1// SPDX-License-Identifier: GPL-2.0
2/*
3 * PCI Endpoint *Function* (EPF) library
4 *
5 * Copyright (C) 2017 Texas Instruments
6 * Author: Kishon Vijay Abraham I <kishon@ti.com>
7 */
8
9#include <linux/device.h>
10#include <linux/dma-mapping.h>
11#include <linux/slab.h>
12#include <linux/module.h>
13
14#include <linux/pci-epc.h>
15#include <linux/pci-epf.h>
16#include <linux/pci-ep-cfs.h>
17
18static DEFINE_MUTEX(pci_epf_mutex);
19
20static const struct bus_type pci_epf_bus_type;
21static const struct device_type pci_epf_type;
22
23/**
24 * pci_epf_unbind() - Notify the function driver that the binding between the
25 * EPF device and EPC device has been lost
26 * @epf: the EPF device which has lost the binding with the EPC device
27 *
28 * Invoke to notify the function driver that the binding between the EPF device
29 * and EPC device has been lost.
30 */
31void pci_epf_unbind(struct pci_epf *epf)
32{
33 struct pci_epf *epf_vf;
34
35 if (!epf->driver) {
36 dev_WARN(&epf->dev, "epf device not bound to driver\n");
37 return;
38 }
39
40 mutex_lock(&epf->lock);
41 list_for_each_entry(epf_vf, &epf->pci_vepf, list) {
42 if (epf_vf->is_bound)
43 epf_vf->driver->ops->unbind(epf_vf);
44 }
45 if (epf->is_bound)
46 epf->driver->ops->unbind(epf);
47 mutex_unlock(lock: &epf->lock);
48 module_put(module: epf->driver->owner);
49}
50EXPORT_SYMBOL_GPL(pci_epf_unbind);
51
52/**
53 * pci_epf_bind() - Notify the function driver that the EPF device has been
54 * bound to a EPC device
55 * @epf: the EPF device which has been bound to the EPC device
56 *
57 * Invoke to notify the function driver that it has been bound to a EPC device
58 */
59int pci_epf_bind(struct pci_epf *epf)
60{
61 struct device *dev = &epf->dev;
62 struct pci_epf *epf_vf;
63 u8 func_no, vfunc_no;
64 struct pci_epc *epc;
65 int ret;
66
67 if (!epf->driver) {
68 dev_WARN(dev, "epf device not bound to driver\n");
69 return -EINVAL;
70 }
71
72 if (!try_module_get(module: epf->driver->owner))
73 return -EAGAIN;
74
75 mutex_lock(&epf->lock);
76 list_for_each_entry(epf_vf, &epf->pci_vepf, list) {
77 vfunc_no = epf_vf->vfunc_no;
78
79 if (vfunc_no < 1) {
80 dev_err(dev, "Invalid virtual function number\n");
81 ret = -EINVAL;
82 goto ret;
83 }
84
85 epc = epf->epc;
86 func_no = epf->func_no;
87 if (!IS_ERR_OR_NULL(ptr: epc)) {
88 if (!epc->max_vfs) {
89 dev_err(dev, "No support for virt function\n");
90 ret = -EINVAL;
91 goto ret;
92 }
93
94 if (vfunc_no > epc->max_vfs[func_no]) {
95 dev_err(dev, "PF%d: Exceeds max vfunc number\n",
96 func_no);
97 ret = -EINVAL;
98 goto ret;
99 }
100 }
101
102 epc = epf->sec_epc;
103 func_no = epf->sec_epc_func_no;
104 if (!IS_ERR_OR_NULL(ptr: epc)) {
105 if (!epc->max_vfs) {
106 dev_err(dev, "No support for virt function\n");
107 ret = -EINVAL;
108 goto ret;
109 }
110
111 if (vfunc_no > epc->max_vfs[func_no]) {
112 dev_err(dev, "PF%d: Exceeds max vfunc number\n",
113 func_no);
114 ret = -EINVAL;
115 goto ret;
116 }
117 }
118
119 epf_vf->func_no = epf->func_no;
120 epf_vf->sec_epc_func_no = epf->sec_epc_func_no;
121 epf_vf->epc = epf->epc;
122 epf_vf->sec_epc = epf->sec_epc;
123 ret = epf_vf->driver->ops->bind(epf_vf);
124 if (ret)
125 goto ret;
126 epf_vf->is_bound = true;
127 }
128
129 ret = epf->driver->ops->bind(epf);
130 if (ret)
131 goto ret;
132 epf->is_bound = true;
133
134 mutex_unlock(lock: &epf->lock);
135 return 0;
136
137ret:
138 mutex_unlock(lock: &epf->lock);
139 pci_epf_unbind(epf);
140
141 return ret;
142}
143EXPORT_SYMBOL_GPL(pci_epf_bind);
144
145/**
146 * pci_epf_add_vepf() - associate virtual EP function to physical EP function
147 * @epf_pf: the physical EP function to which the virtual EP function should be
148 * associated
149 * @epf_vf: the virtual EP function to be added
150 *
151 * A physical endpoint function can be associated with multiple virtual
152 * endpoint functions. Invoke pci_epf_add_epf() to add a virtual PCI endpoint
153 * function to a physical PCI endpoint function.
154 */
155int pci_epf_add_vepf(struct pci_epf *epf_pf, struct pci_epf *epf_vf)
156{
157 u32 vfunc_no;
158
159 if (IS_ERR_OR_NULL(ptr: epf_pf) || IS_ERR_OR_NULL(ptr: epf_vf))
160 return -EINVAL;
161
162 if (epf_pf->epc || epf_vf->epc || epf_vf->epf_pf)
163 return -EBUSY;
164
165 if (epf_pf->sec_epc || epf_vf->sec_epc)
166 return -EBUSY;
167
168 mutex_lock(&epf_pf->lock);
169 vfunc_no = find_first_zero_bit(addr: &epf_pf->vfunction_num_map,
170 BITS_PER_LONG);
171 if (vfunc_no >= BITS_PER_LONG) {
172 mutex_unlock(lock: &epf_pf->lock);
173 return -EINVAL;
174 }
175
176 set_bit(nr: vfunc_no, addr: &epf_pf->vfunction_num_map);
177 epf_vf->vfunc_no = vfunc_no;
178
179 epf_vf->epf_pf = epf_pf;
180 epf_vf->is_vf = true;
181
182 list_add_tail(new: &epf_vf->list, head: &epf_pf->pci_vepf);
183 mutex_unlock(lock: &epf_pf->lock);
184
185 return 0;
186}
187EXPORT_SYMBOL_GPL(pci_epf_add_vepf);
188
189/**
190 * pci_epf_remove_vepf() - remove virtual EP function from physical EP function
191 * @epf_pf: the physical EP function from which the virtual EP function should
192 * be removed
193 * @epf_vf: the virtual EP function to be removed
194 *
195 * Invoke to remove a virtual endpoint function from the physical endpoint
196 * function.
197 */
198void pci_epf_remove_vepf(struct pci_epf *epf_pf, struct pci_epf *epf_vf)
199{
200 if (IS_ERR_OR_NULL(ptr: epf_pf) || IS_ERR_OR_NULL(ptr: epf_vf))
201 return;
202
203 mutex_lock(&epf_pf->lock);
204 clear_bit(nr: epf_vf->vfunc_no, addr: &epf_pf->vfunction_num_map);
205 list_del(entry: &epf_vf->list);
206 mutex_unlock(lock: &epf_pf->lock);
207}
208EXPORT_SYMBOL_GPL(pci_epf_remove_vepf);
209
210/**
211 * pci_epf_free_space() - free the allocated PCI EPF register space
212 * @epf: the EPF device from whom to free the memory
213 * @addr: the virtual address of the PCI EPF register space
214 * @bar: the BAR number corresponding to the register space
215 * @type: Identifies if the allocated space is for primary EPC or secondary EPC
216 *
217 * Invoke to free the allocated PCI EPF register space.
218 */
219void pci_epf_free_space(struct pci_epf *epf, void *addr, enum pci_barno bar,
220 enum pci_epc_interface_type type)
221{
222 struct device *dev;
223 struct pci_epf_bar *epf_bar;
224 struct pci_epc *epc;
225
226 if (!addr)
227 return;
228
229 if (type == PRIMARY_INTERFACE) {
230 epc = epf->epc;
231 epf_bar = epf->bar;
232 } else {
233 epc = epf->sec_epc;
234 epf_bar = epf->sec_epc_bar;
235 }
236
237 dev = epc->dev.parent;
238 dma_free_coherent(dev, size: epf_bar[bar].size, cpu_addr: addr,
239 dma_handle: epf_bar[bar].phys_addr);
240
241 epf_bar[bar].phys_addr = 0;
242 epf_bar[bar].addr = NULL;
243 epf_bar[bar].size = 0;
244 epf_bar[bar].barno = 0;
245 epf_bar[bar].flags = 0;
246}
247EXPORT_SYMBOL_GPL(pci_epf_free_space);
248
249/**
250 * pci_epf_alloc_space() - allocate memory for the PCI EPF register space
251 * @epf: the EPF device to whom allocate the memory
252 * @size: the size of the memory that has to be allocated
253 * @bar: the BAR number corresponding to the allocated register space
254 * @epc_features: the features provided by the EPC specific to this EPF
255 * @type: Identifies if the allocation is for primary EPC or secondary EPC
256 *
257 * Invoke to allocate memory for the PCI EPF register space.
258 */
259void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno bar,
260 const struct pci_epc_features *epc_features,
261 enum pci_epc_interface_type type)
262{
263 u64 bar_fixed_size = epc_features->bar[bar].fixed_size;
264 size_t align = epc_features->align;
265 struct pci_epf_bar *epf_bar;
266 dma_addr_t phys_addr;
267 struct pci_epc *epc;
268 struct device *dev;
269 void *space;
270
271 if (size < 128)
272 size = 128;
273
274 if (epc_features->bar[bar].type == BAR_FIXED && bar_fixed_size) {
275 if (size > bar_fixed_size) {
276 dev_err(&epf->dev,
277 "requested BAR size is larger than fixed size\n");
278 return NULL;
279 }
280 size = bar_fixed_size;
281 }
282
283 if (align)
284 size = ALIGN(size, align);
285 else
286 size = roundup_pow_of_two(size);
287
288 if (type == PRIMARY_INTERFACE) {
289 epc = epf->epc;
290 epf_bar = epf->bar;
291 } else {
292 epc = epf->sec_epc;
293 epf_bar = epf->sec_epc_bar;
294 }
295
296 dev = epc->dev.parent;
297 space = dma_alloc_coherent(dev, size, dma_handle: &phys_addr, GFP_KERNEL);
298 if (!space) {
299 dev_err(dev, "failed to allocate mem space\n");
300 return NULL;
301 }
302
303 epf_bar[bar].phys_addr = phys_addr;
304 epf_bar[bar].addr = space;
305 epf_bar[bar].size = size;
306 epf_bar[bar].barno = bar;
307 epf_bar[bar].flags |= upper_32_bits(size) ?
308 PCI_BASE_ADDRESS_MEM_TYPE_64 :
309 PCI_BASE_ADDRESS_MEM_TYPE_32;
310
311 return space;
312}
313EXPORT_SYMBOL_GPL(pci_epf_alloc_space);
314
315static void pci_epf_remove_cfs(struct pci_epf_driver *driver)
316{
317 struct config_group *group, *tmp;
318
319 if (!IS_ENABLED(CONFIG_PCI_ENDPOINT_CONFIGFS))
320 return;
321
322 mutex_lock(&pci_epf_mutex);
323 list_for_each_entry_safe(group, tmp, &driver->epf_group, group_entry)
324 pci_ep_cfs_remove_epf_group(group);
325 list_del(entry: &driver->epf_group);
326 mutex_unlock(lock: &pci_epf_mutex);
327}
328
329/**
330 * pci_epf_unregister_driver() - unregister the PCI EPF driver
331 * @driver: the PCI EPF driver that has to be unregistered
332 *
333 * Invoke to unregister the PCI EPF driver.
334 */
335void pci_epf_unregister_driver(struct pci_epf_driver *driver)
336{
337 pci_epf_remove_cfs(driver);
338 driver_unregister(drv: &driver->driver);
339}
340EXPORT_SYMBOL_GPL(pci_epf_unregister_driver);
341
342static int pci_epf_add_cfs(struct pci_epf_driver *driver)
343{
344 struct config_group *group;
345 const struct pci_epf_device_id *id;
346
347 if (!IS_ENABLED(CONFIG_PCI_ENDPOINT_CONFIGFS))
348 return 0;
349
350 INIT_LIST_HEAD(list: &driver->epf_group);
351
352 id = driver->id_table;
353 while (id->name[0]) {
354 group = pci_ep_cfs_add_epf_group(name: id->name);
355 if (IS_ERR(ptr: group)) {
356 pci_epf_remove_cfs(driver);
357 return PTR_ERR(ptr: group);
358 }
359
360 mutex_lock(&pci_epf_mutex);
361 list_add_tail(new: &group->group_entry, head: &driver->epf_group);
362 mutex_unlock(lock: &pci_epf_mutex);
363 id++;
364 }
365
366 return 0;
367}
368
369/**
370 * __pci_epf_register_driver() - register a new PCI EPF driver
371 * @driver: structure representing PCI EPF driver
372 * @owner: the owner of the module that registers the PCI EPF driver
373 *
374 * Invoke to register a new PCI EPF driver.
375 */
376int __pci_epf_register_driver(struct pci_epf_driver *driver,
377 struct module *owner)
378{
379 int ret;
380
381 if (!driver->ops)
382 return -EINVAL;
383
384 if (!driver->ops->bind || !driver->ops->unbind)
385 return -EINVAL;
386
387 driver->driver.bus = &pci_epf_bus_type;
388 driver->driver.owner = owner;
389
390 ret = driver_register(drv: &driver->driver);
391 if (ret)
392 return ret;
393
394 pci_epf_add_cfs(driver);
395
396 return 0;
397}
398EXPORT_SYMBOL_GPL(__pci_epf_register_driver);
399
400/**
401 * pci_epf_destroy() - destroy the created PCI EPF device
402 * @epf: the PCI EPF device that has to be destroyed.
403 *
404 * Invoke to destroy the PCI EPF device created by invoking pci_epf_create().
405 */
406void pci_epf_destroy(struct pci_epf *epf)
407{
408 device_unregister(dev: &epf->dev);
409}
410EXPORT_SYMBOL_GPL(pci_epf_destroy);
411
412/**
413 * pci_epf_create() - create a new PCI EPF device
414 * @name: the name of the PCI EPF device. This name will be used to bind the
415 * EPF device to a EPF driver
416 *
417 * Invoke to create a new PCI EPF device by providing the name of the function
418 * device.
419 */
420struct pci_epf *pci_epf_create(const char *name)
421{
422 int ret;
423 struct pci_epf *epf;
424 struct device *dev;
425 int len;
426
427 epf = kzalloc(size: sizeof(*epf), GFP_KERNEL);
428 if (!epf)
429 return ERR_PTR(error: -ENOMEM);
430
431 len = strchrnul(name, '.') - name;
432 epf->name = kstrndup(s: name, len, GFP_KERNEL);
433 if (!epf->name) {
434 kfree(objp: epf);
435 return ERR_PTR(error: -ENOMEM);
436 }
437
438 /* VFs are numbered starting with 1. So set BIT(0) by default */
439 epf->vfunction_num_map = 1;
440 INIT_LIST_HEAD(list: &epf->pci_vepf);
441
442 dev = &epf->dev;
443 device_initialize(dev);
444 dev->bus = &pci_epf_bus_type;
445 dev->type = &pci_epf_type;
446 mutex_init(&epf->lock);
447
448 ret = dev_set_name(dev, name: "%s", name);
449 if (ret) {
450 put_device(dev);
451 return ERR_PTR(error: ret);
452 }
453
454 ret = device_add(dev);
455 if (ret) {
456 put_device(dev);
457 return ERR_PTR(error: ret);
458 }
459
460 return epf;
461}
462EXPORT_SYMBOL_GPL(pci_epf_create);
463
464static void pci_epf_dev_release(struct device *dev)
465{
466 struct pci_epf *epf = to_pci_epf(dev);
467
468 kfree(objp: epf->name);
469 kfree(objp: epf);
470}
471
472static const struct device_type pci_epf_type = {
473 .release = pci_epf_dev_release,
474};
475
476static const struct pci_epf_device_id *
477pci_epf_match_id(const struct pci_epf_device_id *id, const struct pci_epf *epf)
478{
479 while (id->name[0]) {
480 if (strcmp(epf->name, id->name) == 0)
481 return id;
482 id++;
483 }
484
485 return NULL;
486}
487
488static int pci_epf_device_match(struct device *dev, struct device_driver *drv)
489{
490 struct pci_epf *epf = to_pci_epf(dev);
491 struct pci_epf_driver *driver = to_pci_epf_driver(drv);
492
493 if (driver->id_table)
494 return !!pci_epf_match_id(id: driver->id_table, epf);
495
496 return !strcmp(epf->name, drv->name);
497}
498
499static int pci_epf_device_probe(struct device *dev)
500{
501 struct pci_epf *epf = to_pci_epf(dev);
502 struct pci_epf_driver *driver = to_pci_epf_driver(dev->driver);
503
504 if (!driver->probe)
505 return -ENODEV;
506
507 epf->driver = driver;
508
509 return driver->probe(epf, pci_epf_match_id(id: driver->id_table, epf));
510}
511
512static void pci_epf_device_remove(struct device *dev)
513{
514 struct pci_epf *epf = to_pci_epf(dev);
515 struct pci_epf_driver *driver = to_pci_epf_driver(dev->driver);
516
517 if (driver->remove)
518 driver->remove(epf);
519 epf->driver = NULL;
520}
521
522static const struct bus_type pci_epf_bus_type = {
523 .name = "pci-epf",
524 .match = pci_epf_device_match,
525 .probe = pci_epf_device_probe,
526 .remove = pci_epf_device_remove,
527};
528
529static int __init pci_epf_init(void)
530{
531 int ret;
532
533 ret = bus_register(bus: &pci_epf_bus_type);
534 if (ret) {
535 pr_err("failed to register pci epf bus --> %d\n", ret);
536 return ret;
537 }
538
539 return 0;
540}
541module_init(pci_epf_init);
542
543static void __exit pci_epf_exit(void)
544{
545 bus_unregister(bus: &pci_epf_bus_type);
546}
547module_exit(pci_epf_exit);
548
549MODULE_DESCRIPTION("PCI EPF Library");
550MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@ti.com>");
551

source code of linux/drivers/pci/endpoint/pci-epf-core.c