hw/misc/empty_slot.c

   1 /*
   2  * QEMU Empty Slot
   3  *
   4  * The empty_slot device emulates known to a bus but not connected devices.
   5  *
   6  * Copyright (c) 2010 Artyom Tarasenko
   7  *
   8  * This code is licensed under the GNU GPL v2 or (at your option) any later
   9  * version.
  10  */
  11
  12 #include "qemu/osdep.h"
  13 #include "hw/sysbus.h"
  14 #include "hw/qdev-properties.h"
  15 #include "hw/misc/empty_slot.h"
  16 #include "qapi/error.h"
  17 #include "trace.h"
  18 #include "qom/object.h"
  19
  20 #define TYPE_EMPTY_SLOT "empty_slot"
  21 OBJECT_DECLARE_SIMPLE_TYPE(EmptySlot, EMPTY_SLOT)
  22
  23 struct EmptySlot {
  24     SysBusDevice parent_obj;
  25
  26     MemoryRegion iomem;
  27     char *name;
  28     uint64_t size;
  29 };
  30
  31 static uint64_t empty_slot_read(void *opaque, hwaddr addr,
  32                                 unsigned size)
  33 {
  34     EmptySlot *s = EMPTY_SLOT(opaque);
  35
  36     trace_empty_slot_write(addr, size << 1, 0, size, s->name);
  37
  38     return 0;
  39 }
  40
  41 static void empty_slot_write(void *opaque, hwaddr addr,
  42                              uint64_t val, unsigned size)
  43 {
  44     EmptySlot *s = EMPTY_SLOT(opaque);
  45
  46     trace_empty_slot_write(addr, size << 1, val, size, s->name);
  47 }
  48
  49 static const MemoryRegionOps empty_slot_ops = {
  50     .read = empty_slot_read,
  51     .write = empty_slot_write,
  52     .endianness = DEVICE_NATIVE_ENDIAN,
  53 };
  54
  55 void empty_slot_init(const char *name, hwaddr addr, uint64_t slot_size)
  56 {
  57     if (slot_size > 0) {
  58         /* Only empty slots larger than 0 byte need handling. */
  59         DeviceState *dev;
  60
  61         dev = qdev_new(TYPE_EMPTY_SLOT);
  62
  63         qdev_prop_set_uint64(dev, "size", slot_size);
  64         sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), &error_fatal);
  65
  66         sysbus_mmio_map_overlap(SYS_BUS_DEVICE(dev), 0, addr, -10000);
  67     }
  68 }
  69
  70 static void empty_slot_realize(DeviceState *dev, Error **errp)
  71 {
  72     EmptySlot *s = EMPTY_SLOT(dev);
  73
  74     if (s->name == NULL) {
  75         s->name = g_strdup("empty-slot");
  76     }
  77     memory_region_init_io(&s->iomem, OBJECT(s), &empty_slot_ops, s,
  78                           s->name, s->size);
  79     sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->iomem);
  80 }
  81
  82 static Property empty_slot_properties[] = {
  83     DEFINE_PROP_UINT64("size", EmptySlot, size, 0),
  84     DEFINE_PROP_STRING("name", EmptySlot, name),
  85     DEFINE_PROP_END_OF_LIST(),
  86 };
  87
  88 static void empty_slot_class_init(ObjectClass *klass, void *data)
  89 {
  90     DeviceClass *dc = DEVICE_CLASS(klass);
  91
  92     dc->realize = empty_slot_realize;
  93     device_class_set_props(dc, empty_slot_properties);
  94     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
  95 }
  96
  97 static const TypeInfo empty_slot_info = {
  98     .name          = TYPE_EMPTY_SLOT,
  99     .parent        = TYPE_SYS_BUS_DEVICE,
 100     .instance_size = sizeof(EmptySlot),
 101     .class_init    = empty_slot_class_init,
 102 };
 103
 104 static void empty_slot_register_types(void)
 105 {
 106     type_register_static(&empty_slot_info);
 107 }
 108
 109 type_init(empty_slot_register_types)