---

yaml
---
r: 297198
b: refs/heads/master
c: fc13020
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 6b607e3a658fee490bdabfdeb739a3eb498b1bff
+refs/heads/master: fc13020e086bfedf2afb95c91c026d5af1f80107

trunk/drivers/base/dma-buf.c

@@ -80,7 +80,9 @@ struct dma_buf *dma_buf_export(void *priv, const struct dma_buf_ops *ops,
 	if (WARN_ON(!priv || !ops
 			  || !ops->map_dma_buf
 			  || !ops->unmap_dma_buf
-			  || !ops->release)) {
+			  || !ops->release
+			  || !ops->kmap_atomic
+			  || !ops->kmap)) {
 		return ERR_PTR(-EINVAL);
 	}
 
@@ -284,3 +286,123 @@ void dma_buf_unmap_attachment(struct dma_buf_attachment *attach,
 						direction);
 }
 EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment);
+
+
+/**
+ * dma_buf_begin_cpu_access - Must be called before accessing a dma_buf from the
+ * cpu in the kernel context. Calls begin_cpu_access to allow exporter-specific
+ * preparations. Coherency is only guaranteed in the specified range for the
+ * specified access direction.
+ * @dma_buf:	[in]	buffer to prepare cpu access for.
+ * @start:	[in]	start of range for cpu access.
+ * @len:	[in]	length of range for cpu access.
+ * @direction:	[in]	length of range for cpu access.
+ *
+ * Can return negative error values, returns 0 on success.
+ */
+int dma_buf_begin_cpu_access(struct dma_buf *dmabuf, size_t start, size_t len,
+			     enum dma_data_direction direction)
+{
+	int ret = 0;
+
+	if (WARN_ON(!dmabuf))
+		return -EINVAL;
+
+	if (dmabuf->ops->begin_cpu_access)
+		ret = dmabuf->ops->begin_cpu_access(dmabuf, start, len, direction);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(dma_buf_begin_cpu_access);
+
+/**
+ * dma_buf_end_cpu_access - Must be called after accessing a dma_buf from the
+ * cpu in the kernel context. Calls end_cpu_access to allow exporter-specific
+ * actions. Coherency is only guaranteed in the specified range for the
+ * specified access direction.
+ * @dma_buf:	[in]	buffer to complete cpu access for.
+ * @start:	[in]	start of range for cpu access.
+ * @len:	[in]	length of range for cpu access.
+ * @direction:	[in]	length of range for cpu access.
+ *
+ * This call must always succeed.
+ */
+void dma_buf_end_cpu_access(struct dma_buf *dmabuf, size_t start, size_t len,
+			    enum dma_data_direction direction)
+{
+	WARN_ON(!dmabuf);
+
+	if (dmabuf->ops->end_cpu_access)
+		dmabuf->ops->end_cpu_access(dmabuf, start, len, direction);
+}
+EXPORT_SYMBOL_GPL(dma_buf_end_cpu_access);
+
+/**
+ * dma_buf_kmap_atomic - Map a page of the buffer object into kernel address
+ * space. The same restrictions as for kmap_atomic and friends apply.
+ * @dma_buf:	[in]	buffer to map page from.
+ * @page_num:	[in]	page in PAGE_SIZE units to map.
+ *
+ * This call must always succeed, any necessary preparations that might fail
+ * need to be done in begin_cpu_access.
+ */
+void *dma_buf_kmap_atomic(struct dma_buf *dmabuf, unsigned long page_num)
+{
+	WARN_ON(!dmabuf);
+
+	return dmabuf->ops->kmap_atomic(dmabuf, page_num);
+}
+EXPORT_SYMBOL_GPL(dma_buf_kmap_atomic);
+
+/**
+ * dma_buf_kunmap_atomic - Unmap a page obtained by dma_buf_kmap_atomic.
+ * @dma_buf:	[in]	buffer to unmap page from.
+ * @page_num:	[in]	page in PAGE_SIZE units to unmap.
+ * @vaddr:	[in]	kernel space pointer obtained from dma_buf_kmap_atomic.
+ *
+ * This call must always succeed.
+ */
+void dma_buf_kunmap_atomic(struct dma_buf *dmabuf, unsigned long page_num,
+			   void *vaddr)
+{
+	WARN_ON(!dmabuf);
+
+	if (dmabuf->ops->kunmap_atomic)
+		dmabuf->ops->kunmap_atomic(dmabuf, page_num, vaddr);
+}
+EXPORT_SYMBOL_GPL(dma_buf_kunmap_atomic);
+
+/**
+ * dma_buf_kmap - Map a page of the buffer object into kernel address space. The
+ * same restrictions as for kmap and friends apply.
+ * @dma_buf:	[in]	buffer to map page from.
+ * @page_num:	[in]	page in PAGE_SIZE units to map.
+ *
+ * This call must always succeed, any necessary preparations that might fail
+ * need to be done in begin_cpu_access.
+ */
+void *dma_buf_kmap(struct dma_buf *dmabuf, unsigned long page_num)
+{
+	WARN_ON(!dmabuf);
+
+	return dmabuf->ops->kmap(dmabuf, page_num);
+}
+EXPORT_SYMBOL_GPL(dma_buf_kmap);
+
+/**
+ * dma_buf_kunmap - Unmap a page obtained by dma_buf_kmap.
+ * @dma_buf:	[in]	buffer to unmap page from.
+ * @page_num:	[in]	page in PAGE_SIZE units to unmap.
+ * @vaddr:	[in]	kernel space pointer obtained from dma_buf_kmap.
+ *
+ * This call must always succeed.
+ */
+void dma_buf_kunmap(struct dma_buf *dmabuf, unsigned long page_num,
+		    void *vaddr)
+{
+	WARN_ON(!dmabuf);
+
+	if (dmabuf->ops->kunmap)
+		dmabuf->ops->kunmap(dmabuf, page_num, vaddr);
+}
+EXPORT_SYMBOL_GPL(dma_buf_kunmap);

trunk/include/linux/dma-buf.h

@@ -50,6 +50,17 @@ struct dma_buf_attachment;
  * @unmap_dma_buf: decreases usecount of buffer, might deallocate scatter
  *		   pages.
  * @release: release this buffer; to be called after the last dma_buf_put.
+ * @begin_cpu_access: [optional] called before cpu access to invalidate cpu
+ * 		      caches and allocate backing storage (if not yet done)
+ * 		      respectively pin the objet into memory.
+ * @end_cpu_access: [optional] called after cpu access to flush cashes.
+ * @kmap_atomic: maps a page from the buffer into kernel address
+ * 		 space, users may not block until the subsequent unmap call.
+ * 		 This callback must not sleep.
+ * @kunmap_atomic: [optional] unmaps a atomically mapped page from the buffer.
+ * 		   This Callback must not sleep.
+ * @kmap: maps a page from the buffer into kernel address space.
+ * @kunmap: [optional] unmaps a page from the buffer.
  */
 struct dma_buf_ops {
 	int (*attach)(struct dma_buf *, struct device *,
@@ -73,6 +84,14 @@ struct dma_buf_ops {
 	/* after final dma_buf_put() */
 	void (*release)(struct dma_buf *);
 
+	int (*begin_cpu_access)(struct dma_buf *, size_t, size_t,
+				enum dma_data_direction);
+	void (*end_cpu_access)(struct dma_buf *, size_t, size_t,
+			       enum dma_data_direction);
+	void *(*kmap_atomic)(struct dma_buf *, unsigned long);
+	void (*kunmap_atomic)(struct dma_buf *, unsigned long, void *);
+	void *(*kmap)(struct dma_buf *, unsigned long);
+	void (*kunmap)(struct dma_buf *, unsigned long, void *);
 };
 
 /**
@@ -140,6 +159,14 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *,
 					enum dma_data_direction);
 void dma_buf_unmap_attachment(struct dma_buf_attachment *, struct sg_table *,
 				enum dma_data_direction);
+int dma_buf_begin_cpu_access(struct dma_buf *dma_buf, size_t start, size_t len,
+			     enum dma_data_direction dir);
+void dma_buf_end_cpu_access(struct dma_buf *dma_buf, size_t start, size_t len,
+			    enum dma_data_direction dir);
+void *dma_buf_kmap_atomic(struct dma_buf *, unsigned long);
+void dma_buf_kunmap_atomic(struct dma_buf *, unsigned long, void *);
+void *dma_buf_kmap(struct dma_buf *, unsigned long);
+void dma_buf_kunmap(struct dma_buf *, unsigned long, void *);
 #else
 
 static inline struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf,
@@ -188,6 +215,38 @@ static inline void dma_buf_unmap_attachment(struct dma_buf_attachment *attach,
 	return;
 }
 
+static inline int dma_buf_begin_cpu_access(struct dma_buf *,
+					   size_t, size_t,
+					   enum dma_data_direction)
+{
+	return -ENODEV;
+}
+
+static inline void dma_buf_end_cpu_access(struct dma_buf *,
+					  size_t, size_t,
+					  enum dma_data_direction)
+{
+}
+
+static inline void *dma_buf_kmap_atomic(struct dma_buf *, unsigned long)
+{
+	return NULL;
+}
+
+static inline void dma_buf_kunmap_atomic(struct dma_buf *, unsigned long,
+					 void *)
+{
+}
+
+static inline void *dma_buf_kmap(struct dma_buf *, unsigned long)
+{
+	return NULL;
+}
+
+static inline void dma_buf_kunmap(struct dma_buf *, unsigned long,
+				  void *)
+{
+}
 #endif /* CONFIG_DMA_SHARED_BUFFER */
 
 #endif /* __DMA_BUF_H__ */