common: dma-mapping: add support for generic dma_mmap_* calls

Commit 9adc5374 ('common: dma-mapping: introduce mmap method') added a
generic method for implementing mmap user call to dma_map_ops structure.

This patch converts ARM and PowerPC architectures (the only providers of
dma_mmap_coherent/dma_mmap_writecombine calls) to use this generic
dma_map_ops based call and adds a generic cross architecture
definition for dma_mmap_attrs, dma_mmap_coherent, dma_mmap_writecombine
functions.

The generic mmap virt_to_page-based fallback implementation is provided for
architectures which don't provide their own implementation for mmap method.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Kyungmin Park <kyungmin.park@samsung.com>

2 files changed, 38 insertions, 0 deletions

diff --git a/include/asm-generic/dma-coherent.h b/include/asm-generic/dma-coherent.h
index abfb2682de7f..2be8a2dbc868 100644
--- a/include/asm-generic/dma-coherent.h
+++ b/include/asm-generic/dma-coherent.h
@@ -29,6 +29,7 @@ dma_mark_declared_memory_occupied(struct device *dev,
 #else
 #define dma_alloc_from_coherent(dev, size, handle, ret) (0)
 #define dma_release_from_coherent(dev, order, vaddr) (0)
+#define dma_mmap_from_coherent(dev, vma, vaddr, order, ret) (0)
 #endif
 
 #endif
diff --git a/include/asm-generic/dma-mapping-common.h b/include/asm-generic/dma-mapping-common.h
index 2e248d8924dc..9073aeb3bb1a 100644
--- a/include/asm-generic/dma-mapping-common.h
+++ b/include/asm-generic/dma-mapping-common.h
@@ -176,4 +176,41 @@ dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
 #define dma_map_sg(d, s, n, r) dma_map_sg_attrs(d, s, n, r, NULL)
 #define dma_unmap_sg(d, s, n, r) dma_unmap_sg_attrs(d, s, n, r, NULL)
 
+extern int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
+                           void *cpu_addr, dma_addr_t dma_addr, size_t size);
+
+/**
+ * dma_mmap_attrs - map a coherent DMA allocation into user space
+ * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
+ * @vma: vm_area_struct describing requested user mapping
+ * @cpu_addr: kernel CPU-view address returned from dma_alloc_attrs
+ * @handle: device-view address returned from dma_alloc_attrs
+ * @size: size of memory originally requested in dma_alloc_attrs
+ * @attrs: attributes of mapping properties requested in dma_alloc_attrs
+ *
+ * Map a coherent DMA buffer previously allocated by dma_alloc_attrs
+ * into user space.  The coherent DMA buffer must not be freed by the
+ * driver until the user space mapping has been released.
+ */
+static inline int
+dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma, void *cpu_addr,
+               dma_addr_t dma_addr, size_t size, struct dma_attrs *attrs)
+{
+        struct dma_map_ops *ops = get_dma_ops(dev);
+        BUG_ON(!ops);
+        if (ops->mmap)
+                return ops->mmap(dev, vma, cpu_addr, dma_addr, size, attrs);
+        return dma_common_mmap(dev, vma, cpu_addr, dma_addr, size);
+}
+
+#define dma_mmap_coherent(d, v, c, h, s) dma_mmap_attrs(d, v, c, h, s, NULL)
+
+static inline int dma_mmap_writecombine(struct device *dev, struct vm_area_struct *vma,
+                      void *cpu_addr, dma_addr_t dma_addr, size_t size)
+{
+        DEFINE_DMA_ATTRS(attrs);
+        dma_set_attr(DMA_ATTR_WRITE_COMBINE, &attrs);
+        return dma_mmap_attrs(dev, vma, cpu_addr, dma_addr, size, &attrs);
+}
+
 #endif