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