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/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);
  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 *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}
  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        debugf1("%s()\n", __func__);
  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        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 */
 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        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
 150fail0:
 151        edac_printk(KERN_WARNING, EDAC_PCI,
 152                "%s (%s) %s %s already assigned %d\n",
 153                rover->dev->bus_id, 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 * complete_edac_pci_list_del
 167 *
 168 *      RCU completion callback to indicate item is deleted
 169 */
 170static 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 */
 184static 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#if 0
 193/* Older code, but might use in the future */
 194
 195/*
 196 * edac_pci_find()
 197 *      Search for an edac_pci_ctl_info structure whose index is 'idx'
 198 *
 199 * If found, return a pointer to the structure
 200 * Else return NULL.
 201 *
 202 * Caller must hold pci_ctls_mutex.
 203 */
 204struct edac_pci_ctl_info *edac_pci_find(int idx)
 205{
 206        struct list_head *item;
 207        struct edac_pci_ctl_info *pci;
 208
 209        /* Iterage over list, looking for exact match of ID */
 210        list_for_each(item, &edac_pci_list) {
 211                pci = list_entry(item, struct edac_pci_ctl_info, link);
 212
 213                if (pci->pci_idx >= idx) {
 214                        if (pci->pci_idx == idx)
 215                                return pci;
 216
 217                        /* not on list, so terminate early */
 218                        break;
 219                }
 220        }
 221
 222        return NULL;
 223}
 224EXPORT_SYMBOL_GPL(edac_pci_find);
 225#endif
 226
 227/*
 228 * edac_pci_workq_function()
 229 *
 230 *      periodic function that performs the operation
 231 *      scheduled by a workq request, for a given PCI control struct
 232 */
 233static void edac_pci_workq_function(struct work_struct *work_req)
 234{
 235        struct delayed_work *d_work = (struct delayed_work *)work_req;
 236        struct edac_pci_ctl_info *pci = to_edac_pci_ctl_work(d_work);
 237        int msec;
 238        unsigned long delay;
 239
 240        debugf3("%s() checking\n", __func__);
 241
 242        mutex_lock(&edac_pci_ctls_mutex);
 243
 244        if (pci->op_state == OP_RUNNING_POLL) {
 245                /* we might be in POLL mode, but there may NOT be a poll func
 246                 */
 247                if ((pci->edac_check != NULL) && edac_pci_get_check_errors())
 248                        pci->edac_check(pci);
 249
 250                /* if we are on a one second period, then use round */
 251                msec = edac_pci_get_poll_msec();
 252                if (msec == 1000)
 253                        delay = round_jiffies_relative(msecs_to_jiffies(msec));
 254                else
 255                        delay = msecs_to_jiffies(msec);
 256
 257                /* Reschedule only if we are in POLL mode */
 258                queue_delayed_work(edac_workqueue, &pci->work, delay);
 259        }
 260
 261        mutex_unlock(&edac_pci_ctls_mutex);
 262}
 263
 264/*
 265 * edac_pci_workq_setup()
 266 *      initialize a workq item for this edac_pci instance
 267 *      passing in the new delay period in msec
 268 *
 269 *      locking model:
 270 *              called when 'edac_pci_ctls_mutex' is locked
 271 */
 272static void edac_pci_workq_setup(struct edac_pci_ctl_info *pci,
 273                                 unsigned int msec)
 274{
 275        debugf0("%s()\n", __func__);
 276
 277        INIT_DELAYED_WORK(&pci->work, edac_pci_workq_function);
 278        queue_delayed_work(edac_workqueue, &pci->work,
 279                        msecs_to_jiffies(edac_pci_get_poll_msec()));
 280}
 281
 282/*
 283 * edac_pci_workq_teardown()
 284 *      stop the workq processing on this edac_pci instance
 285 */
 286static void edac_pci_workq_teardown(struct edac_pci_ctl_info *pci)
 287{
 288        int status;
 289
 290        debugf0("%s()\n", __func__);
 291
 292        status = cancel_delayed_work(&pci->work);
 293        if (status == 0)
 294                flush_workqueue(edac_workqueue);
 295}
 296
 297/*
 298 * edac_pci_reset_delay_period
 299 *
 300 *      called with a new period value for the workq period
 301 *      a) stop current workq timer
 302 *      b) restart workq timer with new value
 303 */
 304void edac_pci_reset_delay_period(struct edac_pci_ctl_info *pci,
 305                                 unsigned long value)
 306{
 307        debugf0("%s()\n", __func__);
 308
 309        edac_pci_workq_teardown(pci);
 310
 311        /* need to lock for the setup */
 312        mutex_lock(&edac_pci_ctls_mutex);
 313
 314        edac_pci_workq_setup(pci, value);
 315
 316        mutex_unlock(&edac_pci_ctls_mutex);
 317}
 318EXPORT_SYMBOL_GPL(edac_pci_reset_delay_period);
 319
 320/*
 321 * edac_pci_add_device: Insert the 'edac_dev' structure into the
 322 * edac_pci global list and create sysfs entries associated with
 323 * edac_pci structure.
 324 * @pci: pointer to the edac_device structure to be added to the list
 325 * @edac_idx: A unique numeric identifier to be assigned to the
 326 * 'edac_pci' structure.
 327 *
 328 * Return:
 329 *      0       Success
 330 *      !0      Failure
 331 */
 332int edac_pci_add_device(struct edac_pci_ctl_info *pci, int edac_idx)
 333{
 334        debugf0("%s()\n", __func__);
 335
 336        pci->pci_idx = edac_idx;
 337        pci->start_time = jiffies;
 338
 339        mutex_lock(&edac_pci_ctls_mutex);
 340
 341        if (add_edac_pci_to_global_list(pci))
 342                goto fail0;
 343
 344        if (edac_pci_create_sysfs(pci)) {
 345                edac_pci_printk(pci, KERN_WARNING,
 346                                "failed to create sysfs pci\n");
 347                goto fail1;
 348        }
 349
 350        if (pci->edac_check != NULL) {
 351                pci->op_state = OP_RUNNING_POLL;
 352
 353                edac_pci_workq_setup(pci, 1000);
 354        } else {
 355                pci->op_state = OP_RUNNING_INTERRUPT;
 356        }
 357
 358        edac_pci_printk(pci, KERN_INFO,
 359                        "Giving out device to module '%s' controller '%s':"
 360                        " DEV '%s' (%s)\n",
 361                        pci->mod_name,
 362                        pci->ctl_name,
 363                        edac_dev_name(pci), edac_op_state_to_string(pci->op_state));
 364
 365        mutex_unlock(&edac_pci_ctls_mutex);
 366        return 0;
 367
 368        /* error unwind stack */
 369fail1:
 370        del_edac_pci_from_global_list(pci);
 371fail0:
 372        mutex_unlock(&edac_pci_ctls_mutex);
 373        return 1;
 374}
 375EXPORT_SYMBOL_GPL(edac_pci_add_device);
 376
 377/*
 378 * edac_pci_del_device()
 379 *      Remove sysfs entries for specified edac_pci structure and
 380 *      then remove edac_pci structure from global list
 381 *
 382 * @dev:
 383 *      Pointer to 'struct device' representing edac_pci structure
 384 *      to remove
 385 *
 386 * Return:
 387 *      Pointer to removed edac_pci structure,
 388 *      or NULL if device not found
 389 */
 390struct edac_pci_ctl_info *edac_pci_del_device(struct device *dev)
 391{
 392        struct edac_pci_ctl_info *pci;
 393
 394        debugf0("%s()\n", __func__);
 395
 396        mutex_lock(&edac_pci_ctls_mutex);
 397
 398        /* ensure the control struct is on the global list
 399         * if not, then leave
 400         */
 401        pci = find_edac_pci_by_dev(dev);
 402        if (pci  == NULL) {
 403                mutex_unlock(&edac_pci_ctls_mutex);
 404                return NULL;
 405        }
 406
 407        pci->op_state = OP_OFFLINE;
 408
 409        del_edac_pci_from_global_list(pci);
 410
 411        mutex_unlock(&edac_pci_ctls_mutex);
 412
 413        /* stop the workq timer */
 414        edac_pci_workq_teardown(pci);
 415
 416        edac_printk(KERN_INFO, EDAC_PCI,
 417                "Removed device %d for %s %s: DEV %s\n",
 418                pci->pci_idx, pci->mod_name, pci->ctl_name, edac_dev_name(pci));
 419
 420        return pci;
 421}
 422EXPORT_SYMBOL_GPL(edac_pci_del_device);
 423
 424/*
 425 * edac_pci_generic_check
 426 *
 427 *      a Generic parity check API
 428 */
 429static void edac_pci_generic_check(struct edac_pci_ctl_info *pci)
 430{
 431        debugf4("%s()\n", __func__);
 432        edac_pci_do_parity_check();
 433}
 434
 435/* free running instance index counter */
 436static int edac_pci_idx;
 437#define EDAC_PCI_GENCTL_NAME    "EDAC PCI controller"
 438
 439struct edac_pci_gen_data {
 440        int edac_idx;
 441};
 442
 443/*
 444 * edac_pci_create_generic_ctl
 445 *
 446 *      A generic constructor for a PCI parity polling device
 447 *      Some systems have more than one domain of PCI busses.
 448 *      For systems with one domain, then this API will
 449 *      provide for a generic poller.
 450 *
 451 *      This routine calls the edac_pci_alloc_ctl_info() for
 452 *      the generic device, with default values
 453 */
 454struct edac_pci_ctl_info *edac_pci_create_generic_ctl(struct device *dev,
 455                                                const char *mod_name)
 456{
 457        struct edac_pci_ctl_info *pci;
 458        struct edac_pci_gen_data *pdata;
 459
 460        pci = edac_pci_alloc_ctl_info(sizeof(*pdata), EDAC_PCI_GENCTL_NAME);
 461        if (!pci)
 462                return NULL;
 463
 464        pdata = pci->pvt_info;
 465        pci->dev = dev;
 466        dev_set_drvdata(pci->dev, pci);
 467        pci->dev_name = pci_name(to_pci_dev(dev));
 468
 469        pci->mod_name = mod_name;
 470        pci->ctl_name = EDAC_PCI_GENCTL_NAME;
 471        pci->edac_check = edac_pci_generic_check;
 472
 473        pdata->edac_idx = edac_pci_idx++;
 474
 475        if (edac_pci_add_device(pci, pdata->edac_idx) > 0) {
 476                debugf3("%s(): failed edac_pci_add_device()\n", __func__);
 477                edac_pci_free_ctl_info(pci);
 478                return NULL;
 479        }
 480
 481        return pci;
 482}
 483EXPORT_SYMBOL_GPL(edac_pci_create_generic_ctl);
 484
 485/*
 486 * edac_pci_release_generic_ctl
 487 *
 488 *      The release function of a generic EDAC PCI polling device
 489 */
 490void edac_pci_release_generic_ctl(struct edac_pci_ctl_info *pci)
 491{
 492        debugf0("%s() pci mod=%s\n", __func__, pci->mod_name);
 493
 494        edac_pci_del_device(pci->dev);
 495        edac_pci_free_ctl_info(pci);
 496}
 497EXPORT_SYMBOL_GPL(edac_pci_release_generic_ctl);
 498