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 "qemu/osdep.h"
23
24 #include "qemu/module.h"
25 #include "qemu/timer.h"
26 #include "sysemu/watchdog.h"
27 #include "hw/pci/pci_device.h"
28 #include "migration/vmstate.h"
29 #include "qom/object.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 /* PCI configuration registers */
41 #define ESB_CONFIG_REG 0x60 /* Config register */
42 #define ESB_LOCK_REG 0x68 /* WDT lock register */
43
44 /* Memory mapped registers (offset from base address) */
45 #define ESB_TIMER1_REG 0x00 /* Timer1 value after each reset */
46 #define ESB_TIMER2_REG 0x04 /* Timer2 value after each reset */
47 #define ESB_GINTSR_REG 0x08 /* General Interrupt Status Register */
48 #define ESB_RELOAD_REG 0x0c /* Reload register */
49
50 /* Lock register bits */
51 #define ESB_WDT_FUNC (0x01 << 2) /* Watchdog functionality */
52 #define ESB_WDT_ENABLE (0x01 << 1) /* Enable WDT */
53 #define ESB_WDT_LOCK (0x01 << 0) /* Lock (nowayout) */
54
55 /* Config register bits */
56 #define ESB_WDT_REBOOT (0x01 << 5) /* Enable reboot on timeout */
57 #define ESB_WDT_FREQ (0x01 << 2) /* Decrement frequency */
58 #define ESB_WDT_INTTYPE (0x11 << 0) /* Interrupt type on timer1 timeout */
59
60 /* Reload register bits */
61 #define ESB_WDT_RELOAD (0x01 << 8) /* prevent timeout */
62
63 /* Magic constants */
64 #define ESB_UNLOCK1 0x80 /* Step 1 to unlock reset registers */
65 #define ESB_UNLOCK2 0x86 /* Step 2 to unlock reset registers */
66
67 /* Device state. */
68 struct I6300State {
69 PCIDevice dev;
70 MemoryRegion io_mem;
71
72 int reboot_enabled; /* "Reboot" on timer expiry. The real action
73 * performed depends on the -watchdog-action
74 * param passed on QEMU command line.
75 */
76 int clock_scale; /* Clock scale. */
77 #define CLOCK_SCALE_1KHZ 0
78 #define CLOCK_SCALE_1MHZ 1
79
80 int int_type; /* Interrupt type generated. */
81 #define INT_TYPE_IRQ 0 /* APIC 1, INT 10 */
82 #define INT_TYPE_SMI 2
83 #define INT_TYPE_DISABLED 3
84
85 int free_run; /* If true, reload timer on expiry. */
86 int locked; /* If true, enabled field cannot be changed. */
87 int enabled; /* If true, watchdog is enabled. */
88
89 QEMUTimer *timer; /* The actual watchdog timer. */
90
91 uint32_t timer1_preload; /* Values preloaded into timer1, timer2. */
92 uint32_t timer2_preload;
93 int stage; /* Stage (1 or 2). */
94
95 int unlock_state; /* Guest writes 0x80, 0x86 to unlock the
96 * registers, and we transition through
97 * states 0 -> 1 -> 2 when this happens.
98 */
99
100 int previous_reboot_flag; /* If the watchdog caused the previous
101 * reboot, this flag will be set.
102 */
103 };
104
105
106 #define TYPE_WATCHDOG_I6300ESB_DEVICE "i6300esb"
OBJECT_DECLARE_SIMPLE_TYPE(I6300State,WATCHDOG_I6300ESB_DEVICE)107 OBJECT_DECLARE_SIMPLE_TYPE(I6300State, WATCHDOG_I6300ESB_DEVICE)
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 nanoseconds. */
132
133 timeout = timeout * 30; /* on a PCI bus, 1 tick is 30 ns*/
134
135 i6300esb_debug("stage %d, timeout %" PRIi64 "\n", d->stage, timeout);
136
137 timer_mod(d->timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + timeout);
138 }
139
140 /* This is called when the guest disables the watchdog. */
i6300esb_disable_timer(I6300State * d)141 static void i6300esb_disable_timer(I6300State *d)
142 {
143 i6300esb_debug("timer disabled\n");
144
145 timer_del(d->timer);
146 }
147
i6300esb_reset(DeviceState * dev)148 static void i6300esb_reset(DeviceState *dev)
149 {
150 PCIDevice *pdev = PCI_DEVICE(dev);
151 I6300State *d = WATCHDOG_I6300ESB_DEVICE(pdev);
152
153 i6300esb_debug("I6300State = %p\n", d);
154
155 i6300esb_disable_timer(d);
156
157 /* NB: Don't change d->previous_reboot_flag in this function. */
158
159 d->reboot_enabled = 1;
160 d->clock_scale = CLOCK_SCALE_1KHZ;
161 d->int_type = INT_TYPE_IRQ;
162 d->free_run = 0;
163 d->locked = 0;
164 d->enabled = 0;
165 d->timer1_preload = 0xfffff;
166 d->timer2_preload = 0xfffff;
167 d->stage = 1;
168 d->unlock_state = 0;
169 }
170
171 /* This function is called when the watchdog expires. Note that
172 * the hardware has two timers, and so expiry happens in two stages.
173 * If d->stage == 1 then we perform the first stage action (usually,
174 * sending an interrupt) and then restart the timer again for the
175 * second stage. If the second stage expires then the watchdog
176 * really has run out.
177 */
i6300esb_timer_expired(void * vp)178 static void i6300esb_timer_expired(void *vp)
179 {
180 I6300State *d = vp;
181
182 i6300esb_debug("stage %d\n", d->stage);
183
184 if (d->stage == 1) {
185 /* What to do at the end of stage 1? */
186 switch (d->int_type) {
187 case INT_TYPE_IRQ:
188 fprintf(stderr, "i6300esb_timer_expired: I would send APIC 1 INT 10 here if I knew how (XXX)\n");
189 break;
190 case INT_TYPE_SMI:
191 fprintf(stderr, "i6300esb_timer_expired: I would send SMI here if I knew how (XXX)\n");
192 break;
193 }
194
195 /* Start the second stage. */
196 i6300esb_restart_timer(d, 2);
197 } else {
198 /* Second stage expired, reboot for real. */
199 if (d->reboot_enabled) {
200 d->previous_reboot_flag = 1;
201 watchdog_perform_action(); /* This reboots, exits, etc */
202 i6300esb_reset(DEVICE(d));
203 }
204
205 /* In "free running mode" we start stage 1 again. */
206 if (d->free_run)
207 i6300esb_restart_timer(d, 1);
208 }
209 }
210
i6300esb_config_write(PCIDevice * dev,uint32_t addr,uint32_t data,int len)211 static void i6300esb_config_write(PCIDevice *dev, uint32_t addr,
212 uint32_t data, int len)
213 {
214 I6300State *d = WATCHDOG_I6300ESB_DEVICE(dev);
215 int old;
216
217 i6300esb_debug("addr = %x, data = %x, len = %d\n", addr, data, len);
218
219 if (addr == ESB_CONFIG_REG && len == 2) {
220 d->reboot_enabled = (data & ESB_WDT_REBOOT) == 0;
221 d->clock_scale =
222 (data & ESB_WDT_FREQ) != 0 ? CLOCK_SCALE_1MHZ : CLOCK_SCALE_1KHZ;
223 d->int_type = (data & ESB_WDT_INTTYPE);
224 } else if (addr == ESB_LOCK_REG && len == 1) {
225 if (!d->locked) {
226 d->locked = (data & ESB_WDT_LOCK) != 0;
227 d->free_run = (data & ESB_WDT_FUNC) != 0;
228 old = d->enabled;
229 d->enabled = (data & ESB_WDT_ENABLE) != 0;
230 if (!old && d->enabled) /* Enabled transitioned from 0 -> 1 */
231 i6300esb_restart_timer(d, 1);
232 else if (!d->enabled)
233 i6300esb_disable_timer(d);
234 }
235 } else {
236 pci_default_write_config(dev, addr, data, len);
237 }
238 }
239
i6300esb_config_read(PCIDevice * dev,uint32_t addr,int len)240 static uint32_t i6300esb_config_read(PCIDevice *dev, uint32_t addr, int len)
241 {
242 I6300State *d = WATCHDOG_I6300ESB_DEVICE(dev);
243 uint32_t data;
244
245 i6300esb_debug ("addr = %x, len = %d\n", addr, len);
246
247 if (addr == ESB_CONFIG_REG && len == 2) {
248 data =
249 (d->reboot_enabled ? 0 : ESB_WDT_REBOOT) |
250 (d->clock_scale == CLOCK_SCALE_1MHZ ? ESB_WDT_FREQ : 0) |
251 d->int_type;
252 return data;
253 } else if (addr == ESB_LOCK_REG && len == 1) {
254 data =
255 (d->free_run ? ESB_WDT_FUNC : 0) |
256 (d->locked ? ESB_WDT_LOCK : 0) |
257 (d->enabled ? ESB_WDT_ENABLE : 0);
258 return data;
259 } else {
260 return pci_default_read_config(dev, addr, len);
261 }
262 }
263
i6300esb_mem_readb(void * vp,hwaddr addr)264 static uint32_t i6300esb_mem_readb(void *vp, hwaddr addr)
265 {
266 i6300esb_debug ("addr = %x\n", (int) addr);
267
268 return 0;
269 }
270
i6300esb_mem_readw(void * vp,hwaddr addr)271 static uint32_t i6300esb_mem_readw(void *vp, hwaddr addr)
272 {
273 uint32_t data = 0;
274 I6300State *d = vp;
275
276 i6300esb_debug("addr = %x\n", (int) addr);
277
278 if (addr == 0xc) {
279 /* The previous reboot flag is really bit 9, but there is
280 * a bug in the Linux driver where it thinks it's bit 12.
281 * Set both.
282 */
283 data = d->previous_reboot_flag ? 0x1200 : 0;
284 }
285
286 return data;
287 }
288
i6300esb_mem_readl(void * vp,hwaddr addr)289 static uint32_t i6300esb_mem_readl(void *vp, hwaddr addr)
290 {
291 i6300esb_debug("addr = %x\n", (int) addr);
292
293 return 0;
294 }
295
i6300esb_mem_writeb(void * vp,hwaddr addr,uint32_t val)296 static void i6300esb_mem_writeb(void *vp, hwaddr addr, uint32_t val)
297 {
298 I6300State *d = vp;
299
300 i6300esb_debug("addr = %x, val = %x\n", (int) addr, val);
301
302 if (addr == 0xc && val == 0x80)
303 d->unlock_state = 1;
304 else if (addr == 0xc && val == 0x86 && d->unlock_state == 1)
305 d->unlock_state = 2;
306 }
307
i6300esb_mem_writew(void * vp,hwaddr addr,uint32_t val)308 static void i6300esb_mem_writew(void *vp, hwaddr addr, uint32_t val)
309 {
310 I6300State *d = vp;
311
312 i6300esb_debug("addr = %x, val = %x\n", (int) addr, val);
313
314 if (addr == 0xc && val == 0x80)
315 d->unlock_state = 1;
316 else if (addr == 0xc && val == 0x86 && d->unlock_state == 1)
317 d->unlock_state = 2;
318 else {
319 if (d->unlock_state == 2) {
320 if (addr == 0xc) {
321 if ((val & 0x100) != 0)
322 /* This is the "ping" from the userspace watchdog in
323 * the guest ...
324 */
325 i6300esb_restart_timer(d, 1);
326
327 /* Setting bit 9 resets the previous reboot flag.
328 * There's a bug in the Linux driver where it sets
329 * bit 12 instead.
330 */
331 if ((val & 0x200) != 0 || (val & 0x1000) != 0) {
332 d->previous_reboot_flag = 0;
333 }
334 }
335
336 d->unlock_state = 0;
337 }
338 }
339 }
340
i6300esb_mem_writel(void * vp,hwaddr addr,uint32_t val)341 static void i6300esb_mem_writel(void *vp, hwaddr addr, uint32_t val)
342 {
343 I6300State *d = vp;
344
345 i6300esb_debug ("addr = %x, val = %x\n", (int) addr, val);
346
347 if (addr == 0xc && val == 0x80)
348 d->unlock_state = 1;
349 else if (addr == 0xc && val == 0x86 && d->unlock_state == 1)
350 d->unlock_state = 2;
351 else {
352 if (d->unlock_state == 2) {
353 if (addr == 0)
354 d->timer1_preload = val & 0xfffff;
355 else if (addr == 4)
356 d->timer2_preload = val & 0xfffff;
357
358 d->unlock_state = 0;
359 }
360 }
361 }
362
i6300esb_mem_readfn(void * opaque,hwaddr addr,unsigned size)363 static uint64_t i6300esb_mem_readfn(void *opaque, hwaddr addr, unsigned size)
364 {
365 switch (size) {
366 case 1:
367 return i6300esb_mem_readb(opaque, addr);
368 case 2:
369 return i6300esb_mem_readw(opaque, addr);
370 case 4:
371 return i6300esb_mem_readl(opaque, addr);
372 default:
373 g_assert_not_reached();
374 }
375 }
376
i6300esb_mem_writefn(void * opaque,hwaddr addr,uint64_t value,unsigned size)377 static void i6300esb_mem_writefn(void *opaque, hwaddr addr,
378 uint64_t value, unsigned size)
379 {
380 switch (size) {
381 case 1:
382 i6300esb_mem_writeb(opaque, addr, value);
383 break;
384 case 2:
385 i6300esb_mem_writew(opaque, addr, value);
386 break;
387 case 4:
388 i6300esb_mem_writel(opaque, addr, value);
389 break;
390 default:
391 g_assert_not_reached();
392 }
393 }
394
395 static const MemoryRegionOps i6300esb_ops = {
396 .read = i6300esb_mem_readfn,
397 .write = i6300esb_mem_writefn,
398 .valid.min_access_size = 1,
399 .valid.max_access_size = 4,
400 .endianness = DEVICE_LITTLE_ENDIAN,
401 };
402
403 static const VMStateDescription vmstate_i6300esb = {
404 .name = "i6300esb_wdt",
405 /* With this VMSD's introduction, version_id/minimum_version_id were
406 * erroneously set to sizeof(I6300State), causing a somewhat random
407 * version_id to be set for every build. This eventually broke
408 * migration.
409 *
410 * To correct this without breaking old->new migration for older
411 * versions of QEMU, we've set version_id to a value high enough
412 * to exceed all past values of sizeof(I6300State) across various
413 * build environments, and have reset minimum_version_id to 1,
414 * since this VMSD has never changed and thus can accept all past
415 * versions.
416 *
417 * For future changes we can treat these values as we normally would.
418 */
419 .version_id = 10000,
420 .minimum_version_id = 1,
421 .fields = (const VMStateField[]) {
422 VMSTATE_PCI_DEVICE(dev, I6300State),
423 VMSTATE_INT32(reboot_enabled, I6300State),
424 VMSTATE_INT32(clock_scale, I6300State),
425 VMSTATE_INT32(int_type, I6300State),
426 VMSTATE_INT32(free_run, I6300State),
427 VMSTATE_INT32(locked, I6300State),
428 VMSTATE_INT32(enabled, I6300State),
429 VMSTATE_TIMER_PTR(timer, I6300State),
430 VMSTATE_UINT32(timer1_preload, I6300State),
431 VMSTATE_UINT32(timer2_preload, I6300State),
432 VMSTATE_INT32(stage, I6300State),
433 VMSTATE_INT32(unlock_state, I6300State),
434 VMSTATE_INT32(previous_reboot_flag, I6300State),
435 VMSTATE_END_OF_LIST()
436 }
437 };
438
i6300esb_realize(PCIDevice * dev,Error ** errp)439 static void i6300esb_realize(PCIDevice *dev, Error **errp)
440 {
441 I6300State *d = WATCHDOG_I6300ESB_DEVICE(dev);
442
443 i6300esb_debug("I6300State = %p\n", d);
444
445 d->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, i6300esb_timer_expired, d);
446 d->previous_reboot_flag = 0;
447
448 memory_region_init_io(&d->io_mem, OBJECT(d), &i6300esb_ops, d,
449 "i6300esb", 0x10);
450 pci_register_bar(&d->dev, 0, 0, &d->io_mem);
451 }
452
i6300esb_exit(PCIDevice * dev)453 static void i6300esb_exit(PCIDevice *dev)
454 {
455 I6300State *d = WATCHDOG_I6300ESB_DEVICE(dev);
456
457 timer_free(d->timer);
458 }
459
i6300esb_class_init(ObjectClass * klass,void * data)460 static void i6300esb_class_init(ObjectClass *klass, void *data)
461 {
462 DeviceClass *dc = DEVICE_CLASS(klass);
463 PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
464
465 k->config_read = i6300esb_config_read;
466 k->config_write = i6300esb_config_write;
467 k->realize = i6300esb_realize;
468 k->exit = i6300esb_exit;
469 k->vendor_id = PCI_VENDOR_ID_INTEL;
470 k->device_id = PCI_DEVICE_ID_INTEL_ESB_9;
471 k->class_id = PCI_CLASS_SYSTEM_OTHER;
472 dc->reset = i6300esb_reset;
473 dc->vmsd = &vmstate_i6300esb;
474 set_bit(DEVICE_CATEGORY_WATCHDOG, dc->categories);
475 dc->desc = "Intel 6300ESB";
476 }
477
478 static const TypeInfo i6300esb_info = {
479 .name = TYPE_WATCHDOG_I6300ESB_DEVICE,
480 .parent = TYPE_PCI_DEVICE,
481 .instance_size = sizeof(I6300State),
482 .class_init = i6300esb_class_init,
483 .interfaces = (InterfaceInfo[]) {
484 { INTERFACE_CONVENTIONAL_PCI_DEVICE },
485 { },
486 },
487 };
488
i6300esb_register_types(void)489 static void i6300esb_register_types(void)
490 {
491 type_register_static(&i6300esb_info);
492 }
493
494 type_init(i6300esb_register_types)
495