Messages in this thread | | | From | Arnd Bergmann <> | Date | Thu, 13 Jan 2022 12:47:34 +0100 | Subject | Re: [PATCH 1/2] arm64: Add Cortex-X2 CPU part definition |
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On Thu, Jan 13, 2022 at 4:03 AM Anshuman Khandual <anshuman.khandual@arm.com> wrote: > On 1/12/22 4:20 PM, Arnd Bergmann wrote: > > On Wed, Jan 12, 2022 at 10:34 AM Anshuman Khandual <anshuman.khandual@arm.com> wrote: > >> Add the CPU Partnumbers for the new Arm designs. > >> @@ -74,6 +74,7 @@ > >> #define ARM_CPU_PART_NEOVERSE_N1 0xD0C > >> #define ARM_CPU_PART_CORTEX_A77 0xD0D > >> #define ARM_CPU_PART_CORTEX_A710 0xD47 > >> +#define ARM_CPU_PART_CORTEX_X2 0xD48 > >> #define ARM_CPU_PART_NEOVERSE_N2 0xD49 > > > > No objections to the patch, but would it be possible to just add all the missing > > ones here to the degree that they are known already? I don't see any entries for > > Cortex-A34, Cortex-A65AE, Cortex-A78, Cortex-A78C, Cortex-A78AE, > > Neoverse-E1, Neoverse-V1, Cortex-X1, Cortex-X2, Cortex-A510, Cortex-A710 > > and Cortex-R82 among the Arm-designed cores that can run Linux, and there > > are probably others that I missed going through the list. > > Hi Arnd, > > IIUC the part numbers are enumerated here only if there is an errata > applicable for them which needs to be detected at boot. I am not sure > whether all cpu versions that can run Linux, needs to be defined here. > But then I might be missing something.
They clearly don't need to be defined here, and for other constants such as the system registers we may not want to list them all, but I think for the CPU IDs it makes sense to just list them all here rather than adding them one at a time, as we tend to need them sooner or later anyway.
It also helps me personally to have a known place to look up the names by value rather than chasing through reference manuals.
Arnd
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