On Thu, Apr 13, 2023 at 7:46 PM Conor Dooley <conor@xxxxxxxxxx> wrote:
>
> > Is
> > dma-noncoherent.c also valid for RISCV-32? If not then we can make
> > pmem.c compile conditionally if DMA non-coherenet is enabled and we
> > make DMA non-coherent depend on 64bit.
>
> Could you drop the {s,l}d in exchange for {s,l}w instead, or am I
> progressing even further into braino territory?
Just the direct exchange wont work in addition shifting + oring to
take care of 64-bit will require. (Correct me if I'm wrong here)
I was wondering now if we need to store/restore the s0 and ra
registers. I stumbled on an X86 implementation which has call [0] in
the ALTERNATIVE_X() macro but here we dont store/restore the
registers. Is the RISC-V implementation of ALT macro different
compared to x86?
[0] https://elixir.bootlin.com/linux/latest/source/arch/x86/include/asm/uaccess_64.h#L105
Cheers,
Prabhakar
