[PATCH 00/32] x86/msr: Drop 32-bit MSR interfaces

[Jürgen Groß]

On 29.06.26 10:06, Arnd Bergmann wrote:
> On Mon, Jun 29, 2026, at 09:01, Jürgen Groß wrote:
>> On 29.06.26 08:52, Arnd Bergmann wrote:
>>> On Mon, Jun 29, 2026, at 08:04, Juergen Gross wrote:
>>>
>>> I assume this is fine, but since you don't mention it explicitly here,
>>> please clarify what this means for 32-bit CPUs without the rdmsrq
>>> instruction. Those will continue using the same instructions as before
>>> and just change the calling conventions, right?
>>
>> Yes. I thought this would be clear from the following:
>>
>>     - They are based on primitives using 64-bit sized values anyway.
> 
> Right, that was my reading of it as well, but it's not entirely
> clear when the function name is the same as the mnemonic of an
> instruction that only exists on newer CPUs and the later patch

There is no RDMSRQ instruction on any x86 CPU. Are you mixing this up with
WRMSRNS/RDMSR using an immediate for addressing the MSR?


Juergen
-------------- next part --------------
A non-text attachment was scrubbed...
Name: OpenPGP_0xB0DE9DD628BF132F.asc
Type: application/pgp-keys
Size: 3683 bytes
Desc: OpenPGP public key
URL: <http://lists.infradead.org/pipermail/linux-mtd/attachments/20260629/289c5b79/attachment-0001.bin>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: OpenPGP_signature.asc
Type: application/pgp-signature
Size: 495 bytes
Desc: OpenPGP digital signature
URL: <http://lists.infradead.org/pipermail/linux-mtd/attachments/20260629/289c5b79/attachment-0001.sig>