qemu/hw/watchdog/sbsa_gwdt.c

294 lines
7.9 KiB
C

/*
* Generic watchdog device model for SBSA
*
* The watchdog device has been implemented as revision 1 variant of
* the ARM SBSA specification v6.0
* (https://developer.arm.com/documentation/den0029/d?lang=en)
*
* Copyright Linaro.org 2020
*
* Authors:
* Shashi Mallela <shashi.mallela@linaro.org>
*
* This work is licensed under the terms of the GNU GPL, version 2 or (at your
* option) any later version. See the COPYING file in the top-level directory.
*
*/
#include "qemu/osdep.h"
#include "sysemu/reset.h"
#include "sysemu/watchdog.h"
#include "hw/watchdog/sbsa_gwdt.h"
#include "qemu/timer.h"
#include "migration/vmstate.h"
#include "qemu/log.h"
#include "qemu/module.h"
static WatchdogTimerModel model = {
.wdt_name = TYPE_WDT_SBSA,
.wdt_description = "SBSA-compliant generic watchdog device",
};
static const VMStateDescription vmstate_sbsa_gwdt = {
.name = "sbsa-gwdt",
.version_id = 1,
.minimum_version_id = 1,
.fields = (VMStateField[]) {
VMSTATE_TIMER_PTR(timer, SBSA_GWDTState),
VMSTATE_UINT32(wcs, SBSA_GWDTState),
VMSTATE_UINT32(worl, SBSA_GWDTState),
VMSTATE_UINT32(woru, SBSA_GWDTState),
VMSTATE_UINT32(wcvl, SBSA_GWDTState),
VMSTATE_UINT32(wcvu, SBSA_GWDTState),
VMSTATE_END_OF_LIST()
}
};
typedef enum WdtRefreshType {
EXPLICIT_REFRESH = 0,
TIMEOUT_REFRESH = 1,
} WdtRefreshType;
static uint64_t sbsa_gwdt_rread(void *opaque, hwaddr addr, unsigned int size)
{
SBSA_GWDTState *s = SBSA_GWDT(opaque);
uint32_t ret = 0;
switch (addr) {
case SBSA_GWDT_WRR:
/* watch refresh read has no effect and returns 0 */
ret = 0;
break;
case SBSA_GWDT_W_IIDR:
ret = s->id;
break;
default:
qemu_log_mask(LOG_GUEST_ERROR, "bad address in refresh frame read :"
" 0x%x\n", (int)addr);
}
return ret;
}
static uint64_t sbsa_gwdt_read(void *opaque, hwaddr addr, unsigned int size)
{
SBSA_GWDTState *s = SBSA_GWDT(opaque);
uint32_t ret = 0;
switch (addr) {
case SBSA_GWDT_WCS:
ret = s->wcs;
break;
case SBSA_GWDT_WOR:
ret = s->worl;
break;
case SBSA_GWDT_WORU:
ret = s->woru;
break;
case SBSA_GWDT_WCV:
ret = s->wcvl;
break;
case SBSA_GWDT_WCVU:
ret = s->wcvu;
break;
case SBSA_GWDT_W_IIDR:
ret = s->id;
break;
default:
qemu_log_mask(LOG_GUEST_ERROR, "bad address in control frame read :"
" 0x%x\n", (int)addr);
}
return ret;
}
static void sbsa_gwdt_update_timer(SBSA_GWDTState *s, WdtRefreshType rtype)
{
uint64_t timeout = 0;
timer_del(s->timer);
if (s->wcs & SBSA_GWDT_WCS_EN) {
/*
* Extract the upper 16 bits from woru & 32 bits from worl
* registers to construct the 48 bit offset value
*/
timeout = s->woru;
timeout <<= 32;
timeout |= s->worl;
timeout = muldiv64(timeout, NANOSECONDS_PER_SECOND, SBSA_TIMER_FREQ);
timeout += qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
if ((rtype == EXPLICIT_REFRESH) || ((rtype == TIMEOUT_REFRESH) &&
(!(s->wcs & SBSA_GWDT_WCS_WS0)))) {
/* store the current timeout value into compare registers */
s->wcvu = timeout >> 32;
s->wcvl = timeout;
}
timer_mod(s->timer, timeout);
}
}
static void sbsa_gwdt_rwrite(void *opaque, hwaddr offset, uint64_t data,
unsigned size) {
SBSA_GWDTState *s = SBSA_GWDT(opaque);
if (offset == SBSA_GWDT_WRR) {
s->wcs &= ~(SBSA_GWDT_WCS_WS0 | SBSA_GWDT_WCS_WS1);
sbsa_gwdt_update_timer(s, EXPLICIT_REFRESH);
} else {
qemu_log_mask(LOG_GUEST_ERROR, "bad address in refresh frame write :"
" 0x%x\n", (int)offset);
}
}
static void sbsa_gwdt_write(void *opaque, hwaddr offset, uint64_t data,
unsigned size) {
SBSA_GWDTState *s = SBSA_GWDT(opaque);
switch (offset) {
case SBSA_GWDT_WCS:
s->wcs = data & SBSA_GWDT_WCS_EN;
qemu_set_irq(s->irq, 0);
sbsa_gwdt_update_timer(s, EXPLICIT_REFRESH);
break;
case SBSA_GWDT_WOR:
s->worl = data;
s->wcs &= ~(SBSA_GWDT_WCS_WS0 | SBSA_GWDT_WCS_WS1);
qemu_set_irq(s->irq, 0);
sbsa_gwdt_update_timer(s, EXPLICIT_REFRESH);
break;
case SBSA_GWDT_WORU:
s->woru = data & SBSA_GWDT_WOR_MASK;
s->wcs &= ~(SBSA_GWDT_WCS_WS0 | SBSA_GWDT_WCS_WS1);
qemu_set_irq(s->irq, 0);
sbsa_gwdt_update_timer(s, EXPLICIT_REFRESH);
break;
case SBSA_GWDT_WCV:
s->wcvl = data;
break;
case SBSA_GWDT_WCVU:
s->wcvu = data;
break;
default:
qemu_log_mask(LOG_GUEST_ERROR, "bad address in control frame write :"
" 0x%x\n", (int)offset);
}
return;
}
static void wdt_sbsa_gwdt_reset(DeviceState *dev)
{
SBSA_GWDTState *s = SBSA_GWDT(dev);
timer_del(s->timer);
s->wcs = 0;
s->wcvl = 0;
s->wcvu = 0;
s->worl = 0;
s->woru = 0;
s->id = SBSA_GWDT_ID;
}
static void sbsa_gwdt_timer_sysinterrupt(void *opaque)
{
SBSA_GWDTState *s = SBSA_GWDT(opaque);
if (!(s->wcs & SBSA_GWDT_WCS_WS0)) {
s->wcs |= SBSA_GWDT_WCS_WS0;
sbsa_gwdt_update_timer(s, TIMEOUT_REFRESH);
qemu_set_irq(s->irq, 1);
} else {
s->wcs |= SBSA_GWDT_WCS_WS1;
qemu_log_mask(CPU_LOG_RESET, "Watchdog timer expired.\n");
/*
* Reset the watchdog only if the guest gets notified about
* expiry. watchdog_perform_action() may temporarily relinquish
* the BQL; reset before triggering the action to avoid races with
* sbsa_gwdt instructions.
*/
switch (get_watchdog_action()) {
case WATCHDOG_ACTION_DEBUG:
case WATCHDOG_ACTION_NONE:
case WATCHDOG_ACTION_PAUSE:
break;
default:
wdt_sbsa_gwdt_reset(DEVICE(s));
}
watchdog_perform_action();
}
}
static const MemoryRegionOps sbsa_gwdt_rops = {
.read = sbsa_gwdt_rread,
.write = sbsa_gwdt_rwrite,
.endianness = DEVICE_LITTLE_ENDIAN,
.valid.min_access_size = 4,
.valid.max_access_size = 4,
.valid.unaligned = false,
};
static const MemoryRegionOps sbsa_gwdt_ops = {
.read = sbsa_gwdt_read,
.write = sbsa_gwdt_write,
.endianness = DEVICE_LITTLE_ENDIAN,
.valid.min_access_size = 4,
.valid.max_access_size = 4,
.valid.unaligned = false,
};
static void wdt_sbsa_gwdt_realize(DeviceState *dev, Error **errp)
{
SBSA_GWDTState *s = SBSA_GWDT(dev);
SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
memory_region_init_io(&s->rmmio, OBJECT(dev),
&sbsa_gwdt_rops, s,
"sbsa_gwdt.refresh",
SBSA_GWDT_RMMIO_SIZE);
memory_region_init_io(&s->cmmio, OBJECT(dev),
&sbsa_gwdt_ops, s,
"sbsa_gwdt.control",
SBSA_GWDT_CMMIO_SIZE);
sysbus_init_mmio(sbd, &s->rmmio);
sysbus_init_mmio(sbd, &s->cmmio);
sysbus_init_irq(sbd, &s->irq);
s->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, sbsa_gwdt_timer_sysinterrupt,
dev);
}
static void wdt_sbsa_gwdt_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
dc->realize = wdt_sbsa_gwdt_realize;
dc->reset = wdt_sbsa_gwdt_reset;
dc->hotpluggable = false;
set_bit(DEVICE_CATEGORY_MISC, dc->categories);
dc->vmsd = &vmstate_sbsa_gwdt;
}
static const TypeInfo wdt_sbsa_gwdt_info = {
.class_init = wdt_sbsa_gwdt_class_init,
.parent = TYPE_SYS_BUS_DEVICE,
.name = TYPE_WDT_SBSA,
.instance_size = sizeof(SBSA_GWDTState),
};
static void wdt_sbsa_gwdt_register_types(void)
{
watchdog_add_model(&model);
type_register_static(&wdt_sbsa_gwdt_info);
}
type_init(wdt_sbsa_gwdt_register_types)