[deliverable/linux.git] / arch / s390 / mm / cmm.c

/*
 *  Collaborative memory management interface.
 *
 *    Copyright IBM Corp 2003, 2010
 *    Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
 *
 */

#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/gfp.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 <linux/uaccess.h>

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

#ifdef CONFIG_CMM_IUCV
static char *cmm_default_sender = "VMRMSVM";
#endif
static char *sender;
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 DECLARE_WAIT_QUEUE_HEAD(cmm_thread_wait);
static DEFINE_TIMER(cmm_timer, NULL, 0, 0);

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_range(addr >> PAGE_SHIFT, 1);
		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();
}

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

static long cmm_get_pages(void)
{
	return cmm_pages;
}

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

static long cmm_get_timed_pages(void)
{
	return cmm_timed_pages;
}

static 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;
}

static struct ctl_table cmm_table[];

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

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

#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 __init cmm_init(void)
{
	int rc = -ENOMEM;

	cmm_sysctl_header = register_sysctl_table(cmm_dir_table);
	if (!cmm_sysctl_header)
		goto out_sysctl;
#ifdef CONFIG_CMM_IUCV
	/* convert sender to uppercase characters */
	if (sender) {
		int len = strlen(sender);
		while (len--)
			sender[len] = toupper(sender[len]);
	} else {
		sender = cmm_default_sender;
	}

	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;
	cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread");
	if (!IS_ERR(cmm_thread_ptr))
		return 0;

	rc = PTR_ERR(cmm_thread_ptr);
	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
	unregister_sysctl_table(cmm_sysctl_header);
out_sysctl:
	del_timer_sync(&cmm_timer);
	return rc;
}
module_init(cmm_init);

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

MODULE_LICENSE("GPL");
Commit	Line	Data
1da177e4	1	/*
db705e83	2	* Collaborative memory management interface.
1da177e4	3	*
a53c8fab	4	* Copyright IBM Corp 2003, 2010
db705e83	5	* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
1da177e4	6	*
1da177e4 LT	7	*/
1da177e4 LT	8
1da177e4 LT	9	#include <linux/errno.h>
	10	#include <linux/fs.h>
	11	#include <linux/init.h>
	12	#include <linux/module.h>
5a0e3ad6	13	#include <linux/gfp.h>
1da177e4 LT	14	#include <linux/sched.h>
	15	#include <linux/sysctl.h>
	16	#include <linux/ctype.h>
8bc719d3	17	#include <linux/swap.h>
e8216dee	18	#include <linux/kthread.h>
5a3135c2	19	#include <linux/oom.h>
52b169c8	20	#include <linux/suspend.h>
db705e83	21	#include <linux/uaccess.h>
1da177e4 LT	22
1da177e4 LT	23	#include <asm/pgalloc.h>
0a87c5cf	24	#include <asm/diag.h>
1da177e4	25
a20852d2 HC	26	#ifdef CONFIG_CMM_IUCV
	27	static char *cmm_default_sender = "VMRMSVM";
	28	#endif
	29	static char *sender;
447570cf	30	module_param(sender, charp, 0400);
15439d74 MS	31	MODULE_PARM_DESC(sender,
	32	"Guest name that may send SMSG messages (default VMRMSVM)");
	33
1da177e4 LT	34	#include "../../../drivers/s390/net/smsgiucv.h"
	35
	36	#define CMM_NR_PAGES ((PAGE_SIZE / sizeof(unsigned long)) - 2)
	37
	38	struct cmm_page_array {
	39	struct cmm_page_array *next;
	40	unsigned long index;
	41	unsigned long pages[CMM_NR_PAGES];
	42	};
	43
8bc719d3 MS	44	static long cmm_pages;
	45	static long cmm_timed_pages;
	46	static volatile long cmm_pages_target;
	47	static volatile long cmm_timed_pages_target;
	48	static long cmm_timeout_pages;
	49	static long cmm_timeout_seconds;
52b169c8	50	static int cmm_suspended;
1da177e4	51
8bc719d3 MS	52	static struct cmm_page_array *cmm_page_list;
	53	static struct cmm_page_array *cmm_timed_page_list;
	54	static DEFINE_SPINLOCK(cmm_lock);
1da177e4	55
e8216dee	56	static struct task_struct *cmm_thread_ptr;
1ef6acf5 HC	57	static DECLARE_WAIT_QUEUE_HEAD(cmm_thread_wait);
1ef6acf5 HC	58	static DEFINE_TIMER(cmm_timer, NULL, 0, 0);
1da177e4 LT	59
	60	static void cmm_timer_fn(unsigned long);
	61	static void cmm_set_timer(void);
	62
db705e83 HC	63	static long cmm_alloc_pages(long nr, long *counter,
db705e83 HC	64	struct cmm_page_array **list)
1da177e4	65	{
8bc719d3 MS	66	struct cmm_page_array pa, npa;
8bc719d3 MS	67	unsigned long addr;
1da177e4	68
8bc719d3 MS	69	while (nr) {
	70	addr = __get_free_page(GFP_NOIO);
	71	if (!addr)
1da177e4	72	break;
8bc719d3 MS	73	spin_lock(&cmm_lock);
8bc719d3 MS	74	pa = *list;
1da177e4 LT	75	if (!pa \|\| pa->index >= CMM_NR_PAGES) {
1da177e4 LT	76	/* Need a new page for the page list. */
8bc719d3 MS	77	spin_unlock(&cmm_lock);
8bc719d3 MS	78	npa = (struct cmm_page_array *)
1da177e4	79	__get_free_page(GFP_NOIO);
8bc719d3 MS	80	if (!npa) {
8bc719d3 MS	81	free_page(addr);
1da177e4 LT	82	break;
1da177e4 LT	83	}
8bc719d3 MS	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);
1da177e4	93	}
83ace270	94	diag10_range(addr >> PAGE_SHIFT, 1);
8bc719d3	95	pa->pages[pa->index++] = addr;
1da177e4	96	(*counter)++;
8bc719d3 MS	97	spin_unlock(&cmm_lock);
8bc719d3 MS	98	nr--;
1da177e4	99	}
8bc719d3	100	return nr;
1da177e4 LT	101	}
1da177e4 LT	102
db705e83	103	static long cmm_free_pages(long nr, long counter, struct cmm_page_array *list)
1da177e4 LT	104	{
1da177e4 LT	105	struct cmm_page_array *pa;
8bc719d3	106	unsigned long addr;
1da177e4	107
8bc719d3	108	spin_lock(&cmm_lock);
1da177e4	109	pa = *list;
8bc719d3	110	while (nr) {
1da177e4 LT	111	if (!pa \|\| pa->index <= 0)
1da177e4 LT	112	break;
8bc719d3	113	addr = pa->pages[--pa->index];
1da177e4 LT	114	if (pa->index == 0) {
	115	pa = pa->next;
	116	free_page((unsigned long) *list);
	117	*list = pa;
	118	}
8bc719d3	119	free_page(addr);
1da177e4	120	(*counter)--;
8bc719d3	121	nr--;
1da177e4	122	}
8bc719d3 MS	123	spin_unlock(&cmm_lock);
8bc719d3 MS	124	return nr;
1da177e4 LT	125	}
1da177e4 LT	126
8bc719d3 MS	127	static 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
	142	static struct notifier_block cmm_oom_nb = {
db705e83	143	.notifier_call = cmm_oom_notify,
8bc719d3 MS	144	};
8bc719d3 MS	145
db705e83	146	static int cmm_thread(void *dummy)
1da177e4 LT	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,
db705e83	172	&cmm_timed_page_list);
1da177e4 LT	173	}
	174	if (cmm_timed_pages > 0 && !timer_pending(&cmm_timer))
	175	cmm_set_timer();
	176	}
	177	return 0;
	178	}
	179
db705e83	180	static void cmm_kick_thread(void)
1da177e4	181	{
1da177e4 LT	182	wake_up(&cmm_thread_wait);
	183	}
	184
db705e83	185	static void cmm_set_timer(void)
1da177e4 LT	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
db705e83	202	static void cmm_timer_fn(unsigned long ignored)
1da177e4	203	{
8bc719d3	204	long nr;
1da177e4	205
8bc719d3 MS	206	nr = cmm_timed_pages_target - cmm_timeout_pages;
8bc719d3 MS	207	if (nr < 0)
1da177e4 LT	208	cmm_timed_pages_target = 0;
1da177e4 LT	209	else
8bc719d3	210	cmm_timed_pages_target = nr;
1da177e4 LT	211	cmm_kick_thread();
	212	cmm_set_timer();
	213	}
	214
db705e83	215	static void cmm_set_pages(long nr)
1da177e4	216	{
8bc719d3	217	cmm_pages_target = nr;
1da177e4 LT	218	cmm_kick_thread();
	219	}
	220
db705e83	221	static long cmm_get_pages(void)
1da177e4 LT	222	{
	223	return cmm_pages;
	224	}
	225
db705e83	226	static void cmm_add_timed_pages(long nr)
1da177e4	227	{
8bc719d3	228	cmm_timed_pages_target += nr;
1da177e4 LT	229	cmm_kick_thread();
	230	}
	231
db705e83	232	static long cmm_get_timed_pages(void)
1da177e4 LT	233	{
	234	return cmm_timed_pages;
	235	}
	236
db705e83	237	static void cmm_set_timeout(long nr, long seconds)
1da177e4	238	{
8bc719d3	239	cmm_timeout_pages = nr;
1da177e4 LT	240	cmm_timeout_seconds = seconds;
	241	cmm_set_timer();
	242	}
	243
db705e83	244	static int cmm_skip_blanks(char cp, char *endp)
1da177e4 LT	245	{
	246	char *str;
	247
db705e83 HC	248	for (str = cp; str == ' ' \|\| str == '\t'; str++)
db705e83 HC	249	;
1da177e4 LT	250	*endp = str;
	251	return str != cp;
	252	}
	253
1da177e4 LT	254	static struct ctl_table cmm_table[];
1da177e4 LT	255
302bfe20 JP	256	static int cmm_pages_handler(struct ctl_table *ctl, int write,
302bfe20 JP	257	void __user buffer, size_t lenp, loff_t *ppos)
1da177e4 LT	258	{
1da177e4 LT	259	char buf[16], *p;
041058a1	260	unsigned int len;
8bc719d3	261	long nr;
1da177e4 LT	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);
8bc719d3	275	nr = simple_strtoul(p, &p, 0);
1da177e4	276	if (ctl == &cmm_table[0])
8bc719d3	277	cmm_set_pages(nr);
1da177e4	278	else
8bc719d3	279	cmm_add_timed_pages(nr);
1da177e4 LT	280	} else {
1da177e4 LT	281	if (ctl == &cmm_table[0])
8bc719d3	282	nr = cmm_get_pages();
1da177e4	283	else
8bc719d3 MS	284	nr = cmm_get_timed_pages();
8bc719d3 MS	285	len = sprintf(buf, "%ld\n", nr);
1da177e4 LT	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
302bfe20 JP	296	static int cmm_timeout_handler(struct ctl_table *ctl, int write,
302bfe20 JP	297	void __user buffer, size_t lenp, loff_t *ppos)
1da177e4 LT	298	{
1da177e4 LT	299	char buf[64], *p;
8bc719d3	300	long nr, seconds;
041058a1	301	unsigned int len;
1da177e4 LT	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);
8bc719d3	315	nr = simple_strtoul(p, &p, 0);
1da177e4	316	cmm_skip_blanks(p, &p);
7d5d688f	317	seconds = simple_strtoul(p, &p, 0);
8bc719d3	318	cmm_set_timeout(nr, seconds);
1da177e4 LT	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
	332	static struct ctl_table cmm_table[] = {
	333	{
1da177e4	334	.procname = "cmm_pages",
5e8b1c40	335	.mode = 0644,
6d456111	336	.proc_handler = cmm_pages_handler,
1da177e4 LT	337	},
1da177e4 LT	338	{
1da177e4	339	.procname = "cmm_timed_pages",
5e8b1c40	340	.mode = 0644,
6d456111	341	.proc_handler = cmm_pages_handler,
1da177e4 LT	342	},
1da177e4 LT	343	{
1da177e4	344	.procname = "cmm_timeout",
5e8b1c40	345	.mode = 0644,
6d456111	346	.proc_handler = cmm_timeout_handler,
1da177e4	347	},
b05fd35d	348	{ }
1da177e4 LT	349	};
	350
	351	static struct ctl_table cmm_dir_table[] = {
	352	{
1da177e4 LT	353	.procname = "vm",
	354	.maxlen = 0,
	355	.mode = 0555,
	356	.child = cmm_table,
	357	},
b05fd35d	358	{ }
1da177e4	359	};
1da177e4 LT	360
	361	#ifdef CONFIG_CMM_IUCV
	362	#define SMSG_PREFIX "CMM"
db705e83	363	static void cmm_smsg_target(const char from, char msg)
1da177e4	364	{
8bc719d3	365	long nr, seconds;
1da177e4	366
15439d74 MS	367	if (strlen(sender) > 0 && strcmp(from, sender) != 0)
15439d74 MS	368	return;
1da177e4 LT	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;
8bc719d3	374	nr = simple_strtoul(msg, &msg, 0);
1da177e4 LT	375	cmm_skip_blanks(msg, &msg);
1da177e4 LT	376	if (*msg == '\0')
8bc719d3	377	cmm_set_pages(nr);
1da177e4 LT	378	} else if (strncmp(msg, "RELEASE", 7) == 0) {
	379	if (!cmm_skip_blanks(msg + 7, &msg))
	380	return;
8bc719d3	381	nr = simple_strtoul(msg, &msg, 0);
1da177e4 LT	382	cmm_skip_blanks(msg, &msg);
1da177e4 LT	383	if (*msg == '\0')
8bc719d3	384	cmm_add_timed_pages(nr);
1da177e4 LT	385	} else if (strncmp(msg, "REUSE", 5) == 0) {
	386	if (!cmm_skip_blanks(msg + 5, &msg))
	387	return;
8bc719d3	388	nr = simple_strtoul(msg, &msg, 0);
1da177e4 LT	389	if (!cmm_skip_blanks(msg, &msg))
1da177e4 LT	390	return;
7d5d688f	391	seconds = simple_strtoul(msg, &msg, 0);
1da177e4 LT	392	cmm_skip_blanks(msg, &msg);
1da177e4 LT	393	if (*msg == '\0')
8bc719d3	394	cmm_set_timeout(nr, seconds);
1da177e4 LT	395	}
	396	}
	397	#endif
	398
2b67fc46	399	static struct ctl_table_header *cmm_sysctl_header;
1da177e4	400
52b169c8 MS	401	static 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
	409	static int cmm_resume(void)
	410	{
	411	cmm_suspended = 0;
	412	cmm_kick_thread();
	413	return 0;
	414	}
	415
	416	static 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
	429	static struct notifier_block cmm_power_notifier = {
	430	.notifier_call = cmm_power_event,
	431	};
	432
2e85ba51	433	static int __init cmm_init(void)
1da177e4	434	{
e8216dee HC	435	int rc = -ENOMEM;
e8216dee HC	436
0b4d4147	437	cmm_sysctl_header = register_sysctl_table(cmm_dir_table);
e8216dee	438	if (!cmm_sysctl_header)
52b169c8	439	goto out_sysctl;
1da177e4	440	#ifdef CONFIG_CMM_IUCV
41b42876 HB	441	/* convert sender to uppercase characters */
	442	if (sender) {
	443	int len = strlen(sender);
	444	while (len--)
	445	sender[len] = toupper(sender[len]);
a20852d2 HC	446	} else {
a20852d2 HC	447	sender = cmm_default_sender;
41b42876 HB	448	}
41b42876 HB	449
e8216dee HC	450	rc = smsg_register_callback(SMSG_PREFIX, cmm_smsg_target);
	451	if (rc < 0)
	452	goto out_smsg;
1da177e4	453	#endif
e8216dee HC	454	rc = register_oom_notifier(&cmm_oom_nb);
	455	if (rc < 0)
	456	goto out_oom_notify;
52b169c8 MS	457	rc = register_pm_notifier(&cmm_power_notifier);
	458	if (rc)
	459	goto out_pm;
e8216dee	460	cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread");
8fe853f3 AG	461	if (!IS_ERR(cmm_thread_ptr))
8fe853f3 AG	462	return 0;
e8216dee	463
8fe853f3	464	rc = PTR_ERR(cmm_thread_ptr);
52b169c8 MS	465	unregister_pm_notifier(&cmm_power_notifier);
	466	out_pm:
	467	unregister_oom_notifier(&cmm_oom_nb);
e8216dee HC	468	out_oom_notify:
	469	#ifdef CONFIG_CMM_IUCV
	470	smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
	471	out_smsg:
	472	#endif
e8216dee	473	unregister_sysctl_table(cmm_sysctl_header);
52b169c8	474	out_sysctl:
1ef6acf5	475	del_timer_sync(&cmm_timer);
e8216dee	476	return rc;
1da177e4	477	}
db705e83	478	module_init(cmm_init);
1da177e4	479
2e85ba51	480	static void __exit cmm_exit(void)
1da177e4	481	{
1da177e4	482	unregister_sysctl_table(cmm_sysctl_header);
1da177e4 LT	483	#ifdef CONFIG_CMM_IUCV
	484	smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
	485	#endif
1ef6acf5 HC	486	unregister_pm_notifier(&cmm_power_notifier);
	487	unregister_oom_notifier(&cmm_oom_nb);
	488	kthread_stop(cmm_thread_ptr);
	489	del_timer_sync(&cmm_timer);
	490	cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list);
	491	cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list);
1da177e4	492	}
1da177e4 LT	493	module_exit(cmm_exit);
1da177e4 LT	494
1da177e4	495	MODULE_LICENSE("GPL");