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v6.2
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 *  Collaborative memory management interface.
  4 *
  5 *    Copyright IBM Corp 2003, 2010
  6 *    Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
  7 *
  8 */
  9
 10#include <linux/errno.h>
 11#include <linux/fs.h>
 12#include <linux/init.h>
 13#include <linux/module.h>
 14#include <linux/moduleparam.h>
 15#include <linux/gfp.h>
 16#include <linux/sched.h>
 17#include <linux/string_helpers.h>
 18#include <linux/sysctl.h>
 
 19#include <linux/swap.h>
 20#include <linux/kthread.h>
 21#include <linux/oom.h>
 
 22#include <linux/uaccess.h>
 23
 
 24#include <asm/diag.h>
 25
 26#ifdef CONFIG_CMM_IUCV
 27static char *cmm_default_sender = "VMRMSVM";
 28#endif
 29static char *sender;
 30module_param(sender, charp, 0400);
 31MODULE_PARM_DESC(sender,
 32		 "Guest name that may send SMSG messages (default VMRMSVM)");
 33
 34#include "../../../drivers/s390/net/smsgiucv.h"
 35
 36#define CMM_NR_PAGES ((PAGE_SIZE / sizeof(unsigned long)) - 2)
 37
 38struct cmm_page_array {
 39	struct cmm_page_array *next;
 40	unsigned long index;
 41	unsigned long pages[CMM_NR_PAGES];
 42};
 43
 44static long cmm_pages;
 45static long cmm_timed_pages;
 46static volatile long cmm_pages_target;
 47static volatile long cmm_timed_pages_target;
 48static long cmm_timeout_pages;
 49static long cmm_timeout_seconds;
 
 50
 51static struct cmm_page_array *cmm_page_list;
 52static struct cmm_page_array *cmm_timed_page_list;
 53static DEFINE_SPINLOCK(cmm_lock);
 54
 55static struct task_struct *cmm_thread_ptr;
 56static DECLARE_WAIT_QUEUE_HEAD(cmm_thread_wait);
 
 57
 58static void cmm_timer_fn(struct timer_list *);
 59static void cmm_set_timer(void);
 60static DEFINE_TIMER(cmm_timer, cmm_timer_fn);
 61
 62static long cmm_alloc_pages(long nr, long *counter,
 63			    struct cmm_page_array **list)
 64{
 65	struct cmm_page_array *pa, *npa;
 66	unsigned long addr;
 67
 68	while (nr) {
 69		addr = __get_free_page(GFP_NOIO);
 70		if (!addr)
 71			break;
 72		spin_lock(&cmm_lock);
 73		pa = *list;
 74		if (!pa || pa->index >= CMM_NR_PAGES) {
 75			/* Need a new page for the page list. */
 76			spin_unlock(&cmm_lock);
 77			npa = (struct cmm_page_array *)
 78				__get_free_page(GFP_NOIO);
 79			if (!npa) {
 80				free_page(addr);
 81				break;
 82			}
 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);
 92		}
 93		diag10_range(virt_to_pfn(addr), 1);
 94		pa->pages[pa->index++] = addr;
 95		(*counter)++;
 96		spin_unlock(&cmm_lock);
 97		nr--;
 98	}
 99	return nr;
100}
101
102static long cmm_free_pages(long nr, long *counter, struct cmm_page_array **list)
103{
104	struct cmm_page_array *pa;
105	unsigned long addr;
106
107	spin_lock(&cmm_lock);
108	pa = *list;
109	while (nr) {
110		if (!pa || pa->index <= 0)
111			break;
112		addr = pa->pages[--pa->index];
113		if (pa->index == 0) {
114			pa = pa->next;
115			free_page((unsigned long) *list);
116			*list = pa;
117		}
118		free_page(addr);
119		(*counter)--;
120		nr--;
121	}
122	spin_unlock(&cmm_lock);
123	return nr;
124}
125
126static 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
141static struct notifier_block cmm_oom_nb = {
142	.notifier_call = cmm_oom_notify,
143};
144
145static int cmm_thread(void *dummy)
146{
147	int rc;
148
149	while (1) {
150		rc = wait_event_interruptible(cmm_thread_wait,
151			cmm_pages != cmm_pages_target ||
152			cmm_timed_pages != cmm_timed_pages_target ||
153			kthread_should_stop());
154		if (kthread_should_stop() || rc == -ERESTARTSYS) {
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,
171				       &cmm_timed_page_list);
172		}
173		if (cmm_timed_pages > 0 && !timer_pending(&cmm_timer))
174			cmm_set_timer();
175	}
176	return 0;
177}
178
179static void cmm_kick_thread(void)
180{
181	wake_up(&cmm_thread_wait);
182}
183
184static void cmm_set_timer(void)
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	}
191	mod_timer(&cmm_timer, jiffies + msecs_to_jiffies(cmm_timeout_seconds * MSEC_PER_SEC));
 
 
 
 
 
 
 
192}
193
194static void cmm_timer_fn(struct timer_list *unused)
195{
196	long nr;
197
198	nr = cmm_timed_pages_target - cmm_timeout_pages;
199	if (nr < 0)
200		cmm_timed_pages_target = 0;
201	else
202		cmm_timed_pages_target = nr;
203	cmm_kick_thread();
204	cmm_set_timer();
205}
206
207static void cmm_set_pages(long nr)
208{
209	cmm_pages_target = nr;
210	cmm_kick_thread();
211}
212
213static long cmm_get_pages(void)
214{
215	return cmm_pages;
216}
217
218static void cmm_add_timed_pages(long nr)
219{
220	cmm_timed_pages_target += nr;
221	cmm_kick_thread();
222}
223
224static long cmm_get_timed_pages(void)
225{
226	return cmm_timed_pages;
227}
228
229static void cmm_set_timeout(long nr, long seconds)
230{
231	cmm_timeout_pages = nr;
232	cmm_timeout_seconds = seconds;
233	cmm_set_timer();
234}
235
236static int cmm_skip_blanks(char *cp, char **endp)
237{
238	char *str;
239
240	for (str = cp; *str == ' ' || *str == '\t'; str++)
241		;
242	*endp = str;
243	return str != cp;
244}
245
246static int cmm_pages_handler(struct ctl_table *ctl, int write,
247			     void *buffer, size_t *lenp, loff_t *ppos)
248{
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;
256
257	rc = proc_doulongvec_minmax(&ctl_entry, write, buffer, lenp, ppos);
258	if (rc < 0 || !write)
259		return rc;
260
261	cmm_set_pages(nr);
262	return 0;
263}
264
265static int cmm_timed_pages_handler(struct ctl_table *ctl, int write,
266				   void *buffer, size_t *lenp,
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);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
282	return 0;
283}
284
285static int cmm_timeout_handler(struct ctl_table *ctl, int write,
286			       void *buffer, size_t *lenp, loff_t *ppos)
287{
288	char buf[64], *p;
289	long nr, seconds;
290	unsigned int len;
291
292	if (!*lenp || (*ppos && !write)) {
293		*lenp = 0;
294		return 0;
295	}
296
297	if (write) {
298		len = min(*lenp, sizeof(buf));
299		memcpy(buf, buffer, len);
300		buf[len - 1] = '\0';
 
 
301		cmm_skip_blanks(buf, &p);
302		nr = simple_strtoul(p, &p, 0);
303		cmm_skip_blanks(p, &p);
304		seconds = simple_strtoul(p, &p, 0);
305		cmm_set_timeout(nr, seconds);
306		*ppos += *lenp;
307	} else {
308		len = sprintf(buf, "%ld %ld\n",
309			      cmm_timeout_pages, cmm_timeout_seconds);
310		if (len > *lenp)
311			len = *lenp;
312		memcpy(buffer, buf, len);
313		*lenp = len;
314		*ppos += len;
315	}
 
 
316	return 0;
317}
318
319static struct ctl_table cmm_table[] = {
320	{
321		.procname	= "cmm_pages",
322		.mode		= 0644,
323		.proc_handler	= cmm_pages_handler,
324	},
325	{
326		.procname	= "cmm_timed_pages",
327		.mode		= 0644,
328		.proc_handler	= cmm_timed_pages_handler,
329	},
330	{
331		.procname	= "cmm_timeout",
332		.mode		= 0644,
333		.proc_handler	= cmm_timeout_handler,
334	},
335	{ }
336};
337
338static struct ctl_table cmm_dir_table[] = {
339	{
340		.procname	= "vm",
341		.maxlen		= 0,
342		.mode		= 0555,
343		.child		= cmm_table,
344	},
345	{ }
346};
347
348#ifdef CONFIG_CMM_IUCV
349#define SMSG_PREFIX "CMM"
350static void cmm_smsg_target(const char *from, char *msg)
351{
352	long nr, seconds;
353
354	if (strlen(sender) > 0 && strcmp(from, sender) != 0)
355		return;
356	if (!cmm_skip_blanks(msg + strlen(SMSG_PREFIX), &msg))
357		return;
358	if (strncmp(msg, "SHRINK", 6) == 0) {
359		if (!cmm_skip_blanks(msg + 6, &msg))
360			return;
361		nr = simple_strtoul(msg, &msg, 0);
362		cmm_skip_blanks(msg, &msg);
363		if (*msg == '\0')
364			cmm_set_pages(nr);
365	} else if (strncmp(msg, "RELEASE", 7) == 0) {
366		if (!cmm_skip_blanks(msg + 7, &msg))
367			return;
368		nr = simple_strtoul(msg, &msg, 0);
369		cmm_skip_blanks(msg, &msg);
370		if (*msg == '\0')
371			cmm_add_timed_pages(nr);
372	} else if (strncmp(msg, "REUSE", 5) == 0) {
373		if (!cmm_skip_blanks(msg + 5, &msg))
374			return;
375		nr = simple_strtoul(msg, &msg, 0);
376		if (!cmm_skip_blanks(msg, &msg))
377			return;
378		seconds = simple_strtoul(msg, &msg, 0);
379		cmm_skip_blanks(msg, &msg);
380		if (*msg == '\0')
381			cmm_set_timeout(nr, seconds);
382	}
383}
384#endif
385
386static struct ctl_table_header *cmm_sysctl_header;
387
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
388static int __init cmm_init(void)
389{
390	int rc = -ENOMEM;
391
392	cmm_sysctl_header = register_sysctl_table(cmm_dir_table);
393	if (!cmm_sysctl_header)
394		goto out_sysctl;
395#ifdef CONFIG_CMM_IUCV
396	/* convert sender to uppercase characters */
397	if (sender)
398		string_upper(sender, sender);
399	else
 
 
400		sender = cmm_default_sender;
 
401
402	rc = smsg_register_callback(SMSG_PREFIX, cmm_smsg_target);
403	if (rc < 0)
404		goto out_smsg;
405#endif
406	rc = register_oom_notifier(&cmm_oom_nb);
407	if (rc < 0)
408		goto out_oom_notify;
 
 
 
409	cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread");
410	if (!IS_ERR(cmm_thread_ptr))
411		return 0;
 
 
412
413	rc = PTR_ERR(cmm_thread_ptr);
 
 
414	unregister_oom_notifier(&cmm_oom_nb);
415out_oom_notify:
416#ifdef CONFIG_CMM_IUCV
417	smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
418out_smsg:
419#endif
420	unregister_sysctl_table(cmm_sysctl_header);
421out_sysctl:
422	del_timer_sync(&cmm_timer);
423	return rc;
424}
425module_init(cmm_init);
426
427static void __exit cmm_exit(void)
428{
429	unregister_sysctl_table(cmm_sysctl_header);
430#ifdef CONFIG_CMM_IUCV
431	smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
432#endif
 
433	unregister_oom_notifier(&cmm_oom_nb);
434	kthread_stop(cmm_thread_ptr);
435	del_timer_sync(&cmm_timer);
436	cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list);
437	cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list);
438}
439module_exit(cmm_exit);
440
441MODULE_LICENSE("GPL");
v3.5.6
 
  1/*
  2 *  Collaborative memory management interface.
  3 *
  4 *    Copyright IBM Corp 2003,2010
  5 *    Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
  6 *
  7 */
  8
  9#include <linux/errno.h>
 10#include <linux/fs.h>
 11#include <linux/init.h>
 12#include <linux/module.h>
 
 13#include <linux/gfp.h>
 14#include <linux/sched.h>
 
 15#include <linux/sysctl.h>
 16#include <linux/ctype.h>
 17#include <linux/swap.h>
 18#include <linux/kthread.h>
 19#include <linux/oom.h>
 20#include <linux/suspend.h>
 21#include <linux/uaccess.h>
 22
 23#include <asm/pgalloc.h>
 24#include <asm/diag.h>
 25
 26#ifdef CONFIG_CMM_IUCV
 27static char *cmm_default_sender = "VMRMSVM";
 28#endif
 29static char *sender;
 30module_param(sender, charp, 0400);
 31MODULE_PARM_DESC(sender,
 32		 "Guest name that may send SMSG messages (default VMRMSVM)");
 33
 34#include "../../../drivers/s390/net/smsgiucv.h"
 35
 36#define CMM_NR_PAGES ((PAGE_SIZE / sizeof(unsigned long)) - 2)
 37
 38struct cmm_page_array {
 39	struct cmm_page_array *next;
 40	unsigned long index;
 41	unsigned long pages[CMM_NR_PAGES];
 42};
 43
 44static long cmm_pages;
 45static long cmm_timed_pages;
 46static volatile long cmm_pages_target;
 47static volatile long cmm_timed_pages_target;
 48static long cmm_timeout_pages;
 49static long cmm_timeout_seconds;
 50static int cmm_suspended;
 51
 52static struct cmm_page_array *cmm_page_list;
 53static struct cmm_page_array *cmm_timed_page_list;
 54static DEFINE_SPINLOCK(cmm_lock);
 55
 56static struct task_struct *cmm_thread_ptr;
 57static DECLARE_WAIT_QUEUE_HEAD(cmm_thread_wait);
 58static DEFINE_TIMER(cmm_timer, NULL, 0, 0);
 59
 60static void cmm_timer_fn(unsigned long);
 61static void cmm_set_timer(void);
 
 62
 63static long cmm_alloc_pages(long nr, long *counter,
 64			    struct cmm_page_array **list)
 65{
 66	struct cmm_page_array *pa, *npa;
 67	unsigned long addr;
 68
 69	while (nr) {
 70		addr = __get_free_page(GFP_NOIO);
 71		if (!addr)
 72			break;
 73		spin_lock(&cmm_lock);
 74		pa = *list;
 75		if (!pa || pa->index >= CMM_NR_PAGES) {
 76			/* Need a new page for the page list. */
 77			spin_unlock(&cmm_lock);
 78			npa = (struct cmm_page_array *)
 79				__get_free_page(GFP_NOIO);
 80			if (!npa) {
 81				free_page(addr);
 82				break;
 83			}
 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);
 93		}
 94		diag10_range(addr >> PAGE_SHIFT, 1);
 95		pa->pages[pa->index++] = addr;
 96		(*counter)++;
 97		spin_unlock(&cmm_lock);
 98		nr--;
 99	}
100	return nr;
101}
102
103static long cmm_free_pages(long nr, long *counter, struct cmm_page_array **list)
104{
105	struct cmm_page_array *pa;
106	unsigned long addr;
107
108	spin_lock(&cmm_lock);
109	pa = *list;
110	while (nr) {
111		if (!pa || pa->index <= 0)
112			break;
113		addr = 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(addr);
120		(*counter)--;
121		nr--;
122	}
123	spin_unlock(&cmm_lock);
124	return nr;
125}
126
127static 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
142static struct notifier_block cmm_oom_nb = {
143	.notifier_call = cmm_oom_notify,
144};
145
146static int cmm_thread(void *dummy)
147{
148	int rc;
149
150	while (1) {
151		rc = wait_event_interruptible(cmm_thread_wait,
152			(!cmm_suspended && (cmm_pages != cmm_pages_target ||
153			 cmm_timed_pages != cmm_timed_pages_target)) ||
154			 kthread_should_stop());
155		if (kthread_should_stop() || rc == -ERESTARTSYS) {
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,
172				       &cmm_timed_page_list);
173		}
174		if (cmm_timed_pages > 0 && !timer_pending(&cmm_timer))
175			cmm_set_timer();
176	}
177	return 0;
178}
179
180static void cmm_kick_thread(void)
181{
182	wake_up(&cmm_thread_wait);
183}
184
185static void cmm_set_timer(void)
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	}
192	if (timer_pending(&cmm_timer)) {
193		if (mod_timer(&cmm_timer, jiffies + cmm_timeout_seconds*HZ))
194			return;
195	}
196	cmm_timer.function = cmm_timer_fn;
197	cmm_timer.data = 0;
198	cmm_timer.expires = jiffies + cmm_timeout_seconds*HZ;
199	add_timer(&cmm_timer);
200}
201
202static void cmm_timer_fn(unsigned long ignored)
203{
204	long nr;
205
206	nr = cmm_timed_pages_target - cmm_timeout_pages;
207	if (nr < 0)
208		cmm_timed_pages_target = 0;
209	else
210		cmm_timed_pages_target = nr;
211	cmm_kick_thread();
212	cmm_set_timer();
213}
214
215static void cmm_set_pages(long nr)
216{
217	cmm_pages_target = nr;
218	cmm_kick_thread();
219}
220
221static long cmm_get_pages(void)
222{
223	return cmm_pages;
224}
225
226static void cmm_add_timed_pages(long nr)
227{
228	cmm_timed_pages_target += nr;
229	cmm_kick_thread();
230}
231
232static long cmm_get_timed_pages(void)
233{
234	return cmm_timed_pages;
235}
236
237static void cmm_set_timeout(long nr, long seconds)
238{
239	cmm_timeout_pages = nr;
240	cmm_timeout_seconds = seconds;
241	cmm_set_timer();
242}
243
244static int cmm_skip_blanks(char *cp, char **endp)
245{
246	char *str;
247
248	for (str = cp; *str == ' ' || *str == '\t'; str++)
249		;
250	*endp = str;
251	return str != cp;
252}
253
254static struct ctl_table cmm_table[];
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
255
256static int cmm_pages_handler(ctl_table *ctl, int write, void __user *buffer,
257			     size_t *lenp, loff_t *ppos)
258{
259	char buf[16], *p;
260	long nr;
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		nr = simple_strtoul(p, &p, 0);
276		if (ctl == &cmm_table[0])
277			cmm_set_pages(nr);
278		else
279			cmm_add_timed_pages(nr);
280	} else {
281		if (ctl == &cmm_table[0])
282			nr = cmm_get_pages();
283		else
284			nr = cmm_get_timed_pages();
285		len = sprintf(buf, "%ld\n", nr);
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
296static int cmm_timeout_handler(ctl_table *ctl, int write,  void __user *buffer,
297			       size_t *lenp, loff_t *ppos)
298{
299	char buf[64], *p;
300	long nr, seconds;
301	int len;
302
303	if (!*lenp || (*ppos && !write)) {
304		*lenp = 0;
305		return 0;
306	}
307
308	if (write) {
309		len = *lenp;
310		if (copy_from_user(buf, buffer,
311				   len > sizeof(buf) ? sizeof(buf) : len))
312			return -EFAULT;
313		buf[sizeof(buf) - 1] = '\0';
314		cmm_skip_blanks(buf, &p);
315		nr = simple_strtoul(p, &p, 0);
316		cmm_skip_blanks(p, &p);
317		seconds = simple_strtoul(p, &p, 0);
318		cmm_set_timeout(nr, seconds);
 
319	} else {
320		len = sprintf(buf, "%ld %ld\n",
321			      cmm_timeout_pages, cmm_timeout_seconds);
322		if (len > *lenp)
323			len = *lenp;
324		if (copy_to_user(buffer, buf, len))
325			return -EFAULT;
 
326	}
327	*lenp = len;
328	*ppos += len;
329	return 0;
330}
331
332static struct ctl_table cmm_table[] = {
333	{
334		.procname	= "cmm_pages",
335		.mode		= 0644,
336		.proc_handler	= cmm_pages_handler,
337	},
338	{
339		.procname	= "cmm_timed_pages",
340		.mode		= 0644,
341		.proc_handler	= cmm_pages_handler,
342	},
343	{
344		.procname	= "cmm_timeout",
345		.mode		= 0644,
346		.proc_handler	= cmm_timeout_handler,
347	},
348	{ }
349};
350
351static struct ctl_table cmm_dir_table[] = {
352	{
353		.procname	= "vm",
354		.maxlen		= 0,
355		.mode		= 0555,
356		.child		= cmm_table,
357	},
358	{ }
359};
360
361#ifdef CONFIG_CMM_IUCV
362#define SMSG_PREFIX "CMM"
363static void cmm_smsg_target(const char *from, char *msg)
364{
365	long nr, seconds;
366
367	if (strlen(sender) > 0 && strcmp(from, sender) != 0)
368		return;
369	if (!cmm_skip_blanks(msg + strlen(SMSG_PREFIX), &msg))
370		return;
371	if (strncmp(msg, "SHRINK", 6) == 0) {
372		if (!cmm_skip_blanks(msg + 6, &msg))
373			return;
374		nr = simple_strtoul(msg, &msg, 0);
375		cmm_skip_blanks(msg, &msg);
376		if (*msg == '\0')
377			cmm_set_pages(nr);
378	} else if (strncmp(msg, "RELEASE", 7) == 0) {
379		if (!cmm_skip_blanks(msg + 7, &msg))
380			return;
381		nr = simple_strtoul(msg, &msg, 0);
382		cmm_skip_blanks(msg, &msg);
383		if (*msg == '\0')
384			cmm_add_timed_pages(nr);
385	} else if (strncmp(msg, "REUSE", 5) == 0) {
386		if (!cmm_skip_blanks(msg + 5, &msg))
387			return;
388		nr = simple_strtoul(msg, &msg, 0);
389		if (!cmm_skip_blanks(msg, &msg))
390			return;
391		seconds = simple_strtoul(msg, &msg, 0);
392		cmm_skip_blanks(msg, &msg);
393		if (*msg == '\0')
394			cmm_set_timeout(nr, seconds);
395	}
396}
397#endif
398
399static struct ctl_table_header *cmm_sysctl_header;
400
401static int cmm_suspend(void)
402{
403	cmm_suspended = 1;
404	cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list);
405	cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list);
406	return 0;
407}
408
409static int cmm_resume(void)
410{
411	cmm_suspended = 0;
412	cmm_kick_thread();
413	return 0;
414}
415
416static int cmm_power_event(struct notifier_block *this,
417			   unsigned long event, void *ptr)
418{
419	switch (event) {
420	case PM_POST_HIBERNATION:
421		return cmm_resume();
422	case PM_HIBERNATION_PREPARE:
423		return cmm_suspend();
424	default:
425		return NOTIFY_DONE;
426	}
427}
428
429static struct notifier_block cmm_power_notifier = {
430	.notifier_call = cmm_power_event,
431};
432
433static int __init cmm_init(void)
434{
435	int rc = -ENOMEM;
436
437	cmm_sysctl_header = register_sysctl_table(cmm_dir_table);
438	if (!cmm_sysctl_header)
439		goto out_sysctl;
440#ifdef CONFIG_CMM_IUCV
441	/* convert sender to uppercase characters */
442	if (sender) {
443		int len = strlen(sender);
444		while (len--)
445			sender[len] = toupper(sender[len]);
446	} else {
447		sender = cmm_default_sender;
448	}
449
450	rc = smsg_register_callback(SMSG_PREFIX, cmm_smsg_target);
451	if (rc < 0)
452		goto out_smsg;
453#endif
454	rc = register_oom_notifier(&cmm_oom_nb);
455	if (rc < 0)
456		goto out_oom_notify;
457	rc = register_pm_notifier(&cmm_power_notifier);
458	if (rc)
459		goto out_pm;
460	cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread");
461	rc = IS_ERR(cmm_thread_ptr) ? PTR_ERR(cmm_thread_ptr) : 0;
462	if (rc)
463		goto out_kthread;
464	return 0;
465
466out_kthread:
467	unregister_pm_notifier(&cmm_power_notifier);
468out_pm:
469	unregister_oom_notifier(&cmm_oom_nb);
470out_oom_notify:
471#ifdef CONFIG_CMM_IUCV
472	smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
473out_smsg:
474#endif
475	unregister_sysctl_table(cmm_sysctl_header);
476out_sysctl:
477	del_timer_sync(&cmm_timer);
478	return rc;
479}
480module_init(cmm_init);
481
482static void __exit cmm_exit(void)
483{
484	unregister_sysctl_table(cmm_sysctl_header);
485#ifdef CONFIG_CMM_IUCV
486	smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
487#endif
488	unregister_pm_notifier(&cmm_power_notifier);
489	unregister_oom_notifier(&cmm_oom_nb);
490	kthread_stop(cmm_thread_ptr);
491	del_timer_sync(&cmm_timer);
492	cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list);
493	cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list);
494}
495module_exit(cmm_exit);
496
497MODULE_LICENSE("GPL");