[linux-2.6-block.git] / arch / s390 / mm / cmm.c

// SPDX-License-Identifier: GPL-2.0
/*
 *  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/moduleparam.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/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 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 void cmm_timer_fn(struct timer_list *);
static void cmm_set_timer(void);
static DEFINE_TIMER(cmm_timer, cmm_timer_fn);

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_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;
	}
	mod_timer(&cmm_timer, jiffies + cmm_timeout_seconds * HZ);
}

static void cmm_timer_fn(struct timer_list *unused)
{
	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 int cmm_pages_handler(struct ctl_table *ctl, int write,
			     void *buffer, size_t *lenp, loff_t *ppos)
{
	long nr = cmm_get_pages();
	struct ctl_table ctl_entry = {
		.procname	= ctl->procname,
		.data		= &nr,
		.maxlen		= sizeof(long),
	};
	int rc;

	rc = proc_doulongvec_minmax(&ctl_entry, write, buffer, lenp, ppos);
	if (rc < 0 || !write)
		return rc;

	cmm_set_pages(nr);
	return 0;
}

static int cmm_timed_pages_handler(struct ctl_table *ctl, int write,
				   void *buffer, size_t *lenp,
				   loff_t *ppos)
{
	long nr = cmm_get_timed_pages();
	struct ctl_table ctl_entry = {
		.procname	= ctl->procname,
		.data		= &nr,
		.maxlen		= sizeof(long),
	};
	int rc;

	rc = proc_doulongvec_minmax(&ctl_entry, write, buffer, lenp, ppos);
	if (rc < 0 || !write)
		return rc;

	cmm_add_timed_pages(nr);
	return 0;
}

static int cmm_timeout_handler(struct ctl_table *ctl, int write,
			       void *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 = min(*lenp, sizeof(buf));
		memcpy(buf, buffer, len);
		buf[len - 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);
		*ppos += *lenp;
	} else {
		len = sprintf(buf, "%ld %ld\n",
			      cmm_timeout_pages, cmm_timeout_seconds);
		if (len > *lenp)
			len = *lenp;
		memcpy(buffer, buf, len);
		*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_timed_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 __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;
	cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread");
	if (!IS_ERR(cmm_thread_ptr))
		return 0;

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