include/xen/balloon.h

   1 /******************************************************************************
   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  */
  44 void balloon_update_driver_allowance(long delta);
  45
  46 /* Allocate/free a set of empty pages in low memory (i.e., no RAM mapped). */
  47 struct page **alloc_empty_pages_and_pagevec(int nr_pages);
  48 void free_empty_pages_and_pagevec(struct page **pagevec, int nr_pages);
  49
  50 void 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  */
  56 extern 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__ */