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x86: gart alloc_coherent does virtual mapppings only when necessary 

gart alloc_coherent need to do virtual mapppings only when an
allocated buffer is not DMA-capable for a device.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
FUJITA Tomonori 2008-09-11 23:08:48 +09:00 committed by Ingo Molnar
parent f10ac8a232
commit f6a32a36ab
1 changed files with 9 additions and 1 deletions
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10
arch/x86/kernel/pci-gart_64.c
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@ -505,15 +505,23 @@ gart_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_addr,
gfp_t flag)
{
void *vaddr;
dma_addr_t paddr;
unsigned long align_mask;
u64 dma_mask = dma_alloc_coherent_mask(dev, flag);
vaddr = (void *)__get_free_pages(flag | __GFP_ZERO, get_order(size));
if (!vaddr)
return NULL;
paddr = virt_to_phys(vaddr);
if (is_buffer_dma_capable(dma_mask, paddr, size)) {
*dma_addr = paddr;
return vaddr;
}
align_mask = (1UL << get_order(size)) - 1;
*dma_addr = dma_map_area(dev, __pa(vaddr), size, DMA_BIDIRECTIONAL,
*dma_addr = dma_map_area(dev, paddr, size, DMA_BIDIRECTIONAL,
align_mask, dma_mask);
flush_gart();