Merge rsync://rsync.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

[linux-2.6-omap-h63xx.git] / include / linux / pipe_fs_i.h

diff --git a/include/linux/pipe_fs_i.h b/include/linux/pipe_fs_i.h
index 0008d4bd4059622972dce43aaf5d78acbdab0b80..2e19478e9e84f90e93a6445b53aed3ca78656fa5 100644 (file)
--- a/include/linux/pipe_fs_i.h
+++ b/include/linux/pipe_fs_i.h
@@ -5,20 +5,34 @@
 
 #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;
        unsigned int offset, len;
-       struct pipe_buf_operations *ops;
+       const struct pipe_buf_operations *ops;
        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 *);
@@ -27,9 +41,7 @@ struct pipe_buf_operations {
 struct pipe_inode_info {
        wait_queue_head_t wait;
        unsigned int nrbufs, curbuf;
-       struct pipe_buffer bufs[PIPE_BUFFERS];
        struct page *tmp_page;
-       unsigned int start;
        unsigned int readers;
        unsigned int writers;
        unsigned int waiting_writers;
@@ -38,6 +50,7 @@ struct pipe_inode_info {
        struct fasync_struct *fasync_readers;
        struct fasync_struct *fasync_writers;
        struct inode *inode;
+       struct pipe_buffer bufs[PIPE_BUFFERS];
 };
 
 /* Differs from PIPE_BUF in that PIPE_SIZE is the length of the actual
@@ -51,6 +64,13 @@ 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 *);
+int generic_pipe_buf_steal(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