1 /******************************************************************************
4 * Xen balloon driver - enables returning/claiming memory to/from Xen.
6 * Copyright (c) 2003, B Dragovic
7 * Copyright (c) 2003-2004, M Williamson, K Fraser
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:
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:
22 * The above copyright notice and this permission notice shall be included in
23 * all copies or substantial portions of the Software.
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
34 #ifndef __ASM_BALLOON_H__
35 #define __ASM_BALLOON_H__
38 * Inform the balloon driver that it should allow some slop for device-driver
41 void balloon_update_driver_allowance(long delta);
43 /* Allocate/free a set of empty pages in low memory (i.e., no RAM mapped). */
44 struct page **alloc_empty_pages_and_pagevec(int nr_pages);
45 void free_empty_pages_and_pagevec(struct page **pagevec, int nr_pages);
47 void balloon_release_driver_page(struct page *page);
50 * Prevent the balloon driver from changing the memory reservation during
51 * a driver critical region.
53 extern spinlock_t balloon_lock;
54 #define balloon_lock(__flags) spin_lock_irqsave(&balloon_lock, __flags)
55 #define balloon_unlock(__flags) spin_unlock_irqrestore(&balloon_lock, __flags)
57 #endif /* __ASM_BALLOON_H__ */