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 5D69D421EF4 for ; Fri, 10 Jul 2026 11:56:06 +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=1783684576; cv=none; b=t9RZsAJ6/4xidfFkcGUqLUzQ2lBFSNYv8efhCtzlJDWR4O1FXTzeaPBi8tHuXt3W8HFwjcXa4/a4NI5Dtva/7Y7RVQxfAOaysnWP5GSnlhKGFjYrPSJhxxvjOQXkfwA5wf5ExGnLtBIaICYeACD5hvOJ4BkfdwaLNmoY3frLTak= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783684576; c=relaxed/simple; bh=nuBpyWDhg01mGE5l/NpZBdUueEbff+jPNB0ll2EAWDs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=chhMK/tIAXX5BjbIgRsJMoY6MbXRnhzXNp8Y/MxfJn0CblCpgUM86xhO2aqcnY/9s1f4SQduSf9Fv0iVZ13UoAs/Z1Z95SDCBU4Z75UYqOLvW/JTxY4OPydbGU/6XVyQM1zB1Calxki90qgKrSgx09QNX05B0ZaEUpjDTjTuT0A= 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=Bpo82Xlo; 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="Bpo82Xlo" 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 592661FC7; Fri, 10 Jul 2026 04:55:58 -0700 (PDT) Received: from e134344.cambridge.arm.com (e134344.arm.com [10.2.212.8]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 64C083F85F; Fri, 10 Jul 2026 04:56:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1783684562; bh=nuBpyWDhg01mGE5l/NpZBdUueEbff+jPNB0ll2EAWDs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Bpo82XloTyfop1H+/X+gjvyK+b+6o4mN8JjbsxDvVKtrkQ08SqcPmDMPnyR+w5tqd 4iSOxN6020bi8CL0Q9g2l847PV2Z0Iog24QeDa5KITH9PfQcCDLaW8DgDQ4QhDgLeO C5PHcqhkZhX6h3z2dXfFq9R/7moDeTjXEOH5r1X8= From: Ben Horgan To: ben.horgan@arm.com Cc: james.morse@arm.com, reinette.chatre@intel.com, fenghuay@nvidia.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, dave.martin@arm.com, andre.przywara@arm.com Subject: [PATCH v1 04/11] arm_mpam: Add missing mon_sel locking in MBWU restore Date: Fri, 10 Jul 2026 12:55:38 +0100 Message-ID: <20260710115546.29644-5-ben.horgan@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260710115546.29644-1-ben.horgan@arm.com> References: <20260710115546.29644-1-ben.horgan@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 The mon_sel_lock is used to protect the mbwu_state, as well as h/w accesses that use MPAMCFG_MON_SEL. However, in mpam_restore_mbwu_state() mbwu_state is accessed without holding the mon_sel_lock. Add the missing locking. Fixes: 41e8a14950e1 ("arm_mpam: Track bandwidth counter state for power management") Signed-off-by: Ben Horgan --- drivers/resctrl/mpam_devices.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c index 11b10c3bc334..b34e2a368516 100644 --- a/drivers/resctrl/mpam_devices.c +++ b/drivers/resctrl/mpam_devices.c @@ -1648,16 +1648,24 @@ static int mpam_restore_mbwu_state(void *_ris) u64 val; struct mon_read mwbu_arg; struct mpam_msc_ris *ris = _ris; + struct mpam_msc *msc = ris->vmsc->msc; struct mpam_class *class = ris->vmsc->comp->class; for (i = 0; i < ris->props.num_mbwu_mon; i++) { + if (WARN_ON_ONCE(!mpam_mon_sel_lock(msc))) + return -EIO; + if (ris->mbwu_state[i].enabled) { mwbu_arg.ris = ris; mwbu_arg.ctx = &ris->mbwu_state[i].cfg; mwbu_arg.type = mpam_msmon_choose_counter(class); mwbu_arg.val = &val; + mpam_mon_sel_unlock(msc); + __ris_msmon_read(&mwbu_arg); + } else { + mpam_mon_sel_unlock(msc); } } -- 2.43.0