drivers/edac/edac_device_sysfs.c

   1 /*
   2  * file for managing the edac_device subsystem of devices for EDAC
   3  *
   4  * (C) 2007 SoftwareBitMaker
   5  *
   6  * This file may be distributed under the terms of the
   7  * GNU General Public License.
   8  *
   9  * Written Doug Thompson <norsk5@xmission.com>
  10  *
  11  */
  12
  13 #include <linux/ctype.h>
  14 #include <linux/module.h>
  15 #include <linux/slab.h>
  16 #include <linux/edac.h>
  17
  18 #include "edac_core.h"
  19 #include "edac_module.h"
  20
  21 #define EDAC_DEVICE_SYMLINK     "device"
  22
  23 #define to_edacdev(k) container_of(k, struct edac_device_ctl_info, kobj)
  24 #define to_edacdev_attr(a) container_of(a, struct edacdev_attribute, attr)
  25
  26
  27 /*
  28  * Set of edac_device_ctl_info attribute store/show functions
  29  */
  30
  31 /* 'log_ue' */
  32 static ssize_t edac_device_ctl_log_ue_show(struct edac_device_ctl_info
  33                                         *ctl_info, char *data)
  34 {
  35         return sprintf(data, "%u\n", ctl_info->log_ue);
  36 }
  37
  38 static ssize_t edac_device_ctl_log_ue_store(struct edac_device_ctl_info
  39                                         *ctl_info, const char *data,
  40                                         size_t count)
  41 {
  42         /* if parameter is zero, turn off flag, if non-zero turn on flag */
  43         ctl_info->log_ue = (simple_strtoul(data, NULL, 0) != 0);
  44
  45         return count;
  46 }
  47
  48 /* 'log_ce' */
  49 static ssize_t edac_device_ctl_log_ce_show(struct edac_device_ctl_info
  50                                         *ctl_info, char *data)
  51 {
  52         return sprintf(data, "%u\n", ctl_info->log_ce);
  53 }
  54
  55 static ssize_t edac_device_ctl_log_ce_store(struct edac_device_ctl_info
  56                                         *ctl_info, const char *data,
  57                                         size_t count)
  58 {
  59         /* if parameter is zero, turn off flag, if non-zero turn on flag */
  60         ctl_info->log_ce = (simple_strtoul(data, NULL, 0) != 0);
  61
  62         return count;
  63 }
  64
  65 /* 'panic_on_ue' */
  66 static ssize_t edac_device_ctl_panic_on_ue_show(struct edac_device_ctl_info
  67                                                 *ctl_info, char *data)
  68 {
  69         return sprintf(data, "%u\n", ctl_info->panic_on_ue);
  70 }
  71
  72 static ssize_t edac_device_ctl_panic_on_ue_store(struct edac_device_ctl_info
  73                                                  *ctl_info, const char *data,
  74                                                  size_t count)
  75 {
  76         /* if parameter is zero, turn off flag, if non-zero turn on flag */
  77         ctl_info->panic_on_ue = (simple_strtoul(data, NULL, 0) != 0);
  78
  79         return count;
  80 }
  81
  82 /* 'poll_msec' show and store functions*/
  83 static ssize_t edac_device_ctl_poll_msec_show(struct edac_device_ctl_info
  84                                         *ctl_info, char *data)
  85 {
  86         return sprintf(data, "%u\n", ctl_info->poll_msec);
  87 }
  88
  89 static ssize_t edac_device_ctl_poll_msec_store(struct edac_device_ctl_info
  90                                         *ctl_info, const char *data,
  91                                         size_t count)
  92 {
  93         unsigned long value;
  94
  95         /* get the value and enforce that it is non-zero, must be at least
  96          * one millisecond for the delay period, between scans
  97          * Then cancel last outstanding delay for the work request
  98          * and set a new one.
  99          */
 100         value = simple_strtoul(data, NULL, 0);
 101         edac_device_reset_delay_period(ctl_info, value);
 102
 103         return count;
 104 }
 105
 106 /* edac_device_ctl_info specific attribute structure */
 107 struct ctl_info_attribute {
 108         struct attribute attr;
 109         ssize_t(*show) (struct edac_device_ctl_info *, char *);
 110         ssize_t(*store) (struct edac_device_ctl_info *, const char *, size_t);
 111 };
 112
 113 #define to_ctl_info(k) container_of(k, struct edac_device_ctl_info, kobj)
 114 #define to_ctl_info_attr(a) container_of(a,struct ctl_info_attribute,attr)
 115
 116 /* Function to 'show' fields from the edac_dev 'ctl_info' structure */
 117 static ssize_t edac_dev_ctl_info_show(struct kobject *kobj,
 118                                 struct attribute *attr, char *buffer)
 119 {
 120         struct edac_device_ctl_info *edac_dev = to_ctl_info(kobj);
 121         struct ctl_info_attribute *ctl_info_attr = to_ctl_info_attr(attr);
 122
 123         if (ctl_info_attr->show)
 124                 return ctl_info_attr->show(edac_dev, buffer);
 125         return -EIO;
 126 }
 127
 128 /* Function to 'store' fields into the edac_dev 'ctl_info' structure */
 129 static ssize_t edac_dev_ctl_info_store(struct kobject *kobj,
 130                                 struct attribute *attr,
 131                                 const char *buffer, size_t count)
 132 {
 133         struct edac_device_ctl_info *edac_dev = to_ctl_info(kobj);
 134         struct ctl_info_attribute *ctl_info_attr = to_ctl_info_attr(attr);
 135
 136         if (ctl_info_attr->store)
 137                 return ctl_info_attr->store(edac_dev, buffer, count);
 138         return -EIO;
 139 }
 140
 141 /* edac_dev file operations for an 'ctl_info' */
 142 static const struct sysfs_ops device_ctl_info_ops = {
 143         .show = edac_dev_ctl_info_show,
 144         .store = edac_dev_ctl_info_store
 145 };
 146
 147 #define CTL_INFO_ATTR(_name,_mode,_show,_store)        \
 148 static struct ctl_info_attribute attr_ctl_info_##_name = {      \
 149         .attr = {.name = __stringify(_name), .mode = _mode },   \
 150         .show   = _show,                                        \
 151         .store  = _store,                                       \
 152 };
 153
 154 /* Declare the various ctl_info attributes here and their respective ops */
 155 CTL_INFO_ATTR(log_ue, S_IRUGO | S_IWUSR,
 156         edac_device_ctl_log_ue_show, edac_device_ctl_log_ue_store);
 157 CTL_INFO_ATTR(log_ce, S_IRUGO | S_IWUSR,
 158         edac_device_ctl_log_ce_show, edac_device_ctl_log_ce_store);
 159 CTL_INFO_ATTR(panic_on_ue, S_IRUGO | S_IWUSR,
 160         edac_device_ctl_panic_on_ue_show,
 161         edac_device_ctl_panic_on_ue_store);
 162 CTL_INFO_ATTR(poll_msec, S_IRUGO | S_IWUSR,
 163         edac_device_ctl_poll_msec_show, edac_device_ctl_poll_msec_store);
 164
 165 /* Base Attributes of the EDAC_DEVICE ECC object */
 166 static struct ctl_info_attribute *device_ctrl_attr[] = {
 167         &attr_ctl_info_panic_on_ue,
 168         &attr_ctl_info_log_ue,
 169         &attr_ctl_info_log_ce,
 170         &attr_ctl_info_poll_msec,
 171         NULL,
 172 };
 173
 174 /*
 175  * edac_device_ctrl_master_release
 176  *
 177  *      called when the reference count for the 'main' kobj
 178  *      for a edac_device control struct reaches zero
 179  *
 180  *      Reference count model:
 181  *              One 'main' kobject for each control structure allocated.
 182  *              That main kobj is initially set to one AND
 183  *              the reference count for the EDAC 'core' module is
 184  *              bumped by one, thus added 'keep in memory' dependency.
 185  *
 186  *              Each new internal kobj (in instances and blocks) then
 187  *              bumps the 'main' kobject.
 188  *
 189  *              When they are released their release functions decrement
 190  *              the 'main' kobj.
 191  *
 192  *              When the main kobj reaches zero (0) then THIS function
 193  *              is called which then decrements the EDAC 'core' module.
 194  *              When the module reference count reaches zero then the
 195  *              module no longer has dependency on keeping the release
 196  *              function code in memory and module can be unloaded.
 197  *
 198  *              This will support several control objects as well, each
 199  *              with its own 'main' kobj.
 200  */
 201 static void edac_device_ctrl_master_release(struct kobject *kobj)
 202 {
 203         struct edac_device_ctl_info *edac_dev = to_edacdev(kobj);
 204
 205         edac_dbg(4, "control index=%d\n", edac_dev->dev_idx);
 206
 207         /* decrement the EDAC CORE module ref count */
 208         module_put(edac_dev->owner);
 209
 210         /* free the control struct containing the 'main' kobj
 211          * passed in to this routine
 212          */
 213         kfree(edac_dev);
 214 }
 215
 216 /* ktype for the main (master) kobject */
 217 static struct kobj_type ktype_device_ctrl = {
 218         .release = edac_device_ctrl_master_release,
 219         .sysfs_ops = &device_ctl_info_ops,
 220         .default_attrs = (struct attribute **)device_ctrl_attr,
 221 };
 222
 223 /*
 224  * edac_device_register_sysfs_main_kobj
 225  *
 226  *      perform the high level setup for the new edac_device instance
 227  *
 228  * Return:  0 SUCCESS
 229  *         !0 FAILURE
 230  */
 231 int edac_device_register_sysfs_main_kobj(struct edac_device_ctl_info *edac_dev)
 232 {
 233         struct bus_type *edac_subsys;
 234         int err;
 235
 236         edac_dbg(1, "\n");
 237
 238         /* get the /sys/devices/system/edac reference */
 239         edac_subsys = edac_get_sysfs_subsys();
 240         if (edac_subsys == NULL) {
 241                 edac_dbg(1, "no edac_subsys error\n");
 242                 err = -ENODEV;
 243                 goto err_out;
 244         }
 245
 246         /* Point to the 'edac_subsys' this instance 'reports' to */
 247         edac_dev->edac_subsys = edac_subsys;
 248
 249         /* Init the devices's kobject */
 250         memset(&edac_dev->kobj, 0, sizeof(struct kobject));
 251
 252         /* Record which module 'owns' this control structure
 253          * and bump the ref count of the module
 254          */
 255         edac_dev->owner = THIS_MODULE;
 256
 257         if (!try_module_get(edac_dev->owner)) {
 258                 err = -ENODEV;
 259                 goto err_mod_get;
 260         }
 261
 262         /* register */
 263         err = kobject_init_and_add(&edac_dev->kobj, &ktype_device_ctrl,
 264                                    &edac_subsys->dev_root->kobj,
 265                                    "%s", edac_dev->name);
 266         if (err) {
 267                 edac_dbg(1, "Failed to register '.../edac/%s'\n",
 268                          edac_dev->name);
 269                 goto err_kobj_reg;
 270         }
 271         kobject_uevent(&edac_dev->kobj, KOBJ_ADD);
 272
 273         /* At this point, to 'free' the control struct,
 274          * edac_device_unregister_sysfs_main_kobj() must be used
 275          */
 276
 277         edac_dbg(4, "Registered '.../edac/%s' kobject\n", edac_dev->name);
 278
 279         return 0;
 280
 281         /* Error exit stack */
 282 err_kobj_reg:
 283         module_put(edac_dev->owner);
 284
 285 err_mod_get:
 286         edac_put_sysfs_subsys();
 287
 288 err_out:
 289         return err;
 290 }
 291
 292 /*
 293  * edac_device_unregister_sysfs_main_kobj:
 294  *      the '..../edac/<name>' kobject
 295  */
 296 void edac_device_unregister_sysfs_main_kobj(struct edac_device_ctl_info *dev)
 297 {
 298         edac_dbg(0, "\n");
 299         edac_dbg(4, "name of kobject is: %s\n", kobject_name(&dev->kobj));
 300
 301         /*
 302          * Unregister the edac device's kobject and
 303          * allow for reference count to reach 0 at which point
 304          * the callback will be called to:
 305          *   a) module_put() this module
 306          *   b) 'kfree' the memory
 307          */
 308         kobject_put(&dev->kobj);
 309         edac_put_sysfs_subsys();
 310 }
 311
 312 /* edac_dev -> instance information */
 313
 314 /*
 315  * Set of low-level instance attribute show functions
 316  */
 317 static ssize_t instance_ue_count_show(struct edac_device_instance *instance,
 318                                 char *data)
 319 {
 320         return sprintf(data, "%u\n", instance->counters.ue_count);
 321 }
 322
 323 static ssize_t instance_ce_count_show(struct edac_device_instance *instance,
 324                                 char *data)
 325 {
 326         return sprintf(data, "%u\n", instance->counters.ce_count);
 327 }
 328
 329 #define to_instance(k) container_of(k, struct edac_device_instance, kobj)
 330 #define to_instance_attr(a) container_of(a,struct instance_attribute,attr)
 331
 332 /* DEVICE instance kobject release() function */
 333 static void edac_device_ctrl_instance_release(struct kobject *kobj)
 334 {
 335         struct edac_device_instance *instance;
 336
 337         edac_dbg(1, "\n");
 338
 339         /* map from this kobj to the main control struct
 340          * and then dec the main kobj count
 341          */
 342         instance = to_instance(kobj);
 343         kobject_put(&instance->ctl->kobj);
 344 }
 345
 346 /* instance specific attribute structure */
 347 struct instance_attribute {
 348         struct attribute attr;
 349         ssize_t(*show) (struct edac_device_instance *, char *);
 350         ssize_t(*store) (struct edac_device_instance *, const char *, size_t);
 351 };
 352
 353 /* Function to 'show' fields from the edac_dev 'instance' structure */
 354 static ssize_t edac_dev_instance_show(struct kobject *kobj,
 355                                 struct attribute *attr, char *buffer)
 356 {
 357         struct edac_device_instance *instance = to_instance(kobj);
 358         struct instance_attribute *instance_attr = to_instance_attr(attr);
 359
 360         if (instance_attr->show)
 361                 return instance_attr->show(instance, buffer);
 362         return -EIO;
 363 }
 364
 365 /* Function to 'store' fields into the edac_dev 'instance' structure */
 366 static ssize_t edac_dev_instance_store(struct kobject *kobj,
 367                                 struct attribute *attr,
 368                                 const char *buffer, size_t count)
 369 {
 370         struct edac_device_instance *instance = to_instance(kobj);
 371         struct instance_attribute *instance_attr = to_instance_attr(attr);
 372
 373         if (instance_attr->store)
 374                 return instance_attr->store(instance, buffer, count);
 375         return -EIO;
 376 }
 377
 378 /* edac_dev file operations for an 'instance' */
 379 static const struct sysfs_ops device_instance_ops = {
 380         .show = edac_dev_instance_show,
 381         .store = edac_dev_instance_store
 382 };
 383
 384 #define INSTANCE_ATTR(_name,_mode,_show,_store)        \
 385 static struct instance_attribute attr_instance_##_name = {      \
 386         .attr = {.name = __stringify(_name), .mode = _mode },   \
 387         .show   = _show,                                        \
 388         .store  = _store,                                       \
 389 };
 390
 391 /*
 392  * Define attributes visible for the edac_device instance object
 393  *      Each contains a pointer to a show and an optional set
 394  *      function pointer that does the low level output/input
 395  */
 396 INSTANCE_ATTR(ce_count, S_IRUGO, instance_ce_count_show, NULL);
 397 INSTANCE_ATTR(ue_count, S_IRUGO, instance_ue_count_show, NULL);
 398
 399 /* list of edac_dev 'instance' attributes */
 400 static struct instance_attribute *device_instance_attr[] = {
 401         &attr_instance_ce_count,
 402         &attr_instance_ue_count,
 403         NULL,
 404 };
 405
 406 /* The 'ktype' for each edac_dev 'instance' */
 407 static struct kobj_type ktype_instance_ctrl = {
 408         .release = edac_device_ctrl_instance_release,
 409         .sysfs_ops = &device_instance_ops,
 410         .default_attrs = (struct attribute **)device_instance_attr,
 411 };
 412
 413 /* edac_dev -> instance -> block information */
 414
 415 #define to_block(k) container_of(k, struct edac_device_block, kobj)
 416 #define to_block_attr(a) \
 417         container_of(a, struct edac_dev_sysfs_block_attribute, attr)
 418
 419 /*
 420  * Set of low-level block attribute show functions
 421  */
 422 static ssize_t block_ue_count_show(struct kobject *kobj,
 423                                         struct attribute *attr, char *data)
 424 {
 425         struct edac_device_block *block = to_block(kobj);
 426
 427         return sprintf(data, "%u\n", block->counters.ue_count);
 428 }
 429
 430 static ssize_t block_ce_count_show(struct kobject *kobj,
 431                                         struct attribute *attr, char *data)
 432 {
 433         struct edac_device_block *block = to_block(kobj);
 434
 435         return sprintf(data, "%u\n", block->counters.ce_count);
 436 }
 437
 438 /* DEVICE block kobject release() function */
 439 static void edac_device_ctrl_block_release(struct kobject *kobj)
 440 {
 441         struct edac_device_block *block;
 442
 443         edac_dbg(1, "\n");
 444
 445         /* get the container of the kobj */
 446         block = to_block(kobj);
 447
 448         /* map from 'block kobj' to 'block->instance->controller->main_kobj'
 449          * now 'release' the block kobject
 450          */
 451         kobject_put(&block->instance->ctl->kobj);
 452 }
 453
 454
 455 /* Function to 'show' fields from the edac_dev 'block' structure */
 456 static ssize_t edac_dev_block_show(struct kobject *kobj,
 457                                 struct attribute *attr, char *buffer)
 458 {
 459         struct edac_dev_sysfs_block_attribute *block_attr =
 460                                                 to_block_attr(attr);
 461
 462         if (block_attr->show)
 463                 return block_attr->show(kobj, attr, buffer);
 464         return -EIO;
 465 }
 466
 467 /* Function to 'store' fields into the edac_dev 'block' structure */
 468 static ssize_t edac_dev_block_store(struct kobject *kobj,
 469                                 struct attribute *attr,
 470                                 const char *buffer, size_t count)
 471 {
 472         struct edac_dev_sysfs_block_attribute *block_attr;
 473
 474         block_attr = to_block_attr(attr);
 475
 476         if (block_attr->store)
 477                 return block_attr->store(kobj, attr, buffer, count);
 478         return -EIO;
 479 }
 480
 481 /* edac_dev file operations for a 'block' */
 482 static const struct sysfs_ops device_block_ops = {
 483         .show = edac_dev_block_show,
 484         .store = edac_dev_block_store
 485 };
 486
 487 #define BLOCK_ATTR(_name,_mode,_show,_store)        \
 488 static struct edac_dev_sysfs_block_attribute attr_block_##_name = {     \
 489         .attr = {.name = __stringify(_name), .mode = _mode },   \
 490         .show   = _show,                                        \
 491         .store  = _store,                                       \
 492 };
 493
 494 BLOCK_ATTR(ce_count, S_IRUGO, block_ce_count_show, NULL);
 495 BLOCK_ATTR(ue_count, S_IRUGO, block_ue_count_show, NULL);
 496
 497 /* list of edac_dev 'block' attributes */
 498 static struct edac_dev_sysfs_block_attribute *device_block_attr[] = {
 499         &attr_block_ce_count,
 500         &attr_block_ue_count,
 501         NULL,
 502 };
 503
 504 /* The 'ktype' for each edac_dev 'block' */
 505 static struct kobj_type ktype_block_ctrl = {
 506         .release = edac_device_ctrl_block_release,
 507         .sysfs_ops = &device_block_ops,
 508         .default_attrs = (struct attribute **)device_block_attr,
 509 };
 510
 511 /* block ctor/dtor  code */
 512
 513 /*
 514  * edac_device_create_block
 515  */
 516 static int edac_device_create_block(struct edac_device_ctl_info *edac_dev,
 517                                 struct edac_device_instance *instance,
 518                                 struct edac_device_block *block)
 519 {
 520         int i;
 521         int err;
 522         struct edac_dev_sysfs_block_attribute *sysfs_attrib;
 523         struct kobject *main_kobj;
 524
 525         edac_dbg(4, "Instance '%s' inst_p=%p  block '%s'  block_p=%p\n",
 526                  instance->name, instance, block->name, block);
 527         edac_dbg(4, "block kobj=%p  block kobj->parent=%p\n",
 528                  &block->kobj, &block->kobj.parent);
 529
 530         /* init this block's kobject */
 531         memset(&block->kobj, 0, sizeof(struct kobject));
 532
 533         /* bump the main kobject's reference count for this controller
 534          * and this instance is dependent on the main
 535          */
 536         main_kobj = kobject_get(&edac_dev->kobj);
 537         if (!main_kobj) {
 538                 err = -ENODEV;
 539                 goto err_out;
 540         }
 541
 542         /* Add this block's kobject */
 543         err = kobject_init_and_add(&block->kobj, &ktype_block_ctrl,
 544                                    &instance->kobj,
 545                                    "%s", block->name);
 546         if (err) {
 547                 edac_dbg(1, "Failed to register instance '%s'\n", block->name);
 548                 kobject_put(main_kobj);
 549                 err = -ENODEV;
 550                 goto err_out;
 551         }
 552
 553         /* If there are driver level block attributes, then added them
 554          * to the block kobject
 555          */
 556         sysfs_attrib = block->block_attributes;
 557         if (sysfs_attrib && block->nr_attribs) {
 558                 for (i = 0; i < block->nr_attribs; i++, sysfs_attrib++) {
 559
 560                         edac_dbg(4, "creating block attrib='%s' attrib->%p to kobj=%p\n",
 561                                  sysfs_attrib->attr.name,
 562                                  sysfs_attrib, &block->kobj);
 563
 564                         /* Create each block_attribute file */
 565                         err = sysfs_create_file(&block->kobj,
 566                                 &sysfs_attrib->attr);
 567                         if (err)
 568                                 goto err_on_attrib;
 569                 }
 570         }
 571         kobject_uevent(&block->kobj, KOBJ_ADD);
 572
 573         return 0;
 574
 575         /* Error unwind stack */
 576 err_on_attrib:
 577         kobject_put(&block->kobj);
 578
 579 err_out:
 580         return err;
 581 }
 582
 583 /*
 584  * edac_device_delete_block(edac_dev,block);
 585  */
 586 static void edac_device_delete_block(struct edac_device_ctl_info *edac_dev,
 587                                 struct edac_device_block *block)
 588 {
 589         struct edac_dev_sysfs_block_attribute *sysfs_attrib;
 590         int i;
 591
 592         /* if this block has 'attributes' then we need to iterate over the list
 593          * and 'remove' the attributes on this block
 594          */
 595         sysfs_attrib = block->block_attributes;
 596         if (sysfs_attrib && block->nr_attribs) {
 597                 for (i = 0; i < block->nr_attribs; i++, sysfs_attrib++) {
 598
 599                         /* remove each block_attrib file */
 600                         sysfs_remove_file(&block->kobj,
 601                                 (struct attribute *) sysfs_attrib);
 602                 }
 603         }
 604
 605         /* unregister this block's kobject, SEE:
 606          *      edac_device_ctrl_block_release() callback operation
 607          */
 608         kobject_put(&block->kobj);
 609 }
 610
 611 /* instance ctor/dtor code */
 612
 613 /*
 614  * edac_device_create_instance
 615  *      create just one instance of an edac_device 'instance'
 616  */
 617 static int edac_device_create_instance(struct edac_device_ctl_info *edac_dev,
 618                                 int idx)
 619 {
 620         int i, j;
 621         int err;
 622         struct edac_device_instance *instance;
 623         struct kobject *main_kobj;
 624
 625         instance = &edac_dev->instances[idx];
 626
 627         /* Init the instance's kobject */
 628         memset(&instance->kobj, 0, sizeof(struct kobject));
 629
 630         instance->ctl = edac_dev;
 631
 632         /* bump the main kobject's reference count for this controller
 633          * and this instance is dependent on the main
 634          */
 635         main_kobj = kobject_get(&edac_dev->kobj);
 636         if (!main_kobj) {
 637                 err = -ENODEV;
 638                 goto err_out;
 639         }
 640
 641         /* Formally register this instance's kobject under the edac_device */
 642         err = kobject_init_and_add(&instance->kobj, &ktype_instance_ctrl,
 643                                    &edac_dev->kobj, "%s", instance->name);
 644         if (err != 0) {
 645                 edac_dbg(2, "Failed to register instance '%s'\n",
 646                          instance->name);
 647                 kobject_put(main_kobj);
 648                 goto err_out;
 649         }
 650
 651         edac_dbg(4, "now register '%d' blocks for instance %d\n",
 652                  instance->nr_blocks, idx);
 653
 654         /* register all blocks of this instance */
 655         for (i = 0; i < instance->nr_blocks; i++) {
 656                 err = edac_device_create_block(edac_dev, instance,
 657                                                 &instance->blocks[i]);
 658                 if (err) {
 659                         /* If any fail, remove all previous ones */
 660                         for (j = 0; j < i; j++)
 661                                 edac_device_delete_block(edac_dev,
 662                                                         &instance->blocks[j]);
 663                         goto err_release_instance_kobj;
 664                 }
 665         }
 666         kobject_uevent(&instance->kobj, KOBJ_ADD);
 667
 668         edac_dbg(4, "Registered instance %d '%s' kobject\n",
 669                  idx, instance->name);
 670
 671         return 0;
 672
 673         /* error unwind stack */
 674 err_release_instance_kobj:
 675         kobject_put(&instance->kobj);
 676
 677 err_out:
 678         return err;
 679 }
 680
 681 /*
 682  * edac_device_remove_instance
 683  *      remove an edac_device instance
 684  */
 685 static void edac_device_delete_instance(struct edac_device_ctl_info *edac_dev,
 686                                         int idx)
 687 {
 688         struct edac_device_instance *instance;
 689         int i;
 690
 691         instance = &edac_dev->instances[idx];
 692
 693         /* unregister all blocks in this instance */
 694         for (i = 0; i < instance->nr_blocks; i++)
 695                 edac_device_delete_block(edac_dev, &instance->blocks[i]);
 696
 697         /* unregister this instance's kobject, SEE:
 698          *      edac_device_ctrl_instance_release() for callback operation
 699          */
 700         kobject_put(&instance->kobj);
 701 }
 702
 703 /*
 704  * edac_device_create_instances
 705  *      create the first level of 'instances' for this device
 706  *      (ie  'cache' might have 'cache0', 'cache1', 'cache2', etc
 707  */
 708 static int edac_device_create_instances(struct edac_device_ctl_info *edac_dev)
 709 {
 710         int i, j;
 711         int err;
 712
 713         edac_dbg(0, "\n");
 714
 715         /* iterate over creation of the instances */
 716         for (i = 0; i < edac_dev->nr_instances; i++) {
 717                 err = edac_device_create_instance(edac_dev, i);
 718                 if (err) {
 719                         /* unwind previous instances on error */
 720                         for (j = 0; j < i; j++)
 721                                 edac_device_delete_instance(edac_dev, j);
 722                         return err;
 723                 }
 724         }
 725
 726         return 0;
 727 }
 728
 729 /*
 730  * edac_device_delete_instances(edac_dev);
 731  *      unregister all the kobjects of the instances
 732  */
 733 static void edac_device_delete_instances(struct edac_device_ctl_info *edac_dev)
 734 {
 735         int i;
 736
 737         /* iterate over creation of the instances */
 738         for (i = 0; i < edac_dev->nr_instances; i++)
 739                 edac_device_delete_instance(edac_dev, i);
 740 }
 741
 742 /* edac_dev sysfs ctor/dtor  code */
 743
 744 /*
 745  * edac_device_add_main_sysfs_attributes
 746  *      add some attributes to this instance's main kobject
 747  */
 748 static int edac_device_add_main_sysfs_attributes(
 749                         struct edac_device_ctl_info *edac_dev)
 750 {
 751         struct edac_dev_sysfs_attribute *sysfs_attrib;
 752         int err = 0;
 753
 754         sysfs_attrib = edac_dev->sysfs_attributes;
 755         if (sysfs_attrib) {
 756                 /* iterate over the array and create an attribute for each
 757                  * entry in the list
 758                  */
 759                 while (sysfs_attrib->attr.name != NULL) {
 760                         err = sysfs_create_file(&edac_dev->kobj,
 761                                 (struct attribute*) sysfs_attrib);
 762                         if (err)
 763                                 goto err_out;
 764
 765                         sysfs_attrib++;
 766                 }
 767         }
 768
 769 err_out:
 770         return err;
 771 }
 772
 773 /*
 774  * edac_device_remove_main_sysfs_attributes
 775  *      remove any attributes to this instance's main kobject
 776  */
 777 static void edac_device_remove_main_sysfs_attributes(
 778                         struct edac_device_ctl_info *edac_dev)
 779 {
 780         struct edac_dev_sysfs_attribute *sysfs_attrib;
 781
 782         /* if there are main attributes, defined, remove them. First,
 783          * point to the start of the array and iterate over it
 784          * removing each attribute listed from this device's instance's kobject
 785          */
 786         sysfs_attrib = edac_dev->sysfs_attributes;
 787         if (sysfs_attrib) {
 788                 while (sysfs_attrib->attr.name != NULL) {
 789                         sysfs_remove_file(&edac_dev->kobj,
 790                                         (struct attribute *) sysfs_attrib);
 791                         sysfs_attrib++;
 792                 }
 793         }
 794 }
 795
 796 /*
 797  * edac_device_create_sysfs() Constructor
 798  *
 799  * accept a created edac_device control structure
 800  * and 'export' it to sysfs. The 'main' kobj should already have been
 801  * created. 'instance' and 'block' kobjects should be registered
 802  * along with any 'block' attributes from the low driver. In addition,
 803  * the main attributes (if any) are connected to the main kobject of
 804  * the control structure.
 805  *
 806  * Return:
 807  *      0       Success
 808  *      !0      Failure
 809  */
 810 int edac_device_create_sysfs(struct edac_device_ctl_info *edac_dev)
 811 {
 812         int err;
 813         struct kobject *edac_kobj = &edac_dev->kobj;
 814
 815         edac_dbg(0, "idx=%d\n", edac_dev->dev_idx);
 816
 817         /*  go create any main attributes callers wants */
 818         err = edac_device_add_main_sysfs_attributes(edac_dev);
 819         if (err) {
 820                 edac_dbg(0, "failed to add sysfs attribs\n");
 821                 goto err_out;
 822         }
 823
 824         /* create a symlink from the edac device
 825          * to the platform 'device' being used for this
 826          */
 827         err = sysfs_create_link(edac_kobj,
 828                                 &edac_dev->dev->kobj, EDAC_DEVICE_SYMLINK);
 829         if (err) {
 830                 edac_dbg(0, "sysfs_create_link() returned err= %d\n", err);
 831                 goto err_remove_main_attribs;
 832         }
 833
 834         /* Create the first level instance directories
 835          * In turn, the nested blocks beneath the instances will
 836          * be registered as well
 837          */
 838         err = edac_device_create_instances(edac_dev);
 839         if (err) {
 840                 edac_dbg(0, "edac_device_create_instances() returned err= %d\n",
 841                          err);
 842                 goto err_remove_link;
 843         }
 844
 845
 846         edac_dbg(4, "create-instances done, idx=%d\n", edac_dev->dev_idx);
 847
 848         return 0;
 849
 850         /* Error unwind stack */
 851 err_remove_link:
 852         /* remove the sym link */
 853         sysfs_remove_link(&edac_dev->kobj, EDAC_DEVICE_SYMLINK);
 854
 855 err_remove_main_attribs:
 856         edac_device_remove_main_sysfs_attributes(edac_dev);
 857
 858 err_out:
 859         return err;
 860 }
 861
 862 /*
 863  * edac_device_remove_sysfs() destructor
 864  *
 865  * given an edac_device struct, tear down the kobject resources
 866  */
 867 void edac_device_remove_sysfs(struct edac_device_ctl_info *edac_dev)
 868 {
 869         edac_dbg(0, "\n");
 870
 871         /* remove any main attributes for this device */
 872         edac_device_remove_main_sysfs_attributes(edac_dev);
 873
 874         /* remove the device sym link */
 875         sysfs_remove_link(&edac_dev->kobj, EDAC_DEVICE_SYMLINK);
 876
 877         /* walk the instance/block kobject tree, deconstructing it */
 878         edac_device_delete_instances(edac_dev);
 879 }