Messages in this thread | | | Subject | Re: [PATCH 08/21] dma-iommu: refactor iommu_dma_mmap | From | Robin Murphy <> | Date | Tue, 9 Apr 2019 16:29:07 +0100 |
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On 27/03/2019 08:04, Christoph Hellwig wrote: > Move the vm_area handling into __iommu_dma_mmap, which is renamed > to iommu_dma_mmap_remap. > > Inline __iommu_dma_mmap_pfn into the main function to simplify the code > flow a bit. > > Signed-off-by: Christoph Hellwig <hch@lst.de> > --- > drivers/iommu/dma-iommu.c | 50 ++++++++++++++------------------------- > 1 file changed, 18 insertions(+), 32 deletions(-) > > diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c > index d14fe9f8c692..43bd3c7e0f6b 100644 > --- a/drivers/iommu/dma-iommu.c > +++ b/drivers/iommu/dma-iommu.c > @@ -597,23 +597,27 @@ static struct page **__iommu_dma_alloc(struct device *dev, size_t size, > } > > /** > - * __iommu_dma_mmap - Map a buffer into provided user VMA > - * @pages: Array representing buffer from __iommu_dma_alloc() > + * iommu_dma_mmap_remap - Map a remapped page array into provided user VMA > + * @cpu_addr: virtual address of the memory to be remapped > * @size: Size of buffer in bytes > * @vma: VMA describing requested userspace mapping > * > - * Maps the pages of the buffer in @pages into @vma. The caller is responsible > + * Maps the pages pointed to by @cpu_addr into @vma. The caller is responsible > * for verifying the correct size and protection of @vma beforehand. > */ > -static int __iommu_dma_mmap(struct page **pages, size_t size, > +static int iommu_dma_mmap_remap(void *cpu_addr, size_t size, > struct vm_area_struct *vma) > { > + struct vm_struct *area = find_vm_area(cpu_addr); > unsigned long uaddr = vma->vm_start; > unsigned int i, count = PAGE_ALIGN(size) >> PAGE_SHIFT; > int ret = -ENXIO; > > + if (WARN_ON(!area || !area->pages)) > + return -ENXIO; > + > for (i = vma->vm_pgoff; i < count && uaddr < vma->vm_end; i++) { > - ret = vm_insert_page(vma, uaddr, pages[i]); > + ret = vm_insert_page(vma, uaddr, area->pages[i]); > if (ret) > break; > uaddr += PAGE_SIZE; > @@ -1052,21 +1056,13 @@ static void iommu_dma_free(struct device *dev, size_t size, void *cpu_addr, > } > } > > -static int __iommu_dma_mmap_pfn(struct vm_area_struct *vma, > - unsigned long pfn, size_t size) > -{ > - return remap_pfn_range(vma, vma->vm_start, pfn + vma->vm_pgoff, > - vma->vm_end - vma->vm_start, > - vma->vm_page_prot); > -} > - > static int iommu_dma_mmap(struct device *dev, struct vm_area_struct *vma, > void *cpu_addr, dma_addr_t dma_addr, size_t size, > unsigned long attrs) > { > unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT; > unsigned long off = vma->vm_pgoff; > - struct vm_struct *area; > + unsigned long pfn; > int ret; > > vma->vm_page_prot = arch_dma_mmap_pgprot(dev, vma->vm_page_prot, attrs); > @@ -1077,25 +1073,15 @@ static int iommu_dma_mmap(struct device *dev, struct vm_area_struct *vma, > if (off >= nr_pages || vma_pages(vma) > nr_pages - off) > return -ENXIO; > > - if (!is_vmalloc_addr(cpu_addr)) { > - unsigned long pfn = page_to_pfn(virt_to_page(cpu_addr)); > - return __iommu_dma_mmap_pfn(vma, pfn, size); > - } > + if (is_vmalloc_addr(cpu_addr)) { > + if (!(attrs & DMA_ATTR_FORCE_CONTIGUOUS)) > + return iommu_dma_mmap_remap(cpu_addr, size, vma); > + pfn = vmalloc_to_pfn(cpu_addr); > + } else > + pfn = page_to_pfn(virt_to_page(cpu_addr));
Nit: braces around the else clause for correct style.
Otherwise, this seems to make sense;
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
> > - if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) { > - /* > - * DMA_ATTR_FORCE_CONTIGUOUS allocations are always remapped, > - * hence in the vmalloc space. > - */ > - unsigned long pfn = vmalloc_to_pfn(cpu_addr); > - return __iommu_dma_mmap_pfn(vma, pfn, size); > - } > - > - area = find_vm_area(cpu_addr); > - if (WARN_ON(!area || !area->pages)) > - return -ENXIO; > - > - return __iommu_dma_mmap(area->pages, size, vma); > + return remap_pfn_range(vma, vma->vm_start, pfn + vma->vm_pgoff, > + vma_pages(vma) << PAGE_SHIFT, vma->vm_page_prot); > } > > static int __iommu_dma_get_sgtable_page(struct sg_table *sgt, struct page *page, >
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