2 files changed, 48 insertions, 0 deletions

diff --git a/drivers/base/dma-buf.c b/drivers/base/dma-buf.c
index 7cfb405b1ad5..d43d80256fda 100644
--- a/drivers/base/dma-buf.c
+++ b/drivers/base/dma-buf.c
@@ -468,3 +468,37 @@ int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma,
         return dmabuf->ops->mmap(dmabuf, vma);
 }
 EXPORT_SYMBOL_GPL(dma_buf_mmap);
+
+/**
+ * dma_buf_vmap - Create virtual mapping for the buffer object into kernel address space. Same restrictions as for vmap and friends apply.
+ * @dma_buf:    [in]    buffer to vmap
+ *
+ * This call may fail due to lack of virtual mapping address space.
+ * These calls are optional in drivers. The intended use for them
+ * is for mapping objects linear in kernel space for high use objects.
+ * Please attempt to use kmap/kunmap before thinking about these interfaces.
+ */
+void *dma_buf_vmap(struct dma_buf *dmabuf)
+{
+        if (WARN_ON(!dmabuf))
+                return NULL;
+
+        if (dmabuf->ops->vmap)
+                return dmabuf->ops->vmap(dmabuf);
+        return NULL;
+}
+EXPORT_SYMBOL_GPL(dma_buf_vmap);
+
+/**
+ * dma_buf_vunmap - Unmap a vmap obtained by dma_buf_vmap.
+ * @dma_buf:    [in]    buffer to vmap
+ */
+void dma_buf_vunmap(struct dma_buf *dmabuf, void *vaddr)
+{
+        if (WARN_ON(!dmabuf))
+                return;
+
+        if (dmabuf->ops->vunmap)
+                dmabuf->ops->vunmap(dmabuf, vaddr);
+}
+EXPORT_SYMBOL_GPL(dma_buf_vunmap);
diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
index 1f78d1594cc7..a02b1ff6488e 100644
--- a/include/linux/dma-buf.h
+++ b/include/linux/dma-buf.h
@@ -98,6 +98,9 @@ struct dma_buf_ops {
         void (*kunmap)(struct dma_buf *, unsigned long, void *);
 
         int (*mmap)(struct dma_buf *, struct vm_area_struct *vma);
+
+        void *(*vmap)(struct dma_buf *);
+        void (*vunmap)(struct dma_buf *, void *vaddr);
 };
 
 /**
@@ -176,6 +179,8 @@ void dma_buf_kunmap(struct dma_buf *, unsigned long, void *);
 
 int dma_buf_mmap(struct dma_buf *, struct vm_area_struct *,
                  unsigned long);
+void *dma_buf_vmap(struct dma_buf *);
+void dma_buf_vunmap(struct dma_buf *, void *vaddr);
 #else
 
 static inline struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf,
@@ -264,6 +269,15 @@ static inline int dma_buf_mmap(struct dma_buf *dmabuf,
 {
         return -ENODEV;
 }
+
+static inline void *dma_buf_vmap(struct dma_buf *dmabuf)
+{
+        return NULL;
+}
+
+static inline void dma_buf_vunmap(struct dma_buf *dmabuf, void *vaddr)
+{
+}
 #endif /* CONFIG_DMA_SHARED_BUFFER */
 
 #endif /* __DMA_BUF_H__ */