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 93315389116; Fri, 3 Jul 2026 09:00:57 +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=1783069259; cv=none; b=bi1E2o0m/prqrscgqdZEgf6aAdj9eIksoi6KDPsiT9W2wDw9fgRcW9oT3pMaY7kiajGinIOUuqJLisisQBcrSyLtQ1SA4KqEeu3UrgSNqQfiH4xB9BZDN2DhFGRB8ngwOTwjPS458x8T+S0ihPz8/Ype+92SFlpP2wNfXNqsaIM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783069259; c=relaxed/simple; bh=FaTU6ZiyPyiPxJG4iwJWWSF1yEgoyNUyWDD0Eltw0Nc=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=N3Gl972a/iZ7bdQIjYfKqPl3KHWSjQKjLz5tOaxdtjA1dmJ+zY+iqHDHeXapAswMZM+IpP/deCiLa2YlTjQfc7Z5s2FUFzyVpos5WGaRr6VuHgfyx2vogVFPxkIv3POh60BLyUt0sMuWNk45Z7HuS/A4WPc7iDjbT7bWMr85ROQ= 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=lN7tnWTi; 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="lN7tnWTi" 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 84C9B1684; Fri, 3 Jul 2026 02:00:52 -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 58C973F905; Fri, 3 Jul 2026 02:00:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1783069256; bh=FaTU6ZiyPyiPxJG4iwJWWSF1yEgoyNUyWDD0Eltw0Nc=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=lN7tnWTipISpo9m4CaYXRl0gVWPXXDKsf7gAD4vvvnJ/Z4/jkg6moMIhL/WWyqExu 2p0O7hjGjA1NK3XdyTd7HNkneZ+hFShU5sf2L4PtUuBSxpMvEhQkIsRe2eKcPosD3T O+0OMCcSvHl2wEQqYAMeWyW7RCewAh8P1/gyzpJw= Message-ID: Date: Wed, 1 Jul 2026 21:19:28 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Thunderbird Daily Subject: Re: [PATCH v2 07/15] arm_mpam: propagate MSC read errors for state saving 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> <20260702162229.4008659-8-andre.przywara@arm.com> Content-Language: en-US From: Ben Horgan In-Reply-To: <20260702162229.4008659-8-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 mpam_save_mbwu_state() function to return an error, and > propagate read errors from the lower level up. > > Signed-off-by: Andre Przywara > --- > drivers/resctrl/mpam_devices.c | 47 +++++++++++++++++++++------------- > 1 file changed, 29 insertions(+), 18 deletions(-) > > diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c > index d18c7be86aaa..c50ca0e4f426 100644 > --- a/drivers/resctrl/mpam_devices.c > +++ b/drivers/resctrl/mpam_devices.c > @@ -1773,6 +1773,7 @@ static int mpam_save_mbwu_state(void *arg) > { > int i; > u64 val; > + int ret; > struct mon_cfg *cfg; > u32 cur_flt, cur_ctl, mon_sel; > struct mpam_msc_ris *ris = arg; > @@ -1789,31 +1790,41 @@ static int mpam_save_mbwu_state(void *arg) > mon_sel = FIELD_PREP(MSMON_CFG_MON_SEL_MON_SEL, i) | > FIELD_PREP(MSMON_CFG_MON_SEL_RIS, ris->ris_idx); > mpam_write_monsel_reg(msc, CFG_MON_SEL, mon_sel); > - mpam_read_monsel_reg(msc, CFG_MBWU_FLT, &cur_flt); > - mpam_read_monsel_reg(msc, CFG_MBWU_CTL, &cur_ctl); > - mpam_write_monsel_reg(msc, CFG_MBWU_CTL, 0); > + ret = mpam_read_monsel_reg(msc, CFG_MBWU_FLT, &cur_flt); > + if (!ret) > + ret = mpam_read_monsel_reg(msc, CFG_MBWU_CTL, &cur_ctl); > + if (!ret) > + mpam_write_monsel_reg(msc, CFG_MBWU_CTL, 0); > > - if (mpam_ris_has_mbwu_long_counter(ris)) { > - val = mpam_msc_read_mbwu_l(msc); > - mpam_msc_zero_mbwu_l(msc); > - } else { > - u32 val32; > + if (!ret) { > + if (mpam_ris_has_mbwu_long_counter(ris)) { > + val = mpam_msc_read_mbwu_l(msc); > + mpam_msc_zero_mbwu_l(msc); > + } else { > + u32 val32; > > - mpam_read_monsel_reg(msc, MBWU, &val32); > - val = val32; > - mpam_write_monsel_reg(msc, MBWU, 0); > + ret = mpam_read_monsel_reg(msc, MBWU, &val32); > + if (!ret) { > + val = val32; > + mpam_write_monsel_reg(msc, MBWU, 0); > + } > + } > } > > - cfg->mon = i; > - cfg->pmg = FIELD_GET(MSMON_CFG_x_FLT_PMG, cur_flt); > - cfg->match_pmg = FIELD_GET(MSMON_CFG_x_CTL_MATCH_PMG, cur_ctl); > - cfg->partid = FIELD_GET(MSMON_CFG_x_FLT_PARTID, cur_flt); > - mbwu_state->correction += val; > - mbwu_state->enabled = FIELD_GET(MSMON_CFG_x_CTL_EN, cur_ctl); > + if (!ret && val != MSMON___L_NRDY) { > + cfg->mon = i; > + cfg->pmg = FIELD_GET(MSMON_CFG_x_FLT_PMG, cur_flt); > + cfg->match_pmg = FIELD_GET(MSMON_CFG_x_CTL_MATCH_PMG, cur_ctl); > + cfg->partid = FIELD_GET(MSMON_CFG_x_FLT_PARTID, cur_flt); > + mbwu_state->correction += val; > + mbwu_state->enabled = FIELD_GET(MSMON_CFG_x_CTL_EN, cur_ctl); > + } > mpam_mon_sel_unlock(msc); > + if (ret) > + break; There is a lot of if(!ret) in this loop. Does it not end up cleaner to add an out_unlock label after the loop and jump to that in the failure cases? Thanks, Ben > } > > - return 0; > + return ret; > } > > /*