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 683551D9A66; Fri, 10 Jul 2026 14:45:48 +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=1783694754; cv=none; b=JbLDMKJ2S1fESNduS3zeUeeuWgdKVJ8gthbDGoeiHsJGdPXu1VjPLx/ADE+FIy5GwkE7IfRElUVh39Fywr7dMLaj2eL/GCz7Gg05rwRj8ZbV8b0fysQi6uK34VHc0TbuYTfEOG3kg+aZn8UbTcvGAFTfcwFY6LjKkwJiUbxYnBY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783694754; c=relaxed/simple; bh=A0Ru/2N7sEwl2kjzGbay+ACwN2GYOjiwicjcdxvroYU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=blyOTb6YQ8EPOpjtthnhmN4GRSiuCm73Ww0amtRZgn/gVdKwvzNj8TRg6czCxu66IThzgKWDZfz8IytE1kN6cH2yloNJRZcct+ObGFqGy8L8nMdwcUWRpgarX5DPA8nciyoknplTRscBB3FUWe23WzwnQgIfUUwRxpbHO0zV4ZM= 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=lYeH8lkC; 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="lYeH8lkC" 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 50BD7176A; Fri, 10 Jul 2026 07:45:43 -0700 (PDT) Received: from e142021.munich.arm.com (e142021.arm.com [10.41.150.148]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A916B3F7B4; Fri, 10 Jul 2026 07:45:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1783694747; bh=A0Ru/2N7sEwl2kjzGbay+ACwN2GYOjiwicjcdxvroYU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lYeH8lkC38rrivzwvgAAyLkAed/DP2usQZyo9E6HMW4gXychIo87JR7nDxG4IVCbJ 7ziPBCSbJ+UGlQ0q66nYBRBJrMcjl3hBD6kmvLMwF+D27X18amhnLZNgGAXIkVcQvL CkmUUYpkeJpwwQMSmLMdfc5VJDKbcloWqYA3bGu0= 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 , linux-acpi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 04/16] arm_mpam: propagate MSC read errors for mpam_msc_read_mbwu_l() Date: Fri, 10 Jul 2026 16:45:08 +0200 Message-ID: <20260710144520.917375-5-andre.przywara@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260710144520.917375-1-andre.przywara@arm.com> References: <20260710144520.917375-1-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 read errors from the lower level up. So far we were using a special value to indicate the "unstable read" condition, replace that with the actual Linux error code, since it's now easy to do. Signed-off-by: Andre Przywara --- drivers/resctrl/mpam_devices.c | 54 +++++++++++++++++++++++++--------- 1 file changed, 40 insertions(+), 14 deletions(-) diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index b1bd047da203..3b6f9e552a9f 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -1112,8 +1112,9 @@ 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; @@ -1123,20 +1124,30 @@ 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"); + ret = -EBUSY; + } - pr_warn("Failed to read a stable value\n"); - return MSMON___L_NRDY; + return ret; } static void mpam_msc_zero_mbwu_l(struct mpam_msc *msc) @@ -1283,6 +1294,7 @@ static u64 mpam_msmon_overflow_val(enum mpam_device_features type, static void __ris_msmon_read(void *arg) { u64 now; + int ret; u32 now32; bool nrdy = false; bool config_mismatch; @@ -1358,8 +1370,9 @@ 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); - nrdy = now & MSMON___L_NRDY; + ret = mpam_msc_read_mbwu_l(msc, &now); + if (ret) + goto out_unlock; if (m->type == mpam_feat_msmon_mbwu_63counter) now = FIELD_GET(MSMON___LWD_VALUE, now); @@ -1397,10 +1410,15 @@ static void __ris_msmon_read(void *arg) if (nrdy) m->err = -EBUSY; - if (m->err) - return; + if (!m->err) + *m->val += now; + + return; + +out_unlock: + mpam_mon_sel_unlock(msc); - *m->val += now; + m->err = ret; } static int _msmon_read(struct mpam_component *comp, struct mon_read *arg) @@ -1747,6 +1765,7 @@ static int mpam_save_mbwu_state(void *arg) { int i; u64 val; + int ret = 0; struct mon_cfg *cfg; u32 cur_flt, cur_ctl, mon_sel; struct mpam_msc_ris *ris = arg; @@ -1768,7 +1787,9 @@ 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) + goto out_unlock; mpam_msc_zero_mbwu_l(msc); } else { u32 val32; @@ -1788,6 +1809,11 @@ static int mpam_save_mbwu_state(void *arg) } return 0; + +out_unlock: + mpam_mon_sel_unlock(msc); + + return ret; } /* -- 2.43.0