[mirror_ubuntu-artful-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 <asm/pgalloc.h>
#include <asm/uaccess.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 struct cmm_page_array *cmm_page_list;
static struct cmm_page_array *cmm_timed_page_list;
static DEFINE_SPINLOCK(cmm_lock);

static unsigned long cmm_thread_active;
static struct work_struct cmm_thread_starter;
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;

	daemonize("cmmthread");
	while (1) {
		rc = wait_event_interruptible(cmm_thread_wait,
			(cmm_pages != cmm_pages_target ||
			 cmm_timed_pages != cmm_timed_pages_target));
		if (rc == -ERESTARTSYS) {
			/* Got kill signal. End thread. */
			clear_bit(0, &cmm_thread_active);
			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_start_thread(void)
{
	kernel_thread(cmm_thread, NULL, 0);
}

static void
cmm_kick_thread(void)
{
	if (!test_and_set_bit(0, &cmm_thread_active))
		schedule_work(&cmm_thread_starter);
	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 inline 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
/* These will someday get removed. */
#define VM_CMM_PAGES		1111
#define VM_CMM_TIMED_PAGES	1112
#define VM_CMM_TIMEOUT		1113

static struct ctl_table cmm_table[];

static int
cmm_pages_handler(ctl_table *ctl, int write, struct file *filp,
		  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, struct file *filp,
		    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[] = {
	{
		.ctl_name	= VM_CMM_PAGES,
		.procname	= "cmm_pages",
		.mode		= 0644,
		.proc_handler	= &cmm_pages_handler,
	},
	{
		.ctl_name	= VM_CMM_TIMED_PAGES,
		.procname	= "cmm_timed_pages",
		.mode		= 0644,
		.proc_handler	= &cmm_pages_handler,
	},
	{
		.ctl_name	= VM_CMM_TIMEOUT,
		.procname	= "cmm_timeout",
		.mode		= 0644,
		.proc_handler	= &cmm_timeout_handler,
	},
	{ .ctl_name = 0 }
};

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

#ifdef CONFIG_CMM_IUCV
#define SMSG_PREFIX "CMM"
static void
cmm_smsg_target(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

struct ctl_table_header *cmm_sysctl_header;

static int
cmm_init (void)
{
#ifdef CONFIG_CMM_PROC
	cmm_sysctl_header = register_sysctl_table(cmm_dir_table, 1);
#endif
#ifdef CONFIG_CMM_IUCV
	smsg_register_callback(SMSG_PREFIX, cmm_smsg_target);
#endif
	register_oom_notifier(&cmm_oom_nb);
	INIT_WORK(&cmm_thread_starter, (void *) cmm_start_thread, NULL);
	init_waitqueue_head(&cmm_thread_wait);
	init_timer(&cmm_timer);
	return 0;
}

static void
cmm_exit(void)
{
	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>
1da177e4 LT	19
	20	#include <asm/pgalloc.h>
	21	#include <asm/uaccess.h>
	22
15439d74	23	static char *sender = "VMRMSVM";
447570cf	24	module_param(sender, charp, 0400);
15439d74 MS	25	MODULE_PARM_DESC(sender,
	26	"Guest name that may send SMSG messages (default VMRMSVM)");
	27
1da177e4 LT	28	#include "../../../drivers/s390/net/smsgiucv.h"
	29
	30	#define CMM_NR_PAGES ((PAGE_SIZE / sizeof(unsigned long)) - 2)
	31
	32	struct cmm_page_array {
	33	struct cmm_page_array *next;
	34	unsigned long index;
	35	unsigned long pages[CMM_NR_PAGES];
	36	};
	37
8bc719d3 MS	38	static long cmm_pages;
	39	static long cmm_timed_pages;
	40	static volatile long cmm_pages_target;
	41	static volatile long cmm_timed_pages_target;
	42	static long cmm_timeout_pages;
	43	static long cmm_timeout_seconds;
1da177e4	44
8bc719d3 MS	45	static struct cmm_page_array *cmm_page_list;
	46	static struct cmm_page_array *cmm_timed_page_list;
	47	static DEFINE_SPINLOCK(cmm_lock);
1da177e4	48
8bc719d3	49	static unsigned long cmm_thread_active;
1da177e4 LT	50	static struct work_struct cmm_thread_starter;
	51	static wait_queue_head_t cmm_thread_wait;
	52	static struct timer_list cmm_timer;
	53
	54	static void cmm_timer_fn(unsigned long);
	55	static void cmm_set_timer(void);
	56
1da177e4	57	static long
8bc719d3	58	cmm_alloc_pages(long nr, long counter, struct cmm_page_array *list)
1da177e4	59	{
8bc719d3 MS	60	struct cmm_page_array pa, npa;
8bc719d3 MS	61	unsigned long addr;
1da177e4	62
8bc719d3 MS	63	while (nr) {
	64	addr = __get_free_page(GFP_NOIO);
	65	if (!addr)
1da177e4	66	break;
8bc719d3 MS	67	spin_lock(&cmm_lock);
8bc719d3 MS	68	pa = *list;
1da177e4 LT	69	if (!pa \|\| pa->index >= CMM_NR_PAGES) {
1da177e4 LT	70	/* Need a new page for the page list. */
8bc719d3 MS	71	spin_unlock(&cmm_lock);
8bc719d3 MS	72	npa = (struct cmm_page_array *)
1da177e4	73	__get_free_page(GFP_NOIO);
8bc719d3 MS	74	if (!npa) {
8bc719d3 MS	75	free_page(addr);
1da177e4 LT	76	break;
1da177e4 LT	77	}
8bc719d3 MS	78	spin_lock(&cmm_lock);
	79	pa = *list;
	80	if (!pa \|\| pa->index >= CMM_NR_PAGES) {
	81	npa->next = pa;
	82	npa->index = 0;
	83	pa = npa;
	84	*list = pa;
	85	} else
	86	free_page((unsigned long) npa);
1da177e4	87	}
8bc719d3 MS	88	diag10(addr);
8bc719d3 MS	89	pa->pages[pa->index++] = addr;
1da177e4	90	(*counter)++;
8bc719d3 MS	91	spin_unlock(&cmm_lock);
8bc719d3 MS	92	nr--;
1da177e4	93	}
8bc719d3	94	return nr;
1da177e4 LT	95	}
1da177e4 LT	96
8bc719d3 MS	97	static long
8bc719d3 MS	98	cmm_free_pages(long nr, long counter, struct cmm_page_array *list)
1da177e4 LT	99	{
1da177e4 LT	100	struct cmm_page_array *pa;
8bc719d3	101	unsigned long addr;
1da177e4	102
8bc719d3	103	spin_lock(&cmm_lock);
1da177e4	104	pa = *list;
8bc719d3	105	while (nr) {
1da177e4 LT	106	if (!pa \|\| pa->index <= 0)
1da177e4 LT	107	break;
8bc719d3	108	addr = pa->pages[--pa->index];
1da177e4 LT	109	if (pa->index == 0) {
	110	pa = pa->next;
	111	free_page((unsigned long) *list);
	112	*list = pa;
	113	}
8bc719d3	114	free_page(addr);
1da177e4	115	(*counter)--;
8bc719d3	116	nr--;
1da177e4	117	}
8bc719d3 MS	118	spin_unlock(&cmm_lock);
8bc719d3 MS	119	return nr;
1da177e4 LT	120	}
1da177e4 LT	121
8bc719d3 MS	122	static int cmm_oom_notify(struct notifier_block *self,
	123	unsigned long dummy, void *parm)
	124	{
	125	unsigned long *freed = parm;
	126	long nr = 256;
	127
	128	nr = cmm_free_pages(nr, &cmm_timed_pages, &cmm_timed_page_list);
	129	if (nr > 0)
	130	nr = cmm_free_pages(nr, &cmm_pages, &cmm_page_list);
	131	cmm_pages_target = cmm_pages;
	132	cmm_timed_pages_target = cmm_timed_pages;
	133	*freed += 256 - nr;
	134	return NOTIFY_OK;
	135	}
	136
	137	static struct notifier_block cmm_oom_nb = {
	138	.notifier_call = cmm_oom_notify
	139	};
	140
1da177e4 LT	141	static int
	142	cmm_thread(void *dummy)
	143	{
	144	int rc;
	145
	146	daemonize("cmmthread");
	147	while (1) {
	148	rc = wait_event_interruptible(cmm_thread_wait,
	149	(cmm_pages != cmm_pages_target \|\|
	150	cmm_timed_pages != cmm_timed_pages_target));
	151	if (rc == -ERESTARTSYS) {
	152	/* Got kill signal. End thread. */
	153	clear_bit(0, &cmm_thread_active);
	154	cmm_pages_target = cmm_pages;
	155	cmm_timed_pages_target = cmm_timed_pages;
	156	break;
	157	}
	158	if (cmm_pages_target > cmm_pages) {
	159	if (cmm_alloc_pages(1, &cmm_pages, &cmm_page_list))
	160	cmm_pages_target = cmm_pages;
	161	} else if (cmm_pages_target < cmm_pages) {
	162	cmm_free_pages(1, &cmm_pages, &cmm_page_list);
	163	}
	164	if (cmm_timed_pages_target > cmm_timed_pages) {
	165	if (cmm_alloc_pages(1, &cmm_timed_pages,
	166	&cmm_timed_page_list))
	167	cmm_timed_pages_target = cmm_timed_pages;
	168	} else if (cmm_timed_pages_target < cmm_timed_pages) {
	169	cmm_free_pages(1, &cmm_timed_pages,
	170	&cmm_timed_page_list);
	171	}
	172	if (cmm_timed_pages > 0 && !timer_pending(&cmm_timer))
	173	cmm_set_timer();
	174	}
	175	return 0;
	176	}
	177
	178	static void
	179	cmm_start_thread(void)
	180	{
d2c993d8	181	kernel_thread(cmm_thread, NULL, 0);
1da177e4 LT	182	}
	183
	184	static void
	185	cmm_kick_thread(void)
	186	{
	187	if (!test_and_set_bit(0, &cmm_thread_active))
	188	schedule_work(&cmm_thread_starter);
	189	wake_up(&cmm_thread_wait);
	190	}
	191
	192	static void
	193	cmm_set_timer(void)
	194	{
	195	if (cmm_timed_pages_target <= 0 \|\| cmm_timeout_seconds <= 0) {
	196	if (timer_pending(&cmm_timer))
	197	del_timer(&cmm_timer);
	198	return;
	199	}
	200	if (timer_pending(&cmm_timer)) {
	201	if (mod_timer(&cmm_timer, jiffies + cmm_timeout_seconds*HZ))
	202	return;
	203	}
	204	cmm_timer.function = cmm_timer_fn;
	205	cmm_timer.data = 0;
	206	cmm_timer.expires = jiffies + cmm_timeout_seconds*HZ;
	207	add_timer(&cmm_timer);
	208	}
	209
	210	static void
	211	cmm_timer_fn(unsigned long ignored)
	212	{
8bc719d3	213	long nr;
1da177e4	214
8bc719d3 MS	215	nr = cmm_timed_pages_target - cmm_timeout_pages;
8bc719d3 MS	216	if (nr < 0)
1da177e4 LT	217	cmm_timed_pages_target = 0;
1da177e4 LT	218	else
8bc719d3	219	cmm_timed_pages_target = nr;
1da177e4 LT	220	cmm_kick_thread();
	221	cmm_set_timer();
	222	}
	223
	224	void
8bc719d3	225	cmm_set_pages(long nr)
1da177e4	226	{
8bc719d3	227	cmm_pages_target = nr;
1da177e4 LT	228	cmm_kick_thread();
	229	}
	230
	231	long
	232	cmm_get_pages(void)
	233	{
	234	return cmm_pages;
	235	}
	236
	237	void
8bc719d3	238	cmm_add_timed_pages(long nr)
1da177e4	239	{
8bc719d3	240	cmm_timed_pages_target += nr;
1da177e4 LT	241	cmm_kick_thread();
	242	}
	243
	244	long
	245	cmm_get_timed_pages(void)
	246	{
	247	return cmm_timed_pages;
	248	}
	249
	250	void
8bc719d3	251	cmm_set_timeout(long nr, long seconds)
1da177e4	252	{
8bc719d3	253	cmm_timeout_pages = nr;
1da177e4 LT	254	cmm_timeout_seconds = seconds;
	255	cmm_set_timer();
	256	}
	257
	258	static inline int
	259	cmm_skip_blanks(char cp, char *endp)
	260	{
	261	char *str;
	262
	263	for (str = cp; str == ' ' \|\| str == '\t'; str++);
	264	*endp = str;
	265	return str != cp;
	266	}
	267
	268	#ifdef CONFIG_CMM_PROC
	269	/* These will someday get removed. */
	270	#define VM_CMM_PAGES 1111
	271	#define VM_CMM_TIMED_PAGES 1112
	272	#define VM_CMM_TIMEOUT 1113
	273
	274	static struct ctl_table cmm_table[];
	275
	276	static int
	277	cmm_pages_handler(ctl_table ctl, int write, struct file filp,
aaedd944	278	void __user buffer, size_t lenp, loff_t *ppos)
1da177e4 LT	279	{
1da177e4 LT	280	char buf[16], *p;
8bc719d3	281	long nr;
1da177e4 LT	282	int len;
	283
	284	if (!lenp \|\| (ppos && !write)) {
	285	*lenp = 0;
	286	return 0;
	287	}
	288
	289	if (write) {
	290	len = *lenp;
	291	if (copy_from_user(buf, buffer,
	292	len > sizeof(buf) ? sizeof(buf) : len))
	293	return -EFAULT;
	294	buf[sizeof(buf) - 1] = '\0';
	295	cmm_skip_blanks(buf, &p);
8bc719d3	296	nr = simple_strtoul(p, &p, 0);
1da177e4	297	if (ctl == &cmm_table[0])
8bc719d3	298	cmm_set_pages(nr);
1da177e4	299	else
8bc719d3	300	cmm_add_timed_pages(nr);
1da177e4 LT	301	} else {
1da177e4 LT	302	if (ctl == &cmm_table[0])
8bc719d3	303	nr = cmm_get_pages();
1da177e4	304	else
8bc719d3 MS	305	nr = cmm_get_timed_pages();
8bc719d3 MS	306	len = sprintf(buf, "%ld\n", nr);
1da177e4 LT	307	if (len > *lenp)
	308	len = *lenp;
	309	if (copy_to_user(buffer, buf, len))
	310	return -EFAULT;
	311	}
	312	*lenp = len;
	313	*ppos += len;
	314	return 0;
	315	}
	316
	317	static int
	318	cmm_timeout_handler(ctl_table ctl, int write, struct file filp,
aaedd944	319	void __user buffer, size_t lenp, loff_t *ppos)
1da177e4 LT	320	{
1da177e4 LT	321	char buf[64], *p;
8bc719d3	322	long nr, seconds;
1da177e4 LT	323	int len;
	324
	325	if (!lenp \|\| (ppos && !write)) {
	326	*lenp = 0;
	327	return 0;
	328	}
	329
	330	if (write) {
	331	len = *lenp;
	332	if (copy_from_user(buf, buffer,
	333	len > sizeof(buf) ? sizeof(buf) : len))
	334	return -EFAULT;
	335	buf[sizeof(buf) - 1] = '\0';
	336	cmm_skip_blanks(buf, &p);
8bc719d3	337	nr = simple_strtoul(p, &p, 0);
1da177e4	338	cmm_skip_blanks(p, &p);
7d5d688f	339	seconds = simple_strtoul(p, &p, 0);
8bc719d3	340	cmm_set_timeout(nr, seconds);
1da177e4 LT	341	} else {
	342	len = sprintf(buf, "%ld %ld\n",
	343	cmm_timeout_pages, cmm_timeout_seconds);
	344	if (len > *lenp)
	345	len = *lenp;
	346	if (copy_to_user(buffer, buf, len))
	347	return -EFAULT;
	348	}
	349	*lenp = len;
	350	*ppos += len;
	351	return 0;
	352	}
	353
	354	static struct ctl_table cmm_table[] = {
	355	{
	356	.ctl_name = VM_CMM_PAGES,
	357	.procname = "cmm_pages",
5e8b1c40	358	.mode = 0644,
1da177e4 LT	359	.proc_handler = &cmm_pages_handler,
	360	},
	361	{
	362	.ctl_name = VM_CMM_TIMED_PAGES,
	363	.procname = "cmm_timed_pages",
5e8b1c40	364	.mode = 0644,
1da177e4 LT	365	.proc_handler = &cmm_pages_handler,
	366	},
	367	{
	368	.ctl_name = VM_CMM_TIMEOUT,
	369	.procname = "cmm_timeout",
5e8b1c40	370	.mode = 0644,
1da177e4 LT	371	.proc_handler = &cmm_timeout_handler,
	372	},
	373	{ .ctl_name = 0 }
	374	};
	375
	376	static struct ctl_table cmm_dir_table[] = {
	377	{
	378	.ctl_name = CTL_VM,
	379	.procname = "vm",
	380	.maxlen = 0,
	381	.mode = 0555,
	382	.child = cmm_table,
	383	},
	384	{ .ctl_name = 0 }
	385	};
	386	#endif
	387
	388	#ifdef CONFIG_CMM_IUCV
	389	#define SMSG_PREFIX "CMM"
	390	static void
15439d74	391	cmm_smsg_target(char from, char msg)
1da177e4	392	{
8bc719d3	393	long nr, seconds;
1da177e4	394
15439d74 MS	395	if (strlen(sender) > 0 && strcmp(from, sender) != 0)
15439d74 MS	396	return;
1da177e4 LT	397	if (!cmm_skip_blanks(msg + strlen(SMSG_PREFIX), &msg))
	398	return;
	399	if (strncmp(msg, "SHRINK", 6) == 0) {
	400	if (!cmm_skip_blanks(msg + 6, &msg))
	401	return;
8bc719d3	402	nr = simple_strtoul(msg, &msg, 0);
1da177e4 LT	403	cmm_skip_blanks(msg, &msg);
1da177e4 LT	404	if (*msg == '\0')
8bc719d3	405	cmm_set_pages(nr);
1da177e4 LT	406	} else if (strncmp(msg, "RELEASE", 7) == 0) {
	407	if (!cmm_skip_blanks(msg + 7, &msg))
	408	return;
8bc719d3	409	nr = simple_strtoul(msg, &msg, 0);
1da177e4 LT	410	cmm_skip_blanks(msg, &msg);
1da177e4 LT	411	if (*msg == '\0')
8bc719d3	412	cmm_add_timed_pages(nr);
1da177e4 LT	413	} else if (strncmp(msg, "REUSE", 5) == 0) {
	414	if (!cmm_skip_blanks(msg + 5, &msg))
	415	return;
8bc719d3	416	nr = simple_strtoul(msg, &msg, 0);
1da177e4 LT	417	if (!cmm_skip_blanks(msg, &msg))
1da177e4 LT	418	return;
7d5d688f	419	seconds = simple_strtoul(msg, &msg, 0);
1da177e4 LT	420	cmm_skip_blanks(msg, &msg);
1da177e4 LT	421	if (*msg == '\0')
8bc719d3	422	cmm_set_timeout(nr, seconds);
1da177e4 LT	423	}
	424	}
	425	#endif
	426
	427	struct ctl_table_header *cmm_sysctl_header;
	428
	429	static int
	430	cmm_init (void)
	431	{
	432	#ifdef CONFIG_CMM_PROC
	433	cmm_sysctl_header = register_sysctl_table(cmm_dir_table, 1);
	434	#endif
	435	#ifdef CONFIG_CMM_IUCV
	436	smsg_register_callback(SMSG_PREFIX, cmm_smsg_target);
	437	#endif
8bc719d3	438	register_oom_notifier(&cmm_oom_nb);
aaedd944	439	INIT_WORK(&cmm_thread_starter, (void *) cmm_start_thread, NULL);
1da177e4 LT	440	init_waitqueue_head(&cmm_thread_wait);
	441	init_timer(&cmm_timer);
	442	return 0;
	443	}
	444
	445	static void
	446	cmm_exit(void)
	447	{
8bc719d3	448	unregister_oom_notifier(&cmm_oom_nb);
1da177e4 LT	449	cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list);
	450	cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list);
	451	#ifdef CONFIG_CMM_PROC
	452	unregister_sysctl_table(cmm_sysctl_header);
	453	#endif
	454	#ifdef CONFIG_CMM_IUCV
	455	smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
	456	#endif
	457	}
	458
	459	module_init(cmm_init);
	460	module_exit(cmm_exit);
	461
	462	EXPORT_SYMBOL(cmm_set_pages);
	463	EXPORT_SYMBOL(cmm_get_pages);
	464	EXPORT_SYMBOL(cmm_add_timed_pages);
	465	EXPORT_SYMBOL(cmm_get_timed_pages);
	466	EXPORT_SYMBOL(cmm_set_timeout);
	467
	468	MODULE_LICENSE("GPL");