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1 | /* | |
2 | * arch/s390/mm/cmm.c | |
3 | * | |
4 | * S390 version | |
5 | * Copyright (C) 2003 IBM Deutschland Entwicklung GmbH, IBM Corporation | |
6 | * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com) | |
7 | * | |
8 | * Collaborative memory management interface. | |
9 | */ | |
10 | ||
11 | #include <linux/errno.h> | |
12 | #include <linux/fs.h> | |
13 | #include <linux/init.h> | |
14 | #include <linux/module.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 | ||
22 | #include <asm/pgalloc.h> | |
23 | #include <asm/uaccess.h> | |
24 | #include <asm/diag.h> | |
25 | ||
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)"); | |
30 | ||
31 | #include "../../../drivers/s390/net/smsgiucv.h" | |
32 | ||
33 | #define CMM_NR_PAGES ((PAGE_SIZE / sizeof(unsigned long)) - 2) | |
34 | ||
35 | struct cmm_page_array { | |
36 | struct cmm_page_array *next; | |
37 | unsigned long index; | |
38 | unsigned long pages[CMM_NR_PAGES]; | |
39 | }; | |
40 | ||
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 | ||
48 | static struct cmm_page_array *cmm_page_list; | |
49 | static struct cmm_page_array *cmm_timed_page_list; | |
50 | static DEFINE_SPINLOCK(cmm_lock); | |
51 | ||
52 | static struct task_struct *cmm_thread_ptr; | |
53 | static wait_queue_head_t cmm_thread_wait; | |
54 | static struct timer_list cmm_timer; | |
55 | ||
56 | static void cmm_timer_fn(unsigned long); | |
57 | static void cmm_set_timer(void); | |
58 | ||
59 | static long | |
60 | cmm_alloc_pages(long nr, long *counter, struct cmm_page_array **list) | |
61 | { | |
62 | struct cmm_page_array *pa, *npa; | |
63 | unsigned long addr; | |
64 | ||
65 | while (nr) { | |
66 | addr = __get_free_page(GFP_NOIO); | |
67 | if (!addr) | |
68 | break; | |
69 | spin_lock(&cmm_lock); | |
70 | pa = *list; | |
71 | if (!pa || pa->index >= CMM_NR_PAGES) { | |
72 | /* Need a new page for the page list. */ | |
73 | spin_unlock(&cmm_lock); | |
74 | npa = (struct cmm_page_array *) | |
75 | __get_free_page(GFP_NOIO); | |
76 | if (!npa) { | |
77 | free_page(addr); | |
78 | break; | |
79 | } | |
80 | spin_lock(&cmm_lock); | |
81 | pa = *list; | |
82 | if (!pa || pa->index >= CMM_NR_PAGES) { | |
83 | npa->next = pa; | |
84 | npa->index = 0; | |
85 | pa = npa; | |
86 | *list = pa; | |
87 | } else | |
88 | free_page((unsigned long) npa); | |
89 | } | |
90 | diag10(addr); | |
91 | pa->pages[pa->index++] = addr; | |
92 | (*counter)++; | |
93 | spin_unlock(&cmm_lock); | |
94 | nr--; | |
95 | } | |
96 | return nr; | |
97 | } | |
98 | ||
99 | static long | |
100 | cmm_free_pages(long nr, long *counter, struct cmm_page_array **list) | |
101 | { | |
102 | struct cmm_page_array *pa; | |
103 | unsigned long addr; | |
104 | ||
105 | spin_lock(&cmm_lock); | |
106 | pa = *list; | |
107 | while (nr) { | |
108 | if (!pa || pa->index <= 0) | |
109 | break; | |
110 | addr = pa->pages[--pa->index]; | |
111 | if (pa->index == 0) { | |
112 | pa = pa->next; | |
113 | free_page((unsigned long) *list); | |
114 | *list = pa; | |
115 | } | |
116 | free_page(addr); | |
117 | (*counter)--; | |
118 | nr--; | |
119 | } | |
120 | spin_unlock(&cmm_lock); | |
121 | return nr; | |
122 | } | |
123 | ||
124 | static int cmm_oom_notify(struct notifier_block *self, | |
125 | unsigned long dummy, void *parm) | |
126 | { | |
127 | unsigned long *freed = parm; | |
128 | long nr = 256; | |
129 | ||
130 | nr = cmm_free_pages(nr, &cmm_timed_pages, &cmm_timed_page_list); | |
131 | if (nr > 0) | |
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; | |
135 | *freed += 256 - nr; | |
136 | return NOTIFY_OK; | |
137 | } | |
138 | ||
139 | static struct notifier_block cmm_oom_nb = { | |
140 | .notifier_call = cmm_oom_notify | |
141 | }; | |
142 | ||
143 | static int | |
144 | cmm_thread(void *dummy) | |
145 | { | |
146 | int rc; | |
147 | ||
148 | while (1) { | |
149 | rc = wait_event_interruptible(cmm_thread_wait, | |
150 | (cmm_pages != cmm_pages_target || | |
151 | cmm_timed_pages != cmm_timed_pages_target || | |
152 | kthread_should_stop())); | |
153 | if (kthread_should_stop() || rc == -ERESTARTSYS) { | |
154 | cmm_pages_target = cmm_pages; | |
155 | cmm_timed_pages_target = cmm_timed_pages; | |
156 | break; | |
157 | } | |
158 | if (cmm_pages_target > cmm_pages) { | |
159 | if (cmm_alloc_pages(1, &cmm_pages, &cmm_page_list)) | |
160 | cmm_pages_target = cmm_pages; | |
161 | } else if (cmm_pages_target < cmm_pages) { | |
162 | cmm_free_pages(1, &cmm_pages, &cmm_page_list); | |
163 | } | |
164 | if (cmm_timed_pages_target > cmm_timed_pages) { | |
165 | if (cmm_alloc_pages(1, &cmm_timed_pages, | |
166 | &cmm_timed_page_list)) | |
167 | cmm_timed_pages_target = cmm_timed_pages; | |
168 | } else if (cmm_timed_pages_target < cmm_timed_pages) { | |
169 | cmm_free_pages(1, &cmm_timed_pages, | |
170 | &cmm_timed_page_list); | |
171 | } | |
172 | if (cmm_timed_pages > 0 && !timer_pending(&cmm_timer)) | |
173 | cmm_set_timer(); | |
174 | } | |
175 | return 0; | |
176 | } | |
177 | ||
178 | static void | |
179 | cmm_kick_thread(void) | |
180 | { | |
181 | wake_up(&cmm_thread_wait); | |
182 | } | |
183 | ||
184 | static void | |
185 | 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 | ||
202 | static void | |
203 | cmm_timer_fn(unsigned long ignored) | |
204 | { | |
205 | long nr; | |
206 | ||
207 | nr = cmm_timed_pages_target - cmm_timeout_pages; | |
208 | if (nr < 0) | |
209 | cmm_timed_pages_target = 0; | |
210 | else | |
211 | cmm_timed_pages_target = nr; | |
212 | cmm_kick_thread(); | |
213 | cmm_set_timer(); | |
214 | } | |
215 | ||
216 | void | |
217 | cmm_set_pages(long nr) | |
218 | { | |
219 | cmm_pages_target = nr; | |
220 | cmm_kick_thread(); | |
221 | } | |
222 | ||
223 | long | |
224 | cmm_get_pages(void) | |
225 | { | |
226 | return cmm_pages; | |
227 | } | |
228 | ||
229 | void | |
230 | cmm_add_timed_pages(long nr) | |
231 | { | |
232 | cmm_timed_pages_target += nr; | |
233 | cmm_kick_thread(); | |
234 | } | |
235 | ||
236 | long | |
237 | cmm_get_timed_pages(void) | |
238 | { | |
239 | return cmm_timed_pages; | |
240 | } | |
241 | ||
242 | void | |
243 | cmm_set_timeout(long nr, long seconds) | |
244 | { | |
245 | cmm_timeout_pages = nr; | |
246 | cmm_timeout_seconds = seconds; | |
247 | cmm_set_timer(); | |
248 | } | |
249 | ||
250 | static int | |
251 | cmm_skip_blanks(char *cp, char **endp) | |
252 | { | |
253 | char *str; | |
254 | ||
255 | for (str = cp; *str == ' ' || *str == '\t'; str++); | |
256 | *endp = str; | |
257 | return str != cp; | |
258 | } | |
259 | ||
260 | #ifdef CONFIG_CMM_PROC | |
261 | ||
262 | static struct ctl_table cmm_table[]; | |
263 | ||
264 | static int | |
265 | cmm_pages_handler(ctl_table *ctl, int write, struct file *filp, | |
266 | void __user *buffer, size_t *lenp, loff_t *ppos) | |
267 | { | |
268 | char buf[16], *p; | |
269 | long nr; | |
270 | int len; | |
271 | ||
272 | if (!*lenp || (*ppos && !write)) { | |
273 | *lenp = 0; | |
274 | return 0; | |
275 | } | |
276 | ||
277 | if (write) { | |
278 | len = *lenp; | |
279 | if (copy_from_user(buf, buffer, | |
280 | len > sizeof(buf) ? sizeof(buf) : len)) | |
281 | return -EFAULT; | |
282 | buf[sizeof(buf) - 1] = '\0'; | |
283 | cmm_skip_blanks(buf, &p); | |
284 | nr = simple_strtoul(p, &p, 0); | |
285 | if (ctl == &cmm_table[0]) | |
286 | cmm_set_pages(nr); | |
287 | else | |
288 | cmm_add_timed_pages(nr); | |
289 | } else { | |
290 | if (ctl == &cmm_table[0]) | |
291 | nr = cmm_get_pages(); | |
292 | else | |
293 | nr = cmm_get_timed_pages(); | |
294 | len = sprintf(buf, "%ld\n", nr); | |
295 | if (len > *lenp) | |
296 | len = *lenp; | |
297 | if (copy_to_user(buffer, buf, len)) | |
298 | return -EFAULT; | |
299 | } | |
300 | *lenp = len; | |
301 | *ppos += len; | |
302 | return 0; | |
303 | } | |
304 | ||
305 | static int | |
306 | cmm_timeout_handler(ctl_table *ctl, int write, struct file *filp, | |
307 | void __user *buffer, size_t *lenp, loff_t *ppos) | |
308 | { | |
309 | char buf[64], *p; | |
310 | long nr, seconds; | |
311 | int len; | |
312 | ||
313 | if (!*lenp || (*ppos && !write)) { | |
314 | *lenp = 0; | |
315 | return 0; | |
316 | } | |
317 | ||
318 | if (write) { | |
319 | len = *lenp; | |
320 | if (copy_from_user(buf, buffer, | |
321 | len > sizeof(buf) ? sizeof(buf) : len)) | |
322 | return -EFAULT; | |
323 | buf[sizeof(buf) - 1] = '\0'; | |
324 | cmm_skip_blanks(buf, &p); | |
325 | nr = simple_strtoul(p, &p, 0); | |
326 | cmm_skip_blanks(p, &p); | |
327 | seconds = simple_strtoul(p, &p, 0); | |
328 | cmm_set_timeout(nr, seconds); | |
329 | } else { | |
330 | len = sprintf(buf, "%ld %ld\n", | |
331 | cmm_timeout_pages, cmm_timeout_seconds); | |
332 | if (len > *lenp) | |
333 | len = *lenp; | |
334 | if (copy_to_user(buffer, buf, len)) | |
335 | return -EFAULT; | |
336 | } | |
337 | *lenp = len; | |
338 | *ppos += len; | |
339 | return 0; | |
340 | } | |
341 | ||
342 | static struct ctl_table cmm_table[] = { | |
343 | { | |
344 | .procname = "cmm_pages", | |
345 | .mode = 0644, | |
346 | .proc_handler = &cmm_pages_handler, | |
347 | }, | |
348 | { | |
349 | .procname = "cmm_timed_pages", | |
350 | .mode = 0644, | |
351 | .proc_handler = &cmm_pages_handler, | |
352 | }, | |
353 | { | |
354 | .procname = "cmm_timeout", | |
355 | .mode = 0644, | |
356 | .proc_handler = &cmm_timeout_handler, | |
357 | }, | |
358 | { .ctl_name = 0 } | |
359 | }; | |
360 | ||
361 | static struct ctl_table cmm_dir_table[] = { | |
362 | { | |
363 | .ctl_name = CTL_VM, | |
364 | .procname = "vm", | |
365 | .maxlen = 0, | |
366 | .mode = 0555, | |
367 | .child = cmm_table, | |
368 | }, | |
369 | { .ctl_name = 0 } | |
370 | }; | |
371 | #endif | |
372 | ||
373 | #ifdef CONFIG_CMM_IUCV | |
374 | #define SMSG_PREFIX "CMM" | |
375 | static void | |
376 | cmm_smsg_target(char *from, char *msg) | |
377 | { | |
378 | long nr, seconds; | |
379 | ||
380 | if (strlen(sender) > 0 && strcmp(from, sender) != 0) | |
381 | return; | |
382 | if (!cmm_skip_blanks(msg + strlen(SMSG_PREFIX), &msg)) | |
383 | return; | |
384 | if (strncmp(msg, "SHRINK", 6) == 0) { | |
385 | if (!cmm_skip_blanks(msg + 6, &msg)) | |
386 | return; | |
387 | nr = simple_strtoul(msg, &msg, 0); | |
388 | cmm_skip_blanks(msg, &msg); | |
389 | if (*msg == '\0') | |
390 | cmm_set_pages(nr); | |
391 | } else if (strncmp(msg, "RELEASE", 7) == 0) { | |
392 | if (!cmm_skip_blanks(msg + 7, &msg)) | |
393 | return; | |
394 | nr = simple_strtoul(msg, &msg, 0); | |
395 | cmm_skip_blanks(msg, &msg); | |
396 | if (*msg == '\0') | |
397 | cmm_add_timed_pages(nr); | |
398 | } else if (strncmp(msg, "REUSE", 5) == 0) { | |
399 | if (!cmm_skip_blanks(msg + 5, &msg)) | |
400 | return; | |
401 | nr = simple_strtoul(msg, &msg, 0); | |
402 | if (!cmm_skip_blanks(msg, &msg)) | |
403 | return; | |
404 | seconds = simple_strtoul(msg, &msg, 0); | |
405 | cmm_skip_blanks(msg, &msg); | |
406 | if (*msg == '\0') | |
407 | cmm_set_timeout(nr, seconds); | |
408 | } | |
409 | } | |
410 | #endif | |
411 | ||
412 | static struct ctl_table_header *cmm_sysctl_header; | |
413 | ||
414 | static int | |
415 | cmm_init (void) | |
416 | { | |
417 | int rc = -ENOMEM; | |
418 | ||
419 | #ifdef CONFIG_CMM_PROC | |
420 | cmm_sysctl_header = register_sysctl_table(cmm_dir_table); | |
421 | if (!cmm_sysctl_header) | |
422 | goto out; | |
423 | #endif | |
424 | #ifdef CONFIG_CMM_IUCV | |
425 | rc = smsg_register_callback(SMSG_PREFIX, cmm_smsg_target); | |
426 | if (rc < 0) | |
427 | goto out_smsg; | |
428 | #endif | |
429 | rc = register_oom_notifier(&cmm_oom_nb); | |
430 | if (rc < 0) | |
431 | goto out_oom_notify; | |
432 | init_waitqueue_head(&cmm_thread_wait); | |
433 | init_timer(&cmm_timer); | |
434 | cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread"); | |
435 | rc = IS_ERR(cmm_thread_ptr) ? PTR_ERR(cmm_thread_ptr) : 0; | |
436 | if (!rc) | |
437 | goto out; | |
438 | /* | |
439 | * kthread_create failed. undo all the stuff from above again. | |
440 | */ | |
441 | unregister_oom_notifier(&cmm_oom_nb); | |
442 | ||
443 | out_oom_notify: | |
444 | #ifdef CONFIG_CMM_IUCV | |
445 | smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target); | |
446 | out_smsg: | |
447 | #endif | |
448 | #ifdef CONFIG_CMM_PROC | |
449 | unregister_sysctl_table(cmm_sysctl_header); | |
450 | #endif | |
451 | out: | |
452 | return rc; | |
453 | } | |
454 | ||
455 | static void | |
456 | cmm_exit(void) | |
457 | { | |
458 | kthread_stop(cmm_thread_ptr); | |
459 | unregister_oom_notifier(&cmm_oom_nb); | |
460 | cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list); | |
461 | cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list); | |
462 | #ifdef CONFIG_CMM_PROC | |
463 | unregister_sysctl_table(cmm_sysctl_header); | |
464 | #endif | |
465 | #ifdef CONFIG_CMM_IUCV | |
466 | smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target); | |
467 | #endif | |
468 | } | |
469 | ||
470 | module_init(cmm_init); | |
471 | module_exit(cmm_exit); | |
472 | ||
473 | EXPORT_SYMBOL(cmm_set_pages); | |
474 | EXPORT_SYMBOL(cmm_get_pages); | |
475 | EXPORT_SYMBOL(cmm_add_timed_pages); | |
476 | EXPORT_SYMBOL(cmm_get_timed_pages); | |
477 | EXPORT_SYMBOL(cmm_set_timeout); | |
478 | ||
479 | MODULE_LICENSE("GPL"); |