2 * Virtual hardware watchdog.
4 * Copyright (C) 2009 Red Hat Inc.
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.
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.
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/>.
19 * By Richard W.M. Jones (rjones@redhat.com).
22 #include "qemu/osdep.h"
24 #include "qemu/module.h"
25 #include "qemu/timer.h"
26 #include "sysemu/watchdog.h"
27 #include "hw/pci/pci.h"
28 #include "migration/vmstate.h"
29 #include "qom/object.h"
31 /*#define I6300ESB_DEBUG 1*/
34 #define i6300esb_debug(fs,...) \
35 fprintf(stderr,"i6300esb: %s: "fs,__func__,##__VA_ARGS__)
37 #define i6300esb_debug(fs,...)
40 /* PCI configuration registers */
41 #define ESB_CONFIG_REG 0x60 /* Config register */
42 #define ESB_LOCK_REG 0x68 /* WDT lock register */
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 */
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) */
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 */
60 /* Reload register bits */
61 #define ESB_WDT_RELOAD (0x01 << 8) /* prevent timeout */
64 #define ESB_UNLOCK1 0x80 /* Step 1 to unlock reset registers */
65 #define ESB_UNLOCK2 0x86 /* Step 2 to unlock reset registers */
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.
76 int clock_scale
; /* Clock scale. */
77 #define CLOCK_SCALE_1KHZ 0
78 #define CLOCK_SCALE_1MHZ 1
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
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. */
89 QEMUTimer
*timer
; /* The actual watchdog timer. */
91 uint32_t timer1_preload
; /* Values preloaded into timer1, timer2. */
92 uint32_t timer2_preload
;
93 int stage
; /* Stage (1 or 2). */
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.
100 int previous_reboot_flag
; /* If the watchdog caused the previous
101 * reboot, this flag will be set.
105 typedef struct I6300State I6300State
;
107 #define TYPE_WATCHDOG_I6300ESB_DEVICE "i6300esb"
108 DECLARE_INSTANCE_CHECKER(I6300State
, WATCHDOG_I6300ESB_DEVICE
,
109 TYPE_WATCHDOG_I6300ESB_DEVICE
)
111 /* This function is called when the watchdog has either been enabled
112 * (hence it starts counting down) or has been keep-alived.
114 static void i6300esb_restart_timer(I6300State
*d
, int stage
)
124 timeout
= d
->timer1_preload
;
126 timeout
= d
->timer2_preload
;
128 if (d
->clock_scale
== CLOCK_SCALE_1KHZ
)
133 /* Get the timeout in nanoseconds. */
135 timeout
= timeout
* 30; /* on a PCI bus, 1 tick is 30 ns*/
137 i6300esb_debug("stage %d, timeout %" PRIi64
"\n", d
->stage
, timeout
);
139 timer_mod(d
->timer
, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL
) + timeout
);
142 /* This is called when the guest disables the watchdog. */
143 static void i6300esb_disable_timer(I6300State
*d
)
145 i6300esb_debug("timer disabled\n");
150 static void i6300esb_reset(DeviceState
*dev
)
152 PCIDevice
*pdev
= PCI_DEVICE(dev
);
153 I6300State
*d
= WATCHDOG_I6300ESB_DEVICE(pdev
);
155 i6300esb_debug("I6300State = %p\n", d
);
157 i6300esb_disable_timer(d
);
159 /* NB: Don't change d->previous_reboot_flag in this function. */
161 d
->reboot_enabled
= 1;
162 d
->clock_scale
= CLOCK_SCALE_1KHZ
;
163 d
->int_type
= INT_TYPE_IRQ
;
167 d
->timer1_preload
= 0xfffff;
168 d
->timer2_preload
= 0xfffff;
173 /* This function is called when the watchdog expires. Note that
174 * the hardware has two timers, and so expiry happens in two stages.
175 * If d->stage == 1 then we perform the first stage action (usually,
176 * sending an interrupt) and then restart the timer again for the
177 * second stage. If the second stage expires then the watchdog
178 * really has run out.
180 static void i6300esb_timer_expired(void *vp
)
184 i6300esb_debug("stage %d\n", d
->stage
);
187 /* What to do at the end of stage 1? */
188 switch (d
->int_type
) {
190 fprintf(stderr
, "i6300esb_timer_expired: I would send APIC 1 INT 10 here if I knew how (XXX)\n");
193 fprintf(stderr
, "i6300esb_timer_expired: I would send SMI here if I knew how (XXX)\n");
197 /* Start the second stage. */
198 i6300esb_restart_timer(d
, 2);
200 /* Second stage expired, reboot for real. */
201 if (d
->reboot_enabled
) {
202 d
->previous_reboot_flag
= 1;
203 watchdog_perform_action(); /* This reboots, exits, etc */
204 i6300esb_reset(DEVICE(d
));
207 /* In "free running mode" we start stage 1 again. */
209 i6300esb_restart_timer(d
, 1);
213 static void i6300esb_config_write(PCIDevice
*dev
, uint32_t addr
,
214 uint32_t data
, int len
)
216 I6300State
*d
= WATCHDOG_I6300ESB_DEVICE(dev
);
219 i6300esb_debug("addr = %x, data = %x, len = %d\n", addr
, data
, len
);
221 if (addr
== ESB_CONFIG_REG
&& len
== 2) {
222 d
->reboot_enabled
= (data
& ESB_WDT_REBOOT
) == 0;
224 (data
& ESB_WDT_FREQ
) != 0 ? CLOCK_SCALE_1MHZ
: CLOCK_SCALE_1KHZ
;
225 d
->int_type
= (data
& ESB_WDT_INTTYPE
);
226 } else if (addr
== ESB_LOCK_REG
&& len
== 1) {
228 d
->locked
= (data
& ESB_WDT_LOCK
) != 0;
229 d
->free_run
= (data
& ESB_WDT_FUNC
) != 0;
231 d
->enabled
= (data
& ESB_WDT_ENABLE
) != 0;
232 if (!old
&& d
->enabled
) /* Enabled transitioned from 0 -> 1 */
233 i6300esb_restart_timer(d
, 1);
234 else if (!d
->enabled
)
235 i6300esb_disable_timer(d
);
238 pci_default_write_config(dev
, addr
, data
, len
);
242 static uint32_t i6300esb_config_read(PCIDevice
*dev
, uint32_t addr
, int len
)
244 I6300State
*d
= WATCHDOG_I6300ESB_DEVICE(dev
);
247 i6300esb_debug ("addr = %x, len = %d\n", addr
, len
);
249 if (addr
== ESB_CONFIG_REG
&& len
== 2) {
251 (d
->reboot_enabled
? 0 : ESB_WDT_REBOOT
) |
252 (d
->clock_scale
== CLOCK_SCALE_1MHZ
? ESB_WDT_FREQ
: 0) |
255 } else if (addr
== ESB_LOCK_REG
&& len
== 1) {
257 (d
->free_run
? ESB_WDT_FUNC
: 0) |
258 (d
->locked
? ESB_WDT_LOCK
: 0) |
259 (d
->enabled
? ESB_WDT_ENABLE
: 0);
262 return pci_default_read_config(dev
, addr
, len
);
266 static uint32_t i6300esb_mem_readb(void *vp
, hwaddr addr
)
268 i6300esb_debug ("addr = %x\n", (int) addr
);
273 static uint32_t i6300esb_mem_readw(void *vp
, hwaddr addr
)
278 i6300esb_debug("addr = %x\n", (int) addr
);
281 /* The previous reboot flag is really bit 9, but there is
282 * a bug in the Linux driver where it thinks it's bit 12.
285 data
= d
->previous_reboot_flag
? 0x1200 : 0;
291 static uint32_t i6300esb_mem_readl(void *vp
, hwaddr addr
)
293 i6300esb_debug("addr = %x\n", (int) addr
);
298 static void i6300esb_mem_writeb(void *vp
, hwaddr addr
, uint32_t val
)
302 i6300esb_debug("addr = %x, val = %x\n", (int) addr
, val
);
304 if (addr
== 0xc && val
== 0x80)
306 else if (addr
== 0xc && val
== 0x86 && d
->unlock_state
== 1)
310 static void i6300esb_mem_writew(void *vp
, hwaddr addr
, uint32_t val
)
314 i6300esb_debug("addr = %x, val = %x\n", (int) addr
, val
);
316 if (addr
== 0xc && val
== 0x80)
318 else if (addr
== 0xc && val
== 0x86 && d
->unlock_state
== 1)
321 if (d
->unlock_state
== 2) {
323 if ((val
& 0x100) != 0)
324 /* This is the "ping" from the userspace watchdog in
327 i6300esb_restart_timer(d
, 1);
329 /* Setting bit 9 resets the previous reboot flag.
330 * There's a bug in the Linux driver where it sets
333 if ((val
& 0x200) != 0 || (val
& 0x1000) != 0) {
334 d
->previous_reboot_flag
= 0;
343 static void i6300esb_mem_writel(void *vp
, hwaddr addr
, uint32_t val
)
347 i6300esb_debug ("addr = %x, val = %x\n", (int) addr
, val
);
349 if (addr
== 0xc && val
== 0x80)
351 else if (addr
== 0xc && val
== 0x86 && d
->unlock_state
== 1)
354 if (d
->unlock_state
== 2) {
356 d
->timer1_preload
= val
& 0xfffff;
358 d
->timer2_preload
= val
& 0xfffff;
365 static uint64_t i6300esb_mem_readfn(void *opaque
, hwaddr addr
, unsigned size
)
369 return i6300esb_mem_readb(opaque
, addr
);
371 return i6300esb_mem_readw(opaque
, addr
);
373 return i6300esb_mem_readl(opaque
, addr
);
375 g_assert_not_reached();
379 static void i6300esb_mem_writefn(void *opaque
, hwaddr addr
,
380 uint64_t value
, unsigned size
)
384 i6300esb_mem_writeb(opaque
, addr
, value
);
387 i6300esb_mem_writew(opaque
, addr
, value
);
390 i6300esb_mem_writel(opaque
, addr
, value
);
393 g_assert_not_reached();
397 static const MemoryRegionOps i6300esb_ops
= {
398 .read
= i6300esb_mem_readfn
,
399 .write
= i6300esb_mem_writefn
,
400 .valid
.min_access_size
= 1,
401 .valid
.max_access_size
= 4,
402 .endianness
= DEVICE_LITTLE_ENDIAN
,
405 static const VMStateDescription vmstate_i6300esb
= {
406 .name
= "i6300esb_wdt",
407 /* With this VMSD's introduction, version_id/minimum_version_id were
408 * erroneously set to sizeof(I6300State), causing a somewhat random
409 * version_id to be set for every build. This eventually broke
412 * To correct this without breaking old->new migration for older
413 * versions of QEMU, we've set version_id to a value high enough
414 * to exceed all past values of sizeof(I6300State) across various
415 * build environments, and have reset minimum_version_id to 1,
416 * since this VMSD has never changed and thus can accept all past
419 * For future changes we can treat these values as we normally would.
422 .minimum_version_id
= 1,
423 .fields
= (VMStateField
[]) {
424 VMSTATE_PCI_DEVICE(dev
, I6300State
),
425 VMSTATE_INT32(reboot_enabled
, I6300State
),
426 VMSTATE_INT32(clock_scale
, I6300State
),
427 VMSTATE_INT32(int_type
, I6300State
),
428 VMSTATE_INT32(free_run
, I6300State
),
429 VMSTATE_INT32(locked
, I6300State
),
430 VMSTATE_INT32(enabled
, I6300State
),
431 VMSTATE_TIMER_PTR(timer
, I6300State
),
432 VMSTATE_UINT32(timer1_preload
, I6300State
),
433 VMSTATE_UINT32(timer2_preload
, I6300State
),
434 VMSTATE_INT32(stage
, I6300State
),
435 VMSTATE_INT32(unlock_state
, I6300State
),
436 VMSTATE_INT32(previous_reboot_flag
, I6300State
),
437 VMSTATE_END_OF_LIST()
441 static void i6300esb_realize(PCIDevice
*dev
, Error
**errp
)
443 I6300State
*d
= WATCHDOG_I6300ESB_DEVICE(dev
);
445 i6300esb_debug("I6300State = %p\n", d
);
447 d
->timer
= timer_new_ns(QEMU_CLOCK_VIRTUAL
, i6300esb_timer_expired
, d
);
448 d
->previous_reboot_flag
= 0;
450 memory_region_init_io(&d
->io_mem
, OBJECT(d
), &i6300esb_ops
, d
,
452 pci_register_bar(&d
->dev
, 0, 0, &d
->io_mem
);
455 static void i6300esb_exit(PCIDevice
*dev
)
457 I6300State
*d
= WATCHDOG_I6300ESB_DEVICE(dev
);
460 timer_free(d
->timer
);
463 static WatchdogTimerModel model
= {
464 .wdt_name
= "i6300esb",
465 .wdt_description
= "Intel 6300ESB",
468 static void i6300esb_class_init(ObjectClass
*klass
, void *data
)
470 DeviceClass
*dc
= DEVICE_CLASS(klass
);
471 PCIDeviceClass
*k
= PCI_DEVICE_CLASS(klass
);
473 k
->config_read
= i6300esb_config_read
;
474 k
->config_write
= i6300esb_config_write
;
475 k
->realize
= i6300esb_realize
;
476 k
->exit
= i6300esb_exit
;
477 k
->vendor_id
= PCI_VENDOR_ID_INTEL
;
478 k
->device_id
= PCI_DEVICE_ID_INTEL_ESB_9
;
479 k
->class_id
= PCI_CLASS_SYSTEM_OTHER
;
480 dc
->reset
= i6300esb_reset
;
481 dc
->vmsd
= &vmstate_i6300esb
;
482 set_bit(DEVICE_CATEGORY_MISC
, dc
->categories
);
485 static const TypeInfo i6300esb_info
= {
486 .name
= TYPE_WATCHDOG_I6300ESB_DEVICE
,
487 .parent
= TYPE_PCI_DEVICE
,
488 .instance_size
= sizeof(I6300State
),
489 .class_init
= i6300esb_class_init
,
490 .interfaces
= (InterfaceInfo
[]) {
491 { INTERFACE_CONVENTIONAL_PCI_DEVICE
},
496 static void i6300esb_register_types(void)
498 watchdog_add_model(&model
);
499 type_register_static(&i6300esb_info
);
502 type_init(i6300esb_register_types
)