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 7B48D342523; Fri, 3 Jul 2026 08:55:57 +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=1783068960; cv=none; b=VJo62MZpQJoeLQxjDYY2zU6HGowkH1u2vUG9O6QnzQZ7GuZ3VSZ9s1xvaMaBipomlbz9CioQHB4KsdTj5CUTsPsCsWjxR+KOteIgHBQNox5waJXqnBRa5BtZzdEmDjgAEwXpRBSglkaLArSv1VsK0hoYtynpX8vbyAg7S1Bk8dw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783068960; c=relaxed/simple; bh=+KB54fHhiLJ7QJHqj8KD4+z0cUvnDc9dzs+QfuUqKrU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=D/Eyy0Pz/CcdE1/MgT4nZc0a2RuKjZUsCu5Vbh94w6dG/HjRG7xWE5IGCdzbfa/1es8wyQOI28wbIkpUbcCIB8Z2NRbndOO/GHvF+RfOlcaLWJBS1QjpW9XjV0hvDByK7pSm/2y0SteC/9fdW+rIY+6HE2V30b4EmgI7vSm6Hhk= 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=UPDgItcV; 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="UPDgItcV" 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 C72251F60; Fri, 3 Jul 2026 01:55:51 -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 CF5D23F905; Fri, 3 Jul 2026 01:55:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1783068956; bh=+KB54fHhiLJ7QJHqj8KD4+z0cUvnDc9dzs+QfuUqKrU=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=UPDgItcVp7b5gJHl98aXaC78cmuWm17hyGjnqb1XIfXOjEEtOk493dvXvCa8NvSKZ ugPsi9QDZ8z/fuWuTv9vkJ1ddjd89GR55lfYDPKRAcQBm4TZdE8f8LEO0Qiw3P20sR a7Bm+t5A/z1KmjnpJ26F3w/ZYDGrhZyqFFR5ndrg= Message-ID: <332b1348-285f-4b4a-9d3d-97f040739703@arm.com> Date: Wed, 1 Jul 2026 21:14:27 +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 06/15] arm_mpam: propagate MSC read 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 , linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <20260702162229.4008659-1-andre.przywara@arm.com> <20260702162229.4008659-7-andre.przywara@arm.com> Content-Language: en-US From: Ben Horgan In-Reply-To: <20260702162229.4008659-7-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 function for RIS accesses to return an error, and propagate > read errors from the lower level up. > > Signed-off-by: Andre Przywara > --- > drivers/resctrl/mpam_devices.c | 35 +++++++++++++++++++++++++++------- > 1 file changed, 28 insertions(+), 7 deletions(-) > > diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c > index b259fe20a614..d18c7be86aaa 100644 > --- a/drivers/resctrl/mpam_devices.c > +++ b/drivers/resctrl/mpam_devices.c > @@ -1285,9 +1285,14 @@ 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; > + int ret; > u32 now32; > bool nrdy = false; > bool config_mismatch; > @@ -1326,7 +1331,9 @@ 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); > + ret = read_msmon_ctl_flt_vals(m, &cur_ctl, &cur_flt); > + if (ret) > + goto out_unlock; > > if (mpam_feat_msmon_mbwu_31counter == m->type) > overflow = cur_ctl & MSMON_CFG_x_CTL_OFLOW_STATUS; > @@ -1351,7 +1358,9 @@ static void __ris_msmon_read(void *arg) > > switch (m->type) { > case mpam_feat_msmon_csu: > - mpam_read_monsel_reg(msc, CSU, &now32); > + ret = mpam_read_monsel_reg(msc, CSU, &now32); > + if (ret) > + goto out_unlock; > nrdy = now32 & MSMON___NRDY; > now = FIELD_GET(MSMON___VALUE, now32); > > @@ -1371,7 +1380,9 @@ static void __ris_msmon_read(void *arg) > else > now = FIELD_GET(MSMON___L_VALUE, now); > } else { > - mpam_read_monsel_reg(msc, MBWU, &now32); > + ret = mpam_read_monsel_reg(msc, MBWU, &now32); > + if (ret) > + goto out_unlock; > nrdy = now32 & MSMON___NRDY; > now = FIELD_GET(MSMON___VALUE, now32); > } > @@ -1402,10 +1413,15 @@ static void __ris_msmon_read(void *arg) > if (nrdy) > m->err = -EBUSY; > > - if (m->err) > - return; > + if (!m->err) > + *m->val += now; Why does this change? Can't you keep this the 'if' statement as before and more the 'return' after the '*m->val += now;'? Thanks, Ben > + > + return; > > - *m->val += now; > +out_unlock: > + mpam_mon_sel_unlock(msc); > + > + m->err = ret; > } > > static int _msmon_read(struct mpam_component *comp, struct mon_read *arg) > @@ -1729,6 +1745,7 @@ static int mpam_restore_mbwu_state(void *_ris) > { > int i; > u64 val; > + int ret = 0; > struct mon_read mwbu_arg; > struct mpam_msc_ris *ris = _ris; > struct mpam_class *class = ris->vmsc->comp->class; > @@ -1741,10 +1758,14 @@ static int mpam_restore_mbwu_state(void *_ris) > mwbu_arg.val = &val; > > __ris_msmon_read(&mwbu_arg); > + if (mwbu_arg.err) { > + ret = mwbu_arg.err; > + break; > + } > } > } > > - return 0; > + return ret; > } > > /* Call with MSC cfg_lock held */