Re: [PATCH 2/3] powerpc: fix build errors

Segher Boessenkool
2022-02-23T16:03:53Z

Hi!

On Wed, Feb 23, 2022 at 02:58:19PM +0100, Anders Roxell wrote:
> Building tinyconfig with gcc (Debian 11.2.0-16) and assembler (Debian
> 2.37.90.20220207) the following build error shows up:
>
> {standard input}: Assembler messages:
> {standard input}:1190: Error: unrecognized opcode: `stbcix'
> {standard input}:1433: Error: unrecognized opcode: `lwzcix'
> {standard input}:1453: Error: unrecognized opcode: `stbcix'
> {standard input}:1460: Error: unrecognized opcode: `stwcix'
> {standard input}:1596: Error: unrecognized opcode: `stbcix'
> ...
>
> Rework to add assembler directives [1] around the instruction. Going
> through the them one by one shows that the changes should be safe. Like
> __get_user_atomic_128_aligned() is only called in p9_hmi_special_emu(),
> which according to the name is specific to power9. And __raw_rm_read*()
> are only called in things that are powernv or book3s_hv specific.

Thanks for doing this.

> + __asm__ __volatile__(".machine \"push\"\n"
> + ".machine \"power6\"\n"
> + "stbcix %0,0,%1\n"
> + ".machine \"pop\"\n"

Just leave out the quotes completely? Assembler is not C, barewords are
normal and expected and better style.

Other than that this looks perfect to me :-)

Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>

Segher