| Message ID | 20171229081911.2802-27-hch@lst.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 29/12/17 08:18, Christoph Hellwig wrote: > This means it uses whatever linear remapping scheme that the architecture > provides is used in the generic dma_direct ops. > > Signed-off-by: Christoph Hellwig <hch@lst.de> > --- > lib/dma-direct.c | 18 +++++++----------- > 1 file changed, 7 insertions(+), 11 deletions(-) > > diff --git a/lib/dma-direct.c b/lib/dma-direct.c > index 439db40854b7..0e087650e86b 100644 > --- a/lib/dma-direct.c > +++ b/lib/dma-direct.c > @@ -1,12 +1,11 @@ > // SPDX-License-Identifier: GPL-2.0 > /* > - * lib/dma-noop.c > - * > - * DMA operations that map to physical addresses without flushing memory. > + * DMA operations that map physical memory directly without using an IOMMU or > + * flushing caches. > */ > #include <linux/export.h> > #include <linux/mm.h> > -#include <linux/dma-mapping.h> > +#include <linux/dma-direct.h> > #include <linux/scatterlist.h> > #include <linux/pfn.h> > > @@ -17,7 +16,7 @@ static void *dma_direct_alloc(struct device *dev, size_t size, > > ret = (void *)__get_free_pages(gfp, get_order(size)); > if (ret) > - *dma_handle = virt_to_phys(ret) - PFN_PHYS(dev->dma_pfn_offset); > + *dma_handle = phys_to_dma(dev, virt_to_phys(ret)); > > return ret; > } > @@ -32,7 +31,7 @@ static dma_addr_t dma_direct_map_page(struct device *dev, struct page *page, > unsigned long offset, size_t size, enum dma_data_direction dir, > unsigned long attrs) > { > - return page_to_phys(page) + offset - PFN_PHYS(dev->dma_pfn_offset); > + return phys_to_dma(dev, page_to_phys(page)) + offset; > } > > static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, > @@ -42,12 +41,9 @@ static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, > struct scatterlist *sg; > > for_each_sg(sgl, sg, nents, i) { > - dma_addr_t offset = PFN_PHYS(dev->dma_pfn_offset); > - void *va; > - > BUG_ON(!sg_page(sg)); > - va = sg_virt(sg); > - sg_dma_address(sg) = (dma_addr_t)virt_to_phys(va) - offset; > + > + sg_dma_address(sg) = phys_to_dma(dev, sg_phys(sg)); > sg_dma_len(sg) = sg->length; > } > > From ARM NOMMU perspective Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com> Thanks Vladimir
diff --git a/lib/dma-direct.c b/lib/dma-direct.c index 439db40854b7..0e087650e86b 100644 --- a/lib/dma-direct.c +++ b/lib/dma-direct.c @@ -1,12 +1,11 @@ // SPDX-License-Identifier: GPL-2.0 /* - * lib/dma-noop.c - * - * DMA operations that map to physical addresses without flushing memory. + * DMA operations that map physical memory directly without using an IOMMU or + * flushing caches. */ #include <linux/export.h> #include <linux/mm.h> -#include <linux/dma-mapping.h> +#include <linux/dma-direct.h> #include <linux/scatterlist.h> #include <linux/pfn.h> @@ -17,7 +16,7 @@ static void *dma_direct_alloc(struct device *dev, size_t size, ret = (void *)__get_free_pages(gfp, get_order(size)); if (ret) - *dma_handle = virt_to_phys(ret) - PFN_PHYS(dev->dma_pfn_offset); + *dma_handle = phys_to_dma(dev, virt_to_phys(ret)); return ret; } @@ -32,7 +31,7 @@ static dma_addr_t dma_direct_map_page(struct device *dev, struct page *page, unsigned long offset, size_t size, enum dma_data_direction dir, unsigned long attrs) { - return page_to_phys(page) + offset - PFN_PHYS(dev->dma_pfn_offset); + return phys_to_dma(dev, page_to_phys(page)) + offset; } static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, @@ -42,12 +41,9 @@ static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, struct scatterlist *sg; for_each_sg(sgl, sg, nents, i) { - dma_addr_t offset = PFN_PHYS(dev->dma_pfn_offset); - void *va; - BUG_ON(!sg_page(sg)); - va = sg_virt(sg); - sg_dma_address(sg) = (dma_addr_t)virt_to_phys(va) - offset; + + sg_dma_address(sg) = phys_to_dma(dev, sg_phys(sg)); sg_dma_len(sg) = sg->length; }
This means it uses whatever linear remapping scheme that the architecture provides is used in the generic dma_direct ops. Signed-off-by: Christoph Hellwig <hch@lst.de> --- lib/dma-direct.c | 18 +++++++----------- 1 file changed, 7 insertions(+), 11 deletions(-)