1 /*
2  * (C) 2005, 2006 Linux Networx (http://lnxi.com)
3  * This file may be distributed under the terms of the
4  * GNU General Public License.
5  *
6  * Written Doug Thompson <norsk5@xmission.com>
7  *
8  */
9 #include <linux/module.h>
10 #include <linux/edac.h>
11 #include <linux/slab.h>
12 #include <linux/ctype.h>
13 
14 #include "edac_core.h"
15 #include "edac_module.h"
16 
17 /* Turn off this whole feature if PCI is not configured */
18 #ifdef CONFIG_PCI
19 
20 #define EDAC_PCI_SYMLINK	"device"
21 
22 /* data variables exported via sysfs */
23 static int check_pci_errors;		/* default NO check PCI parity */
24 static int edac_pci_panic_on_pe;	/* default NO panic on PCI Parity */
25 static int edac_pci_log_pe = 1;		/* log PCI parity errors */
26 static int edac_pci_log_npe = 1;	/* log PCI non-parity error errors */
27 static int edac_pci_poll_msec = 1000;	/* one second workq period */
28 
29 static atomic_t pci_parity_count = ATOMIC_INIT(0);
30 static atomic_t pci_nonparity_count = ATOMIC_INIT(0);
31 
32 static struct kobject *edac_pci_top_main_kobj;
33 static atomic_t edac_pci_sysfs_refcount = ATOMIC_INIT(0);
34 
35 /* getter functions for the data variables */
edac_pci_get_check_errors(void)36 int edac_pci_get_check_errors(void)
37 {
38 	return check_pci_errors;
39 }
40 
edac_pci_get_log_pe(void)41 static int edac_pci_get_log_pe(void)
42 {
43 	return edac_pci_log_pe;
44 }
45 
edac_pci_get_log_npe(void)46 static int edac_pci_get_log_npe(void)
47 {
48 	return edac_pci_log_npe;
49 }
50 
edac_pci_get_panic_on_pe(void)51 static int edac_pci_get_panic_on_pe(void)
52 {
53 	return edac_pci_panic_on_pe;
54 }
55 
edac_pci_get_poll_msec(void)56 int edac_pci_get_poll_msec(void)
57 {
58 	return edac_pci_poll_msec;
59 }
60 
61 /**************************** EDAC PCI sysfs instance *******************/
instance_pe_count_show(struct edac_pci_ctl_info * pci,char * data)62 static ssize_t instance_pe_count_show(struct edac_pci_ctl_info *pci, char *data)
63 {
64 	return sprintf(data, "%u\n", atomic_read(&pci->counters.pe_count));
65 }
66 
instance_npe_count_show(struct edac_pci_ctl_info * pci,char * data)67 static ssize_t instance_npe_count_show(struct edac_pci_ctl_info *pci,
68 				char *data)
69 {
70 	return sprintf(data, "%u\n", atomic_read(&pci->counters.npe_count));
71 }
72 
73 #define to_instance(k) container_of(k, struct edac_pci_ctl_info, kobj)
74 #define to_instance_attr(a) container_of(a, struct instance_attribute, attr)
75 
76 /* DEVICE instance kobject release() function */
edac_pci_instance_release(struct kobject * kobj)77 static void edac_pci_instance_release(struct kobject *kobj)
78 {
79 	struct edac_pci_ctl_info *pci;
80 
81 	debugf0("%s()\n", __func__);
82 
83 	/* Form pointer to containing struct, the pci control struct */
84 	pci = to_instance(kobj);
85 
86 	/* decrement reference count on top main kobj */
87 	kobject_put(edac_pci_top_main_kobj);
88 
89 	kfree(pci);	/* Free the control struct */
90 }
91 
92 /* instance specific attribute structure */
93 struct instance_attribute {
94 	struct attribute attr;
95 	ssize_t(*show) (struct edac_pci_ctl_info *, char *);
96 	ssize_t(*store) (struct edac_pci_ctl_info *, const char *, size_t);
97 };
98 
99 /* Function to 'show' fields from the edac_pci 'instance' structure */
edac_pci_instance_show(struct kobject * kobj,struct attribute * attr,char * buffer)100 static ssize_t edac_pci_instance_show(struct kobject *kobj,
101 				struct attribute *attr, char *buffer)
102 {
103 	struct edac_pci_ctl_info *pci = to_instance(kobj);
104 	struct instance_attribute *instance_attr = to_instance_attr(attr);
105 
106 	if (instance_attr->show)
107 		return instance_attr->show(pci, buffer);
108 	return -EIO;
109 }
110 
111 /* Function to 'store' fields into the edac_pci 'instance' structure */
edac_pci_instance_store(struct kobject * kobj,struct attribute * attr,const char * buffer,size_t count)112 static ssize_t edac_pci_instance_store(struct kobject *kobj,
113 				struct attribute *attr,
114 				const char *buffer, size_t count)
115 {
116 	struct edac_pci_ctl_info *pci = to_instance(kobj);
117 	struct instance_attribute *instance_attr = to_instance_attr(attr);
118 
119 	if (instance_attr->store)
120 		return instance_attr->store(pci, buffer, count);
121 	return -EIO;
122 }
123 
124 /* fs_ops table */
125 static const struct sysfs_ops pci_instance_ops = {
126 	.show = edac_pci_instance_show,
127 	.store = edac_pci_instance_store
128 };
129 
130 #define INSTANCE_ATTR(_name, _mode, _show, _store)	\
131 static struct instance_attribute attr_instance_##_name = {	\
132 	.attr	= {.name = __stringify(_name), .mode = _mode },	\
133 	.show	= _show,					\
134 	.store	= _store,					\
135 };
136 
137 INSTANCE_ATTR(pe_count, S_IRUGO, instance_pe_count_show, NULL);
138 INSTANCE_ATTR(npe_count, S_IRUGO, instance_npe_count_show, NULL);
139 
140 /* pci instance attributes */
141 static struct instance_attribute *pci_instance_attr[] = {
142 	&attr_instance_pe_count,
143 	&attr_instance_npe_count,
144 	NULL
145 };
146 
147 /* the ktype for a pci instance */
148 static struct kobj_type ktype_pci_instance = {
149 	.release = edac_pci_instance_release,
150 	.sysfs_ops = &pci_instance_ops,
151 	.default_attrs = (struct attribute **)pci_instance_attr,
152 };
153 
154 /*
155  * edac_pci_create_instance_kobj
156  *
157  *	construct one EDAC PCI instance's kobject for use
158  */
edac_pci_create_instance_kobj(struct edac_pci_ctl_info * pci,int idx)159 static int edac_pci_create_instance_kobj(struct edac_pci_ctl_info *pci, int idx)
160 {
161 	struct kobject *main_kobj;
162 	int err;
163 
164 	debugf0("%s()\n", __func__);
165 
166 	/* First bump the ref count on the top main kobj, which will
167 	 * track the number of PCI instances we have, and thus nest
168 	 * properly on keeping the module loaded
169 	 */
170 	main_kobj = kobject_get(edac_pci_top_main_kobj);
171 	if (!main_kobj) {
172 		err = -ENODEV;
173 		goto error_out;
174 	}
175 
176 	/* And now register this new kobject under the main kobj */
177 	err = kobject_init_and_add(&pci->kobj, &ktype_pci_instance,
178 				   edac_pci_top_main_kobj, "pci%d", idx);
179 	if (err != 0) {
180 		debugf2("%s() failed to register instance pci%d\n",
181 			__func__, idx);
182 		kobject_put(edac_pci_top_main_kobj);
183 		goto error_out;
184 	}
185 
186 	kobject_uevent(&pci->kobj, KOBJ_ADD);
187 	debugf1("%s() Register instance 'pci%d' kobject\n", __func__, idx);
188 
189 	return 0;
190 
191 	/* Error unwind statck */
192 error_out:
193 	return err;
194 }
195 
196 /*
197  * edac_pci_unregister_sysfs_instance_kobj
198  *
199  *	unregister the kobj for the EDAC PCI instance
200  */
edac_pci_unregister_sysfs_instance_kobj(struct edac_pci_ctl_info * pci)201 static void edac_pci_unregister_sysfs_instance_kobj(
202 			struct edac_pci_ctl_info *pci)
203 {
204 	debugf0("%s()\n", __func__);
205 
206 	/* Unregister the instance kobject and allow its release
207 	 * function release the main reference count and then
208 	 * kfree the memory
209 	 */
210 	kobject_put(&pci->kobj);
211 }
212 
213 /***************************** EDAC PCI sysfs root **********************/
214 #define to_edacpci(k) container_of(k, struct edac_pci_ctl_info, kobj)
215 #define to_edacpci_attr(a) container_of(a, struct edac_pci_attr, attr)
216 
217 /* simple show/store functions for attributes */
edac_pci_int_show(void * ptr,char * buffer)218 static ssize_t edac_pci_int_show(void *ptr, char *buffer)
219 {
220 	int *value = ptr;
221 	return sprintf(buffer, "%d\n", *value);
222 }
223 
edac_pci_int_store(void * ptr,const char * buffer,size_t count)224 static ssize_t edac_pci_int_store(void *ptr, const char *buffer, size_t count)
225 {
226 	int *value = ptr;
227 
228 	if (isdigit(*buffer))
229 		*value = simple_strtoul(buffer, NULL, 0);
230 
231 	return count;
232 }
233 
234 struct edac_pci_dev_attribute {
235 	struct attribute attr;
236 	void *value;
237 	 ssize_t(*show) (void *, char *);
238 	 ssize_t(*store) (void *, const char *, size_t);
239 };
240 
241 /* Set of show/store abstract level functions for PCI Parity object */
edac_pci_dev_show(struct kobject * kobj,struct attribute * attr,char * buffer)242 static ssize_t edac_pci_dev_show(struct kobject *kobj, struct attribute *attr,
243 				 char *buffer)
244 {
245 	struct edac_pci_dev_attribute *edac_pci_dev;
246 	edac_pci_dev = (struct edac_pci_dev_attribute *)attr;
247 
248 	if (edac_pci_dev->show)
249 		return edac_pci_dev->show(edac_pci_dev->value, buffer);
250 	return -EIO;
251 }
252 
edac_pci_dev_store(struct kobject * kobj,struct attribute * attr,const char * buffer,size_t count)253 static ssize_t edac_pci_dev_store(struct kobject *kobj,
254 				struct attribute *attr, const char *buffer,
255 				size_t count)
256 {
257 	struct edac_pci_dev_attribute *edac_pci_dev;
258 	edac_pci_dev = (struct edac_pci_dev_attribute *)attr;
259 
260 	if (edac_pci_dev->store)
261 		return edac_pci_dev->store(edac_pci_dev->value, buffer, count);
262 	return -EIO;
263 }
264 
265 static const struct sysfs_ops edac_pci_sysfs_ops = {
266 	.show = edac_pci_dev_show,
267 	.store = edac_pci_dev_store
268 };
269 
270 #define EDAC_PCI_ATTR(_name,_mode,_show,_store)			\
271 static struct edac_pci_dev_attribute edac_pci_attr_##_name = {		\
272 	.attr = {.name = __stringify(_name), .mode = _mode },	\
273 	.value  = &_name,					\
274 	.show   = _show,					\
275 	.store  = _store,					\
276 };
277 
278 #define EDAC_PCI_STRING_ATTR(_name,_data,_mode,_show,_store)	\
279 static struct edac_pci_dev_attribute edac_pci_attr_##_name = {		\
280 	.attr = {.name = __stringify(_name), .mode = _mode },	\
281 	.value  = _data,					\
282 	.show   = _show,					\
283 	.store  = _store,					\
284 };
285 
286 /* PCI Parity control files */
287 EDAC_PCI_ATTR(check_pci_errors, S_IRUGO | S_IWUSR, edac_pci_int_show,
288 	edac_pci_int_store);
289 EDAC_PCI_ATTR(edac_pci_log_pe, S_IRUGO | S_IWUSR, edac_pci_int_show,
290 	edac_pci_int_store);
291 EDAC_PCI_ATTR(edac_pci_log_npe, S_IRUGO | S_IWUSR, edac_pci_int_show,
292 	edac_pci_int_store);
293 EDAC_PCI_ATTR(edac_pci_panic_on_pe, S_IRUGO | S_IWUSR, edac_pci_int_show,
294 	edac_pci_int_store);
295 EDAC_PCI_ATTR(pci_parity_count, S_IRUGO, edac_pci_int_show, NULL);
296 EDAC_PCI_ATTR(pci_nonparity_count, S_IRUGO, edac_pci_int_show, NULL);
297 
298 /* Base Attributes of the memory ECC object */
299 static struct edac_pci_dev_attribute *edac_pci_attr[] = {
300 	&edac_pci_attr_check_pci_errors,
301 	&edac_pci_attr_edac_pci_log_pe,
302 	&edac_pci_attr_edac_pci_log_npe,
303 	&edac_pci_attr_edac_pci_panic_on_pe,
304 	&edac_pci_attr_pci_parity_count,
305 	&edac_pci_attr_pci_nonparity_count,
306 	NULL,
307 };
308 
309 /*
310  * edac_pci_release_main_kobj
311  *
312  *	This release function is called when the reference count to the
313  *	passed kobj goes to zero.
314  *
315  *	This kobj is the 'main' kobject that EDAC PCI instances
316  *	link to, and thus provide for proper nesting counts
317  */
edac_pci_release_main_kobj(struct kobject * kobj)318 static void edac_pci_release_main_kobj(struct kobject *kobj)
319 {
320 	debugf0("%s() here to module_put(THIS_MODULE)\n", __func__);
321 
322 	kfree(kobj);
323 
324 	/* last reference to top EDAC PCI kobject has been removed,
325 	 * NOW release our ref count on the core module
326 	 */
327 	module_put(THIS_MODULE);
328 }
329 
330 /* ktype struct for the EDAC PCI main kobj */
331 static struct kobj_type ktype_edac_pci_main_kobj = {
332 	.release = edac_pci_release_main_kobj,
333 	.sysfs_ops = &edac_pci_sysfs_ops,
334 	.default_attrs = (struct attribute **)edac_pci_attr,
335 };
336 
337 /**
338  * edac_pci_main_kobj_setup()
339  *
340  *	setup the sysfs for EDAC PCI attributes
341  *	assumes edac_subsys has already been initialized
342  */
edac_pci_main_kobj_setup(void)343 static int edac_pci_main_kobj_setup(void)
344 {
345 	int err;
346 	struct bus_type *edac_subsys;
347 
348 	debugf0("%s()\n", __func__);
349 
350 	/* check and count if we have already created the main kobject */
351 	if (atomic_inc_return(&edac_pci_sysfs_refcount) != 1)
352 		return 0;
353 
354 	/* First time, so create the main kobject and its
355 	 * controls and attributes
356 	 */
357 	edac_subsys = edac_get_sysfs_subsys();
358 	if (edac_subsys == NULL) {
359 		debugf1("%s() no edac_subsys\n", __func__);
360 		err = -ENODEV;
361 		goto decrement_count_fail;
362 	}
363 
364 	/* Bump the reference count on this module to ensure the
365 	 * modules isn't unloaded until we deconstruct the top
366 	 * level main kobj for EDAC PCI
367 	 */
368 	if (!try_module_get(THIS_MODULE)) {
369 		debugf1("%s() try_module_get() failed\n", __func__);
370 		err = -ENODEV;
371 		goto mod_get_fail;
372 	}
373 
374 	edac_pci_top_main_kobj = kzalloc(sizeof(struct kobject), GFP_KERNEL);
375 	if (!edac_pci_top_main_kobj) {
376 		debugf1("Failed to allocate\n");
377 		err = -ENOMEM;
378 		goto kzalloc_fail;
379 	}
380 
381 	/* Instanstiate the pci object */
382 	err = kobject_init_and_add(edac_pci_top_main_kobj,
383 				   &ktype_edac_pci_main_kobj,
384 				   &edac_subsys->dev_root->kobj, "pci");
385 	if (err) {
386 		debugf1("Failed to register '.../edac/pci'\n");
387 		goto kobject_init_and_add_fail;
388 	}
389 
390 	/* At this point, to 'release' the top level kobject
391 	 * for EDAC PCI, then edac_pci_main_kobj_teardown()
392 	 * must be used, for resources to be cleaned up properly
393 	 */
394 	kobject_uevent(edac_pci_top_main_kobj, KOBJ_ADD);
395 	debugf1("Registered '.../edac/pci' kobject\n");
396 
397 	return 0;
398 
399 	/* Error unwind statck */
400 kobject_init_and_add_fail:
401 	kfree(edac_pci_top_main_kobj);
402 
403 kzalloc_fail:
404 	module_put(THIS_MODULE);
405 
406 mod_get_fail:
407 	edac_put_sysfs_subsys();
408 
409 decrement_count_fail:
410 	/* if are on this error exit, nothing to tear down */
411 	atomic_dec(&edac_pci_sysfs_refcount);
412 
413 	return err;
414 }
415 
416 /*
417  * edac_pci_main_kobj_teardown()
418  *
419  *	if no longer linked (needed) remove the top level EDAC PCI
420  *	kobject with its controls and attributes
421  */
edac_pci_main_kobj_teardown(void)422 static void edac_pci_main_kobj_teardown(void)
423 {
424 	debugf0("%s()\n", __func__);
425 
426 	/* Decrement the count and only if no more controller instances
427 	 * are connected perform the unregisteration of the top level
428 	 * main kobj
429 	 */
430 	if (atomic_dec_return(&edac_pci_sysfs_refcount) == 0) {
431 		debugf0("%s() called kobject_put on main kobj\n",
432 			__func__);
433 		kobject_put(edac_pci_top_main_kobj);
434 	}
435 	edac_put_sysfs_subsys();
436 }
437 
438 /*
439  *
440  * edac_pci_create_sysfs
441  *
442  *	Create the controls/attributes for the specified EDAC PCI device
443  */
edac_pci_create_sysfs(struct edac_pci_ctl_info * pci)444 int edac_pci_create_sysfs(struct edac_pci_ctl_info *pci)
445 {
446 	int err;
447 	struct kobject *edac_kobj = &pci->kobj;
448 
449 	debugf0("%s() idx=%d\n", __func__, pci->pci_idx);
450 
451 	/* create the top main EDAC PCI kobject, IF needed */
452 	err = edac_pci_main_kobj_setup();
453 	if (err)
454 		return err;
455 
456 	/* Create this instance's kobject under the MAIN kobject */
457 	err = edac_pci_create_instance_kobj(pci, pci->pci_idx);
458 	if (err)
459 		goto unregister_cleanup;
460 
461 	err = sysfs_create_link(edac_kobj, &pci->dev->kobj, EDAC_PCI_SYMLINK);
462 	if (err) {
463 		debugf0("%s() sysfs_create_link() returned err= %d\n",
464 			__func__, err);
465 		goto symlink_fail;
466 	}
467 
468 	return 0;
469 
470 	/* Error unwind stack */
471 symlink_fail:
472 	edac_pci_unregister_sysfs_instance_kobj(pci);
473 
474 unregister_cleanup:
475 	edac_pci_main_kobj_teardown();
476 
477 	return err;
478 }
479 
480 /*
481  * edac_pci_remove_sysfs
482  *
483  *	remove the controls and attributes for this EDAC PCI device
484  */
edac_pci_remove_sysfs(struct edac_pci_ctl_info * pci)485 void edac_pci_remove_sysfs(struct edac_pci_ctl_info *pci)
486 {
487 	debugf0("%s() index=%d\n", __func__, pci->pci_idx);
488 
489 	/* Remove the symlink */
490 	sysfs_remove_link(&pci->kobj, EDAC_PCI_SYMLINK);
491 
492 	/* remove this PCI instance's sysfs entries */
493 	edac_pci_unregister_sysfs_instance_kobj(pci);
494 
495 	/* Call the main unregister function, which will determine
496 	 * if this 'pci' is the last instance.
497 	 * If it is, the main kobject will be unregistered as a result
498 	 */
499 	debugf0("%s() calling edac_pci_main_kobj_teardown()\n", __func__);
500 	edac_pci_main_kobj_teardown();
501 }
502 
503 /************************ PCI error handling *************************/
get_pci_parity_status(struct pci_dev * dev,int secondary)504 static u16 get_pci_parity_status(struct pci_dev *dev, int secondary)
505 {
506 	int where;
507 	u16 status;
508 
509 	where = secondary ? PCI_SEC_STATUS : PCI_STATUS;
510 	pci_read_config_word(dev, where, &status);
511 
512 	/* If we get back 0xFFFF then we must suspect that the card has been
513 	 * pulled but the Linux PCI layer has not yet finished cleaning up.
514 	 * We don't want to report on such devices
515 	 */
516 
517 	if (status == 0xFFFF) {
518 		u32 sanity;
519 
520 		pci_read_config_dword(dev, 0, &sanity);
521 
522 		if (sanity == 0xFFFFFFFF)
523 			return 0;
524 	}
525 
526 	status &= PCI_STATUS_DETECTED_PARITY | PCI_STATUS_SIG_SYSTEM_ERROR |
527 		PCI_STATUS_PARITY;
528 
529 	if (status)
530 		/* reset only the bits we are interested in */
531 		pci_write_config_word(dev, where, status);
532 
533 	return status;
534 }
535 
536 
537 /* Clear any PCI parity errors logged by this device. */
edac_pci_dev_parity_clear(struct pci_dev * dev)538 static void edac_pci_dev_parity_clear(struct pci_dev *dev)
539 {
540 	u8 header_type;
541 
542 	get_pci_parity_status(dev, 0);
543 
544 	/* read the device TYPE, looking for bridges */
545 	pci_read_config_byte(dev, PCI_HEADER_TYPE, &header_type);
546 
547 	if ((header_type & 0x7F) == PCI_HEADER_TYPE_BRIDGE)
548 		get_pci_parity_status(dev, 1);
549 }
550 
551 /*
552  *  PCI Parity polling
553  *
554  *	Function to retrieve the current parity status
555  *	and decode it
556  *
557  */
edac_pci_dev_parity_test(struct pci_dev * dev)558 static void edac_pci_dev_parity_test(struct pci_dev *dev)
559 {
560 	unsigned long flags;
561 	u16 status;
562 	u8 header_type;
563 
564 	/* stop any interrupts until we can acquire the status */
565 	local_irq_save(flags);
566 
567 	/* read the STATUS register on this device */
568 	status = get_pci_parity_status(dev, 0);
569 
570 	/* read the device TYPE, looking for bridges */
571 	pci_read_config_byte(dev, PCI_HEADER_TYPE, &header_type);
572 
573 	local_irq_restore(flags);
574 
575 	debugf4("PCI STATUS= 0x%04x %s\n", status, dev_name(&dev->dev));
576 
577 	/* check the status reg for errors on boards NOT marked as broken
578 	 * if broken, we cannot trust any of the status bits
579 	 */
580 	if (status && !dev->broken_parity_status) {
581 		if (status & (PCI_STATUS_SIG_SYSTEM_ERROR)) {
582 			edac_printk(KERN_CRIT, EDAC_PCI,
583 				"Signaled System Error on %s\n",
584 				pci_name(dev));
585 			atomic_inc(&pci_nonparity_count);
586 		}
587 
588 		if (status & (PCI_STATUS_PARITY)) {
589 			edac_printk(KERN_CRIT, EDAC_PCI,
590 				"Master Data Parity Error on %s\n",
591 				pci_name(dev));
592 
593 			atomic_inc(&pci_parity_count);
594 		}
595 
596 		if (status & (PCI_STATUS_DETECTED_PARITY)) {
597 			edac_printk(KERN_CRIT, EDAC_PCI,
598 				"Detected Parity Error on %s\n",
599 				pci_name(dev));
600 
601 			atomic_inc(&pci_parity_count);
602 		}
603 	}
604 
605 
606 	debugf4("PCI HEADER TYPE= 0x%02x %s\n", header_type, dev_name(&dev->dev));
607 
608 	if ((header_type & 0x7F) == PCI_HEADER_TYPE_BRIDGE) {
609 		/* On bridges, need to examine secondary status register  */
610 		status = get_pci_parity_status(dev, 1);
611 
612 		debugf4("PCI SEC_STATUS= 0x%04x %s\n", status, dev_name(&dev->dev));
613 
614 		/* check the secondary status reg for errors,
615 		 * on NOT broken boards
616 		 */
617 		if (status && !dev->broken_parity_status) {
618 			if (status & (PCI_STATUS_SIG_SYSTEM_ERROR)) {
619 				edac_printk(KERN_CRIT, EDAC_PCI, "Bridge "
620 					"Signaled System Error on %s\n",
621 					pci_name(dev));
622 				atomic_inc(&pci_nonparity_count);
623 			}
624 
625 			if (status & (PCI_STATUS_PARITY)) {
626 				edac_printk(KERN_CRIT, EDAC_PCI, "Bridge "
627 					"Master Data Parity Error on "
628 					"%s\n", pci_name(dev));
629 
630 				atomic_inc(&pci_parity_count);
631 			}
632 
633 			if (status & (PCI_STATUS_DETECTED_PARITY)) {
634 				edac_printk(KERN_CRIT, EDAC_PCI, "Bridge "
635 					"Detected Parity Error on %s\n",
636 					pci_name(dev));
637 
638 				atomic_inc(&pci_parity_count);
639 			}
640 		}
641 	}
642 }
643 
644 /* reduce some complexity in definition of the iterator */
645 typedef void (*pci_parity_check_fn_t) (struct pci_dev *dev);
646 
647 /*
648  * pci_dev parity list iterator
649  *	Scan the PCI device list for one pass, looking for SERRORs
650  *	Master Parity ERRORS or Parity ERRORs on primary or secondary devices
651  */
edac_pci_dev_parity_iterator(pci_parity_check_fn_t fn)652 static inline void edac_pci_dev_parity_iterator(pci_parity_check_fn_t fn)
653 {
654 	struct pci_dev *dev = NULL;
655 
656 	/* request for kernel access to the next PCI device, if any,
657 	 * and while we are looking at it have its reference count
658 	 * bumped until we are done with it
659 	 */
660 	while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) {
661 		fn(dev);
662 	}
663 }
664 
665 /*
666  * edac_pci_do_parity_check
667  *
668  *	performs the actual PCI parity check operation
669  */
edac_pci_do_parity_check(void)670 void edac_pci_do_parity_check(void)
671 {
672 	int before_count;
673 
674 	debugf3("%s()\n", __func__);
675 
676 	/* if policy has PCI check off, leave now */
677 	if (!check_pci_errors)
678 		return;
679 
680 	before_count = atomic_read(&pci_parity_count);
681 
682 	/* scan all PCI devices looking for a Parity Error on devices and
683 	 * bridges.
684 	 * The iterator calls pci_get_device() which might sleep, thus
685 	 * we cannot disable interrupts in this scan.
686 	 */
687 	edac_pci_dev_parity_iterator(edac_pci_dev_parity_test);
688 
689 	/* Only if operator has selected panic on PCI Error */
690 	if (edac_pci_get_panic_on_pe()) {
691 		/* If the count is different 'after' from 'before' */
692 		if (before_count != atomic_read(&pci_parity_count))
693 			panic("EDAC: PCI Parity Error");
694 	}
695 }
696 
697 /*
698  * edac_pci_clear_parity_errors
699  *
700  *	function to perform an iteration over the PCI devices
701  *	and clearn their current status
702  */
edac_pci_clear_parity_errors(void)703 void edac_pci_clear_parity_errors(void)
704 {
705 	/* Clear any PCI bus parity errors that devices initially have logged
706 	 * in their registers.
707 	 */
708 	edac_pci_dev_parity_iterator(edac_pci_dev_parity_clear);
709 }
710 
711 /*
712  * edac_pci_handle_pe
713  *
714  *	Called to handle a PARITY ERROR event
715  */
edac_pci_handle_pe(struct edac_pci_ctl_info * pci,const char * msg)716 void edac_pci_handle_pe(struct edac_pci_ctl_info *pci, const char *msg)
717 {
718 
719 	/* global PE counter incremented by edac_pci_do_parity_check() */
720 	atomic_inc(&pci->counters.pe_count);
721 
722 	if (edac_pci_get_log_pe())
723 		edac_pci_printk(pci, KERN_WARNING,
724 				"Parity Error ctl: %s %d: %s\n",
725 				pci->ctl_name, pci->pci_idx, msg);
726 
727 	/*
728 	 * poke all PCI devices and see which one is the troublemaker
729 	 * panic() is called if set
730 	 */
731 	edac_pci_do_parity_check();
732 }
733 EXPORT_SYMBOL_GPL(edac_pci_handle_pe);
734 
735 
736 /*
737  * edac_pci_handle_npe
738  *
739  *	Called to handle a NON-PARITY ERROR event
740  */
edac_pci_handle_npe(struct edac_pci_ctl_info * pci,const char * msg)741 void edac_pci_handle_npe(struct edac_pci_ctl_info *pci, const char *msg)
742 {
743 
744 	/* global NPE counter incremented by edac_pci_do_parity_check() */
745 	atomic_inc(&pci->counters.npe_count);
746 
747 	if (edac_pci_get_log_npe())
748 		edac_pci_printk(pci, KERN_WARNING,
749 				"Non-Parity Error ctl: %s %d: %s\n",
750 				pci->ctl_name, pci->pci_idx, msg);
751 
752 	/*
753 	 * poke all PCI devices and see which one is the troublemaker
754 	 * panic() is called if set
755 	 */
756 	edac_pci_do_parity_check();
757 }
758 EXPORT_SYMBOL_GPL(edac_pci_handle_npe);
759 
760 /*
761  * Define the PCI parameter to the module
762  */
763 module_param(check_pci_errors, int, 0644);
764 MODULE_PARM_DESC(check_pci_errors,
765 		 "Check for PCI bus parity errors: 0=off 1=on");
766 module_param(edac_pci_panic_on_pe, int, 0644);
767 MODULE_PARM_DESC(edac_pci_panic_on_pe,
768 		 "Panic on PCI Bus Parity error: 0=off 1=on");
769 
770 #endif				/* CONFIG_PCI */
771