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/edac.h>
  11 #include <linux/slab.h>
  12 #include <linux/ctype.h>
  13
  14 #include "edac_core.h"
  15 #include "edac_module.h"
  16
  17 /* Turn off this whole feature if PCI is not configured */
  18 #ifdef CONFIG_PCI
  19
  20 #define EDAC_PCI_SYMLINK        "device"
  21
  22 /* data variables exported via sysfs */
  23 static int check_pci_errors;            /* default NO check PCI parity */
  24 static int edac_pci_panic_on_pe;        /* default NO panic on PCI Parity */
  25 static int edac_pci_log_pe = 1;         /* log PCI parity errors */
  26 static int edac_pci_log_npe = 1;        /* log PCI non-parity error errors */
  27 static int edac_pci_poll_msec = 1000;   /* one second workq period */
  28
  29 static atomic_t pci_parity_count = ATOMIC_INIT(0);
  30 static atomic_t pci_nonparity_count = ATOMIC_INIT(0);
  31
  32 static struct kobject *edac_pci_top_main_kobj;
  33 static atomic_t edac_pci_sysfs_refcount = ATOMIC_INIT(0);
  34
  35 /* getter functions for the data variables */
  36 int edac_pci_get_check_errors(void)
  37 {
  38         return check_pci_errors;
  39 }
  40
  41 static int edac_pci_get_log_pe(void)
  42 {
  43         return edac_pci_log_pe;
  44 }
  45
  46 static int edac_pci_get_log_npe(void)
  47 {
  48         return edac_pci_log_npe;
  49 }
  50
  51 static int edac_pci_get_panic_on_pe(void)
  52 {
  53         return edac_pci_panic_on_pe;
  54 }
  55
  56 int edac_pci_get_poll_msec(void)
  57 {
  58         return edac_pci_poll_msec;
  59 }
  60
  61 /**************************** EDAC PCI sysfs instance *******************/
  62 static ssize_t instance_pe_count_show(struct edac_pci_ctl_info *pci, char *data)
  63 {
  64         return sprintf(data, "%u\n", atomic_read(&pci->counters.pe_count));
  65 }
  66
  67 static ssize_t instance_npe_count_show(struct edac_pci_ctl_info *pci,
  68                                 char *data)
  69 {
  70         return sprintf(data, "%u\n", atomic_read(&pci->counters.npe_count));
  71 }
  72
  73 #define to_instance(k) container_of(k, struct edac_pci_ctl_info, kobj)
  74 #define to_instance_attr(a) container_of(a, struct instance_attribute, attr)
  75
  76 /* DEVICE instance kobject release() function */
  77 static void edac_pci_instance_release(struct kobject *kobj)
  78 {
  79         struct edac_pci_ctl_info *pci;
  80
  81         debugf0("%s()\n", __func__);
  82
  83         /* Form pointer to containing struct, the pci control struct */
  84         pci = to_instance(kobj);
  85
  86         /* decrement reference count on top main kobj */
  87         kobject_put(edac_pci_top_main_kobj);
  88
  89         kfree(pci);     /* Free the control struct */
  90 }
  91
  92 /* instance specific attribute structure */
  93 struct instance_attribute {
  94         struct attribute attr;
  95         ssize_t(*show) (struct edac_pci_ctl_info *, char *);
  96         ssize_t(*store) (struct edac_pci_ctl_info *, const char *, size_t);
  97 };
  98
  99 /* Function to 'show' fields from the edac_pci 'instance' structure */
 100 static ssize_t edac_pci_instance_show(struct kobject *kobj,
 101                                 struct attribute *attr, char *buffer)
 102 {
 103         struct edac_pci_ctl_info *pci = to_instance(kobj);
 104         struct instance_attribute *instance_attr = to_instance_attr(attr);
 105
 106         if (instance_attr->show)
 107                 return instance_attr->show(pci, buffer);
 108         return -EIO;
 109 }
 110
 111 /* Function to 'store' fields into the edac_pci 'instance' structure */
 112 static ssize_t edac_pci_instance_store(struct kobject *kobj,
 113                                 struct attribute *attr,
 114                                 const char *buffer, size_t count)
 115 {
 116         struct edac_pci_ctl_info *pci = to_instance(kobj);
 117         struct instance_attribute *instance_attr = to_instance_attr(attr);
 118
 119         if (instance_attr->store)
 120                 return instance_attr->store(pci, buffer, count);
 121         return -EIO;
 122 }
 123
 124 /* fs_ops table */
 125 static const struct sysfs_ops pci_instance_ops = {
 126         .show = edac_pci_instance_show,
 127         .store = edac_pci_instance_store
 128 };
 129
 130 #define INSTANCE_ATTR(_name, _mode, _show, _store)      \
 131 static struct instance_attribute attr_instance_##_name = {      \
 132         .attr   = {.name = __stringify(_name), .mode = _mode }, \
 133         .show   = _show,                                        \
 134         .store  = _store,                                       \
 135 };
 136
 137 INSTANCE_ATTR(pe_count, S_IRUGO, instance_pe_count_show, NULL);
 138 INSTANCE_ATTR(npe_count, S_IRUGO, instance_npe_count_show, NULL);
 139
 140 /* pci instance attributes */
 141 static struct instance_attribute *pci_instance_attr[] = {
 142         &attr_instance_pe_count,
 143         &attr_instance_npe_count,
 144         NULL
 145 };
 146
 147 /* the ktype for a pci instance */
 148 static struct kobj_type ktype_pci_instance = {
 149         .release = edac_pci_instance_release,
 150         .sysfs_ops = &pci_instance_ops,
 151         .default_attrs = (struct attribute **)pci_instance_attr,
 152 };
 153
 154 /*
 155  * edac_pci_create_instance_kobj
 156  *
 157  *      construct one EDAC PCI instance's kobject for use
 158  */
 159 static int edac_pci_create_instance_kobj(struct edac_pci_ctl_info *pci, int idx)
 160 {
 161         struct kobject *main_kobj;
 162         int err;
 163
 164         debugf0("%s()\n", __func__);
 165
 166         /* First bump the ref count on the top main kobj, which will
 167          * track the number of PCI instances we have, and thus nest
 168          * properly on keeping the module loaded
 169          */
 170         main_kobj = kobject_get(edac_pci_top_main_kobj);
 171         if (!main_kobj) {
 172                 err = -ENODEV;
 173                 goto error_out;
 174         }
 175
 176         /* And now register this new kobject under the main kobj */
 177         err = kobject_init_and_add(&pci->kobj, &ktype_pci_instance,
 178                                    edac_pci_top_main_kobj, "pci%d", idx);
 179         if (err != 0) {
 180                 debugf2("%s() failed to register instance pci%d\n",
 181                         __func__, idx);
 182                 kobject_put(edac_pci_top_main_kobj);
 183                 goto error_out;
 184         }
 185
 186         kobject_uevent(&pci->kobj, KOBJ_ADD);
 187         debugf1("%s() Register instance 'pci%d' kobject\n", __func__, idx);
 188
 189         return 0;
 190
 191         /* Error unwind statck */
 192 error_out:
 193         return err;
 194 }
 195
 196 /*
 197  * edac_pci_unregister_sysfs_instance_kobj
 198  *
 199  *      unregister the kobj for the EDAC PCI instance
 200  */
 201 static void edac_pci_unregister_sysfs_instance_kobj(
 202                         struct edac_pci_ctl_info *pci)
 203 {
 204         debugf0("%s()\n", __func__);
 205
 206         /* Unregister the instance kobject and allow its release
 207          * function release the main reference count and then
 208          * kfree the memory
 209          */
 210         kobject_put(&pci->kobj);
 211 }
 212
 213 /***************************** EDAC PCI sysfs root **********************/
 214 #define to_edacpci(k) container_of(k, struct edac_pci_ctl_info, kobj)
 215 #define to_edacpci_attr(a) container_of(a, struct edac_pci_attr, attr)
 216
 217 /* simple show/store functions for attributes */
 218 static ssize_t edac_pci_int_show(void *ptr, char *buffer)
 219 {
 220         int *value = ptr;
 221         return sprintf(buffer, "%d\n", *value);
 222 }
 223
 224 static ssize_t edac_pci_int_store(void *ptr, const char *buffer, size_t count)
 225 {
 226         int *value = ptr;
 227
 228         if (isdigit(*buffer))
 229                 *value = simple_strtoul(buffer, NULL, 0);
 230
 231         return count;
 232 }
 233
 234 struct edac_pci_dev_attribute {
 235         struct attribute attr;
 236         void *value;
 237          ssize_t(*show) (void *, char *);
 238          ssize_t(*store) (void *, const char *, size_t);
 239 };
 240
 241 /* Set of show/store abstract level functions for PCI Parity object */
 242 static ssize_t edac_pci_dev_show(struct kobject *kobj, struct attribute *attr,
 243                                  char *buffer)
 244 {
 245         struct edac_pci_dev_attribute *edac_pci_dev;
 246         edac_pci_dev = (struct edac_pci_dev_attribute *)attr;
 247
 248         if (edac_pci_dev->show)
 249                 return edac_pci_dev->show(edac_pci_dev->value, buffer);
 250         return -EIO;
 251 }
 252
 253 static ssize_t edac_pci_dev_store(struct kobject *kobj,
 254                                 struct attribute *attr, const char *buffer,
 255                                 size_t count)
 256 {
 257         struct edac_pci_dev_attribute *edac_pci_dev;
 258         edac_pci_dev = (struct edac_pci_dev_attribute *)attr;
 259
 260         if (edac_pci_dev->show)
 261                 return edac_pci_dev->store(edac_pci_dev->value, buffer, count);
 262         return -EIO;
 263 }
 264
 265 static const struct sysfs_ops edac_pci_sysfs_ops = {
 266         .show = edac_pci_dev_show,
 267         .store = edac_pci_dev_store
 268 };
 269
 270 #define EDAC_PCI_ATTR(_name,_mode,_show,_store)                 \
 271 static struct edac_pci_dev_attribute edac_pci_attr_##_name = {          \
 272         .attr = {.name = __stringify(_name), .mode = _mode },   \
 273         .value  = &_name,                                       \
 274         .show   = _show,                                        \
 275         .store  = _store,                                       \
 276 };
 277
 278 #define EDAC_PCI_STRING_ATTR(_name,_data,_mode,_show,_store)    \
 279 static struct edac_pci_dev_attribute edac_pci_attr_##_name = {          \
 280         .attr = {.name = __stringify(_name), .mode = _mode },   \
 281         .value  = _data,                                        \
 282         .show   = _show,                                        \
 283         .store  = _store,                                       \
 284 };
 285
 286 /* PCI Parity control files */
 287 EDAC_PCI_ATTR(check_pci_errors, S_IRUGO | S_IWUSR, edac_pci_int_show,
 288         edac_pci_int_store);
 289 EDAC_PCI_ATTR(edac_pci_log_pe, S_IRUGO | S_IWUSR, edac_pci_int_show,
 290         edac_pci_int_store);
 291 EDAC_PCI_ATTR(edac_pci_log_npe, S_IRUGO | S_IWUSR, edac_pci_int_show,
 292         edac_pci_int_store);
 293 EDAC_PCI_ATTR(edac_pci_panic_on_pe, S_IRUGO | S_IWUSR, edac_pci_int_show,
 294         edac_pci_int_store);
 295 EDAC_PCI_ATTR(pci_parity_count, S_IRUGO, edac_pci_int_show, NULL);
 296 EDAC_PCI_ATTR(pci_nonparity_count, S_IRUGO, edac_pci_int_show, NULL);
 297
 298 /* Base Attributes of the memory ECC object */
 299 static struct edac_pci_dev_attribute *edac_pci_attr[] = {
 300         &edac_pci_attr_check_pci_errors,
 301         &edac_pci_attr_edac_pci_log_pe,
 302         &edac_pci_attr_edac_pci_log_npe,
 303         &edac_pci_attr_edac_pci_panic_on_pe,
 304         &edac_pci_attr_pci_parity_count,
 305         &edac_pci_attr_pci_nonparity_count,
 306         NULL,
 307 };
 308
 309 /*
 310  * edac_pci_release_main_kobj
 311  *
 312  *      This release function is called when the reference count to the
 313  *      passed kobj goes to zero.
 314  *
 315  *      This kobj is the 'main' kobject that EDAC PCI instances
 316  *      link to, and thus provide for proper nesting counts
 317  */
 318 static void edac_pci_release_main_kobj(struct kobject *kobj)
 319 {
 320         debugf0("%s() here to module_put(THIS_MODULE)\n", __func__);
 321
 322         kfree(kobj);
 323
 324         /* last reference to top EDAC PCI kobject has been removed,
 325          * NOW release our ref count on the core module
 326          */
 327         module_put(THIS_MODULE);
 328 }
 329
 330 /* ktype struct for the EDAC PCI main kobj */
 331 static struct kobj_type ktype_edac_pci_main_kobj = {
 332         .release = edac_pci_release_main_kobj,
 333         .sysfs_ops = &edac_pci_sysfs_ops,
 334         .default_attrs = (struct attribute **)edac_pci_attr,
 335 };
 336
 337 /**
 338  * edac_pci_main_kobj_setup()
 339  *
 340  *      setup the sysfs for EDAC PCI attributes
 341  *      assumes edac_subsys has already been initialized
 342  */
 343 static int edac_pci_main_kobj_setup(void)
 344 {
 345         int err;
 346         struct bus_type *edac_subsys;
 347
 348         debugf0("%s()\n", __func__);
 349
 350         /* check and count if we have already created the main kobject */
 351         if (atomic_inc_return(&edac_pci_sysfs_refcount) != 1)
 352                 return 0;
 353
 354         /* First time, so create the main kobject and its
 355          * controls and attributes
 356          */
 357         edac_subsys = edac_get_sysfs_subsys();
 358         if (edac_subsys == NULL) {
 359                 debugf1("%s() no edac_subsys\n", __func__);
 360                 err = -ENODEV;
 361                 goto decrement_count_fail;
 362         }
 363
 364         /* Bump the reference count on this module to ensure the
 365          * modules isn't unloaded until we deconstruct the top
 366          * level main kobj for EDAC PCI
 367          */
 368         if (!try_module_get(THIS_MODULE)) {
 369                 debugf1("%s() try_module_get() failed\n", __func__);
 370                 err = -ENODEV;
 371                 goto mod_get_fail;
 372         }
 373
 374         edac_pci_top_main_kobj = kzalloc(sizeof(struct kobject), GFP_KERNEL);
 375         if (!edac_pci_top_main_kobj) {
 376                 debugf1("Failed to allocate\n");
 377                 err = -ENOMEM;
 378                 goto kzalloc_fail;
 379         }
 380
 381         /* Instanstiate the pci object */
 382         err = kobject_init_and_add(edac_pci_top_main_kobj,
 383                                    &ktype_edac_pci_main_kobj,
 384                                    &edac_subsys->dev_root->kobj, "pci");
 385         if (err) {
 386                 debugf1("Failed to register '.../edac/pci'\n");
 387                 goto kobject_init_and_add_fail;
 388         }
 389
 390         /* At this point, to 'release' the top level kobject
 391          * for EDAC PCI, then edac_pci_main_kobj_teardown()
 392          * must be used, for resources to be cleaned up properly
 393          */
 394         kobject_uevent(edac_pci_top_main_kobj, KOBJ_ADD);
 395         debugf1("Registered '.../edac/pci' kobject\n");
 396
 397         return 0;
 398
 399         /* Error unwind statck */
 400 kobject_init_and_add_fail:
 401         kfree(edac_pci_top_main_kobj);
 402
 403 kzalloc_fail:
 404         module_put(THIS_MODULE);
 405
 406 mod_get_fail:
 407         edac_put_sysfs_subsys();
 408
 409 decrement_count_fail:
 410         /* if are on this error exit, nothing to tear down */
 411         atomic_dec(&edac_pci_sysfs_refcount);
 412
 413         return err;
 414 }
 415
 416 /*
 417  * edac_pci_main_kobj_teardown()
 418  *
 419  *      if no longer linked (needed) remove the top level EDAC PCI
 420  *      kobject with its controls and attributes
 421  */
 422 static void edac_pci_main_kobj_teardown(void)
 423 {
 424         debugf0("%s()\n", __func__);
 425
 426         /* Decrement the count and only if no more controller instances
 427          * are connected perform the unregisteration of the top level
 428          * main kobj
 429          */
 430         if (atomic_dec_return(&edac_pci_sysfs_refcount) == 0) {
 431                 debugf0("%s() called kobject_put on main kobj\n",
 432                         __func__);
 433                 kobject_put(edac_pci_top_main_kobj);
 434         }
 435         edac_put_sysfs_subsys();
 436 }
 437
 438 /*
 439  *
 440  * edac_pci_create_sysfs
 441  *
 442  *      Create the controls/attributes for the specified EDAC PCI device
 443  */
 444 int edac_pci_create_sysfs(struct edac_pci_ctl_info *pci)
 445 {
 446         int err;
 447         struct kobject *edac_kobj = &pci->kobj;
 448
 449         debugf0("%s() idx=%d\n", __func__, pci->pci_idx);
 450
 451         /* create the top main EDAC PCI kobject, IF needed */
 452         err = edac_pci_main_kobj_setup();
 453         if (err)
 454                 return err;
 455
 456         /* Create this instance's kobject under the MAIN kobject */
 457         err = edac_pci_create_instance_kobj(pci, pci->pci_idx);
 458         if (err)
 459                 goto unregister_cleanup;
 460
 461         err = sysfs_create_link(edac_kobj, &pci->dev->kobj, EDAC_PCI_SYMLINK);
 462         if (err) {
 463                 debugf0("%s() sysfs_create_link() returned err= %d\n",
 464                         __func__, err);
 465                 goto symlink_fail;
 466         }
 467
 468         return 0;
 469
 470         /* Error unwind stack */
 471 symlink_fail:
 472         edac_pci_unregister_sysfs_instance_kobj(pci);
 473
 474 unregister_cleanup:
 475         edac_pci_main_kobj_teardown();
 476
 477         return err;
 478 }
 479
 480 /*
 481  * edac_pci_remove_sysfs
 482  *
 483  *      remove the controls and attributes for this EDAC PCI device
 484  */
 485 void edac_pci_remove_sysfs(struct edac_pci_ctl_info *pci)
 486 {
 487         debugf0("%s() index=%d\n", __func__, pci->pci_idx);
 488
 489         /* Remove the symlink */
 490         sysfs_remove_link(&pci->kobj, EDAC_PCI_SYMLINK);
 491
 492         /* remove this PCI instance's sysfs entries */
 493         edac_pci_unregister_sysfs_instance_kobj(pci);
 494
 495         /* Call the main unregister function, which will determine
 496          * if this 'pci' is the last instance.
 497          * If it is, the main kobject will be unregistered as a result
 498          */
 499         debugf0("%s() calling edac_pci_main_kobj_teardown()\n", __func__);
 500         edac_pci_main_kobj_teardown();
 501 }
 502
 503 /************************ PCI error handling *************************/
 504 static u16 get_pci_parity_status(struct pci_dev *dev, int secondary)
 505 {
 506         int where;
 507         u16 status;
 508
 509         where = secondary ? PCI_SEC_STATUS : PCI_STATUS;
 510         pci_read_config_word(dev, where, &status);
 511
 512         /* If we get back 0xFFFF then we must suspect that the card has been
 513          * pulled but the Linux PCI layer has not yet finished cleaning up.
 514          * We don't want to report on such devices
 515          */
 516
 517         if (status == 0xFFFF) {
 518                 u32 sanity;
 519
 520                 pci_read_config_dword(dev, 0, &sanity);
 521
 522                 if (sanity == 0xFFFFFFFF)
 523                         return 0;
 524         }
 525
 526         status &= PCI_STATUS_DETECTED_PARITY | PCI_STATUS_SIG_SYSTEM_ERROR |
 527                 PCI_STATUS_PARITY;
 528
 529         if (status)
 530                 /* reset only the bits we are interested in */
 531                 pci_write_config_word(dev, where, status);
 532
 533         return status;
 534 }
 535
 536
 537 /* Clear any PCI parity errors logged by this device. */
 538 static void edac_pci_dev_parity_clear(struct pci_dev *dev)
 539 {
 540         u8 header_type;
 541
 542         get_pci_parity_status(dev, 0);
 543
 544         /* read the device TYPE, looking for bridges */
 545         pci_read_config_byte(dev, PCI_HEADER_TYPE, &header_type);
 546
 547         if ((header_type & 0x7F) == PCI_HEADER_TYPE_BRIDGE)
 548                 get_pci_parity_status(dev, 1);
 549 }
 550
 551 /*
 552  *  PCI Parity polling
 553  *
 554  *      Function to retrieve the current parity status
 555  *      and decode it
 556  *
 557  */
 558 static void edac_pci_dev_parity_test(struct pci_dev *dev)
 559 {
 560         unsigned long flags;
 561         u16 status;
 562         u8 header_type;
 563
 564         /* stop any interrupts until we can acquire the status */
 565         local_irq_save(flags);
 566
 567         /* read the STATUS register on this device */
 568         status = get_pci_parity_status(dev, 0);
 569
 570         /* read the device TYPE, looking for bridges */
 571         pci_read_config_byte(dev, PCI_HEADER_TYPE, &header_type);
 572
 573         local_irq_restore(flags);
 574
 575         debugf4("PCI STATUS= 0x%04x %s\n", status, dev_name(&dev->dev));
 576
 577         /* check the status reg for errors on boards NOT marked as broken
 578          * if broken, we cannot trust any of the status bits
 579          */
 580         if (status && !dev->broken_parity_status) {
 581                 if (status & (PCI_STATUS_SIG_SYSTEM_ERROR)) {
 582                         edac_printk(KERN_CRIT, EDAC_PCI,
 583                                 "Signaled System Error on %s\n",
 584                                 pci_name(dev));
 585                         atomic_inc(&pci_nonparity_count);
 586                 }
 587
 588                 if (status & (PCI_STATUS_PARITY)) {
 589                         edac_printk(KERN_CRIT, EDAC_PCI,
 590                                 "Master Data Parity Error on %s\n",
 591                                 pci_name(dev));
 592
 593                         atomic_inc(&pci_parity_count);
 594                 }
 595
 596                 if (status & (PCI_STATUS_DETECTED_PARITY)) {
 597                         edac_printk(KERN_CRIT, EDAC_PCI,
 598                                 "Detected Parity Error on %s\n",
 599                                 pci_name(dev));
 600
 601                         atomic_inc(&pci_parity_count);
 602                 }
 603         }
 604
 605
 606         debugf4("PCI HEADER TYPE= 0x%02x %s\n", header_type, dev_name(&dev->dev));
 607
 608         if ((header_type & 0x7F) == PCI_HEADER_TYPE_BRIDGE) {
 609                 /* On bridges, need to examine secondary status register  */
 610                 status = get_pci_parity_status(dev, 1);
 611
 612                 debugf4("PCI SEC_STATUS= 0x%04x %s\n", status, dev_name(&dev->dev));
 613
 614                 /* check the secondary status reg for errors,
 615                  * on NOT broken boards
 616                  */
 617                 if (status && !dev->broken_parity_status) {
 618                         if (status & (PCI_STATUS_SIG_SYSTEM_ERROR)) {
 619                                 edac_printk(KERN_CRIT, EDAC_PCI, "Bridge "
 620                                         "Signaled System Error on %s\n",
 621                                         pci_name(dev));
 622                                 atomic_inc(&pci_nonparity_count);
 623                         }
 624
 625                         if (status & (PCI_STATUS_PARITY)) {
 626                                 edac_printk(KERN_CRIT, EDAC_PCI, "Bridge "
 627                                         "Master Data Parity Error on "
 628                                         "%s\n", pci_name(dev));
 629
 630                                 atomic_inc(&pci_parity_count);
 631                         }
 632
 633                         if (status & (PCI_STATUS_DETECTED_PARITY)) {
 634                                 edac_printk(KERN_CRIT, EDAC_PCI, "Bridge "
 635                                         "Detected Parity Error on %s\n",
 636                                         pci_name(dev));
 637
 638                                 atomic_inc(&pci_parity_count);
 639                         }
 640                 }
 641         }
 642 }
 643
 644 /* reduce some complexity in definition of the iterator */
 645 typedef void (*pci_parity_check_fn_t) (struct pci_dev *dev);
 646
 647 /*
 648  * pci_dev parity list iterator
 649  *      Scan the PCI device list for one pass, looking for SERRORs
 650  *      Master Parity ERRORS or Parity ERRORs on primary or secondary devices
 651  */
 652 static inline void edac_pci_dev_parity_iterator(pci_parity_check_fn_t fn)
 653 {
 654         struct pci_dev *dev = NULL;
 655
 656         /* request for kernel access to the next PCI device, if any,
 657          * and while we are looking at it have its reference count
 658          * bumped until we are done with it
 659          */
 660         while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
 661                 fn(dev);
 662         }
 663 }
 664
 665 /*
 666  * edac_pci_do_parity_check
 667  *
 668  *      performs the actual PCI parity check operation
 669  */
 670 void edac_pci_do_parity_check(void)
 671 {
 672         int before_count;
 673
 674         debugf3("%s()\n", __func__);
 675
 676         /* if policy has PCI check off, leave now */
 677         if (!check_pci_errors)
 678                 return;
 679
 680         before_count = atomic_read(&pci_parity_count);
 681
 682         /* scan all PCI devices looking for a Parity Error on devices and
 683          * bridges.
 684          * The iterator calls pci_get_device() which might sleep, thus
 685          * we cannot disable interrupts in this scan.
 686          */
 687         edac_pci_dev_parity_iterator(edac_pci_dev_parity_test);
 688
 689         /* Only if operator has selected panic on PCI Error */
 690         if (edac_pci_get_panic_on_pe()) {
 691                 /* If the count is different 'after' from 'before' */
 692                 if (before_count != atomic_read(&pci_parity_count))
 693                         panic("EDAC: PCI Parity Error");
 694         }
 695 }
 696
 697 /*
 698  * edac_pci_clear_parity_errors
 699  *
 700  *      function to perform an iteration over the PCI devices
 701  *      and clearn their current status
 702  */
 703 void edac_pci_clear_parity_errors(void)
 704 {
 705         /* Clear any PCI bus parity errors that devices initially have logged
 706          * in their registers.
 707          */
 708         edac_pci_dev_parity_iterator(edac_pci_dev_parity_clear);
 709 }
 710
 711 /*
 712  * edac_pci_handle_pe
 713  *
 714  *      Called to handle a PARITY ERROR event
 715  */
 716 void edac_pci_handle_pe(struct edac_pci_ctl_info *pci, const char *msg)
 717 {
 718
 719         /* global PE counter incremented by edac_pci_do_parity_check() */
 720         atomic_inc(&pci->counters.pe_count);
 721
 722         if (edac_pci_get_log_pe())
 723                 edac_pci_printk(pci, KERN_WARNING,
 724                                 "Parity Error ctl: %s %d: %s\n",
 725                                 pci->ctl_name, pci->pci_idx, msg);
 726
 727         /*
 728          * poke all PCI devices and see which one is the troublemaker
 729          * panic() is called if set
 730          */
 731         edac_pci_do_parity_check();
 732 }
 733 EXPORT_SYMBOL_GPL(edac_pci_handle_pe);
 734
 735
 736 /*
 737  * edac_pci_handle_npe
 738  *
 739  *      Called to handle a NON-PARITY ERROR event
 740  */
 741 void edac_pci_handle_npe(struct edac_pci_ctl_info *pci, const char *msg)
 742 {
 743
 744         /* global NPE counter incremented by edac_pci_do_parity_check() */
 745         atomic_inc(&pci->counters.npe_count);
 746
 747         if (edac_pci_get_log_npe())
 748                 edac_pci_printk(pci, KERN_WARNING,
 749                                 "Non-Parity Error ctl: %s %d: %s\n",
 750                                 pci->ctl_name, pci->pci_idx, msg);
 751
 752         /*
 753          * poke all PCI devices and see which one is the troublemaker
 754          * panic() is called if set
 755          */
 756         edac_pci_do_parity_check();
 757 }
 758 EXPORT_SYMBOL_GPL(edac_pci_handle_npe);
 759
 760 /*
 761  * Define the PCI parameter to the module
 762  */
 763 module_param(check_pci_errors, int, 0644);
 764 MODULE_PARM_DESC(check_pci_errors,
 765                  "Check for PCI bus parity errors: 0=off 1=on");
 766 module_param(edac_pci_panic_on_pe, int, 0644);
 767 MODULE_PARM_DESC(edac_pci_panic_on_pe,
 768                  "Panic on PCI Bus Parity error: 0=off 1=on");
 769
 770 #endif                          /* CONFIG_PCI */