1// SPDX-License-Identifier: GPL-2.0
2/*
3 * configfs to configure the PCI endpoint
4 *
5 * Copyright (C) 2017 Texas Instruments
6 * Author: Kishon Vijay Abraham I <kishon@ti.com>
7 */
8
9#include <linux/module.h>
10#include <linux/idr.h>
11#include <linux/slab.h>
12
13#include <linux/pci-epc.h>
14#include <linux/pci-epf.h>
15#include <linux/pci-ep-cfs.h>
16
17static DEFINE_IDR(functions_idr);
18static DEFINE_MUTEX(functions_mutex);
19static struct config_group *functions_group;
20static struct config_group *controllers_group;
21
22struct pci_epf_group {
23 struct config_group group;
24 struct config_group primary_epc_group;
25 struct config_group secondary_epc_group;
26 struct config_group *type_group;
27 struct delayed_work cfs_work;
28 struct pci_epf *epf;
29 int index;
30};
31
32struct pci_epc_group {
33 struct config_group group;
34 struct pci_epc *epc;
35 bool start;
36};
37
38static inline struct pci_epf_group *to_pci_epf_group(struct config_item *item)
39{
40 return container_of(to_config_group(item), struct pci_epf_group, group);
41}
42
43static inline struct pci_epc_group *to_pci_epc_group(struct config_item *item)
44{
45 return container_of(to_config_group(item), struct pci_epc_group, group);
46}
47
48static int pci_secondary_epc_epf_link(struct config_item *epf_item,
49 struct config_item *epc_item)
50{
51 int ret;
52 struct pci_epf_group *epf_group = to_pci_epf_group(item: epf_item->ci_parent);
53 struct pci_epc_group *epc_group = to_pci_epc_group(item: epc_item);
54 struct pci_epc *epc = epc_group->epc;
55 struct pci_epf *epf = epf_group->epf;
56
57 ret = pci_epc_add_epf(epc, epf, type: SECONDARY_INTERFACE);
58 if (ret)
59 return ret;
60
61 ret = pci_epf_bind(epf);
62 if (ret) {
63 pci_epc_remove_epf(epc, epf, type: SECONDARY_INTERFACE);
64 return ret;
65 }
66
67 return 0;
68}
69
70static void pci_secondary_epc_epf_unlink(struct config_item *epc_item,
71 struct config_item *epf_item)
72{
73 struct pci_epf_group *epf_group = to_pci_epf_group(item: epf_item->ci_parent);
74 struct pci_epc_group *epc_group = to_pci_epc_group(item: epc_item);
75 struct pci_epc *epc;
76 struct pci_epf *epf;
77
78 WARN_ON_ONCE(epc_group->start);
79
80 epc = epc_group->epc;
81 epf = epf_group->epf;
82 pci_epf_unbind(epf);
83 pci_epc_remove_epf(epc, epf, type: SECONDARY_INTERFACE);
84}
85
86static struct configfs_item_operations pci_secondary_epc_item_ops = {
87 .allow_link = pci_secondary_epc_epf_link,
88 .drop_link = pci_secondary_epc_epf_unlink,
89};
90
91static const struct config_item_type pci_secondary_epc_type = {
92 .ct_item_ops = &pci_secondary_epc_item_ops,
93 .ct_owner = THIS_MODULE,
94};
95
96static struct config_group
97*pci_ep_cfs_add_secondary_group(struct pci_epf_group *epf_group)
98{
99 struct config_group *secondary_epc_group;
100
101 secondary_epc_group = &epf_group->secondary_epc_group;
102 config_group_init_type_name(group: secondary_epc_group, name: "secondary",
103 type: &pci_secondary_epc_type);
104 configfs_register_group(parent_group: &epf_group->group, group: secondary_epc_group);
105
106 return secondary_epc_group;
107}
108
109static int pci_primary_epc_epf_link(struct config_item *epf_item,
110 struct config_item *epc_item)
111{
112 int ret;
113 struct pci_epf_group *epf_group = to_pci_epf_group(item: epf_item->ci_parent);
114 struct pci_epc_group *epc_group = to_pci_epc_group(item: epc_item);
115 struct pci_epc *epc = epc_group->epc;
116 struct pci_epf *epf = epf_group->epf;
117
118 ret = pci_epc_add_epf(epc, epf, type: PRIMARY_INTERFACE);
119 if (ret)
120 return ret;
121
122 ret = pci_epf_bind(epf);
123 if (ret) {
124 pci_epc_remove_epf(epc, epf, type: PRIMARY_INTERFACE);
125 return ret;
126 }
127
128 return 0;
129}
130
131static void pci_primary_epc_epf_unlink(struct config_item *epc_item,
132 struct config_item *epf_item)
133{
134 struct pci_epf_group *epf_group = to_pci_epf_group(item: epf_item->ci_parent);
135 struct pci_epc_group *epc_group = to_pci_epc_group(item: epc_item);
136 struct pci_epc *epc;
137 struct pci_epf *epf;
138
139 WARN_ON_ONCE(epc_group->start);
140
141 epc = epc_group->epc;
142 epf = epf_group->epf;
143 pci_epf_unbind(epf);
144 pci_epc_remove_epf(epc, epf, type: PRIMARY_INTERFACE);
145}
146
147static struct configfs_item_operations pci_primary_epc_item_ops = {
148 .allow_link = pci_primary_epc_epf_link,
149 .drop_link = pci_primary_epc_epf_unlink,
150};
151
152static const struct config_item_type pci_primary_epc_type = {
153 .ct_item_ops = &pci_primary_epc_item_ops,
154 .ct_owner = THIS_MODULE,
155};
156
157static struct config_group
158*pci_ep_cfs_add_primary_group(struct pci_epf_group *epf_group)
159{
160 struct config_group *primary_epc_group = &epf_group->primary_epc_group;
161
162 config_group_init_type_name(group: primary_epc_group, name: "primary",
163 type: &pci_primary_epc_type);
164 configfs_register_group(parent_group: &epf_group->group, group: primary_epc_group);
165
166 return primary_epc_group;
167}
168
169static ssize_t pci_epc_start_store(struct config_item *item, const char *page,
170 size_t len)
171{
172 int ret;
173 bool start;
174 struct pci_epc *epc;
175 struct pci_epc_group *epc_group = to_pci_epc_group(item);
176
177 epc = epc_group->epc;
178
179 if (kstrtobool(s: page, res: &start) < 0)
180 return -EINVAL;
181
182 if (start == epc_group->start)
183 return -EALREADY;
184
185 if (!start) {
186 pci_epc_stop(epc);
187 epc_group->start = 0;
188 return len;
189 }
190
191 ret = pci_epc_start(epc);
192 if (ret) {
193 dev_err(&epc->dev, "failed to start endpoint controller\n");
194 return -EINVAL;
195 }
196
197 epc_group->start = start;
198
199 return len;
200}
201
202static ssize_t pci_epc_start_show(struct config_item *item, char *page)
203{
204 return sysfs_emit(buf: page, fmt: "%d\n", to_pci_epc_group(item)->start);
205}
206
207CONFIGFS_ATTR(pci_epc_, start);
208
209static struct configfs_attribute *pci_epc_attrs[] = {
210 &pci_epc_attr_start,
211 NULL,
212};
213
214static int pci_epc_epf_link(struct config_item *epc_item,
215 struct config_item *epf_item)
216{
217 int ret;
218 struct pci_epf_group *epf_group = to_pci_epf_group(item: epf_item);
219 struct pci_epc_group *epc_group = to_pci_epc_group(item: epc_item);
220 struct pci_epc *epc = epc_group->epc;
221 struct pci_epf *epf = epf_group->epf;
222
223 ret = pci_epc_add_epf(epc, epf, type: PRIMARY_INTERFACE);
224 if (ret)
225 return ret;
226
227 ret = pci_epf_bind(epf);
228 if (ret) {
229 pci_epc_remove_epf(epc, epf, type: PRIMARY_INTERFACE);
230 return ret;
231 }
232
233 return 0;
234}
235
236static void pci_epc_epf_unlink(struct config_item *epc_item,
237 struct config_item *epf_item)
238{
239 struct pci_epc *epc;
240 struct pci_epf *epf;
241 struct pci_epf_group *epf_group = to_pci_epf_group(item: epf_item);
242 struct pci_epc_group *epc_group = to_pci_epc_group(item: epc_item);
243
244 WARN_ON_ONCE(epc_group->start);
245
246 epc = epc_group->epc;
247 epf = epf_group->epf;
248 pci_epf_unbind(epf);
249 pci_epc_remove_epf(epc, epf, type: PRIMARY_INTERFACE);
250}
251
252static struct configfs_item_operations pci_epc_item_ops = {
253 .allow_link = pci_epc_epf_link,
254 .drop_link = pci_epc_epf_unlink,
255};
256
257static const struct config_item_type pci_epc_type = {
258 .ct_item_ops = &pci_epc_item_ops,
259 .ct_attrs = pci_epc_attrs,
260 .ct_owner = THIS_MODULE,
261};
262
263struct config_group *pci_ep_cfs_add_epc_group(const char *name)
264{
265 int ret;
266 struct pci_epc *epc;
267 struct config_group *group;
268 struct pci_epc_group *epc_group;
269
270 epc_group = kzalloc(size: sizeof(*epc_group), GFP_KERNEL);
271 if (!epc_group) {
272 ret = -ENOMEM;
273 goto err;
274 }
275
276 group = &epc_group->group;
277
278 config_group_init_type_name(group, name, type: &pci_epc_type);
279 ret = configfs_register_group(parent_group: controllers_group, group);
280 if (ret) {
281 pr_err("failed to register configfs group for %s\n", name);
282 goto err_register_group;
283 }
284
285 epc = pci_epc_get(epc_name: name);
286 if (IS_ERR(ptr: epc)) {
287 ret = PTR_ERR(ptr: epc);
288 goto err_epc_get;
289 }
290
291 epc_group->epc = epc;
292
293 return group;
294
295err_epc_get:
296 configfs_unregister_group(group);
297
298err_register_group:
299 kfree(objp: epc_group);
300
301err:
302 return ERR_PTR(error: ret);
303}
304EXPORT_SYMBOL(pci_ep_cfs_add_epc_group);
305
306void pci_ep_cfs_remove_epc_group(struct config_group *group)
307{
308 struct pci_epc_group *epc_group;
309
310 if (!group)
311 return;
312
313 epc_group = container_of(group, struct pci_epc_group, group);
314 pci_epc_put(epc: epc_group->epc);
315 configfs_unregister_group(group: &epc_group->group);
316 kfree(objp: epc_group);
317}
318EXPORT_SYMBOL(pci_ep_cfs_remove_epc_group);
319
320#define PCI_EPF_HEADER_R(_name) \
321static ssize_t pci_epf_##_name##_show(struct config_item *item, char *page) \
322{ \
323 struct pci_epf *epf = to_pci_epf_group(item)->epf; \
324 if (WARN_ON_ONCE(!epf->header)) \
325 return -EINVAL; \
326 return sysfs_emit(page, "0x%04x\n", epf->header->_name); \
327}
328
329#define PCI_EPF_HEADER_W_u32(_name) \
330static ssize_t pci_epf_##_name##_store(struct config_item *item, \
331 const char *page, size_t len) \
332{ \
333 u32 val; \
334 struct pci_epf *epf = to_pci_epf_group(item)->epf; \
335 if (WARN_ON_ONCE(!epf->header)) \
336 return -EINVAL; \
337 if (kstrtou32(page, 0, &val) < 0) \
338 return -EINVAL; \
339 epf->header->_name = val; \
340 return len; \
341}
342
343#define PCI_EPF_HEADER_W_u16(_name) \
344static ssize_t pci_epf_##_name##_store(struct config_item *item, \
345 const char *page, size_t len) \
346{ \
347 u16 val; \
348 struct pci_epf *epf = to_pci_epf_group(item)->epf; \
349 if (WARN_ON_ONCE(!epf->header)) \
350 return -EINVAL; \
351 if (kstrtou16(page, 0, &val) < 0) \
352 return -EINVAL; \
353 epf->header->_name = val; \
354 return len; \
355}
356
357#define PCI_EPF_HEADER_W_u8(_name) \
358static ssize_t pci_epf_##_name##_store(struct config_item *item, \
359 const char *page, size_t len) \
360{ \
361 u8 val; \
362 struct pci_epf *epf = to_pci_epf_group(item)->epf; \
363 if (WARN_ON_ONCE(!epf->header)) \
364 return -EINVAL; \
365 if (kstrtou8(page, 0, &val) < 0) \
366 return -EINVAL; \
367 epf->header->_name = val; \
368 return len; \
369}
370
371static ssize_t pci_epf_msi_interrupts_store(struct config_item *item,
372 const char *page, size_t len)
373{
374 u8 val;
375
376 if (kstrtou8(s: page, base: 0, res: &val) < 0)
377 return -EINVAL;
378
379 to_pci_epf_group(item)->epf->msi_interrupts = val;
380
381 return len;
382}
383
384static ssize_t pci_epf_msi_interrupts_show(struct config_item *item,
385 char *page)
386{
387 return sysfs_emit(buf: page, fmt: "%d\n",
388 to_pci_epf_group(item)->epf->msi_interrupts);
389}
390
391static ssize_t pci_epf_msix_interrupts_store(struct config_item *item,
392 const char *page, size_t len)
393{
394 u16 val;
395
396 if (kstrtou16(s: page, base: 0, res: &val) < 0)
397 return -EINVAL;
398
399 to_pci_epf_group(item)->epf->msix_interrupts = val;
400
401 return len;
402}
403
404static ssize_t pci_epf_msix_interrupts_show(struct config_item *item,
405 char *page)
406{
407 return sysfs_emit(buf: page, fmt: "%d\n",
408 to_pci_epf_group(item)->epf->msix_interrupts);
409}
410
411PCI_EPF_HEADER_R(vendorid)
412PCI_EPF_HEADER_W_u16(vendorid)
413
414PCI_EPF_HEADER_R(deviceid)
415PCI_EPF_HEADER_W_u16(deviceid)
416
417PCI_EPF_HEADER_R(revid)
418PCI_EPF_HEADER_W_u8(revid)
419
420PCI_EPF_HEADER_R(progif_code)
421PCI_EPF_HEADER_W_u8(progif_code)
422
423PCI_EPF_HEADER_R(subclass_code)
424PCI_EPF_HEADER_W_u8(subclass_code)
425
426PCI_EPF_HEADER_R(baseclass_code)
427PCI_EPF_HEADER_W_u8(baseclass_code)
428
429PCI_EPF_HEADER_R(cache_line_size)
430PCI_EPF_HEADER_W_u8(cache_line_size)
431
432PCI_EPF_HEADER_R(subsys_vendor_id)
433PCI_EPF_HEADER_W_u16(subsys_vendor_id)
434
435PCI_EPF_HEADER_R(subsys_id)
436PCI_EPF_HEADER_W_u16(subsys_id)
437
438PCI_EPF_HEADER_R(interrupt_pin)
439PCI_EPF_HEADER_W_u8(interrupt_pin)
440
441CONFIGFS_ATTR(pci_epf_, vendorid);
442CONFIGFS_ATTR(pci_epf_, deviceid);
443CONFIGFS_ATTR(pci_epf_, revid);
444CONFIGFS_ATTR(pci_epf_, progif_code);
445CONFIGFS_ATTR(pci_epf_, subclass_code);
446CONFIGFS_ATTR(pci_epf_, baseclass_code);
447CONFIGFS_ATTR(pci_epf_, cache_line_size);
448CONFIGFS_ATTR(pci_epf_, subsys_vendor_id);
449CONFIGFS_ATTR(pci_epf_, subsys_id);
450CONFIGFS_ATTR(pci_epf_, interrupt_pin);
451CONFIGFS_ATTR(pci_epf_, msi_interrupts);
452CONFIGFS_ATTR(pci_epf_, msix_interrupts);
453
454static struct configfs_attribute *pci_epf_attrs[] = {
455 &pci_epf_attr_vendorid,
456 &pci_epf_attr_deviceid,
457 &pci_epf_attr_revid,
458 &pci_epf_attr_progif_code,
459 &pci_epf_attr_subclass_code,
460 &pci_epf_attr_baseclass_code,
461 &pci_epf_attr_cache_line_size,
462 &pci_epf_attr_subsys_vendor_id,
463 &pci_epf_attr_subsys_id,
464 &pci_epf_attr_interrupt_pin,
465 &pci_epf_attr_msi_interrupts,
466 &pci_epf_attr_msix_interrupts,
467 NULL,
468};
469
470static int pci_epf_vepf_link(struct config_item *epf_pf_item,
471 struct config_item *epf_vf_item)
472{
473 struct pci_epf_group *epf_vf_group = to_pci_epf_group(item: epf_vf_item);
474 struct pci_epf_group *epf_pf_group = to_pci_epf_group(item: epf_pf_item);
475 struct pci_epf *epf_pf = epf_pf_group->epf;
476 struct pci_epf *epf_vf = epf_vf_group->epf;
477
478 return pci_epf_add_vepf(epf_pf, epf_vf);
479}
480
481static void pci_epf_vepf_unlink(struct config_item *epf_pf_item,
482 struct config_item *epf_vf_item)
483{
484 struct pci_epf_group *epf_vf_group = to_pci_epf_group(item: epf_vf_item);
485 struct pci_epf_group *epf_pf_group = to_pci_epf_group(item: epf_pf_item);
486 struct pci_epf *epf_pf = epf_pf_group->epf;
487 struct pci_epf *epf_vf = epf_vf_group->epf;
488
489 pci_epf_remove_vepf(epf_pf, epf_vf);
490}
491
492static void pci_epf_release(struct config_item *item)
493{
494 struct pci_epf_group *epf_group = to_pci_epf_group(item);
495
496 mutex_lock(&functions_mutex);
497 idr_remove(&functions_idr, id: epf_group->index);
498 mutex_unlock(lock: &functions_mutex);
499 pci_epf_destroy(epf: epf_group->epf);
500 kfree(objp: epf_group);
501}
502
503static struct configfs_item_operations pci_epf_ops = {
504 .allow_link = pci_epf_vepf_link,
505 .drop_link = pci_epf_vepf_unlink,
506 .release = pci_epf_release,
507};
508
509static const struct config_item_type pci_epf_type = {
510 .ct_item_ops = &pci_epf_ops,
511 .ct_attrs = pci_epf_attrs,
512 .ct_owner = THIS_MODULE,
513};
514
515/**
516 * pci_epf_type_add_cfs() - Help function drivers to expose function specific
517 * attributes in configfs
518 * @epf: the EPF device that has to be configured using configfs
519 * @group: the parent configfs group (corresponding to entries in
520 * pci_epf_device_id)
521 *
522 * Invoke to expose function specific attributes in configfs.
523 *
524 * Return: A pointer to a config_group structure or NULL if the function driver
525 * does not have anything to expose (attributes configured by user) or if
526 * the function driver does not implement the add_cfs() method.
527 *
528 * Returns an error pointer if this function is called for an unbound EPF device
529 * or if the EPF driver add_cfs() method fails.
530 */
531static struct config_group *pci_epf_type_add_cfs(struct pci_epf *epf,
532 struct config_group *group)
533{
534 struct config_group *epf_type_group;
535
536 if (!epf->driver) {
537 dev_err(&epf->dev, "epf device not bound to driver\n");
538 return ERR_PTR(error: -ENODEV);
539 }
540
541 if (!epf->driver->ops->add_cfs)
542 return NULL;
543
544 mutex_lock(&epf->lock);
545 epf_type_group = epf->driver->ops->add_cfs(epf, group);
546 mutex_unlock(lock: &epf->lock);
547
548 return epf_type_group;
549}
550
551static void pci_ep_cfs_add_type_group(struct pci_epf_group *epf_group)
552{
553 struct config_group *group;
554
555 group = pci_epf_type_add_cfs(epf: epf_group->epf, group: &epf_group->group);
556 if (!group)
557 return;
558
559 if (IS_ERR(ptr: group)) {
560 dev_err(&epf_group->epf->dev,
561 "failed to create epf type specific attributes\n");
562 return;
563 }
564
565 configfs_register_group(parent_group: &epf_group->group, group);
566}
567
568static void pci_epf_cfs_work(struct work_struct *work)
569{
570 struct pci_epf_group *epf_group;
571 struct config_group *group;
572
573 epf_group = container_of(work, struct pci_epf_group, cfs_work.work);
574 group = pci_ep_cfs_add_primary_group(epf_group);
575 if (IS_ERR(ptr: group)) {
576 pr_err("failed to create 'primary' EPC interface\n");
577 return;
578 }
579
580 group = pci_ep_cfs_add_secondary_group(epf_group);
581 if (IS_ERR(ptr: group)) {
582 pr_err("failed to create 'secondary' EPC interface\n");
583 return;
584 }
585
586 pci_ep_cfs_add_type_group(epf_group);
587}
588
589static struct config_group *pci_epf_make(struct config_group *group,
590 const char *name)
591{
592 struct pci_epf_group *epf_group;
593 struct pci_epf *epf;
594 char *epf_name;
595 int index, err;
596
597 epf_group = kzalloc(size: sizeof(*epf_group), GFP_KERNEL);
598 if (!epf_group)
599 return ERR_PTR(error: -ENOMEM);
600
601 mutex_lock(&functions_mutex);
602 index = idr_alloc(&functions_idr, ptr: epf_group, start: 0, end: 0, GFP_KERNEL);
603 mutex_unlock(lock: &functions_mutex);
604 if (index < 0) {
605 err = index;
606 goto free_group;
607 }
608
609 epf_group->index = index;
610
611 config_group_init_type_name(group: &epf_group->group, name, type: &pci_epf_type);
612
613 epf_name = kasprintf(GFP_KERNEL, fmt: "%s.%d",
614 group->cg_item.ci_name, epf_group->index);
615 if (!epf_name) {
616 err = -ENOMEM;
617 goto remove_idr;
618 }
619
620 epf = pci_epf_create(name: epf_name);
621 if (IS_ERR(ptr: epf)) {
622 pr_err("failed to create endpoint function device\n");
623 err = -EINVAL;
624 goto free_name;
625 }
626
627 epf->group = &epf_group->group;
628 epf_group->epf = epf;
629
630 kfree(objp: epf_name);
631
632 INIT_DELAYED_WORK(&epf_group->cfs_work, pci_epf_cfs_work);
633 queue_delayed_work(wq: system_wq, dwork: &epf_group->cfs_work,
634 delay: msecs_to_jiffies(m: 1));
635
636 return &epf_group->group;
637
638free_name:
639 kfree(objp: epf_name);
640
641remove_idr:
642 mutex_lock(&functions_mutex);
643 idr_remove(&functions_idr, id: epf_group->index);
644 mutex_unlock(lock: &functions_mutex);
645
646free_group:
647 kfree(objp: epf_group);
648
649 return ERR_PTR(error: err);
650}
651
652static void pci_epf_drop(struct config_group *group, struct config_item *item)
653{
654 config_item_put(item);
655}
656
657static struct configfs_group_operations pci_epf_group_ops = {
658 .make_group = &pci_epf_make,
659 .drop_item = &pci_epf_drop,
660};
661
662static const struct config_item_type pci_epf_group_type = {
663 .ct_group_ops = &pci_epf_group_ops,
664 .ct_owner = THIS_MODULE,
665};
666
667struct config_group *pci_ep_cfs_add_epf_group(const char *name)
668{
669 struct config_group *group;
670
671 group = configfs_register_default_group(parent_group: functions_group, name,
672 item_type: &pci_epf_group_type);
673 if (IS_ERR(ptr: group))
674 pr_err("failed to register configfs group for %s function\n",
675 name);
676
677 return group;
678}
679EXPORT_SYMBOL(pci_ep_cfs_add_epf_group);
680
681void pci_ep_cfs_remove_epf_group(struct config_group *group)
682{
683 if (IS_ERR_OR_NULL(ptr: group))
684 return;
685
686 configfs_unregister_default_group(group);
687}
688EXPORT_SYMBOL(pci_ep_cfs_remove_epf_group);
689
690static const struct config_item_type pci_functions_type = {
691 .ct_owner = THIS_MODULE,
692};
693
694static const struct config_item_type pci_controllers_type = {
695 .ct_owner = THIS_MODULE,
696};
697
698static const struct config_item_type pci_ep_type = {
699 .ct_owner = THIS_MODULE,
700};
701
702static struct configfs_subsystem pci_ep_cfs_subsys = {
703 .su_group = {
704 .cg_item = {
705 .ci_namebuf = "pci_ep",
706 .ci_type = &pci_ep_type,
707 },
708 },
709 .su_mutex = __MUTEX_INITIALIZER(pci_ep_cfs_subsys.su_mutex),
710};
711
712static int __init pci_ep_cfs_init(void)
713{
714 int ret;
715 struct config_group *root = &pci_ep_cfs_subsys.su_group;
716
717 config_group_init(group: root);
718
719 ret = configfs_register_subsystem(subsys: &pci_ep_cfs_subsys);
720 if (ret) {
721 pr_err("Error %d while registering subsystem %s\n",
722 ret, root->cg_item.ci_namebuf);
723 goto err;
724 }
725
726 functions_group = configfs_register_default_group(parent_group: root, name: "functions",
727 item_type: &pci_functions_type);
728 if (IS_ERR(ptr: functions_group)) {
729 ret = PTR_ERR(ptr: functions_group);
730 pr_err("Error %d while registering functions group\n",
731 ret);
732 goto err_functions_group;
733 }
734
735 controllers_group =
736 configfs_register_default_group(parent_group: root, name: "controllers",
737 item_type: &pci_controllers_type);
738 if (IS_ERR(ptr: controllers_group)) {
739 ret = PTR_ERR(ptr: controllers_group);
740 pr_err("Error %d while registering controllers group\n",
741 ret);
742 goto err_controllers_group;
743 }
744
745 return 0;
746
747err_controllers_group:
748 configfs_unregister_default_group(group: functions_group);
749
750err_functions_group:
751 configfs_unregister_subsystem(subsys: &pci_ep_cfs_subsys);
752
753err:
754 return ret;
755}
756module_init(pci_ep_cfs_init);
757
758static void __exit pci_ep_cfs_exit(void)
759{
760 configfs_unregister_default_group(group: controllers_group);
761 configfs_unregister_default_group(group: functions_group);
762 configfs_unregister_subsystem(subsys: &pci_ep_cfs_subsys);
763}
764module_exit(pci_ep_cfs_exit);
765
766MODULE_DESCRIPTION("PCI EP CONFIGFS");
767MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@ti.com>");
768

source code of linux/drivers/pci/endpoint/pci-ep-cfs.c