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  * del_edac_pci_from_global_list
 168  *
 169  *      remove the PCI control struct from the global list
 170  */
 171 static void del_edac_pci_from_global_list(struct edac_pci_ctl_info *pci)
 172 {
 173         list_del_rcu(&pci->link);
 174
 175         /* these are for safe removal of devices from global list while
 176          * NMI handlers may be traversing list
 177          */
 178         synchronize_rcu();
 179         INIT_LIST_HEAD(&pci->link);
 180 }
 181
 182 #if 0
 183 /* Older code, but might use in the future */
 184
 185 /*
 186  * edac_pci_find()
 187  *      Search for an edac_pci_ctl_info structure whose index is 'idx'
 188  *
 189  * If found, return a pointer to the structure
 190  * Else return NULL.
 191  *
 192  * Caller must hold pci_ctls_mutex.
 193  */
 194 struct edac_pci_ctl_info *edac_pci_find(int idx)
 195 {
 196         struct list_head *item;
 197         struct edac_pci_ctl_info *pci;
 198
 199         /* Iterage over list, looking for exact match of ID */
 200         list_for_each(item, &edac_pci_list) {
 201                 pci = list_entry(item, struct edac_pci_ctl_info, link);
 202
 203                 if (pci->pci_idx >= idx) {
 204                         if (pci->pci_idx == idx)
 205                                 return pci;
 206
 207                         /* not on list, so terminate early */
 208                         break;
 209                 }
 210         }
 211
 212         return NULL;
 213 }
 214 EXPORT_SYMBOL_GPL(edac_pci_find);
 215 #endif
 216
 217 /*
 218  * edac_pci_workq_function()
 219  *
 220  *      periodic function that performs the operation
 221  *      scheduled by a workq request, for a given PCI control struct
 222  */
 223 static void edac_pci_workq_function(struct work_struct *work_req)
 224 {
 225         struct delayed_work *d_work = to_delayed_work(work_req);
 226         struct edac_pci_ctl_info *pci = to_edac_pci_ctl_work(d_work);
 227         int msec;
 228         unsigned long delay;
 229
 230         debugf3("%s() checking\n", __func__);
 231
 232         mutex_lock(&edac_pci_ctls_mutex);
 233
 234         if (pci->op_state == OP_RUNNING_POLL) {
 235                 /* we might be in POLL mode, but there may NOT be a poll func
 236                  */
 237                 if ((pci->edac_check != NULL) && edac_pci_get_check_errors())
 238                         pci->edac_check(pci);
 239
 240                 /* if we are on a one second period, then use round */
 241                 msec = edac_pci_get_poll_msec();
 242                 if (msec == 1000)
 243                         delay = round_jiffies_relative(msecs_to_jiffies(msec));
 244                 else
 245                         delay = msecs_to_jiffies(msec);
 246
 247                 /* Reschedule only if we are in POLL mode */
 248                 queue_delayed_work(edac_workqueue, &pci->work, delay);
 249         }
 250
 251         mutex_unlock(&edac_pci_ctls_mutex);
 252 }
 253
 254 /*
 255  * edac_pci_workq_setup()
 256  *      initialize a workq item for this edac_pci instance
 257  *      passing in the new delay period in msec
 258  *
 259  *      locking model:
 260  *              called when 'edac_pci_ctls_mutex' is locked
 261  */
 262 static void edac_pci_workq_setup(struct edac_pci_ctl_info *pci,
 263                                  unsigned int msec)
 264 {
 265         debugf0("%s()\n", __func__);
 266
 267         INIT_DELAYED_WORK(&pci->work, edac_pci_workq_function);
 268         queue_delayed_work(edac_workqueue, &pci->work,
 269                         msecs_to_jiffies(edac_pci_get_poll_msec()));
 270 }
 271
 272 /*
 273  * edac_pci_workq_teardown()
 274  *      stop the workq processing on this edac_pci instance
 275  */
 276 static void edac_pci_workq_teardown(struct edac_pci_ctl_info *pci)
 277 {
 278         int status;
 279
 280         debugf0("%s()\n", __func__);
 281
 282         status = cancel_delayed_work(&pci->work);
 283         if (status == 0)
 284                 flush_workqueue(edac_workqueue);
 285 }
 286
 287 /*
 288  * edac_pci_reset_delay_period
 289  *
 290  *      called with a new period value for the workq period
 291  *      a) stop current workq timer
 292  *      b) restart workq timer with new value
 293  */
 294 void edac_pci_reset_delay_period(struct edac_pci_ctl_info *pci,
 295                                  unsigned long value)
 296 {
 297         debugf0("%s()\n", __func__);
 298
 299         edac_pci_workq_teardown(pci);
 300
 301         /* need to lock for the setup */
 302         mutex_lock(&edac_pci_ctls_mutex);
 303
 304         edac_pci_workq_setup(pci, value);
 305
 306         mutex_unlock(&edac_pci_ctls_mutex);
 307 }
 308 EXPORT_SYMBOL_GPL(edac_pci_reset_delay_period);
 309
 310 /*
 311  * edac_pci_alloc_index: Allocate a unique PCI index number
 312  *
 313  * Return:
 314  *      allocated index number
 315  *
 316  */
 317 int edac_pci_alloc_index(void)
 318 {
 319         return atomic_inc_return(&pci_indexes) - 1;
 320 }
 321 EXPORT_SYMBOL_GPL(edac_pci_alloc_index);
 322
 323 /*
 324  * edac_pci_add_device: Insert the 'edac_dev' structure into the
 325  * edac_pci global list and create sysfs entries associated with
 326  * edac_pci structure.
 327  * @pci: pointer to the edac_device structure to be added to the list
 328  * @edac_idx: A unique numeric identifier to be assigned to the
 329  * 'edac_pci' structure.
 330  *
 331  * Return:
 332  *      0       Success
 333  *      !0      Failure
 334  */
 335 int edac_pci_add_device(struct edac_pci_ctl_info *pci, int edac_idx)
 336 {
 337         debugf0("%s()\n", __func__);
 338
 339         pci->pci_idx = edac_idx;
 340         pci->start_time = jiffies;
 341
 342         mutex_lock(&edac_pci_ctls_mutex);
 343
 344         if (add_edac_pci_to_global_list(pci))
 345                 goto fail0;
 346
 347         if (edac_pci_create_sysfs(pci)) {
 348                 edac_pci_printk(pci, KERN_WARNING,
 349                                 "failed to create sysfs pci\n");
 350                 goto fail1;
 351         }
 352
 353         if (pci->edac_check != NULL) {
 354                 pci->op_state = OP_RUNNING_POLL;
 355
 356                 edac_pci_workq_setup(pci, 1000);
 357         } else {
 358                 pci->op_state = OP_RUNNING_INTERRUPT;
 359         }
 360
 361         edac_pci_printk(pci, KERN_INFO,
 362                         "Giving out device to module '%s' controller '%s':"
 363                         " DEV '%s' (%s)\n",
 364                         pci->mod_name,
 365                         pci->ctl_name,
 366                         edac_dev_name(pci), edac_op_state_to_string(pci->op_state));
 367
 368         mutex_unlock(&edac_pci_ctls_mutex);
 369         return 0;
 370
 371         /* error unwind stack */
 372 fail1:
 373         del_edac_pci_from_global_list(pci);
 374 fail0:
 375         mutex_unlock(&edac_pci_ctls_mutex);
 376         return 1;
 377 }
 378 EXPORT_SYMBOL_GPL(edac_pci_add_device);
 379
 380 /*
 381  * edac_pci_del_device()
 382  *      Remove sysfs entries for specified edac_pci structure and
 383  *      then remove edac_pci structure from global list
 384  *
 385  * @dev:
 386  *      Pointer to 'struct device' representing edac_pci structure
 387  *      to remove
 388  *
 389  * Return:
 390  *      Pointer to removed edac_pci structure,
 391  *      or NULL if device not found
 392  */
 393 struct edac_pci_ctl_info *edac_pci_del_device(struct device *dev)
 394 {
 395         struct edac_pci_ctl_info *pci;
 396
 397         debugf0("%s()\n", __func__);
 398
 399         mutex_lock(&edac_pci_ctls_mutex);
 400
 401         /* ensure the control struct is on the global list
 402          * if not, then leave
 403          */
 404         pci = find_edac_pci_by_dev(dev);
 405         if (pci  == NULL) {
 406                 mutex_unlock(&edac_pci_ctls_mutex);
 407                 return NULL;
 408         }
 409
 410         pci->op_state = OP_OFFLINE;
 411
 412         del_edac_pci_from_global_list(pci);
 413
 414         mutex_unlock(&edac_pci_ctls_mutex);
 415
 416         /* stop the workq timer */
 417         edac_pci_workq_teardown(pci);
 418
 419         edac_printk(KERN_INFO, EDAC_PCI,
 420                 "Removed device %d for %s %s: DEV %s\n",
 421                 pci->pci_idx, pci->mod_name, pci->ctl_name, edac_dev_name(pci));
 422
 423         return pci;
 424 }
 425 EXPORT_SYMBOL_GPL(edac_pci_del_device);
 426
 427 /*
 428  * edac_pci_generic_check
 429  *
 430  *      a Generic parity check API
 431  */
 432 static void edac_pci_generic_check(struct edac_pci_ctl_info *pci)
 433 {
 434         debugf4("%s()\n", __func__);
 435         edac_pci_do_parity_check();
 436 }
 437
 438 /* free running instance index counter */
 439 static int edac_pci_idx;
 440 #define EDAC_PCI_GENCTL_NAME    "EDAC PCI controller"
 441
 442 struct edac_pci_gen_data {
 443         int edac_idx;
 444 };
 445
 446 /*
 447  * edac_pci_create_generic_ctl
 448  *
 449  *      A generic constructor for a PCI parity polling device
 450  *      Some systems have more than one domain of PCI busses.
 451  *      For systems with one domain, then this API will
 452  *      provide for a generic poller.
 453  *
 454  *      This routine calls the edac_pci_alloc_ctl_info() for
 455  *      the generic device, with default values
 456  */
 457 struct edac_pci_ctl_info *edac_pci_create_generic_ctl(struct device *dev,
 458                                                 const char *mod_name)
 459 {
 460         struct edac_pci_ctl_info *pci;
 461         struct edac_pci_gen_data *pdata;
 462
 463         pci = edac_pci_alloc_ctl_info(sizeof(*pdata), EDAC_PCI_GENCTL_NAME);
 464         if (!pci)
 465                 return NULL;
 466
 467         pdata = pci->pvt_info;
 468         pci->dev = dev;
 469         dev_set_drvdata(pci->dev, pci);
 470         pci->dev_name = pci_name(to_pci_dev(dev));
 471
 472         pci->mod_name = mod_name;
 473         pci->ctl_name = EDAC_PCI_GENCTL_NAME;
 474         pci->edac_check = edac_pci_generic_check;
 475
 476         pdata->edac_idx = edac_pci_idx++;
 477
 478         if (edac_pci_add_device(pci, pdata->edac_idx) > 0) {
 479                 debugf3("%s(): failed edac_pci_add_device()\n", __func__);
 480                 edac_pci_free_ctl_info(pci);
 481                 return NULL;
 482         }
 483
 484         return pci;
 485 }
 486 EXPORT_SYMBOL_GPL(edac_pci_create_generic_ctl);
 487
 488 /*
 489  * edac_pci_release_generic_ctl
 490  *
 491  *      The release function of a generic EDAC PCI polling device
 492  */
 493 void edac_pci_release_generic_ctl(struct edac_pci_ctl_info *pci)
 494 {
 495         debugf0("%s() pci mod=%s\n", __func__, pci->mod_name);
 496
 497         edac_pci_del_device(pci->dev);
 498         edac_pci_free_ctl_info(pci);
 499 }
 500 EXPORT_SYMBOL_GPL(edac_pci_release_generic_ctl);