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10#include <linux/errno.h>
11#include <linux/fs.h>
12#include <linux/init.h>
13#include <linux/module.h>
14#include <linux/moduleparam.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>
23#include <linux/uaccess.h>
24
25#include <asm/pgalloc.h>
26#include <asm/diag.h>
27
28#ifdef CONFIG_CMM_IUCV
29static char *cmm_default_sender = "VMRMSVM";
30#endif
31static char *sender;
32module_param(sender, charp, 0400);
33MODULE_PARM_DESC(sender,
34 "Guest name that may send SMSG messages (default VMRMSVM)");
35
36#include "../../../drivers/s390/net/smsgiucv.h"
37
38#define CMM_NR_PAGES ((PAGE_SIZE / sizeof(unsigned long)) - 2)
39
40struct cmm_page_array {
41 struct cmm_page_array *next;
42 unsigned long index;
43 unsigned long pages[CMM_NR_PAGES];
44};
45
46static long cmm_pages;
47static long cmm_timed_pages;
48static volatile long cmm_pages_target;
49static volatile long cmm_timed_pages_target;
50static long cmm_timeout_pages;
51static long cmm_timeout_seconds;
52static int cmm_suspended;
53
54static struct cmm_page_array *cmm_page_list;
55static struct cmm_page_array *cmm_timed_page_list;
56static DEFINE_SPINLOCK(cmm_lock);
57
58static struct task_struct *cmm_thread_ptr;
59static DECLARE_WAIT_QUEUE_HEAD(cmm_thread_wait);
60
61static void cmm_timer_fn(struct timer_list *);
62static void cmm_set_timer(void);
63static DEFINE_TIMER(cmm_timer, cmm_timer_fn);
64
65static long cmm_alloc_pages(long nr, long *counter,
66 struct cmm_page_array **list)
67{
68 struct cmm_page_array *pa, *npa;
69 unsigned long addr;
70
71 while (nr) {
72 addr = __get_free_page(GFP_NOIO);
73 if (!addr)
74 break;
75 spin_lock(&cmm_lock);
76 pa = *list;
77 if (!pa || pa->index >= CMM_NR_PAGES) {
78
79 spin_unlock(&cmm_lock);
80 npa = (struct cmm_page_array *)
81 __get_free_page(GFP_NOIO);
82 if (!npa) {
83 free_page(addr);
84 break;
85 }
86 spin_lock(&cmm_lock);
87 pa = *list;
88 if (!pa || pa->index >= CMM_NR_PAGES) {
89 npa->next = pa;
90 npa->index = 0;
91 pa = npa;
92 *list = pa;
93 } else
94 free_page((unsigned long) npa);
95 }
96 diag10_range(addr >> PAGE_SHIFT, 1);
97 pa->pages[pa->index++] = addr;
98 (*counter)++;
99 spin_unlock(&cmm_lock);
100 nr--;
101 }
102 return nr;
103}
104
105static long cmm_free_pages(long nr, long *counter, struct cmm_page_array **list)
106{
107 struct cmm_page_array *pa;
108 unsigned long addr;
109
110 spin_lock(&cmm_lock);
111 pa = *list;
112 while (nr) {
113 if (!pa || pa->index <= 0)
114 break;
115 addr = pa->pages[--pa->index];
116 if (pa->index == 0) {
117 pa = pa->next;
118 free_page((unsigned long) *list);
119 *list = pa;
120 }
121 free_page(addr);
122 (*counter)--;
123 nr--;
124 }
125 spin_unlock(&cmm_lock);
126 return nr;
127}
128
129static int cmm_oom_notify(struct notifier_block *self,
130 unsigned long dummy, void *parm)
131{
132 unsigned long *freed = parm;
133 long nr = 256;
134
135 nr = cmm_free_pages(nr, &cmm_timed_pages, &cmm_timed_page_list);
136 if (nr > 0)
137 nr = cmm_free_pages(nr, &cmm_pages, &cmm_page_list);
138 cmm_pages_target = cmm_pages;
139 cmm_timed_pages_target = cmm_timed_pages;
140 *freed += 256 - nr;
141 return NOTIFY_OK;
142}
143
144static struct notifier_block cmm_oom_nb = {
145 .notifier_call = cmm_oom_notify,
146};
147
148static int cmm_thread(void *dummy)
149{
150 int rc;
151
152 while (1) {
153 rc = wait_event_interruptible(cmm_thread_wait,
154 (!cmm_suspended && (cmm_pages != cmm_pages_target ||
155 cmm_timed_pages != cmm_timed_pages_target)) ||
156 kthread_should_stop());
157 if (kthread_should_stop() || rc == -ERESTARTSYS) {
158 cmm_pages_target = cmm_pages;
159 cmm_timed_pages_target = cmm_timed_pages;
160 break;
161 }
162 if (cmm_pages_target > cmm_pages) {
163 if (cmm_alloc_pages(1, &cmm_pages, &cmm_page_list))
164 cmm_pages_target = cmm_pages;
165 } else if (cmm_pages_target < cmm_pages) {
166 cmm_free_pages(1, &cmm_pages, &cmm_page_list);
167 }
168 if (cmm_timed_pages_target > cmm_timed_pages) {
169 if (cmm_alloc_pages(1, &cmm_timed_pages,
170 &cmm_timed_page_list))
171 cmm_timed_pages_target = cmm_timed_pages;
172 } else if (cmm_timed_pages_target < cmm_timed_pages) {
173 cmm_free_pages(1, &cmm_timed_pages,
174 &cmm_timed_page_list);
175 }
176 if (cmm_timed_pages > 0 && !timer_pending(&cmm_timer))
177 cmm_set_timer();
178 }
179 return 0;
180}
181
182static void cmm_kick_thread(void)
183{
184 wake_up(&cmm_thread_wait);
185}
186
187static void cmm_set_timer(void)
188{
189 if (cmm_timed_pages_target <= 0 || cmm_timeout_seconds <= 0) {
190 if (timer_pending(&cmm_timer))
191 del_timer(&cmm_timer);
192 return;
193 }
194 mod_timer(&cmm_timer, jiffies + cmm_timeout_seconds * HZ);
195}
196
197static void cmm_timer_fn(struct timer_list *unused)
198{
199 long nr;
200
201 nr = cmm_timed_pages_target - cmm_timeout_pages;
202 if (nr < 0)
203 cmm_timed_pages_target = 0;
204 else
205 cmm_timed_pages_target = nr;
206 cmm_kick_thread();
207 cmm_set_timer();
208}
209
210static void cmm_set_pages(long nr)
211{
212 cmm_pages_target = nr;
213 cmm_kick_thread();
214}
215
216static long cmm_get_pages(void)
217{
218 return cmm_pages;
219}
220
221static void cmm_add_timed_pages(long nr)
222{
223 cmm_timed_pages_target += nr;
224 cmm_kick_thread();
225}
226
227static long cmm_get_timed_pages(void)
228{
229 return cmm_timed_pages;
230}
231
232static void cmm_set_timeout(long nr, long seconds)
233{
234 cmm_timeout_pages = nr;
235 cmm_timeout_seconds = seconds;
236 cmm_set_timer();
237}
238
239static int cmm_skip_blanks(char *cp, char **endp)
240{
241 char *str;
242
243 for (str = cp; *str == ' ' || *str == '\t'; str++)
244 ;
245 *endp = str;
246 return str != cp;
247}
248
249static int cmm_pages_handler(struct ctl_table *ctl, int write,
250 void __user *buffer, size_t *lenp, loff_t *ppos)
251{
252 long nr = cmm_get_pages();
253 struct ctl_table ctl_entry = {
254 .procname = ctl->procname,
255 .data = &nr,
256 .maxlen = sizeof(long),
257 };
258 int rc;
259
260 rc = proc_doulongvec_minmax(&ctl_entry, write, buffer, lenp, ppos);
261 if (rc < 0 || !write)
262 return rc;
263
264 cmm_set_pages(nr);
265 return 0;
266}
267
268static int cmm_timed_pages_handler(struct ctl_table *ctl, int write,
269 void __user *buffer, size_t *lenp,
270 loff_t *ppos)
271{
272 long nr = cmm_get_timed_pages();
273 struct ctl_table ctl_entry = {
274 .procname = ctl->procname,
275 .data = &nr,
276 .maxlen = sizeof(long),
277 };
278 int rc;
279
280 rc = proc_doulongvec_minmax(&ctl_entry, write, buffer, lenp, ppos);
281 if (rc < 0 || !write)
282 return rc;
283
284 cmm_add_timed_pages(nr);
285 return 0;
286}
287
288static int cmm_timeout_handler(struct ctl_table *ctl, int write,
289 void __user *buffer, size_t *lenp, loff_t *ppos)
290{
291 char buf[64], *p;
292 long nr, seconds;
293 unsigned int len;
294
295 if (!*lenp || (*ppos && !write)) {
296 *lenp = 0;
297 return 0;
298 }
299
300 if (write) {
301 len = *lenp;
302 if (copy_from_user(buf, buffer,
303 len > sizeof(buf) ? sizeof(buf) : len))
304 return -EFAULT;
305 buf[sizeof(buf) - 1] = '\0';
306 cmm_skip_blanks(buf, &p);
307 nr = simple_strtoul(p, &p, 0);
308 cmm_skip_blanks(p, &p);
309 seconds = simple_strtoul(p, &p, 0);
310 cmm_set_timeout(nr, seconds);
311 } else {
312 len = sprintf(buf, "%ld %ld\n",
313 cmm_timeout_pages, cmm_timeout_seconds);
314 if (len > *lenp)
315 len = *lenp;
316 if (copy_to_user(buffer, buf, len))
317 return -EFAULT;
318 }
319 *lenp = len;
320 *ppos += len;
321 return 0;
322}
323
324static struct ctl_table cmm_table[] = {
325 {
326 .procname = "cmm_pages",
327 .mode = 0644,
328 .proc_handler = cmm_pages_handler,
329 },
330 {
331 .procname = "cmm_timed_pages",
332 .mode = 0644,
333 .proc_handler = cmm_timed_pages_handler,
334 },
335 {
336 .procname = "cmm_timeout",
337 .mode = 0644,
338 .proc_handler = cmm_timeout_handler,
339 },
340 { }
341};
342
343static struct ctl_table cmm_dir_table[] = {
344 {
345 .procname = "vm",
346 .maxlen = 0,
347 .mode = 0555,
348 .child = cmm_table,
349 },
350 { }
351};
352
353#ifdef CONFIG_CMM_IUCV
354#define SMSG_PREFIX "CMM"
355static void cmm_smsg_target(const char *from, char *msg)
356{
357 long nr, seconds;
358
359 if (strlen(sender) > 0 && strcmp(from, sender) != 0)
360 return;
361 if (!cmm_skip_blanks(msg + strlen(SMSG_PREFIX), &msg))
362 return;
363 if (strncmp(msg, "SHRINK", 6) == 0) {
364 if (!cmm_skip_blanks(msg + 6, &msg))
365 return;
366 nr = simple_strtoul(msg, &msg, 0);
367 cmm_skip_blanks(msg, &msg);
368 if (*msg == '\0')
369 cmm_set_pages(nr);
370 } else if (strncmp(msg, "RELEASE", 7) == 0) {
371 if (!cmm_skip_blanks(msg + 7, &msg))
372 return;
373 nr = simple_strtoul(msg, &msg, 0);
374 cmm_skip_blanks(msg, &msg);
375 if (*msg == '\0')
376 cmm_add_timed_pages(nr);
377 } else if (strncmp(msg, "REUSE", 5) == 0) {
378 if (!cmm_skip_blanks(msg + 5, &msg))
379 return;
380 nr = simple_strtoul(msg, &msg, 0);
381 if (!cmm_skip_blanks(msg, &msg))
382 return;
383 seconds = simple_strtoul(msg, &msg, 0);
384 cmm_skip_blanks(msg, &msg);
385 if (*msg == '\0')
386 cmm_set_timeout(nr, seconds);
387 }
388}
389#endif
390
391static struct ctl_table_header *cmm_sysctl_header;
392
393static int cmm_suspend(void)
394{
395 cmm_suspended = 1;
396 cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list);
397 cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list);
398 return 0;
399}
400
401static int cmm_resume(void)
402{
403 cmm_suspended = 0;
404 cmm_kick_thread();
405 return 0;
406}
407
408static int cmm_power_event(struct notifier_block *this,
409 unsigned long event, void *ptr)
410{
411 switch (event) {
412 case PM_POST_HIBERNATION:
413 return cmm_resume();
414 case PM_HIBERNATION_PREPARE:
415 return cmm_suspend();
416 default:
417 return NOTIFY_DONE;
418 }
419}
420
421static struct notifier_block cmm_power_notifier = {
422 .notifier_call = cmm_power_event,
423};
424
425static int __init cmm_init(void)
426{
427 int rc = -ENOMEM;
428
429 cmm_sysctl_header = register_sysctl_table(cmm_dir_table);
430 if (!cmm_sysctl_header)
431 goto out_sysctl;
432#ifdef CONFIG_CMM_IUCV
433
434 if (sender) {
435 int len = strlen(sender);
436 while (len--)
437 sender[len] = toupper(sender[len]);
438 } else {
439 sender = cmm_default_sender;
440 }
441
442 rc = smsg_register_callback(SMSG_PREFIX, cmm_smsg_target);
443 if (rc < 0)
444 goto out_smsg;
445#endif
446 rc = register_oom_notifier(&cmm_oom_nb);
447 if (rc < 0)
448 goto out_oom_notify;
449 rc = register_pm_notifier(&cmm_power_notifier);
450 if (rc)
451 goto out_pm;
452 cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread");
453 if (!IS_ERR(cmm_thread_ptr))
454 return 0;
455
456 rc = PTR_ERR(cmm_thread_ptr);
457 unregister_pm_notifier(&cmm_power_notifier);
458out_pm:
459 unregister_oom_notifier(&cmm_oom_nb);
460out_oom_notify:
461#ifdef CONFIG_CMM_IUCV
462 smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
463out_smsg:
464#endif
465 unregister_sysctl_table(cmm_sysctl_header);
466out_sysctl:
467 del_timer_sync(&cmm_timer);
468 return rc;
469}
470module_init(cmm_init);
471
472static void __exit cmm_exit(void)
473{
474 unregister_sysctl_table(cmm_sysctl_header);
475#ifdef CONFIG_CMM_IUCV
476 smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
477#endif
478 unregister_pm_notifier(&cmm_power_notifier);
479 unregister_oom_notifier(&cmm_oom_nb);
480 kthread_stop(cmm_thread_ptr);
481 del_timer_sync(&cmm_timer);
482 cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list);
483 cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list);
484}
485module_exit(cmm_exit);
486
487MODULE_LICENSE("GPL");
488
