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/gfp.h>
14 #include <linux/sched.h>
15 #include <linux/sysctl.h>
16 #include <linux/ctype.h>
17 #include <linux/swap.h>
18 #include <linux/kthread.h>
19 #include <linux/oom.h>
20 #include <linux/suspend.h>
21 #include <linux/uaccess.h>
23 #include <asm/pgalloc.h>
26 static char *sender = "VMRMSVM";
27 module_param(sender, charp, 0400);
28 MODULE_PARM_DESC(sender,
29 "Guest name that may send SMSG messages (default VMRMSVM)");
31 #include "../../../drivers/s390/net/smsgiucv.h"
33 #define CMM_NR_PAGES ((PAGE_SIZE / sizeof(unsigned long)) - 2)
35 struct cmm_page_array {
36 struct cmm_page_array *next;
38 unsigned long pages[CMM_NR_PAGES];
41 static long cmm_pages;
42 static long cmm_timed_pages;
43 static volatile long cmm_pages_target;
44 static volatile long cmm_timed_pages_target;
45 static long cmm_timeout_pages;
46 static long cmm_timeout_seconds;
47 static int cmm_suspended;
49 static struct cmm_page_array *cmm_page_list;
50 static struct cmm_page_array *cmm_timed_page_list;
51 static DEFINE_SPINLOCK(cmm_lock);
53 static struct task_struct *cmm_thread_ptr;
54 static DECLARE_WAIT_QUEUE_HEAD(cmm_thread_wait);
55 static DEFINE_TIMER(cmm_timer, NULL, 0, 0);
57 static void cmm_timer_fn(unsigned long);
58 static void cmm_set_timer(void);
60 static long cmm_alloc_pages(long nr, long *counter,
61 struct cmm_page_array **list)
63 struct cmm_page_array *pa, *npa;
67 addr = __get_free_page(GFP_NOIO);
72 if (!pa || pa->index >= CMM_NR_PAGES) {
73 /* Need a new page for the page list. */
74 spin_unlock(&cmm_lock);
75 npa = (struct cmm_page_array *)
76 __get_free_page(GFP_NOIO);
83 if (!pa || pa->index >= CMM_NR_PAGES) {
89 free_page((unsigned long) npa);
92 pa->pages[pa->index++] = addr;
94 spin_unlock(&cmm_lock);
100 static long cmm_free_pages(long nr, long *counter, struct cmm_page_array **list)
102 struct cmm_page_array *pa;
105 spin_lock(&cmm_lock);
108 if (!pa || pa->index <= 0)
110 addr = pa->pages[--pa->index];
111 if (pa->index == 0) {
113 free_page((unsigned long) *list);
120 spin_unlock(&cmm_lock);
124 static int cmm_oom_notify(struct notifier_block *self,
125 unsigned long dummy, void *parm)
127 unsigned long *freed = parm;
130 nr = cmm_free_pages(nr, &cmm_timed_pages, &cmm_timed_page_list);
132 nr = cmm_free_pages(nr, &cmm_pages, &cmm_page_list);
133 cmm_pages_target = cmm_pages;
134 cmm_timed_pages_target = cmm_timed_pages;
139 static struct notifier_block cmm_oom_nb = {
140 .notifier_call = cmm_oom_notify,
143 static int cmm_thread(void *dummy)
148 rc = wait_event_interruptible(cmm_thread_wait,
149 (!cmm_suspended && (cmm_pages != cmm_pages_target ||
150 cmm_timed_pages != cmm_timed_pages_target)) ||
151 kthread_should_stop());
152 if (kthread_should_stop() || rc == -ERESTARTSYS) {
153 cmm_pages_target = cmm_pages;
154 cmm_timed_pages_target = cmm_timed_pages;
157 if (cmm_pages_target > cmm_pages) {
158 if (cmm_alloc_pages(1, &cmm_pages, &cmm_page_list))
159 cmm_pages_target = cmm_pages;
160 } else if (cmm_pages_target < cmm_pages) {
161 cmm_free_pages(1, &cmm_pages, &cmm_page_list);
163 if (cmm_timed_pages_target > cmm_timed_pages) {
164 if (cmm_alloc_pages(1, &cmm_timed_pages,
165 &cmm_timed_page_list))
166 cmm_timed_pages_target = cmm_timed_pages;
167 } else if (cmm_timed_pages_target < cmm_timed_pages) {
168 cmm_free_pages(1, &cmm_timed_pages,
169 &cmm_timed_page_list);
171 if (cmm_timed_pages > 0 && !timer_pending(&cmm_timer))
177 static void cmm_kick_thread(void)
179 wake_up(&cmm_thread_wait);
182 static void cmm_set_timer(void)
184 if (cmm_timed_pages_target <= 0 || cmm_timeout_seconds <= 0) {
185 if (timer_pending(&cmm_timer))
186 del_timer(&cmm_timer);
189 if (timer_pending(&cmm_timer)) {
190 if (mod_timer(&cmm_timer, jiffies + cmm_timeout_seconds*HZ))
193 cmm_timer.function = cmm_timer_fn;
195 cmm_timer.expires = jiffies + cmm_timeout_seconds*HZ;
196 add_timer(&cmm_timer);
199 static void cmm_timer_fn(unsigned long ignored)
203 nr = cmm_timed_pages_target - cmm_timeout_pages;
205 cmm_timed_pages_target = 0;
207 cmm_timed_pages_target = nr;
212 static void cmm_set_pages(long nr)
214 cmm_pages_target = nr;
218 static long cmm_get_pages(void)
223 static void cmm_add_timed_pages(long nr)
225 cmm_timed_pages_target += nr;
229 static long cmm_get_timed_pages(void)
231 return cmm_timed_pages;
234 static void cmm_set_timeout(long nr, long seconds)
236 cmm_timeout_pages = nr;
237 cmm_timeout_seconds = seconds;
241 static int cmm_skip_blanks(char *cp, char **endp)
245 for (str = cp; *str == ' ' || *str == '\t'; str++)
251 static struct ctl_table cmm_table[];
253 static int cmm_pages_handler(ctl_table *ctl, int write, void __user *buffer,
254 size_t *lenp, loff_t *ppos)
260 if (!*lenp || (*ppos && !write)) {
267 if (copy_from_user(buf, buffer,
268 len > sizeof(buf) ? sizeof(buf) : len))
270 buf[sizeof(buf) - 1] = '\0';
271 cmm_skip_blanks(buf, &p);
272 nr = simple_strtoul(p, &p, 0);
273 if (ctl == &cmm_table[0])
276 cmm_add_timed_pages(nr);
278 if (ctl == &cmm_table[0])
279 nr = cmm_get_pages();
281 nr = cmm_get_timed_pages();
282 len = sprintf(buf, "%ld\n", nr);
285 if (copy_to_user(buffer, buf, len))
293 static int cmm_timeout_handler(ctl_table *ctl, int write, void __user *buffer,
294 size_t *lenp, loff_t *ppos)
300 if (!*lenp || (*ppos && !write)) {
307 if (copy_from_user(buf, buffer,
308 len > sizeof(buf) ? sizeof(buf) : len))
310 buf[sizeof(buf) - 1] = '\0';
311 cmm_skip_blanks(buf, &p);
312 nr = simple_strtoul(p, &p, 0);
313 cmm_skip_blanks(p, &p);
314 seconds = simple_strtoul(p, &p, 0);
315 cmm_set_timeout(nr, seconds);
317 len = sprintf(buf, "%ld %ld\n",
318 cmm_timeout_pages, cmm_timeout_seconds);
321 if (copy_to_user(buffer, buf, len))
329 static struct ctl_table cmm_table[] = {
331 .procname = "cmm_pages",
333 .proc_handler = cmm_pages_handler,
336 .procname = "cmm_timed_pages",
338 .proc_handler = cmm_pages_handler,
341 .procname = "cmm_timeout",
343 .proc_handler = cmm_timeout_handler,
348 static struct ctl_table cmm_dir_table[] = {
358 #ifdef CONFIG_CMM_IUCV
359 #define SMSG_PREFIX "CMM"
360 static void cmm_smsg_target(const char *from, char *msg)
364 if (strlen(sender) > 0 && strcmp(from, sender) != 0)
366 if (!cmm_skip_blanks(msg + strlen(SMSG_PREFIX), &msg))
368 if (strncmp(msg, "SHRINK", 6) == 0) {
369 if (!cmm_skip_blanks(msg + 6, &msg))
371 nr = simple_strtoul(msg, &msg, 0);
372 cmm_skip_blanks(msg, &msg);
375 } else if (strncmp(msg, "RELEASE", 7) == 0) {
376 if (!cmm_skip_blanks(msg + 7, &msg))
378 nr = simple_strtoul(msg, &msg, 0);
379 cmm_skip_blanks(msg, &msg);
381 cmm_add_timed_pages(nr);
382 } else if (strncmp(msg, "REUSE", 5) == 0) {
383 if (!cmm_skip_blanks(msg + 5, &msg))
385 nr = simple_strtoul(msg, &msg, 0);
386 if (!cmm_skip_blanks(msg, &msg))
388 seconds = simple_strtoul(msg, &msg, 0);
389 cmm_skip_blanks(msg, &msg);
391 cmm_set_timeout(nr, seconds);
396 static struct ctl_table_header *cmm_sysctl_header;
398 static int cmm_suspend(void)
401 cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list);
402 cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list);
406 static int cmm_resume(void)
413 static int cmm_power_event(struct notifier_block *this,
414 unsigned long event, void *ptr)
417 case PM_POST_HIBERNATION:
419 case PM_HIBERNATION_PREPARE:
420 return cmm_suspend();
426 static struct notifier_block cmm_power_notifier = {
427 .notifier_call = cmm_power_event,
430 static int cmm_init(void)
434 cmm_sysctl_header = register_sysctl_table(cmm_dir_table);
435 if (!cmm_sysctl_header)
437 #ifdef CONFIG_CMM_IUCV
438 rc = smsg_register_callback(SMSG_PREFIX, cmm_smsg_target);
442 rc = register_oom_notifier(&cmm_oom_nb);
445 rc = register_pm_notifier(&cmm_power_notifier);
448 cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread");
449 rc = IS_ERR(cmm_thread_ptr) ? PTR_ERR(cmm_thread_ptr) : 0;
455 unregister_pm_notifier(&cmm_power_notifier);
457 unregister_oom_notifier(&cmm_oom_nb);
459 #ifdef CONFIG_CMM_IUCV
460 smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
463 unregister_sysctl_table(cmm_sysctl_header);
465 del_timer_sync(&cmm_timer);
468 module_init(cmm_init);
470 static void cmm_exit(void)
472 unregister_sysctl_table(cmm_sysctl_header);
473 #ifdef CONFIG_CMM_IUCV
474 smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
476 unregister_pm_notifier(&cmm_power_notifier);
477 unregister_oom_notifier(&cmm_oom_nb);
478 kthread_stop(cmm_thread_ptr);
479 del_timer_sync(&cmm_timer);
480 cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list);
481 cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list);
483 module_exit(cmm_exit);
485 MODULE_LICENSE("GPL");