linux-kernel - Re: [PATCH v2 10/45] arm64: mpam: Add cpu

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20260105170958.00007c32@huawei.com>
Date: Mon, 5 Jan 2026 17:09:58 +0000
From: Jonathan Cameron <jonathan.cameron@...wei.com>
To: Ben Horgan <ben.horgan@....com>
CC: <amitsinght@...vell.com>, <baisheng.gao@...soc.com>,
	<baolin.wang@...ux.alibaba.com>, <carl@...amperecomputing.com>,
	<dave.martin@....com>, <david@...nel.org>, <dfustini@...libre.com>,
	<fenghuay@...dia.com>, <gshan@...hat.com>, <james.morse@....com>,
	<kobak@...dia.com>, <lcherian@...vell.com>,
	<linux-arm-kernel@...ts.infradead.org>, <linux-kernel@...r.kernel.org>,
	<peternewman@...gle.com>, <punit.agrawal@....qualcomm.com>,
	<quic_jiles@...cinc.com>, <reinette.chatre@...el.com>,
	<rohit.mathew@....com>, <scott@...amperecomputing.com>,
	<sdonthineni@...dia.com>, <tan.shaopeng@...itsu.com>,
	<xhao@...ux.alibaba.com>, <catalin.marinas@....com>, <will@...nel.org>,
	<corbet@....net>, <maz@...nel.org>, <oupton@...nel.org>,
	<joey.gouly@....com>, <suzuki.poulose@....com>, <kvmarm@...ts.linux.dev>
Subject: Re: [PATCH v2 10/45] arm64: mpam: Add cpu_pm notifier to restore
 MPAM sysregs

On Fri, 19 Dec 2025 18:11:12 +0000
Ben Horgan <ben.horgan@....com> wrote:

> From: James Morse <james.morse@....com>
> 
> The MPAM system registers will be lost if the CPU is reset during PSCI's
> CPU_SUSPEND.
> 
> Add a PM notifier to restore them.
> 
> mpam_thread_switch(current) can't be used as this won't make any changes if
> the in-memory copy says the register already has the correct value. In
> reality the system register is UNKNOWN out of reset.
> 
> Signed-off-by: James Morse <james.morse@....com>
> Signed-off-by: Ben Horgan <ben.horgan@....com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@...wei.com>