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(const char *name, 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) 108