xref: /openbmc/linux/drivers/edac/edac_pci_sysfs.c (revision cb4a0bec)
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_pci.h"
15 #include "edac_module.h"
16 
17 #define EDAC_PCI_SYMLINK	"device"
18 
19 /* data variables exported via sysfs */
20 static int check_pci_errors;		/* default NO check PCI parity */
21 static int edac_pci_panic_on_pe;	/* default NO panic on PCI Parity */
22 static int edac_pci_log_pe = 1;		/* log PCI parity errors */
23 static int edac_pci_log_npe = 1;	/* log PCI non-parity error errors */
24 static int edac_pci_poll_msec = 1000;	/* one second workq period */
25 
26 static atomic_t pci_parity_count = ATOMIC_INIT(0);
27 static atomic_t pci_nonparity_count = ATOMIC_INIT(0);
28 
29 static struct kobject *edac_pci_top_main_kobj;
30 static atomic_t edac_pci_sysfs_refcount = ATOMIC_INIT(0);
31 
32 /* getter functions for the data variables */
edac_pci_get_check_errors(void)33 int edac_pci_get_check_errors(void)
34 {
35 	return check_pci_errors;
36 }
37 
edac_pci_get_log_pe(void)38 static int edac_pci_get_log_pe(void)
39 {
40 	return edac_pci_log_pe;
41 }
42 
edac_pci_get_log_npe(void)43 static int edac_pci_get_log_npe(void)
44 {
45 	return edac_pci_log_npe;
46 }
47 
edac_pci_get_panic_on_pe(void)48 static int edac_pci_get_panic_on_pe(void)
49 {
50 	return edac_pci_panic_on_pe;
51 }
52 
edac_pci_get_poll_msec(void)53 int edac_pci_get_poll_msec(void)
54 {
55 	return edac_pci_poll_msec;
56 }
57 
58 /**************************** EDAC PCI sysfs instance *******************/
instance_pe_count_show(struct edac_pci_ctl_info * pci,char * data)59 static ssize_t instance_pe_count_show(struct edac_pci_ctl_info *pci, char *data)
60 {
61 	return sprintf(data, "%u\n", atomic_read(&pci->counters.pe_count));
62 }
63 
instance_npe_count_show(struct edac_pci_ctl_info * pci,char * data)64 static ssize_t instance_npe_count_show(struct edac_pci_ctl_info *pci,
65 				char *data)
66 {
67 	return sprintf(data, "%u\n", atomic_read(&pci->counters.npe_count));
68 }
69 
70 #define to_instance(k) container_of(k, struct edac_pci_ctl_info, kobj)
71 #define to_instance_attr(a) container_of(a, struct instance_attribute, attr)
72 
73 /* DEVICE instance kobject release() function */
edac_pci_instance_release(struct kobject * kobj)74 static void edac_pci_instance_release(struct kobject *kobj)
75 {
76 	struct edac_pci_ctl_info *pci;
77 
78 	edac_dbg(0, "\n");
79 
80 	/* Form pointer to containing struct, the pci control struct */
81 	pci = to_instance(kobj);
82 
83 	/* decrement reference count on top main kobj */
84 	kobject_put(edac_pci_top_main_kobj);
85 
86 	kfree(pci);	/* Free the control struct */
87 }
88 
89 /* instance specific attribute structure */
90 struct instance_attribute {
91 	struct attribute attr;
92 	ssize_t(*show) (struct edac_pci_ctl_info *, char *);
93 	ssize_t(*store) (struct edac_pci_ctl_info *, const char *, size_t);
94 };
95 
96 /* Function to 'show' fields from the edac_pci 'instance' structure */
edac_pci_instance_show(struct kobject * kobj,struct attribute * attr,char * buffer)97 static ssize_t edac_pci_instance_show(struct kobject *kobj,
98 				struct attribute *attr, char *buffer)
99 {
100 	struct edac_pci_ctl_info *pci = to_instance(kobj);
101 	struct instance_attribute *instance_attr = to_instance_attr(attr);
102 
103 	if (instance_attr->show)
104 		return instance_attr->show(pci, buffer);
105 	return -EIO;
106 }
107 
108 /* 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)109 static ssize_t edac_pci_instance_store(struct kobject *kobj,
110 				struct attribute *attr,
111 				const char *buffer, size_t count)
112 {
113 	struct edac_pci_ctl_info *pci = to_instance(kobj);
114 	struct instance_attribute *instance_attr = to_instance_attr(attr);
115 
116 	if (instance_attr->store)
117 		return instance_attr->store(pci, buffer, count);
118 	return -EIO;
119 }
120 
121 /* fs_ops table */
122 static const struct sysfs_ops pci_instance_ops = {
123 	.show = edac_pci_instance_show,
124 	.store = edac_pci_instance_store
125 };
126 
127 #define INSTANCE_ATTR(_name, _mode, _show, _store)	\
128 static struct instance_attribute attr_instance_##_name = {	\
129 	.attr	= {.name = __stringify(_name), .mode = _mode },	\
130 	.show	= _show,					\
131 	.store	= _store,					\
132 };
133 
134 INSTANCE_ATTR(pe_count, S_IRUGO, instance_pe_count_show, NULL);
135 INSTANCE_ATTR(npe_count, S_IRUGO, instance_npe_count_show, NULL);
136 
137 /* pci instance attributes */
138 static struct attribute *pci_instance_attrs[] = {
139 	&attr_instance_pe_count.attr,
140 	&attr_instance_npe_count.attr,
141 	NULL
142 };
143 ATTRIBUTE_GROUPS(pci_instance);
144 
145 /* the ktype for a pci instance */
146 static struct kobj_type ktype_pci_instance = {
147 	.release = edac_pci_instance_release,
148 	.sysfs_ops = &pci_instance_ops,
149 	.default_groups = pci_instance_groups,
150 };
151 
152 /*
153  * edac_pci_create_instance_kobj
154  *
155  *	construct one EDAC PCI instance's kobject for use
156  */
edac_pci_create_instance_kobj(struct edac_pci_ctl_info * pci,int idx)157 static int edac_pci_create_instance_kobj(struct edac_pci_ctl_info *pci, int idx)
158 {
159 	struct kobject *main_kobj;
160 	int err;
161 
162 	edac_dbg(0, "\n");
163 
164 	/* First bump the ref count on the top main kobj, which will
165 	 * track the number of PCI instances we have, and thus nest
166 	 * properly on keeping the module loaded
167 	 */
168 	main_kobj = kobject_get(edac_pci_top_main_kobj);
169 	if (!main_kobj) {
170 		err = -ENODEV;
171 		goto error_out;
172 	}
173 
174 	/* And now register this new kobject under the main kobj */
175 	err = kobject_init_and_add(&pci->kobj, &ktype_pci_instance,
176 				   edac_pci_top_main_kobj, "pci%d", idx);
177 	if (err != 0) {
178 		edac_dbg(2, "failed to register instance pci%d\n", idx);
179 		kobject_put(edac_pci_top_main_kobj);
180 		goto error_out;
181 	}
182 
183 	kobject_uevent(&pci->kobj, KOBJ_ADD);
184 	edac_dbg(1, "Register instance 'pci%d' kobject\n", idx);
185 
186 	return 0;
187 
188 	/* Error unwind statck */
189 error_out:
190 	return err;
191 }
192 
193 /*
194  * edac_pci_unregister_sysfs_instance_kobj
195  *
196  *	unregister the kobj for the EDAC PCI instance
197  */
edac_pci_unregister_sysfs_instance_kobj(struct edac_pci_ctl_info * pci)198 static void edac_pci_unregister_sysfs_instance_kobj(
199 			struct edac_pci_ctl_info *pci)
200 {
201 	edac_dbg(0, "\n");
202 
203 	/* Unregister the instance kobject and allow its release
204 	 * function release the main reference count and then
205 	 * kfree the memory
206 	 */
207 	kobject_put(&pci->kobj);
208 }
209 
210 /***************************** EDAC PCI sysfs root **********************/
211 #define to_edacpci(k) container_of(k, struct edac_pci_ctl_info, kobj)
212 #define to_edacpci_attr(a) container_of(a, struct edac_pci_attr, attr)
213 
214 /* simple show/store functions for attributes */
edac_pci_int_show(void * ptr,char * buffer)215 static ssize_t edac_pci_int_show(void *ptr, char *buffer)
216 {
217 	int *value = ptr;
218 	return sprintf(buffer, "%d\n", *value);
219 }
220 
edac_pci_int_store(void * ptr,const char * buffer,size_t count)221 static ssize_t edac_pci_int_store(void *ptr, const char *buffer, size_t count)
222 {
223 	int *value = ptr;
224 
225 	if (isdigit(*buffer))
226 		*value = simple_strtoul(buffer, NULL, 0);
227 
228 	return count;
229 }
230 
231 struct edac_pci_dev_attribute {
232 	struct attribute attr;
233 	void *value;
234 	 ssize_t(*show) (void *, char *);
235 	 ssize_t(*store) (void *, const char *, size_t);
236 };
237 
238 /* Set of show/store abstract level functions for PCI Parity object */
edac_pci_dev_show(struct kobject * kobj,struct attribute * attr,char * buffer)239 static ssize_t edac_pci_dev_show(struct kobject *kobj, struct attribute *attr,
240 				 char *buffer)
241 {
242 	struct edac_pci_dev_attribute *edac_pci_dev;
243 	edac_pci_dev = (struct edac_pci_dev_attribute *)attr;
244 
245 	if (edac_pci_dev->show)
246 		return edac_pci_dev->show(edac_pci_dev->value, buffer);
247 	return -EIO;
248 }
249 
edac_pci_dev_store(struct kobject * kobj,struct attribute * attr,const char * buffer,size_t count)250 static ssize_t edac_pci_dev_store(struct kobject *kobj,
251 				struct attribute *attr, const char *buffer,
252 				size_t count)
253 {
254 	struct edac_pci_dev_attribute *edac_pci_dev;
255 	edac_pci_dev = (struct edac_pci_dev_attribute *)attr;
256 
257 	if (edac_pci_dev->store)
258 		return edac_pci_dev->store(edac_pci_dev->value, buffer, count);
259 	return -EIO;
260 }
261 
262 static const struct sysfs_ops edac_pci_sysfs_ops = {
263 	.show = edac_pci_dev_show,
264 	.store = edac_pci_dev_store
265 };
266 
267 #define EDAC_PCI_ATTR(_name,_mode,_show,_store)			\
268 static struct edac_pci_dev_attribute edac_pci_attr_##_name = {		\
269 	.attr = {.name = __stringify(_name), .mode = _mode },	\
270 	.value  = &_name,					\
271 	.show   = _show,					\
272 	.store  = _store,					\
273 };
274 
275 #define EDAC_PCI_STRING_ATTR(_name,_data,_mode,_show,_store)	\
276 static struct edac_pci_dev_attribute edac_pci_attr_##_name = {		\
277 	.attr = {.name = __stringify(_name), .mode = _mode },	\
278 	.value  = _data,					\
279 	.show   = _show,					\
280 	.store  = _store,					\
281 };
282 
283 /* PCI Parity control files */
284 EDAC_PCI_ATTR(check_pci_errors, S_IRUGO | S_IWUSR, edac_pci_int_show,
285 	edac_pci_int_store);
286 EDAC_PCI_ATTR(edac_pci_log_pe, S_IRUGO | S_IWUSR, edac_pci_int_show,
287 	edac_pci_int_store);
288 EDAC_PCI_ATTR(edac_pci_log_npe, S_IRUGO | S_IWUSR, edac_pci_int_show,
289 	edac_pci_int_store);
290 EDAC_PCI_ATTR(edac_pci_panic_on_pe, S_IRUGO | S_IWUSR, edac_pci_int_show,
291 	edac_pci_int_store);
292 EDAC_PCI_ATTR(pci_parity_count, S_IRUGO, edac_pci_int_show, NULL);
293 EDAC_PCI_ATTR(pci_nonparity_count, S_IRUGO, edac_pci_int_show, NULL);
294 
295 /* Base Attributes of the memory ECC object */
296 static struct attribute *edac_pci_attrs[] = {
297 	&edac_pci_attr_check_pci_errors.attr,
298 	&edac_pci_attr_edac_pci_log_pe.attr,
299 	&edac_pci_attr_edac_pci_log_npe.attr,
300 	&edac_pci_attr_edac_pci_panic_on_pe.attr,
301 	&edac_pci_attr_pci_parity_count.attr,
302 	&edac_pci_attr_pci_nonparity_count.attr,
303 	NULL,
304 };
305 ATTRIBUTE_GROUPS(edac_pci);
306 
307 /*
308  * edac_pci_release_main_kobj
309  *
310  *	This release function is called when the reference count to the
311  *	passed kobj goes to zero.
312  *
313  *	This kobj is the 'main' kobject that EDAC PCI instances
314  *	link to, and thus provide for proper nesting counts
315  */
edac_pci_release_main_kobj(struct kobject * kobj)316 static void edac_pci_release_main_kobj(struct kobject *kobj)
317 {
318 	edac_dbg(0, "here to module_put(THIS_MODULE)\n");
319 
320 	kfree(kobj);
321 
322 	/* last reference to top EDAC PCI kobject has been removed,
323 	 * NOW release our ref count on the core module
324 	 */
325 	module_put(THIS_MODULE);
326 }
327 
328 /* ktype struct for the EDAC PCI main kobj */
329 static struct kobj_type ktype_edac_pci_main_kobj = {
330 	.release = edac_pci_release_main_kobj,
331 	.sysfs_ops = &edac_pci_sysfs_ops,
332 	.default_groups = edac_pci_groups,
333 };
334 
335 /**
336  * edac_pci_main_kobj_setup: Setup the sysfs for EDAC PCI attributes.
337  */
edac_pci_main_kobj_setup(void)338 static int edac_pci_main_kobj_setup(void)
339 {
340 	int err = -ENODEV;
341 	struct bus_type *edac_subsys;
342 	struct device *dev_root;
343 
344 	edac_dbg(0, "\n");
345 
346 	/* check and count if we have already created the main kobject */
347 	if (atomic_inc_return(&edac_pci_sysfs_refcount) != 1)
348 		return 0;
349 
350 	/* First time, so create the main kobject and its
351 	 * controls and attributes
352 	 */
353 	edac_subsys = edac_get_sysfs_subsys();
354 
355 	/* Bump the reference count on this module to ensure the
356 	 * modules isn't unloaded until we deconstruct the top
357 	 * level main kobj for EDAC PCI
358 	 */
359 	if (!try_module_get(THIS_MODULE)) {
360 		edac_dbg(1, "try_module_get() failed\n");
361 		goto decrement_count_fail;
362 	}
363 
364 	edac_pci_top_main_kobj = kzalloc(sizeof(struct kobject), GFP_KERNEL);
365 	if (!edac_pci_top_main_kobj) {
366 		edac_dbg(1, "Failed to allocate\n");
367 		err = -ENOMEM;
368 		goto kzalloc_fail;
369 	}
370 
371 	/* Instanstiate the pci object */
372 	dev_root = bus_get_dev_root(edac_subsys);
373 	if (dev_root) {
374 		err = kobject_init_and_add(edac_pci_top_main_kobj,
375 					   &ktype_edac_pci_main_kobj,
376 					   &dev_root->kobj, "pci");
377 		put_device(dev_root);
378 	}
379 	if (err) {
380 		edac_dbg(1, "Failed to register '.../edac/pci'\n");
381 		goto kobject_init_and_add_fail;
382 	}
383 
384 	/* At this point, to 'release' the top level kobject
385 	 * for EDAC PCI, then edac_pci_main_kobj_teardown()
386 	 * must be used, for resources to be cleaned up properly
387 	 */
388 	kobject_uevent(edac_pci_top_main_kobj, KOBJ_ADD);
389 	edac_dbg(1, "Registered '.../edac/pci' kobject\n");
390 
391 	return 0;
392 
393 	/* Error unwind statck */
394 kobject_init_and_add_fail:
395 	kobject_put(edac_pci_top_main_kobj);
396 
397 kzalloc_fail:
398 	module_put(THIS_MODULE);
399 
400 decrement_count_fail:
401 	/* if are on this error exit, nothing to tear down */
402 	atomic_dec(&edac_pci_sysfs_refcount);
403 
404 	return err;
405 }
406 
407 /*
408  * edac_pci_main_kobj_teardown()
409  *
410  *	if no longer linked (needed) remove the top level EDAC PCI
411  *	kobject with its controls and attributes
412  */
edac_pci_main_kobj_teardown(void)413 static void edac_pci_main_kobj_teardown(void)
414 {
415 	edac_dbg(0, "\n");
416 
417 	/* Decrement the count and only if no more controller instances
418 	 * are connected perform the unregisteration of the top level
419 	 * main kobj
420 	 */
421 	if (atomic_dec_return(&edac_pci_sysfs_refcount) == 0) {
422 		edac_dbg(0, "called kobject_put on main kobj\n");
423 		kobject_put(edac_pci_top_main_kobj);
424 	}
425 }
426 
edac_pci_create_sysfs(struct edac_pci_ctl_info * pci)427 int edac_pci_create_sysfs(struct edac_pci_ctl_info *pci)
428 {
429 	int err;
430 	struct kobject *edac_kobj = &pci->kobj;
431 
432 	edac_dbg(0, "idx=%d\n", pci->pci_idx);
433 
434 	/* create the top main EDAC PCI kobject, IF needed */
435 	err = edac_pci_main_kobj_setup();
436 	if (err)
437 		return err;
438 
439 	/* Create this instance's kobject under the MAIN kobject */
440 	err = edac_pci_create_instance_kobj(pci, pci->pci_idx);
441 	if (err)
442 		goto unregister_cleanup;
443 
444 	err = sysfs_create_link(edac_kobj, &pci->dev->kobj, EDAC_PCI_SYMLINK);
445 	if (err) {
446 		edac_dbg(0, "sysfs_create_link() returned err= %d\n", err);
447 		goto symlink_fail;
448 	}
449 
450 	return 0;
451 
452 	/* Error unwind stack */
453 symlink_fail:
454 	edac_pci_unregister_sysfs_instance_kobj(pci);
455 
456 unregister_cleanup:
457 	edac_pci_main_kobj_teardown();
458 
459 	return err;
460 }
461 
edac_pci_remove_sysfs(struct edac_pci_ctl_info * pci)462 void edac_pci_remove_sysfs(struct edac_pci_ctl_info *pci)
463 {
464 	edac_dbg(0, "index=%d\n", pci->pci_idx);
465 
466 	/* Remove the symlink */
467 	sysfs_remove_link(&pci->kobj, EDAC_PCI_SYMLINK);
468 
469 	/* remove this PCI instance's sysfs entries */
470 	edac_pci_unregister_sysfs_instance_kobj(pci);
471 
472 	/* Call the main unregister function, which will determine
473 	 * if this 'pci' is the last instance.
474 	 * If it is, the main kobject will be unregistered as a result
475 	 */
476 	edac_dbg(0, "calling edac_pci_main_kobj_teardown()\n");
477 	edac_pci_main_kobj_teardown();
478 }
479 
480 /************************ PCI error handling *************************/
get_pci_parity_status(struct pci_dev * dev,int secondary)481 static u16 get_pci_parity_status(struct pci_dev *dev, int secondary)
482 {
483 	int where;
484 	u16 status;
485 
486 	where = secondary ? PCI_SEC_STATUS : PCI_STATUS;
487 	pci_read_config_word(dev, where, &status);
488 
489 	/* If we get back 0xFFFF then we must suspect that the card has been
490 	 * pulled but the Linux PCI layer has not yet finished cleaning up.
491 	 * We don't want to report on such devices
492 	 */
493 
494 	if (status == 0xFFFF) {
495 		u32 sanity;
496 
497 		pci_read_config_dword(dev, 0, &sanity);
498 
499 		if (sanity == 0xFFFFFFFF)
500 			return 0;
501 	}
502 
503 	status &= PCI_STATUS_DETECTED_PARITY | PCI_STATUS_SIG_SYSTEM_ERROR |
504 		PCI_STATUS_PARITY;
505 
506 	if (status)
507 		/* reset only the bits we are interested in */
508 		pci_write_config_word(dev, where, status);
509 
510 	return status;
511 }
512 
513 
514 /* Clear any PCI parity errors logged by this device. */
edac_pci_dev_parity_clear(struct pci_dev * dev)515 static void edac_pci_dev_parity_clear(struct pci_dev *dev)
516 {
517 	u8 header_type;
518 
519 	get_pci_parity_status(dev, 0);
520 
521 	/* read the device TYPE, looking for bridges */
522 	pci_read_config_byte(dev, PCI_HEADER_TYPE, &header_type);
523 
524 	if ((header_type & 0x7F) == PCI_HEADER_TYPE_BRIDGE)
525 		get_pci_parity_status(dev, 1);
526 }
527 
528 /*
529  *  PCI Parity polling
530  *
531  *	Function to retrieve the current parity status
532  *	and decode it
533  *
534  */
edac_pci_dev_parity_test(struct pci_dev * dev)535 static void edac_pci_dev_parity_test(struct pci_dev *dev)
536 {
537 	unsigned long flags;
538 	u16 status;
539 	u8 header_type;
540 
541 	/* stop any interrupts until we can acquire the status */
542 	local_irq_save(flags);
543 
544 	/* read the STATUS register on this device */
545 	status = get_pci_parity_status(dev, 0);
546 
547 	/* read the device TYPE, looking for bridges */
548 	pci_read_config_byte(dev, PCI_HEADER_TYPE, &header_type);
549 
550 	local_irq_restore(flags);
551 
552 	edac_dbg(4, "PCI STATUS= 0x%04x %s\n", status, dev_name(&dev->dev));
553 
554 	/* check the status reg for errors on boards NOT marked as broken
555 	 * if broken, we cannot trust any of the status bits
556 	 */
557 	if (status && !dev->broken_parity_status) {
558 		if (status & (PCI_STATUS_SIG_SYSTEM_ERROR)) {
559 			edac_printk(KERN_CRIT, EDAC_PCI,
560 				"Signaled System Error on %s\n",
561 				pci_name(dev));
562 			atomic_inc(&pci_nonparity_count);
563 		}
564 
565 		if (status & (PCI_STATUS_PARITY)) {
566 			edac_printk(KERN_CRIT, EDAC_PCI,
567 				"Master Data Parity Error on %s\n",
568 				pci_name(dev));
569 
570 			atomic_inc(&pci_parity_count);
571 		}
572 
573 		if (status & (PCI_STATUS_DETECTED_PARITY)) {
574 			edac_printk(KERN_CRIT, EDAC_PCI,
575 				"Detected Parity Error on %s\n",
576 				pci_name(dev));
577 
578 			atomic_inc(&pci_parity_count);
579 		}
580 	}
581 
582 
583 	edac_dbg(4, "PCI HEADER TYPE= 0x%02x %s\n",
584 		 header_type, dev_name(&dev->dev));
585 
586 	if ((header_type & 0x7F) == PCI_HEADER_TYPE_BRIDGE) {
587 		/* On bridges, need to examine secondary status register  */
588 		status = get_pci_parity_status(dev, 1);
589 
590 		edac_dbg(4, "PCI SEC_STATUS= 0x%04x %s\n",
591 			 status, dev_name(&dev->dev));
592 
593 		/* check the secondary status reg for errors,
594 		 * on NOT broken boards
595 		 */
596 		if (status && !dev->broken_parity_status) {
597 			if (status & (PCI_STATUS_SIG_SYSTEM_ERROR)) {
598 				edac_printk(KERN_CRIT, EDAC_PCI, "Bridge "
599 					"Signaled System Error on %s\n",
600 					pci_name(dev));
601 				atomic_inc(&pci_nonparity_count);
602 			}
603 
604 			if (status & (PCI_STATUS_PARITY)) {
605 				edac_printk(KERN_CRIT, EDAC_PCI, "Bridge "
606 					"Master Data Parity Error on "
607 					"%s\n", pci_name(dev));
608 
609 				atomic_inc(&pci_parity_count);
610 			}
611 
612 			if (status & (PCI_STATUS_DETECTED_PARITY)) {
613 				edac_printk(KERN_CRIT, EDAC_PCI, "Bridge "
614 					"Detected Parity Error on %s\n",
615 					pci_name(dev));
616 
617 				atomic_inc(&pci_parity_count);
618 			}
619 		}
620 	}
621 }
622 
623 /* reduce some complexity in definition of the iterator */
624 typedef void (*pci_parity_check_fn_t) (struct pci_dev *dev);
625 
626 /*
627  * pci_dev parity list iterator
628  *
629  *	Scan the PCI device list looking for SERRORs, Master Parity ERRORS or
630  *	Parity ERRORs on primary or secondary devices.
631  */
edac_pci_dev_parity_iterator(pci_parity_check_fn_t fn)632 static inline void edac_pci_dev_parity_iterator(pci_parity_check_fn_t fn)
633 {
634 	struct pci_dev *dev = NULL;
635 
636 	for_each_pci_dev(dev)
637 		fn(dev);
638 }
639 
640 /*
641  * edac_pci_do_parity_check
642  *
643  *	performs the actual PCI parity check operation
644  */
edac_pci_do_parity_check(void)645 void edac_pci_do_parity_check(void)
646 {
647 	int before_count;
648 
649 	edac_dbg(3, "\n");
650 
651 	/* if policy has PCI check off, leave now */
652 	if (!check_pci_errors)
653 		return;
654 
655 	before_count = atomic_read(&pci_parity_count);
656 
657 	/* scan all PCI devices looking for a Parity Error on devices and
658 	 * bridges.
659 	 * The iterator calls pci_get_device() which might sleep, thus
660 	 * we cannot disable interrupts in this scan.
661 	 */
662 	edac_pci_dev_parity_iterator(edac_pci_dev_parity_test);
663 
664 	/* Only if operator has selected panic on PCI Error */
665 	if (edac_pci_get_panic_on_pe()) {
666 		/* If the count is different 'after' from 'before' */
667 		if (before_count != atomic_read(&pci_parity_count))
668 			panic("EDAC: PCI Parity Error");
669 	}
670 }
671 
672 /*
673  * edac_pci_clear_parity_errors
674  *
675  *	function to perform an iteration over the PCI devices
676  *	and clearn their current status
677  */
edac_pci_clear_parity_errors(void)678 void edac_pci_clear_parity_errors(void)
679 {
680 	/* Clear any PCI bus parity errors that devices initially have logged
681 	 * in their registers.
682 	 */
683 	edac_pci_dev_parity_iterator(edac_pci_dev_parity_clear);
684 }
685 
686 /*
687  * edac_pci_handle_pe
688  *
689  *	Called to handle a PARITY ERROR event
690  */
edac_pci_handle_pe(struct edac_pci_ctl_info * pci,const char * msg)691 void edac_pci_handle_pe(struct edac_pci_ctl_info *pci, const char *msg)
692 {
693 
694 	/* global PE counter incremented by edac_pci_do_parity_check() */
695 	atomic_inc(&pci->counters.pe_count);
696 
697 	if (edac_pci_get_log_pe())
698 		edac_pci_printk(pci, KERN_WARNING,
699 				"Parity Error ctl: %s %d: %s\n",
700 				pci->ctl_name, pci->pci_idx, msg);
701 
702 	/*
703 	 * poke all PCI devices and see which one is the troublemaker
704 	 * panic() is called if set
705 	 */
706 	edac_pci_do_parity_check();
707 }
708 EXPORT_SYMBOL_GPL(edac_pci_handle_pe);
709 
710 
711 /*
712  * edac_pci_handle_npe
713  *
714  *	Called to handle a NON-PARITY ERROR event
715  */
edac_pci_handle_npe(struct edac_pci_ctl_info * pci,const char * msg)716 void edac_pci_handle_npe(struct edac_pci_ctl_info *pci, const char *msg)
717 {
718 
719 	/* global NPE counter incremented by edac_pci_do_parity_check() */
720 	atomic_inc(&pci->counters.npe_count);
721 
722 	if (edac_pci_get_log_npe())
723 		edac_pci_printk(pci, KERN_WARNING,
724 				"Non-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_npe);
734 
735 /*
736  * Define the PCI parameter to the module
737  */
738 module_param(check_pci_errors, int, 0644);
739 MODULE_PARM_DESC(check_pci_errors,
740 		 "Check for PCI bus parity errors: 0=off 1=on");
741 module_param(edac_pci_panic_on_pe, int, 0644);
742 MODULE_PARM_DESC(edac_pci_panic_on_pe,
743 		 "Panic on PCI Bus Parity error: 0=off 1=on");
744