2 * linux/kernel/power/swsusp.c
4 * This file provides code to write suspend image to swap and read it back.
6 * Copyright (C) 1998-2001 Gabor Kuti <seasons@fornax.hu>
7 * Copyright (C) 1998,2001-2005 Pavel Machek <pavel@suse.cz>
9 * This file is released under the GPLv2.
11 * I'd like to thank the following people for their work:
13 * Pavel Machek <pavel@ucw.cz>:
14 * Modifications, defectiveness pointing, being with me at the very beginning,
15 * suspend to swap space, stop all tasks. Port to 2.4.18-ac and 2.5.17.
17 * Steve Doddi <dirk@loth.demon.co.uk>:
18 * Support the possibility of hardware state restoring.
20 * Raph <grey.havens@earthling.net>:
21 * Support for preserving states of network devices and virtual console
22 * (including X and svgatextmode)
24 * Kurt Garloff <garloff@suse.de>:
25 * Straightened the critical function in order to prevent compilers from
26 * playing tricks with local variables.
28 * Andreas Mohr <a.mohr@mailto.de>
30 * Alex Badea <vampire@go.ro>:
33 * Rafael J. Wysocki <rjw@sisk.pl>
34 * Reworked the freeing of memory and the handling of swap
36 * More state savers are welcome. Especially for the scsi layer...
38 * For TODOs,FIXMEs also look in Documentation/power/swsusp.txt
42 #include <linux/suspend.h>
43 #include <linux/spinlock.h>
44 #include <linux/kernel.h>
45 #include <linux/major.h>
46 #include <linux/swap.h>
48 #include <linux/swapops.h>
49 #include <linux/bootmem.h>
50 #include <linux/syscalls.h>
51 #include <linux/highmem.h>
52 #include <linux/time.h>
53 #include <linux/rbtree.h>
58 int in_suspend __nosavedata
= 0;
61 * The following functions are used for tracing the allocated
62 * swap pages, so that they can be freed in case of an error.
65 struct swsusp_extent
{
71 static struct rb_root swsusp_extents
= RB_ROOT
;
73 static int swsusp_extents_insert(unsigned long swap_offset
)
75 struct rb_node
**new = &(swsusp_extents
.rb_node
);
76 struct rb_node
*parent
= NULL
;
77 struct swsusp_extent
*ext
;
79 /* Figure out where to put the new node */
81 ext
= container_of(*new, struct swsusp_extent
, node
);
83 if (swap_offset
< ext
->start
) {
85 if (swap_offset
== ext
->start
- 1) {
89 new = &((*new)->rb_left
);
90 } else if (swap_offset
> ext
->end
) {
92 if (swap_offset
== ext
->end
+ 1) {
96 new = &((*new)->rb_right
);
98 /* It already is in the tree */
102 /* Add the new node and rebalance the tree. */
103 ext
= kzalloc(sizeof(struct swsusp_extent
), GFP_KERNEL
);
107 ext
->start
= swap_offset
;
108 ext
->end
= swap_offset
;
109 rb_link_node(&ext
->node
, parent
, new);
110 rb_insert_color(&ext
->node
, &swsusp_extents
);
115 * alloc_swapdev_block - allocate a swap page and register that it has
116 * been allocated, so that it can be freed in case of an error.
119 sector_t
alloc_swapdev_block(int swap
)
121 unsigned long offset
;
123 offset
= swp_offset(get_swap_page_of_type(swap
));
125 if (swsusp_extents_insert(offset
))
126 swap_free(swp_entry(swap
, offset
));
128 return swapdev_block(swap
, offset
);
134 * free_all_swap_pages - free swap pages allocated for saving image data.
135 * It also frees the extents used to register which swap entres had been
139 void free_all_swap_pages(int swap
)
141 struct rb_node
*node
;
143 while ((node
= swsusp_extents
.rb_node
)) {
144 struct swsusp_extent
*ext
;
145 unsigned long offset
;
147 ext
= container_of(node
, struct swsusp_extent
, node
);
148 rb_erase(node
, &swsusp_extents
);
149 for (offset
= ext
->start
; offset
<= ext
->end
; offset
++)
150 swap_free(swp_entry(swap
, offset
));
156 int swsusp_swap_in_use(void)
158 return (swsusp_extents
.rb_node
!= NULL
);
162 * swsusp_show_speed - print the time elapsed between two events represented by
165 * @nr_pages - number of pages processed between @start and @stop
166 * @msg - introductory message to print
169 void swsusp_show_speed(struct timeval
*start
, struct timeval
*stop
,
170 unsigned nr_pages
, char *msg
)
172 s64 elapsed_centisecs64
;
177 elapsed_centisecs64
= timeval_to_ns(stop
) - timeval_to_ns(start
);
178 do_div(elapsed_centisecs64
, NSEC_PER_SEC
/ 100);
179 centisecs
= elapsed_centisecs64
;
181 centisecs
= 1; /* avoid div-by-zero */
182 k
= nr_pages
* (PAGE_SIZE
/ 1024);
183 kps
= (k
* 100) / centisecs
;
184 printk(KERN_INFO
"PM: %s %d kbytes in %d.%02d seconds (%d.%02d MB/s)\n",
186 centisecs
/ 100, centisecs
% 100,
187 kps
/ 1000, (kps
% 1000) / 10);
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