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 ABB2344E679; Thu, 23 Jul 2026 15:55:12 +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=1784822115; cv=none; b=Lp/WhNzYZcoHsEAhQPMnUd3KuoURbgfzgjG84gU6+KqofPVjYlQPx3k6o44Kke9Ut3EcATE5XSZKFOvyaj/5VEPUQg5Li68AVH63jTVBzie7kr9B0IPI8Q7/lyUlY0FhOlc8gD/DeSmnWOGHf45DyIRcIlN2pq/JhRxXpkF7uVE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784822115; c=relaxed/simple; bh=gRBsK2XXpdqJk9qjuat4AR6gYBmA1l94CmOgVQCns2M=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=U5K1gwG2TIRjXjPdNuIHb52wPkHqWPJq8F58ReyfwEBjc7gmxBndCibfmLADP5QB103bvbNyb3tAz8H3sWyn9ZE81F0S3fd/UOo8YLjUVtGs1BLsI2eHR0c+Z6qzapO5xhWOXYcyHf20Y/I0NxZn75xvphnaT0zuLxwY5U8qqb4= 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=AU90jM55; 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="AU90jM55" 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 774FE1477; Thu, 23 Jul 2026 08:55:07 -0700 (PDT) Received: from e142021.fritz.box (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 3ED9D3F66F; Thu, 23 Jul 2026 08:55:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1784822111; bh=gRBsK2XXpdqJk9qjuat4AR6gYBmA1l94CmOgVQCns2M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AU90jM55LVKYweB0a4JY116y7y/hpadHywkYyTXWvTxL7EhqKY42AezSJszkbX995 BxNMXITwtulwzyuyAdJ6TzouvJG71xz0LdBDY29C7W7HA9mSxmiocB3sLPZVHAeYub zvW68GuV/FOHi7BgdC0h5KiI5Zl8mDHVXVdEqvck= From: Andre Przywara To: Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , "Rafael J . Wysocki" , Len Brown , James Morse , Ben Horgan , 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 Subject: [PATCH v4 03/10] arm_mpam: propagate MSC access errors for MBWU counters Date: Thu, 23 Jul 2026 17:54:47 +0200 Message-ID: <20260723155454.1760823-4-andre.przywara@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260723155454.1760823-1-andre.przywara@arm.com> References: <20260723155454.1760823-1-andre.przywara@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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. Signed-off-by: Andre Przywara --- drivers/resctrl/mpam_devices.c | 45 +++++++++++++++++++++++----------- 1 file changed, 31 insertions(+), 14 deletions(-) diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index ecd45a585942..fce29fa9ef78 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -1127,8 +1127,9 @@ static bool mpam_ris_has_mbwu_long_counter(struct mpam_msc_ris *ris) mpam_has_feature(mpam_feat_msmon_mbwu_44counter, &ris->props)); } -static u64 mpam_msc_read_mbwu_l(struct mpam_msc *msc) +static int mpam_msc_read_mbwu_l(struct mpam_msc *msc, u64 *res) { + int ret; int retry = 3; u32 mbwu_l_low; u32 mbwu_l_high1, mbwu_l_high2; @@ -1138,20 +1139,30 @@ static u64 mpam_msc_read_mbwu_l(struct mpam_msc *msc) WARN_ON_ONCE((MSMON_MBWU_L + sizeof(u64)) > msc->mapped_hwpage_sz); WARN_ON_ONCE(!cpumask_test_cpu(smp_processor_id(), &msc->accessibility)); - __mpam_read_reg(msc, MSMON_MBWU_L + 4, &mbwu_l_high2); + ret = __mpam_read_reg(msc, MSMON_MBWU_L + 4, &mbwu_l_high2); + if (ret) + return ret; + do { mbwu_l_high1 = mbwu_l_high2; - __mpam_read_reg(msc, MSMON_MBWU_L, &mbwu_l_low); - __mpam_read_reg(msc, MSMON_MBWU_L + 4, &mbwu_l_high2); + ret = __mpam_read_reg(msc, MSMON_MBWU_L, &mbwu_l_low); + if (ret) + return ret; + ret = __mpam_read_reg(msc, MSMON_MBWU_L + 4, &mbwu_l_high2); + if (ret) + return ret; retry--; } while (mbwu_l_high1 != mbwu_l_high2 && retry > 0); - if (mbwu_l_high1 == mbwu_l_high2) - return ((u64)mbwu_l_high1 << 32) | mbwu_l_low; + if (mbwu_l_high1 == mbwu_l_high2) { + *res = ((u64)mbwu_l_high1 << 32) | mbwu_l_low; + } else { + pr_warn("Failed to read a stable value\n"); + *res = MSMON___L_NRDY; + } - pr_warn("Failed to read a stable value\n"); - return MSMON___L_NRDY; + return 0; } static void mpam_msc_zero_mbwu_l(struct mpam_msc *msc) @@ -1310,10 +1321,12 @@ 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); @@ -1373,7 +1386,9 @@ static void __ris_msmon_read(void *arg) case mpam_feat_msmon_mbwu_44counter: case mpam_feat_msmon_mbwu_63counter: if (m->type != mpam_feat_msmon_mbwu_31counter) { - now = mpam_msc_read_mbwu_l(msc); + m->err = mpam_msc_read_mbwu_l(msc, &now); + if (m->err) + return; nrdy = now & MSMON___L_NRDY; if (m->type == mpam_feat_msmon_mbwu_63counter) @@ -1407,7 +1422,6 @@ static void __ris_msmon_read(void *arg) default: m->err = -EINVAL; } - mpam_mon_sel_unlock(msc); if (nrdy) m->err = -EBUSY; @@ -1762,6 +1776,7 @@ 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; @@ -1772,7 +1787,8 @@ 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) | @@ -1783,7 +1799,9 @@ 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; @@ -1799,7 +1817,6 @@ 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; -- 2.43.0