1 /* 2 * QEMU Macintosh Nubus 3 * 4 * Copyright (c) 2013-2018 Laurent Vivier <laurent@vivier.eu> 5 * 6 * This work is licensed under the terms of the GNU GPL, version 2 or later. 7 * See the COPYING file in the top-level directory. 8 * 9 */ 10 11 /* 12 * References: 13 * Nubus Specification (TI) 14 * http://www.bitsavers.org/pdf/ti/nubus/2242825-0001_NuBus_Spec1983.pdf 15 * 16 * Designing Cards and Drivers for the Macintosh Family (Apple) 17 */ 18 19 #include "qemu/osdep.h" 20 #include "hw/nubus/nubus.h" 21 #include "qapi/error.h" 22 23 24 static NubusBus *nubus_find(void) 25 { 26 /* Returns NULL unless there is exactly one nubus device */ 27 return NUBUS_BUS(object_resolve_path_type("", TYPE_NUBUS_BUS, NULL)); 28 } 29 30 static void nubus_slot_write(void *opaque, hwaddr addr, uint64_t val, 31 unsigned int size) 32 { 33 /* read only */ 34 } 35 36 37 static uint64_t nubus_slot_read(void *opaque, hwaddr addr, 38 unsigned int size) 39 { 40 return 0; 41 } 42 43 static const MemoryRegionOps nubus_slot_ops = { 44 .read = nubus_slot_read, 45 .write = nubus_slot_write, 46 .endianness = DEVICE_BIG_ENDIAN, 47 .valid = { 48 .min_access_size = 1, 49 .max_access_size = 1, 50 }, 51 }; 52 53 static void nubus_super_slot_write(void *opaque, hwaddr addr, uint64_t val, 54 unsigned int size) 55 { 56 /* read only */ 57 } 58 59 static uint64_t nubus_super_slot_read(void *opaque, hwaddr addr, 60 unsigned int size) 61 { 62 return 0; 63 } 64 65 static const MemoryRegionOps nubus_super_slot_ops = { 66 .read = nubus_super_slot_read, 67 .write = nubus_super_slot_write, 68 .endianness = DEVICE_BIG_ENDIAN, 69 .valid = { 70 .min_access_size = 1, 71 .max_access_size = 1, 72 }, 73 }; 74 75 static void nubus_realize(BusState *bus, Error **errp) 76 { 77 if (!nubus_find()) { 78 error_setg(errp, "at most one %s device is permitted", TYPE_NUBUS_BUS); 79 return; 80 } 81 } 82 83 static void nubus_init(Object *obj) 84 { 85 NubusBus *nubus = NUBUS_BUS(obj); 86 87 memory_region_init_io(&nubus->super_slot_io, obj, &nubus_super_slot_ops, 88 nubus, "nubus-super-slots", 89 (NUBUS_SUPER_SLOT_NB + 1) * NUBUS_SUPER_SLOT_SIZE); 90 91 memory_region_init_io(&nubus->slot_io, obj, &nubus_slot_ops, 92 nubus, "nubus-slots", 93 NUBUS_SLOT_NB * NUBUS_SLOT_SIZE); 94 95 nubus->slot_available_mask = MAKE_64BIT_MASK(NUBUS_FIRST_SLOT, 96 NUBUS_SLOT_NB); 97 } 98 99 static bool nubus_check_address(BusState *bus, DeviceState *dev, Error **errp) 100 { 101 NubusDevice *nd = NUBUS_DEVICE(dev); 102 NubusBus *nubus = NUBUS_BUS(bus); 103 104 if (nd->slot == -1) { 105 /* No slot specified, find first available free slot */ 106 int s = ctz32(nubus->slot_available_mask); 107 if (s != 32) { 108 nd->slot = s; 109 } else { 110 error_setg(errp, "Cannot register nubus card, no free slot " 111 "available"); 112 return false; 113 } 114 } else { 115 /* Slot specified, make sure the slot is available */ 116 if (!(nubus->slot_available_mask & BIT(nd->slot))) { 117 error_setg(errp, "Cannot register nubus card, slot %d is " 118 "unavailable or already occupied", nd->slot); 119 return false; 120 } 121 } 122 123 nubus->slot_available_mask &= ~BIT(nd->slot); 124 return true; 125 } 126 127 static void nubus_class_init(ObjectClass *oc, void *data) 128 { 129 BusClass *bc = BUS_CLASS(oc); 130 131 bc->realize = nubus_realize; 132 bc->check_address = nubus_check_address; 133 } 134 135 static const TypeInfo nubus_bus_info = { 136 .name = TYPE_NUBUS_BUS, 137 .parent = TYPE_BUS, 138 .instance_size = sizeof(NubusBus), 139 .instance_init = nubus_init, 140 .class_init = nubus_class_init, 141 }; 142 143 static void nubus_register_types(void) 144 { 145 type_register_static(&nubus_bus_info); 146 } 147 148 type_init(nubus_register_types) 149