qemu

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/*
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 * BCM2835 Power Management emulation
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 *
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 * Copyright (C) 2017 Marcin Chojnacki <marcinch7@gmail.com>
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 * Copyright (C) 2021 Nolan Leake <nolan@sigbus.net>
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 *
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 * This work is licensed under the terms of the GNU GPL, version 2 or later.
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 * See the COPYING file in the top-level directory.
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 */
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#include "qemu/osdep.h"
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#include "qemu/log.h"
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#include "qemu/module.h"
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#include "hw/misc/bcm2835_powermgt.h"
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#include "migration/vmstate.h"
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#include "sysemu/runstate.h"
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#define PASSWORD 0x5a000000
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#define PASSWORD_MASK 0xff000000
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#define R_RSTC 0x1c
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#define V_RSTC_RESET 0x20
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#define R_RSTS 0x20
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#define V_RSTS_POWEROFF 0x555 /* Linux uses partition 63 to indicate halt. */
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#define R_WDOG 0x24
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static uint64_t bcm2835_powermgt_read(void *opaque, hwaddr offset,
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                                      unsigned size)
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{
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    BCM2835PowerMgtState *s = (BCM2835PowerMgtState *)opaque;
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    uint32_t res = 0;
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    switch (offset) {
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    case R_RSTC:
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        res = s->rstc;
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        break;
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    case R_RSTS:
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        res = s->rsts;
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        break;
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    case R_WDOG:
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        res = s->wdog;
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        break;
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    default:
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        qemu_log_mask(LOG_UNIMP,
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                      "bcm2835_powermgt_read: Unknown offset 0x%08"HWADDR_PRIx
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                      "\n", offset);
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        res = 0;
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        break;
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    }
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    return res;
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}
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static void bcm2835_powermgt_write(void *opaque, hwaddr offset,
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                                   uint64_t value, unsigned size)
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{
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    BCM2835PowerMgtState *s = (BCM2835PowerMgtState *)opaque;
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    if ((value & PASSWORD_MASK) != PASSWORD) {
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        qemu_log_mask(LOG_GUEST_ERROR,
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                      "bcm2835_powermgt_write: Bad password 0x%"PRIx64
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                      " at offset 0x%08"HWADDR_PRIx"\n",
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                      value, offset);
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        return;
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    }
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    value = value & ~PASSWORD_MASK;
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    switch (offset) {
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    case R_RSTC:
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        s->rstc = value;
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        if (value & V_RSTC_RESET) {
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            if ((s->rsts & 0xfff) == V_RSTS_POWEROFF) {
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                qemu_system_shutdown_request(SHUTDOWN_CAUSE_GUEST_SHUTDOWN);
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            } else {
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                qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET);
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            }
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        }
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        break;
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    case R_RSTS:
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        qemu_log_mask(LOG_UNIMP,
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                      "bcm2835_powermgt_write: RSTS\n");
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        s->rsts = value;
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        break;
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    case R_WDOG:
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        qemu_log_mask(LOG_UNIMP,
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                      "bcm2835_powermgt_write: WDOG\n");
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        s->wdog = value;
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        break;
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    default:
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        qemu_log_mask(LOG_UNIMP,
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                      "bcm2835_powermgt_write: Unknown offset 0x%08"HWADDR_PRIx
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                      "\n", offset);
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        break;
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    }
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}
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static const MemoryRegionOps bcm2835_powermgt_ops = {
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    .read = bcm2835_powermgt_read,
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    .write = bcm2835_powermgt_write,
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    .endianness = DEVICE_NATIVE_ENDIAN,
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    .impl.min_access_size = 4,
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    .impl.max_access_size = 4,
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};
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static const VMStateDescription vmstate_bcm2835_powermgt = {
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    .name = TYPE_BCM2835_POWERMGT,
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    .version_id = 1,
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    .minimum_version_id = 1,
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    .fields = (const VMStateField[]) {
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        VMSTATE_UINT32(rstc, BCM2835PowerMgtState),
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        VMSTATE_UINT32(rsts, BCM2835PowerMgtState),
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        VMSTATE_UINT32(wdog, BCM2835PowerMgtState),
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        VMSTATE_END_OF_LIST()
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    }
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};
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static void bcm2835_powermgt_init(Object *obj)
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{
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    BCM2835PowerMgtState *s = BCM2835_POWERMGT(obj);
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    memory_region_init_io(&s->iomem, obj, &bcm2835_powermgt_ops, s,
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                          TYPE_BCM2835_POWERMGT, 0x200);
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    sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->iomem);
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}
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static void bcm2835_powermgt_reset(DeviceState *dev)
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{
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    BCM2835PowerMgtState *s = BCM2835_POWERMGT(dev);
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    /* https://elinux.org/BCM2835_registers#PM */
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    s->rstc = 0x00000102;
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    s->rsts = 0x00001000;
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    s->wdog = 0x00000000;
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}
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static void bcm2835_powermgt_class_init(ObjectClass *klass, void *data)
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{
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    DeviceClass *dc = DEVICE_CLASS(klass);
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    dc->reset = bcm2835_powermgt_reset;
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    dc->vmsd = &vmstate_bcm2835_powermgt;
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}
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static const TypeInfo bcm2835_powermgt_info = {
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    .name          = TYPE_BCM2835_POWERMGT,
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    .parent        = TYPE_SYS_BUS_DEVICE,
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    .instance_size = sizeof(BCM2835PowerMgtState),
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    .class_init    = bcm2835_powermgt_class_init,
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    .instance_init = bcm2835_powermgt_init,
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};
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static void bcm2835_powermgt_register_types(void)
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{
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    type_register_static(&bcm2835_powermgt_info);
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}
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type_init(bcm2835_powermgt_register_types)
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