diff options
Diffstat (limited to 'drivers/watchdog/watchdog_dev.c')
| -rw-r--r-- | drivers/watchdog/watchdog_dev.c | 648 |
1 files changed, 396 insertions, 252 deletions
diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c index f6c24b22b37c..8369fd94fc1a 100644 --- a/drivers/watchdog/watchdog_dev.c +++ b/drivers/watchdog/watchdog_dev.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0+ /* * watchdog_dev.c * @@ -6,6 +7,7 @@ * * (c) Copyright 2008-2011 Wim Van Sebroeck <wim@iguana.be>. * + * (c) Copyright 2021 Hewlett Packard Enterprise Development LP. * * This source code is part of the generic code that can be used * by all the watchdog timer drivers. @@ -20,11 +22,6 @@ * Satyam Sharma <satyam@infradead.org> * Randy Dunlap <randy.dunlap@oracle.com> * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation; either version - * 2 of the License, or (at your option) any later version. - * * Neither Alan Cox, CymruNet Ltd., Wim Van Sebroeck nor Iguana vzw. * admit liability nor provide warranty for any of this software. * This material is provided "AS-IS" and at no charge. @@ -38,44 +35,20 @@ #include <linux/init.h> /* For __init/__exit/... */ #include <linux/hrtimer.h> /* For hrtimers */ #include <linux/kernel.h> /* For printk/panic/... */ -#include <linux/kref.h> /* For data references */ +#include <linux/kstrtox.h> /* For kstrto* */ #include <linux/kthread.h> /* For kthread_work */ #include <linux/miscdevice.h> /* For handling misc devices */ #include <linux/module.h> /* For module stuff/... */ #include <linux/mutex.h> /* For mutexes */ -#include <linux/reboot.h> /* For reboot notifier */ #include <linux/slab.h> /* For memory functions */ #include <linux/types.h> /* For standard types (like size_t) */ #include <linux/watchdog.h> /* For watchdog specific items */ #include <linux/uaccess.h> /* For copy_to_user/put_user/... */ -#include <uapi/linux/sched/types.h> /* For struct sched_param */ - #include "watchdog_core.h" #include "watchdog_pretimeout.h" -/* - * struct watchdog_core_data - watchdog core internal data - * @kref: Reference count. - * @cdev: The watchdog's Character device. - * @wdd: Pointer to watchdog device. - * @lock: Lock for watchdog core. - * @status: Watchdog core internal status bits. - */ -struct watchdog_core_data { - struct kref kref; - struct cdev cdev; - struct watchdog_device *wdd; - struct mutex lock; - ktime_t last_keepalive; - ktime_t last_hw_keepalive; - struct hrtimer timer; - struct kthread_work work; - unsigned long status; /* Internal status bits */ -#define _WDOG_DEV_OPEN 0 /* Opened ? */ -#define _WDOG_ALLOW_RELEASE 1 /* Did we receive the magic char ? */ -#define _WDOG_KEEPALIVE 2 /* Did we receive a keepalive ? */ -}; +#include <trace/events/watchdog.h> /* the dev_t structure to store the dynamically allocated watchdog devices */ static dev_t watchdog_devt; @@ -87,6 +60,19 @@ static struct kthread_worker *watchdog_kworker; static bool handle_boot_enabled = IS_ENABLED(CONFIG_WATCHDOG_HANDLE_BOOT_ENABLED); +static unsigned open_timeout = CONFIG_WATCHDOG_OPEN_TIMEOUT; + +static bool watchdog_past_open_deadline(struct watchdog_core_data *data) +{ + return ktime_after(ktime_get(), data->open_deadline); +} + +static void watchdog_set_open_deadline(struct watchdog_core_data *data) +{ + data->open_deadline = open_timeout ? + ktime_get() + ktime_set(open_timeout, 0) : KTIME_MAX; +} + static inline bool watchdog_need_worker(struct watchdog_device *wdd) { /* All variables in milli-seconds */ @@ -119,14 +105,15 @@ static ktime_t watchdog_next_keepalive(struct watchdog_device *wdd) ktime_t virt_timeout; unsigned int hw_heartbeat_ms; - virt_timeout = ktime_add(wd_data->last_keepalive, - ms_to_ktime(timeout_ms)); + if (watchdog_active(wdd)) + virt_timeout = ktime_add(wd_data->last_keepalive, + ms_to_ktime(timeout_ms)); + else + virt_timeout = wd_data->open_deadline; + hw_heartbeat_ms = min_not_zero(timeout_ms, wdd->max_hw_heartbeat_ms); keepalive_interval = ms_to_ktime(hw_heartbeat_ms / 2); - if (!watchdog_active(wdd)) - return keepalive_interval; - /* * To ensure that the watchdog times out wdd->timeout seconds * after the most recent ping from userspace, the last @@ -147,7 +134,8 @@ static inline void watchdog_update_worker(struct watchdog_device *wdd) ktime_t t = watchdog_next_keepalive(wdd); if (t > 0) - hrtimer_start(&wd_data->timer, t, HRTIMER_MODE_REL); + hrtimer_start(&wd_data->timer, t, + HRTIMER_MODE_REL_HARD); } else { hrtimer_cancel(&wd_data->timer); } @@ -166,16 +154,22 @@ static int __watchdog_ping(struct watchdog_device *wdd) if (ktime_after(earliest_keepalive, now)) { hrtimer_start(&wd_data->timer, ktime_sub(earliest_keepalive, now), - HRTIMER_MODE_REL); + HRTIMER_MODE_REL_HARD); return 0; } wd_data->last_hw_keepalive = now; - if (wdd->ops->ping) + if (wdd->ops->ping) { err = wdd->ops->ping(wdd); /* ping the watchdog */ - else + trace_watchdog_ping(wdd, err); + } else { err = wdd->ops->start(wdd); /* restart watchdog */ + trace_watchdog_start(wdd, err); + } + + if (err == 0) + watchdog_hrtimer_pretimeout_start(wdd); watchdog_update_worker(wdd); @@ -183,22 +177,22 @@ static int __watchdog_ping(struct watchdog_device *wdd) } /* - * watchdog_ping: ping the watchdog. - * @wdd: the watchdog device to ping + * watchdog_ping - ping the watchdog + * @wdd: The watchdog device to ping * - * The caller must hold wd_data->lock. + * If the watchdog has no own ping operation then it needs to be + * restarted via the start operation. This wrapper function does + * exactly that. + * We only ping when the watchdog device is running. + * The caller must hold wd_data->lock. * - * If the watchdog has no own ping operation then it needs to be - * restarted via the start operation. This wrapper function does - * exactly that. - * We only ping when the watchdog device is running. + * Return: 0 on success, error otherwise. */ - static int watchdog_ping(struct watchdog_device *wdd) { struct watchdog_core_data *wd_data = wdd->wd_data; - if (!watchdog_active(wdd) && !watchdog_hw_running(wdd)) + if (!watchdog_hw_running(wdd)) return 0; set_bit(_WDOG_KEEPALIVE, &wd_data->status); @@ -211,7 +205,13 @@ static bool watchdog_worker_should_ping(struct watchdog_core_data *wd_data) { struct watchdog_device *wdd = wd_data->wdd; - return wdd && (watchdog_active(wdd) || watchdog_hw_running(wdd)); + if (!wdd) + return false; + + if (watchdog_active(wdd)) + return true; + + return watchdog_hw_running(wdd) && !watchdog_past_open_deadline(wd_data); } static void watchdog_ping_work(struct kthread_work *work) @@ -237,16 +237,14 @@ static enum hrtimer_restart watchdog_timer_expired(struct hrtimer *timer) } /* - * watchdog_start: wrapper to start the watchdog. - * @wdd: the watchdog device to start + * watchdog_start - wrapper to start the watchdog + * @wdd: The watchdog device to start * - * The caller must hold wd_data->lock. + * Start the watchdog if it is not active and mark it active. + * The caller must hold wd_data->lock. * - * Start the watchdog if it is not active and mark it active. - * This function returns zero on success or a negative errno code for - * failure. + * Return: 0 on success or a negative errno code for failure. */ - static int watchdog_start(struct watchdog_device *wdd) { struct watchdog_core_data *wd_data = wdd->wd_data; @@ -259,31 +257,38 @@ static int watchdog_start(struct watchdog_device *wdd) set_bit(_WDOG_KEEPALIVE, &wd_data->status); started_at = ktime_get(); - if (watchdog_hw_running(wdd) && wdd->ops->ping) - err = wdd->ops->ping(wdd); - else + if (watchdog_hw_running(wdd) && wdd->ops->ping) { + err = __watchdog_ping(wdd); + if (err == 0) { + set_bit(WDOG_ACTIVE, &wdd->status); + watchdog_hrtimer_pretimeout_start(wdd); + } + } else { err = wdd->ops->start(wdd); - if (err == 0) { - set_bit(WDOG_ACTIVE, &wdd->status); - wd_data->last_keepalive = started_at; - watchdog_update_worker(wdd); + trace_watchdog_start(wdd, err); + if (err == 0) { + set_bit(WDOG_ACTIVE, &wdd->status); + set_bit(WDOG_HW_RUNNING, &wdd->status); + wd_data->last_keepalive = started_at; + wd_data->last_hw_keepalive = started_at; + watchdog_update_worker(wdd); + watchdog_hrtimer_pretimeout_start(wdd); + } } return err; } /* - * watchdog_stop: wrapper to stop the watchdog. - * @wdd: the watchdog device to stop + * watchdog_stop - wrapper to stop the watchdog + * @wdd: The watchdog device to stop * - * The caller must hold wd_data->lock. + * Stop the watchdog if it is still active and unmark it active. + * If the 'nowayout' feature was set, the watchdog cannot be stopped. + * The caller must hold wd_data->lock. * - * Stop the watchdog if it is still active and unmark it active. - * This function returns zero on success or a negative errno code for - * failure. - * If the 'nowayout' feature was set, the watchdog cannot be stopped. + * Return: 0 on success or a negative errno code for failure. */ - static int watchdog_stop(struct watchdog_device *wdd) { int err = 0; @@ -300,6 +305,7 @@ static int watchdog_stop(struct watchdog_device *wdd) if (wdd->ops->stop) { clear_bit(WDOG_HW_RUNNING, &wdd->status); err = wdd->ops->stop(wdd); + trace_watchdog_stop(wdd, err); } else { set_bit(WDOG_HW_RUNNING, &wdd->status); } @@ -307,20 +313,21 @@ static int watchdog_stop(struct watchdog_device *wdd) if (err == 0) { clear_bit(WDOG_ACTIVE, &wdd->status); watchdog_update_worker(wdd); + watchdog_hrtimer_pretimeout_stop(wdd); } return err; } /* - * watchdog_get_status: wrapper to get the watchdog status - * @wdd: the watchdog device to get the status from + * watchdog_get_status - wrapper to get the watchdog status + * @wdd: The watchdog device to get the status from * - * The caller must hold wd_data->lock. + * Get the watchdog's status flags. + * The caller must hold wd_data->lock. * - * Get the watchdog's status flags. + * Return: watchdog's status flags. */ - static unsigned int watchdog_get_status(struct watchdog_device *wdd) { struct watchdog_core_data *wd_data = wdd->wd_data; @@ -343,17 +350,21 @@ static unsigned int watchdog_get_status(struct watchdog_device *wdd) if (test_and_clear_bit(_WDOG_KEEPALIVE, &wd_data->status)) status |= WDIOF_KEEPALIVEPING; + if (IS_ENABLED(CONFIG_WATCHDOG_HRTIMER_PRETIMEOUT)) + status |= WDIOF_PRETIMEOUT; + return status; } /* - * watchdog_set_timeout: set the watchdog timer timeout - * @wdd: the watchdog device to set the timeout for - * @timeout: timeout to set in seconds + * watchdog_set_timeout - set the watchdog timer timeout + * @wdd: The watchdog device to set the timeout for + * @timeout: Timeout to set in seconds + * + * The caller must hold wd_data->lock. * - * The caller must hold wd_data->lock. + * Return: 0 if successful, error otherwise. */ - static int watchdog_set_timeout(struct watchdog_device *wdd, unsigned int timeout) { @@ -367,6 +378,7 @@ static int watchdog_set_timeout(struct watchdog_device *wdd, if (wdd->ops->set_timeout) { err = wdd->ops->set_timeout(wdd, timeout); + trace_watchdog_set_timeout(wdd, timeout, err); } else { wdd->timeout = timeout; /* Disable pretimeout if it doesn't fit the new timeout */ @@ -380,23 +392,24 @@ static int watchdog_set_timeout(struct watchdog_device *wdd, } /* - * watchdog_set_pretimeout: set the watchdog timer pretimeout - * @wdd: the watchdog device to set the timeout for - * @timeout: pretimeout to set in seconds + * watchdog_set_pretimeout - set the watchdog timer pretimeout + * @wdd: The watchdog device to set the timeout for + * @timeout: pretimeout to set in seconds + * + * Return: 0 if successful, error otherwise. */ - static int watchdog_set_pretimeout(struct watchdog_device *wdd, unsigned int timeout) { int err = 0; - if (!(wdd->info->options & WDIOF_PRETIMEOUT)) + if (!watchdog_have_pretimeout(wdd)) return -EOPNOTSUPP; if (watchdog_pretimeout_invalid(wdd, timeout)) return -EINVAL; - if (wdd->ops->set_pretimeout) + if (wdd->ops->set_pretimeout && (wdd->info->options & WDIOF_PRETIMEOUT)) err = wdd->ops->set_pretimeout(wdd, timeout); else wdd->pretimeout = timeout; @@ -405,15 +418,15 @@ static int watchdog_set_pretimeout(struct watchdog_device *wdd, } /* - * watchdog_get_timeleft: wrapper to get the time left before a reboot - * @wdd: the watchdog device to get the remaining time from - * @timeleft: the time that's left + * watchdog_get_timeleft - wrapper to get the time left before a reboot + * @wdd: The watchdog device to get the remaining time from + * @timeleft: The time that's left * - * The caller must hold wd_data->lock. + * Get the time before a watchdog will reboot (if not pinged). + * The caller must hold wd_data->lock. * - * Get the time before a watchdog will reboot (if not pinged). + * Return: 0 if successful, error otherwise. */ - static int watchdog_get_timeleft(struct watchdog_device *wdd, unsigned int *timeleft) { @@ -433,9 +446,29 @@ static ssize_t nowayout_show(struct device *dev, struct device_attribute *attr, { struct watchdog_device *wdd = dev_get_drvdata(dev); - return sprintf(buf, "%d\n", !!test_bit(WDOG_NO_WAY_OUT, &wdd->status)); + return sysfs_emit(buf, "%d\n", !!test_bit(WDOG_NO_WAY_OUT, + &wdd->status)); +} + +static ssize_t nowayout_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t len) +{ + struct watchdog_device *wdd = dev_get_drvdata(dev); + unsigned int value; + int ret; + + ret = kstrtouint(buf, 0, &value); + if (ret) + return ret; + if (value > 1) + return -EINVAL; + /* nowayout cannot be disabled once set */ + if (test_bit(WDOG_NO_WAY_OUT, &wdd->status) && !value) + return -EPERM; + watchdog_set_nowayout(wdd, value); + return len; } -static DEVICE_ATTR_RO(nowayout); +static DEVICE_ATTR_RW(nowayout); static ssize_t status_show(struct device *dev, struct device_attribute *attr, char *buf) @@ -448,7 +481,7 @@ static ssize_t status_show(struct device *dev, struct device_attribute *attr, status = watchdog_get_status(wdd); mutex_unlock(&wd_data->lock); - return sprintf(buf, "0x%x\n", status); + return sysfs_emit(buf, "0x%x\n", status); } static DEVICE_ATTR_RO(status); @@ -457,7 +490,7 @@ static ssize_t bootstatus_show(struct device *dev, { struct watchdog_device *wdd = dev_get_drvdata(dev); - return sprintf(buf, "%u\n", wdd->bootstatus); + return sysfs_emit(buf, "%u\n", wdd->bootstatus); } static DEVICE_ATTR_RO(bootstatus); @@ -473,7 +506,7 @@ static ssize_t timeleft_show(struct device *dev, struct device_attribute *attr, status = watchdog_get_timeleft(wdd, &val); mutex_unlock(&wd_data->lock); if (!status) - status = sprintf(buf, "%u\n", val); + status = sysfs_emit(buf, "%u\n", val); return status; } @@ -484,25 +517,61 @@ static ssize_t timeout_show(struct device *dev, struct device_attribute *attr, { struct watchdog_device *wdd = dev_get_drvdata(dev); - return sprintf(buf, "%u\n", wdd->timeout); + return sysfs_emit(buf, "%u\n", wdd->timeout); } static DEVICE_ATTR_RO(timeout); +static ssize_t min_timeout_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct watchdog_device *wdd = dev_get_drvdata(dev); + + return sysfs_emit(buf, "%u\n", wdd->min_timeout); +} +static DEVICE_ATTR_RO(min_timeout); + +static ssize_t max_timeout_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct watchdog_device *wdd = dev_get_drvdata(dev); + + return sysfs_emit(buf, "%u\n", wdd->max_timeout); +} +static DEVICE_ATTR_RO(max_timeout); + static ssize_t pretimeout_show(struct device *dev, struct device_attribute *attr, char *buf) { struct watchdog_device *wdd = dev_get_drvdata(dev); - return sprintf(buf, "%u\n", wdd->pretimeout); + return sysfs_emit(buf, "%u\n", wdd->pretimeout); } static DEVICE_ATTR_RO(pretimeout); +static ssize_t options_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct watchdog_device *wdd = dev_get_drvdata(dev); + + return sysfs_emit(buf, "0x%x\n", wdd->info->options); +} +static DEVICE_ATTR_RO(options); + +static ssize_t fw_version_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct watchdog_device *wdd = dev_get_drvdata(dev); + + return sysfs_emit(buf, "%d\n", wdd->info->firmware_version); +} +static DEVICE_ATTR_RO(fw_version); + static ssize_t identity_show(struct device *dev, struct device_attribute *attr, char *buf) { struct watchdog_device *wdd = dev_get_drvdata(dev); - return sprintf(buf, "%s\n", wdd->info->identity); + return sysfs_emit(buf, "%s\n", wdd->info->identity); } static DEVICE_ATTR_RO(identity); @@ -512,9 +581,9 @@ static ssize_t state_show(struct device *dev, struct device_attribute *attr, struct watchdog_device *wdd = dev_get_drvdata(dev); if (watchdog_active(wdd)) - return sprintf(buf, "active\n"); + return sysfs_emit(buf, "active\n"); - return sprintf(buf, "inactive\n"); + return sysfs_emit(buf, "inactive\n"); } static DEVICE_ATTR_RO(state); @@ -551,27 +620,29 @@ static DEVICE_ATTR_RW(pretimeout_governor); static umode_t wdt_is_visible(struct kobject *kobj, struct attribute *attr, int n) { - struct device *dev = container_of(kobj, struct device, kobj); + struct device *dev = kobj_to_dev(kobj); struct watchdog_device *wdd = dev_get_drvdata(dev); umode_t mode = attr->mode; if (attr == &dev_attr_timeleft.attr && !wdd->ops->get_timeleft) mode = 0; - else if (attr == &dev_attr_pretimeout.attr && - !(wdd->info->options & WDIOF_PRETIMEOUT)) + else if (attr == &dev_attr_pretimeout.attr && !watchdog_have_pretimeout(wdd)) mode = 0; else if ((attr == &dev_attr_pretimeout_governor.attr || attr == &dev_attr_pretimeout_available_governors.attr) && - (!(wdd->info->options & WDIOF_PRETIMEOUT) || - !IS_ENABLED(CONFIG_WATCHDOG_PRETIMEOUT_GOV))) + (!watchdog_have_pretimeout(wdd) || !IS_ENABLED(CONFIG_WATCHDOG_PRETIMEOUT_GOV))) mode = 0; return mode; } static struct attribute *wdt_attrs[] = { &dev_attr_state.attr, + &dev_attr_options.attr, + &dev_attr_fw_version.attr, &dev_attr_identity.attr, &dev_attr_timeout.attr, + &dev_attr_min_timeout.attr, + &dev_attr_max_timeout.attr, &dev_attr_pretimeout.attr, &dev_attr_timeleft.attr, &dev_attr_bootstatus.attr, @@ -592,14 +663,15 @@ __ATTRIBUTE_GROUPS(wdt); #endif /* - * watchdog_ioctl_op: call the watchdog drivers ioctl op if defined - * @wdd: the watchdog device to do the ioctl on - * @cmd: watchdog command - * @arg: argument pointer + * watchdog_ioctl_op - call the watchdog drivers ioctl op if defined + * @wdd: The watchdog device to do the ioctl on + * @cmd: Watchdog command + * @arg: Argument pointer + * + * The caller must hold wd_data->lock. * - * The caller must hold wd_data->lock. + * Return: 0 if successful, error otherwise. */ - static int watchdog_ioctl_op(struct watchdog_device *wdd, unsigned int cmd, unsigned long arg) { @@ -610,17 +682,18 @@ static int watchdog_ioctl_op(struct watchdog_device *wdd, unsigned int cmd, } /* - * watchdog_write: writes to the watchdog. - * @file: file from VFS - * @data: user address of data - * @len: length of data - * @ppos: pointer to the file offset + * watchdog_write - writes to the watchdog + * @file: File from VFS + * @data: User address of data + * @len: Length of data + * @ppos: Pointer to the file offset + * + * A write to a watchdog device is defined as a keepalive ping. + * Writing the magic 'V' sequence allows the next close to turn + * off the watchdog (if 'nowayout' is not set). * - * A write to a watchdog device is defined as a keepalive ping. - * Writing the magic 'V' sequence allows the next close to turn - * off the watchdog (if 'nowayout' is not set). + * Return: @len if successful, error otherwise. */ - static ssize_t watchdog_write(struct file *file, const char __user *data, size_t len, loff_t *ppos) { @@ -663,13 +736,15 @@ static ssize_t watchdog_write(struct file *file, const char __user *data, } /* - * watchdog_ioctl: handle the different ioctl's for the watchdog device. - * @file: file handle to the device - * @cmd: watchdog command - * @arg: argument pointer + * watchdog_ioctl - handle the different ioctl's for the watchdog device + * @file: File handle to the device + * @cmd: Watchdog command + * @arg: Argument pointer * - * The watchdog API defines a common set of functions for all watchdogs - * according to their available features. + * The watchdog API defines a common set of functions for all watchdogs + * according to their available features. + * + * Return: 0 if successful, error otherwise. */ static long watchdog_ioctl(struct file *file, unsigned int cmd, @@ -740,7 +815,7 @@ static long watchdog_ioctl(struct file *file, unsigned int cmd, err = watchdog_ping(wdd); if (err < 0) break; - /* fall through */ + fallthrough; case WDIOC_GETTIMEOUT: /* timeout == 0 means that we don't know the timeout */ if (wdd->timeout == 0) { @@ -776,15 +851,16 @@ out_ioctl: } /* - * watchdog_open: open the /dev/watchdog* devices. - * @inode: inode of device - * @file: file handle to device + * watchdog_open - open the /dev/watchdog* devices + * @inode: Inode of device + * @file: File handle to device + * + * When the /dev/watchdog* device gets opened, we start the watchdog. + * Watch out: the /dev/watchdog device is single open, so we make sure + * it can only be opened once. * - * When the /dev/watchdog* device gets opened, we start the watchdog. - * Watch out: the /dev/watchdog device is single open, so we make sure - * it can only be opened once. + * Return: 0 if successful, error otherwise. */ - static int watchdog_open(struct inode *inode, struct file *file) { struct watchdog_core_data *wd_data; @@ -822,10 +898,19 @@ static int watchdog_open(struct inode *inode, struct file *file) file->private_data = wd_data; if (!hw_running) - kref_get(&wd_data->kref); + get_device(&wd_data->dev); + + /* + * open_timeout only applies for the first open from + * userspace. Set open_deadline to infinity so that the kernel + * will take care of an always-running hardware watchdog in + * case the device gets magic-closed or WDIOS_DISABLECARD is + * applied. + */ + wd_data->open_deadline = KTIME_MAX; /* dev/watchdog is a virtual (and thus non-seekable) filesystem */ - return nonseekable_open(inode, file); + return stream_open(inode, file); out_mod: module_put(wd_data->wdd->ops->owner); @@ -834,25 +919,26 @@ out_clear: return err; } -static void watchdog_core_data_release(struct kref *kref) +static void watchdog_core_data_release(struct device *dev) { struct watchdog_core_data *wd_data; - wd_data = container_of(kref, struct watchdog_core_data, kref); + wd_data = container_of(dev, struct watchdog_core_data, dev); kfree(wd_data); } /* - * watchdog_release: release the watchdog device. - * @inode: inode of device - * @file: file handle to device + * watchdog_release - release the watchdog device + * @inode: Inode of device + * @file: File handle to device * - * This is the code for when /dev/watchdog gets closed. We will only - * stop the watchdog when we have received the magic char (and nowayout - * was not set), else the watchdog will keep running. + * This is the code for when /dev/watchdog gets closed. We will only + * stop the watchdog when we have received the magic char (and nowayout + * was not set), else the watchdog will keep running. + * + * Always returns 0. */ - static int watchdog_release(struct inode *inode, struct file *file) { struct watchdog_core_data *wd_data = file->private_data; @@ -871,7 +957,7 @@ static int watchdog_release(struct inode *inode, struct file *file) * or if WDIOF_MAGICCLOSE is not set. If nowayout was set then * watchdog_stop will fail. */ - if (!test_bit(WDOG_ACTIVE, &wdd->status)) + if (!watchdog_active(wdd)) err = 0; else if (test_and_clear_bit(_WDOG_ALLOW_RELEASE, &wd_data->status) || !(wdd->info->options & WDIOF_MAGICCLOSE)) @@ -898,7 +984,7 @@ done: */ if (!running) { module_put(wd_data->cdev.owner); - kref_put(&wd_data->kref, watchdog_core_data_release); + put_device(&wd_data->dev); } return 0; } @@ -907,6 +993,7 @@ static const struct file_operations watchdog_fops = { .owner = THIS_MODULE, .write = watchdog_write, .unlocked_ioctl = watchdog_ioctl, + .compat_ioctl = compat_ptr_ioctl, .open = watchdog_open, .release = watchdog_release, }; @@ -917,17 +1004,22 @@ static struct miscdevice watchdog_miscdev = { .fops = &watchdog_fops, }; +static const struct class watchdog_class = { + .name = "watchdog", + .dev_groups = wdt_groups, +}; + /* - * watchdog_cdev_register: register watchdog character device - * @wdd: watchdog device - * @devno: character device number + * watchdog_cdev_register - register watchdog character device + * @wdd: Watchdog device + * + * Register a watchdog character device including handling the legacy + * /dev/watchdog node. /dev/watchdog is actually a miscdevice and + * thus we set it up like that. * - * Register a watchdog character device including handling the legacy - * /dev/watchdog node. /dev/watchdog is actually a miscdevice and - * thus we set it up like that. + * Return: 0 if successful, error otherwise. */ - -static int watchdog_cdev_register(struct watchdog_device *wdd, dev_t devno) +static int watchdog_cdev_register(struct watchdog_device *wdd) { struct watchdog_core_data *wd_data; int err; @@ -935,18 +1027,33 @@ static int watchdog_cdev_register(struct watchdog_device *wdd, dev_t devno) wd_data = kzalloc(sizeof(struct watchdog_core_data), GFP_KERNEL); if (!wd_data) return -ENOMEM; - kref_init(&wd_data->kref); mutex_init(&wd_data->lock); wd_data->wdd = wdd; wdd->wd_data = wd_data; - if (IS_ERR_OR_NULL(watchdog_kworker)) + if (IS_ERR_OR_NULL(watchdog_kworker)) { + kfree(wd_data); return -ENODEV; + } + + device_initialize(&wd_data->dev); + wd_data->dev.devt = MKDEV(MAJOR(watchdog_devt), wdd->id); + wd_data->dev.class = &watchdog_class; + wd_data->dev.parent = wdd->parent; + wd_data->dev.groups = wdd->groups; + wd_data->dev.release = watchdog_core_data_release; + dev_set_drvdata(&wd_data->dev, wdd); + err = dev_set_name(&wd_data->dev, "watchdog%d", wdd->id); + if (err) { + put_device(&wd_data->dev); + return err; + } kthread_init_work(&wd_data->work, watchdog_ping_work); - hrtimer_init(&wd_data->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); - wd_data->timer.function = watchdog_timer_expired; + hrtimer_setup(&wd_data->timer, watchdog_timer_expired, CLOCK_MONOTONIC, + HRTIMER_MODE_REL_HARD); + watchdog_hrtimer_pretimeout_init(wdd); if (wdd->id == 0) { old_wd_data = wd_data; @@ -959,7 +1066,7 @@ static int watchdog_cdev_register(struct watchdog_device *wdd, dev_t devno) pr_err("%s: a legacy watchdog module is probably present.\n", wdd->info->identity); old_wd_data = NULL; - kfree(wd_data); + put_device(&wd_data->dev); return err; } } @@ -969,20 +1076,21 @@ static int watchdog_cdev_register(struct watchdog_device *wdd, dev_t devno) wd_data->cdev.owner = wdd->ops->owner; /* Add the device */ - err = cdev_add(&wd_data->cdev, devno, 1); + err = cdev_device_add(&wd_data->cdev, &wd_data->dev); if (err) { pr_err("watchdog%d unable to add device %d:%d\n", wdd->id, MAJOR(watchdog_devt), wdd->id); if (wdd->id == 0) { misc_deregister(&watchdog_miscdev); old_wd_data = NULL; - kref_put(&wd_data->kref, watchdog_core_data_release); } + put_device(&wd_data->dev); return err; } /* Record time of most recent heartbeat as 'just before now'. */ wd_data->last_hw_keepalive = ktime_sub(ktime_get(), 1); + watchdog_set_open_deadline(wd_data); /* * If the watchdog is running, prevent its driver from being unloaded, @@ -990,9 +1098,10 @@ static int watchdog_cdev_register(struct watchdog_device *wdd, dev_t devno) */ if (watchdog_hw_running(wdd)) { __module_get(wdd->ops->owner); - kref_get(&wd_data->kref); + get_device(&wd_data->dev); if (handle_boot_enabled) - hrtimer_start(&wd_data->timer, 0, HRTIMER_MODE_REL); + hrtimer_start(&wd_data->timer, 0, + HRTIMER_MODE_REL_HARD); else pr_info("watchdog%d running and kernel based pre-userspace handler disabled\n", wdd->id); @@ -1002,18 +1111,17 @@ static int watchdog_cdev_register(struct watchdog_device *wdd, dev_t devno) } /* - * watchdog_cdev_unregister: unregister watchdog character device - * @watchdog: watchdog device + * watchdog_cdev_unregister - unregister watchdog character device + * @wdd: Watchdog device * - * Unregister watchdog character device and if needed the legacy - * /dev/watchdog device. + * Unregister watchdog character device and if needed the legacy + * /dev/watchdog device. */ - static void watchdog_cdev_unregister(struct watchdog_device *wdd) { struct watchdog_core_data *wd_data = wdd->wd_data; - cdev_del(&wd_data->cdev); + cdev_device_del(&wd_data->cdev, &wd_data->dev); if (wdd->id == 0) { misc_deregister(&watchdog_miscdev); old_wd_data = NULL; @@ -1024,6 +1132,8 @@ static void watchdog_cdev_unregister(struct watchdog_device *wdd) watchdog_stop(wdd); } + watchdog_hrtimer_pretimeout_stop(wdd); + mutex_lock(&wd_data->lock); wd_data->wdd = NULL; wdd->wd_data = NULL; @@ -1032,116 +1142,99 @@ static void watchdog_cdev_unregister(struct watchdog_device *wdd) hrtimer_cancel(&wd_data->timer); kthread_cancel_work_sync(&wd_data->work); - kref_put(&wd_data->kref, watchdog_core_data_release); + put_device(&wd_data->dev); } -static struct class watchdog_class = { - .name = "watchdog", - .owner = THIS_MODULE, - .dev_groups = wdt_groups, -}; - -static int watchdog_reboot_notifier(struct notifier_block *nb, - unsigned long code, void *data) -{ - struct watchdog_device *wdd; - - wdd = container_of(nb, struct watchdog_device, reboot_nb); - if (code == SYS_DOWN || code == SYS_HALT) { - if (watchdog_active(wdd)) { - int ret; - - ret = wdd->ops->stop(wdd); - if (ret) - return NOTIFY_BAD; - } - } - - return NOTIFY_DONE; -} - -/* - * watchdog_dev_register: register a watchdog device - * @wdd: watchdog device +/** + * watchdog_dev_register - register a watchdog device + * @wdd: Watchdog device + * + * Register a watchdog device including handling the legacy + * /dev/watchdog node. /dev/watchdog is actually a miscdevice and + * thus we set it up like that. * - * Register a watchdog device including handling the legacy - * /dev/watchdog node. /dev/watchdog is actually a miscdevice and - * thus we set it up like that. + * Return: 0 if successful, error otherwise. */ - int watchdog_dev_register(struct watchdog_device *wdd) { - struct device *dev; - dev_t devno; int ret; - devno = MKDEV(MAJOR(watchdog_devt), wdd->id); - - ret = watchdog_cdev_register(wdd, devno); + ret = watchdog_cdev_register(wdd); if (ret) return ret; - dev = device_create_with_groups(&watchdog_class, wdd->parent, - devno, wdd, wdd->groups, - "watchdog%d", wdd->id); - if (IS_ERR(dev)) { - watchdog_cdev_unregister(wdd); - return PTR_ERR(dev); - } - ret = watchdog_register_pretimeout(wdd); - if (ret) { - device_destroy(&watchdog_class, devno); + if (ret) watchdog_cdev_unregister(wdd); - return ret; - } - - if (test_bit(WDOG_STOP_ON_REBOOT, &wdd->status)) { - wdd->reboot_nb.notifier_call = watchdog_reboot_notifier; - - ret = devm_register_reboot_notifier(dev, &wdd->reboot_nb); - if (ret) { - pr_err("watchdog%d: Cannot register reboot notifier (%d)\n", - wdd->id, ret); - watchdog_dev_unregister(wdd); - } - } return ret; } -/* - * watchdog_dev_unregister: unregister a watchdog device - * @watchdog: watchdog device +/** + * watchdog_dev_unregister - unregister a watchdog device + * @wdd: watchdog device * - * Unregister watchdog device and if needed the legacy - * /dev/watchdog device. + * Unregister watchdog device and if needed the legacy + * /dev/watchdog device. */ - void watchdog_dev_unregister(struct watchdog_device *wdd) { watchdog_unregister_pretimeout(wdd); - device_destroy(&watchdog_class, wdd->wd_data->cdev.dev); watchdog_cdev_unregister(wdd); } -/* - * watchdog_dev_init: init dev part of watchdog core +/** + * watchdog_set_last_hw_keepalive - set last HW keepalive time for watchdog + * @wdd: Watchdog device + * @last_ping_ms: Time since last HW heartbeat * - * Allocate a range of chardev nodes to use for watchdog devices + * Adjusts the last known HW keepalive time for a watchdog timer. + * This is needed if the watchdog is already running when the probe + * function is called, and it can't be pinged immediately. This + * function must be called immediately after watchdog registration, + * and min_hw_heartbeat_ms must be set for this to be useful. + * + * Return: 0 if successful, error otherwise. */ +int watchdog_set_last_hw_keepalive(struct watchdog_device *wdd, + unsigned int last_ping_ms) +{ + struct watchdog_core_data *wd_data; + ktime_t now; + + if (!wdd) + return -EINVAL; + + wd_data = wdd->wd_data; + + now = ktime_get(); + + wd_data->last_hw_keepalive = ktime_sub(now, ms_to_ktime(last_ping_ms)); + + if (watchdog_hw_running(wdd) && handle_boot_enabled) + return __watchdog_ping(wdd); + + return 0; +} +EXPORT_SYMBOL_GPL(watchdog_set_last_hw_keepalive); +/** + * watchdog_dev_init - init dev part of watchdog core + * + * Allocate a range of chardev nodes to use for watchdog devices. + * + * Return: 0 if successful, error otherwise. + */ int __init watchdog_dev_init(void) { int err; - struct sched_param param = {.sched_priority = MAX_RT_PRIO - 1,}; - watchdog_kworker = kthread_create_worker(0, "watchdogd"); + watchdog_kworker = kthread_run_worker(0, "watchdogd"); if (IS_ERR(watchdog_kworker)) { pr_err("Failed to create watchdog kworker\n"); return PTR_ERR(watchdog_kworker); } - sched_setscheduler(watchdog_kworker->task, SCHED_FIFO, ¶m); + sched_set_fifo(watchdog_kworker->task); err = class_register(&watchdog_class); if (err < 0) { @@ -1164,12 +1257,11 @@ err_register: return err; } -/* - * watchdog_dev_exit: exit dev part of watchdog core +/** + * watchdog_dev_exit - exit dev part of watchdog core * - * Release the range of chardev nodes used for watchdog devices + * Release the range of chardev nodes used for watchdog devices. */ - void __exit watchdog_dev_exit(void) { unregister_chrdev_region(watchdog_devt, MAX_DOGS); @@ -1177,7 +1269,59 @@ void __exit watchdog_dev_exit(void) kthread_destroy_worker(watchdog_kworker); } +int watchdog_dev_suspend(struct watchdog_device *wdd) +{ + struct watchdog_core_data *wd_data = wdd->wd_data; + int ret = 0; + + if (!wdd->wd_data) + return -ENODEV; + + /* ping for the last time before suspend */ + mutex_lock(&wd_data->lock); + if (watchdog_worker_should_ping(wd_data)) + ret = __watchdog_ping(wd_data->wdd); + mutex_unlock(&wd_data->lock); + + if (ret) + return ret; + + /* + * make sure that watchdog worker will not kick in when the wdog is + * suspended + */ + hrtimer_cancel(&wd_data->timer); + kthread_cancel_work_sync(&wd_data->work); + + return 0; +} + +int watchdog_dev_resume(struct watchdog_device *wdd) +{ + struct watchdog_core_data *wd_data = wdd->wd_data; + int ret = 0; + + if (!wdd->wd_data) + return -ENODEV; + + /* + * __watchdog_ping will also retrigger hrtimer and therefore restore the + * ping worker if needed. + */ + mutex_lock(&wd_data->lock); + if (watchdog_worker_should_ping(wd_data)) + ret = __watchdog_ping(wd_data->wdd); + mutex_unlock(&wd_data->lock); + + return ret; +} + module_param(handle_boot_enabled, bool, 0444); MODULE_PARM_DESC(handle_boot_enabled, "Watchdog core auto-updates boot enabled watchdogs before userspace takes over (default=" __MODULE_STRING(IS_ENABLED(CONFIG_WATCHDOG_HANDLE_BOOT_ENABLED)) ")"); + +module_param(open_timeout, uint, 0644); +MODULE_PARM_DESC(open_timeout, + "Maximum time (in seconds, 0 means infinity) for userspace to take over a running watchdog (default=" + __MODULE_STRING(CONFIG_WATCHDOG_OPEN_TIMEOUT) ")"); |