1 /* 2 * HPE WatchDog Driver 3 * based on 4 * 5 * SoftDog 0.05: A Software Watchdog Device 6 * 7 * (c) Copyright 2015 Hewlett Packard Enterprise Development LP 8 * Thomas Mingarelli <thomas.mingarelli@hpe.com> 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public License 12 * version 2 as published by the Free Software Foundation 13 * 14 */ 15 16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 17 18 #include <linux/device.h> 19 #include <linux/fs.h> 20 #include <linux/io.h> 21 #include <linux/bitops.h> 22 #include <linux/kernel.h> 23 #include <linux/miscdevice.h> 24 #include <linux/module.h> 25 #include <linux/moduleparam.h> 26 #include <linux/pci.h> 27 #include <linux/pci_ids.h> 28 #include <linux/types.h> 29 #include <linux/uaccess.h> 30 #include <linux/watchdog.h> 31 #include <asm/nmi.h> 32 33 #define HPWDT_VERSION "1.4.0" 34 #define SECS_TO_TICKS(secs) ((secs) * 1000 / 128) 35 #define TICKS_TO_SECS(ticks) ((ticks) * 128 / 1000) 36 #define HPWDT_MAX_TIMER TICKS_TO_SECS(65535) 37 #define DEFAULT_MARGIN 30 38 39 static unsigned int soft_margin = DEFAULT_MARGIN; /* in seconds */ 40 static unsigned int reload; /* the computed soft_margin */ 41 static bool nowayout = WATCHDOG_NOWAYOUT; 42 #ifdef CONFIG_HPWDT_NMI_DECODING 43 static unsigned int allow_kdump = 1; 44 #endif 45 static char expect_release; 46 static unsigned long hpwdt_is_open; 47 48 static void __iomem *pci_mem_addr; /* the PCI-memory address */ 49 static unsigned long __iomem *hpwdt_nmistat; 50 static unsigned long __iomem *hpwdt_timer_reg; 51 static unsigned long __iomem *hpwdt_timer_con; 52 53 static const struct pci_device_id hpwdt_devices[] = { 54 { PCI_DEVICE(PCI_VENDOR_ID_COMPAQ, 0xB203) }, /* iLO2 */ 55 { PCI_DEVICE(PCI_VENDOR_ID_HP, 0x3306) }, /* iLO3 */ 56 {0}, /* terminate list */ 57 }; 58 MODULE_DEVICE_TABLE(pci, hpwdt_devices); 59 60 61 /* 62 * Watchdog operations 63 */ 64 static void hpwdt_start(void) 65 { 66 reload = SECS_TO_TICKS(soft_margin); 67 iowrite16(reload, hpwdt_timer_reg); 68 iowrite8(0x85, hpwdt_timer_con); 69 } 70 71 static void hpwdt_stop(void) 72 { 73 unsigned long data; 74 75 data = ioread8(hpwdt_timer_con); 76 data &= 0xFE; 77 iowrite8(data, hpwdt_timer_con); 78 } 79 80 static void hpwdt_ping(void) 81 { 82 iowrite16(reload, hpwdt_timer_reg); 83 } 84 85 static int hpwdt_change_timer(int new_margin) 86 { 87 if (new_margin < 1 || new_margin > HPWDT_MAX_TIMER) { 88 pr_warn("New value passed in is invalid: %d seconds\n", 89 new_margin); 90 return -EINVAL; 91 } 92 93 soft_margin = new_margin; 94 pr_debug("New timer passed in is %d seconds\n", new_margin); 95 reload = SECS_TO_TICKS(soft_margin); 96 97 return 0; 98 } 99 100 static int hpwdt_time_left(void) 101 { 102 return TICKS_TO_SECS(ioread16(hpwdt_timer_reg)); 103 } 104 105 #ifdef CONFIG_HPWDT_NMI_DECODING 106 static int hpwdt_my_nmi(void) 107 { 108 return ioread8(hpwdt_nmistat) & 0x6; 109 } 110 111 /* 112 * NMI Handler 113 */ 114 static int hpwdt_pretimeout(unsigned int ulReason, struct pt_regs *regs) 115 { 116 if ((ulReason == NMI_UNKNOWN) && !hpwdt_my_nmi()) 117 return NMI_DONE; 118 119 if (allow_kdump) 120 hpwdt_stop(); 121 122 nmi_panic(regs, "An NMI occurred. Depending on your system the reason " 123 "for the NMI is logged in any one of the following " 124 "resources:\n" 125 "1. Integrated Management Log (IML)\n" 126 "2. OA Syslog\n" 127 "3. OA Forward Progress Log\n" 128 "4. iLO Event Log"); 129 130 return NMI_HANDLED; 131 } 132 #endif /* CONFIG_HPWDT_NMI_DECODING */ 133 134 /* 135 * /dev/watchdog handling 136 */ 137 static int hpwdt_open(struct inode *inode, struct file *file) 138 { 139 /* /dev/watchdog can only be opened once */ 140 if (test_and_set_bit(0, &hpwdt_is_open)) 141 return -EBUSY; 142 143 /* Start the watchdog */ 144 hpwdt_start(); 145 hpwdt_ping(); 146 147 return nonseekable_open(inode, file); 148 } 149 150 static int hpwdt_release(struct inode *inode, struct file *file) 151 { 152 /* Stop the watchdog */ 153 if (expect_release == 42) { 154 hpwdt_stop(); 155 } else { 156 pr_crit("Unexpected close, not stopping watchdog!\n"); 157 hpwdt_ping(); 158 } 159 160 expect_release = 0; 161 162 /* /dev/watchdog is being closed, make sure it can be re-opened */ 163 clear_bit(0, &hpwdt_is_open); 164 165 return 0; 166 } 167 168 static ssize_t hpwdt_write(struct file *file, const char __user *data, 169 size_t len, loff_t *ppos) 170 { 171 /* See if we got the magic character 'V' and reload the timer */ 172 if (len) { 173 if (!nowayout) { 174 size_t i; 175 176 /* note: just in case someone wrote the magic character 177 * five months ago... */ 178 expect_release = 0; 179 180 /* scan to see whether or not we got the magic char. */ 181 for (i = 0; i != len; i++) { 182 char c; 183 if (get_user(c, data + i)) 184 return -EFAULT; 185 if (c == 'V') 186 expect_release = 42; 187 } 188 } 189 190 /* someone wrote to us, we should reload the timer */ 191 hpwdt_ping(); 192 } 193 194 return len; 195 } 196 197 static const struct watchdog_info ident = { 198 .options = WDIOF_SETTIMEOUT | 199 WDIOF_KEEPALIVEPING | 200 WDIOF_MAGICCLOSE, 201 .identity = "HPE iLO2+ HW Watchdog Timer", 202 }; 203 204 static long hpwdt_ioctl(struct file *file, unsigned int cmd, 205 unsigned long arg) 206 { 207 void __user *argp = (void __user *)arg; 208 int __user *p = argp; 209 int new_margin, options; 210 int ret = -ENOTTY; 211 212 switch (cmd) { 213 case WDIOC_GETSUPPORT: 214 ret = 0; 215 if (copy_to_user(argp, &ident, sizeof(ident))) 216 ret = -EFAULT; 217 break; 218 219 case WDIOC_GETSTATUS: 220 case WDIOC_GETBOOTSTATUS: 221 ret = put_user(0, p); 222 break; 223 224 case WDIOC_KEEPALIVE: 225 hpwdt_ping(); 226 ret = 0; 227 break; 228 229 case WDIOC_SETOPTIONS: 230 ret = get_user(options, p); 231 if (ret) 232 break; 233 234 if (options & WDIOS_DISABLECARD) 235 hpwdt_stop(); 236 237 if (options & WDIOS_ENABLECARD) { 238 hpwdt_start(); 239 hpwdt_ping(); 240 } 241 break; 242 243 case WDIOC_SETTIMEOUT: 244 ret = get_user(new_margin, p); 245 if (ret) 246 break; 247 248 ret = hpwdt_change_timer(new_margin); 249 if (ret) 250 break; 251 252 hpwdt_ping(); 253 /* Fall */ 254 case WDIOC_GETTIMEOUT: 255 ret = put_user(soft_margin, p); 256 break; 257 258 case WDIOC_GETTIMELEFT: 259 ret = put_user(hpwdt_time_left(), p); 260 break; 261 } 262 return ret; 263 } 264 265 /* 266 * Kernel interfaces 267 */ 268 static const struct file_operations hpwdt_fops = { 269 .owner = THIS_MODULE, 270 .llseek = no_llseek, 271 .write = hpwdt_write, 272 .unlocked_ioctl = hpwdt_ioctl, 273 .open = hpwdt_open, 274 .release = hpwdt_release, 275 }; 276 277 static struct miscdevice hpwdt_miscdev = { 278 .minor = WATCHDOG_MINOR, 279 .name = "watchdog", 280 .fops = &hpwdt_fops, 281 }; 282 283 /* 284 * Init & Exit 285 */ 286 287 288 static int hpwdt_init_nmi_decoding(struct pci_dev *dev) 289 { 290 #ifdef CONFIG_HPWDT_NMI_DECODING 291 int retval; 292 /* 293 * Only one function can register for NMI_UNKNOWN 294 */ 295 retval = register_nmi_handler(NMI_UNKNOWN, hpwdt_pretimeout, 0, "hpwdt"); 296 if (retval) 297 goto error; 298 retval = register_nmi_handler(NMI_SERR, hpwdt_pretimeout, 0, "hpwdt"); 299 if (retval) 300 goto error1; 301 retval = register_nmi_handler(NMI_IO_CHECK, hpwdt_pretimeout, 0, "hpwdt"); 302 if (retval) 303 goto error2; 304 305 dev_info(&dev->dev, 306 "HPE Watchdog Timer Driver: NMI decoding initialized" 307 ", allow kernel dump: %s (default = 1/ON)\n", 308 (allow_kdump == 0) ? "OFF" : "ON"); 309 return 0; 310 311 error2: 312 unregister_nmi_handler(NMI_SERR, "hpwdt"); 313 error1: 314 unregister_nmi_handler(NMI_UNKNOWN, "hpwdt"); 315 error: 316 dev_warn(&dev->dev, 317 "Unable to register a die notifier (err=%d).\n", 318 retval); 319 return retval; 320 #endif /* CONFIG_HPWDT_NMI_DECODING */ 321 return 0; 322 } 323 324 static void hpwdt_exit_nmi_decoding(void) 325 { 326 #ifdef CONFIG_HPWDT_NMI_DECODING 327 unregister_nmi_handler(NMI_UNKNOWN, "hpwdt"); 328 unregister_nmi_handler(NMI_SERR, "hpwdt"); 329 unregister_nmi_handler(NMI_IO_CHECK, "hpwdt"); 330 #endif 331 } 332 333 static int hpwdt_init_one(struct pci_dev *dev, 334 const struct pci_device_id *ent) 335 { 336 int retval; 337 338 /* 339 * First let's find out if we are on an iLO2+ server. We will 340 * not run on a legacy ASM box. 341 * So we only support the G5 ProLiant servers and higher. 342 */ 343 if (dev->subsystem_vendor != PCI_VENDOR_ID_HP && 344 dev->subsystem_vendor != PCI_VENDOR_ID_HP_3PAR) { 345 dev_warn(&dev->dev, 346 "This server does not have an iLO2+ ASIC.\n"); 347 return -ENODEV; 348 } 349 350 /* 351 * Ignore all auxilary iLO devices with the following PCI ID 352 */ 353 if (dev->subsystem_vendor == PCI_VENDOR_ID_HP && 354 dev->subsystem_device == 0x1979) 355 return -ENODEV; 356 357 if (pci_enable_device(dev)) { 358 dev_warn(&dev->dev, 359 "Not possible to enable PCI Device: 0x%x:0x%x.\n", 360 ent->vendor, ent->device); 361 return -ENODEV; 362 } 363 364 pci_mem_addr = pci_iomap(dev, 1, 0x80); 365 if (!pci_mem_addr) { 366 dev_warn(&dev->dev, 367 "Unable to detect the iLO2+ server memory.\n"); 368 retval = -ENOMEM; 369 goto error_pci_iomap; 370 } 371 hpwdt_nmistat = pci_mem_addr + 0x6e; 372 hpwdt_timer_reg = pci_mem_addr + 0x70; 373 hpwdt_timer_con = pci_mem_addr + 0x72; 374 375 /* Make sure that timer is disabled until /dev/watchdog is opened */ 376 hpwdt_stop(); 377 378 /* Make sure that we have a valid soft_margin */ 379 if (hpwdt_change_timer(soft_margin)) 380 hpwdt_change_timer(DEFAULT_MARGIN); 381 382 /* Initialize NMI Decoding functionality */ 383 retval = hpwdt_init_nmi_decoding(dev); 384 if (retval != 0) 385 goto error_init_nmi_decoding; 386 387 retval = misc_register(&hpwdt_miscdev); 388 if (retval < 0) { 389 dev_warn(&dev->dev, 390 "Unable to register miscdev on minor=%d (err=%d).\n", 391 WATCHDOG_MINOR, retval); 392 goto error_misc_register; 393 } 394 395 dev_info(&dev->dev, "HPE Watchdog Timer Driver: %s" 396 ", timer margin: %d seconds (nowayout=%d).\n", 397 HPWDT_VERSION, soft_margin, nowayout); 398 return 0; 399 400 error_misc_register: 401 hpwdt_exit_nmi_decoding(); 402 error_init_nmi_decoding: 403 pci_iounmap(dev, pci_mem_addr); 404 error_pci_iomap: 405 pci_disable_device(dev); 406 return retval; 407 } 408 409 static void hpwdt_exit(struct pci_dev *dev) 410 { 411 if (!nowayout) 412 hpwdt_stop(); 413 414 misc_deregister(&hpwdt_miscdev); 415 hpwdt_exit_nmi_decoding(); 416 pci_iounmap(dev, pci_mem_addr); 417 pci_disable_device(dev); 418 } 419 420 static struct pci_driver hpwdt_driver = { 421 .name = "hpwdt", 422 .id_table = hpwdt_devices, 423 .probe = hpwdt_init_one, 424 .remove = hpwdt_exit, 425 }; 426 427 MODULE_AUTHOR("Tom Mingarelli"); 428 MODULE_DESCRIPTION("hp watchdog driver"); 429 MODULE_LICENSE("GPL"); 430 MODULE_VERSION(HPWDT_VERSION); 431 432 module_param(soft_margin, int, 0); 433 MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds"); 434 435 module_param(nowayout, bool, 0); 436 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" 437 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 438 439 #ifdef CONFIG_HPWDT_NMI_DECODING 440 module_param(allow_kdump, int, 0); 441 MODULE_PARM_DESC(allow_kdump, "Start a kernel dump after NMI occurs"); 442 #endif /* CONFIG_HPWDT_NMI_DECODING */ 443 444 module_pci_driver(hpwdt_driver); 445