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 {
 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         bss_hotplug_slot->name = kmalloc(SN_SLOT_NAME_SIZE, GFP_KERNEL);
 177         if (!bss_hotplug_slot->name) {
 178                 kfree(bss_hotplug_slot->private);
 179                 return -ENOMEM;
 180         }
 181
 182         slot->device_num = device;
 183         slot->pci_bus = pci_bus;
 184         sprintf(bss_hotplug_slot->name, "%04x:%02x:%02x",
 185                 pci_domain_nr(pci_bus),
 186                 ((u16)pcibus_info->pbi_buscommon.bs_persist_busnum),
 187                 device + 1);
 188
 189         sn_generate_path(pci_bus, slot->physical_path);
 190
 191         slot->hotplug_slot = bss_hotplug_slot;
 192         list_add(&slot->hp_list, &sn_hp_list);
 193
 194         return 0;
 195 }
 196
 197 static struct hotplug_slot * sn_hp_destroy(void)
 198 {
 199         struct slot *slot;
 200         struct hotplug_slot *bss_hotplug_slot = NULL;
 201
 202         list_for_each_entry(slot, &sn_hp_list, hp_list) {
 203                 bss_hotplug_slot = slot->hotplug_slot;
 204                 list_del(&((struct slot *)bss_hotplug_slot->private)->
 205                          hp_list);
 206                 sysfs_remove_file(&bss_hotplug_slot->kobj,
 207                                   &sn_slot_path_attr.attr);
 208                 break;
 209         }
 210         return bss_hotplug_slot;
 211 }
 212
 213 static void sn_bus_free_data(struct pci_dev *dev)
 214 {
 215         struct pci_bus *subordinate_bus;
 216         struct pci_dev *child;
 217
 218         /* Recursively clean up sn_irq_info structs */
 219         if (dev->subordinate) {
 220                 subordinate_bus = dev->subordinate;
 221                 list_for_each_entry(child, &subordinate_bus->devices, bus_list)
 222                         sn_bus_free_data(child);
 223         }
 224         /*
 225          * Some drivers may use dma accesses during the
 226          * driver remove function. We release the sysdata
 227          * areas after the driver remove functions have
 228          * been called.
 229          */
 230         sn_bus_store_sysdata(dev);
 231         sn_pci_unfixup_slot(dev);
 232 }
 233
 234 static int sn_slot_enable(struct hotplug_slot *bss_hotplug_slot,
 235                           int device_num, char **ssdt)
 236 {
 237         struct slot *slot = bss_hotplug_slot->private;
 238         struct pcibus_info *pcibus_info;
 239         struct pcibr_slot_enable_resp resp;
 240         int rc;
 241
 242         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
 243
 244         /*
 245          * Power-on and initialize the slot in the SN
 246          * PCI infrastructure.
 247          */
 248         rc = sal_pcibr_slot_enable(pcibus_info, device_num, &resp, ssdt);
 249
 250
 251         if (rc == PCI_SLOT_ALREADY_UP) {
 252                 dev_dbg(slot->pci_bus->self, "is already active\n");
 253                 return 1; /* return 1 to user */
 254         }
 255
 256         if (rc == PCI_L1_ERR) {
 257                 dev_dbg(slot->pci_bus->self,
 258                         "L1 failure %d with message: %s",
 259                         resp.resp_sub_errno, resp.resp_l1_msg);
 260                 return -EPERM;
 261         }
 262
 263         if (rc) {
 264                 dev_dbg(slot->pci_bus->self,
 265                         "insert failed with error %d sub-error %d\n",
 266                         rc, resp.resp_sub_errno);
 267                 return -EIO;
 268         }
 269
 270         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
 271         pcibus_info->pbi_enabled_devices |= (1 << device_num);
 272
 273         return 0;
 274 }
 275
 276 static int sn_slot_disable(struct hotplug_slot *bss_hotplug_slot,
 277                            int device_num, int action)
 278 {
 279         struct slot *slot = bss_hotplug_slot->private;
 280         struct pcibus_info *pcibus_info;
 281         struct pcibr_slot_disable_resp resp;
 282         int rc;
 283
 284         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
 285
 286         rc = sal_pcibr_slot_disable(pcibus_info, device_num, action, &resp);
 287
 288         if ((action == PCI_REQ_SLOT_ELIGIBLE) &&
 289             (rc == PCI_SLOT_ALREADY_DOWN)) {
 290                 dev_dbg(slot->pci_bus->self, "Slot %s already inactive\n");
 291                 return 1; /* return 1 to user */
 292         }
 293
 294         if ((action == PCI_REQ_SLOT_ELIGIBLE) && (rc == PCI_EMPTY_33MHZ)) {
 295                 dev_dbg(slot->pci_bus->self,
 296                         "Cannot remove last 33MHz card\n");
 297                 return -EPERM;
 298         }
 299
 300         if ((action == PCI_REQ_SLOT_ELIGIBLE) && (rc == PCI_L1_ERR)) {
 301                 dev_dbg(slot->pci_bus->self,
 302                         "L1 failure %d with message \n%s\n",
 303                         resp.resp_sub_errno, resp.resp_l1_msg);
 304                 return -EPERM;
 305         }
 306
 307         if ((action == PCI_REQ_SLOT_ELIGIBLE) && rc) {
 308                 dev_dbg(slot->pci_bus->self,
 309                         "remove failed with error %d sub-error %d\n",
 310                         rc, resp.resp_sub_errno);
 311                 return -EIO;
 312         }
 313
 314         if ((action == PCI_REQ_SLOT_ELIGIBLE) && !rc)
 315                 return 0;
 316
 317         if ((action == PCI_REQ_SLOT_DISABLE) && !rc) {
 318                 pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
 319                 pcibus_info->pbi_enabled_devices &= ~(1 << device_num);
 320                 dev_dbg(slot->pci_bus->self, "remove successful\n");
 321                 return 0;
 322         }
 323
 324         if ((action == PCI_REQ_SLOT_DISABLE) && rc) {
 325                 dev_dbg(slot->pci_bus->self,"remove failed rc = %d\n", rc);
 326         }
 327
 328         return rc;
 329 }
 330
 331 /*
 332  * Power up and configure the slot via a SAL call to PROM.
 333  * Scan slot (and any children), do any platform specific fixup,
 334  * and find device driver.
 335  */
 336 static int enable_slot(struct hotplug_slot *bss_hotplug_slot)
 337 {
 338         struct slot *slot = bss_hotplug_slot->private;
 339         struct pci_bus *new_bus = NULL;
 340         struct pci_dev *dev;
 341         int func, num_funcs;
 342         int new_ppb = 0;
 343         int rc;
 344         char *ssdt = NULL;
 345         void pcibios_fixup_device_resources(struct pci_dev *);
 346
 347         /* Serialize the Linux PCI infrastructure */
 348         mutex_lock(&sn_hotplug_mutex);
 349
 350         /*
 351          * Power-on and initialize the slot in the SN
 352          * PCI infrastructure. Also, retrieve the ACPI SSDT
 353          * table for the slot (if ACPI capable PROM).
 354          */
 355         rc = sn_slot_enable(bss_hotplug_slot, slot->device_num, &ssdt);
 356         if (rc) {
 357                 mutex_unlock(&sn_hotplug_mutex);
 358                 return rc;
 359         }
 360
 361         if (ssdt)
 362                 ssdt = __va(ssdt);
 363         /* Add the new SSDT for the slot to the ACPI namespace */
 364         if (SN_ACPI_BASE_SUPPORT() && ssdt) {
 365                 acpi_status ret;
 366
 367                 ret = acpi_load_table((struct acpi_table_header *)ssdt);
 368                 if (ACPI_FAILURE(ret)) {
 369                         printk(KERN_ERR "%s: acpi_load_table failed (0x%x)\n",
 370                                __FUNCTION__, ret);
 371                         /* try to continue on */
 372                 }
 373         }
 374
 375         num_funcs = pci_scan_slot(slot->pci_bus,
 376                                   PCI_DEVFN(slot->device_num + 1, 0));
 377         if (!num_funcs) {
 378                 dev_dbg(slot->pci_bus->self, "no device in slot\n");
 379                 mutex_unlock(&sn_hotplug_mutex);
 380                 return -ENODEV;
 381         }
 382
 383         /*
 384          * Map SN resources for all functions on the card
 385          * to the Linux PCI interface and tell the drivers
 386          * about them.
 387          */
 388         for (func = 0; func < num_funcs;  func++) {
 389                 dev = pci_get_slot(slot->pci_bus,
 390                                    PCI_DEVFN(slot->device_num + 1,
 391                                              PCI_FUNC(func)));
 392                 if (dev) {
 393                         /* Need to do slot fixup on PPB before fixup of children
 394                          * (PPB's pcidev_info needs to be in pcidev_info list
 395                          * before child's SN_PCIDEV_INFO() call to setup
 396                          * pdi_host_pcidev_info).
 397                          */
 398                         pcibios_fixup_device_resources(dev);
 399                         if (SN_ACPI_BASE_SUPPORT())
 400                                 sn_acpi_slot_fixup(dev);
 401                         else
 402                                 sn_io_slot_fixup(dev);
 403                         if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
 404                                 unsigned char sec_bus;
 405                                 pci_read_config_byte(dev, PCI_SECONDARY_BUS,
 406                                                      &sec_bus);
 407                                 new_bus = pci_add_new_bus(dev->bus, dev,
 408                                                           sec_bus);
 409                                 pci_scan_child_bus(new_bus);
 410                                 new_ppb = 1;
 411                         }
 412                         pci_dev_put(dev);
 413                 }
 414         }
 415
 416         /*
 417          * Add the slot's devices to the ACPI infrastructure */
 418         if (SN_ACPI_BASE_SUPPORT() && ssdt) {
 419                 unsigned long adr;
 420                 struct acpi_device *pdevice;
 421                 struct acpi_device *device;
 422                 acpi_handle phandle;
 423                 acpi_handle chandle = NULL;
 424                 acpi_handle rethandle;
 425                 acpi_status ret;
 426
 427                 phandle = PCI_CONTROLLER(slot->pci_bus)->acpi_handle;
 428
 429                 if (acpi_bus_get_device(phandle, &pdevice)) {
 430                         dev_dbg(slot->pci_bus->self,
 431                                 "no parent device, assuming NULL\n");
 432                         pdevice = NULL;
 433                 }
 434
 435                 /*
 436                  * Walk the rootbus node's immediate children looking for
 437                  * the slot's device node(s). There can be more than
 438                  * one for multifunction devices.
 439                  */
 440                 for (;;) {
 441                         rethandle = NULL;
 442                         ret = acpi_get_next_object(ACPI_TYPE_DEVICE,
 443                                                    phandle, chandle,
 444                                                    &rethandle);
 445
 446                         if (ret == AE_NOT_FOUND || rethandle == NULL)
 447                                 break;
 448
 449                         chandle = rethandle;
 450
 451                         ret = acpi_evaluate_integer(chandle, METHOD_NAME__ADR,
 452                                                     NULL, &adr);
 453
 454                         if (ACPI_SUCCESS(ret) &&
 455                             (adr>>16) == (slot->device_num + 1)) {
 456
 457                                 ret = acpi_bus_add(&device, pdevice, chandle,
 458                                                    ACPI_BUS_TYPE_DEVICE);
 459                                 if (ACPI_FAILURE(ret)) {
 460                                         printk(KERN_ERR "%s: acpi_bus_add "
 461                                                "failed (0x%x) for slot %d "
 462                                                "func %d\n", __FUNCTION__,
 463                                                ret, (int)(adr>>16),
 464                                                (int)(adr&0xffff));
 465                                         /* try to continue on */
 466                                 } else {
 467                                         acpi_bus_start(device);
 468                                 }
 469                         }
 470                 }
 471         }
 472
 473         /* Call the driver for the new device */
 474         pci_bus_add_devices(slot->pci_bus);
 475         /* Call the drivers for the new devices subordinate to PPB */
 476         if (new_ppb)
 477                 pci_bus_add_devices(new_bus);
 478
 479         mutex_unlock(&sn_hotplug_mutex);
 480
 481         if (rc == 0)
 482                 dev_dbg(slot->pci_bus->self,
 483                         "insert operation successful\n");
 484         else
 485                 dev_dbg(slot->pci_bus->self,
 486                         "insert operation failed rc = %d\n", rc);
 487
 488         return rc;
 489 }
 490
 491 static int disable_slot(struct hotplug_slot *bss_hotplug_slot)
 492 {
 493         struct slot *slot = bss_hotplug_slot->private;
 494         struct pci_dev *dev;
 495         int func;
 496         int rc;
 497         acpi_owner_id ssdt_id = 0;
 498
 499         /* Acquire update access to the bus */
 500         mutex_lock(&sn_hotplug_mutex);
 501
 502         /* is it okay to bring this slot down? */
 503         rc = sn_slot_disable(bss_hotplug_slot, slot->device_num,
 504                              PCI_REQ_SLOT_ELIGIBLE);
 505         if (rc)
 506                 goto leaving;
 507
 508         /* free the ACPI resources for the slot */
 509         if (SN_ACPI_BASE_SUPPORT() &&
 510             PCI_CONTROLLER(slot->pci_bus)->acpi_handle) {
 511                 unsigned long adr;
 512                 struct acpi_device *device;
 513                 acpi_handle phandle;
 514                 acpi_handle chandle = NULL;
 515                 acpi_handle rethandle;
 516                 acpi_status ret;
 517
 518                 /* Get the rootbus node pointer */
 519                 phandle = PCI_CONTROLLER(slot->pci_bus)->acpi_handle;
 520
 521                 /*
 522                  * Walk the rootbus node's immediate children looking for
 523                  * the slot's device node(s). There can be more than
 524                  * one for multifunction devices.
 525                  */
 526                 for (;;) {
 527                         rethandle = NULL;
 528                         ret = acpi_get_next_object(ACPI_TYPE_DEVICE,
 529                                                    phandle, chandle,
 530                                                    &rethandle);
 531
 532                         if (ret == AE_NOT_FOUND || rethandle == NULL)
 533                                 break;
 534
 535                         chandle = rethandle;
 536
 537                         ret = acpi_evaluate_integer(chandle,
 538                                                     METHOD_NAME__ADR,
 539                                                     NULL, &adr);
 540                         if (ACPI_SUCCESS(ret) &&
 541                             (adr>>16) == (slot->device_num + 1)) {
 542                                 /* retain the owner id */
 543                                 acpi_get_id(chandle, &ssdt_id);
 544
 545                                 ret = acpi_bus_get_device(chandle,
 546                                                           &device);
 547                                 if (ACPI_SUCCESS(ret))
 548                                         acpi_bus_trim(device, 1);
 549                         }
 550                 }
 551
 552         }
 553
 554         /* Free the SN resources assigned to the Linux device.*/
 555         for (func = 0; func < 8;  func++) {
 556                 dev = pci_get_slot(slot->pci_bus,
 557                                    PCI_DEVFN(slot->device_num + 1,
 558                                              PCI_FUNC(func)));
 559                 if (dev) {
 560                         sn_bus_free_data(dev);
 561                         pci_remove_bus_device(dev);
 562                         pci_dev_put(dev);
 563                 }
 564         }
 565
 566         /* Remove the SSDT for the slot from the ACPI namespace */
 567         if (SN_ACPI_BASE_SUPPORT() && ssdt_id) {
 568                 acpi_status ret;
 569                 ret = acpi_unload_table_id(ssdt_id);
 570                 if (ACPI_FAILURE(ret)) {
 571                         printk(KERN_ERR "%s: acpi_unload_table_id "
 572                                "failed (0x%x) for id %d\n",
 573                                __FUNCTION__, ret, ssdt_id);
 574                         /* try to continue on */
 575                 }
 576         }
 577
 578         /* free the collected sysdata pointers */
 579         sn_bus_free_sysdata();
 580
 581         /* Deactivate slot */
 582         rc = sn_slot_disable(bss_hotplug_slot, slot->device_num,
 583                              PCI_REQ_SLOT_DISABLE);
 584  leaving:
 585         /* Release the bus lock */
 586         mutex_unlock(&sn_hotplug_mutex);
 587
 588         return rc;
 589 }
 590
 591 static inline int get_power_status(struct hotplug_slot *bss_hotplug_slot,
 592                                    u8 *value)
 593 {
 594         struct slot *slot = bss_hotplug_slot->private;
 595         struct pcibus_info *pcibus_info;
 596         u32 power;
 597
 598         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
 599         mutex_lock(&sn_hotplug_mutex);
 600         power = pcibus_info->pbi_enabled_devices & (1 << slot->device_num);
 601         *value = power ? 1 : 0;
 602         mutex_unlock(&sn_hotplug_mutex);
 603         return 0;
 604 }
 605
 606 static void sn_release_slot(struct hotplug_slot *bss_hotplug_slot)
 607 {
 608         kfree(bss_hotplug_slot->info);
 609         kfree(bss_hotplug_slot->name);
 610         kfree(bss_hotplug_slot->private);
 611         kfree(bss_hotplug_slot);
 612 }
 613
 614 static int sn_hotplug_slot_register(struct pci_bus *pci_bus)
 615 {
 616         int device;
 617         struct hotplug_slot *bss_hotplug_slot;
 618         int rc = 0;
 619
 620         /*
 621          * Currently only four devices are supported,
 622          * in the future there maybe more -- up to 32.
 623          */
 624
 625         for (device = 0; device < SN_MAX_HP_SLOTS ; device++) {
 626                 if (sn_pci_slot_valid(pci_bus, device) != 1)
 627                         continue;
 628
 629                 bss_hotplug_slot = kzalloc(sizeof(*bss_hotplug_slot),
 630                                            GFP_KERNEL);
 631                 if (!bss_hotplug_slot) {
 632                         rc = -ENOMEM;
 633                         goto alloc_err;
 634                 }
 635
 636                 bss_hotplug_slot->info =
 637                         kzalloc(sizeof(struct hotplug_slot_info),
 638                                 GFP_KERNEL);
 639                 if (!bss_hotplug_slot->info) {
 640                         rc = -ENOMEM;
 641                         goto alloc_err;
 642                 }
 643
 644                 if (sn_hp_slot_private_alloc(bss_hotplug_slot,
 645                                              pci_bus, device)) {
 646                         rc = -ENOMEM;
 647                         goto alloc_err;
 648                 }
 649
 650                 bss_hotplug_slot->ops = &sn_hotplug_slot_ops;
 651                 bss_hotplug_slot->release = &sn_release_slot;
 652
 653                 rc = pci_hp_register(bss_hotplug_slot);
 654                 if (rc)
 655                         goto register_err;
 656
 657                 rc = sysfs_create_file(&bss_hotplug_slot->kobj,
 658                                        &sn_slot_path_attr.attr);
 659                 if (rc)
 660                         goto register_err;
 661         }
 662         dev_dbg(pci_bus->self, "Registered bus with hotplug\n");
 663         return rc;
 664
 665 register_err:
 666         dev_dbg(pci_bus->self, "bus failed to register with err = %d\n",
 667                 rc);
 668
 669 alloc_err:
 670         if (rc == -ENOMEM)
 671                 dev_dbg(pci_bus->self, "Memory allocation error\n");
 672
 673         /* destroy THIS element */
 674         if (bss_hotplug_slot)
 675                 sn_release_slot(bss_hotplug_slot);
 676
 677         /* destroy anything else on the list */
 678         while ((bss_hotplug_slot = sn_hp_destroy()))
 679                 pci_hp_deregister(bss_hotplug_slot);
 680
 681         return rc;
 682 }
 683
 684 static int sn_pci_hotplug_init(void)
 685 {
 686         struct pci_bus *pci_bus = NULL;
 687         int rc;
 688         int registered = 0;
 689
 690         if (!sn_prom_feature_available(PRF_HOTPLUG_SUPPORT)) {
 691                 printk(KERN_ERR "%s: PROM version does not support hotplug.\n",
 692                        __FUNCTION__);
 693                 return -EPERM;
 694         }
 695
 696         INIT_LIST_HEAD(&sn_hp_list);
 697
 698         while ((pci_bus = pci_find_next_bus(pci_bus))) {
 699                 if (!pci_bus->sysdata)
 700                         continue;
 701
 702                 rc = sn_pci_bus_valid(pci_bus);
 703                 if (rc != 1) {
 704                         dev_dbg(pci_bus->self, "not a valid hotplug bus\n");
 705                         continue;
 706                 }
 707                 dev_dbg(pci_bus->self, "valid hotplug bus\n");
 708
 709                 rc = sn_hotplug_slot_register(pci_bus);
 710                 if (!rc) {
 711                         registered = 1;
 712                 } else {
 713                         registered = 0;
 714                         break;
 715                 }
 716         }
 717
 718         return registered == 1 ? 0 : -ENODEV;
 719 }
 720
 721 static void sn_pci_hotplug_exit(void)
 722 {
 723         struct hotplug_slot *bss_hotplug_slot;
 724
 725         while ((bss_hotplug_slot = sn_hp_destroy()))
 726                 pci_hp_deregister(bss_hotplug_slot);
 727
 728         if (!list_empty(&sn_hp_list))
 729                 printk(KERN_ERR "%s: internal list is not empty\n", __FILE__);
 730 }
 731
 732 module_init(sn_pci_hotplug_init);
 733 module_exit(sn_pci_hotplug_exit);