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 /*
 182  * edac_pci_workq_function()
 183  *
 184  *      periodic function that performs the operation
 185  *      scheduled by a workq request, for a given PCI control struct
 186  */
 187 static void edac_pci_workq_function(struct work_struct *work_req)
 188 {
 189         struct delayed_work *d_work = to_delayed_work(work_req);
 190         struct edac_pci_ctl_info *pci = to_edac_pci_ctl_work(d_work);
 191         int msec;
 192         unsigned long delay;
 193
 194         edac_dbg(3, "checking\n");
 195
 196         mutex_lock(&edac_pci_ctls_mutex);
 197
 198         if (pci->op_state == OP_RUNNING_POLL) {
 199                 /* we might be in POLL mode, but there may NOT be a poll func
 200                  */
 201                 if ((pci->edac_check != NULL) && edac_pci_get_check_errors())
 202                         pci->edac_check(pci);
 203
 204                 /* if we are on a one second period, then use round */
 205                 msec = edac_pci_get_poll_msec();
 206                 if (msec == 1000)
 207                         delay = round_jiffies_relative(msecs_to_jiffies(msec));
 208                 else
 209                         delay = msecs_to_jiffies(msec);
 210
 211                 /* Reschedule only if we are in POLL mode */
 212                 edac_queue_work(&pci->work, delay);
 213         }
 214
 215         mutex_unlock(&edac_pci_ctls_mutex);
 216 }
 217
 218 /*
 219  * edac_pci_workq_setup()
 220  *      initialize a workq item for this edac_pci instance
 221  *      passing in the new delay period in msec
 222  *
 223  *      locking model:
 224  *              called when 'edac_pci_ctls_mutex' is locked
 225  */
 226 static void edac_pci_workq_setup(struct edac_pci_ctl_info *pci,
 227                                  unsigned int msec)
 228 {
 229         edac_dbg(0, "\n");
 230
 231         INIT_DELAYED_WORK(&pci->work, edac_pci_workq_function);
 232
 233         edac_queue_work(&pci->work, msecs_to_jiffies(edac_pci_get_poll_msec()));
 234 }
 235
 236 /*
 237  * edac_pci_workq_teardown()
 238  *      stop the workq processing on this edac_pci instance
 239  */
 240 static void edac_pci_workq_teardown(struct edac_pci_ctl_info *pci)
 241 {
 242         edac_dbg(0, "\n");
 243
 244         pci->op_state = OP_OFFLINE;
 245
 246         edac_stop_work(&pci->work);
 247 }
 248
 249 /*
 250  * edac_pci_alloc_index: Allocate a unique PCI index number
 251  *
 252  * Return:
 253  *      allocated index number
 254  *
 255  */
 256 int edac_pci_alloc_index(void)
 257 {
 258         return atomic_inc_return(&pci_indexes) - 1;
 259 }
 260 EXPORT_SYMBOL_GPL(edac_pci_alloc_index);
 261
 262 /*
 263  * edac_pci_add_device: Insert the 'edac_dev' structure into the
 264  * edac_pci global list and create sysfs entries associated with
 265  * edac_pci structure.
 266  * @pci: pointer to the edac_device structure to be added to the list
 267  * @edac_idx: A unique numeric identifier to be assigned to the
 268  * 'edac_pci' structure.
 269  *
 270  * Return:
 271  *      0       Success
 272  *      !0      Failure
 273  */
 274 int edac_pci_add_device(struct edac_pci_ctl_info *pci, int edac_idx)
 275 {
 276         edac_dbg(0, "\n");
 277
 278         pci->pci_idx = edac_idx;
 279         pci->start_time = jiffies;
 280
 281         mutex_lock(&edac_pci_ctls_mutex);
 282
 283         if (add_edac_pci_to_global_list(pci))
 284                 goto fail0;
 285
 286         if (edac_pci_create_sysfs(pci)) {
 287                 edac_pci_printk(pci, KERN_WARNING,
 288                                 "failed to create sysfs pci\n");
 289                 goto fail1;
 290         }
 291
 292         if (pci->edac_check != NULL) {
 293                 pci->op_state = OP_RUNNING_POLL;
 294
 295                 edac_pci_workq_setup(pci, 1000);
 296         } else {
 297                 pci->op_state = OP_RUNNING_INTERRUPT;
 298         }
 299
 300         edac_pci_printk(pci, KERN_INFO,
 301                 "Giving out device to module %s controller %s: DEV %s (%s)\n",
 302                 pci->mod_name, pci->ctl_name, pci->dev_name,
 303                 edac_op_state_to_string(pci->op_state));
 304
 305         mutex_unlock(&edac_pci_ctls_mutex);
 306         return 0;
 307
 308         /* error unwind stack */
 309 fail1:
 310         del_edac_pci_from_global_list(pci);
 311 fail0:
 312         mutex_unlock(&edac_pci_ctls_mutex);
 313         return 1;
 314 }
 315 EXPORT_SYMBOL_GPL(edac_pci_add_device);
 316
 317 /*
 318  * edac_pci_del_device()
 319  *      Remove sysfs entries for specified edac_pci structure and
 320  *      then remove edac_pci structure from global list
 321  *
 322  * @dev:
 323  *      Pointer to 'struct device' representing edac_pci structure
 324  *      to remove
 325  *
 326  * Return:
 327  *      Pointer to removed edac_pci structure,
 328  *      or NULL if device not found
 329  */
 330 struct edac_pci_ctl_info *edac_pci_del_device(struct device *dev)
 331 {
 332         struct edac_pci_ctl_info *pci;
 333
 334         edac_dbg(0, "\n");
 335
 336         mutex_lock(&edac_pci_ctls_mutex);
 337
 338         /* ensure the control struct is on the global list
 339          * if not, then leave
 340          */
 341         pci = find_edac_pci_by_dev(dev);
 342         if (pci  == NULL) {
 343                 mutex_unlock(&edac_pci_ctls_mutex);
 344                 return NULL;
 345         }
 346
 347         pci->op_state = OP_OFFLINE;
 348
 349         del_edac_pci_from_global_list(pci);
 350
 351         mutex_unlock(&edac_pci_ctls_mutex);
 352
 353         /* stop the workq timer */
 354         edac_pci_workq_teardown(pci);
 355
 356         edac_printk(KERN_INFO, EDAC_PCI,
 357                 "Removed device %d for %s %s: DEV %s\n",
 358                 pci->pci_idx, pci->mod_name, pci->ctl_name, edac_dev_name(pci));
 359
 360         return pci;
 361 }
 362 EXPORT_SYMBOL_GPL(edac_pci_del_device);
 363
 364 /*
 365  * edac_pci_generic_check
 366  *
 367  *      a Generic parity check API
 368  */
 369 static void edac_pci_generic_check(struct edac_pci_ctl_info *pci)
 370 {
 371         edac_dbg(4, "\n");
 372         edac_pci_do_parity_check();
 373 }
 374
 375 /* free running instance index counter */
 376 static int edac_pci_idx;
 377 #define EDAC_PCI_GENCTL_NAME    "EDAC PCI controller"
 378
 379 struct edac_pci_gen_data {
 380         int edac_idx;
 381 };
 382
 383 /*
 384  * edac_pci_create_generic_ctl
 385  *
 386  *      A generic constructor for a PCI parity polling device
 387  *      Some systems have more than one domain of PCI busses.
 388  *      For systems with one domain, then this API will
 389  *      provide for a generic poller.
 390  *
 391  *      This routine calls the edac_pci_alloc_ctl_info() for
 392  *      the generic device, with default values
 393  */
 394 struct edac_pci_ctl_info *edac_pci_create_generic_ctl(struct device *dev,
 395                                                 const char *mod_name)
 396 {
 397         struct edac_pci_ctl_info *pci;
 398         struct edac_pci_gen_data *pdata;
 399
 400         pci = edac_pci_alloc_ctl_info(sizeof(*pdata), EDAC_PCI_GENCTL_NAME);
 401         if (!pci)
 402                 return NULL;
 403
 404         pdata = pci->pvt_info;
 405         pci->dev = dev;
 406         dev_set_drvdata(pci->dev, pci);
 407         pci->dev_name = pci_name(to_pci_dev(dev));
 408
 409         pci->mod_name = mod_name;
 410         pci->ctl_name = EDAC_PCI_GENCTL_NAME;
 411         if (edac_op_state == EDAC_OPSTATE_POLL)
 412                 pci->edac_check = edac_pci_generic_check;
 413
 414         pdata->edac_idx = edac_pci_idx++;
 415
 416         if (edac_pci_add_device(pci, pdata->edac_idx) > 0) {
 417                 edac_dbg(3, "failed edac_pci_add_device()\n");
 418                 edac_pci_free_ctl_info(pci);
 419                 return NULL;
 420         }
 421
 422         return pci;
 423 }
 424 EXPORT_SYMBOL_GPL(edac_pci_create_generic_ctl);
 425
 426 /*
 427  * edac_pci_release_generic_ctl
 428  *
 429  *      The release function of a generic EDAC PCI polling device
 430  */
 431 void edac_pci_release_generic_ctl(struct edac_pci_ctl_info *pci)
 432 {
 433         edac_dbg(0, "pci mod=%s\n", pci->mod_name);
 434
 435         edac_pci_del_device(pci->dev);
 436         edac_pci_free_ctl_info(pci);
 437 }
 438 EXPORT_SYMBOL_GPL(edac_pci_release_generic_ctl);