Re: [RFC] generic device DMA implementation

[James Bottomley]

[e-mail] said:
> How is the driver supposed to tell whether a given dma_addr_t value
> represents consistent memory or not?  It seems like an (arch-specific)
> `dma_addr_is_consistent' function is necessary, but I couldn't see one
> in your patch. 

well, the patch was only for x86, which is fully consistent.  For parisc, that 
becomes a field for the dma accessor functions.

However, even on parisc, the (supported) machines are either entirely 
consistent or entirely inconsistent.

If you have a machine that has both consistent and inconsistent blocks, you 
need to encode that in dma_addr_t (which is a platform definable type).

The sync functions would just decode the type and either nop or perform the 
sync.

James