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 107E53783B0; Fri, 3 Jul 2026 08:42:25 +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=1783068150; cv=none; b=Xx1R8LYRD9ZWONQjSOiHJgNosw4hzp86CjOC6XuwoH/3rkpDvXvTlP9NeMJht9RSQu4SzZZ/0OZWW2scEL5mrqnKtnDCrCNZx0FA4R2cRNcv5uf8s8YZhFa7dMvMUcsfr9nIgPTD9faKD9KQC3mGVAUTzxaKJXl46s6WKxCsNNc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783068150; c=relaxed/simple; bh=qPN+0EoXG8L0C7DiygFnkIw7nf3VUC+KuOM6KpifZ7o=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=HCNvu0ytPKRVh/sFLEIyqVPhQhlFhQ0sDvPzPNyfauAj5vPLio+95aQNPLPIRlqnufZeFh+t1DuvGIYhbpv6PD+osdVlWtQMtXGqm0FaYzMsD3NTPDwO2dhJeWK1rGaHr8Q1C85hAaYlcZD3dJ/hcfN8dUDOwk5ypkBLu6MvWo8= 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; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=XaKFecEs; 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 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="XaKFecEs" 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 3FE8F1F60; Fri, 3 Jul 2026 01:42:20 -0700 (PDT) Received: from [10.211.55.3] (unknown [10.57.73.238]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 4A2B93F905; Fri, 3 Jul 2026 01:42:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1783068144; bh=qPN+0EoXG8L0C7DiygFnkIw7nf3VUC+KuOM6KpifZ7o=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=XaKFecEsN7h+h2apNY8Z5g5/vb6bQ8rBudcHUdrG+LIyv62g4MFnziVs7rErL/mOH JIv2BmjgLfeoUjXKH5MdWvdQ3zmKcxHfRIZSgjQo7wtUdTrp05GtUza/5xKeoDWO+K G2meiIX+/C8s2tppnOtBnTkhwI0ddASocLXfKZiM= Message-ID: Date: Wed, 1 Jul 2026 21:00:56 +0100 Precedence: bulk X-Mailing-List: linux-acpi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Thunderbird Daily Subject: Re: [PATCH v2 03/15] arm_mpam: propagate MSC read errors for hw_probe functions To: Andre Przywara , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , "Rafael J . Wysocki" , Len Brown , James Morse , Reinette Chatre , Fenghua Yu Cc: Jonathan Cameron , Srivathsa L Rao , Ganapatrao Kulkarni , Trilok Soni , Srinivas Ramana , Niyas Sait , linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <20260702162229.4008659-1-andre.przywara@arm.com> <20260702162229.4008659-4-andre.przywara@arm.com> Content-Language: en-US From: Ben Horgan In-Reply-To: <20260702162229.4008659-4-andre.przywara@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Hi Andre, On 7/2/26 17:22, Andre Przywara wrote: > Allow the functions probing for MSC hardware and features to return an > error, and propagate read errors from the lower level up. > > Signed-off-by: Andre Przywara > --- > drivers/resctrl/mpam_devices.c | 62 ++++++++++++++++++++++++---------- > 1 file changed, 44 insertions(+), 18 deletions(-) > > diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c > index ce8738adb6ff..011d1e3544d7 100644 > --- a/drivers/resctrl/mpam_devices.c > +++ b/drivers/resctrl/mpam_devices.c > @@ -800,20 +800,22 @@ static bool mpam_ris_hw_probe_csu_nrdy(struct mpam_msc_ris *ris) > mpam_write_monsel_reg(msc, CFG_CSU_CTL, ctl_val); > > _mpam_write_monsel_reg(msc, MSMON_CSU, MSMON___NRDY); > - _mpam_read_monsel_reg(msc, MSMON_CSU, &now); > + if (_mpam_read_monsel_reg(msc, MSMON_CSU, &now)) > + return false; This early return leaves the mon_sel lock held. > can_set = now & MSMON___NRDY; As you're adding early returns to this function does it make sense to return early if can_set is false? Thanks, Ben > > _mpam_write_monsel_reg(msc, MSMON_CSU, 0); > /* Configuration change to try and coax hardware into setting nrdy */ > mpam_write_monsel_reg(msc, CFG_CSU_FLT, 0x1); > - _mpam_read_monsel_reg(msc, MSMON_CSU, &now); > + if (_mpam_read_monsel_reg(msc, MSMON_CSU, &now)) > + return false; > can_clear = !(now & MSMON___NRDY); > mpam_mon_sel_unlock(msc); > > return (!can_set || !can_clear); > } > > -static void mpam_ris_hw_probe(struct mpam_msc_ris *ris) > +static int mpam_ris_hw_probe(struct mpam_msc_ris *ris) > { > int err; > struct mpam_msc *msc = ris->vmsc->msc; > @@ -828,7 +830,9 @@ static void mpam_ris_hw_probe(struct mpam_msc_ris *ris) > if (FIELD_GET(MPAMF_IDR_HAS_CCAP_PART, ris->idr)) { > u32 ccap_features; > > - mpam_read_partsel_reg(msc, CCAP_IDR, &ccap_features); > + err = mpam_read_partsel_reg(msc, CCAP_IDR, &ccap_features); > + if (err) > + return err; > > props->cmax_wd = FIELD_GET(MPAMF_CCAP_IDR_CMAX_WD, ccap_features); > if (props->cmax_wd && > @@ -853,7 +857,9 @@ static void mpam_ris_hw_probe(struct mpam_msc_ris *ris) > if (FIELD_GET(MPAMF_IDR_HAS_CPOR_PART, ris->idr)) { > u32 cpor_features; > > - mpam_read_partsel_reg(msc, CPOR_IDR, &cpor_features); > + err = mpam_read_partsel_reg(msc, CPOR_IDR, &cpor_features); > + if (err) > + return err; > > props->cpbm_wd = FIELD_GET(MPAMF_CPOR_IDR_CPBM_WD, cpor_features); > if (props->cpbm_wd) > @@ -863,8 +869,9 @@ static void mpam_ris_hw_probe(struct mpam_msc_ris *ris) > /* Memory bandwidth partitioning */ > if (FIELD_GET(MPAMF_IDR_HAS_MBW_PART, ris->idr)) { > u32 mbw_features; > - > - mpam_read_partsel_reg(msc, MBW_IDR, &mbw_features); > + err = mpam_read_partsel_reg(msc, MBW_IDR, &mbw_features); > + if (err) > + return err; > > /* portion bitmap resolution */ > props->mbw_pbm_bits = FIELD_GET(MPAMF_MBW_IDR_BWPBM_WD, mbw_features); > @@ -893,8 +900,9 @@ static void mpam_ris_hw_probe(struct mpam_msc_ris *ris) > /* Priority partitioning */ > if (FIELD_GET(MPAMF_IDR_HAS_PRI_PART, ris->idr)) { > u32 pri_features; > - > - mpam_read_partsel_reg(msc, PRI_IDR, &pri_features); > + err = mpam_read_partsel_reg(msc, PRI_IDR, &pri_features); > + if (err) > + return err; > > props->intpri_wd = FIELD_GET(MPAMF_PRI_IDR_INTPRI_WD, pri_features); > if (props->intpri_wd && FIELD_GET(MPAMF_PRI_IDR_HAS_INTPRI, pri_features)) { > @@ -915,7 +923,9 @@ static void mpam_ris_hw_probe(struct mpam_msc_ris *ris) > if (FIELD_GET(MPAMF_IDR_HAS_MSMON, ris->idr)) { > u32 msmon_features; > > - mpam_read_partsel_reg(msc, MSMON_IDR, &msmon_features); > + err = mpam_read_partsel_reg(msc, MSMON_IDR, &msmon_features); > + if (err) > + return err; > > /* > * If the firmware max-nrdy-us property is missing, the > @@ -928,7 +938,9 @@ static void mpam_ris_hw_probe(struct mpam_msc_ris *ris) > if (FIELD_GET(MPAMF_MSMON_IDR_MSMON_CSU, msmon_features)) { > u32 csumonidr; > > - mpam_read_partsel_reg(msc, CSUMON_IDR, &csumonidr); > + err = mpam_read_partsel_reg(msc, CSUMON_IDR, &csumonidr); > + if (err) > + return err; > > props->num_csu_mon = FIELD_GET(MPAMF_CSUMON_IDR_NUM_MON, csumonidr); > if (props->num_csu_mon) { > @@ -954,7 +966,9 @@ static void mpam_ris_hw_probe(struct mpam_msc_ris *ris) > bool has_long; > u32 mbwumon_idr; > > - mpam_read_partsel_reg(msc, MBWUMON_IDR, &mbwumon_idr); > + err = mpam_read_partsel_reg(msc, MBWUMON_IDR, &mbwumon_idr); > + if (err) > + return err; > > props->num_mbwu_mon = FIELD_GET(MPAMF_MBWUMON_IDR_NUM_MON, mbwumon_idr); > if (props->num_mbwu_mon) { > @@ -987,16 +1001,22 @@ static void mpam_ris_hw_probe(struct mpam_msc_ris *ris) > u16 partid_max; > u32 nrwidr; > > - mpam_read_partsel_reg(msc, PARTID_NRW_IDR, &nrwidr); > + err = mpam_read_partsel_reg(msc, PARTID_NRW_IDR, &nrwidr); > + if (err) > + return err; > + > partid_max = FIELD_GET(MPAMF_PARTID_NRW_IDR_INTPARTID_MAX, nrwidr); > > mpam_set_feature(mpam_feat_partid_nrw, props); > msc->partid_max = min(msc->partid_max, partid_max); > } > + > + return 0; > } > > static int mpam_msc_hw_probe(struct mpam_msc *msc) > { > + int ret; > u64 idr; > u16 partid_max; > u8 ris_idx, pmg_max; > @@ -1012,10 +1032,12 @@ static int mpam_msc_hw_probe(struct mpam_msc *msc) > > /* Grab an IDR value to find out how many RIS there are */ > mutex_lock(&msc->part_sel_lock); > - mpam_msc_read_idr(msc, &idr); > - mpam_read_partsel_reg(msc, IIDR, &msc->iidr); > - > + ret = mpam_msc_read_idr(msc, &idr); > + if (!ret) > + ret = mpam_read_partsel_reg(msc, IIDR, &msc->iidr); > mutex_unlock(&msc->part_sel_lock); > + if (ret) > + return ret; > > mpam_enable_quirks(msc); > > @@ -1028,8 +1050,10 @@ static int mpam_msc_hw_probe(struct mpam_msc *msc) > for (ris_idx = 0; ris_idx <= msc->ris_max; ris_idx++) { > mutex_lock(&msc->part_sel_lock); > __mpam_part_sel(ris_idx, 0, msc); > - mpam_msc_read_idr(msc, &idr); > + ret = mpam_msc_read_idr(msc, &idr); > mutex_unlock(&msc->part_sel_lock); > + if (ret) > + return ret; > > partid_max = FIELD_GET(MPAMF_IDR_PARTID_MAX, idr); > pmg_max = FIELD_GET(MPAMF_IDR_PMG_MAX, idr); > @@ -1046,8 +1070,10 @@ static int mpam_msc_hw_probe(struct mpam_msc *msc) > > mutex_lock(&msc->part_sel_lock); > __mpam_part_sel(ris_idx, 0, msc); > - mpam_ris_hw_probe(ris); > + ret = mpam_ris_hw_probe(ris); > mutex_unlock(&msc->part_sel_lock); > + if (ret) > + return ret; > } > > /* Clear any stale errors */