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Date: Thu, 5 Feb 2026 16:54:22 +0000
From: Catalin Marinas <catalin.marinas@arm.com>
To: Ben Horgan <ben.horgan@arm.com>
Cc: amitsinght@marvell.com, baisheng.gao@unisoc.com,
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	Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Subject: Re: [PATCH v4 08/41] arm64: mpam: Add cpu_pm notifier to restore
 MPAM sysregs
Message-ID: <aYTLPqpRmwDap6fM@arm.com>
References: <20260203214342.584712-1-ben.horgan@arm.com>
 <20260203214342.584712-9-ben.horgan@arm.com>
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In-Reply-To: <20260203214342.584712-9-ben.horgan@arm.com>

On Tue, Feb 03, 2026 at 09:43:09PM +0000, Ben Horgan wrote:
> From: James Morse <james.morse@arm.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.
> 
> Tested-by: Gavin Shan <gshan@redhat.com>
> Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
> Tested-by: Peter Newman <peternewman@google.com>
> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
> Reviewed-by: Gavin Shan <gshan@redhat.com>
> Signed-off-by: James Morse <james.morse@arm.com>
> Signed-off-by: Ben Horgan <ben.horgan@arm.com>

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>