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 "trace.h"
  17
  18 #define TYPE_EMPTY_SLOT "empty_slot"
  19 #define EMPTY_SLOT(obj) OBJECT_CHECK(EmptySlot, (obj), TYPE_EMPTY_SLOT)
  20
  21 typedef struct EmptySlot {
  22     SysBusDevice parent_obj;
  23
  24     MemoryRegion iomem;
  25     char *name;
  26     uint64_t size;
  27 } EmptySlot;
  28
  29 static uint64_t empty_slot_read(void *opaque, hwaddr addr,
  30                                 unsigned size)
  31 {
  32     EmptySlot *s = EMPTY_SLOT(opaque);
  33
  34     trace_empty_slot_write(addr, size << 1, 0, size, s->name);
  35
  36     return 0;
  37 }
  38
  39 static void empty_slot_write(void *opaque, hwaddr addr,
  40                              uint64_t val, unsigned size)
  41 {
  42     EmptySlot *s = EMPTY_SLOT(opaque);
  43
  44     trace_empty_slot_write(addr, size << 1, val, size, s->name);
  45 }
  46
  47 static const MemoryRegionOps empty_slot_ops = {
  48     .read = empty_slot_read,
  49     .write = empty_slot_write,
  50     .endianness = DEVICE_NATIVE_ENDIAN,
  51 };
  52
  53 void empty_slot_init(hwaddr addr, uint64_t slot_size)
  54 {
  55     if (slot_size > 0) {
  56         /* Only empty slots larger than 0 byte need handling. */
  57         DeviceState *dev;
  58
  59         dev = qdev_create(NULL, TYPE_EMPTY_SLOT);
  60
  61         qdev_prop_set_uint64(dev, "size", slot_size);
  62         qdev_init_nofail(dev);
  63
  64         sysbus_mmio_map_overlap(SYS_BUS_DEVICE(dev), 0, addr, -10000);
  65     }
  66 }
  67
  68 static void empty_slot_realize(DeviceState *dev, Error **errp)
  69 {
  70     EmptySlot *s = EMPTY_SLOT(dev);
  71
  72     if (s->name == NULL) {
  73         s->name = g_strdup("empty-slot");
  74     }
  75     memory_region_init_io(&s->iomem, OBJECT(s), &empty_slot_ops, s,
  76                           s->name, s->size);
  77     sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->iomem);
  78 }
  79
  80 static Property empty_slot_properties[] = {
  81     DEFINE_PROP_UINT64("size", EmptySlot, size, 0),
  82     DEFINE_PROP_STRING("name", EmptySlot, name),
  83     DEFINE_PROP_END_OF_LIST(),
  84 };
  85
  86 static void empty_slot_class_init(ObjectClass *klass, void *data)
  87 {
  88     DeviceClass *dc = DEVICE_CLASS(klass);
  89
  90     dc->realize = empty_slot_realize;
  91     device_class_set_props(dc, empty_slot_properties);
  92     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
  93 }
  94
  95 static const TypeInfo empty_slot_info = {
  96     .name          = TYPE_EMPTY_SLOT,
  97     .parent        = TYPE_SYS_BUS_DEVICE,
  98     .instance_size = sizeof(EmptySlot),
  99     .class_init    = empty_slot_class_init,
 100 };
 101
 102 static void empty_slot_register_types(void)
 103 {
 104     type_register_static(&empty_slot_info);
 105 }
 106
 107 type_init(empty_slot_register_types)