On Tue, Apr 09, 2019 at 04:29:07PM +0100, Robin Murphy wrote: > 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 <h...@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.
So I generally prefer that style too. But in this case one of the later patches will add an ifdef around the if { ... } else, and adding braces would make that a lot more awkware. There is another occurance or two of this patter in this series elsewhere as well. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu