Re: [PATCH v9] block: Add n64 cart driver

Lauri Kasanen
2021-01-22T18:15:31Z

On Fri, 22 Jan 2021 09:11:20 -0800
Keith Busch <kbusch@kernel.org> wrote:
> Each bio_vec segment is physically contiguous.

What's the official way to get that buffer's physical address? I
couldn't find any driver that does DMA to the bio buffer, to use as an
example. Maybe used wrong keywords.

> > I grepped around, but apparently no driver under drivers/block does
> > direct DMA to the bio buffer. They all use their own buffer and memcpy,
> > like this patch. ps3vram, ps3disk, amiflop, etc etc.
>
> block/brd.c

That uses memcpy, not DMA? It uses the virtual address. I was hoping
for an example that does direct DMA to the bio_data buffer.

- Lauri