iommu/dma: Refactor the page array remapping allocator

Move the call to dma_common_pages_remap into __iommu_dma_alloc and
rename it to iommu_dma_alloc_remap.  This creates a self-contained
helper for remapped pages allocation and mapping.

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 5e81165e6755c92b8b37edb6d83feecb980c3658..0ffb7805de77a813b1c1830788c8b617f30d99e7 100644 (file)
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -564,9 +564,9 @@ static struct page **__iommu_dma_get_pages(void *cpu_addr)
 }
 
 /**
- * iommu_dma_free - Free a buffer allocated by __iommu_dma_alloc()
+ * iommu_dma_free - Free a buffer allocated by iommu_dma_alloc_remap()
  * @dev: Device which owns this buffer
- * @pages: Array of buffer pages as returned by __iommu_dma_alloc()
+ * @pages: Array of buffer pages as returned by __iommu_dma_alloc_remap()
  * @size: Size of buffer in bytes
  * @handle: DMA address of buffer
  *
@@ -582,33 +582,35 @@ static void __iommu_dma_free(struct device *dev, struct page **pages,
 }
 
 /**
- * __iommu_dma_alloc - Allocate and map a buffer contiguous in IOVA space
+ * iommu_dma_alloc_remap - Allocate and map a buffer contiguous in IOVA space
  * @dev: Device to allocate memory for. Must be a real device
  *      attached to an iommu_dma_domain
  * @size: Size of buffer in bytes
+ * @dma_handle: Out argument for allocated DMA handle
  * @gfp: Allocation flags
  * @attrs: DMA attributes for this allocation
- * @prot: IOMMU mapping flags
- * @handle: Out argument for allocated DMA handle
  *
  * If @size is less than PAGE_SIZE, then a full CPU page will be allocated,
  * but an IOMMU which supports smaller pages might not map the whole thing.
  *
- * Return: Array of struct page pointers describing the buffer,
- *        or NULL on failure.
+ * Return: Mapped virtual address, or NULL on failure.
  */
-static struct page **__iommu_dma_alloc(struct device *dev, size_t size,
-               gfp_t gfp, unsigned long attrs, int prot, dma_addr_t *handle)
+static void *iommu_dma_alloc_remap(struct device *dev, size_t size,
+               dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
 {
        struct iommu_domain *domain = iommu_get_dma_domain(dev);
        struct iommu_dma_cookie *cookie = domain->iova_cookie;
        struct iova_domain *iovad = &cookie->iovad;
+       bool coherent = dev_is_dma_coherent(dev);
+       int ioprot = dma_info_to_prot(DMA_BIDIRECTIONAL, coherent, attrs);
+       pgprot_t prot = arch_dma_mmap_pgprot(dev, PAGE_KERNEL, attrs);
+       unsigned int count, min_size, alloc_sizes = domain->pgsize_bitmap;
        struct page **pages;
        struct sg_table sgt;
        dma_addr_t iova;
-       unsigned int count, min_size, alloc_sizes = domain->pgsize_bitmap;
+       void *vaddr;
 
-       *handle = DMA_MAPPING_ERROR;
+       *dma_handle = DMA_MAPPING_ERROR;
 
        min_size = alloc_sizes & -alloc_sizes;
        if (min_size < PAGE_SIZE) {
@@ -634,7 +636,7 @@ static struct page **__iommu_dma_alloc(struct device *dev, size_t size,
        if (sg_alloc_table_from_pages(&sgt, pages, count, 0, size, GFP_KERNEL))
                goto out_free_iova;
 
-       if (!(prot & IOMMU_CACHE)) {
+       if (!(ioprot & IOMMU_CACHE)) {
                struct scatterlist *sg;
                int i;
 
@@ -642,14 +644,21 @@ static struct page **__iommu_dma_alloc(struct device *dev, size_t size,
                        arch_dma_prep_coherent(sg_page(sg), sg->length);
        }
 
-       if (iommu_map_sg(domain, iova, sgt.sgl, sgt.orig_nents, prot)
+       if (iommu_map_sg(domain, iova, sgt.sgl, sgt.orig_nents, ioprot)
                        < size)
                goto out_free_sg;
 
-       *handle = iova;
+       vaddr = dma_common_pages_remap(pages, size, VM_USERMAP, prot,
+                       __builtin_return_address(0));
+       if (!vaddr)
+               goto out_unmap;
+
+       *dma_handle = iova;
        sg_free_table(&sgt);
-       return pages;
+       return vaddr;
 
+out_unmap:
+       __iommu_dma_unmap(dev, iova, size);
 out_free_sg:
        sg_free_table(&sgt);
 out_free_iova:
@@ -1008,18 +1017,7 @@ static void *iommu_dma_alloc(struct device *dev, size_t size,
                                                    size >> PAGE_SHIFT);
                }
        } else {
-               pgprot_t prot = arch_dma_mmap_pgprot(dev, PAGE_KERNEL, attrs);
-               struct page **pages;
-
-               pages = __iommu_dma_alloc(dev, iosize, gfp, attrs, ioprot,
-                                       handle);
-               if (!pages)
-                       return NULL;
-
-               addr = dma_common_pages_remap(pages, size, VM_USERMAP, prot,
-                                             __builtin_return_address(0));
-               if (!addr)
-                       __iommu_dma_free(dev, pages, iosize, handle);
+               addr = iommu_dma_alloc_remap(dev, iosize, handle, gfp, attrs);
        }
        return addr;
 }
@@ -1033,7 +1031,7 @@ static void iommu_dma_free(struct device *dev, size_t size, void *cpu_addr,
        /*
         * @cpu_addr will be one of 4 things depending on how it was allocated:
         * - A remapped array of pages for contiguous allocations.
-        * - A remapped array of pages from __iommu_dma_alloc(), for all
+        * - A remapped array of pages from iommu_dma_alloc_remap(), for all
         *   non-atomic allocations.
         * - A non-cacheable alias from the atomic pool, for atomic
         *   allocations by non-coherent devices.