[RFC PATCH 2/3] riscv: use VA+PA variant of CMO macros for DMA synchorization
Icenowy Zheng
uwu at icenowy.me
Wed Jan 4 00:59:00 PST 2023
在 2023-01-04星期三的 16:50 +0800,Guo Ren写道:
> On Wed, Jan 4, 2023 at 3:43 PM Icenowy Zheng <uwu at icenowy.me> wrote:
> >
> > DMA synchorization is done on PA and the VA is calculated from the
> > PA.
> >
> > Use the alternative macro variant that takes both VA and PA as
> > parameters, thus in case the ISA extension used support PA
> > directly, the
> > overhead for re-converting VA to PA can be omitted.
> >
> > Suggested-by: Guo Ren <guoren at kernel.org>
> > Signed-off-by: Icenowy Zheng <uwu at icenowy.me>
> > ---
> > arch/riscv/mm/dma-noncoherent.c | 8 ++++----
> > 1 file changed, 4 insertions(+), 4 deletions(-)
> >
> > diff --git a/arch/riscv/mm/dma-noncoherent.c b/arch/riscv/mm/dma-
> > noncoherent.c
> > index d919efab6eba..a751f4aece62 100644
> > --- a/arch/riscv/mm/dma-noncoherent.c
> > +++ b/arch/riscv/mm/dma-noncoherent.c
> > @@ -19,13 +19,13 @@ void arch_sync_dma_for_device(phys_addr_t
> > paddr, size_t size,
> >
> > switch (dir) {
> > case DMA_TO_DEVICE:
> > - ALT_CMO_OP(clean, vaddr, size,
> > riscv_cbom_block_size);
> > + ALT_CMO_OP_VPA(clean, vaddr, paddr, size,
> > riscv_cbom_block_size);
> ALT_CMO_OP -> ALT_CMO_OP_VPA, is the renaming necessary?
I didn't rename the original ALT_CMO_OP, ALT_CMO_OP_VPA is something
new.
>
> Others:
> Reviewed-by: Guo Ren <guoren at kernel.org>
>
> > break;
> > case DMA_FROM_DEVICE:
> > - ALT_CMO_OP(clean, vaddr, size,
> > riscv_cbom_block_size);
> > + ALT_CMO_OP_VPA(clean, vaddr, paddr, size,
> > riscv_cbom_block_size);
> > break;
> > case DMA_BIDIRECTIONAL:
> > - ALT_CMO_OP(flush, vaddr, size,
> > riscv_cbom_block_size);
> > + ALT_CMO_OP_VPA(flush, vaddr, paddr, size,
> > riscv_cbom_block_size);
> > break;
> > default:
> > break;
> > @@ -42,7 +42,7 @@ void arch_sync_dma_for_cpu(phys_addr_t paddr,
> > size_t size,
> > break;
> > case DMA_FROM_DEVICE:
> > case DMA_BIDIRECTIONAL:
> > - ALT_CMO_OP(flush, vaddr, size,
> > riscv_cbom_block_size);
> > + ALT_CMO_OP_VPA(flush, vaddr, paddr, size,
> > riscv_cbom_block_size);
> > break;
> > default:
> > break;
> > --
> > 2.38.1
> >
>
>
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