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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
committed by
Martin Schwidefsky
Martin Schwidefsky
parent
f2485f5d1c
commit
f7a94db4e9
@@ -1295,9 +1295,10 @@ config WATCHDOG_RTAS
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# S390 Architecture
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config ZVM_WATCHDOG
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tristate "z/VM Watchdog Timer"
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config DIAG288_WATCHDOG
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tristate "System z diag288 Watchdog"
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depends on S390
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select WATCHDOG_CORE
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help
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IBM s/390 and zSeries machines running under z/VM 5.1 or later
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provide a virtual watchdog timer to their guest that cause a
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@@ -154,6 +154,7 @@ obj-$(CONFIG_MEN_A21_WDT) += mena21_wdt.o
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obj-$(CONFIG_WATCHDOG_RTAS) += wdrtas.o
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# S390 Architecture
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obj-$(CONFIG_DIAG288_WATCHDOG) += diag288_wdt.o
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# SUPERH (sh + sh64) Architecture
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obj-$(CONFIG_SH_WDT) += shwdt.o
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@@ -0,0 +1,287 @@
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/*
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* Watchdog driver for z/VM using the diag 288 interface.
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*
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* Under z/VM, expiration of the watchdog will send a "system restart" command
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* to CP.
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*
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* The command can be altered using the module parameter "cmd".
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*
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* Copyright IBM Corp. 2004, 2013
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* Author(s): Arnd Bergmann (arndb@de.ibm.com)
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* Philipp Hachtmann (phacht@de.ibm.com)
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*
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*/
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#define KMSG_COMPONENT "diag288_wdt"
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#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/slab.h>
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#include <linux/miscdevice.h>
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#include <linux/watchdog.h>
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#include <linux/suspend.h>
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#include <asm/ebcdic.h>
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#include <linux/io.h>
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#include <linux/uaccess.h>
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#define MAX_CMDLEN 240
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#define DEFAULT_CMD "SYSTEM RESTART"
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#define MIN_INTERVAL 15 /* Minimal time supported by diag88 */
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#define MAX_INTERVAL 3600 /* One hour should be enough - pure estimation */
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#define WDT_DEFAULT_TIMEOUT 30
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/* Function codes - init, change, cancel */
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#define WDT_FUNC_INIT 0
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#define WDT_FUNC_CHANGE 1
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#define WDT_FUNC_CANCEL 2
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#define WDT_FUNC_CONCEAL 0x80000000
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static char wdt_cmd[MAX_CMDLEN] = DEFAULT_CMD;
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static bool conceal_on;
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static bool nowayout_info = WATCHDOG_NOWAYOUT;
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Arnd Bergmann <arndb@de.ibm.com>");
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MODULE_AUTHOR("Philipp Hachtmann <phacht@de.ibm.com>");
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MODULE_DESCRIPTION("System z diag288 Watchdog Timer");
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module_param_string(cmd, wdt_cmd, MAX_CMDLEN, 0644);
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MODULE_PARM_DESC(cmd, "CP command that is run when the watchdog triggers (z/VM only)");
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module_param_named(conceal, conceal_on, bool, 0644);
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MODULE_PARM_DESC(conceal, "Enable the CONCEAL CP option while the watchdog is active (z/VM only)");
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module_param_named(nowayout, nowayout_info, bool, 0444);
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MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default = CONFIG_WATCHDOG_NOWAYOUT)");
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MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
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MODULE_ALIAS("vmwatchdog");
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static int __diag288(unsigned int func, unsigned int timeout,
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unsigned long action, unsigned int len)
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{
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register unsigned long __func asm("2") = func;
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register unsigned long __timeout asm("3") = timeout;
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register unsigned long __action asm("4") = action;
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register unsigned long __len asm("5") = len;
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int err;
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err = -EINVAL;
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asm volatile(
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" diag %1, %3, 0x288\n"
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"0: la %0, 0\n"
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"1:\n"
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EX_TABLE(0b, 1b)
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: "+d" (err) : "d"(__func), "d"(__timeout),
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"d"(__action), "d"(__len) : "1", "cc");
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return err;
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}
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static int __diag288_vm(unsigned int func, unsigned int timeout,
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char *cmd, size_t len)
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{
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return __diag288(func, timeout, virt_to_phys(cmd), len);
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}
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static int wdt_start(struct watchdog_device *dev)
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{
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char *ebc_cmd;
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size_t len;
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int ret;
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unsigned int func;
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ret = -ENODEV;
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if (MACHINE_IS_VM) {
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ebc_cmd = kmalloc(MAX_CMDLEN, GFP_KERNEL);
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if (!ebc_cmd)
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return -ENOMEM;
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len = strlcpy(ebc_cmd, wdt_cmd, MAX_CMDLEN);
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ASCEBC(ebc_cmd, MAX_CMDLEN);
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EBC_TOUPPER(ebc_cmd, MAX_CMDLEN);
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func = conceal_on ? (WDT_FUNC_INIT | WDT_FUNC_CONCEAL)
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: WDT_FUNC_INIT;
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ret = __diag288_vm(func, dev->timeout, ebc_cmd, len);
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WARN_ON(ret != 0);
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kfree(ebc_cmd);
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}
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if (ret) {
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pr_err("The watchdog cannot be activated\n");
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return ret;
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}
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pr_info("The watchdog was activated\n");
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return 0;
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}
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static int wdt_stop(struct watchdog_device *dev)
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{
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int ret;
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ret = __diag288(WDT_FUNC_CANCEL, 0, 0, 0);
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pr_info("The watchdog was deactivated\n");
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return ret;
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}
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static int wdt_ping(struct watchdog_device *dev)
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{
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char *ebc_cmd;
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size_t len;
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int ret;
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unsigned int func;
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ret = -ENODEV;
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if (MACHINE_IS_VM) {
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ebc_cmd = kmalloc(MAX_CMDLEN, GFP_KERNEL);
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if (!ebc_cmd)
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return -ENOMEM;
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len = strlcpy(ebc_cmd, wdt_cmd, MAX_CMDLEN);
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ASCEBC(ebc_cmd, MAX_CMDLEN);
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EBC_TOUPPER(ebc_cmd, MAX_CMDLEN);
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/*
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* It seems to be ok to z/VM to use the init function to
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* retrigger the watchdog.
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*/
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func = conceal_on ? (WDT_FUNC_INIT | WDT_FUNC_CONCEAL)
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: WDT_FUNC_INIT;
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ret = __diag288_vm(func, dev->timeout, ebc_cmd, len);
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WARN_ON(ret != 0);
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kfree(ebc_cmd);
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}
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if (ret)
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pr_err("The watchdog timer cannot be started or reset\n");
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return ret;
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}
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static int wdt_set_timeout(struct watchdog_device * dev, unsigned int new_to)
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{
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dev->timeout = new_to;
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return wdt_ping(dev);
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}
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static struct watchdog_ops wdt_ops = {
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.owner = THIS_MODULE,
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.start = wdt_start,
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.stop = wdt_stop,
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.ping = wdt_ping,
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.set_timeout = wdt_set_timeout,
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};
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static struct watchdog_info wdt_info = {
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.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
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.firmware_version = 0,
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.identity = "z Watchdog",
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};
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static struct watchdog_device wdt_dev = {
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.parent = NULL,
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.info = &wdt_info,
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.ops = &wdt_ops,
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.bootstatus = 0,
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.timeout = WDT_DEFAULT_TIMEOUT,
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.min_timeout = MIN_INTERVAL,
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.max_timeout = MAX_INTERVAL,
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};
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/*
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* It makes no sense to go into suspend while the watchdog is running.
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* Depending on the memory size, the watchdog might trigger, while we
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* are still saving the memory.
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* We reuse the open flag to ensure that suspend and watchdog open are
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* exclusive operations
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*/
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static int wdt_suspend(void)
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{
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if (test_and_set_bit(WDOG_DEV_OPEN, &wdt_dev.status)) {
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pr_err("Linux cannot be suspended while the watchdog is in use\n");
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return notifier_from_errno(-EBUSY);
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}
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if (test_bit(WDOG_ACTIVE, &wdt_dev.status)) {
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clear_bit(WDOG_DEV_OPEN, &wdt_dev.status);
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pr_err("Linux cannot be suspended while the watchdog is in use\n");
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return notifier_from_errno(-EBUSY);
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}
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return NOTIFY_DONE;
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}
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static int wdt_resume(void)
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{
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clear_bit(WDOG_DEV_OPEN, &wdt_dev.status);
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return NOTIFY_DONE;
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}
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static int wdt_power_event(struct notifier_block *this, unsigned long event,
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void *ptr)
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{
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switch (event) {
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case PM_POST_HIBERNATION:
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case PM_POST_SUSPEND:
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return wdt_resume();
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case PM_HIBERNATION_PREPARE:
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case PM_SUSPEND_PREPARE:
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return wdt_suspend();
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default:
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return NOTIFY_DONE;
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}
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}
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static struct notifier_block wdt_power_notifier = {
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.notifier_call = wdt_power_event,
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};
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static int __init diag288_init(void)
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{
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int ret;
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char ebc_begin[] = {
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194, 197, 199, 201, 213
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};
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watchdog_set_nowayout(&wdt_dev, nowayout_info);
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if (MACHINE_IS_VM) {
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pr_info("The watchdog device driver detected a z/VM environment\n");
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if (__diag288_vm(WDT_FUNC_INIT, 15,
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ebc_begin, sizeof(ebc_begin)) != 0) {
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pr_err("The watchdog cannot be initialized\n");
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return -EINVAL;
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}
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} else {
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pr_err("Linux runs in an environment that does not support the diag288 watchdog\n");
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return -ENODEV;
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}
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if (__diag288_vm(WDT_FUNC_CANCEL, 0, NULL, 0)) {
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pr_err("The watchdog cannot be deactivated\n");
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return -EINVAL;
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}
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ret = register_pm_notifier(&wdt_power_notifier);
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if (ret)
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return ret;
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ret = watchdog_register_device(&wdt_dev);
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if (ret)
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unregister_pm_notifier(&wdt_power_notifier);
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return ret;
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}
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static void __exit diag288_exit(void)
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{
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watchdog_unregister_device(&wdt_dev);
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unregister_pm_notifier(&wdt_power_notifier);
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}
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module_init(diag288_init);
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module_exit(diag288_exit);
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