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 "pc.h"
  29 #include "pci.h"
  30
  31 /*#define I6300ESB_DEBUG 1*/
  32
  33 #ifdef I6300ESB_DEBUG
  34 #define i6300esb_debug(fs,...) \
  35     fprintf(stderr,"i6300esb: %s: "fs,__func__,##__VA_ARGS__)
  36 #else
  37 #define i6300esb_debug(fs,...)
  38 #endif
  39
  40 #ifndef PCI_DEVICE_ID_INTEL_ESB_9
  41 #define PCI_DEVICE_ID_INTEL_ESB_9 0x25ab
  42 #endif
  43
  44 /* PCI configuration registers */
  45 #define ESB_CONFIG_REG  0x60            /* Config register                   */
  46 #define ESB_LOCK_REG    0x68            /* WDT lock register                 */
  47
  48 /* Memory mapped registers (offset from base address) */
  49 #define ESB_TIMER1_REG  0x00            /* Timer1 value after each reset     */
  50 #define ESB_TIMER2_REG  0x04            /* Timer2 value after each reset     */
  51 #define ESB_GINTSR_REG  0x08            /* General Interrupt Status Register */
  52 #define ESB_RELOAD_REG  0x0c            /* Reload register                   */
  53
  54 /* Lock register bits */
  55 #define ESB_WDT_FUNC    (0x01 << 2)   /* Watchdog functionality            */
  56 #define ESB_WDT_ENABLE  (0x01 << 1)   /* Enable WDT                        */
  57 #define ESB_WDT_LOCK    (0x01 << 0)   /* Lock (nowayout)                   */
  58
  59 /* Config register bits */
  60 #define ESB_WDT_REBOOT  (0x01 << 5)   /* Enable reboot on timeout          */
  61 #define ESB_WDT_FREQ    (0x01 << 2)   /* Decrement frequency               */
  62 #define ESB_WDT_INTTYPE (0x11 << 0)   /* Interrupt type on timer1 timeout  */
  63
  64 /* Reload register bits */
  65 #define ESB_WDT_RELOAD  (0x01 << 8)    /* prevent timeout                   */
  66
  67 /* Magic constants */
  68 #define ESB_UNLOCK1     0x80            /* Step 1 to unlock reset registers  */
  69 #define ESB_UNLOCK2     0x86            /* Step 2 to unlock reset registers  */
  70
  71 /* Device state. */
  72 struct I6300State {
  73     PCIDevice dev;
  74
  75     int reboot_enabled;         /* "Reboot" on timer expiry.  The real action
  76                                  * performed depends on the -watchdog-action
  77                                  * param passed on QEMU command line.
  78                                  */
  79     int clock_scale;            /* Clock scale. */
  80 #define CLOCK_SCALE_1KHZ 0
  81 #define CLOCK_SCALE_1MHZ 1
  82
  83     int int_type;               /* Interrupt type generated. */
  84 #define INT_TYPE_IRQ 0          /* APIC 1, INT 10 */
  85 #define INT_TYPE_SMI 2
  86 #define INT_TYPE_DISABLED 3
  87
  88     int free_run;               /* If true, reload timer on expiry. */
  89     int locked;                 /* If true, enabled field cannot be changed. */
  90     int enabled;                /* If true, watchdog is enabled. */
  91
  92     QEMUTimer *timer;           /* The actual watchdog timer. */
  93
  94     uint32_t timer1_preload;    /* Values preloaded into timer1, timer2. */
  95     uint32_t timer2_preload;
  96     int stage;                  /* Stage (1 or 2). */
  97
  98     int unlock_state;           /* Guest writes 0x80, 0x86 to unlock the
  99                                  * registers, and we transition through
 100                                  * states 0 -> 1 -> 2 when this happens.
 101                                  */
 102
 103     int previous_reboot_flag;   /* If the watchdog caused the previous
 104                                  * reboot, this flag will be set.
 105                                  */
 106 };
 107
 108 typedef struct I6300State I6300State;
 109
 110 /* This function is called when the watchdog has either been enabled
 111  * (hence it starts counting down) or has been keep-alived.
 112  */
 113 static void i6300esb_restart_timer(I6300State *d, int stage)
 114 {
 115     int64_t timeout;
 116
 117     if (!d->enabled)
 118         return;
 119
 120     d->stage = stage;
 121
 122     if (d->stage <= 1)
 123         timeout = d->timer1_preload;
 124     else
 125         timeout = d->timer2_preload;
 126
 127     if (d->clock_scale == CLOCK_SCALE_1KHZ)
 128         timeout <<= 15;
 129     else
 130         timeout <<= 5;
 131
 132     /* Get the timeout in units of ticks_per_sec. */
 133     timeout = ticks_per_sec * timeout / 33000000;
 134
 135     i6300esb_debug("stage %d, timeout %" PRIi64 "\n", d->stage, timeout);
 136
 137     qemu_mod_timer(d->timer, qemu_get_clock(vm_clock) + timeout);
 138 }
 139
 140 /* This is called when the guest disables the watchdog. */
 141 static void i6300esb_disable_timer(I6300State *d)
 142 {
 143     i6300esb_debug("timer disabled\n");
 144
 145     qemu_del_timer(d->timer);
 146 }
 147
 148 static void i6300esb_reset(I6300State *d)
 149 {
 150     /* XXX We should probably reset other parts of the state here,
 151      * but we should also reset our state on general machine reset
 152      * too.  For now just disable the timer so it doesn't fire
 153      * again after the reboot.
 154      */
 155     i6300esb_disable_timer(d);
 156 }
 157
 158 /* This function is called when the watchdog expires.  Note that
 159  * the hardware has two timers, and so expiry happens in two stages.
 160  * If d->stage == 1 then we perform the first stage action (usually,
 161  * sending an interrupt) and then restart the timer again for the
 162  * second stage.  If the second stage expires then the watchdog
 163  * really has run out.
 164  */
 165 static void i6300esb_timer_expired(void *vp)
 166 {
 167     I6300State *d = (I6300State *) vp;
 168
 169     i6300esb_debug("stage %d\n", d->stage);
 170
 171     if (d->stage == 1) {
 172         /* What to do at the end of stage 1? */
 173         switch (d->int_type) {
 174         case INT_TYPE_IRQ:
 175             fprintf(stderr, "i6300esb_timer_expired: I would send APIC 1 INT 10 here if I knew how (XXX)\n");
 176             break;
 177         case INT_TYPE_SMI:
 178             fprintf(stderr, "i6300esb_timer_expired: I would send SMI here if I knew how (XXX)\n");
 179             break;
 180         }
 181
 182         /* Start the second stage. */
 183         i6300esb_restart_timer(d, 2);
 184     } else {
 185         /* Second stage expired, reboot for real. */
 186         if (d->reboot_enabled) {
 187             d->previous_reboot_flag = 1;
 188             watchdog_perform_action(); /* This reboots, exits, etc */
 189             i6300esb_reset(d);
 190         }
 191
 192         /* In "free running mode" we start stage 1 again. */
 193         if (d->free_run)
 194             i6300esb_restart_timer(d, 1);
 195     }
 196 }
 197
 198 static void i6300esb_config_write(PCIDevice *dev, uint32_t addr,
 199                                   uint32_t data, int len)
 200 {
 201     I6300State *d = container_of(dev, I6300State, dev);
 202     int old;
 203
 204     i6300esb_debug("addr = %x, data = %x, len = %d\n", addr, data, len);
 205
 206     if (addr == ESB_CONFIG_REG && len == 2) {
 207         d->reboot_enabled = (data & ESB_WDT_REBOOT) == 0;
 208         d->clock_scale =
 209             (data & ESB_WDT_FREQ) != 0 ? CLOCK_SCALE_1MHZ : CLOCK_SCALE_1KHZ;
 210         d->int_type = (data & ESB_WDT_INTTYPE);
 211     } else if (addr == ESB_LOCK_REG && len == 1) {
 212         if (!d->locked) {
 213             d->locked = (data & ESB_WDT_LOCK) != 0;
 214             d->free_run = (data & ESB_WDT_FUNC) != 0;
 215             old = d->enabled;
 216             d->enabled = (data & ESB_WDT_ENABLE) != 0;
 217             if (!old && d->enabled) /* Enabled transitioned from 0 -> 1 */
 218                 i6300esb_restart_timer(d, 1);
 219             else if (!d->enabled)
 220                 i6300esb_disable_timer(d);
 221         }
 222     } else {
 223         pci_default_write_config(dev, addr, data, len);
 224     }
 225 }
 226
 227 static uint32_t i6300esb_config_read(PCIDevice *dev, uint32_t addr, int len)
 228 {
 229     I6300State *d = container_of(dev, I6300State, dev);
 230     uint32_t data;
 231
 232     i6300esb_debug ("addr = %x, len = %d\n", addr, len);
 233
 234     if (addr == ESB_CONFIG_REG && len == 2) {
 235         data =
 236             (d->reboot_enabled ? 0 : ESB_WDT_REBOOT) |
 237             (d->clock_scale == CLOCK_SCALE_1MHZ ? ESB_WDT_FREQ : 0) |
 238             d->int_type;
 239         return data;
 240     } else if (addr == ESB_LOCK_REG && len == 1) {
 241         data =
 242             (d->free_run ? ESB_WDT_FUNC : 0) |
 243             (d->locked ? ESB_WDT_LOCK : 0) |
 244             (d->enabled ? ESB_WDT_ENABLE : 0);
 245         return data;
 246     } else {
 247         return pci_default_read_config(dev, addr, len);
 248     }
 249 }
 250
 251 static uint32_t i6300esb_mem_readb(void *vp, target_phys_addr_t addr)
 252 {
 253     i6300esb_debug ("addr = %x\n", (int) addr);
 254
 255     return 0;
 256 }
 257
 258 static uint32_t i6300esb_mem_readw(void *vp, target_phys_addr_t addr)
 259 {
 260     uint32_t data = 0;
 261     I6300State *d = (I6300State *) vp;
 262
 263     i6300esb_debug("addr = %x\n", (int) addr);
 264
 265     if (addr == 0xc) {
 266         /* The previous reboot flag is really bit 9, but there is
 267          * a bug in the Linux driver where it thinks it's bit 12.
 268          * Set both.
 269          */
 270         data = d->previous_reboot_flag ? 0x1200 : 0;
 271     }
 272
 273     return data;
 274 }
 275
 276 static uint32_t i6300esb_mem_readl(void *vp, target_phys_addr_t addr)
 277 {
 278     i6300esb_debug("addr = %x\n", (int) addr);
 279
 280     return 0;
 281 }
 282
 283 static void i6300esb_mem_writeb(void *vp, target_phys_addr_t addr, uint32_t val)
 284 {
 285     I6300State *d = (I6300State *) vp;
 286
 287     i6300esb_debug("addr = %x, val = %x\n", (int) addr, val);
 288
 289     if (addr == 0xc && val == 0x80)
 290         d->unlock_state = 1;
 291     else if (addr == 0xc && val == 0x86 && d->unlock_state == 1)
 292         d->unlock_state = 2;
 293 }
 294
 295 static void i6300esb_mem_writew(void *vp, target_phys_addr_t addr, uint32_t val)
 296 {
 297     I6300State *d = (I6300State *) vp;
 298
 299     i6300esb_debug("addr = %x, val = %x\n", (int) addr, val);
 300
 301     if (addr == 0xc && val == 0x80)
 302         d->unlock_state = 1;
 303     else if (addr == 0xc && val == 0x86 && d->unlock_state == 1)
 304         d->unlock_state = 2;
 305     else {
 306         if (d->unlock_state == 2) {
 307             if (addr == 0xc) {
 308                 if ((val & 0x100) != 0)
 309                     /* This is the "ping" from the userspace watchdog in
 310                      * the guest ...
 311                      */
 312                     i6300esb_restart_timer(d, 1);
 313
 314                 /* Setting bit 9 resets the previous reboot flag.
 315                  * There's a bug in the Linux driver where it sets
 316                  * bit 12 instead.
 317                  */
 318                 if ((val & 0x200) != 0 || (val & 0x1000) != 0) {
 319                     d->previous_reboot_flag = 0;
 320                 }
 321             }
 322
 323             d->unlock_state = 0;
 324         }
 325     }
 326 }
 327
 328 static void i6300esb_mem_writel(void *vp, target_phys_addr_t addr, uint32_t val)
 329 {
 330     I6300State *d = (I6300State *) vp;
 331
 332     i6300esb_debug ("addr = %x, val = %x\n", (int) addr, val);
 333
 334     if (addr == 0xc && val == 0x80)
 335         d->unlock_state = 1;
 336     else if (addr == 0xc && val == 0x86 && d->unlock_state == 1)
 337         d->unlock_state = 2;
 338     else {
 339         if (d->unlock_state == 2) {
 340             if (addr == 0)
 341                 d->timer1_preload = val & 0xfffff;
 342             else if (addr == 4)
 343                 d->timer2_preload = val & 0xfffff;
 344
 345             d->unlock_state = 0;
 346         }
 347     }
 348 }
 349
 350 static void i6300esb_map(PCIDevice *dev, int region_num,
 351                          uint32_t addr, uint32_t size, int type)
 352 {
 353     static CPUReadMemoryFunc * const mem_read[3] = {
 354         i6300esb_mem_readb,
 355         i6300esb_mem_readw,
 356         i6300esb_mem_readl,
 357     };
 358     static CPUWriteMemoryFunc * const mem_write[3] = {
 359         i6300esb_mem_writeb,
 360         i6300esb_mem_writew,
 361         i6300esb_mem_writel,
 362     };
 363     I6300State *d = container_of(dev, I6300State, dev);
 364     int io_mem;
 365
 366     i6300esb_debug("addr = %x, size = %x, type = %d\n", addr, size, type);
 367
 368     io_mem = cpu_register_io_memory(mem_read, mem_write, d);
 369     cpu_register_physical_memory (addr, 0x10, io_mem);
 370     /* qemu_register_coalesced_mmio (addr, 0x10); ? */
 371 }
 372
 373 static void i6300esb_save(QEMUFile *f, void *vp)
 374 {
 375     I6300State *d = (I6300State *) vp;
 376
 377     pci_device_save(&d->dev, f);
 378     qemu_put_be32(f, d->reboot_enabled);
 379     qemu_put_be32(f, d->clock_scale);
 380     qemu_put_be32(f, d->int_type);
 381     qemu_put_be32(f, d->free_run);
 382     qemu_put_be32(f, d->locked);
 383     qemu_put_be32(f, d->enabled);
 384     qemu_put_timer(f, d->timer);
 385     qemu_put_be32(f, d->timer1_preload);
 386     qemu_put_be32(f, d->timer2_preload);
 387     qemu_put_be32(f, d->stage);
 388     qemu_put_be32(f, d->unlock_state);
 389     qemu_put_be32(f, d->previous_reboot_flag);
 390 }
 391
 392 static int i6300esb_load(QEMUFile *f, void *vp, int version)
 393 {
 394     I6300State *d = (I6300State *) vp;
 395
 396     if (version != sizeof (I6300State))
 397         return -EINVAL;
 398
 399     pci_device_load(&d->dev, f);
 400     d->reboot_enabled = qemu_get_be32(f);
 401     d->clock_scale = qemu_get_be32(f);
 402     d->int_type = qemu_get_be32(f);
 403     d->free_run = qemu_get_be32(f);
 404     d->locked = qemu_get_be32(f);
 405     d->enabled = qemu_get_be32(f);
 406     qemu_get_timer(f, d->timer);
 407     d->timer1_preload = qemu_get_be32(f);
 408     d->timer2_preload = qemu_get_be32(f);
 409     d->stage = qemu_get_be32(f);
 410     d->unlock_state = qemu_get_be32(f);
 411     d->previous_reboot_flag = qemu_get_be32(f);
 412
 413     return 0;
 414 }
 415
 416 static int i6300esb_init(PCIDevice *dev)
 417 {
 418     I6300State *d = container_of(dev, I6300State, dev);
 419     uint8_t *pci_conf;
 420
 421     d->reboot_enabled = 1;
 422     d->clock_scale = CLOCK_SCALE_1KHZ;
 423     d->int_type = INT_TYPE_IRQ;
 424     d->free_run = 0;
 425     d->locked = 0;
 426     d->enabled = 0;
 427     d->timer = qemu_new_timer(vm_clock, i6300esb_timer_expired, d);
 428     d->timer1_preload = 0xfffff;
 429     d->timer2_preload = 0xfffff;
 430     d->stage = 1;
 431     d->unlock_state = 0;
 432     d->previous_reboot_flag = 0;
 433
 434     pci_conf = d->dev.config;
 435     pci_config_set_vendor_id(pci_conf, PCI_VENDOR_ID_INTEL);
 436     pci_config_set_device_id(pci_conf, PCI_DEVICE_ID_INTEL_ESB_9);
 437     pci_config_set_class(pci_conf, PCI_CLASS_SYSTEM_OTHER);
 438     pci_conf[0x0e] = 0x00;
 439
 440     pci_register_bar(&d->dev, 0, 0x10,
 441                             PCI_ADDRESS_SPACE_MEM, i6300esb_map);
 442
 443     register_savevm("i6300esb_wdt", -1, sizeof(I6300State),
 444                      i6300esb_save, i6300esb_load, d);
 445
 446     return 0;
 447 }
 448
 449 static WatchdogTimerModel model = {
 450     .wdt_name = "i6300esb",
 451     .wdt_description = "Intel 6300ESB",
 452 };
 453
 454 static PCIDeviceInfo i6300esb_info = {
 455     .qdev.name    = "i6300esb",
 456     .qdev.size    = sizeof(I6300State),
 457     .config_read  = i6300esb_config_read,
 458     .config_write = i6300esb_config_write,
 459     .init         = i6300esb_init,
 460 };
 461
 462 static void i6300esb_register_devices(void)
 463 {
 464     watchdog_add_model(&model);
 465     pci_qdev_register(&i6300esb_info);
 466 }
 467
 468 device_init(i6300esb_register_devices);