Messages in this thread | | | Subject | Re: [PATCH 2/3] swiotlb: prefix dma_to_phys and phys_to_dma functions | From | Robin Murphy <> | Date | Fri, 18 Mar 2016 12:12:10 +0000 |
| |
On 17/03/16 22:02, Sinan Kaya wrote: > Prefixing dma_to_phys and phys_to_dma API with swiotlb so that > they are no longer part of the DMA API. These APIs do not exist > on all architectures and breaks compatibility. > > In preparation for the clean up, also make the ARCH implementation > known by defining swiotlb_phys_do_dma and swiotlb_dma_to_phys. > > Signed-off-by: Sinan Kaya <okaya@codeaurora.org> > --- > arch/arm/include/asm/dma-mapping.h | 8 ++- > arch/arm64/include/asm/dma-mapping.h | 9 ++- > arch/arm64/mm/dma-mapping.c | 75 ++++++++++++++--------
[...]
> diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c > index a6e757c..ada00c3 100644 > --- a/arch/arm64/mm/dma-mapping.c > +++ b/arch/arm64/mm/dma-mapping.c > @@ -107,7 +107,7 @@ static void *__dma_alloc_coherent(struct device *dev, size_t size, > if (!page) > return NULL; > > - *dma_handle = phys_to_dma(dev, page_to_phys(page)); > + *dma_handle = swiotlb_phys_to_dma(dev, page_to_phys(page)); > addr = page_address(page); > memset(addr, 0, size); > return addr; > @@ -121,7 +121,7 @@ static void __dma_free_coherent(struct device *dev, size_t size, > struct dma_attrs *attrs) > { > bool freed; > - phys_addr_t paddr = dma_to_phys(dev, dma_handle); > + phys_addr_t paddr = swiotlb_dma_to_phys(dev, dma_handle); > > if (dev == NULL) { > WARN_ONCE(1, "Use an actual device structure for DMA allocation\n"); > @@ -151,7 +151,8 @@ static void *__dma_alloc(struct device *dev, size_t size, > void *addr = __alloc_from_pool(size, &page, flags); > > if (addr) > - *dma_handle = phys_to_dma(dev, page_to_phys(page)); > + *dma_handle = swiotlb_phys_to_dma(dev, > + page_to_phys(page)); > > return addr; > } > @@ -187,7 +188,7 @@ static void __dma_free(struct device *dev, size_t size, > void *vaddr, dma_addr_t dma_handle, > struct dma_attrs *attrs) > { > - void *swiotlb_addr = phys_to_virt(dma_to_phys(dev, dma_handle)); > + void *swiotlb_addr = phys_to_virt(swiotlb_dma_to_phys(dev, dma_handle)); > > size = PAGE_ALIGN(size); > > @@ -208,7 +209,8 @@ static dma_addr_t __swiotlb_map_page(struct device *dev, struct page *page, > > dev_addr = swiotlb_map_page(dev, page, offset, size, dir, attrs); > if (!is_device_dma_coherent(dev)) > - __dma_map_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir); > + __dma_map_area(phys_to_virt(swiotlb_dma_to_phys(dev, dev_addr)), > + size, dir); > > return dev_addr; > } > @@ -218,8 +220,11 @@ static void __swiotlb_unmap_page(struct device *dev, dma_addr_t dev_addr, > size_t size, enum dma_data_direction dir, > struct dma_attrs *attrs) > { > - if (!is_device_dma_coherent(dev)) > - __dma_unmap_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir); > + if (!is_device_dma_coherent(dev)) { > + phys_addr_t phys = swiotlb_dma_to_phys(dev, dev_addr); > + > + __dma_unmap_area(phys_to_virt(phys), size, dir); > + } > swiotlb_unmap_page(dev, dev_addr, size, dir, attrs); > } > > @@ -232,9 +237,12 @@ static int __swiotlb_map_sg_attrs(struct device *dev, struct scatterlist *sgl, > > ret = swiotlb_map_sg_attrs(dev, sgl, nelems, dir, attrs); > if (!is_device_dma_coherent(dev)) > - for_each_sg(sgl, sg, ret, i) > - __dma_map_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)), > - sg->length, dir); > + for_each_sg(sgl, sg, ret, i) { > + dma_addr_t dma = sg->dma_address; > + phys_addr_t phys = swiotlb_dma_to_phys(dev, dma); > + > + __dma_map_area(phys_to_virt(phys), sg->length, dir); > + } > > return ret; > } > @@ -248,9 +256,12 @@ static void __swiotlb_unmap_sg_attrs(struct device *dev, > int i; > > if (!is_device_dma_coherent(dev)) > - for_each_sg(sgl, sg, nelems, i) > - __dma_unmap_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)), > - sg->length, dir); > + for_each_sg(sgl, sg, nelems, i) { > + dma_addr_t dma = sg->dma_address; > + phys_addr_t phys = swiotlb_dma_to_phys(dev, dma); > + > + __dma_unmap_area(phys_to_virt(phys), sg->length, dir); > + } > swiotlb_unmap_sg_attrs(dev, sgl, nelems, dir, attrs); > } > > @@ -258,8 +269,11 @@ static void __swiotlb_sync_single_for_cpu(struct device *dev, > dma_addr_t dev_addr, size_t size, > enum dma_data_direction dir) > { > - if (!is_device_dma_coherent(dev)) > - __dma_unmap_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir); > + if (!is_device_dma_coherent(dev)) { > + phys_addr_t phys = swiotlb_dma_to_phys(dev, dev_addr); > + > + __dma_unmap_area(phys_to_virt(phys), size, dir); > + } > swiotlb_sync_single_for_cpu(dev, dev_addr, size, dir); > } > > @@ -269,7 +283,8 @@ static void __swiotlb_sync_single_for_device(struct device *dev, > { > swiotlb_sync_single_for_device(dev, dev_addr, size, dir); > if (!is_device_dma_coherent(dev)) > - __dma_map_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir); > + __dma_map_area(phys_to_virt(swiotlb_dma_to_phys(dev, dev_addr)), > + size, dir); > } > > static void __swiotlb_sync_sg_for_cpu(struct device *dev, > @@ -280,9 +295,12 @@ static void __swiotlb_sync_sg_for_cpu(struct device *dev, > int i; > > if (!is_device_dma_coherent(dev)) > - for_each_sg(sgl, sg, nelems, i) > - __dma_unmap_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)), > - sg->length, dir); > + for_each_sg(sgl, sg, nelems, i) { > + dma_addr_t dma = sg->dma_address; > + phys_addr_t phys = swiotlb_dma_to_phys(dev, dma); > + > + __dma_unmap_area(phys_to_virt(phys), sg->length, dir); > + } > swiotlb_sync_sg_for_cpu(dev, sgl, nelems, dir); > } > > @@ -295,9 +313,12 @@ static void __swiotlb_sync_sg_for_device(struct device *dev, > > swiotlb_sync_sg_for_device(dev, sgl, nelems, dir); > if (!is_device_dma_coherent(dev)) > - for_each_sg(sgl, sg, nelems, i) > - __dma_map_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)), > - sg->length, dir); > + for_each_sg(sgl, sg, nelems, i) { > + dma_addr_t dma = sg->dma_address; > + phys_addr_t phys = swiotlb_dma_to_phys(dev, dma); > + > + __dma_map_area(phys_to_virt(phys), sg->length, dir); > + } > } > > static int __swiotlb_mmap(struct device *dev, > @@ -309,7 +330,7 @@ static int __swiotlb_mmap(struct device *dev, > unsigned long nr_vma_pages = (vma->vm_end - vma->vm_start) >> > PAGE_SHIFT; > unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT; > - unsigned long pfn = dma_to_phys(dev, dma_addr) >> PAGE_SHIFT; > + unsigned long pfn = swiotlb_dma_to_phys(dev, dma_addr) >> PAGE_SHIFT; > unsigned long off = vma->vm_pgoff; > > vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot, > @@ -334,9 +355,11 @@ static int __swiotlb_get_sgtable(struct device *dev, struct sg_table *sgt, > { > int ret = sg_alloc_table(sgt, 1, GFP_KERNEL); > > - if (!ret) > - sg_set_page(sgt->sgl, phys_to_page(dma_to_phys(dev, handle)), > - PAGE_ALIGN(size), 0); > + if (!ret) { > + phys_addr_t phys = swiotlb_dma_to_phys(dev, handle); > + > + sg_set_page(sgt->sgl, phys_to_page(phys), PAGE_ALIGN(size), 0); > + } > > return ret; > }
Since we know for sure that swiotlb_to_phys is a no-op on arm64, it might be cleaner to simply not reference it at all. I suppose we could have some private local wrappers, e.g.:
#define swiotlb_to_virt(addr) phys_to_virt((phys_addr_t)(addr))
to keep the intent of the code clear (and just in case anyone ever builds a system mad enough to warrant switching out that definition, but I'd hope that never happens).
Otherwise, looks good - thanks for doing this!
Robin.
| |