Re: [Linux-ia64] Re: 64 Bits DMA Addresses for Alloc Consistent

James Bottomley
2003-05-17T18:36:01Z

On Fri, 2003-05-16 at 13:18, Russell King wrote:
> Isn't the common use (eg, net devices):
>
> buffer passed from lower levels
>
> map buffer
>
> (device owns buffer)
>
> device uses buffer
>
> unmap buffer
>
> (cpu owns buffer)
>
> free buffer
>
> So, to use your example:
>
> (cpu owns region)
>
> map
>
> (device owns region)
>
> dma_sync...cpu
>
> (cpu owns region)
>
> dma_sync...device
>
> (device owns region)
>
> unmap
>
> (cpu owns region)

A grep through the tree implies that you (for arm) and me (for parisc)
are the only current implementors of the dma_ API.

The only consumers seem to be: lasi_82596, 53c700 and sym53c8xx_comm.h
(all of which I did anyway), and usb/core/usb.c

How would you feel about making this API change? I take it you have a
preference for using _to_cpu and _to_device call variants?

James