drivers/watchdog/hpwdt.c

   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);