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/init.h>
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/pci.h>
  16 #include <linux/pci_hotplug.h>
  17 #include <linux/proc_fs.h>
  18 #include <linux/types.h>
  19 #include <linux/mutex.h>
  20
  21 #include <asm/sn/addrs.h>
  22 #include <asm/sn/geo.h>
  23 #include <asm/sn/l1.h>
  24 #include <asm/sn/module.h>
  25 #include <asm/sn/pcibr_provider.h>
  26 #include <asm/sn/pcibus_provider_defs.h>
  27 #include <asm/sn/pcidev.h>
  28 #include <asm/sn/sn_feature_sets.h>
  29 #include <asm/sn/sn_sal.h>
  30 #include <asm/sn/types.h>
  31 #include <linux/acpi.h>
  32 #include <asm/sn/acpi.h>
  33
  34 #include "../pci.h"
  35
  36 MODULE_LICENSE("GPL");
  37 MODULE_AUTHOR("SGI (prarit@sgi.com, dickie@sgi.com, habeck@sgi.com)");
  38 MODULE_DESCRIPTION("SGI Altix Hot Plug PCI Controller Driver");
  39
  40
  41 /* SAL call error codes. Keep in sync with prom header io/include/pcibr.h */
  42 #define PCI_SLOT_ALREADY_UP             2       /* slot already up */
  43 #define PCI_SLOT_ALREADY_DOWN           3       /* slot already down */
  44 #define PCI_L1_ERR                      7       /* L1 console command error */
  45 #define PCI_EMPTY_33MHZ                 15      /* empty 33 MHz bus */
  46
  47
  48 #define PCIIO_ASIC_TYPE_TIOCA           4
  49 #define PCI_L1_QSIZE                    128     /* our L1 message buffer size */
  50 #define SN_MAX_HP_SLOTS                 32      /* max hotplug slots */
  51 #define SN_SLOT_NAME_SIZE               33      /* size of name string */
  52
  53 /* internal list head */
  54 static struct list_head sn_hp_list;
  55
  56 /* hotplug_slot struct's private pointer */
  57 struct slot {
  58         int device_num;
  59         struct pci_bus *pci_bus;
  60         /* this struct for glue internal only */
  61         struct hotplug_slot *hotplug_slot;
  62         struct list_head hp_list;
  63         char physical_path[SN_SLOT_NAME_SIZE];
  64 };
  65
  66 struct pcibr_slot_enable_resp {
  67         int resp_sub_errno;
  68         char resp_l1_msg[PCI_L1_QSIZE + 1];
  69 };
  70
  71 struct pcibr_slot_disable_resp {
  72         int resp_sub_errno;
  73         char resp_l1_msg[PCI_L1_QSIZE + 1];
  74 };
  75
  76 enum sn_pci_req_e {
  77         PCI_REQ_SLOT_ELIGIBLE,
  78         PCI_REQ_SLOT_DISABLE
  79 };
  80
  81 static int enable_slot(struct hotplug_slot *slot);
  82 static int disable_slot(struct hotplug_slot *slot);
  83 static inline int get_power_status(struct hotplug_slot *slot, u8 *value);
  84
  85 static struct hotplug_slot_ops sn_hotplug_slot_ops = {
  86         .owner                  = THIS_MODULE,
  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 hotplug_slot *bss_hotplug_slot,
  95                           char *buf)
  96 {
  97         int retval = -ENOENT;
  98         struct slot *slot = bss_hotplug_slot->private;
  99
 100         if (!slot)
 101                 return retval;
 102
 103         retval = sprintf (buf, "%s\n", slot->physical_path);
 104         return retval;
 105 }
 106
 107 static struct hotplug_slot_attribute sn_slot_path_attr = __ATTR_RO(path);
 108
 109 static int sn_pci_slot_valid(struct pci_bus *pci_bus, int device)
 110 {
 111         struct pcibus_info *pcibus_info;
 112         u16 busnum, segment, ioboard_type;
 113
 114         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(pci_bus);
 115
 116         /* Check to see if this is a valid slot on 'pci_bus' */
 117         if (!(pcibus_info->pbi_valid_devices & (1 << device)))
 118                 return -EPERM;
 119
 120         ioboard_type = sn_ioboard_to_pci_bus(pci_bus);
 121         busnum = pcibus_info->pbi_buscommon.bs_persist_busnum;
 122         segment = pci_domain_nr(pci_bus) & 0xf;
 123
 124         /* Do not allow hotplug operations on base I/O cards */
 125         if ((ioboard_type == L1_BRICKTYPE_IX ||
 126              ioboard_type == L1_BRICKTYPE_IA) &&
 127             (segment == 1 && busnum == 0 && device != 1))
 128                 return -EPERM;
 129
 130         return 1;
 131 }
 132
 133 static int sn_pci_bus_valid(struct pci_bus *pci_bus)
 134 {
 135         struct pcibus_info *pcibus_info;
 136         u32 asic_type;
 137         u16 ioboard_type;
 138
 139         /* Don't register slots hanging off the TIOCA bus */
 140         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(pci_bus);
 141         asic_type = pcibus_info->pbi_buscommon.bs_asic_type;
 142         if (asic_type == PCIIO_ASIC_TYPE_TIOCA)
 143                 return -EPERM;
 144
 145         /* Only register slots in I/O Bricks that support hotplug */
 146         ioboard_type = sn_ioboard_to_pci_bus(pci_bus);
 147         switch (ioboard_type) {
 148                 case L1_BRICKTYPE_IX:
 149                 case L1_BRICKTYPE_PX:
 150                 case L1_BRICKTYPE_IA:
 151                 case L1_BRICKTYPE_PA:
 152                 case L1_BOARDTYPE_PCIX3SLOT:
 153                         return 1;
 154                         break;
 155                 default:
 156                         return -EPERM;
 157                         break;
 158         }
 159
 160         return -EIO;
 161 }
 162
 163 static int sn_hp_slot_private_alloc(struct hotplug_slot *bss_hotplug_slot,
 164                                     struct pci_bus *pci_bus, int device,
 165                                     char *name)
 166 {
 167         struct pcibus_info *pcibus_info;
 168         struct slot *slot;
 169
 170         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(pci_bus);
 171
 172         slot = kzalloc(sizeof(*slot), GFP_KERNEL);
 173         if (!slot)
 174                 return -ENOMEM;
 175         bss_hotplug_slot->private = slot;
 176
 177         slot->device_num = device;
 178         slot->pci_bus = pci_bus;
 179         sprintf(name, "%04x:%02x:%02x",
 180                 pci_domain_nr(pci_bus),
 181                 ((u16)pcibus_info->pbi_buscommon.bs_persist_busnum),
 182                 device + 1);
 183
 184         sn_generate_path(pci_bus, slot->physical_path);
 185
 186         slot->hotplug_slot = bss_hotplug_slot;
 187         list_add(&slot->hp_list, &sn_hp_list);
 188
 189         return 0;
 190 }
 191
 192 static struct hotplug_slot * sn_hp_destroy(void)
 193 {
 194         struct slot *slot;
 195         struct pci_slot *pci_slot;
 196         struct hotplug_slot *bss_hotplug_slot = NULL;
 197
 198         list_for_each_entry(slot, &sn_hp_list, hp_list) {
 199                 bss_hotplug_slot = slot->hotplug_slot;
 200                 pci_slot = bss_hotplug_slot->pci_slot;
 201                 list_del(&((struct slot *)bss_hotplug_slot->private)->
 202                          hp_list);
 203                 sysfs_remove_file(&pci_slot->kobj,
 204                                   &sn_slot_path_attr.attr);
 205                 break;
 206         }
 207         return bss_hotplug_slot;
 208 }
 209
 210 static void sn_bus_free_data(struct pci_dev *dev)
 211 {
 212         struct pci_bus *subordinate_bus;
 213         struct pci_dev *child;
 214
 215         /* Recursively clean up sn_irq_info structs */
 216         if (dev->subordinate) {
 217                 subordinate_bus = dev->subordinate;
 218                 list_for_each_entry(child, &subordinate_bus->devices, bus_list)
 219                         sn_bus_free_data(child);
 220         }
 221         /*
 222          * Some drivers may use dma accesses during the
 223          * driver remove function. We release the sysdata
 224          * areas after the driver remove functions have
 225          * been called.
 226          */
 227         sn_bus_store_sysdata(dev);
 228         sn_pci_unfixup_slot(dev);
 229 }
 230
 231 static int sn_slot_enable(struct hotplug_slot *bss_hotplug_slot,
 232                           int device_num, char **ssdt)
 233 {
 234         struct slot *slot = bss_hotplug_slot->private;
 235         struct pcibus_info *pcibus_info;
 236         struct pcibr_slot_enable_resp resp;
 237         int rc;
 238
 239         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
 240
 241         /*
 242          * Power-on and initialize the slot in the SN
 243          * PCI infrastructure.
 244          */
 245         rc = sal_pcibr_slot_enable(pcibus_info, device_num, &resp, ssdt);
 246
 247
 248         if (rc == PCI_SLOT_ALREADY_UP) {
 249                 dev_dbg(&slot->pci_bus->self->dev, "is already active\n");
 250                 return 1; /* return 1 to user */
 251         }
 252
 253         if (rc == PCI_L1_ERR) {
 254                 dev_dbg(&slot->pci_bus->self->dev,
 255                         "L1 failure %d with message: %s",
 256                         resp.resp_sub_errno, resp.resp_l1_msg);
 257                 return -EPERM;
 258         }
 259
 260         if (rc) {
 261                 dev_dbg(&slot->pci_bus->self->dev,
 262                         "insert failed with error %d sub-error %d\n",
 263                         rc, resp.resp_sub_errno);
 264                 return -EIO;
 265         }
 266
 267         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
 268         pcibus_info->pbi_enabled_devices |= (1 << device_num);
 269
 270         return 0;
 271 }
 272
 273 static int sn_slot_disable(struct hotplug_slot *bss_hotplug_slot,
 274                            int device_num, int action)
 275 {
 276         struct slot *slot = bss_hotplug_slot->private;
 277         struct pcibus_info *pcibus_info;
 278         struct pcibr_slot_disable_resp resp;
 279         int rc;
 280
 281         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
 282
 283         rc = sal_pcibr_slot_disable(pcibus_info, device_num, action, &resp);
 284
 285         if ((action == PCI_REQ_SLOT_ELIGIBLE) &&
 286             (rc == PCI_SLOT_ALREADY_DOWN)) {
 287                 dev_dbg(&slot->pci_bus->self->dev, "Slot %s already inactive\n", slot->physical_path);
 288                 return 1; /* return 1 to user */
 289         }
 290
 291         if ((action == PCI_REQ_SLOT_ELIGIBLE) && (rc == PCI_EMPTY_33MHZ)) {
 292                 dev_dbg(&slot->pci_bus->self->dev,
 293                         "Cannot remove last 33MHz card\n");
 294                 return -EPERM;
 295         }
 296
 297         if ((action == PCI_REQ_SLOT_ELIGIBLE) && (rc == PCI_L1_ERR)) {
 298                 dev_dbg(&slot->pci_bus->self->dev,
 299                         "L1 failure %d with message \n%s\n",
 300                         resp.resp_sub_errno, resp.resp_l1_msg);
 301                 return -EPERM;
 302         }
 303
 304         if ((action == PCI_REQ_SLOT_ELIGIBLE) && rc) {
 305                 dev_dbg(&slot->pci_bus->self->dev,
 306                         "remove failed with error %d sub-error %d\n",
 307                         rc, resp.resp_sub_errno);
 308                 return -EIO;
 309         }
 310
 311         if ((action == PCI_REQ_SLOT_ELIGIBLE) && !rc)
 312                 return 0;
 313
 314         if ((action == PCI_REQ_SLOT_DISABLE) && !rc) {
 315                 pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
 316                 pcibus_info->pbi_enabled_devices &= ~(1 << device_num);
 317                 dev_dbg(&slot->pci_bus->self->dev, "remove successful\n");
 318                 return 0;
 319         }
 320
 321         if ((action == PCI_REQ_SLOT_DISABLE) && rc) {
 322                 dev_dbg(&slot->pci_bus->self->dev,"remove failed rc = %d\n", rc);
 323         }
 324
 325         return rc;
 326 }
 327
 328 /*
 329  * Power up and configure the slot via a SAL call to PROM.
 330  * Scan slot (and any children), do any platform specific fixup,
 331  * and find device driver.
 332  */
 333 static int enable_slot(struct hotplug_slot *bss_hotplug_slot)
 334 {
 335         struct slot *slot = bss_hotplug_slot->private;
 336         struct pci_bus *new_bus = NULL;
 337         struct pci_dev *dev;
 338         int func, num_funcs;
 339         int new_ppb = 0;
 340         int rc;
 341         char *ssdt = NULL;
 342         void pcibios_fixup_device_resources(struct pci_dev *);
 343
 344         /* Serialize the Linux PCI infrastructure */
 345         mutex_lock(&sn_hotplug_mutex);
 346
 347         /*
 348          * Power-on and initialize the slot in the SN
 349          * PCI infrastructure. Also, retrieve the ACPI SSDT
 350          * table for the slot (if ACPI capable PROM).
 351          */
 352         rc = sn_slot_enable(bss_hotplug_slot, slot->device_num, &ssdt);
 353         if (rc) {
 354                 mutex_unlock(&sn_hotplug_mutex);
 355                 return rc;
 356         }
 357
 358         if (ssdt)
 359                 ssdt = __va(ssdt);
 360         /* Add the new SSDT for the slot to the ACPI namespace */
 361         if (SN_ACPI_BASE_SUPPORT() && ssdt) {
 362                 acpi_status ret;
 363
 364                 ret = acpi_load_table((struct acpi_table_header *)ssdt);
 365                 if (ACPI_FAILURE(ret)) {
 366                         printk(KERN_ERR "%s: acpi_load_table failed (0x%x)\n",
 367                                __func__, ret);
 368                         /* try to continue on */
 369                 }
 370         }
 371
 372         num_funcs = pci_scan_slot(slot->pci_bus,
 373                                   PCI_DEVFN(slot->device_num + 1, 0));
 374         if (!num_funcs) {
 375                 dev_dbg(&slot->pci_bus->self->dev, "no device in slot\n");
 376                 mutex_unlock(&sn_hotplug_mutex);
 377                 return -ENODEV;
 378         }
 379
 380         /*
 381          * Map SN resources for all functions on the card
 382          * to the Linux PCI interface and tell the drivers
 383          * about them.
 384          */
 385         for (func = 0; func < num_funcs;  func++) {
 386                 dev = pci_get_slot(slot->pci_bus,
 387                                    PCI_DEVFN(slot->device_num + 1,
 388                                              PCI_FUNC(func)));
 389                 if (dev) {
 390                         /* Need to do slot fixup on PPB before fixup of children
 391                          * (PPB's pcidev_info needs to be in pcidev_info list
 392                          * before child's SN_PCIDEV_INFO() call to setup
 393                          * pdi_host_pcidev_info).
 394                          */
 395                         pcibios_fixup_device_resources(dev);
 396                         if (SN_ACPI_BASE_SUPPORT())
 397                                 sn_acpi_slot_fixup(dev);
 398                         else
 399                                 sn_io_slot_fixup(dev);
 400                         if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
 401                                 unsigned char sec_bus;
 402                                 pci_read_config_byte(dev, PCI_SECONDARY_BUS,
 403                                                      &sec_bus);
 404                                 new_bus = pci_add_new_bus(dev->bus, dev,
 405                                                           sec_bus);
 406                                 pci_scan_child_bus(new_bus);
 407                                 new_ppb = 1;
 408                         }
 409                         pci_dev_put(dev);
 410                 }
 411         }
 412
 413         /*
 414          * Add the slot's devices to the ACPI infrastructure */
 415         if (SN_ACPI_BASE_SUPPORT() && ssdt) {
 416                 unsigned long long adr;
 417                 struct acpi_device *pdevice;
 418                 struct acpi_device *device;
 419                 acpi_handle phandle;
 420                 acpi_handle chandle = NULL;
 421                 acpi_handle rethandle;
 422                 acpi_status ret;
 423
 424                 phandle = PCI_CONTROLLER(slot->pci_bus)->acpi_handle;
 425
 426                 if (acpi_bus_get_device(phandle, &pdevice)) {
 427                         dev_dbg(&slot->pci_bus->self->dev,
 428                                 "no parent device, assuming NULL\n");
 429                         pdevice = NULL;
 430                 }
 431
 432                 /*
 433                  * Walk the rootbus node's immediate children looking for
 434                  * the slot's device node(s). There can be more than
 435                  * one for multifunction devices.
 436                  */
 437                 for (;;) {
 438                         rethandle = NULL;
 439                         ret = acpi_get_next_object(ACPI_TYPE_DEVICE,
 440                                                    phandle, chandle,
 441                                                    &rethandle);
 442
 443                         if (ret == AE_NOT_FOUND || rethandle == NULL)
 444                                 break;
 445
 446                         chandle = rethandle;
 447
 448                         ret = acpi_evaluate_integer(chandle, METHOD_NAME__ADR,
 449                                                     NULL, &adr);
 450
 451                         if (ACPI_SUCCESS(ret) &&
 452                             (adr>>16) == (slot->device_num + 1)) {
 453
 454                                 ret = acpi_bus_add(&device, pdevice, chandle,
 455                                                    ACPI_BUS_TYPE_DEVICE);
 456                                 if (ACPI_FAILURE(ret)) {
 457                                         printk(KERN_ERR "%s: acpi_bus_add "
 458                                                "failed (0x%x) for slot %d "
 459                                                "func %d\n", __func__,
 460                                                ret, (int)(adr>>16),
 461                                                (int)(adr&0xffff));
 462                                         /* try to continue on */
 463                                 } else {
 464                                         acpi_bus_start(device);
 465                                 }
 466                         }
 467                 }
 468         }
 469
 470         /* Call the driver for the new device */
 471         pci_bus_add_devices(slot->pci_bus);
 472         /* Call the drivers for the new devices subordinate to PPB */
 473         if (new_ppb)
 474                 pci_bus_add_devices(new_bus);
 475
 476         mutex_unlock(&sn_hotplug_mutex);
 477
 478         if (rc == 0)
 479                 dev_dbg(&slot->pci_bus->self->dev,
 480                         "insert operation successful\n");
 481         else
 482                 dev_dbg(&slot->pci_bus->self->dev,
 483                         "insert operation failed rc = %d\n", rc);
 484
 485         return rc;
 486 }
 487
 488 static int disable_slot(struct hotplug_slot *bss_hotplug_slot)
 489 {
 490         struct slot *slot = bss_hotplug_slot->private;
 491         struct pci_dev *dev;
 492         int func;
 493         int rc;
 494         acpi_owner_id ssdt_id = 0;
 495
 496         /* Acquire update access to the bus */
 497         mutex_lock(&sn_hotplug_mutex);
 498
 499         /* is it okay to bring this slot down? */
 500         rc = sn_slot_disable(bss_hotplug_slot, slot->device_num,
 501                              PCI_REQ_SLOT_ELIGIBLE);
 502         if (rc)
 503                 goto leaving;
 504
 505         /* free the ACPI resources for the slot */
 506         if (SN_ACPI_BASE_SUPPORT() &&
 507             PCI_CONTROLLER(slot->pci_bus)->acpi_handle) {
 508                 unsigned long long adr;
 509                 struct acpi_device *device;
 510                 acpi_handle phandle;
 511                 acpi_handle chandle = NULL;
 512                 acpi_handle rethandle;
 513                 acpi_status ret;
 514
 515                 /* Get the rootbus node pointer */
 516                 phandle = PCI_CONTROLLER(slot->pci_bus)->acpi_handle;
 517
 518                 /*
 519                  * Walk the rootbus node's immediate children looking for
 520                  * the slot's device node(s). There can be more than
 521                  * one for multifunction devices.
 522                  */
 523                 for (;;) {
 524                         rethandle = NULL;
 525                         ret = acpi_get_next_object(ACPI_TYPE_DEVICE,
 526                                                    phandle, chandle,
 527                                                    &rethandle);
 528
 529                         if (ret == AE_NOT_FOUND || rethandle == NULL)
 530                                 break;
 531
 532                         chandle = rethandle;
 533
 534                         ret = acpi_evaluate_integer(chandle,
 535                                                     METHOD_NAME__ADR,
 536                                                     NULL, &adr);
 537                         if (ACPI_SUCCESS(ret) &&
 538                             (adr>>16) == (slot->device_num + 1)) {
 539                                 /* retain the owner id */
 540                                 acpi_get_id(chandle, &ssdt_id);
 541
 542                                 ret = acpi_bus_get_device(chandle,
 543                                                           &device);
 544                                 if (ACPI_SUCCESS(ret))
 545                                         acpi_bus_trim(device, 1);
 546                         }
 547                 }
 548
 549         }
 550
 551         /* Free the SN resources assigned to the Linux device.*/
 552         for (func = 0; func < 8;  func++) {
 553                 dev = pci_get_slot(slot->pci_bus,
 554                                    PCI_DEVFN(slot->device_num + 1,
 555                                              PCI_FUNC(func)));
 556                 if (dev) {
 557                         sn_bus_free_data(dev);
 558                         pci_remove_bus_device(dev);
 559                         pci_dev_put(dev);
 560                 }
 561         }
 562
 563         /* Remove the SSDT for the slot from the ACPI namespace */
 564         if (SN_ACPI_BASE_SUPPORT() && ssdt_id) {
 565                 acpi_status ret;
 566                 ret = acpi_unload_table_id(ssdt_id);
 567                 if (ACPI_FAILURE(ret)) {
 568                         printk(KERN_ERR "%s: acpi_unload_table_id "
 569                                "failed (0x%x) for id %d\n",
 570                                __func__, ret, ssdt_id);
 571                         /* try to continue on */
 572                 }
 573         }
 574
 575         /* free the collected sysdata pointers */
 576         sn_bus_free_sysdata();
 577
 578         /* Deactivate slot */
 579         rc = sn_slot_disable(bss_hotplug_slot, slot->device_num,
 580                              PCI_REQ_SLOT_DISABLE);
 581  leaving:
 582         /* Release the bus lock */
 583         mutex_unlock(&sn_hotplug_mutex);
 584
 585         return rc;
 586 }
 587
 588 static inline int get_power_status(struct hotplug_slot *bss_hotplug_slot,
 589                                    u8 *value)
 590 {
 591         struct slot *slot = bss_hotplug_slot->private;
 592         struct pcibus_info *pcibus_info;
 593         u32 power;
 594
 595         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
 596         mutex_lock(&sn_hotplug_mutex);
 597         power = pcibus_info->pbi_enabled_devices & (1 << slot->device_num);
 598         *value = power ? 1 : 0;
 599         mutex_unlock(&sn_hotplug_mutex);
 600         return 0;
 601 }
 602
 603 static void sn_release_slot(struct hotplug_slot *bss_hotplug_slot)
 604 {
 605         kfree(bss_hotplug_slot->info);
 606         kfree(bss_hotplug_slot->private);
 607         kfree(bss_hotplug_slot);
 608 }
 609
 610 static int sn_hotplug_slot_register(struct pci_bus *pci_bus)
 611 {
 612         int device;
 613         struct pci_slot *pci_slot;
 614         struct hotplug_slot *bss_hotplug_slot;
 615         char name[SN_SLOT_NAME_SIZE];
 616         int rc = 0;
 617
 618         /*
 619          * Currently only four devices are supported,
 620          * in the future there maybe more -- up to 32.
 621          */
 622
 623         for (device = 0; device < SN_MAX_HP_SLOTS ; device++) {
 624                 if (sn_pci_slot_valid(pci_bus, device) != 1)
 625                         continue;
 626
 627                 bss_hotplug_slot = kzalloc(sizeof(*bss_hotplug_slot),
 628                                            GFP_KERNEL);
 629                 if (!bss_hotplug_slot) {
 630                         rc = -ENOMEM;
 631                         goto alloc_err;
 632                 }
 633
 634                 bss_hotplug_slot->info =
 635                         kzalloc(sizeof(struct hotplug_slot_info),
 636                                 GFP_KERNEL);
 637                 if (!bss_hotplug_slot->info) {
 638                         rc = -ENOMEM;
 639                         goto alloc_err;
 640                 }
 641
 642                 if (sn_hp_slot_private_alloc(bss_hotplug_slot,
 643                                              pci_bus, device, name)) {
 644                         rc = -ENOMEM;
 645                         goto alloc_err;
 646                 }
 647                 bss_hotplug_slot->ops = &sn_hotplug_slot_ops;
 648                 bss_hotplug_slot->release = &sn_release_slot;
 649
 650                 rc = pci_hp_register(bss_hotplug_slot, pci_bus, device, name);
 651                 if (rc)
 652                         goto register_err;
 653
 654                 pci_slot = bss_hotplug_slot->pci_slot;
 655                 rc = sysfs_create_file(&pci_slot->kobj,
 656                                        &sn_slot_path_attr.attr);
 657                 if (rc)
 658                         goto register_err;
 659         }
 660         dev_dbg(&pci_bus->self->dev, "Registered bus with hotplug\n");
 661         return rc;
 662
 663 register_err:
 664         dev_dbg(&pci_bus->self->dev, "bus failed to register with err = %d\n",
 665                 rc);
 666
 667 alloc_err:
 668         if (rc == -ENOMEM)
 669                 dev_dbg(&pci_bus->self->dev, "Memory allocation error\n");
 670
 671         /* destroy THIS element */
 672         if (bss_hotplug_slot)
 673                 sn_release_slot(bss_hotplug_slot);
 674
 675         /* destroy anything else on the list */
 676         while ((bss_hotplug_slot = sn_hp_destroy()))
 677                 pci_hp_deregister(bss_hotplug_slot);
 678
 679         return rc;
 680 }
 681
 682 static int sn_pci_hotplug_init(void)
 683 {
 684         struct pci_bus *pci_bus = NULL;
 685         int rc;
 686         int registered = 0;
 687
 688         if (!sn_prom_feature_available(PRF_HOTPLUG_SUPPORT)) {
 689                 printk(KERN_ERR "%s: PROM version does not support hotplug.\n",
 690                        __func__);
 691                 return -EPERM;
 692         }
 693
 694         INIT_LIST_HEAD(&sn_hp_list);
 695
 696         while ((pci_bus = pci_find_next_bus(pci_bus))) {
 697                 if (!pci_bus->sysdata)
 698                         continue;
 699
 700                 rc = sn_pci_bus_valid(pci_bus);
 701                 if (rc != 1) {
 702                         dev_dbg(&pci_bus->self->dev, "not a valid hotplug bus\n");
 703                         continue;
 704                 }
 705                 dev_dbg(&pci_bus->self->dev, "valid hotplug bus\n");
 706
 707                 rc = sn_hotplug_slot_register(pci_bus);
 708                 if (!rc) {
 709                         registered = 1;
 710                 } else {
 711                         registered = 0;
 712                         break;
 713                 }
 714         }
 715
 716         return registered == 1 ? 0 : -ENODEV;
 717 }
 718
 719 static void sn_pci_hotplug_exit(void)
 720 {
 721         struct hotplug_slot *bss_hotplug_slot;
 722
 723         while ((bss_hotplug_slot = sn_hp_destroy()))
 724                 pci_hp_deregister(bss_hotplug_slot);
 725
 726         if (!list_empty(&sn_hp_list))
 727                 printk(KERN_ERR "%s: internal list is not empty\n", __FILE__);
 728 }
 729
 730 module_init(sn_pci_hotplug_init);
 731 module_exit(sn_pci_hotplug_exit);