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authorFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>2008-11-17 02:24:34 -0500
committerIngo Molnar <mingo@elte.hu>2008-11-17 03:12:02 -0500
commit1e74f3000b86969de421ca0da08f42e7d21cbd99 (patch)
tree45dd090997526dbe31f0a2ac781195580772067a /lib
parente47411b1f4456480d6c60ebdc7a733e81ccd5d66 (diff)
swiotlb: use coherent_dma_mask in alloc_coherent
Impact: fix DMA buffer allocation coherency bug in certain configs This patch fixes swiotlb to use dev->coherent_dma_mask in swiotlb_alloc_coherent(). coherent_dma_mask is a subset of dma_mask (equal to it most of the time), enumerating the address range that a given device is able to DMA to/from in a cache-coherent way. But currently, swiotlb uses dev->dma_mask in alloc_coherent() implicitly via address_needs_mapping(), but alloc_coherent is really supposed to use coherent_dma_mask. This bug could break drivers that uses smaller coherent_dma_mask than dma_mask (though the current code works for the majority that use the same mask for coherent_dma_mask and dma_mask). Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: tony.luck@intel.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'lib')
-rw-r--r--lib/swiotlb.c10
1 files changed, 7 insertions, 3 deletions
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index 78330c37a61b..5f6c629a924d 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -467,9 +467,13 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size,
467 dma_addr_t dev_addr; 467 dma_addr_t dev_addr;
468 void *ret; 468 void *ret;
469 int order = get_order(size); 469 int order = get_order(size);
470 u64 dma_mask = DMA_32BIT_MASK;
471
472 if (hwdev && hwdev->coherent_dma_mask)
473 dma_mask = hwdev->coherent_dma_mask;
470 474
471 ret = (void *)__get_free_pages(flags, order); 475 ret = (void *)__get_free_pages(flags, order);
472 if (ret && address_needs_mapping(hwdev, virt_to_bus(ret), size)) { 476 if (ret && !is_buffer_dma_capable(dma_mask, virt_to_bus(ret), size)) {
473 /* 477 /*
474 * The allocated memory isn't reachable by the device. 478 * The allocated memory isn't reachable by the device.
475 * Fall back on swiotlb_map_single(). 479 * Fall back on swiotlb_map_single().
@@ -493,9 +497,9 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size,
493 dev_addr = virt_to_bus(ret); 497 dev_addr = virt_to_bus(ret);
494 498
495 /* Confirm address can be DMA'd by device */ 499 /* Confirm address can be DMA'd by device */
496 if (address_needs_mapping(hwdev, dev_addr, size)) { 500 if (!is_buffer_dma_capable(dma_mask, dev_addr, size)) {
497 printk("hwdev DMA mask = 0x%016Lx, dev_addr = 0x%016Lx\n", 501 printk("hwdev DMA mask = 0x%016Lx, dev_addr = 0x%016Lx\n",
498 (unsigned long long)*hwdev->dma_mask, 502 (unsigned long long)dma_mask,
499 (unsigned long long)dev_addr); 503 (unsigned long long)dev_addr);
500 504
501 /* DMA_TO_DEVICE to avoid memcpy in unmap_single */ 505 /* DMA_TO_DEVICE to avoid memcpy in unmap_single */