[mirror_ubuntu-hirsute-kernel.git] / arch / s390 / mm / cmm.c

/*
 *  arch/s390/mm/cmm.c
 *
 *  S390 version
 *    Copyright (C) 2003 IBM Deutschland Entwicklung GmbH, IBM Corporation
 *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
 *
 *  Collaborative memory management interface.
 */

#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/sysctl.h>
#include <linux/ctype.h>
#include <linux/swap.h>
#include <linux/kthread.h>
#include <linux/oom.h>
#include <linux/suspend.h>

#include <asm/pgalloc.h>
#include <asm/uaccess.h>
#include <asm/diag.h>

static char *sender = "VMRMSVM";
module_param(sender, charp, 0400);
MODULE_PARM_DESC(sender,
		 "Guest name that may send SMSG messages (default VMRMSVM)");

#include "../../../drivers/s390/net/smsgiucv.h"

#define CMM_NR_PAGES ((PAGE_SIZE / sizeof(unsigned long)) - 2)

struct cmm_page_array {
	struct cmm_page_array *next;
	unsigned long index;
	unsigned long pages[CMM_NR_PAGES];
};

static long cmm_pages;
static long cmm_timed_pages;
static volatile long cmm_pages_target;
static volatile long cmm_timed_pages_target;
static long cmm_timeout_pages;
static long cmm_timeout_seconds;
static int cmm_suspended;

static struct cmm_page_array *cmm_page_list;
static struct cmm_page_array *cmm_timed_page_list;
static DEFINE_SPINLOCK(cmm_lock);

static struct task_struct *cmm_thread_ptr;
static wait_queue_head_t cmm_thread_wait;
static struct timer_list cmm_timer;

static void cmm_timer_fn(unsigned long);
static void cmm_set_timer(void);

static long
cmm_alloc_pages(long nr, long *counter, struct cmm_page_array **list)
{
	struct cmm_page_array *pa, *npa;
	unsigned long addr;

	while (nr) {
		addr = __get_free_page(GFP_NOIO);
		if (!addr)
			break;
		spin_lock(&cmm_lock);
		pa = *list;
		if (!pa || pa->index >= CMM_NR_PAGES) {
			/* Need a new page for the page list. */
			spin_unlock(&cmm_lock);
			npa = (struct cmm_page_array *)
				__get_free_page(GFP_NOIO);
			if (!npa) {
				free_page(addr);
				break;
			}
			spin_lock(&cmm_lock);
			pa = *list;
			if (!pa || pa->index >= CMM_NR_PAGES) {
				npa->next = pa;
				npa->index = 0;
				pa = npa;
				*list = pa;
			} else
				free_page((unsigned long) npa);
		}
		diag10(addr);
		pa->pages[pa->index++] = addr;
		(*counter)++;
		spin_unlock(&cmm_lock);
		nr--;
	}
	return nr;
}

static long
cmm_free_pages(long nr, long *counter, struct cmm_page_array **list)
{
	struct cmm_page_array *pa;
	unsigned long addr;

	spin_lock(&cmm_lock);
	pa = *list;
	while (nr) {
		if (!pa || pa->index <= 0)
			break;
		addr = pa->pages[--pa->index];
		if (pa->index == 0) {
			pa = pa->next;
			free_page((unsigned long) *list);
			*list = pa;
		}
		free_page(addr);
		(*counter)--;
		nr--;
	}
	spin_unlock(&cmm_lock);
	return nr;
}

static int cmm_oom_notify(struct notifier_block *self,
			  unsigned long dummy, void *parm)
{
	unsigned long *freed = parm;
	long nr = 256;

	nr = cmm_free_pages(nr, &cmm_timed_pages, &cmm_timed_page_list);
	if (nr > 0)
		nr = cmm_free_pages(nr, &cmm_pages, &cmm_page_list);
	cmm_pages_target = cmm_pages;
	cmm_timed_pages_target = cmm_timed_pages;
	*freed += 256 - nr;
	return NOTIFY_OK;
}

static struct notifier_block cmm_oom_nb = {
	.notifier_call = cmm_oom_notify
};

static int
cmm_thread(void *dummy)
{
	int rc;

	while (1) {
		rc = wait_event_interruptible(cmm_thread_wait,
			(!cmm_suspended && (cmm_pages != cmm_pages_target ||
			 cmm_timed_pages != cmm_timed_pages_target)) ||
			 kthread_should_stop());
		if (kthread_should_stop() || rc == -ERESTARTSYS) {
			cmm_pages_target = cmm_pages;
			cmm_timed_pages_target = cmm_timed_pages;
			break;
		}
		if (cmm_pages_target > cmm_pages) {
			if (cmm_alloc_pages(1, &cmm_pages, &cmm_page_list))
				cmm_pages_target = cmm_pages;
		} else if (cmm_pages_target < cmm_pages) {
			cmm_free_pages(1, &cmm_pages, &cmm_page_list);
		}
		if (cmm_timed_pages_target > cmm_timed_pages) {
			if (cmm_alloc_pages(1, &cmm_timed_pages,
					   &cmm_timed_page_list))
				cmm_timed_pages_target = cmm_timed_pages;
		} else if (cmm_timed_pages_target < cmm_timed_pages) {
			cmm_free_pages(1, &cmm_timed_pages,
			       	       &cmm_timed_page_list);
		}
		if (cmm_timed_pages > 0 && !timer_pending(&cmm_timer))
			cmm_set_timer();
	}
	return 0;
}

static void
cmm_kick_thread(void)
{
	wake_up(&cmm_thread_wait);
}

static void
cmm_set_timer(void)
{
	if (cmm_timed_pages_target <= 0 || cmm_timeout_seconds <= 0) {
		if (timer_pending(&cmm_timer))
			del_timer(&cmm_timer);
		return;
	}
	if (timer_pending(&cmm_timer)) {
		if (mod_timer(&cmm_timer, jiffies + cmm_timeout_seconds*HZ))
			return;
	}
	cmm_timer.function = cmm_timer_fn;
	cmm_timer.data = 0;
	cmm_timer.expires = jiffies + cmm_timeout_seconds*HZ;
	add_timer(&cmm_timer);
}

static void
cmm_timer_fn(unsigned long ignored)
{
	long nr;

	nr = cmm_timed_pages_target - cmm_timeout_pages;
	if (nr < 0)
		cmm_timed_pages_target = 0;
	else
		cmm_timed_pages_target = nr;
	cmm_kick_thread();
	cmm_set_timer();
}

void
cmm_set_pages(long nr)
{
	cmm_pages_target = nr;
	cmm_kick_thread();
}

long
cmm_get_pages(void)
{
	return cmm_pages;
}

void
cmm_add_timed_pages(long nr)
{
	cmm_timed_pages_target += nr;
	cmm_kick_thread();
}

long
cmm_get_timed_pages(void)
{
	return cmm_timed_pages;
}

void
cmm_set_timeout(long nr, long seconds)
{
	cmm_timeout_pages = nr;
	cmm_timeout_seconds = seconds;
	cmm_set_timer();
}

static int
cmm_skip_blanks(char *cp, char **endp)
{
	char *str;

	for (str = cp; *str == ' ' || *str == '\t'; str++);
	*endp = str;
	return str != cp;
}

#ifdef CONFIG_CMM_PROC

static struct ctl_table cmm_table[];

static int
cmm_pages_handler(ctl_table *ctl, int write,
		  void __user *buffer, size_t *lenp, loff_t *ppos)
{
	char buf[16], *p;
	long nr;
	int len;

	if (!*lenp || (*ppos && !write)) {
		*lenp = 0;
		return 0;
	}

	if (write) {
		len = *lenp;
		if (copy_from_user(buf, buffer,
				   len > sizeof(buf) ? sizeof(buf) : len))
			return -EFAULT;
		buf[sizeof(buf) - 1] = '\0';
		cmm_skip_blanks(buf, &p);
		nr = simple_strtoul(p, &p, 0);
		if (ctl == &cmm_table[0])
			cmm_set_pages(nr);
		else
			cmm_add_timed_pages(nr);
	} else {
		if (ctl == &cmm_table[0])
			nr = cmm_get_pages();
		else
			nr = cmm_get_timed_pages();
		len = sprintf(buf, "%ld\n", nr);
		if (len > *lenp)
			len = *lenp;
		if (copy_to_user(buffer, buf, len))
			return -EFAULT;
	}
	*lenp = len;
	*ppos += len;
	return 0;
}

static int
cmm_timeout_handler(ctl_table *ctl, int write,
		    void __user *buffer, size_t *lenp, loff_t *ppos)
{
	char buf[64], *p;
	long nr, seconds;
	int len;

	if (!*lenp || (*ppos && !write)) {
		*lenp = 0;
		return 0;
	}

	if (write) {
		len = *lenp;
		if (copy_from_user(buf, buffer,
				   len > sizeof(buf) ? sizeof(buf) : len))
			return -EFAULT;
		buf[sizeof(buf) - 1] = '\0';
		cmm_skip_blanks(buf, &p);
		nr = simple_strtoul(p, &p, 0);
		cmm_skip_blanks(p, &p);
		seconds = simple_strtoul(p, &p, 0);
		cmm_set_timeout(nr, seconds);
	} else {
		len = sprintf(buf, "%ld %ld\n",
			      cmm_timeout_pages, cmm_timeout_seconds);
		if (len > *lenp)
			len = *lenp;
		if (copy_to_user(buffer, buf, len))
			return -EFAULT;
	}
	*lenp = len;
	*ppos += len;
	return 0;
}

static struct ctl_table cmm_table[] = {
	{
		.procname	= "cmm_pages",
		.mode		= 0644,
		.proc_handler	= cmm_pages_handler,
	},
	{
		.procname	= "cmm_timed_pages",
		.mode		= 0644,
		.proc_handler	= cmm_pages_handler,
	},
	{
		.procname	= "cmm_timeout",
		.mode		= 0644,
		.proc_handler	= cmm_timeout_handler,
	},
	{ }
};

static struct ctl_table cmm_dir_table[] = {
	{
		.procname	= "vm",
		.maxlen		= 0,
		.mode		= 0555,
		.child		= cmm_table,
	},
	{ }
};
#endif

#ifdef CONFIG_CMM_IUCV
#define SMSG_PREFIX "CMM"
static void
cmm_smsg_target(const char *from, char *msg)
{
	long nr, seconds;

	if (strlen(sender) > 0 && strcmp(from, sender) != 0)
		return;
	if (!cmm_skip_blanks(msg + strlen(SMSG_PREFIX), &msg))
		return;
	if (strncmp(msg, "SHRINK", 6) == 0) {
		if (!cmm_skip_blanks(msg + 6, &msg))
			return;
		nr = simple_strtoul(msg, &msg, 0);
		cmm_skip_blanks(msg, &msg);
		if (*msg == '\0')
			cmm_set_pages(nr);
	} else if (strncmp(msg, "RELEASE", 7) == 0) {
		if (!cmm_skip_blanks(msg + 7, &msg))
			return;
		nr = simple_strtoul(msg, &msg, 0);
		cmm_skip_blanks(msg, &msg);
		if (*msg == '\0')
			cmm_add_timed_pages(nr);
	} else if (strncmp(msg, "REUSE", 5) == 0) {
		if (!cmm_skip_blanks(msg + 5, &msg))
			return;
		nr = simple_strtoul(msg, &msg, 0);
		if (!cmm_skip_blanks(msg, &msg))
			return;
		seconds = simple_strtoul(msg, &msg, 0);
		cmm_skip_blanks(msg, &msg);
		if (*msg == '\0')
			cmm_set_timeout(nr, seconds);
	}
}
#endif

static struct ctl_table_header *cmm_sysctl_header;

static int cmm_suspend(void)
{
	cmm_suspended = 1;
	cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list);
	cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list);
	return 0;
}

static int cmm_resume(void)
{
	cmm_suspended = 0;
	cmm_kick_thread();
	return 0;
}

static int cmm_power_event(struct notifier_block *this,
			   unsigned long event, void *ptr)
{
	switch (event) {
	case PM_POST_HIBERNATION:
		return cmm_resume();
	case PM_HIBERNATION_PREPARE:
		return cmm_suspend();
	default:
		return NOTIFY_DONE;
	}
}

static struct notifier_block cmm_power_notifier = {
	.notifier_call = cmm_power_event,
};

static int
cmm_init (void)
{
	int rc = -ENOMEM;

#ifdef CONFIG_CMM_PROC
	cmm_sysctl_header = register_sysctl_table(cmm_dir_table);
	if (!cmm_sysctl_header)
		goto out_sysctl;
#endif
#ifdef CONFIG_CMM_IUCV
	rc = smsg_register_callback(SMSG_PREFIX, cmm_smsg_target);
	if (rc < 0)
		goto out_smsg;
#endif
	rc = register_oom_notifier(&cmm_oom_nb);
	if (rc < 0)
		goto out_oom_notify;
	rc = register_pm_notifier(&cmm_power_notifier);
	if (rc)
		goto out_pm;
	init_waitqueue_head(&cmm_thread_wait);
	init_timer(&cmm_timer);
	cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread");
	rc = IS_ERR(cmm_thread_ptr) ? PTR_ERR(cmm_thread_ptr) : 0;
	if (rc)
		goto out_kthread;
	return 0;

out_kthread:
	unregister_pm_notifier(&cmm_power_notifier);
out_pm:
	unregister_oom_notifier(&cmm_oom_nb);
out_oom_notify:
#ifdef CONFIG_CMM_IUCV
	smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
out_smsg:
#endif
#ifdef CONFIG_CMM_PROC
	unregister_sysctl_table(cmm_sysctl_header);
out_sysctl:
#endif
	return rc;
}

static void
cmm_exit(void)
{
	kthread_stop(cmm_thread_ptr);
	unregister_pm_notifier(&cmm_power_notifier);
	unregister_oom_notifier(&cmm_oom_nb);
	cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list);
	cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list);
#ifdef CONFIG_CMM_PROC
	unregister_sysctl_table(cmm_sysctl_header);
#endif
#ifdef CONFIG_CMM_IUCV
	smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
#endif
}

module_init(cmm_init);
module_exit(cmm_exit);

EXPORT_SYMBOL(cmm_set_pages);
EXPORT_SYMBOL(cmm_get_pages);
EXPORT_SYMBOL(cmm_add_timed_pages);
EXPORT_SYMBOL(cmm_get_timed_pages);
EXPORT_SYMBOL(cmm_set_timeout);

MODULE_LICENSE("GPL");
Commit	Line	Data
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
1da177e4 LT	11	#include <linux/errno.h>
	12	#include <linux/fs.h>
	13	#include <linux/init.h>
	14	#include <linux/module.h>
	15	#include <linux/sched.h>
	16	#include <linux/sysctl.h>
	17	#include <linux/ctype.h>
8bc719d3	18	#include <linux/swap.h>
e8216dee	19	#include <linux/kthread.h>
5a3135c2	20	#include <linux/oom.h>
52b169c8	21	#include <linux/suspend.h>
1da177e4 LT	22
	23	#include <asm/pgalloc.h>
	24	#include <asm/uaccess.h>
0a87c5cf	25	#include <asm/diag.h>
1da177e4	26
15439d74	27	static char *sender = "VMRMSVM";
447570cf	28	module_param(sender, charp, 0400);
15439d74 MS	29	MODULE_PARM_DESC(sender,
	30	"Guest name that may send SMSG messages (default VMRMSVM)");
	31
1da177e4 LT	32	#include "../../../drivers/s390/net/smsgiucv.h"
	33
	34	#define CMM_NR_PAGES ((PAGE_SIZE / sizeof(unsigned long)) - 2)
	35
	36	struct cmm_page_array {
	37	struct cmm_page_array *next;
	38	unsigned long index;
	39	unsigned long pages[CMM_NR_PAGES];
	40	};
	41
8bc719d3 MS	42	static long cmm_pages;
	43	static long cmm_timed_pages;
	44	static volatile long cmm_pages_target;
	45	static volatile long cmm_timed_pages_target;
	46	static long cmm_timeout_pages;
	47	static long cmm_timeout_seconds;
52b169c8	48	static int cmm_suspended;
1da177e4	49
8bc719d3 MS	50	static struct cmm_page_array *cmm_page_list;
	51	static struct cmm_page_array *cmm_timed_page_list;
	52	static DEFINE_SPINLOCK(cmm_lock);
1da177e4	53
e8216dee	54	static struct task_struct *cmm_thread_ptr;
1da177e4 LT	55	static wait_queue_head_t cmm_thread_wait;
	56	static struct timer_list cmm_timer;
	57
	58	static void cmm_timer_fn(unsigned long);
	59	static void cmm_set_timer(void);
	60
1da177e4	61	static long
8bc719d3	62	cmm_alloc_pages(long nr, long counter, struct cmm_page_array *list)
1da177e4	63	{
8bc719d3 MS	64	struct cmm_page_array pa, npa;
8bc719d3 MS	65	unsigned long addr;
1da177e4	66
8bc719d3 MS	67	while (nr) {
	68	addr = __get_free_page(GFP_NOIO);
	69	if (!addr)
1da177e4	70	break;
8bc719d3 MS	71	spin_lock(&cmm_lock);
8bc719d3 MS	72	pa = *list;
1da177e4 LT	73	if (!pa \|\| pa->index >= CMM_NR_PAGES) {
1da177e4 LT	74	/* Need a new page for the page list. */
8bc719d3 MS	75	spin_unlock(&cmm_lock);
8bc719d3 MS	76	npa = (struct cmm_page_array *)
1da177e4	77	__get_free_page(GFP_NOIO);
8bc719d3 MS	78	if (!npa) {
8bc719d3 MS	79	free_page(addr);
1da177e4 LT	80	break;
1da177e4 LT	81	}
8bc719d3 MS	82	spin_lock(&cmm_lock);
	83	pa = *list;
	84	if (!pa \|\| pa->index >= CMM_NR_PAGES) {
	85	npa->next = pa;
	86	npa->index = 0;
	87	pa = npa;
	88	*list = pa;
	89	} else
	90	free_page((unsigned long) npa);
1da177e4	91	}
8bc719d3 MS	92	diag10(addr);
8bc719d3 MS	93	pa->pages[pa->index++] = addr;
1da177e4	94	(*counter)++;
8bc719d3 MS	95	spin_unlock(&cmm_lock);
8bc719d3 MS	96	nr--;
1da177e4	97	}
8bc719d3	98	return nr;
1da177e4 LT	99	}
1da177e4 LT	100
8bc719d3 MS	101	static long
8bc719d3 MS	102	cmm_free_pages(long nr, long counter, struct cmm_page_array *list)
1da177e4 LT	103	{
1da177e4 LT	104	struct cmm_page_array *pa;
8bc719d3	105	unsigned long addr;
1da177e4	106
8bc719d3	107	spin_lock(&cmm_lock);
1da177e4	108	pa = *list;
8bc719d3	109	while (nr) {
1da177e4 LT	110	if (!pa \|\| pa->index <= 0)
1da177e4 LT	111	break;
8bc719d3	112	addr = pa->pages[--pa->index];
1da177e4 LT	113	if (pa->index == 0) {
	114	pa = pa->next;
	115	free_page((unsigned long) *list);
	116	*list = pa;
	117	}
8bc719d3	118	free_page(addr);
1da177e4	119	(*counter)--;
8bc719d3	120	nr--;
1da177e4	121	}
8bc719d3 MS	122	spin_unlock(&cmm_lock);
8bc719d3 MS	123	return nr;
1da177e4 LT	124	}
1da177e4 LT	125
8bc719d3 MS	126	static 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
	141	static struct notifier_block cmm_oom_nb = {
	142	.notifier_call = cmm_oom_notify
	143	};
	144
1da177e4 LT	145	static int
	146	cmm_thread(void *dummy)
	147	{
	148	int rc;
	149
1da177e4 LT	150	while (1) {
1da177e4 LT	151	rc = wait_event_interruptible(cmm_thread_wait,
52b169c8 MS	152	(!cmm_suspended && (cmm_pages != cmm_pages_target \|\|
	153	cmm_timed_pages != cmm_timed_pages_target)) \|\|
	154	kthread_should_stop());
e8216dee	155	if (kthread_should_stop() \|\| rc == -ERESTARTSYS) {
1da177e4 LT	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
1da177e4 LT	180	static void
	181	cmm_kick_thread(void)
	182	{
1da177e4 LT	183	wake_up(&cmm_thread_wait);
	184	}
	185
	186	static void
	187	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	if (timer_pending(&cmm_timer)) {
	195	if (mod_timer(&cmm_timer, jiffies + cmm_timeout_seconds*HZ))
	196	return;
	197	}
	198	cmm_timer.function = cmm_timer_fn;
	199	cmm_timer.data = 0;
	200	cmm_timer.expires = jiffies + cmm_timeout_seconds*HZ;
	201	add_timer(&cmm_timer);
	202	}
	203
	204	static void
	205	cmm_timer_fn(unsigned long ignored)
	206	{
8bc719d3	207	long nr;
1da177e4	208
8bc719d3 MS	209	nr = cmm_timed_pages_target - cmm_timeout_pages;
8bc719d3 MS	210	if (nr < 0)
1da177e4 LT	211	cmm_timed_pages_target = 0;
1da177e4 LT	212	else
8bc719d3	213	cmm_timed_pages_target = nr;
1da177e4 LT	214	cmm_kick_thread();
	215	cmm_set_timer();
	216	}
	217
	218	void
8bc719d3	219	cmm_set_pages(long nr)
1da177e4	220	{
8bc719d3	221	cmm_pages_target = nr;
1da177e4 LT	222	cmm_kick_thread();
	223	}
	224
	225	long
	226	cmm_get_pages(void)
	227	{
	228	return cmm_pages;
	229	}
	230
	231	void
8bc719d3	232	cmm_add_timed_pages(long nr)
1da177e4	233	{
8bc719d3	234	cmm_timed_pages_target += nr;
1da177e4 LT	235	cmm_kick_thread();
	236	}
	237
	238	long
	239	cmm_get_timed_pages(void)
	240	{
	241	return cmm_timed_pages;
	242	}
	243
	244	void
8bc719d3	245	cmm_set_timeout(long nr, long seconds)
1da177e4	246	{
8bc719d3	247	cmm_timeout_pages = nr;
1da177e4 LT	248	cmm_timeout_seconds = seconds;
	249	cmm_set_timer();
	250	}
	251
4d284cac	252	static int
1da177e4 LT	253	cmm_skip_blanks(char cp, char *endp)
	254	{
	255	char *str;
	256
	257	for (str = cp; str == ' ' \|\| str == '\t'; str++);
	258	*endp = str;
	259	return str != cp;
	260	}
	261
	262	#ifdef CONFIG_CMM_PROC
1da177e4 LT	263
	264	static struct ctl_table cmm_table[];
	265
	266	static int
8d65af78	267	cmm_pages_handler(ctl_table *ctl, int write,
aaedd944	268	void __user buffer, size_t lenp, loff_t *ppos)
1da177e4 LT	269	{
1da177e4 LT	270	char buf[16], *p;
8bc719d3	271	long nr;
1da177e4 LT	272	int len;
	273
	274	if (!lenp \|\| (ppos && !write)) {
	275	*lenp = 0;
	276	return 0;
	277	}
	278
	279	if (write) {
	280	len = *lenp;
	281	if (copy_from_user(buf, buffer,
	282	len > sizeof(buf) ? sizeof(buf) : len))
	283	return -EFAULT;
	284	buf[sizeof(buf) - 1] = '\0';
	285	cmm_skip_blanks(buf, &p);
8bc719d3	286	nr = simple_strtoul(p, &p, 0);
1da177e4	287	if (ctl == &cmm_table[0])
8bc719d3	288	cmm_set_pages(nr);
1da177e4	289	else
8bc719d3	290	cmm_add_timed_pages(nr);
1da177e4 LT	291	} else {
1da177e4 LT	292	if (ctl == &cmm_table[0])
8bc719d3	293	nr = cmm_get_pages();
1da177e4	294	else
8bc719d3 MS	295	nr = cmm_get_timed_pages();
8bc719d3 MS	296	len = sprintf(buf, "%ld\n", nr);
1da177e4 LT	297	if (len > *lenp)
	298	len = *lenp;
	299	if (copy_to_user(buffer, buf, len))
	300	return -EFAULT;
	301	}
	302	*lenp = len;
	303	*ppos += len;
	304	return 0;
	305	}
	306
	307	static int
8d65af78	308	cmm_timeout_handler(ctl_table *ctl, int write,
aaedd944	309	void __user buffer, size_t lenp, loff_t *ppos)
1da177e4 LT	310	{
1da177e4 LT	311	char buf[64], *p;
8bc719d3	312	long nr, seconds;
1da177e4 LT	313	int len;
	314
	315	if (!lenp \|\| (ppos && !write)) {
	316	*lenp = 0;
	317	return 0;
	318	}
	319
	320	if (write) {
	321	len = *lenp;
	322	if (copy_from_user(buf, buffer,
	323	len > sizeof(buf) ? sizeof(buf) : len))
	324	return -EFAULT;
	325	buf[sizeof(buf) - 1] = '\0';
	326	cmm_skip_blanks(buf, &p);
8bc719d3	327	nr = simple_strtoul(p, &p, 0);
1da177e4	328	cmm_skip_blanks(p, &p);
7d5d688f	329	seconds = simple_strtoul(p, &p, 0);
8bc719d3	330	cmm_set_timeout(nr, seconds);
1da177e4 LT	331	} else {
	332	len = sprintf(buf, "%ld %ld\n",
	333	cmm_timeout_pages, cmm_timeout_seconds);
	334	if (len > *lenp)
	335	len = *lenp;
	336	if (copy_to_user(buffer, buf, len))
	337	return -EFAULT;
	338	}
	339	*lenp = len;
	340	*ppos += len;
	341	return 0;
	342	}
	343
	344	static struct ctl_table cmm_table[] = {
	345	{
1da177e4	346	.procname = "cmm_pages",
5e8b1c40	347	.mode = 0644,
6d456111	348	.proc_handler = cmm_pages_handler,
1da177e4 LT	349	},
1da177e4 LT	350	{
1da177e4	351	.procname = "cmm_timed_pages",
5e8b1c40	352	.mode = 0644,
6d456111	353	.proc_handler = cmm_pages_handler,
1da177e4 LT	354	},
1da177e4 LT	355	{
1da177e4	356	.procname = "cmm_timeout",
5e8b1c40	357	.mode = 0644,
6d456111	358	.proc_handler = cmm_timeout_handler,
1da177e4	359	},
b05fd35d	360	{ }
1da177e4 LT	361	};
	362
	363	static struct ctl_table cmm_dir_table[] = {
	364	{
1da177e4 LT	365	.procname = "vm",
	366	.maxlen = 0,
	367	.mode = 0555,
	368	.child = cmm_table,
	369	},
b05fd35d	370	{ }
1da177e4 LT	371	};
	372	#endif
	373
	374	#ifdef CONFIG_CMM_IUCV
	375	#define SMSG_PREFIX "CMM"
	376	static void
09003ed9	377	cmm_smsg_target(const char from, char msg)
1da177e4	378	{
8bc719d3	379	long nr, seconds;
1da177e4	380
15439d74 MS	381	if (strlen(sender) > 0 && strcmp(from, sender) != 0)
15439d74 MS	382	return;
1da177e4 LT	383	if (!cmm_skip_blanks(msg + strlen(SMSG_PREFIX), &msg))
	384	return;
	385	if (strncmp(msg, "SHRINK", 6) == 0) {
	386	if (!cmm_skip_blanks(msg + 6, &msg))
	387	return;
8bc719d3	388	nr = simple_strtoul(msg, &msg, 0);
1da177e4 LT	389	cmm_skip_blanks(msg, &msg);
1da177e4 LT	390	if (*msg == '\0')
8bc719d3	391	cmm_set_pages(nr);
1da177e4 LT	392	} else if (strncmp(msg, "RELEASE", 7) == 0) {
	393	if (!cmm_skip_blanks(msg + 7, &msg))
	394	return;
8bc719d3	395	nr = simple_strtoul(msg, &msg, 0);
1da177e4 LT	396	cmm_skip_blanks(msg, &msg);
1da177e4 LT	397	if (*msg == '\0')
8bc719d3	398	cmm_add_timed_pages(nr);
1da177e4 LT	399	} else if (strncmp(msg, "REUSE", 5) == 0) {
	400	if (!cmm_skip_blanks(msg + 5, &msg))
	401	return;
8bc719d3	402	nr = simple_strtoul(msg, &msg, 0);
1da177e4 LT	403	if (!cmm_skip_blanks(msg, &msg))
1da177e4 LT	404	return;
7d5d688f	405	seconds = simple_strtoul(msg, &msg, 0);
1da177e4 LT	406	cmm_skip_blanks(msg, &msg);
1da177e4 LT	407	if (*msg == '\0')
8bc719d3	408	cmm_set_timeout(nr, seconds);
1da177e4 LT	409	}
	410	}
	411	#endif
	412
2b67fc46	413	static struct ctl_table_header *cmm_sysctl_header;
1da177e4	414
52b169c8 MS	415	static int cmm_suspend(void)
	416	{
	417	cmm_suspended = 1;
	418	cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list);
	419	cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list);
	420	return 0;
	421	}
	422
	423	static int cmm_resume(void)
	424	{
	425	cmm_suspended = 0;
	426	cmm_kick_thread();
	427	return 0;
	428	}
	429
	430	static int cmm_power_event(struct notifier_block *this,
	431	unsigned long event, void *ptr)
	432	{
	433	switch (event) {
	434	case PM_POST_HIBERNATION:
	435	return cmm_resume();
	436	case PM_HIBERNATION_PREPARE:
	437	return cmm_suspend();
	438	default:
	439	return NOTIFY_DONE;
	440	}
	441	}
	442
	443	static struct notifier_block cmm_power_notifier = {
	444	.notifier_call = cmm_power_event,
	445	};
	446
1da177e4 LT	447	static int
	448	cmm_init (void)
	449	{
e8216dee HC	450	int rc = -ENOMEM;
e8216dee HC	451
1da177e4	452	#ifdef CONFIG_CMM_PROC
0b4d4147	453	cmm_sysctl_header = register_sysctl_table(cmm_dir_table);
e8216dee	454	if (!cmm_sysctl_header)
52b169c8	455	goto out_sysctl;
1da177e4 LT	456	#endif
1da177e4 LT	457	#ifdef CONFIG_CMM_IUCV
e8216dee HC	458	rc = smsg_register_callback(SMSG_PREFIX, cmm_smsg_target);
	459	if (rc < 0)
	460	goto out_smsg;
1da177e4	461	#endif
e8216dee HC	462	rc = register_oom_notifier(&cmm_oom_nb);
	463	if (rc < 0)
	464	goto out_oom_notify;
52b169c8 MS	465	rc = register_pm_notifier(&cmm_power_notifier);
	466	if (rc)
	467	goto out_pm;
1da177e4 LT	468	init_waitqueue_head(&cmm_thread_wait);
1da177e4 LT	469	init_timer(&cmm_timer);
e8216dee HC	470	cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread");
e8216dee HC	471	rc = IS_ERR(cmm_thread_ptr) ? PTR_ERR(cmm_thread_ptr) : 0;
52b169c8 MS	472	if (rc)
	473	goto out_kthread;
	474	return 0;
e8216dee	475
52b169c8 MS	476	out_kthread:
	477	unregister_pm_notifier(&cmm_power_notifier);
	478	out_pm:
	479	unregister_oom_notifier(&cmm_oom_nb);
e8216dee HC	480	out_oom_notify:
	481	#ifdef CONFIG_CMM_IUCV
	482	smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
	483	out_smsg:
	484	#endif
	485	#ifdef CONFIG_CMM_PROC
	486	unregister_sysctl_table(cmm_sysctl_header);
52b169c8	487	out_sysctl:
e8216dee	488	#endif
e8216dee	489	return rc;
1da177e4 LT	490	}
	491
	492	static void
	493	cmm_exit(void)
	494	{
e8216dee	495	kthread_stop(cmm_thread_ptr);
52b169c8	496	unregister_pm_notifier(&cmm_power_notifier);
8bc719d3	497	unregister_oom_notifier(&cmm_oom_nb);
1da177e4 LT	498	cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list);
	499	cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list);
	500	#ifdef CONFIG_CMM_PROC
	501	unregister_sysctl_table(cmm_sysctl_header);
	502	#endif
	503	#ifdef CONFIG_CMM_IUCV
	504	smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
	505	#endif
	506	}
	507
	508	module_init(cmm_init);
	509	module_exit(cmm_exit);
	510
	511	EXPORT_SYMBOL(cmm_set_pages);
	512	EXPORT_SYMBOL(cmm_get_pages);
	513	EXPORT_SYMBOL(cmm_add_timed_pages);
	514	EXPORT_SYMBOL(cmm_get_timed_pages);
	515	EXPORT_SYMBOL(cmm_set_timeout);
	516
	517	MODULE_LICENSE("GPL");