On Tue, Oct 15, 2019 at 1:36 AM Anup Patel <anup.pa...@wdc.com> wrote:
>
> This patch adds model for Google Goldfish virtual platform RTC device.
>
> We will be adding Goldfish RTC device to the QEMU RISC-V virt machine
> for providing real date-time to Guest Linux. The corresponding Linux
> driver for Goldfish RTC device is already available in upstream Linux.
>
> For now, VM migration support is available but untested for Goldfish RTC
> device. It will be hardened in-future when we implement VM migration for
> KVM RISC-V.
>
> Signed-off-by: Anup Patel <anup.pa...@wdc.com>
> ---
> hw/rtc/Kconfig | 3 +
> hw/rtc/Makefile.objs | 1 +
> hw/rtc/goldfish_rtc.c | 278 ++++++++++++++++++++++++++++++++
> include/hw/timer/goldfish_rtc.h | 46 ++++++
> 4 files changed, 328 insertions(+)
> create mode 100644 hw/rtc/goldfish_rtc.c
> create mode 100644 include/hw/timer/goldfish_rtc.h
>
> diff --git a/hw/rtc/Kconfig b/hw/rtc/Kconfig
> index 45daa8d655..bafe6ac2c9 100644
> --- a/hw/rtc/Kconfig
> +++ b/hw/rtc/Kconfig
> @@ -21,3 +21,6 @@ config MC146818RTC
>
> config SUN4V_RTC
> bool
> +
> +config GOLDFISH_RTC
> + bool
> diff --git a/hw/rtc/Makefile.objs b/hw/rtc/Makefile.objs
> index 8dc9fcd3a9..aa208d0d10 100644
> --- a/hw/rtc/Makefile.objs
> +++ b/hw/rtc/Makefile.objs
> @@ -11,3 +11,4 @@ common-obj-$(CONFIG_EXYNOS4) += exynos4210_rtc.o
> obj-$(CONFIG_MC146818RTC) += mc146818rtc.o
> common-obj-$(CONFIG_SUN4V_RTC) += sun4v-rtc.o
> common-obj-$(CONFIG_ASPEED_SOC) += aspeed_rtc.o
> +common-obj-$(CONFIG_GOLDFISH_RTC) += goldfish_rtc.o
> diff --git a/hw/rtc/goldfish_rtc.c b/hw/rtc/goldfish_rtc.c
> new file mode 100644
> index 0000000000..223616ed75
> --- /dev/null
> +++ b/hw/rtc/goldfish_rtc.c
> @@ -0,0 +1,278 @@
> +/*
> + * Goldfish virtual platform RTC
> + *
> + * Copyright (C) 2019 Western Digital Corporation or its affiliates.
> + *
> + * For more details on Google Goldfish virtual platform refer:
> + *
> https://android.googlesource.com/platform/external/qemu/+/master/docs/GOLDFISH-VIRTUAL-HARDWARE.TXT
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2 or later, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope 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 <http://www.gnu.org/licenses/>.
> + */
> +
> +#include "qemu/osdep.h"
> +#include "qemu-common.h"
> +#include "hw/timer/goldfish_rtc.h"
> +#include "migration/vmstate.h"
> +#include "hw/irq.h"
> +#include "hw/qdev-properties.h"
> +#include "hw/sysbus.h"
> +#include "qemu/timer.h"
> +#include "sysemu/sysemu.h"
> +#include "qemu/cutils.h"
> +#include "qemu/log.h"
> +
> +#define RTC_TIME_LOW 0x00
> +#define RTC_TIME_HIGH 0x04
> +#define RTC_ALARM_LOW 0x08
> +#define RTC_ALARM_HIGH 0x0c
> +#define RTC_IRQ_ENABLED 0x10
> +#define RTC_CLEAR_ALARM 0x14
> +#define RTC_ALARM_STATUS 0x18
> +#define RTC_CLEAR_INTERRUPT 0x1c
> +
> +static void goldfish_rtc_update(GoldfishRTCState *s)
> +{
> + qemu_set_irq(s->irq, (s->irq_pending & s->irq_enabled) ? 1 : 0);
> +}
> +
> +static void goldfish_rtc_interrupt(void *opaque)
> +{
> + GoldfishRTCState *s = (GoldfishRTCState *)opaque;
> +
> + s->alarm_running = 0;
> + s->irq_pending = 1;
> + goldfish_rtc_update(s);
> +}
> +
> +static uint64_t goldfish_rtc_get_count(GoldfishRTCState *s)
> +{
> + return s->tick_offset + (uint64_t)qemu_clock_get_ns(rtc_clock);
> +}
> +
> +static void goldfish_rtc_clear_alarm(GoldfishRTCState *s)
> +{
> + timer_del(s->timer);
> + s->alarm_running = 0;
> +}
> +
> +static void goldfish_rtc_set_alarm(GoldfishRTCState *s)
> +{
> + uint64_t ticks = goldfish_rtc_get_count(s);
> + uint64_t event = s->alarm_next;
> +
> + if (event <= ticks) {
> + goldfish_rtc_clear_alarm(s);
> + goldfish_rtc_interrupt(s);
> + } else {
> + int64_t now = qemu_clock_get_ns(rtc_clock);
> + timer_mod(s->timer, now + (event - ticks));
Isn't this just: event - s->tick_offset?
> + s->alarm_running = 1;
> + }
> +}
> +
> +static uint64_t goldfish_rtc_read(void *opaque, hwaddr offset,
> + unsigned size)
> +{
> + GoldfishRTCState *s = (GoldfishRTCState *)opaque;
> + uint64_t r;
There should be a trace or debug print showing read/write operations.
> +
> + switch (offset) {
> + case RTC_TIME_LOW:
> + r = goldfish_rtc_get_count(s) & 0xffffffff;
> + break;
> + case RTC_TIME_HIGH:
> + r = goldfish_rtc_get_count(s) >> 32;
> + break;
> + case RTC_ALARM_LOW:
> + r = s->alarm_next & 0xffffffff;
> + break;
> + case RTC_ALARM_HIGH:
> + r = s->alarm_next >> 32;
> + break;
> + case RTC_IRQ_ENABLED:
> + r = s->irq_enabled;
> + break;
> + case RTC_ALARM_STATUS:
> + r = s->alarm_running;
> + break;
> + default:
> + qemu_log_mask(LOG_GUEST_ERROR,
> + "goldfish_rtc_read: Bad offset 0x%x\n", (int)offset);
> + r = 0;
Just set 0 as the init value and remove this.
> + break;
> + }
> +
> + return r;
> +}
> +
> +static void goldfish_rtc_write(void *opaque, hwaddr offset,
> + uint64_t value, unsigned size)
> +{
> + uint64_t current_tick, new_tick;
> + GoldfishRTCState *s = (GoldfishRTCState *)opaque;
The state struct should be first.
> +
> + switch (offset) {
> + case RTC_TIME_LOW:
> + current_tick = goldfish_rtc_get_count(s);
> + new_tick = current_tick & (0xffffffffULL << 32);
> + new_tick |= value;
> + s->tick_offset += new_tick - current_tick;
> + break;
> + case RTC_TIME_HIGH:
> + current_tick = goldfish_rtc_get_count(s);
> + new_tick = current_tick & 0xffffffffULL;
> + new_tick |= (value << 32);
> + s->tick_offset += new_tick - current_tick;
> + break;
> + case RTC_ALARM_LOW:
> + s->alarm_next &= (0xffffffffULL << 32);
> + s->alarm_next |= value;
> + goldfish_rtc_set_alarm(s);
> + break;
> + case RTC_ALARM_HIGH:
> + s->alarm_next &= 0xffffffffULL;
> + s->alarm_next |= (value << 32);
> + break;
> + case RTC_IRQ_ENABLED:
> + s->irq_enabled = (uint32_t)(value & 0x1);
> + goldfish_rtc_update(s);
> + break;
> + case RTC_CLEAR_ALARM:
> + goldfish_rtc_clear_alarm(s);
> + break;
> + case RTC_CLEAR_INTERRUPT:
> + s->irq_pending = 0;
> + goldfish_rtc_update(s);
> + break;
> + default:
> + qemu_log_mask(LOG_GUEST_ERROR,
> + "goldfish_rtc_write: Bad offset 0x%x\n", (int)offset);
> + break;
> + }
> +}
> +
> +static int goldfish_rtc_pre_save(void *opaque)
> +{
> + uint64_t delta;
> + GoldfishRTCState *s = opaque;
> +
> + /*
> + * We want to migrate this offset, which sounds straightforward.
> + * Unfortunately, we cannot directly pass tick_offset because
> + * rtc_clock on destinetion Host might not be same source Host.
s/destinetion/destination/g
and below as well.
Alistair
> + *
> + * To tackle, this we pass tick_offset relative to vm_clock from
> + * source Host and make it relative to rtc_clock at destinetion Host.
> + */
> + delta = qemu_clock_get_ns(rtc_clock) -
> + qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
> + s->tick_offset_vmstate = s->tick_offset + delta;
> +
> + return 0;
> +}
> +
> +static int goldfish_rtc_post_load(void *opaque, int version_id)
> +{
> + uint64_t delta;
> + GoldfishRTCState *s = opaque;
> +
> + /*
> + * We extract tick_offset from tick_offset_vmstate by doing
> + * reverse math compared to pre_save() function.
> + */
> + delta = qemu_clock_get_ns(rtc_clock) -
> + qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
> + s->tick_offset = s->tick_offset_vmstate - delta;
> +
> + return 0;
> +}
> +
> +static const MemoryRegionOps goldfish_rtc_ops = {
> + .read = goldfish_rtc_read,
> + .write = goldfish_rtc_write,
> + .endianness = DEVICE_LITTLE_ENDIAN,
> + .valid = {
> + .min_access_size = 4,
> + .max_access_size = 4
> + }
> +};
> +
> +static const VMStateDescription goldfish_rtc_vmstate = {
> + .name = TYPE_GOLDFISH_RTC,
> + .version_id = 1,
> + .pre_save = goldfish_rtc_pre_save,
> + .post_load = goldfish_rtc_post_load,
> + .fields = (VMStateField[]) {
> + VMSTATE_UINT64(tick_offset_vmstate, GoldfishRTCState),
> + VMSTATE_UINT64(alarm_next, GoldfishRTCState),
> + VMSTATE_UINT32(alarm_running, GoldfishRTCState),
> + VMSTATE_UINT32(irq_pending, GoldfishRTCState),
> + VMSTATE_UINT32(irq_enabled, GoldfishRTCState),
> + VMSTATE_END_OF_LIST()
> + }
> +};
> +
> +static void goldfish_rtc_reset(DeviceState *dev)
> +{
> + GoldfishRTCState *s = GOLDFISH_RTC(dev);
> + struct tm tm;
> +
> + timer_del(s->timer);
> +
> + qemu_get_timedate(&tm, 0);
> + s->tick_offset = mktimegm(&tm);
> + s->tick_offset *= NANOSECONDS_PER_SECOND;
> + s->tick_offset -= qemu_clock_get_ns(rtc_clock);
> + s->tick_offset_vmstate = 0;
> + s->alarm_next = 0;
> + s->alarm_running = 0;
> + s->irq_pending = 0;
> + s->irq_enabled = 0;
> +}
> +
> +static void goldfish_rtc_realize(DeviceState *d, Error **errp)
> +{
> + SysBusDevice *dev = SYS_BUS_DEVICE(d);
> + GoldfishRTCState *s = GOLDFISH_RTC(d);
> +
> + memory_region_init_io(&s->iomem, OBJECT(s), &goldfish_rtc_ops, s,
> + "goldfish_rtc", 0x1000);
> + sysbus_init_mmio(dev, &s->iomem);
> +
> + sysbus_init_irq(dev, &s->irq);
> +
> + s->timer = timer_new_ns(rtc_clock, goldfish_rtc_interrupt, s);
> +}
> +
> +static void goldfish_rtc_class_init(ObjectClass *klass, void *data)
> +{
> + DeviceClass *dc = DEVICE_CLASS(klass);
> +
> + dc->realize = goldfish_rtc_realize;
> + dc->reset = goldfish_rtc_reset;
> + dc->vmsd = &goldfish_rtc_vmstate;
> +}
> +
> +static const TypeInfo goldfish_rtc_info = {
> + .name = TYPE_GOLDFISH_RTC,
> + .parent = TYPE_SYS_BUS_DEVICE,
> + .instance_size = sizeof(GoldfishRTCState),
> + .class_init = goldfish_rtc_class_init,
> +};
> +
> +static void goldfish_rtc_register_types(void)
> +{
> + type_register_static(&goldfish_rtc_info);
> +}
> +
> +type_init(goldfish_rtc_register_types)
> diff --git a/include/hw/timer/goldfish_rtc.h b/include/hw/timer/goldfish_rtc.h
> new file mode 100644
> index 0000000000..dfb6d70b86
> --- /dev/null
> +++ b/include/hw/timer/goldfish_rtc.h
> @@ -0,0 +1,46 @@
> +/*
> + * Goldfish virtual platform RTC
> + *
> + * Copyright (C) 2019 Western Digital Corporation or its affiliates.
> + *
> + * For more details on Google Goldfish virtual platform refer:
> + *
> https://android.googlesource.com/platform/external/qemu/+/master/docs/GOLDFISH-VIRTUAL-HARDWARE.TXT
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2 or later, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope 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 <http://www.gnu.org/licenses/>.
> + */
> +
> +#ifndef HW_TIMER_GOLDFISH_RTC_H
> +#define HW_TIMER_GOLDFISH_RTC_H
> +
> +#include "hw/sysbus.h"
> +
> +#define TYPE_GOLDFISH_RTC "goldfish_rtc"
> +#define GOLDFISH_RTC(obj) \
> +OBJECT_CHECK(GoldfishRTCState, (obj), TYPE_GOLDFISH_RTC)
> +
> +typedef struct GoldfishRTCState {
> + SysBusDevice parent_obj;
> +
> + MemoryRegion iomem;
> + QEMUTimer *timer;
> + qemu_irq irq;
> +
> + uint64_t tick_offset;
> + uint64_t tick_offset_vmstate;
> + uint64_t alarm_next;
> + uint32_t alarm_running;
> + uint32_t irq_pending;
> + uint32_t irq_enabled;
> +} GoldfishRTCState;
> +
> +#endif
> --
> 2.17.1
>
>
