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 6E648CA0EFA for ; Sat, 23 Aug 2025 06:38:12 +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=Rhs5lfnCklt2Yr93A2wNvEAaQilhu0cFdXOgANlFWBw=; b=145fq42eqWturd7aQfeGEa9I7O WxKVd369m+GCkq5vw5WseQeVudtpsf86XIfXLS2FOectPbHO4/znvLdrC6h5T5xKlMt8Gw5g1viPH padX7Mix/Xzy+XoOooE5v7UeFlr5O+8O3QLz3kKlbZWQCWZgJzgj1RrMTNeKftnJgq5dlIb8w41ZE Cmf8C2eM/97gNls4bBr9YAdDHILQGUq92tToObTTIFqQSO9XqP6p+yyqboRSuseLIDyeEzeqKviV3 uElDcEqx7Vel0utq7zIcjM98eV8EuiTRtyIT/nb1u1Q373A+/BjYfo5cF7TCnlfmlTNwdnUltiO/z lt7IAQyw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1upht6-0000000499g-0X1d; Sat, 23 Aug 2025 06:38:04 +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 1upTo2-000000034Lu-2PSB for linux-arm-kernel@lists.infradead.org; Fri, 22 Aug 2025 15:35:55 +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 01BDA2880; Fri, 22 Aug 2025 08:35:46 -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 C77773F63F; Fri, 22 Aug 2025 08:35:48 -0700 (PDT) From: James Morse To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org, devicetree@vger.kernel.org Cc: 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, baisheng.gao@unisoc.com, Jonathan Cameron , Rob Herring , Rohit Mathew , Rafael Wysocki , Len Brown , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Krzysztof Kozlowski , Conor Dooley , Catalin Marinas , Will Deacon , Greg Kroah-Hartman , Danilo Krummrich , Dave Martin Subject: [PATCH 17/33] arm_mpam: Probe the hardware features resctrl supports Date: Fri, 22 Aug 2025 15:30:32 +0000 Message-Id: <20250822153048.2287-52-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20250822153048.2287-1-james.morse@arm.com> References: <20250822153048.2287-1-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-20250822_083554_689629_9681F67D X-CRM114-Status: GOOD ( 21.61 ) 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 Expand the probing support with the control and monitor types we can use with resctrl. CC: Dave Martin Signed-off-by: James Morse --- Changes since RFC: * Made mpam_ris_hw_probe_hw_nrdy() more in C. * Added static assert on features bitmap size. --- drivers/resctrl/mpam_devices.c | 156 +++++++++++++++++++++++++++++++- drivers/resctrl/mpam_internal.h | 54 +++++++++++ 2 files changed, 209 insertions(+), 1 deletion(-) diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index 012e09e80300..290a04f8654f 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -102,7 +102,7 @@ static LLIST_HEAD(mpam_garbage); static u32 __mpam_read_reg(struct mpam_msc *msc, u16 reg) { - WARN_ON_ONCE(reg > msc->mapped_hwpage_sz); + WARN_ON_ONCE(reg + sizeof(u32) > msc->mapped_hwpage_sz); WARN_ON_ONCE(!cpumask_test_cpu(smp_processor_id(), &msc->accessibility)); return readl_relaxed(msc->mapped_hwpage + reg); @@ -131,6 +131,20 @@ static inline void _mpam_write_partsel_reg(struct mpam_msc *msc, u16 reg, u32 va } #define mpam_write_partsel_reg(msc, reg, val) _mpam_write_partsel_reg(msc, MPAMCFG_##reg, val) +static inline u32 _mpam_read_monsel_reg(struct mpam_msc *msc, u16 reg) +{ + mpam_mon_sel_lock_held(msc); + return __mpam_read_reg(msc, reg); +} +#define mpam_read_monsel_reg(msc, reg) _mpam_read_monsel_reg(msc, MSMON_##reg) + +static inline void _mpam_write_monsel_reg(struct mpam_msc *msc, u16 reg, u32 val) +{ + mpam_mon_sel_lock_held(msc); + __mpam_write_reg(msc, reg, val); +} +#define mpam_write_monsel_reg(msc, reg, val) _mpam_write_monsel_reg(msc, MSMON_##reg, val) + static u64 mpam_msc_read_idr(struct mpam_msc *msc) { u64 idr_high = 0, idr_low; @@ -643,6 +657,139 @@ static struct mpam_msc_ris *mpam_get_or_create_ris(struct mpam_msc *msc, return found; } +/* + * IHI009A.a has this nugget: "If a monitor does not support automatic behaviour + * of NRDY, software can use this bit for any purpose" - so hardware might not + * implement this - but it isn't RES0. + * + * Try and see what values stick in this bit. If we can write either value, + * its probably not implemented by hardware. + */ +static bool _mpam_ris_hw_probe_hw_nrdy(struct mpam_msc_ris * ris, u32 mon_reg) +{ + u32 now; + u64 mon_sel; + bool can_set, can_clear; + struct mpam_msc *msc = ris->vmsc->msc; + + if (WARN_ON_ONCE(!mpam_mon_sel_inner_lock(msc))) + return false; + + mon_sel = FIELD_PREP(MSMON_CFG_MON_SEL_MON_SEL, 0) | + FIELD_PREP(MSMON_CFG_MON_SEL_RIS, ris->ris_idx); + _mpam_write_monsel_reg(msc, mon_reg, mon_sel); + + _mpam_write_monsel_reg(msc, mon_reg, MSMON___NRDY); + now = _mpam_read_monsel_reg(msc, mon_reg); + can_set = now & MSMON___NRDY; + + _mpam_write_monsel_reg(msc, mon_reg, 0); + now = _mpam_read_monsel_reg(msc, mon_reg); + can_clear = !(now & MSMON___NRDY); + mpam_mon_sel_inner_unlock(msc); + + return (!can_set || !can_clear); +} + +#define mpam_ris_hw_probe_hw_nrdy(_ris, _mon_reg) \ + _mpam_ris_hw_probe_hw_nrdy(_ris, MSMON_##_mon_reg) + +static void mpam_ris_hw_probe(struct mpam_msc_ris *ris) +{ + int err; + struct mpam_msc *msc = ris->vmsc->msc; + struct mpam_props *props = &ris->props; + + lockdep_assert_held(&msc->probe_lock); + lockdep_assert_held(&msc->part_sel_lock); + + /* Cache Portion partitioning */ + if (FIELD_GET(MPAMF_IDR_HAS_CPOR_PART, ris->idr)) { + u32 cpor_features = mpam_read_partsel_reg(msc, CPOR_IDR); + + props->cpbm_wd = FIELD_GET(MPAMF_CPOR_IDR_CPBM_WD, cpor_features); + if (props->cpbm_wd) + mpam_set_feature(mpam_feat_cpor_part, props); + } + + /* Memory bandwidth partitioning */ + if (FIELD_GET(MPAMF_IDR_HAS_MBW_PART, ris->idr)) { + u32 mbw_features = mpam_read_partsel_reg(msc, MBW_IDR); + + /* portion bitmap resolution */ + props->mbw_pbm_bits = FIELD_GET(MPAMF_MBW_IDR_BWPBM_WD, mbw_features); + if (props->mbw_pbm_bits && + FIELD_GET(MPAMF_MBW_IDR_HAS_PBM, mbw_features)) + mpam_set_feature(mpam_feat_mbw_part, props); + + props->bwa_wd = FIELD_GET(MPAMF_MBW_IDR_BWA_WD, mbw_features); + if (props->bwa_wd && FIELD_GET(MPAMF_MBW_IDR_HAS_MAX, mbw_features)) + mpam_set_feature(mpam_feat_mbw_max, props); + } + + /* Performance Monitoring */ + if (FIELD_GET(MPAMF_IDR_HAS_MSMON, ris->idr)) { + u32 msmon_features = mpam_read_partsel_reg(msc, MSMON_IDR); + + /* + * If the firmware max-nrdy-us property is missing, the + * CSU counters can't be used. Should we wait forever? + */ + err = device_property_read_u32(&msc->pdev->dev, + "arm,not-ready-us", + &msc->nrdy_usec); + + if (FIELD_GET(MPAMF_MSMON_IDR_MSMON_CSU, msmon_features)) { + u32 csumonidr; + + csumonidr = mpam_read_partsel_reg(msc, CSUMON_IDR); + props->num_csu_mon = FIELD_GET(MPAMF_CSUMON_IDR_NUM_MON, csumonidr); + if (props->num_csu_mon) { + bool hw_managed; + + mpam_set_feature(mpam_feat_msmon_csu, props); + + /* Is NRDY hardware managed? */ + mpam_mon_sel_outer_lock(msc); + hw_managed = mpam_ris_hw_probe_hw_nrdy(ris, CSU); + mpam_mon_sel_outer_unlock(msc); + if (hw_managed) + mpam_set_feature(mpam_feat_msmon_csu_hw_nrdy, props); + } + + /* + * Accept the missing firmware property if NRDY appears + * un-implemented. + */ + if (err && mpam_has_feature(mpam_feat_msmon_csu_hw_nrdy, props)) + pr_err_once("Counters are not usable because not-ready timeout was not provided by firmware."); + } + if (FIELD_GET(MPAMF_MSMON_IDR_MSMON_MBWU, msmon_features)) { + bool hw_managed; + u32 mbwumonidr = mpam_read_partsel_reg(msc, MBWUMON_IDR); + + props->num_mbwu_mon = FIELD_GET(MPAMF_MBWUMON_IDR_NUM_MON, mbwumonidr); + if (props->num_mbwu_mon) + mpam_set_feature(mpam_feat_msmon_mbwu, props); + + if (FIELD_GET(MPAMF_MBWUMON_IDR_HAS_RWBW, mbwumonidr)) + mpam_set_feature(mpam_feat_msmon_mbwu_rwbw, props); + + /* Is NRDY hardware managed? */ + mpam_mon_sel_outer_lock(msc); + hw_managed = mpam_ris_hw_probe_hw_nrdy(ris, MBWU); + mpam_mon_sel_outer_unlock(msc); + if (hw_managed) + mpam_set_feature(mpam_feat_msmon_mbwu_hw_nrdy, props); + + /* + * Don't warn about any missing firmware property for + * MBWU NRDY - it doesn't make any sense! + */ + } + } +} + static int mpam_msc_hw_probe(struct mpam_msc *msc) { u64 idr; @@ -663,6 +810,7 @@ static int mpam_msc_hw_probe(struct mpam_msc *msc) idr = mpam_msc_read_idr(msc); mutex_unlock(&msc->part_sel_lock); + msc->ris_max = FIELD_GET(MPAMF_IDR_RIS_MAX, idr); /* Use these values so partid/pmg always starts with a valid value */ @@ -683,6 +831,12 @@ static int mpam_msc_hw_probe(struct mpam_msc *msc) ris = mpam_get_or_create_ris(msc, ris_idx); if (IS_ERR(ris)) return PTR_ERR(ris); + ris->idr = idr; + + mutex_lock(&msc->part_sel_lock); + __mpam_part_sel(ris_idx, 0, msc); + mpam_ris_hw_probe(ris); + mutex_unlock(&msc->part_sel_lock); } spin_lock(&partid_max_lock); diff --git a/drivers/resctrl/mpam_internal.h b/drivers/resctrl/mpam_internal.h index c6f087f9fa7d..9f6cd4a68cce 100644 --- a/drivers/resctrl/mpam_internal.h +++ b/drivers/resctrl/mpam_internal.h @@ -136,6 +136,56 @@ static inline void mpam_mon_sel_lock_held(struct mpam_msc *msc) lockdep_assert_preemption_enabled(); } +/* + * When we compact the supported features, we don't care what they are. + * Storing them as a bitmap makes life easy. + */ +typedef u16 mpam_features_t; + +/* Bits for mpam_features_t */ +enum mpam_device_features { + mpam_feat_ccap_part = 0, + mpam_feat_cpor_part, + mpam_feat_mbw_part, + mpam_feat_mbw_min, + mpam_feat_mbw_max, + mpam_feat_mbw_prop, + mpam_feat_msmon, + mpam_feat_msmon_csu, + mpam_feat_msmon_csu_capture, + mpam_feat_msmon_csu_hw_nrdy, + mpam_feat_msmon_mbwu, + mpam_feat_msmon_mbwu_capture, + mpam_feat_msmon_mbwu_rwbw, + mpam_feat_msmon_mbwu_hw_nrdy, + mpam_feat_msmon_capt, + MPAM_FEATURE_LAST, +}; +static_assert(BITS_PER_TYPE(mpam_features_t) >= MPAM_FEATURE_LAST); +#define MPAM_ALL_FEATURES ((1 << MPAM_FEATURE_LAST) - 1) + +struct mpam_props { + mpam_features_t features; + + u16 cpbm_wd; + u16 mbw_pbm_bits; + u16 bwa_wd; + u16 num_csu_mon; + u16 num_mbwu_mon; +}; + +static inline bool mpam_has_feature(enum mpam_device_features feat, + struct mpam_props *props) +{ + return (1 << feat) & props->features; +} + +static inline void mpam_set_feature(enum mpam_device_features feat, + struct mpam_props *props) +{ + props->features |= (1 << feat); +} + struct mpam_class { /* mpam_components in this class */ struct list_head components; @@ -175,6 +225,8 @@ struct mpam_vmsc { /* mpam_msc_ris in this vmsc */ struct list_head ris; + struct mpam_props props; + /* All RIS in this vMSC are members of this MSC */ struct mpam_msc *msc; @@ -186,6 +238,8 @@ struct mpam_vmsc { struct mpam_msc_ris { u8 ris_idx; + u64 idr; + struct mpam_props props; cpumask_t affinity; -- 2.20.1