From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 1184E2877F5; Fri, 22 Aug 2025 15:37:14 +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=1755877035; cv=none; b=npZZl2RML82A8SnFED8UBtWIY7y9ASE1hLLWTdxjG1yjUX8JugQUQYYKLMqNdpqe5HlHsgSlJI2Z6or+aGFeHsNtp9lsbhQeiniK1LGbBxvlkuP9Qdm+kCyTXtytSBKTVmhTak6Nx2ROU7FB27BmmasHFiMO74FgGUBpArohwEc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755877035; c=relaxed/simple; bh=18sehYH0E8APdpVHinIWVpga+ncSNyEOb9yu9LBVPzI=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=PQo6S91Z2SuLH7vh0sM1osZUX5PxU5yQn0QSy0HwurMJpn97y70NmAqci0DlI7j6HRrWQYsf7vZaif78NAe6mEFMbWzhv6pGvahPAy0EhuRD3lOeDs5KfGziLK0mLQunk8wfqiyMz47Kt1rZqDlSnQ7BmWK0uuWiLMCRm9xVdK0= 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 6A1CD15A1; Fri, 22 Aug 2025 08:37:05 -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 4247A3F63F; Fri, 22 Aug 2025 08:37:08 -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 Subject: [PATCH 31/33] arm_mpam: Add helper to reset saved mbwu state Date: Fri, 22 Aug 2025 15:30:46 +0000 Message-Id: <20250822153048.2287-66-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> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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 | 49 +++++++++++++++++++++++++++++++-- drivers/resctrl/mpam_internal.h | 5 +++- 2 files changed, 51 insertions(+), 3 deletions(-) diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index 8fbcf6eb946a..65c30ebfe001 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -1155,9 +1155,11 @@ 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; @@ -1172,6 +1174,14 @@ 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. @@ -1179,7 +1189,10 @@ 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) { @@ -1212,7 +1225,6 @@ static void __ris_msmon_read(void *arg) if (nrdy) break; - mbwu_state = &ris->mbwu_state[ctx->mon]; if (!mbwu_state) break; @@ -1314,6 +1326,39 @@ 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; + mpam_mon_sel_outer_lock(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_inner_lock(msc))) + continue; + + ris->mbwu_state[ctx->mon].correction = 0; + ris->mbwu_state[ctx->mon].reset_on_next_read = true; + mpam_mon_sel_inner_unlock(msc); + } + mpam_mon_sel_outer_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 9f627b5f72a1..bbf0306abc82 100644 --- a/drivers/resctrl/mpam_internal.h +++ b/drivers/resctrl/mpam_internal.h @@ -297,10 +297,12 @@ 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. */ @@ -410,6 +412,7 @@ 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); -- 2.20.1