hw/arm/allwinner: add Security Identifier device

The Security Identifier device found in various Allwinner System on Chip
designs gives applications a per-board unique identifier. This commit
adds support for the Allwinner Security Identifier using a 128-bit
UUID value as input.

Signed-off-by: Niek Linnenbank <nieklinnenbank@gmail.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 20200311221854.30370-8-nieklinnenbank@gmail.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 168 insertions, 0 deletions

diff --git a/hw/misc/allwinner-sid.c b/hw/misc/allwinner-sid.c
new file mode 100644
index 0000000000..196380c33a
--- /dev/null
+++ b/hw/misc/allwinner-sid.c
@@ -0,0 +1,168 @@
+/*
+ * Allwinner Security ID emulation
+ *
+ * Copyright (C) 2019 Niek Linnenbank <nieklinnenbank@gmail.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that 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/units.h"
+#include "hw/sysbus.h"
+#include "migration/vmstate.h"
+#include "qemu/log.h"
+#include "qemu/module.h"
+#include "qemu/guest-random.h"
+#include "qapi/error.h"
+#include "hw/qdev-properties.h"
+#include "hw/misc/allwinner-sid.h"
+#include "trace.h"
+
+/* SID register offsets */
+enum {
+    REG_PRCTL = 0x40,   /* Control */
+    REG_RDKEY = 0x60,   /* Read Key */
+};
+
+/* SID register flags */
+enum {
+    REG_PRCTL_WRITE   = 0x0002, /* Unknown write flag */
+    REG_PRCTL_OP_LOCK = 0xAC00, /* Lock operation */
+};
+
+static uint64_t allwinner_sid_read(void *opaque, hwaddr offset,
+                                   unsigned size)
+{
+    const AwSidState *s = AW_SID(opaque);
+    uint64_t val = 0;
+
+    switch (offset) {
+    case REG_PRCTL:    /* Control */
+        val = s->control;
+        break;
+    case REG_RDKEY:    /* Read Key */
+        val = s->rdkey;
+        break;
+    default:
+        qemu_log_mask(LOG_GUEST_ERROR, "%s: out-of-bounds offset 0x%04x\n",
+                      __func__, (uint32_t)offset);
+        return 0;
+    }
+
+    trace_allwinner_sid_read(offset, val, size);
+
+    return val;
+}
+
+static void allwinner_sid_write(void *opaque, hwaddr offset,
+                                uint64_t val, unsigned size)
+{
+    AwSidState *s = AW_SID(opaque);
+
+    trace_allwinner_sid_write(offset, val, size);
+
+    switch (offset) {
+    case REG_PRCTL:    /* Control */
+        s->control = val;
+
+        if ((s->control & REG_PRCTL_OP_LOCK) &&
+            (s->control & REG_PRCTL_WRITE)) {
+            uint32_t id = s->control >> 16;
+
+            if (id <= sizeof(QemuUUID) - sizeof(s->rdkey)) {
+                s->rdkey = ldl_be_p(&s->identifier.data[id]);
+            }
+        }
+        s->control &= ~REG_PRCTL_WRITE;
+        break;
+    case REG_RDKEY:    /* Read Key */
+        break;
+    default:
+        qemu_log_mask(LOG_GUEST_ERROR, "%s: out-of-bounds offset 0x%04x\n",
+                      __func__, (uint32_t)offset);
+        break;
+    }
+}
+
+static const MemoryRegionOps allwinner_sid_ops = {
+    .read = allwinner_sid_read,
+    .write = allwinner_sid_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+    .valid = {
+        .min_access_size = 4,
+        .max_access_size = 4,
+    },
+    .impl.min_access_size = 4,
+};
+
+static void allwinner_sid_reset(DeviceState *dev)
+{
+    AwSidState *s = AW_SID(dev);
+
+    /* Set default values for registers */
+    s->control = 0;
+    s->rdkey = 0;
+}
+
+static void allwinner_sid_init(Object *obj)
+{
+    SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
+    AwSidState *s = AW_SID(obj);
+
+    /* Memory mapping */
+    memory_region_init_io(&s->iomem, OBJECT(s), &allwinner_sid_ops, s,
+                           TYPE_AW_SID, 1 * KiB);
+    sysbus_init_mmio(sbd, &s->iomem);
+}
+
+static Property allwinner_sid_properties[] = {
+    DEFINE_PROP_UUID_NODEFAULT("identifier", AwSidState, identifier),
+    DEFINE_PROP_END_OF_LIST()
+};
+
+static const VMStateDescription allwinner_sid_vmstate = {
+    .name = "allwinner-sid",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT32(control, AwSidState),
+        VMSTATE_UINT32(rdkey, AwSidState),
+        VMSTATE_UINT8_ARRAY_V(identifier.data, AwSidState, sizeof(QemuUUID), 1),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static void allwinner_sid_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->reset = allwinner_sid_reset;
+    dc->vmsd = &allwinner_sid_vmstate;
+    device_class_set_props(dc, allwinner_sid_properties);
+}
+
+static const TypeInfo allwinner_sid_info = {
+    .name          = TYPE_AW_SID,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_init = allwinner_sid_init,
+    .instance_size = sizeof(AwSidState),
+    .class_init    = allwinner_sid_class_init,
+};
+
+static void allwinner_sid_register(void)
+{
+    type_register_static(&allwinner_sid_info);
+}
+
+type_init(allwinner_sid_register)