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