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s390/watchdog: use watchdog API 

Converted the vmwatchdog driver to use the kernel's watchdog API.

Signed-off-by: Philipp Hachtmann <phacht@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Philipp Hachtmann 2014-06-05 11:01:43 +02:00 committed by Martin Schwidefsky
parent f2485f5d1c
commit f7a94db4e9
8 changed files with 294 additions and 341 deletions
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1
arch/s390/configs/default_defconfig
View File

@ -456,6 +456,7 @@ CONFIG_TN3270_FS=y
CONFIG_WATCHDOG=y
CONFIG_WATCHDOG_NOWAYOUT=y
CONFIG_SOFT_WATCHDOG=m
CONFIG_DIAG288_WATCHDOG=m
# CONFIG_HID is not set
# CONFIG_USB_SUPPORT is not set
CONFIG_INFINIBAND=m

1
arch/s390/configs/gcov_defconfig
View File

@ -453,6 +453,7 @@ CONFIG_TN3270_FS=y
CONFIG_WATCHDOG=y
CONFIG_WATCHDOG_NOWAYOUT=y
CONFIG_SOFT_WATCHDOG=m
CONFIG_DIAG288_WATCHDOG=m
# CONFIG_HID is not set
# CONFIG_USB_SUPPORT is not set
CONFIG_INFINIBAND=m

1
arch/s390/configs/performance_defconfig
View File

@ -451,6 +451,7 @@ CONFIG_TN3270_FS=y
CONFIG_WATCHDOG=y
CONFIG_WATCHDOG_NOWAYOUT=y
CONFIG_SOFT_WATCHDOG=m
CONFIG_DIAG288_WATCHDOG=m
# CONFIG_HID is not set
# CONFIG_USB_SUPPORT is not set
CONFIG_INFINIBAND=m

1
drivers/s390/char/Makefile
View File

@ -19,7 +19,6 @@ obj-$(CONFIG_SCLP_VT220_TTY) += sclp_vt220.o
obj-$(CONFIG_SCLP_CPI) += sclp_cpi.o
obj-$(CONFIG_SCLP_ASYNC) += sclp_async.o
obj-$(CONFIG_ZVM_WATCHDOG) += vmwatchdog.o
obj-$(CONFIG_VMLOGRDR) += vmlogrdr.o
obj-$(CONFIG_VMCP) += vmcp.o

338
drivers/s390/char/vmwatchdog.c
View File

@ -1,338 +0,0 @@
/*
* Watchdog implementation based on z/VM Watchdog Timer API
*
* Copyright IBM Corp. 2004, 2009
*
* 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.
*/
#define KMSG_COMPONENT "vmwatchdog"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#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/slab.h>
#include <linux/suspend.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 bool vmwdt_conceal;
static bool vmwdt_nowayout = WATCHDOG_NOWAYOUT;
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;
static DEFINE_MUTEX(vmwdt_mutex);
#define VMWDT_OPEN 0 /* devnode is open or suspend in progress */
#define VMWDT_RUNNING 1 /* The watchdog is armed */
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") = func;
register unsigned long __timeout asm("3") = timeout;
register unsigned long __cmdp asm("4") = virt_to_phys(cmd);
register unsigned long __cmdl asm("5") = len;
int err;
err = -EINVAL;
asm volatile(
" diag %1,%3,0x288\n"
"0: la %0,0\n"
"1:\n"
EX_TABLE(0b,1b)
: "+d" (err) : "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;
set_bit(VMWDT_RUNNING, &vmwdt_is_open);
ret = __diag288(func, vmwdt_interval, ebc_cmd, len);
WARN_ON(ret != 0);
kfree(ebc_cmd);
return ret;
}
static int vmwdt_disable(void)
{
char cmd[] = {'\0'};
int ret = __diag288(wdt_cancel, 0, cmd, 0);
WARN_ON(ret != 0);
clear_bit(VMWDT_RUNNING, &vmwdt_is_open);
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 */
char ebc_begin[] = {
194, 197, 199, 201, 213
};
if (__diag288(wdt_init, 15, ebc_begin, sizeof(ebc_begin)) != 0)
return -EINVAL;
return vmwdt_disable();
}
static int vmwdt_open(struct inode *i, struct file *f)
{
int ret;
if (test_and_set_bit(VMWDT_OPEN, &vmwdt_is_open))
return -EBUSY;
ret = vmwdt_keepalive();
if (ret)
clear_bit(VMWDT_OPEN, &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(VMWDT_OPEN, &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(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 __user *)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 long vmwdt_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
{
int rc;
mutex_lock(&vmwdt_mutex);
rc = __vmwdt_ioctl(cmd, arg);
mutex_unlock(&vmwdt_mutex);
return (long) rc;
}
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 int vmwdt_resume(void)
{
clear_bit(VMWDT_OPEN, &vmwdt_is_open);
return NOTIFY_DONE;
}
/*
* It makes no sense to go into suspend while the watchdog is running.
* Depending on the memory size, the watchdog might trigger, while we
* are still saving the memory.
* We reuse the open flag to ensure that suspend and watchdog open are
* exclusive operations
*/
static int vmwdt_suspend(void)
{
if (test_and_set_bit(VMWDT_OPEN, &vmwdt_is_open)) {
pr_err("The system cannot be suspended while the watchdog"
" is in use\n");
return notifier_from_errno(-EBUSY);
}
if (test_bit(VMWDT_RUNNING, &vmwdt_is_open)) {
clear_bit(VMWDT_OPEN, &vmwdt_is_open);
pr_err("The system cannot be suspended while the watchdog"
" is running\n");
return notifier_from_errno(-EBUSY);
}
return NOTIFY_DONE;
}
/*
* This function is called for suspend and resume.
*/
static int vmwdt_power_event(struct notifier_block *this, unsigned long event,
void *ptr)
{
switch (event) {
case PM_POST_HIBERNATION:
case PM_POST_SUSPEND:
return vmwdt_resume();
case PM_HIBERNATION_PREPARE:
case PM_SUSPEND_PREPARE:
return vmwdt_suspend();
default:
return NOTIFY_DONE;
}
}
static struct notifier_block vmwdt_power_notifier = {
.notifier_call = vmwdt_power_event,
};
static const struct file_operations vmwdt_fops = {
.open = &vmwdt_open,
.release = &vmwdt_close,
.unlocked_ioctl = &vmwdt_ioctl,
.write = &vmwdt_write,
.owner = THIS_MODULE,
.llseek = noop_llseek,
};
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;
ret = register_pm_notifier(&vmwdt_power_notifier);
if (ret)
return ret;
/*
* misc_register() has to be the last action in module_init(), because
* file operations will be available right after this.
*/
ret = misc_register(&vmwdt_dev);
if (ret) {
unregister_pm_notifier(&vmwdt_power_notifier);
return ret;
}
return 0;
}
module_init(vmwdt_init);
static void __exit vmwdt_exit(void)
{
unregister_pm_notifier(&vmwdt_power_notifier);
misc_deregister(&vmwdt_dev);
}
module_exit(vmwdt_exit);

5
drivers/watchdog/Kconfig
View File

@ -1295,9 +1295,10 @@ config WATCHDOG_RTAS
# S390 Architecture
config ZVM_WATCHDOG
tristate "z/VM Watchdog Timer"
config DIAG288_WATCHDOG
tristate "System z diag288 Watchdog"
depends on S390
select WATCHDOG_CORE
help
IBM s/390 and zSeries machines running under z/VM 5.1 or later
provide a virtual watchdog timer to their guest that cause a

1
drivers/watchdog/Makefile
View File

@ -154,6 +154,7 @@ obj-$(CONFIG_MEN_A21_WDT) += mena21_wdt.o
obj-$(CONFIG_WATCHDOG_RTAS) += wdrtas.o
# S390 Architecture
obj-$(CONFIG_DIAG288_WATCHDOG) += diag288_wdt.o
# SUPERH (sh + sh64) Architecture
obj-$(CONFIG_SH_WDT) += shwdt.o

287
drivers/watchdog/diag288_wdt.c Normal file
View File

@ -0,0 +1,287 @@
/*
* Watchdog driver for z/VM using the diag 288 interface.
*
* Under z/VM, expiration of the watchdog will send a "system restart" command
* to CP.
*
* The command can be altered using the module parameter "cmd".
*
* Copyright IBM Corp. 2004, 2013
* Author(s): Arnd Bergmann (arndb@de.ibm.com)
* Philipp Hachtmann (phacht@de.ibm.com)
*
*/
#define KMSG_COMPONENT "diag288_wdt"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/slab.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/suspend.h>
#include <asm/ebcdic.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#define MAX_CMDLEN 240
#define DEFAULT_CMD "SYSTEM RESTART"
#define MIN_INTERVAL 15 /* Minimal time supported by diag88 */
#define MAX_INTERVAL 3600 /* One hour should be enough - pure estimation */
#define WDT_DEFAULT_TIMEOUT 30
/* Function codes - init, change, cancel */
#define WDT_FUNC_INIT 0
#define WDT_FUNC_CHANGE 1
#define WDT_FUNC_CANCEL 2
#define WDT_FUNC_CONCEAL 0x80000000
static char wdt_cmd[MAX_CMDLEN] = DEFAULT_CMD;
static bool conceal_on;
static bool nowayout_info = WATCHDOG_NOWAYOUT;
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Arnd Bergmann <arndb@de.ibm.com>");
MODULE_AUTHOR("Philipp Hachtmann <phacht@de.ibm.com>");
MODULE_DESCRIPTION("System z diag288 Watchdog Timer");
module_param_string(cmd, wdt_cmd, MAX_CMDLEN, 0644);
MODULE_PARM_DESC(cmd, "CP command that is run when the watchdog triggers (z/VM only)");
module_param_named(conceal, conceal_on, bool, 0644);
MODULE_PARM_DESC(conceal, "Enable the CONCEAL CP option while the watchdog is active (z/VM only)");
module_param_named(nowayout, nowayout_info, bool, 0444);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default = CONFIG_WATCHDOG_NOWAYOUT)");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
MODULE_ALIAS("vmwatchdog");
static int __diag288(unsigned int func, unsigned int timeout,
unsigned long action, unsigned int len)
{
register unsigned long __func asm("2") = func;
register unsigned long __timeout asm("3") = timeout;
register unsigned long __action asm("4") = action;
register unsigned long __len asm("5") = len;
int err;
err = -EINVAL;
asm volatile(
" diag %1, %3, 0x288\n"
"0: la %0, 0\n"
"1:\n"
EX_TABLE(0b, 1b)
: "+d" (err) : "d"(__func), "d"(__timeout),
"d"(__action), "d"(__len) : "1", "cc");
return err;
}
static int __diag288_vm(unsigned int func, unsigned int timeout,
char *cmd, size_t len)
{
return __diag288(func, timeout, virt_to_phys(cmd), len);
}
static int wdt_start(struct watchdog_device *dev)
{
char *ebc_cmd;
size_t len;
int ret;
unsigned int func;
ret = -ENODEV;
if (MACHINE_IS_VM) {
ebc_cmd = kmalloc(MAX_CMDLEN, GFP_KERNEL);
if (!ebc_cmd)
return -ENOMEM;
len = strlcpy(ebc_cmd, wdt_cmd, MAX_CMDLEN);
ASCEBC(ebc_cmd, MAX_CMDLEN);
EBC_TOUPPER(ebc_cmd, MAX_CMDLEN);
func = conceal_on ? (WDT_FUNC_INIT | WDT_FUNC_CONCEAL)
: WDT_FUNC_INIT;
ret = __diag288_vm(func, dev->timeout, ebc_cmd, len);
WARN_ON(ret != 0);
kfree(ebc_cmd);
}
if (ret) {
pr_err("The watchdog cannot be activated\n");
return ret;
}
pr_info("The watchdog was activated\n");
return 0;
}
static int wdt_stop(struct watchdog_device *dev)
{
int ret;
ret = __diag288(WDT_FUNC_CANCEL, 0, 0, 0);
pr_info("The watchdog was deactivated\n");
return ret;
}
static int wdt_ping(struct watchdog_device *dev)
{
char *ebc_cmd;
size_t len;
int ret;
unsigned int func;
ret = -ENODEV;
if (MACHINE_IS_VM) {
ebc_cmd = kmalloc(MAX_CMDLEN, GFP_KERNEL);
if (!ebc_cmd)
return -ENOMEM;
len = strlcpy(ebc_cmd, wdt_cmd, MAX_CMDLEN);
ASCEBC(ebc_cmd, MAX_CMDLEN);
EBC_TOUPPER(ebc_cmd, MAX_CMDLEN);
/*
* It seems to be ok to z/VM to use the init function to
* retrigger the watchdog.
*/
func = conceal_on ? (WDT_FUNC_INIT | WDT_FUNC_CONCEAL)
: WDT_FUNC_INIT;
ret = __diag288_vm(func, dev->timeout, ebc_cmd, len);
WARN_ON(ret != 0);
kfree(ebc_cmd);
}
if (ret)
pr_err("The watchdog timer cannot be started or reset\n");
return ret;
}
static int wdt_set_timeout(struct watchdog_device * dev, unsigned int new_to)
{
dev->timeout = new_to;
return wdt_ping(dev);
}
static struct watchdog_ops wdt_ops = {
.owner = THIS_MODULE,
.start = wdt_start,
.stop = wdt_stop,
.ping = wdt_ping,
.set_timeout = wdt_set_timeout,
};
static struct watchdog_info wdt_info = {
.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
.firmware_version = 0,
.identity = "z Watchdog",
};
static struct watchdog_device wdt_dev = {
.parent = NULL,
.info = &wdt_info,
.ops = &wdt_ops,
.bootstatus = 0,
.timeout = WDT_DEFAULT_TIMEOUT,
.min_timeout = MIN_INTERVAL,
.max_timeout = MAX_INTERVAL,
};
/*
* It makes no sense to go into suspend while the watchdog is running.
* Depending on the memory size, the watchdog might trigger, while we
* are still saving the memory.
* We reuse the open flag to ensure that suspend and watchdog open are
* exclusive operations
*/
static int wdt_suspend(void)
{
if (test_and_set_bit(WDOG_DEV_OPEN, &wdt_dev.status)) {
pr_err("Linux cannot be suspended while the watchdog is in use\n");
return notifier_from_errno(-EBUSY);
}
if (test_bit(WDOG_ACTIVE, &wdt_dev.status)) {
clear_bit(WDOG_DEV_OPEN, &wdt_dev.status);
pr_err("Linux cannot be suspended while the watchdog is in use\n");
return notifier_from_errno(-EBUSY);
}
return NOTIFY_DONE;
}
static int wdt_resume(void)
{
clear_bit(WDOG_DEV_OPEN, &wdt_dev.status);
return NOTIFY_DONE;
}
static int wdt_power_event(struct notifier_block *this, unsigned long event,
void *ptr)
{
switch (event) {
case PM_POST_HIBERNATION:
case PM_POST_SUSPEND:
return wdt_resume();
case PM_HIBERNATION_PREPARE:
case PM_SUSPEND_PREPARE:
return wdt_suspend();
default:
return NOTIFY_DONE;
}
}
static struct notifier_block wdt_power_notifier = {
.notifier_call = wdt_power_event,
};
static int __init diag288_init(void)
{
int ret;
char ebc_begin[] = {
194, 197, 199, 201, 213
};
watchdog_set_nowayout(&wdt_dev, nowayout_info);
if (MACHINE_IS_VM) {
pr_info("The watchdog device driver detected a z/VM environment\n");
if (__diag288_vm(WDT_FUNC_INIT, 15,
ebc_begin, sizeof(ebc_begin)) != 0) {
pr_err("The watchdog cannot be initialized\n");
return -EINVAL;
}
} else {
pr_err("Linux runs in an environment that does not support the diag288 watchdog\n");
return -ENODEV;
}
if (__diag288_vm(WDT_FUNC_CANCEL, 0, NULL, 0)) {
pr_err("The watchdog cannot be deactivated\n");
return -EINVAL;
}
ret = register_pm_notifier(&wdt_power_notifier);
if (ret)
return ret;
ret = watchdog_register_device(&wdt_dev);
if (ret)
unregister_pm_notifier(&wdt_power_notifier);
return ret;
}
static void __exit diag288_exit(void)
{
watchdog_unregister_device(&wdt_dev);
unregister_pm_notifier(&wdt_power_notifier);
}
module_init(diag288_init);
module_exit(diag288_exit);