qemu

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/*
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 * Allwinner Security ID emulation
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 *
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 * Copyright (C) 2019 Niek Linnenbank <nieklinnenbank@gmail.com>
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 *
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 * This program is free software: you can redistribute it and/or modify
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 * it under the terms of the GNU General Public License as published by
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 * the Free Software Foundation, either version 2 of the License, or
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 * (at your option) any later version.
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 *
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 * This program is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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 * GNU General Public License for more details.
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 *
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 * You should have received a copy of the GNU General Public License
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 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
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 */
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#include "qemu/osdep.h"
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#include "qemu/units.h"
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#include "hw/sysbus.h"
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#include "migration/vmstate.h"
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#include "qemu/log.h"
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#include "qemu/module.h"
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#include "qemu/guest-random.h"
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#include "qapi/error.h"
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#include "hw/qdev-properties.h"
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#include "hw/qdev-properties-system.h"
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#include "hw/misc/allwinner-sid.h"
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#include "trace.h"
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/* SID register offsets */
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enum {
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    REG_PRCTL = 0x40,   /* Control */
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    REG_RDKEY = 0x60,   /* Read Key */
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};
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/* SID register flags */
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enum {
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    REG_PRCTL_WRITE   = 0x0002, /* Unknown write flag */
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    REG_PRCTL_OP_LOCK = 0xAC00, /* Lock operation */
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};
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static uint64_t allwinner_sid_read(void *opaque, hwaddr offset,
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                                   unsigned size)
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{
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    const AwSidState *s = AW_SID(opaque);
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    uint64_t val = 0;
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    switch (offset) {
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    case REG_PRCTL:    /* Control */
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        val = s->control;
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        break;
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    case REG_RDKEY:    /* Read Key */
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        val = s->rdkey;
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        break;
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    default:
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        qemu_log_mask(LOG_GUEST_ERROR, "%s: out-of-bounds offset 0x%04x\n",
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                      __func__, (uint32_t)offset);
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        return 0;
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    }
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    trace_allwinner_sid_read(offset, val, size);
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    return val;
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}
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static void allwinner_sid_write(void *opaque, hwaddr offset,
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                                uint64_t val, unsigned size)
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{
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    AwSidState *s = AW_SID(opaque);
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    trace_allwinner_sid_write(offset, val, size);
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    switch (offset) {
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    case REG_PRCTL:    /* Control */
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        s->control = val;
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        if ((s->control & REG_PRCTL_OP_LOCK) &&
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            (s->control & REG_PRCTL_WRITE)) {
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            uint32_t id = s->control >> 16;
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            if (id <= sizeof(QemuUUID) - sizeof(s->rdkey)) {
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                s->rdkey = ldl_be_p(&s->identifier.data[id]);
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            }
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        }
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        s->control &= ~REG_PRCTL_WRITE;
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        break;
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    case REG_RDKEY:    /* Read Key */
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        break;
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    default:
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        qemu_log_mask(LOG_GUEST_ERROR, "%s: out-of-bounds offset 0x%04x\n",
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                      __func__, (uint32_t)offset);
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        break;
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    }
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}
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static const MemoryRegionOps allwinner_sid_ops = {
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    .read = allwinner_sid_read,
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    .write = allwinner_sid_write,
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    .endianness = DEVICE_NATIVE_ENDIAN,
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    .valid = {
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        .min_access_size = 4,
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        .max_access_size = 4,
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    },
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    .impl.min_access_size = 4,
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};
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static void allwinner_sid_reset(DeviceState *dev)
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{
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    AwSidState *s = AW_SID(dev);
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    /* Set default values for registers */
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    s->control = 0;
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    s->rdkey = 0;
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}
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static void allwinner_sid_init(Object *obj)
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{
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    SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
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    AwSidState *s = AW_SID(obj);
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    /* Memory mapping */
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    memory_region_init_io(&s->iomem, OBJECT(s), &allwinner_sid_ops, s,
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                           TYPE_AW_SID, 1 * KiB);
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    sysbus_init_mmio(sbd, &s->iomem);
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}
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static Property allwinner_sid_properties[] = {
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    DEFINE_PROP_UUID_NODEFAULT("identifier", AwSidState, identifier),
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    DEFINE_PROP_END_OF_LIST()
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};
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static const VMStateDescription allwinner_sid_vmstate = {
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    .name = "allwinner-sid",
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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(control, AwSidState),
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        VMSTATE_UINT32(rdkey, AwSidState),
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        VMSTATE_UINT8_ARRAY_V(identifier.data, AwSidState, sizeof(QemuUUID), 1),
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        VMSTATE_END_OF_LIST()
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    }
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};
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static void allwinner_sid_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 = allwinner_sid_reset;
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    dc->vmsd = &allwinner_sid_vmstate;
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    device_class_set_props(dc, allwinner_sid_properties);
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}
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static const TypeInfo allwinner_sid_info = {
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    .name          = TYPE_AW_SID,
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    .parent        = TYPE_SYS_BUS_DEVICE,
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    .instance_init = allwinner_sid_init,
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    .instance_size = sizeof(AwSidState),
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    .class_init    = allwinner_sid_class_init,
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};
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static void allwinner_sid_register(void)
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{
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    type_register_static(&allwinner_sid_info);
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}
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type_init(allwinner_sid_register)
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