[PATCH 14/19] dma-iommu: factor contiguous remapped allocations into helpers

[Christoph Hellwig]

This moves the last remaning non-dispatch code out of iommu_dma_alloc,
preparing to refactor the allocation method selection.

Signed-off-by: Christoph Hellwig <h...@lst.de>
---
 drivers/iommu/dma-iommu.c | 48 +++++++++++++++++++++++----------------
 1 file changed, 29 insertions(+), 19 deletions(-)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 710814a370b9..956cb218c6ba 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -667,6 +667,29 @@ static void *iommu_dma_alloc_remap(struct device *dev, 
size_t size,
        return NULL;
 }
 
+static void *iommu_dma_alloc_contiguous_remap(struct device *dev, size_t size,
+               dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
+{
+       pgprot_t prot = arch_dma_mmap_pgprot(dev, PAGE_KERNEL, attrs);
+       struct page *page;
+       void *addr;
+
+       addr = iommu_dma_alloc_contiguous(dev, size, dma_handle, gfp, attrs);
+       if (!addr)
+               return NULL;
+
+       page = virt_to_page(addr);
+       addr = dma_common_contiguous_remap(page, PAGE_ALIGN(size), VM_USERMAP,
+                       prot, __builtin_return_address(0));
+       if (!addr)
+               goto out_free;
+       arch_dma_prep_coherent(page, size);
+       return addr;
+out_free:
+       iommu_dma_free_contiguous(dev, size, page, *dma_handle);
+       return NULL;
+}
+
 /**
  * iommu_dma_mmap_remap - Map a remapped page array into provided user VMA
  * @cpu_addr: virtual address of the memory to be remapped
@@ -1016,8 +1039,6 @@ static void *iommu_dma_alloc(struct device *dev, size_t 
size,
        size_t iosize = size;
        void *addr;
 
-       size = PAGE_ALIGN(size);
-
        /*
         * Some drivers rely on this, and we probably don't want the
         * possibility of stale kernel data being read by devices anyway.
@@ -1036,23 +1057,12 @@ static void *iommu_dma_alloc(struct device *dev, size_t 
size,
                return iommu_dma_alloc_contiguous(dev, iosize, handle, gfp,
                                attrs);
        } else if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) {
-               pgprot_t prot = arch_dma_mmap_pgprot(dev, PAGE_KERNEL, attrs);
-               struct page *page;
-
-               addr = iommu_dma_alloc_contiguous(dev, iosize, handle, gfp,
-                               attrs);
-               if (coherent || !addr)
-                       return addr;
-
-               page = virt_to_page(addr);
-               addr = dma_common_contiguous_remap(page, size, VM_USERMAP, prot,
-                               __builtin_return_address(0));
-               if (!addr) {
-                       iommu_dma_free_contiguous(dev, iosize, page, *handle);
-                       return NULL;
-               }
-
-               arch_dma_prep_coherent(page, iosize);
+               if (coherent)
+                       addr = iommu_dma_alloc_contiguous(dev, iosize, handle,
+                                       gfp, attrs);
+               else
+                       addr = iommu_dma_alloc_contiguous_remap(dev, iosize,
+                                       handle, gfp, attrs);
        } else {
                addr = iommu_dma_alloc_remap(dev, iosize, handle, gfp, attrs);
        }
-- 
2.20.1