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 059293803CC; Thu, 9 Jul 2026 10:03:08 +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=1783591390; cv=none; b=CLOb1y8Kcas7gAmzePMbTsxs/c8d1BBKLtg7B8zmoAetmt04yARONI02tX2yNd8IneXfhhIltDOFRnp0Ir6fERd+2MAIiB4r83kzCjsR3y/UjGfAczgUn+LAmVRCE4wPMU7/lTEImsdoo/gHPB91iEOSLupSPIWjjJpbt8WlMJA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783591390; c=relaxed/simple; bh=ecLtVnEwb3NP4soxChOKajrwfO3Sl/4YUqD3QznhpYs=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Nu2H+aEabcaLAkSpw5kRaJNMCkhpi92kLLNXQwQRjS0BDhKIzD/fRK2Or2DRdChR9NPd097mRKpvPrs1YB8ilFfi6OyPuoEX/FvbC0XMBYBhbJVxuOWjnd2VETx5ff6w+mXiYr56T+7GYYfuCM/Zldg+S9RvWb4OVjuc0i7SHuw= 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=ooBPQon+; 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="ooBPQon+" 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 EF0F9357C; Thu, 9 Jul 2026 03:03:03 -0700 (PDT) Received: from [10.41.150.148] (e142021.arm.com [10.41.150.148]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 287803F7B4; Thu, 9 Jul 2026 03:03:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1783591388; bh=ecLtVnEwb3NP4soxChOKajrwfO3Sl/4YUqD3QznhpYs=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=ooBPQon+vGBTV5jo+7tu6X1T4i29xOLgqNL8HUdyjPh8ZLWLNeyLIf9Qqw0Y7Eu3n DeIaW22GaUUVClAfamohQb2ua55C9PHP1MNQI0jTLbY94ROaSSX/1UduhoDv3AXCRu lU+hs0CyEiS/cnSueZDDsOLCwj2BH/tNUK3yt8hE= Message-ID: <9498c202-ed82-49ae-b960-df44b53596e6@arm.com> Date: Thu, 9 Jul 2026 12:03:03 +0200 Precedence: bulk X-Mailing-List: linux-acpi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 07/15] arm_mpam: propagate MSC read errors for state saving functions To: Ben Horgan , 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-GB From: Andre Przywara In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Hi, On 7/1/26 22:19, Ben Horgan wrote: > 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? Yeah, I changed it, I guess the diff looks better. Not entirely sure it's cleaner, there is now this little bitter taste of a global unlock where the current lock/unlock pair is *inside* the loop. Feel free to have a look and comment on an eventual v3 post. Cheers, Andre > > Thanks, > > Ben > >> } >> >> - return 0; >> + return ret; >> } >> >> /* >