Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
This commit is contained in:
Linus Torvalds
292
drivers/s390/char/vmwatchdog.c
Normal file
292
drivers/s390/char/vmwatchdog.c
Normal file
@@ -0,0 +1,292 @@
|
||||
/*
|
||||
* Watchdog implementation based on z/VM Watchdog Timer API
|
||||
*
|
||||
* The user space watchdog daemon can use this driver as
|
||||
* /dev/vmwatchdog to have z/VM execute the specified CP
|
||||
* command when the timeout expires. The default command is
|
||||
* "IPL", which which cause an immediate reboot.
|
||||
*/
|
||||
#include <linux/init.h>
|
||||
#include <linux/fs.h>
|
||||
#include <linux/kernel.h>
|
||||
#include <linux/miscdevice.h>
|
||||
#include <linux/module.h>
|
||||
#include <linux/moduleparam.h>
|
||||
#include <linux/watchdog.h>
|
||||
|
||||
#include <asm/ebcdic.h>
|
||||
#include <asm/io.h>
|
||||
#include <asm/uaccess.h>
|
||||
|
||||
#define MAX_CMDLEN 240
|
||||
#define MIN_INTERVAL 15
|
||||
static char vmwdt_cmd[MAX_CMDLEN] = "IPL";
|
||||
static int vmwdt_conceal;
|
||||
|
||||
#ifdef CONFIG_WATCHDOG_NOWAYOUT
|
||||
static int vmwdt_nowayout = 1;
|
||||
#else
|
||||
static int vmwdt_nowayout = 0;
|
||||
#endif
|
||||
|
||||
MODULE_LICENSE("GPL");
|
||||
MODULE_AUTHOR("Arnd Bergmann <arndb@de.ibm.com>");
|
||||
MODULE_DESCRIPTION("z/VM Watchdog Timer");
|
||||
module_param_string(cmd, vmwdt_cmd, MAX_CMDLEN, 0644);
|
||||
MODULE_PARM_DESC(cmd, "CP command that is run when the watchdog triggers");
|
||||
module_param_named(conceal, vmwdt_conceal, bool, 0644);
|
||||
MODULE_PARM_DESC(conceal, "Enable the CONCEAL CP option while the watchdog "
|
||||
" is active");
|
||||
module_param_named(nowayout, vmwdt_nowayout, bool, 0);
|
||||
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started"
|
||||
" (default=CONFIG_WATCHDOG_NOWAYOUT)");
|
||||
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
|
||||
|
||||
static unsigned int vmwdt_interval = 60;
|
||||
static unsigned long vmwdt_is_open;
|
||||
static int vmwdt_expect_close;
|
||||
|
||||
enum vmwdt_func {
|
||||
/* function codes */
|
||||
wdt_init = 0,
|
||||
wdt_change = 1,
|
||||
wdt_cancel = 2,
|
||||
/* flags */
|
||||
wdt_conceal = 0x80000000,
|
||||
};
|
||||
|
||||
static int __diag288(enum vmwdt_func func, unsigned int timeout,
|
||||
char *cmd, size_t len)
|
||||
{
|
||||
register unsigned long __func asm("2");
|
||||
register unsigned long __timeout asm("3");
|
||||
register unsigned long __cmdp asm("4");
|
||||
register unsigned long __cmdl asm("5");
|
||||
int err;
|
||||
|
||||
__func = func;
|
||||
__timeout = timeout;
|
||||
__cmdp = virt_to_phys(cmd);
|
||||
__cmdl = len;
|
||||
err = 0;
|
||||
asm volatile (
|
||||
#ifdef __s390x__
|
||||
"diag %2,%4,0x288\n"
|
||||
"1: \n"
|
||||
".section .fixup,\"ax\"\n"
|
||||
"2: lghi %0,%1\n"
|
||||
" jg 1b\n"
|
||||
".previous\n"
|
||||
".section __ex_table,\"a\"\n"
|
||||
" .align 8\n"
|
||||
" .quad 1b,2b\n"
|
||||
".previous\n"
|
||||
#else
|
||||
"diag %2,%4,0x288\n"
|
||||
"1: \n"
|
||||
".section .fixup,\"ax\"\n"
|
||||
"2: lhi %0,%1\n"
|
||||
" bras 1,3f\n"
|
||||
" .long 1b\n"
|
||||
"3: l 1,0(1)\n"
|
||||
" br 1\n"
|
||||
".previous\n"
|
||||
".section __ex_table,\"a\"\n"
|
||||
" .align 4\n"
|
||||
" .long 1b,2b\n"
|
||||
".previous\n"
|
||||
#endif
|
||||
: "+&d"(err)
|
||||
: "i"(-EINVAL), "d"(__func), "d"(__timeout),
|
||||
"d"(__cmdp), "d"(__cmdl)
|
||||
: "1", "cc");
|
||||
return err;
|
||||
}
|
||||
|
||||
static int vmwdt_keepalive(void)
|
||||
{
|
||||
/* we allocate new memory every time to avoid having
|
||||
* to track the state. static allocation is not an
|
||||
* option since that might not be contiguous in real
|
||||
* storage in case of a modular build */
|
||||
static char *ebc_cmd;
|
||||
size_t len;
|
||||
int ret;
|
||||
unsigned int func;
|
||||
|
||||
ebc_cmd = kmalloc(MAX_CMDLEN, GFP_KERNEL);
|
||||
if (!ebc_cmd)
|
||||
return -ENOMEM;
|
||||
|
||||
len = strlcpy(ebc_cmd, vmwdt_cmd, MAX_CMDLEN);
|
||||
ASCEBC(ebc_cmd, MAX_CMDLEN);
|
||||
EBC_TOUPPER(ebc_cmd, MAX_CMDLEN);
|
||||
|
||||
func = vmwdt_conceal ? (wdt_init | wdt_conceal) : wdt_init;
|
||||
ret = __diag288(func, vmwdt_interval, ebc_cmd, len);
|
||||
kfree(ebc_cmd);
|
||||
|
||||
if (ret) {
|
||||
printk(KERN_WARNING "%s: problem setting interval %d, "
|
||||
"cmd %s\n", __FUNCTION__, vmwdt_interval,
|
||||
vmwdt_cmd);
|
||||
}
|
||||
return ret;
|
||||
}
|
||||
|
||||
static int vmwdt_disable(void)
|
||||
{
|
||||
int ret = __diag288(wdt_cancel, 0, "", 0);
|
||||
if (ret) {
|
||||
printk(KERN_WARNING "%s: problem disabling watchdog\n",
|
||||
__FUNCTION__);
|
||||
}
|
||||
return ret;
|
||||
}
|
||||
|
||||
static int __init vmwdt_probe(void)
|
||||
{
|
||||
/* there is no real way to see if the watchdog is supported,
|
||||
* so we try initializing it with a NOP command ("BEGIN")
|
||||
* that won't cause any harm even if the following disable
|
||||
* fails for some reason */
|
||||
static char __initdata ebc_begin[] = {
|
||||
194, 197, 199, 201, 213
|
||||
};
|
||||
if (__diag288(wdt_init, 15, ebc_begin, sizeof(ebc_begin)) != 0) {
|
||||
printk(KERN_INFO "z/VM watchdog not available\n");
|
||||
return -EINVAL;
|
||||
}
|
||||
return vmwdt_disable();
|
||||
}
|
||||
|
||||
static int vmwdt_open(struct inode *i, struct file *f)
|
||||
{
|
||||
int ret;
|
||||
if (test_and_set_bit(0, &vmwdt_is_open))
|
||||
return -EBUSY;
|
||||
ret = vmwdt_keepalive();
|
||||
if (ret)
|
||||
clear_bit(0, &vmwdt_is_open);
|
||||
return ret ? ret : nonseekable_open(i, f);
|
||||
}
|
||||
|
||||
static int vmwdt_close(struct inode *i, struct file *f)
|
||||
{
|
||||
if (vmwdt_expect_close == 42)
|
||||
vmwdt_disable();
|
||||
vmwdt_expect_close = 0;
|
||||
clear_bit(0, &vmwdt_is_open);
|
||||
return 0;
|
||||
}
|
||||
|
||||
static struct watchdog_info vmwdt_info = {
|
||||
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
|
||||
.firmware_version = 0,
|
||||
.identity = "z/VM Watchdog Timer",
|
||||
};
|
||||
|
||||
static int vmwdt_ioctl(struct inode *i, struct file *f,
|
||||
unsigned int cmd, unsigned long arg)
|
||||
{
|
||||
switch (cmd) {
|
||||
case WDIOC_GETSUPPORT:
|
||||
if (copy_to_user((void __user *)arg, &vmwdt_info,
|
||||
sizeof(vmwdt_info)))
|
||||
return -EFAULT;
|
||||
return 0;
|
||||
case WDIOC_GETSTATUS:
|
||||
case WDIOC_GETBOOTSTATUS:
|
||||
return put_user(0, (int *)arg);
|
||||
case WDIOC_GETTEMP:
|
||||
return -EINVAL;
|
||||
case WDIOC_SETOPTIONS:
|
||||
{
|
||||
int options, ret;
|
||||
if (get_user(options, (int __user *)arg))
|
||||
return -EFAULT;
|
||||
ret = -EINVAL;
|
||||
if (options & WDIOS_DISABLECARD) {
|
||||
ret = vmwdt_disable();
|
||||
if (ret)
|
||||
return ret;
|
||||
}
|
||||
if (options & WDIOS_ENABLECARD) {
|
||||
ret = vmwdt_keepalive();
|
||||
}
|
||||
return ret;
|
||||
}
|
||||
case WDIOC_GETTIMEOUT:
|
||||
return put_user(vmwdt_interval, (int __user *)arg);
|
||||
case WDIOC_SETTIMEOUT:
|
||||
{
|
||||
int interval;
|
||||
if (get_user(interval, (int __user *)arg))
|
||||
return -EFAULT;
|
||||
if (interval < MIN_INTERVAL)
|
||||
return -EINVAL;
|
||||
vmwdt_interval = interval;
|
||||
}
|
||||
return vmwdt_keepalive();
|
||||
case WDIOC_KEEPALIVE:
|
||||
return vmwdt_keepalive();
|
||||
}
|
||||
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
static ssize_t vmwdt_write(struct file *f, const char __user *buf,
|
||||
size_t count, loff_t *ppos)
|
||||
{
|
||||
if(count) {
|
||||
if (!vmwdt_nowayout) {
|
||||
size_t i;
|
||||
|
||||
/* note: just in case someone wrote the magic character
|
||||
* five months ago... */
|
||||
vmwdt_expect_close = 0;
|
||||
|
||||
for (i = 0; i != count; i++) {
|
||||
char c;
|
||||
if (get_user(c, buf+i))
|
||||
return -EFAULT;
|
||||
if (c == 'V')
|
||||
vmwdt_expect_close = 42;
|
||||
}
|
||||
}
|
||||
/* someone wrote to us, we should restart timer */
|
||||
vmwdt_keepalive();
|
||||
}
|
||||
return count;
|
||||
}
|
||||
|
||||
static struct file_operations vmwdt_fops = {
|
||||
.open = &vmwdt_open,
|
||||
.release = &vmwdt_close,
|
||||
.ioctl = &vmwdt_ioctl,
|
||||
.write = &vmwdt_write,
|
||||
.owner = THIS_MODULE,
|
||||
};
|
||||
|
||||
static struct miscdevice vmwdt_dev = {
|
||||
.minor = WATCHDOG_MINOR,
|
||||
.name = "watchdog",
|
||||
.fops = &vmwdt_fops,
|
||||
};
|
||||
|
||||
static int __init vmwdt_init(void)
|
||||
{
|
||||
int ret;
|
||||
|
||||
ret = vmwdt_probe();
|
||||
if (ret)
|
||||
return ret;
|
||||
return misc_register(&vmwdt_dev);
|
||||
}
|
||||
module_init(vmwdt_init);
|
||||
|
||||
static void __exit vmwdt_exit(void)
|
||||
{
|
||||
WARN_ON(misc_deregister(&vmwdt_dev) != 0);
|
||||
}
|
||||
module_exit(vmwdt_exit);
|
||||
Reference in New Issue
Block a user