summaryrefslogtreecommitdiffstats
path: root/drivers/edac/edac_pci.c
blob: f1ac866498864dfbfc8e73ad091860d790142a68 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
/*
 * EDAC PCI component
 *
 * Author: Dave Jiang <djiang@mvista.com>
 *
 * 2007 (c) MontaVista Software, Inc. This file is licensed under
 * the terms of the GNU General Public License version 2. This program
 * is licensed "as is" without any warranty of any kind, whether express
 * or implied.
 *
 */
#include <linux/module.h>
#include <linux/types.h>
#include <linux/smp.h>
#include <linux/init.h>
#include <linux/sysctl.h>
#include <linux/highmem.h>
#include <linux/timer.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/ctype.h>
#include <linux/workqueue.h>
#include <asm/uaccess.h>
#include <asm/page.h>

#include "edac_core.h"
#include "edac_module.h"

static DEFINE_MUTEX(edac_pci_ctls_mutex);
static LIST_HEAD(edac_pci_list);
static atomic_t pci_indexes = ATOMIC_INIT(0);

/*
 * edac_pci_alloc_ctl_info
 *
 *	The alloc() function for the 'edac_pci' control info
 *	structure. The chip driver will allocate one of these for each
 *	edac_pci it is going to control/register with the EDAC CORE.
 */
struct edac_pci_ctl_info *edac_pci_alloc_ctl_info(unsigned int sz_pvt,
						const char *edac_pci_name)
{
	struct edac_pci_ctl_info *pci;
	void *p = NULL, *pvt;
	unsigned int size;

	debugf1("%s()\n", __func__);

	pci = edac_align_ptr(&p, sizeof(*pci), 1);
	pvt = edac_align_ptr(&p, 1, sz_pvt);
	size = ((unsigned long)pvt) + sz_pvt;

	/* Alloc the needed control struct memory */
	pci = kzalloc(size, GFP_KERNEL);
	if (pci  == NULL)
		return NULL;

	/* Now much private space */
	pvt = sz_pvt ? ((char *)pci) + ((unsigned long)pvt) : NULL;

	pci->pvt_info = pvt;
	pci->op_state = OP_ALLOC;

	snprintf(pci->name, strlen(edac_pci_name) + 1, "%s", edac_pci_name);

	return pci;
}
EXPORT_SYMBOL_GPL(edac_pci_alloc_ctl_info);

/*
 * edac_pci_free_ctl_info()
 *
 *	Last action on the pci control structure.
 *
 *	call the remove sysfs information, which will unregister
 *	this control struct's kobj. When that kobj's ref count
 *	goes to zero, its release function will be call and then
 *	kfree() the memory.
 */
void edac_pci_free_ctl_info(struct edac_pci_ctl_info *pci)
{
	debugf1("%s()\n", __func__);

	edac_pci_remove_sysfs(pci);
}
EXPORT_SYMBOL_GPL(edac_pci_free_ctl_info);

/*
 * find_edac_pci_by_dev()
 * 	scans the edac_pci list for a specific 'struct device *'
 *
 *	return NULL if not found, or return control struct pointer
 */
static struct edac_pci_ctl_info *find_edac_pci_by_dev(struct device *dev)
{
	struct edac_pci_ctl_info *pci;
	struct list_head *item;

	debugf1("%s()\n", __func__);

	list_for_each(item, &edac_pci_list) {
		pci = list_entry(item, struct edac_pci_ctl_info, link);

		if (pci->dev == dev)
			return pci;
	}

	return NULL;
}

/*
 * add_edac_pci_to_global_list
 * 	Before calling this function, caller must assign a unique value to
 * 	edac_dev->pci_idx.
 * 	Return:
 * 		0 on success
 * 		1 on failure
 */
static int add_edac_pci_to_global_list(struct edac_pci_ctl_info *pci)
{
	struct list_head *item, *insert_before;
	struct edac_pci_ctl_info *rover;

	debugf1("%s()\n", __func__);

	insert_before = &edac_pci_list;

	/* Determine if already on the list */
	rover = find_edac_pci_by_dev(pci->dev);
	if (unlikely(rover != NULL))
		goto fail0;

	/* Insert in ascending order by 'pci_idx', so find position */
	list_for_each(item, &edac_pci_list) {
		rover = list_entry(item, struct edac_pci_ctl_info, link);

		if (rover->pci_idx >= pci->pci_idx) {
			if (unlikely(rover->pci_idx == pci->pci_idx))
				goto fail1;

			insert_before = item;
			break;
		}
	}

	list_add_tail_rcu(&pci->link, insert_before);
	return 0;

fail0:
	edac_printk(KERN_WARNING, EDAC_PCI,
		"%s (%s) %s %s already assigned %d\n",
		dev_name(rover->dev), edac_dev_name(rover),
		rover->mod_name, rover->ctl_name, rover->pci_idx);
	return 1;

fail1:
	edac_printk(KERN_WARNING, EDAC_PCI,
		"but in low-level driver: attempt to assign\n"
		"\tduplicate pci_idx %d in %s()\n", rover->pci_idx,
		__func__);
	return 1;
}

/*
 * del_edac_pci_from_global_list
 *
 *	remove the PCI control struct from the global list
 */
static void del_edac_pci_from_global_list(struct edac_pci_ctl_info *pci)
{
	list_del_rcu(&pci->link);

	/* these are for safe removal of devices from global list while
	 * NMI handlers may be traversing list
	 */
	synchronize_rcu();
	INIT_LIST_HEAD(&pci->link);
}

#if 0
/* Older code, but might use in the future */

/*
 * edac_pci_find()
 * 	Search for an edac_pci_ctl_info structure whose index is 'idx'
 *
 * If found, return a pointer to the structure
 * Else return NULL.
 *
 * Caller must hold pci_ctls_mutex.
 */
struct edac_pci_ctl_info *edac_pci_find(int idx)
{
	struct list_head *item;
	struct edac_pci_ctl_info *pci;

	/* Iterage over list, looking for exact match of ID */
	list_for_each(item, &edac_pci_list) {
		pci = list_entry(item, struct edac_pci_ctl_info, link);

		if (pci->pci_idx >= idx) {
			if (pci->pci_idx == idx)
				return pci;

			/* not on list, so terminate early */
			break;
		}
	}

	return NULL;
}
EXPORT_SYMBOL_GPL(edac_pci_find);
#endif

/*
 * edac_pci_workq_function()
 *
 * 	periodic function that performs the operation
 *	scheduled by a workq request, for a given PCI control struct
 */
static void edac_pci_workq_function(struct work_struct *work_req)
{
	struct delayed_work *d_work = to_delayed_work(work_req);
	struct edac_pci_ctl_info *pci = to_edac_pci_ctl_work(d_work);
	int msec;
	unsigned long delay;

	debugf3("%s() checking\n", __func__);

	mutex_lock(&edac_pci_ctls_mutex);

	if (pci->op_state == OP_RUNNING_POLL) {
		/* we might be in POLL mode, but there may NOT be a poll func
		 */
		if ((pci->edac_check != NULL) && edac_pci_get_check_errors())
			pci->edac_check(pci);

		/* if we are on a one second period, then use round */
		msec = edac_pci_get_poll_msec();
		if (msec == 1000)
			delay = round_jiffies_relative(msecs_to_jiffies(msec));
		else
			delay = msecs_to_jiffies(msec);

		/* Reschedule only if we are in POLL mode */
		queue_delayed_work(edac_workqueue, &pci->work, delay);
	}

	mutex_unlock(&edac_pci_ctls_mutex);
}

/*
 * edac_pci_workq_setup()
 * 	initialize a workq item for this edac_pci instance
 * 	passing in the new delay period in msec
 *
 *	locking model:
 *		called when 'edac_pci_ctls_mutex' is locked
 */
static void edac_pci_workq_setup(struct edac_pci_ctl_info *pci,
				 unsigned int msec)
{
	debugf0("%s()\n", __func__);

	INIT_DELAYED_WORK(&pci->work, edac_pci_workq_function);
	queue_delayed_work(edac_workqueue, &pci->work,
			msecs_to_jiffies(edac_pci_get_poll_msec()));
}

/*
 * edac_pci_workq_teardown()
 * 	stop the workq processing on this edac_pci instance
 */
static void edac_pci_workq_teardown(struct edac_pci_ctl_info *pci)
{
	int status;

	debugf0("%s()\n", __func__);

	status = cancel_delayed_work(&pci->work);
	if (status == 0)
		flush_workqueue(edac_workqueue);
}

/*
 * edac_pci_reset_delay_period
 *
 *	called with a new period value for the workq period
 *	a) stop current workq timer
 *	b) restart workq timer with new value
 */
void edac_pci_reset_delay_period(struct edac_pci_ctl_info *pci,
				 unsigned long value)
{
	debugf0("%s()\n", __func__);

	edac_pci_workq_teardown(pci);

	/* need to lock for the setup */
	mutex_lock(&edac_pci_ctls_mutex);

	edac_pci_workq_setup(pci, value);

	mutex_unlock(&edac_pci_ctls_mutex);
}
EXPORT_SYMBOL_GPL(edac_pci_reset_delay_period);

/*
 * edac_pci_alloc_index: Allocate a unique PCI index number
 *
 * Return:
 *      allocated index number
 *
 */
int edac_pci_alloc_index(void)
{
	return atomic_inc_return(&pci_indexes) - 1;
}
EXPORT_SYMBOL_GPL(edac_pci_alloc_index);

/*
 * edac_pci_add_device: Insert the 'edac_dev' structure into the
 * edac_pci global list and create sysfs entries associated with
 * edac_pci structure.
 * @pci: pointer to the edac_device structure to be added to the list
 * @edac_idx: A unique numeric identifier to be assigned to the
 * 'edac_pci' structure.
 *
 * Return:
 *      0       Success
 *      !0      Failure
 */
int edac_pci_add_device(struct edac_pci_ctl_info *pci, int edac_idx)
{
	debugf0("%s()\n", __func__);

	pci->pci_idx = edac_idx;
	pci->start_time = jiffies;

	mutex_lock(&edac_pci_ctls_mutex);

	if (add_edac_pci_to_global_list(pci))
		goto fail0;

	if (edac_pci_create_sysfs(pci)) {
		edac_pci_printk(pci, KERN_WARNING,
				"failed to create sysfs pci\n");
		goto fail1;
	}

	if (pci->edac_check != NULL) {
		pci->op_state = OP_RUNNING_POLL;

		edac_pci_workq_setup(pci, 1000);
	} else {
		pci->op_state = OP_RUNNING_INTERRUPT;
	}

	edac_pci_printk(pci, KERN_INFO,
			"Giving out device to module '%s' controller '%s':"
			" DEV '%s' (%s)\n",
			pci->mod_name,
			pci->ctl_name,
			edac_dev_name(pci), edac_op_state_to_string(pci->op_state));

	mutex_unlock(&edac_pci_ctls_mutex);
	return 0;

	/* error unwind stack */
fail1:
	del_edac_pci_from_global_list(pci);
fail0:
	mutex_unlock(&edac_pci_ctls_mutex);
	return 1;
}
EXPORT_SYMBOL_GPL(edac_pci_add_device);

/*
 * edac_pci_del_device()
 * 	Remove sysfs entries for specified edac_pci structure and
 * 	then remove edac_pci structure from global list
 *
 * @dev:
 * 	Pointer to 'struct device' representing edac_pci structure
 * 	to remove
 *
 * Return:
 * 	Pointer to removed edac_pci structure,
 * 	or NULL if device not found
 */
struct edac_pci_ctl_info *edac_pci_del_device(struct device *dev)
{
	struct edac_pci_ctl_info *pci;

	debugf0("%s()\n", __func__);

	mutex_lock(&edac_pci_ctls_mutex);

	/* ensure the control struct is on the global list
	 * if not, then leave
	 */
	pci = find_edac_pci_by_dev(dev);
	if (pci  == NULL) {
		mutex_unlock(&edac_pci_ctls_mutex);
		return NULL;
	}

	pci->op_state = OP_OFFLINE;

	del_edac_pci_from_global_list(pci);

	mutex_unlock(&edac_pci_ctls_mutex);

	/* stop the workq timer */
	edac_pci_workq_teardown(pci);

	edac_printk(KERN_INFO, EDAC_PCI,
		"Removed device %d for %s %s: DEV %s\n",
		pci->pci_idx, pci->mod_name, pci->ctl_name, edac_dev_name(pci));

	return pci;
}
EXPORT_SYMBOL_GPL(edac_pci_del_device);

/*
 * edac_pci_generic_check
 *
 *	a Generic parity check API
 */
static void edac_pci_generic_check(struct edac_pci_ctl_info *pci)
{
	debugf4("%s()\n", __func__);
	edac_pci_do_parity_check();
}

/* free running instance index counter */
static int edac_pci_idx;
#define EDAC_PCI_GENCTL_NAME	"EDAC PCI controller"

struct edac_pci_gen_data {
	int edac_idx;
};

/*
 * edac_pci_create_generic_ctl
 *
 *	A generic constructor for a PCI parity polling device
 *	Some systems have more than one domain of PCI busses.
 *	For systems with one domain, then this API will
 *	provide for a generic poller.
 *
 *	This routine calls the edac_pci_alloc_ctl_info() for
 *	the generic device, with default values
 */
struct edac_pci_ctl_info *edac_pci_create_generic_ctl(struct device *dev,
						const char *mod_name)
{
	struct edac_pci_ctl_info *pci;
	struct edac_pci_gen_data *pdata;

	pci = edac_pci_alloc_ctl_info(sizeof(*pdata), EDAC_PCI_GENCTL_NAME);
	if (!pci)
		return NULL;

	pdata = pci->pvt_info;
	pci->dev = dev;
	dev_set_drvdata(pci->dev, pci);
	pci->dev_name = pci_name(to_pci_dev(dev));

	pci->mod_name = mod_name;
	pci->ctl_name = EDAC_PCI_GENCTL_NAME;
	pci->edac_check = edac_pci_generic_check;

	pdata->edac_idx = edac_pci_idx++;

	if (edac_pci_add_device(pci, pdata->edac_idx) > 0) {
		debugf3("%s(): failed edac_pci_add_device()\n", __func__);
		edac_pci_free_ctl_info(pci);
		return NULL;
	}

	return pci;
}
EXPORT_SYMBOL_GPL(edac_pci_create_generic_ctl);

/*
 * edac_pci_release_generic_ctl
 *
 *	The release function of a generic EDAC PCI polling device
 */
void edac_pci_release_generic_ctl(struct edac_pci_ctl_info *pci)
{
	debugf0("%s() pci mod=%s\n", __func__, pci->mod_name);

	edac_pci_del_device(pci->dev);
	edac_pci_free_ctl_info(pci);
}
EXPORT_SYMBOL_GPL(edac_pci_release_generic_ctl);