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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