From: Catalin Marinas <catalin.marinas@arm.com>
To: James Morse <james.morse@arm.com>
Cc: linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, zengheng4@huawei.com,
wangkefeng.wang@huawei.com, xry111@xry111.site,
yang@os.amperecomputing.com, reinette.chatre@intel.com,
will@kernel.org, thuth@redhat.com, ben.horgan@arm.com,
mrigendra.chaubey@gmail.com, fenghuay@nvidia.com,
ahmed.genidi@arm.com
Subject: Re: [PATCH v3 3/4] arm64: cpufeature: Add support for the MPAM v0.1 architecture version
Date: Thu, 14 May 2026 15:22:04 +0100 [thread overview]
Message-ID: <agXajDtWt9RmgOXT@arm.com> (raw)
In-Reply-To: <20260508162341.3762549-4-james.morse@arm.com>
On Fri, May 08, 2026 at 05:23:40PM +0100, James Morse wrote:
> From: Zeng Heng <zengheng4@huawei.com>
>
> According to the MPAM spec [1], the supported architecture versions are
> v1.0, v1.1 and v0.1. MPAM versions v0.1 and v1.1 are functionally
> identical, but v0.1 additionally supports the FORCE_NS feature.
>
> ID_AA64PR | ID_AA64PR | MPAM Extension | Notes
> F0_EL1. | F1_EL1. | Architecture |
> MPAM | MPAM_frac | version |
> ---------------------------------------------------------------------------
> 0b0000 | 0b0001 | v0.1 | MPAM v0.1 is implemented.
> | | | MPAM v0.1 is the same as MPAM v1.1
> | | | with FORCE_NS which is
> | | | incompatible with MPAM v1.0.
> ---------------------------------------------------------------------------
> 0b0001 | 0b0000 | v1.0 | MPAM v1.0 is implemented.
> ---------------------------------------------------------------------------
> 0b0001 | 0b0001 | v1.1 | MPAM v1.1 is implemented.
> | | | MPAM v1.1 includes all features of
> | | | MPAM v1.0.
> | | | It must not include FORCE_NS.
>
> FORCE_NS is a feature that operates in EL3 mode. Consequently, the current
> Linux MPAM driver is also compatible with MPAM v0.1. To support v0.1, the
> existing driver which only checks ID_AA64PFR0_EL1.MPAM for the major
> version needs to examine ID_AA64PFR1_EL1.MPAM_frac for the minor version
> as well.
>
> [1] https://developer.arm.com/documentation/ddi0598/db/?lang=en
>
> Signed-off-by: Zeng Heng <zengheng4@huawei.com>
> Reviewed-by: James Morse <james.morse@arm.com>
> Signed-off-by: James Morse <james.morse@arm.com>
Not sure how this will go in for 7.2, so:
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
next prev parent reply other threads:[~2026-05-14 14:22 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-08 16:23 [PATCH v3 0/4] arm_mpam: Add support for the MPAM v0.1 architecture version James Morse
2026-05-08 16:23 ` [PATCH v3 1/4] arm_mpam: Fix false positive assert failure during mpam_disable() James Morse
2026-05-11 11:19 ` Ben Horgan
2026-05-08 16:23 ` [PATCH v3 2/4] arm_mpam: Check whether the config array is allocated before destroying it James Morse
2026-05-11 11:23 ` Ben Horgan
2026-05-08 16:23 ` [PATCH v3 3/4] arm64: cpufeature: Add support for the MPAM v0.1 architecture version James Morse
2026-05-14 14:22 ` Catalin Marinas [this message]
2026-05-08 16:23 ` [PATCH v3 4/4] arm_mpam: Update architecture version check for MPAM MSC James Morse
2026-05-08 16:35 ` Ben Horgan
2026-05-09 6:26 ` Zeng Heng
2026-05-14 14:08 ` (subset) [PATCH v3 0/4] arm_mpam: Add support for the MPAM v0.1 architecture version Catalin Marinas
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