qemu/hw/ppc/spapr_vio.c
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   1/*
   2 * QEMU sPAPR VIO code
   3 *
   4 * Copyright (c) 2010 David Gibson, IBM Corporation <dwg@au1.ibm.com>
   5 * Based on the s390 virtio bus code:
   6 * Copyright (c) 2009 Alexander Graf <agraf@suse.de>
   7 *
   8 * This library is free software; you can redistribute it and/or
   9 * modify it under the terms of the GNU Lesser General Public
  10 * License as published by the Free Software Foundation; either
  11 * version 2 of the License, or (at your option) any later version.
  12 *
  13 * This library is distributed in the hope that it will be useful,
  14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16 * Lesser General Public License for more details.
  17 *
  18 * You should have received a copy of the GNU Lesser General Public
  19 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22#include "qemu/osdep.h"
  23#include "qemu/error-report.h"
  24#include "qapi/error.h"
  25#include "hw/hw.h"
  26#include "qemu/log.h"
  27#include "sysemu/sysemu.h"
  28#include "hw/boards.h"
  29#include "hw/loader.h"
  30#include "elf.h"
  31#include "hw/sysbus.h"
  32#include "sysemu/kvm.h"
  33#include "sysemu/device_tree.h"
  34#include "kvm_ppc.h"
  35
  36#include "hw/ppc/spapr.h"
  37#include "hw/ppc/spapr_vio.h"
  38#include "hw/ppc/xics.h"
  39#include "hw/ppc/fdt.h"
  40#include "trace.h"
  41
  42#include <libfdt.h>
  43
  44static Property spapr_vio_props[] = {
  45    DEFINE_PROP_UINT32("irq", VIOsPAPRDevice, irq, 0), \
  46    DEFINE_PROP_END_OF_LIST(),
  47};
  48
  49static char *spapr_vio_get_dev_name(DeviceState *qdev)
  50{
  51    VIOsPAPRDevice *dev = VIO_SPAPR_DEVICE(qdev);
  52    VIOsPAPRDeviceClass *pc = VIO_SPAPR_DEVICE_GET_CLASS(dev);
  53
  54    /* Device tree style name device@reg */
  55    return g_strdup_printf("%s@%x", pc->dt_name, dev->reg);
  56}
  57
  58static void spapr_vio_bus_class_init(ObjectClass *klass, void *data)
  59{
  60    BusClass *k = BUS_CLASS(klass);
  61
  62    k->get_dev_path = spapr_vio_get_dev_name;
  63    k->get_fw_dev_path = spapr_vio_get_dev_name;
  64}
  65
  66static const TypeInfo spapr_vio_bus_info = {
  67    .name = TYPE_SPAPR_VIO_BUS,
  68    .parent = TYPE_BUS,
  69    .class_init = spapr_vio_bus_class_init,
  70    .instance_size = sizeof(VIOsPAPRBus),
  71};
  72
  73VIOsPAPRDevice *spapr_vio_find_by_reg(VIOsPAPRBus *bus, uint32_t reg)
  74{
  75    BusChild *kid;
  76    VIOsPAPRDevice *dev = NULL;
  77
  78    QTAILQ_FOREACH(kid, &bus->bus.children, sibling) {
  79        dev = (VIOsPAPRDevice *)kid->child;
  80        if (dev->reg == reg) {
  81            return dev;
  82        }
  83    }
  84
  85    return NULL;
  86}
  87
  88static int vio_make_devnode(VIOsPAPRDevice *dev,
  89                            void *fdt)
  90{
  91    VIOsPAPRDeviceClass *pc = VIO_SPAPR_DEVICE_GET_CLASS(dev);
  92    int vdevice_off, node_off, ret;
  93    char *dt_name;
  94
  95    vdevice_off = fdt_path_offset(fdt, "/vdevice");
  96    if (vdevice_off < 0) {
  97        return vdevice_off;
  98    }
  99
 100    dt_name = spapr_vio_get_dev_name(DEVICE(dev));
 101    node_off = fdt_add_subnode(fdt, vdevice_off, dt_name);
 102    g_free(dt_name);
 103    if (node_off < 0) {
 104        return node_off;
 105    }
 106
 107    ret = fdt_setprop_cell(fdt, node_off, "reg", dev->reg);
 108    if (ret < 0) {
 109        return ret;
 110    }
 111
 112    if (pc->dt_type) {
 113        ret = fdt_setprop_string(fdt, node_off, "device_type",
 114                                 pc->dt_type);
 115        if (ret < 0) {
 116            return ret;
 117        }
 118    }
 119
 120    if (pc->dt_compatible) {
 121        ret = fdt_setprop_string(fdt, node_off, "compatible",
 122                                 pc->dt_compatible);
 123        if (ret < 0) {
 124            return ret;
 125        }
 126    }
 127
 128    if (dev->irq) {
 129        uint32_t ints_prop[] = {cpu_to_be32(dev->irq), 0};
 130
 131        ret = fdt_setprop(fdt, node_off, "interrupts", ints_prop,
 132                          sizeof(ints_prop));
 133        if (ret < 0) {
 134            return ret;
 135        }
 136    }
 137
 138    ret = spapr_tcet_dma_dt(fdt, node_off, "ibm,my-dma-window", dev->tcet);
 139    if (ret < 0) {
 140        return ret;
 141    }
 142
 143    if (pc->devnode) {
 144        ret = (pc->devnode)(dev, fdt, node_off);
 145        if (ret < 0) {
 146            return ret;
 147        }
 148    }
 149
 150    return node_off;
 151}
 152
 153/*
 154 * CRQ handling
 155 */
 156static target_ulong h_reg_crq(PowerPCCPU *cpu, sPAPRMachineState *spapr,
 157                              target_ulong opcode, target_ulong *args)
 158{
 159    target_ulong reg = args[0];
 160    target_ulong queue_addr = args[1];
 161    target_ulong queue_len = args[2];
 162    VIOsPAPRDevice *dev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
 163
 164    if (!dev) {
 165        hcall_dprintf("Unit 0x" TARGET_FMT_lx " does not exist\n", reg);
 166        return H_PARAMETER;
 167    }
 168
 169    /* We can't grok a queue size bigger than 256M for now */
 170    if (queue_len < 0x1000 || queue_len > 0x10000000) {
 171        hcall_dprintf("Queue size too small or too big (0x" TARGET_FMT_lx
 172                      ")\n", queue_len);
 173        return H_PARAMETER;
 174    }
 175
 176    /* Check queue alignment */
 177    if (queue_addr & 0xfff) {
 178        hcall_dprintf("Queue not aligned (0x" TARGET_FMT_lx ")\n", queue_addr);
 179        return H_PARAMETER;
 180    }
 181
 182    /* Check if device supports CRQs */
 183    if (!dev->crq.SendFunc) {
 184        hcall_dprintf("Device does not support CRQ\n");
 185        return H_NOT_FOUND;
 186    }
 187
 188    /* Already a queue ? */
 189    if (dev->crq.qsize) {
 190        hcall_dprintf("CRQ already registered\n");
 191        return H_RESOURCE;
 192    }
 193    dev->crq.qladdr = queue_addr;
 194    dev->crq.qsize = queue_len;
 195    dev->crq.qnext = 0;
 196
 197    trace_spapr_vio_h_reg_crq(reg, queue_addr, queue_len);
 198    return H_SUCCESS;
 199}
 200
 201static target_ulong free_crq(VIOsPAPRDevice *dev)
 202{
 203    dev->crq.qladdr = 0;
 204    dev->crq.qsize = 0;
 205    dev->crq.qnext = 0;
 206
 207    trace_spapr_vio_free_crq(dev->reg);
 208
 209    return H_SUCCESS;
 210}
 211
 212static target_ulong h_free_crq(PowerPCCPU *cpu, sPAPRMachineState *spapr,
 213                               target_ulong opcode, target_ulong *args)
 214{
 215    target_ulong reg = args[0];
 216    VIOsPAPRDevice *dev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
 217
 218    if (!dev) {
 219        hcall_dprintf("Unit 0x" TARGET_FMT_lx " does not exist\n", reg);
 220        return H_PARAMETER;
 221    }
 222
 223    return free_crq(dev);
 224}
 225
 226static target_ulong h_send_crq(PowerPCCPU *cpu, sPAPRMachineState *spapr,
 227                               target_ulong opcode, target_ulong *args)
 228{
 229    target_ulong reg = args[0];
 230    target_ulong msg_hi = args[1];
 231    target_ulong msg_lo = args[2];
 232    VIOsPAPRDevice *dev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
 233    uint64_t crq_mangle[2];
 234
 235    if (!dev) {
 236        hcall_dprintf("Unit 0x" TARGET_FMT_lx " does not exist\n", reg);
 237        return H_PARAMETER;
 238    }
 239    crq_mangle[0] = cpu_to_be64(msg_hi);
 240    crq_mangle[1] = cpu_to_be64(msg_lo);
 241
 242    if (dev->crq.SendFunc) {
 243        return dev->crq.SendFunc(dev, (uint8_t *)crq_mangle);
 244    }
 245
 246    return H_HARDWARE;
 247}
 248
 249static target_ulong h_enable_crq(PowerPCCPU *cpu, sPAPRMachineState *spapr,
 250                                 target_ulong opcode, target_ulong *args)
 251{
 252    target_ulong reg = args[0];
 253    VIOsPAPRDevice *dev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
 254
 255    if (!dev) {
 256        hcall_dprintf("Unit 0x" TARGET_FMT_lx " does not exist\n", reg);
 257        return H_PARAMETER;
 258    }
 259
 260    return 0;
 261}
 262
 263/* Returns negative error, 0 success, or positive: queue full */
 264int spapr_vio_send_crq(VIOsPAPRDevice *dev, uint8_t *crq)
 265{
 266    int rc;
 267    uint8_t byte;
 268
 269    if (!dev->crq.qsize) {
 270        error_report("spapr_vio_send_creq on uninitialized queue");
 271        return -1;
 272    }
 273
 274    /* Maybe do a fast path for KVM just writing to the pages */
 275    rc = spapr_vio_dma_read(dev, dev->crq.qladdr + dev->crq.qnext, &byte, 1);
 276    if (rc) {
 277        return rc;
 278    }
 279    if (byte != 0) {
 280        return 1;
 281    }
 282
 283    rc = spapr_vio_dma_write(dev, dev->crq.qladdr + dev->crq.qnext + 8,
 284                             &crq[8], 8);
 285    if (rc) {
 286        return rc;
 287    }
 288
 289    kvmppc_eieio();
 290
 291    rc = spapr_vio_dma_write(dev, dev->crq.qladdr + dev->crq.qnext, crq, 8);
 292    if (rc) {
 293        return rc;
 294    }
 295
 296    dev->crq.qnext = (dev->crq.qnext + 16) % dev->crq.qsize;
 297
 298    if (dev->signal_state & 1) {
 299        qemu_irq_pulse(spapr_vio_qirq(dev));
 300    }
 301
 302    return 0;
 303}
 304
 305/* "quiesce" handling */
 306
 307static void spapr_vio_quiesce_one(VIOsPAPRDevice *dev)
 308{
 309    if (dev->tcet) {
 310        device_reset(DEVICE(dev->tcet));
 311    }
 312    free_crq(dev);
 313}
 314
 315void spapr_vio_set_bypass(VIOsPAPRDevice *dev, bool bypass)
 316{
 317    if (!dev->tcet) {
 318        return;
 319    }
 320
 321    memory_region_set_enabled(&dev->mrbypass, bypass);
 322    memory_region_set_enabled(spapr_tce_get_iommu(dev->tcet), !bypass);
 323
 324    dev->tcet->bypass = bypass;
 325}
 326
 327static void rtas_set_tce_bypass(PowerPCCPU *cpu, sPAPRMachineState *spapr,
 328                                uint32_t token,
 329                                uint32_t nargs, target_ulong args,
 330                                uint32_t nret, target_ulong rets)
 331{
 332    VIOsPAPRBus *bus = spapr->vio_bus;
 333    VIOsPAPRDevice *dev;
 334    uint32_t unit, enable;
 335
 336    if (nargs != 2) {
 337        rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
 338        return;
 339    }
 340    unit = rtas_ld(args, 0);
 341    enable = rtas_ld(args, 1);
 342    dev = spapr_vio_find_by_reg(bus, unit);
 343    if (!dev) {
 344        rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
 345        return;
 346    }
 347
 348    if (!dev->tcet) {
 349        rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
 350        return;
 351    }
 352
 353    spapr_vio_set_bypass(dev, !!enable);
 354
 355    rtas_st(rets, 0, RTAS_OUT_SUCCESS);
 356}
 357
 358static void rtas_quiesce(PowerPCCPU *cpu, sPAPRMachineState *spapr,
 359                         uint32_t token,
 360                         uint32_t nargs, target_ulong args,
 361                         uint32_t nret, target_ulong rets)
 362{
 363    VIOsPAPRBus *bus = spapr->vio_bus;
 364    BusChild *kid;
 365    VIOsPAPRDevice *dev = NULL;
 366
 367    if (nargs != 0) {
 368        rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
 369        return;
 370    }
 371
 372    QTAILQ_FOREACH(kid, &bus->bus.children, sibling) {
 373        dev = (VIOsPAPRDevice *)kid->child;
 374        spapr_vio_quiesce_one(dev);
 375    }
 376
 377    rtas_st(rets, 0, RTAS_OUT_SUCCESS);
 378}
 379
 380static VIOsPAPRDevice *reg_conflict(VIOsPAPRDevice *dev)
 381{
 382    VIOsPAPRBus *bus = SPAPR_VIO_BUS(dev->qdev.parent_bus);
 383    BusChild *kid;
 384    VIOsPAPRDevice *other;
 385
 386    /*
 387     * Check for a device other than the given one which is already
 388     * using the requested address. We have to open code this because
 389     * the given dev might already be in the list.
 390     */
 391    QTAILQ_FOREACH(kid, &bus->bus.children, sibling) {
 392        other = VIO_SPAPR_DEVICE(kid->child);
 393
 394        if (other != dev && other->reg == dev->reg) {
 395            return other;
 396        }
 397    }
 398
 399    return 0;
 400}
 401
 402static void spapr_vio_busdev_reset(DeviceState *qdev)
 403{
 404    VIOsPAPRDevice *dev = VIO_SPAPR_DEVICE(qdev);
 405    VIOsPAPRDeviceClass *pc = VIO_SPAPR_DEVICE_GET_CLASS(dev);
 406
 407    /* Shut down the request queue and TCEs if necessary */
 408    spapr_vio_quiesce_one(dev);
 409
 410    dev->signal_state = 0;
 411
 412    spapr_vio_set_bypass(dev, false);
 413    if (pc->reset) {
 414        pc->reset(dev);
 415    }
 416}
 417
 418static void spapr_vio_busdev_realize(DeviceState *qdev, Error **errp)
 419{
 420    sPAPRMachineState *spapr = SPAPR_MACHINE(qdev_get_machine());
 421    VIOsPAPRDevice *dev = (VIOsPAPRDevice *)qdev;
 422    VIOsPAPRDeviceClass *pc = VIO_SPAPR_DEVICE_GET_CLASS(dev);
 423    char *id;
 424    Error *local_err = NULL;
 425
 426    if (dev->reg != -1) {
 427        /*
 428         * Explicitly assigned address, just verify that no-one else
 429         * is using it.  other mechanism). We have to open code this
 430         * rather than using spapr_vio_find_by_reg() because sdev
 431         * itself is already in the list.
 432         */
 433        VIOsPAPRDevice *other = reg_conflict(dev);
 434
 435        if (other) {
 436            error_setg(errp, "%s and %s devices conflict at address %#x",
 437                       object_get_typename(OBJECT(qdev)),
 438                       object_get_typename(OBJECT(&other->qdev)),
 439                       dev->reg);
 440            return;
 441        }
 442    } else {
 443        /* Need to assign an address */
 444        VIOsPAPRBus *bus = SPAPR_VIO_BUS(dev->qdev.parent_bus);
 445
 446        do {
 447            dev->reg = bus->next_reg++;
 448        } while (reg_conflict(dev));
 449    }
 450
 451    /* Don't overwrite ids assigned on the command line */
 452    if (!dev->qdev.id) {
 453        id = spapr_vio_get_dev_name(DEVICE(dev));
 454        dev->qdev.id = id;
 455    }
 456
 457    dev->irq = spapr_ics_alloc(spapr->ics, dev->irq, false, &local_err);
 458    if (local_err) {
 459        error_propagate(errp, local_err);
 460        return;
 461    }
 462
 463    if (pc->rtce_window_size) {
 464        uint32_t liobn = SPAPR_VIO_LIOBN(dev->reg);
 465
 466        memory_region_init(&dev->mrroot, OBJECT(dev), "iommu-spapr-root",
 467                           ram_size);
 468        memory_region_init_alias(&dev->mrbypass, OBJECT(dev),
 469                                 "iommu-spapr-bypass", get_system_memory(),
 470                                 0, ram_size);
 471        memory_region_add_subregion_overlap(&dev->mrroot, 0, &dev->mrbypass, 1);
 472        address_space_init(&dev->as, &dev->mrroot, qdev->id);
 473
 474        dev->tcet = spapr_tce_new_table(qdev, liobn);
 475        spapr_tce_table_enable(dev->tcet, SPAPR_TCE_PAGE_SHIFT, 0,
 476                               pc->rtce_window_size >> SPAPR_TCE_PAGE_SHIFT);
 477        dev->tcet->vdev = dev;
 478        memory_region_add_subregion_overlap(&dev->mrroot, 0,
 479                                            spapr_tce_get_iommu(dev->tcet), 2);
 480    }
 481
 482    pc->realize(dev, errp);
 483}
 484
 485static target_ulong h_vio_signal(PowerPCCPU *cpu, sPAPRMachineState *spapr,
 486                                 target_ulong opcode,
 487                                 target_ulong *args)
 488{
 489    target_ulong reg = args[0];
 490    target_ulong mode = args[1];
 491    VIOsPAPRDevice *dev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
 492    VIOsPAPRDeviceClass *pc;
 493
 494    if (!dev) {
 495        return H_PARAMETER;
 496    }
 497
 498    pc = VIO_SPAPR_DEVICE_GET_CLASS(dev);
 499
 500    if (mode & ~pc->signal_mask) {
 501        return H_PARAMETER;
 502    }
 503
 504    dev->signal_state = mode;
 505
 506    return H_SUCCESS;
 507}
 508
 509VIOsPAPRBus *spapr_vio_bus_init(void)
 510{
 511    VIOsPAPRBus *bus;
 512    BusState *qbus;
 513    DeviceState *dev;
 514
 515    /* Create bridge device */
 516    dev = qdev_create(NULL, TYPE_SPAPR_VIO_BRIDGE);
 517    qdev_init_nofail(dev);
 518
 519    /* Create bus on bridge device */
 520    qbus = qbus_create(TYPE_SPAPR_VIO_BUS, dev, "spapr-vio");
 521    bus = SPAPR_VIO_BUS(qbus);
 522    bus->next_reg = 0x71000000;
 523
 524    /* hcall-vio */
 525    spapr_register_hypercall(H_VIO_SIGNAL, h_vio_signal);
 526
 527    /* hcall-crq */
 528    spapr_register_hypercall(H_REG_CRQ, h_reg_crq);
 529    spapr_register_hypercall(H_FREE_CRQ, h_free_crq);
 530    spapr_register_hypercall(H_SEND_CRQ, h_send_crq);
 531    spapr_register_hypercall(H_ENABLE_CRQ, h_enable_crq);
 532
 533    /* RTAS calls */
 534    spapr_rtas_register(RTAS_IBM_SET_TCE_BYPASS, "ibm,set-tce-bypass",
 535                        rtas_set_tce_bypass);
 536    spapr_rtas_register(RTAS_QUIESCE, "quiesce", rtas_quiesce);
 537
 538    return bus;
 539}
 540
 541static void spapr_vio_bridge_class_init(ObjectClass *klass, void *data)
 542{
 543    DeviceClass *dc = DEVICE_CLASS(klass);
 544
 545    dc->fw_name = "vdevice";
 546}
 547
 548static const TypeInfo spapr_vio_bridge_info = {
 549    .name          = TYPE_SPAPR_VIO_BRIDGE,
 550    .parent        = TYPE_SYS_BUS_DEVICE,
 551    .class_init    = spapr_vio_bridge_class_init,
 552};
 553
 554const VMStateDescription vmstate_spapr_vio = {
 555    .name = "spapr_vio",
 556    .version_id = 1,
 557    .minimum_version_id = 1,
 558    .fields = (VMStateField[]) {
 559        /* Sanity check */
 560        VMSTATE_UINT32_EQUAL(reg, VIOsPAPRDevice, NULL),
 561        VMSTATE_UINT32_EQUAL(irq, VIOsPAPRDevice, NULL),
 562
 563        /* General VIO device state */
 564        VMSTATE_UINT64(signal_state, VIOsPAPRDevice),
 565        VMSTATE_UINT64(crq.qladdr, VIOsPAPRDevice),
 566        VMSTATE_UINT32(crq.qsize, VIOsPAPRDevice),
 567        VMSTATE_UINT32(crq.qnext, VIOsPAPRDevice),
 568
 569        VMSTATE_END_OF_LIST()
 570    },
 571};
 572
 573static void vio_spapr_device_class_init(ObjectClass *klass, void *data)
 574{
 575    DeviceClass *k = DEVICE_CLASS(klass);
 576    k->realize = spapr_vio_busdev_realize;
 577    k->reset = spapr_vio_busdev_reset;
 578    k->bus_type = TYPE_SPAPR_VIO_BUS;
 579    k->props = spapr_vio_props;
 580}
 581
 582static const TypeInfo spapr_vio_type_info = {
 583    .name = TYPE_VIO_SPAPR_DEVICE,
 584    .parent = TYPE_DEVICE,
 585    .instance_size = sizeof(VIOsPAPRDevice),
 586    .abstract = true,
 587    .class_size = sizeof(VIOsPAPRDeviceClass),
 588    .class_init = vio_spapr_device_class_init,
 589};
 590
 591static void spapr_vio_register_types(void)
 592{
 593    type_register_static(&spapr_vio_bus_info);
 594    type_register_static(&spapr_vio_bridge_info);
 595    type_register_static(&spapr_vio_type_info);
 596}
 597
 598type_init(spapr_vio_register_types)
 599
 600static int compare_reg(const void *p1, const void *p2)
 601{
 602    VIOsPAPRDevice const *dev1, *dev2;
 603
 604    dev1 = (VIOsPAPRDevice *)*(DeviceState **)p1;
 605    dev2 = (VIOsPAPRDevice *)*(DeviceState **)p2;
 606
 607    if (dev1->reg < dev2->reg) {
 608        return -1;
 609    }
 610    if (dev1->reg == dev2->reg) {
 611        return 0;
 612    }
 613
 614    /* dev1->reg > dev2->reg */
 615    return 1;
 616}
 617
 618void spapr_dt_vdevice(VIOsPAPRBus *bus, void *fdt)
 619{
 620    DeviceState *qdev, **qdevs;
 621    BusChild *kid;
 622    int i, num, ret = 0;
 623    int node;
 624
 625    _FDT(node = fdt_add_subnode(fdt, 0, "vdevice"));
 626
 627    _FDT(fdt_setprop_string(fdt, node, "device_type", "vdevice"));
 628    _FDT(fdt_setprop_string(fdt, node, "compatible", "IBM,vdevice"));
 629    _FDT(fdt_setprop_cell(fdt, node, "#address-cells", 1));
 630    _FDT(fdt_setprop_cell(fdt, node, "#size-cells", 0));
 631    _FDT(fdt_setprop_cell(fdt, node, "#interrupt-cells", 2));
 632    _FDT(fdt_setprop(fdt, node, "interrupt-controller", NULL, 0));
 633
 634    /* Count qdevs on the bus list */
 635    num = 0;
 636    QTAILQ_FOREACH(kid, &bus->bus.children, sibling) {
 637        num++;
 638    }
 639
 640    /* Copy out into an array of pointers */
 641    qdevs = g_malloc(sizeof(qdev) * num);
 642    num = 0;
 643    QTAILQ_FOREACH(kid, &bus->bus.children, sibling) {
 644        qdevs[num++] = kid->child;
 645    }
 646
 647    /* Sort the array */
 648    qsort(qdevs, num, sizeof(qdev), compare_reg);
 649
 650    /* Hack alert. Give the devices to libfdt in reverse order, we happen
 651     * to know that will mean they are in forward order in the tree. */
 652    for (i = num - 1; i >= 0; i--) {
 653        VIOsPAPRDevice *dev = (VIOsPAPRDevice *)(qdevs[i]);
 654        VIOsPAPRDeviceClass *vdc = VIO_SPAPR_DEVICE_GET_CLASS(dev);
 655
 656        ret = vio_make_devnode(dev, fdt);
 657        if (ret < 0) {
 658            error_report("Couldn't create device node /vdevice/%s@%"PRIx32,
 659                         vdc->dt_name, dev->reg);
 660            exit(1);
 661        }
 662    }
 663
 664    g_free(qdevs);
 665}
 666
 667gchar *spapr_vio_stdout_path(VIOsPAPRBus *bus)
 668{
 669    VIOsPAPRDevice *dev;
 670    char *name, *path;
 671
 672    dev = spapr_vty_get_default(bus);
 673    if (!dev) {
 674        return NULL;
 675    }
 676
 677    name = spapr_vio_get_dev_name(DEVICE(dev));
 678    path = g_strdup_printf("/vdevice/%s", name);
 679
 680    g_free(name);
 681    return path;
 682}
 683