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 2018 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/io.h>
  20 #include <linux/kernel.h>
  21 #include <linux/module.h>
  22 #include <linux/moduleparam.h>
  23 #include <linux/pci.h>
  24 #include <linux/pci_ids.h>
  25 #include <linux/types.h>
  26 #include <linux/watchdog.h>
  27 #include <asm/nmi.h>
  28
  29 #define HPWDT_VERSION                   "2.0.1"
  30 #define SECS_TO_TICKS(secs)             ((secs) * 1000 / 128)
  31 #define TICKS_TO_SECS(ticks)            ((ticks) * 128 / 1000)
  32 #define HPWDT_MAX_TIMER                 TICKS_TO_SECS(65535)
  33 #define DEFAULT_MARGIN                  30
  34 #define PRETIMEOUT_SEC                  9
  35
  36 static bool ilo5;
  37 static unsigned int soft_margin = DEFAULT_MARGIN;       /* in seconds */
  38 static bool nowayout = WATCHDOG_NOWAYOUT;
  39 static bool pretimeout = IS_ENABLED(CONFIG_HPWDT_NMI_DECODING);
  40
  41 static void __iomem *pci_mem_addr;              /* the PCI-memory address */
  42 static unsigned long __iomem *hpwdt_nmistat;
  43 static unsigned long __iomem *hpwdt_timer_reg;
  44 static unsigned long __iomem *hpwdt_timer_con;
  45
  46 static const struct pci_device_id hpwdt_devices[] = {
  47         { PCI_DEVICE(PCI_VENDOR_ID_COMPAQ, 0xB203) },   /* iLO2 */
  48         { PCI_DEVICE(PCI_VENDOR_ID_HP, 0x3306) },       /* iLO3 */
  49         {0},                    /* terminate list */
  50 };
  51 MODULE_DEVICE_TABLE(pci, hpwdt_devices);
  52
  53
  54 /*
  55  *      Watchdog operations
  56  */
  57 static int hpwdt_start(struct watchdog_device *wdd)
  58 {
  59         int control = 0x81 | (pretimeout ? 0x4 : 0);
  60         int reload = SECS_TO_TICKS(wdd->timeout);
  61
  62         dev_dbg(wdd->parent, "start watchdog 0x%08x:0x%02x\n", reload, control);
  63         iowrite16(reload, hpwdt_timer_reg);
  64         iowrite8(control, hpwdt_timer_con);
  65
  66         return 0;
  67 }
  68
  69 static void hpwdt_stop(void)
  70 {
  71         unsigned long data;
  72
  73         pr_debug("stop  watchdog\n");
  74
  75         data = ioread8(hpwdt_timer_con);
  76         data &= 0xFE;
  77         iowrite8(data, hpwdt_timer_con);
  78 }
  79
  80 static int hpwdt_stop_core(struct watchdog_device *wdd)
  81 {
  82         hpwdt_stop();
  83
  84         return 0;
  85 }
  86
  87 static int hpwdt_ping(struct watchdog_device *wdd)
  88 {
  89         int reload = SECS_TO_TICKS(wdd->timeout);
  90
  91         dev_dbg(wdd->parent, "ping  watchdog 0x%08x\n", reload);
  92         iowrite16(reload, hpwdt_timer_reg);
  93
  94         return 0;
  95 }
  96
  97 static unsigned int hpwdt_gettimeleft(struct watchdog_device *wdd)
  98 {
  99         return TICKS_TO_SECS(ioread16(hpwdt_timer_reg));
 100 }
 101
 102 static int hpwdt_settimeout(struct watchdog_device *wdd, unsigned int val)
 103 {
 104         dev_dbg(wdd->parent, "set_timeout = %d\n", val);
 105
 106         wdd->timeout = val;
 107         if (val <= wdd->pretimeout) {
 108                 dev_dbg(wdd->parent, "pretimeout < timeout. Setting to zero\n");
 109                 wdd->pretimeout = 0;
 110                 pretimeout = 0;
 111                 if (watchdog_active(wdd))
 112                         hpwdt_start(wdd);
 113         }
 114         hpwdt_ping(wdd);
 115
 116         return 0;
 117 }
 118
 119 #ifdef CONFIG_HPWDT_NMI_DECODING
 120 static int hpwdt_set_pretimeout(struct watchdog_device *wdd, unsigned int req)
 121 {
 122         unsigned int val = 0;
 123
 124         dev_dbg(wdd->parent, "set_pretimeout = %d\n", req);
 125         if (req) {
 126                 val = PRETIMEOUT_SEC;
 127                 if (val >= wdd->timeout)
 128                         return -EINVAL;
 129         }
 130
 131         if (val != req)
 132                 dev_dbg(wdd->parent, "Rounding pretimeout to: %d\n", val);
 133
 134         wdd->pretimeout = val;
 135         pretimeout = !!val;
 136
 137         if (watchdog_active(wdd))
 138                 hpwdt_start(wdd);
 139
 140         return 0;
 141 }
 142
 143 static int hpwdt_my_nmi(void)
 144 {
 145         return ioread8(hpwdt_nmistat) & 0x6;
 146 }
 147
 148 /*
 149  *      NMI Handler
 150  */
 151 static int hpwdt_pretimeout(unsigned int ulReason, struct pt_regs *regs)
 152 {
 153         unsigned int mynmi = hpwdt_my_nmi();
 154         static char panic_msg[] =
 155                 "00: An NMI occurred. Depending on your system the reason "
 156                 "for the NMI is logged in any one of the following resources:\n"
 157                 "1. Integrated Management Log (IML)\n"
 158                 "2. OA Syslog\n"
 159                 "3. OA Forward Progress Log\n"
 160                 "4. iLO Event Log";
 161
 162         if (ilo5 && ulReason == NMI_UNKNOWN && !mynmi)
 163                 return NMI_DONE;
 164
 165         if (ilo5 && !pretimeout && !mynmi)
 166                 return NMI_DONE;
 167
 168         hpwdt_stop();
 169
 170         hex_byte_pack(panic_msg, mynmi);
 171         nmi_panic(regs, panic_msg);
 172
 173         return NMI_HANDLED;
 174 }
 175 #endif /* CONFIG_HPWDT_NMI_DECODING */
 176
 177
 178 static const struct watchdog_info ident = {
 179         .options = WDIOF_PRETIMEOUT    |
 180                    WDIOF_SETTIMEOUT    |
 181                    WDIOF_KEEPALIVEPING |
 182                    WDIOF_MAGICCLOSE,
 183         .identity = "HPE iLO2+ HW Watchdog Timer",
 184 };
 185
 186 /*
 187  *      Kernel interfaces
 188  */
 189
 190 static const struct watchdog_ops hpwdt_ops = {
 191         .owner          = THIS_MODULE,
 192         .start          = hpwdt_start,
 193         .stop           = hpwdt_stop_core,
 194         .ping           = hpwdt_ping,
 195         .set_timeout    = hpwdt_settimeout,
 196         .get_timeleft   = hpwdt_gettimeleft,
 197 #ifdef CONFIG_HPWDT_NMI_DECODING
 198         .set_pretimeout = hpwdt_set_pretimeout,
 199 #endif
 200 };
 201
 202 static struct watchdog_device hpwdt_dev = {
 203         .info           = &ident,
 204         .ops            = &hpwdt_ops,
 205         .min_timeout    = 1,
 206         .max_timeout    = HPWDT_MAX_TIMER,
 207         .timeout        = DEFAULT_MARGIN,
 208         .pretimeout     = PRETIMEOUT_SEC,
 209 };
 210
 211
 212 /*
 213  *      Init & Exit
 214  */
 215
 216 static int hpwdt_init_nmi_decoding(struct pci_dev *dev)
 217 {
 218 #ifdef CONFIG_HPWDT_NMI_DECODING
 219         int retval;
 220         /*
 221          * Only one function can register for NMI_UNKNOWN
 222          */
 223         retval = register_nmi_handler(NMI_UNKNOWN, hpwdt_pretimeout, 0, "hpwdt");
 224         if (retval)
 225                 goto error;
 226         retval = register_nmi_handler(NMI_SERR, hpwdt_pretimeout, 0, "hpwdt");
 227         if (retval)
 228                 goto error1;
 229         retval = register_nmi_handler(NMI_IO_CHECK, hpwdt_pretimeout, 0, "hpwdt");
 230         if (retval)
 231                 goto error2;
 232
 233         dev_info(&dev->dev,
 234                 "HPE Watchdog Timer Driver: NMI decoding initialized\n");
 235
 236         return 0;
 237
 238 error2:
 239         unregister_nmi_handler(NMI_SERR, "hpwdt");
 240 error1:
 241         unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
 242 error:
 243         dev_warn(&dev->dev,
 244                 "Unable to register a die notifier (err=%d).\n",
 245                 retval);
 246         return retval;
 247 #endif  /* CONFIG_HPWDT_NMI_DECODING */
 248         return 0;
 249 }
 250
 251 static void hpwdt_exit_nmi_decoding(void)
 252 {
 253 #ifdef CONFIG_HPWDT_NMI_DECODING
 254         unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
 255         unregister_nmi_handler(NMI_SERR, "hpwdt");
 256         unregister_nmi_handler(NMI_IO_CHECK, "hpwdt");
 257 #endif
 258 }
 259
 260 static int hpwdt_init_one(struct pci_dev *dev,
 261                                         const struct pci_device_id *ent)
 262 {
 263         int retval;
 264
 265         /*
 266          * First let's find out if we are on an iLO2+ server. We will
 267          * not run on a legacy ASM box.
 268          * So we only support the G5 ProLiant servers and higher.
 269          */
 270         if (dev->subsystem_vendor != PCI_VENDOR_ID_HP &&
 271             dev->subsystem_vendor != PCI_VENDOR_ID_HP_3PAR) {
 272                 dev_warn(&dev->dev,
 273                         "This server does not have an iLO2+ ASIC.\n");
 274                 return -ENODEV;
 275         }
 276
 277         /*
 278          * Ignore all auxilary iLO devices with the following PCI ID
 279          */
 280         if (dev->subsystem_vendor == PCI_VENDOR_ID_HP &&
 281             dev->subsystem_device == 0x1979)
 282                 return -ENODEV;
 283
 284         if (pci_enable_device(dev)) {
 285                 dev_warn(&dev->dev,
 286                         "Not possible to enable PCI Device: 0x%x:0x%x.\n",
 287                         ent->vendor, ent->device);
 288                 return -ENODEV;
 289         }
 290
 291         pci_mem_addr = pci_iomap(dev, 1, 0x80);
 292         if (!pci_mem_addr) {
 293                 dev_warn(&dev->dev,
 294                         "Unable to detect the iLO2+ server memory.\n");
 295                 retval = -ENOMEM;
 296                 goto error_pci_iomap;
 297         }
 298         hpwdt_nmistat   = pci_mem_addr + 0x6e;
 299         hpwdt_timer_reg = pci_mem_addr + 0x70;
 300         hpwdt_timer_con = pci_mem_addr + 0x72;
 301
 302         /* Make sure that timer is disabled until /dev/watchdog is opened */
 303         hpwdt_stop();
 304
 305         /* Initialize NMI Decoding functionality */
 306         retval = hpwdt_init_nmi_decoding(dev);
 307         if (retval != 0)
 308                 goto error_init_nmi_decoding;
 309
 310         watchdog_set_nowayout(&hpwdt_dev, nowayout);
 311         if (watchdog_init_timeout(&hpwdt_dev, soft_margin, NULL))
 312                 dev_warn(&dev->dev, "Invalid soft_margin: %d.\n", soft_margin);
 313
 314         if (pretimeout && hpwdt_dev.timeout <= PRETIMEOUT_SEC) {
 315                 dev_warn(&dev->dev, "timeout <= pretimeout. Setting pretimeout to zero\n");
 316                 pretimeout = 0;
 317         }
 318         hpwdt_dev.pretimeout = pretimeout ? PRETIMEOUT_SEC : 0;
 319
 320         hpwdt_dev.parent = &dev->dev;
 321         retval = watchdog_register_device(&hpwdt_dev);
 322         if (retval < 0) {
 323                 dev_err(&dev->dev, "watchdog register failed: %d.\n", retval);
 324                 goto error_wd_register;
 325         }
 326
 327         dev_info(&dev->dev, "HPE Watchdog Timer Driver: Version: %s\n",
 328                                 HPWDT_VERSION);
 329         dev_info(&dev->dev, "timeout: %d seconds (nowayout=%d)\n",
 330                                 hpwdt_dev.timeout, nowayout);
 331         dev_info(&dev->dev, "pretimeout: %s.\n",
 332                                 pretimeout ? "on" : "off");
 333
 334         if (dev->subsystem_vendor == PCI_VENDOR_ID_HP_3PAR)
 335                 ilo5 = true;
 336
 337         return 0;
 338
 339 error_wd_register:
 340         hpwdt_exit_nmi_decoding();
 341 error_init_nmi_decoding:
 342         pci_iounmap(dev, pci_mem_addr);
 343 error_pci_iomap:
 344         pci_disable_device(dev);
 345         return retval;
 346 }
 347
 348 static void hpwdt_exit(struct pci_dev *dev)
 349 {
 350         if (!nowayout)
 351                 hpwdt_stop();
 352
 353         watchdog_unregister_device(&hpwdt_dev);
 354         hpwdt_exit_nmi_decoding();
 355         pci_iounmap(dev, pci_mem_addr);
 356         pci_disable_device(dev);
 357 }
 358
 359 static struct pci_driver hpwdt_driver = {
 360         .name = "hpwdt",
 361         .id_table = hpwdt_devices,
 362         .probe = hpwdt_init_one,
 363         .remove = hpwdt_exit,
 364 };
 365
 366 MODULE_AUTHOR("Tom Mingarelli");
 367 MODULE_DESCRIPTION("hpe watchdog driver");
 368 MODULE_LICENSE("GPL");
 369 MODULE_VERSION(HPWDT_VERSION);
 370
 371 module_param(soft_margin, int, 0);
 372 MODULE_PARM_DESC(soft_margin, "Watchdog timeout in seconds");
 373
 374 module_param_named(timeout, soft_margin, int, 0);
 375 MODULE_PARM_DESC(timeout, "Alias of soft_margin");
 376
 377 module_param(nowayout, bool, 0);
 378 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
 379                 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 380
 381 #ifdef CONFIG_HPWDT_NMI_DECODING
 382 module_param(pretimeout, bool, 0);
 383 MODULE_PARM_DESC(pretimeout, "Watchdog pretimeout enabled");
 384 #endif
 385
 386 module_pci_driver(hpwdt_driver);