drivers/pci/hotplug/pci_hotplug_core.c

   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 */
  54 static int 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
  63 static LIST_HEAD(pci_hotplug_slot_list);
  64 static DEFINE_MUTEX(pci_hp_mutex);
  65
  66 #ifdef CONFIG_HOTPLUG_PCI_CPCI
  67 extern int cpci_hotplug_init(int debug);
  68 extern void cpci_hotplug_exit(void);
  69 #else
  70 static inline int cpci_hotplug_init(int debug) { return 0; }
  71 static inline void cpci_hotplug_exit(void) { }
  72 #endif
  73
  74 /* Weee, fun with macros... */
  75 #define GET_STATUS(name,type)   \
  76 static 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
  90 GET_STATUS(power_status, u8)
  91 GET_STATUS(attention_status, u8)
  92 GET_STATUS(latch_status, u8)
  93 GET_STATUS(adapter_status, u8)
  94
  95 static 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);
 104 exit:
 105         return retval;
 106 }
 107
 108 static 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
 141 exit:
 142         if (retval)
 143                 return retval;
 144         return count;
 145 }
 146
 147 static 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
 153 static 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
 163 exit:
 164         return retval;
 165 }
 166
 167 static 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
 187 exit:
 188         if (retval)
 189                 return retval;
 190         return count;
 191 }
 192
 193 static 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
 199 static 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
 209 exit:
 210         return retval;
 211 }
 212
 213 static struct pci_slot_attribute hotplug_slot_attr_latch = {
 214         .attr = {.name = "latch", .mode = S_IFREG | S_IRUGO},
 215         .show = latch_read_file,
 216 };
 217
 218 static 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
 228 exit:
 229         return retval;
 230 }
 231
 232 static struct pci_slot_attribute hotplug_slot_attr_presence = {
 233         .attr = {.name = "adapter", .mode = S_IFREG | S_IRUGO},
 234         .show = presence_read_file,
 235 };
 236
 237 static 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
 257 exit:
 258         if (retval)
 259                 return retval;
 260         return count;
 261 }
 262
 263 static 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
 268 static 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
 280 static 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
 291 static 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
 301 static 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
 311 static 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
 321 static 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
 365 exit_test:
 366         if (has_adapter_file(slot))
 367                 sysfs_remove_file(&slot->kobj,
 368                                   &hotplug_slot_attr_presence.attr);
 369 exit_adapter:
 370         if (has_latch_file(slot))
 371                 sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_latch.attr);
 372 exit_latch:
 373         if (has_attention_file(slot))
 374                 sysfs_remove_file(&slot->kobj,
 375                                   &hotplug_slot_attr_attention.attr);
 376 exit_attention:
 377         if (has_power_file(slot))
 378                 sysfs_remove_file(&slot->kobj, &hotplug_slot_attr_power.attr);
 379 exit_power:
 380         pci_hp_remove_module_link(slot);
 381 exit:
 382         return retval;
 383 }
 384
 385 static 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
 407 static 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  */
 434 int __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);
 474 out:
 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  */
 488 int 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  */
 527 int __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
 540 static 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
 552 err_cpci:
 553         return result;
 554 }
 555
 556 static void __exit pci_hotplug_exit (void)
 557 {
 558         cpci_hotplug_exit();
 559 }
 560
 561 module_init(pci_hotplug_init);
 562 module_exit(pci_hotplug_exit);
 563
 564 MODULE_AUTHOR(DRIVER_AUTHOR);
 565 MODULE_DESCRIPTION(DRIVER_DESC);
 566 MODULE_LICENSE("GPL");
 567 module_param(debug, bool, 0644);
 568 MODULE_PARM_DESC(debug, "Debugging mode enabled or not");
 569
 570 EXPORT_SYMBOL_GPL(__pci_hp_register);
 571 EXPORT_SYMBOL_GPL(pci_hp_deregister);
 572 EXPORT_SYMBOL_GPL(pci_hp_change_slot_info);