5 * Copyright (C) 2003 IBM Deutschland Entwicklung GmbH, IBM Corporation
6 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
8 * Collaborative memory management interface.
11 #include <linux/config.h>
12 #include <linux/errno.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>
20 #include <asm/pgalloc.h>
21 #include <asm/uaccess.h>
23 #include "../../../drivers/s390/net/smsgiucv.h"
25 #define CMM_NR_PAGES ((PAGE_SIZE / sizeof(unsigned long)) - 2)
27 struct cmm_page_array {
28 struct cmm_page_array *next;
30 unsigned long pages[CMM_NR_PAGES];
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;
40 static struct cmm_page_array *cmm_page_list = 0;
41 static struct cmm_page_array *cmm_timed_page_list = 0;
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;
48 static void cmm_timer_fn(unsigned long);
49 static void cmm_set_timer(void);
52 cmm_strtoul(const char *cp, char **endp)
54 unsigned int base = 10;
59 if ((*cp == 'x' || *cp == 'X') && isxdigit(cp[1])) {
64 return simple_strtoul(cp, endp, base);
68 cmm_alloc_pages(long pages, long *counter, struct cmm_page_array **list)
70 struct cmm_page_array *pa;
75 page = __get_free_page(GFP_NOIO);
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);
91 pa->pages[pa->index++] = page;
99 cmm_free_pages(long pages, long *counter, struct cmm_page_array **list)
101 struct cmm_page_array *pa;
106 if (!pa || pa->index <= 0)
108 page = pa->pages[--pa->index];
109 if (pa->index == 0) {
111 free_page((unsigned long) *list);
121 cmm_thread(void *dummy)
125 daemonize("cmmthread");
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;
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);
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);
151 if (cmm_timed_pages > 0 && !timer_pending(&cmm_timer))
158 cmm_start_thread(void)
160 kernel_thread(cmm_thread, 0, 0);
164 cmm_kick_thread(void)
166 if (!test_and_set_bit(0, &cmm_thread_active))
167 schedule_work(&cmm_thread_starter);
168 wake_up(&cmm_thread_wait);
174 if (cmm_timed_pages_target <= 0 || cmm_timeout_seconds <= 0) {
175 if (timer_pending(&cmm_timer))
176 del_timer(&cmm_timer);
179 if (timer_pending(&cmm_timer)) {
180 if (mod_timer(&cmm_timer, jiffies + cmm_timeout_seconds*HZ))
183 cmm_timer.function = cmm_timer_fn;
185 cmm_timer.expires = jiffies + cmm_timeout_seconds*HZ;
186 add_timer(&cmm_timer);
190 cmm_timer_fn(unsigned long ignored)
194 pages = cmm_timed_pages_target - cmm_timeout_pages;
196 cmm_timed_pages_target = 0;
198 cmm_timed_pages_target = pages;
204 cmm_set_pages(long pages)
206 cmm_pages_target = pages;
217 cmm_add_timed_pages(long pages)
219 cmm_timed_pages_target += pages;
224 cmm_get_timed_pages(void)
226 return cmm_timed_pages;
230 cmm_set_timeout(long pages, long seconds)
232 cmm_timeout_pages = pages;
233 cmm_timeout_seconds = seconds;
238 cmm_skip_blanks(char *cp, char **endp)
242 for (str = cp; *str == ' ' || *str == '\t'; str++);
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
253 static struct ctl_table cmm_table[];
256 cmm_pages_handler(ctl_table *ctl, int write, struct file *filp,
257 void *buffer, size_t *lenp, loff_t *ppos)
263 if (!*lenp || (*ppos && !write)) {
270 if (copy_from_user(buf, buffer,
271 len > sizeof(buf) ? sizeof(buf) : len))
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);
279 cmm_add_timed_pages(pages);
281 if (ctl == &cmm_table[0])
282 pages = cmm_get_pages();
284 pages = cmm_get_timed_pages();
285 len = sprintf(buf, "%ld\n", pages);
288 if (copy_to_user(buffer, buf, len))
297 cmm_timeout_handler(ctl_table *ctl, int write, struct file *filp,
298 void *buffer, size_t *lenp, loff_t *ppos)
304 if (!*lenp || (*ppos && !write)) {
311 if (copy_from_user(buf, buffer,
312 len > sizeof(buf) ? sizeof(buf) : len))
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);
321 len = sprintf(buf, "%ld %ld\n",
322 cmm_timeout_pages, cmm_timeout_seconds);
325 if (copy_to_user(buffer, buf, len))
333 static struct ctl_table cmm_table[] = {
335 .ctl_name = VM_CMM_PAGES,
336 .procname = "cmm_pages",
338 .proc_handler = &cmm_pages_handler,
341 .ctl_name = VM_CMM_TIMED_PAGES,
342 .procname = "cmm_timed_pages",
344 .proc_handler = &cmm_pages_handler,
347 .ctl_name = VM_CMM_TIMEOUT,
348 .procname = "cmm_timeout",
350 .proc_handler = &cmm_timeout_handler,
355 static struct ctl_table cmm_dir_table[] = {
367 #ifdef CONFIG_CMM_IUCV
368 #define SMSG_PREFIX "CMM"
370 cmm_smsg_target(char *msg)
374 if (!cmm_skip_blanks(msg + strlen(SMSG_PREFIX), &msg))
376 if (strncmp(msg, "SHRINK", 6) == 0) {
377 if (!cmm_skip_blanks(msg + 6, &msg))
379 pages = cmm_strtoul(msg, &msg);
380 cmm_skip_blanks(msg, &msg);
382 cmm_set_pages(pages);
383 } else if (strncmp(msg, "RELEASE", 7) == 0) {
384 if (!cmm_skip_blanks(msg + 7, &msg))
386 pages = cmm_strtoul(msg, &msg);
387 cmm_skip_blanks(msg, &msg);
389 cmm_add_timed_pages(pages);
390 } else if (strncmp(msg, "REUSE", 5) == 0) {
391 if (!cmm_skip_blanks(msg + 5, &msg))
393 pages = cmm_strtoul(msg, &msg);
394 if (!cmm_skip_blanks(msg, &msg))
396 seconds = cmm_strtoul(msg, &msg);
397 cmm_skip_blanks(msg, &msg);
399 cmm_set_timeout(pages, seconds);
404 struct ctl_table_header *cmm_sysctl_header;
409 #ifdef CONFIG_CMM_PROC
410 cmm_sysctl_header = register_sysctl_table(cmm_dir_table, 1);
412 #ifdef CONFIG_CMM_IUCV
413 smsg_register_callback(SMSG_PREFIX, cmm_smsg_target);
415 INIT_WORK(&cmm_thread_starter, (void *) cmm_start_thread, 0);
416 init_waitqueue_head(&cmm_thread_wait);
417 init_timer(&cmm_timer);
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);
429 #ifdef CONFIG_CMM_IUCV
430 smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
434 module_init(cmm_init);
435 module_exit(cmm_exit);
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);
443 MODULE_LICENSE("GPL");