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Jeremy Fitzhardinge17758262008-04-02 10:54:13 -07001/******************************************************************************
2 * balloon.h
3 *
4 * Xen balloon driver - enables returning/claiming memory to/from Xen.
5 *
6 * Copyright (c) 2003, B Dragovic
7 * Copyright (c) 2003-2004, M Williamson, K Fraser
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License version 2
11 * as published by the Free Software Foundation; or, when distributed
12 * separately from the Linux kernel or incorporated into other
13 * software packages, subject to the following license:
14 *
15 * Permission is hereby granted, free of charge, to any person obtaining a copy
16 * of this source file (the "Software"), to deal in the Software without
17 * restriction, including without limitation the rights to use, copy, modify,
18 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
19 * and to permit persons to whom the Software is furnished to do so, subject to
20 * the following conditions:
21 *
22 * The above copyright notice and this permission notice shall be included in
23 * all copies or substantial portions of the Software.
24 *
25 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
26 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
27 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
28 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
29 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
30 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
31 * IN THE SOFTWARE.
32 */
33
34#ifndef __XEN_BALLOON_H__
35#define __XEN_BALLOON_H__
36
37#include <linux/spinlock.h>
38
39#if 0
40/*
41 * Inform the balloon driver that it should allow some slop for device-driver
42 * memory activities.
43 */
44void balloon_update_driver_allowance(long delta);
45
46/* Allocate/free a set of empty pages in low memory (i.e., no RAM mapped). */
47struct page **alloc_empty_pages_and_pagevec(int nr_pages);
48void free_empty_pages_and_pagevec(struct page **pagevec, int nr_pages);
49
50void balloon_release_driver_page(struct page *page);
51
52/*
53 * Prevent the balloon driver from changing the memory reservation during
54 * a driver critical region.
55 */
56extern spinlock_t balloon_lock;
57#define balloon_lock(__flags) spin_lock_irqsave(&balloon_lock, __flags)
58#define balloon_unlock(__flags) spin_unlock_irqrestore(&balloon_lock, __flags)
59#endif
60
61#endif /* __XEN_BALLOON_H__ */