Re: can device drivers return non-ram via vm_ops->nopage?
From: Jeff Garzik
Date: Sun Mar 21 2004 - 18:24:17 EST
Linus Torvalds wrote:
In fact, on a lot of architectures (well, at least x86, and likely
anything else that doesn't use any IOTLB and just allocates a chunk of
physical memory), I think the "map_dma_coherent()" thing should basically
just become a "remap_page_range()". Ie something like
#define map_dma_coherent(vma, vaddr, len) \
remap_page_range(vma, vma->vm_start, __pa(vaddr), len, vma->vm_page_prot)
for the simple case.
That would be nice, though the reason I avoided remap_page_range() in
via82cxxx_audio is that it discourages S/G. Because remap_page_range()
is easier and more portable, several drivers allocate one-big-area and
then create an S/G list describing individual portions of that area.
I want to avoid that. Most decent h/w is s/g these days.
Jeff
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