arch/ppc64/kernel/vio.c

   1 /*
   2  * IBM PowerPC Virtual I/O Infrastructure Support.
   3  *
   4  *    Copyright (c) 2003 IBM Corp.
   5  *     Dave Engebretsen engebret@us.ibm.com
   6  *     Santiago Leon santil@us.ibm.com
   7  *     Hollis Blanchard <hollisb@us.ibm.com>
   8  *
   9  *      This program is free software; you can redistribute it and/or
  10  *      modify it under the terms of the GNU General Public License
  11  *      as published by the Free Software Foundation; either version
  12  *      2 of the License, or (at your option) any later version.
  13  */
  14
  15 #include <linux/init.h>
  16 #include <linux/console.h>
  17 #include <linux/version.h>
  18 #include <linux/module.h>
  19 #include <linux/kobject.h>
  20 #include <linux/mm.h>
  21 #include <linux/dma-mapping.h>
  22 #include <asm/rtas.h>
  23 #include <asm/iommu.h>
  24 #include <asm/dma.h>
  25 #include <asm/ppcdebug.h>
  26 #include <asm/vio.h>
  27 #include <asm/hvcall.h>
  28 #include <asm/iSeries/vio.h>
  29 #include <asm/iSeries/HvTypes.h>
  30 #include <asm/iSeries/HvCallXm.h>
  31 #include <asm/iSeries/HvLpConfig.h>
  32
  33 #define DBGENTER() pr_debug("%s entered\n", __FUNCTION__)
  34
  35 extern struct subsystem devices_subsys; /* needed for vio_find_name() */
  36
  37 static const struct vio_device_id *vio_match_device(
  38                 const struct vio_device_id *, const struct vio_dev *);
  39
  40 #ifdef CONFIG_PPC_PSERIES
  41 static struct iommu_table *vio_build_iommu_table(struct vio_dev *);
  42 static int vio_num_address_cells;
  43 #endif
  44 static struct vio_dev *vio_bus_device; /* fake "parent" device */
  45
  46 #ifdef CONFIG_PPC_ISERIES
  47 static struct vio_dev *__init vio_register_device_iseries(char *type,
  48                 uint32_t unit_num);
  49
  50 static struct iommu_table veth_iommu_table;
  51 static struct iommu_table vio_iommu_table;
  52
  53 static struct vio_dev _vio_dev  = {
  54         .iommu_table = &vio_iommu_table,
  55         .dev.bus = &vio_bus_type
  56 };
  57 struct device *iSeries_vio_dev = &_vio_dev.dev;
  58 EXPORT_SYMBOL(iSeries_vio_dev);
  59
  60 #define device_is_compatible(a, b)      1
  61
  62 #endif
  63
  64 /* convert from struct device to struct vio_dev and pass to driver.
  65  * dev->driver has already been set by generic code because vio_bus_match
  66  * succeeded. */
  67 static int vio_bus_probe(struct device *dev)
  68 {
  69         struct vio_dev *viodev = to_vio_dev(dev);
  70         struct vio_driver *viodrv = to_vio_driver(dev->driver);
  71         const struct vio_device_id *id;
  72         int error = -ENODEV;
  73
  74         DBGENTER();
  75
  76         if (!viodrv->probe)
  77                 return error;
  78
  79         id = vio_match_device(viodrv->id_table, viodev);
  80         if (id) {
  81                 error = viodrv->probe(viodev, id);
  82         }
  83
  84         return error;
  85 }
  86
  87 /* convert from struct device to struct vio_dev and pass to driver. */
  88 static int vio_bus_remove(struct device *dev)
  89 {
  90         struct vio_dev *viodev = to_vio_dev(dev);
  91         struct vio_driver *viodrv = to_vio_driver(dev->driver);
  92
  93         DBGENTER();
  94
  95         if (viodrv->remove) {
  96                 return viodrv->remove(viodev);
  97         }
  98
  99         /* driver can't remove */
 100         return 1;
 101 }
 102
 103 /**
 104  * vio_register_driver: - Register a new vio driver
 105  * @drv:        The vio_driver structure to be registered.
 106  */
 107 int vio_register_driver(struct vio_driver *viodrv)
 108 {
 109         printk(KERN_DEBUG "%s: driver %s registering\n", __FUNCTION__,
 110                 viodrv->name);
 111
 112         /* fill in 'struct driver' fields */
 113         viodrv->driver.name = viodrv->name;
 114         viodrv->driver.bus = &vio_bus_type;
 115         viodrv->driver.probe = vio_bus_probe;
 116         viodrv->driver.remove = vio_bus_remove;
 117
 118         return driver_register(&viodrv->driver);
 119 }
 120 EXPORT_SYMBOL(vio_register_driver);
 121
 122 /**
 123  * vio_unregister_driver - Remove registration of vio driver.
 124  * @driver:     The vio_driver struct to be removed form registration
 125  */
 126 void vio_unregister_driver(struct vio_driver *viodrv)
 127 {
 128         driver_unregister(&viodrv->driver);
 129 }
 130 EXPORT_SYMBOL(vio_unregister_driver);
 131
 132 /**
 133  * vio_match_device: - Tell if a VIO device has a matching VIO device id structure.
 134  * @ids:        array of VIO device id structures to search in
 135  * @dev:        the VIO device structure to match against
 136  *
 137  * Used by a driver to check whether a VIO device present in the
 138  * system is in its list of supported devices. Returns the matching
 139  * vio_device_id structure or NULL if there is no match.
 140  */
 141 static const struct vio_device_id * vio_match_device(const struct vio_device_id *ids,
 142         const struct vio_dev *dev)
 143 {
 144         DBGENTER();
 145
 146         while (ids->type) {
 147                 if ((strncmp(dev->type, ids->type, strlen(ids->type)) == 0) &&
 148                         device_is_compatible(dev->dev.platform_data, ids->compat))
 149                         return ids;
 150                 ids++;
 151         }
 152         return NULL;
 153 }
 154
 155 #ifdef CONFIG_PPC_ISERIES
 156 void __init iommu_vio_init(void)
 157 {
 158         struct iommu_table *t;
 159         struct iommu_table_cb cb;
 160         unsigned long cbp;
 161         unsigned long itc_entries;
 162
 163         cb.itc_busno = 255;    /* Bus 255 is the virtual bus */
 164         cb.itc_virtbus = 0xff; /* Ask for virtual bus */
 165
 166         cbp = virt_to_abs(&cb);
 167         HvCallXm_getTceTableParms(cbp);
 168
 169         itc_entries = cb.itc_size * PAGE_SIZE / sizeof(union tce_entry);
 170         veth_iommu_table.it_size        = itc_entries / 2;
 171         veth_iommu_table.it_busno       = cb.itc_busno;
 172         veth_iommu_table.it_offset      = cb.itc_offset;
 173         veth_iommu_table.it_index       = cb.itc_index;
 174         veth_iommu_table.it_type        = TCE_VB;
 175         veth_iommu_table.it_blocksize   = 1;
 176
 177         t = iommu_init_table(&veth_iommu_table);
 178
 179         if (!t)
 180                 printk("Virtual Bus VETH TCE table failed.\n");
 181
 182         vio_iommu_table.it_size         = itc_entries - veth_iommu_table.it_size;
 183         vio_iommu_table.it_busno        = cb.itc_busno;
 184         vio_iommu_table.it_offset       = cb.itc_offset +
 185                                           veth_iommu_table.it_size;
 186         vio_iommu_table.it_index        = cb.itc_index;
 187         vio_iommu_table.it_type         = TCE_VB;
 188         vio_iommu_table.it_blocksize    = 1;
 189
 190         t = iommu_init_table(&vio_iommu_table);
 191
 192         if (!t)
 193                 printk("Virtual Bus VIO TCE table failed.\n");
 194 }
 195 #endif
 196
 197 #ifdef CONFIG_PPC_PSERIES
 198 static void probe_bus_pseries(void)
 199 {
 200         struct device_node *node_vroot, *of_node;
 201
 202         node_vroot = find_devices("vdevice");
 203         if ((node_vroot == NULL) || (node_vroot->child == NULL))
 204                 /* this machine doesn't do virtual IO, and that's ok */
 205                 return;
 206
 207         vio_num_address_cells = prom_n_addr_cells(node_vroot->child);
 208
 209         /*
 210          * Create struct vio_devices for each virtual device in the device tree.
 211          * Drivers will associate with them later.
 212          */
 213         for (of_node = node_vroot->child; of_node != NULL;
 214                         of_node = of_node->sibling) {
 215                 printk(KERN_DEBUG "%s: processing %p\n", __FUNCTION__, of_node);
 216                 vio_register_device_node(of_node);
 217         }
 218 }
 219 #endif
 220
 221 #ifdef CONFIG_PPC_ISERIES
 222 static void probe_bus_iseries(void)
 223 {
 224         HvLpIndexMap vlan_map = HvLpConfig_getVirtualLanIndexMap();
 225         struct vio_dev *viodev;
 226         int i;
 227
 228         /* there is only one of each of these */
 229         vio_register_device_iseries("viocons", 0);
 230         vio_register_device_iseries("vscsi", 0);
 231
 232         vlan_map = HvLpConfig_getVirtualLanIndexMap();
 233         for (i = 0; i < HVMAXARCHITECTEDVIRTUALLANS; i++) {
 234                 if ((vlan_map & (0x8000 >> i)) == 0)
 235                         continue;
 236                 viodev = vio_register_device_iseries("vlan", i);
 237                 /* veth is special and has it own iommu_table */
 238                 viodev->iommu_table = &veth_iommu_table;
 239         }
 240         for (i = 0; i < HVMAXARCHITECTEDVIRTUALDISKS; i++)
 241                 vio_register_device_iseries("viodasd", i);
 242         for (i = 0; i < HVMAXARCHITECTEDVIRTUALCDROMS; i++)
 243                 vio_register_device_iseries("viocd", i);
 244         for (i = 0; i < HVMAXARCHITECTEDVIRTUALTAPES; i++)
 245                 vio_register_device_iseries("viotape", i);
 246 }
 247 #endif
 248
 249 /**
 250  * vio_bus_init: - Initialize the virtual IO bus
 251  */
 252 static int __init vio_bus_init(void)
 253 {
 254         int err;
 255
 256         err = bus_register(&vio_bus_type);
 257         if (err) {
 258                 printk(KERN_ERR "failed to register VIO bus\n");
 259                 return err;
 260         }
 261
 262         /* the fake parent of all vio devices, just to give us a nice directory */
 263         vio_bus_device = kmalloc(sizeof(struct vio_dev), GFP_KERNEL);
 264         if (!vio_bus_device) {
 265                 return 1;
 266         }
 267         memset(vio_bus_device, 0, sizeof(struct vio_dev));
 268         strcpy(vio_bus_device->dev.bus_id, "vio");
 269
 270         err = device_register(&vio_bus_device->dev);
 271         if (err) {
 272                 printk(KERN_WARNING "%s: device_register returned %i\n", __FUNCTION__,
 273                         err);
 274                 kfree(vio_bus_device);
 275                 return err;
 276         }
 277
 278 #ifdef CONFIG_PPC_PSERIES
 279         probe_bus_pseries();
 280 #endif
 281 #ifdef CONFIG_PPC_ISERIES
 282         probe_bus_iseries();
 283 #endif
 284
 285         return 0;
 286 }
 287
 288 __initcall(vio_bus_init);
 289
 290 /* vio_dev refcount hit 0 */
 291 static void __devinit vio_dev_release(struct device *dev)
 292 {
 293         DBGENTER();
 294
 295 #ifdef CONFIG_PPC_PSERIES
 296         /* XXX free TCE table */
 297         of_node_put(dev->platform_data);
 298 #endif
 299         kfree(to_vio_dev(dev));
 300 }
 301
 302 #ifdef CONFIG_PPC_PSERIES
 303 static ssize_t viodev_show_devspec(struct device *dev, char *buf)
 304 {
 305         struct device_node *of_node = dev->platform_data;
 306
 307         return sprintf(buf, "%s\n", of_node->full_name);
 308 }
 309 DEVICE_ATTR(devspec, S_IRUSR | S_IRGRP | S_IROTH, viodev_show_devspec, NULL);
 310 #endif
 311
 312 static ssize_t viodev_show_name(struct device *dev, char *buf)
 313 {
 314         return sprintf(buf, "%s\n", to_vio_dev(dev)->name);
 315 }
 316 DEVICE_ATTR(name, S_IRUSR | S_IRGRP | S_IROTH, viodev_show_name, NULL);
 317
 318 static struct vio_dev * __devinit vio_register_device_common(
 319                 struct vio_dev *viodev, char *name, char *type,
 320                 uint32_t unit_address, struct iommu_table *iommu_table)
 321 {
 322         DBGENTER();
 323
 324         viodev->name = name;
 325         viodev->type = type;
 326         viodev->unit_address = unit_address;
 327         viodev->iommu_table = iommu_table;
 328         /* init generic 'struct device' fields: */
 329         viodev->dev.parent = &vio_bus_device->dev;
 330         viodev->dev.bus = &vio_bus_type;
 331         viodev->dev.release = vio_dev_release;
 332
 333         /* register with generic device framework */
 334         if (device_register(&viodev->dev)) {
 335                 printk(KERN_ERR "%s: failed to register device %s\n",
 336                                 __FUNCTION__, viodev->dev.bus_id);
 337                 return NULL;
 338         }
 339         device_create_file(&viodev->dev, &dev_attr_name);
 340
 341         return viodev;
 342 }
 343
 344 #ifdef CONFIG_PPC_PSERIES
 345 /**
 346  * vio_register_device_node: - Register a new vio device.
 347  * @of_node:    The OF node for this device.
 348  *
 349  * Creates and initializes a vio_dev structure from the data in
 350  * of_node (dev.platform_data) and adds it to the list of virtual devices.
 351  * Returns a pointer to the created vio_dev or NULL if node has
 352  * NULL device_type or compatible fields.
 353  */
 354 struct vio_dev * __devinit vio_register_device_node(struct device_node *of_node)
 355 {
 356         struct vio_dev *viodev;
 357         unsigned int *unit_address;
 358         unsigned int *irq_p;
 359
 360         DBGENTER();
 361
 362         /* we need the 'device_type' property, in order to match with drivers */
 363         if ((NULL == of_node->type)) {
 364                 printk(KERN_WARNING
 365                         "%s: node %s missing 'device_type'\n", __FUNCTION__,
 366                         of_node->name ? of_node->name : "<unknown>");
 367                 return NULL;
 368         }
 369
 370         unit_address = (unsigned int *)get_property(of_node, "reg", NULL);
 371         if (!unit_address) {
 372                 printk(KERN_WARNING "%s: node %s missing 'reg'\n", __FUNCTION__,
 373                         of_node->name ? of_node->name : "<unknown>");
 374                 return NULL;
 375         }
 376
 377         /* allocate a vio_dev for this node */
 378         viodev = kmalloc(sizeof(struct vio_dev), GFP_KERNEL);
 379         if (!viodev) {
 380                 return NULL;
 381         }
 382         memset(viodev, 0, sizeof(struct vio_dev));
 383
 384         viodev->dev.platform_data = of_node_get(of_node);
 385
 386         viodev->irq = NO_IRQ;
 387         irq_p = (unsigned int *)get_property(of_node, "interrupts", NULL);
 388         if (irq_p) {
 389                 int virq = virt_irq_create_mapping(*irq_p);
 390                 if (virq == NO_IRQ) {
 391                         printk(KERN_ERR "Unable to allocate interrupt "
 392                                "number for %s\n", of_node->full_name);
 393                 } else
 394                         viodev->irq = irq_offset_up(virq);
 395         }
 396
 397         snprintf(viodev->dev.bus_id, BUS_ID_SIZE, "%x", *unit_address);
 398
 399         /* register with generic device framework */
 400         if (vio_register_device_common(viodev, of_node->name, of_node->type,
 401                                 *unit_address, vio_build_iommu_table(viodev))
 402                         == NULL) {
 403                 /* XXX free TCE table */
 404                 kfree(viodev);
 405                 return NULL;
 406         }
 407         device_create_file(&viodev->dev, &dev_attr_devspec);
 408
 409         return viodev;
 410 }
 411 EXPORT_SYMBOL(vio_register_device_node);
 412 #endif
 413
 414 #ifdef CONFIG_PPC_ISERIES
 415 /**
 416  * vio_register_device: - Register a new vio device.
 417  * @voidev:     The device to register.
 418  */
 419 static struct vio_dev *__init vio_register_device_iseries(char *type,
 420                 uint32_t unit_num)
 421 {
 422         struct vio_dev *viodev;
 423
 424         DBGENTER();
 425
 426         /* allocate a vio_dev for this node */
 427         viodev = kmalloc(sizeof(struct vio_dev), GFP_KERNEL);
 428         if (!viodev)
 429                 return NULL;
 430         memset(viodev, 0, sizeof(struct vio_dev));
 431
 432         snprintf(viodev->dev.bus_id, BUS_ID_SIZE, "%s%d", type, unit_num);
 433
 434         return vio_register_device_common(viodev, viodev->dev.bus_id, type,
 435                         unit_num, &vio_iommu_table);
 436 }
 437 #endif
 438
 439 void __devinit vio_unregister_device(struct vio_dev *viodev)
 440 {
 441         DBGENTER();
 442 #ifdef CONFIG_PPC_PSERIES
 443         device_remove_file(&viodev->dev, &dev_attr_devspec);
 444 #endif
 445         device_remove_file(&viodev->dev, &dev_attr_name);
 446         device_unregister(&viodev->dev);
 447 }
 448 EXPORT_SYMBOL(vio_unregister_device);
 449
 450 #ifdef CONFIG_PPC_PSERIES
 451 /**
 452  * vio_get_attribute: - get attribute for virtual device
 453  * @vdev:       The vio device to get property.
 454  * @which:      The property/attribute to be extracted.
 455  * @length:     Pointer to length of returned data size (unused if NULL).
 456  *
 457  * Calls prom.c's get_property() to return the value of the
 458  * attribute specified by the preprocessor constant @which
 459 */
 460 const void * vio_get_attribute(struct vio_dev *vdev, void* which, int* length)
 461 {
 462         return get_property(vdev->dev.platform_data, (char*)which, length);
 463 }
 464 EXPORT_SYMBOL(vio_get_attribute);
 465
 466 /* vio_find_name() - internal because only vio.c knows how we formatted the
 467  * kobject name
 468  * XXX once vio_bus_type.devices is actually used as a kset in
 469  * drivers/base/bus.c, this function should be removed in favor of
 470  * "device_find(kobj_name, &vio_bus_type)"
 471  */
 472 static struct vio_dev *vio_find_name(const char *kobj_name)
 473 {
 474         struct kobject *found;
 475
 476         found = kset_find_obj(&devices_subsys.kset, kobj_name);
 477         if (!found)
 478                 return NULL;
 479
 480         return to_vio_dev(container_of(found, struct device, kobj));
 481 }
 482
 483 /**
 484  * vio_find_node - find an already-registered vio_dev
 485  * @vnode: device_node of the virtual device we're looking for
 486  */
 487 struct vio_dev *vio_find_node(struct device_node *vnode)
 488 {
 489         uint32_t *unit_address;
 490         char kobj_name[BUS_ID_SIZE];
 491
 492         /* construct the kobject name from the device node */
 493         unit_address = (uint32_t *)get_property(vnode, "reg", NULL);
 494         if (!unit_address)
 495                 return NULL;
 496         snprintf(kobj_name, BUS_ID_SIZE, "%x", *unit_address);
 497
 498         return vio_find_name(kobj_name);
 499 }
 500 EXPORT_SYMBOL(vio_find_node);
 501
 502 /**
 503  * vio_build_iommu_table: - gets the dma information from OF and builds the TCE tree.
 504  * @dev: the virtual device.
 505  *
 506  * Returns a pointer to the built tce tree, or NULL if it can't
 507  * find property.
 508 */
 509 static struct iommu_table * vio_build_iommu_table(struct vio_dev *dev)
 510 {
 511         unsigned int *dma_window;
 512         struct iommu_table *newTceTable;
 513         unsigned long offset;
 514         int dma_window_property_size;
 515
 516         dma_window = (unsigned int *) get_property(dev->dev.platform_data, "ibm,my-dma-window", &dma_window_property_size);
 517         if(!dma_window) {
 518                 return NULL;
 519         }
 520
 521         newTceTable = (struct iommu_table *) kmalloc(sizeof(struct iommu_table), GFP_KERNEL);
 522
 523         /*  There should be some code to extract the phys-encoded offset
 524                 using prom_n_addr_cells(). However, according to a comment
 525                 on earlier versions, it's always zero, so we don't bother */
 526         offset = dma_window[1] >>  PAGE_SHIFT;
 527
 528         /* TCE table size - measured in tce entries */
 529         newTceTable->it_size            = dma_window[4] >> PAGE_SHIFT;
 530         /* offset for VIO should always be 0 */
 531         newTceTable->it_offset          = offset;
 532         newTceTable->it_busno           = 0;
 533         newTceTable->it_index           = (unsigned long)dma_window[0];
 534         newTceTable->it_type            = TCE_VB;
 535
 536         return iommu_init_table(newTceTable);
 537 }
 538
 539 int vio_enable_interrupts(struct vio_dev *dev)
 540 {
 541         int rc = h_vio_signal(dev->unit_address, VIO_IRQ_ENABLE);
 542         if (rc != H_Success) {
 543                 printk(KERN_ERR "vio: Error 0x%x enabling interrupts\n", rc);
 544         }
 545         return rc;
 546 }
 547 EXPORT_SYMBOL(vio_enable_interrupts);
 548
 549 int vio_disable_interrupts(struct vio_dev *dev)
 550 {
 551         int rc = h_vio_signal(dev->unit_address, VIO_IRQ_DISABLE);
 552         if (rc != H_Success) {
 553                 printk(KERN_ERR "vio: Error 0x%x disabling interrupts\n", rc);
 554         }
 555         return rc;
 556 }
 557 EXPORT_SYMBOL(vio_disable_interrupts);
 558 #endif
 559
 560 static dma_addr_t vio_map_single(struct device *dev, void *vaddr,
 561                           size_t size, enum dma_data_direction direction)
 562 {
 563         return iommu_map_single(to_vio_dev(dev)->iommu_table, vaddr, size,
 564                         direction);
 565 }
 566
 567 static void vio_unmap_single(struct device *dev, dma_addr_t dma_handle,
 568                       size_t size, enum dma_data_direction direction)
 569 {
 570         iommu_unmap_single(to_vio_dev(dev)->iommu_table, dma_handle, size,
 571                         direction);
 572 }
 573
 574 static int vio_map_sg(struct device *dev, struct scatterlist *sglist,
 575                 int nelems, enum dma_data_direction direction)
 576 {
 577         return iommu_map_sg(dev, to_vio_dev(dev)->iommu_table, sglist,
 578                         nelems, direction);
 579 }
 580
 581 static void vio_unmap_sg(struct device *dev, struct scatterlist *sglist,
 582                 int nelems, enum dma_data_direction direction)
 583 {
 584         iommu_unmap_sg(to_vio_dev(dev)->iommu_table, sglist, nelems, direction);
 585 }
 586
 587 static void *vio_alloc_coherent(struct device *dev, size_t size,
 588                            dma_addr_t *dma_handle, unsigned int __nocast flag)
 589 {
 590         return iommu_alloc_coherent(to_vio_dev(dev)->iommu_table, size,
 591                         dma_handle, flag);
 592 }
 593
 594 static void vio_free_coherent(struct device *dev, size_t size,
 595                          void *vaddr, dma_addr_t dma_handle)
 596 {
 597         iommu_free_coherent(to_vio_dev(dev)->iommu_table, size, vaddr,
 598                         dma_handle);
 599 }
 600
 601 static int vio_dma_supported(struct device *dev, u64 mask)
 602 {
 603         return 1;
 604 }
 605
 606 struct dma_mapping_ops vio_dma_ops = {
 607         .alloc_coherent = vio_alloc_coherent,
 608         .free_coherent = vio_free_coherent,
 609         .map_single = vio_map_single,
 610         .unmap_single = vio_unmap_single,
 611         .map_sg = vio_map_sg,
 612         .unmap_sg = vio_unmap_sg,
 613         .dma_supported = vio_dma_supported,
 614 };
 615
 616 static int vio_bus_match(struct device *dev, struct device_driver *drv)
 617 {
 618         const struct vio_dev *vio_dev = to_vio_dev(dev);
 619         struct vio_driver *vio_drv = to_vio_driver(drv);
 620         const struct vio_device_id *ids = vio_drv->id_table;
 621         const struct vio_device_id *found_id;
 622
 623         DBGENTER();
 624
 625         if (!ids)
 626                 return 0;
 627
 628         found_id = vio_match_device(ids, vio_dev);
 629         if (found_id)
 630                 return 1;
 631
 632         return 0;
 633 }
 634
 635 struct bus_type vio_bus_type = {
 636         .name = "vio",
 637         .match = vio_bus_match,
 638 };
 639
 640 EXPORT_SYMBOL(vio_bus_type);