On 22/04/2019 18:59, Christoph Hellwig wrote:
Inline __iommu_dma_mmap_pfn 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.

...and later we can squash __iommu_dma_mmap() once the dust settles on vm_map_pages() - seems good to me.

Reviewed-by: Robin Murphy <[email protected]>

Signed-off-by: Christoph Hellwig <[email protected]>
---
  drivers/iommu/dma-iommu.c | 36 +++++++++++-------------------------
  1 file changed, 11 insertions(+), 25 deletions(-)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 138b85e675c8..8fc6098c1eeb 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -1025,21 +1025,12 @@ static void *iommu_dma_alloc(struct device *dev, size_t 
size,
        return 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 page **pages;
+       unsigned long pfn, off = vma->vm_pgoff;
        int ret;
vma->vm_page_prot = arch_dma_mmap_pgprot(dev, vma->vm_page_prot, attrs);
@@ -1050,24 +1041,19 @@ 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)) {
+               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.
-                */
-               unsigned long pfn = vmalloc_to_pfn(cpu_addr);
-               return __iommu_dma_mmap_pfn(vma, pfn, size);
+               if (pages)
+                       return __iommu_dma_mmap(pages, size, vma);
+               pfn = vmalloc_to_pfn(cpu_addr);
+       } else {
+               pfn = page_to_pfn(virt_to_page(cpu_addr));
        }
- pages = __iommu_dma_get_pages(cpu_addr);
-       if (WARN_ON_ONCE(!pages))
-               return -ENXIO;
-       return __iommu_dma_mmap(pages, size, vma);
+       return remap_pfn_range(vma, vma->vm_start, pfn + off,
+                              vma->vm_end - vma->vm_start,
+                              vma->vm_page_prot);
  }
static int iommu_dma_get_sgtable(struct device *dev, struct sg_table *sgt,

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