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
#ifdef CONFIG_CMM_IUCV
27
static char *cmm_default_sender = "VMRMSVM";
30
module_param(sender, charp, 0400);
31
MODULE_PARM_DESC(sender,
32
"Guest name that may send SMSG messages (default VMRMSVM)");
34
#include "../../../drivers/s390/net/smsgiucv.h"
36
#define CMM_NR_PAGES ((PAGE_SIZE / sizeof(unsigned long)) - 2)
38
struct cmm_page_array {
39
struct cmm_page_array *next;
41
unsigned long pages[CMM_NR_PAGES];
44
static long cmm_pages;
45
static long cmm_timed_pages;
46
static volatile long cmm_pages_target;
47
static volatile long cmm_timed_pages_target;
48
static long cmm_timeout_pages;
49
static long cmm_timeout_seconds;
50
static int cmm_suspended;
52
static struct cmm_page_array *cmm_page_list;
53
static struct cmm_page_array *cmm_timed_page_list;
54
static DEFINE_SPINLOCK(cmm_lock);
56
static struct task_struct *cmm_thread_ptr;
57
static DECLARE_WAIT_QUEUE_HEAD(cmm_thread_wait);
58
static DEFINE_TIMER(cmm_timer, NULL, 0, 0);
60
static void cmm_timer_fn(unsigned long);
61
static void cmm_set_timer(void);
63
static long cmm_alloc_pages(long nr, long *counter,
64
struct cmm_page_array **list)
66
struct cmm_page_array *pa, *npa;
70
addr = __get_free_page(GFP_NOIO);
75
if (!pa || pa->index >= CMM_NR_PAGES) {
76
/* Need a new page for the page list. */
77
spin_unlock(&cmm_lock);
78
npa = (struct cmm_page_array *)
79
__get_free_page(GFP_NOIO);
86
if (!pa || pa->index >= CMM_NR_PAGES) {
92
free_page((unsigned long) npa);
94
diag10_range(addr >> PAGE_SHIFT, 1);
95
pa->pages[pa->index++] = addr;
97
spin_unlock(&cmm_lock);
103
static long 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,
146
static int cmm_thread(void *dummy)
151
rc = wait_event_interruptible(cmm_thread_wait,
152
(!cmm_suspended && (cmm_pages != cmm_pages_target ||
153
cmm_timed_pages != cmm_timed_pages_target)) ||
154
kthread_should_stop());
155
if (kthread_should_stop() || rc == -ERESTARTSYS) {
156
cmm_pages_target = cmm_pages;
157
cmm_timed_pages_target = cmm_timed_pages;
160
if (cmm_pages_target > cmm_pages) {
161
if (cmm_alloc_pages(1, &cmm_pages, &cmm_page_list))
162
cmm_pages_target = cmm_pages;
163
} else if (cmm_pages_target < cmm_pages) {
164
cmm_free_pages(1, &cmm_pages, &cmm_page_list);
166
if (cmm_timed_pages_target > cmm_timed_pages) {
167
if (cmm_alloc_pages(1, &cmm_timed_pages,
168
&cmm_timed_page_list))
169
cmm_timed_pages_target = cmm_timed_pages;
170
} else if (cmm_timed_pages_target < cmm_timed_pages) {
171
cmm_free_pages(1, &cmm_timed_pages,
172
&cmm_timed_page_list);
174
if (cmm_timed_pages > 0 && !timer_pending(&cmm_timer))
180
static void cmm_kick_thread(void)
182
wake_up(&cmm_thread_wait);
185
static void cmm_set_timer(void)
187
if (cmm_timed_pages_target <= 0 || cmm_timeout_seconds <= 0) {
188
if (timer_pending(&cmm_timer))
189
del_timer(&cmm_timer);
192
if (timer_pending(&cmm_timer)) {
193
if (mod_timer(&cmm_timer, jiffies + cmm_timeout_seconds*HZ))
196
cmm_timer.function = cmm_timer_fn;
198
cmm_timer.expires = jiffies + cmm_timeout_seconds*HZ;
199
add_timer(&cmm_timer);
202
static void cmm_timer_fn(unsigned long ignored)
206
nr = cmm_timed_pages_target - cmm_timeout_pages;
208
cmm_timed_pages_target = 0;
210
cmm_timed_pages_target = nr;
215
static void cmm_set_pages(long nr)
217
cmm_pages_target = nr;
221
static long cmm_get_pages(void)
226
static void cmm_add_timed_pages(long nr)
228
cmm_timed_pages_target += nr;
232
static long cmm_get_timed_pages(void)
234
return cmm_timed_pages;
237
static void cmm_set_timeout(long nr, long seconds)
239
cmm_timeout_pages = nr;
240
cmm_timeout_seconds = seconds;
244
static int cmm_skip_blanks(char *cp, char **endp)
248
for (str = cp; *str == ' ' || *str == '\t'; str++)
254
static struct ctl_table cmm_table[];
256
static int cmm_pages_handler(ctl_table *ctl, int write, void __user *buffer,
257
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
nr = simple_strtoul(p, &p, 0);
276
if (ctl == &cmm_table[0])
279
cmm_add_timed_pages(nr);
281
if (ctl == &cmm_table[0])
282
nr = cmm_get_pages();
284
nr = cmm_get_timed_pages();
285
len = sprintf(buf, "%ld\n", nr);
288
if (copy_to_user(buffer, buf, len))
296
static int cmm_timeout_handler(ctl_table *ctl, int write, void __user *buffer,
297
size_t *lenp, loff_t *ppos)
303
if (!*lenp || (*ppos && !write)) {
310
if (copy_from_user(buf, buffer,
311
len > sizeof(buf) ? sizeof(buf) : len))
313
buf[sizeof(buf) - 1] = '\0';
314
cmm_skip_blanks(buf, &p);
315
nr = simple_strtoul(p, &p, 0);
316
cmm_skip_blanks(p, &p);
317
seconds = simple_strtoul(p, &p, 0);
318
cmm_set_timeout(nr, seconds);
320
len = sprintf(buf, "%ld %ld\n",
321
cmm_timeout_pages, cmm_timeout_seconds);
324
if (copy_to_user(buffer, buf, len))
332
static struct ctl_table cmm_table[] = {
334
.procname = "cmm_pages",
336
.proc_handler = cmm_pages_handler,
339
.procname = "cmm_timed_pages",
341
.proc_handler = cmm_pages_handler,
344
.procname = "cmm_timeout",
346
.proc_handler = cmm_timeout_handler,
351
static struct ctl_table cmm_dir_table[] = {
361
#ifdef CONFIG_CMM_IUCV
362
#define SMSG_PREFIX "CMM"
363
static void cmm_smsg_target(const char *from, char *msg)
367
if (strlen(sender) > 0 && strcmp(from, sender) != 0)
369
if (!cmm_skip_blanks(msg + strlen(SMSG_PREFIX), &msg))
371
if (strncmp(msg, "SHRINK", 6) == 0) {
372
if (!cmm_skip_blanks(msg + 6, &msg))
374
nr = simple_strtoul(msg, &msg, 0);
375
cmm_skip_blanks(msg, &msg);
378
} else if (strncmp(msg, "RELEASE", 7) == 0) {
379
if (!cmm_skip_blanks(msg + 7, &msg))
381
nr = simple_strtoul(msg, &msg, 0);
382
cmm_skip_blanks(msg, &msg);
384
cmm_add_timed_pages(nr);
385
} else if (strncmp(msg, "REUSE", 5) == 0) {
386
if (!cmm_skip_blanks(msg + 5, &msg))
388
nr = simple_strtoul(msg, &msg, 0);
389
if (!cmm_skip_blanks(msg, &msg))
391
seconds = simple_strtoul(msg, &msg, 0);
392
cmm_skip_blanks(msg, &msg);
394
cmm_set_timeout(nr, seconds);
399
static struct ctl_table_header *cmm_sysctl_header;
401
static int cmm_suspend(void)
404
cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list);
405
cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list);
409
static int cmm_resume(void)
416
static int cmm_power_event(struct notifier_block *this,
417
unsigned long event, void *ptr)
420
case PM_POST_HIBERNATION:
422
case PM_HIBERNATION_PREPARE:
423
return cmm_suspend();
429
static struct notifier_block cmm_power_notifier = {
430
.notifier_call = cmm_power_event,
433
static int __init cmm_init(void)
437
cmm_sysctl_header = register_sysctl_table(cmm_dir_table);
438
if (!cmm_sysctl_header)
440
#ifdef CONFIG_CMM_IUCV
441
/* convert sender to uppercase characters */
443
int len = strlen(sender);
445
sender[len] = toupper(sender[len]);
447
sender = cmm_default_sender;
450
rc = smsg_register_callback(SMSG_PREFIX, cmm_smsg_target);
454
rc = register_oom_notifier(&cmm_oom_nb);
457
rc = register_pm_notifier(&cmm_power_notifier);
460
cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread");
461
rc = IS_ERR(cmm_thread_ptr) ? PTR_ERR(cmm_thread_ptr) : 0;
467
unregister_pm_notifier(&cmm_power_notifier);
469
unregister_oom_notifier(&cmm_oom_nb);
471
#ifdef CONFIG_CMM_IUCV
472
smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
475
unregister_sysctl_table(cmm_sysctl_header);
477
del_timer_sync(&cmm_timer);
480
module_init(cmm_init);
482
static void __exit cmm_exit(void)
484
unregister_sysctl_table(cmm_sysctl_header);
485
#ifdef CONFIG_CMM_IUCV
486
smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
488
unregister_pm_notifier(&cmm_power_notifier);
489
unregister_oom_notifier(&cmm_oom_nb);
490
kthread_stop(cmm_thread_ptr);
491
del_timer_sync(&cmm_timer);
492
cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list);
493
cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list);
495
module_exit(cmm_exit);
497
MODULE_LICENSE("GPL");