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