linux-kernel - Re: [PATCH v2 11/45] arm64: mpam: Initialise and context switch the MPAMSM

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Message-ID: <20260105172027.0000113c@huawei.com>
Date: Mon, 5 Jan 2026 17:20:27 +0000
From: Jonathan Cameron <jonathan.cameron@...wei.com>
To: Ben Horgan <ben.horgan@....com>
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Subject: Re: [PATCH v2 11/45] arm64: mpam: Initialise and context switch the
 MPAMSM_EL1 register

On Fri, 19 Dec 2025 18:11:13 +0000
Ben Horgan <ben.horgan@....com> wrote:

> The MPAMSM_EL1 sets the MPAM labels, PMG and PARTID, for loads and stores
> generated by a shared SMCU. Disable the traps so the kernel can use it and
> set it to the same configuration as the per-EL cpu MPAM configuration.
> 
> If an SMCU is not shared with other cpus then it is implementation defined
> whether the configuration from MPAMSM_EL1 is used or that from the
> appropriate MPAMy_ELx. As we set the same configuration for MPAM0_EL1,
> MPAM1_EL1 and MPAMSM_EL1 the resulting configuration is the same
> regardless.
Maybe tighten that last sentence up to talk about the matching fields
rather than the 'same configuration'.

Whole bunch of stuff in the first two that aren't in MPAMSM_EL1.
> 
> Signed-off-by: Ben Horgan <ben.horgan@....com>
LGTM
Reviewed-by: Jonathan Cameron <jonathan.cameron@...wei.com>