Commit | Line | Data |
---|---|---|
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 | 16 | #include <linux/sched.h> |
b2f58393 | 17 | #include <linux/string_helpers.h> |
1da177e4 | 18 | #include <linux/sysctl.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 | 23 | |
0a87c5cf | 24 | #include <asm/diag.h> |
1da177e4 | 25 | |
a20852d2 HC |
26 | #ifdef CONFIG_CMM_IUCV |
27 | static char *cmm_default_sender = "VMRMSVM"; | |
28 | #endif | |
29 | static char *sender; | |
447570cf | 30 | module_param(sender, charp, 0400); |
15439d74 MS |
31 | MODULE_PARM_DESC(sender, |
32 | "Guest name that may send SMSG messages (default VMRMSVM)"); | |
33 | ||
1da177e4 LT |
34 | #include "../../../drivers/s390/net/smsgiucv.h" |
35 | ||
36 | #define CMM_NR_PAGES ((PAGE_SIZE / sizeof(unsigned long)) - 2) | |
37 | ||
38 | struct cmm_page_array { | |
39 | struct cmm_page_array *next; | |
40 | unsigned long index; | |
41 | unsigned long pages[CMM_NR_PAGES]; | |
42 | }; | |
43 | ||
8bc719d3 MS |
44 | static long cmm_pages; |
45 | static long cmm_timed_pages; | |
46 | static volatile long cmm_pages_target; | |
47 | static volatile long cmm_timed_pages_target; | |
48 | static long cmm_timeout_pages; | |
49 | static long cmm_timeout_seconds; | |
1da177e4 | 50 | |
8bc719d3 MS |
51 | static struct cmm_page_array *cmm_page_list; |
52 | static struct cmm_page_array *cmm_timed_page_list; | |
53 | static DEFINE_SPINLOCK(cmm_lock); | |
1da177e4 | 54 | |
e8216dee | 55 | static struct task_struct *cmm_thread_ptr; |
1ef6acf5 | 56 | static DECLARE_WAIT_QUEUE_HEAD(cmm_thread_wait); |
1da177e4 | 57 | |
6cc73a06 | 58 | static void cmm_timer_fn(struct timer_list *); |
1da177e4 | 59 | static void cmm_set_timer(void); |
6cc73a06 | 60 | static DEFINE_TIMER(cmm_timer, cmm_timer_fn); |
1da177e4 | 61 | |
db705e83 HC |
62 | static long cmm_alloc_pages(long nr, long *counter, |
63 | struct cmm_page_array **list) | |
1da177e4 | 64 | { |
8bc719d3 MS |
65 | struct cmm_page_array *pa, *npa; |
66 | unsigned long addr; | |
1da177e4 | 67 | |
8bc719d3 MS |
68 | while (nr) { |
69 | addr = __get_free_page(GFP_NOIO); | |
70 | if (!addr) | |
1da177e4 | 71 | break; |
8bc719d3 MS |
72 | spin_lock(&cmm_lock); |
73 | pa = *list; | |
1da177e4 LT |
74 | if (!pa || pa->index >= CMM_NR_PAGES) { |
75 | /* Need a new page for the page list. */ | |
8bc719d3 MS |
76 | spin_unlock(&cmm_lock); |
77 | npa = (struct cmm_page_array *) | |
1da177e4 | 78 | __get_free_page(GFP_NOIO); |
8bc719d3 MS |
79 | if (!npa) { |
80 | free_page(addr); | |
1da177e4 LT |
81 | break; |
82 | } | |
8bc719d3 MS |
83 | spin_lock(&cmm_lock); |
84 | pa = *list; | |
85 | if (!pa || pa->index >= CMM_NR_PAGES) { | |
86 | npa->next = pa; | |
87 | npa->index = 0; | |
88 | pa = npa; | |
89 | *list = pa; | |
90 | } else | |
91 | free_page((unsigned long) npa); | |
1da177e4 | 92 | } |
2d1494fb | 93 | diag10_range(virt_to_pfn((void *)addr), 1); |
8bc719d3 | 94 | pa->pages[pa->index++] = addr; |
1da177e4 | 95 | (*counter)++; |
8bc719d3 MS |
96 | spin_unlock(&cmm_lock); |
97 | nr--; | |
1da177e4 | 98 | } |
8bc719d3 | 99 | return nr; |
1da177e4 LT |
100 | } |
101 | ||
db705e83 | 102 | static long cmm_free_pages(long nr, long *counter, struct cmm_page_array **list) |
1da177e4 LT |
103 | { |
104 | struct cmm_page_array *pa; | |
8bc719d3 | 105 | unsigned long addr; |
1da177e4 | 106 | |
8bc719d3 | 107 | spin_lock(&cmm_lock); |
1da177e4 | 108 | pa = *list; |
8bc719d3 | 109 | while (nr) { |
1da177e4 LT |
110 | if (!pa || pa->index <= 0) |
111 | break; | |
8bc719d3 | 112 | addr = pa->pages[--pa->index]; |
1da177e4 LT |
113 | if (pa->index == 0) { |
114 | pa = pa->next; | |
115 | free_page((unsigned long) *list); | |
116 | *list = pa; | |
117 | } | |
8bc719d3 | 118 | free_page(addr); |
1da177e4 | 119 | (*counter)--; |
8bc719d3 | 120 | nr--; |
1da177e4 | 121 | } |
8bc719d3 MS |
122 | spin_unlock(&cmm_lock); |
123 | return nr; | |
1da177e4 LT |
124 | } |
125 | ||
8bc719d3 MS |
126 | static int cmm_oom_notify(struct notifier_block *self, |
127 | unsigned long dummy, void *parm) | |
128 | { | |
129 | unsigned long *freed = parm; | |
130 | long nr = 256; | |
131 | ||
132 | nr = cmm_free_pages(nr, &cmm_timed_pages, &cmm_timed_page_list); | |
133 | if (nr > 0) | |
134 | nr = cmm_free_pages(nr, &cmm_pages, &cmm_page_list); | |
135 | cmm_pages_target = cmm_pages; | |
136 | cmm_timed_pages_target = cmm_timed_pages; | |
137 | *freed += 256 - nr; | |
138 | return NOTIFY_OK; | |
139 | } | |
140 | ||
141 | static struct notifier_block cmm_oom_nb = { | |
db705e83 | 142 | .notifier_call = cmm_oom_notify, |
8bc719d3 MS |
143 | }; |
144 | ||
db705e83 | 145 | static int cmm_thread(void *dummy) |
1da177e4 LT |
146 | { |
147 | int rc; | |
148 | ||
1da177e4 LT |
149 | while (1) { |
150 | rc = wait_event_interruptible(cmm_thread_wait, | |
39421627 HC |
151 | cmm_pages != cmm_pages_target || |
152 | cmm_timed_pages != cmm_timed_pages_target || | |
153 | kthread_should_stop()); | |
e8216dee | 154 | if (kthread_should_stop() || rc == -ERESTARTSYS) { |
1da177e4 LT |
155 | cmm_pages_target = cmm_pages; |
156 | cmm_timed_pages_target = cmm_timed_pages; | |
157 | break; | |
158 | } | |
159 | if (cmm_pages_target > cmm_pages) { | |
160 | if (cmm_alloc_pages(1, &cmm_pages, &cmm_page_list)) | |
161 | cmm_pages_target = cmm_pages; | |
162 | } else if (cmm_pages_target < cmm_pages) { | |
163 | cmm_free_pages(1, &cmm_pages, &cmm_page_list); | |
164 | } | |
165 | if (cmm_timed_pages_target > cmm_timed_pages) { | |
166 | if (cmm_alloc_pages(1, &cmm_timed_pages, | |
167 | &cmm_timed_page_list)) | |
168 | cmm_timed_pages_target = cmm_timed_pages; | |
169 | } else if (cmm_timed_pages_target < cmm_timed_pages) { | |
170 | cmm_free_pages(1, &cmm_timed_pages, | |
db705e83 | 171 | &cmm_timed_page_list); |
1da177e4 LT |
172 | } |
173 | if (cmm_timed_pages > 0 && !timer_pending(&cmm_timer)) | |
174 | cmm_set_timer(); | |
175 | } | |
176 | return 0; | |
177 | } | |
178 | ||
db705e83 | 179 | static void cmm_kick_thread(void) |
1da177e4 | 180 | { |
1da177e4 LT |
181 | wake_up(&cmm_thread_wait); |
182 | } | |
183 | ||
db705e83 | 184 | static void cmm_set_timer(void) |
1da177e4 LT |
185 | { |
186 | if (cmm_timed_pages_target <= 0 || cmm_timeout_seconds <= 0) { | |
187 | if (timer_pending(&cmm_timer)) | |
188 | del_timer(&cmm_timer); | |
189 | return; | |
190 | } | |
0188d08a | 191 | mod_timer(&cmm_timer, jiffies + msecs_to_jiffies(cmm_timeout_seconds * MSEC_PER_SEC)); |
1da177e4 LT |
192 | } |
193 | ||
6cc73a06 | 194 | static void cmm_timer_fn(struct timer_list *unused) |
1da177e4 | 195 | { |
8bc719d3 | 196 | long nr; |
1da177e4 | 197 | |
8bc719d3 MS |
198 | nr = cmm_timed_pages_target - cmm_timeout_pages; |
199 | if (nr < 0) | |
1da177e4 LT |
200 | cmm_timed_pages_target = 0; |
201 | else | |
8bc719d3 | 202 | cmm_timed_pages_target = nr; |
1da177e4 LT |
203 | cmm_kick_thread(); |
204 | cmm_set_timer(); | |
205 | } | |
206 | ||
db705e83 | 207 | static void cmm_set_pages(long nr) |
1da177e4 | 208 | { |
8bc719d3 | 209 | cmm_pages_target = nr; |
1da177e4 LT |
210 | cmm_kick_thread(); |
211 | } | |
212 | ||
db705e83 | 213 | static long cmm_get_pages(void) |
1da177e4 LT |
214 | { |
215 | return cmm_pages; | |
216 | } | |
217 | ||
db705e83 | 218 | static void cmm_add_timed_pages(long nr) |
1da177e4 | 219 | { |
8bc719d3 | 220 | cmm_timed_pages_target += nr; |
1da177e4 LT |
221 | cmm_kick_thread(); |
222 | } | |
223 | ||
db705e83 | 224 | static long cmm_get_timed_pages(void) |
1da177e4 LT |
225 | { |
226 | return cmm_timed_pages; | |
227 | } | |
228 | ||
db705e83 | 229 | static void cmm_set_timeout(long nr, long seconds) |
1da177e4 | 230 | { |
8bc719d3 | 231 | cmm_timeout_pages = nr; |
1da177e4 LT |
232 | cmm_timeout_seconds = seconds; |
233 | cmm_set_timer(); | |
234 | } | |
235 | ||
db705e83 | 236 | static int cmm_skip_blanks(char *cp, char **endp) |
1da177e4 LT |
237 | { |
238 | char *str; | |
239 | ||
db705e83 HC |
240 | for (str = cp; *str == ' ' || *str == '\t'; str++) |
241 | ; | |
1da177e4 LT |
242 | *endp = str; |
243 | return str != cp; | |
244 | } | |
245 | ||
302bfe20 | 246 | static int cmm_pages_handler(struct ctl_table *ctl, int write, |
32927393 | 247 | void *buffer, size_t *lenp, loff_t *ppos) |
1da177e4 | 248 | { |
71e33a1d VG |
249 | long nr = cmm_get_pages(); |
250 | struct ctl_table ctl_entry = { | |
251 | .procname = ctl->procname, | |
252 | .data = &nr, | |
253 | .maxlen = sizeof(long), | |
254 | }; | |
255 | int rc; | |
1da177e4 | 256 | |
71e33a1d VG |
257 | rc = proc_doulongvec_minmax(&ctl_entry, write, buffer, lenp, ppos); |
258 | if (rc < 0 || !write) | |
259 | return rc; | |
1da177e4 | 260 | |
71e33a1d VG |
261 | cmm_set_pages(nr); |
262 | return 0; | |
263 | } | |
264 | ||
265 | static int cmm_timed_pages_handler(struct ctl_table *ctl, int write, | |
32927393 | 266 | void *buffer, size_t *lenp, |
71e33a1d VG |
267 | loff_t *ppos) |
268 | { | |
269 | long nr = cmm_get_timed_pages(); | |
270 | struct ctl_table ctl_entry = { | |
271 | .procname = ctl->procname, | |
272 | .data = &nr, | |
273 | .maxlen = sizeof(long), | |
274 | }; | |
275 | int rc; | |
276 | ||
277 | rc = proc_doulongvec_minmax(&ctl_entry, write, buffer, lenp, ppos); | |
278 | if (rc < 0 || !write) | |
279 | return rc; | |
280 | ||
281 | cmm_add_timed_pages(nr); | |
1da177e4 LT |
282 | return 0; |
283 | } | |
284 | ||
302bfe20 | 285 | static int cmm_timeout_handler(struct ctl_table *ctl, int write, |
32927393 | 286 | void *buffer, size_t *lenp, loff_t *ppos) |
1da177e4 LT |
287 | { |
288 | char buf[64], *p; | |
8bc719d3 | 289 | long nr, seconds; |
041058a1 | 290 | unsigned int len; |
1da177e4 LT |
291 | |
292 | if (!*lenp || (*ppos && !write)) { | |
293 | *lenp = 0; | |
294 | return 0; | |
295 | } | |
296 | ||
297 | if (write) { | |
b8e51a6a | 298 | len = min(*lenp, sizeof(buf)); |
32927393 | 299 | memcpy(buf, buffer, len); |
b8e51a6a | 300 | buf[len - 1] = '\0'; |
1da177e4 | 301 | cmm_skip_blanks(buf, &p); |
8bc719d3 | 302 | nr = simple_strtoul(p, &p, 0); |
1da177e4 | 303 | cmm_skip_blanks(p, &p); |
7d5d688f | 304 | seconds = simple_strtoul(p, &p, 0); |
8bc719d3 | 305 | cmm_set_timeout(nr, seconds); |
b8e51a6a | 306 | *ppos += *lenp; |
1da177e4 LT |
307 | } else { |
308 | len = sprintf(buf, "%ld %ld\n", | |
309 | cmm_timeout_pages, cmm_timeout_seconds); | |
310 | if (len > *lenp) | |
311 | len = *lenp; | |
32927393 | 312 | memcpy(buffer, buf, len); |
b8e51a6a YZ |
313 | *lenp = len; |
314 | *ppos += len; | |
1da177e4 | 315 | } |
1da177e4 LT |
316 | return 0; |
317 | } | |
318 | ||
319 | static struct ctl_table cmm_table[] = { | |
320 | { | |
1da177e4 | 321 | .procname = "cmm_pages", |
5e8b1c40 | 322 | .mode = 0644, |
6d456111 | 323 | .proc_handler = cmm_pages_handler, |
1da177e4 LT |
324 | }, |
325 | { | |
1da177e4 | 326 | .procname = "cmm_timed_pages", |
5e8b1c40 | 327 | .mode = 0644, |
71e33a1d | 328 | .proc_handler = cmm_timed_pages_handler, |
1da177e4 LT |
329 | }, |
330 | { | |
1da177e4 | 331 | .procname = "cmm_timeout", |
5e8b1c40 | 332 | .mode = 0644, |
6d456111 | 333 | .proc_handler = cmm_timeout_handler, |
1da177e4 | 334 | }, |
1da177e4 LT |
335 | }; |
336 | ||
1da177e4 LT |
337 | #ifdef CONFIG_CMM_IUCV |
338 | #define SMSG_PREFIX "CMM" | |
db705e83 | 339 | static void cmm_smsg_target(const char *from, char *msg) |
1da177e4 | 340 | { |
8bc719d3 | 341 | long nr, seconds; |
1da177e4 | 342 | |
15439d74 MS |
343 | if (strlen(sender) > 0 && strcmp(from, sender) != 0) |
344 | return; | |
1da177e4 LT |
345 | if (!cmm_skip_blanks(msg + strlen(SMSG_PREFIX), &msg)) |
346 | return; | |
347 | if (strncmp(msg, "SHRINK", 6) == 0) { | |
348 | if (!cmm_skip_blanks(msg + 6, &msg)) | |
349 | return; | |
8bc719d3 | 350 | nr = simple_strtoul(msg, &msg, 0); |
1da177e4 LT |
351 | cmm_skip_blanks(msg, &msg); |
352 | if (*msg == '\0') | |
8bc719d3 | 353 | cmm_set_pages(nr); |
1da177e4 LT |
354 | } else if (strncmp(msg, "RELEASE", 7) == 0) { |
355 | if (!cmm_skip_blanks(msg + 7, &msg)) | |
356 | return; | |
8bc719d3 | 357 | nr = simple_strtoul(msg, &msg, 0); |
1da177e4 LT |
358 | cmm_skip_blanks(msg, &msg); |
359 | if (*msg == '\0') | |
8bc719d3 | 360 | cmm_add_timed_pages(nr); |
1da177e4 LT |
361 | } else if (strncmp(msg, "REUSE", 5) == 0) { |
362 | if (!cmm_skip_blanks(msg + 5, &msg)) | |
363 | return; | |
8bc719d3 | 364 | nr = simple_strtoul(msg, &msg, 0); |
1da177e4 LT |
365 | if (!cmm_skip_blanks(msg, &msg)) |
366 | return; | |
7d5d688f | 367 | seconds = simple_strtoul(msg, &msg, 0); |
1da177e4 LT |
368 | cmm_skip_blanks(msg, &msg); |
369 | if (*msg == '\0') | |
8bc719d3 | 370 | cmm_set_timeout(nr, seconds); |
1da177e4 LT |
371 | } |
372 | } | |
373 | #endif | |
374 | ||
2b67fc46 | 375 | static struct ctl_table_header *cmm_sysctl_header; |
1da177e4 | 376 | |
2e85ba51 | 377 | static int __init cmm_init(void) |
1da177e4 | 378 | { |
e8216dee HC |
379 | int rc = -ENOMEM; |
380 | ||
414b2a96 | 381 | cmm_sysctl_header = register_sysctl("vm", cmm_table); |
e8216dee | 382 | if (!cmm_sysctl_header) |
52b169c8 | 383 | goto out_sysctl; |
1da177e4 | 384 | #ifdef CONFIG_CMM_IUCV |
41b42876 | 385 | /* convert sender to uppercase characters */ |
b2f58393 AS |
386 | if (sender) |
387 | string_upper(sender, sender); | |
388 | else | |
a20852d2 | 389 | sender = cmm_default_sender; |
41b42876 | 390 | |
e8216dee HC |
391 | rc = smsg_register_callback(SMSG_PREFIX, cmm_smsg_target); |
392 | if (rc < 0) | |
393 | goto out_smsg; | |
1da177e4 | 394 | #endif |
e8216dee HC |
395 | rc = register_oom_notifier(&cmm_oom_nb); |
396 | if (rc < 0) | |
397 | goto out_oom_notify; | |
e8216dee | 398 | cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread"); |
8fe853f3 AG |
399 | if (!IS_ERR(cmm_thread_ptr)) |
400 | return 0; | |
e8216dee | 401 | |
8fe853f3 | 402 | rc = PTR_ERR(cmm_thread_ptr); |
52b169c8 | 403 | unregister_oom_notifier(&cmm_oom_nb); |
e8216dee HC |
404 | out_oom_notify: |
405 | #ifdef CONFIG_CMM_IUCV | |
406 | smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target); | |
407 | out_smsg: | |
408 | #endif | |
e8216dee | 409 | unregister_sysctl_table(cmm_sysctl_header); |
52b169c8 | 410 | out_sysctl: |
1ef6acf5 | 411 | del_timer_sync(&cmm_timer); |
e8216dee | 412 | return rc; |
1da177e4 | 413 | } |
db705e83 | 414 | module_init(cmm_init); |
1da177e4 | 415 | |
2e85ba51 | 416 | static void __exit cmm_exit(void) |
1da177e4 | 417 | { |
1da177e4 | 418 | unregister_sysctl_table(cmm_sysctl_header); |
1da177e4 LT |
419 | #ifdef CONFIG_CMM_IUCV |
420 | smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target); | |
421 | #endif | |
1ef6acf5 HC |
422 | unregister_oom_notifier(&cmm_oom_nb); |
423 | kthread_stop(cmm_thread_ptr); | |
424 | del_timer_sync(&cmm_timer); | |
425 | cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list); | |
426 | cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list); | |
1da177e4 | 427 | } |
1da177e4 LT |
428 | module_exit(cmm_exit); |
429 | ||
1da177e4 | 430 | MODULE_LICENSE("GPL"); |