| Message ID | 20190422175942.18788-22-hch@lst.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [01/26] arm64/iommu: handle non-remapped addresses in ->mmap and ->get_sgtable | expand |
On 22/04/2019 18:59, Christoph Hellwig wrote: > Inline __iommu_dma_get_sgtable_page into the main function, and use the > fact that __iommu_dma_get_pages return NULL for remapped contigous > allocations to simplify the code flow a bit. Yeah, even I was a bit dubious about the readability of "if (page)... else if (pages)..." that my attempt ended up with, so I don't really have anything to complain about here. Reviewed-by: Robin Murphy <robin.murphy@arm.com> > Signed-off-by: Christoph Hellwig <hch@lst.de> > --- > drivers/iommu/dma-iommu.c | 45 +++++++++++++++------------------------ > 1 file changed, 17 insertions(+), 28 deletions(-) > > diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c > index acdfe866cb29..138b85e675c8 100644 > --- a/drivers/iommu/dma-iommu.c > +++ b/drivers/iommu/dma-iommu.c > @@ -1070,42 +1070,31 @@ static int iommu_dma_mmap(struct device *dev, struct vm_area_struct *vma, > return __iommu_dma_mmap(pages, size, vma); > } > > -static int __iommu_dma_get_sgtable_page(struct sg_table *sgt, struct page *page, > - size_t size) > -{ > - int ret = sg_alloc_table(sgt, 1, GFP_KERNEL); > - > - if (!ret) > - sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0); > - return ret; > -} > - > static int iommu_dma_get_sgtable(struct device *dev, struct sg_table *sgt, > void *cpu_addr, dma_addr_t dma_addr, size_t size, > unsigned long attrs) > { > - unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT; > - struct page **pages; > + struct page *page; > + int ret; > > - if (!is_vmalloc_addr(cpu_addr)) { > - struct page *page = virt_to_page(cpu_addr); > - return __iommu_dma_get_sgtable_page(sgt, page, size); > - } > + if (is_vmalloc_addr(cpu_addr)) { > + struct page **pages = __iommu_dma_get_pages(cpu_addr); > > - if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) { > - /* > - * DMA_ATTR_FORCE_CONTIGUOUS allocations are always remapped, > - * hence in the vmalloc space. > - */ > - struct page *page = vmalloc_to_page(cpu_addr); > - return __iommu_dma_get_sgtable_page(sgt, page, size); > + if (pages) { > + return sg_alloc_table_from_pages(sgt, pages, > + PAGE_ALIGN(size) >> PAGE_SHIFT, > + 0, size, GFP_KERNEL); > + } > + > + page = vmalloc_to_page(cpu_addr); > + } else { > + page = virt_to_page(cpu_addr); > } > > - pages = __iommu_dma_get_pages(cpu_addr); > - if (WARN_ON_ONCE(!pages)) > - return -ENXIO; > - return sg_alloc_table_from_pages(sgt, pages, count, 0, size, > - GFP_KERNEL); > + ret = sg_alloc_table(sgt, 1, GFP_KERNEL); > + if (!ret) > + sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0); > + return ret; > } > > static const struct dma_map_ops iommu_dma_ops = { >
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index acdfe866cb29..138b85e675c8 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -1070,42 +1070,31 @@ static int iommu_dma_mmap(struct device *dev, struct vm_area_struct *vma, return __iommu_dma_mmap(pages, size, vma); } -static int __iommu_dma_get_sgtable_page(struct sg_table *sgt, struct page *page, - size_t size) -{ - int ret = sg_alloc_table(sgt, 1, GFP_KERNEL); - - if (!ret) - sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0); - return ret; -} - static int iommu_dma_get_sgtable(struct device *dev, struct sg_table *sgt, void *cpu_addr, dma_addr_t dma_addr, size_t size, unsigned long attrs) { - unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT; - struct page **pages; + struct page *page; + int ret; - if (!is_vmalloc_addr(cpu_addr)) { - struct page *page = virt_to_page(cpu_addr); - return __iommu_dma_get_sgtable_page(sgt, page, size); - } + if (is_vmalloc_addr(cpu_addr)) { + struct page **pages = __iommu_dma_get_pages(cpu_addr); - if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) { - /* - * DMA_ATTR_FORCE_CONTIGUOUS allocations are always remapped, - * hence in the vmalloc space. - */ - struct page *page = vmalloc_to_page(cpu_addr); - return __iommu_dma_get_sgtable_page(sgt, page, size); + if (pages) { + return sg_alloc_table_from_pages(sgt, pages, + PAGE_ALIGN(size) >> PAGE_SHIFT, + 0, size, GFP_KERNEL); + } + + page = vmalloc_to_page(cpu_addr); + } else { + page = virt_to_page(cpu_addr); } - pages = __iommu_dma_get_pages(cpu_addr); - if (WARN_ON_ONCE(!pages)) - return -ENXIO; - return sg_alloc_table_from_pages(sgt, pages, count, 0, size, - GFP_KERNEL); + ret = sg_alloc_table(sgt, 1, GFP_KERNEL); + if (!ret) + sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0); + return ret; } static const struct dma_map_ops iommu_dma_ops = {
Inline __iommu_dma_get_sgtable_page into the main function, and use the fact that __iommu_dma_get_pages return NULL for remapped contigous allocations to simplify the code flow a bit. Signed-off-by: Christoph Hellwig <hch@lst.de> --- drivers/iommu/dma-iommu.c | 45 +++++++++++++++------------------------ 1 file changed, 17 insertions(+), 28 deletions(-)