Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / include / linux / splice.h

diff --git a/kernel/include/linux/splice.h b/kernel/include/linux/splice.h
new file mode 100644 (file)
index 0000000..da2751d
--- /dev/null
+++ b/kernel/include/linux/splice.h
@@ -0,0 +1,86 @@
+/*
+ * Function declerations and data structures related to the splice
+ * implementation.
+ *
+ * Copyright (C) 2007 Jens Axboe <jens.axboe@oracle.com>
+ *
+ */
+#ifndef SPLICE_H
+#define SPLICE_H
+
+#include <linux/pipe_fs_i.h>
+
+/*
+ * Flags passed in from splice/tee/vmsplice
+ */
+#define SPLICE_F_MOVE  (0x01)  /* move pages instead of copying */
+#define SPLICE_F_NONBLOCK (0x02) /* don't block on the pipe splicing (but */
+                                /* 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
+ */
+struct splice_desc {
+       size_t total_len;               /* remaining length */
+       unsigned int len;               /* current length */
+       unsigned int flags;             /* splice flags */
+       /*
+        * actor() private data
+        */
+       union {
+               void __user *userptr;   /* memory to write to */
+               struct file *file;      /* file to read/write */
+               void *data;             /* cookie */
+       } u;
+       loff_t pos;                     /* file position */
+       loff_t *opos;                   /* sendfile: output position */
+       size_t num_spliced;             /* number of bytes already spliced */
+       bool need_wakeup;               /* need to wake up writer */
+};
+
+struct partial_page {
+       unsigned int offset;
+       unsigned int len;
+       unsigned long private;
+};
+
+/*
+ * Passed to splice_to_pipe
+ */
+struct splice_pipe_desc {
+       struct page **pages;            /* page map */
+       struct partial_page *partial;   /* pages[] may not be contig */
+       int nr_pages;                   /* number of populated pages in map */
+       unsigned int nr_pages_max;      /* pages[] & partial[] arrays size */
+       unsigned int flags;             /* splice flags */
+       const struct pipe_buf_operations *ops;/* ops associated with output pipe */
+       void (*spd_release)(struct splice_pipe_desc *, unsigned int);
+};
+
+typedef int (splice_actor)(struct pipe_inode_info *, struct pipe_buffer *,
+                          struct splice_desc *);
+typedef int (splice_direct_actor)(struct pipe_inode_info *,
+                                 struct splice_desc *);
+
+extern ssize_t splice_from_pipe(struct pipe_inode_info *, struct file *,
+                               loff_t *, size_t, unsigned int,
+                               splice_actor *);
+extern ssize_t __splice_from_pipe(struct pipe_inode_info *,
+                                 struct splice_desc *, splice_actor *);
+extern ssize_t splice_to_pipe(struct pipe_inode_info *,
+                             struct splice_pipe_desc *);
+extern ssize_t splice_direct_to_actor(struct file *, struct splice_desc *,
+                                     splice_direct_actor *);
+
+/*
+ * for dynamic pipe sizing
+ */
+extern int splice_grow_spd(const struct pipe_inode_info *, struct splice_pipe_desc *);
+extern void splice_shrink_spd(struct splice_pipe_desc *);
+extern void spd_release_page(struct splice_pipe_desc *, unsigned int);
+
+extern const struct pipe_buf_operations page_cache_pipe_buf_ops;
+#endif