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 78817105F7AE for ; Fri, 13 Mar 2026 14:46:47 +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=WBLKBRHNsXFh8imSzslYv8gQEABDHKgC68iOHayW4QY=; b=MbikNVpqbYP5iIdgG46Ig0RkM6 1/79uhiSUa/ssqf6M+fz9Sy8NZ+6i3ipT2oOcAjyirrVxo7tRx7l6SqukNT1vo/NqFM/057bqu/3B innjo6wZHnWrXBbQ9Foj/C1GJwtoShLeEoKciXVoGJPxOOpcNdaPZXgWBkmq6FZhM3xPDu5SnJcCz BBSa/XqpGQRoFwJ9V0lajYFCuK2Y8XAH2usePKaVqM41PvVJ4B8GxS2nJKFSP4aotQ8ZcGMDVHVHe sBR+/EDi/aTVUhkuzTT5s5NekBb9hqkbOIdZ8gx+Dq8LQw3LFG7hRcqu9a+KiIdLWgXV5127BhHZ1 K4eTbvRQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1w13ml-00000000QMT-07ma; Fri, 13 Mar 2026 14:46:43 +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 1w13mi-00000000QLG-3rpj for linux-arm-kernel@lists.infradead.org; Fri, 13 Mar 2026 14:46:42 +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 534C522C7; Fri, 13 Mar 2026 07:46:34 -0700 (PDT) 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 9F6D73F7BD; Fri, 13 Mar 2026 07:46:36 -0700 (PDT) From: Ben Horgan To: ben.horgan@arm.com Cc: amitsinght@marvell.com, baisheng.gao@unisoc.com, baolin.wang@linux.alibaba.com, carl@os.amperecomputing.com, dave.martin@arm.com, david@kernel.org, dfustini@baylibre.com, fenghuay@nvidia.com, gshan@redhat.com, james.morse@arm.com, jonathan.cameron@huawei.com, kobak@nvidia.com, lcherian@marvell.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, peternewman@google.com, punit.agrawal@oss.qualcomm.com, quic_jiles@quicinc.com, reinette.chatre@intel.com, rohit.mathew@arm.com, scott@os.amperecomputing.com, sdonthineni@nvidia.com, tan.shaopeng@fujitsu.com, xhao@linux.alibaba.com, catalin.marinas@arm.com, will@kernel.org, corbet@lwn.net, maz@kernel.org, oupton@kernel.org, joey.gouly@arm.com, suzuki.poulose@arm.com, kvmarm@lists.linux.dev, zengheng4@huawei.com, linux-doc@vger.kernel.org Subject: [PATCH v6 02/40] arm_mpam: Reset when feature configuration bit unset Date: Fri, 13 Mar 2026 14:45:39 +0000 Message-ID: <20260313144617.3420416-3-ben.horgan@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260313144617.3420416-1-ben.horgan@arm.com> References: <20260313144617.3420416-1-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-20260313_074641_048834_A7A00B57 X-CRM114-Status: GOOD ( 14.66 ) 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 To indicate that the configuration, of the controls used by resctrl, in a RIS need resetting to driver defaults the reset flags in mpam_config are set. However, these flags are only ever set temporarily at RIS scope in mpam_reset_ris() and hence mpam_cpu_online() will never reset these controls to default. As the hardware reset is unknown this leads to unknown configuration when the control values haven't been configured away from the defaults. Use the policy that an unset feature configuration bit means reset. In this way the mpam_config in the component can encode that it should be in reset state and mpam_reprogram_msc() will reset controls as needed. Fixes: 09b89d2a72f3 ("arm_mpam: Allow configuration to be applied and restored during cpu online") Signed-off-by: Ben Horgan --- This goes back to the initial feature configuration policy that James used in the MPAM base driver rfc but I unfortunately suggested him to change it. --- drivers/resctrl/mpam_devices.c | 40 ++++++++++------------------------ 1 file changed, 12 insertions(+), 28 deletions(-) diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index 0fd6590a9b5c..ff861291bd4e 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -1364,17 +1364,15 @@ static void mpam_reprogram_ris_partid(struct mpam_msc_ris *ris, u16 partid, __mpam_intpart_sel(ris->ris_idx, partid, msc); } - if (mpam_has_feature(mpam_feat_cpor_part, rprops) && - mpam_has_feature(mpam_feat_cpor_part, cfg)) { - if (cfg->reset_cpbm) - mpam_reset_msc_bitmap(msc, MPAMCFG_CPBM, rprops->cpbm_wd); - else + if (mpam_has_feature(mpam_feat_cpor_part, rprops)) { + if (mpam_has_feature(mpam_feat_cpor_part, cfg)) mpam_write_partsel_reg(msc, CPBM, cfg->cpbm); + else + mpam_reset_msc_bitmap(msc, MPAMCFG_CPBM, rprops->cpbm_wd); } - if (mpam_has_feature(mpam_feat_mbw_part, rprops) && - mpam_has_feature(mpam_feat_mbw_part, cfg)) { - if (cfg->reset_mbw_pbm) + if (mpam_has_feature(mpam_feat_mbw_part, rprops)) { + if (mpam_has_feature(mpam_feat_mbw_part, cfg)) mpam_reset_msc_bitmap(msc, MPAMCFG_MBW_PBM, rprops->mbw_pbm_bits); else mpam_write_partsel_reg(msc, MBW_PBM, cfg->mbw_pbm); @@ -1384,16 +1382,14 @@ static void mpam_reprogram_ris_partid(struct mpam_msc_ris *ris, u16 partid, mpam_has_feature(mpam_feat_mbw_min, cfg)) mpam_write_partsel_reg(msc, MBW_MIN, 0); - if (mpam_has_feature(mpam_feat_mbw_max, rprops) && - mpam_has_feature(mpam_feat_mbw_max, cfg)) { - if (cfg->reset_mbw_max) - mpam_write_partsel_reg(msc, MBW_MAX, MPAMCFG_MBW_MAX_MAX); - else + if (mpam_has_feature(mpam_feat_mbw_max, rprops)) { + if (mpam_has_feature(mpam_feat_mbw_max, cfg)) mpam_write_partsel_reg(msc, MBW_MAX, cfg->mbw_max); + else + mpam_write_partsel_reg(msc, MBW_MAX, MPAMCFG_MBW_MAX_MAX); } - if (mpam_has_feature(mpam_feat_mbw_prop, rprops) && - mpam_has_feature(mpam_feat_mbw_prop, cfg)) + if (mpam_has_feature(mpam_feat_mbw_prop, rprops)) mpam_write_partsel_reg(msc, MBW_PROP, 0); if (mpam_has_feature(mpam_feat_cmax_cmax, rprops)) @@ -1491,16 +1487,6 @@ static int mpam_save_mbwu_state(void *arg) return 0; } -static void mpam_init_reset_cfg(struct mpam_config *reset_cfg) -{ - *reset_cfg = (struct mpam_config) { - .reset_cpbm = true, - .reset_mbw_pbm = true, - .reset_mbw_max = true, - }; - bitmap_fill(reset_cfg->features, MPAM_FEATURE_LAST); -} - /* * Called via smp_call_on_cpu() to prevent migration, while still being * pre-emptible. Caller must hold mpam_srcu. @@ -1508,14 +1494,12 @@ static void mpam_init_reset_cfg(struct mpam_config *reset_cfg) static int mpam_reset_ris(void *arg) { u16 partid, partid_max; - struct mpam_config reset_cfg; + struct mpam_config reset_cfg = {}; struct mpam_msc_ris *ris = arg; if (ris->in_reset_state) return 0; - mpam_init_reset_cfg(&reset_cfg); - spin_lock(&partid_max_lock); partid_max = mpam_partid_max; spin_unlock(&partid_max_lock); -- 2.43.0