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 * del_edac_pci_from_global_list 168 * 169 * remove the PCI control struct from the global list 170 */ 171 static void del_edac_pci_from_global_list(struct edac_pci_ctl_info *pci) 172 { 173 list_del_rcu(&pci->link); 174 175 /* these are for safe removal of devices from global list while 176 * NMI handlers may be traversing list 177 */ 178 synchronize_rcu(); 179 INIT_LIST_HEAD(&pci->link); 180 } 181 182 #if 0 183 /* Older code, but might use in the future */ 184 185 /* 186 * edac_pci_find() 187 * Search for an edac_pci_ctl_info structure whose index is 'idx' 188 * 189 * If found, return a pointer to the structure 190 * Else return NULL. 191 * 192 * Caller must hold pci_ctls_mutex. 193 */ 194 struct edac_pci_ctl_info *edac_pci_find(int idx) 195 { 196 struct list_head *item; 197 struct edac_pci_ctl_info *pci; 198 199 /* Iterage over list, looking for exact match of ID */ 200 list_for_each(item, &edac_pci_list) { 201 pci = list_entry(item, struct edac_pci_ctl_info, link); 202 203 if (pci->pci_idx >= idx) { 204 if (pci->pci_idx == idx) 205 return pci; 206 207 /* not on list, so terminate early */ 208 break; 209 } 210 } 211 212 return NULL; 213 } 214 EXPORT_SYMBOL_GPL(edac_pci_find); 215 #endif 216 217 /* 218 * edac_pci_workq_function() 219 * 220 * periodic function that performs the operation 221 * scheduled by a workq request, for a given PCI control struct 222 */ 223 static void edac_pci_workq_function(struct work_struct *work_req) 224 { 225 struct delayed_work *d_work = to_delayed_work(work_req); 226 struct edac_pci_ctl_info *pci = to_edac_pci_ctl_work(d_work); 227 int msec; 228 unsigned long delay; 229 230 debugf3("%s() checking\n", __func__); 231 232 mutex_lock(&edac_pci_ctls_mutex); 233 234 if (pci->op_state == OP_RUNNING_POLL) { 235 /* we might be in POLL mode, but there may NOT be a poll func 236 */ 237 if ((pci->edac_check != NULL) && edac_pci_get_check_errors()) 238 pci->edac_check(pci); 239 240 /* if we are on a one second period, then use round */ 241 msec = edac_pci_get_poll_msec(); 242 if (msec == 1000) 243 delay = round_jiffies_relative(msecs_to_jiffies(msec)); 244 else 245 delay = msecs_to_jiffies(msec); 246 247 /* Reschedule only if we are in POLL mode */ 248 queue_delayed_work(edac_workqueue, &pci->work, delay); 249 } 250 251 mutex_unlock(&edac_pci_ctls_mutex); 252 } 253 254 /* 255 * edac_pci_workq_setup() 256 * initialize a workq item for this edac_pci instance 257 * passing in the new delay period in msec 258 * 259 * locking model: 260 * called when 'edac_pci_ctls_mutex' is locked 261 */ 262 static void edac_pci_workq_setup(struct edac_pci_ctl_info *pci, 263 unsigned int msec) 264 { 265 debugf0("%s()\n", __func__); 266 267 INIT_DELAYED_WORK(&pci->work, edac_pci_workq_function); 268 queue_delayed_work(edac_workqueue, &pci->work, 269 msecs_to_jiffies(edac_pci_get_poll_msec())); 270 } 271 272 /* 273 * edac_pci_workq_teardown() 274 * stop the workq processing on this edac_pci instance 275 */ 276 static void edac_pci_workq_teardown(struct edac_pci_ctl_info *pci) 277 { 278 int status; 279 280 debugf0("%s()\n", __func__); 281 282 status = cancel_delayed_work(&pci->work); 283 if (status == 0) 284 flush_workqueue(edac_workqueue); 285 } 286 287 /* 288 * edac_pci_reset_delay_period 289 * 290 * called with a new period value for the workq period 291 * a) stop current workq timer 292 * b) restart workq timer with new value 293 */ 294 void edac_pci_reset_delay_period(struct edac_pci_ctl_info *pci, 295 unsigned long value) 296 { 297 debugf0("%s()\n", __func__); 298 299 edac_pci_workq_teardown(pci); 300 301 /* need to lock for the setup */ 302 mutex_lock(&edac_pci_ctls_mutex); 303 304 edac_pci_workq_setup(pci, value); 305 306 mutex_unlock(&edac_pci_ctls_mutex); 307 } 308 EXPORT_SYMBOL_GPL(edac_pci_reset_delay_period); 309 310 /* 311 * edac_pci_alloc_index: Allocate a unique PCI index number 312 * 313 * Return: 314 * allocated index number 315 * 316 */ 317 int edac_pci_alloc_index(void) 318 { 319 return atomic_inc_return(&pci_indexes) - 1; 320 } 321 EXPORT_SYMBOL_GPL(edac_pci_alloc_index); 322 323 /* 324 * edac_pci_add_device: Insert the 'edac_dev' structure into the 325 * edac_pci global list and create sysfs entries associated with 326 * edac_pci structure. 327 * @pci: pointer to the edac_device structure to be added to the list 328 * @edac_idx: A unique numeric identifier to be assigned to the 329 * 'edac_pci' structure. 330 * 331 * Return: 332 * 0 Success 333 * !0 Failure 334 */ 335 int edac_pci_add_device(struct edac_pci_ctl_info *pci, int edac_idx) 336 { 337 debugf0("%s()\n", __func__); 338 339 pci->pci_idx = edac_idx; 340 pci->start_time = jiffies; 341 342 mutex_lock(&edac_pci_ctls_mutex); 343 344 if (add_edac_pci_to_global_list(pci)) 345 goto fail0; 346 347 if (edac_pci_create_sysfs(pci)) { 348 edac_pci_printk(pci, KERN_WARNING, 349 "failed to create sysfs pci\n"); 350 goto fail1; 351 } 352 353 if (pci->edac_check != NULL) { 354 pci->op_state = OP_RUNNING_POLL; 355 356 edac_pci_workq_setup(pci, 1000); 357 } else { 358 pci->op_state = OP_RUNNING_INTERRUPT; 359 } 360 361 edac_pci_printk(pci, KERN_INFO, 362 "Giving out device to module '%s' controller '%s':" 363 " DEV '%s' (%s)\n", 364 pci->mod_name, 365 pci->ctl_name, 366 edac_dev_name(pci), edac_op_state_to_string(pci->op_state)); 367 368 mutex_unlock(&edac_pci_ctls_mutex); 369 return 0; 370 371 /* error unwind stack */ 372 fail1: 373 del_edac_pci_from_global_list(pci); 374 fail0: 375 mutex_unlock(&edac_pci_ctls_mutex); 376 return 1; 377 } 378 EXPORT_SYMBOL_GPL(edac_pci_add_device); 379 380 /* 381 * edac_pci_del_device() 382 * Remove sysfs entries for specified edac_pci structure and 383 * then remove edac_pci structure from global list 384 * 385 * @dev: 386 * Pointer to 'struct device' representing edac_pci structure 387 * to remove 388 * 389 * Return: 390 * Pointer to removed edac_pci structure, 391 * or NULL if device not found 392 */ 393 struct edac_pci_ctl_info *edac_pci_del_device(struct device *dev) 394 { 395 struct edac_pci_ctl_info *pci; 396 397 debugf0("%s()\n", __func__); 398 399 mutex_lock(&edac_pci_ctls_mutex); 400 401 /* ensure the control struct is on the global list 402 * if not, then leave 403 */ 404 pci = find_edac_pci_by_dev(dev); 405 if (pci == NULL) { 406 mutex_unlock(&edac_pci_ctls_mutex); 407 return NULL; 408 } 409 410 pci->op_state = OP_OFFLINE; 411 412 del_edac_pci_from_global_list(pci); 413 414 mutex_unlock(&edac_pci_ctls_mutex); 415 416 /* stop the workq timer */ 417 edac_pci_workq_teardown(pci); 418 419 edac_printk(KERN_INFO, EDAC_PCI, 420 "Removed device %d for %s %s: DEV %s\n", 421 pci->pci_idx, pci->mod_name, pci->ctl_name, edac_dev_name(pci)); 422 423 return pci; 424 } 425 EXPORT_SYMBOL_GPL(edac_pci_del_device); 426 427 /* 428 * edac_pci_generic_check 429 * 430 * a Generic parity check API 431 */ 432 static void edac_pci_generic_check(struct edac_pci_ctl_info *pci) 433 { 434 debugf4("%s()\n", __func__); 435 edac_pci_do_parity_check(); 436 } 437 438 /* free running instance index counter */ 439 static int edac_pci_idx; 440 #define EDAC_PCI_GENCTL_NAME "EDAC PCI controller" 441 442 struct edac_pci_gen_data { 443 int edac_idx; 444 }; 445 446 /* 447 * edac_pci_create_generic_ctl 448 * 449 * A generic constructor for a PCI parity polling device 450 * Some systems have more than one domain of PCI busses. 451 * For systems with one domain, then this API will 452 * provide for a generic poller. 453 * 454 * This routine calls the edac_pci_alloc_ctl_info() for 455 * the generic device, with default values 456 */ 457 struct edac_pci_ctl_info *edac_pci_create_generic_ctl(struct device *dev, 458 const char *mod_name) 459 { 460 struct edac_pci_ctl_info *pci; 461 struct edac_pci_gen_data *pdata; 462 463 pci = edac_pci_alloc_ctl_info(sizeof(*pdata), EDAC_PCI_GENCTL_NAME); 464 if (!pci) 465 return NULL; 466 467 pdata = pci->pvt_info; 468 pci->dev = dev; 469 dev_set_drvdata(pci->dev, pci); 470 pci->dev_name = pci_name(to_pci_dev(dev)); 471 472 pci->mod_name = mod_name; 473 pci->ctl_name = EDAC_PCI_GENCTL_NAME; 474 pci->edac_check = edac_pci_generic_check; 475 476 pdata->edac_idx = edac_pci_idx++; 477 478 if (edac_pci_add_device(pci, pdata->edac_idx) > 0) { 479 debugf3("%s(): failed edac_pci_add_device()\n", __func__); 480 edac_pci_free_ctl_info(pci); 481 return NULL; 482 } 483 484 return pci; 485 } 486 EXPORT_SYMBOL_GPL(edac_pci_create_generic_ctl); 487 488 /* 489 * edac_pci_release_generic_ctl 490 * 491 * The release function of a generic EDAC PCI polling device 492 */ 493 void edac_pci_release_generic_ctl(struct edac_pci_ctl_info *pci) 494 { 495 debugf0("%s() pci mod=%s\n", __func__, pci->mod_name); 496 497 edac_pci_del_device(pci->dev); 498 edac_pci_free_ctl_info(pci); 499 } 500 EXPORT_SYMBOL_GPL(edac_pci_release_generic_ctl); 501