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 31F76514776 for ; Fri, 2 Oct 2026 17:39:34 +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=1790962804; cv=none; b=hbcehP52JjCasaNzTBVm6dcIZhPRdw5d/1/QCRwqiqFApyhVmS4iU2j1fdsmkS2yVe0246Lp5W2mAqr9rVgEQXckA8tKRWPElhHr4+2OGBqGM5oSDu2arua1YWQwEp4OvFNMWDJGtDD0KsGjY169NG+fDTWOMNGVzqapqlfMxRA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790962804; c=relaxed/simple; bh=8AOzxXFPkwZXoPCLFKcDeivji18LzJ50iTSm+cbY8ko=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Cl/YBta4H+D8m3E0A3TPa3yVZtIz5qXB8m9z5HS5QAI+m3fIQBXjMaA2f0gjJ7osM+oNtiFqmRTNsq2YVl4qWmOEEJ8IwJ2cBxaCDTBXqKGAc/y+QkXBjCUEAgdEB3iP2xMoaiibxJj2mO5fs/vHGPxekPiF9DoLec2jeCf+bYE= 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=kjG7HIVx; 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="kjG7HIVx" 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 2F9FC143D; Fri, 2 Oct 2026 10:39:29 -0700 (PDT) Received: from [10.2.212.14] (eglon.cambridge.arm.com [10.2.212.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0093F3F85F; Fri, 2 Oct 2026 10:39:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1790962772; bh=8AOzxXFPkwZXoPCLFKcDeivji18LzJ50iTSm+cbY8ko=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=kjG7HIVxVIENDoXL11f0gaBtvKOuWmSfU1kJ5KeXEapofDmepwbGaBJ48wyelyrU5 Tm/DuKphEBpP7Vxww9OYm69SPICuNmwFu1utqna+g93kPHg2X/PxnmRpBughyB3cn8 sl7f9/Pc9LD14c3PGOD/J4VLg3HxhI/yZ6qctCJQ= Message-ID: <0bedf04c-24ef-40de-909f-b41dd72b8e78@arm.com> Date: Fri, 2 Oct 2026 18:39:28 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v12 03/13] arm_mpam: propagate MSC access errors for MBWU counters To: Andre Przywara , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , "Rafael J . Wysocki" , Len Brown , Ben Horgan , Reinette Chatre , Fenghua Yu Cc: Jonathan Cameron , Srivathsa L Rao , Ganapatrao Kulkarni , Trilok Soni , Srinivas Ramana , Niyas Sait , Lee Trager , Ritwick Sharma , Gavin Shan , linux-acpi@vger.kernel.org--cc, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <20261001153439.3295416-1-andre.przywara@arm.com> <20261001153439.3295416-4-andre.przywara@arm.com> Content-Language: en-GB From: James Morse In-Reply-To: <20261001153439.3295416-4-andre.przywara@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Hi Andre, I've picked up this series to send on to Catalin and Will ... On 01/10/2026 16:34, Andre Przywara wrote: > Allow the mpam_msc_read_mbwu_l() function to return an error, and > propagate errors from the lower level up. This also changes the users > of this function. > diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c > index 3aefeab371788..583560798dd8b 100644 > --- a/drivers/resctrl/mpam_devices.c > +++ b/drivers/resctrl/mpam_devices.c > @@ -1327,10 +1338,12 @@ static void __ris_msmon_read(void *arg) > struct mpam_msc *msc = m->ris->vmsc->msc; > u32 mon_sel, ctl_val, flt_val, cur_ctl, cur_flt; > > - if (!mpam_mon_sel_lock(msc)) { > + ACQUIRE(mon_sel_lock, guard)(msc); > + if (ACQUIRE_ERR(mon_sel_lock, &guard)) { > m->err = -EIO; > return; > } > + > mon_sel = FIELD_PREP(MSMON_CFG_MON_SEL_MON_SEL, ctx->mon) | > FIELD_PREP(MSMON_CFG_MON_SEL_RIS, ris->ris_idx); > mpam_write_monsel_reg(msc, CFG_MON_SEL, mon_sel); This conflicts with Ben's fixes [0] that turn this into __ris_msmon_read_locked(). I don't think the ACQUIRE buys us anything after that, as none of the callers need to return early, and __ris_msmon_read_locked() can always just return. The same thing happens in mpam_save_mbwu_state() where Ben's change means you no longer need an early return after mpam_msc_read_mbwu_l(). Please double check I've not botched your patch when fixing up the conflict! https://git.kernel.org/pub/scm/linux/kernel/git/morse/linux.git/tag/?h=mpam/for-next/v7.4_v2 Thanks, James [0] https://lore.kernel.org/linux-arm-kernel/20260917145617.2202986-1-ben.horgan@arm.com/ > @@ -1423,7 +1438,6 @@ static void __ris_msmon_read(void *arg) > default: > m->err = -EINVAL; > } > - mpam_mon_sel_unlock(msc); > > if (nrdy) > m->err = -EBUSY; > @@ -1784,6 +1798,7 @@ 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; > @@ -1794,7 +1809,8 @@ static int mpam_save_mbwu_state(void *arg) > mbwu_state = &ris->mbwu_state[i]; > cfg = &mbwu_state->cfg; > > - if (WARN_ON_ONCE(!mpam_mon_sel_lock(msc))) > + ACQUIRE(mon_sel_lock, guard)(msc); > + if (ACQUIRE_ERR(mon_sel_lock, &guard)) > return -EIO; > > mon_sel = FIELD_PREP(MSMON_CFG_MON_SEL_MON_SEL, i) | > @@ -1805,7 +1821,9 @@ static int mpam_save_mbwu_state(void *arg) > mpam_write_monsel_reg(msc, CFG_MBWU_CTL, 0); > > if (mpam_ris_has_mbwu_long_counter(ris)) { > - val = mpam_msc_read_mbwu_l(msc); > + ret = mpam_msc_read_mbwu_l(msc, &val); > + if (ret) > + return ret; > mpam_msc_zero_mbwu_l(msc); > } else { > u32 val32; > @@ -1821,7 +1839,6 @@ static int mpam_save_mbwu_state(void *arg) > 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); > } > > return 0;