1 files changed, 53 insertions, 3 deletions

diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
index 763d59c1eb6..6cd08e145bf 100644
--- a/drivers/base/dma-mapping.c
+++ b/drivers/base/dma-mapping.c
@@ -8,7 +8,9 @@
  */
 
 #include <linux/dma-mapping.h>
+#include <linux/export.h>
 #include <linux/gfp.h>
+#include <asm-generic/dma-coherent.h>
 
 /*
  * Managed DMA API
@@ -173,7 +175,7 @@ static void dmam_coherent_decl_release(struct device *dev, void *res)
 /**
  * dmam_declare_coherent_memory - Managed dma_declare_coherent_memory()
  * @dev: Device to declare coherent memory for
- * @bus_addr: Bus address of coherent memory to be declared
+ * @phys_addr: Physical address of coherent memory to be declared
  * @device_addr: Device address of coherent memory to be declared
  * @size: Size of coherent memory to be declared
  * @flags: Flags
@@ -183,7 +185,7 @@ static void dmam_coherent_decl_release(struct device *dev, void *res)
  * RETURNS:
  * 0 on success, -errno on failure.
  */
-int dmam_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
+int dmam_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
 				 dma_addr_t device_addr, size_t size, int flags)
 {
 	void *res;
@@ -193,7 +195,7 @@ int dmam_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
 	if (!res)
 		return -ENOMEM;
 
-	rc = dma_declare_coherent_memory(dev, bus_addr, device_addr, size,
+	rc = dma_declare_coherent_memory(dev, phys_addr, device_addr, size,
 					 flags);
 	if (rc == 0)
 		devres_add(dev, res);
@@ -217,3 +219,51 @@ void dmam_release_declared_memory(struct device *dev)
 EXPORT_SYMBOL(dmam_release_declared_memory);
 
 #endif
+
+/*
+ * Create scatter-list for the already allocated DMA buffer.
+ */
+int dma_common_get_sgtable(struct device *dev, struct sg_table *sgt,
+		 void *cpu_addr, dma_addr_t handle, size_t size)
+{
+	struct page *page = virt_to_page(cpu_addr);
+	int ret;
+
+	ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
+	if (unlikely(ret))
+		return ret;
+
+	sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);
+	return 0;
+}
+EXPORT_SYMBOL(dma_common_get_sgtable);
+
+/*
+ * Create userspace mapping for the DMA-coherent memory.
+ */
+int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
+		    void *cpu_addr, dma_addr_t dma_addr, size_t size)
+{
+	int ret = -ENXIO;
+#ifdef CONFIG_MMU
+	unsigned long user_count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
+	unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
+	unsigned long pfn = page_to_pfn(virt_to_page(cpu_addr));
+	unsigned long off = vma->vm_pgoff;
+
+	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+
+	if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
+		return ret;
+
+	if (off < count && user_count <= (count - off)) {
+		ret = remap_pfn_range(vma, vma->vm_start,
+				      pfn + off,
+				      user_count << PAGE_SHIFT,
+				      vma->vm_page_prot);
+	}
+#endif	/* CONFIG_MMU */
+
+	return ret;
+}
+EXPORT_SYMBOL(dma_common_mmap);