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 typedef struct EmptySlot EmptySlot;
  22 DECLARE_INSTANCE_CHECKER(EmptySlot, EMPTY_SLOT,
  23                          TYPE_EMPTY_SLOT)
  24
  25 struct EmptySlot {
  26     SysBusDevice parent_obj;
  27
  28     MemoryRegion iomem;
  29     char *name;
  30     uint64_t size;
  31 };
  32
  33 static uint64_t empty_slot_read(void *opaque, hwaddr addr,
  34                                 unsigned size)
  35 {
  36     EmptySlot *s = EMPTY_SLOT(opaque);
  37
  38     trace_empty_slot_write(addr, size << 1, 0, size, s->name);
  39
  40     return 0;
  41 }
  42
  43 static void empty_slot_write(void *opaque, hwaddr addr,
  44                              uint64_t val, unsigned size)
  45 {
  46     EmptySlot *s = EMPTY_SLOT(opaque);
  47
  48     trace_empty_slot_write(addr, size << 1, val, size, s->name);
  49 }
  50
  51 static const MemoryRegionOps empty_slot_ops = {
  52     .read = empty_slot_read,
  53     .write = empty_slot_write,
  54     .endianness = DEVICE_NATIVE_ENDIAN,
  55 };
  56
  57 void empty_slot_init(const char *name, hwaddr addr, uint64_t slot_size)
  58 {
  59     if (slot_size > 0) {
  60         /* Only empty slots larger than 0 byte need handling. */
  61         DeviceState *dev;
  62
  63         dev = qdev_new(TYPE_EMPTY_SLOT);
  64
  65         qdev_prop_set_uint64(dev, "size", slot_size);
  66         sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), &error_fatal);
  67
  68         sysbus_mmio_map_overlap(SYS_BUS_DEVICE(dev), 0, addr, -10000);
  69     }
  70 }
  71
  72 static void empty_slot_realize(DeviceState *dev, Error **errp)
  73 {
  74     EmptySlot *s = EMPTY_SLOT(dev);
  75
  76     if (s->name == NULL) {
  77         s->name = g_strdup("empty-slot");
  78     }
  79     memory_region_init_io(&s->iomem, OBJECT(s), &empty_slot_ops, s,
  80                           s->name, s->size);
  81     sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->iomem);
  82 }
  83
  84 static Property empty_slot_properties[] = {
  85     DEFINE_PROP_UINT64("size", EmptySlot, size, 0),
  86     DEFINE_PROP_STRING("name", EmptySlot, name),
  87     DEFINE_PROP_END_OF_LIST(),
  88 };
  89
  90 static void empty_slot_class_init(ObjectClass *klass, void *data)
  91 {
  92     DeviceClass *dc = DEVICE_CLASS(klass);
  93
  94     dc->realize = empty_slot_realize;
  95     device_class_set_props(dc, empty_slot_properties);
  96     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
  97 }
  98
  99 static const TypeInfo empty_slot_info = {
 100     .name          = TYPE_EMPTY_SLOT,
 101     .parent        = TYPE_SYS_BUS_DEVICE,
 102     .instance_size = sizeof(EmptySlot),
 103     .class_init    = empty_slot_class_init,
 104 };
 105
 106 static void empty_slot_register_types(void)
 107 {
 108     type_register_static(&empty_slot_info);
 109 }
 110
 111 type_init(empty_slot_register_types)