cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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splice.h (3060B)

      1/* SPDX-License-Identifier: GPL-2.0 */
      2/*
      3 * Function declerations and data structures related to the splice
      4 * implementation.
      5 *
      6 * Copyright (C) 2007 Jens Axboe <jens.axboe@oracle.com>
      7 *
      8 */
      9#ifndef SPLICE_H
     10#define SPLICE_H
     11
     12#include <linux/pipe_fs_i.h>
     13
     14/*
     15 * Flags passed in from splice/tee/vmsplice
     16 */
     17#define SPLICE_F_MOVE	(0x01)	/* move pages instead of copying */
     18#define SPLICE_F_NONBLOCK (0x02) /* don't block on the pipe splicing (but */
     19				 /* we may still block on the fd we splice */
     20				 /* from/to, of course */
     21#define SPLICE_F_MORE	(0x04)	/* expect more data */
     22#define SPLICE_F_GIFT	(0x08)	/* pages passed in are a gift */
     23
     24#define SPLICE_F_ALL (SPLICE_F_MOVE|SPLICE_F_NONBLOCK|SPLICE_F_MORE|SPLICE_F_GIFT)
     25
     26/*
     27 * Passed to the actors
     28 */
     29struct splice_desc {
     30	size_t total_len;		/* remaining length */
     31	unsigned int len;		/* current length */
     32	unsigned int flags;		/* splice flags */
     33	/*
     34	 * actor() private data
     35	 */
     36	union {
     37		void __user *userptr;	/* memory to write to */
     38		struct file *file;	/* file to read/write */
     39		void *data;		/* cookie */
     40	} u;
     41	loff_t pos;			/* file position */
     42	loff_t *opos;			/* sendfile: output position */
     43	size_t num_spliced;		/* number of bytes already spliced */
     44	bool need_wakeup;		/* need to wake up writer */
     45};
     46
     47struct partial_page {
     48	unsigned int offset;
     49	unsigned int len;
     50	unsigned long private;
     51};
     52
     53/*
     54 * Passed to splice_to_pipe
     55 */
     56struct splice_pipe_desc {
     57	struct page **pages;		/* page map */
     58	struct partial_page *partial;	/* pages[] may not be contig */
     59	int nr_pages;			/* number of populated pages in map */
     60	unsigned int nr_pages_max;	/* pages[] & partial[] arrays size */
     61	const struct pipe_buf_operations *ops;/* ops associated with output pipe */
     62	void (*spd_release)(struct splice_pipe_desc *, unsigned int);
     63};
     64
     65typedef int (splice_actor)(struct pipe_inode_info *, struct pipe_buffer *,
     66			   struct splice_desc *);
     67typedef int (splice_direct_actor)(struct pipe_inode_info *,
     68				  struct splice_desc *);
     69
     70extern ssize_t splice_from_pipe(struct pipe_inode_info *, struct file *,
     71				loff_t *, size_t, unsigned int,
     72				splice_actor *);
     73extern ssize_t __splice_from_pipe(struct pipe_inode_info *,
     74				  struct splice_desc *, splice_actor *);
     75extern ssize_t splice_to_pipe(struct pipe_inode_info *,
     76			      struct splice_pipe_desc *);
     77extern ssize_t add_to_pipe(struct pipe_inode_info *,
     78			      struct pipe_buffer *);
     79extern ssize_t splice_direct_to_actor(struct file *, struct splice_desc *,
     80				      splice_direct_actor *);
     81extern long do_splice(struct file *in, loff_t *off_in,
     82		      struct file *out, loff_t *off_out,
     83		      size_t len, unsigned int flags);
     84
     85extern long do_tee(struct file *in, struct file *out, size_t len,
     86		   unsigned int flags);
     87
     88/*
     89 * for dynamic pipe sizing
     90 */
     91extern int splice_grow_spd(const struct pipe_inode_info *, struct splice_pipe_desc *);
     92extern void splice_shrink_spd(struct splice_pipe_desc *);
     93
     94extern const struct pipe_buf_operations page_cache_pipe_buf_ops;
     95extern const struct pipe_buf_operations default_pipe_buf_ops;
     96#endif