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authorLinus Torvalds <torvalds@linux-foundation.org>2012-03-28 15:02:41 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-03-28 15:02:41 -0700
commited0bb8ea059764c3fc882fb135473afd347335e9 (patch)
tree5274b8335afe85f76d1eb945eb03ffe4040737b4 /include/linux/dma-buf.h
parent47b816ff7d520509176154748713e7d66b3ad6ac (diff)
parent3e0b2a1993c06e646d90d71e163d03869a211a4c (diff)
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Merge branch 'for-linus-3.4' of git://git.linaro.org/people/sumitsemwal/linux-dma-buf
Pull dma-buf updates from Sumit Semwal: "This includes the following key items: - kernel cpu access support, - flag-passing to dma_buf_fd, - relevant Documentation updates, and - some minor cleanups and fixes. These changes are needed for the drm prime/dma-buf interface code that Dave Airlie plans to submit in this merge window." * 'for-linus-3.4' of git://git.linaro.org/people/sumitsemwal/linux-dma-buf: dma-buf: correct dummy function declarations. dma-buf: document fd flags and O_CLOEXEC requirement dma_buf: Add documentation for the new cpu access support dma-buf: add support for kernel cpu access dma-buf: don't hold the mutex around map/unmap calls dma-buf: add get_dma_buf() dma-buf: pass flags into dma_buf_fd. dma-buf: add dma_data_direction to unmap dma_buf_op dma-buf: Move code out of mutex-protected section in dma_buf_attach() dma-buf: Return error instead of using a goto statement when possible dma-buf: Remove unneeded sanity checks dma-buf: Constify ops argument to dma_buf_export()
Diffstat (limited to 'include/linux/dma-buf.h')
-rw-r--r--include/linux/dma-buf.h97
1 files changed, 87 insertions, 10 deletions
diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
index 887dcd487062..3efbfc2145c3 100644
--- a/include/linux/dma-buf.h
+++ b/include/linux/dma-buf.h
@@ -29,6 +29,7 @@
#include <linux/scatterlist.h>
#include <linux/list.h>
#include <linux/dma-mapping.h>
+#include <linux/fs.h>
struct device;
struct dma_buf;
@@ -49,6 +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 *,
@@ -63,7 +75,8 @@ struct dma_buf_ops {
struct sg_table * (*map_dma_buf)(struct dma_buf_attachment *,
enum dma_data_direction);
void (*unmap_dma_buf)(struct dma_buf_attachment *,
- struct sg_table *);
+ struct sg_table *,
+ enum dma_data_direction);
/* TODO: Add try_map_dma_buf version, to return immed with -EBUSY
* if the call would block.
*/
@@ -71,6 +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 *);
};
/**
@@ -86,7 +107,7 @@ struct dma_buf {
struct file *file;
struct list_head attachments;
const struct dma_buf_ops *ops;
- /* mutex to serialize list manipulation and other ops */
+ /* mutex to serialize list manipulation and attach/detach */
struct mutex lock;
void *priv;
};
@@ -109,20 +130,43 @@ struct dma_buf_attachment {
void *priv;
};
+/**
+ * get_dma_buf - convenience wrapper for get_file.
+ * @dmabuf: [in] pointer to dma_buf
+ *
+ * Increments the reference count on the dma-buf, needed in case of drivers
+ * that either need to create additional references to the dmabuf on the
+ * kernel side. For example, an exporter that needs to keep a dmabuf ptr
+ * so that subsequent exports don't create a new dmabuf.
+ */
+static inline void get_dma_buf(struct dma_buf *dmabuf)
+{
+ get_file(dmabuf->file);
+}
+
#ifdef CONFIG_DMA_SHARED_BUFFER
struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf,
struct device *dev);
void dma_buf_detach(struct dma_buf *dmabuf,
struct dma_buf_attachment *dmabuf_attach);
-struct dma_buf *dma_buf_export(void *priv, struct dma_buf_ops *ops,
- size_t size, int flags);
-int dma_buf_fd(struct dma_buf *dmabuf);
+struct dma_buf *dma_buf_export(void *priv, const struct dma_buf_ops *ops,
+ size_t size, int flags);
+int dma_buf_fd(struct dma_buf *dmabuf, int flags);
struct dma_buf *dma_buf_get(int fd);
void dma_buf_put(struct dma_buf *dmabuf);
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 *);
+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,
@@ -138,13 +182,13 @@ static inline void dma_buf_detach(struct dma_buf *dmabuf,
}
static inline struct dma_buf *dma_buf_export(void *priv,
- struct dma_buf_ops *ops,
- size_t size, int flags)
+ const struct dma_buf_ops *ops,
+ size_t size, int flags)
{
return ERR_PTR(-ENODEV);
}
-static inline int dma_buf_fd(struct dma_buf *dmabuf)
+static inline int dma_buf_fd(struct dma_buf *dmabuf, int flags)
{
return -ENODEV;
}
@@ -166,11 +210,44 @@ static inline struct sg_table *dma_buf_map_attachment(
}
static inline void dma_buf_unmap_attachment(struct dma_buf_attachment *attach,
- struct sg_table *sg)
+ struct sg_table *sg, enum dma_data_direction dir)
{
return;
}
+static inline int dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
+ size_t start, size_t len,
+ enum dma_data_direction dir)
+{
+ return -ENODEV;
+}
+
+static inline void dma_buf_end_cpu_access(struct dma_buf *dmabuf,
+ size_t start, size_t len,
+ enum dma_data_direction dir)
+{
+}
+
+static inline void *dma_buf_kmap_atomic(struct dma_buf *dmabuf,
+ unsigned long pnum)
+{
+ return NULL;
+}
+
+static inline void dma_buf_kunmap_atomic(struct dma_buf *dmabuf,
+ unsigned long pnum, void *vaddr)
+{
+}
+
+static inline void *dma_buf_kmap(struct dma_buf *dmabuf, unsigned long pnum)
+{
+ return NULL;
+}
+
+static inline void dma_buf_kunmap(struct dma_buf *dmabuf,
+ unsigned long pnum, void *vaddr)
+{
+}
#endif /* CONFIG_DMA_SHARED_BUFFER */
#endif /* __DMA_BUF_H__ */