Hi Mark, > > +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. Just for confirmation. so change to "mtefar" -> "mte_far" Am I missing? -- Sincerely, Yeoreum Yun ________________________________________ From: Mark Brown Sent: Wednesday, June 11, 2025 12:43 To: Yeo Reum Yun Cc: Catalin Marinas; pcc@xxxxxxxxxx; will@xxxxxxxxxx; Anshuman Khandual; Joey Gouly; Yury Khrustalev; maz@xxxxxxxxxx; oliver.upton@xxxxxxxxx; frederic@xxxxxxxxxx; akpm@xxxxxxxxxxxxxxxxxxxx; surenb@xxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linux-doc@xxxxxxxxxxxxxxx Subject: Re: [PATCH v6 2/9] arm64: report address tag when FEAT_MTE_TAGGED_FAR is supported 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? I think KNOWN is corret since this is Otherwise case (when MET_FAR is supported). Thanks.
