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 *pvt;
46 	unsigned int size;
47 
48 	debugf1("%s()\n", __func__);
49 
50 	pci = (struct edac_pci_ctl_info *)0;
51 	pvt = edac_align_ptr(&pci[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 	debugf1("%s()\n", __func__);
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 	debugf1("%s()\n", __func__);
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 	debugf1("%s()\n", __func__);
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 	debugf3("%s() checking\n", __func__);
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 	debugf0("%s()\n", __func__);
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 	int status;
278 
279 	debugf0("%s()\n", __func__);
280 
281 	status = cancel_delayed_work(&pci->work);
282 	if (status == 0)
283 		flush_workqueue(edac_workqueue);
284 }
285 
286 /*
287  * edac_pci_reset_delay_period
288  *
289  *	called with a new period value for the workq period
290  *	a) stop current workq timer
291  *	b) restart workq timer with new value
292  */
edac_pci_reset_delay_period(struct edac_pci_ctl_info * pci,unsigned long value)293 void edac_pci_reset_delay_period(struct edac_pci_ctl_info *pci,
294 				 unsigned long value)
295 {
296 	debugf0("%s()\n", __func__);
297 
298 	edac_pci_workq_teardown(pci);
299 
300 	/* need to lock for the setup */
301 	mutex_lock(&edac_pci_ctls_mutex);
302 
303 	edac_pci_workq_setup(pci, value);
304 
305 	mutex_unlock(&edac_pci_ctls_mutex);
306 }
307 EXPORT_SYMBOL_GPL(edac_pci_reset_delay_period);
308 
309 /*
310  * edac_pci_alloc_index: Allocate a unique PCI index number
311  *
312  * Return:
313  *      allocated index number
314  *
315  */
edac_pci_alloc_index(void)316 int edac_pci_alloc_index(void)
317 {
318 	return atomic_inc_return(&pci_indexes) - 1;
319 }
320 EXPORT_SYMBOL_GPL(edac_pci_alloc_index);
321 
322 /*
323  * edac_pci_add_device: Insert the 'edac_dev' structure into the
324  * edac_pci global list and create sysfs entries associated with
325  * edac_pci structure.
326  * @pci: pointer to the edac_device structure to be added to the list
327  * @edac_idx: A unique numeric identifier to be assigned to the
328  * 'edac_pci' structure.
329  *
330  * Return:
331  *      0       Success
332  *      !0      Failure
333  */
edac_pci_add_device(struct edac_pci_ctl_info * pci,int edac_idx)334 int edac_pci_add_device(struct edac_pci_ctl_info *pci, int edac_idx)
335 {
336 	debugf0("%s()\n", __func__);
337 
338 	pci->pci_idx = edac_idx;
339 	pci->start_time = jiffies;
340 
341 	mutex_lock(&edac_pci_ctls_mutex);
342 
343 	if (add_edac_pci_to_global_list(pci))
344 		goto fail0;
345 
346 	if (edac_pci_create_sysfs(pci)) {
347 		edac_pci_printk(pci, KERN_WARNING,
348 				"failed to create sysfs pci\n");
349 		goto fail1;
350 	}
351 
352 	if (pci->edac_check != NULL) {
353 		pci->op_state = OP_RUNNING_POLL;
354 
355 		edac_pci_workq_setup(pci, 1000);
356 	} else {
357 		pci->op_state = OP_RUNNING_INTERRUPT;
358 	}
359 
360 	edac_pci_printk(pci, KERN_INFO,
361 			"Giving out device to module '%s' controller '%s':"
362 			" DEV '%s' (%s)\n",
363 			pci->mod_name,
364 			pci->ctl_name,
365 			edac_dev_name(pci), edac_op_state_to_string(pci->op_state));
366 
367 	mutex_unlock(&edac_pci_ctls_mutex);
368 	return 0;
369 
370 	/* error unwind stack */
371 fail1:
372 	del_edac_pci_from_global_list(pci);
373 fail0:
374 	mutex_unlock(&edac_pci_ctls_mutex);
375 	return 1;
376 }
377 EXPORT_SYMBOL_GPL(edac_pci_add_device);
378 
379 /*
380  * edac_pci_del_device()
381  * 	Remove sysfs entries for specified edac_pci structure and
382  * 	then remove edac_pci structure from global list
383  *
384  * @dev:
385  * 	Pointer to 'struct device' representing edac_pci structure
386  * 	to remove
387  *
388  * Return:
389  * 	Pointer to removed edac_pci structure,
390  * 	or NULL if device not found
391  */
edac_pci_del_device(struct device * dev)392 struct edac_pci_ctl_info *edac_pci_del_device(struct device *dev)
393 {
394 	struct edac_pci_ctl_info *pci;
395 
396 	debugf0("%s()\n", __func__);
397 
398 	mutex_lock(&edac_pci_ctls_mutex);
399 
400 	/* ensure the control struct is on the global list
401 	 * if not, then leave
402 	 */
403 	pci = find_edac_pci_by_dev(dev);
404 	if (pci  == NULL) {
405 		mutex_unlock(&edac_pci_ctls_mutex);
406 		return NULL;
407 	}
408 
409 	pci->op_state = OP_OFFLINE;
410 
411 	del_edac_pci_from_global_list(pci);
412 
413 	mutex_unlock(&edac_pci_ctls_mutex);
414 
415 	/* stop the workq timer */
416 	edac_pci_workq_teardown(pci);
417 
418 	edac_printk(KERN_INFO, EDAC_PCI,
419 		"Removed device %d for %s %s: DEV %s\n",
420 		pci->pci_idx, pci->mod_name, pci->ctl_name, edac_dev_name(pci));
421 
422 	return pci;
423 }
424 EXPORT_SYMBOL_GPL(edac_pci_del_device);
425 
426 /*
427  * edac_pci_generic_check
428  *
429  *	a Generic parity check API
430  */
edac_pci_generic_check(struct edac_pci_ctl_info * pci)431 static void edac_pci_generic_check(struct edac_pci_ctl_info *pci)
432 {
433 	debugf4("%s()\n", __func__);
434 	edac_pci_do_parity_check();
435 }
436 
437 /* free running instance index counter */
438 static int edac_pci_idx;
439 #define EDAC_PCI_GENCTL_NAME	"EDAC PCI controller"
440 
441 struct edac_pci_gen_data {
442 	int edac_idx;
443 };
444 
445 /*
446  * edac_pci_create_generic_ctl
447  *
448  *	A generic constructor for a PCI parity polling device
449  *	Some systems have more than one domain of PCI busses.
450  *	For systems with one domain, then this API will
451  *	provide for a generic poller.
452  *
453  *	This routine calls the edac_pci_alloc_ctl_info() for
454  *	the generic device, with default values
455  */
edac_pci_create_generic_ctl(struct device * dev,const char * mod_name)456 struct edac_pci_ctl_info *edac_pci_create_generic_ctl(struct device *dev,
457 						const char *mod_name)
458 {
459 	struct edac_pci_ctl_info *pci;
460 	struct edac_pci_gen_data *pdata;
461 
462 	pci = edac_pci_alloc_ctl_info(sizeof(*pdata), EDAC_PCI_GENCTL_NAME);
463 	if (!pci)
464 		return NULL;
465 
466 	pdata = pci->pvt_info;
467 	pci->dev = dev;
468 	dev_set_drvdata(pci->dev, pci);
469 	pci->dev_name = pci_name(to_pci_dev(dev));
470 
471 	pci->mod_name = mod_name;
472 	pci->ctl_name = EDAC_PCI_GENCTL_NAME;
473 	pci->edac_check = edac_pci_generic_check;
474 
475 	pdata->edac_idx = edac_pci_idx++;
476 
477 	if (edac_pci_add_device(pci, pdata->edac_idx) > 0) {
478 		debugf3("%s(): failed edac_pci_add_device()\n", __func__);
479 		edac_pci_free_ctl_info(pci);
480 		return NULL;
481 	}
482 
483 	return pci;
484 }
485 EXPORT_SYMBOL_GPL(edac_pci_create_generic_ctl);
486 
487 /*
488  * edac_pci_release_generic_ctl
489  *
490  *	The release function of a generic EDAC PCI polling device
491  */
edac_pci_release_generic_ctl(struct edac_pci_ctl_info * pci)492 void edac_pci_release_generic_ctl(struct edac_pci_ctl_info *pci)
493 {
494 	debugf0("%s() pci mod=%s\n", __func__, pci->mod_name);
495 
496 	edac_pci_del_device(pci->dev);
497 	edac_pci_free_ctl_info(pci);
498 }
499 EXPORT_SYMBOL_GPL(edac_pci_release_generic_ctl);
500