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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 | ||
11 | #include <linux/config.h> | |
12 | #include <linux/errno.h> | |
13 | #include <linux/fs.h> | |
14 | #include <linux/init.h> | |
15 | #include <linux/module.h> | |
16 | #include <linux/sched.h> | |
17 | #include <linux/sysctl.h> | |
18 | #include <linux/ctype.h> | |
19 | ||
20 | #include <asm/pgalloc.h> | |
21 | #include <asm/uaccess.h> | |
22 | ||
15439d74 | 23 | static char *sender = "VMRMSVM"; |
447570cf | 24 | module_param(sender, charp, 0400); |
15439d74 MS |
25 | MODULE_PARM_DESC(sender, |
26 | "Guest name that may send SMSG messages (default VMRMSVM)"); | |
27 | ||
1da177e4 LT |
28 | #include "../../../drivers/s390/net/smsgiucv.h" |
29 | ||
30 | #define CMM_NR_PAGES ((PAGE_SIZE / sizeof(unsigned long)) - 2) | |
31 | ||
32 | struct cmm_page_array { | |
33 | struct cmm_page_array *next; | |
34 | unsigned long index; | |
35 | unsigned long pages[CMM_NR_PAGES]; | |
36 | }; | |
37 | ||
38 | static long cmm_pages = 0; | |
39 | static long cmm_timed_pages = 0; | |
40 | static volatile long cmm_pages_target = 0; | |
41 | static volatile long cmm_timed_pages_target = 0; | |
42 | static long cmm_timeout_pages = 0; | |
43 | static long cmm_timeout_seconds = 0; | |
44 | ||
45 | static struct cmm_page_array *cmm_page_list = 0; | |
46 | static struct cmm_page_array *cmm_timed_page_list = 0; | |
47 | ||
48 | static unsigned long cmm_thread_active = 0; | |
49 | static struct work_struct cmm_thread_starter; | |
50 | static wait_queue_head_t cmm_thread_wait; | |
51 | static struct timer_list cmm_timer; | |
52 | ||
53 | static void cmm_timer_fn(unsigned long); | |
54 | static void cmm_set_timer(void); | |
55 | ||
56 | static long | |
57 | cmm_strtoul(const char *cp, char **endp) | |
58 | { | |
59 | unsigned int base = 10; | |
60 | ||
61 | if (*cp == '0') { | |
62 | base = 8; | |
63 | cp++; | |
64 | if ((*cp == 'x' || *cp == 'X') && isxdigit(cp[1])) { | |
65 | base = 16; | |
66 | cp++; | |
67 | } | |
68 | } | |
69 | return simple_strtoul(cp, endp, base); | |
70 | } | |
71 | ||
72 | static long | |
73 | cmm_alloc_pages(long pages, long *counter, struct cmm_page_array **list) | |
74 | { | |
75 | struct cmm_page_array *pa; | |
76 | unsigned long page; | |
77 | ||
78 | pa = *list; | |
79 | while (pages) { | |
80 | page = __get_free_page(GFP_NOIO); | |
81 | if (!page) | |
82 | break; | |
83 | if (!pa || pa->index >= CMM_NR_PAGES) { | |
84 | /* Need a new page for the page list. */ | |
85 | pa = (struct cmm_page_array *) | |
86 | __get_free_page(GFP_NOIO); | |
87 | if (!pa) { | |
88 | free_page(page); | |
89 | break; | |
90 | } | |
91 | pa->next = *list; | |
92 | pa->index = 0; | |
93 | *list = pa; | |
94 | } | |
95 | diag10(page); | |
96 | pa->pages[pa->index++] = page; | |
97 | (*counter)++; | |
98 | pages--; | |
99 | } | |
100 | return pages; | |
101 | } | |
102 | ||
103 | static void | |
104 | cmm_free_pages(long pages, long *counter, struct cmm_page_array **list) | |
105 | { | |
106 | struct cmm_page_array *pa; | |
107 | unsigned long page; | |
108 | ||
109 | pa = *list; | |
110 | while (pages) { | |
111 | if (!pa || pa->index <= 0) | |
112 | break; | |
113 | page = pa->pages[--pa->index]; | |
114 | if (pa->index == 0) { | |
115 | pa = pa->next; | |
116 | free_page((unsigned long) *list); | |
117 | *list = pa; | |
118 | } | |
119 | free_page(page); | |
120 | (*counter)--; | |
121 | pages--; | |
122 | } | |
123 | } | |
124 | ||
125 | static int | |
126 | cmm_thread(void *dummy) | |
127 | { | |
128 | int rc; | |
129 | ||
130 | daemonize("cmmthread"); | |
131 | while (1) { | |
132 | rc = wait_event_interruptible(cmm_thread_wait, | |
133 | (cmm_pages != cmm_pages_target || | |
134 | cmm_timed_pages != cmm_timed_pages_target)); | |
135 | if (rc == -ERESTARTSYS) { | |
136 | /* Got kill signal. End thread. */ | |
137 | clear_bit(0, &cmm_thread_active); | |
138 | cmm_pages_target = cmm_pages; | |
139 | cmm_timed_pages_target = cmm_timed_pages; | |
140 | break; | |
141 | } | |
142 | if (cmm_pages_target > cmm_pages) { | |
143 | if (cmm_alloc_pages(1, &cmm_pages, &cmm_page_list)) | |
144 | cmm_pages_target = cmm_pages; | |
145 | } else if (cmm_pages_target < cmm_pages) { | |
146 | cmm_free_pages(1, &cmm_pages, &cmm_page_list); | |
147 | } | |
148 | if (cmm_timed_pages_target > cmm_timed_pages) { | |
149 | if (cmm_alloc_pages(1, &cmm_timed_pages, | |
150 | &cmm_timed_page_list)) | |
151 | cmm_timed_pages_target = cmm_timed_pages; | |
152 | } else if (cmm_timed_pages_target < cmm_timed_pages) { | |
153 | cmm_free_pages(1, &cmm_timed_pages, | |
154 | &cmm_timed_page_list); | |
155 | } | |
156 | if (cmm_timed_pages > 0 && !timer_pending(&cmm_timer)) | |
157 | cmm_set_timer(); | |
158 | } | |
159 | return 0; | |
160 | } | |
161 | ||
162 | static void | |
163 | cmm_start_thread(void) | |
164 | { | |
165 | kernel_thread(cmm_thread, 0, 0); | |
166 | } | |
167 | ||
168 | static void | |
169 | cmm_kick_thread(void) | |
170 | { | |
171 | if (!test_and_set_bit(0, &cmm_thread_active)) | |
172 | schedule_work(&cmm_thread_starter); | |
173 | wake_up(&cmm_thread_wait); | |
174 | } | |
175 | ||
176 | static void | |
177 | cmm_set_timer(void) | |
178 | { | |
179 | if (cmm_timed_pages_target <= 0 || cmm_timeout_seconds <= 0) { | |
180 | if (timer_pending(&cmm_timer)) | |
181 | del_timer(&cmm_timer); | |
182 | return; | |
183 | } | |
184 | if (timer_pending(&cmm_timer)) { | |
185 | if (mod_timer(&cmm_timer, jiffies + cmm_timeout_seconds*HZ)) | |
186 | return; | |
187 | } | |
188 | cmm_timer.function = cmm_timer_fn; | |
189 | cmm_timer.data = 0; | |
190 | cmm_timer.expires = jiffies + cmm_timeout_seconds*HZ; | |
191 | add_timer(&cmm_timer); | |
192 | } | |
193 | ||
194 | static void | |
195 | cmm_timer_fn(unsigned long ignored) | |
196 | { | |
197 | long pages; | |
198 | ||
199 | pages = cmm_timed_pages_target - cmm_timeout_pages; | |
200 | if (pages < 0) | |
201 | cmm_timed_pages_target = 0; | |
202 | else | |
203 | cmm_timed_pages_target = pages; | |
204 | cmm_kick_thread(); | |
205 | cmm_set_timer(); | |
206 | } | |
207 | ||
208 | void | |
209 | cmm_set_pages(long pages) | |
210 | { | |
211 | cmm_pages_target = pages; | |
212 | cmm_kick_thread(); | |
213 | } | |
214 | ||
215 | long | |
216 | cmm_get_pages(void) | |
217 | { | |
218 | return cmm_pages; | |
219 | } | |
220 | ||
221 | void | |
222 | cmm_add_timed_pages(long pages) | |
223 | { | |
224 | cmm_timed_pages_target += pages; | |
225 | cmm_kick_thread(); | |
226 | } | |
227 | ||
228 | long | |
229 | cmm_get_timed_pages(void) | |
230 | { | |
231 | return cmm_timed_pages; | |
232 | } | |
233 | ||
234 | void | |
235 | cmm_set_timeout(long pages, long seconds) | |
236 | { | |
237 | cmm_timeout_pages = pages; | |
238 | cmm_timeout_seconds = seconds; | |
239 | cmm_set_timer(); | |
240 | } | |
241 | ||
242 | static inline int | |
243 | cmm_skip_blanks(char *cp, char **endp) | |
244 | { | |
245 | char *str; | |
246 | ||
247 | for (str = cp; *str == ' ' || *str == '\t'; str++); | |
248 | *endp = str; | |
249 | return str != cp; | |
250 | } | |
251 | ||
252 | #ifdef CONFIG_CMM_PROC | |
253 | /* These will someday get removed. */ | |
254 | #define VM_CMM_PAGES 1111 | |
255 | #define VM_CMM_TIMED_PAGES 1112 | |
256 | #define VM_CMM_TIMEOUT 1113 | |
257 | ||
258 | static struct ctl_table cmm_table[]; | |
259 | ||
260 | static int | |
261 | cmm_pages_handler(ctl_table *ctl, int write, struct file *filp, | |
262 | void *buffer, size_t *lenp, loff_t *ppos) | |
263 | { | |
264 | char buf[16], *p; | |
265 | long pages; | |
266 | int len; | |
267 | ||
268 | if (!*lenp || (*ppos && !write)) { | |
269 | *lenp = 0; | |
270 | return 0; | |
271 | } | |
272 | ||
273 | if (write) { | |
274 | len = *lenp; | |
275 | if (copy_from_user(buf, buffer, | |
276 | len > sizeof(buf) ? sizeof(buf) : len)) | |
277 | return -EFAULT; | |
278 | buf[sizeof(buf) - 1] = '\0'; | |
279 | cmm_skip_blanks(buf, &p); | |
280 | pages = cmm_strtoul(p, &p); | |
281 | if (ctl == &cmm_table[0]) | |
282 | cmm_set_pages(pages); | |
283 | else | |
284 | cmm_add_timed_pages(pages); | |
285 | } else { | |
286 | if (ctl == &cmm_table[0]) | |
287 | pages = cmm_get_pages(); | |
288 | else | |
289 | pages = cmm_get_timed_pages(); | |
290 | len = sprintf(buf, "%ld\n", pages); | |
291 | if (len > *lenp) | |
292 | len = *lenp; | |
293 | if (copy_to_user(buffer, buf, len)) | |
294 | return -EFAULT; | |
295 | } | |
296 | *lenp = len; | |
297 | *ppos += len; | |
298 | return 0; | |
299 | } | |
300 | ||
301 | static int | |
302 | cmm_timeout_handler(ctl_table *ctl, int write, struct file *filp, | |
303 | void *buffer, size_t *lenp, loff_t *ppos) | |
304 | { | |
305 | char buf[64], *p; | |
306 | long pages, seconds; | |
307 | int len; | |
308 | ||
309 | if (!*lenp || (*ppos && !write)) { | |
310 | *lenp = 0; | |
311 | return 0; | |
312 | } | |
313 | ||
314 | if (write) { | |
315 | len = *lenp; | |
316 | if (copy_from_user(buf, buffer, | |
317 | len > sizeof(buf) ? sizeof(buf) : len)) | |
318 | return -EFAULT; | |
319 | buf[sizeof(buf) - 1] = '\0'; | |
320 | cmm_skip_blanks(buf, &p); | |
321 | pages = cmm_strtoul(p, &p); | |
322 | cmm_skip_blanks(p, &p); | |
323 | seconds = cmm_strtoul(p, &p); | |
324 | cmm_set_timeout(pages, seconds); | |
325 | } else { | |
326 | len = sprintf(buf, "%ld %ld\n", | |
327 | cmm_timeout_pages, cmm_timeout_seconds); | |
328 | if (len > *lenp) | |
329 | len = *lenp; | |
330 | if (copy_to_user(buffer, buf, len)) | |
331 | return -EFAULT; | |
332 | } | |
333 | *lenp = len; | |
334 | *ppos += len; | |
335 | return 0; | |
336 | } | |
337 | ||
338 | static struct ctl_table cmm_table[] = { | |
339 | { | |
340 | .ctl_name = VM_CMM_PAGES, | |
341 | .procname = "cmm_pages", | |
342 | .mode = 0600, | |
343 | .proc_handler = &cmm_pages_handler, | |
344 | }, | |
345 | { | |
346 | .ctl_name = VM_CMM_TIMED_PAGES, | |
347 | .procname = "cmm_timed_pages", | |
348 | .mode = 0600, | |
349 | .proc_handler = &cmm_pages_handler, | |
350 | }, | |
351 | { | |
352 | .ctl_name = VM_CMM_TIMEOUT, | |
353 | .procname = "cmm_timeout", | |
354 | .mode = 0600, | |
355 | .proc_handler = &cmm_timeout_handler, | |
356 | }, | |
357 | { .ctl_name = 0 } | |
358 | }; | |
359 | ||
360 | static struct ctl_table cmm_dir_table[] = { | |
361 | { | |
362 | .ctl_name = CTL_VM, | |
363 | .procname = "vm", | |
364 | .maxlen = 0, | |
365 | .mode = 0555, | |
366 | .child = cmm_table, | |
367 | }, | |
368 | { .ctl_name = 0 } | |
369 | }; | |
370 | #endif | |
371 | ||
372 | #ifdef CONFIG_CMM_IUCV | |
373 | #define SMSG_PREFIX "CMM" | |
374 | static void | |
15439d74 | 375 | cmm_smsg_target(char *from, char *msg) |
1da177e4 LT |
376 | { |
377 | long pages, seconds; | |
378 | ||
15439d74 MS |
379 | if (strlen(sender) > 0 && strcmp(from, sender) != 0) |
380 | return; | |
1da177e4 LT |
381 | if (!cmm_skip_blanks(msg + strlen(SMSG_PREFIX), &msg)) |
382 | return; | |
383 | if (strncmp(msg, "SHRINK", 6) == 0) { | |
384 | if (!cmm_skip_blanks(msg + 6, &msg)) | |
385 | return; | |
386 | pages = cmm_strtoul(msg, &msg); | |
387 | cmm_skip_blanks(msg, &msg); | |
388 | if (*msg == '\0') | |
389 | cmm_set_pages(pages); | |
390 | } else if (strncmp(msg, "RELEASE", 7) == 0) { | |
391 | if (!cmm_skip_blanks(msg + 7, &msg)) | |
392 | return; | |
393 | pages = cmm_strtoul(msg, &msg); | |
394 | cmm_skip_blanks(msg, &msg); | |
395 | if (*msg == '\0') | |
396 | cmm_add_timed_pages(pages); | |
397 | } else if (strncmp(msg, "REUSE", 5) == 0) { | |
398 | if (!cmm_skip_blanks(msg + 5, &msg)) | |
399 | return; | |
400 | pages = cmm_strtoul(msg, &msg); | |
401 | if (!cmm_skip_blanks(msg, &msg)) | |
402 | return; | |
403 | seconds = cmm_strtoul(msg, &msg); | |
404 | cmm_skip_blanks(msg, &msg); | |
405 | if (*msg == '\0') | |
406 | cmm_set_timeout(pages, seconds); | |
407 | } | |
408 | } | |
409 | #endif | |
410 | ||
411 | struct ctl_table_header *cmm_sysctl_header; | |
412 | ||
413 | static int | |
414 | cmm_init (void) | |
415 | { | |
416 | #ifdef CONFIG_CMM_PROC | |
417 | cmm_sysctl_header = register_sysctl_table(cmm_dir_table, 1); | |
418 | #endif | |
419 | #ifdef CONFIG_CMM_IUCV | |
420 | smsg_register_callback(SMSG_PREFIX, cmm_smsg_target); | |
421 | #endif | |
422 | INIT_WORK(&cmm_thread_starter, (void *) cmm_start_thread, 0); | |
423 | init_waitqueue_head(&cmm_thread_wait); | |
424 | init_timer(&cmm_timer); | |
425 | return 0; | |
426 | } | |
427 | ||
428 | static void | |
429 | cmm_exit(void) | |
430 | { | |
431 | cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list); | |
432 | cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list); | |
433 | #ifdef CONFIG_CMM_PROC | |
434 | unregister_sysctl_table(cmm_sysctl_header); | |
435 | #endif | |
436 | #ifdef CONFIG_CMM_IUCV | |
437 | smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target); | |
438 | #endif | |
439 | } | |
440 | ||
441 | module_init(cmm_init); | |
442 | module_exit(cmm_exit); | |
443 | ||
444 | EXPORT_SYMBOL(cmm_set_pages); | |
445 | EXPORT_SYMBOL(cmm_get_pages); | |
446 | EXPORT_SYMBOL(cmm_add_timed_pages); | |
447 | EXPORT_SYMBOL(cmm_get_timed_pages); | |
448 | EXPORT_SYMBOL(cmm_set_timeout); | |
449 | ||
450 | MODULE_LICENSE("GPL"); |