linux/drivers/pci/hotplug/pci_hotplug_core.c
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   1/*
   2 * PCI HotPlug Controller Core
   3 *
   4 * Copyright (C) 2001-2002 Greg Kroah-Hartman (greg@kroah.com)
   5 * Copyright (C) 2001-2002 IBM Corp.
   6 *
   7 * All rights reserved.
   8 *
   9 * This program is free software; you can redistribute it and/or modify
  10 * it under the terms of the GNU General Public License as published by
  11 * the Free Software Foundation; either version 2 of the License, or (at
  12 * your option) any later version.
  13 *
  14 * This program is distributed in the hope that it will be useful, but
  15 * WITHOUT ANY WARRANTY; without even the implied warranty of
  16 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  17 * NON INFRINGEMENT.  See the GNU General Public License for more
  18 * details.
  19 *
  20 * You should have received a copy of the GNU General Public License
  21 * along with this program; if not, write to the Free Software
  22 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  23 *
  24 * Send feedback to <kristen.c.accardi@intel.com>
  25 *
  26 */
  27
  28#include <linux/module.h>
  29#include <linux/moduleparam.h>
  30#include <linux/kernel.h>
  31#include <linux/types.h>
  32#include <linux/list.h>
  33#include <linux/kobject.h>
  34#include <linux/sysfs.h>
  35#include <linux/pagemap.h>
  36#include <linux/init.h>
  37#include <linux/mount.h>
  38#include <linux/namei.h>
  39#include <linux/mutex.h>
  40#include <linux/pci.h>
  41#include <linux/pci_hotplug.h>
  42#include <asm/uaccess.h>
  43#include "../pci.h"
  44
  45#define MY_NAME "pci_hotplug"
  46
  47#define dbg(fmt, arg...) do { if (debug) printk(KERN_DEBUG "%s: %s: " fmt , MY_NAME , __func__ , ## arg); } while (0)
  48#define err(format, arg...) printk(KERN_ERR "%s: " format , MY_NAME , ## arg)
  49#define info(format, arg...) printk(KERN_INFO "%s: " format , MY_NAME , ## arg)
  50#define warn(format, arg...) printk(KERN_WARNING "%s: " format , MY_NAME , ## arg)
  51
  52
  53/* local variables */
  54static bool debug;
  55
  56#define DRIVER_VERSION  "0.5"
  57#define DRIVER_AUTHOR   "Greg Kroah-Hartman <greg@kroah.com>, Scott Murray <scottm@somanetworks.com>"
  58#define DRIVER_DESC     "PCI Hot Plug PCI Core"
  59
  60
  61//////////////////////////////////////////////////////////////////
  62
  63static LIST_HEAD(pci_hotplug_slot_list);
  64static DEFINE_MUTEX(pci_hp_mutex);
  65
  66#ifdef CONFIG_HOTPLUG_PCI_CPCI
  67extern int cpci_hotplug_init(int debug);
  68extern void cpci_hotplug_exit(void);
  69#else
  70static inline int cpci_hotplug_init(int debug) { return 0; }
  71static inline void cpci_hotplug_exit(void) { }
  72#endif
  73
  74/* Weee, fun with macros... */
  75#define GET_STATUS(name,type)   \
  76static int get_##name (struct hotplug_slot *slot, type *value)          \
  77{                                                                       \
  78        struct hotplug_slot_ops *ops = slot->ops;                       \
  79        int retval = 0;                                                 \
  80        if (!try_module_get(ops->owner))                                \
  81                return -ENODEV;                                         \
  82        if (ops->get_##name)                                            \
  83                retval = ops->get_##name(slot, value);                  \
  84        else                                                            \
  85                *value = slot->info->name;                              \
  86        module_put(ops->owner);                                         \
  87        return retval;                                                  \
  88}
  89
  90GET_STATUS(power_status, u8)
  91GET_STATUS(attention_status, u8)
  92GET_STATUS(latch_status, u8)
  93GET_STATUS(adapter_status, u8)
  94
  95static ssize_t power_read_file(struct pci_slot *slot, char *buf)
  96{
  97        int retval;
  98        u8 value;
  99
 100        retval = get_power_status(slot->hotplug, &value);
 101        if (retval)
 102                goto exit;
 103        retval = sprintf (buf, "%d\n", value);
 104exit:
 105        return retval;
 106}
 107
 108static ssize_t power_write_file(struct pci_slot *pci_slot, const char *buf,
 109                size_t count)
 110{
 111        struct hotplug_slot *slot = pci_slot->hotplug;
 112        unsigned long lpower;
 113        u8 power;
 114        int retval = 0;
 115
 116        lpower = simple_strtoul (buf, NULL, 10);
 117        power = (u8)(lpower & 0xff);
 118        dbg ("power = %d\n", power);
 119
 120        if (!try_module_get(slot->ops->owner)) {
 121                retval = -ENODEV;
 122                goto exit;
 123        }
 124        switch (power) {
 125                case 0:
 126                        if (slot->ops->disable_slot)
 127                                retval = slot->ops->disable_slot(slot);
 128                        break;
 129
 130                case 1:
 131                        if (slot->ops->enable_slot)
 132                                retval = slot->ops->enable_slot(slot);
 133                        break;
 134
 135                default:
 136                        err ("Illegal value specified for power\n");
 137                        retval = -EINVAL;
 138        }
 139        module_put(slot->ops->owner);
 140
 141exit:   
 142        if (retval)
 143                return retval;
 144        return count;
 145}
 146
 147static struct pci_slot_attribute hotplug_slot_attr_power = {
 148        .attr = {.name = "power", .mode = S_IFREG | S_IRUGO | S_IWUSR},
 149        .show = power_read_file,
 150        .store = power_write_file
 151};
 152
 153static ssize_t attention_read_file(struct pci_slot *slot, char *buf)
 154{
 155        int retval;
 156        u8 value;
 157
 158        retval = get_attention_status(slot->hotplug, &value);
 159        if (retval)
 160                goto exit;
 161        retval = sprintf(buf, "%d\n", value);
 162
 163exit:
 164        return retval;
 165}
 166
 167static ssize_t attention_write_file(struct pci_slot *slot, const char *buf,
 168                size_t count)
 169{
 170        struct hotplug_slot_ops *ops = slot->hotplug->ops;
 171        unsigned long lattention;
 172        u8 attention;
 173        int retval = 0;
 174
 175        lattention = simple_strtoul (buf, NULL, 10);
 176        attention = (u8)(lattention & 0xff);
 177        dbg (" - attention = %d\n", attention);
 178
 179        if (!try_module_get(ops->owner)) {
 180                retval = -ENODEV;
 181                goto exit;
 182        }
 183        if (ops->set_attention_status)
 184                retval = ops->set_attention_status(slot->hotplug, attention);
 185        module_put(ops->owner);
 186
 187exit:   
 188        if (retval)
 189                return retval;
 190        return count;
 191}
 192
 193static struct pci_slot_attribute hotplug_slot_attr_attention = {
 194        .attr = {.name = "attention", .mode = S_IFREG | S_IRUGO | S_IWUSR},
 195        .show = attention_read_file,
 196        .store = attention_write_file
 197};
 198
 199static ssize_t latch_read_file(struct pci_slot *slot, char *buf)
 200{
 201        int retval;
 202        u8 value;
 203
 204        retval = get_latch_status(slot->hotplug, &value);
 205        if (retval)
 206                goto exit;
 207        retval = sprintf (buf, "%d\n", value);
 208
 209exit:
 210        return retval;
 211}
 212
 213static struct pci_slot_attribute hotplug_slot_attr_latch = {
 214        .attr = {.name = "latch", .mode = S_IFREG | S_IRUGO},
 215        .show = latch_read_file,
 216};
 217
 218static ssize_t presence_read_file(struct pci_slot *slot, char *buf)
 219{
 220        int retval;
 221        u8 value;
 222
 223        retval = get_adapter_status(slot->hotplug, &value);
 224        if (retval)
 225                goto exit;
 226        retval = sprintf (buf, "%d\n", value);
 227
 228exit:
 229        return retval;
 230}
 231
 232static struct pci_slot_attribute hotplug_slot_attr_presence = {
 233        .attr = {.name = "adapter", .mode = S_IFREG | S_IRUGO},
 234        .show = presence_read_file,
 235};
 236
 237static ssize_t test_write_file(struct pci_slot *pci_slot, const char *buf,
 238                size_t count)
 239{
 240        struct hotplug_slot *slot = pci_slot->hotplug;
 241        unsigned long ltest;
 242        u32 test;
 243        int retval = 0;
 244
 245        ltest = simple_strtoul (buf, NULL, 10);
 246        test = (u32)(ltest & 0xffffffff);
 247        dbg ("test = %d\n", test);
 248
 249        if (!try_module_get(slot->ops->owner)) {
 250                retval = -ENODEV;
 251                goto exit;
 252        }
 253        if (slot->ops->hardware_test)
 254                retval = slot->ops->hardware_test(slot, test);
 255        module_put(slot->ops->owner);
 256
 257exit:   
 258        if (retval)
 259                return retval;
 260        return count;
 261}
 262
 263static struct pci_slot_attribute hotplug_slot_attr_test = {
 264        .attr = {.name = "test", .mode = S_IFREG | S_IRUGO | S_IWUSR},
 265        .store = test_write_file
 266};
 267
 268static bool has_power_file(struct pci_slot *pci_slot)
 269{
 270        struct hotplug_slot *slot = pci_slot->hotplug;
 271        if ((!slot) || (!slot->ops))
 272                return false;
 273        if ((slot->ops->enable_slot) ||
 274            (slot->ops->disable_slot) ||
 275            (slot->ops->get_power_status))
 276                return true;
 277        return false;
 278}
 279
 280static bool has_attention_file(struct pci_slot *pci_slot)
 281{
 282        struct hotplug_slot *slot = pci_slot->hotplug;
 283        if ((!slot) || (!slot->ops))
 284                return false;
 285        if ((slot->ops->set_attention_status) ||
 286            (slot->ops->get_attention_status))
 287                return true;
 288        return false;
 289}
 290
 291static bool has_latch_file(struct pci_slot *pci_slot)
 292{
 293        struct hotplug_slot *slot = pci_slot->hotplug;
 294        if ((!slot) || (!slot->ops))
 295                return false;
 296        if (slot->ops->get_latch_status)
 297                return true;
 298        return false;
 299}
 300
 301static bool has_adapter_file(struct pci_slot *pci_slot)
 302{
 303        struct hotplug_slot *slot = pci_slot->hotplug;
 304        if ((!slot) || (!slot->ops))
 305                return false;
 306        if (slot->ops->get_adapter_status)
 307                return true;
 308        return false;
 309}
 310
 311static bool has_test_file(struct pci_slot *pci_slot)
 312{
 313        struct hotplug_slot *slot = pci_slot->hotplug;
 314        if ((!slot) || (!slot->ops))
 315                return false;
 316        if (slot->ops->hardware_test)
 317                return true;
 318        return false;
 319}
 320
 321static int fs_add_slot(struct pci_slot *slot)
 322{
 323        int retval = 0;
 324
 325        /* Create symbolic link to the hotplug driver module */
 326        pci_hp_create_module_link(slot);
 327
 328        if (has_power_file(slot)) {
 329                retval = sysfs_create_file(&slot->kobj,
 330                                           &hotplug_slot_attr_power.attr);
 331                if (retval)
 332                        goto exit_power;
 333        }
 334
 335        if (has_attention_file(slot)) {
 336                retval = sysfs_create_file(&slot->kobj,
 337                                           &hotplug_slot_attr_attention.attr);
 338                if (retval)
 339                        goto exit_attention;
 340        }
 341
 342        if (has_latch_file(slot)) {
 343                retval = sysfs_create_file(&slot->kobj,
 344                                           &hotplug_slot_attr_latch.attr);
 345                if (retval)
 346                        goto exit_latch;
 347        }
 348
 349        if (has_adapter_file(slot)) {
 350                retval = sysfs_create_file(&slot->kobj,
 351                                           &hotplug_slot_attr_presence.attr);
 352                if (retval)
 353                        goto exit_adapter;
 354        }
 355
 356        if (has_test_file(slot)) {
 357                retval = sysfs_create_file(&slot->kobj,
 358                                           &hotplug_slot_attr_test.attr);
 359                if (retval)
 360                        goto exit_test;
 361        }
 362
 363        goto exit;
 364
 365exit_test:
 366        if (has_adapter_file(slot))
 367                sysfs_remove_file(&slot->kobj,
 368                                  &hotplug_slot_attr_presence.attr);
 369exit_adapter:
 370        if (has_latch_file(slot))
 371                sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_latch.attr);
 372exit_latch:
 373        if (has_attention_file(slot))
 374                sysfs_remove_file(&slot->kobj,
 375                                  &hotplug_slot_attr_attention.attr);
 376exit_attention:
 377        if (has_power_file(slot))
 378                sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_power.attr);
 379exit_power:
 380        pci_hp_remove_module_link(slot);
 381exit:
 382        return retval;
 383}
 384
 385static void fs_remove_slot(struct pci_slot *slot)
 386{
 387        if (has_power_file(slot))
 388                sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_power.attr);
 389
 390        if (has_attention_file(slot))
 391                sysfs_remove_file(&slot->kobj,
 392                                  &hotplug_slot_attr_attention.attr);
 393
 394        if (has_latch_file(slot))
 395                sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_latch.attr);
 396
 397        if (has_adapter_file(slot))
 398                sysfs_remove_file(&slot->kobj,
 399                                  &hotplug_slot_attr_presence.attr);
 400
 401        if (has_test_file(slot))
 402                sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_test.attr);
 403
 404        pci_hp_remove_module_link(slot);
 405}
 406
 407static struct hotplug_slot *get_slot_from_name (const char *name)
 408{
 409        struct hotplug_slot *slot;
 410        struct list_head *tmp;
 411
 412        list_for_each (tmp, &pci_hotplug_slot_list) {
 413                slot = list_entry (tmp, struct hotplug_slot, slot_list);
 414                if (strcmp(hotplug_slot_name(slot), name) == 0)
 415                        return slot;
 416        }
 417        return NULL;
 418}
 419
 420/**
 421 * __pci_hp_register - register a hotplug_slot with the PCI hotplug subsystem
 422 * @bus: bus this slot is on
 423 * @slot: pointer to the &struct hotplug_slot to register
 424 * @devnr: device number
 425 * @name: name registered with kobject core
 426 * @owner: caller module owner
 427 * @mod_name: caller module name
 428 *
 429 * Registers a hotplug slot with the pci hotplug subsystem, which will allow
 430 * userspace interaction to the slot.
 431 *
 432 * Returns 0 if successful, anything else for an error.
 433 */
 434int __pci_hp_register(struct hotplug_slot *slot, struct pci_bus *bus,
 435                      int devnr, const char *name,
 436                      struct module *owner, const char *mod_name)
 437{
 438        int result;
 439        struct pci_slot *pci_slot;
 440
 441        if (slot == NULL)
 442                return -ENODEV;
 443        if ((slot->info == NULL) || (slot->ops == NULL))
 444                return -EINVAL;
 445        if (slot->release == NULL) {
 446                dbg("Why are you trying to register a hotplug slot "
 447                    "without a proper release function?\n");
 448                return -EINVAL;
 449        }
 450
 451        slot->ops->owner = owner;
 452        slot->ops->mod_name = mod_name;
 453
 454        mutex_lock(&pci_hp_mutex);
 455        /*
 456         * No problems if we call this interface from both ACPI_PCI_SLOT
 457         * driver and call it here again. If we've already created the
 458         * pci_slot, the interface will simply bump the refcount.
 459         */
 460        pci_slot = pci_create_slot(bus, devnr, name, slot);
 461        if (IS_ERR(pci_slot)) {
 462                result = PTR_ERR(pci_slot);
 463                goto out;
 464        }
 465
 466        slot->pci_slot = pci_slot;
 467        pci_slot->hotplug = slot;
 468
 469        list_add(&slot->slot_list, &pci_hotplug_slot_list);
 470
 471        result = fs_add_slot(pci_slot);
 472        kobject_uevent(&pci_slot->kobj, KOBJ_ADD);
 473        dbg("Added slot %s to the list\n", name);
 474out:
 475        mutex_unlock(&pci_hp_mutex);
 476        return result;
 477}
 478
 479/**
 480 * pci_hp_deregister - deregister a hotplug_slot with the PCI hotplug subsystem
 481 * @hotplug: pointer to the &struct hotplug_slot to deregister
 482 *
 483 * The @slot must have been registered with the pci hotplug subsystem
 484 * previously with a call to pci_hp_register().
 485 *
 486 * Returns 0 if successful, anything else for an error.
 487 */
 488int pci_hp_deregister(struct hotplug_slot *hotplug)
 489{
 490        struct hotplug_slot *temp;
 491        struct pci_slot *slot;
 492
 493        if (!hotplug)
 494                return -ENODEV;
 495
 496        mutex_lock(&pci_hp_mutex);
 497        temp = get_slot_from_name(hotplug_slot_name(hotplug));
 498        if (temp != hotplug) {
 499                mutex_unlock(&pci_hp_mutex);
 500                return -ENODEV;
 501        }
 502
 503        list_del(&hotplug->slot_list);
 504
 505        slot = hotplug->pci_slot;
 506        fs_remove_slot(slot);
 507        dbg("Removed slot %s from the list\n", hotplug_slot_name(hotplug));
 508
 509        hotplug->release(hotplug);
 510        slot->hotplug = NULL;
 511        pci_destroy_slot(slot);
 512        mutex_unlock(&pci_hp_mutex);
 513
 514        return 0;
 515}
 516
 517/**
 518 * pci_hp_change_slot_info - changes the slot's information structure in the core
 519 * @hotplug: pointer to the slot whose info has changed
 520 * @info: pointer to the info copy into the slot's info structure
 521 *
 522 * @slot must have been registered with the pci 
 523 * hotplug subsystem previously with a call to pci_hp_register().
 524 *
 525 * Returns 0 if successful, anything else for an error.
 526 */
 527int __must_check pci_hp_change_slot_info(struct hotplug_slot *hotplug,
 528                                         struct hotplug_slot_info *info)
 529{
 530        struct pci_slot *slot;
 531        if (!hotplug || !info)
 532                return -ENODEV;
 533        slot = hotplug->pci_slot;
 534
 535        memcpy(hotplug->info, info, sizeof(struct hotplug_slot_info));
 536
 537        return 0;
 538}
 539
 540static int __init pci_hotplug_init (void)
 541{
 542        int result;
 543
 544        result = cpci_hotplug_init(debug);
 545        if (result) {
 546                err ("cpci_hotplug_init with error %d\n", result);
 547                goto err_cpci;
 548        }
 549
 550        info (DRIVER_DESC " version: " DRIVER_VERSION "\n");
 551
 552err_cpci:
 553        return result;
 554}
 555
 556static void __exit pci_hotplug_exit (void)
 557{
 558        cpci_hotplug_exit();
 559}
 560
 561module_init(pci_hotplug_init);
 562module_exit(pci_hotplug_exit);
 563
 564MODULE_AUTHOR(DRIVER_AUTHOR);
 565MODULE_DESCRIPTION(DRIVER_DESC);
 566MODULE_LICENSE("GPL");
 567module_param(debug, bool, 0644);
 568MODULE_PARM_DESC(debug, "Debugging mode enabled or not");
 569
 570EXPORT_SYMBOL_GPL(__pci_hp_register);
 571EXPORT_SYMBOL_GPL(pci_hp_deregister);
 572EXPORT_SYMBOL_GPL(pci_hp_change_slot_info);
 573