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-rw-r--r--include/linux/pipe_fs_i.h29
1 files changed, 25 insertions, 4 deletions
diff --git a/include/linux/pipe_fs_i.h b/include/linux/pipe_fs_i.h
index 0008d4bd405..df4d3fa7d3d 100644
--- a/include/linux/pipe_fs_i.h
+++ b/include/linux/pipe_fs_i.h
@@ -5,8 +5,9 @@
#define PIPE_BUFFERS (16)
-#define PIPE_BUF_FLAG_STOLEN 0x01
-#define PIPE_BUF_FLAG_LRU 0x02
+#define PIPE_BUF_FLAG_LRU 0x01 /* page is on the LRU */
+#define PIPE_BUF_FLAG_ATOMIC 0x02 /* was atomically mapped */
+#define PIPE_BUF_FLAG_GIFT 0x04 /* page is a gift */
struct pipe_buffer {
struct page *page;
@@ -15,10 +16,23 @@ struct pipe_buffer {
unsigned int flags;
};
+/*
+ * Note on the nesting of these functions:
+ *
+ * ->pin()
+ * ->steal()
+ * ...
+ * ->map()
+ * ...
+ * ->unmap()
+ *
+ * That is, ->map() must be called on a pinned buffer, same goes for ->steal().
+ */
struct pipe_buf_operations {
int can_merge;
- void * (*map)(struct file *, struct pipe_inode_info *, struct pipe_buffer *);
- void (*unmap)(struct pipe_inode_info *, struct pipe_buffer *);
+ void * (*map)(struct pipe_inode_info *, struct pipe_buffer *, int);
+ void (*unmap)(struct pipe_inode_info *, struct pipe_buffer *, void *);
+ int (*pin)(struct pipe_inode_info *, struct pipe_buffer *);
void (*release)(struct pipe_inode_info *, struct pipe_buffer *);
int (*steal)(struct pipe_inode_info *, struct pipe_buffer *);
void (*get)(struct pipe_inode_info *, struct pipe_buffer *);
@@ -51,6 +65,12 @@ struct pipe_inode_info * alloc_pipe_info(struct inode * inode);
void free_pipe_info(struct inode * inode);
void __free_pipe_info(struct pipe_inode_info *);
+/* Generic pipe buffer ops functions */
+void *generic_pipe_buf_map(struct pipe_inode_info *, struct pipe_buffer *, int);
+void generic_pipe_buf_unmap(struct pipe_inode_info *, struct pipe_buffer *, void *);
+void generic_pipe_buf_get(struct pipe_inode_info *, struct pipe_buffer *);
+int generic_pipe_buf_pin(struct pipe_inode_info *, struct pipe_buffer *);
+
/*
* splice is tied to pipes as a transport (at least for now), so we'll just
* add the splice flags here.
@@ -60,6 +80,7 @@ void __free_pipe_info(struct pipe_inode_info *);
/* we may still block on the fd we splice */
/* from/to, of course */
#define SPLICE_F_MORE (0x04) /* expect more data */
+#define SPLICE_F_GIFT (0x08) /* pages passed in are a gift */
/*
* Passed to the actors