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 B17A7408614; Thu, 30 Jul 2026 09:52:29 +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=1785405151; cv=none; b=H7RzQxuIvY19GXbFlJtb4PsubfV+9nznrnk4gLrWUJ6x5mTPZJOdgnWhRjuQdJ8bVcWoOQ66qvwiqpCSQvwoKnEVFfx3v/EIy95us0/s+KVyrIEiy+KIYBCpVfJI9GFYsz6L/7fmVuSDWvVLDWfZTyQLKVeX0JzbcUXO5afUFTM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785405151; c=relaxed/simple; bh=xYT95HwP3Wxou2PQvp2OVBtuUoGkxFQDOtYH+TmyHjY=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=JunJ7JLnyzY1RHOXoR4YfK3C2sdWiAHyX2f/6Vt0ooI9G4+6Q4nw+Nmtq07HA9F25x7JiiChRkiwu3InGkCa+jCi877mSberpsLVb+PIz8wEmPYLoMti3N6O/EHJAWNgNs9W48PSJK/hHjGhatuxdk4APVMgq5ZzND0/ffvVRuM= 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=uDrxJYLs; 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="uDrxJYLs" 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 1037A204C; Thu, 30 Jul 2026 02:52:25 -0700 (PDT) Received: from [10.2.212.8] (e134344.arm.com [10.2.212.8]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id CEF8B3F99C; Thu, 30 Jul 2026 02:52:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1785405149; bh=xYT95HwP3Wxou2PQvp2OVBtuUoGkxFQDOtYH+TmyHjY=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=uDrxJYLs3DSCDzYb5Sj92HjNYVKmzlL55LET42ZXWuRbCnl+0UlETc23PLFgUSslV lZRvImDO1QIixSUB5pPseoLaKxW0AIFHUcwDwCfALYTHQoNinngzNfxlKn569GHc6Z +qylh1FwjDCkE+XtLaRgWL6uM7SQj2ngQdQvnUyg= Message-ID: Date: Thu, 30 Jul 2026 10:52:25 +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 v5 05/10] arm_mpam: propagate MSC access errors for __ris_msmon_read() 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 , Lee Trager , linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <20260729134124.2506269-1-andre.przywara@arm.com> <20260729134124.2506269-6-andre.przywara@arm.com> Content-Language: en-US From: Ben Horgan In-Reply-To: <20260729134124.2506269-6-andre.przywara@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Hi Andre, On 7/29/26 14:41, Andre Przywara wrote: > Allow the function for RIS accesses to return an error, and propagate > read and write errors from the lower level up. > This function is a bit special, since it can be called via an SMP > helper, so the prototype must stay as void. So propagate any errors > using the "err" field in the struct passed in as the sole argument to > that function. > > Signed-off-by: Andre Przywara > Reviewed-by: Jonathan Cameron > --- > drivers/resctrl/mpam_devices.c | 36 +++++++++++++++++++++++++--------- > 1 file changed, 27 insertions(+), 9 deletions(-) > > diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c > index 9d9f0c635527..44eafef1e7ab 100644 > --- a/drivers/resctrl/mpam_devices.c > +++ b/drivers/resctrl/mpam_devices.c > @@ -1333,6 +1333,10 @@ static u64 mpam_msmon_overflow_val(enum mpam_device_features type, > return overflow_val; > } > > +/* > + * This function might be called via smp_call_function_any(), so propagate > + * errors inside the arg struct. > + */ > static void __ris_msmon_read(void *arg) > { > u64 now; > @@ -1356,7 +1360,9 @@ static void __ris_msmon_read(void *arg) > > 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); > + m->err = mpam_write_monsel_reg(msc, CFG_MON_SEL, mon_sel); > + if (m->err) > + return; > > switch (m->type) { > case mpam_feat_msmon_mbwu_31counter: > @@ -1376,7 +1382,9 @@ static void __ris_msmon_read(void *arg) > * Read the existing configuration to avoid re-writing the same values. > * This saves waiting for 'nrdy' on subsequent reads. > */ > - read_msmon_ctl_flt_vals(m, &cur_ctl, &cur_flt); > + m->err = read_msmon_ctl_flt_vals(m, &cur_ctl, &cur_flt); > + if (m->err) > + return; > > if (mpam_feat_msmon_mbwu_31counter == m->type) > overflow = cur_ctl & MSMON_CFG_x_CTL_OFLOW_STATUS; > @@ -1390,18 +1398,24 @@ static void __ris_msmon_read(void *arg) > cur_ctl != (ctl_val | MSMON_CFG_x_CTL_EN); > > if (config_mismatch || reset_on_next_read) { > - write_msmon_ctl_flt_vals(m, ctl_val, flt_val); > + m->err = write_msmon_ctl_flt_vals(m, ctl_val, flt_val); > + if (m->err) > + return; > overflow = false; > } else if (overflow) { > - mpam_write_monsel_reg(msc, CFG_MBWU_CTL, > - cur_ctl & > - ~(MSMON_CFG_x_CTL_OFLOW_STATUS | > - MSMON_CFG_MBWU_CTL_OFLOW_STATUS_L)); > + m->err = mpam_write_monsel_reg(msc, CFG_MBWU_CTL, > + cur_ctl & > + ~(MSMON_CFG_x_CTL_OFLOW_STATUS | > + MSMON_CFG_MBWU_CTL_OFLOW_STATUS_L)); > + if (m->err) > + return; > } > > switch (m->type) { > case mpam_feat_msmon_csu: > - mpam_read_monsel_reg(msc, CSU, &now32); > + m->err = mpam_read_monsel_reg(msc, CSU, &now32); > + if (m->err) > + return; > nrdy = now32 & MSMON___NRDY; > now = FIELD_GET(MSMON___VALUE, now32); > > @@ -1423,7 +1437,9 @@ static void __ris_msmon_read(void *arg) > else > now = FIELD_GET(MSMON___L_VALUE, now); > } else { > - mpam_read_monsel_reg(msc, MBWU, &now32); > + m->err = mpam_read_monsel_reg(msc, MBWU, &now32); > + if (m->err) > + return; > nrdy = now32 & MSMON___NRDY; > now = FIELD_GET(MSMON___VALUE, now32); > } > @@ -1792,6 +1808,8 @@ static int mpam_restore_mbwu_state(void *_ris) > mwbu_arg.val = &val; > > __ris_msmon_read(&mwbu_arg); > + if (mwbu_arg.err) > + return mwbu_arg.err; As sashiko points out [1], this is a change of behaviour as mbwu_arg.err could already be non-zero previous to this patch. In particular, -EBUSY when NRDY is set. When this is the case we should continue restoring the other counters rather than changing to bailing out early. As -EBUSY is only used in the NRDY case you could change the condition to be: if (mbwu_arg.err && mbwu_arg.err != -EBUSY) return mwbu_arg.err; [1] https://sashiko.dev/#/patchset/20260729134124.2506269-1-andre.przywara%40arm.com Thanks, Ben > } > } >