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/proc_fs.h>
  17 #include <linux/types.h>
  18 #include <linux/mutex.h>
  19
  20 #include <asm/sn/addrs.h>
  21 #include <asm/sn/geo.h>
  22 #include <asm/sn/l1.h>
  23 #include <asm/sn/module.h>
  24 #include <asm/sn/pcibr_provider.h>
  25 #include <asm/sn/pcibus_provider_defs.h>
  26 #include <asm/sn/pcidev.h>
  27 #include <asm/sn/sn_feature_sets.h>
  28 #include <asm/sn/sn_sal.h>
  29 #include <asm/sn/types.h>
  30
  31 #include "../pci.h"
  32 #include "pci_hotplug.h"
  33
  34 MODULE_LICENSE("GPL");
  35 MODULE_AUTHOR("SGI (prarit@sgi.com, dickie@sgi.com, habeck@sgi.com)");
  36 MODULE_DESCRIPTION("SGI Altix Hot Plug PCI Controller Driver");
  37
  38 #define PCIIO_ASIC_TYPE_TIOCA           4
  39 #define PCI_SLOT_ALREADY_UP             2       /* slot already up */
  40 #define PCI_SLOT_ALREADY_DOWN           3       /* slot already down */
  41 #define PCI_L1_ERR                      7       /* L1 console command error */
  42 #define PCI_EMPTY_33MHZ                 15      /* empty 33 MHz bus */
  43 #define PCI_L1_QSIZE                    128     /* our L1 message buffer size */
  44 #define SN_MAX_HP_SLOTS                 32      /* max hotplug slots */
  45 #define SGI_HOTPLUG_PROM_REV            0x0430  /* Min. required PROM version */
  46 #define SN_SLOT_NAME_SIZE               33      /* size of name string */
  47
  48 /* internal list head */
  49 static struct list_head sn_hp_list;
  50
  51 /* hotplug_slot struct's private pointer */
  52 struct slot {
  53         int device_num;
  54         struct pci_bus *pci_bus;
  55         /* this struct for glue internal only */
  56         struct hotplug_slot *hotplug_slot;
  57         struct list_head hp_list;
  58         char physical_path[SN_SLOT_NAME_SIZE];
  59 };
  60
  61 struct pcibr_slot_enable_resp {
  62         int resp_sub_errno;
  63         char resp_l1_msg[PCI_L1_QSIZE + 1];
  64 };
  65
  66 struct pcibr_slot_disable_resp {
  67         int resp_sub_errno;
  68         char resp_l1_msg[PCI_L1_QSIZE + 1];
  69 };
  70
  71 enum sn_pci_req_e {
  72         PCI_REQ_SLOT_ELIGIBLE,
  73         PCI_REQ_SLOT_DISABLE
  74 };
  75
  76 static int enable_slot(struct hotplug_slot *slot);
  77 static int disable_slot(struct hotplug_slot *slot);
  78 static inline int get_power_status(struct hotplug_slot *slot, u8 *value);
  79
  80 static struct hotplug_slot_ops sn_hotplug_slot_ops = {
  81         .owner                  = THIS_MODULE,
  82         .enable_slot            = enable_slot,
  83         .disable_slot           = disable_slot,
  84         .get_power_status       = get_power_status,
  85 };
  86
  87 static DEFINE_MUTEX(sn_hotplug_mutex);
  88
  89 static ssize_t path_show (struct hotplug_slot *bss_hotplug_slot,
  90                           char *buf)
  91 {
  92         int retval = -ENOENT;
  93         struct slot *slot = bss_hotplug_slot->private;
  94
  95         if (!slot)
  96                 return retval;
  97
  98         retval = sprintf (buf, "%s\n", slot->physical_path);
  99         return retval;
 100 }
 101
 102 static struct hotplug_slot_attribute sn_slot_path_attr = __ATTR_RO(path);
 103
 104 static int sn_pci_slot_valid(struct pci_bus *pci_bus, int device)
 105 {
 106         struct pcibus_info *pcibus_info;
 107         u16 busnum, segment, ioboard_type;
 108
 109         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(pci_bus);
 110
 111         /* Check to see if this is a valid slot on 'pci_bus' */
 112         if (!(pcibus_info->pbi_valid_devices & (1 << device)))
 113                 return -EPERM;
 114
 115         ioboard_type = sn_ioboard_to_pci_bus(pci_bus);
 116         busnum = pcibus_info->pbi_buscommon.bs_persist_busnum;
 117         segment = pci_domain_nr(pci_bus) & 0xf;
 118
 119         /* Do not allow hotplug operations on base I/O cards */
 120         if ((ioboard_type == L1_BRICKTYPE_IX ||
 121              ioboard_type == L1_BRICKTYPE_IA) &&
 122             (segment == 1 && busnum == 0 && device != 1))
 123                 return -EPERM;
 124
 125         return 1;
 126 }
 127
 128 static int sn_pci_bus_valid(struct pci_bus *pci_bus)
 129 {
 130         struct pcibus_info *pcibus_info;
 131         u32 asic_type;
 132         u16 ioboard_type;
 133
 134         /* Don't register slots hanging off the TIOCA bus */
 135         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(pci_bus);
 136         asic_type = pcibus_info->pbi_buscommon.bs_asic_type;
 137         if (asic_type == PCIIO_ASIC_TYPE_TIOCA)
 138                 return -EPERM;
 139
 140         /* Only register slots in I/O Bricks that support hotplug */
 141         ioboard_type = sn_ioboard_to_pci_bus(pci_bus);
 142         switch (ioboard_type) {
 143                 case L1_BRICKTYPE_IX:
 144                 case L1_BRICKTYPE_PX:
 145                 case L1_BRICKTYPE_IA:
 146                 case L1_BRICKTYPE_PA:
 147                 case L1_BOARDTYPE_PCIX3SLOT:
 148                         return 1;
 149                         break;
 150                 default:
 151                         return -EPERM;
 152                         break;
 153         }
 154
 155         return -EIO;
 156 }
 157
 158 static int sn_hp_slot_private_alloc(struct hotplug_slot *bss_hotplug_slot,
 159                                     struct pci_bus *pci_bus, int device)
 160 {
 161         struct pcibus_info *pcibus_info;
 162         struct slot *slot;
 163
 164         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(pci_bus);
 165
 166         slot = kzalloc(sizeof(*slot), GFP_KERNEL);
 167         if (!slot)
 168                 return -ENOMEM;
 169         bss_hotplug_slot->private = slot;
 170
 171         bss_hotplug_slot->name = kmalloc(SN_SLOT_NAME_SIZE, GFP_KERNEL);
 172         if (!bss_hotplug_slot->name) {
 173                 kfree(bss_hotplug_slot->private);
 174                 return -ENOMEM;
 175         }
 176
 177         slot->device_num = device;
 178         slot->pci_bus = pci_bus;
 179         sprintf(bss_hotplug_slot->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 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                 list_del(&((struct slot *)bss_hotplug_slot->private)->
 200                          hp_list);
 201                 sysfs_remove_file(&bss_hotplug_slot->kobj,
 202                                   &sn_slot_path_attr.attr);
 203                 break;
 204         }
 205         return bss_hotplug_slot;
 206 }
 207
 208 static void sn_bus_alloc_data(struct pci_dev *dev)
 209 {
 210         struct pci_bus *subordinate_bus;
 211         struct pci_dev *child;
 212
 213         sn_pci_fixup_slot(dev);
 214
 215         /* Recursively sets up the 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_alloc_data(child);
 220         }
 221 }
 222
 223 static void sn_bus_free_data(struct pci_dev *dev)
 224 {
 225         struct pci_bus *subordinate_bus;
 226         struct pci_dev *child;
 227
 228         /* Recursively clean up sn_irq_info structs */
 229         if (dev->subordinate) {
 230                 subordinate_bus = dev->subordinate;
 231                 list_for_each_entry(child, &subordinate_bus->devices, bus_list)
 232                         sn_bus_free_data(child);
 233         }
 234         /*
 235          * Some drivers may use dma accesses during the
 236          * driver remove function. We release the sysdata
 237          * areas after the driver remove functions have
 238          * been called.
 239          */
 240         sn_bus_store_sysdata(dev);
 241         sn_pci_unfixup_slot(dev);
 242 }
 243
 244 static int sn_slot_enable(struct hotplug_slot *bss_hotplug_slot,
 245                           int device_num)
 246 {
 247         struct slot *slot = bss_hotplug_slot->private;
 248         struct pcibus_info *pcibus_info;
 249         struct pcibr_slot_enable_resp resp;
 250         int rc;
 251
 252         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
 253
 254         /*
 255          * Power-on and initialize the slot in the SN
 256          * PCI infrastructure.
 257          */
 258         rc = sal_pcibr_slot_enable(pcibus_info, device_num, &resp);
 259
 260         if (rc == PCI_SLOT_ALREADY_UP) {
 261                 dev_dbg(slot->pci_bus->self, "is already active\n");
 262                 return 1; /* return 1 to user */
 263         }
 264
 265         if (rc == PCI_L1_ERR) {
 266                 dev_dbg(slot->pci_bus->self,
 267                         "L1 failure %d with message: %s",
 268                         resp.resp_sub_errno, resp.resp_l1_msg);
 269                 return -EPERM;
 270         }
 271
 272         if (rc) {
 273                 dev_dbg(slot->pci_bus->self,
 274                         "insert failed with error %d sub-error %d\n",
 275                         rc, resp.resp_sub_errno);
 276                 return -EIO;
 277         }
 278
 279         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
 280         pcibus_info->pbi_enabled_devices |= (1 << device_num);
 281
 282         return 0;
 283 }
 284
 285 static int sn_slot_disable(struct hotplug_slot *bss_hotplug_slot,
 286                            int device_num, int action)
 287 {
 288         struct slot *slot = bss_hotplug_slot->private;
 289         struct pcibus_info *pcibus_info;
 290         struct pcibr_slot_disable_resp resp;
 291         int rc;
 292
 293         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
 294
 295         rc = sal_pcibr_slot_disable(pcibus_info, device_num, action, &resp);
 296
 297         if ((action == PCI_REQ_SLOT_ELIGIBLE) &&
 298             (rc == PCI_SLOT_ALREADY_DOWN)) {
 299                 dev_dbg(slot->pci_bus->self, "Slot %s already inactive\n");
 300                 return 1; /* return 1 to user */
 301         }
 302
 303         if ((action == PCI_REQ_SLOT_ELIGIBLE) && (rc == PCI_EMPTY_33MHZ)) {
 304                 dev_dbg(slot->pci_bus->self,
 305                         "Cannot remove last 33MHz card\n");
 306                 return -EPERM;
 307         }
 308
 309         if ((action == PCI_REQ_SLOT_ELIGIBLE) && (rc == PCI_L1_ERR)) {
 310                 dev_dbg(slot->pci_bus->self,
 311                         "L1 failure %d with message \n%s\n",
 312                         resp.resp_sub_errno, resp.resp_l1_msg);
 313                 return -EPERM;
 314         }
 315
 316         if ((action == PCI_REQ_SLOT_ELIGIBLE) && rc) {
 317                 dev_dbg(slot->pci_bus->self,
 318                         "remove failed with error %d sub-error %d\n",
 319                         rc, resp.resp_sub_errno);
 320                 return -EIO;
 321         }
 322
 323         if ((action == PCI_REQ_SLOT_ELIGIBLE) && !rc)
 324                 return 0;
 325
 326         if ((action == PCI_REQ_SLOT_DISABLE) && !rc) {
 327                 pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
 328                 pcibus_info->pbi_enabled_devices &= ~(1 << device_num);
 329                 dev_dbg(slot->pci_bus->self, "remove successful\n");
 330                 return 0;
 331         }
 332
 333         if ((action == PCI_REQ_SLOT_DISABLE) && rc) {
 334                 dev_dbg(slot->pci_bus->self,"remove failed rc = %d\n", rc);
 335         }
 336
 337         return rc;
 338 }
 339
 340 static int enable_slot(struct hotplug_slot *bss_hotplug_slot)
 341 {
 342         struct slot *slot = bss_hotplug_slot->private;
 343         struct pci_bus *new_bus = NULL;
 344         struct pci_dev *dev;
 345         int func, num_funcs;
 346         int new_ppb = 0;
 347         int rc;
 348
 349         /* Serialize the Linux PCI infrastructure */
 350         mutex_lock(&sn_hotplug_mutex);
 351
 352         /*
 353          * Power-on and initialize the slot in the SN
 354          * PCI infrastructure.
 355          */
 356         rc = sn_slot_enable(bss_hotplug_slot, slot->device_num);
 357         if (rc) {
 358                 mutex_unlock(&sn_hotplug_mutex);
 359                 return rc;
 360         }
 361
 362         num_funcs = pci_scan_slot(slot->pci_bus,
 363                                   PCI_DEVFN(slot->device_num + 1, 0));
 364         if (!num_funcs) {
 365                 dev_dbg(slot->pci_bus->self, "no device in slot\n");
 366                 mutex_unlock(&sn_hotplug_mutex);
 367                 return -ENODEV;
 368         }
 369
 370         sn_pci_controller_fixup(pci_domain_nr(slot->pci_bus),
 371                                 slot->pci_bus->number,
 372                                 slot->pci_bus);
 373         /*
 374          * Map SN resources for all functions on the card
 375          * to the Linux PCI interface and tell the drivers
 376          * about them.
 377          */
 378         for (func = 0; func < num_funcs;  func++) {
 379                 dev = pci_get_slot(slot->pci_bus,
 380                                    PCI_DEVFN(slot->device_num + 1,
 381                                              PCI_FUNC(func)));
 382                 if (dev) {
 383                         if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
 384                                 unsigned char sec_bus;
 385                                 pci_read_config_byte(dev, PCI_SECONDARY_BUS,
 386                                                      &sec_bus);
 387                                 new_bus = pci_add_new_bus(dev->bus, dev,
 388                                                           sec_bus);
 389                                 pci_scan_child_bus(new_bus);
 390                                 sn_pci_controller_fixup(pci_domain_nr(new_bus),
 391                                                         new_bus->number,
 392                                                         new_bus);
 393                                 new_ppb = 1;
 394                         }
 395                         sn_bus_alloc_data(dev);
 396                         pci_dev_put(dev);
 397                 }
 398         }
 399
 400         /* Call the driver for the new device */
 401         pci_bus_add_devices(slot->pci_bus);
 402         /* Call the drivers for the new devices subordinate to PPB */
 403         if (new_ppb)
 404                 pci_bus_add_devices(new_bus);
 405
 406         mutex_unlock(&sn_hotplug_mutex);
 407
 408         if (rc == 0)
 409                 dev_dbg(slot->pci_bus->self,
 410                         "insert operation successful\n");
 411         else
 412                 dev_dbg(slot->pci_bus->self,
 413                         "insert operation failed rc = %d\n", rc);
 414
 415         return rc;
 416 }
 417
 418 static int disable_slot(struct hotplug_slot *bss_hotplug_slot)
 419 {
 420         struct slot *slot = bss_hotplug_slot->private;
 421         struct pci_dev *dev;
 422         int func;
 423         int rc;
 424
 425         /* Acquire update access to the bus */
 426         mutex_lock(&sn_hotplug_mutex);
 427
 428         /* is it okay to bring this slot down? */
 429         rc = sn_slot_disable(bss_hotplug_slot, slot->device_num,
 430                              PCI_REQ_SLOT_ELIGIBLE);
 431         if (rc)
 432                 goto leaving;
 433
 434         /* Free the SN resources assigned to the Linux device.*/
 435         for (func = 0; func < 8;  func++) {
 436                 dev = pci_get_slot(slot->pci_bus,
 437                                    PCI_DEVFN(slot->device_num + 1,
 438                                              PCI_FUNC(func)));
 439                 if (dev) {
 440                         sn_bus_free_data(dev);
 441                         pci_remove_bus_device(dev);
 442                         pci_dev_put(dev);
 443                 }
 444         }
 445
 446         /* free the collected sysdata pointers */
 447         sn_bus_free_sysdata();
 448
 449         /* Deactivate slot */
 450         rc = sn_slot_disable(bss_hotplug_slot, slot->device_num,
 451                              PCI_REQ_SLOT_DISABLE);
 452  leaving:
 453         /* Release the bus lock */
 454         mutex_unlock(&sn_hotplug_mutex);
 455
 456         return rc;
 457 }
 458
 459 static inline int get_power_status(struct hotplug_slot *bss_hotplug_slot,
 460                                    u8 *value)
 461 {
 462         struct slot *slot = bss_hotplug_slot->private;
 463         struct pcibus_info *pcibus_info;
 464         u32 power;
 465
 466         pcibus_info = SN_PCIBUS_BUSSOFT_INFO(slot->pci_bus);
 467         mutex_lock(&sn_hotplug_mutex);
 468         power = pcibus_info->pbi_enabled_devices & (1 << slot->device_num);
 469         *value = power ? 1 : 0;
 470         mutex_unlock(&sn_hotplug_mutex);
 471         return 0;
 472 }
 473
 474 static void sn_release_slot(struct hotplug_slot *bss_hotplug_slot)
 475 {
 476         kfree(bss_hotplug_slot->info);
 477         kfree(bss_hotplug_slot->name);
 478         kfree(bss_hotplug_slot->private);
 479         kfree(bss_hotplug_slot);
 480 }
 481
 482 static int sn_hotplug_slot_register(struct pci_bus *pci_bus)
 483 {
 484         int device;
 485         struct hotplug_slot *bss_hotplug_slot;
 486         int rc = 0;
 487
 488         /*
 489          * Currently only four devices are supported,
 490          * in the future there maybe more -- up to 32.
 491          */
 492
 493         for (device = 0; device < SN_MAX_HP_SLOTS ; device++) {
 494                 if (sn_pci_slot_valid(pci_bus, device) != 1)
 495                         continue;
 496
 497                 bss_hotplug_slot = kzalloc(sizeof(*bss_hotplug_slot),
 498                                            GFP_KERNEL);
 499                 if (!bss_hotplug_slot) {
 500                         rc = -ENOMEM;
 501                         goto alloc_err;
 502                 }
 503
 504                 bss_hotplug_slot->info =
 505                         kzalloc(sizeof(struct hotplug_slot_info),
 506                                 GFP_KERNEL);
 507                 if (!bss_hotplug_slot->info) {
 508                         rc = -ENOMEM;
 509                         goto alloc_err;
 510                 }
 511
 512                 if (sn_hp_slot_private_alloc(bss_hotplug_slot,
 513                                              pci_bus, device)) {
 514                         rc = -ENOMEM;
 515                         goto alloc_err;
 516                 }
 517
 518                 bss_hotplug_slot->ops = &sn_hotplug_slot_ops;
 519                 bss_hotplug_slot->release = &sn_release_slot;
 520
 521                 rc = pci_hp_register(bss_hotplug_slot);
 522                 if (rc)
 523                         goto register_err;
 524
 525                 rc = sysfs_create_file(&bss_hotplug_slot->kobj,
 526                                        &sn_slot_path_attr.attr);
 527                 if (rc)
 528                         goto register_err;
 529         }
 530         dev_dbg(pci_bus->self, "Registered bus with hotplug\n");
 531         return rc;
 532
 533 register_err:
 534         dev_dbg(pci_bus->self, "bus failed to register with err = %d\n",
 535                 rc);
 536
 537 alloc_err:
 538         if (rc == -ENOMEM)
 539                 dev_dbg(pci_bus->self, "Memory allocation error\n");
 540
 541         /* destroy THIS element */
 542         if (bss_hotplug_slot)
 543                 sn_release_slot(bss_hotplug_slot);
 544
 545         /* destroy anything else on the list */
 546         while ((bss_hotplug_slot = sn_hp_destroy()))
 547                 pci_hp_deregister(bss_hotplug_slot);
 548
 549         return rc;
 550 }
 551
 552 static int sn_pci_hotplug_init(void)
 553 {
 554         struct pci_bus *pci_bus = NULL;
 555         int rc;
 556         int registered = 0;
 557
 558         if (!sn_prom_feature_available(PRF_HOTPLUG_SUPPORT)) {
 559                 printk(KERN_ERR "%s: PROM version does not support hotplug.\n",
 560                        __FUNCTION__);
 561                 return -EPERM;
 562         }
 563
 564         INIT_LIST_HEAD(&sn_hp_list);
 565
 566         while ((pci_bus = pci_find_next_bus(pci_bus))) {
 567                 if (!pci_bus->sysdata)
 568                         continue;
 569
 570                 rc = sn_pci_bus_valid(pci_bus);
 571                 if (rc != 1) {
 572                         dev_dbg(pci_bus->self, "not a valid hotplug bus\n");
 573                         continue;
 574                 }
 575                 dev_dbg(pci_bus->self, "valid hotplug bus\n");
 576
 577                 rc = sn_hotplug_slot_register(pci_bus);
 578                 if (!rc) {
 579                         registered = 1;
 580                 } else {
 581                         registered = 0;
 582                         break;
 583                 }
 584         }
 585
 586         return registered == 1 ? 0 : -ENODEV;
 587 }
 588
 589 static void sn_pci_hotplug_exit(void)
 590 {
 591         struct hotplug_slot *bss_hotplug_slot;
 592
 593         while ((bss_hotplug_slot = sn_hp_destroy()))
 594                 pci_hp_deregister(bss_hotplug_slot);
 595
 596         if (!list_empty(&sn_hp_list))
 597                 printk(KERN_ERR "%s: internal list is not empty\n", __FILE__);
 598 }
 599
 600 module_init(sn_pci_hotplug_init);
 601 module_exit(sn_pci_hotplug_exit);