5 * Copyright (C) 2003 IBM Deutschland Entwicklung GmbH, IBM Corporation
6 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
8 * Collaborative memory management interface.
11 #include <linux/config.h>
12 #include <linux/errno.h>
14 #include <linux/init.h>
15 #include <linux/module.h>
16 #include <linux/sched.h>
17 #include <linux/sysctl.h>
18 #include <linux/ctype.h>
20 #include <asm/pgalloc.h>
21 #include <asm/uaccess.h>
23 #include "../../../drivers/s390/net/smsgiucv.h"
25 #define CMM_NR_PAGES ((PAGE_SIZE / sizeof(unsigned long)) - 2)
27 struct cmm_page_array
{
28 struct cmm_page_array
*next
;
30 unsigned long pages
[CMM_NR_PAGES
];
33 static long cmm_pages
= 0;
34 static long cmm_timed_pages
= 0;
35 static volatile long cmm_pages_target
= 0;
36 static volatile long cmm_timed_pages_target
= 0;
37 static long cmm_timeout_pages
= 0;
38 static long cmm_timeout_seconds
= 0;
40 static struct cmm_page_array
*cmm_page_list
= 0;
41 static struct cmm_page_array
*cmm_timed_page_list
= 0;
43 static unsigned long cmm_thread_active
= 0;
44 static struct work_struct cmm_thread_starter
;
45 static wait_queue_head_t cmm_thread_wait
;
46 static struct timer_list cmm_timer
;
48 static void cmm_timer_fn(unsigned long);
49 static void cmm_set_timer(void);
52 cmm_strtoul(const char *cp
, char **endp
)
54 unsigned int base
= 10;
59 if ((*cp
== 'x' || *cp
== 'X') && isxdigit(cp
[1])) {
64 return simple_strtoul(cp
, endp
, base
);
68 cmm_alloc_pages(long pages
, long *counter
, struct cmm_page_array
**list
)
70 struct cmm_page_array
*pa
;
75 page
= __get_free_page(GFP_NOIO
);
78 if (!pa
|| pa
->index
>= CMM_NR_PAGES
) {
79 /* Need a new page for the page list. */
80 pa
= (struct cmm_page_array
*)
81 __get_free_page(GFP_NOIO
);
91 pa
->pages
[pa
->index
++] = page
;
99 cmm_free_pages(long pages
, long *counter
, struct cmm_page_array
**list
)
101 struct cmm_page_array
*pa
;
106 if (!pa
|| pa
->index
<= 0)
108 page
= pa
->pages
[--pa
->index
];
109 if (pa
->index
== 0) {
111 free_page((unsigned long) *list
);
121 cmm_thread(void *dummy
)
125 daemonize("cmmthread");
127 rc
= wait_event_interruptible(cmm_thread_wait
,
128 (cmm_pages
!= cmm_pages_target
||
129 cmm_timed_pages
!= cmm_timed_pages_target
));
130 if (rc
== -ERESTARTSYS
) {
131 /* Got kill signal. End thread. */
132 clear_bit(0, &cmm_thread_active
);
133 cmm_pages_target
= cmm_pages
;
134 cmm_timed_pages_target
= cmm_timed_pages
;
137 if (cmm_pages_target
> cmm_pages
) {
138 if (cmm_alloc_pages(1, &cmm_pages
, &cmm_page_list
))
139 cmm_pages_target
= cmm_pages
;
140 } else if (cmm_pages_target
< cmm_pages
) {
141 cmm_free_pages(1, &cmm_pages
, &cmm_page_list
);
143 if (cmm_timed_pages_target
> cmm_timed_pages
) {
144 if (cmm_alloc_pages(1, &cmm_timed_pages
,
145 &cmm_timed_page_list
))
146 cmm_timed_pages_target
= cmm_timed_pages
;
147 } else if (cmm_timed_pages_target
< cmm_timed_pages
) {
148 cmm_free_pages(1, &cmm_timed_pages
,
149 &cmm_timed_page_list
);
151 if (cmm_timed_pages
> 0 && !timer_pending(&cmm_timer
))
158 cmm_start_thread(void)
160 kernel_thread(cmm_thread
, 0, 0);
164 cmm_kick_thread(void)
166 if (!test_and_set_bit(0, &cmm_thread_active
))
167 schedule_work(&cmm_thread_starter
);
168 wake_up(&cmm_thread_wait
);
174 if (cmm_timed_pages_target
<= 0 || cmm_timeout_seconds
<= 0) {
175 if (timer_pending(&cmm_timer
))
176 del_timer(&cmm_timer
);
179 if (timer_pending(&cmm_timer
)) {
180 if (mod_timer(&cmm_timer
, jiffies
+ cmm_timeout_seconds
*HZ
))
183 cmm_timer
.function
= cmm_timer_fn
;
185 cmm_timer
.expires
= jiffies
+ cmm_timeout_seconds
*HZ
;
186 add_timer(&cmm_timer
);
190 cmm_timer_fn(unsigned long ignored
)
194 pages
= cmm_timed_pages_target
- cmm_timeout_pages
;
196 cmm_timed_pages_target
= 0;
198 cmm_timed_pages_target
= pages
;
204 cmm_set_pages(long pages
)
206 cmm_pages_target
= pages
;
217 cmm_add_timed_pages(long pages
)
219 cmm_timed_pages_target
+= pages
;
224 cmm_get_timed_pages(void)
226 return cmm_timed_pages
;
230 cmm_set_timeout(long pages
, long seconds
)
232 cmm_timeout_pages
= pages
;
233 cmm_timeout_seconds
= seconds
;
238 cmm_skip_blanks(char *cp
, char **endp
)
242 for (str
= cp
; *str
== ' ' || *str
== '\t'; str
++);
247 #ifdef CONFIG_CMM_PROC
248 /* These will someday get removed. */
249 #define VM_CMM_PAGES 1111
250 #define VM_CMM_TIMED_PAGES 1112
251 #define VM_CMM_TIMEOUT 1113
253 static struct ctl_table cmm_table
[];
256 cmm_pages_handler(ctl_table
*ctl
, int write
, struct file
*filp
,
257 void *buffer
, size_t *lenp
, loff_t
*ppos
)
263 if (!*lenp
|| (*ppos
&& !write
)) {
270 if (copy_from_user(buf
, buffer
,
271 len
> sizeof(buf
) ? sizeof(buf
) : len
))
273 buf
[sizeof(buf
) - 1] = '\0';
274 cmm_skip_blanks(buf
, &p
);
275 pages
= cmm_strtoul(p
, &p
);
276 if (ctl
== &cmm_table
[0])
277 cmm_set_pages(pages
);
279 cmm_add_timed_pages(pages
);
281 if (ctl
== &cmm_table
[0])
282 pages
= cmm_get_pages();
284 pages
= cmm_get_timed_pages();
285 len
= sprintf(buf
, "%ld\n", pages
);
288 if (copy_to_user(buffer
, buf
, len
))
297 cmm_timeout_handler(ctl_table
*ctl
, int write
, struct file
*filp
,
298 void *buffer
, size_t *lenp
, loff_t
*ppos
)
304 if (!*lenp
|| (*ppos
&& !write
)) {
311 if (copy_from_user(buf
, buffer
,
312 len
> sizeof(buf
) ? sizeof(buf
) : len
))
314 buf
[sizeof(buf
) - 1] = '\0';
315 cmm_skip_blanks(buf
, &p
);
316 pages
= cmm_strtoul(p
, &p
);
317 cmm_skip_blanks(p
, &p
);
318 seconds
= cmm_strtoul(p
, &p
);
319 cmm_set_timeout(pages
, seconds
);
321 len
= sprintf(buf
, "%ld %ld\n",
322 cmm_timeout_pages
, cmm_timeout_seconds
);
325 if (copy_to_user(buffer
, buf
, len
))
333 static struct ctl_table cmm_table
[] = {
335 .ctl_name
= VM_CMM_PAGES
,
336 .procname
= "cmm_pages",
338 .proc_handler
= &cmm_pages_handler
,
341 .ctl_name
= VM_CMM_TIMED_PAGES
,
342 .procname
= "cmm_timed_pages",
344 .proc_handler
= &cmm_pages_handler
,
347 .ctl_name
= VM_CMM_TIMEOUT
,
348 .procname
= "cmm_timeout",
350 .proc_handler
= &cmm_timeout_handler
,
355 static struct ctl_table cmm_dir_table
[] = {
367 #ifdef CONFIG_CMM_IUCV
368 #define SMSG_PREFIX "CMM"
370 cmm_smsg_target(char *msg
)
374 if (!cmm_skip_blanks(msg
+ strlen(SMSG_PREFIX
), &msg
))
376 if (strncmp(msg
, "SHRINK", 6) == 0) {
377 if (!cmm_skip_blanks(msg
+ 6, &msg
))
379 pages
= cmm_strtoul(msg
, &msg
);
380 cmm_skip_blanks(msg
, &msg
);
382 cmm_set_pages(pages
);
383 } else if (strncmp(msg
, "RELEASE", 7) == 0) {
384 if (!cmm_skip_blanks(msg
+ 7, &msg
))
386 pages
= cmm_strtoul(msg
, &msg
);
387 cmm_skip_blanks(msg
, &msg
);
389 cmm_add_timed_pages(pages
);
390 } else if (strncmp(msg
, "REUSE", 5) == 0) {
391 if (!cmm_skip_blanks(msg
+ 5, &msg
))
393 pages
= cmm_strtoul(msg
, &msg
);
394 if (!cmm_skip_blanks(msg
, &msg
))
396 seconds
= cmm_strtoul(msg
, &msg
);
397 cmm_skip_blanks(msg
, &msg
);
399 cmm_set_timeout(pages
, seconds
);
404 struct ctl_table_header
*cmm_sysctl_header
;
409 #ifdef CONFIG_CMM_PROC
410 cmm_sysctl_header
= register_sysctl_table(cmm_dir_table
, 1);
412 #ifdef CONFIG_CMM_IUCV
413 smsg_register_callback(SMSG_PREFIX
, cmm_smsg_target
);
415 INIT_WORK(&cmm_thread_starter
, (void *) cmm_start_thread
, 0);
416 init_waitqueue_head(&cmm_thread_wait
);
417 init_timer(&cmm_timer
);
424 cmm_free_pages(cmm_pages
, &cmm_pages
, &cmm_page_list
);
425 cmm_free_pages(cmm_timed_pages
, &cmm_timed_pages
, &cmm_timed_page_list
);
426 #ifdef CONFIG_CMM_PROC
427 unregister_sysctl_table(cmm_sysctl_header
);
429 #ifdef CONFIG_CMM_IUCV
430 smsg_unregister_callback(SMSG_PREFIX
, cmm_smsg_target
);
434 module_init(cmm_init
);
435 module_exit(cmm_exit
);
437 EXPORT_SYMBOL(cmm_set_pages
);
438 EXPORT_SYMBOL(cmm_get_pages
);
439 EXPORT_SYMBOL(cmm_add_timed_pages
);
440 EXPORT_SYMBOL(cmm_get_timed_pages
);
441 EXPORT_SYMBOL(cmm_set_timeout
);
443 MODULE_LICENSE("GPL");