iommu/dma: Refactor iommu_dma_mmap

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.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index fa95794..84150ca 100644 (file)
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -1042,31 +1042,12 @@ 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)
-{
-       int ret = -ENXIO;
-       unsigned long nr_vma_pages = vma_pages(vma);
-       unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
-       unsigned long off = vma->vm_pgoff;
-
-       if (off < nr_pages && nr_vma_pages <= (nr_pages - off)) {
-               ret = remap_pfn_range(vma, vma->vm_start,
-                                     pfn + off,
-                                     vma->vm_end - vma->vm_start,
-                                     vma->vm_page_prot);
-       }
-
-       return ret;
-}
-
 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);
@@ -1077,24 +1058,19 @@ 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 (!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,