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/errno.h>
13 #include <linux/init.h>
14 #include <linux/module.h>
15 #include <linux/sched.h>
16 #include <linux/sysctl.h>
17 #include <linux/ctype.h>
18 #include <linux/swap.h>
19 #include <linux/kthread.h>
21 #include <asm/pgalloc.h>
22 #include <asm/uaccess.h>
24 static char *sender
= "VMRMSVM";
25 module_param(sender
, charp
, 0400);
26 MODULE_PARM_DESC(sender
,
27 "Guest name that may send SMSG messages (default VMRMSVM)");
29 #include "../../../drivers/s390/net/smsgiucv.h"
31 #define CMM_NR_PAGES ((PAGE_SIZE / sizeof(unsigned long)) - 2)
33 struct cmm_page_array
{
34 struct cmm_page_array
*next
;
36 unsigned long pages
[CMM_NR_PAGES
];
39 static long cmm_pages
;
40 static long cmm_timed_pages
;
41 static volatile long cmm_pages_target
;
42 static volatile long cmm_timed_pages_target
;
43 static long cmm_timeout_pages
;
44 static long cmm_timeout_seconds
;
46 static struct cmm_page_array
*cmm_page_list
;
47 static struct cmm_page_array
*cmm_timed_page_list
;
48 static DEFINE_SPINLOCK(cmm_lock
);
50 static struct task_struct
*cmm_thread_ptr
;
51 static wait_queue_head_t cmm_thread_wait
;
52 static struct timer_list cmm_timer
;
54 static void cmm_timer_fn(unsigned long);
55 static void cmm_set_timer(void);
58 cmm_alloc_pages(long nr
, long *counter
, struct cmm_page_array
**list
)
60 struct cmm_page_array
*pa
, *npa
;
64 addr
= __get_free_page(GFP_NOIO
);
69 if (!pa
|| pa
->index
>= CMM_NR_PAGES
) {
70 /* Need a new page for the page list. */
71 spin_unlock(&cmm_lock
);
72 npa
= (struct cmm_page_array
*)
73 __get_free_page(GFP_NOIO
);
80 if (!pa
|| pa
->index
>= CMM_NR_PAGES
) {
86 free_page((unsigned long) npa
);
89 pa
->pages
[pa
->index
++] = addr
;
91 spin_unlock(&cmm_lock
);
98 cmm_free_pages(long nr
, long *counter
, struct cmm_page_array
**list
)
100 struct cmm_page_array
*pa
;
103 spin_lock(&cmm_lock
);
106 if (!pa
|| pa
->index
<= 0)
108 addr
= pa
->pages
[--pa
->index
];
109 if (pa
->index
== 0) {
111 free_page((unsigned long) *list
);
118 spin_unlock(&cmm_lock
);
122 static int cmm_oom_notify(struct notifier_block
*self
,
123 unsigned long dummy
, void *parm
)
125 unsigned long *freed
= parm
;
128 nr
= cmm_free_pages(nr
, &cmm_timed_pages
, &cmm_timed_page_list
);
130 nr
= cmm_free_pages(nr
, &cmm_pages
, &cmm_page_list
);
131 cmm_pages_target
= cmm_pages
;
132 cmm_timed_pages_target
= cmm_timed_pages
;
137 static struct notifier_block cmm_oom_nb
= {
138 .notifier_call
= cmm_oom_notify
142 cmm_thread(void *dummy
)
147 rc
= wait_event_interruptible(cmm_thread_wait
,
148 (cmm_pages
!= cmm_pages_target
||
149 cmm_timed_pages
!= cmm_timed_pages_target
||
150 kthread_should_stop()));
151 if (kthread_should_stop() || rc
== -ERESTARTSYS
) {
152 cmm_pages_target
= cmm_pages
;
153 cmm_timed_pages_target
= cmm_timed_pages
;
156 if (cmm_pages_target
> cmm_pages
) {
157 if (cmm_alloc_pages(1, &cmm_pages
, &cmm_page_list
))
158 cmm_pages_target
= cmm_pages
;
159 } else if (cmm_pages_target
< cmm_pages
) {
160 cmm_free_pages(1, &cmm_pages
, &cmm_page_list
);
162 if (cmm_timed_pages_target
> cmm_timed_pages
) {
163 if (cmm_alloc_pages(1, &cmm_timed_pages
,
164 &cmm_timed_page_list
))
165 cmm_timed_pages_target
= cmm_timed_pages
;
166 } else if (cmm_timed_pages_target
< cmm_timed_pages
) {
167 cmm_free_pages(1, &cmm_timed_pages
,
168 &cmm_timed_page_list
);
170 if (cmm_timed_pages
> 0 && !timer_pending(&cmm_timer
))
177 cmm_kick_thread(void)
179 wake_up(&cmm_thread_wait
);
185 if (cmm_timed_pages_target
<= 0 || cmm_timeout_seconds
<= 0) {
186 if (timer_pending(&cmm_timer
))
187 del_timer(&cmm_timer
);
190 if (timer_pending(&cmm_timer
)) {
191 if (mod_timer(&cmm_timer
, jiffies
+ cmm_timeout_seconds
*HZ
))
194 cmm_timer
.function
= cmm_timer_fn
;
196 cmm_timer
.expires
= jiffies
+ cmm_timeout_seconds
*HZ
;
197 add_timer(&cmm_timer
);
201 cmm_timer_fn(unsigned long ignored
)
205 nr
= cmm_timed_pages_target
- cmm_timeout_pages
;
207 cmm_timed_pages_target
= 0;
209 cmm_timed_pages_target
= nr
;
215 cmm_set_pages(long nr
)
217 cmm_pages_target
= nr
;
228 cmm_add_timed_pages(long nr
)
230 cmm_timed_pages_target
+= nr
;
235 cmm_get_timed_pages(void)
237 return cmm_timed_pages
;
241 cmm_set_timeout(long nr
, long seconds
)
243 cmm_timeout_pages
= nr
;
244 cmm_timeout_seconds
= seconds
;
249 cmm_skip_blanks(char *cp
, char **endp
)
253 for (str
= cp
; *str
== ' ' || *str
== '\t'; str
++);
258 #ifdef CONFIG_CMM_PROC
260 static struct ctl_table cmm_table
[];
263 cmm_pages_handler(ctl_table
*ctl
, int write
, struct file
*filp
,
264 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
270 if (!*lenp
|| (*ppos
&& !write
)) {
277 if (copy_from_user(buf
, buffer
,
278 len
> sizeof(buf
) ? sizeof(buf
) : len
))
280 buf
[sizeof(buf
) - 1] = '\0';
281 cmm_skip_blanks(buf
, &p
);
282 nr
= simple_strtoul(p
, &p
, 0);
283 if (ctl
== &cmm_table
[0])
286 cmm_add_timed_pages(nr
);
288 if (ctl
== &cmm_table
[0])
289 nr
= cmm_get_pages();
291 nr
= cmm_get_timed_pages();
292 len
= sprintf(buf
, "%ld\n", nr
);
295 if (copy_to_user(buffer
, buf
, len
))
304 cmm_timeout_handler(ctl_table
*ctl
, int write
, struct file
*filp
,
305 void __user
*buffer
, size_t *lenp
, loff_t
*ppos
)
311 if (!*lenp
|| (*ppos
&& !write
)) {
318 if (copy_from_user(buf
, buffer
,
319 len
> sizeof(buf
) ? sizeof(buf
) : len
))
321 buf
[sizeof(buf
) - 1] = '\0';
322 cmm_skip_blanks(buf
, &p
);
323 nr
= simple_strtoul(p
, &p
, 0);
324 cmm_skip_blanks(p
, &p
);
325 seconds
= simple_strtoul(p
, &p
, 0);
326 cmm_set_timeout(nr
, seconds
);
328 len
= sprintf(buf
, "%ld %ld\n",
329 cmm_timeout_pages
, cmm_timeout_seconds
);
332 if (copy_to_user(buffer
, buf
, len
))
340 static struct ctl_table cmm_table
[] = {
342 .ctl_name
= VM_CMM_PAGES
,
343 .procname
= "cmm_pages",
345 .proc_handler
= &cmm_pages_handler
,
348 .ctl_name
= VM_CMM_TIMED_PAGES
,
349 .procname
= "cmm_timed_pages",
351 .proc_handler
= &cmm_pages_handler
,
354 .ctl_name
= VM_CMM_TIMEOUT
,
355 .procname
= "cmm_timeout",
357 .proc_handler
= &cmm_timeout_handler
,
362 static struct ctl_table cmm_dir_table
[] = {
374 #ifdef CONFIG_CMM_IUCV
375 #define SMSG_PREFIX "CMM"
377 cmm_smsg_target(char *from
, char *msg
)
381 if (strlen(sender
) > 0 && strcmp(from
, sender
) != 0)
383 if (!cmm_skip_blanks(msg
+ strlen(SMSG_PREFIX
), &msg
))
385 if (strncmp(msg
, "SHRINK", 6) == 0) {
386 if (!cmm_skip_blanks(msg
+ 6, &msg
))
388 nr
= simple_strtoul(msg
, &msg
, 0);
389 cmm_skip_blanks(msg
, &msg
);
392 } else if (strncmp(msg
, "RELEASE", 7) == 0) {
393 if (!cmm_skip_blanks(msg
+ 7, &msg
))
395 nr
= simple_strtoul(msg
, &msg
, 0);
396 cmm_skip_blanks(msg
, &msg
);
398 cmm_add_timed_pages(nr
);
399 } else if (strncmp(msg
, "REUSE", 5) == 0) {
400 if (!cmm_skip_blanks(msg
+ 5, &msg
))
402 nr
= simple_strtoul(msg
, &msg
, 0);
403 if (!cmm_skip_blanks(msg
, &msg
))
405 seconds
= simple_strtoul(msg
, &msg
, 0);
406 cmm_skip_blanks(msg
, &msg
);
408 cmm_set_timeout(nr
, seconds
);
413 static struct ctl_table_header
*cmm_sysctl_header
;
420 #ifdef CONFIG_CMM_PROC
421 cmm_sysctl_header
= register_sysctl_table(cmm_dir_table
);
422 if (!cmm_sysctl_header
)
425 #ifdef CONFIG_CMM_IUCV
426 rc
= smsg_register_callback(SMSG_PREFIX
, cmm_smsg_target
);
430 rc
= register_oom_notifier(&cmm_oom_nb
);
433 init_waitqueue_head(&cmm_thread_wait
);
434 init_timer(&cmm_timer
);
435 cmm_thread_ptr
= kthread_run(cmm_thread
, NULL
, "cmmthread");
436 rc
= IS_ERR(cmm_thread_ptr
) ? PTR_ERR(cmm_thread_ptr
) : 0;
440 * kthread_create failed. undo all the stuff from above again.
442 unregister_oom_notifier(&cmm_oom_nb
);
445 #ifdef CONFIG_CMM_IUCV
446 smsg_unregister_callback(SMSG_PREFIX
, cmm_smsg_target
);
449 #ifdef CONFIG_CMM_PROC
450 unregister_sysctl_table(cmm_sysctl_header
);
459 kthread_stop(cmm_thread_ptr
);
460 unregister_oom_notifier(&cmm_oom_nb
);
461 cmm_free_pages(cmm_pages
, &cmm_pages
, &cmm_page_list
);
462 cmm_free_pages(cmm_timed_pages
, &cmm_timed_pages
, &cmm_timed_page_list
);
463 #ifdef CONFIG_CMM_PROC
464 unregister_sysctl_table(cmm_sysctl_header
);
466 #ifdef CONFIG_CMM_IUCV
467 smsg_unregister_callback(SMSG_PREFIX
, cmm_smsg_target
);
471 module_init(cmm_init
);
472 module_exit(cmm_exit
);
474 EXPORT_SYMBOL(cmm_set_pages
);
475 EXPORT_SYMBOL(cmm_get_pages
);
476 EXPORT_SYMBOL(cmm_add_timed_pages
);
477 EXPORT_SYMBOL(cmm_get_timed_pages
);
478 EXPORT_SYMBOL(cmm_set_timeout
);
480 MODULE_LICENSE("GPL");