2 * Collaborative memory management interface.
4 * Copyright IBM Corp 2003, 2010
5 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
9 #include <linux/errno.h>
11 #include <linux/init.h>
12 #include <linux/module.h>
13 #include <linux/moduleparam.h>
14 #include <linux/gfp.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>
20 #include <linux/oom.h>
21 #include <linux/suspend.h>
22 #include <linux/uaccess.h>
24 #include <asm/pgalloc.h>
27 #ifdef CONFIG_CMM_IUCV
28 static char *cmm_default_sender = "VMRMSVM";
31 module_param(sender, charp, 0400);
32 MODULE_PARM_DESC(sender,
33 "Guest name that may send SMSG messages (default VMRMSVM)");
35 #include "../../../drivers/s390/net/smsgiucv.h"
37 #define CMM_NR_PAGES ((PAGE_SIZE / sizeof(unsigned long)) - 2)
39 struct cmm_page_array {
40 struct cmm_page_array *next;
42 unsigned long pages[CMM_NR_PAGES];
45 static long cmm_pages;
46 static long cmm_timed_pages;
47 static volatile long cmm_pages_target;
48 static volatile long cmm_timed_pages_target;
49 static long cmm_timeout_pages;
50 static long cmm_timeout_seconds;
51 static int cmm_suspended;
53 static struct cmm_page_array *cmm_page_list;
54 static struct cmm_page_array *cmm_timed_page_list;
55 static DEFINE_SPINLOCK(cmm_lock);
57 static struct task_struct *cmm_thread_ptr;
58 static DECLARE_WAIT_QUEUE_HEAD(cmm_thread_wait);
60 static void cmm_timer_fn(struct timer_list *);
61 static void cmm_set_timer(void);
62 static DEFINE_TIMER(cmm_timer, cmm_timer_fn);
64 static long cmm_alloc_pages(long nr, long *counter,
65 struct cmm_page_array **list)
67 struct cmm_page_array *pa, *npa;
71 addr = __get_free_page(GFP_NOIO);
76 if (!pa || pa->index >= CMM_NR_PAGES) {
77 /* Need a new page for the page list. */
78 spin_unlock(&cmm_lock);
79 npa = (struct cmm_page_array *)
80 __get_free_page(GFP_NOIO);
87 if (!pa || pa->index >= CMM_NR_PAGES) {
93 free_page((unsigned long) npa);
95 diag10_range(addr >> PAGE_SHIFT, 1);
96 pa->pages[pa->index++] = addr;
98 spin_unlock(&cmm_lock);
104 static long cmm_free_pages(long nr, long *counter, struct cmm_page_array **list)
106 struct cmm_page_array *pa;
109 spin_lock(&cmm_lock);
112 if (!pa || pa->index <= 0)
114 addr = pa->pages[--pa->index];
115 if (pa->index == 0) {
117 free_page((unsigned long) *list);
124 spin_unlock(&cmm_lock);
128 static int cmm_oom_notify(struct notifier_block *self,
129 unsigned long dummy, void *parm)
131 unsigned long *freed = parm;
134 nr = cmm_free_pages(nr, &cmm_timed_pages, &cmm_timed_page_list);
136 nr = cmm_free_pages(nr, &cmm_pages, &cmm_page_list);
137 cmm_pages_target = cmm_pages;
138 cmm_timed_pages_target = cmm_timed_pages;
143 static struct notifier_block cmm_oom_nb = {
144 .notifier_call = cmm_oom_notify,
147 static int 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))
181 static void cmm_kick_thread(void)
183 wake_up(&cmm_thread_wait);
186 static void cmm_set_timer(void)
188 if (cmm_timed_pages_target <= 0 || cmm_timeout_seconds <= 0) {
189 if (timer_pending(&cmm_timer))
190 del_timer(&cmm_timer);
193 if (timer_pending(&cmm_timer)) {
194 if (mod_timer(&cmm_timer, jiffies + cmm_timeout_seconds*HZ))
197 cmm_timer.expires = jiffies + cmm_timeout_seconds*HZ;
198 add_timer(&cmm_timer);
201 static void cmm_timer_fn(struct timer_list *unused)
205 nr = cmm_timed_pages_target - cmm_timeout_pages;
207 cmm_timed_pages_target = 0;
209 cmm_timed_pages_target = nr;
214 static void cmm_set_pages(long nr)
216 cmm_pages_target = nr;
220 static long cmm_get_pages(void)
225 static void cmm_add_timed_pages(long nr)
227 cmm_timed_pages_target += nr;
231 static long cmm_get_timed_pages(void)
233 return cmm_timed_pages;
236 static void cmm_set_timeout(long nr, long seconds)
238 cmm_timeout_pages = nr;
239 cmm_timeout_seconds = seconds;
243 static int cmm_skip_blanks(char *cp, char **endp)
247 for (str = cp; *str == ' ' || *str == '\t'; str++)
253 static struct ctl_table cmm_table[];
255 static int cmm_pages_handler(struct ctl_table *ctl, int write,
256 void __user *buffer, size_t *lenp, loff_t *ppos)
262 if (!*lenp || (*ppos && !write)) {
269 if (copy_from_user(buf, buffer,
270 len > sizeof(buf) ? sizeof(buf) : len))
272 buf[sizeof(buf) - 1] = '\0';
273 cmm_skip_blanks(buf, &p);
274 nr = simple_strtoul(p, &p, 0);
275 if (ctl == &cmm_table[0])
278 cmm_add_timed_pages(nr);
280 if (ctl == &cmm_table[0])
281 nr = cmm_get_pages();
283 nr = cmm_get_timed_pages();
284 len = sprintf(buf, "%ld\n", nr);
287 if (copy_to_user(buffer, buf, len))
295 static int cmm_timeout_handler(struct ctl_table *ctl, int write,
296 void __user *buffer, size_t *lenp, loff_t *ppos)
302 if (!*lenp || (*ppos && !write)) {
309 if (copy_from_user(buf, buffer,
310 len > sizeof(buf) ? sizeof(buf) : len))
312 buf[sizeof(buf) - 1] = '\0';
313 cmm_skip_blanks(buf, &p);
314 nr = simple_strtoul(p, &p, 0);
315 cmm_skip_blanks(p, &p);
316 seconds = simple_strtoul(p, &p, 0);
317 cmm_set_timeout(nr, seconds);
319 len = sprintf(buf, "%ld %ld\n",
320 cmm_timeout_pages, cmm_timeout_seconds);
323 if (copy_to_user(buffer, buf, len))
331 static struct ctl_table cmm_table[] = {
333 .procname = "cmm_pages",
335 .proc_handler = cmm_pages_handler,
338 .procname = "cmm_timed_pages",
340 .proc_handler = cmm_pages_handler,
343 .procname = "cmm_timeout",
345 .proc_handler = cmm_timeout_handler,
350 static struct ctl_table cmm_dir_table[] = {
360 #ifdef CONFIG_CMM_IUCV
361 #define SMSG_PREFIX "CMM"
362 static void cmm_smsg_target(const char *from, char *msg)
366 if (strlen(sender) > 0 && strcmp(from, sender) != 0)
368 if (!cmm_skip_blanks(msg + strlen(SMSG_PREFIX), &msg))
370 if (strncmp(msg, "SHRINK", 6) == 0) {
371 if (!cmm_skip_blanks(msg + 6, &msg))
373 nr = simple_strtoul(msg, &msg, 0);
374 cmm_skip_blanks(msg, &msg);
377 } else if (strncmp(msg, "RELEASE", 7) == 0) {
378 if (!cmm_skip_blanks(msg + 7, &msg))
380 nr = simple_strtoul(msg, &msg, 0);
381 cmm_skip_blanks(msg, &msg);
383 cmm_add_timed_pages(nr);
384 } else if (strncmp(msg, "REUSE", 5) == 0) {
385 if (!cmm_skip_blanks(msg + 5, &msg))
387 nr = simple_strtoul(msg, &msg, 0);
388 if (!cmm_skip_blanks(msg, &msg))
390 seconds = simple_strtoul(msg, &msg, 0);
391 cmm_skip_blanks(msg, &msg);
393 cmm_set_timeout(nr, seconds);
398 static struct ctl_table_header *cmm_sysctl_header;
400 static int cmm_suspend(void)
403 cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list);
404 cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list);
408 static int cmm_resume(void)
415 static int cmm_power_event(struct notifier_block *this,
416 unsigned long event, void *ptr)
419 case PM_POST_HIBERNATION:
421 case PM_HIBERNATION_PREPARE:
422 return cmm_suspend();
428 static struct notifier_block cmm_power_notifier = {
429 .notifier_call = cmm_power_event,
432 static int __init cmm_init(void)
436 cmm_sysctl_header = register_sysctl_table(cmm_dir_table);
437 if (!cmm_sysctl_header)
439 #ifdef CONFIG_CMM_IUCV
440 /* convert sender to uppercase characters */
442 int len = strlen(sender);
444 sender[len] = toupper(sender[len]);
446 sender = cmm_default_sender;
449 rc = smsg_register_callback(SMSG_PREFIX, cmm_smsg_target);
453 rc = register_oom_notifier(&cmm_oom_nb);
456 rc = register_pm_notifier(&cmm_power_notifier);
459 cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread");
460 if (!IS_ERR(cmm_thread_ptr))
463 rc = PTR_ERR(cmm_thread_ptr);
464 unregister_pm_notifier(&cmm_power_notifier);
466 unregister_oom_notifier(&cmm_oom_nb);
468 #ifdef CONFIG_CMM_IUCV
469 smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
472 unregister_sysctl_table(cmm_sysctl_header);
474 del_timer_sync(&cmm_timer);
477 module_init(cmm_init);
479 static void __exit cmm_exit(void)
481 unregister_sysctl_table(cmm_sysctl_header);
482 #ifdef CONFIG_CMM_IUCV
483 smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
485 unregister_pm_notifier(&cmm_power_notifier);
486 unregister_oom_notifier(&cmm_oom_nb);
487 kthread_stop(cmm_thread_ptr);
488 del_timer_sync(&cmm_timer);
489 cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list);
490 cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list);
492 module_exit(cmm_exit);
494 MODULE_LICENSE("GPL");