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authorAlexander Duyck <alexander.h.duyck@intel.com>2012-10-15 10:19:39 -0700
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2012-10-30 09:32:06 -0400
commite05ed4d1fad9e730995abb08cb9bc3bffac5018b (patch)
tree72a2662e8b85308bad057c904a5231d890d7fbba /drivers/xen
parentee3f6ba896c7e62004b677b0018a0b29b9b26472 (diff)
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swiotlb: Return physical addresses when calling swiotlb_tbl_map_single
This change makes it so that swiotlb_tbl_map_single will return a physical address instead of a virtual address when called. The advantage to this once again is that we are avoiding a number of virt_to_phys and phys_to_virt translations by working with everything as a physical address. One change I had to make in order to support using physical addresses is that I could no longer trust 0 to be a invalid physical address on all platforms. So instead I made it so that ~0 is returned on error. This should never be a valid return value as it implies that only one byte would be available for use. In order to clarify things since we now have 2 physical addresses in use inside of swiotlb_tbl_map_single I am renaming phys to orig_addr, and dma_addr to tlb_addr. This way is should be clear that orig_addr is contained within io_orig_addr and tlb_addr is an address within the io_tlb_addr buffer. Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'drivers/xen')
-rw-r--r--drivers/xen/swiotlb-xen.c22
1 files changed, 11 insertions, 11 deletions
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 58db6df..8a6035a 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -338,9 +338,8 @@ dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page,
enum dma_data_direction dir,
struct dma_attrs *attrs)
{
- phys_addr_t phys = page_to_phys(page) + offset;
+ phys_addr_t map, phys = page_to_phys(page) + offset;
dma_addr_t dev_addr = xen_phys_to_bus(phys);
- void *map;
BUG_ON(dir == DMA_NONE);
/*
@@ -356,16 +355,16 @@ dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page,
* Oh well, have to allocate and map a bounce buffer.
*/
map = swiotlb_tbl_map_single(dev, start_dma_addr, phys, size, dir);
- if (!map)
+ if (map == SWIOTLB_MAP_ERROR)
return DMA_ERROR_CODE;
- dev_addr = xen_virt_to_bus(map);
+ dev_addr = xen_phys_to_bus(map);
/*
* Ensure that the address returned is DMA'ble
*/
if (!dma_capable(dev, dev_addr, size)) {
- swiotlb_tbl_unmap_single(dev, map, size, dir);
+ swiotlb_tbl_unmap_single(dev, phys_to_virt(map), size, dir);
dev_addr = 0;
}
return dev_addr;
@@ -494,11 +493,12 @@ xen_swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
if (swiotlb_force ||
!dma_capable(hwdev, dev_addr, sg->length) ||
range_straddles_page_boundary(paddr, sg->length)) {
- void *map = swiotlb_tbl_map_single(hwdev,
- start_dma_addr,
- sg_phys(sg),
- sg->length, dir);
- if (!map) {
+ phys_addr_t map = swiotlb_tbl_map_single(hwdev,
+ start_dma_addr,
+ sg_phys(sg),
+ sg->length,
+ dir);
+ if (map == SWIOTLB_MAP_ERROR) {
/* Don't panic here, we expect map_sg users
to do proper error handling. */
xen_swiotlb_unmap_sg_attrs(hwdev, sgl, i, dir,
@@ -506,7 +506,7 @@ xen_swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
sgl[0].dma_length = 0;
return DMA_ERROR_CODE;
}
- sg->dma_address = xen_virt_to_bus(map);
+ sg->dma_address = xen_phys_to_bus(map);
} else
sg->dma_address = dev_addr;
sg->dma_length = sg->length;
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