drivers/edac/edac_pci_sysfs.c

   1 /*
   2  * (C) 2005, 2006 Linux Networx (http://lnxi.com)
   3  * This file may be distributed under the terms of the
   4  * GNU General Public License.
   5  *
   6  * Written Doug Thompson <norsk5@xmission.com>
   7  *
   8  */
   9 #include <linux/module.h>
  10 #include <linux/sysdev.h>
  11 #include <linux/ctype.h>
  12
  13 #include "edac_core.h"
  14 #include "edac_module.h"
  15
  16 /* Turn off this whole feature if PCI is not configured */
  17 #ifdef CONFIG_PCI
  18
  19 #define EDAC_PCI_SYMLINK        "device"
  20
  21 /* data variables exported via sysfs */
  22 static int check_pci_errors;            /* default NO check PCI parity */
  23 static int edac_pci_panic_on_pe;        /* default NO panic on PCI Parity */
  24 static int edac_pci_log_pe = 1;         /* log PCI parity errors */
  25 static int edac_pci_log_npe = 1;        /* log PCI non-parity error errors */
  26 static int edac_pci_poll_msec = 1000;   /* one second workq period */
  27
  28 static atomic_t pci_parity_count = ATOMIC_INIT(0);
  29 static atomic_t pci_nonparity_count = ATOMIC_INIT(0);
  30
  31 static struct kobject *edac_pci_top_main_kobj;
  32 static atomic_t edac_pci_sysfs_refcount = ATOMIC_INIT(0);
  33
  34 /* getter functions for the data variables */
  35 int edac_pci_get_check_errors(void)
  36 {
  37         return check_pci_errors;
  38 }
  39
  40 static int edac_pci_get_log_pe(void)
  41 {
  42         return edac_pci_log_pe;
  43 }
  44
  45 static int edac_pci_get_log_npe(void)
  46 {
  47         return edac_pci_log_npe;
  48 }
  49
  50 static int edac_pci_get_panic_on_pe(void)
  51 {
  52         return edac_pci_panic_on_pe;
  53 }
  54
  55 int edac_pci_get_poll_msec(void)
  56 {
  57         return edac_pci_poll_msec;
  58 }
  59
  60 /**************************** EDAC PCI sysfs instance *******************/
  61 static ssize_t instance_pe_count_show(struct edac_pci_ctl_info *pci, char *data)
  62 {
  63         return sprintf(data, "%u\n", atomic_read(&pci->counters.pe_count));
  64 }
  65
  66 static ssize_t instance_npe_count_show(struct edac_pci_ctl_info *pci,
  67                                 char *data)
  68 {
  69         return sprintf(data, "%u\n", atomic_read(&pci->counters.npe_count));
  70 }
  71
  72 #define to_instance(k) container_of(k, struct edac_pci_ctl_info, kobj)
  73 #define to_instance_attr(a) container_of(a, struct instance_attribute, attr)
  74
  75 /* DEVICE instance kobject release() function */
  76 static void edac_pci_instance_release(struct kobject *kobj)
  77 {
  78         struct edac_pci_ctl_info *pci;
  79
  80         debugf0("%s()\n", __func__);
  81
  82         /* Form pointer to containing struct, the pci control struct */
  83         pci = to_instance(kobj);
  84
  85         /* decrement reference count on top main kobj */
  86         kobject_put(edac_pci_top_main_kobj);
  87
  88         kfree(pci);     /* Free the control struct */
  89 }
  90
  91 /* instance specific attribute structure */
  92 struct instance_attribute {
  93         struct attribute attr;
  94         ssize_t(*show) (struct edac_pci_ctl_info *, char *);
  95         ssize_t(*store) (struct edac_pci_ctl_info *, const char *, size_t);
  96 };
  97
  98 /* Function to 'show' fields from the edac_pci 'instance' structure */
  99 static ssize_t edac_pci_instance_show(struct kobject *kobj,
 100                                 struct attribute *attr, char *buffer)
 101 {
 102         struct edac_pci_ctl_info *pci = to_instance(kobj);
 103         struct instance_attribute *instance_attr = to_instance_attr(attr);
 104
 105         if (instance_attr->show)
 106                 return instance_attr->show(pci, buffer);
 107         return -EIO;
 108 }
 109
 110 /* Function to 'store' fields into the edac_pci 'instance' structure */
 111 static ssize_t edac_pci_instance_store(struct kobject *kobj,
 112                                 struct attribute *attr,
 113                                 const char *buffer, size_t count)
 114 {
 115         struct edac_pci_ctl_info *pci = to_instance(kobj);
 116         struct instance_attribute *instance_attr = to_instance_attr(attr);
 117
 118         if (instance_attr->store)
 119                 return instance_attr->store(pci, buffer, count);
 120         return -EIO;
 121 }
 122
 123 /* fs_ops table */
 124 static struct sysfs_ops pci_instance_ops = {
 125         .show = edac_pci_instance_show,
 126         .store = edac_pci_instance_store
 127 };
 128
 129 #define INSTANCE_ATTR(_name, _mode, _show, _store)      \
 130 static struct instance_attribute attr_instance_##_name = {      \
 131         .attr   = {.name = __stringify(_name), .mode = _mode }, \
 132         .show   = _show,                                        \
 133         .store  = _store,                                       \
 134 };
 135
 136 INSTANCE_ATTR(pe_count, S_IRUGO, instance_pe_count_show, NULL);
 137 INSTANCE_ATTR(npe_count, S_IRUGO, instance_npe_count_show, NULL);
 138
 139 /* pci instance attributes */
 140 static struct instance_attribute *pci_instance_attr[] = {
 141         &attr_instance_pe_count,
 142         &attr_instance_npe_count,
 143         NULL
 144 };
 145
 146 /* the ktype for a pci instance */
 147 static struct kobj_type ktype_pci_instance = {
 148         .release = edac_pci_instance_release,
 149         .sysfs_ops = &pci_instance_ops,
 150         .default_attrs = (struct attribute **)pci_instance_attr,
 151 };
 152
 153 /*
 154  * edac_pci_create_instance_kobj
 155  *
 156  *      construct one EDAC PCI instance's kobject for use
 157  */
 158 static int edac_pci_create_instance_kobj(struct edac_pci_ctl_info *pci, int idx)
 159 {
 160         struct kobject *main_kobj;
 161         int err;
 162
 163         debugf0("%s()\n", __func__);
 164
 165         /* First bump the ref count on the top main kobj, which will
 166          * track the number of PCI instances we have, and thus nest
 167          * properly on keeping the module loaded
 168          */
 169         main_kobj = kobject_get(edac_pci_top_main_kobj);
 170         if (!main_kobj) {
 171                 err = -ENODEV;
 172                 goto error_out;
 173         }
 174
 175         /* And now register this new kobject under the main kobj */
 176         err = kobject_init_and_add(&pci->kobj, &ktype_pci_instance,
 177                                    edac_pci_top_main_kobj, "pci%d", idx);
 178         if (err != 0) {
 179                 debugf2("%s() failed to register instance pci%d\n",
 180                         __func__, idx);
 181                 kobject_put(edac_pci_top_main_kobj);
 182                 goto error_out;
 183         }
 184
 185         kobject_uevent(&pci->kobj, KOBJ_ADD);
 186         debugf1("%s() Register instance 'pci%d' kobject\n", __func__, idx);
 187
 188         return 0;
 189
 190         /* Error unwind statck */
 191 error_out:
 192         return err;
 193 }
 194
 195 /*
 196  * edac_pci_unregister_sysfs_instance_kobj
 197  *
 198  *      unregister the kobj for the EDAC PCI instance
 199  */
 200 static void edac_pci_unregister_sysfs_instance_kobj(
 201                         struct edac_pci_ctl_info *pci)
 202 {
 203         debugf0("%s()\n", __func__);
 204
 205         /* Unregister the instance kobject and allow its release
 206          * function release the main reference count and then
 207          * kfree the memory
 208          */
 209         kobject_put(&pci->kobj);
 210 }
 211
 212 /***************************** EDAC PCI sysfs root **********************/
 213 #define to_edacpci(k) container_of(k, struct edac_pci_ctl_info, kobj)
 214 #define to_edacpci_attr(a) container_of(a, struct edac_pci_attr, attr)
 215
 216 /* simple show/store functions for attributes */
 217 static ssize_t edac_pci_int_show(void *ptr, char *buffer)
 218 {
 219         int *value = ptr;
 220         return sprintf(buffer, "%d\n", *value);
 221 }
 222
 223 static ssize_t edac_pci_int_store(void *ptr, const char *buffer, size_t count)
 224 {
 225         int *value = ptr;
 226
 227         if (isdigit(*buffer))
 228                 *value = simple_strtoul(buffer, NULL, 0);
 229
 230         return count;
 231 }
 232
 233 struct edac_pci_dev_attribute {
 234         struct attribute attr;
 235         void *value;
 236          ssize_t(*show) (void *, char *);
 237          ssize_t(*store) (void *, const char *, size_t);
 238 };
 239
 240 /* Set of show/store abstract level functions for PCI Parity object */
 241 static ssize_t edac_pci_dev_show(struct kobject *kobj, struct attribute *attr,
 242                                  char *buffer)
 243 {
 244         struct edac_pci_dev_attribute *edac_pci_dev;
 245         edac_pci_dev = (struct edac_pci_dev_attribute *)attr;
 246
 247         if (edac_pci_dev->show)
 248                 return edac_pci_dev->show(edac_pci_dev->value, buffer);
 249         return -EIO;
 250 }
 251
 252 static ssize_t edac_pci_dev_store(struct kobject *kobj,
 253                                 struct attribute *attr, const char *buffer,
 254                                 size_t count)
 255 {
 256         struct edac_pci_dev_attribute *edac_pci_dev;
 257         edac_pci_dev = (struct edac_pci_dev_attribute *)attr;
 258
 259         if (edac_pci_dev->show)
 260                 return edac_pci_dev->store(edac_pci_dev->value, buffer, count);
 261         return -EIO;
 262 }
 263
 264 static struct sysfs_ops edac_pci_sysfs_ops = {
 265         .show = edac_pci_dev_show,
 266         .store = edac_pci_dev_store
 267 };
 268
 269 #define EDAC_PCI_ATTR(_name,_mode,_show,_store)                 \
 270 static struct edac_pci_dev_attribute edac_pci_attr_##_name = {          \
 271         .attr = {.name = __stringify(_name), .mode = _mode },   \
 272         .value  = &_name,                                       \
 273         .show   = _show,                                        \
 274         .store  = _store,                                       \
 275 };
 276
 277 #define EDAC_PCI_STRING_ATTR(_name,_data,_mode,_show,_store)    \
 278 static struct edac_pci_dev_attribute edac_pci_attr_##_name = {          \
 279         .attr = {.name = __stringify(_name), .mode = _mode },   \
 280         .value  = _data,                                        \
 281         .show   = _show,                                        \
 282         .store  = _store,                                       \
 283 };
 284
 285 /* PCI Parity control files */
 286 EDAC_PCI_ATTR(check_pci_errors, S_IRUGO | S_IWUSR, edac_pci_int_show,
 287         edac_pci_int_store);
 288 EDAC_PCI_ATTR(edac_pci_log_pe, S_IRUGO | S_IWUSR, edac_pci_int_show,
 289         edac_pci_int_store);
 290 EDAC_PCI_ATTR(edac_pci_log_npe, S_IRUGO | S_IWUSR, edac_pci_int_show,
 291         edac_pci_int_store);
 292 EDAC_PCI_ATTR(edac_pci_panic_on_pe, S_IRUGO | S_IWUSR, edac_pci_int_show,
 293         edac_pci_int_store);
 294 EDAC_PCI_ATTR(pci_parity_count, S_IRUGO, edac_pci_int_show, NULL);
 295 EDAC_PCI_ATTR(pci_nonparity_count, S_IRUGO, edac_pci_int_show, NULL);
 296
 297 /* Base Attributes of the memory ECC object */
 298 static struct edac_pci_dev_attribute *edac_pci_attr[] = {
 299         &edac_pci_attr_check_pci_errors,
 300         &edac_pci_attr_edac_pci_log_pe,
 301         &edac_pci_attr_edac_pci_log_npe,
 302         &edac_pci_attr_edac_pci_panic_on_pe,
 303         &edac_pci_attr_pci_parity_count,
 304         &edac_pci_attr_pci_nonparity_count,
 305         NULL,
 306 };
 307
 308 /*
 309  * edac_pci_release_main_kobj
 310  *
 311  *      This release function is called when the reference count to the
 312  *      passed kobj goes to zero.
 313  *
 314  *      This kobj is the 'main' kobject that EDAC PCI instances
 315  *      link to, and thus provide for proper nesting counts
 316  */
 317 static void edac_pci_release_main_kobj(struct kobject *kobj)
 318 {
 319         debugf0("%s() here to module_put(THIS_MODULE)\n", __func__);
 320
 321         kfree(kobj);
 322
 323         /* last reference to top EDAC PCI kobject has been removed,
 324          * NOW release our ref count on the core module
 325          */
 326         module_put(THIS_MODULE);
 327 }
 328
 329 /* ktype struct for the EDAC PCI main kobj */
 330 static struct kobj_type ktype_edac_pci_main_kobj = {
 331         .release = edac_pci_release_main_kobj,
 332         .sysfs_ops = &edac_pci_sysfs_ops,
 333         .default_attrs = (struct attribute **)edac_pci_attr,
 334 };
 335
 336 /**
 337  * edac_pci_main_kobj_setup()
 338  *
 339  *      setup the sysfs for EDAC PCI attributes
 340  *      assumes edac_class has already been initialized
 341  */
 342 static int edac_pci_main_kobj_setup(void)
 343 {
 344         int err;
 345         struct sysdev_class *edac_class;
 346
 347         debugf0("%s()\n", __func__);
 348
 349         /* check and count if we have already created the main kobject */
 350         if (atomic_inc_return(&edac_pci_sysfs_refcount) != 1)
 351                 return 0;
 352
 353         /* First time, so create the main kobject and its
 354          * controls and atributes
 355          */
 356         edac_class = edac_get_edac_class();
 357         if (edac_class == NULL) {
 358                 debugf1("%s() no edac_class\n", __func__);
 359                 err = -ENODEV;
 360                 goto decrement_count_fail;
 361         }
 362
 363         /* Bump the reference count on this module to ensure the
 364          * modules isn't unloaded until we deconstruct the top
 365          * level main kobj for EDAC PCI
 366          */
 367         if (!try_module_get(THIS_MODULE)) {
 368                 debugf1("%s() try_module_get() failed\n", __func__);
 369                 err = -ENODEV;
 370                 goto decrement_count_fail;
 371         }
 372
 373         edac_pci_top_main_kobj = kzalloc(sizeof(struct kobject), GFP_KERNEL);
 374         if (!edac_pci_top_main_kobj) {
 375                 debugf1("Failed to allocate\n");
 376                 err = -ENOMEM;
 377                 goto kzalloc_fail;
 378         }
 379
 380         /* Instanstiate the pci object */
 381         err = kobject_init_and_add(edac_pci_top_main_kobj,
 382                                    &ktype_edac_pci_main_kobj,
 383                                    &edac_class->kset.kobj, "pci");
 384         if (err) {
 385                 debugf1("Failed to register '.../edac/pci'\n");
 386                 goto kobject_init_and_add_fail;
 387         }
 388
 389         /* At this point, to 'release' the top level kobject
 390          * for EDAC PCI, then edac_pci_main_kobj_teardown()
 391          * must be used, for resources to be cleaned up properly
 392          */
 393         kobject_uevent(edac_pci_top_main_kobj, KOBJ_ADD);
 394         debugf1("Registered '.../edac/pci' kobject\n");
 395
 396         return 0;
 397
 398         /* Error unwind statck */
 399 kobject_init_and_add_fail:
 400         kfree(edac_pci_top_main_kobj);
 401
 402 kzalloc_fail:
 403         module_put(THIS_MODULE);
 404
 405 decrement_count_fail:
 406         /* if are on this error exit, nothing to tear down */
 407         atomic_dec(&edac_pci_sysfs_refcount);
 408
 409         return err;
 410 }
 411
 412 /*
 413  * edac_pci_main_kobj_teardown()
 414  *
 415  *      if no longer linked (needed) remove the top level EDAC PCI
 416  *      kobject with its controls and attributes
 417  */
 418 static void edac_pci_main_kobj_teardown(void)
 419 {
 420         debugf0("%s()\n", __func__);
 421
 422         /* Decrement the count and only if no more controller instances
 423          * are connected perform the unregisteration of the top level
 424          * main kobj
 425          */
 426         if (atomic_dec_return(&edac_pci_sysfs_refcount) == 0) {
 427                 debugf0("%s() called kobject_put on main kobj\n",
 428                         __func__);
 429                 kobject_put(edac_pci_top_main_kobj);
 430         }
 431 }
 432
 433 /*
 434  *
 435  * edac_pci_create_sysfs
 436  *
 437  *      Create the controls/attributes for the specified EDAC PCI device
 438  */
 439 int edac_pci_create_sysfs(struct edac_pci_ctl_info *pci)
 440 {
 441         int err;
 442         struct kobject *edac_kobj = &pci->kobj;
 443
 444         debugf0("%s() idx=%d\n", __func__, pci->pci_idx);
 445
 446         /* create the top main EDAC PCI kobject, IF needed */
 447         err = edac_pci_main_kobj_setup();
 448         if (err)
 449                 return err;
 450
 451         /* Create this instance's kobject under the MAIN kobject */
 452         err = edac_pci_create_instance_kobj(pci, pci->pci_idx);
 453         if (err)
 454                 goto unregister_cleanup;
 455
 456         err = sysfs_create_link(edac_kobj, &pci->dev->kobj, EDAC_PCI_SYMLINK);
 457         if (err) {
 458                 debugf0("%s() sysfs_create_link() returned err= %d\n",
 459                         __func__, err);
 460                 goto symlink_fail;
 461         }
 462
 463         return 0;
 464
 465         /* Error unwind stack */
 466 symlink_fail:
 467         edac_pci_unregister_sysfs_instance_kobj(pci);
 468
 469 unregister_cleanup:
 470         edac_pci_main_kobj_teardown();
 471
 472         return err;
 473 }
 474
 475 /*
 476  * edac_pci_remove_sysfs
 477  *
 478  *      remove the controls and attributes for this EDAC PCI device
 479  */
 480 void edac_pci_remove_sysfs(struct edac_pci_ctl_info *pci)
 481 {
 482         debugf0("%s() index=%d\n", __func__, pci->pci_idx);
 483
 484         /* Remove the symlink */
 485         sysfs_remove_link(&pci->kobj, EDAC_PCI_SYMLINK);
 486
 487         /* remove this PCI instance's sysfs entries */
 488         edac_pci_unregister_sysfs_instance_kobj(pci);
 489
 490         /* Call the main unregister function, which will determine
 491          * if this 'pci' is the last instance.
 492          * If it is, the main kobject will be unregistered as a result
 493          */
 494         debugf0("%s() calling edac_pci_main_kobj_teardown()\n", __func__);
 495         edac_pci_main_kobj_teardown();
 496 }
 497
 498 /************************ PCI error handling *************************/
 499 static u16 get_pci_parity_status(struct pci_dev *dev, int secondary)
 500 {
 501         int where;
 502         u16 status;
 503
 504         where = secondary ? PCI_SEC_STATUS : PCI_STATUS;
 505         pci_read_config_word(dev, where, &status);
 506
 507         /* If we get back 0xFFFF then we must suspect that the card has been
 508          * pulled but the Linux PCI layer has not yet finished cleaning up.
 509          * We don't want to report on such devices
 510          */
 511
 512         if (status == 0xFFFF) {
 513                 u32 sanity;
 514
 515                 pci_read_config_dword(dev, 0, &sanity);
 516
 517                 if (sanity == 0xFFFFFFFF)
 518                         return 0;
 519         }
 520
 521         status &= PCI_STATUS_DETECTED_PARITY | PCI_STATUS_SIG_SYSTEM_ERROR |
 522                 PCI_STATUS_PARITY;
 523
 524         if (status)
 525                 /* reset only the bits we are interested in */
 526                 pci_write_config_word(dev, where, status);
 527
 528         return status;
 529 }
 530
 531
 532 /* Clear any PCI parity errors logged by this device. */
 533 static void edac_pci_dev_parity_clear(struct pci_dev *dev)
 534 {
 535         u8 header_type;
 536
 537         get_pci_parity_status(dev, 0);
 538
 539         /* read the device TYPE, looking for bridges */
 540         pci_read_config_byte(dev, PCI_HEADER_TYPE, &header_type);
 541
 542         if ((header_type & 0x7F) == PCI_HEADER_TYPE_BRIDGE)
 543                 get_pci_parity_status(dev, 1);
 544 }
 545
 546 /*
 547  *  PCI Parity polling
 548  *
 549  *      Fucntion to retrieve the current parity status
 550  *      and decode it
 551  *
 552  */
 553 static void edac_pci_dev_parity_test(struct pci_dev *dev)
 554 {
 555         unsigned long flags;
 556         u16 status;
 557         u8 header_type;
 558
 559         /* stop any interrupts until we can acquire the status */
 560         local_irq_save(flags);
 561
 562         /* read the STATUS register on this device */
 563         status = get_pci_parity_status(dev, 0);
 564
 565         /* read the device TYPE, looking for bridges */
 566         pci_read_config_byte(dev, PCI_HEADER_TYPE, &header_type);
 567
 568         local_irq_restore(flags);
 569
 570         debugf4("PCI STATUS= 0x%04x %s\n", status, dev_name(&dev->dev));
 571
 572         /* check the status reg for errors on boards NOT marked as broken
 573          * if broken, we cannot trust any of the status bits
 574          */
 575         if (status && !dev->broken_parity_status) {
 576                 if (status & (PCI_STATUS_SIG_SYSTEM_ERROR)) {
 577                         edac_printk(KERN_CRIT, EDAC_PCI,
 578                                 "Signaled System Error on %s\n",
 579                                 pci_name(dev));
 580                         atomic_inc(&pci_nonparity_count);
 581                 }
 582
 583                 if (status & (PCI_STATUS_PARITY)) {
 584                         edac_printk(KERN_CRIT, EDAC_PCI,
 585                                 "Master Data Parity Error on %s\n",
 586                                 pci_name(dev));
 587
 588                         atomic_inc(&pci_parity_count);
 589                 }
 590
 591                 if (status & (PCI_STATUS_DETECTED_PARITY)) {
 592                         edac_printk(KERN_CRIT, EDAC_PCI,
 593                                 "Detected Parity Error on %s\n",
 594                                 pci_name(dev));
 595
 596                         atomic_inc(&pci_parity_count);
 597                 }
 598         }
 599
 600
 601         debugf4("PCI HEADER TYPE= 0x%02x %s\n", header_type, dev_name(&dev->dev));
 602
 603         if ((header_type & 0x7F) == PCI_HEADER_TYPE_BRIDGE) {
 604                 /* On bridges, need to examine secondary status register  */
 605                 status = get_pci_parity_status(dev, 1);
 606
 607                 debugf4("PCI SEC_STATUS= 0x%04x %s\n", status, dev_name(&dev->dev));
 608
 609                 /* check the secondary status reg for errors,
 610                  * on NOT broken boards
 611                  */
 612                 if (status && !dev->broken_parity_status) {
 613                         if (status & (PCI_STATUS_SIG_SYSTEM_ERROR)) {
 614                                 edac_printk(KERN_CRIT, EDAC_PCI, "Bridge "
 615                                         "Signaled System Error on %s\n",
 616                                         pci_name(dev));
 617                                 atomic_inc(&pci_nonparity_count);
 618                         }
 619
 620                         if (status & (PCI_STATUS_PARITY)) {
 621                                 edac_printk(KERN_CRIT, EDAC_PCI, "Bridge "
 622                                         "Master Data Parity Error on "
 623                                         "%s\n", pci_name(dev));
 624
 625                                 atomic_inc(&pci_parity_count);
 626                         }
 627
 628                         if (status & (PCI_STATUS_DETECTED_PARITY)) {
 629                                 edac_printk(KERN_CRIT, EDAC_PCI, "Bridge "
 630                                         "Detected Parity Error on %s\n",
 631                                         pci_name(dev));
 632
 633                                 atomic_inc(&pci_parity_count);
 634                         }
 635                 }
 636         }
 637 }
 638
 639 /* reduce some complexity in definition of the iterator */
 640 typedef void (*pci_parity_check_fn_t) (struct pci_dev *dev);
 641
 642 /*
 643  * pci_dev parity list iterator
 644  *      Scan the PCI device list for one pass, looking for SERRORs
 645  *      Master Parity ERRORS or Parity ERRORs on primary or secondary devices
 646  */
 647 static inline void edac_pci_dev_parity_iterator(pci_parity_check_fn_t fn)
 648 {
 649         struct pci_dev *dev = NULL;
 650
 651         /* request for kernel access to the next PCI device, if any,
 652          * and while we are looking at it have its reference count
 653          * bumped until we are done with it
 654          */
 655         while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
 656                 fn(dev);
 657         }
 658 }
 659
 660 /*
 661  * edac_pci_do_parity_check
 662  *
 663  *      performs the actual PCI parity check operation
 664  */
 665 void edac_pci_do_parity_check(void)
 666 {
 667         int before_count;
 668
 669         debugf3("%s()\n", __func__);
 670
 671         /* if policy has PCI check off, leave now */
 672         if (!check_pci_errors)
 673                 return;
 674
 675         before_count = atomic_read(&pci_parity_count);
 676
 677         /* scan all PCI devices looking for a Parity Error on devices and
 678          * bridges.
 679          * The iterator calls pci_get_device() which might sleep, thus
 680          * we cannot disable interrupts in this scan.
 681          */
 682         edac_pci_dev_parity_iterator(edac_pci_dev_parity_test);
 683
 684         /* Only if operator has selected panic on PCI Error */
 685         if (edac_pci_get_panic_on_pe()) {
 686                 /* If the count is different 'after' from 'before' */
 687                 if (before_count != atomic_read(&pci_parity_count))
 688                         panic("EDAC: PCI Parity Error");
 689         }
 690 }
 691
 692 /*
 693  * edac_pci_clear_parity_errors
 694  *
 695  *      function to perform an iteration over the PCI devices
 696  *      and clearn their current status
 697  */
 698 void edac_pci_clear_parity_errors(void)
 699 {
 700         /* Clear any PCI bus parity errors that devices initially have logged
 701          * in their registers.
 702          */
 703         edac_pci_dev_parity_iterator(edac_pci_dev_parity_clear);
 704 }
 705
 706 /*
 707  * edac_pci_handle_pe
 708  *
 709  *      Called to handle a PARITY ERROR event
 710  */
 711 void edac_pci_handle_pe(struct edac_pci_ctl_info *pci, const char *msg)
 712 {
 713
 714         /* global PE counter incremented by edac_pci_do_parity_check() */
 715         atomic_inc(&pci->counters.pe_count);
 716
 717         if (edac_pci_get_log_pe())
 718                 edac_pci_printk(pci, KERN_WARNING,
 719                                 "Parity Error ctl: %s %d: %s\n",
 720                                 pci->ctl_name, pci->pci_idx, msg);
 721
 722         /*
 723          * poke all PCI devices and see which one is the troublemaker
 724          * panic() is called if set
 725          */
 726         edac_pci_do_parity_check();
 727 }
 728 EXPORT_SYMBOL_GPL(edac_pci_handle_pe);
 729
 730
 731 /*
 732  * edac_pci_handle_npe
 733  *
 734  *      Called to handle a NON-PARITY ERROR event
 735  */
 736 void edac_pci_handle_npe(struct edac_pci_ctl_info *pci, const char *msg)
 737 {
 738
 739         /* global NPE counter incremented by edac_pci_do_parity_check() */
 740         atomic_inc(&pci->counters.npe_count);
 741
 742         if (edac_pci_get_log_npe())
 743                 edac_pci_printk(pci, KERN_WARNING,
 744                                 "Non-Parity Error ctl: %s %d: %s\n",
 745                                 pci->ctl_name, pci->pci_idx, msg);
 746
 747         /*
 748          * poke all PCI devices and see which one is the troublemaker
 749          * panic() is called if set
 750          */
 751         edac_pci_do_parity_check();
 752 }
 753 EXPORT_SYMBOL_GPL(edac_pci_handle_npe);
 754
 755 /*
 756  * Define the PCI parameter to the module
 757  */
 758 module_param(check_pci_errors, int, 0644);
 759 MODULE_PARM_DESC(check_pci_errors,
 760                  "Check for PCI bus parity errors: 0=off 1=on");
 761 module_param(edac_pci_panic_on_pe, int, 0644);
 762 MODULE_PARM_DESC(edac_pci_panic_on_pe,
 763                  "Panic on PCI Bus Parity error: 0=off 1=on");
 764
 765 #endif                          /* CONFIG_PCI */