/*
* Virtual hardware watchdog.
*
* Copyright (C) 2009 Red Hat Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see .
*
* By Richard W.M. Jones (rjones@redhat.com).
*/
#include
#include "qemu-common.h"
#include "qemu-timer.h"
#include "watchdog.h"
#include "hw.h"
#include "pci.h"
/*#define I6300ESB_DEBUG 1*/
#ifdef I6300ESB_DEBUG
#define i6300esb_debug(fs,...) \
fprintf(stderr,"i6300esb: %s: "fs,__func__,##__VA_ARGS__)
#else
#define i6300esb_debug(fs,...)
#endif
/* PCI configuration registers */
#define ESB_CONFIG_REG 0x60 /* Config register */
#define ESB_LOCK_REG 0x68 /* WDT lock register */
/* Memory mapped registers (offset from base address) */
#define ESB_TIMER1_REG 0x00 /* Timer1 value after each reset */
#define ESB_TIMER2_REG 0x04 /* Timer2 value after each reset */
#define ESB_GINTSR_REG 0x08 /* General Interrupt Status Register */
#define ESB_RELOAD_REG 0x0c /* Reload register */
/* Lock register bits */
#define ESB_WDT_FUNC (0x01 << 2) /* Watchdog functionality */
#define ESB_WDT_ENABLE (0x01 << 1) /* Enable WDT */
#define ESB_WDT_LOCK (0x01 << 0) /* Lock (nowayout) */
/* Config register bits */
#define ESB_WDT_REBOOT (0x01 << 5) /* Enable reboot on timeout */
#define ESB_WDT_FREQ (0x01 << 2) /* Decrement frequency */
#define ESB_WDT_INTTYPE (0x11 << 0) /* Interrupt type on timer1 timeout */
/* Reload register bits */
#define ESB_WDT_RELOAD (0x01 << 8) /* prevent timeout */
/* Magic constants */
#define ESB_UNLOCK1 0x80 /* Step 1 to unlock reset registers */
#define ESB_UNLOCK2 0x86 /* Step 2 to unlock reset registers */
/* Device state. */
struct I6300State {
PCIDevice dev;
MemoryRegion io_mem;
int reboot_enabled; /* "Reboot" on timer expiry. The real action
* performed depends on the -watchdog-action
* param passed on QEMU command line.
*/
int clock_scale; /* Clock scale. */
#define CLOCK_SCALE_1KHZ 0
#define CLOCK_SCALE_1MHZ 1
int int_type; /* Interrupt type generated. */
#define INT_TYPE_IRQ 0 /* APIC 1, INT 10 */
#define INT_TYPE_SMI 2
#define INT_TYPE_DISABLED 3
int free_run; /* If true, reload timer on expiry. */
int locked; /* If true, enabled field cannot be changed. */
int enabled; /* If true, watchdog is enabled. */
QEMUTimer *timer; /* The actual watchdog timer. */
uint32_t timer1_preload; /* Values preloaded into timer1, timer2. */
uint32_t timer2_preload;
int stage; /* Stage (1 or 2). */
int unlock_state; /* Guest writes 0x80, 0x86 to unlock the
* registers, and we transition through
* states 0 -> 1 -> 2 when this happens.
*/
int previous_reboot_flag; /* If the watchdog caused the previous
* reboot, this flag will be set.
*/
};
typedef struct I6300State I6300State;
/* This function is called when the watchdog has either been enabled
* (hence it starts counting down) or has been keep-alived.
*/
static void i6300esb_restart_timer(I6300State *d, int stage)
{
int64_t timeout;
if (!d->enabled)
return;
d->stage = stage;
if (d->stage <= 1)
timeout = d->timer1_preload;
else
timeout = d->timer2_preload;
if (d->clock_scale == CLOCK_SCALE_1KHZ)
timeout <<= 15;
else
timeout <<= 5;
/* Get the timeout in units of ticks_per_sec. */
timeout = get_ticks_per_sec() * timeout / 33000000;
i6300esb_debug("stage %d, timeout %" PRIi64 "\n", d->stage, timeout);
qemu_mod_timer(d->timer, qemu_get_clock_ns(vm_clock) + timeout);
}
/* This is called when the guest disables the watchdog. */
static void i6300esb_disable_timer(I6300State *d)
{
i6300esb_debug("timer disabled\n");
qemu_del_timer(d->timer);
}
static void i6300esb_reset(DeviceState *dev)
{
PCIDevice *pdev = PCI_DEVICE(dev);
I6300State *d = DO_UPCAST(I6300State, dev, pdev);
i6300esb_debug("I6300State = %p\n", d);
i6300esb_disable_timer(d);
/* NB: Don't change d->previous_reboot_flag in this function. */
d->reboot_enabled = 1;
d->clock_scale = CLOCK_SCALE_1KHZ;
d->int_type = INT_TYPE_IRQ;
d->free_run = 0;
d->locked = 0;
d->enabled = 0;
d->timer1_preload = 0xfffff;
d->timer2_preload = 0xfffff;
d->stage = 1;
d->unlock_state = 0;
}
/* This function is called when the watchdog expires. Note that
* the hardware has two timers, and so expiry happens in two stages.
* If d->stage == 1 then we perform the first stage action (usually,
* sending an interrupt) and then restart the timer again for the
* second stage. If the second stage expires then the watchdog
* really has run out.
*/
static void i6300esb_timer_expired(void *vp)
{
I6300State *d = vp;
i6300esb_debug("stage %d\n", d->stage);
if (d->stage == 1) {
/* What to do at the end of stage 1? */
switch (d->int_type) {
case INT_TYPE_IRQ:
fprintf(stderr, "i6300esb_timer_expired: I would send APIC 1 INT 10 here if I knew how (XXX)\n");
break;
case INT_TYPE_SMI:
fprintf(stderr, "i6300esb_timer_expired: I would send SMI here if I knew how (XXX)\n");
break;
}
/* Start the second stage. */
i6300esb_restart_timer(d, 2);
} else {
/* Second stage expired, reboot for real. */
if (d->reboot_enabled) {
d->previous_reboot_flag = 1;
watchdog_perform_action(); /* This reboots, exits, etc */
i6300esb_reset(&d->dev.qdev);
}
/* In "free running mode" we start stage 1 again. */
if (d->free_run)
i6300esb_restart_timer(d, 1);
}
}
static void i6300esb_config_write(PCIDevice *dev, uint32_t addr,
uint32_t data, int len)
{
I6300State *d = DO_UPCAST(I6300State, dev, dev);
int old;
i6300esb_debug("addr = %x, data = %x, len = %d\n", addr, data, len);
if (addr == ESB_CONFIG_REG && len == 2) {
d->reboot_enabled = (data & ESB_WDT_REBOOT) == 0;
d->clock_scale =
(data & ESB_WDT_FREQ) != 0 ? CLOCK_SCALE_1MHZ : CLOCK_SCALE_1KHZ;
d->int_type = (data & ESB_WDT_INTTYPE);
} else if (addr == ESB_LOCK_REG && len == 1) {
if (!d->locked) {
d->locked = (data & ESB_WDT_LOCK) != 0;
d->free_run = (data & ESB_WDT_FUNC) != 0;
old = d->enabled;
d->enabled = (data & ESB_WDT_ENABLE) != 0;
if (!old && d->enabled) /* Enabled transitioned from 0 -> 1 */
i6300esb_restart_timer(d, 1);
else if (!d->enabled)
i6300esb_disable_timer(d);
}
} else {
pci_default_write_config(dev, addr, data, len);
}
}
static uint32_t i6300esb_config_read(PCIDevice *dev, uint32_t addr, int len)
{
I6300State *d = DO_UPCAST(I6300State, dev, dev);
uint32_t data;
i6300esb_debug ("addr = %x, len = %d\n", addr, len);
if (addr == ESB_CONFIG_REG && len == 2) {
data =
(d->reboot_enabled ? 0 : ESB_WDT_REBOOT) |
(d->clock_scale == CLOCK_SCALE_1MHZ ? ESB_WDT_FREQ : 0) |
d->int_type;
return data;
} else if (addr == ESB_LOCK_REG && len == 1) {
data =
(d->free_run ? ESB_WDT_FUNC : 0) |
(d->locked ? ESB_WDT_LOCK : 0) |
(d->enabled ? ESB_WDT_ENABLE : 0);
return data;
} else {
return pci_default_read_config(dev, addr, len);
}
}
static uint32_t i6300esb_mem_readb(void *vp, target_phys_addr_t addr)
{
i6300esb_debug ("addr = %x\n", (int) addr);
return 0;
}
static uint32_t i6300esb_mem_readw(void *vp, target_phys_addr_t addr)
{
uint32_t data = 0;
I6300State *d = vp;
i6300esb_debug("addr = %x\n", (int) addr);
if (addr == 0xc) {
/* The previous reboot flag is really bit 9, but there is
* a bug in the Linux driver where it thinks it's bit 12.
* Set both.
*/
data = d->previous_reboot_flag ? 0x1200 : 0;
}
return data;
}
static uint32_t i6300esb_mem_readl(void *vp, target_phys_addr_t addr)
{
i6300esb_debug("addr = %x\n", (int) addr);
return 0;
}
static void i6300esb_mem_writeb(void *vp, target_phys_addr_t addr, uint32_t val)
{
I6300State *d = vp;
i6300esb_debug("addr = %x, val = %x\n", (int) addr, val);
if (addr == 0xc && val == 0x80)
d->unlock_state = 1;
else if (addr == 0xc && val == 0x86 && d->unlock_state == 1)
d->unlock_state = 2;
}
static void i6300esb_mem_writew(void *vp, target_phys_addr_t addr, uint32_t val)
{
I6300State *d = vp;
i6300esb_debug("addr = %x, val = %x\n", (int) addr, val);
if (addr == 0xc && val == 0x80)
d->unlock_state = 1;
else if (addr == 0xc && val == 0x86 && d->unlock_state == 1)
d->unlock_state = 2;
else {
if (d->unlock_state == 2) {
if (addr == 0xc) {
if ((val & 0x100) != 0)
/* This is the "ping" from the userspace watchdog in
* the guest ...
*/
i6300esb_restart_timer(d, 1);
/* Setting bit 9 resets the previous reboot flag.
* There's a bug in the Linux driver where it sets
* bit 12 instead.
*/
if ((val & 0x200) != 0 || (val & 0x1000) != 0) {
d->previous_reboot_flag = 0;
}
}
d->unlock_state = 0;
}
}
}
static void i6300esb_mem_writel(void *vp, target_phys_addr_t addr, uint32_t val)
{
I6300State *d = vp;
i6300esb_debug ("addr = %x, val = %x\n", (int) addr, val);
if (addr == 0xc && val == 0x80)
d->unlock_state = 1;
else if (addr == 0xc && val == 0x86 && d->unlock_state == 1)
d->unlock_state = 2;
else {
if (d->unlock_state == 2) {
if (addr == 0)
d->timer1_preload = val & 0xfffff;
else if (addr == 4)
d->timer2_preload = val & 0xfffff;
d->unlock_state = 0;
}
}
}
static const MemoryRegionOps i6300esb_ops = {
.old_mmio = {
.read = {
i6300esb_mem_readb,
i6300esb_mem_readw,
i6300esb_mem_readl,
},
.write = {
i6300esb_mem_writeb,
i6300esb_mem_writew,
i6300esb_mem_writel,
},
},
.endianness = DEVICE_NATIVE_ENDIAN,
};
static const VMStateDescription vmstate_i6300esb = {
.name = "i6300esb_wdt",
.version_id = sizeof(I6300State),
.minimum_version_id = sizeof(I6300State),
.minimum_version_id_old = sizeof(I6300State),
.fields = (VMStateField []) {
VMSTATE_PCI_DEVICE(dev, I6300State),
VMSTATE_INT32(reboot_enabled, I6300State),
VMSTATE_INT32(clock_scale, I6300State),
VMSTATE_INT32(int_type, I6300State),
VMSTATE_INT32(free_run, I6300State),
VMSTATE_INT32(locked, I6300State),
VMSTATE_INT32(enabled, I6300State),
VMSTATE_TIMER(timer, I6300State),
VMSTATE_UINT32(timer1_preload, I6300State),
VMSTATE_UINT32(timer2_preload, I6300State),
VMSTATE_INT32(stage, I6300State),
VMSTATE_INT32(unlock_state, I6300State),
VMSTATE_INT32(previous_reboot_flag, I6300State),
VMSTATE_END_OF_LIST()
}
};
static int i6300esb_init(PCIDevice *dev)
{
I6300State *d = DO_UPCAST(I6300State, dev, dev);
i6300esb_debug("I6300State = %p\n", d);
d->timer = qemu_new_timer_ns(vm_clock, i6300esb_timer_expired, d);
d->previous_reboot_flag = 0;
memory_region_init_io(&d->io_mem, &i6300esb_ops, d, "i6300esb", 0x10);
pci_register_bar(&d->dev, 0, 0, &d->io_mem);
/* qemu_register_coalesced_mmio (addr, 0x10); ? */
return 0;
}
static int i6300esb_exit(PCIDevice *dev)
{
I6300State *d = DO_UPCAST(I6300State, dev, dev);
memory_region_destroy(&d->io_mem);
return 0;
}
static WatchdogTimerModel model = {
.wdt_name = "i6300esb",
.wdt_description = "Intel 6300ESB",
};
static void i6300esb_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
k->config_read = i6300esb_config_read;
k->config_write = i6300esb_config_write;
k->init = i6300esb_init;
k->exit = i6300esb_exit;
k->vendor_id = PCI_VENDOR_ID_INTEL;
k->device_id = PCI_DEVICE_ID_INTEL_ESB_9;
k->class_id = PCI_CLASS_SYSTEM_OTHER;
dc->reset = i6300esb_reset;
dc->vmsd = &vmstate_i6300esb;
}
static TypeInfo i6300esb_info = {
.name = "i6300esb",
.parent = TYPE_PCI_DEVICE,
.instance_size = sizeof(I6300State),
.class_init = i6300esb_class_init,
};
static void i6300esb_register_types(void)
{
watchdog_add_model(&model);
type_register_static(&i6300esb_info);
}
type_init(i6300esb_register_types)