon_cfg cfg; + + /* + * The value to add to the new reading to account for power management. + */ + u64 correction; + + struct mpam_garbage garbage; +}; + struct mpam_class { /* mpam_components in this class */ struct list_head components; @@ -295,6 +311,9 @@ struct mpam_msc_ris { /* parent: */ struct mpam_vmsc *vmsc; + /* msmon mbwu configuration is preserved over reset */ + struct msmon_mbwu_state *mbwu_state; + struct mpam_garbage garbage; }; -- 2.43.0