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linux/arch/s390/mm/cmm.c
Heiko Carstens a53c8fab3f s390/comments: unify copyright messages and remove file names 
Remove the file name from the comment at top of many files. In most
cases the file name was wrong anyway, so it's rather pointless.

Also unify the IBM copyright statement. We did have a lot of sightly
different statements and wanted to change them one after another
whenever a file gets touched. However that never happened. Instead
people start to take the old/"wrong" statements to use as a template
for new files.
So unify all of them in one go.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2012-07-20 11:15:04 +02:00

498 lines
11 KiB
C
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/*
* 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/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;
}
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_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;
}
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();
}
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 struct ctl_table cmm_table[];
static int cmm_pages_handler(ctl_table *ctl, int write, 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, 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,
},
{ }
};
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 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;
}
static int cmm_resume(void)
{
cmm_suspended = 0;
cmm_kick_thread();
return 0;
}
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;
}
}
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");
rc = IS_ERR(cmm_thread_ptr) ? PTR_ERR(cmm_thread_ptr) : 0;
if (rc)
goto out_kthread;
return 0;
out_kthread:
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;
}
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);
}
module_exit(cmm_exit);
MODULE_LICENSE("GPL");
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