1 files changed, 107 insertions, 0 deletions
diff --git a/hw/misc/empty_slot.c b/hw/misc/empty_slot.c
new file mode 100644
index 0000000000..54be085189
--- /dev/null
+++ b/hw/misc/empty_slot.c
@@ -0,0 +1,107 @@
+/*
+ * QEMU Empty Slot
+ *
+ * The empty_slot device emulates known to a bus but not connected devices.
+ *
+ * Copyright (c) 2010 Artyom Tarasenko
+ *
+ * This code is licensed under the GNU GPL v2 or (at your option) any later
+ * version.
+ */
+
+#include "qemu/osdep.h"
+#include "hw/sysbus.h"
+#include "hw/qdev-properties.h"
+#include "hw/misc/empty_slot.h"
+#include "trace.h"
+
+#define TYPE_EMPTY_SLOT "empty_slot"
+#define EMPTY_SLOT(obj) OBJECT_CHECK(EmptySlot, (obj), TYPE_EMPTY_SLOT)
+
+typedef struct EmptySlot {
+    SysBusDevice parent_obj;
+
+    MemoryRegion iomem;
+    char *name;
+    uint64_t size;
+} EmptySlot;
+
+static uint64_t empty_slot_read(void *opaque, hwaddr addr,
+                                unsigned size)
+{
+    EmptySlot *s = EMPTY_SLOT(opaque);
+
+    trace_empty_slot_write(addr, size << 1, 0, size, s->name);
+
+    return 0;
+}
+
+static void empty_slot_write(void *opaque, hwaddr addr,
+                             uint64_t val, unsigned size)
+{
+    EmptySlot *s = EMPTY_SLOT(opaque);
+
+    trace_empty_slot_write(addr, size << 1, val, size, s->name);
+}
+
+static const MemoryRegionOps empty_slot_ops = {
+    .read = empty_slot_read,
+    .write = empty_slot_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+};
+
+void empty_slot_init(hwaddr addr, uint64_t slot_size)
+{
+    if (slot_size > 0) {
+        /* Only empty slots larger than 0 byte need handling. */
+        DeviceState *dev;
+
+        dev = qdev_create(NULL, TYPE_EMPTY_SLOT);
+
+        qdev_prop_set_uint64(dev, "size", slot_size);
+        qdev_init_nofail(dev);
+
+        sysbus_mmio_map_overlap(SYS_BUS_DEVICE(dev), 0, addr, -10000);
+    }
+}
+
+static void empty_slot_realize(DeviceState *dev, Error **errp)
+{
+    EmptySlot *s = EMPTY_SLOT(dev);
+
+    if (s->name == NULL) {
+        s->name = g_strdup("empty-slot");
+    }
+    memory_region_init_io(&s->iomem, OBJECT(s), &empty_slot_ops, s,
+                          s->name, s->size);
+    sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->iomem);
+}
+
+static Property empty_slot_properties[] = {
+    DEFINE_PROP_UINT64("size", EmptySlot, size, 0),
+    DEFINE_PROP_STRING("name", EmptySlot, name),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void empty_slot_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->realize = empty_slot_realize;
+    device_class_set_props(dc, empty_slot_properties);
+    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
+}
+
+static const TypeInfo empty_slot_info = {
+    .name          = TYPE_EMPTY_SLOT,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(EmptySlot),
+    .class_init    = empty_slot_class_init,
+};
+
+static void empty_slot_register_types(void)
+{
+    type_register_static(&empty_slot_info);
+}
+
+type_init(empty_slot_register_types)