Re: [RFC] generic device DMA implementation

["Adam J. Richter" <adam@yggdrasil.com>]

James Bottomley wrote:
>how about dma_alloc to take two flags

>DRIVER_SUPPORTS_CONSISTENT_ONLY

	It's pretty much impossible not to support consistent memory.

	I'd suggest a shorter name for code readability and particularly
to hint that this is the standard usage.  I'd suggest DMA_CONSISTENT
or "0".

>and

>DRIVER_SUPPORTS_NON_CONSISTENT

	There is a pretty strong convention for medium to short names
in the kernel, although this name will be used much less, so its
length is not as important.  I'd like something that would match the
names of the corresponding cache flushing and invalidation functions.
I think I had previously suggested DMA_MAYBE_CONSISTENT and wmb_maybe
or dma_sync_maybe but I'm not that attached to the "maybe" word.

[...]

>and dma_alloc_consistent to be equivalent to dma_alloc with  
>DRIVER_SUPPORTS_CONSISTENT_ONLY (and hence equivalent to pci_alloc_consistent)

Why have a separate dma_alloc_consistent function?

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