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/ctype.h>
23 #include <linux/workqueue.h>
24 #include <asm/uaccess.h>
25 #include <asm/page.h>
26
27 #include "edac_core.h"
28 #include "edac_module.h"
29
30 static DEFINE_MUTEX(edac_pci_ctls_mutex);
31 static LIST_HEAD(edac_pci_list);
32 static atomic_t pci_indexes = ATOMIC_INIT(0);
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 */
edac_pci_alloc_ctl_info(unsigned int sz_pvt,const char * edac_pci_name)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 *p = NULL, *pvt;
46 unsigned int size;
47
48 edac_dbg(1, "\n");
49
50 pci = edac_align_ptr(&p, sizeof(*pci), 1);
51 pvt = edac_align_ptr(&p, 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 */
edac_pci_free_ctl_info(struct edac_pci_ctl_info * pci)81 void edac_pci_free_ctl_info(struct edac_pci_ctl_info *pci)
82 {
83 edac_dbg(1, "\n");
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 */
find_edac_pci_by_dev(struct device * dev)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 edac_dbg(1, "\n");
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 */
add_edac_pci_to_global_list(struct edac_pci_ctl_info * pci)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 edac_dbg(1, "\n");
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 dev_name(rover->dev), 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 * del_edac_pci_from_global_list
167 *
168 * remove the PCI control struct from the global list
169 */
del_edac_pci_from_global_list(struct edac_pci_ctl_info * pci)170 static void del_edac_pci_from_global_list(struct edac_pci_ctl_info *pci)
171 {
172 list_del_rcu(&pci->link);
173
174 /* these are for safe removal of devices from global list while
175 * NMI handlers may be traversing list
176 */
177 synchronize_rcu();
178 INIT_LIST_HEAD(&pci->link);
179 }
180
181 #if 0
182 /* Older code, but might use in the future */
183
184 /*
185 * edac_pci_find()
186 * Search for an edac_pci_ctl_info structure whose index is 'idx'
187 *
188 * If found, return a pointer to the structure
189 * Else return NULL.
190 *
191 * Caller must hold pci_ctls_mutex.
192 */
193 struct edac_pci_ctl_info *edac_pci_find(int idx)
194 {
195 struct list_head *item;
196 struct edac_pci_ctl_info *pci;
197
198 /* Iterage over list, looking for exact match of ID */
199 list_for_each(item, &edac_pci_list) {
200 pci = list_entry(item, struct edac_pci_ctl_info, link);
201
202 if (pci->pci_idx >= idx) {
203 if (pci->pci_idx == idx)
204 return pci;
205
206 /* not on list, so terminate early */
207 break;
208 }
209 }
210
211 return NULL;
212 }
213 EXPORT_SYMBOL_GPL(edac_pci_find);
214 #endif
215
216 /*
217 * edac_pci_workq_function()
218 *
219 * periodic function that performs the operation
220 * scheduled by a workq request, for a given PCI control struct
221 */
edac_pci_workq_function(struct work_struct * work_req)222 static void edac_pci_workq_function(struct work_struct *work_req)
223 {
224 struct delayed_work *d_work = to_delayed_work(work_req);
225 struct edac_pci_ctl_info *pci = to_edac_pci_ctl_work(d_work);
226 int msec;
227 unsigned long delay;
228
229 edac_dbg(3, "checking\n");
230
231 mutex_lock(&edac_pci_ctls_mutex);
232
233 if (pci->op_state == OP_RUNNING_POLL) {
234 /* we might be in POLL mode, but there may NOT be a poll func
235 */
236 if ((pci->edac_check != NULL) && edac_pci_get_check_errors())
237 pci->edac_check(pci);
238
239 /* if we are on a one second period, then use round */
240 msec = edac_pci_get_poll_msec();
241 if (msec == 1000)
242 delay = round_jiffies_relative(msecs_to_jiffies(msec));
243 else
244 delay = msecs_to_jiffies(msec);
245
246 /* Reschedule only if we are in POLL mode */
247 queue_delayed_work(edac_workqueue, &pci->work, delay);
248 }
249
250 mutex_unlock(&edac_pci_ctls_mutex);
251 }
252
253 /*
254 * edac_pci_workq_setup()
255 * initialize a workq item for this edac_pci instance
256 * passing in the new delay period in msec
257 *
258 * locking model:
259 * called when 'edac_pci_ctls_mutex' is locked
260 */
edac_pci_workq_setup(struct edac_pci_ctl_info * pci,unsigned int msec)261 static void edac_pci_workq_setup(struct edac_pci_ctl_info *pci,
262 unsigned int msec)
263 {
264 edac_dbg(0, "\n");
265
266 INIT_DELAYED_WORK(&pci->work, edac_pci_workq_function);
267 queue_delayed_work(edac_workqueue, &pci->work,
268 msecs_to_jiffies(edac_pci_get_poll_msec()));
269 }
270
271 /*
272 * edac_pci_workq_teardown()
273 * stop the workq processing on this edac_pci instance
274 */
edac_pci_workq_teardown(struct edac_pci_ctl_info * pci)275 static void edac_pci_workq_teardown(struct edac_pci_ctl_info *pci)
276 {
277 edac_dbg(0, "\n");
278
279 pci->op_state = OP_OFFLINE;
280
281 cancel_delayed_work_sync(&pci->work);
282 flush_workqueue(edac_workqueue);
283 }
284
285 /*
286 * edac_pci_reset_delay_period
287 *
288 * called with a new period value for the workq period
289 * a) stop current workq timer
290 * b) restart workq timer with new value
291 */
edac_pci_reset_delay_period(struct edac_pci_ctl_info * pci,unsigned long value)292 void edac_pci_reset_delay_period(struct edac_pci_ctl_info *pci,
293 unsigned long value)
294 {
295 edac_dbg(0, "\n");
296
297 edac_pci_workq_teardown(pci);
298
299 /* need to lock for the setup */
300 mutex_lock(&edac_pci_ctls_mutex);
301
302 edac_pci_workq_setup(pci, value);
303
304 mutex_unlock(&edac_pci_ctls_mutex);
305 }
306 EXPORT_SYMBOL_GPL(edac_pci_reset_delay_period);
307
308 /*
309 * edac_pci_alloc_index: Allocate a unique PCI index number
310 *
311 * Return:
312 * allocated index number
313 *
314 */
edac_pci_alloc_index(void)315 int edac_pci_alloc_index(void)
316 {
317 return atomic_inc_return(&pci_indexes) - 1;
318 }
319 EXPORT_SYMBOL_GPL(edac_pci_alloc_index);
320
321 /*
322 * edac_pci_add_device: Insert the 'edac_dev' structure into the
323 * edac_pci global list and create sysfs entries associated with
324 * edac_pci structure.
325 * @pci: pointer to the edac_device structure to be added to the list
326 * @edac_idx: A unique numeric identifier to be assigned to the
327 * 'edac_pci' structure.
328 *
329 * Return:
330 * 0 Success
331 * !0 Failure
332 */
edac_pci_add_device(struct edac_pci_ctl_info * pci,int edac_idx)333 int edac_pci_add_device(struct edac_pci_ctl_info *pci, int edac_idx)
334 {
335 edac_dbg(0, "\n");
336
337 pci->pci_idx = edac_idx;
338 pci->start_time = jiffies;
339
340 mutex_lock(&edac_pci_ctls_mutex);
341
342 if (add_edac_pci_to_global_list(pci))
343 goto fail0;
344
345 if (edac_pci_create_sysfs(pci)) {
346 edac_pci_printk(pci, KERN_WARNING,
347 "failed to create sysfs pci\n");
348 goto fail1;
349 }
350
351 if (pci->edac_check != NULL) {
352 pci->op_state = OP_RUNNING_POLL;
353
354 edac_pci_workq_setup(pci, 1000);
355 } else {
356 pci->op_state = OP_RUNNING_INTERRUPT;
357 }
358
359 edac_pci_printk(pci, KERN_INFO,
360 "Giving out device to module %s controller %s: DEV %s (%s)\n",
361 pci->mod_name, pci->ctl_name, pci->dev_name,
362 edac_op_state_to_string(pci->op_state));
363
364 mutex_unlock(&edac_pci_ctls_mutex);
365 return 0;
366
367 /* error unwind stack */
368 fail1:
369 del_edac_pci_from_global_list(pci);
370 fail0:
371 mutex_unlock(&edac_pci_ctls_mutex);
372 return 1;
373 }
374 EXPORT_SYMBOL_GPL(edac_pci_add_device);
375
376 /*
377 * edac_pci_del_device()
378 * Remove sysfs entries for specified edac_pci structure and
379 * then remove edac_pci structure from global list
380 *
381 * @dev:
382 * Pointer to 'struct device' representing edac_pci structure
383 * to remove
384 *
385 * Return:
386 * Pointer to removed edac_pci structure,
387 * or NULL if device not found
388 */
edac_pci_del_device(struct device * dev)389 struct edac_pci_ctl_info *edac_pci_del_device(struct device *dev)
390 {
391 struct edac_pci_ctl_info *pci;
392
393 edac_dbg(0, "\n");
394
395 mutex_lock(&edac_pci_ctls_mutex);
396
397 /* ensure the control struct is on the global list
398 * if not, then leave
399 */
400 pci = find_edac_pci_by_dev(dev);
401 if (pci == NULL) {
402 mutex_unlock(&edac_pci_ctls_mutex);
403 return NULL;
404 }
405
406 pci->op_state = OP_OFFLINE;
407
408 del_edac_pci_from_global_list(pci);
409
410 mutex_unlock(&edac_pci_ctls_mutex);
411
412 /* stop the workq timer */
413 edac_pci_workq_teardown(pci);
414
415 edac_printk(KERN_INFO, EDAC_PCI,
416 "Removed device %d for %s %s: DEV %s\n",
417 pci->pci_idx, pci->mod_name, pci->ctl_name, edac_dev_name(pci));
418
419 return pci;
420 }
421 EXPORT_SYMBOL_GPL(edac_pci_del_device);
422
423 /*
424 * edac_pci_generic_check
425 *
426 * a Generic parity check API
427 */
edac_pci_generic_check(struct edac_pci_ctl_info * pci)428 static void edac_pci_generic_check(struct edac_pci_ctl_info *pci)
429 {
430 edac_dbg(4, "\n");
431 edac_pci_do_parity_check();
432 }
433
434 /* free running instance index counter */
435 static int edac_pci_idx;
436 #define EDAC_PCI_GENCTL_NAME "EDAC PCI controller"
437
438 struct edac_pci_gen_data {
439 int edac_idx;
440 };
441
442 /*
443 * edac_pci_create_generic_ctl
444 *
445 * A generic constructor for a PCI parity polling device
446 * Some systems have more than one domain of PCI busses.
447 * For systems with one domain, then this API will
448 * provide for a generic poller.
449 *
450 * This routine calls the edac_pci_alloc_ctl_info() for
451 * the generic device, with default values
452 */
edac_pci_create_generic_ctl(struct device * dev,const char * mod_name)453 struct edac_pci_ctl_info *edac_pci_create_generic_ctl(struct device *dev,
454 const char *mod_name)
455 {
456 struct edac_pci_ctl_info *pci;
457 struct edac_pci_gen_data *pdata;
458
459 pci = edac_pci_alloc_ctl_info(sizeof(*pdata), EDAC_PCI_GENCTL_NAME);
460 if (!pci)
461 return NULL;
462
463 pdata = pci->pvt_info;
464 pci->dev = dev;
465 dev_set_drvdata(pci->dev, pci);
466 pci->dev_name = pci_name(to_pci_dev(dev));
467
468 pci->mod_name = mod_name;
469 pci->ctl_name = EDAC_PCI_GENCTL_NAME;
470 if (edac_op_state == EDAC_OPSTATE_POLL)
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 edac_dbg(3, "failed edac_pci_add_device()\n");
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 */
edac_pci_release_generic_ctl(struct edac_pci_ctl_info * pci)490 void edac_pci_release_generic_ctl(struct edac_pci_ctl_info *pci)
491 {
492 edac_dbg(0, "pci mod=%s\n", 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