From f7a94db4e9594fd4b67e715d7b26864b7bd74a75 Mon Sep 17 00:00:00 2001 From: Philipp Hachtmann Date: Thu, 5 Jun 2014 11:01:43 +0200 Subject: s390/watchdog: use watchdog API Converted the vmwatchdog driver to use the kernel's watchdog API. Signed-off-by: Philipp Hachtmann Signed-off-by: Martin Schwidefsky diff --git a/arch/s390/configs/default_defconfig b/arch/s390/configs/default_defconfig index 8df022c..350ea0d 100644 --- a/arch/s390/configs/default_defconfig +++ b/arch/s390/configs/default_defconfig @@ -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 diff --git a/arch/s390/configs/gcov_defconfig b/arch/s390/configs/gcov_defconfig index c81a74e..6870648 100644 --- a/arch/s390/configs/gcov_defconfig +++ b/arch/s390/configs/gcov_defconfig @@ -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 diff --git a/arch/s390/configs/performance_defconfig b/arch/s390/configs/performance_defconfig index b5ba8fe..54ebb85 100644 --- a/arch/s390/configs/performance_defconfig +++ b/arch/s390/configs/performance_defconfig @@ -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 diff --git a/drivers/s390/char/Makefile b/drivers/s390/char/Makefile index 629fcc2..78b6ace 100644 --- a/drivers/s390/char/Makefile +++ b/drivers/s390/char/Makefile @@ -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 diff --git a/drivers/s390/char/vmwatchdog.c b/drivers/s390/char/vmwatchdog.c deleted file mode 100644 index d5eac98..0000000 --- a/drivers/s390/char/vmwatchdog.c +++ /dev/null @@ -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 -#include -#include -#include -#include -#include -#include -#include -#include - -#include -#include -#include - -#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 "); -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); diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 74ec8fc..daf9441 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -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 diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 1b5f3d5..5a7fb1f 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -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 diff --git a/drivers/watchdog/diag288_wdt.c b/drivers/watchdog/diag288_wdt.c new file mode 100644 index 0000000..d406711 --- /dev/null +++ b/drivers/watchdog/diag288_wdt.c @@ -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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#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 "); +MODULE_AUTHOR("Philipp Hachtmann "); + +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); -- cgit v0.10.2