[PATCH v4 07/13] riscv: Implement arch_cmpxchg128() using Zacas

[Andrew Jones]

On Wed, Jul 31, 2024 at 09:23:59AM GMT, Alexandre Ghiti wrote:
> Now that Zacas is supported in the kernel, let's use the double word
> atomic version of amocas to improve the SLUB allocator.
> 
> Note that we have to select fixed registers, otherwise gcc fails to pick
> even registers and then produces a reserved encoding which fails to
> assemble.
> 
> Signed-off-by: Alexandre Ghiti <alexghiti at rivosinc.com>
> ---
>  arch/riscv/Kconfig               |  1 +
>  arch/riscv/include/asm/cmpxchg.h | 38 ++++++++++++++++++++++++++++++++
>  2 files changed, 39 insertions(+)
>

Reviewed-by: Andrew Jones <ajones at ventanamicro.com>