hw/misc/allwinner-sid.c

   1 /*
   2  * Allwinner Security ID emulation
   3  *
   4  * Copyright (C) 2019 Niek Linnenbank <nieklinnenbank@gmail.com>
   5  *
   6  * This program is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation, either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include "qemu/osdep.h"
  21 #include "qemu/units.h"
  22 #include "hw/sysbus.h"
  23 #include "migration/vmstate.h"
  24 #include "qemu/log.h"
  25 #include "qemu/module.h"
  26 #include "qemu/guest-random.h"
  27 #include "qapi/error.h"
  28 #include "hw/qdev-properties.h"
  29 #include "hw/qdev-properties-system.h"
  30 #include "hw/misc/allwinner-sid.h"
  31 #include "trace.h"
  32
  33 /* SID register offsets */
  34 enum {
  35     REG_PRCTL = 0x40,   /* Control */
  36     REG_RDKEY = 0x60,   /* Read Key */
  37 };
  38
  39 /* SID register flags */
  40 enum {
  41     REG_PRCTL_WRITE   = 0x0002, /* Unknown write flag */
  42     REG_PRCTL_OP_LOCK = 0xAC00, /* Lock operation */
  43 };
  44
  45 static uint64_t allwinner_sid_read(void *opaque, hwaddr offset,
  46                                    unsigned size)
  47 {
  48     const AwSidState *s = AW_SID(opaque);
  49     uint64_t val = 0;
  50
  51     switch (offset) {
  52     case REG_PRCTL:    /* Control */
  53         val = s->control;
  54         break;
  55     case REG_RDKEY:    /* Read Key */
  56         val = s->rdkey;
  57         break;
  58     default:
  59         qemu_log_mask(LOG_GUEST_ERROR, "%s: out-of-bounds offset 0x%04x\n",
  60                       __func__, (uint32_t)offset);
  61         return 0;
  62     }
  63
  64     trace_allwinner_sid_read(offset, val, size);
  65
  66     return val;
  67 }
  68
  69 static void allwinner_sid_write(void *opaque, hwaddr offset,
  70                                 uint64_t val, unsigned size)
  71 {
  72     AwSidState *s = AW_SID(opaque);
  73
  74     trace_allwinner_sid_write(offset, val, size);
  75
  76     switch (offset) {
  77     case REG_PRCTL:    /* Control */
  78         s->control = val;
  79
  80         if ((s->control & REG_PRCTL_OP_LOCK) &&
  81             (s->control & REG_PRCTL_WRITE)) {
  82             uint32_t id = s->control >> 16;
  83
  84             if (id <= sizeof(QemuUUID) - sizeof(s->rdkey)) {
  85                 s->rdkey = ldl_be_p(&s->identifier.data[id]);
  86             }
  87         }
  88         s->control &= ~REG_PRCTL_WRITE;
  89         break;
  90     case REG_RDKEY:    /* Read Key */
  91         break;
  92     default:
  93         qemu_log_mask(LOG_GUEST_ERROR, "%s: out-of-bounds offset 0x%04x\n",
  94                       __func__, (uint32_t)offset);
  95         break;
  96     }
  97 }
  98
  99 static const MemoryRegionOps allwinner_sid_ops = {
 100     .read = allwinner_sid_read,
 101     .write = allwinner_sid_write,
 102     .endianness = DEVICE_NATIVE_ENDIAN,
 103     .valid = {
 104         .min_access_size = 4,
 105         .max_access_size = 4,
 106     },
 107     .impl.min_access_size = 4,
 108 };
 109
 110 static void allwinner_sid_reset(DeviceState *dev)
 111 {
 112     AwSidState *s = AW_SID(dev);
 113
 114     /* Set default values for registers */
 115     s->control = 0;
 116     s->rdkey = 0;
 117 }
 118
 119 static void allwinner_sid_init(Object *obj)
 120 {
 121     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
 122     AwSidState *s = AW_SID(obj);
 123
 124     /* Memory mapping */
 125     memory_region_init_io(&s->iomem, OBJECT(s), &allwinner_sid_ops, s,
 126                            TYPE_AW_SID, 1 * KiB);
 127     sysbus_init_mmio(sbd, &s->iomem);
 128 }
 129
 130 static Property allwinner_sid_properties[] = {
 131     DEFINE_PROP_UUID_NODEFAULT("identifier", AwSidState, identifier),
 132     DEFINE_PROP_END_OF_LIST()
 133 };
 134
 135 static const VMStateDescription allwinner_sid_vmstate = {
 136     .name = "allwinner-sid",
 137     .version_id = 1,
 138     .minimum_version_id = 1,
 139     .fields = (VMStateField[]) {
 140         VMSTATE_UINT32(control, AwSidState),
 141         VMSTATE_UINT32(rdkey, AwSidState),
 142         VMSTATE_UINT8_ARRAY_V(identifier.data, AwSidState, sizeof(QemuUUID), 1),
 143         VMSTATE_END_OF_LIST()
 144     }
 145 };
 146
 147 static void allwinner_sid_class_init(ObjectClass *klass, void *data)
 148 {
 149     DeviceClass *dc = DEVICE_CLASS(klass);
 150
 151     dc->reset = allwinner_sid_reset;
 152     dc->vmsd = &allwinner_sid_vmstate;
 153     device_class_set_props(dc, allwinner_sid_properties);
 154 }
 155
 156 static const TypeInfo allwinner_sid_info = {
 157     .name          = TYPE_AW_SID,
 158     .parent        = TYPE_SYS_BUS_DEVICE,
 159     .instance_init = allwinner_sid_init,
 160     .instance_size = sizeof(AwSidState),
 161     .class_init    = allwinner_sid_class_init,
 162 };
 163
 164 static void allwinner_sid_register(void)
 165 {
 166     type_register_static(&allwinner_sid_info);
 167 }
 168
 169 type_init(allwinner_sid_register)