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/gfp.h>
16 #include <linux/sched.h>
17 #include <linux/sysctl.h>
18 #include <linux/ctype.h>
19 #include <linux/swap.h>
20 #include <linux/kthread.h>
21 #include <linux/oom.h>
22 #include <linux/suspend.h>
24 #include <asm/pgalloc.h>
25 #include <asm/uaccess.h>
28 static char *sender = "VMRMSVM";
29 module_param(sender, charp, 0400);
30 MODULE_PARM_DESC(sender,
31 "Guest name that may send SMSG messages (default VMRMSVM)");
33 #include "../../../drivers/s390/net/smsgiucv.h"
35 #define CMM_NR_PAGES ((PAGE_SIZE / sizeof(unsigned long)) - 2)
37 struct cmm_page_array {
38 struct cmm_page_array *next;
40 unsigned long pages[CMM_NR_PAGES];
43 static long cmm_pages;
44 static long cmm_timed_pages;
45 static volatile long cmm_pages_target;
46 static volatile long cmm_timed_pages_target;
47 static long cmm_timeout_pages;
48 static long cmm_timeout_seconds;
49 static int cmm_suspended;
51 static struct cmm_page_array *cmm_page_list;
52 static struct cmm_page_array *cmm_timed_page_list;
53 static DEFINE_SPINLOCK(cmm_lock);
55 static struct task_struct *cmm_thread_ptr;
56 static wait_queue_head_t cmm_thread_wait;
57 static struct timer_list cmm_timer;
59 static void cmm_timer_fn(unsigned long);
60 static void cmm_set_timer(void);
63 cmm_alloc_pages(long nr, long *counter, struct cmm_page_array **list)
65 struct cmm_page_array *pa, *npa;
69 addr = __get_free_page(GFP_NOIO);
74 if (!pa || pa->index >= CMM_NR_PAGES) {
75 /* Need a new page for the page list. */
76 spin_unlock(&cmm_lock);
77 npa = (struct cmm_page_array *)
78 __get_free_page(GFP_NOIO);
85 if (!pa || pa->index >= CMM_NR_PAGES) {
91 free_page((unsigned long) npa);
94 pa->pages[pa->index++] = addr;
96 spin_unlock(&cmm_lock);
103 cmm_free_pages(long nr, long *counter, struct cmm_page_array **list)
105 struct cmm_page_array *pa;
108 spin_lock(&cmm_lock);
111 if (!pa || pa->index <= 0)
113 addr = pa->pages[--pa->index];
114 if (pa->index == 0) {
116 free_page((unsigned long) *list);
123 spin_unlock(&cmm_lock);
127 static int cmm_oom_notify(struct notifier_block *self,
128 unsigned long dummy, void *parm)
130 unsigned long *freed = parm;
133 nr = cmm_free_pages(nr, &cmm_timed_pages, &cmm_timed_page_list);
135 nr = cmm_free_pages(nr, &cmm_pages, &cmm_page_list);
136 cmm_pages_target = cmm_pages;
137 cmm_timed_pages_target = cmm_timed_pages;
142 static struct notifier_block cmm_oom_nb = {
143 .notifier_call = cmm_oom_notify
147 cmm_thread(void *dummy)
152 rc = wait_event_interruptible(cmm_thread_wait,
153 (!cmm_suspended && (cmm_pages != cmm_pages_target ||
154 cmm_timed_pages != cmm_timed_pages_target)) ||
155 kthread_should_stop());
156 if (kthread_should_stop() || rc == -ERESTARTSYS) {
157 cmm_pages_target = cmm_pages;
158 cmm_timed_pages_target = cmm_timed_pages;
161 if (cmm_pages_target > cmm_pages) {
162 if (cmm_alloc_pages(1, &cmm_pages, &cmm_page_list))
163 cmm_pages_target = cmm_pages;
164 } else if (cmm_pages_target < cmm_pages) {
165 cmm_free_pages(1, &cmm_pages, &cmm_page_list);
167 if (cmm_timed_pages_target > cmm_timed_pages) {
168 if (cmm_alloc_pages(1, &cmm_timed_pages,
169 &cmm_timed_page_list))
170 cmm_timed_pages_target = cmm_timed_pages;
171 } else if (cmm_timed_pages_target < cmm_timed_pages) {
172 cmm_free_pages(1, &cmm_timed_pages,
173 &cmm_timed_page_list);
175 if (cmm_timed_pages > 0 && !timer_pending(&cmm_timer))
182 cmm_kick_thread(void)
184 wake_up(&cmm_thread_wait);
190 if (cmm_timed_pages_target <= 0 || cmm_timeout_seconds <= 0) {
191 if (timer_pending(&cmm_timer))
192 del_timer(&cmm_timer);
195 if (timer_pending(&cmm_timer)) {
196 if (mod_timer(&cmm_timer, jiffies + cmm_timeout_seconds*HZ))
199 cmm_timer.function = cmm_timer_fn;
201 cmm_timer.expires = jiffies + cmm_timeout_seconds*HZ;
202 add_timer(&cmm_timer);
206 cmm_timer_fn(unsigned long ignored)
210 nr = cmm_timed_pages_target - cmm_timeout_pages;
212 cmm_timed_pages_target = 0;
214 cmm_timed_pages_target = nr;
220 cmm_set_pages(long nr)
222 cmm_pages_target = nr;
233 cmm_add_timed_pages(long nr)
235 cmm_timed_pages_target += nr;
240 cmm_get_timed_pages(void)
242 return cmm_timed_pages;
246 cmm_set_timeout(long nr, long seconds)
248 cmm_timeout_pages = nr;
249 cmm_timeout_seconds = seconds;
254 cmm_skip_blanks(char *cp, char **endp)
258 for (str = cp; *str == ' ' || *str == '\t'; str++);
263 #ifdef CONFIG_CMM_PROC
265 static struct ctl_table cmm_table[];
268 cmm_pages_handler(ctl_table *ctl, int write,
269 void __user *buffer, size_t *lenp, loff_t *ppos)
275 if (!*lenp || (*ppos && !write)) {
282 if (copy_from_user(buf, buffer,
283 len > sizeof(buf) ? sizeof(buf) : len))
285 buf[sizeof(buf) - 1] = '\0';
286 cmm_skip_blanks(buf, &p);
287 nr = simple_strtoul(p, &p, 0);
288 if (ctl == &cmm_table[0])
291 cmm_add_timed_pages(nr);
293 if (ctl == &cmm_table[0])
294 nr = cmm_get_pages();
296 nr = cmm_get_timed_pages();
297 len = sprintf(buf, "%ld\n", nr);
300 if (copy_to_user(buffer, buf, len))
309 cmm_timeout_handler(ctl_table *ctl, int write,
310 void __user *buffer, size_t *lenp, loff_t *ppos)
316 if (!*lenp || (*ppos && !write)) {
323 if (copy_from_user(buf, buffer,
324 len > sizeof(buf) ? sizeof(buf) : len))
326 buf[sizeof(buf) - 1] = '\0';
327 cmm_skip_blanks(buf, &p);
328 nr = simple_strtoul(p, &p, 0);
329 cmm_skip_blanks(p, &p);
330 seconds = simple_strtoul(p, &p, 0);
331 cmm_set_timeout(nr, seconds);
333 len = sprintf(buf, "%ld %ld\n",
334 cmm_timeout_pages, cmm_timeout_seconds);
337 if (copy_to_user(buffer, buf, len))
345 static struct ctl_table cmm_table[] = {
347 .procname = "cmm_pages",
349 .proc_handler = cmm_pages_handler,
352 .procname = "cmm_timed_pages",
354 .proc_handler = cmm_pages_handler,
357 .procname = "cmm_timeout",
359 .proc_handler = cmm_timeout_handler,
364 static struct ctl_table cmm_dir_table[] = {
375 #ifdef CONFIG_CMM_IUCV
376 #define SMSG_PREFIX "CMM"
378 cmm_smsg_target(const char *from, char *msg)
382 if (strlen(sender) > 0 && strcmp(from, sender) != 0)
384 if (!cmm_skip_blanks(msg + strlen(SMSG_PREFIX), &msg))
386 if (strncmp(msg, "SHRINK", 6) == 0) {
387 if (!cmm_skip_blanks(msg + 6, &msg))
389 nr = simple_strtoul(msg, &msg, 0);
390 cmm_skip_blanks(msg, &msg);
393 } else if (strncmp(msg, "RELEASE", 7) == 0) {
394 if (!cmm_skip_blanks(msg + 7, &msg))
396 nr = simple_strtoul(msg, &msg, 0);
397 cmm_skip_blanks(msg, &msg);
399 cmm_add_timed_pages(nr);
400 } else if (strncmp(msg, "REUSE", 5) == 0) {
401 if (!cmm_skip_blanks(msg + 5, &msg))
403 nr = simple_strtoul(msg, &msg, 0);
404 if (!cmm_skip_blanks(msg, &msg))
406 seconds = simple_strtoul(msg, &msg, 0);
407 cmm_skip_blanks(msg, &msg);
409 cmm_set_timeout(nr, seconds);
414 static struct ctl_table_header *cmm_sysctl_header;
416 static int cmm_suspend(void)
419 cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list);
420 cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list);
424 static int cmm_resume(void)
431 static int cmm_power_event(struct notifier_block *this,
432 unsigned long event, void *ptr)
435 case PM_POST_HIBERNATION:
437 case PM_HIBERNATION_PREPARE:
438 return cmm_suspend();
444 static struct notifier_block cmm_power_notifier = {
445 .notifier_call = cmm_power_event,
453 #ifdef CONFIG_CMM_PROC
454 cmm_sysctl_header = register_sysctl_table(cmm_dir_table);
455 if (!cmm_sysctl_header)
458 #ifdef CONFIG_CMM_IUCV
459 rc = smsg_register_callback(SMSG_PREFIX, cmm_smsg_target);
463 rc = register_oom_notifier(&cmm_oom_nb);
466 rc = register_pm_notifier(&cmm_power_notifier);
469 init_waitqueue_head(&cmm_thread_wait);
470 init_timer(&cmm_timer);
471 cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread");
472 rc = IS_ERR(cmm_thread_ptr) ? PTR_ERR(cmm_thread_ptr) : 0;
478 unregister_pm_notifier(&cmm_power_notifier);
480 unregister_oom_notifier(&cmm_oom_nb);
482 #ifdef CONFIG_CMM_IUCV
483 smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
486 #ifdef CONFIG_CMM_PROC
487 unregister_sysctl_table(cmm_sysctl_header);
496 kthread_stop(cmm_thread_ptr);
497 unregister_pm_notifier(&cmm_power_notifier);
498 unregister_oom_notifier(&cmm_oom_nb);
499 cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list);
500 cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list);
501 #ifdef CONFIG_CMM_PROC
502 unregister_sysctl_table(cmm_sysctl_header);
504 #ifdef CONFIG_CMM_IUCV
505 smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
509 module_init(cmm_init);
510 module_exit(cmm_exit);
512 EXPORT_SYMBOL(cmm_set_pages);
513 EXPORT_SYMBOL(cmm_get_pages);
514 EXPORT_SYMBOL(cmm_add_timed_pages);
515 EXPORT_SYMBOL(cmm_get_timed_pages);
516 EXPORT_SYMBOL(cmm_set_timeout);
518 MODULE_LICENSE("GPL");