summaryrefslogtreecommitdiff
path: root/drivers/pci/endpoint/pci-epc-core.c
blob: dd750ad29485ed903bb4827f26c477b4cc8038f3 (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
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
// SPDX-License-Identifier: GPL-2.0
/*
 * PCI Endpoint *Controller* (EPC) library
 *
 * Copyright (C) 2017 Texas Instruments
 * Author: Kishon Vijay Abraham I <kishon@ti.com>
 */

#include <linux/device.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/of_device.h>

#include <linux/pci-epc.h>
#include <linux/pci-epf.h>
#include <linux/pci-ep-cfs.h>

static struct class *pci_epc_class;

static void devm_pci_epc_release(struct device *dev, void *res)
{
	struct pci_epc *epc = *(struct pci_epc **)res;

	pci_epc_destroy(epc);
}

static int devm_pci_epc_match(struct device *dev, void *res, void *match_data)
{
	struct pci_epc **epc = res;

	return *epc == match_data;
}

/**
 * pci_epc_put() - release the PCI endpoint controller
 * @epc: epc returned by pci_epc_get()
 *
 * release the refcount the caller obtained by invoking pci_epc_get()
 */
void pci_epc_put(struct pci_epc *epc)
{
	if (!epc || IS_ERR(epc))
		return;

	module_put(epc->ops->owner);
	put_device(&epc->dev);
}
EXPORT_SYMBOL_GPL(pci_epc_put);

/**
 * pci_epc_get() - get the PCI endpoint controller
 * @epc_name: device name of the endpoint controller
 *
 * Invoke to get struct pci_epc * corresponding to the device name of the
 * endpoint controller
 */
struct pci_epc *pci_epc_get(const char *epc_name)
{
	int ret = -EINVAL;
	struct pci_epc *epc;
	struct device *dev;
	struct class_dev_iter iter;

	class_dev_iter_init(&iter, pci_epc_class, NULL, NULL);
	while ((dev = class_dev_iter_next(&iter))) {
		if (strcmp(epc_name, dev_name(dev)))
			continue;

		epc = to_pci_epc(dev);
		if (!try_module_get(epc->ops->owner)) {
			ret = -EINVAL;
			goto err;
		}

		class_dev_iter_exit(&iter);
		get_device(&epc->dev);
		return epc;
	}

err:
	class_dev_iter_exit(&iter);
	return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(pci_epc_get);

/**
 * pci_epc_get_first_free_bar() - helper to get first unreserved BAR
 * @epc_features: pci_epc_features structure that holds the reserved bar bitmap
 *
 * Invoke to get the first unreserved BAR that can be used by the endpoint
 * function. For any incorrect value in reserved_bar return '0'.
 */
enum pci_barno
pci_epc_get_first_free_bar(const struct pci_epc_features *epc_features)
{
	return pci_epc_get_next_free_bar(epc_features, BAR_0);
}
EXPORT_SYMBOL_GPL(pci_epc_get_first_free_bar);

/**
 * pci_epc_get_next_free_bar() - helper to get unreserved BAR starting from @bar
 * @epc_features: pci_epc_features structure that holds the reserved bar bitmap
 * @bar: the starting BAR number from where unreserved BAR should be searched
 *
 * Invoke to get the next unreserved BAR starting from @bar that can be used
 * for endpoint function. For any incorrect value in reserved_bar return '0'.
 */
enum pci_barno pci_epc_get_next_free_bar(const struct pci_epc_features
					 *epc_features, enum pci_barno bar)
{
	unsigned long free_bar;

	if (!epc_features)
		return BAR_0;

	/* If 'bar - 1' is a 64-bit BAR, move to the next BAR */
	if ((epc_features->bar_fixed_64bit << 1) & 1 << bar)
		bar++;

	/* Find if the reserved BAR is also a 64-bit BAR */
	free_bar = epc_features->reserved_bar & epc_features->bar_fixed_64bit;

	/* Set the adjacent bit if the reserved BAR is also a 64-bit BAR */
	free_bar <<= 1;
	free_bar |= epc_features->reserved_bar;

	free_bar = find_next_zero_bit(&free_bar, 6, bar);
	if (free_bar > 5)
		return NO_BAR;

	return free_bar;
}
EXPORT_SYMBOL_GPL(pci_epc_get_next_free_bar);

/**
 * pci_epc_get_features() - get the features supported by EPC
 * @epc: the features supported by *this* EPC device will be returned
 * @func_no: the features supported by the EPC device specific to the
 *	     endpoint function with func_no will be returned
 * @vfunc_no: the features supported by the EPC device specific to the
 *	     virtual endpoint function with vfunc_no will be returned
 *
 * Invoke to get the features provided by the EPC which may be
 * specific to an endpoint function. Returns pci_epc_features on success
 * and NULL for any failures.
 */
const struct pci_epc_features *pci_epc_get_features(struct pci_epc *epc,
						    u8 func_no, u8 vfunc_no)
{
	const struct pci_epc_features *epc_features;

	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)
		return NULL;

	if (vfunc_no > 0 && (!epc->max_vfs || vfunc_no > epc->max_vfs[func_no]))
		return NULL;

	if (!epc->ops->get_features)
		return NULL;

	mutex_lock(&epc->lock);
	epc_features = epc->ops->get_features(epc, func_no, vfunc_no);
	mutex_unlock(&epc->lock);

	return epc_features;
}
EXPORT_SYMBOL_GPL(pci_epc_get_features);

/**
 * pci_epc_stop() - stop the PCI link
 * @epc: the link of the EPC device that has to be stopped
 *
 * Invoke to stop the PCI link
 */
void pci_epc_stop(struct pci_epc *epc)
{
	if (IS_ERR(epc) || !epc->ops->stop)
		return;

	mutex_lock(&epc->lock);
	epc->ops->stop(epc);
	mutex_unlock(&epc->lock);
}
EXPORT_SYMBOL_GPL(pci_epc_stop);

/**
 * pci_epc_start() - start the PCI link
 * @epc: the link of *this* EPC device has to be started
 *
 * Invoke to start the PCI link
 */
int pci_epc_start(struct pci_epc *epc)
{
	int ret;

	if (IS_ERR(epc))
		return -EINVAL;

	if (!epc->ops->start)
		return 0;

	mutex_lock(&epc->lock);
	ret = epc->ops->start(epc);
	mutex_unlock(&epc->lock);

	return ret;
}
EXPORT_SYMBOL_GPL(pci_epc_start);

/**
 * pci_epc_raise_irq() - interrupt the host system
 * @epc: the EPC device which has to interrupt the host
 * @func_no: the physical endpoint function number in the EPC device
 * @vfunc_no: the virtual endpoint function number in the physical function
 * @type: specify the type of interrupt; legacy, MSI or MSI-X
 * @interrupt_num: the MSI or MSI-X interrupt number
 *
 * Invoke to raise an legacy, MSI or MSI-X interrupt
 */
int pci_epc_raise_irq(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
		      enum pci_epc_irq_type type, u16 interrupt_num)
{
	int ret;

	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)
		return -EINVAL;

	if (vfunc_no > 0 && (!epc->max_vfs || vfunc_no > epc->max_vfs[func_no]))
		return -EINVAL;

	if (!epc->ops->raise_irq)
		return 0;

	mutex_lock(&epc->lock);
	ret = epc->ops->raise_irq(epc, func_no, vfunc_no, type, interrupt_num);
	mutex_unlock(&epc->lock);

	return ret;
}
EXPORT_SYMBOL_GPL(pci_epc_raise_irq);

/**
 * pci_epc_map_msi_irq() - Map physical address to MSI address and return
 *                         MSI data
 * @epc: the EPC device which has the MSI capability
 * @func_no: the physical endpoint function number in the EPC device
 * @vfunc_no: the virtual endpoint function number in the physical function
 * @phys_addr: the physical address of the outbound region
 * @interrupt_num: the MSI interrupt number
 * @entry_size: Size of Outbound address region for each interrupt
 * @msi_data: the data that should be written in order to raise MSI interrupt
 *            with interrupt number as 'interrupt num'
 * @msi_addr_offset: Offset of MSI address from the aligned outbound address
 *                   to which the MSI address is mapped
 *
 * Invoke to map physical address to MSI address and return MSI data. The
 * physical address should be an address in the outbound region. This is
 * required to implement doorbell functionality of NTB wherein EPC on either
 * side of the interface (primary and secondary) can directly write to the
 * physical address (in outbound region) of the other interface to ring
 * doorbell.
 */
int pci_epc_map_msi_irq(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
			phys_addr_t phys_addr, u8 interrupt_num, u32 entry_size,
			u32 *msi_data, u32 *msi_addr_offset)
{
	int ret;

	if (IS_ERR_OR_NULL(epc))
		return -EINVAL;

	if (vfunc_no > 0 && (!epc->max_vfs || vfunc_no > epc->max_vfs[func_no]))
		return -EINVAL;

	if (!epc->ops->map_msi_irq)
		return -EINVAL;

	mutex_lock(&epc->lock);
	ret = epc->ops->map_msi_irq(epc, func_no, vfunc_no, phys_addr,
				    interrupt_num, entry_size, msi_data,
				    msi_addr_offset);
	mutex_unlock(&epc->lock);

	return ret;
}
EXPORT_SYMBOL_GPL(pci_epc_map_msi_irq);

/**
 * pci_epc_get_msi() - get the number of MSI interrupt numbers allocated
 * @epc: the EPC device to which MSI interrupts was requested
 * @func_no: the physical endpoint function number in the EPC device
 * @vfunc_no: the virtual endpoint function number in the physical function
 *
 * Invoke to get the number of MSI interrupts allocated by the RC
 */
int pci_epc_get_msi(struct pci_epc *epc, u8 func_no, u8 vfunc_no)
{
	int interrupt;

	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)
		return 0;

	if (vfunc_no > 0 && (!epc->max_vfs || vfunc_no > epc->max_vfs[func_no]))
		return 0;

	if (!epc->ops->get_msi)
		return 0;

	mutex_lock(&epc->lock);
	interrupt = epc->ops->get_msi(epc, func_no, vfunc_no);
	mutex_unlock(&epc->lock);

	if (interrupt < 0)
		return 0;

	interrupt = 1 << interrupt;

	return interrupt;
}
EXPORT_SYMBOL_GPL(pci_epc_get_msi);

/**
 * pci_epc_set_msi() - set the number of MSI interrupt numbers required
 * @epc: the EPC device on which MSI has to be configured
 * @func_no: the physical endpoint function number in the EPC device
 * @vfunc_no: the virtual endpoint function number in the physical function
 * @interrupts: number of MSI interrupts required by the EPF
 *
 * Invoke to set the required number of MSI interrupts.
 */
int pci_epc_set_msi(struct pci_epc *epc, u8 func_no, u8 vfunc_no, u8 interrupts)
{
	int ret;
	u8 encode_int;

	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions ||
	    interrupts < 1 || interrupts > 32)
		return -EINVAL;

	if (vfunc_no > 0 && (!epc->max_vfs || vfunc_no > epc->max_vfs[func_no]))
		return -EINVAL;

	if (!epc->ops->set_msi)
		return 0;

	encode_int = order_base_2(interrupts);

	mutex_lock(&epc->lock);
	ret = epc->ops->set_msi(epc, func_no, vfunc_no, encode_int);
	mutex_unlock(&epc->lock);

	return ret;
}
EXPORT_SYMBOL_GPL(pci_epc_set_msi);

/**
 * pci_epc_get_msix() - get the number of MSI-X interrupt numbers allocated
 * @epc: the EPC device to which MSI-X interrupts was requested
 * @func_no: the physical endpoint function number in the EPC device
 * @vfunc_no: the virtual endpoint function number in the physical function
 *
 * Invoke to get the number of MSI-X interrupts allocated by the RC
 */
int pci_epc_get_msix(struct pci_epc *epc, u8 func_no, u8 vfunc_no)
{
	int interrupt;

	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)
		return 0;

	if (vfunc_no > 0 && (!epc->max_vfs || vfunc_no > epc->max_vfs[func_no]))
		return 0;

	if (!epc->ops->get_msix)
		return 0;

	mutex_lock(&epc->lock);
	interrupt = epc->ops->get_msix(epc, func_no, vfunc_no);
	mutex_unlock(&epc->lock);

	if (interrupt < 0)
		return 0;

	return interrupt + 1;
}
EXPORT_SYMBOL_GPL(pci_epc_get_msix);

/**
 * pci_epc_set_msix() - set the number of MSI-X interrupt numbers required
 * @epc: the EPC device on which MSI-X has to be configured
 * @func_no: the physical endpoint function number in the EPC device
 * @vfunc_no: the virtual endpoint function number in the physical function
 * @interrupts: number of MSI-X interrupts required by the EPF
 * @bir: BAR where the MSI-X table resides
 * @offset: Offset pointing to the start of MSI-X table
 *
 * Invoke to set the required number of MSI-X interrupts.
 */
int pci_epc_set_msix(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
		     u16 interrupts, enum pci_barno bir, u32 offset)
{
	int ret;

	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions ||
	    interrupts < 1 || interrupts > 2048)
		return -EINVAL;

	if (vfunc_no > 0 && (!epc->max_vfs || vfunc_no > epc->max_vfs[func_no]))
		return -EINVAL;

	if (!epc->ops->set_msix)
		return 0;

	mutex_lock(&epc->lock);
	ret = epc->ops->set_msix(epc, func_no, vfunc_no, interrupts - 1, bir,
				 offset);
	mutex_unlock(&epc->lock);

	return ret;
}
EXPORT_SYMBOL_GPL(pci_epc_set_msix);

/**
 * pci_epc_unmap_addr() - unmap CPU address from PCI address
 * @epc: the EPC device on which address is allocated
 * @func_no: the physical endpoint function number in the EPC device
 * @vfunc_no: the virtual endpoint function number in the physical function
 * @phys_addr: physical address of the local system
 *
 * Invoke to unmap the CPU address from PCI address.
 */
void pci_epc_unmap_addr(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
			phys_addr_t phys_addr)
{
	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)
		return;

	if (vfunc_no > 0 && (!epc->max_vfs || vfunc_no > epc->max_vfs[func_no]))
		return;

	if (!epc->ops->unmap_addr)
		return;

	mutex_lock(&epc->lock);
	epc->ops->unmap_addr(epc, func_no, vfunc_no, phys_addr);
	mutex_unlock(&epc->lock);
}
EXPORT_SYMBOL_GPL(pci_epc_unmap_addr);

/**
 * pci_epc_map_addr() - map CPU address to PCI address
 * @epc: the EPC device on which address is allocated
 * @func_no: the physical endpoint function number in the EPC device
 * @vfunc_no: the virtual endpoint function number in the physical function
 * @phys_addr: physical address of the local system
 * @pci_addr: PCI address to which the physical address should be mapped
 * @size: the size of the allocation
 *
 * Invoke to map CPU address with PCI address.
 */
int pci_epc_map_addr(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
		     phys_addr_t phys_addr, u64 pci_addr, size_t size)
{
	int ret;

	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)
		return -EINVAL;

	if (vfunc_no > 0 && (!epc->max_vfs || vfunc_no > epc->max_vfs[func_no]))
		return -EINVAL;

	if (!epc->ops->map_addr)
		return 0;

	mutex_lock(&epc->lock);
	ret = epc->ops->map_addr(epc, func_no, vfunc_no, phys_addr, pci_addr,
				 size);
	mutex_unlock(&epc->lock);

	return ret;
}
EXPORT_SYMBOL_GPL(pci_epc_map_addr);

/**
 * pci_epc_clear_bar() - reset the BAR
 * @epc: the EPC device for which the BAR has to be cleared
 * @func_no: the physical endpoint function number in the EPC device
 * @vfunc_no: the virtual endpoint function number in the physical function
 * @epf_bar: the struct epf_bar that contains the BAR information
 *
 * Invoke to reset the BAR of the endpoint device.
 */
void pci_epc_clear_bar(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
		       struct pci_epf_bar *epf_bar)
{
	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions ||
	    (epf_bar->barno == BAR_5 &&
	     epf_bar->flags & PCI_BASE_ADDRESS_MEM_TYPE_64))
		return;

	if (vfunc_no > 0 && (!epc->max_vfs || vfunc_no > epc->max_vfs[func_no]))
		return;

	if (!epc->ops->clear_bar)
		return;

	mutex_lock(&epc->lock);
	epc->ops->clear_bar(epc, func_no, vfunc_no, epf_bar);
	mutex_unlock(&epc->lock);
}
EXPORT_SYMBOL_GPL(pci_epc_clear_bar);

/**
 * pci_epc_set_bar() - configure BAR in order for host to assign PCI addr space
 * @epc: the EPC device on which BAR has to be configured
 * @func_no: the physical endpoint function number in the EPC device
 * @vfunc_no: the virtual endpoint function number in the physical function
 * @epf_bar: the struct epf_bar that contains the BAR information
 *
 * Invoke to configure the BAR of the endpoint device.
 */
int pci_epc_set_bar(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
		    struct pci_epf_bar *epf_bar)
{
	int ret;
	int flags = epf_bar->flags;

	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions ||
	    (epf_bar->barno == BAR_5 &&
	     flags & PCI_BASE_ADDRESS_MEM_TYPE_64) ||
	    (flags & PCI_BASE_ADDRESS_SPACE_IO &&
	     flags & PCI_BASE_ADDRESS_IO_MASK) ||
	    (upper_32_bits(epf_bar->size) &&
	     !(flags & PCI_BASE_ADDRESS_MEM_TYPE_64)))
		return -EINVAL;

	if (vfunc_no > 0 && (!epc->max_vfs || vfunc_no > epc->max_vfs[func_no]))
		return -EINVAL;

	if (!epc->ops->set_bar)
		return 0;

	mutex_lock(&epc->lock);
	ret = epc->ops->set_bar(epc, func_no, vfunc_no, epf_bar);
	mutex_unlock(&epc->lock);

	return ret;
}
EXPORT_SYMBOL_GPL(pci_epc_set_bar);

/**
 * pci_epc_write_header() - write standard configuration header
 * @epc: the EPC device to which the configuration header should be written
 * @func_no: the physical endpoint function number in the EPC device
 * @vfunc_no: the virtual endpoint function number in the physical function
 * @header: standard configuration header fields
 *
 * Invoke to write the configuration header to the endpoint controller. Every
 * endpoint controller will have a dedicated location to which the standard
 * configuration header would be written. The callback function should write
 * the header fields to this dedicated location.
 */
int pci_epc_write_header(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
			 struct pci_epf_header *header)
{
	int ret;

	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)
		return -EINVAL;

	if (vfunc_no > 0 && (!epc->max_vfs || vfunc_no > epc->max_vfs[func_no]))
		return -EINVAL;

	/* Only Virtual Function #1 has deviceID */
	if (vfunc_no > 1)
		return -EINVAL;

	if (!epc->ops->write_header)
		return 0;

	mutex_lock(&epc->lock);
	ret = epc->ops->write_header(epc, func_no, vfunc_no, header);
	mutex_unlock(&epc->lock);

	return ret;
}
EXPORT_SYMBOL_GPL(pci_epc_write_header);

/**
 * pci_epc_add_epf() - bind PCI endpoint function to an endpoint controller
 * @epc: the EPC device to which the endpoint function should be added
 * @epf: the endpoint function to be added
 * @type: Identifies if the EPC is connected to the primary or secondary
 *        interface of EPF
 *
 * A PCI endpoint device can have one or more functions. In the case of PCIe,
 * the specification allows up to 8 PCIe endpoint functions. Invoke
 * pci_epc_add_epf() to add a PCI endpoint function to an endpoint controller.
 */
int pci_epc_add_epf(struct pci_epc *epc, struct pci_epf *epf,
		    enum pci_epc_interface_type type)
{
	struct list_head *list;
	u32 func_no;
	int ret = 0;

	if (IS_ERR_OR_NULL(epc) || epf->is_vf)
		return -EINVAL;

	if (type == PRIMARY_INTERFACE && epf->epc)
		return -EBUSY;

	if (type == SECONDARY_INTERFACE && epf->sec_epc)
		return -EBUSY;

	mutex_lock(&epc->lock);
	func_no = find_first_zero_bit(&epc->function_num_map,
				      BITS_PER_LONG);
	if (func_no >= BITS_PER_LONG) {
		ret = -EINVAL;
		goto ret;
	}

	if (func_no > epc->max_functions - 1) {
		dev_err(&epc->dev, "Exceeding max supported Function Number\n");
		ret = -EINVAL;
		goto ret;
	}

	set_bit(func_no, &epc->function_num_map);
	if (type == PRIMARY_INTERFACE) {
		epf->func_no = func_no;
		epf->epc = epc;
		list = &epf->list;
	} else {
		epf->sec_epc_func_no = func_no;
		epf->sec_epc = epc;
		list = &epf->sec_epc_list;
	}

	list_add_tail(list, &epc->pci_epf);
ret:
	mutex_unlock(&epc->lock);

	return ret;
}
EXPORT_SYMBOL_GPL(pci_epc_add_epf);

/**
 * pci_epc_remove_epf() - remove PCI endpoint function from endpoint controller
 * @epc: the EPC device from which the endpoint function should be removed
 * @epf: the endpoint function to be removed
 * @type: identifies if the EPC is connected to the primary or secondary
 *        interface of EPF
 *
 * Invoke to remove PCI endpoint function from the endpoint controller.
 */
void pci_epc_remove_epf(struct pci_epc *epc, struct pci_epf *epf,
			enum pci_epc_interface_type type)
{
	struct list_head *list;
	u32 func_no = 0;

	if (!epc || IS_ERR(epc) || !epf)
		return;

	if (type == PRIMARY_INTERFACE) {
		func_no = epf->func_no;
		list = &epf->list;
	} else {
		func_no = epf->sec_epc_func_no;
		list = &epf->sec_epc_list;
	}

	mutex_lock(&epc->lock);
	clear_bit(func_no, &epc->function_num_map);
	list_del(list);
	epf->epc = NULL;
	mutex_unlock(&epc->lock);
}
EXPORT_SYMBOL_GPL(pci_epc_remove_epf);

/**
 * pci_epc_linkup() - Notify the EPF device that EPC device has established a
 *		      connection with the Root Complex.
 * @epc: the EPC device which has established link with the host
 *
 * Invoke to Notify the EPF device that the EPC device has established a
 * connection with the Root Complex.
 */
void pci_epc_linkup(struct pci_epc *epc)
{
	if (!epc || IS_ERR(epc))
		return;

	atomic_notifier_call_chain(&epc->notifier, LINK_UP, NULL);
}
EXPORT_SYMBOL_GPL(pci_epc_linkup);

/**
 * pci_epc_init_notify() - Notify the EPF device that EPC device's core
 *			   initialization is completed.
 * @epc: the EPC device whose core initialization is completed
 *
 * Invoke to Notify the EPF device that the EPC device's initialization
 * is completed.
 */
void pci_epc_init_notify(struct pci_epc *epc)
{
	if (!epc || IS_ERR(epc))
		return;

	atomic_notifier_call_chain(&epc->notifier, CORE_INIT, NULL);
}
EXPORT_SYMBOL_GPL(pci_epc_init_notify);

/**
 * pci_epc_destroy() - destroy the EPC device
 * @epc: the EPC device that has to be destroyed
 *
 * Invoke to destroy the PCI EPC device
 */
void pci_epc_destroy(struct pci_epc *epc)
{
	pci_ep_cfs_remove_epc_group(epc->group);
	device_unregister(&epc->dev);
}
EXPORT_SYMBOL_GPL(pci_epc_destroy);

/**
 * devm_pci_epc_destroy() - destroy the EPC device
 * @dev: device that wants to destroy the EPC
 * @epc: the EPC device that has to be destroyed
 *
 * Invoke to destroy the devres associated with this
 * pci_epc and destroy the EPC device.
 */
void devm_pci_epc_destroy(struct device *dev, struct pci_epc *epc)
{
	int r;

	r = devres_destroy(dev, devm_pci_epc_release, devm_pci_epc_match,
			   epc);
	dev_WARN_ONCE(dev, r, "couldn't find PCI EPC resource\n");
}
EXPORT_SYMBOL_GPL(devm_pci_epc_destroy);

static void pci_epc_release(struct device *dev)
{
	kfree(to_pci_epc(dev));
}

/**
 * __pci_epc_create() - create a new endpoint controller (EPC) device
 * @dev: device that is creating the new EPC
 * @ops: function pointers for performing EPC operations
 * @owner: the owner of the module that creates the EPC device
 *
 * Invoke to create a new EPC device and add it to pci_epc class.
 */
struct pci_epc *
__pci_epc_create(struct device *dev, const struct pci_epc_ops *ops,
		 struct module *owner)
{
	int ret;
	struct pci_epc *epc;

	if (WARN_ON(!dev)) {
		ret = -EINVAL;
		goto err_ret;
	}

	epc = kzalloc(sizeof(*epc), GFP_KERNEL);
	if (!epc) {
		ret = -ENOMEM;
		goto err_ret;
	}

	mutex_init(&epc->lock);
	INIT_LIST_HEAD(&epc->pci_epf);
	ATOMIC_INIT_NOTIFIER_HEAD(&epc->notifier);

	device_initialize(&epc->dev);
	epc->dev.class = pci_epc_class;
	epc->dev.parent = dev;
	epc->dev.release = pci_epc_release;
	epc->ops = ops;

	ret = dev_set_name(&epc->dev, "%s", dev_name(dev));
	if (ret)
		goto put_dev;

	ret = device_add(&epc->dev);
	if (ret)
		goto put_dev;

	epc->group = pci_ep_cfs_add_epc_group(dev_name(dev));

	return epc;

put_dev:
	put_device(&epc->dev);
	kfree(epc);

err_ret:
	return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(__pci_epc_create);

/**
 * __devm_pci_epc_create() - create a new endpoint controller (EPC) device
 * @dev: device that is creating the new EPC
 * @ops: function pointers for performing EPC operations
 * @owner: the owner of the module that creates the EPC device
 *
 * Invoke to create a new EPC device and add it to pci_epc class.
 * While at that, it also associates the device with the pci_epc using devres.
 * On driver detach, release function is invoked on the devres data,
 * then, devres data is freed.
 */
struct pci_epc *
__devm_pci_epc_create(struct device *dev, const struct pci_epc_ops *ops,
		      struct module *owner)
{
	struct pci_epc **ptr, *epc;

	ptr = devres_alloc(devm_pci_epc_release, sizeof(*ptr), GFP_KERNEL);
	if (!ptr)
		return ERR_PTR(-ENOMEM);

	epc = __pci_epc_create(dev, ops, owner);
	if (!IS_ERR(epc)) {
		*ptr = epc;
		devres_add(dev, ptr);
	} else {
		devres_free(ptr);
	}

	return epc;
}
EXPORT_SYMBOL_GPL(__devm_pci_epc_create);

static int __init pci_epc_init(void)
{
	pci_epc_class = class_create(THIS_MODULE, "pci_epc");
	if (IS_ERR(pci_epc_class)) {
		pr_err("failed to create pci epc class --> %ld\n",
		       PTR_ERR(pci_epc_class));
		return PTR_ERR(pci_epc_class);
	}

	return 0;
}
module_init(pci_epc_init);

static void __exit pci_epc_exit(void)
{
	class_destroy(pci_epc_class);
}
module_exit(pci_epc_exit);

MODULE_DESCRIPTION("PCI EPC Library");
MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@ti.com>");