Re: [PATCH v10 2/2] riscv: Add runtime constant support

[Klara Modin <klarasmodin@gmail.com>]

Hi Alex,

On 3/28/25 18:35, Alexandre Ghiti wrote:
> Hi Klara,
> 
> On Fri, Mar 28, 2025 at 4:42 PM Klara Modin <klarasmodin@gmail.com> wrote:
>>
>> Hi,
>>
>> On 3/19/25 19:35, Charlie Jenkins wrote:
>>> Implement the runtime constant infrastructure for riscv. Use this
>>> infrastructure to generate constants to be used by the d_hash()
>>> function.
>>>
>>> This is the riscv variant of commit 94a2bc0f611c ("arm64: add 'runtime
>>> constant' support") and commit e3c92e81711d ("runtime constants: add
>>> x86 architecture support").
>>
>> This patch causes the following build failure for me:
>>
>> fs/dcache.c: Assembler messages:
>> fs/dcache.c:157: Error: attempt to move .org backwards
>> fs/dcache.c:157: Error: attempt to move .org backwards
>> fs/dcache.c:157: Error: attempt to move .org backwards
>> fs/dcache.c:157: Error: attempt to move .org backwards
>> fs/dcache.c:157: Error: attempt to move .org backwards
>> make[3]: *** [scripts/Makefile.build:203: fs/dcache.o] Error 1
>>
>> The value of CONFIG_RISCV_ISA_ZBKB doesn't seem to have an impact.
>> Reverting the patch on top of next-20250328 resolved the issue for me. I
>> attached the generated fs/dcache.s.
> 
> Thanks for your report!
> 
> Kernel test robot reported the following issue, do you have the same errors?
> 
>     fs/dcache.c: Assembler messages:
>>> fs/dcache.c:143: Warning: Unrecognized .option directive: arch,+zba
> --
>>> fs/dcache.c:145: Error: unrecognized opcode `add.uw s1,s1,a5'
>>> fs/dcache.c:143: Warning: Unrecognized .option directive: arch,+zba
> --
>>> fs/dcache.c:145: Error: unrecognized opcode `add.uw a4,a4,a5'
>>> fs/dcache.c:143: Warning: Unrecognized .option directive: arch,+zba
> --
>>> fs/dcache.c:145: Error: unrecognized opcode `add.uw s4,s4,a5'
>>> fs/dcache.c:143: Warning: Unrecognized .option directive: arch,+zba
> --
>>> fs/dcache.c:145: Error: unrecognized opcode `add.uw s1,s1,a5'
>>> fs/dcache.c:152: Error: attempt to move .org backwards
>>> fs/dcache.c:152: Error: attempt to move .org backwards
>>> fs/dcache.c:152: Error: attempt to move .org backwards
>>> fs/dcache.c:152: Error: attempt to move .org backwards
> 
>   If so, I sent a fix, don't hesitate to add your Tested-by:
> https://lore.kernel.org/linux-riscv/c0f425ec-6c76-45b2-b1bc-8d9be028a878@rivosinc.com/T/#me1469bfb2e6f69e1422a136014b753a6acaa3bc6

I only saw the attempt to move .org backwards error. I'm using binutils 
2.44 and a GCC 15 snapshot from 2025-03-23 so I don't think the 
toolchain support for zba should be the issue. The fix didn't make any 
difference for me.

However, it seems this could be something in GCC 15 as when I retried 
with GCC 14.2 and 12.4 I could no longer see the issue.

Regards,
Klara Modin

> 
> Thanks,
> 
> Alex
> 
> 
>>
>> Please let me know if there's anything else you need.
>>
>> Regards,
>> Klara Modin
>>