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