[PATCH 03/04] Freescale Ethernet combined driver

[Rune Torgersen]

> > What's the recommended function to call to go from a
> > virtual -> physical address, but without doing a cache
> > flush/invalidate?
> 
> There is no generic function to do that in a driver since
> no mainstream drivers in the kernel need to do it. Generally
> you can rework the driver such that you cache the DMA address
> as Dan suggested already.  I don't know your exact usage, however,
> you can allocate memory with dma_alloc_noncoherent() that is
> cached on ppc32 NOT_CACHE_COHERENT prcoessors and stash the
> dma_addr_t/void * for later use. The other way is to kmalloc and
> dma_map_single() (stashing the same way) which is basically the
> same thing.

For 8xx/82xx (and other PQ cpus) there is a lot of drivers liberally
using
__pa and __va to get physical and virtual adresses for structures and
buffer descriptor tables for the CPM.

What would the preferred way of handling both of these be?
__pa() -> dma_map_single() ?

__va() -> ?