diff options
author | Alexander Duyck <alexander.h.duyck@intel.com> | 2012-10-15 10:19:39 -0700 |
---|---|---|
committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2012-10-30 09:32:06 -0400 |
commit | e05ed4d1fad9e730995abb08cb9bc3bffac5018b (patch) | |
tree | 72a2662e8b85308bad057c904a5231d890d7fbba /drivers | |
parent | ee3f6ba896c7e62004b677b0018a0b29b9b26472 (diff) | |
download | linux-e05ed4d1fad9e730995abb08cb9bc3bffac5018b.tar.bz2 |
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')
-rw-r--r-- | drivers/xen/swiotlb-xen.c | 22 |
1 files changed, 11 insertions, 11 deletions
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index 58db6df866ef..8a6035aa69c9 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; |