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,
 254                         "L1 failure %d with message: %s",
 255                         resp.resp_sub_errno, resp.resp_l1_msg);
 256                 return -EPERM;
 257         }
 258
 259         if (rc) {
 260                 dev_dbg(&slot->pci_bus->self->dev,
 261                         "insert failed with error %d sub-error %d\n",
 262                         rc, resp.resp_sub_errno);
 263                 return -EIO;
 264         }
 265
 266         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
 267         pcibus_info->pbi_enabled_devices |= (1 << device_num);
 268
 269         return 0;
 270 }
 271
 272 static int sn_slot_disable(struct hotplug_slot *bss_hotplug_slot,
 273                            int device_num, int action)
 274 {
 275         struct slot *slot = bss_hotplug_slot->private;
 276         struct pcibus_info *pcibus_info;
 277         struct pcibr_slot_disable_resp resp;
 278         int rc;
 279
 280         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
 281
 282         rc = sal_pcibr_slot_disable(pcibus_info, device_num, action, &resp);
 283
 284         if ((action == PCI_REQ_SLOT_ELIGIBLE) &&
 285             (rc == PCI_SLOT_ALREADY_DOWN)) {
 286                 dev_dbg(&slot->pci_bus->self->dev, "Slot %s already inactive\n", slot->physical_path);
 287                 return 1; /* return 1 to user */
 288         }
 289
 290         if ((action == PCI_REQ_SLOT_ELIGIBLE) && (rc == PCI_EMPTY_33MHZ)) {
 291                 dev_dbg(&slot->pci_bus->self->dev,
 292                         "Cannot remove last 33MHz card\n");
 293                 return -EPERM;
 294         }
 295
 296         if ((action == PCI_REQ_SLOT_ELIGIBLE) && (rc == PCI_L1_ERR)) {
 297                 dev_dbg(&slot->pci_bus->self->dev,
 298                         "L1 failure %d with message \n%s\n",
 299                         resp.resp_sub_errno, resp.resp_l1_msg);
 300                 return -EPERM;
 301         }
 302
 303         if ((action == PCI_REQ_SLOT_ELIGIBLE) && rc) {
 304                 dev_dbg(&slot->pci_bus->self->dev,
 305                         "remove failed with error %d sub-error %d\n",
 306                         rc, resp.resp_sub_errno);
 307                 return -EIO;
 308         }
 309
 310         if ((action == PCI_REQ_SLOT_ELIGIBLE) && !rc)
 311                 return 0;
 312
 313         if ((action == PCI_REQ_SLOT_DISABLE) && !rc) {
 314                 pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
 315                 pcibus_info->pbi_enabled_devices &= ~(1 << device_num);
 316                 dev_dbg(&slot->pci_bus->self->dev, "remove successful\n");
 317                 return 0;
 318         }
 319
 320         if ((action == PCI_REQ_SLOT_DISABLE) && rc) {
 321                 dev_dbg(&slot->pci_bus->self->dev,"remove failed rc = %d\n", rc);
 322         }
 323
 324         return rc;
 325 }
 326
 327 /*
 328  * Power up and configure the slot via a SAL call to PROM.
 329  * Scan slot (and any children), do any platform specific fixup,
 330  * and find device driver.
 331  */
 332 static int enable_slot(struct hotplug_slot *bss_hotplug_slot)
 333 {
 334         struct slot *slot = bss_hotplug_slot->private;
 335         struct pci_bus *new_bus = NULL;
 336         struct pci_dev *dev;
 337         int num_funcs;
 338         int new_ppb = 0;
 339         int rc;
 340         char *ssdt = NULL;
 341         void pcibios_fixup_device_resources(struct pci_dev *);
 342
 343         /* Serialize the Linux PCI infrastructure */
 344         mutex_lock(&sn_hotplug_mutex);
 345
 346         /*
 347          * Power-on and initialize the slot in the SN
 348          * PCI infrastructure. Also, retrieve the ACPI SSDT
 349          * table for the slot (if ACPI capable PROM).
 350          */
 351         rc = sn_slot_enable(bss_hotplug_slot, slot->device_num, &ssdt);
 352         if (rc) {
 353                 mutex_unlock(&sn_hotplug_mutex);
 354                 return rc;
 355         }
 356
 357         if (ssdt)
 358                 ssdt = __va(ssdt);
 359         /* Add the new SSDT for the slot to the ACPI namespace */
 360         if (SN_ACPI_BASE_SUPPORT() && ssdt) {
 361                 acpi_status ret;
 362
 363                 ret = acpi_load_table((struct acpi_table_header *)ssdt);
 364                 if (ACPI_FAILURE(ret)) {
 365                         printk(KERN_ERR "%s: acpi_load_table failed (0x%x)\n",
 366                                __func__, ret);
 367                         /* try to continue on */
 368                 }
 369         }
 370
 371         num_funcs = pci_scan_slot(slot->pci_bus,
 372                                   PCI_DEVFN(slot->device_num + 1, 0));
 373         if (!num_funcs) {
 374                 dev_dbg(&slot->pci_bus->self->dev, "no device in slot\n");
 375                 mutex_unlock(&sn_hotplug_mutex);
 376                 return -ENODEV;
 377         }
 378
 379         /*
 380          * Map SN resources for all functions on the card
 381          * to the Linux PCI interface and tell the drivers
 382          * about them.
 383          */
 384         list_for_each_entry(dev, &slot->pci_bus->devices, bus_list) {
 385                 if (PCI_SLOT(dev->devfn) != slot->device_num + 1)
 386                         continue;
 387
 388                 /* Need to do slot fixup on PPB before fixup of children
 389                  * (PPB's pcidev_info needs to be in pcidev_info list
 390                  * before child's SN_PCIDEV_INFO() call to setup
 391                  * pdi_host_pcidev_info).
 392                  */
 393                 pcibios_fixup_device_resources(dev);
 394                 if (SN_ACPI_BASE_SUPPORT())
 395                         sn_acpi_slot_fixup(dev);
 396                 else
 397                         sn_io_slot_fixup(dev);
 398                 if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
 399                         pci_hp_add_bridge(dev);
 400                         if (dev->subordinate) {
 401                                 new_bus = dev->subordinate;
 402                                 new_ppb = 1;
 403                         }
 404                 }
 405         }
 406
 407         /*
 408          * Add the slot's devices to the ACPI infrastructure */
 409         if (SN_ACPI_BASE_SUPPORT() && ssdt) {
 410                 unsigned long long adr;
 411                 struct acpi_device *pdevice;
 412                 acpi_handle phandle;
 413                 acpi_handle chandle = NULL;
 414                 acpi_handle rethandle;
 415                 acpi_status ret;
 416
 417                 phandle = acpi_device_handle(PCI_CONTROLLER(slot->pci_bus)->companion);
 418
 419                 if (acpi_bus_get_device(phandle, &pdevice)) {
 420                         dev_dbg(&slot->pci_bus->self->dev,
 421                                 "no parent device, assuming NULL\n");
 422                         pdevice = NULL;
 423                 }
 424
 425                 acpi_scan_lock_acquire();
 426                 /*
 427                  * Walk the rootbus node's immediate children looking for
 428                  * the slot's device node(s). There can be more than
 429                  * one for multifunction devices.
 430                  */
 431                 for (;;) {
 432                         rethandle = NULL;
 433                         ret = acpi_get_next_object(ACPI_TYPE_DEVICE,
 434                                                    phandle, chandle,
 435                                                    &rethandle);
 436
 437                         if (ret == AE_NOT_FOUND || rethandle == NULL)
 438                                 break;
 439
 440                         chandle = rethandle;
 441
 442                         ret = acpi_evaluate_integer(chandle, METHOD_NAME__ADR,
 443                                                     NULL, &adr);
 444
 445                         if (ACPI_SUCCESS(ret) &&
 446                             (adr>>16) == (slot->device_num + 1)) {
 447
 448                                 ret = acpi_bus_scan(chandle);
 449                                 if (ACPI_FAILURE(ret)) {
 450                                         printk(KERN_ERR "%s: acpi_bus_scan "
 451                                                "failed (0x%x) for slot %d "
 452                                                "func %d\n", __func__,
 453                                                ret, (int)(adr>>16),
 454                                                (int)(adr&0xffff));
 455                                         /* try to continue on */
 456                                 }
 457                         }
 458                 }
 459                 acpi_scan_lock_release();
 460         }
 461
 462         /* Call the driver for the new device */
 463         pci_bus_add_devices(slot->pci_bus);
 464         /* Call the drivers for the new devices subordinate to PPB */
 465         if (new_ppb)
 466                 pci_bus_add_devices(new_bus);
 467
 468         mutex_unlock(&sn_hotplug_mutex);
 469
 470         if (rc == 0)
 471                 dev_dbg(&slot->pci_bus->self->dev,
 472                         "insert operation successful\n");
 473         else
 474                 dev_dbg(&slot->pci_bus->self->dev,
 475                         "insert operation failed rc = %d\n", rc);
 476
 477         return rc;
 478 }
 479
 480 static int disable_slot(struct hotplug_slot *bss_hotplug_slot)
 481 {
 482         struct slot *slot = bss_hotplug_slot->private;
 483         struct pci_dev *dev, *temp;
 484         int rc;
 485         acpi_owner_id ssdt_id = 0;
 486
 487         /* Acquire update access to the bus */
 488         mutex_lock(&sn_hotplug_mutex);
 489
 490         /* is it okay to bring this slot down? */
 491         rc = sn_slot_disable(bss_hotplug_slot, slot->device_num,
 492                              PCI_REQ_SLOT_ELIGIBLE);
 493         if (rc)
 494                 goto leaving;
 495
 496         /* free the ACPI resources for the slot */
 497         if (SN_ACPI_BASE_SUPPORT() &&
 498             PCI_CONTROLLER(slot->pci_bus)->companion) {
 499                 unsigned long long adr;
 500                 struct acpi_device *device;
 501                 acpi_handle phandle;
 502                 acpi_handle chandle = NULL;
 503                 acpi_handle rethandle;
 504                 acpi_status ret;
 505
 506                 /* Get the rootbus node pointer */
 507                 phandle = acpi_device_handle(PCI_CONTROLLER(slot->pci_bus)->companion);
 508
 509                 acpi_scan_lock_acquire();
 510                 /*
 511                  * Walk the rootbus node's immediate children looking for
 512                  * the slot's device node(s). There can be more than
 513                  * one for multifunction devices.
 514                  */
 515                 for (;;) {
 516                         rethandle = NULL;
 517                         ret = acpi_get_next_object(ACPI_TYPE_DEVICE,
 518                                                    phandle, chandle,
 519                                                    &rethandle);
 520
 521                         if (ret == AE_NOT_FOUND || rethandle == NULL)
 522                                 break;
 523
 524                         chandle = rethandle;
 525
 526                         ret = acpi_evaluate_integer(chandle,
 527                                                     METHOD_NAME__ADR,
 528                                                     NULL, &adr);
 529                         if (ACPI_SUCCESS(ret) &&
 530                             (adr>>16) == (slot->device_num + 1)) {
 531                                 /* retain the owner id */
 532                                 acpi_get_id(chandle, &ssdt_id);
 533
 534                                 ret = acpi_bus_get_device(chandle,
 535                                                           &device);
 536                                 if (ACPI_SUCCESS(ret))
 537                                         acpi_bus_trim(device);
 538                         }
 539                 }
 540                 acpi_scan_lock_release();
 541         }
 542
 543         /* Free the SN resources assigned to the Linux device.*/
 544         list_for_each_entry_safe(dev, temp, &slot->pci_bus->devices, bus_list) {
 545                 if (PCI_SLOT(dev->devfn) != slot->device_num + 1)
 546                         continue;
 547
 548                 pci_dev_get(dev);
 549                 sn_bus_free_data(dev);
 550                 pci_stop_and_remove_bus_device(dev);
 551                 pci_dev_put(dev);
 552         }
 553
 554         /* Remove the SSDT for the slot from the ACPI namespace */
 555         if (SN_ACPI_BASE_SUPPORT() && ssdt_id) {
 556                 acpi_status ret;
 557                 ret = acpi_unload_table_id(ssdt_id);
 558                 if (ACPI_FAILURE(ret)) {
 559                         printk(KERN_ERR "%s: acpi_unload_table_id "
 560                                "failed (0x%x) for id %d\n",
 561                                __func__, ret, ssdt_id);
 562                         /* try to continue on */
 563                 }
 564         }
 565
 566         /* free the collected sysdata pointers */
 567         sn_bus_free_sysdata();
 568
 569         /* Deactivate slot */
 570         rc = sn_slot_disable(bss_hotplug_slot, slot->device_num,
 571                              PCI_REQ_SLOT_DISABLE);
 572  leaving:
 573         /* Release the bus lock */
 574         mutex_unlock(&sn_hotplug_mutex);
 575
 576         return rc;
 577 }
 578
 579 static inline int get_power_status(struct hotplug_slot *bss_hotplug_slot,
 580                                    u8 *value)
 581 {
 582         struct slot *slot = bss_hotplug_slot->private;
 583         struct pcibus_info *pcibus_info;
 584         u32 power;
 585
 586         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
 587         mutex_lock(&sn_hotplug_mutex);
 588         power = pcibus_info->pbi_enabled_devices & (1 << slot->device_num);
 589         *value = power ? 1 : 0;
 590         mutex_unlock(&sn_hotplug_mutex);
 591         return 0;
 592 }
 593
 594 static void sn_release_slot(struct hotplug_slot *bss_hotplug_slot)
 595 {
 596         kfree(bss_hotplug_slot->info);
 597         kfree(bss_hotplug_slot->private);
 598         kfree(bss_hotplug_slot);
 599 }
 600
 601 static int sn_hotplug_slot_register(struct pci_bus *pci_bus)
 602 {
 603         int device;
 604         struct pci_slot *pci_slot;
 605         struct hotplug_slot *bss_hotplug_slot;
 606         char name[SN_SLOT_NAME_SIZE];
 607         int rc = 0;
 608
 609         /*
 610          * Currently only four devices are supported,
 611          * in the future there maybe more -- up to 32.
 612          */
 613
 614         for (device = 0; device < SN_MAX_HP_SLOTS ; device++) {
 615                 if (sn_pci_slot_valid(pci_bus, device) != 1)
 616                         continue;
 617
 618                 bss_hotplug_slot = kzalloc(sizeof(*bss_hotplug_slot),
 619                                            GFP_KERNEL);
 620                 if (!bss_hotplug_slot) {
 621                         rc = -ENOMEM;
 622                         goto alloc_err;
 623                 }
 624
 625                 bss_hotplug_slot->info =
 626                         kzalloc(sizeof(struct hotplug_slot_info),
 627                                 GFP_KERNEL);
 628                 if (!bss_hotplug_slot->info) {
 629                         rc = -ENOMEM;
 630                         goto alloc_err;
 631                 }
 632
 633                 if (sn_hp_slot_private_alloc(bss_hotplug_slot,
 634                                              pci_bus, device, name)) {
 635                         rc = -ENOMEM;
 636                         goto alloc_err;
 637                 }
 638                 bss_hotplug_slot->ops = &sn_hotplug_slot_ops;
 639                 bss_hotplug_slot->release = &sn_release_slot;
 640
 641                 rc = pci_hp_register(bss_hotplug_slot, pci_bus, device, name);
 642                 if (rc)
 643                         goto register_err;
 644
 645                 pci_slot = bss_hotplug_slot->pci_slot;
 646                 rc = sysfs_create_file(&pci_slot->kobj,
 647                                        &sn_slot_path_attr.attr);
 648                 if (rc)
 649                         goto register_err;
 650         }
 651         dev_dbg(&pci_bus->self->dev, "Registered bus with hotplug\n");
 652         return rc;
 653
 654 register_err:
 655         dev_dbg(&pci_bus->self->dev, "bus failed to register with err = %d\n",
 656                 rc);
 657
 658 alloc_err:
 659         if (rc == -ENOMEM)
 660                 dev_dbg(&pci_bus->self->dev, "Memory allocation error\n");
 661
 662         /* destroy THIS element */
 663         if (bss_hotplug_slot)
 664                 sn_release_slot(bss_hotplug_slot);
 665
 666         /* destroy anything else on the list */
 667         while ((bss_hotplug_slot = sn_hp_destroy()))
 668                 pci_hp_deregister(bss_hotplug_slot);
 669
 670         return rc;
 671 }
 672
 673 static int __init sn_pci_hotplug_init(void)
 674 {
 675         struct pci_bus *pci_bus = NULL;
 676         int rc;
 677         int registered = 0;
 678
 679         if (!sn_prom_feature_available(PRF_HOTPLUG_SUPPORT)) {
 680                 printk(KERN_ERR "%s: PROM version does not support hotplug.\n",
 681                        __func__);
 682                 return -EPERM;
 683         }
 684
 685         INIT_LIST_HEAD(&sn_hp_list);
 686
 687         while ((pci_bus = pci_find_next_bus(pci_bus))) {
 688                 if (!pci_bus->sysdata)
 689                         continue;
 690
 691                 rc = sn_pci_bus_valid(pci_bus);
 692                 if (rc != 1) {
 693                         dev_dbg(&pci_bus->self->dev, "not a valid hotplug bus\n");
 694                         continue;
 695                 }
 696                 dev_dbg(&pci_bus->self->dev, "valid hotplug bus\n");
 697
 698                 rc = sn_hotplug_slot_register(pci_bus);
 699                 if (!rc) {
 700                         registered = 1;
 701                 } else {
 702                         registered = 0;
 703                         break;
 704                 }
 705         }
 706
 707         return registered == 1 ? 0 : -ENODEV;
 708 }
 709
 710 static void __exit sn_pci_hotplug_exit(void)
 711 {
 712         struct hotplug_slot *bss_hotplug_slot;
 713
 714         while ((bss_hotplug_slot = sn_hp_destroy()))
 715                 pci_hp_deregister(bss_hotplug_slot);
 716
 717         if (!list_empty(&sn_hp_list))
 718                 printk(KERN_ERR "%s: internal list is not empty\n", __FILE__);
 719 }
 720
 721 module_init(sn_pci_hotplug_init);
 722 module_exit(sn_pci_hotplug_exit);