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From: Ben Horgan <ben.horgan@arm.com>
To: Ping Li <leeonion.muyu@gmail.com>, james.morse@arm.com
Cc: linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org, reinette.chatre@intel.com,
	fenghuay@nvidia.com
Subject: Re: [PATCH] arm_mpam: Only program MATCH_PMG when the monitor supports it
Date: Tue, 3 Nov 2026 11:57:10 +0000	[thread overview]
Message-ID: <c6213995-fa80-40ab-a5ea-5d1072e70ad2@arm.com> (raw)
In-Reply-To: <20261103095526.238470-1-leeonion.muyu@gmail.com>

Hi Ping,

On 03/11/2026 09:55, Ping Li wrote:
> Hi Ben,
> 
> Sharing the outcome of our discussions with the hardware team and Arm
> support, to close this thread:
> 
> Although the MPAM specification allows up to 8 bits of PMG, our
> hardware team found that the DSU120AE and the Cortex-A520 only
> propagate 1 bit of PMG. Assuming 1 bit was as good as none, and
> without consulting the software team, they considered the 2 monitor
> groups it would allow dispensable. So the MSC they designed
> implements MSMON but no PMG support, and the bus carries PARTID only,
> without the PMG bit.

Thanks for sharing this information. 1 bit of PMG is common because
until recently CHI didn't allow more.

Ben

> 
> Sorry for the noise again on this one, and thanks for the pointers.
> 
> Ping


      reply	other threads:[~2026-11-03 11:57 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-11-02  7:13 Ping Li
2026-11-02  9:46 ` Ben Horgan
2026-11-02 12:05   ` Ping Li
2026-11-03  2:37   ` Ping Li
2026-11-03 11:50     ` Ben Horgan
2026-11-03  9:55   ` Ping Li
2026-11-03 11:57     ` Ben Horgan [this message]

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