Blame view
drivers/watchdog/xen_wdt.c
7.45 KB
066d6c7f4 watchdog: Xen wat... |
1 2 3 4 5 6 7 8 9 10 |
/* * Xen Watchdog Driver * * (c) Copyright 2010 Novell, Inc. * * 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. */ |
27c766aaa watchdog: Use pr_... |
11 |
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
066d6c7f4 watchdog: Xen wat... |
12 13 |
#define DRV_NAME "wdt" #define DRV_VERSION "0.01" |
066d6c7f4 watchdog: Xen wat... |
14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 |
#include <linux/bug.h> #include <linux/errno.h> #include <linux/fs.h> #include <linux/hrtimer.h> #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 __kernel_time_t wdt_expires; static bool is_active, expect_release; #define WATCHDOG_TIMEOUT 60 /* in seconds */ static unsigned int timeout = WATCHDOG_TIMEOUT; module_param(timeout, uint, S_IRUGO); MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds " "(default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ")"); static bool nowayout = WATCHDOG_NOWAYOUT; module_param(nowayout, bool, S_IRUGO); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started " "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); static inline __kernel_time_t set_timeout(void) { wdt.timeout = timeout; return ktime_to_timespec(ktime_get()).tv_sec + timeout; } static int xen_wdt_start(void) { __kernel_time_t expires; int err; spin_lock(&wdt_lock); expires = set_timeout(); if (!wdt.id) err = HYPERVISOR_sched_op(SCHEDOP_watchdog, &wdt); else err = -EBUSY; if (err > 0) { wdt.id = err; wdt_expires = expires; err = 0; } else BUG_ON(!err); spin_unlock(&wdt_lock); return err; } static int xen_wdt_stop(void) { 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) { __kernel_time_t expires; int err; spin_lock(&wdt_lock); expires = set_timeout(); if (wdt.id) err = HYPERVISOR_sched_op(SCHEDOP_watchdog, &wdt); else err = -ENXIO; if (!err) wdt_expires = expires; spin_unlock(&wdt_lock); return err; } static int xen_wdt_open(struct inode *inode, struct file *file) { 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); } static int xen_wdt_release(struct inode *inode, struct file *file) { |
38c484fa1 watchdog: xen: do... |
133 |
int err = 0; |
066d6c7f4 watchdog: Xen wat... |
134 |
if (expect_release) |
38c484fa1 watchdog: xen: do... |
135 |
err = xen_wdt_stop(); |
066d6c7f4 watchdog: Xen wat... |
136 |
else { |
27c766aaa watchdog: Use pr_... |
137 138 |
pr_crit("unexpected close, not stopping watchdog! "); |
066d6c7f4 watchdog: Xen wat... |
139 140 |
xen_wdt_kick(); } |
38c484fa1 watchdog: xen: do... |
141 |
is_active = err; |
066d6c7f4 watchdog: Xen wat... |
142 |
expect_release = false; |
38c484fa1 watchdog: xen: do... |
143 |
return err; |
066d6c7f4 watchdog: Xen wat... |
144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 |
} 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_to_timespec(ktime_get()).tv_sec; return put_user(retval, argp); } return -ENOTTY; } 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 struct miscdevice xen_wdt_miscdev = { .minor = WATCHDOG_MINOR, .name = "watchdog", .fops = &xen_wdt_fops, }; |
2d991a164 watchdog: remove ... |
244 |
static int xen_wdt_probe(struct platform_device *dev) |
066d6c7f4 watchdog: Xen wat... |
245 246 247 248 249 250 251 252 |
{ struct sched_watchdog wd = { .id = ~0 }; int ret = HYPERVISOR_sched_op(SCHEDOP_watchdog, &wd); switch (ret) { case -EINVAL: if (!timeout) { timeout = WATCHDOG_TIMEOUT; |
27c766aaa watchdog: Use pr_... |
253 254 |
pr_info("timeout value invalid, using %d ", timeout); |
066d6c7f4 watchdog: Xen wat... |
255 256 257 258 |
} ret = misc_register(&xen_wdt_miscdev); if (ret) { |
27c766aaa watchdog: Use pr_... |
259 260 |
pr_err("cannot register miscdev on minor=%d (%d) ", |
066d6c7f4 watchdog: Xen wat... |
261 262 263 |
WATCHDOG_MINOR, ret); break; } |
27c766aaa watchdog: Use pr_... |
264 265 266 |
pr_info("initialized (timeout=%ds, nowayout=%d) ", timeout, nowayout); |
066d6c7f4 watchdog: Xen wat... |
267 268 269 |
break; case -ENOSYS: |
27c766aaa watchdog: Use pr_... |
270 271 |
pr_info("not supported "); |
066d6c7f4 watchdog: Xen wat... |
272 273 274 275 |
ret = -ENODEV; break; default: |
27c766aaa watchdog: Use pr_... |
276 277 |
pr_info("bogus return value %d ", ret); |
066d6c7f4 watchdog: Xen wat... |
278 279 280 281 282 |
break; } return ret; } |
4b12b896c watchdog: remove ... |
283 |
static int xen_wdt_remove(struct platform_device *dev) |
066d6c7f4 watchdog: Xen wat... |
284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 |
{ /* Stop the timer before we leave */ if (!nowayout) xen_wdt_stop(); misc_deregister(&xen_wdt_miscdev); 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) { |
83448bf78 watchdog: xen: do... |
301 302 303 304 305 |
typeof(wdt.id) id = wdt.id; int rc = xen_wdt_stop(); wdt.id = id; return rc; |
066d6c7f4 watchdog: Xen wat... |
306 307 308 309 |
} static int xen_wdt_resume(struct platform_device *dev) { |
83448bf78 watchdog: xen: do... |
310 311 312 |
if (!wdt.id) return 0; wdt.id = 0; |
066d6c7f4 watchdog: Xen wat... |
313 314 315 316 317 |
return xen_wdt_start(); } static struct platform_driver xen_wdt_driver = { .probe = xen_wdt_probe, |
82268714b watchdog: remove ... |
318 |
.remove = xen_wdt_remove, |
066d6c7f4 watchdog: Xen wat... |
319 320 321 322 |
.shutdown = xen_wdt_shutdown, .suspend = xen_wdt_suspend, .resume = xen_wdt_resume, .driver = { |
066d6c7f4 watchdog: Xen wat... |
323 324 325 326 327 328 329 330 331 332 |
.name = DRV_NAME, }, }; static int __init xen_wdt_init_module(void) { int err; if (!xen_domain()) return -ENODEV; |
27c766aaa watchdog: Use pr_... |
333 334 |
pr_info("Xen WatchDog Timer Driver v%s ", DRV_VERSION); |
066d6c7f4 watchdog: Xen wat... |
335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 |
err = platform_driver_register(&xen_wdt_driver); if (err) return err; platform_device = platform_device_register_simple(DRV_NAME, -1, NULL, 0); if (IS_ERR(platform_device)) { err = PTR_ERR(platform_device); platform_driver_unregister(&xen_wdt_driver); } return err; } static void __exit xen_wdt_cleanup_module(void) { platform_device_unregister(platform_device); platform_driver_unregister(&xen_wdt_driver); |
27c766aaa watchdog: Use pr_... |
354 355 |
pr_info("module unloaded "); |
066d6c7f4 watchdog: Xen wat... |
356 357 358 359 360 361 362 363 364 |
} module_init(xen_wdt_init_module); module_exit(xen_wdt_cleanup_module); MODULE_AUTHOR("Jan Beulich <jbeulich@novell.com>"); MODULE_DESCRIPTION("Xen WatchDog Timer Driver"); MODULE_VERSION(DRV_VERSION); MODULE_LICENSE("GPL"); |