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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> |
db705e83 | 22 | #include <linux/uaccess.h> |
1da177e4 LT |
23 | |
24 | #include <asm/pgalloc.h> | |
0a87c5cf | 25 | #include <asm/diag.h> |
1da177e4 | 26 | |
a20852d2 HC |
27 | #ifdef CONFIG_CMM_IUCV |
28 | static char *cmm_default_sender = "VMRMSVM"; | |
29 | #endif | |
30 | static char *sender; | |
447570cf | 31 | module_param(sender, charp, 0400); |
15439d74 MS |
32 | MODULE_PARM_DESC(sender, |
33 | "Guest name that may send SMSG messages (default VMRMSVM)"); | |
34 | ||
1da177e4 LT |
35 | #include "../../../drivers/s390/net/smsgiucv.h" |
36 | ||
37 | #define CMM_NR_PAGES ((PAGE_SIZE / sizeof(unsigned long)) - 2) | |
38 | ||
39 | struct cmm_page_array { | |
40 | struct cmm_page_array *next; | |
41 | unsigned long index; | |
42 | unsigned long pages[CMM_NR_PAGES]; | |
43 | }; | |
44 | ||
8bc719d3 MS |
45 | static long cmm_pages; |
46 | static long cmm_timed_pages; | |
47 | static volatile long cmm_pages_target; | |
48 | static volatile long cmm_timed_pages_target; | |
49 | static long cmm_timeout_pages; | |
50 | static long cmm_timeout_seconds; | |
1da177e4 | 51 | |
8bc719d3 MS |
52 | static struct cmm_page_array *cmm_page_list; |
53 | static struct cmm_page_array *cmm_timed_page_list; | |
54 | static DEFINE_SPINLOCK(cmm_lock); | |
1da177e4 | 55 | |
e8216dee | 56 | static struct task_struct *cmm_thread_ptr; |
1ef6acf5 | 57 | static DECLARE_WAIT_QUEUE_HEAD(cmm_thread_wait); |
1da177e4 | 58 | |
6cc73a06 | 59 | static void cmm_timer_fn(struct timer_list *); |
1da177e4 | 60 | static void cmm_set_timer(void); |
6cc73a06 | 61 | static DEFINE_TIMER(cmm_timer, cmm_timer_fn); |
1da177e4 | 62 | |
db705e83 HC |
63 | static long cmm_alloc_pages(long nr, long *counter, |
64 | struct cmm_page_array **list) | |
1da177e4 | 65 | { |
8bc719d3 MS |
66 | struct cmm_page_array *pa, *npa; |
67 | unsigned long addr; | |
1da177e4 | 68 | |
8bc719d3 MS |
69 | while (nr) { |
70 | addr = __get_free_page(GFP_NOIO); | |
71 | if (!addr) | |
1da177e4 | 72 | break; |
8bc719d3 MS |
73 | spin_lock(&cmm_lock); |
74 | pa = *list; | |
1da177e4 LT |
75 | if (!pa || pa->index >= CMM_NR_PAGES) { |
76 | /* Need a new page for the page list. */ | |
8bc719d3 MS |
77 | spin_unlock(&cmm_lock); |
78 | npa = (struct cmm_page_array *) | |
1da177e4 | 79 | __get_free_page(GFP_NOIO); |
8bc719d3 MS |
80 | if (!npa) { |
81 | free_page(addr); | |
1da177e4 LT |
82 | break; |
83 | } | |
8bc719d3 MS |
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); | |
1da177e4 | 93 | } |
83ace270 | 94 | diag10_range(addr >> PAGE_SHIFT, 1); |
8bc719d3 | 95 | pa->pages[pa->index++] = addr; |
1da177e4 | 96 | (*counter)++; |
8bc719d3 MS |
97 | spin_unlock(&cmm_lock); |
98 | nr--; | |
1da177e4 | 99 | } |
8bc719d3 | 100 | return nr; |
1da177e4 LT |
101 | } |
102 | ||
db705e83 | 103 | static long cmm_free_pages(long nr, long *counter, struct cmm_page_array **list) |
1da177e4 LT |
104 | { |
105 | struct cmm_page_array *pa; | |
8bc719d3 | 106 | unsigned long addr; |
1da177e4 | 107 | |
8bc719d3 | 108 | spin_lock(&cmm_lock); |
1da177e4 | 109 | pa = *list; |
8bc719d3 | 110 | while (nr) { |
1da177e4 LT |
111 | if (!pa || pa->index <= 0) |
112 | break; | |
8bc719d3 | 113 | addr = pa->pages[--pa->index]; |
1da177e4 LT |
114 | if (pa->index == 0) { |
115 | pa = pa->next; | |
116 | free_page((unsigned long) *list); | |
117 | *list = pa; | |
118 | } | |
8bc719d3 | 119 | free_page(addr); |
1da177e4 | 120 | (*counter)--; |
8bc719d3 | 121 | nr--; |
1da177e4 | 122 | } |
8bc719d3 MS |
123 | spin_unlock(&cmm_lock); |
124 | return nr; | |
1da177e4 LT |
125 | } |
126 | ||
8bc719d3 MS |
127 | static 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 | ||
142 | static struct notifier_block cmm_oom_nb = { | |
db705e83 | 143 | .notifier_call = cmm_oom_notify, |
8bc719d3 MS |
144 | }; |
145 | ||
db705e83 | 146 | static int cmm_thread(void *dummy) |
1da177e4 LT |
147 | { |
148 | int rc; | |
149 | ||
1da177e4 LT |
150 | while (1) { |
151 | rc = wait_event_interruptible(cmm_thread_wait, | |
39421627 HC |
152 | cmm_pages != cmm_pages_target || |
153 | cmm_timed_pages != cmm_timed_pages_target || | |
154 | kthread_should_stop()); | |
e8216dee | 155 | if (kthread_should_stop() || rc == -ERESTARTSYS) { |
1da177e4 LT |
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, | |
db705e83 | 172 | &cmm_timed_page_list); |
1da177e4 LT |
173 | } |
174 | if (cmm_timed_pages > 0 && !timer_pending(&cmm_timer)) | |
175 | cmm_set_timer(); | |
176 | } | |
177 | return 0; | |
178 | } | |
179 | ||
db705e83 | 180 | static void cmm_kick_thread(void) |
1da177e4 | 181 | { |
1da177e4 LT |
182 | wake_up(&cmm_thread_wait); |
183 | } | |
184 | ||
db705e83 | 185 | static void cmm_set_timer(void) |
1da177e4 LT |
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 | } | |
ac4c4fc8 | 192 | mod_timer(&cmm_timer, jiffies + cmm_timeout_seconds * HZ); |
1da177e4 LT |
193 | } |
194 | ||
6cc73a06 | 195 | static void cmm_timer_fn(struct timer_list *unused) |
1da177e4 | 196 | { |
8bc719d3 | 197 | long nr; |
1da177e4 | 198 | |
8bc719d3 MS |
199 | nr = cmm_timed_pages_target - cmm_timeout_pages; |
200 | if (nr < 0) | |
1da177e4 LT |
201 | cmm_timed_pages_target = 0; |
202 | else | |
8bc719d3 | 203 | cmm_timed_pages_target = nr; |
1da177e4 LT |
204 | cmm_kick_thread(); |
205 | cmm_set_timer(); | |
206 | } | |
207 | ||
db705e83 | 208 | static void cmm_set_pages(long nr) |
1da177e4 | 209 | { |
8bc719d3 | 210 | cmm_pages_target = nr; |
1da177e4 LT |
211 | cmm_kick_thread(); |
212 | } | |
213 | ||
db705e83 | 214 | static long cmm_get_pages(void) |
1da177e4 LT |
215 | { |
216 | return cmm_pages; | |
217 | } | |
218 | ||
db705e83 | 219 | static void cmm_add_timed_pages(long nr) |
1da177e4 | 220 | { |
8bc719d3 | 221 | cmm_timed_pages_target += nr; |
1da177e4 LT |
222 | cmm_kick_thread(); |
223 | } | |
224 | ||
db705e83 | 225 | static long cmm_get_timed_pages(void) |
1da177e4 LT |
226 | { |
227 | return cmm_timed_pages; | |
228 | } | |
229 | ||
db705e83 | 230 | static void cmm_set_timeout(long nr, long seconds) |
1da177e4 | 231 | { |
8bc719d3 | 232 | cmm_timeout_pages = nr; |
1da177e4 LT |
233 | cmm_timeout_seconds = seconds; |
234 | cmm_set_timer(); | |
235 | } | |
236 | ||
db705e83 | 237 | static int cmm_skip_blanks(char *cp, char **endp) |
1da177e4 LT |
238 | { |
239 | char *str; | |
240 | ||
db705e83 HC |
241 | for (str = cp; *str == ' ' || *str == '\t'; str++) |
242 | ; | |
1da177e4 LT |
243 | *endp = str; |
244 | return str != cp; | |
245 | } | |
246 | ||
302bfe20 | 247 | static int cmm_pages_handler(struct ctl_table *ctl, int write, |
32927393 | 248 | void *buffer, size_t *lenp, loff_t *ppos) |
1da177e4 | 249 | { |
71e33a1d VG |
250 | long nr = cmm_get_pages(); |
251 | struct ctl_table ctl_entry = { | |
252 | .procname = ctl->procname, | |
253 | .data = &nr, | |
254 | .maxlen = sizeof(long), | |
255 | }; | |
256 | int rc; | |
1da177e4 | 257 | |
71e33a1d VG |
258 | rc = proc_doulongvec_minmax(&ctl_entry, write, buffer, lenp, ppos); |
259 | if (rc < 0 || !write) | |
260 | return rc; | |
1da177e4 | 261 | |
71e33a1d VG |
262 | cmm_set_pages(nr); |
263 | return 0; | |
264 | } | |
265 | ||
266 | static int cmm_timed_pages_handler(struct ctl_table *ctl, int write, | |
32927393 | 267 | void *buffer, size_t *lenp, |
71e33a1d VG |
268 | loff_t *ppos) |
269 | { | |
270 | long nr = cmm_get_timed_pages(); | |
271 | struct ctl_table ctl_entry = { | |
272 | .procname = ctl->procname, | |
273 | .data = &nr, | |
274 | .maxlen = sizeof(long), | |
275 | }; | |
276 | int rc; | |
277 | ||
278 | rc = proc_doulongvec_minmax(&ctl_entry, write, buffer, lenp, ppos); | |
279 | if (rc < 0 || !write) | |
280 | return rc; | |
281 | ||
282 | cmm_add_timed_pages(nr); | |
1da177e4 LT |
283 | return 0; |
284 | } | |
285 | ||
302bfe20 | 286 | static int cmm_timeout_handler(struct ctl_table *ctl, int write, |
32927393 | 287 | void *buffer, size_t *lenp, loff_t *ppos) |
1da177e4 LT |
288 | { |
289 | char buf[64], *p; | |
8bc719d3 | 290 | long nr, seconds; |
041058a1 | 291 | unsigned int len; |
1da177e4 LT |
292 | |
293 | if (!*lenp || (*ppos && !write)) { | |
294 | *lenp = 0; | |
295 | return 0; | |
296 | } | |
297 | ||
298 | if (write) { | |
b8e51a6a | 299 | len = min(*lenp, sizeof(buf)); |
32927393 | 300 | memcpy(buf, buffer, len); |
b8e51a6a | 301 | buf[len - 1] = '\0'; |
1da177e4 | 302 | cmm_skip_blanks(buf, &p); |
8bc719d3 | 303 | nr = simple_strtoul(p, &p, 0); |
1da177e4 | 304 | cmm_skip_blanks(p, &p); |
7d5d688f | 305 | seconds = simple_strtoul(p, &p, 0); |
8bc719d3 | 306 | cmm_set_timeout(nr, seconds); |
b8e51a6a | 307 | *ppos += *lenp; |
1da177e4 LT |
308 | } else { |
309 | len = sprintf(buf, "%ld %ld\n", | |
310 | cmm_timeout_pages, cmm_timeout_seconds); | |
311 | if (len > *lenp) | |
312 | len = *lenp; | |
32927393 | 313 | memcpy(buffer, buf, len); |
b8e51a6a YZ |
314 | *lenp = len; |
315 | *ppos += len; | |
1da177e4 | 316 | } |
1da177e4 LT |
317 | return 0; |
318 | } | |
319 | ||
320 | static struct ctl_table cmm_table[] = { | |
321 | { | |
1da177e4 | 322 | .procname = "cmm_pages", |
5e8b1c40 | 323 | .mode = 0644, |
6d456111 | 324 | .proc_handler = cmm_pages_handler, |
1da177e4 LT |
325 | }, |
326 | { | |
1da177e4 | 327 | .procname = "cmm_timed_pages", |
5e8b1c40 | 328 | .mode = 0644, |
71e33a1d | 329 | .proc_handler = cmm_timed_pages_handler, |
1da177e4 LT |
330 | }, |
331 | { | |
1da177e4 | 332 | .procname = "cmm_timeout", |
5e8b1c40 | 333 | .mode = 0644, |
6d456111 | 334 | .proc_handler = cmm_timeout_handler, |
1da177e4 | 335 | }, |
b05fd35d | 336 | { } |
1da177e4 LT |
337 | }; |
338 | ||
339 | static struct ctl_table cmm_dir_table[] = { | |
340 | { | |
1da177e4 LT |
341 | .procname = "vm", |
342 | .maxlen = 0, | |
343 | .mode = 0555, | |
344 | .child = cmm_table, | |
345 | }, | |
b05fd35d | 346 | { } |
1da177e4 | 347 | }; |
1da177e4 LT |
348 | |
349 | #ifdef CONFIG_CMM_IUCV | |
350 | #define SMSG_PREFIX "CMM" | |
db705e83 | 351 | static void cmm_smsg_target(const char *from, char *msg) |
1da177e4 | 352 | { |
8bc719d3 | 353 | long nr, seconds; |
1da177e4 | 354 | |
15439d74 MS |
355 | if (strlen(sender) > 0 && strcmp(from, sender) != 0) |
356 | return; | |
1da177e4 LT |
357 | if (!cmm_skip_blanks(msg + strlen(SMSG_PREFIX), &msg)) |
358 | return; | |
359 | if (strncmp(msg, "SHRINK", 6) == 0) { | |
360 | if (!cmm_skip_blanks(msg + 6, &msg)) | |
361 | return; | |
8bc719d3 | 362 | nr = simple_strtoul(msg, &msg, 0); |
1da177e4 LT |
363 | cmm_skip_blanks(msg, &msg); |
364 | if (*msg == '\0') | |
8bc719d3 | 365 | cmm_set_pages(nr); |
1da177e4 LT |
366 | } else if (strncmp(msg, "RELEASE", 7) == 0) { |
367 | if (!cmm_skip_blanks(msg + 7, &msg)) | |
368 | return; | |
8bc719d3 | 369 | nr = simple_strtoul(msg, &msg, 0); |
1da177e4 LT |
370 | cmm_skip_blanks(msg, &msg); |
371 | if (*msg == '\0') | |
8bc719d3 | 372 | cmm_add_timed_pages(nr); |
1da177e4 LT |
373 | } else if (strncmp(msg, "REUSE", 5) == 0) { |
374 | if (!cmm_skip_blanks(msg + 5, &msg)) | |
375 | return; | |
8bc719d3 | 376 | nr = simple_strtoul(msg, &msg, 0); |
1da177e4 LT |
377 | if (!cmm_skip_blanks(msg, &msg)) |
378 | return; | |
7d5d688f | 379 | seconds = simple_strtoul(msg, &msg, 0); |
1da177e4 LT |
380 | cmm_skip_blanks(msg, &msg); |
381 | if (*msg == '\0') | |
8bc719d3 | 382 | cmm_set_timeout(nr, seconds); |
1da177e4 LT |
383 | } |
384 | } | |
385 | #endif | |
386 | ||
2b67fc46 | 387 | static struct ctl_table_header *cmm_sysctl_header; |
1da177e4 | 388 | |
2e85ba51 | 389 | static int __init cmm_init(void) |
1da177e4 | 390 | { |
e8216dee HC |
391 | int rc = -ENOMEM; |
392 | ||
0b4d4147 | 393 | cmm_sysctl_header = register_sysctl_table(cmm_dir_table); |
e8216dee | 394 | if (!cmm_sysctl_header) |
52b169c8 | 395 | goto out_sysctl; |
1da177e4 | 396 | #ifdef CONFIG_CMM_IUCV |
41b42876 HB |
397 | /* convert sender to uppercase characters */ |
398 | if (sender) { | |
399 | int len = strlen(sender); | |
400 | while (len--) | |
401 | sender[len] = toupper(sender[len]); | |
a20852d2 HC |
402 | } else { |
403 | sender = cmm_default_sender; | |
41b42876 HB |
404 | } |
405 | ||
e8216dee HC |
406 | rc = smsg_register_callback(SMSG_PREFIX, cmm_smsg_target); |
407 | if (rc < 0) | |
408 | goto out_smsg; | |
1da177e4 | 409 | #endif |
e8216dee HC |
410 | rc = register_oom_notifier(&cmm_oom_nb); |
411 | if (rc < 0) | |
412 | goto out_oom_notify; | |
e8216dee | 413 | cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread"); |
8fe853f3 AG |
414 | if (!IS_ERR(cmm_thread_ptr)) |
415 | return 0; | |
e8216dee | 416 | |
8fe853f3 | 417 | rc = PTR_ERR(cmm_thread_ptr); |
52b169c8 | 418 | unregister_oom_notifier(&cmm_oom_nb); |
e8216dee HC |
419 | out_oom_notify: |
420 | #ifdef CONFIG_CMM_IUCV | |
421 | smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target); | |
422 | out_smsg: | |
423 | #endif | |
e8216dee | 424 | unregister_sysctl_table(cmm_sysctl_header); |
52b169c8 | 425 | out_sysctl: |
1ef6acf5 | 426 | del_timer_sync(&cmm_timer); |
e8216dee | 427 | return rc; |
1da177e4 | 428 | } |
db705e83 | 429 | module_init(cmm_init); |
1da177e4 | 430 | |
2e85ba51 | 431 | static void __exit cmm_exit(void) |
1da177e4 | 432 | { |
1da177e4 | 433 | unregister_sysctl_table(cmm_sysctl_header); |
1da177e4 LT |
434 | #ifdef CONFIG_CMM_IUCV |
435 | smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target); | |
436 | #endif | |
1ef6acf5 HC |
437 | unregister_oom_notifier(&cmm_oom_nb); |
438 | kthread_stop(cmm_thread_ptr); | |
439 | del_timer_sync(&cmm_timer); | |
440 | cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list); | |
441 | cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list); | |
1da177e4 | 442 | } |
1da177e4 LT |
443 | module_exit(cmm_exit); |
444 | ||
1da177e4 | 445 | MODULE_LICENSE("GPL"); |