linux/drivers/edac/edac_pci.c
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   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
  30static DEFINE_MUTEX(edac_pci_ctls_mutex);
  31static LIST_HEAD(edac_pci_list);
  32static 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 */
  41struct 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}
  69EXPORT_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 */
  81void 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}
  87EXPORT_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 */
  95static 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 */
 120static 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
 150fail0:
 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
 157fail1:
 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 */
 170static 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 */
 193struct 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}
 213EXPORT_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 */
 222static 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 */
 261static 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 */
 275static 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 */
 293void 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}
 307EXPORT_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 */
 316int edac_pci_alloc_index(void)
 317{
 318        return atomic_inc_return(&pci_indexes) - 1;
 319}
 320EXPORT_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 */
 334int 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 */
 371fail1:
 372        del_edac_pci_from_global_list(pci);
 373fail0:
 374        mutex_unlock(&edac_pci_ctls_mutex);
 375        return 1;
 376}
 377EXPORT_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 */
 392struct 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}
 424EXPORT_SYMBOL_GPL(edac_pci_del_device);
 425
 426/*
 427 * edac_pci_generic_check
 428 *
 429 *      a Generic parity check API
 430 */
 431static 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 */
 438static int edac_pci_idx;
 439#define EDAC_PCI_GENCTL_NAME    "EDAC PCI controller"
 440
 441struct 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 */
 456struct 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        if (edac_op_state == EDAC_OPSTATE_POLL)
 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                edac_dbg(3, "failed edac_pci_add_device()\n");
 480                edac_pci_free_ctl_info(pci);
 481                return NULL;
 482        }
 483
 484        return pci;
 485}
 486EXPORT_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 */
 493void edac_pci_release_generic_ctl(struct edac_pci_ctl_info *pci)
 494{
 495        edac_dbg(0, "pci mod=%s\n", pci->mod_name);
 496
 497        edac_pci_del_device(pci->dev);
 498        edac_pci_free_ctl_info(pci);
 499}
 500EXPORT_SYMBOL_GPL(edac_pci_release_generic_ctl);
 501
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