swh:1:snp:49cd9498d6cccc5e78252c27dcb645bcf7bf0c91
Tip revision: 741b2252a5e14d6c60a913c77a6099abe73a854a authored by Linus Torvalds on 28 October 2005, 00:02:08 UTC
Linux v2.6.14
Linux v2.6.14
Tip revision: 741b225
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/config.h>
#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 <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 = 0;
static long cmm_timed_pages = 0;
static volatile long cmm_pages_target = 0;
static volatile long cmm_timed_pages_target = 0;
static long cmm_timeout_pages = 0;
static long cmm_timeout_seconds = 0;
static struct cmm_page_array *cmm_page_list = 0;
static struct cmm_page_array *cmm_timed_page_list = 0;
static unsigned long cmm_thread_active = 0;
static struct work_struct cmm_thread_starter;
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_strtoul(const char *cp, char **endp)
{
unsigned int base = 10;
if (*cp == '0') {
base = 8;
cp++;
if ((*cp == 'x' || *cp == 'X') && isxdigit(cp[1])) {
base = 16;
cp++;
}
}
return simple_strtoul(cp, endp, base);
}
static long
cmm_alloc_pages(long pages, long *counter, struct cmm_page_array **list)
{
struct cmm_page_array *pa;
unsigned long page;
pa = *list;
while (pages) {
page = __get_free_page(GFP_NOIO);
if (!page)
break;
if (!pa || pa->index >= CMM_NR_PAGES) {
/* Need a new page for the page list. */
pa = (struct cmm_page_array *)
__get_free_page(GFP_NOIO);
if (!pa) {
free_page(page);
break;
}
pa->next = *list;
pa->index = 0;
*list = pa;
}
diag10(page);
pa->pages[pa->index++] = page;
(*counter)++;
pages--;
}
return pages;
}
static void
cmm_free_pages(long pages, long *counter, struct cmm_page_array **list)
{
struct cmm_page_array *pa;
unsigned long page;
pa = *list;
while (pages) {
if (!pa || pa->index <= 0)
break;
page = pa->pages[--pa->index];
if (pa->index == 0) {
pa = pa->next;
free_page((unsigned long) *list);
*list = pa;
}
free_page(page);
(*counter)--;
pages--;
}
}
static int
cmm_thread(void *dummy)
{
int rc;
daemonize("cmmthread");
while (1) {
rc = wait_event_interruptible(cmm_thread_wait,
(cmm_pages != cmm_pages_target ||
cmm_timed_pages != cmm_timed_pages_target));
if (rc == -ERESTARTSYS) {
/* Got kill signal. End thread. */
clear_bit(0, &cmm_thread_active);
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_start_thread(void)
{
kernel_thread(cmm_thread, 0, 0);
}
static void
cmm_kick_thread(void)
{
if (!test_and_set_bit(0, &cmm_thread_active))
schedule_work(&cmm_thread_starter);
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 pages;
pages = cmm_timed_pages_target - cmm_timeout_pages;
if (pages < 0)
cmm_timed_pages_target = 0;
else
cmm_timed_pages_target = pages;
cmm_kick_thread();
cmm_set_timer();
}
void
cmm_set_pages(long pages)
{
cmm_pages_target = pages;
cmm_kick_thread();
}
long
cmm_get_pages(void)
{
return cmm_pages;
}
void
cmm_add_timed_pages(long pages)
{
cmm_timed_pages_target += pages;
cmm_kick_thread();
}
long
cmm_get_timed_pages(void)
{
return cmm_timed_pages;
}
void
cmm_set_timeout(long pages, long seconds)
{
cmm_timeout_pages = pages;
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 *buffer, size_t *lenp, loff_t *ppos)
{
char buf[16], *p;
long pages;
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);
pages = cmm_strtoul(p, &p);
if (ctl == &cmm_table[0])
cmm_set_pages(pages);
else
cmm_add_timed_pages(pages);
} else {
if (ctl == &cmm_table[0])
pages = cmm_get_pages();
else
pages = cmm_get_timed_pages();
len = sprintf(buf, "%ld\n", pages);
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 *buffer, size_t *lenp, loff_t *ppos)
{
char buf[64], *p;
long pages, 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);
pages = cmm_strtoul(p, &p);
cmm_skip_blanks(p, &p);
seconds = cmm_strtoul(p, &p);
cmm_set_timeout(pages, 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 = 0600,
.proc_handler = &cmm_pages_handler,
},
{
.ctl_name = VM_CMM_TIMED_PAGES,
.procname = "cmm_timed_pages",
.mode = 0600,
.proc_handler = &cmm_pages_handler,
},
{
.ctl_name = VM_CMM_TIMEOUT,
.procname = "cmm_timeout",
.mode = 0600,
.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 pages, 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;
pages = cmm_strtoul(msg, &msg);
cmm_skip_blanks(msg, &msg);
if (*msg == '\0')
cmm_set_pages(pages);
} else if (strncmp(msg, "RELEASE", 7) == 0) {
if (!cmm_skip_blanks(msg + 7, &msg))
return;
pages = cmm_strtoul(msg, &msg);
cmm_skip_blanks(msg, &msg);
if (*msg == '\0')
cmm_add_timed_pages(pages);
} else if (strncmp(msg, "REUSE", 5) == 0) {
if (!cmm_skip_blanks(msg + 5, &msg))
return;
pages = cmm_strtoul(msg, &msg);
if (!cmm_skip_blanks(msg, &msg))
return;
seconds = cmm_strtoul(msg, &msg);
cmm_skip_blanks(msg, &msg);
if (*msg == '\0')
cmm_set_timeout(pages, seconds);
}
}
#endif
struct ctl_table_header *cmm_sysctl_header;
static int
cmm_init (void)
{
#ifdef CONFIG_CMM_PROC
cmm_sysctl_header = register_sysctl_table(cmm_dir_table, 1);
#endif
#ifdef CONFIG_CMM_IUCV
smsg_register_callback(SMSG_PREFIX, cmm_smsg_target);
#endif
INIT_WORK(&cmm_thread_starter, (void *) cmm_start_thread, 0);
init_waitqueue_head(&cmm_thread_wait);
init_timer(&cmm_timer);
return 0;
}
static void
cmm_exit(void)
{
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");