[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 <linux/kthread.h>
#include <linux/oom.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 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_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, 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[] = {
	{
		.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,
	},
	{ .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

static struct ctl_table_header *cmm_sysctl_header;

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;
#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;
	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_create failed. undo all the stuff from above again.
	 */
	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);
#endif
out:
	return rc;
}

static void
cmm_exit(void)
{
	kthread_stop(cmm_thread_ptr);
	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>
1da177e4 LT	21
	22	#include <asm/pgalloc.h>
	23	#include <asm/uaccess.h>
0a87c5cf	24	#include <asm/diag.h>
1da177e4	25
15439d74	26	static char *sender = "VMRMSVM";
447570cf	27	module_param(sender, charp, 0400);
15439d74 MS	28	MODULE_PARM_DESC(sender,
	29	"Guest name that may send SMSG messages (default VMRMSVM)");
	30
1da177e4 LT	31	#include "../../../drivers/s390/net/smsgiucv.h"
	32
	33	#define CMM_NR_PAGES ((PAGE_SIZE / sizeof(unsigned long)) - 2)
	34
	35	struct cmm_page_array {
	36	struct cmm_page_array *next;
	37	unsigned long index;
	38	unsigned long pages[CMM_NR_PAGES];
	39	};
	40
8bc719d3 MS	41	static long cmm_pages;
	42	static long cmm_timed_pages;
	43	static volatile long cmm_pages_target;
	44	static volatile long cmm_timed_pages_target;
	45	static long cmm_timeout_pages;
	46	static long cmm_timeout_seconds;
1da177e4	47
8bc719d3 MS	48	static struct cmm_page_array *cmm_page_list;
	49	static struct cmm_page_array *cmm_timed_page_list;
	50	static DEFINE_SPINLOCK(cmm_lock);
1da177e4	51
e8216dee	52	static struct task_struct *cmm_thread_ptr;
1da177e4 LT	53	static wait_queue_head_t cmm_thread_wait;
	54	static struct timer_list cmm_timer;
	55
	56	static void cmm_timer_fn(unsigned long);
	57	static void cmm_set_timer(void);
	58
1da177e4	59	static long
8bc719d3	60	cmm_alloc_pages(long nr, long counter, struct cmm_page_array *list)
1da177e4	61	{
8bc719d3 MS	62	struct cmm_page_array pa, npa;
8bc719d3 MS	63	unsigned long addr;
1da177e4	64
8bc719d3 MS	65	while (nr) {
	66	addr = __get_free_page(GFP_NOIO);
	67	if (!addr)
1da177e4	68	break;
8bc719d3 MS	69	spin_lock(&cmm_lock);
8bc719d3 MS	70	pa = *list;
1da177e4 LT	71	if (!pa \|\| pa->index >= CMM_NR_PAGES) {
1da177e4 LT	72	/* Need a new page for the page list. */
8bc719d3 MS	73	spin_unlock(&cmm_lock);
8bc719d3 MS	74	npa = (struct cmm_page_array *)
1da177e4	75	__get_free_page(GFP_NOIO);
8bc719d3 MS	76	if (!npa) {
8bc719d3 MS	77	free_page(addr);
1da177e4 LT	78	break;
1da177e4 LT	79	}
8bc719d3 MS	80	spin_lock(&cmm_lock);
	81	pa = *list;
	82	if (!pa \|\| pa->index >= CMM_NR_PAGES) {
	83	npa->next = pa;
	84	npa->index = 0;
	85	pa = npa;
	86	*list = pa;
	87	} else
	88	free_page((unsigned long) npa);
1da177e4	89	}
8bc719d3 MS	90	diag10(addr);
8bc719d3 MS	91	pa->pages[pa->index++] = addr;
1da177e4	92	(*counter)++;
8bc719d3 MS	93	spin_unlock(&cmm_lock);
8bc719d3 MS	94	nr--;
1da177e4	95	}
8bc719d3	96	return nr;
1da177e4 LT	97	}
1da177e4 LT	98
8bc719d3 MS	99	static long
8bc719d3 MS	100	cmm_free_pages(long nr, long counter, struct cmm_page_array *list)
1da177e4 LT	101	{
1da177e4 LT	102	struct cmm_page_array *pa;
8bc719d3	103	unsigned long addr;
1da177e4	104
8bc719d3	105	spin_lock(&cmm_lock);
1da177e4	106	pa = *list;
8bc719d3	107	while (nr) {
1da177e4 LT	108	if (!pa \|\| pa->index <= 0)
1da177e4 LT	109	break;
8bc719d3	110	addr = pa->pages[--pa->index];
1da177e4 LT	111	if (pa->index == 0) {
	112	pa = pa->next;
	113	free_page((unsigned long) *list);
	114	*list = pa;
	115	}
8bc719d3	116	free_page(addr);
1da177e4	117	(*counter)--;
8bc719d3	118	nr--;
1da177e4	119	}
8bc719d3 MS	120	spin_unlock(&cmm_lock);
8bc719d3 MS	121	return nr;
1da177e4 LT	122	}
1da177e4 LT	123
8bc719d3 MS	124	static int cmm_oom_notify(struct notifier_block *self,
	125	unsigned long dummy, void *parm)
	126	{
	127	unsigned long *freed = parm;
	128	long nr = 256;
	129
	130	nr = cmm_free_pages(nr, &cmm_timed_pages, &cmm_timed_page_list);
	131	if (nr > 0)
	132	nr = cmm_free_pages(nr, &cmm_pages, &cmm_page_list);
	133	cmm_pages_target = cmm_pages;
	134	cmm_timed_pages_target = cmm_timed_pages;
	135	*freed += 256 - nr;
	136	return NOTIFY_OK;
	137	}
	138
	139	static struct notifier_block cmm_oom_nb = {
	140	.notifier_call = cmm_oom_notify
	141	};
	142
1da177e4 LT	143	static int
	144	cmm_thread(void *dummy)
	145	{
	146	int rc;
	147
1da177e4 LT	148	while (1) {
	149	rc = wait_event_interruptible(cmm_thread_wait,
	150	(cmm_pages != cmm_pages_target \|\|
e8216dee HC	151	cmm_timed_pages != cmm_timed_pages_target \|\|
	152	kthread_should_stop()));
	153	if (kthread_should_stop() \|\| rc == -ERESTARTSYS) {
1da177e4 LT	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
1da177e4 LT	178	static void
	179	cmm_kick_thread(void)
	180	{
1da177e4 LT	181	wake_up(&cmm_thread_wait);
	182	}
	183
	184	static void
	185	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	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
	202	static void
	203	cmm_timer_fn(unsigned long ignored)
	204	{
8bc719d3	205	long nr;
1da177e4	206
8bc719d3 MS	207	nr = cmm_timed_pages_target - cmm_timeout_pages;
8bc719d3 MS	208	if (nr < 0)
1da177e4 LT	209	cmm_timed_pages_target = 0;
1da177e4 LT	210	else
8bc719d3	211	cmm_timed_pages_target = nr;
1da177e4 LT	212	cmm_kick_thread();
	213	cmm_set_timer();
	214	}
	215
	216	void
8bc719d3	217	cmm_set_pages(long nr)
1da177e4	218	{
8bc719d3	219	cmm_pages_target = nr;
1da177e4 LT	220	cmm_kick_thread();
	221	}
	222
	223	long
	224	cmm_get_pages(void)
	225	{
	226	return cmm_pages;
	227	}
	228
	229	void
8bc719d3	230	cmm_add_timed_pages(long nr)
1da177e4	231	{
8bc719d3	232	cmm_timed_pages_target += nr;
1da177e4 LT	233	cmm_kick_thread();
	234	}
	235
	236	long
	237	cmm_get_timed_pages(void)
	238	{
	239	return cmm_timed_pages;
	240	}
	241
	242	void
8bc719d3	243	cmm_set_timeout(long nr, long seconds)
1da177e4	244	{
8bc719d3	245	cmm_timeout_pages = nr;
1da177e4 LT	246	cmm_timeout_seconds = seconds;
	247	cmm_set_timer();
	248	}
	249
4d284cac	250	static int
1da177e4 LT	251	cmm_skip_blanks(char cp, char *endp)
	252	{
	253	char *str;
	254
	255	for (str = cp; str == ' ' \|\| str == '\t'; str++);
	256	*endp = str;
	257	return str != cp;
	258	}
	259
	260	#ifdef CONFIG_CMM_PROC
1da177e4 LT	261
	262	static struct ctl_table cmm_table[];
	263
	264	static int
	265	cmm_pages_handler(ctl_table ctl, int write, struct file filp,
aaedd944	266	void __user buffer, size_t lenp, loff_t *ppos)
1da177e4 LT	267	{
1da177e4 LT	268	char buf[16], *p;
8bc719d3	269	long nr;
1da177e4 LT	270	int len;
	271
	272	if (!lenp \|\| (ppos && !write)) {
	273	*lenp = 0;
	274	return 0;
	275	}
	276
	277	if (write) {
	278	len = *lenp;
	279	if (copy_from_user(buf, buffer,
	280	len > sizeof(buf) ? sizeof(buf) : len))
	281	return -EFAULT;
	282	buf[sizeof(buf) - 1] = '\0';
	283	cmm_skip_blanks(buf, &p);
8bc719d3	284	nr = simple_strtoul(p, &p, 0);
1da177e4	285	if (ctl == &cmm_table[0])
8bc719d3	286	cmm_set_pages(nr);
1da177e4	287	else
8bc719d3	288	cmm_add_timed_pages(nr);
1da177e4 LT	289	} else {
1da177e4 LT	290	if (ctl == &cmm_table[0])
8bc719d3	291	nr = cmm_get_pages();
1da177e4	292	else
8bc719d3 MS	293	nr = cmm_get_timed_pages();
8bc719d3 MS	294	len = sprintf(buf, "%ld\n", nr);
1da177e4 LT	295	if (len > *lenp)
	296	len = *lenp;
	297	if (copy_to_user(buffer, buf, len))
	298	return -EFAULT;
	299	}
	300	*lenp = len;
	301	*ppos += len;
	302	return 0;
	303	}
	304
	305	static int
	306	cmm_timeout_handler(ctl_table ctl, int write, struct file filp,
aaedd944	307	void __user buffer, size_t lenp, loff_t *ppos)
1da177e4 LT	308	{
1da177e4 LT	309	char buf[64], *p;
8bc719d3	310	long nr, seconds;
1da177e4 LT	311	int len;
	312
	313	if (!lenp \|\| (ppos && !write)) {
	314	*lenp = 0;
	315	return 0;
	316	}
	317
	318	if (write) {
	319	len = *lenp;
	320	if (copy_from_user(buf, buffer,
	321	len > sizeof(buf) ? sizeof(buf) : len))
	322	return -EFAULT;
	323	buf[sizeof(buf) - 1] = '\0';
	324	cmm_skip_blanks(buf, &p);
8bc719d3	325	nr = simple_strtoul(p, &p, 0);
1da177e4	326	cmm_skip_blanks(p, &p);
7d5d688f	327	seconds = simple_strtoul(p, &p, 0);
8bc719d3	328	cmm_set_timeout(nr, seconds);
1da177e4 LT	329	} else {
	330	len = sprintf(buf, "%ld %ld\n",
	331	cmm_timeout_pages, cmm_timeout_seconds);
	332	if (len > *lenp)
	333	len = *lenp;
	334	if (copy_to_user(buffer, buf, len))
	335	return -EFAULT;
	336	}
	337	*lenp = len;
	338	*ppos += len;
	339	return 0;
	340	}
	341
	342	static struct ctl_table cmm_table[] = {
	343	{
1da177e4	344	.procname = "cmm_pages",
5e8b1c40	345	.mode = 0644,
1da177e4 LT	346	.proc_handler = &cmm_pages_handler,
	347	},
	348	{
1da177e4	349	.procname = "cmm_timed_pages",
5e8b1c40	350	.mode = 0644,
1da177e4 LT	351	.proc_handler = &cmm_pages_handler,
	352	},
	353	{
1da177e4	354	.procname = "cmm_timeout",
5e8b1c40	355	.mode = 0644,
1da177e4 LT	356	.proc_handler = &cmm_timeout_handler,
	357	},
	358	{ .ctl_name = 0 }
	359	};
	360
	361	static struct ctl_table cmm_dir_table[] = {
	362	{
	363	.ctl_name = CTL_VM,
	364	.procname = "vm",
	365	.maxlen = 0,
	366	.mode = 0555,
	367	.child = cmm_table,
	368	},
	369	{ .ctl_name = 0 }
	370	};
	371	#endif
	372
	373	#ifdef CONFIG_CMM_IUCV
	374	#define SMSG_PREFIX "CMM"
	375	static void
15439d74	376	cmm_smsg_target(char from, char msg)
1da177e4	377	{
8bc719d3	378	long nr, seconds;
1da177e4	379
15439d74 MS	380	if (strlen(sender) > 0 && strcmp(from, sender) != 0)
15439d74 MS	381	return;
1da177e4 LT	382	if (!cmm_skip_blanks(msg + strlen(SMSG_PREFIX), &msg))
	383	return;
	384	if (strncmp(msg, "SHRINK", 6) == 0) {
	385	if (!cmm_skip_blanks(msg + 6, &msg))
	386	return;
8bc719d3	387	nr = simple_strtoul(msg, &msg, 0);
1da177e4 LT	388	cmm_skip_blanks(msg, &msg);
1da177e4 LT	389	if (*msg == '\0')
8bc719d3	390	cmm_set_pages(nr);
1da177e4 LT	391	} else if (strncmp(msg, "RELEASE", 7) == 0) {
	392	if (!cmm_skip_blanks(msg + 7, &msg))
	393	return;
8bc719d3	394	nr = simple_strtoul(msg, &msg, 0);
1da177e4 LT	395	cmm_skip_blanks(msg, &msg);
1da177e4 LT	396	if (*msg == '\0')
8bc719d3	397	cmm_add_timed_pages(nr);
1da177e4 LT	398	} else if (strncmp(msg, "REUSE", 5) == 0) {
	399	if (!cmm_skip_blanks(msg + 5, &msg))
	400	return;
8bc719d3	401	nr = simple_strtoul(msg, &msg, 0);
1da177e4 LT	402	if (!cmm_skip_blanks(msg, &msg))
1da177e4 LT	403	return;
7d5d688f	404	seconds = simple_strtoul(msg, &msg, 0);
1da177e4 LT	405	cmm_skip_blanks(msg, &msg);
1da177e4 LT	406	if (*msg == '\0')
8bc719d3	407	cmm_set_timeout(nr, seconds);
1da177e4 LT	408	}
	409	}
	410	#endif
	411
2b67fc46	412	static struct ctl_table_header *cmm_sysctl_header;
1da177e4 LT	413
	414	static int
	415	cmm_init (void)
	416	{
e8216dee HC	417	int rc = -ENOMEM;
e8216dee HC	418
1da177e4	419	#ifdef CONFIG_CMM_PROC
0b4d4147	420	cmm_sysctl_header = register_sysctl_table(cmm_dir_table);
e8216dee HC	421	if (!cmm_sysctl_header)
e8216dee HC	422	goto out;
1da177e4 LT	423	#endif
1da177e4 LT	424	#ifdef CONFIG_CMM_IUCV
e8216dee HC	425	rc = smsg_register_callback(SMSG_PREFIX, cmm_smsg_target);
	426	if (rc < 0)
	427	goto out_smsg;
1da177e4	428	#endif
e8216dee HC	429	rc = register_oom_notifier(&cmm_oom_nb);
	430	if (rc < 0)
	431	goto out_oom_notify;
1da177e4 LT	432	init_waitqueue_head(&cmm_thread_wait);
1da177e4 LT	433	init_timer(&cmm_timer);
e8216dee HC	434	cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread");
	435	rc = IS_ERR(cmm_thread_ptr) ? PTR_ERR(cmm_thread_ptr) : 0;
	436	if (!rc)
	437	goto out;
	438	/*
	439	* kthread_create failed. undo all the stuff from above again.
	440	*/
	441	unregister_oom_notifier(&cmm_oom_nb);
	442
	443	out_oom_notify:
	444	#ifdef CONFIG_CMM_IUCV
	445	smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
	446	out_smsg:
	447	#endif
	448	#ifdef CONFIG_CMM_PROC
	449	unregister_sysctl_table(cmm_sysctl_header);
	450	#endif
	451	out:
	452	return rc;
1da177e4 LT	453	}
	454
	455	static void
	456	cmm_exit(void)
	457	{
e8216dee	458	kthread_stop(cmm_thread_ptr);
8bc719d3	459	unregister_oom_notifier(&cmm_oom_nb);
1da177e4 LT	460	cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list);
	461	cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list);
	462	#ifdef CONFIG_CMM_PROC
	463	unregister_sysctl_table(cmm_sysctl_header);
	464	#endif
	465	#ifdef CONFIG_CMM_IUCV
	466	smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
	467	#endif
	468	}
	469
	470	module_init(cmm_init);
	471	module_exit(cmm_exit);
	472
	473	EXPORT_SYMBOL(cmm_set_pages);
	474	EXPORT_SYMBOL(cmm_get_pages);
	475	EXPORT_SYMBOL(cmm_add_timed_pages);
	476	EXPORT_SYMBOL(cmm_get_timed_pages);
	477	EXPORT_SYMBOL(cmm_set_timeout);
	478
	479	MODULE_LICENSE("GPL");