acrn-hypervisor/devicemodel/hw/pci/wdt_i6300esb.c

426 lines
11 KiB
C

/*
* Copyright (C) 2018-2022 Intel Corporation.
*
* SPDX-License-Identifier: BSD-3-Clause
*
*/
/*
* WatchDog Timer (WDT): emulate i6300esb PCI wdt Intel SOC devices,
* used to monitor guest OS
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include "vmmapi.h"
#include "mevent.h"
#include "pci_core.h"
#include "timer.h"
#define WDT_REG_BAR_SIZE 0x10
#define PCI_VENDOR_ID_INTEL 0x8086
#define PCI_DEVICE_ID_INTEL_ESB 0x25ab
#define ESB_CONFIG_REG 0x60 /* Config register*/
#define ESB_LOCK_REG 0x68 /* WDT lock register*/
/* Memory mapped registers */
#define ESB_TIMER1_REG 0x00 /* Timer1 value after each reset */
#define ESB_TIMER2_REG 0x04 /* Timer2 value after each reset */
#define ESB_GIS_REG 0x08 /* General Interrupt Status register */
#define ESB_RELOAD_REG 0x0c /* Reload register */
#define ESB_WDT_ENABLE (0x01 << 1) /* Enable WDT */
#define ESB_WDT_LOCK (0x01 << 0) /* Lock (nowayout) */
#define ESB_WDT_INT_ACT (0x01 << 0) /* WDT INT is active */
#define ESB_WDT_INT_MSK 0x3 /* WDT INT TYPE mask */
#define ESB_WDT_REBOOT (0x01 << 5) /* Enable reboot on timeout */
#define ESB_WDT_RELOAD (0x01 << 8) /* Ping/kick dog */
#define ESB_WDT_TIMEOUT (0x01 << 9) /* WDT timeout happened? */
/* Per i6300esb spec, in default watchdog timer prescaler
* the 20-bit Preload Value is loaded into bits 34:15 of the
* main down counter. The resulting timer clock is the PCI
* Clock (33 MHz) divided by 2^^15 . The approximate clock
* generated is 1 KHz, so right shift 10 bits of preload value
* to get the exact seconds for this timer.
*/
#define TIMER_TO_SECONDS(val) (val >> 10)
/* Magic constants */
#define ESB_UNLOCK1 0x80 /* Step 1 to unlock reset registers */
#define ESB_UNLOCK2 0x86 /* Step 2 to unlock reset registers */
/* the default 20-bit preload value */
#define DEFAULT_MAX_TIMER_VAL 0x000FFFFF
/* stage timer is set to 60s after reset, then left shift 10 bits of seconds
* to transform to the preload value of the watchdog timer which run in
* 1KHz clock.
*/
#define DEFAULT_RESET_TIMER_VAL (60 << 10)
/* for debug */
/* #define WDT_DEBUG */
#ifdef WDT_DEBUG
static FILE * dbg_file;
#define DPRINTF(format, args...) \
do { fprintf(dbg_file, format, args); fflush(dbg_file); } while (0)
#else
#define DPRINTF(format, arg...)
#endif
struct info_wdt {
struct acrn_timer timer;
bool reboot_enabled;/* "reboot" on wdt out */
bool intr_enabled; /* "intr" on wdt stage 1 time out */
bool intr_active; /* interrupt is active */
bool locked; /* If true, enabled field cannot be changed. */
bool wdt_enabled; /* If true, watchdog is enabled. */
bool wdt_armed;
uint32_t timer1_val;
uint32_t timer2_val;
int stage; /* stage 1 or 2. */
int unlock_state; /* unlock states 0 -> 1 -> 2 */
};
/* Whether watchdog is timeout. This info should cross reset. So
* we didn't add to struct info_wdt.
*/
static int wdt_timeout = 0;
static struct info_wdt wdt_state;
static void start_wdt_timer(void);
/*
* WDT timer, start when guest OS start watchdog service; and re-start for
* each dog-kick / ping action if time out, it will trigger reboot or other
* action to guest OS
*/
static void
wdt_expired_handler(void *arg, uint64_t nexp)
{
struct pci_vdev *dev = (struct pci_vdev *)arg;
DPRINTF("wdt timer out! stage=%d, reboot=%d\n",
wdt_state.stage, wdt_state.reboot_enabled);
if (wdt_state.stage == 1) {
if (wdt_state.intr_enabled) {
if (pci_msi_enabled(dev))
pci_generate_msi(dev, 0);
else
pci_lintr_assert(dev);
wdt_state.intr_active = true;
}
wdt_state.stage = 2;
start_wdt_timer();
} else {
if (wdt_state.reboot_enabled) {
wdt_state.stage = 1;
wdt_timeout = 1;
/* watchdog timer out, set the User VM to reboot */
#ifdef DM_DEBUG
pr_info("%s: setting VM state to %s\n", __func__, vm_state_to_str(VM_SUSPEND_SYSTEM_RESET));
vm_set_suspend_mode(VM_SUSPEND_SYSTEM_RESET);
/* Notify vm thread to handle VM_SUSPEND_SYSTEM_RESET request */
notify_vmloop_thread();
#else
pr_info("%s: setting VM state to %s\n", __func__, vm_state_to_str(VM_SUSPEND_FULL_RESET));
vm_set_suspend_mode(VM_SUSPEND_FULL_RESET);
#endif
mevent_notify();
} else {
/* if not need reboot, just loop timer */
wdt_state.stage = 1;
start_wdt_timer();
}
}
}
static void
stop_wdt_timer(void)
{
struct itimerspec timer_val;
DPRINTF("%s: wdt_armed=%d\n", __func__, wdt_state.wdt_armed);
if (!wdt_state.wdt_armed)
return;
memset(&timer_val, 0, sizeof(struct itimerspec));
acrn_timer_settime(&wdt_state.timer, &timer_val);
wdt_state.wdt_armed = false;
}
static void
start_wdt_timer(void)
{
int seconds;
struct itimerspec timer_val;
if (!wdt_state.wdt_enabled)
return;
if (wdt_state.stage == 1)
seconds = TIMER_TO_SECONDS(wdt_state.timer1_val);
else
seconds = TIMER_TO_SECONDS(wdt_state.timer2_val);
DPRINTF("%s: armed=%d, time=%d\n", __func__,
wdt_state.wdt_armed, seconds);
memset(&timer_val, 0, sizeof(struct itimerspec));
timer_val.it_value.tv_sec = seconds;
if (acrn_timer_settime(&wdt_state.timer, &timer_val) == -1) {
pr_err("WDT timerfd_settime failed.\n");
wdt_state.wdt_armed = false;
return;
}
wdt_state.wdt_armed = true;
}
static int
pci_wdt_cfg_read(struct vmctx *ctx, int vcpu, struct pci_vdev *dev,
int offset, int bytes, uint32_t *rv)
{
int need_cfg = 1;
DPRINTF("%s: offset = %x, len = %d\n", __func__, offset, bytes);
if (offset == ESB_LOCK_REG && bytes == 1) {
*rv = (wdt_state.locked ? ESB_WDT_LOCK : 0) |
(wdt_state.wdt_enabled ? ESB_WDT_ENABLE : 0);
need_cfg = 0;
}
return need_cfg;
}
static int
pci_wdt_cfg_write(struct vmctx *ctx, int vcpu, struct pci_vdev *dev,
int offset, int bytes, uint32_t val)
{
bool old_flag;
int need_cfg = 1;
DPRINTF("%s: offset = %x, len = %d, val = 0x%x\n",
__func__, offset, bytes, val);
if (offset == ESB_CONFIG_REG && bytes == 2) {
wdt_state.reboot_enabled = ((val & ESB_WDT_REBOOT) == 0);
wdt_state.intr_enabled = ((val & ESB_WDT_INT_MSK) == 0);
need_cfg = 0;
} else if (offset == ESB_LOCK_REG && bytes == 1) {
if (!wdt_state.locked) {
wdt_state.locked = ((val & ESB_WDT_LOCK) != 0);
old_flag = wdt_state.wdt_enabled;
wdt_state.wdt_enabled = ((val & ESB_WDT_ENABLE) != 0);
if (!old_flag && wdt_state.wdt_enabled) {
wdt_state.stage = 1;
start_wdt_timer();
} else if (!wdt_state.wdt_enabled)
stop_wdt_timer();
}
need_cfg = 0;
}
return need_cfg;
}
static void
pci_wdt_bar_write(struct vmctx *ctx, int vcpu, struct pci_vdev *dev,
int baridx, uint64_t offset, int size, uint64_t value)
{
DPRINTF("%s: addr = 0x%x, val = 0x%x, size=%d\n",
__func__, (int) offset, (int)value, size);
if (offset == ESB_GIS_REG) {
if ((value & ESB_WDT_INT_ACT) == 1) {
wdt_state.intr_active = false;
if ((wdt_state.intr_enabled == true)
&& (dev->lintr.state == ASSERTED)) {
pci_lintr_deassert(dev);
DPRINTF("%s: intr deasserted\n\r", __func__);
}
}
} else if (offset == ESB_RELOAD_REG) {
if (size != 2)
return;
if (value == ESB_UNLOCK1)
wdt_state.unlock_state = 1;
else if ((value == ESB_UNLOCK2)
&& (wdt_state.unlock_state == 1))
wdt_state.unlock_state = 2;
else if (wdt_state.unlock_state == 2) {
if (value & ESB_WDT_RELOAD) {
wdt_state.stage = 1;
start_wdt_timer();
}
/* write ES_WDT_TIMEOUT bit clear wdt timeout */
if (value & ESB_WDT_TIMEOUT) {
DPRINTF("%s: timeout cleaned\n\r", __func__);
wdt_timeout = 0;
}
wdt_state.unlock_state = 0;
}
} else if (wdt_state.unlock_state == 2) {
if (offset == ESB_TIMER1_REG)
wdt_state.timer1_val = value & DEFAULT_MAX_TIMER_VAL;
else if (offset == ESB_TIMER2_REG)
wdt_state.timer2_val = value & DEFAULT_MAX_TIMER_VAL;
wdt_state.unlock_state = 0;
}
}
uint64_t
pci_wdt_bar_read(struct vmctx *ctx, int vcpu, struct pci_vdev *dev,
int baridx, uint64_t offset, int size)
{
uint64_t ret = 0;
DPRINTF("%s: addr = 0x%x, size=%d\n\r", __func__, (int) offset, size);
if (offset == ESB_GIS_REG) {
if ((wdt_state.intr_enabled == true)
&& (wdt_state.intr_active == true))
ret |= ESB_WDT_INT_ACT;
} else if (offset == ESB_RELOAD_REG) {
if (size != 2)
return 0;
DPRINTF("%s: timeout: %d\n\r", __func__, wdt_timeout);
if (wdt_timeout != 0)
ret |= ESB_WDT_TIMEOUT;
if (wdt_state.stage == 1)
ret |= ESB_WDT_RELOAD;
}
return ret;
}
static int
pci_wdt_init(struct vmctx *ctx, struct pci_vdev *dev, char *opts)
{
/*the wdt just has one inistance */
if (wdt_state.reboot_enabled && wdt_state.timer1_val) {
pr_err("wdt can't be initialized twice, please check!");
return -1;
}
/* init wdt state info */
wdt_state.timer.clockid = CLOCK_MONOTONIC;
if (acrn_timer_init(&wdt_state.timer, wdt_expired_handler, dev) != 0) {
return -1;
}
wdt_state.reboot_enabled = true;
wdt_state.intr_enabled = false;
wdt_state.intr_active = false;
wdt_state.locked = false;
wdt_state.wdt_armed = false;
wdt_state.wdt_enabled = false;
wdt_state.stage = 1;
wdt_state.timer1_val = DEFAULT_MAX_TIMER_VAL;
wdt_state.timer2_val = DEFAULT_MAX_TIMER_VAL;
wdt_state.unlock_state = 0;
pci_emul_alloc_bar(dev, 0, PCIBAR_MEM32, WDT_REG_BAR_SIZE);
/* initialize config space */
pci_set_cfgdata16(dev, PCIR_VENDOR, PCI_VENDOR_ID_INTEL);
pci_set_cfgdata16(dev, PCIR_DEVICE, PCI_DEVICE_ID_INTEL_ESB);
pci_set_cfgdata8(dev, PCIR_CLASS, PCIC_BASEPERIPH);
pci_set_cfgdata8(dev, PCIR_SUBCLASS, PCIS_BASEPERIPH_OTHER);
pci_emul_add_msicap(dev, 1);
pci_lintr_request(dev);
#ifdef WDT_DEBUG
dbg_file = fopen("/tmp/wdt_log", "w+");
#endif
DPRINTF("%s: iobar =0x%lx, size=%ld\n", __func__,
dev->bar[0].addr, dev->bar[0].size);
return 0;
}
static void
pci_wdt_deinit(struct vmctx *ctx, struct pci_vdev *dev, char *opts)
{
acrn_timer_deinit(&wdt_state.timer);
memset(&wdt_state, 0, sizeof(wdt_state));
pci_lintr_release(dev);
}
/* stop/reset watchdog will be invoked during guest enter/exit S3.
* We stop watchdog timer when guest enter S3 to avoid watchdog trigger
* guest reset when guest is in S3 state.
*
* We reset watchdog with a long peroid (2 * 60s) during guest exit
* from S3 to handle system hang before watchdog in guest kernel start to
* work.
*/
void
vm_stop_watchdog(struct vmctx *ctx)
{
stop_wdt_timer();
}
void
vm_reset_watchdog(struct vmctx *ctx)
{
wdt_state.stage = 1;
wdt_state.timer1_val = DEFAULT_RESET_TIMER_VAL;
wdt_state.timer2_val = DEFAULT_RESET_TIMER_VAL;
wdt_state.unlock_state = 0;
start_wdt_timer();
}
struct pci_vdev_ops pci_ops_wdt = {
.class_name = "wdt-i6300esb",
.vdev_init = pci_wdt_init,
.vdev_deinit = pci_wdt_deinit,
.vdev_cfgwrite = pci_wdt_cfg_write,
.vdev_cfgread = pci_wdt_cfg_read,
.vdev_barwrite = pci_wdt_bar_write,
.vdev_barread = pci_wdt_bar_read
};
DEFINE_PCI_DEVTYPE(pci_ops_wdt);