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/misc/allwinner-sid.h"
  30 #include "trace.h"
  31
  32 /* SID register offsets */
  33 enum {
  34     REG_PRCTL = 0x40,   /* Control */
  35     REG_RDKEY = 0x60,   /* Read Key */
  36 };
  37
  38 /* SID register flags */
  39 enum {
  40     REG_PRCTL_WRITE   = 0x0002, /* Unknown write flag */
  41     REG_PRCTL_OP_LOCK = 0xAC00, /* Lock operation */
  42 };
  43
  44 static uint64_t allwinner_sid_read(void *opaque, hwaddr offset,
  45                                    unsigned size)
  46 {
  47     const AwSidState *s = AW_SID(opaque);
  48     uint64_t val = 0;
  49
  50     switch (offset) {
  51     case REG_PRCTL:    /* Control */
  52         val = s->control;
  53         break;
  54     case REG_RDKEY:    /* Read Key */
  55         val = s->rdkey;
  56         break;
  57     default:
  58         qemu_log_mask(LOG_GUEST_ERROR, "%s: out-of-bounds offset 0x%04x\n",
  59                       __func__, (uint32_t)offset);
  60         return 0;
  61     }
  62
  63     trace_allwinner_sid_read(offset, val, size);
  64
  65     return val;
  66 }
  67
  68 static void allwinner_sid_write(void *opaque, hwaddr offset,
  69                                 uint64_t val, unsigned size)
  70 {
  71     AwSidState *s = AW_SID(opaque);
  72
  73     trace_allwinner_sid_write(offset, val, size);
  74
  75     switch (offset) {
  76     case REG_PRCTL:    /* Control */
  77         s->control = val;
  78
  79         if ((s->control & REG_PRCTL_OP_LOCK) &&
  80             (s->control & REG_PRCTL_WRITE)) {
  81             uint32_t id = s->control >> 16;
  82
  83             if (id <= sizeof(QemuUUID) - sizeof(s->rdkey)) {
  84                 s->rdkey = ldl_be_p(&s->identifier.data[id]);
  85             }
  86         }
  87         s->control &= ~REG_PRCTL_WRITE;
  88         break;
  89     case REG_RDKEY:    /* Read Key */
  90         break;
  91     default:
  92         qemu_log_mask(LOG_GUEST_ERROR, "%s: out-of-bounds offset 0x%04x\n",
  93                       __func__, (uint32_t)offset);
  94         break;
  95     }
  96 }
  97
  98 static const MemoryRegionOps allwinner_sid_ops = {
  99     .read = allwinner_sid_read,
 100     .write = allwinner_sid_write,
 101     .endianness = DEVICE_NATIVE_ENDIAN,
 102     .valid = {
 103         .min_access_size = 4,
 104         .max_access_size = 4,
 105     },
 106     .impl.min_access_size = 4,
 107 };
 108
 109 static void allwinner_sid_reset(DeviceState *dev)
 110 {
 111     AwSidState *s = AW_SID(dev);
 112
 113     /* Set default values for registers */
 114     s->control = 0;
 115     s->rdkey = 0;
 116 }
 117
 118 static void allwinner_sid_init(Object *obj)
 119 {
 120     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
 121     AwSidState *s = AW_SID(obj);
 122
 123     /* Memory mapping */
 124     memory_region_init_io(&s->iomem, OBJECT(s), &allwinner_sid_ops, s,
 125                            TYPE_AW_SID, 1 * KiB);
 126     sysbus_init_mmio(sbd, &s->iomem);
 127 }
 128
 129 static Property allwinner_sid_properties[] = {
 130     DEFINE_PROP_UUID_NODEFAULT("identifier", AwSidState, identifier),
 131     DEFINE_PROP_END_OF_LIST()
 132 };
 133
 134 static const VMStateDescription allwinner_sid_vmstate = {
 135     .name = "allwinner-sid",
 136     .version_id = 1,
 137     .minimum_version_id = 1,
 138     .fields = (VMStateField[]) {
 139         VMSTATE_UINT32(control, AwSidState),
 140         VMSTATE_UINT32(rdkey, AwSidState),
 141         VMSTATE_UINT8_ARRAY_V(identifier.data, AwSidState, sizeof(QemuUUID), 1),
 142         VMSTATE_END_OF_LIST()
 143     }
 144 };
 145
 146 static void allwinner_sid_class_init(ObjectClass *klass, void *data)
 147 {
 148     DeviceClass *dc = DEVICE_CLASS(klass);
 149
 150     dc->reset = allwinner_sid_reset;
 151     dc->vmsd = &allwinner_sid_vmstate;
 152     device_class_set_props(dc, allwinner_sid_properties);
 153 }
 154
 155 static const TypeInfo allwinner_sid_info = {
 156     .name          = TYPE_AW_SID,
 157     .parent        = TYPE_SYS_BUS_DEVICE,
 158     .instance_init = allwinner_sid_init,
 159     .instance_size = sizeof(AwSidState),
 160     .class_init    = allwinner_sid_class_init,
 161 };
 162
 163 static void allwinner_sid_register(void)
 164 {
 165     type_register_static(&allwinner_sid_info);
 166 }
 167
 168 type_init(allwinner_sid_register)