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
18 static DEFINE_MUTEX(pci_epf_mutex);
19
20 static struct bus_type pci_epf_bus_type;
21 static 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 */
pci_epf_unbind(struct pci_epf * epf)31 void 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(&epf->lock);
48 module_put(epf->driver->owner);
49 }
50 EXPORT_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 */
pci_epf_bind(struct pci_epf * epf)59 int 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(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(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(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(&epf->lock);
135 return 0;
136
137 ret:
138 mutex_unlock(&epf->lock);
139 pci_epf_unbind(epf);
140
141 return ret;
142 }
143 EXPORT_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 */
pci_epf_add_vepf(struct pci_epf * epf_pf,struct pci_epf * epf_vf)155 int 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(epf_pf) || IS_ERR_OR_NULL(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(&epf_pf->vfunction_num_map,
170 BITS_PER_LONG);
171 if (vfunc_no >= BITS_PER_LONG) {
172 mutex_unlock(&epf_pf->lock);
173 return -EINVAL;
174 }
175
176 set_bit(vfunc_no, &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(&epf_vf->list, &epf_pf->pci_vepf);
183 mutex_unlock(&epf_pf->lock);
184
185 return 0;
186 }
187 EXPORT_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 */
pci_epf_remove_vepf(struct pci_epf * epf_pf,struct pci_epf * epf_vf)198 void pci_epf_remove_vepf(struct pci_epf *epf_pf, struct pci_epf *epf_vf)
199 {
200 if (IS_ERR_OR_NULL(epf_pf) || IS_ERR_OR_NULL(epf_vf))
201 return;
202
203 mutex_lock(&epf_pf->lock);
204 clear_bit(epf_vf->vfunc_no, &epf_pf->vfunction_num_map);
205 list_del(&epf_vf->list);
206 mutex_unlock(&epf_pf->lock);
207 }
208 EXPORT_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 */
pci_epf_free_space(struct pci_epf * epf,void * addr,enum pci_barno bar,enum pci_epc_interface_type type)219 void 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, epf_bar[bar].size, addr,
239 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 }
247 EXPORT_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 * @align: alignment size for the allocation region
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 */
pci_epf_alloc_space(struct pci_epf * epf,size_t size,enum pci_barno bar,size_t align,enum pci_epc_interface_type type)259 void *pci_epf_alloc_space(struct pci_epf *epf, size_t size, enum pci_barno bar,
260 size_t align, enum pci_epc_interface_type type)
261 {
262 struct pci_epf_bar *epf_bar;
263 dma_addr_t phys_addr;
264 struct pci_epc *epc;
265 struct device *dev;
266 void *space;
267
268 if (size < 128)
269 size = 128;
270
271 if (align)
272 size = ALIGN(size, align);
273 else
274 size = roundup_pow_of_two(size);
275
276 if (type == PRIMARY_INTERFACE) {
277 epc = epf->epc;
278 epf_bar = epf->bar;
279 } else {
280 epc = epf->sec_epc;
281 epf_bar = epf->sec_epc_bar;
282 }
283
284 dev = epc->dev.parent;
285 space = dma_alloc_coherent(dev, size, &phys_addr, GFP_KERNEL);
286 if (!space) {
287 dev_err(dev, "failed to allocate mem space\n");
288 return NULL;
289 }
290
291 epf_bar[bar].phys_addr = phys_addr;
292 epf_bar[bar].addr = space;
293 epf_bar[bar].size = size;
294 epf_bar[bar].barno = bar;
295 epf_bar[bar].flags |= upper_32_bits(size) ?
296 PCI_BASE_ADDRESS_MEM_TYPE_64 :
297 PCI_BASE_ADDRESS_MEM_TYPE_32;
298
299 return space;
300 }
301 EXPORT_SYMBOL_GPL(pci_epf_alloc_space);
302
pci_epf_remove_cfs(struct pci_epf_driver * driver)303 static void pci_epf_remove_cfs(struct pci_epf_driver *driver)
304 {
305 struct config_group *group, *tmp;
306
307 if (!IS_ENABLED(CONFIG_PCI_ENDPOINT_CONFIGFS))
308 return;
309
310 mutex_lock(&pci_epf_mutex);
311 list_for_each_entry_safe(group, tmp, &driver->epf_group, group_entry)
312 pci_ep_cfs_remove_epf_group(group);
313 list_del(&driver->epf_group);
314 mutex_unlock(&pci_epf_mutex);
315 }
316
317 /**
318 * pci_epf_unregister_driver() - unregister the PCI EPF driver
319 * @driver: the PCI EPF driver that has to be unregistered
320 *
321 * Invoke to unregister the PCI EPF driver.
322 */
pci_epf_unregister_driver(struct pci_epf_driver * driver)323 void pci_epf_unregister_driver(struct pci_epf_driver *driver)
324 {
325 pci_epf_remove_cfs(driver);
326 driver_unregister(&driver->driver);
327 }
328 EXPORT_SYMBOL_GPL(pci_epf_unregister_driver);
329
pci_epf_add_cfs(struct pci_epf_driver * driver)330 static int pci_epf_add_cfs(struct pci_epf_driver *driver)
331 {
332 struct config_group *group;
333 const struct pci_epf_device_id *id;
334
335 if (!IS_ENABLED(CONFIG_PCI_ENDPOINT_CONFIGFS))
336 return 0;
337
338 INIT_LIST_HEAD(&driver->epf_group);
339
340 id = driver->id_table;
341 while (id->name[0]) {
342 group = pci_ep_cfs_add_epf_group(id->name);
343 if (IS_ERR(group)) {
344 pci_epf_remove_cfs(driver);
345 return PTR_ERR(group);
346 }
347
348 mutex_lock(&pci_epf_mutex);
349 list_add_tail(&group->group_entry, &driver->epf_group);
350 mutex_unlock(&pci_epf_mutex);
351 id++;
352 }
353
354 return 0;
355 }
356
357 /**
358 * __pci_epf_register_driver() - register a new PCI EPF driver
359 * @driver: structure representing PCI EPF driver
360 * @owner: the owner of the module that registers the PCI EPF driver
361 *
362 * Invoke to register a new PCI EPF driver.
363 */
__pci_epf_register_driver(struct pci_epf_driver * driver,struct module * owner)364 int __pci_epf_register_driver(struct pci_epf_driver *driver,
365 struct module *owner)
366 {
367 int ret;
368
369 if (!driver->ops)
370 return -EINVAL;
371
372 if (!driver->ops->bind || !driver->ops->unbind)
373 return -EINVAL;
374
375 driver->driver.bus = &pci_epf_bus_type;
376 driver->driver.owner = owner;
377
378 ret = driver_register(&driver->driver);
379 if (ret)
380 return ret;
381
382 pci_epf_add_cfs(driver);
383
384 return 0;
385 }
386 EXPORT_SYMBOL_GPL(__pci_epf_register_driver);
387
388 /**
389 * pci_epf_destroy() - destroy the created PCI EPF device
390 * @epf: the PCI EPF device that has to be destroyed.
391 *
392 * Invoke to destroy the PCI EPF device created by invoking pci_epf_create().
393 */
pci_epf_destroy(struct pci_epf * epf)394 void pci_epf_destroy(struct pci_epf *epf)
395 {
396 device_unregister(&epf->dev);
397 }
398 EXPORT_SYMBOL_GPL(pci_epf_destroy);
399
400 /**
401 * pci_epf_create() - create a new PCI EPF device
402 * @name: the name of the PCI EPF device. This name will be used to bind the
403 * EPF device to a EPF driver
404 *
405 * Invoke to create a new PCI EPF device by providing the name of the function
406 * device.
407 */
pci_epf_create(const char * name)408 struct pci_epf *pci_epf_create(const char *name)
409 {
410 int ret;
411 struct pci_epf *epf;
412 struct device *dev;
413 int len;
414
415 epf = kzalloc(sizeof(*epf), GFP_KERNEL);
416 if (!epf)
417 return ERR_PTR(-ENOMEM);
418
419 len = strchrnul(name, '.') - name;
420 epf->name = kstrndup(name, len, GFP_KERNEL);
421 if (!epf->name) {
422 kfree(epf);
423 return ERR_PTR(-ENOMEM);
424 }
425
426 /* VFs are numbered starting with 1. So set BIT(0) by default */
427 epf->vfunction_num_map = 1;
428 INIT_LIST_HEAD(&epf->pci_vepf);
429
430 dev = &epf->dev;
431 device_initialize(dev);
432 dev->bus = &pci_epf_bus_type;
433 dev->type = &pci_epf_type;
434 mutex_init(&epf->lock);
435
436 ret = dev_set_name(dev, "%s", name);
437 if (ret) {
438 put_device(dev);
439 return ERR_PTR(ret);
440 }
441
442 ret = device_add(dev);
443 if (ret) {
444 put_device(dev);
445 return ERR_PTR(ret);
446 }
447
448 return epf;
449 }
450 EXPORT_SYMBOL_GPL(pci_epf_create);
451
pci_epf_dev_release(struct device * dev)452 static void pci_epf_dev_release(struct device *dev)
453 {
454 struct pci_epf *epf = to_pci_epf(dev);
455
456 kfree(epf->name);
457 kfree(epf);
458 }
459
460 static const struct device_type pci_epf_type = {
461 .release = pci_epf_dev_release,
462 };
463
464 static const struct pci_epf_device_id *
pci_epf_match_id(const struct pci_epf_device_id * id,const struct pci_epf * epf)465 pci_epf_match_id(const struct pci_epf_device_id *id, const struct pci_epf *epf)
466 {
467 while (id->name[0]) {
468 if (strcmp(epf->name, id->name) == 0)
469 return id;
470 id++;
471 }
472
473 return NULL;
474 }
475
pci_epf_device_match(struct device * dev,struct device_driver * drv)476 static int pci_epf_device_match(struct device *dev, struct device_driver *drv)
477 {
478 struct pci_epf *epf = to_pci_epf(dev);
479 struct pci_epf_driver *driver = to_pci_epf_driver(drv);
480
481 if (driver->id_table)
482 return !!pci_epf_match_id(driver->id_table, epf);
483
484 return !strcmp(epf->name, drv->name);
485 }
486
pci_epf_device_probe(struct device * dev)487 static int pci_epf_device_probe(struct device *dev)
488 {
489 struct pci_epf *epf = to_pci_epf(dev);
490 struct pci_epf_driver *driver = to_pci_epf_driver(dev->driver);
491
492 if (!driver->probe)
493 return -ENODEV;
494
495 epf->driver = driver;
496
497 return driver->probe(epf, pci_epf_match_id(driver->id_table, epf));
498 }
499
pci_epf_device_remove(struct device * dev)500 static void pci_epf_device_remove(struct device *dev)
501 {
502 struct pci_epf *epf = to_pci_epf(dev);
503 struct pci_epf_driver *driver = to_pci_epf_driver(dev->driver);
504
505 if (driver->remove)
506 driver->remove(epf);
507 epf->driver = NULL;
508 }
509
510 static struct bus_type pci_epf_bus_type = {
511 .name = "pci-epf",
512 .match = pci_epf_device_match,
513 .probe = pci_epf_device_probe,
514 .remove = pci_epf_device_remove,
515 };
516
pci_epf_init(void)517 static int __init pci_epf_init(void)
518 {
519 int ret;
520
521 ret = bus_register(&pci_epf_bus_type);
522 if (ret) {
523 pr_err("failed to register pci epf bus --> %d\n", ret);
524 return ret;
525 }
526
527 return 0;
528 }
529 module_init(pci_epf_init);
530
pci_epf_exit(void)531 static void __exit pci_epf_exit(void)
532 {
533 bus_unregister(&pci_epf_bus_type);
534 }
535 module_exit(pci_epf_exit);
536
537 MODULE_DESCRIPTION("PCI EPF Library");
538 MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@ti.com>");
539