drivers/edac/edac_pci.c

   1 /*
   2  * EDAC PCI component
   3  *
   4  * Author: Dave Jiang <djiang@mvista.com>
   5  *
   6  * 2007 (c) MontaVista Software, Inc. This file is licensed under
   7  * the terms of the GNU General Public License version 2. This program
   8  * is licensed "as is" without any warranty of any kind, whether express
   9  * or implied.
  10  *
  11  */
  12 #include <linux/module.h>
  13 #include <linux/types.h>
  14 #include <linux/smp.h>
  15 #include <linux/init.h>
  16 #include <linux/sysctl.h>
  17 #include <linux/highmem.h>
  18 #include <linux/timer.h>
  19 #include <linux/slab.h>
  20 #include <linux/spinlock.h>
  21 #include <linux/list.h>
  22 #include <linux/sysdev.h>
  23 #include <linux/ctype.h>
  24 #include <linux/workqueue.h>
  25 #include <asm/uaccess.h>
  26 #include <asm/page.h>
  27
  28 #include "edac_core.h"
  29 #include "edac_module.h"
  30
  31 static DEFINE_MUTEX(edac_pci_ctls_mutex);
  32 static LIST_HEAD(edac_pci_list);
  33 static atomic_t pci_indexes = ATOMIC_INIT(0);
  34
  35 /*
  36  * edac_pci_alloc_ctl_info
  37  *
  38  *      The alloc() function for the 'edac_pci' control info
  39  *      structure. The chip driver will allocate one of these for each
  40  *      edac_pci it is going to control/register with the EDAC CORE.
  41  */
  42 struct edac_pci_ctl_info *edac_pci_alloc_ctl_info(unsigned int sz_pvt,
  43                                                 const char *edac_pci_name)
  44 {
  45         struct edac_pci_ctl_info *pci;
  46         void *pvt;
  47         unsigned int size;
  48
  49         debugf1("%s()\n", __func__);
  50
  51         pci = (struct edac_pci_ctl_info *)0;
  52         pvt = edac_align_ptr(&pci[1], sz_pvt);
  53         size = ((unsigned long)pvt) + sz_pvt;
  54
  55         /* Alloc the needed control struct memory */
  56         pci = kzalloc(size, GFP_KERNEL);
  57         if (pci  == NULL)
  58                 return NULL;
  59
  60         /* Now much private space */
  61         pvt = sz_pvt ? ((char *)pci) + ((unsigned long)pvt) : NULL;
  62
  63         pci->pvt_info = pvt;
  64         pci->op_state = OP_ALLOC;
  65
  66         snprintf(pci->name, strlen(edac_pci_name) + 1, "%s", edac_pci_name);
  67
  68         return pci;
  69 }
  70 EXPORT_SYMBOL_GPL(edac_pci_alloc_ctl_info);
  71
  72 /*
  73  * edac_pci_free_ctl_info()
  74  *
  75  *      Last action on the pci control structure.
  76  *
  77  *      call the remove sysfs information, which will unregister
  78  *      this control struct's kobj. When that kobj's ref count
  79  *      goes to zero, its release function will be call and then
  80  *      kfree() the memory.
  81  */
  82 void edac_pci_free_ctl_info(struct edac_pci_ctl_info *pci)
  83 {
  84         debugf1("%s()\n", __func__);
  85
  86         edac_pci_remove_sysfs(pci);
  87 }
  88 EXPORT_SYMBOL_GPL(edac_pci_free_ctl_info);
  89
  90 /*
  91  * find_edac_pci_by_dev()
  92  *      scans the edac_pci list for a specific 'struct device *'
  93  *
  94  *      return NULL if not found, or return control struct pointer
  95  */
  96 static struct edac_pci_ctl_info *find_edac_pci_by_dev(struct device *dev)
  97 {
  98         struct edac_pci_ctl_info *pci;
  99         struct list_head *item;
 100
 101         debugf1("%s()\n", __func__);
 102
 103         list_for_each(item, &edac_pci_list) {
 104                 pci = list_entry(item, struct edac_pci_ctl_info, link);
 105
 106                 if (pci->dev == dev)
 107                         return pci;
 108         }
 109
 110         return NULL;
 111 }
 112
 113 /*
 114  * add_edac_pci_to_global_list
 115  *      Before calling this function, caller must assign a unique value to
 116  *      edac_dev->pci_idx.
 117  *      Return:
 118  *              0 on success
 119  *              1 on failure
 120  */
 121 static int add_edac_pci_to_global_list(struct edac_pci_ctl_info *pci)
 122 {
 123         struct list_head *item, *insert_before;
 124         struct edac_pci_ctl_info *rover;
 125
 126         debugf1("%s()\n", __func__);
 127
 128         insert_before = &edac_pci_list;
 129
 130         /* Determine if already on the list */
 131         rover = find_edac_pci_by_dev(pci->dev);
 132         if (unlikely(rover != NULL))
 133                 goto fail0;
 134
 135         /* Insert in ascending order by 'pci_idx', so find position */
 136         list_for_each(item, &edac_pci_list) {
 137                 rover = list_entry(item, struct edac_pci_ctl_info, link);
 138
 139                 if (rover->pci_idx >= pci->pci_idx) {
 140                         if (unlikely(rover->pci_idx == pci->pci_idx))
 141                                 goto fail1;
 142
 143                         insert_before = item;
 144                         break;
 145                 }
 146         }
 147
 148         list_add_tail_rcu(&pci->link, insert_before);
 149         return 0;
 150
 151 fail0:
 152         edac_printk(KERN_WARNING, EDAC_PCI,
 153                 "%s (%s) %s %s already assigned %d\n",
 154                 dev_name(rover->dev), edac_dev_name(rover),
 155                 rover->mod_name, rover->ctl_name, rover->pci_idx);
 156         return 1;
 157
 158 fail1:
 159         edac_printk(KERN_WARNING, EDAC_PCI,
 160                 "but in low-level driver: attempt to assign\n"
 161                 "\tduplicate pci_idx %d in %s()\n", rover->pci_idx,
 162                 __func__);
 163         return 1;
 164 }
 165
 166 /*
 167  * complete_edac_pci_list_del
 168  *
 169  *      RCU completion callback to indicate item is deleted
 170  */
 171 static void complete_edac_pci_list_del(struct rcu_head *head)
 172 {
 173         struct edac_pci_ctl_info *pci;
 174
 175         pci = container_of(head, struct edac_pci_ctl_info, rcu);
 176         INIT_LIST_HEAD(&pci->link);
 177         complete(&pci->complete);
 178 }
 179
 180 /*
 181  * del_edac_pci_from_global_list
 182  *
 183  *      remove the PCI control struct from the global list
 184  */
 185 static void del_edac_pci_from_global_list(struct edac_pci_ctl_info *pci)
 186 {
 187         list_del_rcu(&pci->link);
 188         init_completion(&pci->complete);
 189         call_rcu(&pci->rcu, complete_edac_pci_list_del);
 190         wait_for_completion(&pci->complete);
 191 }
 192
 193 #if 0
 194 /* Older code, but might use in the future */
 195
 196 /*
 197  * edac_pci_find()
 198  *      Search for an edac_pci_ctl_info structure whose index is 'idx'
 199  *
 200  * If found, return a pointer to the structure
 201  * Else return NULL.
 202  *
 203  * Caller must hold pci_ctls_mutex.
 204  */
 205 struct edac_pci_ctl_info *edac_pci_find(int idx)
 206 {
 207         struct list_head *item;
 208         struct edac_pci_ctl_info *pci;
 209
 210         /* Iterage over list, looking for exact match of ID */
 211         list_for_each(item, &edac_pci_list) {
 212                 pci = list_entry(item, struct edac_pci_ctl_info, link);
 213
 214                 if (pci->pci_idx >= idx) {
 215                         if (pci->pci_idx == idx)
 216                                 return pci;
 217
 218                         /* not on list, so terminate early */
 219                         break;
 220                 }
 221         }
 222
 223         return NULL;
 224 }
 225 EXPORT_SYMBOL_GPL(edac_pci_find);
 226 #endif
 227
 228 /*
 229  * edac_pci_workq_function()
 230  *
 231  *      periodic function that performs the operation
 232  *      scheduled by a workq request, for a given PCI control struct
 233  */
 234 static void edac_pci_workq_function(struct work_struct *work_req)
 235 {
 236         struct delayed_work *d_work = to_delayed_work(work_req);
 237         struct edac_pci_ctl_info *pci = to_edac_pci_ctl_work(d_work);
 238         int msec;
 239         unsigned long delay;
 240
 241         debugf3("%s() checking\n", __func__);
 242
 243         mutex_lock(&edac_pci_ctls_mutex);
 244
 245         if (pci->op_state == OP_RUNNING_POLL) {
 246                 /* we might be in POLL mode, but there may NOT be a poll func
 247                  */
 248                 if ((pci->edac_check != NULL) && edac_pci_get_check_errors())
 249                         pci->edac_check(pci);
 250
 251                 /* if we are on a one second period, then use round */
 252                 msec = edac_pci_get_poll_msec();
 253                 if (msec == 1000)
 254                         delay = round_jiffies_relative(msecs_to_jiffies(msec));
 255                 else
 256                         delay = msecs_to_jiffies(msec);
 257
 258                 /* Reschedule only if we are in POLL mode */
 259                 queue_delayed_work(edac_workqueue, &pci->work, delay);
 260         }
 261
 262         mutex_unlock(&edac_pci_ctls_mutex);
 263 }
 264
 265 /*
 266  * edac_pci_workq_setup()
 267  *      initialize a workq item for this edac_pci instance
 268  *      passing in the new delay period in msec
 269  *
 270  *      locking model:
 271  *              called when 'edac_pci_ctls_mutex' is locked
 272  */
 273 static void edac_pci_workq_setup(struct edac_pci_ctl_info *pci,
 274                                  unsigned int msec)
 275 {
 276         debugf0("%s()\n", __func__);
 277
 278         INIT_DELAYED_WORK(&pci->work, edac_pci_workq_function);
 279         queue_delayed_work(edac_workqueue, &pci->work,
 280                         msecs_to_jiffies(edac_pci_get_poll_msec()));
 281 }
 282
 283 /*
 284  * edac_pci_workq_teardown()
 285  *      stop the workq processing on this edac_pci instance
 286  */
 287 static void edac_pci_workq_teardown(struct edac_pci_ctl_info *pci)
 288 {
 289         int status;
 290
 291         debugf0("%s()\n", __func__);
 292
 293         status = cancel_delayed_work(&pci->work);
 294         if (status == 0)
 295                 flush_workqueue(edac_workqueue);
 296 }
 297
 298 /*
 299  * edac_pci_reset_delay_period
 300  *
 301  *      called with a new period value for the workq period
 302  *      a) stop current workq timer
 303  *      b) restart workq timer with new value
 304  */
 305 void edac_pci_reset_delay_period(struct edac_pci_ctl_info *pci,
 306                                  unsigned long value)
 307 {
 308         debugf0("%s()\n", __func__);
 309
 310         edac_pci_workq_teardown(pci);
 311
 312         /* need to lock for the setup */
 313         mutex_lock(&edac_pci_ctls_mutex);
 314
 315         edac_pci_workq_setup(pci, value);
 316
 317         mutex_unlock(&edac_pci_ctls_mutex);
 318 }
 319 EXPORT_SYMBOL_GPL(edac_pci_reset_delay_period);
 320
 321 /*
 322  * edac_pci_alloc_index: Allocate a unique PCI index number
 323  *
 324  * Return:
 325  *      allocated index number
 326  *
 327  */
 328 int edac_pci_alloc_index(void)
 329 {
 330         return atomic_inc_return(&pci_indexes) - 1;
 331 }
 332 EXPORT_SYMBOL_GPL(edac_pci_alloc_index);
 333
 334 /*
 335  * edac_pci_add_device: Insert the 'edac_dev' structure into the
 336  * edac_pci global list and create sysfs entries associated with
 337  * edac_pci structure.
 338  * @pci: pointer to the edac_device structure to be added to the list
 339  * @edac_idx: A unique numeric identifier to be assigned to the
 340  * 'edac_pci' structure.
 341  *
 342  * Return:
 343  *      0       Success
 344  *      !0      Failure
 345  */
 346 int edac_pci_add_device(struct edac_pci_ctl_info *pci, int edac_idx)
 347 {
 348         debugf0("%s()\n", __func__);
 349
 350         pci->pci_idx = edac_idx;
 351         pci->start_time = jiffies;
 352
 353         mutex_lock(&edac_pci_ctls_mutex);
 354
 355         if (add_edac_pci_to_global_list(pci))
 356                 goto fail0;
 357
 358         if (edac_pci_create_sysfs(pci)) {
 359                 edac_pci_printk(pci, KERN_WARNING,
 360                                 "failed to create sysfs pci\n");
 361                 goto fail1;
 362         }
 363
 364         if (pci->edac_check != NULL) {
 365                 pci->op_state = OP_RUNNING_POLL;
 366
 367                 edac_pci_workq_setup(pci, 1000);
 368         } else {
 369                 pci->op_state = OP_RUNNING_INTERRUPT;
 370         }
 371
 372         edac_pci_printk(pci, KERN_INFO,
 373                         "Giving out device to module '%s' controller '%s':"
 374                         " DEV '%s' (%s)\n",
 375                         pci->mod_name,
 376                         pci->ctl_name,
 377                         edac_dev_name(pci), edac_op_state_to_string(pci->op_state));
 378
 379         mutex_unlock(&edac_pci_ctls_mutex);
 380         return 0;
 381
 382         /* error unwind stack */
 383 fail1:
 384         del_edac_pci_from_global_list(pci);
 385 fail0:
 386         mutex_unlock(&edac_pci_ctls_mutex);
 387         return 1;
 388 }
 389 EXPORT_SYMBOL_GPL(edac_pci_add_device);
 390
 391 /*
 392  * edac_pci_del_device()
 393  *      Remove sysfs entries for specified edac_pci structure and
 394  *      then remove edac_pci structure from global list
 395  *
 396  * @dev:
 397  *      Pointer to 'struct device' representing edac_pci structure
 398  *      to remove
 399  *
 400  * Return:
 401  *      Pointer to removed edac_pci structure,
 402  *      or NULL if device not found
 403  */
 404 struct edac_pci_ctl_info *edac_pci_del_device(struct device *dev)
 405 {
 406         struct edac_pci_ctl_info *pci;
 407
 408         debugf0("%s()\n", __func__);
 409
 410         mutex_lock(&edac_pci_ctls_mutex);
 411
 412         /* ensure the control struct is on the global list
 413          * if not, then leave
 414          */
 415         pci = find_edac_pci_by_dev(dev);
 416         if (pci  == NULL) {
 417                 mutex_unlock(&edac_pci_ctls_mutex);
 418                 return NULL;
 419         }
 420
 421         pci->op_state = OP_OFFLINE;
 422
 423         del_edac_pci_from_global_list(pci);
 424
 425         mutex_unlock(&edac_pci_ctls_mutex);
 426
 427         /* stop the workq timer */
 428         edac_pci_workq_teardown(pci);
 429
 430         edac_printk(KERN_INFO, EDAC_PCI,
 431                 "Removed device %d for %s %s: DEV %s\n",
 432                 pci->pci_idx, pci->mod_name, pci->ctl_name, edac_dev_name(pci));
 433
 434         return pci;
 435 }
 436 EXPORT_SYMBOL_GPL(edac_pci_del_device);
 437
 438 /*
 439  * edac_pci_generic_check
 440  *
 441  *      a Generic parity check API
 442  */
 443 static void edac_pci_generic_check(struct edac_pci_ctl_info *pci)
 444 {
 445         debugf4("%s()\n", __func__);
 446         edac_pci_do_parity_check();
 447 }
 448
 449 /* free running instance index counter */
 450 static int edac_pci_idx;
 451 #define EDAC_PCI_GENCTL_NAME    "EDAC PCI controller"
 452
 453 struct edac_pci_gen_data {
 454         int edac_idx;
 455 };
 456
 457 /*
 458  * edac_pci_create_generic_ctl
 459  *
 460  *      A generic constructor for a PCI parity polling device
 461  *      Some systems have more than one domain of PCI busses.
 462  *      For systems with one domain, then this API will
 463  *      provide for a generic poller.
 464  *
 465  *      This routine calls the edac_pci_alloc_ctl_info() for
 466  *      the generic device, with default values
 467  */
 468 struct edac_pci_ctl_info *edac_pci_create_generic_ctl(struct device *dev,
 469                                                 const char *mod_name)
 470 {
 471         struct edac_pci_ctl_info *pci;
 472         struct edac_pci_gen_data *pdata;
 473
 474         pci = edac_pci_alloc_ctl_info(sizeof(*pdata), EDAC_PCI_GENCTL_NAME);
 475         if (!pci)
 476                 return NULL;
 477
 478         pdata = pci->pvt_info;
 479         pci->dev = dev;
 480         dev_set_drvdata(pci->dev, pci);
 481         pci->dev_name = pci_name(to_pci_dev(dev));
 482
 483         pci->mod_name = mod_name;
 484         pci->ctl_name = EDAC_PCI_GENCTL_NAME;
 485         pci->edac_check = edac_pci_generic_check;
 486
 487         pdata->edac_idx = edac_pci_idx++;
 488
 489         if (edac_pci_add_device(pci, pdata->edac_idx) > 0) {
 490                 debugf3("%s(): failed edac_pci_add_device()\n", __func__);
 491                 edac_pci_free_ctl_info(pci);
 492                 return NULL;
 493         }
 494
 495         return pci;
 496 }
 497 EXPORT_SYMBOL_GPL(edac_pci_create_generic_ctl);
 498
 499 /*
 500  * edac_pci_release_generic_ctl
 501  *
 502  *      The release function of a generic EDAC PCI polling device
 503  */
 504 void edac_pci_release_generic_ctl(struct edac_pci_ctl_info *pci)
 505 {
 506         debugf0("%s() pci mod=%s\n", __func__, pci->mod_name);
 507
 508         edac_pci_del_device(pci->dev);
 509         edac_pci_free_ctl_info(pci);
 510 }
 511 EXPORT_SYMBOL_GPL(edac_pci_release_generic_ctl);