linux/drivers/edac/edac_pci.c
<<
>>
Prefs
   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
  31static DEFINE_MUTEX(edac_pci_ctls_mutex);
  32static LIST_HEAD(edac_pci_list);
  33static 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 */
  42struct 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}
  70EXPORT_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 */
  82void 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}
  88EXPORT_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 */
  96static 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 */
 121static 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
 151fail0:
 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
 158fail1:
 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 */
 171static 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}
 178
 179/*
 180 * del_edac_pci_from_global_list
 181 *
 182 *      remove the PCI control struct from the global list
 183 */
 184static void del_edac_pci_from_global_list(struct edac_pci_ctl_info *pci)
 185{
 186        list_del_rcu(&pci->link);
 187        call_rcu(&pci->rcu, complete_edac_pci_list_del);
 188        rcu_barrier();
 189}
 190
 191#if 0
 192/* Older code, but might use in the future */
 193
 194/*
 195 * edac_pci_find()
 196 *      Search for an edac_pci_ctl_info structure whose index is 'idx'
 197 *
 198 * If found, return a pointer to the structure
 199 * Else return NULL.
 200 *
 201 * Caller must hold pci_ctls_mutex.
 202 */
 203struct edac_pci_ctl_info *edac_pci_find(int idx)
 204{
 205        struct list_head *item;
 206        struct edac_pci_ctl_info *pci;
 207
 208        /* Iterage over list, looking for exact match of ID */
 209        list_for_each(item, &edac_pci_list) {
 210                pci = list_entry(item, struct edac_pci_ctl_info, link);
 211
 212                if (pci->pci_idx >= idx) {
 213                        if (pci->pci_idx == idx)
 214                                return pci;
 215
 216                        /* not on list, so terminate early */
 217                        break;
 218                }
 219        }
 220
 221        return NULL;
 222}
 223EXPORT_SYMBOL_GPL(edac_pci_find);
 224#endif
 225
 226/*
 227 * edac_pci_workq_function()
 228 *
 229 *      periodic function that performs the operation
 230 *      scheduled by a workq request, for a given PCI control struct
 231 */
 232static void edac_pci_workq_function(struct work_struct *work_req)
 233{
 234        struct delayed_work *d_work = to_delayed_work(work_req);
 235        struct edac_pci_ctl_info *pci = to_edac_pci_ctl_work(d_work);
 236        int msec;
 237        unsigned long delay;
 238
 239        debugf3("%s() checking\n", __func__);
 240
 241        mutex_lock(&edac_pci_ctls_mutex);
 242
 243        if (pci->op_state == OP_RUNNING_POLL) {
 244                /* we might be in POLL mode, but there may NOT be a poll func
 245                 */
 246                if ((pci->edac_check != NULL) && edac_pci_get_check_errors())
 247                        pci->edac_check(pci);
 248
 249                /* if we are on a one second period, then use round */
 250                msec = edac_pci_get_poll_msec();
 251                if (msec == 1000)
 252                        delay = round_jiffies_relative(msecs_to_jiffies(msec));
 253                else
 254                        delay = msecs_to_jiffies(msec);
 255
 256                /* Reschedule only if we are in POLL mode */
 257                queue_delayed_work(edac_workqueue, &pci->work, delay);
 258        }
 259
 260        mutex_unlock(&edac_pci_ctls_mutex);
 261}
 262
 263/*
 264 * edac_pci_workq_setup()
 265 *      initialize a workq item for this edac_pci instance
 266 *      passing in the new delay period in msec
 267 *
 268 *      locking model:
 269 *              called when 'edac_pci_ctls_mutex' is locked
 270 */
 271static void edac_pci_workq_setup(struct edac_pci_ctl_info *pci,
 272                                 unsigned int msec)
 273{
 274        debugf0("%s()\n", __func__);
 275
 276        INIT_DELAYED_WORK(&pci->work, edac_pci_workq_function);
 277        queue_delayed_work(edac_workqueue, &pci->work,
 278                        msecs_to_jiffies(edac_pci_get_poll_msec()));
 279}
 280
 281/*
 282 * edac_pci_workq_teardown()
 283 *      stop the workq processing on this edac_pci instance
 284 */
 285static void edac_pci_workq_teardown(struct edac_pci_ctl_info *pci)
 286{
 287        int status;
 288
 289        debugf0("%s()\n", __func__);
 290
 291        status = cancel_delayed_work(&pci->work);
 292        if (status == 0)
 293                flush_workqueue(edac_workqueue);
 294}
 295
 296/*
 297 * edac_pci_reset_delay_period
 298 *
 299 *      called with a new period value for the workq period
 300 *      a) stop current workq timer
 301 *      b) restart workq timer with new value
 302 */
 303void edac_pci_reset_delay_period(struct edac_pci_ctl_info *pci,
 304                                 unsigned long value)
 305{
 306        debugf0("%s()\n", __func__);
 307
 308        edac_pci_workq_teardown(pci);
 309
 310        /* need to lock for the setup */
 311        mutex_lock(&edac_pci_ctls_mutex);
 312
 313        edac_pci_workq_setup(pci, value);
 314
 315        mutex_unlock(&edac_pci_ctls_mutex);
 316}
 317EXPORT_SYMBOL_GPL(edac_pci_reset_delay_period);
 318
 319/*
 320 * edac_pci_alloc_index: Allocate a unique PCI index number
 321 *
 322 * Return:
 323 *      allocated index number
 324 *
 325 */
 326int edac_pci_alloc_index(void)
 327{
 328        return atomic_inc_return(&pci_indexes) - 1;
 329}
 330EXPORT_SYMBOL_GPL(edac_pci_alloc_index);
 331
 332/*
 333 * edac_pci_add_device: Insert the 'edac_dev' structure into the
 334 * edac_pci global list and create sysfs entries associated with
 335 * edac_pci structure.
 336 * @pci: pointer to the edac_device structure to be added to the list
 337 * @edac_idx: A unique numeric identifier to be assigned to the
 338 * 'edac_pci' structure.
 339 *
 340 * Return:
 341 *      0       Success
 342 *      !0      Failure
 343 */
 344int edac_pci_add_device(struct edac_pci_ctl_info *pci, int edac_idx)
 345{
 346        debugf0("%s()\n", __func__);
 347
 348        pci->pci_idx = edac_idx;
 349        pci->start_time = jiffies;
 350
 351        mutex_lock(&edac_pci_ctls_mutex);
 352
 353        if (add_edac_pci_to_global_list(pci))
 354                goto fail0;
 355
 356        if (edac_pci_create_sysfs(pci)) {
 357                edac_pci_printk(pci, KERN_WARNING,
 358                                "failed to create sysfs pci\n");
 359                goto fail1;
 360        }
 361
 362        if (pci->edac_check != NULL) {
 363                pci->op_state = OP_RUNNING_POLL;
 364
 365                edac_pci_workq_setup(pci, 1000);
 366        } else {
 367                pci->op_state = OP_RUNNING_INTERRUPT;
 368        }
 369
 370        edac_pci_printk(pci, KERN_INFO,
 371                        "Giving out device to module '%s' controller '%s':"
 372                        " DEV '%s' (%s)\n",
 373                        pci->mod_name,
 374                        pci->ctl_name,
 375                        edac_dev_name(pci), edac_op_state_to_string(pci->op_state));
 376
 377        mutex_unlock(&edac_pci_ctls_mutex);
 378        return 0;
 379
 380        /* error unwind stack */
 381fail1:
 382        del_edac_pci_from_global_list(pci);
 383fail0:
 384        mutex_unlock(&edac_pci_ctls_mutex);
 385        return 1;
 386}
 387EXPORT_SYMBOL_GPL(edac_pci_add_device);
 388
 389/*
 390 * edac_pci_del_device()
 391 *      Remove sysfs entries for specified edac_pci structure and
 392 *      then remove edac_pci structure from global list
 393 *
 394 * @dev:
 395 *      Pointer to 'struct device' representing edac_pci structure
 396 *      to remove
 397 *
 398 * Return:
 399 *      Pointer to removed edac_pci structure,
 400 *      or NULL if device not found
 401 */
 402struct edac_pci_ctl_info *edac_pci_del_device(struct device *dev)
 403{
 404        struct edac_pci_ctl_info *pci;
 405
 406        debugf0("%s()\n", __func__);
 407
 408        mutex_lock(&edac_pci_ctls_mutex);
 409
 410        /* ensure the control struct is on the global list
 411         * if not, then leave
 412         */
 413        pci = find_edac_pci_by_dev(dev);
 414        if (pci  == NULL) {
 415                mutex_unlock(&edac_pci_ctls_mutex);
 416                return NULL;
 417        }
 418
 419        pci->op_state = OP_OFFLINE;
 420
 421        del_edac_pci_from_global_list(pci);
 422
 423        mutex_unlock(&edac_pci_ctls_mutex);
 424
 425        /* stop the workq timer */
 426        edac_pci_workq_teardown(pci);
 427
 428        edac_printk(KERN_INFO, EDAC_PCI,
 429                "Removed device %d for %s %s: DEV %s\n",
 430                pci->pci_idx, pci->mod_name, pci->ctl_name, edac_dev_name(pci));
 431
 432        return pci;
 433}
 434EXPORT_SYMBOL_GPL(edac_pci_del_device);
 435
 436/*
 437 * edac_pci_generic_check
 438 *
 439 *      a Generic parity check API
 440 */
 441static void edac_pci_generic_check(struct edac_pci_ctl_info *pci)
 442{
 443        debugf4("%s()\n", __func__);
 444        edac_pci_do_parity_check();
 445}
 446
 447/* free running instance index counter */
 448static int edac_pci_idx;
 449#define EDAC_PCI_GENCTL_NAME    "EDAC PCI controller"
 450
 451struct edac_pci_gen_data {
 452        int edac_idx;
 453};
 454
 455/*
 456 * edac_pci_create_generic_ctl
 457 *
 458 *      A generic constructor for a PCI parity polling device
 459 *      Some systems have more than one domain of PCI busses.
 460 *      For systems with one domain, then this API will
 461 *      provide for a generic poller.
 462 *
 463 *      This routine calls the edac_pci_alloc_ctl_info() for
 464 *      the generic device, with default values
 465 */
 466struct edac_pci_ctl_info *edac_pci_create_generic_ctl(struct device *dev,
 467                                                const char *mod_name)
 468{
 469        struct edac_pci_ctl_info *pci;
 470        struct edac_pci_gen_data *pdata;
 471
 472        pci = edac_pci_alloc_ctl_info(sizeof(*pdata), EDAC_PCI_GENCTL_NAME);
 473        if (!pci)
 474                return NULL;
 475
 476        pdata = pci->pvt_info;
 477        pci->dev = dev;
 478        dev_set_drvdata(pci->dev, pci);
 479        pci->dev_name = pci_name(to_pci_dev(dev));
 480
 481        pci->mod_name = mod_name;
 482        pci->ctl_name = EDAC_PCI_GENCTL_NAME;
 483        pci->edac_check = edac_pci_generic_check;
 484
 485        pdata->edac_idx = edac_pci_idx++;
 486
 487        if (edac_pci_add_device(pci, pdata->edac_idx) > 0) {
 488                debugf3("%s(): failed edac_pci_add_device()\n", __func__);
 489                edac_pci_free_ctl_info(pci);
 490                return NULL;
 491        }
 492
 493        return pci;
 494}
 495EXPORT_SYMBOL_GPL(edac_pci_create_generic_ctl);
 496
 497/*
 498 * edac_pci_release_generic_ctl
 499 *
 500 *      The release function of a generic EDAC PCI polling device
 501 */
 502void edac_pci_release_generic_ctl(struct edac_pci_ctl_info *pci)
 503{
 504        debugf0("%s() pci mod=%s\n", __func__, pci->mod_name);
 505
 506        edac_pci_del_device(pci->dev);
 507        edac_pci_free_ctl_info(pci);
 508}
 509EXPORT_SYMBOL_GPL(edac_pci_release_generic_ctl);
 510