kernel/drivers/pci/hotplug/sgi_hotplug.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 2005-2006 Silicon Graphics, Inc. All rights reserved.
   7  *
   8  * This work was based on the 2.4/2.6 kernel development by Dick Reigner.
   9  * Work to add BIOS PROM support was completed by Mike Habeck.
  10  */
  11
  12 #include <linux/acpi.h>
  13 #include <linux/init.h>
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/pci.h>
  17 #include <linux/pci_hotplug.h>
  18 #include <linux/proc_fs.h>
  19 #include <linux/slab.h>
  20 #include <linux/types.h>
  21 #include <linux/mutex.h>
  22
  23 #include <asm/sn/addrs.h>
  24 #include <asm/sn/geo.h>
  25 #include <asm/sn/l1.h>
  26 #include <asm/sn/module.h>
  27 #include <asm/sn/pcibr_provider.h>
  28 #include <asm/sn/pcibus_provider_defs.h>
  29 #include <asm/sn/pcidev.h>
  30 #include <asm/sn/sn_feature_sets.h>
  31 #include <asm/sn/sn_sal.h>
  32 #include <asm/sn/types.h>
  33 #include <asm/sn/acpi.h>
  34
  35 #include "../pci.h"
  36
  37 MODULE_LICENSE("GPL");
  38 MODULE_AUTHOR("SGI (prarit@sgi.com, dickie@sgi.com, habeck@sgi.com)");
  39 MODULE_DESCRIPTION("SGI Altix Hot Plug PCI Controller Driver");
  40
  41
  42 /* SAL call error codes. Keep in sync with prom header io/include/pcibr.h */
  43 #define PCI_SLOT_ALREADY_UP             2       /* slot already up */
  44 #define PCI_SLOT_ALREADY_DOWN           3       /* slot already down */
  45 #define PCI_L1_ERR                      7       /* L1 console command error */
  46 #define PCI_EMPTY_33MHZ                 15      /* empty 33 MHz bus */
  47
  48
  49 #define PCIIO_ASIC_TYPE_TIOCA           4
  50 #define PCI_L1_QSIZE                    128     /* our L1 message buffer size */
  51 #define SN_MAX_HP_SLOTS                 32      /* max hotplug slots */
  52 #define SN_SLOT_NAME_SIZE               33      /* size of name string */
  53
  54 /* internal list head */
  55 static struct list_head sn_hp_list;
  56
  57 /* hotplug_slot struct's private pointer */
  58 struct slot {
  59         int device_num;
  60         struct pci_bus *pci_bus;
  61         /* this struct for glue internal only */
  62         struct hotplug_slot *hotplug_slot;
  63         struct list_head hp_list;
  64         char physical_path[SN_SLOT_NAME_SIZE];
  65 };
  66
  67 struct pcibr_slot_enable_resp {
  68         int resp_sub_errno;
  69         char resp_l1_msg[PCI_L1_QSIZE + 1];
  70 };
  71
  72 struct pcibr_slot_disable_resp {
  73         int resp_sub_errno;
  74         char resp_l1_msg[PCI_L1_QSIZE + 1];
  75 };
  76
  77 enum sn_pci_req_e {
  78         PCI_REQ_SLOT_ELIGIBLE,
  79         PCI_REQ_SLOT_DISABLE
  80 };
  81
  82 static int enable_slot(struct hotplug_slot *slot);
  83 static int disable_slot(struct hotplug_slot *slot);
  84 static inline int get_power_status(struct hotplug_slot *slot, u8 *value);
  85
  86 static struct hotplug_slot_ops sn_hotplug_slot_ops = {
  87         .enable_slot            = enable_slot,
  88         .disable_slot           = disable_slot,
  89         .get_power_status       = get_power_status,
  90 };
  91
  92 static DEFINE_MUTEX(sn_hotplug_mutex);
  93
  94 static ssize_t path_show(struct pci_slot *pci_slot, char *buf)
  95 {
  96         int retval = -ENOENT;
  97         struct slot *slot = pci_slot->hotplug->private;
  98
  99         if (!slot)
 100                 return retval;
 101
 102         retval = sprintf (buf, "%s\n", slot->physical_path);
 103         return retval;
 104 }
 105
 106 static struct pci_slot_attribute sn_slot_path_attr = __ATTR_RO(path);
 107
 108 static int sn_pci_slot_valid(struct pci_bus *pci_bus, int device)
 109 {
 110         struct pcibus_info *pcibus_info;
 111         u16 busnum, segment, ioboard_type;
 112
 113         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(pci_bus);
 114
 115         /* Check to see if this is a valid slot on 'pci_bus' */
 116         if (!(pcibus_info->pbi_valid_devices & (1 << device)))
 117                 return -EPERM;
 118
 119         ioboard_type = sn_ioboard_to_pci_bus(pci_bus);
 120         busnum = pcibus_info->pbi_buscommon.bs_persist_busnum;
 121         segment = pci_domain_nr(pci_bus) & 0xf;
 122
 123         /* Do not allow hotplug operations on base I/O cards */
 124         if ((ioboard_type == L1_BRICKTYPE_IX ||
 125              ioboard_type == L1_BRICKTYPE_IA) &&
 126             (segment == 1 && busnum == 0 && device != 1))
 127                 return -EPERM;
 128
 129         return 1;
 130 }
 131
 132 static int sn_pci_bus_valid(struct pci_bus *pci_bus)
 133 {
 134         struct pcibus_info *pcibus_info;
 135         u32 asic_type;
 136         u16 ioboard_type;
 137
 138         /* Don't register slots hanging off the TIOCA bus */
 139         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(pci_bus);
 140         asic_type = pcibus_info->pbi_buscommon.bs_asic_type;
 141         if (asic_type == PCIIO_ASIC_TYPE_TIOCA)
 142                 return -EPERM;
 143
 144         /* Only register slots in I/O Bricks that support hotplug */
 145         ioboard_type = sn_ioboard_to_pci_bus(pci_bus);
 146         switch (ioboard_type) {
 147                 case L1_BRICKTYPE_IX:
 148                 case L1_BRICKTYPE_PX:
 149                 case L1_BRICKTYPE_IA:
 150                 case L1_BRICKTYPE_PA:
 151                 case L1_BOARDTYPE_PCIX3SLOT:
 152                         return 1;
 153                         break;
 154                 default:
 155                         return -EPERM;
 156                         break;
 157         }
 158
 159         return -EIO;
 160 }
 161
 162 static int sn_hp_slot_private_alloc(struct hotplug_slot *bss_hotplug_slot,
 163                                     struct pci_bus *pci_bus, int device,
 164                                     char *name)
 165 {
 166         struct pcibus_info *pcibus_info;
 167         struct slot *slot;
 168
 169         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(pci_bus);
 170
 171         slot = kzalloc(sizeof(*slot), GFP_KERNEL);
 172         if (!slot)
 173                 return -ENOMEM;
 174         bss_hotplug_slot->private = slot;
 175
 176         slot->device_num = device;
 177         slot->pci_bus = pci_bus;
 178         sprintf(name, "%04x:%02x:%02x",
 179                 pci_domain_nr(pci_bus),
 180                 ((u16)pcibus_info->pbi_buscommon.bs_persist_busnum),
 181                 device + 1);
 182
 183         sn_generate_path(pci_bus, slot->physical_path);
 184
 185         slot->hotplug_slot = bss_hotplug_slot;
 186         list_add(&slot->hp_list, &sn_hp_list);
 187
 188         return 0;
 189 }
 190
 191 static struct hotplug_slot *sn_hp_destroy(void)
 192 {
 193         struct slot *slot;
 194         struct pci_slot *pci_slot;
 195         struct hotplug_slot *bss_hotplug_slot = NULL;
 196
 197         list_for_each_entry(slot, &sn_hp_list, hp_list) {
 198                 bss_hotplug_slot = slot->hotplug_slot;
 199                 pci_slot = bss_hotplug_slot->pci_slot;
 200                 list_del(&((struct slot *)bss_hotplug_slot->private)->
 201                          hp_list);
 202                 sysfs_remove_file(&pci_slot->kobj,
 203                                   &sn_slot_path_attr.attr);
 204                 break;
 205         }
 206         return bss_hotplug_slot;
 207 }
 208
 209 static void sn_bus_free_data(struct pci_dev *dev)
 210 {
 211         struct pci_bus *subordinate_bus;
 212         struct pci_dev *child;
 213
 214         /* Recursively clean up sn_irq_info structs */
 215         if (dev->subordinate) {
 216                 subordinate_bus = dev->subordinate;
 217                 list_for_each_entry(child, &subordinate_bus->devices, bus_list)
 218                         sn_bus_free_data(child);
 219         }
 220         /*
 221          * Some drivers may use dma accesses during the
 222          * driver remove function. We release the sysdata
 223          * areas after the driver remove functions have
 224          * been called.
 225          */
 226         sn_bus_store_sysdata(dev);
 227         sn_pci_unfixup_slot(dev);
 228 }
 229
 230 static int sn_slot_enable(struct hotplug_slot *bss_hotplug_slot,
 231                           int device_num, char **ssdt)
 232 {
 233         struct slot *slot = bss_hotplug_slot->private;
 234         struct pcibus_info *pcibus_info;
 235         struct pcibr_slot_enable_resp resp;
 236         int rc;
 237
 238         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
 239
 240         /*
 241          * Power-on and initialize the slot in the SN
 242          * PCI infrastructure.
 243          */
 244         rc = sal_pcibr_slot_enable(pcibus_info, device_num, &resp, ssdt);
 245
 246
 247         if (rc == PCI_SLOT_ALREADY_UP) {
 248                 dev_dbg(&slot->pci_bus->self->dev, "is already active\n");
 249                 return 1; /* return 1 to user */
 250         }
 251
 252         if (rc == PCI_L1_ERR) {
 253                 dev_dbg(&slot->pci_bus->self->dev, "L1 failure %d with message: %s",
 254                         resp.resp_sub_errno, resp.resp_l1_msg);
 255                 return -EPERM;
 256         }
 257
 258         if (rc) {
 259                 dev_dbg(&slot->pci_bus->self->dev, "insert failed with error %d sub-error %d\n",
 260                         rc, resp.resp_sub_errno);
 261                 return -EIO;
 262         }
 263
 264         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
 265         pcibus_info->pbi_enabled_devices |= (1 << device_num);
 266
 267         return 0;
 268 }
 269
 270 static int sn_slot_disable(struct hotplug_slot *bss_hotplug_slot,
 271                            int device_num, int action)
 272 {
 273         struct slot *slot = bss_hotplug_slot->private;
 274         struct pcibus_info *pcibus_info;
 275         struct pcibr_slot_disable_resp resp;
 276         int rc;
 277
 278         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
 279
 280         rc = sal_pcibr_slot_disable(pcibus_info, device_num, action, &resp);
 281
 282         if ((action == PCI_REQ_SLOT_ELIGIBLE) &&
 283             (rc == PCI_SLOT_ALREADY_DOWN)) {
 284                 dev_dbg(&slot->pci_bus->self->dev, "Slot %s already inactive\n", slot->physical_path);
 285                 return 1; /* return 1 to user */
 286         }
 287
 288         if ((action == PCI_REQ_SLOT_ELIGIBLE) && (rc == PCI_EMPTY_33MHZ)) {
 289                 dev_dbg(&slot->pci_bus->self->dev, "Cannot remove last 33MHz card\n");
 290                 return -EPERM;
 291         }
 292
 293         if ((action == PCI_REQ_SLOT_ELIGIBLE) && (rc == PCI_L1_ERR)) {
 294                 dev_dbg(&slot->pci_bus->self->dev, "L1 failure %d with message \n%s\n",
 295                         resp.resp_sub_errno, resp.resp_l1_msg);
 296                 return -EPERM;
 297         }
 298
 299         if ((action == PCI_REQ_SLOT_ELIGIBLE) && rc) {
 300                 dev_dbg(&slot->pci_bus->self->dev, "remove failed with error %d sub-error %d\n",
 301                         rc, resp.resp_sub_errno);
 302                 return -EIO;
 303         }
 304
 305         if ((action == PCI_REQ_SLOT_ELIGIBLE) && !rc)
 306                 return 0;
 307
 308         if ((action == PCI_REQ_SLOT_DISABLE) && !rc) {
 309                 pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
 310                 pcibus_info->pbi_enabled_devices &= ~(1 << device_num);
 311                 dev_dbg(&slot->pci_bus->self->dev, "remove successful\n");
 312                 return 0;
 313         }
 314
 315         if ((action == PCI_REQ_SLOT_DISABLE) && rc) {
 316                 dev_dbg(&slot->pci_bus->self->dev,"remove failed rc = %d\n", rc);
 317         }
 318
 319         return rc;
 320 }
 321
 322 /*
 323  * Power up and configure the slot via a SAL call to PROM.
 324  * Scan slot (and any children), do any platform specific fixup,
 325  * and find device driver.
 326  */
 327 static int enable_slot(struct hotplug_slot *bss_hotplug_slot)
 328 {
 329         struct slot *slot = bss_hotplug_slot->private;
 330         struct pci_bus *new_bus = NULL;
 331         struct pci_dev *dev;
 332         int num_funcs;
 333         int new_ppb = 0;
 334         int rc;
 335         char *ssdt = NULL;
 336         void pcibios_fixup_device_resources(struct pci_dev *);
 337
 338         /* Serialize the Linux PCI infrastructure */
 339         mutex_lock(&sn_hotplug_mutex);
 340
 341         /*
 342          * Power-on and initialize the slot in the SN
 343          * PCI infrastructure. Also, retrieve the ACPI SSDT
 344          * table for the slot (if ACPI capable PROM).
 345          */
 346         rc = sn_slot_enable(bss_hotplug_slot, slot->device_num, &ssdt);
 347         if (rc) {
 348                 mutex_unlock(&sn_hotplug_mutex);
 349                 return rc;
 350         }
 351
 352         if (ssdt)
 353                 ssdt = __va(ssdt);
 354         /* Add the new SSDT for the slot to the ACPI namespace */
 355         if (SN_ACPI_BASE_SUPPORT() && ssdt) {
 356                 acpi_status ret;
 357
 358                 ret = acpi_load_table((struct acpi_table_header *)ssdt);
 359                 if (ACPI_FAILURE(ret)) {
 360                         printk(KERN_ERR "%s: acpi_load_table failed (0x%x)\n",
 361                                __func__, ret);
 362                         /* try to continue on */
 363                 }
 364         }
 365
 366         num_funcs = pci_scan_slot(slot->pci_bus,
 367                                   PCI_DEVFN(slot->device_num + 1, 0));
 368         if (!num_funcs) {
 369                 dev_dbg(&slot->pci_bus->self->dev, "no device in slot\n");
 370                 mutex_unlock(&sn_hotplug_mutex);
 371                 return -ENODEV;
 372         }
 373
 374         /*
 375          * Map SN resources for all functions on the card
 376          * to the Linux PCI interface and tell the drivers
 377          * about them.
 378          */
 379         list_for_each_entry(dev, &slot->pci_bus->devices, bus_list) {
 380                 if (PCI_SLOT(dev->devfn) != slot->device_num + 1)
 381                         continue;
 382
 383                 /* Need to do slot fixup on PPB before fixup of children
 384                  * (PPB's pcidev_info needs to be in pcidev_info list
 385                  * before child's SN_PCIDEV_INFO() call to setup
 386                  * pdi_host_pcidev_info).
 387                  */
 388                 pcibios_fixup_device_resources(dev);
 389                 if (SN_ACPI_BASE_SUPPORT())
 390                         sn_acpi_slot_fixup(dev);
 391                 else
 392                         sn_io_slot_fixup(dev);
 393                 if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
 394                         pci_hp_add_bridge(dev);
 395                         if (dev->subordinate) {
 396                                 new_bus = dev->subordinate;
 397                                 new_ppb = 1;
 398                         }
 399                 }
 400         }
 401
 402         /*
 403          * Add the slot's devices to the ACPI infrastructure */
 404         if (SN_ACPI_BASE_SUPPORT() && ssdt) {
 405                 unsigned long long adr;
 406                 struct acpi_device *pdevice;
 407                 acpi_handle phandle;
 408                 acpi_handle chandle = NULL;
 409                 acpi_handle rethandle;
 410                 acpi_status ret;
 411
 412                 phandle = acpi_device_handle(PCI_CONTROLLER(slot->pci_bus)->companion);
 413
 414                 if (acpi_bus_get_device(phandle, &pdevice)) {
 415                         dev_dbg(&slot->pci_bus->self->dev, "no parent device, assuming NULL\n");
 416                         pdevice = NULL;
 417                 }
 418
 419                 acpi_scan_lock_acquire();
 420                 /*
 421                  * Walk the rootbus node's immediate children looking for
 422                  * the slot's device node(s). There can be more than
 423                  * one for multifunction devices.
 424                  */
 425                 for (;;) {
 426                         rethandle = NULL;
 427                         ret = acpi_get_next_object(ACPI_TYPE_DEVICE,
 428                                                    phandle, chandle,
 429                                                    &rethandle);
 430
 431                         if (ret == AE_NOT_FOUND || rethandle == NULL)
 432                                 break;
 433
 434                         chandle = rethandle;
 435
 436                         ret = acpi_evaluate_integer(chandle, METHOD_NAME__ADR,
 437                                                     NULL, &adr);
 438
 439                         if (ACPI_SUCCESS(ret) &&
 440                             (adr>>16) == (slot->device_num + 1)) {
 441
 442                                 ret = acpi_bus_scan(chandle);
 443                                 if (ACPI_FAILURE(ret)) {
 444                                         printk(KERN_ERR "%s: acpi_bus_scan failed (0x%x) for slot %d func %d\n",
 445                                                __func__, ret, (int)(adr>>16),
 446                                                (int)(adr&0xffff));
 447                                         /* try to continue on */
 448                                 }
 449                         }
 450                 }
 451                 acpi_scan_lock_release();
 452         }
 453
 454         pci_lock_rescan_remove();
 455
 456         /* Call the driver for the new device */
 457         pci_bus_add_devices(slot->pci_bus);
 458         /* Call the drivers for the new devices subordinate to PPB */
 459         if (new_ppb)
 460                 pci_bus_add_devices(new_bus);
 461
 462         pci_unlock_rescan_remove();
 463         mutex_unlock(&sn_hotplug_mutex);
 464
 465         if (rc == 0)
 466                 dev_dbg(&slot->pci_bus->self->dev, "insert operation successful\n");
 467         else
 468                 dev_dbg(&slot->pci_bus->self->dev, "insert operation failed rc = %d\n", rc);
 469
 470         return rc;
 471 }
 472
 473 static int disable_slot(struct hotplug_slot *bss_hotplug_slot)
 474 {
 475         struct slot *slot = bss_hotplug_slot->private;
 476         struct pci_dev *dev, *temp;
 477         int rc;
 478         acpi_handle ssdt_hdl = NULL;
 479
 480         /* Acquire update access to the bus */
 481         mutex_lock(&sn_hotplug_mutex);
 482
 483         /* is it okay to bring this slot down? */
 484         rc = sn_slot_disable(bss_hotplug_slot, slot->device_num,
 485                              PCI_REQ_SLOT_ELIGIBLE);
 486         if (rc)
 487                 goto leaving;
 488
 489         /* free the ACPI resources for the slot */
 490         if (SN_ACPI_BASE_SUPPORT() &&
 491             PCI_CONTROLLER(slot->pci_bus)->companion) {
 492                 unsigned long long adr;
 493                 struct acpi_device *device;
 494                 acpi_handle phandle;
 495                 acpi_handle chandle = NULL;
 496                 acpi_handle rethandle;
 497                 acpi_status ret;
 498
 499                 /* Get the rootbus node pointer */
 500                 phandle = acpi_device_handle(PCI_CONTROLLER(slot->pci_bus)->companion);
 501
 502                 acpi_scan_lock_acquire();
 503                 /*
 504                  * Walk the rootbus node's immediate children looking for
 505                  * the slot's device node(s). There can be more than
 506                  * one for multifunction devices.
 507                  */
 508                 for (;;) {
 509                         rethandle = NULL;
 510                         ret = acpi_get_next_object(ACPI_TYPE_DEVICE,
 511                                                    phandle, chandle,
 512                                                    &rethandle);
 513
 514                         if (ret == AE_NOT_FOUND || rethandle == NULL)
 515                                 break;
 516
 517                         chandle = rethandle;
 518
 519                         ret = acpi_evaluate_integer(chandle,
 520                                                     METHOD_NAME__ADR,
 521                                                     NULL, &adr);
 522                         if (ACPI_SUCCESS(ret) &&
 523                             (adr>>16) == (slot->device_num + 1)) {
 524                                 /* retain the owner id */
 525                                 ssdt_hdl = chandle;
 526
 527                                 ret = acpi_bus_get_device(chandle,
 528                                                           &device);
 529                                 if (ACPI_SUCCESS(ret))
 530                                         acpi_bus_trim(device);
 531                         }
 532                 }
 533                 acpi_scan_lock_release();
 534         }
 535
 536         pci_lock_rescan_remove();
 537         /* Free the SN resources assigned to the Linux device.*/
 538         list_for_each_entry_safe(dev, temp, &slot->pci_bus->devices, bus_list) {
 539                 if (PCI_SLOT(dev->devfn) != slot->device_num + 1)
 540                         continue;
 541
 542                 pci_dev_get(dev);
 543                 sn_bus_free_data(dev);
 544                 pci_stop_and_remove_bus_device(dev);
 545                 pci_dev_put(dev);
 546         }
 547         pci_unlock_rescan_remove();
 548
 549         /* Remove the SSDT for the slot from the ACPI namespace */
 550         if (SN_ACPI_BASE_SUPPORT() && ssdt_hdl) {
 551                 acpi_status ret;
 552                 ret = acpi_unload_parent_table(ssdt_hdl);
 553                 if (ACPI_FAILURE(ret)) {
 554                         acpi_handle_err(ssdt_hdl,
 555                                         "%s: acpi_unload_parent_table failed (0x%x)\n",
 556                                         __func__, ret);
 557                         /* try to continue on */
 558                 }
 559         }
 560
 561         /* free the collected sysdata pointers */
 562         sn_bus_free_sysdata();
 563
 564         /* Deactivate slot */
 565         rc = sn_slot_disable(bss_hotplug_slot, slot->device_num,
 566                              PCI_REQ_SLOT_DISABLE);
 567  leaving:
 568         /* Release the bus lock */
 569         mutex_unlock(&sn_hotplug_mutex);
 570
 571         return rc;
 572 }
 573
 574 static inline int get_power_status(struct hotplug_slot *bss_hotplug_slot,
 575                                    u8 *value)
 576 {
 577         struct slot *slot = bss_hotplug_slot->private;
 578         struct pcibus_info *pcibus_info;
 579         u32 power;
 580
 581         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
 582         mutex_lock(&sn_hotplug_mutex);
 583         power = pcibus_info->pbi_enabled_devices & (1 << slot->device_num);
 584         *value = power ? 1 : 0;
 585         mutex_unlock(&sn_hotplug_mutex);
 586         return 0;
 587 }
 588
 589 static void sn_release_slot(struct hotplug_slot *bss_hotplug_slot)
 590 {
 591         kfree(bss_hotplug_slot->info);
 592         kfree(bss_hotplug_slot->private);
 593         kfree(bss_hotplug_slot);
 594 }
 595
 596 static int sn_hotplug_slot_register(struct pci_bus *pci_bus)
 597 {
 598         int device;
 599         struct pci_slot *pci_slot;
 600         struct hotplug_slot *bss_hotplug_slot;
 601         char name[SN_SLOT_NAME_SIZE];
 602         int rc = 0;
 603
 604         /*
 605          * Currently only four devices are supported,
 606          * in the future there maybe more -- up to 32.
 607          */
 608
 609         for (device = 0; device < SN_MAX_HP_SLOTS ; device++) {
 610                 if (sn_pci_slot_valid(pci_bus, device) != 1)
 611                         continue;
 612
 613                 bss_hotplug_slot = kzalloc(sizeof(*bss_hotplug_slot),
 614                                            GFP_KERNEL);
 615                 if (!bss_hotplug_slot) {
 616                         rc = -ENOMEM;
 617                         goto alloc_err;
 618                 }
 619
 620                 bss_hotplug_slot->info =
 621                         kzalloc(sizeof(struct hotplug_slot_info),
 622                                 GFP_KERNEL);
 623                 if (!bss_hotplug_slot->info) {
 624                         rc = -ENOMEM;
 625                         goto alloc_err;
 626                 }
 627
 628                 if (sn_hp_slot_private_alloc(bss_hotplug_slot,
 629                                              pci_bus, device, name)) {
 630                         rc = -ENOMEM;
 631                         goto alloc_err;
 632                 }
 633                 bss_hotplug_slot->ops = &sn_hotplug_slot_ops;
 634                 bss_hotplug_slot->release = &sn_release_slot;
 635
 636                 rc = pci_hp_register(bss_hotplug_slot, pci_bus, device, name);
 637                 if (rc)
 638                         goto register_err;
 639
 640                 pci_slot = bss_hotplug_slot->pci_slot;
 641                 rc = sysfs_create_file(&pci_slot->kobj,
 642                                        &sn_slot_path_attr.attr);
 643                 if (rc)
 644                         goto register_err;
 645         }
 646         dev_dbg(&pci_bus->self->dev, "Registered bus with hotplug\n");
 647         return rc;
 648
 649 register_err:
 650         dev_dbg(&pci_bus->self->dev, "bus failed to register with err = %d\n",
 651                 rc);
 652
 653 alloc_err:
 654         if (rc == -ENOMEM)
 655                 dev_dbg(&pci_bus->self->dev, "Memory allocation error\n");
 656
 657         /* destroy THIS element */
 658         if (bss_hotplug_slot)
 659                 sn_release_slot(bss_hotplug_slot);
 660
 661         /* destroy anything else on the list */
 662         while ((bss_hotplug_slot = sn_hp_destroy()))
 663                 pci_hp_deregister(bss_hotplug_slot);
 664
 665         return rc;
 666 }
 667
 668 static int __init sn_pci_hotplug_init(void)
 669 {
 670         struct pci_bus *pci_bus = NULL;
 671         int rc;
 672         int registered = 0;
 673
 674         if (!sn_prom_feature_available(PRF_HOTPLUG_SUPPORT)) {
 675                 printk(KERN_ERR "%s: PROM version does not support hotplug.\n",
 676                        __func__);
 677                 return -EPERM;
 678         }
 679
 680         INIT_LIST_HEAD(&sn_hp_list);
 681
 682         while ((pci_bus = pci_find_next_bus(pci_bus))) {
 683                 if (!pci_bus->sysdata)
 684                         continue;
 685
 686                 rc = sn_pci_bus_valid(pci_bus);
 687                 if (rc != 1) {
 688                         dev_dbg(&pci_bus->self->dev, "not a valid hotplug bus\n");
 689                         continue;
 690                 }
 691                 dev_dbg(&pci_bus->self->dev, "valid hotplug bus\n");
 692
 693                 rc = sn_hotplug_slot_register(pci_bus);
 694                 if (!rc) {
 695                         registered = 1;
 696                 } else {
 697                         registered = 0;
 698                         break;
 699                 }
 700         }
 701
 702         return registered == 1 ? 0 : -ENODEV;
 703 }
 704
 705 static void __exit sn_pci_hotplug_exit(void)
 706 {
 707         struct hotplug_slot *bss_hotplug_slot;
 708
 709         while ((bss_hotplug_slot = sn_hp_destroy()))
 710                 pci_hp_deregister(bss_hotplug_slot);
 711
 712         if (!list_empty(&sn_hp_list))
 713                 printk(KERN_ERR "%s: internal list is not empty\n", __FILE__);
 714 }
 715
 716 module_init(sn_pci_hotplug_init);
 717 module_exit(sn_pci_hotplug_exit);