1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * PCI Endpoint *Controller* (EPC) 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/slab.h>
11 #include <linux/module.h>
12 #include <linux/of_device.h>
13 
14 #include <linux/pci-epc.h>
15 #include <linux/pci-epf.h>
16 #include <linux/pci-ep-cfs.h>
17 
18 static struct class *pci_epc_class;
19 
devm_pci_epc_release(struct device * dev,void * res)20 static void devm_pci_epc_release(struct device *dev, void *res)
21 {
22 	struct pci_epc *epc = *(struct pci_epc **)res;
23 
24 	pci_epc_destroy(epc);
25 }
26 
devm_pci_epc_match(struct device * dev,void * res,void * match_data)27 static int devm_pci_epc_match(struct device *dev, void *res, void *match_data)
28 {
29 	struct pci_epc **epc = res;
30 
31 	return *epc == match_data;
32 }
33 
34 /**
35  * pci_epc_put() - release the PCI endpoint controller
36  * @epc: epc returned by pci_epc_get()
37  *
38  * release the refcount the caller obtained by invoking pci_epc_get()
39  */
pci_epc_put(struct pci_epc * epc)40 void pci_epc_put(struct pci_epc *epc)
41 {
42 	if (!epc || IS_ERR(epc))
43 		return;
44 
45 	module_put(epc->ops->owner);
46 	put_device(&epc->dev);
47 }
48 EXPORT_SYMBOL_GPL(pci_epc_put);
49 
50 /**
51  * pci_epc_get() - get the PCI endpoint controller
52  * @epc_name: device name of the endpoint controller
53  *
54  * Invoke to get struct pci_epc * corresponding to the device name of the
55  * endpoint controller
56  */
pci_epc_get(const char * epc_name)57 struct pci_epc *pci_epc_get(const char *epc_name)
58 {
59 	int ret = -EINVAL;
60 	struct pci_epc *epc;
61 	struct device *dev;
62 	struct class_dev_iter iter;
63 
64 	class_dev_iter_init(&iter, pci_epc_class, NULL, NULL);
65 	while ((dev = class_dev_iter_next(&iter))) {
66 		if (strcmp(epc_name, dev_name(dev)))
67 			continue;
68 
69 		epc = to_pci_epc(dev);
70 		if (!try_module_get(epc->ops->owner)) {
71 			ret = -EINVAL;
72 			goto err;
73 		}
74 
75 		class_dev_iter_exit(&iter);
76 		get_device(&epc->dev);
77 		return epc;
78 	}
79 
80 err:
81 	class_dev_iter_exit(&iter);
82 	return ERR_PTR(ret);
83 }
84 EXPORT_SYMBOL_GPL(pci_epc_get);
85 
86 /**
87  * pci_epc_get_first_free_bar() - helper to get first unreserved BAR
88  * @epc_features: pci_epc_features structure that holds the reserved bar bitmap
89  *
90  * Invoke to get the first unreserved BAR that can be used by the endpoint
91  * function. For any incorrect value in reserved_bar return '0'.
92  */
93 enum pci_barno
pci_epc_get_first_free_bar(const struct pci_epc_features * epc_features)94 pci_epc_get_first_free_bar(const struct pci_epc_features *epc_features)
95 {
96 	return pci_epc_get_next_free_bar(epc_features, BAR_0);
97 }
98 EXPORT_SYMBOL_GPL(pci_epc_get_first_free_bar);
99 
100 /**
101  * pci_epc_get_next_free_bar() - helper to get unreserved BAR starting from @bar
102  * @epc_features: pci_epc_features structure that holds the reserved bar bitmap
103  * @bar: the starting BAR number from where unreserved BAR should be searched
104  *
105  * Invoke to get the next unreserved BAR starting from @bar that can be used
106  * for endpoint function. For any incorrect value in reserved_bar return '0'.
107  */
pci_epc_get_next_free_bar(const struct pci_epc_features * epc_features,enum pci_barno bar)108 enum pci_barno pci_epc_get_next_free_bar(const struct pci_epc_features
109 					 *epc_features, enum pci_barno bar)
110 {
111 	unsigned long free_bar;
112 
113 	if (!epc_features)
114 		return BAR_0;
115 
116 	/* If 'bar - 1' is a 64-bit BAR, move to the next BAR */
117 	if ((epc_features->bar_fixed_64bit << 1) & 1 << bar)
118 		bar++;
119 
120 	/* Find if the reserved BAR is also a 64-bit BAR */
121 	free_bar = epc_features->reserved_bar & epc_features->bar_fixed_64bit;
122 
123 	/* Set the adjacent bit if the reserved BAR is also a 64-bit BAR */
124 	free_bar <<= 1;
125 	free_bar |= epc_features->reserved_bar;
126 
127 	free_bar = find_next_zero_bit(&free_bar, 6, bar);
128 	if (free_bar > 5)
129 		return NO_BAR;
130 
131 	return free_bar;
132 }
133 EXPORT_SYMBOL_GPL(pci_epc_get_next_free_bar);
134 
135 /**
136  * pci_epc_get_features() - get the features supported by EPC
137  * @epc: the features supported by *this* EPC device will be returned
138  * @func_no: the features supported by the EPC device specific to the
139  *	     endpoint function with func_no will be returned
140  * @vfunc_no: the features supported by the EPC device specific to the
141  *	     virtual endpoint function with vfunc_no will be returned
142  *
143  * Invoke to get the features provided by the EPC which may be
144  * specific to an endpoint function. Returns pci_epc_features on success
145  * and NULL for any failures.
146  */
pci_epc_get_features(struct pci_epc * epc,u8 func_no,u8 vfunc_no)147 const struct pci_epc_features *pci_epc_get_features(struct pci_epc *epc,
148 						    u8 func_no, u8 vfunc_no)
149 {
150 	const struct pci_epc_features *epc_features;
151 
152 	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)
153 		return NULL;
154 
155 	if (vfunc_no > 0 && (!epc->max_vfs || vfunc_no > epc->max_vfs[func_no]))
156 		return NULL;
157 
158 	if (!epc->ops->get_features)
159 		return NULL;
160 
161 	mutex_lock(&epc->lock);
162 	epc_features = epc->ops->get_features(epc, func_no, vfunc_no);
163 	mutex_unlock(&epc->lock);
164 
165 	return epc_features;
166 }
167 EXPORT_SYMBOL_GPL(pci_epc_get_features);
168 
169 /**
170  * pci_epc_stop() - stop the PCI link
171  * @epc: the link of the EPC device that has to be stopped
172  *
173  * Invoke to stop the PCI link
174  */
pci_epc_stop(struct pci_epc * epc)175 void pci_epc_stop(struct pci_epc *epc)
176 {
177 	if (IS_ERR(epc) || !epc->ops->stop)
178 		return;
179 
180 	mutex_lock(&epc->lock);
181 	epc->ops->stop(epc);
182 	mutex_unlock(&epc->lock);
183 }
184 EXPORT_SYMBOL_GPL(pci_epc_stop);
185 
186 /**
187  * pci_epc_start() - start the PCI link
188  * @epc: the link of *this* EPC device has to be started
189  *
190  * Invoke to start the PCI link
191  */
pci_epc_start(struct pci_epc * epc)192 int pci_epc_start(struct pci_epc *epc)
193 {
194 	int ret;
195 
196 	if (IS_ERR(epc))
197 		return -EINVAL;
198 
199 	if (!epc->ops->start)
200 		return 0;
201 
202 	mutex_lock(&epc->lock);
203 	ret = epc->ops->start(epc);
204 	mutex_unlock(&epc->lock);
205 
206 	return ret;
207 }
208 EXPORT_SYMBOL_GPL(pci_epc_start);
209 
210 /**
211  * pci_epc_raise_irq() - interrupt the host system
212  * @epc: the EPC device which has to interrupt the host
213  * @func_no: the physical endpoint function number in the EPC device
214  * @vfunc_no: the virtual endpoint function number in the physical function
215  * @type: specify the type of interrupt; legacy, MSI or MSI-X
216  * @interrupt_num: the MSI or MSI-X interrupt number
217  *
218  * Invoke to raise an legacy, MSI or MSI-X interrupt
219  */
pci_epc_raise_irq(struct pci_epc * epc,u8 func_no,u8 vfunc_no,enum pci_epc_irq_type type,u16 interrupt_num)220 int pci_epc_raise_irq(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
221 		      enum pci_epc_irq_type type, u16 interrupt_num)
222 {
223 	int ret;
224 
225 	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)
226 		return -EINVAL;
227 
228 	if (vfunc_no > 0 && (!epc->max_vfs || vfunc_no > epc->max_vfs[func_no]))
229 		return -EINVAL;
230 
231 	if (!epc->ops->raise_irq)
232 		return 0;
233 
234 	mutex_lock(&epc->lock);
235 	ret = epc->ops->raise_irq(epc, func_no, vfunc_no, type, interrupt_num);
236 	mutex_unlock(&epc->lock);
237 
238 	return ret;
239 }
240 EXPORT_SYMBOL_GPL(pci_epc_raise_irq);
241 
242 /**
243  * pci_epc_map_msi_irq() - Map physical address to MSI address and return
244  *                         MSI data
245  * @epc: the EPC device which has the MSI capability
246  * @func_no: the physical endpoint function number in the EPC device
247  * @vfunc_no: the virtual endpoint function number in the physical function
248  * @phys_addr: the physical address of the outbound region
249  * @interrupt_num: the MSI interrupt number
250  * @entry_size: Size of Outbound address region for each interrupt
251  * @msi_data: the data that should be written in order to raise MSI interrupt
252  *            with interrupt number as 'interrupt num'
253  * @msi_addr_offset: Offset of MSI address from the aligned outbound address
254  *                   to which the MSI address is mapped
255  *
256  * Invoke to map physical address to MSI address and return MSI data. The
257  * physical address should be an address in the outbound region. This is
258  * required to implement doorbell functionality of NTB wherein EPC on either
259  * side of the interface (primary and secondary) can directly write to the
260  * physical address (in outbound region) of the other interface to ring
261  * doorbell.
262  */
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)263 int pci_epc_map_msi_irq(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
264 			phys_addr_t phys_addr, u8 interrupt_num, u32 entry_size,
265 			u32 *msi_data, u32 *msi_addr_offset)
266 {
267 	int ret;
268 
269 	if (IS_ERR_OR_NULL(epc))
270 		return -EINVAL;
271 
272 	if (vfunc_no > 0 && (!epc->max_vfs || vfunc_no > epc->max_vfs[func_no]))
273 		return -EINVAL;
274 
275 	if (!epc->ops->map_msi_irq)
276 		return -EINVAL;
277 
278 	mutex_lock(&epc->lock);
279 	ret = epc->ops->map_msi_irq(epc, func_no, vfunc_no, phys_addr,
280 				    interrupt_num, entry_size, msi_data,
281 				    msi_addr_offset);
282 	mutex_unlock(&epc->lock);
283 
284 	return ret;
285 }
286 EXPORT_SYMBOL_GPL(pci_epc_map_msi_irq);
287 
288 /**
289  * pci_epc_get_msi() - get the number of MSI interrupt numbers allocated
290  * @epc: the EPC device to which MSI interrupts was requested
291  * @func_no: the physical endpoint function number in the EPC device
292  * @vfunc_no: the virtual endpoint function number in the physical function
293  *
294  * Invoke to get the number of MSI interrupts allocated by the RC
295  */
pci_epc_get_msi(struct pci_epc * epc,u8 func_no,u8 vfunc_no)296 int pci_epc_get_msi(struct pci_epc *epc, u8 func_no, u8 vfunc_no)
297 {
298 	int interrupt;
299 
300 	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)
301 		return 0;
302 
303 	if (vfunc_no > 0 && (!epc->max_vfs || vfunc_no > epc->max_vfs[func_no]))
304 		return 0;
305 
306 	if (!epc->ops->get_msi)
307 		return 0;
308 
309 	mutex_lock(&epc->lock);
310 	interrupt = epc->ops->get_msi(epc, func_no, vfunc_no);
311 	mutex_unlock(&epc->lock);
312 
313 	if (interrupt < 0)
314 		return 0;
315 
316 	interrupt = 1 << interrupt;
317 
318 	return interrupt;
319 }
320 EXPORT_SYMBOL_GPL(pci_epc_get_msi);
321 
322 /**
323  * pci_epc_set_msi() - set the number of MSI interrupt numbers required
324  * @epc: the EPC device on which MSI has to be configured
325  * @func_no: the physical endpoint function number in the EPC device
326  * @vfunc_no: the virtual endpoint function number in the physical function
327  * @interrupts: number of MSI interrupts required by the EPF
328  *
329  * Invoke to set the required number of MSI interrupts.
330  */
pci_epc_set_msi(struct pci_epc * epc,u8 func_no,u8 vfunc_no,u8 interrupts)331 int pci_epc_set_msi(struct pci_epc *epc, u8 func_no, u8 vfunc_no, u8 interrupts)
332 {
333 	int ret;
334 	u8 encode_int;
335 
336 	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions ||
337 	    interrupts < 1 || interrupts > 32)
338 		return -EINVAL;
339 
340 	if (vfunc_no > 0 && (!epc->max_vfs || vfunc_no > epc->max_vfs[func_no]))
341 		return -EINVAL;
342 
343 	if (!epc->ops->set_msi)
344 		return 0;
345 
346 	encode_int = order_base_2(interrupts);
347 
348 	mutex_lock(&epc->lock);
349 	ret = epc->ops->set_msi(epc, func_no, vfunc_no, encode_int);
350 	mutex_unlock(&epc->lock);
351 
352 	return ret;
353 }
354 EXPORT_SYMBOL_GPL(pci_epc_set_msi);
355 
356 /**
357  * pci_epc_get_msix() - get the number of MSI-X interrupt numbers allocated
358  * @epc: the EPC device to which MSI-X interrupts was requested
359  * @func_no: the physical endpoint function number in the EPC device
360  * @vfunc_no: the virtual endpoint function number in the physical function
361  *
362  * Invoke to get the number of MSI-X interrupts allocated by the RC
363  */
pci_epc_get_msix(struct pci_epc * epc,u8 func_no,u8 vfunc_no)364 int pci_epc_get_msix(struct pci_epc *epc, u8 func_no, u8 vfunc_no)
365 {
366 	int interrupt;
367 
368 	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)
369 		return 0;
370 
371 	if (vfunc_no > 0 && (!epc->max_vfs || vfunc_no > epc->max_vfs[func_no]))
372 		return 0;
373 
374 	if (!epc->ops->get_msix)
375 		return 0;
376 
377 	mutex_lock(&epc->lock);
378 	interrupt = epc->ops->get_msix(epc, func_no, vfunc_no);
379 	mutex_unlock(&epc->lock);
380 
381 	if (interrupt < 0)
382 		return 0;
383 
384 	return interrupt + 1;
385 }
386 EXPORT_SYMBOL_GPL(pci_epc_get_msix);
387 
388 /**
389  * pci_epc_set_msix() - set the number of MSI-X interrupt numbers required
390  * @epc: the EPC device on which MSI-X has to be configured
391  * @func_no: the physical endpoint function number in the EPC device
392  * @vfunc_no: the virtual endpoint function number in the physical function
393  * @interrupts: number of MSI-X interrupts required by the EPF
394  * @bir: BAR where the MSI-X table resides
395  * @offset: Offset pointing to the start of MSI-X table
396  *
397  * Invoke to set the required number of MSI-X interrupts.
398  */
pci_epc_set_msix(struct pci_epc * epc,u8 func_no,u8 vfunc_no,u16 interrupts,enum pci_barno bir,u32 offset)399 int pci_epc_set_msix(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
400 		     u16 interrupts, enum pci_barno bir, u32 offset)
401 {
402 	int ret;
403 
404 	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions ||
405 	    interrupts < 1 || interrupts > 2048)
406 		return -EINVAL;
407 
408 	if (vfunc_no > 0 && (!epc->max_vfs || vfunc_no > epc->max_vfs[func_no]))
409 		return -EINVAL;
410 
411 	if (!epc->ops->set_msix)
412 		return 0;
413 
414 	mutex_lock(&epc->lock);
415 	ret = epc->ops->set_msix(epc, func_no, vfunc_no, interrupts - 1, bir,
416 				 offset);
417 	mutex_unlock(&epc->lock);
418 
419 	return ret;
420 }
421 EXPORT_SYMBOL_GPL(pci_epc_set_msix);
422 
423 /**
424  * pci_epc_unmap_addr() - unmap CPU address from PCI address
425  * @epc: the EPC device on which address is allocated
426  * @func_no: the physical endpoint function number in the EPC device
427  * @vfunc_no: the virtual endpoint function number in the physical function
428  * @phys_addr: physical address of the local system
429  *
430  * Invoke to unmap the CPU address from PCI address.
431  */
pci_epc_unmap_addr(struct pci_epc * epc,u8 func_no,u8 vfunc_no,phys_addr_t phys_addr)432 void pci_epc_unmap_addr(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
433 			phys_addr_t phys_addr)
434 {
435 	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)
436 		return;
437 
438 	if (vfunc_no > 0 && (!epc->max_vfs || vfunc_no > epc->max_vfs[func_no]))
439 		return;
440 
441 	if (!epc->ops->unmap_addr)
442 		return;
443 
444 	mutex_lock(&epc->lock);
445 	epc->ops->unmap_addr(epc, func_no, vfunc_no, phys_addr);
446 	mutex_unlock(&epc->lock);
447 }
448 EXPORT_SYMBOL_GPL(pci_epc_unmap_addr);
449 
450 /**
451  * pci_epc_map_addr() - map CPU address to PCI address
452  * @epc: the EPC device on which address is allocated
453  * @func_no: the physical endpoint function number in the EPC device
454  * @vfunc_no: the virtual endpoint function number in the physical function
455  * @phys_addr: physical address of the local system
456  * @pci_addr: PCI address to which the physical address should be mapped
457  * @size: the size of the allocation
458  *
459  * Invoke to map CPU address with PCI address.
460  */
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)461 int pci_epc_map_addr(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
462 		     phys_addr_t phys_addr, u64 pci_addr, size_t size)
463 {
464 	int ret;
465 
466 	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)
467 		return -EINVAL;
468 
469 	if (vfunc_no > 0 && (!epc->max_vfs || vfunc_no > epc->max_vfs[func_no]))
470 		return -EINVAL;
471 
472 	if (!epc->ops->map_addr)
473 		return 0;
474 
475 	mutex_lock(&epc->lock);
476 	ret = epc->ops->map_addr(epc, func_no, vfunc_no, phys_addr, pci_addr,
477 				 size);
478 	mutex_unlock(&epc->lock);
479 
480 	return ret;
481 }
482 EXPORT_SYMBOL_GPL(pci_epc_map_addr);
483 
484 /**
485  * pci_epc_clear_bar() - reset the BAR
486  * @epc: the EPC device for which the BAR has to be cleared
487  * @func_no: the physical endpoint function number in the EPC device
488  * @vfunc_no: the virtual endpoint function number in the physical function
489  * @epf_bar: the struct epf_bar that contains the BAR information
490  *
491  * Invoke to reset the BAR of the endpoint device.
492  */
pci_epc_clear_bar(struct pci_epc * epc,u8 func_no,u8 vfunc_no,struct pci_epf_bar * epf_bar)493 void pci_epc_clear_bar(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
494 		       struct pci_epf_bar *epf_bar)
495 {
496 	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions ||
497 	    (epf_bar->barno == BAR_5 &&
498 	     epf_bar->flags & PCI_BASE_ADDRESS_MEM_TYPE_64))
499 		return;
500 
501 	if (vfunc_no > 0 && (!epc->max_vfs || vfunc_no > epc->max_vfs[func_no]))
502 		return;
503 
504 	if (!epc->ops->clear_bar)
505 		return;
506 
507 	mutex_lock(&epc->lock);
508 	epc->ops->clear_bar(epc, func_no, vfunc_no, epf_bar);
509 	mutex_unlock(&epc->lock);
510 }
511 EXPORT_SYMBOL_GPL(pci_epc_clear_bar);
512 
513 /**
514  * pci_epc_set_bar() - configure BAR in order for host to assign PCI addr space
515  * @epc: the EPC device on which BAR has to be configured
516  * @func_no: the physical endpoint function number in the EPC device
517  * @vfunc_no: the virtual endpoint function number in the physical function
518  * @epf_bar: the struct epf_bar that contains the BAR information
519  *
520  * Invoke to configure the BAR of the endpoint device.
521  */
pci_epc_set_bar(struct pci_epc * epc,u8 func_no,u8 vfunc_no,struct pci_epf_bar * epf_bar)522 int pci_epc_set_bar(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
523 		    struct pci_epf_bar *epf_bar)
524 {
525 	int ret;
526 	int flags = epf_bar->flags;
527 
528 	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions ||
529 	    (epf_bar->barno == BAR_5 &&
530 	     flags & PCI_BASE_ADDRESS_MEM_TYPE_64) ||
531 	    (flags & PCI_BASE_ADDRESS_SPACE_IO &&
532 	     flags & PCI_BASE_ADDRESS_IO_MASK) ||
533 	    (upper_32_bits(epf_bar->size) &&
534 	     !(flags & PCI_BASE_ADDRESS_MEM_TYPE_64)))
535 		return -EINVAL;
536 
537 	if (vfunc_no > 0 && (!epc->max_vfs || vfunc_no > epc->max_vfs[func_no]))
538 		return -EINVAL;
539 
540 	if (!epc->ops->set_bar)
541 		return 0;
542 
543 	mutex_lock(&epc->lock);
544 	ret = epc->ops->set_bar(epc, func_no, vfunc_no, epf_bar);
545 	mutex_unlock(&epc->lock);
546 
547 	return ret;
548 }
549 EXPORT_SYMBOL_GPL(pci_epc_set_bar);
550 
551 /**
552  * pci_epc_write_header() - write standard configuration header
553  * @epc: the EPC device to which the configuration header should be written
554  * @func_no: the physical endpoint function number in the EPC device
555  * @vfunc_no: the virtual endpoint function number in the physical function
556  * @header: standard configuration header fields
557  *
558  * Invoke to write the configuration header to the endpoint controller. Every
559  * endpoint controller will have a dedicated location to which the standard
560  * configuration header would be written. The callback function should write
561  * the header fields to this dedicated location.
562  */
pci_epc_write_header(struct pci_epc * epc,u8 func_no,u8 vfunc_no,struct pci_epf_header * header)563 int pci_epc_write_header(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
564 			 struct pci_epf_header *header)
565 {
566 	int ret;
567 
568 	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)
569 		return -EINVAL;
570 
571 	if (vfunc_no > 0 && (!epc->max_vfs || vfunc_no > epc->max_vfs[func_no]))
572 		return -EINVAL;
573 
574 	/* Only Virtual Function #1 has deviceID */
575 	if (vfunc_no > 1)
576 		return -EINVAL;
577 
578 	if (!epc->ops->write_header)
579 		return 0;
580 
581 	mutex_lock(&epc->lock);
582 	ret = epc->ops->write_header(epc, func_no, vfunc_no, header);
583 	mutex_unlock(&epc->lock);
584 
585 	return ret;
586 }
587 EXPORT_SYMBOL_GPL(pci_epc_write_header);
588 
589 /**
590  * pci_epc_add_epf() - bind PCI endpoint function to an endpoint controller
591  * @epc: the EPC device to which the endpoint function should be added
592  * @epf: the endpoint function to be added
593  * @type: Identifies if the EPC is connected to the primary or secondary
594  *        interface of EPF
595  *
596  * A PCI endpoint device can have one or more functions. In the case of PCIe,
597  * the specification allows up to 8 PCIe endpoint functions. Invoke
598  * pci_epc_add_epf() to add a PCI endpoint function to an endpoint controller.
599  */
pci_epc_add_epf(struct pci_epc * epc,struct pci_epf * epf,enum pci_epc_interface_type type)600 int pci_epc_add_epf(struct pci_epc *epc, struct pci_epf *epf,
601 		    enum pci_epc_interface_type type)
602 {
603 	struct list_head *list;
604 	u32 func_no;
605 	int ret = 0;
606 
607 	if (IS_ERR_OR_NULL(epc) || epf->is_vf)
608 		return -EINVAL;
609 
610 	if (type == PRIMARY_INTERFACE && epf->epc)
611 		return -EBUSY;
612 
613 	if (type == SECONDARY_INTERFACE && epf->sec_epc)
614 		return -EBUSY;
615 
616 	mutex_lock(&epc->lock);
617 	func_no = find_first_zero_bit(&epc->function_num_map,
618 				      BITS_PER_LONG);
619 	if (func_no >= BITS_PER_LONG) {
620 		ret = -EINVAL;
621 		goto ret;
622 	}
623 
624 	if (func_no > epc->max_functions - 1) {
625 		dev_err(&epc->dev, "Exceeding max supported Function Number\n");
626 		ret = -EINVAL;
627 		goto ret;
628 	}
629 
630 	set_bit(func_no, &epc->function_num_map);
631 	if (type == PRIMARY_INTERFACE) {
632 		epf->func_no = func_no;
633 		epf->epc = epc;
634 		list = &epf->list;
635 	} else {
636 		epf->sec_epc_func_no = func_no;
637 		epf->sec_epc = epc;
638 		list = &epf->sec_epc_list;
639 	}
640 
641 	list_add_tail(list, &epc->pci_epf);
642 ret:
643 	mutex_unlock(&epc->lock);
644 
645 	return ret;
646 }
647 EXPORT_SYMBOL_GPL(pci_epc_add_epf);
648 
649 /**
650  * pci_epc_remove_epf() - remove PCI endpoint function from endpoint controller
651  * @epc: the EPC device from which the endpoint function should be removed
652  * @epf: the endpoint function to be removed
653  * @type: identifies if the EPC is connected to the primary or secondary
654  *        interface of EPF
655  *
656  * Invoke to remove PCI endpoint function from the endpoint controller.
657  */
pci_epc_remove_epf(struct pci_epc * epc,struct pci_epf * epf,enum pci_epc_interface_type type)658 void pci_epc_remove_epf(struct pci_epc *epc, struct pci_epf *epf,
659 			enum pci_epc_interface_type type)
660 {
661 	struct list_head *list;
662 	u32 func_no = 0;
663 
664 	if (!epc || IS_ERR(epc) || !epf)
665 		return;
666 
667 	if (type == PRIMARY_INTERFACE) {
668 		func_no = epf->func_no;
669 		list = &epf->list;
670 	} else {
671 		func_no = epf->sec_epc_func_no;
672 		list = &epf->sec_epc_list;
673 	}
674 
675 	mutex_lock(&epc->lock);
676 	clear_bit(func_no, &epc->function_num_map);
677 	list_del(list);
678 	epf->epc = NULL;
679 	mutex_unlock(&epc->lock);
680 }
681 EXPORT_SYMBOL_GPL(pci_epc_remove_epf);
682 
683 /**
684  * pci_epc_linkup() - Notify the EPF device that EPC device has established a
685  *		      connection with the Root Complex.
686  * @epc: the EPC device which has established link with the host
687  *
688  * Invoke to Notify the EPF device that the EPC device has established a
689  * connection with the Root Complex.
690  */
pci_epc_linkup(struct pci_epc * epc)691 void pci_epc_linkup(struct pci_epc *epc)
692 {
693 	if (!epc || IS_ERR(epc))
694 		return;
695 
696 	atomic_notifier_call_chain(&epc->notifier, LINK_UP, NULL);
697 }
698 EXPORT_SYMBOL_GPL(pci_epc_linkup);
699 
700 /**
701  * pci_epc_init_notify() - Notify the EPF device that EPC device's core
702  *			   initialization is completed.
703  * @epc: the EPC device whose core initialization is completed
704  *
705  * Invoke to Notify the EPF device that the EPC device's initialization
706  * is completed.
707  */
pci_epc_init_notify(struct pci_epc * epc)708 void pci_epc_init_notify(struct pci_epc *epc)
709 {
710 	if (!epc || IS_ERR(epc))
711 		return;
712 
713 	atomic_notifier_call_chain(&epc->notifier, CORE_INIT, NULL);
714 }
715 EXPORT_SYMBOL_GPL(pci_epc_init_notify);
716 
717 /**
718  * pci_epc_destroy() - destroy the EPC device
719  * @epc: the EPC device that has to be destroyed
720  *
721  * Invoke to destroy the PCI EPC device
722  */
pci_epc_destroy(struct pci_epc * epc)723 void pci_epc_destroy(struct pci_epc *epc)
724 {
725 	pci_ep_cfs_remove_epc_group(epc->group);
726 	device_unregister(&epc->dev);
727 	kfree(epc);
728 }
729 EXPORT_SYMBOL_GPL(pci_epc_destroy);
730 
731 /**
732  * devm_pci_epc_destroy() - destroy the EPC device
733  * @dev: device that wants to destroy the EPC
734  * @epc: the EPC device that has to be destroyed
735  *
736  * Invoke to destroy the devres associated with this
737  * pci_epc and destroy the EPC device.
738  */
devm_pci_epc_destroy(struct device * dev,struct pci_epc * epc)739 void devm_pci_epc_destroy(struct device *dev, struct pci_epc *epc)
740 {
741 	int r;
742 
743 	r = devres_destroy(dev, devm_pci_epc_release, devm_pci_epc_match,
744 			   epc);
745 	dev_WARN_ONCE(dev, r, "couldn't find PCI EPC resource\n");
746 }
747 EXPORT_SYMBOL_GPL(devm_pci_epc_destroy);
748 
749 /**
750  * __pci_epc_create() - create a new endpoint controller (EPC) device
751  * @dev: device that is creating the new EPC
752  * @ops: function pointers for performing EPC operations
753  * @owner: the owner of the module that creates the EPC device
754  *
755  * Invoke to create a new EPC device and add it to pci_epc class.
756  */
757 struct pci_epc *
__pci_epc_create(struct device * dev,const struct pci_epc_ops * ops,struct module * owner)758 __pci_epc_create(struct device *dev, const struct pci_epc_ops *ops,
759 		 struct module *owner)
760 {
761 	int ret;
762 	struct pci_epc *epc;
763 
764 	if (WARN_ON(!dev)) {
765 		ret = -EINVAL;
766 		goto err_ret;
767 	}
768 
769 	epc = kzalloc(sizeof(*epc), GFP_KERNEL);
770 	if (!epc) {
771 		ret = -ENOMEM;
772 		goto err_ret;
773 	}
774 
775 	mutex_init(&epc->lock);
776 	INIT_LIST_HEAD(&epc->pci_epf);
777 	ATOMIC_INIT_NOTIFIER_HEAD(&epc->notifier);
778 
779 	device_initialize(&epc->dev);
780 	epc->dev.class = pci_epc_class;
781 	epc->dev.parent = dev;
782 	epc->ops = ops;
783 
784 	ret = dev_set_name(&epc->dev, "%s", dev_name(dev));
785 	if (ret)
786 		goto put_dev;
787 
788 	ret = device_add(&epc->dev);
789 	if (ret)
790 		goto put_dev;
791 
792 	epc->group = pci_ep_cfs_add_epc_group(dev_name(dev));
793 
794 	return epc;
795 
796 put_dev:
797 	put_device(&epc->dev);
798 	kfree(epc);
799 
800 err_ret:
801 	return ERR_PTR(ret);
802 }
803 EXPORT_SYMBOL_GPL(__pci_epc_create);
804 
805 /**
806  * __devm_pci_epc_create() - create a new endpoint controller (EPC) device
807  * @dev: device that is creating the new EPC
808  * @ops: function pointers for performing EPC operations
809  * @owner: the owner of the module that creates the EPC device
810  *
811  * Invoke to create a new EPC device and add it to pci_epc class.
812  * While at that, it also associates the device with the pci_epc using devres.
813  * On driver detach, release function is invoked on the devres data,
814  * then, devres data is freed.
815  */
816 struct pci_epc *
__devm_pci_epc_create(struct device * dev,const struct pci_epc_ops * ops,struct module * owner)817 __devm_pci_epc_create(struct device *dev, const struct pci_epc_ops *ops,
818 		      struct module *owner)
819 {
820 	struct pci_epc **ptr, *epc;
821 
822 	ptr = devres_alloc(devm_pci_epc_release, sizeof(*ptr), GFP_KERNEL);
823 	if (!ptr)
824 		return ERR_PTR(-ENOMEM);
825 
826 	epc = __pci_epc_create(dev, ops, owner);
827 	if (!IS_ERR(epc)) {
828 		*ptr = epc;
829 		devres_add(dev, ptr);
830 	} else {
831 		devres_free(ptr);
832 	}
833 
834 	return epc;
835 }
836 EXPORT_SYMBOL_GPL(__devm_pci_epc_create);
837 
pci_epc_init(void)838 static int __init pci_epc_init(void)
839 {
840 	pci_epc_class = class_create(THIS_MODULE, "pci_epc");
841 	if (IS_ERR(pci_epc_class)) {
842 		pr_err("failed to create pci epc class --> %ld\n",
843 		       PTR_ERR(pci_epc_class));
844 		return PTR_ERR(pci_epc_class);
845 	}
846 
847 	return 0;
848 }
849 module_init(pci_epc_init);
850 
pci_epc_exit(void)851 static void __exit pci_epc_exit(void)
852 {
853 	class_destroy(pci_epc_class);
854 }
855 module_exit(pci_epc_exit);
856 
857 MODULE_DESCRIPTION("PCI EPC Library");
858 MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@ti.com>");
859 MODULE_LICENSE("GPL v2");
860