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authorAkinobu Mita <akinobu.mita@gmail.com>2014-06-04 16:06:50 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-06-04 16:53:57 -0700
commit9c5a3621427da68afe6a078cadf807d2c8cc1d12 (patch)
treeb56df6020a1b966544dbb2b9f119bd883405e5a4 /lib
parentd92ef66c4f8fdf7a24736b1ab6c48d32de9bfc07 (diff)
x86: enable DMA CMA with swiotlb
The DMA Contiguous Memory Allocator support on x86 is disabled when swiotlb config option is enabled. So DMA CMA is always disabled on x86_64 because swiotlb is always enabled. This attempts to support for DMA CMA with enabling swiotlb config option. The contiguous memory allocator on x86 is integrated in the function dma_generic_alloc_coherent() which is .alloc callback in nommu_dma_ops for dma_alloc_coherent(). x86_swiotlb_alloc_coherent() which is .alloc callback in swiotlb_dma_ops tries to allocate with dma_generic_alloc_coherent() firstly and then swiotlb_alloc_coherent() is called as a fallback. The main part of supporting DMA CMA with swiotlb is that changing x86_swiotlb_free_coherent() which is .free callback in swiotlb_dma_ops for dma_free_coherent() so that it can distinguish memory allocated by dma_generic_alloc_coherent() from one allocated by swiotlb_alloc_coherent() and release it with dma_generic_free_coherent() which can handle contiguous memory. This change requires making is_swiotlb_buffer() global function. This also needs to change .free callback in the dma_map_ops for amd_gart and sta2x11, because these dma_ops are also using dma_generic_alloc_coherent(). Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Acked-by: Marek Szyprowski <m.szyprowski@samsung.com> Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Don Dutile <ddutile@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/swiotlb.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index b604b831f4d..649d097853a 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -374,7 +374,7 @@ void __init swiotlb_free(void)
io_tlb_nslabs = 0;
}
-static int is_swiotlb_buffer(phys_addr_t paddr)
+int is_swiotlb_buffer(phys_addr_t paddr)
{
return paddr >= io_tlb_start && paddr < io_tlb_end;
}