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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");
v5.4
  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/sysctl.h>
 18#include <linux/ctype.h>
 19#include <linux/swap.h>
 20#include <linux/kthread.h>
 21#include <linux/oom.h>
 22#include <linux/suspend.h>
 23#include <linux/uaccess.h>
 24
 25#include <asm/pgalloc.h>
 26#include <asm/diag.h>
 27
 28#ifdef CONFIG_CMM_IUCV
 29static char *cmm_default_sender = "VMRMSVM";
 30#endif
 31static char *sender;
 32module_param(sender, charp, 0400);
 33MODULE_PARM_DESC(sender,
 34		 "Guest name that may send SMSG messages (default VMRMSVM)");
 35
 36#include "../../../drivers/s390/net/smsgiucv.h"
 37
 38#define CMM_NR_PAGES ((PAGE_SIZE / sizeof(unsigned long)) - 2)
 39
 40struct cmm_page_array {
 41	struct cmm_page_array *next;
 42	unsigned long index;
 43	unsigned long pages[CMM_NR_PAGES];
 44};
 45
 46static long cmm_pages;
 47static long cmm_timed_pages;
 48static volatile long cmm_pages_target;
 49static volatile long cmm_timed_pages_target;
 50static long cmm_timeout_pages;
 51static long cmm_timeout_seconds;
 52static int cmm_suspended;
 53
 54static struct cmm_page_array *cmm_page_list;
 55static struct cmm_page_array *cmm_timed_page_list;
 56static DEFINE_SPINLOCK(cmm_lock);
 57
 58static struct task_struct *cmm_thread_ptr;
 59static DECLARE_WAIT_QUEUE_HEAD(cmm_thread_wait);
 60
 61static void cmm_timer_fn(struct timer_list *);
 62static void cmm_set_timer(void);
 63static DEFINE_TIMER(cmm_timer, cmm_timer_fn);
 64
 65static long cmm_alloc_pages(long nr, long *counter,
 66			    struct cmm_page_array **list)
 67{
 68	struct cmm_page_array *pa, *npa;
 69	unsigned long addr;
 70
 71	while (nr) {
 72		addr = __get_free_page(GFP_NOIO);
 73		if (!addr)
 74			break;
 75		spin_lock(&cmm_lock);
 76		pa = *list;
 77		if (!pa || pa->index >= CMM_NR_PAGES) {
 78			/* Need a new page for the page list. */
 79			spin_unlock(&cmm_lock);
 80			npa = (struct cmm_page_array *)
 81				__get_free_page(GFP_NOIO);
 82			if (!npa) {
 83				free_page(addr);
 84				break;
 85			}
 86			spin_lock(&cmm_lock);
 87			pa = *list;
 88			if (!pa || pa->index >= CMM_NR_PAGES) {
 89				npa->next = pa;
 90				npa->index = 0;
 91				pa = npa;
 92				*list = pa;
 93			} else
 94				free_page((unsigned long) npa);
 95		}
 96		diag10_range(addr >> PAGE_SHIFT, 1);
 97		pa->pages[pa->index++] = addr;
 98		(*counter)++;
 99		spin_unlock(&cmm_lock);
100		nr--;
101	}
102	return nr;
103}
104
105static long cmm_free_pages(long nr, long *counter, struct cmm_page_array **list)
106{
107	struct cmm_page_array *pa;
108	unsigned long addr;
109
110	spin_lock(&cmm_lock);
111	pa = *list;
112	while (nr) {
113		if (!pa || pa->index <= 0)
114			break;
115		addr = pa->pages[--pa->index];
116		if (pa->index == 0) {
117			pa = pa->next;
118			free_page((unsigned long) *list);
119			*list = pa;
120		}
121		free_page(addr);
122		(*counter)--;
123		nr--;
124	}
125	spin_unlock(&cmm_lock);
126	return nr;
127}
128
129static int cmm_oom_notify(struct notifier_block *self,
130			  unsigned long dummy, void *parm)
131{
132	unsigned long *freed = parm;
133	long nr = 256;
134
135	nr = cmm_free_pages(nr, &cmm_timed_pages, &cmm_timed_page_list);
136	if (nr > 0)
137		nr = cmm_free_pages(nr, &cmm_pages, &cmm_page_list);
138	cmm_pages_target = cmm_pages;
139	cmm_timed_pages_target = cmm_timed_pages;
140	*freed += 256 - nr;
141	return NOTIFY_OK;
142}
143
144static struct notifier_block cmm_oom_nb = {
145	.notifier_call = cmm_oom_notify,
146};
147
148static int cmm_thread(void *dummy)
149{
150	int rc;
151
152	while (1) {
153		rc = wait_event_interruptible(cmm_thread_wait,
154			(!cmm_suspended && (cmm_pages != cmm_pages_target ||
155			 cmm_timed_pages != cmm_timed_pages_target)) ||
156			 kthread_should_stop());
157		if (kthread_should_stop() || rc == -ERESTARTSYS) {
158			cmm_pages_target = cmm_pages;
159			cmm_timed_pages_target = cmm_timed_pages;
160			break;
161		}
162		if (cmm_pages_target > cmm_pages) {
163			if (cmm_alloc_pages(1, &cmm_pages, &cmm_page_list))
164				cmm_pages_target = cmm_pages;
165		} else if (cmm_pages_target < cmm_pages) {
166			cmm_free_pages(1, &cmm_pages, &cmm_page_list);
167		}
168		if (cmm_timed_pages_target > cmm_timed_pages) {
169			if (cmm_alloc_pages(1, &cmm_timed_pages,
170					   &cmm_timed_page_list))
171				cmm_timed_pages_target = cmm_timed_pages;
172		} else if (cmm_timed_pages_target < cmm_timed_pages) {
173			cmm_free_pages(1, &cmm_timed_pages,
174				       &cmm_timed_page_list);
175		}
176		if (cmm_timed_pages > 0 && !timer_pending(&cmm_timer))
177			cmm_set_timer();
178	}
179	return 0;
180}
181
182static void cmm_kick_thread(void)
183{
184	wake_up(&cmm_thread_wait);
185}
186
187static void cmm_set_timer(void)
188{
189	if (cmm_timed_pages_target <= 0 || cmm_timeout_seconds <= 0) {
190		if (timer_pending(&cmm_timer))
191			del_timer(&cmm_timer);
192		return;
193	}
194	mod_timer(&cmm_timer, jiffies + cmm_timeout_seconds * HZ);
195}
196
197static void cmm_timer_fn(struct timer_list *unused)
198{
199	long nr;
200
201	nr = cmm_timed_pages_target - cmm_timeout_pages;
202	if (nr < 0)
203		cmm_timed_pages_target = 0;
204	else
205		cmm_timed_pages_target = nr;
206	cmm_kick_thread();
207	cmm_set_timer();
208}
209
210static void cmm_set_pages(long nr)
211{
212	cmm_pages_target = nr;
213	cmm_kick_thread();
214}
215
216static long cmm_get_pages(void)
217{
218	return cmm_pages;
219}
220
221static void cmm_add_timed_pages(long nr)
222{
223	cmm_timed_pages_target += nr;
224	cmm_kick_thread();
225}
226
227static long cmm_get_timed_pages(void)
228{
229	return cmm_timed_pages;
230}
231
232static void cmm_set_timeout(long nr, long seconds)
233{
234	cmm_timeout_pages = nr;
235	cmm_timeout_seconds = seconds;
236	cmm_set_timer();
237}
238
239static int cmm_skip_blanks(char *cp, char **endp)
240{
241	char *str;
242
243	for (str = cp; *str == ' ' || *str == '\t'; str++)
244		;
245	*endp = str;
246	return str != cp;
247}
248
249static int cmm_pages_handler(struct ctl_table *ctl, int write,
250			     void __user *buffer, size_t *lenp, loff_t *ppos)
251{
252	long nr = cmm_get_pages();
253	struct ctl_table ctl_entry = {
254		.procname	= ctl->procname,
255		.data		= &nr,
256		.maxlen		= sizeof(long),
257	};
258	int rc;
259
260	rc = proc_doulongvec_minmax(&ctl_entry, write, buffer, lenp, ppos);
261	if (rc < 0 || !write)
262		return rc;
263
264	cmm_set_pages(nr);
265	return 0;
266}
267
268static int cmm_timed_pages_handler(struct ctl_table *ctl, int write,
269				   void __user *buffer, size_t *lenp,
270				   loff_t *ppos)
271{
272	long nr = cmm_get_timed_pages();
273	struct ctl_table ctl_entry = {
274		.procname	= ctl->procname,
275		.data		= &nr,
276		.maxlen		= sizeof(long),
277	};
278	int rc;
279
280	rc = proc_doulongvec_minmax(&ctl_entry, write, buffer, lenp, ppos);
281	if (rc < 0 || !write)
282		return rc;
283
284	cmm_add_timed_pages(nr);
285	return 0;
286}
287
288static int cmm_timeout_handler(struct ctl_table *ctl, int write,
289			       void __user *buffer, size_t *lenp, loff_t *ppos)
290{
291	char buf[64], *p;
292	long nr, seconds;
293	unsigned int len;
294
295	if (!*lenp || (*ppos && !write)) {
296		*lenp = 0;
297		return 0;
298	}
299
300	if (write) {
301		len = min(*lenp, sizeof(buf));
302		if (copy_from_user(buf, buffer, len))
303			return -EFAULT;
304		buf[len - 1] = '\0';
305		cmm_skip_blanks(buf, &p);
306		nr = simple_strtoul(p, &p, 0);
307		cmm_skip_blanks(p, &p);
308		seconds = simple_strtoul(p, &p, 0);
309		cmm_set_timeout(nr, seconds);
310		*ppos += *lenp;
311	} else {
312		len = sprintf(buf, "%ld %ld\n",
313			      cmm_timeout_pages, cmm_timeout_seconds);
314		if (len > *lenp)
315			len = *lenp;
316		if (copy_to_user(buffer, buf, len))
317			return -EFAULT;
318		*lenp = len;
319		*ppos += len;
320	}
321	return 0;
322}
323
324static struct ctl_table cmm_table[] = {
325	{
326		.procname	= "cmm_pages",
327		.mode		= 0644,
328		.proc_handler	= cmm_pages_handler,
329	},
330	{
331		.procname	= "cmm_timed_pages",
332		.mode		= 0644,
333		.proc_handler	= cmm_timed_pages_handler,
334	},
335	{
336		.procname	= "cmm_timeout",
337		.mode		= 0644,
338		.proc_handler	= cmm_timeout_handler,
339	},
340	{ }
341};
342
343static struct ctl_table cmm_dir_table[] = {
344	{
345		.procname	= "vm",
346		.maxlen		= 0,
347		.mode		= 0555,
348		.child		= cmm_table,
349	},
350	{ }
351};
352
353#ifdef CONFIG_CMM_IUCV
354#define SMSG_PREFIX "CMM"
355static void cmm_smsg_target(const char *from, char *msg)
356{
357	long nr, seconds;
358
359	if (strlen(sender) > 0 && strcmp(from, sender) != 0)
360		return;
361	if (!cmm_skip_blanks(msg + strlen(SMSG_PREFIX), &msg))
362		return;
363	if (strncmp(msg, "SHRINK", 6) == 0) {
364		if (!cmm_skip_blanks(msg + 6, &msg))
365			return;
366		nr = simple_strtoul(msg, &msg, 0);
367		cmm_skip_blanks(msg, &msg);
368		if (*msg == '\0')
369			cmm_set_pages(nr);
370	} else if (strncmp(msg, "RELEASE", 7) == 0) {
371		if (!cmm_skip_blanks(msg + 7, &msg))
372			return;
373		nr = simple_strtoul(msg, &msg, 0);
374		cmm_skip_blanks(msg, &msg);
375		if (*msg == '\0')
376			cmm_add_timed_pages(nr);
377	} else if (strncmp(msg, "REUSE", 5) == 0) {
378		if (!cmm_skip_blanks(msg + 5, &msg))
379			return;
380		nr = simple_strtoul(msg, &msg, 0);
381		if (!cmm_skip_blanks(msg, &msg))
382			return;
383		seconds = simple_strtoul(msg, &msg, 0);
384		cmm_skip_blanks(msg, &msg);
385		if (*msg == '\0')
386			cmm_set_timeout(nr, seconds);
387	}
388}
389#endif
390
391static struct ctl_table_header *cmm_sysctl_header;
392
393static int cmm_suspend(void)
394{
395	cmm_suspended = 1;
396	cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list);
397	cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list);
398	return 0;
399}
400
401static int cmm_resume(void)
402{
403	cmm_suspended = 0;
404	cmm_kick_thread();
405	return 0;
406}
407
408static int cmm_power_event(struct notifier_block *this,
409			   unsigned long event, void *ptr)
410{
411	switch (event) {
412	case PM_POST_HIBERNATION:
413		return cmm_resume();
414	case PM_HIBERNATION_PREPARE:
415		return cmm_suspend();
416	default:
417		return NOTIFY_DONE;
418	}
419}
420
421static struct notifier_block cmm_power_notifier = {
422	.notifier_call = cmm_power_event,
423};
424
425static int __init cmm_init(void)
426{
427	int rc = -ENOMEM;
428
429	cmm_sysctl_header = register_sysctl_table(cmm_dir_table);
430	if (!cmm_sysctl_header)
431		goto out_sysctl;
432#ifdef CONFIG_CMM_IUCV
433	/* convert sender to uppercase characters */
434	if (sender) {
435		int len = strlen(sender);
436		while (len--)
437			sender[len] = toupper(sender[len]);
438	} else {
439		sender = cmm_default_sender;
440	}
441
442	rc = smsg_register_callback(SMSG_PREFIX, cmm_smsg_target);
443	if (rc < 0)
444		goto out_smsg;
445#endif
446	rc = register_oom_notifier(&cmm_oom_nb);
447	if (rc < 0)
448		goto out_oom_notify;
449	rc = register_pm_notifier(&cmm_power_notifier);
450	if (rc)
451		goto out_pm;
452	cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread");
453	if (!IS_ERR(cmm_thread_ptr))
454		return 0;
455
456	rc = PTR_ERR(cmm_thread_ptr);
457	unregister_pm_notifier(&cmm_power_notifier);
458out_pm:
459	unregister_oom_notifier(&cmm_oom_nb);
460out_oom_notify:
461#ifdef CONFIG_CMM_IUCV
462	smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
463out_smsg:
464#endif
465	unregister_sysctl_table(cmm_sysctl_header);
466out_sysctl:
467	del_timer_sync(&cmm_timer);
468	return rc;
469}
470module_init(cmm_init);
471
472static void __exit cmm_exit(void)
473{
474	unregister_sysctl_table(cmm_sysctl_header);
475#ifdef CONFIG_CMM_IUCV
476	smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
477#endif
478	unregister_pm_notifier(&cmm_power_notifier);
479	unregister_oom_notifier(&cmm_oom_nb);
480	kthread_stop(cmm_thread_ptr);
481	del_timer_sync(&cmm_timer);
482	cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list);
483	cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list);
484}
485module_exit(cmm_exit);
486
487MODULE_LICENSE("GPL");