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