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 4301DC88E42 for ; Fri, 11 Sep 2026 06:45:12 +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: Content-Type:In-Reply-To:From:References:CC:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=SnNyIUKsorVAxqnwfpbUZwRMslljnk+vTb4CfKa2qOg=; b=L0xFQfVa2hhn3f+IJr0qIW1zrM 47t4Vl6eg0Z54efAaw39A93OX4bpBYKAm4iCTSw7IyUoV3SfzB9IeL2S+0xL8ZszWOCaD+JTqPFd2 91+QOTNrDL6hVM9Omi1IFpE+SvBN0ZZjWV1m7rzfEWkRj3x2/JQ3rnN4pH4kpF15CU4JLeqYyJsI+ U8nMdgXqZjCdBbS+dKd1vls6GVwf67E+/MNKclCyrrLTlP2mwFPGL+AOsa8h92YapBjCp0Kfu/tQf VHQmMrBk1OyN7MyW4/Rr+a3S1SduJjaflqLkeAg5bdsXqtqMJxxVF0mbDET/s7dNsdipRZ9Y6+FuH zi7Uw+WA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x4v0T-0000000FxdD-0nE7; Fri, 11 Sep 2026 06:45:05 +0000 Received: from canpmsgout06.his.huawei.com ([113.46.200.221]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1x4v0P-0000000Fxc8-3P3T for linux-arm-kernel@lists.infradead.org; Fri, 11 Sep 2026 06:45:03 +0000 dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=SnNyIUKsorVAxqnwfpbUZwRMslljnk+vTb4CfKa2qOg=; b=Qx9AWqzdHat03JckLm3M8BwOru2v7x0iL94Pntu/72z8LkNpVGJ0CuQsvObLbQQZKy7qxI+f7 POuCv4NaoAy2ApgQCxpmYgcqAwymFuufmDUhl++spML+a+SLlMEmg5rpQS//Ncrukr4XM5cLTau hBIxU4k/6aa13wBQtOpnpjM= Received: from mail.maildlp.com (unknown [172.19.162.197]) by canpmsgout06.his.huawei.com (SkyGuard) with ESMTPS id 4hh4WT0hVGzRhQs; Fri, 11 Sep 2026 14:33:57 +0800 (CST) Received: from kwepemk200008.china.huawei.com (unknown [7.202.194.74]) by mail.maildlp.com (Postfix) with ESMTPS id 4382940579; Fri, 11 Sep 2026 14:44:50 +0800 (CST) Received: from [10.67.109.254] (10.67.109.254) by kwepemk200008.china.huawei.com (7.202.194.74) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.45; Fri, 11 Sep 2026 14:44:48 +0800 Message-ID: <7500ec7f-5e65-408c-a4ed-3f7af161219b@huawei.com> Date: Fri, 11 Sep 2026 14:44:47 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v6 02/40] arm_mpam: Reset when feature configuration bit unset To: Ben Horgan CC: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , References: <20260313144617.3420416-1-ben.horgan@arm.com> <20260313144617.3420416-3-ben.horgan@arm.com> From: Jinjie Ruan In-Reply-To: <20260313144617.3420416-3-ben.horgan@arm.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-Originating-IP: [10.67.109.254] X-ClientProxiedBy: kwepems100002.china.huawei.com (7.221.188.206) To kwepemk200008.china.huawei.com (7.202.194.74) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260910_234502_191342_A6ABB4D2 X-CRM114-Status: GOOD ( 22.91 ) 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 在 2026/3/13 22:45, Ben Horgan 写道: > 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); This condition is written backwards, but it looks like it has already been fixed later. Otherwise, LGTM Reviewed-by: Jinjie Ruan > 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);