Re: [PATCH v6 2/9] arm64: report address tag when FEAT_MTE_TAGGED_FAR is supported
From: Mark Brown <broonie@kernel.org>
Date: 2025-06-11 11:43:23
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On Wed, Jun 11, 2025 at 10:41:00AM +0100, Yeoreum Yun wrote:
+HWCAP3_MTE_FAR + Functionality implied by ID_AA64PFR2_EL1.MTEFAR == 0b0001.
+Applications should interpret the values of these bits based on +the support for the 'mte_far' hwcap. If the support is not present, +the values of these bits should be considered as undefined otherwise valid.
The constant is HWCAP3_MTE_FAR and the cpuinfo is mtefar:
+ [KERNEL_HWCAP_MTE_FAR] = "mtefar",
The reference to the hwcap should probably be one of these, I'd go for HWCAP3_MTE_FAR since it says hwcap.
/* * The architecture specifies that bits 63:60 of FAR_EL1 are UNKNOWN * for tag check faults. Set them to corresponding bits in the untagged - * address. + * address if ARM64_MTE_FAR isn't supported. + * Otherwise, bits 63:60 of FAR_EL1 are KNOWN.
Should this say UNKNOWN?
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