hw/wdt_i6300esb.c

   1 /*
   2  * Virtual hardware watchdog.
   3  *
   4  * Copyright (C) 2009 Red Hat Inc.
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version 2
   9  * of the License, or (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  18  *
  19  * By Richard W.M. Jones (rjones@redhat.com).
  20  */
  21
  22 #include <inttypes.h>
  23
  24 #include "qemu-common.h"
  25 #include "qemu/timer.h"
  26 #include "watchdog.h"
  27 #include "hw.h"
  28 #include "pci/pci.h"
  29
  30 /*#define I6300ESB_DEBUG 1*/
  31
  32 #ifdef I6300ESB_DEBUG
  33 #define i6300esb_debug(fs,...) \
  34     fprintf(stderr,"i6300esb: %s: "fs,__func__,##__VA_ARGS__)
  35 #else
  36 #define i6300esb_debug(fs,...)
  37 #endif
  38
  39 /* PCI configuration registers */
  40 #define ESB_CONFIG_REG  0x60            /* Config register                   */
  41 #define ESB_LOCK_REG    0x68            /* WDT lock register                 */
  42
  43 /* Memory mapped registers (offset from base address) */
  44 #define ESB_TIMER1_REG  0x00            /* Timer1 value after each reset     */
  45 #define ESB_TIMER2_REG  0x04            /* Timer2 value after each reset     */
  46 #define ESB_GINTSR_REG  0x08            /* General Interrupt Status Register */
  47 #define ESB_RELOAD_REG  0x0c            /* Reload register                   */
  48
  49 /* Lock register bits */
  50 #define ESB_WDT_FUNC    (0x01 << 2)   /* Watchdog functionality            */
  51 #define ESB_WDT_ENABLE  (0x01 << 1)   /* Enable WDT                        */
  52 #define ESB_WDT_LOCK    (0x01 << 0)   /* Lock (nowayout)                   */
  53
  54 /* Config register bits */
  55 #define ESB_WDT_REBOOT  (0x01 << 5)   /* Enable reboot on timeout          */
  56 #define ESB_WDT_FREQ    (0x01 << 2)   /* Decrement frequency               */
  57 #define ESB_WDT_INTTYPE (0x11 << 0)   /* Interrupt type on timer1 timeout  */
  58
  59 /* Reload register bits */
  60 #define ESB_WDT_RELOAD  (0x01 << 8)    /* prevent timeout                   */
  61
  62 /* Magic constants */
  63 #define ESB_UNLOCK1     0x80            /* Step 1 to unlock reset registers  */
  64 #define ESB_UNLOCK2     0x86            /* Step 2 to unlock reset registers  */
  65
  66 /* Device state. */
  67 struct I6300State {
  68     PCIDevice dev;
  69     MemoryRegion io_mem;
  70
  71     int reboot_enabled;         /* "Reboot" on timer expiry.  The real action
  72                                  * performed depends on the -watchdog-action
  73                                  * param passed on QEMU command line.
  74                                  */
  75     int clock_scale;            /* Clock scale. */
  76 #define CLOCK_SCALE_1KHZ 0
  77 #define CLOCK_SCALE_1MHZ 1
  78
  79     int int_type;               /* Interrupt type generated. */
  80 #define INT_TYPE_IRQ 0          /* APIC 1, INT 10 */
  81 #define INT_TYPE_SMI 2
  82 #define INT_TYPE_DISABLED 3
  83
  84     int free_run;               /* If true, reload timer on expiry. */
  85     int locked;                 /* If true, enabled field cannot be changed. */
  86     int enabled;                /* If true, watchdog is enabled. */
  87
  88     QEMUTimer *timer;           /* The actual watchdog timer. */
  89
  90     uint32_t timer1_preload;    /* Values preloaded into timer1, timer2. */
  91     uint32_t timer2_preload;
  92     int stage;                  /* Stage (1 or 2). */
  93
  94     int unlock_state;           /* Guest writes 0x80, 0x86 to unlock the
  95                                  * registers, and we transition through
  96                                  * states 0 -> 1 -> 2 when this happens.
  97                                  */
  98
  99     int previous_reboot_flag;   /* If the watchdog caused the previous
 100                                  * reboot, this flag will be set.
 101                                  */
 102 };
 103
 104 typedef struct I6300State I6300State;
 105
 106 /* This function is called when the watchdog has either been enabled
 107  * (hence it starts counting down) or has been keep-alived.
 108  */
 109 static void i6300esb_restart_timer(I6300State *d, int stage)
 110 {
 111     int64_t timeout;
 112
 113     if (!d->enabled)
 114         return;
 115
 116     d->stage = stage;
 117
 118     if (d->stage <= 1)
 119         timeout = d->timer1_preload;
 120     else
 121         timeout = d->timer2_preload;
 122
 123     if (d->clock_scale == CLOCK_SCALE_1KHZ)
 124         timeout <<= 15;
 125     else
 126         timeout <<= 5;
 127
 128     /* Get the timeout in units of ticks_per_sec. */
 129     timeout = get_ticks_per_sec() * timeout / 33000000;
 130
 131     i6300esb_debug("stage %d, timeout %" PRIi64 "\n", d->stage, timeout);
 132
 133     qemu_mod_timer(d->timer, qemu_get_clock_ns(vm_clock) + timeout);
 134 }
 135
 136 /* This is called when the guest disables the watchdog. */
 137 static void i6300esb_disable_timer(I6300State *d)
 138 {
 139     i6300esb_debug("timer disabled\n");
 140
 141     qemu_del_timer(d->timer);
 142 }
 143
 144 static void i6300esb_reset(DeviceState *dev)
 145 {
 146     PCIDevice *pdev = PCI_DEVICE(dev);
 147     I6300State *d = DO_UPCAST(I6300State, dev, pdev);
 148
 149     i6300esb_debug("I6300State = %p\n", d);
 150
 151     i6300esb_disable_timer(d);
 152
 153     /* NB: Don't change d->previous_reboot_flag in this function. */
 154
 155     d->reboot_enabled = 1;
 156     d->clock_scale = CLOCK_SCALE_1KHZ;
 157     d->int_type = INT_TYPE_IRQ;
 158     d->free_run = 0;
 159     d->locked = 0;
 160     d->enabled = 0;
 161     d->timer1_preload = 0xfffff;
 162     d->timer2_preload = 0xfffff;
 163     d->stage = 1;
 164     d->unlock_state = 0;
 165 }
 166
 167 /* This function is called when the watchdog expires.  Note that
 168  * the hardware has two timers, and so expiry happens in two stages.
 169  * If d->stage == 1 then we perform the first stage action (usually,
 170  * sending an interrupt) and then restart the timer again for the
 171  * second stage.  If the second stage expires then the watchdog
 172  * really has run out.
 173  */
 174 static void i6300esb_timer_expired(void *vp)
 175 {
 176     I6300State *d = vp;
 177
 178     i6300esb_debug("stage %d\n", d->stage);
 179
 180     if (d->stage == 1) {
 181         /* What to do at the end of stage 1? */
 182         switch (d->int_type) {
 183         case INT_TYPE_IRQ:
 184             fprintf(stderr, "i6300esb_timer_expired: I would send APIC 1 INT 10 here if I knew how (XXX)\n");
 185             break;
 186         case INT_TYPE_SMI:
 187             fprintf(stderr, "i6300esb_timer_expired: I would send SMI here if I knew how (XXX)\n");
 188             break;
 189         }
 190
 191         /* Start the second stage. */
 192         i6300esb_restart_timer(d, 2);
 193     } else {
 194         /* Second stage expired, reboot for real. */
 195         if (d->reboot_enabled) {
 196             d->previous_reboot_flag = 1;
 197             watchdog_perform_action(); /* This reboots, exits, etc */
 198             i6300esb_reset(&d->dev.qdev);
 199         }
 200
 201         /* In "free running mode" we start stage 1 again. */
 202         if (d->free_run)
 203             i6300esb_restart_timer(d, 1);
 204     }
 205 }
 206
 207 static void i6300esb_config_write(PCIDevice *dev, uint32_t addr,
 208                                   uint32_t data, int len)
 209 {
 210     I6300State *d = DO_UPCAST(I6300State, dev, dev);
 211     int old;
 212
 213     i6300esb_debug("addr = %x, data = %x, len = %d\n", addr, data, len);
 214
 215     if (addr == ESB_CONFIG_REG && len == 2) {
 216         d->reboot_enabled = (data & ESB_WDT_REBOOT) == 0;
 217         d->clock_scale =
 218             (data & ESB_WDT_FREQ) != 0 ? CLOCK_SCALE_1MHZ : CLOCK_SCALE_1KHZ;
 219         d->int_type = (data & ESB_WDT_INTTYPE);
 220     } else if (addr == ESB_LOCK_REG && len == 1) {
 221         if (!d->locked) {
 222             d->locked = (data & ESB_WDT_LOCK) != 0;
 223             d->free_run = (data & ESB_WDT_FUNC) != 0;
 224             old = d->enabled;
 225             d->enabled = (data & ESB_WDT_ENABLE) != 0;
 226             if (!old && d->enabled) /* Enabled transitioned from 0 -> 1 */
 227                 i6300esb_restart_timer(d, 1);
 228             else if (!d->enabled)
 229                 i6300esb_disable_timer(d);
 230         }
 231     } else {
 232         pci_default_write_config(dev, addr, data, len);
 233     }
 234 }
 235
 236 static uint32_t i6300esb_config_read(PCIDevice *dev, uint32_t addr, int len)
 237 {
 238     I6300State *d = DO_UPCAST(I6300State, dev, dev);
 239     uint32_t data;
 240
 241     i6300esb_debug ("addr = %x, len = %d\n", addr, len);
 242
 243     if (addr == ESB_CONFIG_REG && len == 2) {
 244         data =
 245             (d->reboot_enabled ? 0 : ESB_WDT_REBOOT) |
 246             (d->clock_scale == CLOCK_SCALE_1MHZ ? ESB_WDT_FREQ : 0) |
 247             d->int_type;
 248         return data;
 249     } else if (addr == ESB_LOCK_REG && len == 1) {
 250         data =
 251             (d->free_run ? ESB_WDT_FUNC : 0) |
 252             (d->locked ? ESB_WDT_LOCK : 0) |
 253             (d->enabled ? ESB_WDT_ENABLE : 0);
 254         return data;
 255     } else {
 256         return pci_default_read_config(dev, addr, len);
 257     }
 258 }
 259
 260 static uint32_t i6300esb_mem_readb(void *vp, hwaddr addr)
 261 {
 262     i6300esb_debug ("addr = %x\n", (int) addr);
 263
 264     return 0;
 265 }
 266
 267 static uint32_t i6300esb_mem_readw(void *vp, hwaddr addr)
 268 {
 269     uint32_t data = 0;
 270     I6300State *d = vp;
 271
 272     i6300esb_debug("addr = %x\n", (int) addr);
 273
 274     if (addr == 0xc) {
 275         /* The previous reboot flag is really bit 9, but there is
 276          * a bug in the Linux driver where it thinks it's bit 12.
 277          * Set both.
 278          */
 279         data = d->previous_reboot_flag ? 0x1200 : 0;
 280     }
 281
 282     return data;
 283 }
 284
 285 static uint32_t i6300esb_mem_readl(void *vp, hwaddr addr)
 286 {
 287     i6300esb_debug("addr = %x\n", (int) addr);
 288
 289     return 0;
 290 }
 291
 292 static void i6300esb_mem_writeb(void *vp, hwaddr addr, uint32_t val)
 293 {
 294     I6300State *d = vp;
 295
 296     i6300esb_debug("addr = %x, val = %x\n", (int) addr, val);
 297
 298     if (addr == 0xc && val == 0x80)
 299         d->unlock_state = 1;
 300     else if (addr == 0xc && val == 0x86 && d->unlock_state == 1)
 301         d->unlock_state = 2;
 302 }
 303
 304 static void i6300esb_mem_writew(void *vp, hwaddr addr, uint32_t val)
 305 {
 306     I6300State *d = vp;
 307
 308     i6300esb_debug("addr = %x, val = %x\n", (int) addr, val);
 309
 310     if (addr == 0xc && val == 0x80)
 311         d->unlock_state = 1;
 312     else if (addr == 0xc && val == 0x86 && d->unlock_state == 1)
 313         d->unlock_state = 2;
 314     else {
 315         if (d->unlock_state == 2) {
 316             if (addr == 0xc) {
 317                 if ((val & 0x100) != 0)
 318                     /* This is the "ping" from the userspace watchdog in
 319                      * the guest ...
 320                      */
 321                     i6300esb_restart_timer(d, 1);
 322
 323                 /* Setting bit 9 resets the previous reboot flag.
 324                  * There's a bug in the Linux driver where it sets
 325                  * bit 12 instead.
 326                  */
 327                 if ((val & 0x200) != 0 || (val & 0x1000) != 0) {
 328                     d->previous_reboot_flag = 0;
 329                 }
 330             }
 331
 332             d->unlock_state = 0;
 333         }
 334     }
 335 }
 336
 337 static void i6300esb_mem_writel(void *vp, hwaddr addr, uint32_t val)
 338 {
 339     I6300State *d = vp;
 340
 341     i6300esb_debug ("addr = %x, val = %x\n", (int) addr, val);
 342
 343     if (addr == 0xc && val == 0x80)
 344         d->unlock_state = 1;
 345     else if (addr == 0xc && val == 0x86 && d->unlock_state == 1)
 346         d->unlock_state = 2;
 347     else {
 348         if (d->unlock_state == 2) {
 349             if (addr == 0)
 350                 d->timer1_preload = val & 0xfffff;
 351             else if (addr == 4)
 352                 d->timer2_preload = val & 0xfffff;
 353
 354             d->unlock_state = 0;
 355         }
 356     }
 357 }
 358
 359 static const MemoryRegionOps i6300esb_ops = {
 360     .old_mmio = {
 361         .read = {
 362             i6300esb_mem_readb,
 363             i6300esb_mem_readw,
 364             i6300esb_mem_readl,
 365         },
 366         .write = {
 367             i6300esb_mem_writeb,
 368             i6300esb_mem_writew,
 369             i6300esb_mem_writel,
 370         },
 371     },
 372     .endianness = DEVICE_NATIVE_ENDIAN,
 373 };
 374
 375 static const VMStateDescription vmstate_i6300esb = {
 376     .name = "i6300esb_wdt",
 377     .version_id = sizeof(I6300State),
 378     .minimum_version_id = sizeof(I6300State),
 379     .minimum_version_id_old = sizeof(I6300State),
 380     .fields      = (VMStateField []) {
 381         VMSTATE_PCI_DEVICE(dev, I6300State),
 382         VMSTATE_INT32(reboot_enabled, I6300State),
 383         VMSTATE_INT32(clock_scale, I6300State),
 384         VMSTATE_INT32(int_type, I6300State),
 385         VMSTATE_INT32(free_run, I6300State),
 386         VMSTATE_INT32(locked, I6300State),
 387         VMSTATE_INT32(enabled, I6300State),
 388         VMSTATE_TIMER(timer, I6300State),
 389         VMSTATE_UINT32(timer1_preload, I6300State),
 390         VMSTATE_UINT32(timer2_preload, I6300State),
 391         VMSTATE_INT32(stage, I6300State),
 392         VMSTATE_INT32(unlock_state, I6300State),
 393         VMSTATE_INT32(previous_reboot_flag, I6300State),
 394         VMSTATE_END_OF_LIST()
 395     }
 396 };
 397
 398 static int i6300esb_init(PCIDevice *dev)
 399 {
 400     I6300State *d = DO_UPCAST(I6300State, dev, dev);
 401
 402     i6300esb_debug("I6300State = %p\n", d);
 403
 404     d->timer = qemu_new_timer_ns(vm_clock, i6300esb_timer_expired, d);
 405     d->previous_reboot_flag = 0;
 406
 407     memory_region_init_io(&d->io_mem, &i6300esb_ops, d, "i6300esb", 0x10);
 408     pci_register_bar(&d->dev, 0, 0, &d->io_mem);
 409     /* qemu_register_coalesced_mmio (addr, 0x10); ? */
 410
 411     return 0;
 412 }
 413
 414 static void i6300esb_exit(PCIDevice *dev)
 415 {
 416     I6300State *d = DO_UPCAST(I6300State, dev, dev);
 417
 418     memory_region_destroy(&d->io_mem);
 419 }
 420
 421 static WatchdogTimerModel model = {
 422     .wdt_name = "i6300esb",
 423     .wdt_description = "Intel 6300ESB",
 424 };
 425
 426 static void i6300esb_class_init(ObjectClass *klass, void *data)
 427 {
 428     DeviceClass *dc = DEVICE_CLASS(klass);
 429     PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
 430
 431     k->config_read = i6300esb_config_read;
 432     k->config_write = i6300esb_config_write;
 433     k->init = i6300esb_init;
 434     k->exit = i6300esb_exit;
 435     k->vendor_id = PCI_VENDOR_ID_INTEL;
 436     k->device_id = PCI_DEVICE_ID_INTEL_ESB_9;
 437     k->class_id = PCI_CLASS_SYSTEM_OTHER;
 438     dc->reset = i6300esb_reset;
 439     dc->vmsd = &vmstate_i6300esb;
 440 }
 441
 442 static const TypeInfo i6300esb_info = {
 443     .name          = "i6300esb",
 444     .parent        = TYPE_PCI_DEVICE,
 445     .instance_size = sizeof(I6300State),
 446     .class_init    = i6300esb_class_init,
 447 };
 448
 449 static void i6300esb_register_types(void)
 450 {
 451     watchdog_add_model(&model);
 452     type_register_static(&i6300esb_info);
 453 }
 454
 455 type_init(i6300esb_register_types)