Re: [PATCH v7 09/11] riscv: cpufeature: Introduce ISA bases bitmap and rva23u64 detection

[Guodong Xu]

Hi Conor,

On Tue, 15 Sep 2026 17:52:23 +0100, Conor Dooley wrote:
> On Tue, Sep 15, 2026 at 03:15:35AM -0400, Guodong Xu wrote:
>> Introduce a per-hart and host-wide bitmap of conformant ISA "bases"
>> (named profile-class sets such as IMA and RVA23U64), computed at init
>> time by riscv_init_isa_bases().
>>
>> Register riscv_init_isa_bases() as an arch_initcall. That is late
>> enough that core_initcall(tagged_addr_init) has probed senvcfg.PMM and
>> populated have_user_pmlen_*; without that ordering,
>> riscv_have_user_pmlen(7) would still return its default false and the
>> RVA23U64 detection path would always bail. It is also early enough that
>> arch_initcall_sync(init_hwprobe_vdso_data) finds the bases populated
>> when it snapshots the hwprobe values into the vDSO data page.
>>
>> Consider this as the cache that subsequent consumers (hwprobe's
>> RVA23U64 base behavior bit, /proc/cpuinfo's "isa bases" lines, etc.)
>> can read without recomputing, which keeps them consistent with
>> each other.
>>
>> Signed-off-by: Andrew Jones <andrew.jones@xxxxxxxxxxxxxxxx>
>> Signed-off-by: Guodong Xu <guodong.xu@xxxxxxxxxxxxxxxx>
>
> Something is wrong here with the signoffs here, Drew's probably missing
> either authorship or a Co-developed-by tag?

Thanks for the review. Yes, will fix in v8.

I didn't look closely enough at authorship (which I should) when I
reworked Drew's RFC into v2. His Signed-off-by was carried over, but
clearly it needed more careful handling than that.

Rechecking these three patches that came over from the RFC (09, 10, 11),
here is what I plan to do:

- Patch 10/11 (cpuinfo) is still mostly Drew's patch; I only switched it
  to the cached bitmap. v8 makes him the author.
- Patch 09/11 and 11/11 were rewritten in v2 (the detection moved out of
  hwprobe into cpufeature), but part of Drew's implementation stayed.
  I'll adds his Co-developed-by in v8.

Drew, please shout if you would like this split differently.

Guodong