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