diff options
| -rw-r--r-- | drivers/watchdog/xen_wdt.c | 245 |
1 files changed, 51 insertions, 194 deletions
diff --git a/drivers/watchdog/xen_wdt.c b/drivers/watchdog/xen_wdt.c index 5dd5c3494d55..51576e15a086 100644 --- a/drivers/watchdog/xen_wdt.c +++ b/drivers/watchdog/xen_wdt.c @@ -9,9 +9,7 @@ * 2 of the License, or (at your option) any later version. */ -#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt - -#define DRV_NAME "wdt" +#define DRV_NAME "xen_wdt" #define DRV_VERSION "0.01" #include <linux/bug.h> @@ -21,25 +19,20 @@ #include <linux/kernel.h> #include <linux/ktime.h> #include <linux/init.h> -#include <linux/miscdevice.h> #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/platform_device.h> -#include <linux/spinlock.h> -#include <linux/uaccess.h> #include <linux/watchdog.h> #include <xen/xen.h> #include <asm/xen/hypercall.h> #include <xen/interface/sched.h> static struct platform_device *platform_device; -static DEFINE_SPINLOCK(wdt_lock); static struct sched_watchdog wdt; static time64_t wdt_expires; -static bool is_active, expect_release; #define WATCHDOG_TIMEOUT 60 /* in seconds */ -static unsigned int timeout = WATCHDOG_TIMEOUT; +static unsigned int timeout; module_param(timeout, uint, S_IRUGO); MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds " "(default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ")"); @@ -49,20 +42,18 @@ module_param(nowayout, bool, S_IRUGO); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started " "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); -static inline time64_t set_timeout(void) +static inline time64_t set_timeout(struct watchdog_device *wdd) { - wdt.timeout = timeout; - return ktime_get_seconds() + timeout; + wdt.timeout = wdd->timeout; + return ktime_get_seconds() + wdd->timeout; } -static int xen_wdt_start(void) +static int xen_wdt_start(struct watchdog_device *wdd) { time64_t expires; int err; - spin_lock(&wdt_lock); - - expires = set_timeout(); + expires = set_timeout(wdd); if (!wdt.id) err = HYPERVISOR_sched_op(SCHEDOP_watchdog, &wdt); else @@ -74,36 +65,28 @@ static int xen_wdt_start(void) } else BUG_ON(!err); - spin_unlock(&wdt_lock); - return err; } -static int xen_wdt_stop(void) +static int xen_wdt_stop(struct watchdog_device *wdd) { int err = 0; - spin_lock(&wdt_lock); - wdt.timeout = 0; if (wdt.id) err = HYPERVISOR_sched_op(SCHEDOP_watchdog, &wdt); if (!err) wdt.id = 0; - spin_unlock(&wdt_lock); - return err; } -static int xen_wdt_kick(void) +static int xen_wdt_kick(struct watchdog_device *wdd) { time64_t expires; int err; - spin_lock(&wdt_lock); - - expires = set_timeout(); + expires = set_timeout(wdd); if (wdt.id) err = HYPERVISOR_sched_op(SCHEDOP_watchdog, &wdt); else @@ -111,195 +94,72 @@ static int xen_wdt_kick(void) if (!err) wdt_expires = expires; - spin_unlock(&wdt_lock); - return err; } -static int xen_wdt_open(struct inode *inode, struct file *file) +static unsigned int xen_wdt_get_timeleft(struct watchdog_device *wdd) { - int err; - - /* /dev/watchdog can only be opened once */ - if (xchg(&is_active, true)) - return -EBUSY; - - err = xen_wdt_start(); - if (err == -EBUSY) - err = xen_wdt_kick(); - return err ?: nonseekable_open(inode, file); + return wdt_expires - ktime_get_seconds(); } -static int xen_wdt_release(struct inode *inode, struct file *file) -{ - int err = 0; - - if (expect_release) - err = xen_wdt_stop(); - else { - pr_crit("unexpected close, not stopping watchdog!\n"); - xen_wdt_kick(); - } - is_active = err; - expect_release = false; - return err; -} - -static ssize_t xen_wdt_write(struct file *file, const char __user *data, - size_t len, loff_t *ppos) -{ - /* See if we got the magic character 'V' and reload the timer */ - if (len) { - if (!nowayout) { - size_t i; - - /* in case it was set long ago */ - expect_release = false; - - /* scan to see whether or not we got the magic - character */ - for (i = 0; i != len; i++) { - char c; - if (get_user(c, data + i)) - return -EFAULT; - if (c == 'V') - expect_release = true; - } - } - - /* someone wrote to us, we should reload the timer */ - xen_wdt_kick(); - } - return len; -} - -static long xen_wdt_ioctl(struct file *file, unsigned int cmd, - unsigned long arg) -{ - int new_options, retval = -EINVAL; - int new_timeout; - int __user *argp = (void __user *)arg; - static const struct watchdog_info ident = { - .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, - .firmware_version = 0, - .identity = DRV_NAME, - }; - - switch (cmd) { - case WDIOC_GETSUPPORT: - return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0; - - case WDIOC_GETSTATUS: - case WDIOC_GETBOOTSTATUS: - return put_user(0, argp); - - case WDIOC_SETOPTIONS: - if (get_user(new_options, argp)) - return -EFAULT; - - if (new_options & WDIOS_DISABLECARD) - retval = xen_wdt_stop(); - if (new_options & WDIOS_ENABLECARD) { - retval = xen_wdt_start(); - if (retval == -EBUSY) - retval = xen_wdt_kick(); - } - return retval; - - case WDIOC_KEEPALIVE: - xen_wdt_kick(); - return 0; - - case WDIOC_SETTIMEOUT: - if (get_user(new_timeout, argp)) - return -EFAULT; - if (!new_timeout) - return -EINVAL; - timeout = new_timeout; - xen_wdt_kick(); - /* fall through */ - case WDIOC_GETTIMEOUT: - return put_user(timeout, argp); - - case WDIOC_GETTIMELEFT: - retval = wdt_expires - ktime_get_seconds(); - return put_user(retval, argp); - } - - return -ENOTTY; -} +static struct watchdog_info xen_wdt_info = { + .identity = DRV_NAME, + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, +}; -static const struct file_operations xen_wdt_fops = { - .owner = THIS_MODULE, - .llseek = no_llseek, - .write = xen_wdt_write, - .unlocked_ioctl = xen_wdt_ioctl, - .open = xen_wdt_open, - .release = xen_wdt_release, +static const struct watchdog_ops xen_wdt_ops = { + .owner = THIS_MODULE, + .start = xen_wdt_start, + .stop = xen_wdt_stop, + .ping = xen_wdt_kick, + .get_timeleft = xen_wdt_get_timeleft, }; -static struct miscdevice xen_wdt_miscdev = { - .minor = WATCHDOG_MINOR, - .name = "watchdog", - .fops = &xen_wdt_fops, +static struct watchdog_device xen_wdt_dev = { + .info = &xen_wdt_info, + .ops = &xen_wdt_ops, + .timeout = WATCHDOG_TIMEOUT, }; -static int xen_wdt_probe(struct platform_device *dev) +static int xen_wdt_probe(struct platform_device *pdev) { struct sched_watchdog wd = { .id = ~0 }; int ret = HYPERVISOR_sched_op(SCHEDOP_watchdog, &wd); - switch (ret) { - case -EINVAL: - if (!timeout) { - timeout = WATCHDOG_TIMEOUT; - pr_info("timeout value invalid, using %d\n", timeout); - } - - ret = misc_register(&xen_wdt_miscdev); - if (ret) { - pr_err("cannot register miscdev on minor=%d (%d)\n", - WATCHDOG_MINOR, ret); - break; - } - - pr_info("initialized (timeout=%ds, nowayout=%d)\n", - timeout, nowayout); - break; - - case -ENOSYS: - pr_info("not supported\n"); - ret = -ENODEV; - break; - - default: - pr_info("bogus return value %d\n", ret); - break; + if (ret == -ENOSYS) { + dev_err(&pdev->dev, "watchdog not supported by hypervisor\n"); + return -ENODEV; } - return ret; -} + if (ret != -EINVAL) { + dev_err(&pdev->dev, "unexpected hypervisor error (%d)\n", ret); + return -ENODEV; + } -static int xen_wdt_remove(struct platform_device *dev) -{ - /* Stop the timer before we leave */ - if (!nowayout) - xen_wdt_stop(); + if (watchdog_init_timeout(&xen_wdt_dev, timeout, NULL)) + dev_info(&pdev->dev, "timeout value invalid, using %d\n", + xen_wdt_dev.timeout); + watchdog_set_nowayout(&xen_wdt_dev, nowayout); + watchdog_stop_on_reboot(&xen_wdt_dev); + watchdog_stop_on_unregister(&xen_wdt_dev); + + ret = devm_watchdog_register_device(&pdev->dev, &xen_wdt_dev); + if (ret) { + dev_err(&pdev->dev, "cannot register watchdog device (%d)\n", + ret); + return ret; + } - misc_deregister(&xen_wdt_miscdev); + dev_info(&pdev->dev, "initialized (timeout=%ds, nowayout=%d)\n", + xen_wdt_dev.timeout, nowayout); return 0; } -static void xen_wdt_shutdown(struct platform_device *dev) -{ - xen_wdt_stop(); -} - static int xen_wdt_suspend(struct platform_device *dev, pm_message_t state) { typeof(wdt.id) id = wdt.id; - int rc = xen_wdt_stop(); + int rc = xen_wdt_stop(&xen_wdt_dev); wdt.id = id; return rc; @@ -310,13 +170,11 @@ static int xen_wdt_resume(struct platform_device *dev) if (!wdt.id) return 0; wdt.id = 0; - return xen_wdt_start(); + return xen_wdt_start(&xen_wdt_dev); } static struct platform_driver xen_wdt_driver = { .probe = xen_wdt_probe, - .remove = xen_wdt_remove, - .shutdown = xen_wdt_shutdown, .suspend = xen_wdt_suspend, .resume = xen_wdt_resume, .driver = { @@ -351,7 +209,6 @@ static void __exit xen_wdt_cleanup_module(void) { platform_device_unregister(platform_device); platform_driver_unregister(&xen_wdt_driver); - pr_info("module unloaded\n"); } module_init(xen_wdt_init_module); |