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author | FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> | 2008-09-24 20:48:37 +0900 |
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committer | Ingo Molnar <mingo@elte.hu> | 2008-09-25 11:02:26 +0200 |
commit | 1d990882153f36723f9e8717c4401689e64c7a36 (patch) | |
tree | e0e09333cf42756d90bf6e8a0e1ae588a852babe /arch/x86/kernel/pci-gart_64.c | |
parent | ecef533ea68b2fb3baaf459beb2f802a240bdb16 (diff) | |
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x86: restore old GART alloc_coherent behavior
Currently, GART alloc_coherent tries to allocate pages with GFP_DMA32
for a device having dma_masks > 24bit < 32bits. If GART gets an
address that a device can't access to, GART try to map the address to
a virtual I/O address that the device can access to.
But Andi pointed out, "The GART is somewhere in the 4GB range so you
cannot use it to map anything < 4GB. Also GART is pretty small."
http://lkml.org/lkml/2008/9/12/43
That is, it's possible that GART doesn't have virtual I/O address
space that a device can access to. The above behavior doesn't work for
a device having dma_masks > 24bit < 32bits.
This patch restores old GART alloc_coherent behavior (before the
alloc_coherent rewrite).
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/pci-gart_64.c')
-rw-r--r-- | arch/x86/kernel/pci-gart_64.c | 43 |
1 files changed, 20 insertions, 23 deletions
diff --git a/arch/x86/kernel/pci-gart_64.c b/arch/x86/kernel/pci-gart_64.c index 7e08e46..25c94fb 100644 --- a/arch/x86/kernel/pci-gart_64.c +++ b/arch/x86/kernel/pci-gart_64.c @@ -487,31 +487,28 @@ static void * 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, paddr, size, DMA_BIDIRECTIONAL, - align_mask); - flush_gart(); - - if (*dma_addr != bad_dma_address) - return vaddr; - - free_pages((unsigned long)vaddr, get_order(size)); + struct page *page; + + if (force_iommu && !(flag & GFP_DMA)) { + flag &= ~(__GFP_DMA | __GFP_HIGHMEM | __GFP_DMA32); + page = alloc_pages(flag | __GFP_ZERO, get_order(size)); + if (!page) + return NULL; + + align_mask = (1UL << get_order(size)) - 1; + paddr = dma_map_area(dev, page_to_phys(page), size, + DMA_BIDIRECTIONAL, align_mask); + + flush_gart(); + if (paddr != bad_dma_address) { + *dma_addr = paddr; + return page_address(page); + } + __free_pages(page, get_order(size)); + } else + return dma_generic_alloc_coherent(dev, size, dma_addr, flag); return NULL; } |