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ac41aaee | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 | 2 | /* |
db705e83 | 3 | * Collaborative memory management interface. |
1da177e4 | 4 | * |
a53c8fab | 5 | * Copyright IBM Corp 2003, 2010 |
db705e83 | 6 | * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>, |
1da177e4 | 7 | * |
1da177e4 LT |
8 | */ |
9 | ||
1da177e4 LT |
10 | #include <linux/errno.h> |
11 | #include <linux/fs.h> | |
12 | #include <linux/init.h> | |
13 | #include <linux/module.h> | |
ff24b07a | 14 | #include <linux/moduleparam.h> |
5a0e3ad6 | 15 | #include <linux/gfp.h> |
1da177e4 LT |
16 | #include <linux/sched.h> |
17 | #include <linux/sysctl.h> | |
18 | #include <linux/ctype.h> | |
8bc719d3 | 19 | #include <linux/swap.h> |
e8216dee | 20 | #include <linux/kthread.h> |
5a3135c2 | 21 | #include <linux/oom.h> |
52b169c8 | 22 | #include <linux/suspend.h> |
db705e83 | 23 | #include <linux/uaccess.h> |
1da177e4 LT |
24 | |
25 | #include <asm/pgalloc.h> | |
0a87c5cf | 26 | #include <asm/diag.h> |
1da177e4 | 27 | |
a20852d2 HC |
28 | #ifdef CONFIG_CMM_IUCV |
29 | static char *cmm_default_sender = "VMRMSVM"; | |
30 | #endif | |
31 | static char *sender; | |
447570cf | 32 | module_param(sender, charp, 0400); |
15439d74 MS |
33 | MODULE_PARM_DESC(sender, |
34 | "Guest name that may send SMSG messages (default VMRMSVM)"); | |
35 | ||
1da177e4 LT |
36 | #include "../../../drivers/s390/net/smsgiucv.h" |
37 | ||
38 | #define CMM_NR_PAGES ((PAGE_SIZE / sizeof(unsigned long)) - 2) | |
39 | ||
40 | struct cmm_page_array { | |
41 | struct cmm_page_array *next; | |
42 | unsigned long index; | |
43 | unsigned long pages[CMM_NR_PAGES]; | |
44 | }; | |
45 | ||
8bc719d3 MS |
46 | static long cmm_pages; |
47 | static long cmm_timed_pages; | |
48 | static volatile long cmm_pages_target; | |
49 | static volatile long cmm_timed_pages_target; | |
50 | static long cmm_timeout_pages; | |
51 | static long cmm_timeout_seconds; | |
52b169c8 | 52 | static int cmm_suspended; |
1da177e4 | 53 | |
8bc719d3 MS |
54 | static struct cmm_page_array *cmm_page_list; |
55 | static struct cmm_page_array *cmm_timed_page_list; | |
56 | static DEFINE_SPINLOCK(cmm_lock); | |
1da177e4 | 57 | |
e8216dee | 58 | static struct task_struct *cmm_thread_ptr; |
1ef6acf5 | 59 | static DECLARE_WAIT_QUEUE_HEAD(cmm_thread_wait); |
1da177e4 | 60 | |
6cc73a06 | 61 | static void cmm_timer_fn(struct timer_list *); |
1da177e4 | 62 | static void cmm_set_timer(void); |
6cc73a06 | 63 | static DEFINE_TIMER(cmm_timer, cmm_timer_fn); |
1da177e4 | 64 | |
db705e83 HC |
65 | static long cmm_alloc_pages(long nr, long *counter, |
66 | struct cmm_page_array **list) | |
1da177e4 | 67 | { |
8bc719d3 MS |
68 | struct cmm_page_array *pa, *npa; |
69 | unsigned long addr; | |
1da177e4 | 70 | |
8bc719d3 MS |
71 | while (nr) { |
72 | addr = __get_free_page(GFP_NOIO); | |
73 | if (!addr) | |
1da177e4 | 74 | break; |
8bc719d3 MS |
75 | spin_lock(&cmm_lock); |
76 | pa = *list; | |
1da177e4 LT |
77 | if (!pa || pa->index >= CMM_NR_PAGES) { |
78 | /* Need a new page for the page list. */ | |
8bc719d3 MS |
79 | spin_unlock(&cmm_lock); |
80 | npa = (struct cmm_page_array *) | |
1da177e4 | 81 | __get_free_page(GFP_NOIO); |
8bc719d3 MS |
82 | if (!npa) { |
83 | free_page(addr); | |
1da177e4 LT |
84 | break; |
85 | } | |
8bc719d3 MS |
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); | |
1da177e4 | 95 | } |
83ace270 | 96 | diag10_range(addr >> PAGE_SHIFT, 1); |
8bc719d3 | 97 | pa->pages[pa->index++] = addr; |
1da177e4 | 98 | (*counter)++; |
8bc719d3 MS |
99 | spin_unlock(&cmm_lock); |
100 | nr--; | |
1da177e4 | 101 | } |
8bc719d3 | 102 | return nr; |
1da177e4 LT |
103 | } |
104 | ||
db705e83 | 105 | static long cmm_free_pages(long nr, long *counter, struct cmm_page_array **list) |
1da177e4 LT |
106 | { |
107 | struct cmm_page_array *pa; | |
8bc719d3 | 108 | unsigned long addr; |
1da177e4 | 109 | |
8bc719d3 | 110 | spin_lock(&cmm_lock); |
1da177e4 | 111 | pa = *list; |
8bc719d3 | 112 | while (nr) { |
1da177e4 LT |
113 | if (!pa || pa->index <= 0) |
114 | break; | |
8bc719d3 | 115 | addr = pa->pages[--pa->index]; |
1da177e4 LT |
116 | if (pa->index == 0) { |
117 | pa = pa->next; | |
118 | free_page((unsigned long) *list); | |
119 | *list = pa; | |
120 | } | |
8bc719d3 | 121 | free_page(addr); |
1da177e4 | 122 | (*counter)--; |
8bc719d3 | 123 | nr--; |
1da177e4 | 124 | } |
8bc719d3 MS |
125 | spin_unlock(&cmm_lock); |
126 | return nr; | |
1da177e4 LT |
127 | } |
128 | ||
8bc719d3 MS |
129 | static 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 | ||
144 | static struct notifier_block cmm_oom_nb = { | |
db705e83 | 145 | .notifier_call = cmm_oom_notify, |
8bc719d3 MS |
146 | }; |
147 | ||
db705e83 | 148 | static int cmm_thread(void *dummy) |
1da177e4 LT |
149 | { |
150 | int rc; | |
151 | ||
1da177e4 LT |
152 | while (1) { |
153 | rc = wait_event_interruptible(cmm_thread_wait, | |
52b169c8 MS |
154 | (!cmm_suspended && (cmm_pages != cmm_pages_target || |
155 | cmm_timed_pages != cmm_timed_pages_target)) || | |
156 | kthread_should_stop()); | |
e8216dee | 157 | if (kthread_should_stop() || rc == -ERESTARTSYS) { |
1da177e4 LT |
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, | |
db705e83 | 174 | &cmm_timed_page_list); |
1da177e4 LT |
175 | } |
176 | if (cmm_timed_pages > 0 && !timer_pending(&cmm_timer)) | |
177 | cmm_set_timer(); | |
178 | } | |
179 | return 0; | |
180 | } | |
181 | ||
db705e83 | 182 | static void cmm_kick_thread(void) |
1da177e4 | 183 | { |
1da177e4 LT |
184 | wake_up(&cmm_thread_wait); |
185 | } | |
186 | ||
db705e83 | 187 | static void cmm_set_timer(void) |
1da177e4 LT |
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 | } | |
ac4c4fc8 | 194 | mod_timer(&cmm_timer, jiffies + cmm_timeout_seconds * HZ); |
1da177e4 LT |
195 | } |
196 | ||
6cc73a06 | 197 | static void cmm_timer_fn(struct timer_list *unused) |
1da177e4 | 198 | { |
8bc719d3 | 199 | long nr; |
1da177e4 | 200 | |
8bc719d3 MS |
201 | nr = cmm_timed_pages_target - cmm_timeout_pages; |
202 | if (nr < 0) | |
1da177e4 LT |
203 | cmm_timed_pages_target = 0; |
204 | else | |
8bc719d3 | 205 | cmm_timed_pages_target = nr; |
1da177e4 LT |
206 | cmm_kick_thread(); |
207 | cmm_set_timer(); | |
208 | } | |
209 | ||
db705e83 | 210 | static void cmm_set_pages(long nr) |
1da177e4 | 211 | { |
8bc719d3 | 212 | cmm_pages_target = nr; |
1da177e4 LT |
213 | cmm_kick_thread(); |
214 | } | |
215 | ||
db705e83 | 216 | static long cmm_get_pages(void) |
1da177e4 LT |
217 | { |
218 | return cmm_pages; | |
219 | } | |
220 | ||
db705e83 | 221 | static void cmm_add_timed_pages(long nr) |
1da177e4 | 222 | { |
8bc719d3 | 223 | cmm_timed_pages_target += nr; |
1da177e4 LT |
224 | cmm_kick_thread(); |
225 | } | |
226 | ||
db705e83 | 227 | static long cmm_get_timed_pages(void) |
1da177e4 LT |
228 | { |
229 | return cmm_timed_pages; | |
230 | } | |
231 | ||
db705e83 | 232 | static void cmm_set_timeout(long nr, long seconds) |
1da177e4 | 233 | { |
8bc719d3 | 234 | cmm_timeout_pages = nr; |
1da177e4 LT |
235 | cmm_timeout_seconds = seconds; |
236 | cmm_set_timer(); | |
237 | } | |
238 | ||
db705e83 | 239 | static int cmm_skip_blanks(char *cp, char **endp) |
1da177e4 LT |
240 | { |
241 | char *str; | |
242 | ||
db705e83 HC |
243 | for (str = cp; *str == ' ' || *str == '\t'; str++) |
244 | ; | |
1da177e4 LT |
245 | *endp = str; |
246 | return str != cp; | |
247 | } | |
248 | ||
302bfe20 JP |
249 | static int cmm_pages_handler(struct ctl_table *ctl, int write, |
250 | void __user *buffer, size_t *lenp, loff_t *ppos) | |
1da177e4 | 251 | { |
71e33a1d VG |
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; | |
1da177e4 | 259 | |
71e33a1d VG |
260 | rc = proc_doulongvec_minmax(&ctl_entry, write, buffer, lenp, ppos); |
261 | if (rc < 0 || !write) | |
262 | return rc; | |
1da177e4 | 263 | |
71e33a1d VG |
264 | cmm_set_pages(nr); |
265 | return 0; | |
266 | } | |
267 | ||
268 | static 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); | |
1da177e4 LT |
285 | return 0; |
286 | } | |
287 | ||
302bfe20 JP |
288 | static int cmm_timeout_handler(struct ctl_table *ctl, int write, |
289 | void __user *buffer, size_t *lenp, loff_t *ppos) | |
1da177e4 LT |
290 | { |
291 | char buf[64], *p; | |
8bc719d3 | 292 | long nr, seconds; |
041058a1 | 293 | unsigned int len; |
1da177e4 LT |
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); | |
8bc719d3 | 307 | nr = simple_strtoul(p, &p, 0); |
1da177e4 | 308 | cmm_skip_blanks(p, &p); |
7d5d688f | 309 | seconds = simple_strtoul(p, &p, 0); |
8bc719d3 | 310 | cmm_set_timeout(nr, seconds); |
1da177e4 LT |
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 | ||
324 | static struct ctl_table cmm_table[] = { | |
325 | { | |
1da177e4 | 326 | .procname = "cmm_pages", |
5e8b1c40 | 327 | .mode = 0644, |
6d456111 | 328 | .proc_handler = cmm_pages_handler, |
1da177e4 LT |
329 | }, |
330 | { | |
1da177e4 | 331 | .procname = "cmm_timed_pages", |
5e8b1c40 | 332 | .mode = 0644, |
71e33a1d | 333 | .proc_handler = cmm_timed_pages_handler, |
1da177e4 LT |
334 | }, |
335 | { | |
1da177e4 | 336 | .procname = "cmm_timeout", |
5e8b1c40 | 337 | .mode = 0644, |
6d456111 | 338 | .proc_handler = cmm_timeout_handler, |
1da177e4 | 339 | }, |
b05fd35d | 340 | { } |
1da177e4 LT |
341 | }; |
342 | ||
343 | static struct ctl_table cmm_dir_table[] = { | |
344 | { | |
1da177e4 LT |
345 | .procname = "vm", |
346 | .maxlen = 0, | |
347 | .mode = 0555, | |
348 | .child = cmm_table, | |
349 | }, | |
b05fd35d | 350 | { } |
1da177e4 | 351 | }; |
1da177e4 LT |
352 | |
353 | #ifdef CONFIG_CMM_IUCV | |
354 | #define SMSG_PREFIX "CMM" | |
db705e83 | 355 | static void cmm_smsg_target(const char *from, char *msg) |
1da177e4 | 356 | { |
8bc719d3 | 357 | long nr, seconds; |
1da177e4 | 358 | |
15439d74 MS |
359 | if (strlen(sender) > 0 && strcmp(from, sender) != 0) |
360 | return; | |
1da177e4 LT |
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; | |
8bc719d3 | 366 | nr = simple_strtoul(msg, &msg, 0); |
1da177e4 LT |
367 | cmm_skip_blanks(msg, &msg); |
368 | if (*msg == '\0') | |
8bc719d3 | 369 | cmm_set_pages(nr); |
1da177e4 LT |
370 | } else if (strncmp(msg, "RELEASE", 7) == 0) { |
371 | if (!cmm_skip_blanks(msg + 7, &msg)) | |
372 | return; | |
8bc719d3 | 373 | nr = simple_strtoul(msg, &msg, 0); |
1da177e4 LT |
374 | cmm_skip_blanks(msg, &msg); |
375 | if (*msg == '\0') | |
8bc719d3 | 376 | cmm_add_timed_pages(nr); |
1da177e4 LT |
377 | } else if (strncmp(msg, "REUSE", 5) == 0) { |
378 | if (!cmm_skip_blanks(msg + 5, &msg)) | |
379 | return; | |
8bc719d3 | 380 | nr = simple_strtoul(msg, &msg, 0); |
1da177e4 LT |
381 | if (!cmm_skip_blanks(msg, &msg)) |
382 | return; | |
7d5d688f | 383 | seconds = simple_strtoul(msg, &msg, 0); |
1da177e4 LT |
384 | cmm_skip_blanks(msg, &msg); |
385 | if (*msg == '\0') | |
8bc719d3 | 386 | cmm_set_timeout(nr, seconds); |
1da177e4 LT |
387 | } |
388 | } | |
389 | #endif | |
390 | ||
2b67fc46 | 391 | static struct ctl_table_header *cmm_sysctl_header; |
1da177e4 | 392 | |
52b169c8 MS |
393 | static 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 | ||
401 | static int cmm_resume(void) | |
402 | { | |
403 | cmm_suspended = 0; | |
404 | cmm_kick_thread(); | |
405 | return 0; | |
406 | } | |
407 | ||
408 | static 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 | ||
421 | static struct notifier_block cmm_power_notifier = { | |
422 | .notifier_call = cmm_power_event, | |
423 | }; | |
424 | ||
2e85ba51 | 425 | static int __init cmm_init(void) |
1da177e4 | 426 | { |
e8216dee HC |
427 | int rc = -ENOMEM; |
428 | ||
0b4d4147 | 429 | cmm_sysctl_header = register_sysctl_table(cmm_dir_table); |
e8216dee | 430 | if (!cmm_sysctl_header) |
52b169c8 | 431 | goto out_sysctl; |
1da177e4 | 432 | #ifdef CONFIG_CMM_IUCV |
41b42876 HB |
433 | /* convert sender to uppercase characters */ |
434 | if (sender) { | |
435 | int len = strlen(sender); | |
436 | while (len--) | |
437 | sender[len] = toupper(sender[len]); | |
a20852d2 HC |
438 | } else { |
439 | sender = cmm_default_sender; | |
41b42876 HB |
440 | } |
441 | ||
e8216dee HC |
442 | rc = smsg_register_callback(SMSG_PREFIX, cmm_smsg_target); |
443 | if (rc < 0) | |
444 | goto out_smsg; | |
1da177e4 | 445 | #endif |
e8216dee HC |
446 | rc = register_oom_notifier(&cmm_oom_nb); |
447 | if (rc < 0) | |
448 | goto out_oom_notify; | |
52b169c8 MS |
449 | rc = register_pm_notifier(&cmm_power_notifier); |
450 | if (rc) | |
451 | goto out_pm; | |
e8216dee | 452 | cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread"); |
8fe853f3 AG |
453 | if (!IS_ERR(cmm_thread_ptr)) |
454 | return 0; | |
e8216dee | 455 | |
8fe853f3 | 456 | rc = PTR_ERR(cmm_thread_ptr); |
52b169c8 MS |
457 | unregister_pm_notifier(&cmm_power_notifier); |
458 | out_pm: | |
459 | unregister_oom_notifier(&cmm_oom_nb); | |
e8216dee HC |
460 | out_oom_notify: |
461 | #ifdef CONFIG_CMM_IUCV | |
462 | smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target); | |
463 | out_smsg: | |
464 | #endif | |
e8216dee | 465 | unregister_sysctl_table(cmm_sysctl_header); |
52b169c8 | 466 | out_sysctl: |
1ef6acf5 | 467 | del_timer_sync(&cmm_timer); |
e8216dee | 468 | return rc; |
1da177e4 | 469 | } |
db705e83 | 470 | module_init(cmm_init); |
1da177e4 | 471 | |
2e85ba51 | 472 | static void __exit cmm_exit(void) |
1da177e4 | 473 | { |
1da177e4 | 474 | unregister_sysctl_table(cmm_sysctl_header); |
1da177e4 LT |
475 | #ifdef CONFIG_CMM_IUCV |
476 | smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target); | |
477 | #endif | |
1ef6acf5 HC |
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); | |
1da177e4 | 484 | } |
1da177e4 LT |
485 | module_exit(cmm_exit); |
486 | ||
1da177e4 | 487 | MODULE_LICENSE("GPL"); |