qemu

nubus-bus.c (5495B)

---

 /*
  * QEMU Macintosh Nubus
  *
  * Copyright (c) 2013-2018 Laurent Vivier <laurent@vivier.eu>
  *
  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  * See the COPYING file in the top-level directory.
  *
  */
 
 /*
  * References:
  *   Nubus Specification (TI)
  *     http://www.bitsavers.org/pdf/ti/nubus/2242825-0001_NuBus_Spec1983.pdf
  *
  *   Designing Cards and Drivers for the Macintosh Family (Apple)
  */
 
 #include "qemu/osdep.h"
 #include "hw/nubus/nubus.h"
 #include "qapi/error.h"
 #include "trace.h"
 
 
 static NubusBus *nubus_find(void)
 {
     /* Returns NULL unless there is exactly one nubus device */
     return NUBUS_BUS(object_resolve_path_type("", TYPE_NUBUS_BUS, NULL));
 }
 
 static MemTxResult nubus_slot_write(void *opaque, hwaddr addr, uint64_t val,
                                     unsigned size, MemTxAttrs attrs)
 {
     trace_nubus_slot_write(addr, val, size);
     return MEMTX_DECODE_ERROR;
 }
 
 static MemTxResult nubus_slot_read(void *opaque, hwaddr addr, uint64_t *data,
                                    unsigned size, MemTxAttrs attrs)
 {
     trace_nubus_slot_read(addr, size);
     return MEMTX_DECODE_ERROR;
 }
 
 static const MemoryRegionOps nubus_slot_ops = {
     .read_with_attrs  = nubus_slot_read,
     .write_with_attrs = nubus_slot_write,
     .endianness = DEVICE_BIG_ENDIAN,
     .valid = {
         .min_access_size = 1,
         .max_access_size = 4,
     },
 };
 
 static MemTxResult nubus_super_slot_write(void *opaque, hwaddr addr,
                                           uint64_t val, unsigned size,
                                           MemTxAttrs attrs)
 {
     trace_nubus_super_slot_write(addr, val, size);
     return MEMTX_DECODE_ERROR;
 }
 
 static MemTxResult nubus_super_slot_read(void *opaque, hwaddr addr,
                                          uint64_t *data, unsigned size,
                                          MemTxAttrs attrs)
 {
     trace_nubus_super_slot_read(addr, size);
     return MEMTX_DECODE_ERROR;
 }
 
 static const MemoryRegionOps nubus_super_slot_ops = {
     .read_with_attrs = nubus_super_slot_read,
     .write_with_attrs = nubus_super_slot_write,
     .endianness = DEVICE_BIG_ENDIAN,
     .valid = {
         .min_access_size = 1,
         .max_access_size = 4,
     },
 };
 
 static void nubus_unrealize(BusState *bus)
 {
     NubusBus *nubus = NUBUS_BUS(bus);
 
     address_space_destroy(&nubus->nubus_as);
 }
 
 static void nubus_realize(BusState *bus, Error **errp)
 {
     NubusBus *nubus = NUBUS_BUS(bus);
 
     if (!nubus_find()) {
         error_setg(errp, "at most one %s device is permitted", TYPE_NUBUS_BUS);
         return;
     }
 
     address_space_init(&nubus->nubus_as, &nubus->nubus_mr, "nubus");
 }
 
 static void nubus_init(Object *obj)
 {
     NubusBus *nubus = NUBUS_BUS(obj);
 
     memory_region_init(&nubus->nubus_mr, obj, "nubus", 0x100000000);
 
     memory_region_init_io(&nubus->super_slot_io, obj, &nubus_super_slot_ops,
                           nubus, "nubus-super-slots",
                           (NUBUS_SUPER_SLOT_NB + 1) * NUBUS_SUPER_SLOT_SIZE);
     memory_region_add_subregion(&nubus->nubus_mr, 0x0, &nubus->super_slot_io);
 
     memory_region_init_io(&nubus->slot_io, obj, &nubus_slot_ops,
                           nubus, "nubus-slots",
                           NUBUS_SLOT_NB * NUBUS_SLOT_SIZE);
     memory_region_add_subregion(&nubus->nubus_mr,
                                 (NUBUS_SUPER_SLOT_NB + 1) *
                                 NUBUS_SUPER_SLOT_SIZE, &nubus->slot_io);
 
     nubus->slot_available_mask = MAKE_64BIT_MASK(NUBUS_FIRST_SLOT,
                                                  NUBUS_SLOT_NB);
 }
 
 static char *nubus_get_dev_path(DeviceState *dev)
 {
     NubusDevice *nd = NUBUS_DEVICE(dev);
     BusState *bus = qdev_get_parent_bus(dev);
     char *p = qdev_get_dev_path(bus->parent);
 
     if (p) {
         char *ret = g_strdup_printf("%s/%s/%02x", p, bus->name, nd->slot);
         g_free(p);
         return ret;
     } else {
         return g_strdup_printf("%s/%02x", bus->name, nd->slot);
     }
 }
 
 static bool nubus_check_address(BusState *bus, DeviceState *dev, Error **errp)
 {
     NubusDevice *nd = NUBUS_DEVICE(dev);
     NubusBus *nubus = NUBUS_BUS(bus);
 
     if (nd->slot == -1) {
         /* No slot specified, find first available free slot */
         int s = ctz32(nubus->slot_available_mask);
         if (s != 32) {
             nd->slot = s;
         } else {
             error_setg(errp, "Cannot register nubus card, no free slot "
                              "available");
             return false;
         }
     } else {
         /* Slot specified, make sure the slot is available */
         if (!(nubus->slot_available_mask & BIT(nd->slot))) {
             error_setg(errp, "Cannot register nubus card, slot %d is "
                              "unavailable or already occupied", nd->slot);
             return false;
         }
     }
 
     nubus->slot_available_mask &= ~BIT(nd->slot);
     return true;
 }
 
 static void nubus_class_init(ObjectClass *oc, void *data)
 {
     BusClass *bc = BUS_CLASS(oc);
 
     bc->realize = nubus_realize;
     bc->unrealize = nubus_unrealize;
     bc->check_address = nubus_check_address;
     bc->get_dev_path = nubus_get_dev_path;
 }
 
 static const TypeInfo nubus_bus_info = {
     .name = TYPE_NUBUS_BUS,
     .parent = TYPE_BUS,
     .instance_size = sizeof(NubusBus),
     .instance_init = nubus_init,
     .class_init = nubus_class_init,
 };
 
 static void nubus_register_types(void)
 {
     type_register_static(&nubus_bus_info);
 }
 
 type_init(nubus_register_types)