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.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 #ifndef PCI_DEVICE_ID_INTEL_ESB_9
  40 #define PCI_DEVICE_ID_INTEL_ESB_9 0x25ab
  41 #endif
  42
  43 /* PCI configuration registers */
  44 #define ESB_CONFIG_REG  0x60            /* Config register                   */
  45 #define ESB_LOCK_REG    0x68            /* WDT lock register                 */
  46
  47 /* Memory mapped registers (offset from base address) */
  48 #define ESB_TIMER1_REG  0x00            /* Timer1 value after each reset     */
  49 #define ESB_TIMER2_REG  0x04            /* Timer2 value after each reset     */
  50 #define ESB_GINTSR_REG  0x08            /* General Interrupt Status Register */
  51 #define ESB_RELOAD_REG  0x0c            /* Reload register                   */
  52
  53 /* Lock register bits */
  54 #define ESB_WDT_FUNC    (0x01 << 2)   /* Watchdog functionality            */
  55 #define ESB_WDT_ENABLE  (0x01 << 1)   /* Enable WDT                        */
  56 #define ESB_WDT_LOCK    (0x01 << 0)   /* Lock (nowayout)                   */
  57
  58 /* Config register bits */
  59 #define ESB_WDT_REBOOT  (0x01 << 5)   /* Enable reboot on timeout          */
  60 #define ESB_WDT_FREQ    (0x01 << 2)   /* Decrement frequency               */
  61 #define ESB_WDT_INTTYPE (0x11 << 0)   /* Interrupt type on timer1 timeout  */
  62
  63 /* Reload register bits */
  64 #define ESB_WDT_RELOAD  (0x01 << 8)    /* prevent timeout                   */
  65
  66 /* Magic constants */
  67 #define ESB_UNLOCK1     0x80            /* Step 1 to unlock reset registers  */
  68 #define ESB_UNLOCK2     0x86            /* Step 2 to unlock reset registers  */
  69
  70 /* Device state. */
  71 struct I6300State {
  72     PCIDevice dev;
  73
  74     int reboot_enabled;         /* "Reboot" on timer expiry.  The real action
  75                                  * performed depends on the -watchdog-action
  76                                  * param passed on QEMU command line.
  77                                  */
  78     int clock_scale;            /* Clock scale. */
  79 #define CLOCK_SCALE_1KHZ 0
  80 #define CLOCK_SCALE_1MHZ 1
  81
  82     int int_type;               /* Interrupt type generated. */
  83 #define INT_TYPE_IRQ 0          /* APIC 1, INT 10 */
  84 #define INT_TYPE_SMI 2
  85 #define INT_TYPE_DISABLED 3
  86
  87     int free_run;               /* If true, reload timer on expiry. */
  88     int locked;                 /* If true, enabled field cannot be changed. */
  89     int enabled;                /* If true, watchdog is enabled. */
  90
  91     QEMUTimer *timer;           /* The actual watchdog timer. */
  92
  93     uint32_t timer1_preload;    /* Values preloaded into timer1, timer2. */
  94     uint32_t timer2_preload;
  95     int stage;                  /* Stage (1 or 2). */
  96
  97     int unlock_state;           /* Guest writes 0x80, 0x86 to unlock the
  98                                  * registers, and we transition through
  99                                  * states 0 -> 1 -> 2 when this happens.
 100                                  */
 101
 102     int previous_reboot_flag;   /* If the watchdog caused the previous
 103                                  * reboot, this flag will be set.
 104                                  */
 105 };
 106
 107 typedef struct I6300State I6300State;
 108
 109 /* This function is called when the watchdog has either been enabled
 110  * (hence it starts counting down) or has been keep-alived.
 111  */
 112 static void i6300esb_restart_timer(I6300State *d, int stage)
 113 {
 114     int64_t timeout;
 115
 116     if (!d->enabled)
 117         return;
 118
 119     d->stage = stage;
 120
 121     if (d->stage <= 1)
 122         timeout = d->timer1_preload;
 123     else
 124         timeout = d->timer2_preload;
 125
 126     if (d->clock_scale == CLOCK_SCALE_1KHZ)
 127         timeout <<= 15;
 128     else
 129         timeout <<= 5;
 130
 131     /* Get the timeout in units of ticks_per_sec. */
 132     timeout = get_ticks_per_sec() * timeout / 33000000;
 133
 134     i6300esb_debug("stage %d, timeout %" PRIi64 "\n", d->stage, timeout);
 135
 136     qemu_mod_timer(d->timer, qemu_get_clock(vm_clock) + timeout);
 137 }
 138
 139 /* This is called when the guest disables the watchdog. */
 140 static void i6300esb_disable_timer(I6300State *d)
 141 {
 142     i6300esb_debug("timer disabled\n");
 143
 144     qemu_del_timer(d->timer);
 145 }
 146
 147 static void i6300esb_reset(I6300State *d)
 148 {
 149     /* XXX We should probably reset other parts of the state here,
 150      * but we should also reset our state on general machine reset
 151      * too.  For now just disable the timer so it doesn't fire
 152      * again after the reboot.
 153      */
 154     i6300esb_disable_timer(d);
 155 }
 156
 157 /* This function is called when the watchdog expires.  Note that
 158  * the hardware has two timers, and so expiry happens in two stages.
 159  * If d->stage == 1 then we perform the first stage action (usually,
 160  * sending an interrupt) and then restart the timer again for the
 161  * second stage.  If the second stage expires then the watchdog
 162  * really has run out.
 163  */
 164 static void i6300esb_timer_expired(void *vp)
 165 {
 166     I6300State *d = vp;
 167
 168     i6300esb_debug("stage %d\n", d->stage);
 169
 170     if (d->stage == 1) {
 171         /* What to do at the end of stage 1? */
 172         switch (d->int_type) {
 173         case INT_TYPE_IRQ:
 174             fprintf(stderr, "i6300esb_timer_expired: I would send APIC 1 INT 10 here if I knew how (XXX)\n");
 175             break;
 176         case INT_TYPE_SMI:
 177             fprintf(stderr, "i6300esb_timer_expired: I would send SMI here if I knew how (XXX)\n");
 178             break;
 179         }
 180
 181         /* Start the second stage. */
 182         i6300esb_restart_timer(d, 2);
 183     } else {
 184         /* Second stage expired, reboot for real. */
 185         if (d->reboot_enabled) {
 186             d->previous_reboot_flag = 1;
 187             watchdog_perform_action(); /* This reboots, exits, etc */
 188             i6300esb_reset(d);
 189         }
 190
 191         /* In "free running mode" we start stage 1 again. */
 192         if (d->free_run)
 193             i6300esb_restart_timer(d, 1);
 194     }
 195 }
 196
 197 static void i6300esb_config_write(PCIDevice *dev, uint32_t addr,
 198                                   uint32_t data, int len)
 199 {
 200     I6300State *d = DO_UPCAST(I6300State, dev, dev);
 201     int old;
 202
 203     i6300esb_debug("addr = %x, data = %x, len = %d\n", addr, data, len);
 204
 205     if (addr == ESB_CONFIG_REG && len == 2) {
 206         d->reboot_enabled = (data & ESB_WDT_REBOOT) == 0;
 207         d->clock_scale =
 208             (data & ESB_WDT_FREQ) != 0 ? CLOCK_SCALE_1MHZ : CLOCK_SCALE_1KHZ;
 209         d->int_type = (data & ESB_WDT_INTTYPE);
 210     } else if (addr == ESB_LOCK_REG && len == 1) {
 211         if (!d->locked) {
 212             d->locked = (data & ESB_WDT_LOCK) != 0;
 213             d->free_run = (data & ESB_WDT_FUNC) != 0;
 214             old = d->enabled;
 215             d->enabled = (data & ESB_WDT_ENABLE) != 0;
 216             if (!old && d->enabled) /* Enabled transitioned from 0 -> 1 */
 217                 i6300esb_restart_timer(d, 1);
 218             else if (!d->enabled)
 219                 i6300esb_disable_timer(d);
 220         }
 221     } else {
 222         pci_default_write_config(dev, addr, data, len);
 223     }
 224 }
 225
 226 static uint32_t i6300esb_config_read(PCIDevice *dev, uint32_t addr, int len)
 227 {
 228     I6300State *d = DO_UPCAST(I6300State, dev, dev);
 229     uint32_t data;
 230
 231     i6300esb_debug ("addr = %x, len = %d\n", addr, len);
 232
 233     if (addr == ESB_CONFIG_REG && len == 2) {
 234         data =
 235             (d->reboot_enabled ? 0 : ESB_WDT_REBOOT) |
 236             (d->clock_scale == CLOCK_SCALE_1MHZ ? ESB_WDT_FREQ : 0) |
 237             d->int_type;
 238         return data;
 239     } else if (addr == ESB_LOCK_REG && len == 1) {
 240         data =
 241             (d->free_run ? ESB_WDT_FUNC : 0) |
 242             (d->locked ? ESB_WDT_LOCK : 0) |
 243             (d->enabled ? ESB_WDT_ENABLE : 0);
 244         return data;
 245     } else {
 246         return pci_default_read_config(dev, addr, len);
 247     }
 248 }
 249
 250 static uint32_t i6300esb_mem_readb(void *vp, target_phys_addr_t addr)
 251 {
 252     i6300esb_debug ("addr = %x\n", (int) addr);
 253
 254     return 0;
 255 }
 256
 257 static uint32_t i6300esb_mem_readw(void *vp, target_phys_addr_t addr)
 258 {
 259     uint32_t data = 0;
 260     I6300State *d = vp;
 261
 262     i6300esb_debug("addr = %x\n", (int) addr);
 263
 264     if (addr == 0xc) {
 265         /* The previous reboot flag is really bit 9, but there is
 266          * a bug in the Linux driver where it thinks it's bit 12.
 267          * Set both.
 268          */
 269         data = d->previous_reboot_flag ? 0x1200 : 0;
 270     }
 271
 272     return data;
 273 }
 274
 275 static uint32_t i6300esb_mem_readl(void *vp, target_phys_addr_t addr)
 276 {
 277     i6300esb_debug("addr = %x\n", (int) addr);
 278
 279     return 0;
 280 }
 281
 282 static void i6300esb_mem_writeb(void *vp, target_phys_addr_t addr, uint32_t val)
 283 {
 284     I6300State *d = vp;
 285
 286     i6300esb_debug("addr = %x, val = %x\n", (int) addr, val);
 287
 288     if (addr == 0xc && val == 0x80)
 289         d->unlock_state = 1;
 290     else if (addr == 0xc && val == 0x86 && d->unlock_state == 1)
 291         d->unlock_state = 2;
 292 }
 293
 294 static void i6300esb_mem_writew(void *vp, target_phys_addr_t addr, uint32_t val)
 295 {
 296     I6300State *d = vp;
 297
 298     i6300esb_debug("addr = %x, val = %x\n", (int) addr, val);
 299
 300     if (addr == 0xc && val == 0x80)
 301         d->unlock_state = 1;
 302     else if (addr == 0xc && val == 0x86 && d->unlock_state == 1)
 303         d->unlock_state = 2;
 304     else {
 305         if (d->unlock_state == 2) {
 306             if (addr == 0xc) {
 307                 if ((val & 0x100) != 0)
 308                     /* This is the "ping" from the userspace watchdog in
 309                      * the guest ...
 310                      */
 311                     i6300esb_restart_timer(d, 1);
 312
 313                 /* Setting bit 9 resets the previous reboot flag.
 314                  * There's a bug in the Linux driver where it sets
 315                  * bit 12 instead.
 316                  */
 317                 if ((val & 0x200) != 0 || (val & 0x1000) != 0) {
 318                     d->previous_reboot_flag = 0;
 319                 }
 320             }
 321
 322             d->unlock_state = 0;
 323         }
 324     }
 325 }
 326
 327 static void i6300esb_mem_writel(void *vp, target_phys_addr_t addr, uint32_t val)
 328 {
 329     I6300State *d = vp;
 330
 331     i6300esb_debug ("addr = %x, val = %x\n", (int) addr, val);
 332
 333     if (addr == 0xc && val == 0x80)
 334         d->unlock_state = 1;
 335     else if (addr == 0xc && val == 0x86 && d->unlock_state == 1)
 336         d->unlock_state = 2;
 337     else {
 338         if (d->unlock_state == 2) {
 339             if (addr == 0)
 340                 d->timer1_preload = val & 0xfffff;
 341             else if (addr == 4)
 342                 d->timer2_preload = val & 0xfffff;
 343
 344             d->unlock_state = 0;
 345         }
 346     }
 347 }
 348
 349 static void i6300esb_map(PCIDevice *dev, int region_num,
 350                          uint32_t addr, uint32_t size, int type)
 351 {
 352     static CPUReadMemoryFunc * const mem_read[3] = {
 353         i6300esb_mem_readb,
 354         i6300esb_mem_readw,
 355         i6300esb_mem_readl,
 356     };
 357     static CPUWriteMemoryFunc * const mem_write[3] = {
 358         i6300esb_mem_writeb,
 359         i6300esb_mem_writew,
 360         i6300esb_mem_writel,
 361     };
 362     I6300State *d = DO_UPCAST(I6300State, dev, dev);
 363     int io_mem;
 364
 365     i6300esb_debug("addr = %x, size = %x, type = %d\n", addr, size, type);
 366
 367     io_mem = cpu_register_io_memory(mem_read, mem_write, d);
 368     cpu_register_physical_memory (addr, 0x10, io_mem);
 369     /* qemu_register_coalesced_mmio (addr, 0x10); ? */
 370 }
 371
 372 static const VMStateDescription vmstate_i6300esb = {
 373     .name = "i6300esb_wdt",
 374     .version_id = sizeof(I6300State),
 375     .minimum_version_id = sizeof(I6300State),
 376     .minimum_version_id_old = sizeof(I6300State),
 377     .fields      = (VMStateField []) {
 378         VMSTATE_PCI_DEVICE(dev, I6300State),
 379         VMSTATE_INT32(reboot_enabled, I6300State),
 380         VMSTATE_INT32(clock_scale, I6300State),
 381         VMSTATE_INT32(int_type, I6300State),
 382         VMSTATE_INT32(free_run, I6300State),
 383         VMSTATE_INT32(locked, I6300State),
 384         VMSTATE_INT32(enabled, I6300State),
 385         VMSTATE_TIMER(timer, I6300State),
 386         VMSTATE_UINT32(timer1_preload, I6300State),
 387         VMSTATE_UINT32(timer2_preload, I6300State),
 388         VMSTATE_INT32(stage, I6300State),
 389         VMSTATE_INT32(unlock_state, I6300State),
 390         VMSTATE_INT32(previous_reboot_flag, I6300State),
 391         VMSTATE_END_OF_LIST()
 392     }
 393 };
 394
 395 static int i6300esb_init(PCIDevice *dev)
 396 {
 397     I6300State *d = DO_UPCAST(I6300State, dev, dev);
 398     uint8_t *pci_conf;
 399
 400     d->reboot_enabled = 1;
 401     d->clock_scale = CLOCK_SCALE_1KHZ;
 402     d->int_type = INT_TYPE_IRQ;
 403     d->free_run = 0;
 404     d->locked = 0;
 405     d->enabled = 0;
 406     d->timer = qemu_new_timer(vm_clock, i6300esb_timer_expired, d);
 407     d->timer1_preload = 0xfffff;
 408     d->timer2_preload = 0xfffff;
 409     d->stage = 1;
 410     d->unlock_state = 0;
 411     d->previous_reboot_flag = 0;
 412
 413     pci_conf = d->dev.config;
 414     pci_config_set_vendor_id(pci_conf, PCI_VENDOR_ID_INTEL);
 415     pci_config_set_device_id(pci_conf, PCI_DEVICE_ID_INTEL_ESB_9);
 416     pci_config_set_class(pci_conf, PCI_CLASS_SYSTEM_OTHER);
 417     pci_conf[0x0e] = 0x00;
 418
 419     pci_register_bar(&d->dev, 0, 0x10,
 420                             PCI_ADDRESS_SPACE_MEM, i6300esb_map);
 421
 422     vmstate_register(-1, &vmstate_i6300esb, d);
 423
 424     return 0;
 425 }
 426
 427 static WatchdogTimerModel model = {
 428     .wdt_name = "i6300esb",
 429     .wdt_description = "Intel 6300ESB",
 430 };
 431
 432 static PCIDeviceInfo i6300esb_info = {
 433     .qdev.name    = "i6300esb",
 434     .qdev.size    = sizeof(I6300State),
 435     .config_read  = i6300esb_config_read,
 436     .config_write = i6300esb_config_write,
 437     .init         = i6300esb_init,
 438 };
 439
 440 static void i6300esb_register_devices(void)
 441 {
 442     watchdog_add_model(&model);
 443     pci_qdev_register(&i6300esb_info);
 444 }
 445
 446 device_init(i6300esb_register_devices);