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 31 static DEFINE_MUTEX(edac_pci_ctls_mutex); 32 static LIST_HEAD(edac_pci_list); 33 static 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 */ 42 struct 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 } 70 EXPORT_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 */ 82 void 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 } 88 EXPORT_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 */ 96 static 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 */ 121 static 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; 150 151 fail0: 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; 157 158 fail1: 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 */ 171 static 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 complete(&pci->complete); 178 } 179 180 /* 181 * del_edac_pci_from_global_list 182 * 183 * remove the PCI control struct from the global list 184 */ 185 static void del_edac_pci_from_global_list(struct edac_pci_ctl_info *pci) 186 { 187 list_del_rcu(&pci->link); 188 init_completion(&pci->complete); 189 call_rcu(&pci->rcu, complete_edac_pci_list_del); 190 wait_for_completion(&pci->complete); 191 } 192 193 #if 0 194 /* Older code, but might use in the future */ 195 196 /* 197 * edac_pci_find() 198 * Search for an edac_pci_ctl_info structure whose index is 'idx' 199 * 200 * If found, return a pointer to the structure 201 * Else return NULL. 202 * 203 * Caller must hold pci_ctls_mutex. 204 */ 205 struct edac_pci_ctl_info *edac_pci_find(int idx) 206 { 207 struct list_head *item; 208 struct edac_pci_ctl_info *pci; 209 210 /* Iterage over list, looking for exact match of ID */ 211 list_for_each(item, &edac_pci_list) { 212 pci = list_entry(item, struct edac_pci_ctl_info, link); 213 214 if (pci->pci_idx >= idx) { 215 if (pci->pci_idx == idx) 216 return pci; 217 218 /* not on list, so terminate early */ 219 break; 220 } 221 } 222 223 return NULL; 224 } 225 EXPORT_SYMBOL_GPL(edac_pci_find); 226 #endif 227 228 /* 229 * edac_pci_workq_function() 230 * 231 * periodic function that performs the operation 232 * scheduled by a workq request, for a given PCI control struct 233 */ 234 static void edac_pci_workq_function(struct work_struct *work_req) 235 { 236 struct delayed_work *d_work = to_delayed_work(work_req); 237 struct edac_pci_ctl_info *pci = to_edac_pci_ctl_work(d_work); 238 int msec; 239 unsigned long delay; 240 241 debugf3("%s() checking\n", __func__); 242 243 mutex_lock(&edac_pci_ctls_mutex); 244 245 if (pci->op_state == OP_RUNNING_POLL) { 246 /* we might be in POLL mode, but there may NOT be a poll func 247 */ 248 if ((pci->edac_check != NULL) && edac_pci_get_check_errors()) 249 pci->edac_check(pci); 250 251 /* if we are on a one second period, then use round */ 252 msec = edac_pci_get_poll_msec(); 253 if (msec == 1000) 254 delay = round_jiffies_relative(msecs_to_jiffies(msec)); 255 else 256 delay = msecs_to_jiffies(msec); 257 258 /* Reschedule only if we are in POLL mode */ 259 queue_delayed_work(edac_workqueue, &pci->work, delay); 260 } 261 262 mutex_unlock(&edac_pci_ctls_mutex); 263 } 264 265 /* 266 * edac_pci_workq_setup() 267 * initialize a workq item for this edac_pci instance 268 * passing in the new delay period in msec 269 * 270 * locking model: 271 * called when 'edac_pci_ctls_mutex' is locked 272 */ 273 static void edac_pci_workq_setup(struct edac_pci_ctl_info *pci, 274 unsigned int msec) 275 { 276 debugf0("%s()\n", __func__); 277 278 INIT_DELAYED_WORK(&pci->work, edac_pci_workq_function); 279 queue_delayed_work(edac_workqueue, &pci->work, 280 msecs_to_jiffies(edac_pci_get_poll_msec())); 281 } 282 283 /* 284 * edac_pci_workq_teardown() 285 * stop the workq processing on this edac_pci instance 286 */ 287 static void edac_pci_workq_teardown(struct edac_pci_ctl_info *pci) 288 { 289 int status; 290 291 debugf0("%s()\n", __func__); 292 293 status = cancel_delayed_work(&pci->work); 294 if (status == 0) 295 flush_workqueue(edac_workqueue); 296 } 297 298 /* 299 * edac_pci_reset_delay_period 300 * 301 * called with a new period value for the workq period 302 * a) stop current workq timer 303 * b) restart workq timer with new value 304 */ 305 void edac_pci_reset_delay_period(struct edac_pci_ctl_info *pci, 306 unsigned long value) 307 { 308 debugf0("%s()\n", __func__); 309 310 edac_pci_workq_teardown(pci); 311 312 /* need to lock for the setup */ 313 mutex_lock(&edac_pci_ctls_mutex); 314 315 edac_pci_workq_setup(pci, value); 316 317 mutex_unlock(&edac_pci_ctls_mutex); 318 } 319 EXPORT_SYMBOL_GPL(edac_pci_reset_delay_period); 320 321 /* 322 * edac_pci_alloc_index: Allocate a unique PCI index number 323 * 324 * Return: 325 * allocated index number 326 * 327 */ 328 int edac_pci_alloc_index(void) 329 { 330 return atomic_inc_return(&pci_indexes) - 1; 331 } 332 EXPORT_SYMBOL_GPL(edac_pci_alloc_index); 333 334 /* 335 * edac_pci_add_device: Insert the 'edac_dev' structure into the 336 * edac_pci global list and create sysfs entries associated with 337 * edac_pci structure. 338 * @pci: pointer to the edac_device structure to be added to the list 339 * @edac_idx: A unique numeric identifier to be assigned to the 340 * 'edac_pci' structure. 341 * 342 * Return: 343 * 0 Success 344 * !0 Failure 345 */ 346 int edac_pci_add_device(struct edac_pci_ctl_info *pci, int edac_idx) 347 { 348 debugf0("%s()\n", __func__); 349 350 pci->pci_idx = edac_idx; 351 pci->start_time = jiffies; 352 353 mutex_lock(&edac_pci_ctls_mutex); 354 355 if (add_edac_pci_to_global_list(pci)) 356 goto fail0; 357 358 if (edac_pci_create_sysfs(pci)) { 359 edac_pci_printk(pci, KERN_WARNING, 360 "failed to create sysfs pci\n"); 361 goto fail1; 362 } 363 364 if (pci->edac_check != NULL) { 365 pci->op_state = OP_RUNNING_POLL; 366 367 edac_pci_workq_setup(pci, 1000); 368 } else { 369 pci->op_state = OP_RUNNING_INTERRUPT; 370 } 371 372 edac_pci_printk(pci, KERN_INFO, 373 "Giving out device to module '%s' controller '%s':" 374 " DEV '%s' (%s)\n", 375 pci->mod_name, 376 pci->ctl_name, 377 edac_dev_name(pci), edac_op_state_to_string(pci->op_state)); 378 379 mutex_unlock(&edac_pci_ctls_mutex); 380 return 0; 381 382 /* error unwind stack */ 383 fail1: 384 del_edac_pci_from_global_list(pci); 385 fail0: 386 mutex_unlock(&edac_pci_ctls_mutex); 387 return 1; 388 } 389 EXPORT_SYMBOL_GPL(edac_pci_add_device); 390 391 /* 392 * edac_pci_del_device() 393 * Remove sysfs entries for specified edac_pci structure and 394 * then remove edac_pci structure from global list 395 * 396 * @dev: 397 * Pointer to 'struct device' representing edac_pci structure 398 * to remove 399 * 400 * Return: 401 * Pointer to removed edac_pci structure, 402 * or NULL if device not found 403 */ 404 struct edac_pci_ctl_info *edac_pci_del_device(struct device *dev) 405 { 406 struct edac_pci_ctl_info *pci; 407 408 debugf0("%s()\n", __func__); 409 410 mutex_lock(&edac_pci_ctls_mutex); 411 412 /* ensure the control struct is on the global list 413 * if not, then leave 414 */ 415 pci = find_edac_pci_by_dev(dev); 416 if (pci == NULL) { 417 mutex_unlock(&edac_pci_ctls_mutex); 418 return NULL; 419 } 420 421 pci->op_state = OP_OFFLINE; 422 423 del_edac_pci_from_global_list(pci); 424 425 mutex_unlock(&edac_pci_ctls_mutex); 426 427 /* stop the workq timer */ 428 edac_pci_workq_teardown(pci); 429 430 edac_printk(KERN_INFO, EDAC_PCI, 431 "Removed device %d for %s %s: DEV %s\n", 432 pci->pci_idx, pci->mod_name, pci->ctl_name, edac_dev_name(pci)); 433 434 return pci; 435 } 436 EXPORT_SYMBOL_GPL(edac_pci_del_device); 437 438 /* 439 * edac_pci_generic_check 440 * 441 * a Generic parity check API 442 */ 443 static void edac_pci_generic_check(struct edac_pci_ctl_info *pci) 444 { 445 debugf4("%s()\n", __func__); 446 edac_pci_do_parity_check(); 447 } 448 449 /* free running instance index counter */ 450 static int edac_pci_idx; 451 #define EDAC_PCI_GENCTL_NAME "EDAC PCI controller" 452 453 struct edac_pci_gen_data { 454 int edac_idx; 455 }; 456 457 /* 458 * edac_pci_create_generic_ctl 459 * 460 * A generic constructor for a PCI parity polling device 461 * Some systems have more than one domain of PCI busses. 462 * For systems with one domain, then this API will 463 * provide for a generic poller. 464 * 465 * This routine calls the edac_pci_alloc_ctl_info() for 466 * the generic device, with default values 467 */ 468 struct edac_pci_ctl_info *edac_pci_create_generic_ctl(struct device *dev, 469 const char *mod_name) 470 { 471 struct edac_pci_ctl_info *pci; 472 struct edac_pci_gen_data *pdata; 473 474 pci = edac_pci_alloc_ctl_info(sizeof(*pdata), EDAC_PCI_GENCTL_NAME); 475 if (!pci) 476 return NULL; 477 478 pdata = pci->pvt_info; 479 pci->dev = dev; 480 dev_set_drvdata(pci->dev, pci); 481 pci->dev_name = pci_name(to_pci_dev(dev)); 482 483 pci->mod_name = mod_name; 484 pci->ctl_name = EDAC_PCI_GENCTL_NAME; 485 pci->edac_check = edac_pci_generic_check; 486 487 pdata->edac_idx = edac_pci_idx++; 488 489 if (edac_pci_add_device(pci, pdata->edac_idx) > 0) { 490 debugf3("%s(): failed edac_pci_add_device()\n", __func__); 491 edac_pci_free_ctl_info(pci); 492 return NULL; 493 } 494 495 return pci; 496 } 497 EXPORT_SYMBOL_GPL(edac_pci_create_generic_ctl); 498 499 /* 500 * edac_pci_release_generic_ctl 501 * 502 * The release function of a generic EDAC PCI polling device 503 */ 504 void edac_pci_release_generic_ctl(struct edac_pci_ctl_info *pci) 505 { 506 debugf0("%s() pci mod=%s\n", __func__, pci->mod_name); 507 508 edac_pci_del_device(pci->dev); 509 edac_pci_free_ctl_info(pci); 510 } 511 EXPORT_SYMBOL_GPL(edac_pci_release_generic_ctl); 512