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 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 *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 } 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 debugf1("%s()\n", __func__); 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 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 */ 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 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; 149 150 fail0: 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; 156 157 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 * complete_edac_pci_list_del 167 * 168 * RCU completion callback to indicate item is deleted 169 */ 170 static 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 */ 184 static 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 */ 204 struct 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 } 224 EXPORT_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 */ 233 static 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 */ 272 static 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 */ 286 static 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 */ 304 void 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 } 318 EXPORT_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 */ 332 int 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 */ 369 fail1: 370 del_edac_pci_from_global_list(pci); 371 fail0: 372 mutex_unlock(&edac_pci_ctls_mutex); 373 return 1; 374 } 375 EXPORT_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 */ 390 struct 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 } 422 EXPORT_SYMBOL_GPL(edac_pci_del_device); 423 424 /* 425 * edac_pci_generic_check 426 * 427 * a Generic parity check API 428 */ 429 static 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 */ 436 static int edac_pci_idx; 437 #define EDAC_PCI_GENCTL_NAME "EDAC PCI controller" 438 439 struct 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 */ 454 struct 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 } 483 EXPORT_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 */ 490 void 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 } 497 EXPORT_SYMBOL_GPL(edac_pci_release_generic_ctl); 498