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 struct list_head edac_pci_list = LIST_HEAD_INIT(edac_pci_list);
  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 *pvt;
  46         unsigned int size;
  47
  48         debugf1("%s()\n", __func__);
  49
  50         pci = (struct edac_pci_ctl_info *)0;
  51         pvt = edac_align_ptr(&pci[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 informaton, 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         debugf1("%s()\n", __func__);
  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         debugf1("%s()\n", __func__);
 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         debugf1("%s()\n", __func__);
 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                 rover->dev->bus_id, 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  * complete_edac_pci_list_del
 167  *
 168  *      RCU completion callback to indicate item is deleted
 169  */
 170 static void complete_edac_pci_list_del(struct rcu_head *head)
 171 {
 172         struct edac_pci_ctl_info *pci;
 173
 174         pci = container_of(head, struct edac_pci_ctl_info, rcu);
 175         INIT_LIST_HEAD(&pci->link);
 176         complete(&pci->complete);
 177 }
 178
 179 /*
 180  * del_edac_pci_from_global_list
 181  *
 182  *      remove the PCI control struct from the global list
 183  */
 184 static void del_edac_pci_from_global_list(struct edac_pci_ctl_info *pci)
 185 {
 186         list_del_rcu(&pci->link);
 187         init_completion(&pci->complete);
 188         call_rcu(&pci->rcu, complete_edac_pci_list_del);
 189         wait_for_completion(&pci->complete);
 190 }
 191
 192 /*
 193  * edac_pci_find()
 194  *      Search for an edac_pci_ctl_info structure whose index is 'idx'
 195  *
 196  * If found, return a pointer to the structure
 197  * Else return NULL.
 198  *
 199  * Caller must hold pci_ctls_mutex.
 200  */
 201 struct edac_pci_ctl_info *edac_pci_find(int idx)
 202 {
 203         struct list_head *item;
 204         struct edac_pci_ctl_info *pci;
 205
 206         /* Iterage over list, looking for exact match of ID */
 207         list_for_each(item, &edac_pci_list) {
 208                 pci = list_entry(item, struct edac_pci_ctl_info, link);
 209
 210                 if (pci->pci_idx >= idx) {
 211                         if (pci->pci_idx == idx)
 212                                 return pci;
 213
 214                         /* not on list, so terminate early */
 215                         break;
 216                 }
 217         }
 218
 219         return NULL;
 220 }
 221 EXPORT_SYMBOL_GPL(edac_pci_find);
 222
 223 /*
 224  * edac_pci_workq_function()
 225  *
 226  *      periodic function that performs the operation
 227  *      scheduled by a workq request, for a given PCI control struct
 228  */
 229 static void edac_pci_workq_function(struct work_struct *work_req)
 230 {
 231         struct delayed_work *d_work = (struct delayed_work *)work_req;
 232         struct edac_pci_ctl_info *pci = to_edac_pci_ctl_work(d_work);
 233         int msec;
 234         unsigned long delay;
 235
 236         debugf3("%s() checking\n", __func__);
 237
 238         mutex_lock(&edac_pci_ctls_mutex);
 239
 240         if (pci->op_state == OP_RUNNING_POLL) {
 241                 /* we might be in POLL mode, but there may NOT be a poll func
 242                  */
 243                 if ((pci->edac_check != NULL) && edac_pci_get_check_errors())
 244                         pci->edac_check(pci);
 245
 246                 /* if we are on a one second period, then use round */
 247                 msec = edac_pci_get_poll_msec();
 248                 if (msec == 1000)
 249                         delay = round_jiffies(msecs_to_jiffies(msec));
 250                 else
 251                         delay = msecs_to_jiffies(msec);
 252
 253                 /* Reschedule only if we are in POLL mode */
 254                 queue_delayed_work(edac_workqueue, &pci->work, delay);
 255         }
 256
 257         mutex_unlock(&edac_pci_ctls_mutex);
 258 }
 259
 260 /*
 261  * edac_pci_workq_setup()
 262  *      initialize a workq item for this edac_pci instance
 263  *      passing in the new delay period in msec
 264  *
 265  *      locking model:
 266  *              called when 'edac_pci_ctls_mutex' is locked
 267  */
 268 static void edac_pci_workq_setup(struct edac_pci_ctl_info *pci,
 269                                  unsigned int msec)
 270 {
 271         debugf0("%s()\n", __func__);
 272
 273         INIT_DELAYED_WORK(&pci->work, edac_pci_workq_function);
 274         queue_delayed_work(edac_workqueue, &pci->work,
 275                         msecs_to_jiffies(edac_pci_get_poll_msec()));
 276 }
 277
 278 /*
 279  * edac_pci_workq_teardown()
 280  *      stop the workq processing on this edac_pci instance
 281  */
 282 static void edac_pci_workq_teardown(struct edac_pci_ctl_info *pci)
 283 {
 284         int status;
 285
 286         debugf0("%s()\n", __func__);
 287
 288         status = cancel_delayed_work(&pci->work);
 289         if (status == 0)
 290                 flush_workqueue(edac_workqueue);
 291 }
 292
 293 /*
 294  * edac_pci_reset_delay_period
 295  *
 296  *      called with a new period value for the workq period
 297  *      a) stop current workq timer
 298  *      b) restart workq timer with new value
 299  */
 300 void edac_pci_reset_delay_period(struct edac_pci_ctl_info *pci,
 301                                  unsigned long value)
 302 {
 303         debugf0("%s()\n", __func__);
 304
 305         edac_pci_workq_teardown(pci);
 306
 307         /* need to lock for the setup */
 308         mutex_lock(&edac_pci_ctls_mutex);
 309
 310         edac_pci_workq_setup(pci, value);
 311
 312         mutex_unlock(&edac_pci_ctls_mutex);
 313 }
 314 EXPORT_SYMBOL_GPL(edac_pci_reset_delay_period);
 315
 316 /*
 317  * edac_pci_add_device: Insert the 'edac_dev' structure into the
 318  * edac_pci global list and create sysfs entries associated with
 319  * edac_pci structure.
 320  * @pci: pointer to the edac_device structure to be added to the list
 321  * @edac_idx: A unique numeric identifier to be assigned to the
 322  * 'edac_pci' structure.
 323  *
 324  * Return:
 325  *      0       Success
 326  *      !0      Failure
 327  */
 328 int edac_pci_add_device(struct edac_pci_ctl_info *pci, int edac_idx)
 329 {
 330         debugf0("%s()\n", __func__);
 331
 332         pci->pci_idx = edac_idx;
 333         pci->start_time = jiffies;
 334
 335         mutex_lock(&edac_pci_ctls_mutex);
 336
 337         if (add_edac_pci_to_global_list(pci))
 338                 goto fail0;
 339
 340         if (edac_pci_create_sysfs(pci)) {
 341                 edac_pci_printk(pci, KERN_WARNING,
 342                                 "failed to create sysfs pci\n");
 343                 goto fail1;
 344         }
 345
 346         if (pci->edac_check != NULL) {
 347                 pci->op_state = OP_RUNNING_POLL;
 348
 349                 edac_pci_workq_setup(pci, 1000);
 350         } else {
 351                 pci->op_state = OP_RUNNING_INTERRUPT;
 352         }
 353
 354         edac_pci_printk(pci, KERN_INFO,
 355                         "Giving out device to module '%s' controller '%s':"
 356                         " DEV '%s' (%s)\n",
 357                         pci->mod_name,
 358                         pci->ctl_name,
 359                         dev_name(pci), edac_op_state_to_string(pci->op_state));
 360
 361         mutex_unlock(&edac_pci_ctls_mutex);
 362         return 0;
 363
 364         /* error unwind stack */
 365 fail1:
 366         del_edac_pci_from_global_list(pci);
 367 fail0:
 368         mutex_unlock(&edac_pci_ctls_mutex);
 369         return 1;
 370 }
 371 EXPORT_SYMBOL_GPL(edac_pci_add_device);
 372
 373 /*
 374  * edac_pci_del_device()
 375  *      Remove sysfs entries for specified edac_pci structure and
 376  *      then remove edac_pci structure from global list
 377  *
 378  * @dev:
 379  *      Pointer to 'struct device' representing edac_pci structure
 380  *      to remove
 381  *
 382  * Return:
 383  *      Pointer to removed edac_pci structure,
 384  *      or NULL if device not found
 385  */
 386 struct edac_pci_ctl_info *edac_pci_del_device(struct device *dev)
 387 {
 388         struct edac_pci_ctl_info *pci;
 389
 390         debugf0("%s()\n", __func__);
 391
 392         mutex_lock(&edac_pci_ctls_mutex);
 393
 394         /* ensure the control struct is on the global list
 395          * if not, then leave
 396          */
 397         pci = find_edac_pci_by_dev(dev);
 398         if (pci  == NULL) {
 399                 mutex_unlock(&edac_pci_ctls_mutex);
 400                 return NULL;
 401         }
 402
 403         pci->op_state = OP_OFFLINE;
 404
 405         del_edac_pci_from_global_list(pci);
 406
 407         mutex_unlock(&edac_pci_ctls_mutex);
 408
 409         /* stop the workq timer */
 410         edac_pci_workq_teardown(pci);
 411
 412         edac_printk(KERN_INFO, EDAC_PCI,
 413                 "Removed device %d for %s %s: DEV %s\n",
 414                 pci->pci_idx, pci->mod_name, pci->ctl_name, dev_name(pci));
 415
 416         return pci;
 417 }
 418 EXPORT_SYMBOL_GPL(edac_pci_del_device);
 419
 420 /*
 421  * edac_pci_generic_check
 422  *
 423  *      a Generic parity check API
 424  */
 425 void edac_pci_generic_check(struct edac_pci_ctl_info *pci)
 426 {
 427         debugf4("%s()\n", __func__);
 428         edac_pci_do_parity_check();
 429 }
 430
 431 /* free running instance index counter */
 432 static int edac_pci_idx;
 433 #define EDAC_PCI_GENCTL_NAME    "EDAC PCI controller"
 434
 435 struct edac_pci_gen_data {
 436         int edac_idx;
 437 };
 438
 439 /*
 440  * edac_pci_create_generic_ctl
 441  *
 442  *      A generic constructor for a PCI parity polling device
 443  *      Some systems have more than one domain of PCI busses.
 444  *      For systems with one domain, then this API will
 445  *      provide for a generic poller.
 446  *
 447  *      This routine calls the edac_pci_alloc_ctl_info() for
 448  *      the generic device, with default values
 449  */
 450 struct edac_pci_ctl_info *edac_pci_create_generic_ctl(struct device *dev,
 451                                                 const char *mod_name)
 452 {
 453         struct edac_pci_ctl_info *pci;
 454         struct edac_pci_gen_data *pdata;
 455
 456         pci = edac_pci_alloc_ctl_info(sizeof(*pdata), EDAC_PCI_GENCTL_NAME);
 457         if (!pci)
 458                 return NULL;
 459
 460         pdata = pci->pvt_info;
 461         pci->dev = dev;
 462         dev_set_drvdata(pci->dev, pci);
 463         pci->dev_name = pci_name(to_pci_dev(dev));
 464
 465         pci->mod_name = mod_name;
 466         pci->ctl_name = EDAC_PCI_GENCTL_NAME;
 467         pci->edac_check = edac_pci_generic_check;
 468
 469         pdata->edac_idx = edac_pci_idx++;
 470
 471         if (edac_pci_add_device(pci, pdata->edac_idx) > 0) {
 472                 debugf3("%s(): failed edac_pci_add_device()\n", __func__);
 473                 edac_pci_free_ctl_info(pci);
 474                 return NULL;
 475         }
 476
 477         return pci;
 478 }
 479 EXPORT_SYMBOL_GPL(edac_pci_create_generic_ctl);
 480
 481 /*
 482  * edac_pci_release_generic_ctl
 483  *
 484  *      The release function of a generic EDAC PCI polling device
 485  */
 486 void edac_pci_release_generic_ctl(struct edac_pci_ctl_info *pci)
 487 {
 488         debugf0("%s() pci mod=%s\n", __func__, pci->mod_name);
 489
 490         edac_pci_del_device(pci->dev);
 491         edac_pci_free_ctl_info(pci);
 492 }
 493 EXPORT_SYMBOL_GPL(edac_pci_release_generic_ctl);