Commit | Line | Data |
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1da177e4 LT |
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 | ||
1da177e4 LT |
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> | |
8bc719d3 | 18 | #include <linux/swap.h> |
e8216dee | 19 | #include <linux/kthread.h> |
1da177e4 LT |
20 | |
21 | #include <asm/pgalloc.h> | |
22 | #include <asm/uaccess.h> | |
23 | ||
15439d74 | 24 | static char *sender = "VMRMSVM"; |
447570cf | 25 | module_param(sender, charp, 0400); |
15439d74 MS |
26 | MODULE_PARM_DESC(sender, |
27 | "Guest name that may send SMSG messages (default VMRMSVM)"); | |
28 | ||
1da177e4 LT |
29 | #include "../../../drivers/s390/net/smsgiucv.h" |
30 | ||
31 | #define CMM_NR_PAGES ((PAGE_SIZE / sizeof(unsigned long)) - 2) | |
32 | ||
33 | struct cmm_page_array { | |
34 | struct cmm_page_array *next; | |
35 | unsigned long index; | |
36 | unsigned long pages[CMM_NR_PAGES]; | |
37 | }; | |
38 | ||
8bc719d3 MS |
39 | static long cmm_pages; |
40 | static long cmm_timed_pages; | |
41 | static volatile long cmm_pages_target; | |
42 | static volatile long cmm_timed_pages_target; | |
43 | static long cmm_timeout_pages; | |
44 | static long cmm_timeout_seconds; | |
1da177e4 | 45 | |
8bc719d3 MS |
46 | static struct cmm_page_array *cmm_page_list; |
47 | static struct cmm_page_array *cmm_timed_page_list; | |
48 | static DEFINE_SPINLOCK(cmm_lock); | |
1da177e4 | 49 | |
e8216dee | 50 | static struct task_struct *cmm_thread_ptr; |
1da177e4 LT |
51 | static wait_queue_head_t cmm_thread_wait; |
52 | static struct timer_list cmm_timer; | |
53 | ||
54 | static void cmm_timer_fn(unsigned long); | |
55 | static void cmm_set_timer(void); | |
56 | ||
1da177e4 | 57 | static long |
8bc719d3 | 58 | cmm_alloc_pages(long nr, long *counter, struct cmm_page_array **list) |
1da177e4 | 59 | { |
8bc719d3 MS |
60 | struct cmm_page_array *pa, *npa; |
61 | unsigned long addr; | |
1da177e4 | 62 | |
8bc719d3 MS |
63 | while (nr) { |
64 | addr = __get_free_page(GFP_NOIO); | |
65 | if (!addr) | |
1da177e4 | 66 | break; |
8bc719d3 MS |
67 | spin_lock(&cmm_lock); |
68 | pa = *list; | |
1da177e4 LT |
69 | if (!pa || pa->index >= CMM_NR_PAGES) { |
70 | /* Need a new page for the page list. */ | |
8bc719d3 MS |
71 | spin_unlock(&cmm_lock); |
72 | npa = (struct cmm_page_array *) | |
1da177e4 | 73 | __get_free_page(GFP_NOIO); |
8bc719d3 MS |
74 | if (!npa) { |
75 | free_page(addr); | |
1da177e4 LT |
76 | break; |
77 | } | |
8bc719d3 MS |
78 | spin_lock(&cmm_lock); |
79 | pa = *list; | |
80 | if (!pa || pa->index >= CMM_NR_PAGES) { | |
81 | npa->next = pa; | |
82 | npa->index = 0; | |
83 | pa = npa; | |
84 | *list = pa; | |
85 | } else | |
86 | free_page((unsigned long) npa); | |
1da177e4 | 87 | } |
8bc719d3 MS |
88 | diag10(addr); |
89 | pa->pages[pa->index++] = addr; | |
1da177e4 | 90 | (*counter)++; |
8bc719d3 MS |
91 | spin_unlock(&cmm_lock); |
92 | nr--; | |
1da177e4 | 93 | } |
8bc719d3 | 94 | return nr; |
1da177e4 LT |
95 | } |
96 | ||
8bc719d3 MS |
97 | static long |
98 | cmm_free_pages(long nr, long *counter, struct cmm_page_array **list) | |
1da177e4 LT |
99 | { |
100 | struct cmm_page_array *pa; | |
8bc719d3 | 101 | unsigned long addr; |
1da177e4 | 102 | |
8bc719d3 | 103 | spin_lock(&cmm_lock); |
1da177e4 | 104 | pa = *list; |
8bc719d3 | 105 | while (nr) { |
1da177e4 LT |
106 | if (!pa || pa->index <= 0) |
107 | break; | |
8bc719d3 | 108 | addr = pa->pages[--pa->index]; |
1da177e4 LT |
109 | if (pa->index == 0) { |
110 | pa = pa->next; | |
111 | free_page((unsigned long) *list); | |
112 | *list = pa; | |
113 | } | |
8bc719d3 | 114 | free_page(addr); |
1da177e4 | 115 | (*counter)--; |
8bc719d3 | 116 | nr--; |
1da177e4 | 117 | } |
8bc719d3 MS |
118 | spin_unlock(&cmm_lock); |
119 | return nr; | |
1da177e4 LT |
120 | } |
121 | ||
8bc719d3 MS |
122 | static int cmm_oom_notify(struct notifier_block *self, |
123 | unsigned long dummy, void *parm) | |
124 | { | |
125 | unsigned long *freed = parm; | |
126 | long nr = 256; | |
127 | ||
128 | nr = cmm_free_pages(nr, &cmm_timed_pages, &cmm_timed_page_list); | |
129 | if (nr > 0) | |
130 | nr = cmm_free_pages(nr, &cmm_pages, &cmm_page_list); | |
131 | cmm_pages_target = cmm_pages; | |
132 | cmm_timed_pages_target = cmm_timed_pages; | |
133 | *freed += 256 - nr; | |
134 | return NOTIFY_OK; | |
135 | } | |
136 | ||
137 | static struct notifier_block cmm_oom_nb = { | |
138 | .notifier_call = cmm_oom_notify | |
139 | }; | |
140 | ||
1da177e4 LT |
141 | static int |
142 | cmm_thread(void *dummy) | |
143 | { | |
144 | int rc; | |
145 | ||
1da177e4 LT |
146 | while (1) { |
147 | rc = wait_event_interruptible(cmm_thread_wait, | |
148 | (cmm_pages != cmm_pages_target || | |
e8216dee HC |
149 | cmm_timed_pages != cmm_timed_pages_target || |
150 | kthread_should_stop())); | |
151 | if (kthread_should_stop() || rc == -ERESTARTSYS) { | |
1da177e4 LT |
152 | cmm_pages_target = cmm_pages; |
153 | cmm_timed_pages_target = cmm_timed_pages; | |
154 | break; | |
155 | } | |
156 | if (cmm_pages_target > cmm_pages) { | |
157 | if (cmm_alloc_pages(1, &cmm_pages, &cmm_page_list)) | |
158 | cmm_pages_target = cmm_pages; | |
159 | } else if (cmm_pages_target < cmm_pages) { | |
160 | cmm_free_pages(1, &cmm_pages, &cmm_page_list); | |
161 | } | |
162 | if (cmm_timed_pages_target > cmm_timed_pages) { | |
163 | if (cmm_alloc_pages(1, &cmm_timed_pages, | |
164 | &cmm_timed_page_list)) | |
165 | cmm_timed_pages_target = cmm_timed_pages; | |
166 | } else if (cmm_timed_pages_target < cmm_timed_pages) { | |
167 | cmm_free_pages(1, &cmm_timed_pages, | |
168 | &cmm_timed_page_list); | |
169 | } | |
170 | if (cmm_timed_pages > 0 && !timer_pending(&cmm_timer)) | |
171 | cmm_set_timer(); | |
172 | } | |
173 | return 0; | |
174 | } | |
175 | ||
1da177e4 LT |
176 | static void |
177 | cmm_kick_thread(void) | |
178 | { | |
1da177e4 LT |
179 | wake_up(&cmm_thread_wait); |
180 | } | |
181 | ||
182 | static void | |
183 | cmm_set_timer(void) | |
184 | { | |
185 | if (cmm_timed_pages_target <= 0 || cmm_timeout_seconds <= 0) { | |
186 | if (timer_pending(&cmm_timer)) | |
187 | del_timer(&cmm_timer); | |
188 | return; | |
189 | } | |
190 | if (timer_pending(&cmm_timer)) { | |
191 | if (mod_timer(&cmm_timer, jiffies + cmm_timeout_seconds*HZ)) | |
192 | return; | |
193 | } | |
194 | cmm_timer.function = cmm_timer_fn; | |
195 | cmm_timer.data = 0; | |
196 | cmm_timer.expires = jiffies + cmm_timeout_seconds*HZ; | |
197 | add_timer(&cmm_timer); | |
198 | } | |
199 | ||
200 | static void | |
201 | cmm_timer_fn(unsigned long ignored) | |
202 | { | |
8bc719d3 | 203 | long nr; |
1da177e4 | 204 | |
8bc719d3 MS |
205 | nr = cmm_timed_pages_target - cmm_timeout_pages; |
206 | if (nr < 0) | |
1da177e4 LT |
207 | cmm_timed_pages_target = 0; |
208 | else | |
8bc719d3 | 209 | cmm_timed_pages_target = nr; |
1da177e4 LT |
210 | cmm_kick_thread(); |
211 | cmm_set_timer(); | |
212 | } | |
213 | ||
214 | void | |
8bc719d3 | 215 | cmm_set_pages(long nr) |
1da177e4 | 216 | { |
8bc719d3 | 217 | cmm_pages_target = nr; |
1da177e4 LT |
218 | cmm_kick_thread(); |
219 | } | |
220 | ||
221 | long | |
222 | cmm_get_pages(void) | |
223 | { | |
224 | return cmm_pages; | |
225 | } | |
226 | ||
227 | void | |
8bc719d3 | 228 | cmm_add_timed_pages(long nr) |
1da177e4 | 229 | { |
8bc719d3 | 230 | cmm_timed_pages_target += nr; |
1da177e4 LT |
231 | cmm_kick_thread(); |
232 | } | |
233 | ||
234 | long | |
235 | cmm_get_timed_pages(void) | |
236 | { | |
237 | return cmm_timed_pages; | |
238 | } | |
239 | ||
240 | void | |
8bc719d3 | 241 | cmm_set_timeout(long nr, long seconds) |
1da177e4 | 242 | { |
8bc719d3 | 243 | cmm_timeout_pages = nr; |
1da177e4 LT |
244 | cmm_timeout_seconds = seconds; |
245 | cmm_set_timer(); | |
246 | } | |
247 | ||
248 | static inline int | |
249 | cmm_skip_blanks(char *cp, char **endp) | |
250 | { | |
251 | char *str; | |
252 | ||
253 | for (str = cp; *str == ' ' || *str == '\t'; str++); | |
254 | *endp = str; | |
255 | return str != cp; | |
256 | } | |
257 | ||
258 | #ifdef CONFIG_CMM_PROC | |
259 | /* These will someday get removed. */ | |
260 | #define VM_CMM_PAGES 1111 | |
261 | #define VM_CMM_TIMED_PAGES 1112 | |
262 | #define VM_CMM_TIMEOUT 1113 | |
263 | ||
264 | static struct ctl_table cmm_table[]; | |
265 | ||
266 | static int | |
267 | cmm_pages_handler(ctl_table *ctl, int write, struct file *filp, | |
aaedd944 | 268 | void __user *buffer, size_t *lenp, loff_t *ppos) |
1da177e4 LT |
269 | { |
270 | char buf[16], *p; | |
8bc719d3 | 271 | long nr; |
1da177e4 LT |
272 | int len; |
273 | ||
274 | if (!*lenp || (*ppos && !write)) { | |
275 | *lenp = 0; | |
276 | return 0; | |
277 | } | |
278 | ||
279 | if (write) { | |
280 | len = *lenp; | |
281 | if (copy_from_user(buf, buffer, | |
282 | len > sizeof(buf) ? sizeof(buf) : len)) | |
283 | return -EFAULT; | |
284 | buf[sizeof(buf) - 1] = '\0'; | |
285 | cmm_skip_blanks(buf, &p); | |
8bc719d3 | 286 | nr = simple_strtoul(p, &p, 0); |
1da177e4 | 287 | if (ctl == &cmm_table[0]) |
8bc719d3 | 288 | cmm_set_pages(nr); |
1da177e4 | 289 | else |
8bc719d3 | 290 | cmm_add_timed_pages(nr); |
1da177e4 LT |
291 | } else { |
292 | if (ctl == &cmm_table[0]) | |
8bc719d3 | 293 | nr = cmm_get_pages(); |
1da177e4 | 294 | else |
8bc719d3 MS |
295 | nr = cmm_get_timed_pages(); |
296 | len = sprintf(buf, "%ld\n", nr); | |
1da177e4 LT |
297 | if (len > *lenp) |
298 | len = *lenp; | |
299 | if (copy_to_user(buffer, buf, len)) | |
300 | return -EFAULT; | |
301 | } | |
302 | *lenp = len; | |
303 | *ppos += len; | |
304 | return 0; | |
305 | } | |
306 | ||
307 | static int | |
308 | cmm_timeout_handler(ctl_table *ctl, int write, struct file *filp, | |
aaedd944 | 309 | void __user *buffer, size_t *lenp, loff_t *ppos) |
1da177e4 LT |
310 | { |
311 | char buf[64], *p; | |
8bc719d3 | 312 | long nr, seconds; |
1da177e4 LT |
313 | int len; |
314 | ||
315 | if (!*lenp || (*ppos && !write)) { | |
316 | *lenp = 0; | |
317 | return 0; | |
318 | } | |
319 | ||
320 | if (write) { | |
321 | len = *lenp; | |
322 | if (copy_from_user(buf, buffer, | |
323 | len > sizeof(buf) ? sizeof(buf) : len)) | |
324 | return -EFAULT; | |
325 | buf[sizeof(buf) - 1] = '\0'; | |
326 | cmm_skip_blanks(buf, &p); | |
8bc719d3 | 327 | nr = simple_strtoul(p, &p, 0); |
1da177e4 | 328 | cmm_skip_blanks(p, &p); |
7d5d688f | 329 | seconds = simple_strtoul(p, &p, 0); |
8bc719d3 | 330 | cmm_set_timeout(nr, seconds); |
1da177e4 LT |
331 | } else { |
332 | len = sprintf(buf, "%ld %ld\n", | |
333 | cmm_timeout_pages, cmm_timeout_seconds); | |
334 | if (len > *lenp) | |
335 | len = *lenp; | |
336 | if (copy_to_user(buffer, buf, len)) | |
337 | return -EFAULT; | |
338 | } | |
339 | *lenp = len; | |
340 | *ppos += len; | |
341 | return 0; | |
342 | } | |
343 | ||
344 | static struct ctl_table cmm_table[] = { | |
345 | { | |
346 | .ctl_name = VM_CMM_PAGES, | |
347 | .procname = "cmm_pages", | |
5e8b1c40 | 348 | .mode = 0644, |
1da177e4 LT |
349 | .proc_handler = &cmm_pages_handler, |
350 | }, | |
351 | { | |
352 | .ctl_name = VM_CMM_TIMED_PAGES, | |
353 | .procname = "cmm_timed_pages", | |
5e8b1c40 | 354 | .mode = 0644, |
1da177e4 LT |
355 | .proc_handler = &cmm_pages_handler, |
356 | }, | |
357 | { | |
358 | .ctl_name = VM_CMM_TIMEOUT, | |
359 | .procname = "cmm_timeout", | |
5e8b1c40 | 360 | .mode = 0644, |
1da177e4 LT |
361 | .proc_handler = &cmm_timeout_handler, |
362 | }, | |
363 | { .ctl_name = 0 } | |
364 | }; | |
365 | ||
366 | static struct ctl_table cmm_dir_table[] = { | |
367 | { | |
368 | .ctl_name = CTL_VM, | |
369 | .procname = "vm", | |
370 | .maxlen = 0, | |
371 | .mode = 0555, | |
372 | .child = cmm_table, | |
373 | }, | |
374 | { .ctl_name = 0 } | |
375 | }; | |
376 | #endif | |
377 | ||
378 | #ifdef CONFIG_CMM_IUCV | |
379 | #define SMSG_PREFIX "CMM" | |
380 | static void | |
15439d74 | 381 | cmm_smsg_target(char *from, char *msg) |
1da177e4 | 382 | { |
8bc719d3 | 383 | long nr, seconds; |
1da177e4 | 384 | |
15439d74 MS |
385 | if (strlen(sender) > 0 && strcmp(from, sender) != 0) |
386 | return; | |
1da177e4 LT |
387 | if (!cmm_skip_blanks(msg + strlen(SMSG_PREFIX), &msg)) |
388 | return; | |
389 | if (strncmp(msg, "SHRINK", 6) == 0) { | |
390 | if (!cmm_skip_blanks(msg + 6, &msg)) | |
391 | return; | |
8bc719d3 | 392 | nr = simple_strtoul(msg, &msg, 0); |
1da177e4 LT |
393 | cmm_skip_blanks(msg, &msg); |
394 | if (*msg == '\0') | |
8bc719d3 | 395 | cmm_set_pages(nr); |
1da177e4 LT |
396 | } else if (strncmp(msg, "RELEASE", 7) == 0) { |
397 | if (!cmm_skip_blanks(msg + 7, &msg)) | |
398 | return; | |
8bc719d3 | 399 | nr = simple_strtoul(msg, &msg, 0); |
1da177e4 LT |
400 | cmm_skip_blanks(msg, &msg); |
401 | if (*msg == '\0') | |
8bc719d3 | 402 | cmm_add_timed_pages(nr); |
1da177e4 LT |
403 | } else if (strncmp(msg, "REUSE", 5) == 0) { |
404 | if (!cmm_skip_blanks(msg + 5, &msg)) | |
405 | return; | |
8bc719d3 | 406 | nr = simple_strtoul(msg, &msg, 0); |
1da177e4 LT |
407 | if (!cmm_skip_blanks(msg, &msg)) |
408 | return; | |
7d5d688f | 409 | seconds = simple_strtoul(msg, &msg, 0); |
1da177e4 LT |
410 | cmm_skip_blanks(msg, &msg); |
411 | if (*msg == '\0') | |
8bc719d3 | 412 | cmm_set_timeout(nr, seconds); |
1da177e4 LT |
413 | } |
414 | } | |
415 | #endif | |
416 | ||
417 | struct ctl_table_header *cmm_sysctl_header; | |
418 | ||
419 | static int | |
420 | cmm_init (void) | |
421 | { | |
e8216dee HC |
422 | int rc = -ENOMEM; |
423 | ||
1da177e4 LT |
424 | #ifdef CONFIG_CMM_PROC |
425 | cmm_sysctl_header = register_sysctl_table(cmm_dir_table, 1); | |
e8216dee HC |
426 | if (!cmm_sysctl_header) |
427 | goto out; | |
1da177e4 LT |
428 | #endif |
429 | #ifdef CONFIG_CMM_IUCV | |
e8216dee HC |
430 | rc = smsg_register_callback(SMSG_PREFIX, cmm_smsg_target); |
431 | if (rc < 0) | |
432 | goto out_smsg; | |
1da177e4 | 433 | #endif |
e8216dee HC |
434 | rc = register_oom_notifier(&cmm_oom_nb); |
435 | if (rc < 0) | |
436 | goto out_oom_notify; | |
1da177e4 LT |
437 | init_waitqueue_head(&cmm_thread_wait); |
438 | init_timer(&cmm_timer); | |
e8216dee HC |
439 | cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread"); |
440 | rc = IS_ERR(cmm_thread_ptr) ? PTR_ERR(cmm_thread_ptr) : 0; | |
441 | if (!rc) | |
442 | goto out; | |
443 | /* | |
444 | * kthread_create failed. undo all the stuff from above again. | |
445 | */ | |
446 | unregister_oom_notifier(&cmm_oom_nb); | |
447 | ||
448 | out_oom_notify: | |
449 | #ifdef CONFIG_CMM_IUCV | |
450 | smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target); | |
451 | out_smsg: | |
452 | #endif | |
453 | #ifdef CONFIG_CMM_PROC | |
454 | unregister_sysctl_table(cmm_sysctl_header); | |
455 | #endif | |
456 | out: | |
457 | return rc; | |
1da177e4 LT |
458 | } |
459 | ||
460 | static void | |
461 | cmm_exit(void) | |
462 | { | |
e8216dee | 463 | kthread_stop(cmm_thread_ptr); |
8bc719d3 | 464 | unregister_oom_notifier(&cmm_oom_nb); |
1da177e4 LT |
465 | cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list); |
466 | cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list); | |
467 | #ifdef CONFIG_CMM_PROC | |
468 | unregister_sysctl_table(cmm_sysctl_header); | |
469 | #endif | |
470 | #ifdef CONFIG_CMM_IUCV | |
471 | smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target); | |
472 | #endif | |
473 | } | |
474 | ||
475 | module_init(cmm_init); | |
476 | module_exit(cmm_exit); | |
477 | ||
478 | EXPORT_SYMBOL(cmm_set_pages); | |
479 | EXPORT_SYMBOL(cmm_get_pages); | |
480 | EXPORT_SYMBOL(cmm_add_timed_pages); | |
481 | EXPORT_SYMBOL(cmm_get_timed_pages); | |
482 | EXPORT_SYMBOL(cmm_set_timeout); | |
483 | ||
484 | MODULE_LICENSE("GPL"); |