Release 4.14 arch/s390/mm/cmm.c

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

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

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

#ifdef CONFIG_CMM_IUCV

static char *cmm_default_sender = "VMRMSVM";
#endif

static char *sender;
module_param(sender, charp, 0400);
MODULE_PARM_DESC(sender,
		 "Guest name that may send SMSG messages (default VMRMSVM)");

#include "../../../drivers/s390/net/smsgiucv.h"


#define CMM_NR_PAGES ((PAGE_SIZE / sizeof(unsigned long)) - 2)


struct cmm_page_array {
	
struct cmm_page_array *next;
	
unsigned long index;
	
unsigned long pages[CMM_NR_PAGES];
};


static long cmm_pages;

static long cmm_timed_pages;

static volatile long cmm_pages_target;

static volatile long cmm_timed_pages_target;

static long cmm_timeout_pages;

static long cmm_timeout_seconds;

static int cmm_suspended;


static struct cmm_page_array *cmm_page_list;

static struct cmm_page_array *cmm_timed_page_list;
static DEFINE_SPINLOCK(cmm_lock);


static struct task_struct *cmm_thread_ptr;
static DECLARE_WAIT_QUEUE_HEAD(cmm_thread_wait);
static DEFINE_TIMER(cmm_timer, NULL, 0, 0);

static void cmm_timer_fn(unsigned long);
static void cmm_set_timer(void);



static long cmm_alloc_pages(long nr, long *counter,
			    struct cmm_page_array **list)
{
	struct cmm_page_array *pa, *npa;
	unsigned long addr;

	while (nr) {
		addr = __get_free_page(GFP_NOIO);
		if (!addr)
			break;
		spin_lock(&cmm_lock);
		pa = *list;
		if (!pa || pa->index >= CMM_NR_PAGES) {
			/* Need a new page for the page list. */
			spin_unlock(&cmm_lock);
			npa = (struct cmm_page_array *)
				__get_free_page(GFP_NOIO);
			if (!npa) {
				free_page(addr);
				break;
			}
			spin_lock(&cmm_lock);
			pa = *list;
			if (!pa || pa->index >= CMM_NR_PAGES) {
				npa->next = pa;
				npa->index = 0;
				pa = npa;
				*list = pa;
			} else
				free_page((unsigned long) npa);
		}
		diag10_range(addr >> PAGE_SHIFT, 1);
		pa->pages[pa->index++] = addr;
		(*counter)++;
		spin_unlock(&cmm_lock);
		nr--;
	}
	return nr;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Andrew Morton
118
59.00%
1
33.33%
Martin Schwidefsky
77
38.50%
1
33.33%
Michael Holzheu
5
2.50%
1
33.33%
Total
200
100.00%
3
100.00%



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;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Andrew Morton
101
82.11%
1
50.00%
Martin Schwidefsky
22
17.89%
1
50.00%
Total
123
100.00%
2
100.00%



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;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Martin Schwidefsky
81
100.00%
1
100.00%
Total
81
100.00%
1
100.00%


static struct notifier_block cmm_oom_nb = {
	.notifier_call = cmm_oom_notify,
};



static int cmm_thread(void *dummy)
{
	int rc;

	while (1) {
		rc = wait_event_interruptible(cmm_thread_wait,
			(!cmm_suspended && (cmm_pages != cmm_pages_target ||
			 cmm_timed_pages != cmm_timed_pages_target)) ||
			 kthread_should_stop());
		if (kthread_should_stop() || rc == -ERESTARTSYS) {
			cmm_pages_target = cmm_pages;
			cmm_timed_pages_target = cmm_timed_pages;
			break;
		}
		if (cmm_pages_target > cmm_pages) {
			if (cmm_alloc_pages(1, &cmm_pages, &cmm_page_list))
				cmm_pages_target = cmm_pages;
		} else if (cmm_pages_target < cmm_pages) {
			cmm_free_pages(1, &cmm_pages, &cmm_page_list);
		}
		if (cmm_timed_pages_target > cmm_timed_pages) {
			if (cmm_alloc_pages(1, &cmm_timed_pages,
					   &cmm_timed_page_list))
				cmm_timed_pages_target = cmm_timed_pages;
		} else if (cmm_timed_pages_target < cmm_timed_pages) {
			cmm_free_pages(1, &cmm_timed_pages,
				       &cmm_timed_page_list);
		}
		if (cmm_timed_pages > 0 && !timer_pending(&cmm_timer))
			cmm_set_timer();
	}
	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Andrew Morton
162
93.10%
1
33.33%
Martin Schwidefsky
6
3.45%
1
33.33%
Heiko Carstens
6
3.45%
1
33.33%
Total
174
100.00%
3
100.00%



static void cmm_kick_thread(void)
{
	wake_up(&cmm_thread_wait);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Andrew Morton
14
100.00%
1
100.00%
Total
14
100.00%
1
100.00%



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);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Andrew Morton
88
100.00%
1
100.00%
Total
88
100.00%
1
100.00%



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();
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Andrew Morton
36
90.00%
1
50.00%
Martin Schwidefsky
4
10.00%
1
50.00%
Total
40
100.00%
2
100.00%



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

Contributors
Person
Tokens
Prop
Commits
CommitProp
Andrew Morton
12
75.00%
1
33.33%
Heiko Carstens
2
12.50%
1
33.33%
Martin Schwidefsky
2
12.50%
1
33.33%
Total
16
100.00%
3
100.00%



static long cmm_get_pages(void)
{
	return cmm_pages;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Andrew Morton
9
81.82%
1
50.00%
Heiko Carstens
2
18.18%
1
50.00%
Total
11
100.00%
2
100.00%



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

Contributors
Person
Tokens
Prop
Commits
CommitProp
Andrew Morton
12
75.00%
1
33.33%
Martin Schwidefsky
2
12.50%
1
33.33%
Heiko Carstens
2
12.50%
1
33.33%
Total
16
100.00%
3
100.00%



static long cmm_get_timed_pages(void)
{
	return cmm_timed_pages;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Andrew Morton
9
81.82%
1
50.00%
Heiko Carstens
2
18.18%
1
50.00%
Total
11
100.00%
2
100.00%



static void cmm_set_timeout(long nr, long seconds)
{
	cmm_timeout_pages = nr;
	cmm_timeout_seconds = seconds;
	cmm_set_timer();
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Andrew Morton
19
82.61%
1
33.33%
Heiko Carstens
2
8.70%
1
33.33%
Martin Schwidefsky
2
8.70%
1
33.33%
Total
23
100.00%
3
100.00%



static int cmm_skip_blanks(char *cp, char **endp)
{
	char *str;

	for (str = cp; *str == ' ' || *str == '\t'; str++)
		;
	*endp = str;
	return str != cp;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Andrew Morton
49
100.00%
1
100.00%
Total
49
100.00%
1
100.00%


static struct ctl_table cmm_table[];



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

	if (!*lenp || (*ppos && !write)) {
		*lenp = 0;
		return 0;
	}

	if (write) {
		len = *lenp;
		if (copy_from_user(buf, buffer,
				   len > sizeof(buf) ? sizeof(buf) : len))
			return -EFAULT;
		buf[sizeof(buf) - 1] = '\0';
		cmm_skip_blanks(buf, &p);
		nr = simple_strtoul(p, &p, 0);
		if (ctl == &cmm_table[0])
			cmm_set_pages(nr);
		else
			cmm_add_timed_pages(nr);
	} else {
		if (ctl == &cmm_table[0])
			nr = cmm_get_pages();
		else
			nr = cmm_get_timed_pages();
		len = sprintf(buf, "%ld\n", nr);
		if (len > *lenp)
			len = *lenp;
		if (copy_to_user(buffer, buf, len))
			return -EFAULT;
	}
	*lenp = len;
	*ppos += len;
	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Andrew Morton
210
90.13%
1
14.29%
Linus Torvalds
8
3.43%
1
14.29%
Heiko Carstens
7
3.00%
2
28.57%
Martin Schwidefsky
6
2.58%
1
14.29%
Joe Perches
1
0.43%
1
14.29%
Al Viro
1
0.43%
1
14.29%
Total
233
100.00%
7
100.00%



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

	if (!*lenp || (*ppos && !write)) {
		*lenp = 0;
		return 0;
	}

	if (write) {
		len = *lenp;
		if (copy_from_user(buf, buffer,
				   len > sizeof(buf) ? sizeof(buf) : len))
			return -EFAULT;
		buf[sizeof(buf) - 1] = '\0';
		cmm_skip_blanks(buf, &p);
		nr = simple_strtoul(p, &p, 0);
		cmm_skip_blanks(p, &p);
		seconds = simple_strtoul(p, &p, 0);
		cmm_set_timeout(nr, seconds);
	} else {
		len = sprintf(buf, "%ld %ld\n",
			      cmm_timeout_pages, cmm_timeout_seconds);
		if (len > *lenp)
			len = *lenp;
		if (copy_to_user(buffer, buf, len))
			return -EFAULT;
	}
	*lenp = len;
	*ppos += len;
	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Andrew Morton
202
90.99%
1
14.29%
Linus Torvalds
8
3.60%
1
14.29%
Heiko Carstens
7
3.15%
2
28.57%
Martin Schwidefsky
3
1.35%
1
14.29%
Al Viro
1
0.45%
1
14.29%
Joe Perches
1
0.45%
1
14.29%
Total
222
100.00%
7
100.00%


static struct ctl_table cmm_table[] = {
	{
		.procname	= "cmm_pages",
		.mode		= 0644,
		.proc_handler	= cmm_pages_handler,
        },
	{
		.procname	= "cmm_timed_pages",
		.mode		= 0644,
		.proc_handler	= cmm_pages_handler,
        },
	{
		.procname	= "cmm_timeout",
		.mode		= 0644,
		.proc_handler	= cmm_timeout_handler,
        },
	{ }
};


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

#ifdef CONFIG_CMM_IUCV

#define SMSG_PREFIX "CMM"


static void cmm_smsg_target(const char *from, char *msg)
{
	long nr, seconds;

	if (strlen(sender) > 0 && strcmp(from, sender) != 0)
		return;
	if (!cmm_skip_blanks(msg + strlen(SMSG_PREFIX), &msg))
		return;
	if (strncmp(msg, "SHRINK", 6) == 0) {
		if (!cmm_skip_blanks(msg + 6, &msg))
			return;
		nr = simple_strtoul(msg, &msg, 0);
		cmm_skip_blanks(msg, &msg);
		if (*msg == '\0')
			cmm_set_pages(nr);
	} else if (strncmp(msg, "RELEASE", 7) == 0) {
		if (!cmm_skip_blanks(msg + 7, &msg))
			return;
		nr = simple_strtoul(msg, &msg, 0);
		cmm_skip_blanks(msg, &msg);
		if (*msg == '\0')
			cmm_add_timed_pages(nr);
	} else if (strncmp(msg, "REUSE", 5) == 0) {
		if (!cmm_skip_blanks(msg + 5, &msg))
			return;
		nr = simple_strtoul(msg, &msg, 0);
		if (!cmm_skip_blanks(msg, &msg))
			return;
		seconds = simple_strtoul(msg, &msg, 0);
		cmm_skip_blanks(msg, &msg);
		if (*msg == '\0')
			cmm_set_timeout(nr, seconds);
	}
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Andrew Morton
224
83.90%
1
20.00%
Martin Schwidefsky
30
11.24%
2
40.00%
Heiko Carstens
12
4.49%
1
20.00%
Hendrik Brueckner
1
0.37%
1
20.00%
Total
267
100.00%
5
100.00%

#endif


static struct ctl_table_header *cmm_sysctl_header;



static int cmm_suspend(void)
{
	cmm_suspended = 1;
	cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list);
	cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list);
	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Martin Schwidefsky
37
100.00%
1
100.00%
Total
37
100.00%
1
100.00%



static int cmm_resume(void)
{
	cmm_suspended = 0;
	cmm_kick_thread();
	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Martin Schwidefsky
18
100.00%
1
100.00%
Total
18
100.00%
1
100.00%



static int cmm_power_event(struct notifier_block *this,
			   unsigned long event, void *ptr)
{
	switch (event) {
	case PM_POST_HIBERNATION:
		return cmm_resume();
	case PM_HIBERNATION_PREPARE:
		return cmm_suspend();
	default:
		return NOTIFY_DONE;
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Martin Schwidefsky
43
100.00%
1
100.00%
Total
43
100.00%
1
100.00%


static struct notifier_block cmm_power_notifier = {
	.notifier_call = cmm_power_event,
};



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

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

	rc = smsg_register_callback(SMSG_PREFIX, cmm_smsg_target);
	if (rc < 0)
		goto out_smsg;
#endif
	rc = register_oom_notifier(&cmm_oom_nb);
	if (rc < 0)
		goto out_oom_notify;
	rc = register_pm_notifier(&cmm_power_notifier);
	if (rc)
		goto out_pm;
	cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread");
	if (!IS_ERR(cmm_thread_ptr))
		return 0;

	rc = PTR_ERR(cmm_thread_ptr);
	unregister_pm_notifier(&cmm_power_notifier);
out_pm:
	unregister_oom_notifier(&cmm_oom_nb);
out_oom_notify:
#ifdef CONFIG_CMM_IUCV
	smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
out_smsg:
#endif
	unregister_sysctl_table(cmm_sysctl_header);
out_sysctl:
	del_timer_sync(&cmm_timer);
	return rc;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Heiko Carstens
86
43.00%
4
40.00%
Andrew Morton
39
19.50%
1
10.00%
Hendrik Brueckner
33
16.50%
1
10.00%
Martin Schwidefsky
32
16.00%
2
20.00%
Alexandru Gheorghiu
9
4.50%
1
10.00%
Al Viro
1
0.50%
1
10.00%
Total
200
100.00%
10
100.00%


module_init(cmm_init);



static void __exit cmm_exit(void)
{
	unregister_sysctl_table(cmm_sysctl_header);
#ifdef CONFIG_CMM_IUCV
	smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
#endif
	unregister_pm_notifier(&cmm_power_notifier);
	unregister_oom_notifier(&cmm_oom_nb);
	kthread_stop(cmm_thread_ptr);
	del_timer_sync(&cmm_timer);
	cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list);
	cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list);
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Andrew Morton
30
42.25%
1
16.67%
Heiko Carstens
29
40.85%
3
50.00%
Martin Schwidefsky
12
16.90%
2
33.33%
Total
71
100.00%
6
100.00%


module_exit(cmm_exit);

MODULE_LICENSE("GPL");
Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
Andrew Morton
1565
68.43%
1
3.70%
Martin Schwidefsky
440
19.24%
4
14.81%
Heiko Carstens
199
8.70%
10
37.04%
Hendrik Brueckner
34
1.49%
2
7.41%
Linus Torvalds
16
0.70%
1
3.70%
Alexandru Gheorghiu
9
0.39%
1
3.70%
Michael Holzheu
8
0.35%
2
7.41%
David Rientjes
3
0.13%
1
3.70%
Al Viro
3
0.13%
1
3.70%
Tejun Heo
3
0.13%
1
3.70%
Paul Gortmaker
3
0.13%
1
3.70%
Joe Perches
2
0.09%
1
3.70%
Eric W. Biedermann
2
0.09%
1
3.70%
Total
2287
100.00%
27
100.00%
Directory: arch/s390/mm

Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.