[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 <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 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 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

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, 1);
	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>
1da177e4 LT	20
	21	#include <asm/pgalloc.h>
	22	#include <asm/uaccess.h>
	23
15439d74	24	static char *sender = "VMRMSVM";
447570cf	25	module_param(sender, charp, 0400);
15439d74 MS	26	MODULE_PARM_DESC(sender,
	27	"Guest name that may send SMSG messages (default VMRMSVM)");
	28
1da177e4 LT	29	#include "../../../drivers/s390/net/smsgiucv.h"
	30
	31	#define CMM_NR_PAGES ((PAGE_SIZE / sizeof(unsigned long)) - 2)
	32
	33	struct cmm_page_array {
	34	struct cmm_page_array *next;
	35	unsigned long index;
	36	unsigned long pages[CMM_NR_PAGES];
	37	};
	38
8bc719d3 MS	39	static long cmm_pages;
	40	static long cmm_timed_pages;
	41	static volatile long cmm_pages_target;
	42	static volatile long cmm_timed_pages_target;
	43	static long cmm_timeout_pages;
	44	static long cmm_timeout_seconds;
1da177e4	45
8bc719d3 MS	46	static struct cmm_page_array *cmm_page_list;
	47	static struct cmm_page_array *cmm_timed_page_list;
	48	static DEFINE_SPINLOCK(cmm_lock);
1da177e4	49
e8216dee	50	static struct task_struct *cmm_thread_ptr;
1da177e4 LT	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
1da177e4 LT	146	while (1) {
	147	rc = wait_event_interruptible(cmm_thread_wait,
	148	(cmm_pages != cmm_pages_target \|\|
e8216dee HC	149	cmm_timed_pages != cmm_timed_pages_target \|\|
	150	kthread_should_stop()));
	151	if (kthread_should_stop() \|\| rc == -ERESTARTSYS) {
1da177e4 LT	152	cmm_pages_target = cmm_pages;
	153	cmm_timed_pages_target = cmm_timed_pages;
	154	break;
	155	}
	156	if (cmm_pages_target > cmm_pages) {
	157	if (cmm_alloc_pages(1, &cmm_pages, &cmm_page_list))
	158	cmm_pages_target = cmm_pages;
	159	} else if (cmm_pages_target < cmm_pages) {
	160	cmm_free_pages(1, &cmm_pages, &cmm_page_list);
	161	}
	162	if (cmm_timed_pages_target > cmm_timed_pages) {
	163	if (cmm_alloc_pages(1, &cmm_timed_pages,
	164	&cmm_timed_page_list))
	165	cmm_timed_pages_target = cmm_timed_pages;
	166	} else if (cmm_timed_pages_target < cmm_timed_pages) {
	167	cmm_free_pages(1, &cmm_timed_pages,
	168	&cmm_timed_page_list);
	169	}
	170	if (cmm_timed_pages > 0 && !timer_pending(&cmm_timer))
	171	cmm_set_timer();
	172	}
	173	return 0;
	174	}
	175
1da177e4 LT	176	static void
	177	cmm_kick_thread(void)
	178	{
1da177e4 LT	179	wake_up(&cmm_thread_wait);
	180	}
	181
	182	static void
	183	cmm_set_timer(void)
	184	{
	185	if (cmm_timed_pages_target <= 0 \|\| cmm_timeout_seconds <= 0) {
	186	if (timer_pending(&cmm_timer))
	187	del_timer(&cmm_timer);
	188	return;
	189	}
	190	if (timer_pending(&cmm_timer)) {
	191	if (mod_timer(&cmm_timer, jiffies + cmm_timeout_seconds*HZ))
	192	return;
	193	}
	194	cmm_timer.function = cmm_timer_fn;
	195	cmm_timer.data = 0;
	196	cmm_timer.expires = jiffies + cmm_timeout_seconds*HZ;
	197	add_timer(&cmm_timer);
	198	}
	199
	200	static void
	201	cmm_timer_fn(unsigned long ignored)
	202	{
8bc719d3	203	long nr;
1da177e4	204
8bc719d3 MS	205	nr = cmm_timed_pages_target - cmm_timeout_pages;
8bc719d3 MS	206	if (nr < 0)
1da177e4 LT	207	cmm_timed_pages_target = 0;
1da177e4 LT	208	else
8bc719d3	209	cmm_timed_pages_target = nr;
1da177e4 LT	210	cmm_kick_thread();
	211	cmm_set_timer();
	212	}
	213
	214	void
8bc719d3	215	cmm_set_pages(long nr)
1da177e4	216	{
8bc719d3	217	cmm_pages_target = nr;
1da177e4 LT	218	cmm_kick_thread();
	219	}
	220
	221	long
	222	cmm_get_pages(void)
	223	{
	224	return cmm_pages;
	225	}
	226
	227	void
8bc719d3	228	cmm_add_timed_pages(long nr)
1da177e4	229	{
8bc719d3	230	cmm_timed_pages_target += nr;
1da177e4 LT	231	cmm_kick_thread();
	232	}
	233
	234	long
	235	cmm_get_timed_pages(void)
	236	{
	237	return cmm_timed_pages;
	238	}
	239
	240	void
8bc719d3	241	cmm_set_timeout(long nr, long seconds)
1da177e4	242	{
8bc719d3	243	cmm_timeout_pages = nr;
1da177e4 LT	244	cmm_timeout_seconds = seconds;
	245	cmm_set_timer();
	246	}
	247
	248	static inline int
	249	cmm_skip_blanks(char cp, char *endp)
	250	{
	251	char *str;
	252
	253	for (str = cp; str == ' ' \|\| str == '\t'; str++);
	254	*endp = str;
	255	return str != cp;
	256	}
	257
	258	#ifdef CONFIG_CMM_PROC
	259	/* These will someday get removed. */
	260	#define VM_CMM_PAGES 1111
	261	#define VM_CMM_TIMED_PAGES 1112
	262	#define VM_CMM_TIMEOUT 1113
	263
	264	static struct ctl_table cmm_table[];
	265
	266	static int
	267	cmm_pages_handler(ctl_table ctl, int write, struct file filp,
aaedd944	268	void __user buffer, size_t lenp, loff_t *ppos)
1da177e4 LT	269	{
1da177e4 LT	270	char buf[16], *p;
8bc719d3	271	long nr;
1da177e4 LT	272	int len;
	273
	274	if (!lenp \|\| (ppos && !write)) {
	275	*lenp = 0;
	276	return 0;
	277	}
	278
	279	if (write) {
	280	len = *lenp;
	281	if (copy_from_user(buf, buffer,
	282	len > sizeof(buf) ? sizeof(buf) : len))
	283	return -EFAULT;
	284	buf[sizeof(buf) - 1] = '\0';
	285	cmm_skip_blanks(buf, &p);
8bc719d3	286	nr = simple_strtoul(p, &p, 0);
1da177e4	287	if (ctl == &cmm_table[0])
8bc719d3	288	cmm_set_pages(nr);
1da177e4	289	else
8bc719d3	290	cmm_add_timed_pages(nr);
1da177e4 LT	291	} else {
1da177e4 LT	292	if (ctl == &cmm_table[0])
8bc719d3	293	nr = cmm_get_pages();
1da177e4	294	else
8bc719d3 MS	295	nr = cmm_get_timed_pages();
8bc719d3 MS	296	len = sprintf(buf, "%ld\n", nr);
1da177e4 LT	297	if (len > *lenp)
	298	len = *lenp;
	299	if (copy_to_user(buffer, buf, len))
	300	return -EFAULT;
	301	}
	302	*lenp = len;
	303	*ppos += len;
	304	return 0;
	305	}
	306
	307	static int
	308	cmm_timeout_handler(ctl_table ctl, int write, struct file filp,
aaedd944	309	void __user buffer, size_t lenp, loff_t *ppos)
1da177e4 LT	310	{
1da177e4 LT	311	char buf[64], *p;
8bc719d3	312	long nr, seconds;
1da177e4 LT	313	int len;
	314
	315	if (!lenp \|\| (ppos && !write)) {
	316	*lenp = 0;
	317	return 0;
	318	}
	319
	320	if (write) {
	321	len = *lenp;
	322	if (copy_from_user(buf, buffer,
	323	len > sizeof(buf) ? sizeof(buf) : len))
	324	return -EFAULT;
	325	buf[sizeof(buf) - 1] = '\0';
	326	cmm_skip_blanks(buf, &p);
8bc719d3	327	nr = simple_strtoul(p, &p, 0);
1da177e4	328	cmm_skip_blanks(p, &p);
7d5d688f	329	seconds = simple_strtoul(p, &p, 0);
8bc719d3	330	cmm_set_timeout(nr, seconds);
1da177e4 LT	331	} else {
	332	len = sprintf(buf, "%ld %ld\n",
	333	cmm_timeout_pages, cmm_timeout_seconds);
	334	if (len > *lenp)
	335	len = *lenp;
	336	if (copy_to_user(buffer, buf, len))
	337	return -EFAULT;
	338	}
	339	*lenp = len;
	340	*ppos += len;
	341	return 0;
	342	}
	343
	344	static struct ctl_table cmm_table[] = {
	345	{
	346	.ctl_name = VM_CMM_PAGES,
	347	.procname = "cmm_pages",
5e8b1c40	348	.mode = 0644,
1da177e4 LT	349	.proc_handler = &cmm_pages_handler,
	350	},
	351	{
	352	.ctl_name = VM_CMM_TIMED_PAGES,
	353	.procname = "cmm_timed_pages",
5e8b1c40	354	.mode = 0644,
1da177e4 LT	355	.proc_handler = &cmm_pages_handler,
	356	},
	357	{
	358	.ctl_name = VM_CMM_TIMEOUT,
	359	.procname = "cmm_timeout",
5e8b1c40	360	.mode = 0644,
1da177e4 LT	361	.proc_handler = &cmm_timeout_handler,
	362	},
	363	{ .ctl_name = 0 }
	364	};
	365
	366	static struct ctl_table cmm_dir_table[] = {
	367	{
	368	.ctl_name = CTL_VM,
	369	.procname = "vm",
	370	.maxlen = 0,
	371	.mode = 0555,
	372	.child = cmm_table,
	373	},
	374	{ .ctl_name = 0 }
	375	};
	376	#endif
	377
	378	#ifdef CONFIG_CMM_IUCV
	379	#define SMSG_PREFIX "CMM"
	380	static void
15439d74	381	cmm_smsg_target(char from, char msg)
1da177e4	382	{
8bc719d3	383	long nr, seconds;
1da177e4	384
15439d74 MS	385	if (strlen(sender) > 0 && strcmp(from, sender) != 0)
15439d74 MS	386	return;
1da177e4 LT	387	if (!cmm_skip_blanks(msg + strlen(SMSG_PREFIX), &msg))
	388	return;
	389	if (strncmp(msg, "SHRINK", 6) == 0) {
	390	if (!cmm_skip_blanks(msg + 6, &msg))
	391	return;
8bc719d3	392	nr = simple_strtoul(msg, &msg, 0);
1da177e4 LT	393	cmm_skip_blanks(msg, &msg);
1da177e4 LT	394	if (*msg == '\0')
8bc719d3	395	cmm_set_pages(nr);
1da177e4 LT	396	} else if (strncmp(msg, "RELEASE", 7) == 0) {
	397	if (!cmm_skip_blanks(msg + 7, &msg))
	398	return;
8bc719d3	399	nr = simple_strtoul(msg, &msg, 0);
1da177e4 LT	400	cmm_skip_blanks(msg, &msg);
1da177e4 LT	401	if (*msg == '\0')
8bc719d3	402	cmm_add_timed_pages(nr);
1da177e4 LT	403	} else if (strncmp(msg, "REUSE", 5) == 0) {
	404	if (!cmm_skip_blanks(msg + 5, &msg))
	405	return;
8bc719d3	406	nr = simple_strtoul(msg, &msg, 0);
1da177e4 LT	407	if (!cmm_skip_blanks(msg, &msg))
1da177e4 LT	408	return;
7d5d688f	409	seconds = simple_strtoul(msg, &msg, 0);
1da177e4 LT	410	cmm_skip_blanks(msg, &msg);
1da177e4 LT	411	if (*msg == '\0')
8bc719d3	412	cmm_set_timeout(nr, seconds);
1da177e4 LT	413	}
	414	}
	415	#endif
	416
2b67fc46	417	static struct ctl_table_header *cmm_sysctl_header;
1da177e4 LT	418
	419	static int
	420	cmm_init (void)
	421	{
e8216dee HC	422	int rc = -ENOMEM;
e8216dee HC	423
1da177e4 LT	424	#ifdef CONFIG_CMM_PROC
1da177e4 LT	425	cmm_sysctl_header = register_sysctl_table(cmm_dir_table, 1);
e8216dee HC	426	if (!cmm_sysctl_header)
e8216dee HC	427	goto out;
1da177e4 LT	428	#endif
1da177e4 LT	429	#ifdef CONFIG_CMM_IUCV
e8216dee HC	430	rc = smsg_register_callback(SMSG_PREFIX, cmm_smsg_target);
	431	if (rc < 0)
	432	goto out_smsg;
1da177e4	433	#endif
e8216dee HC	434	rc = register_oom_notifier(&cmm_oom_nb);
	435	if (rc < 0)
	436	goto out_oom_notify;
1da177e4 LT	437	init_waitqueue_head(&cmm_thread_wait);
1da177e4 LT	438	init_timer(&cmm_timer);
e8216dee HC	439	cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread");
	440	rc = IS_ERR(cmm_thread_ptr) ? PTR_ERR(cmm_thread_ptr) : 0;
	441	if (!rc)
	442	goto out;
	443	/*
	444	* kthread_create failed. undo all the stuff from above again.
	445	*/
	446	unregister_oom_notifier(&cmm_oom_nb);
	447
	448	out_oom_notify:
	449	#ifdef CONFIG_CMM_IUCV
	450	smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
	451	out_smsg:
	452	#endif
	453	#ifdef CONFIG_CMM_PROC
	454	unregister_sysctl_table(cmm_sysctl_header);
	455	#endif
	456	out:
	457	return rc;
1da177e4 LT	458	}
	459
	460	static void
	461	cmm_exit(void)
	462	{
e8216dee	463	kthread_stop(cmm_thread_ptr);
8bc719d3	464	unregister_oom_notifier(&cmm_oom_nb);
1da177e4 LT	465	cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list);
	466	cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list);
	467	#ifdef CONFIG_CMM_PROC
	468	unregister_sysctl_table(cmm_sysctl_header);
	469	#endif
	470	#ifdef CONFIG_CMM_IUCV
	471	smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
	472	#endif
	473	}
	474
	475	module_init(cmm_init);
	476	module_exit(cmm_exit);
	477
	478	EXPORT_SYMBOL(cmm_set_pages);
	479	EXPORT_SYMBOL(cmm_get_pages);
	480	EXPORT_SYMBOL(cmm_add_timed_pages);
	481	EXPORT_SYMBOL(cmm_get_timed_pages);
	482	EXPORT_SYMBOL(cmm_set_timeout);
	483
	484	MODULE_LICENSE("GPL");