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