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9#include <linux/errno.h>
10#include <linux/fs.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>
22
23#include <asm/pgalloc.h>
24#include <asm/diag.h>
25
26#ifdef CONFIG_CMM_IUCV
27static char *cmm_default_sender = "VMRMSVM";
28#endif
29static char *sender;
30module_param(sender, charp, 0400);
31MODULE_PARM_DESC(sender,
32 "Guest name that may send SMSG messages (default VMRMSVM)");
33
34#include "../../../drivers/s390/net/smsgiucv.h"
35
36#define CMM_NR_PAGES ((PAGE_SIZE / sizeof(unsigned long)) - 2)
37
38struct cmm_page_array {
39 struct cmm_page_array *next;
40 unsigned long index;
41 unsigned long pages[CMM_NR_PAGES];
42};
43
44static long cmm_pages;
45static long cmm_timed_pages;
46static volatile long cmm_pages_target;
47static volatile long cmm_timed_pages_target;
48static long cmm_timeout_pages;
49static long cmm_timeout_seconds;
50static int cmm_suspended;
51
52static struct cmm_page_array *cmm_page_list;
53static struct cmm_page_array *cmm_timed_page_list;
54static DEFINE_SPINLOCK(cmm_lock);
55
56static struct task_struct *cmm_thread_ptr;
57static DECLARE_WAIT_QUEUE_HEAD(cmm_thread_wait);
58static DEFINE_TIMER(cmm_timer, NULL, 0, 0);
59
60static void cmm_timer_fn(unsigned long);
61static void cmm_set_timer(void);
62
63static long cmm_alloc_pages(long nr, long *counter,
64 struct cmm_page_array **list)
65{
66 struct cmm_page_array *pa, *npa;
67 unsigned long addr;
68
69 while (nr) {
70 addr = __get_free_page(GFP_NOIO);
71 if (!addr)
72 break;
73 spin_lock(&cmm_lock);
74 pa = *list;
75 if (!pa || pa->index >= CMM_NR_PAGES) {
76
77 spin_unlock(&cmm_lock);
78 npa = (struct cmm_page_array *)
79 __get_free_page(GFP_NOIO);
80 if (!npa) {
81 free_page(addr);
82 break;
83 }
84 spin_lock(&cmm_lock);
85 pa = *list;
86 if (!pa || pa->index >= CMM_NR_PAGES) {
87 npa->next = pa;
88 npa->index = 0;
89 pa = npa;
90 *list = pa;
91 } else
92 free_page((unsigned long) npa);
93 }
94 diag10_range(addr >> PAGE_SHIFT, 1);
95 pa->pages[pa->index++] = addr;
96 (*counter)++;
97 spin_unlock(&cmm_lock);
98 nr--;
99 }
100 return nr;
101}
102
103static long cmm_free_pages(long nr, long *counter, struct cmm_page_array **list)
104{
105 struct cmm_page_array *pa;
106 unsigned long addr;
107
108 spin_lock(&cmm_lock);
109 pa = *list;
110 while (nr) {
111 if (!pa || pa->index <= 0)
112 break;
113 addr = pa->pages[--pa->index];
114 if (pa->index == 0) {
115 pa = pa->next;
116 free_page((unsigned long) *list);
117 *list = pa;
118 }
119 free_page(addr);
120 (*counter)--;
121 nr--;
122 }
123 spin_unlock(&cmm_lock);
124 return nr;
125}
126
127static int cmm_oom_notify(struct notifier_block *self,
128 unsigned long dummy, void *parm)
129{
130 unsigned long *freed = parm;
131 long nr = 256;
132
133 nr = cmm_free_pages(nr, &cmm_timed_pages, &cmm_timed_page_list);
134 if (nr > 0)
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;
138 *freed += 256 - nr;
139 return NOTIFY_OK;
140}
141
142static struct notifier_block cmm_oom_nb = {
143 .notifier_call = cmm_oom_notify,
144};
145
146static int cmm_thread(void *dummy)
147{
148 int rc;
149
150 while (1) {
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;
158 break;
159 }
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);
165 }
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);
173 }
174 if (cmm_timed_pages > 0 && !timer_pending(&cmm_timer))
175 cmm_set_timer();
176 }
177 return 0;
178}
179
180static void cmm_kick_thread(void)
181{
182 wake_up(&cmm_thread_wait);
183}
184
185static void cmm_set_timer(void)
186{
187 if (cmm_timed_pages_target <= 0 || cmm_timeout_seconds <= 0) {
188 if (timer_pending(&cmm_timer))
189 del_timer(&cmm_timer);
190 return;
191 }
192 if (timer_pending(&cmm_timer)) {
193 if (mod_timer(&cmm_timer, jiffies + cmm_timeout_seconds*HZ))
194 return;
195 }
196 cmm_timer.function = cmm_timer_fn;
197 cmm_timer.data = 0;
198 cmm_timer.expires = jiffies + cmm_timeout_seconds*HZ;
199 add_timer(&cmm_timer);
200}
201
202static void cmm_timer_fn(unsigned long ignored)
203{
204 long nr;
205
206 nr = cmm_timed_pages_target - cmm_timeout_pages;
207 if (nr < 0)
208 cmm_timed_pages_target = 0;
209 else
210 cmm_timed_pages_target = nr;
211 cmm_kick_thread();
212 cmm_set_timer();
213}
214
215static void cmm_set_pages(long nr)
216{
217 cmm_pages_target = nr;
218 cmm_kick_thread();
219}
220
221static long cmm_get_pages(void)
222{
223 return cmm_pages;
224}
225
226static void cmm_add_timed_pages(long nr)
227{
228 cmm_timed_pages_target += nr;
229 cmm_kick_thread();
230}
231
232static long cmm_get_timed_pages(void)
233{
234 return cmm_timed_pages;
235}
236
237static void cmm_set_timeout(long nr, long seconds)
238{
239 cmm_timeout_pages = nr;
240 cmm_timeout_seconds = seconds;
241 cmm_set_timer();
242}
243
244static int cmm_skip_blanks(char *cp, char **endp)
245{
246 char *str;
247
248 for (str = cp; *str == ' ' || *str == '\t'; str++)
249 ;
250 *endp = str;
251 return str != cp;
252}
253
254static struct ctl_table cmm_table[];
255
256static int cmm_pages_handler(ctl_table *ctl, int write, void __user *buffer,
257 size_t *lenp, loff_t *ppos)
258{
259 char buf[16], *p;
260 long nr;
261 int len;
262
263 if (!*lenp || (*ppos && !write)) {
264 *lenp = 0;
265 return 0;
266 }
267
268 if (write) {
269 len = *lenp;
270 if (copy_from_user(buf, buffer,
271 len > sizeof(buf) ? sizeof(buf) : len))
272 return -EFAULT;
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])
277 cmm_set_pages(nr);
278 else
279 cmm_add_timed_pages(nr);
280 } else {
281 if (ctl == &cmm_table[0])
282 nr = cmm_get_pages();
283 else
284 nr = cmm_get_timed_pages();
285 len = sprintf(buf, "%ld\n", nr);
286 if (len > *lenp)
287 len = *lenp;
288 if (copy_to_user(buffer, buf, len))
289 return -EFAULT;
290 }
291 *lenp = len;
292 *ppos += len;
293 return 0;
294}
295
296static int cmm_timeout_handler(ctl_table *ctl, int write, void __user *buffer,
297 size_t *lenp, loff_t *ppos)
298{
299 char buf[64], *p;
300 long nr, seconds;
301 int len;
302
303 if (!*lenp || (*ppos && !write)) {
304 *lenp = 0;
305 return 0;
306 }
307
308 if (write) {
309 len = *lenp;
310 if (copy_from_user(buf, buffer,
311 len > sizeof(buf) ? sizeof(buf) : len))
312 return -EFAULT;
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);
319 } else {
320 len = sprintf(buf, "%ld %ld\n",
321 cmm_timeout_pages, cmm_timeout_seconds);
322 if (len > *lenp)
323 len = *lenp;
324 if (copy_to_user(buffer, buf, len))
325 return -EFAULT;
326 }
327 *lenp = len;
328 *ppos += len;
329 return 0;
330}
331
332static struct ctl_table cmm_table[] = {
333 {
334 .procname = "cmm_pages",
335 .mode = 0644,
336 .proc_handler = cmm_pages_handler,
337 },
338 {
339 .procname = "cmm_timed_pages",
340 .mode = 0644,
341 .proc_handler = cmm_pages_handler,
342 },
343 {
344 .procname = "cmm_timeout",
345 .mode = 0644,
346 .proc_handler = cmm_timeout_handler,
347 },
348 { }
349};
350
351static struct ctl_table cmm_dir_table[] = {
352 {
353 .procname = "vm",
354 .maxlen = 0,
355 .mode = 0555,
356 .child = cmm_table,
357 },
358 { }
359};
360
361#ifdef CONFIG_CMM_IUCV
362#define SMSG_PREFIX "CMM"
363static void cmm_smsg_target(const char *from, char *msg)
364{
365 long nr, seconds;
366
367 if (strlen(sender) > 0 && strcmp(from, sender) != 0)
368 return;
369 if (!cmm_skip_blanks(msg + strlen(SMSG_PREFIX), &msg))
370 return;
371 if (strncmp(msg, "SHRINK", 6) == 0) {
372 if (!cmm_skip_blanks(msg + 6, &msg))
373 return;
374 nr = simple_strtoul(msg, &msg, 0);
375 cmm_skip_blanks(msg, &msg);
376 if (*msg == '\0')
377 cmm_set_pages(nr);
378 } else if (strncmp(msg, "RELEASE", 7) == 0) {
379 if (!cmm_skip_blanks(msg + 7, &msg))
380 return;
381 nr = simple_strtoul(msg, &msg, 0);
382 cmm_skip_blanks(msg, &msg);
383 if (*msg == '\0')
384 cmm_add_timed_pages(nr);
385 } else if (strncmp(msg, "REUSE", 5) == 0) {
386 if (!cmm_skip_blanks(msg + 5, &msg))
387 return;
388 nr = simple_strtoul(msg, &msg, 0);
389 if (!cmm_skip_blanks(msg, &msg))
390 return;
391 seconds = simple_strtoul(msg, &msg, 0);
392 cmm_skip_blanks(msg, &msg);
393 if (*msg == '\0')
394 cmm_set_timeout(nr, seconds);
395 }
396}
397#endif
398
399static struct ctl_table_header *cmm_sysctl_header;
400
401static int cmm_suspend(void)
402{
403 cmm_suspended = 1;
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);
406 return 0;
407}
408
409static int cmm_resume(void)
410{
411 cmm_suspended = 0;
412 cmm_kick_thread();
413 return 0;
414}
415
416static int cmm_power_event(struct notifier_block *this,
417 unsigned long event, void *ptr)
418{
419 switch (event) {
420 case PM_POST_HIBERNATION:
421 return cmm_resume();
422 case PM_HIBERNATION_PREPARE:
423 return cmm_suspend();
424 default:
425 return NOTIFY_DONE;
426 }
427}
428
429static struct notifier_block cmm_power_notifier = {
430 .notifier_call = cmm_power_event,
431};
432
433static int __init cmm_init(void)
434{
435 int rc = -ENOMEM;
436
437 cmm_sysctl_header = register_sysctl_table(cmm_dir_table);
438 if (!cmm_sysctl_header)
439 goto out_sysctl;
440#ifdef CONFIG_CMM_IUCV
441
442 if (sender) {
443 int len = strlen(sender);
444 while (len--)
445 sender[len] = toupper(sender[len]);
446 } else {
447 sender = cmm_default_sender;
448 }
449
450 rc = smsg_register_callback(SMSG_PREFIX, cmm_smsg_target);
451 if (rc < 0)
452 goto out_smsg;
453#endif
454 rc = register_oom_notifier(&cmm_oom_nb);
455 if (rc < 0)
456 goto out_oom_notify;
457 rc = register_pm_notifier(&cmm_power_notifier);
458 if (rc)
459 goto out_pm;
460 cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread");
461 rc = IS_ERR(cmm_thread_ptr) ? PTR_ERR(cmm_thread_ptr) : 0;
462 if (rc)
463 goto out_kthread;
464 return 0;
465
466out_kthread:
467 unregister_pm_notifier(&cmm_power_notifier);
468out_pm:
469 unregister_oom_notifier(&cmm_oom_nb);
470out_oom_notify:
471#ifdef CONFIG_CMM_IUCV
472 smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
473out_smsg:
474#endif
475 unregister_sysctl_table(cmm_sysctl_header);
476out_sysctl:
477 del_timer_sync(&cmm_timer);
478 return rc;
479}
480module_init(cmm_init);
481
482static void __exit cmm_exit(void)
483{
484 unregister_sysctl_table(cmm_sysctl_header);
485#ifdef CONFIG_CMM_IUCV
486 smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
487#endif
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);
494}
495module_exit(cmm_exit);
496
497MODULE_LICENSE("GPL");
498
