xref: /linux/drivers/pci/endpoint/functions/pci-epf-vntb.c (revision 7255fcc80d4b525cc10cfaaf7f485830d4ed2000)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Endpoint Function Driver to implement Non-Transparent Bridge functionality
4  * Between PCI RC and EP
5  *
6  * Copyright (C) 2020 Texas Instruments
7  * Copyright (C) 2022 NXP
8  *
9  * Based on pci-epf-ntb.c
10  * Author: Frank Li <Frank.Li@nxp.com>
11  * Author: Kishon Vijay Abraham I <kishon@ti.com>
12  */
13 
14 /*
15  * +------------+         +---------------------------------------+
16  * |            |         |                                       |
17  * +------------+         |                        +--------------+
18  * | NTB        |         |                        | NTB          |
19  * | NetDev     |         |                        | NetDev       |
20  * +------------+         |                        +--------------+
21  * | NTB        |         |                        | NTB          |
22  * | Transfer   |         |                        | Transfer     |
23  * +------------+         |                        +--------------+
24  * |            |         |                        |              |
25  * |  PCI NTB   |         |                        |              |
26  * |    EPF     |         |                        |              |
27  * |   Driver   |         |                        | PCI Virtual  |
28  * |            |         +---------------+        | NTB Driver   |
29  * |            |         | PCI EP NTB    |<------>|              |
30  * |            |         |  FN Driver    |        |              |
31  * +------------+         +---------------+        +--------------+
32  * |            |         |               |        |              |
33  * |  PCI Bus   | <-----> |  PCI EP Bus   |        |  Virtual PCI |
34  * |            |  PCI    |               |        |     Bus      |
35  * +------------+         +---------------+--------+--------------+
36  * PCIe Root Port                        PCI EP
37  */
38 
39 #include <linux/delay.h>
40 #include <linux/io.h>
41 #include <linux/module.h>
42 #include <linux/slab.h>
43 
44 #include <linux/pci-epc.h>
45 #include <linux/pci-epf.h>
46 #include <linux/ntb.h>
47 
48 static struct workqueue_struct *kpcintb_workqueue;
49 
50 #define COMMAND_CONFIGURE_DOORBELL	1
51 #define COMMAND_TEARDOWN_DOORBELL	2
52 #define COMMAND_CONFIGURE_MW		3
53 #define COMMAND_TEARDOWN_MW		4
54 #define COMMAND_LINK_UP			5
55 #define COMMAND_LINK_DOWN		6
56 
57 #define COMMAND_STATUS_OK		1
58 #define COMMAND_STATUS_ERROR		2
59 
60 #define LINK_STATUS_UP			BIT(0)
61 
62 #define SPAD_COUNT			64
63 #define DB_COUNT			4
64 #define NTB_MW_OFFSET			2
65 #define DB_COUNT_MASK			GENMASK(15, 0)
66 #define MSIX_ENABLE			BIT(16)
67 #define MAX_DB_COUNT			32
68 #define MAX_MW				4
69 
70 enum epf_ntb_bar {
71 	BAR_CONFIG,
72 	BAR_DB,
73 	BAR_MW0,
74 	BAR_MW1,
75 	BAR_MW2,
76 };
77 
78 /*
79  * +--------------------------------------------------+ Base
80  * |                                                  |
81  * |                                                  |
82  * |                                                  |
83  * |          Common Control Register                 |
84  * |                                                  |
85  * |                                                  |
86  * |                                                  |
87  * +-----------------------+--------------------------+ Base+spad_offset
88  * |                       |                          |
89  * |    Peer Spad Space    |    Spad Space            |
90  * |                       |                          |
91  * |                       |                          |
92  * +-----------------------+--------------------------+ Base+spad_offset
93  * |                       |                          |     +spad_count * 4
94  * |                       |                          |
95  * |     Spad Space        |   Peer Spad Space        |
96  * |                       |                          |
97  * +-----------------------+--------------------------+
98  *       Virtual PCI             PCIe Endpoint
99  *       NTB Driver               NTB Driver
100  */
101 struct epf_ntb_ctrl {
102 	u32 command;
103 	u32 argument;
104 	u16 command_status;
105 	u16 link_status;
106 	u32 topology;
107 	u64 addr;
108 	u64 size;
109 	u32 num_mws;
110 	u32 reserved;
111 	u32 spad_offset;
112 	u32 spad_count;
113 	u32 db_entry_size;
114 	u32 db_data[MAX_DB_COUNT];
115 	u32 db_offset[MAX_DB_COUNT];
116 } __packed;
117 
118 struct epf_ntb {
119 	struct ntb_dev ntb;
120 	struct pci_epf *epf;
121 	struct config_group group;
122 
123 	u32 num_mws;
124 	u32 db_count;
125 	u32 spad_count;
126 	u64 mws_size[MAX_MW];
127 	u64 db;
128 	u32 vbus_number;
129 	u16 vntb_pid;
130 	u16 vntb_vid;
131 
132 	bool linkup;
133 	u32 spad_size;
134 
135 	enum pci_barno epf_ntb_bar[6];
136 
137 	struct epf_ntb_ctrl *reg;
138 
139 	u32 *epf_db;
140 
141 	phys_addr_t vpci_mw_phy[MAX_MW];
142 	void __iomem *vpci_mw_addr[MAX_MW];
143 
144 	struct delayed_work cmd_handler;
145 };
146 
147 #define to_epf_ntb(epf_group) container_of((epf_group), struct epf_ntb, group)
148 #define ntb_ndev(__ntb) container_of(__ntb, struct epf_ntb, ntb)
149 
150 static struct pci_epf_header epf_ntb_header = {
151 	.vendorid	= PCI_ANY_ID,
152 	.deviceid	= PCI_ANY_ID,
153 	.baseclass_code	= PCI_BASE_CLASS_MEMORY,
154 	.interrupt_pin	= PCI_INTERRUPT_INTA,
155 };
156 
157 /**
158  * epf_ntb_link_up() - Raise link_up interrupt to Virtual Host (VHOST)
159  * @ntb: NTB device that facilitates communication between HOST and VHOST
160  * @link_up: true or false indicating Link is UP or Down
161  *
162  * Once NTB function in HOST invoke ntb_link_enable(),
163  * this NTB function driver will trigger a link event to VHOST.
164  *
165  * Returns: Zero for success, or an error code in case of failure
166  */
167 static int epf_ntb_link_up(struct epf_ntb *ntb, bool link_up)
168 {
169 	if (link_up)
170 		ntb->reg->link_status |= LINK_STATUS_UP;
171 	else
172 		ntb->reg->link_status &= ~LINK_STATUS_UP;
173 
174 	ntb_link_event(&ntb->ntb);
175 	return 0;
176 }
177 
178 /**
179  * epf_ntb_configure_mw() - Configure the Outbound Address Space for VHOST
180  *   to access the memory window of HOST
181  * @ntb: NTB device that facilitates communication between HOST and VHOST
182  * @mw: Index of the memory window (either 0, 1, 2 or 3)
183  *
184  *                          EP Outbound Window
185  * +--------+              +-----------+
186  * |        |              |           |
187  * |        |              |           |
188  * |        |              |           |
189  * |        |              |           |
190  * |        |              +-----------+
191  * | Virtual|              | Memory Win|
192  * | NTB    | -----------> |           |
193  * | Driver |              |           |
194  * |        |              +-----------+
195  * |        |              |           |
196  * |        |              |           |
197  * +--------+              +-----------+
198  *  VHOST                   PCI EP
199  *
200  * Returns: Zero for success, or an error code in case of failure
201  */
202 static int epf_ntb_configure_mw(struct epf_ntb *ntb, u32 mw)
203 {
204 	phys_addr_t phys_addr;
205 	u8 func_no, vfunc_no;
206 	u64 addr, size;
207 	int ret = 0;
208 
209 	phys_addr = ntb->vpci_mw_phy[mw];
210 	addr = ntb->reg->addr;
211 	size = ntb->reg->size;
212 
213 	func_no = ntb->epf->func_no;
214 	vfunc_no = ntb->epf->vfunc_no;
215 
216 	ret = pci_epc_map_addr(ntb->epf->epc, func_no, vfunc_no, phys_addr, addr, size);
217 	if (ret)
218 		dev_err(&ntb->epf->epc->dev,
219 			"Failed to map memory window %d address\n", mw);
220 	return ret;
221 }
222 
223 /**
224  * epf_ntb_teardown_mw() - Teardown the configured OB ATU
225  * @ntb: NTB device that facilitates communication between HOST and VHOST
226  * @mw: Index of the memory window (either 0, 1, 2 or 3)
227  *
228  * Teardown the configured OB ATU configured in epf_ntb_configure_mw() using
229  * pci_epc_unmap_addr()
230  */
231 static void epf_ntb_teardown_mw(struct epf_ntb *ntb, u32 mw)
232 {
233 	pci_epc_unmap_addr(ntb->epf->epc,
234 			   ntb->epf->func_no,
235 			   ntb->epf->vfunc_no,
236 			   ntb->vpci_mw_phy[mw]);
237 }
238 
239 /**
240  * epf_ntb_cmd_handler() - Handle commands provided by the NTB HOST
241  * @work: work_struct for the epf_ntb_epc
242  *
243  * Workqueue function that gets invoked for the two epf_ntb_epc
244  * periodically (once every 5ms) to see if it has received any commands
245  * from NTB HOST. The HOST can send commands to configure doorbell or
246  * configure memory window or to update link status.
247  */
248 static void epf_ntb_cmd_handler(struct work_struct *work)
249 {
250 	struct epf_ntb_ctrl *ctrl;
251 	u32 command, argument;
252 	struct epf_ntb *ntb;
253 	struct device *dev;
254 	int ret;
255 	int i;
256 
257 	ntb = container_of(work, struct epf_ntb, cmd_handler.work);
258 
259 	for (i = 1; i < ntb->db_count; i++) {
260 		if (ntb->epf_db[i]) {
261 			ntb->db |= 1 << (i - 1);
262 			ntb_db_event(&ntb->ntb, i);
263 			ntb->epf_db[i] = 0;
264 		}
265 	}
266 
267 	ctrl = ntb->reg;
268 	command = ctrl->command;
269 	if (!command)
270 		goto reset_handler;
271 	argument = ctrl->argument;
272 
273 	ctrl->command = 0;
274 	ctrl->argument = 0;
275 
276 	ctrl = ntb->reg;
277 	dev = &ntb->epf->dev;
278 
279 	switch (command) {
280 	case COMMAND_CONFIGURE_DOORBELL:
281 		ctrl->command_status = COMMAND_STATUS_OK;
282 		break;
283 	case COMMAND_TEARDOWN_DOORBELL:
284 		ctrl->command_status = COMMAND_STATUS_OK;
285 		break;
286 	case COMMAND_CONFIGURE_MW:
287 		ret = epf_ntb_configure_mw(ntb, argument);
288 		if (ret < 0)
289 			ctrl->command_status = COMMAND_STATUS_ERROR;
290 		else
291 			ctrl->command_status = COMMAND_STATUS_OK;
292 		break;
293 	case COMMAND_TEARDOWN_MW:
294 		epf_ntb_teardown_mw(ntb, argument);
295 		ctrl->command_status = COMMAND_STATUS_OK;
296 		break;
297 	case COMMAND_LINK_UP:
298 		ntb->linkup = true;
299 		ret = epf_ntb_link_up(ntb, true);
300 		if (ret < 0)
301 			ctrl->command_status = COMMAND_STATUS_ERROR;
302 		else
303 			ctrl->command_status = COMMAND_STATUS_OK;
304 		goto reset_handler;
305 	case COMMAND_LINK_DOWN:
306 		ntb->linkup = false;
307 		ret = epf_ntb_link_up(ntb, false);
308 		if (ret < 0)
309 			ctrl->command_status = COMMAND_STATUS_ERROR;
310 		else
311 			ctrl->command_status = COMMAND_STATUS_OK;
312 		break;
313 	default:
314 		dev_err(dev, "UNKNOWN command: %d\n", command);
315 		break;
316 	}
317 
318 reset_handler:
319 	queue_delayed_work(kpcintb_workqueue, &ntb->cmd_handler,
320 			   msecs_to_jiffies(5));
321 }
322 
323 /**
324  * epf_ntb_config_sspad_bar_clear() - Clear Config + Self scratchpad BAR
325  * @ntb: EPC associated with one of the HOST which holds peer's outbound
326  *	 address.
327  *
328  * Clear BAR0 of EP CONTROLLER 1 which contains the HOST1's config and
329  * self scratchpad region (removes inbound ATU configuration). While BAR0 is
330  * the default self scratchpad BAR, an NTB could have other BARs for self
331  * scratchpad (because of reserved BARs). This function can get the exact BAR
332  * used for self scratchpad from epf_ntb_bar[BAR_CONFIG].
333  *
334  * Please note the self scratchpad region and config region is combined to
335  * a single region and mapped using the same BAR. Also note VHOST's peer
336  * scratchpad is HOST's self scratchpad.
337  *
338  * Returns: void
339  */
340 static void epf_ntb_config_sspad_bar_clear(struct epf_ntb *ntb)
341 {
342 	struct pci_epf_bar *epf_bar;
343 	enum pci_barno barno;
344 
345 	barno = ntb->epf_ntb_bar[BAR_CONFIG];
346 	epf_bar = &ntb->epf->bar[barno];
347 
348 	pci_epc_clear_bar(ntb->epf->epc, ntb->epf->func_no, ntb->epf->vfunc_no, epf_bar);
349 }
350 
351 /**
352  * epf_ntb_config_sspad_bar_set() - Set Config + Self scratchpad BAR
353  * @ntb: NTB device that facilitates communication between HOST and VHOST
354  *
355  * Map BAR0 of EP CONTROLLER which contains the VHOST's config and
356  * self scratchpad region.
357  *
358  * Please note the self scratchpad region and config region is combined to
359  * a single region and mapped using the same BAR.
360  *
361  * Returns: Zero for success, or an error code in case of failure
362  */
363 static int epf_ntb_config_sspad_bar_set(struct epf_ntb *ntb)
364 {
365 	struct pci_epf_bar *epf_bar;
366 	enum pci_barno barno;
367 	u8 func_no, vfunc_no;
368 	struct device *dev;
369 	int ret;
370 
371 	dev = &ntb->epf->dev;
372 	func_no = ntb->epf->func_no;
373 	vfunc_no = ntb->epf->vfunc_no;
374 	barno = ntb->epf_ntb_bar[BAR_CONFIG];
375 	epf_bar = &ntb->epf->bar[barno];
376 
377 	ret = pci_epc_set_bar(ntb->epf->epc, func_no, vfunc_no, epf_bar);
378 	if (ret) {
379 		dev_err(dev, "inft: Config/Status/SPAD BAR set failed\n");
380 		return ret;
381 	}
382 	return 0;
383 }
384 
385 /**
386  * epf_ntb_config_spad_bar_free() - Free the physical memory associated with
387  *   config + scratchpad region
388  * @ntb: NTB device that facilitates communication between HOST and VHOST
389  */
390 static void epf_ntb_config_spad_bar_free(struct epf_ntb *ntb)
391 {
392 	enum pci_barno barno;
393 
394 	barno = ntb->epf_ntb_bar[BAR_CONFIG];
395 	pci_epf_free_space(ntb->epf, ntb->reg, barno, 0);
396 }
397 
398 /**
399  * epf_ntb_config_spad_bar_alloc() - Allocate memory for config + scratchpad
400  *   region
401  * @ntb: NTB device that facilitates communication between HOST and VHOST
402  *
403  * Allocate the Local Memory mentioned in the above diagram. The size of
404  * CONFIG REGION is sizeof(struct epf_ntb_ctrl) and size of SCRATCHPAD REGION
405  * is obtained from "spad-count" configfs entry.
406  *
407  * Returns: Zero for success, or an error code in case of failure
408  */
409 static int epf_ntb_config_spad_bar_alloc(struct epf_ntb *ntb)
410 {
411 	size_t align;
412 	enum pci_barno barno;
413 	struct epf_ntb_ctrl *ctrl;
414 	u32 spad_size, ctrl_size;
415 	u64 size;
416 	struct pci_epf *epf = ntb->epf;
417 	struct device *dev = &epf->dev;
418 	u32 spad_count;
419 	void *base;
420 	int i;
421 	const struct pci_epc_features *epc_features = pci_epc_get_features(epf->epc,
422 								epf->func_no,
423 								epf->vfunc_no);
424 	barno = ntb->epf_ntb_bar[BAR_CONFIG];
425 	size = epc_features->bar[barno].fixed_size;
426 	align = epc_features->align;
427 
428 	if ((!IS_ALIGNED(size, align)))
429 		return -EINVAL;
430 
431 	spad_count = ntb->spad_count;
432 
433 	ctrl_size = sizeof(struct epf_ntb_ctrl);
434 	spad_size = 2 * spad_count * sizeof(u32);
435 
436 	if (!align) {
437 		ctrl_size = roundup_pow_of_two(ctrl_size);
438 		spad_size = roundup_pow_of_two(spad_size);
439 	} else {
440 		ctrl_size = ALIGN(ctrl_size, align);
441 		spad_size = ALIGN(spad_size, align);
442 	}
443 
444 	if (!size)
445 		size = ctrl_size + spad_size;
446 	else if (size < ctrl_size + spad_size)
447 		return -EINVAL;
448 
449 	base = pci_epf_alloc_space(epf, size, barno, epc_features, 0);
450 	if (!base) {
451 		dev_err(dev, "Config/Status/SPAD alloc region fail\n");
452 		return -ENOMEM;
453 	}
454 
455 	ntb->reg = base;
456 
457 	ctrl = ntb->reg;
458 	ctrl->spad_offset = ctrl_size;
459 
460 	ctrl->spad_count = spad_count;
461 	ctrl->num_mws = ntb->num_mws;
462 	ntb->spad_size = spad_size;
463 
464 	ctrl->db_entry_size = sizeof(u32);
465 
466 	for (i = 0; i < ntb->db_count; i++) {
467 		ntb->reg->db_data[i] = 1 + i;
468 		ntb->reg->db_offset[i] = 0;
469 	}
470 
471 	return 0;
472 }
473 
474 /**
475  * epf_ntb_configure_interrupt() - Configure MSI/MSI-X capability
476  * @ntb: NTB device that facilitates communication between HOST and VHOST
477  *
478  * Configure MSI/MSI-X capability for each interface with number of
479  * interrupts equal to "db_count" configfs entry.
480  *
481  * Returns: Zero for success, or an error code in case of failure
482  */
483 static int epf_ntb_configure_interrupt(struct epf_ntb *ntb)
484 {
485 	const struct pci_epc_features *epc_features;
486 	struct device *dev;
487 	u32 db_count;
488 	int ret;
489 
490 	dev = &ntb->epf->dev;
491 
492 	epc_features = pci_epc_get_features(ntb->epf->epc, ntb->epf->func_no, ntb->epf->vfunc_no);
493 
494 	if (!(epc_features->msix_capable || epc_features->msi_capable)) {
495 		dev_err(dev, "MSI or MSI-X is required for doorbell\n");
496 		return -EINVAL;
497 	}
498 
499 	db_count = ntb->db_count;
500 	if (db_count > MAX_DB_COUNT) {
501 		dev_err(dev, "DB count cannot be more than %d\n", MAX_DB_COUNT);
502 		return -EINVAL;
503 	}
504 
505 	ntb->db_count = db_count;
506 
507 	if (epc_features->msi_capable) {
508 		ret = pci_epc_set_msi(ntb->epf->epc,
509 				      ntb->epf->func_no,
510 				      ntb->epf->vfunc_no,
511 				      16);
512 		if (ret) {
513 			dev_err(dev, "MSI configuration failed\n");
514 			return ret;
515 		}
516 	}
517 
518 	return 0;
519 }
520 
521 /**
522  * epf_ntb_db_bar_init() - Configure Doorbell window BARs
523  * @ntb: NTB device that facilitates communication between HOST and VHOST
524  *
525  * Returns: Zero for success, or an error code in case of failure
526  */
527 static int epf_ntb_db_bar_init(struct epf_ntb *ntb)
528 {
529 	const struct pci_epc_features *epc_features;
530 	struct device *dev = &ntb->epf->dev;
531 	int ret;
532 	struct pci_epf_bar *epf_bar;
533 	void __iomem *mw_addr;
534 	enum pci_barno barno;
535 	size_t size = sizeof(u32) * ntb->db_count;
536 
537 	epc_features = pci_epc_get_features(ntb->epf->epc,
538 					    ntb->epf->func_no,
539 					    ntb->epf->vfunc_no);
540 	barno = ntb->epf_ntb_bar[BAR_DB];
541 
542 	mw_addr = pci_epf_alloc_space(ntb->epf, size, barno, epc_features, 0);
543 	if (!mw_addr) {
544 		dev_err(dev, "Failed to allocate OB address\n");
545 		return -ENOMEM;
546 	}
547 
548 	ntb->epf_db = mw_addr;
549 
550 	epf_bar = &ntb->epf->bar[barno];
551 
552 	ret = pci_epc_set_bar(ntb->epf->epc, ntb->epf->func_no, ntb->epf->vfunc_no, epf_bar);
553 	if (ret) {
554 		dev_err(dev, "Doorbell BAR set failed\n");
555 			goto err_alloc_peer_mem;
556 	}
557 	return ret;
558 
559 err_alloc_peer_mem:
560 	pci_epf_free_space(ntb->epf, mw_addr, barno, 0);
561 	return -1;
562 }
563 
564 static void epf_ntb_mw_bar_clear(struct epf_ntb *ntb, int num_mws);
565 
566 /**
567  * epf_ntb_db_bar_clear() - Clear doorbell BAR and free memory
568  *   allocated in peer's outbound address space
569  * @ntb: NTB device that facilitates communication between HOST and VHOST
570  */
571 static void epf_ntb_db_bar_clear(struct epf_ntb *ntb)
572 {
573 	enum pci_barno barno;
574 
575 	barno = ntb->epf_ntb_bar[BAR_DB];
576 	pci_epf_free_space(ntb->epf, ntb->epf_db, barno, 0);
577 	pci_epc_clear_bar(ntb->epf->epc,
578 			  ntb->epf->func_no,
579 			  ntb->epf->vfunc_no,
580 			  &ntb->epf->bar[barno]);
581 }
582 
583 /**
584  * epf_ntb_mw_bar_init() - Configure Memory window BARs
585  * @ntb: NTB device that facilitates communication between HOST and VHOST
586  *
587  * Returns: Zero for success, or an error code in case of failure
588  */
589 static int epf_ntb_mw_bar_init(struct epf_ntb *ntb)
590 {
591 	int ret = 0;
592 	int i;
593 	u64 size;
594 	enum pci_barno barno;
595 	struct device *dev = &ntb->epf->dev;
596 
597 	for (i = 0; i < ntb->num_mws; i++) {
598 		size = ntb->mws_size[i];
599 		barno = ntb->epf_ntb_bar[BAR_MW0 + i];
600 
601 		ntb->epf->bar[barno].barno = barno;
602 		ntb->epf->bar[barno].size = size;
603 		ntb->epf->bar[barno].addr = NULL;
604 		ntb->epf->bar[barno].phys_addr = 0;
605 		ntb->epf->bar[barno].flags |= upper_32_bits(size) ?
606 				PCI_BASE_ADDRESS_MEM_TYPE_64 :
607 				PCI_BASE_ADDRESS_MEM_TYPE_32;
608 
609 		ret = pci_epc_set_bar(ntb->epf->epc,
610 				      ntb->epf->func_no,
611 				      ntb->epf->vfunc_no,
612 				      &ntb->epf->bar[barno]);
613 		if (ret) {
614 			dev_err(dev, "MW set failed\n");
615 			goto err_alloc_mem;
616 		}
617 
618 		/* Allocate EPC outbound memory windows to vpci vntb device */
619 		ntb->vpci_mw_addr[i] = pci_epc_mem_alloc_addr(ntb->epf->epc,
620 							      &ntb->vpci_mw_phy[i],
621 							      size);
622 		if (!ntb->vpci_mw_addr[i]) {
623 			ret = -ENOMEM;
624 			dev_err(dev, "Failed to allocate source address\n");
625 			goto err_set_bar;
626 		}
627 	}
628 
629 	return ret;
630 
631 err_set_bar:
632 	pci_epc_clear_bar(ntb->epf->epc,
633 			  ntb->epf->func_no,
634 			  ntb->epf->vfunc_no,
635 			  &ntb->epf->bar[barno]);
636 err_alloc_mem:
637 	epf_ntb_mw_bar_clear(ntb, i);
638 	return ret;
639 }
640 
641 /**
642  * epf_ntb_mw_bar_clear() - Clear Memory window BARs
643  * @ntb: NTB device that facilitates communication between HOST and VHOST
644  * @num_mws: the number of Memory window BARs that to be cleared
645  */
646 static void epf_ntb_mw_bar_clear(struct epf_ntb *ntb, int num_mws)
647 {
648 	enum pci_barno barno;
649 	int i;
650 
651 	for (i = 0; i < num_mws; i++) {
652 		barno = ntb->epf_ntb_bar[BAR_MW0 + i];
653 		pci_epc_clear_bar(ntb->epf->epc,
654 				  ntb->epf->func_no,
655 				  ntb->epf->vfunc_no,
656 				  &ntb->epf->bar[barno]);
657 
658 		pci_epc_mem_free_addr(ntb->epf->epc,
659 				      ntb->vpci_mw_phy[i],
660 				      ntb->vpci_mw_addr[i],
661 				      ntb->mws_size[i]);
662 	}
663 }
664 
665 /**
666  * epf_ntb_epc_destroy() - Cleanup NTB EPC interface
667  * @ntb: NTB device that facilitates communication between HOST and VHOST
668  *
669  * Wrapper for epf_ntb_epc_destroy_interface() to cleanup all the NTB interfaces
670  */
671 static void epf_ntb_epc_destroy(struct epf_ntb *ntb)
672 {
673 	pci_epc_remove_epf(ntb->epf->epc, ntb->epf, 0);
674 	pci_epc_put(ntb->epf->epc);
675 }
676 
677 /**
678  * epf_ntb_init_epc_bar() - Identify BARs to be used for each of the NTB
679  * constructs (scratchpad region, doorbell, memorywindow)
680  * @ntb: NTB device that facilitates communication between HOST and VHOST
681  *
682  * Returns: Zero for success, or an error code in case of failure
683  */
684 static int epf_ntb_init_epc_bar(struct epf_ntb *ntb)
685 {
686 	const struct pci_epc_features *epc_features;
687 	enum pci_barno barno;
688 	enum epf_ntb_bar bar;
689 	struct device *dev;
690 	u32 num_mws;
691 	int i;
692 
693 	barno = BAR_0;
694 	num_mws = ntb->num_mws;
695 	dev = &ntb->epf->dev;
696 	epc_features = pci_epc_get_features(ntb->epf->epc, ntb->epf->func_no, ntb->epf->vfunc_no);
697 
698 	/* These are required BARs which are mandatory for NTB functionality */
699 	for (bar = BAR_CONFIG; bar <= BAR_MW0; bar++, barno++) {
700 		barno = pci_epc_get_next_free_bar(epc_features, barno);
701 		if (barno < 0) {
702 			dev_err(dev, "Fail to get NTB function BAR\n");
703 			return barno;
704 		}
705 		ntb->epf_ntb_bar[bar] = barno;
706 	}
707 
708 	/* These are optional BARs which don't impact NTB functionality */
709 	for (bar = BAR_MW1, i = 1; i < num_mws; bar++, barno++, i++) {
710 		barno = pci_epc_get_next_free_bar(epc_features, barno);
711 		if (barno < 0) {
712 			ntb->num_mws = i;
713 			dev_dbg(dev, "BAR not available for > MW%d\n", i + 1);
714 		}
715 		ntb->epf_ntb_bar[bar] = barno;
716 	}
717 
718 	return 0;
719 }
720 
721 /**
722  * epf_ntb_epc_init() - Initialize NTB interface
723  * @ntb: NTB device that facilitates communication between HOST and VHOST
724  *
725  * Wrapper to initialize a particular EPC interface and start the workqueue
726  * to check for commands from HOST. This function will write to the
727  * EP controller HW for configuring it.
728  *
729  * Returns: Zero for success, or an error code in case of failure
730  */
731 static int epf_ntb_epc_init(struct epf_ntb *ntb)
732 {
733 	u8 func_no, vfunc_no;
734 	struct pci_epc *epc;
735 	struct pci_epf *epf;
736 	struct device *dev;
737 	int ret;
738 
739 	epf = ntb->epf;
740 	dev = &epf->dev;
741 	epc = epf->epc;
742 	func_no = ntb->epf->func_no;
743 	vfunc_no = ntb->epf->vfunc_no;
744 
745 	ret = epf_ntb_config_sspad_bar_set(ntb);
746 	if (ret) {
747 		dev_err(dev, "Config/self SPAD BAR init failed");
748 		return ret;
749 	}
750 
751 	ret = epf_ntb_configure_interrupt(ntb);
752 	if (ret) {
753 		dev_err(dev, "Interrupt configuration failed\n");
754 		goto err_config_interrupt;
755 	}
756 
757 	ret = epf_ntb_db_bar_init(ntb);
758 	if (ret) {
759 		dev_err(dev, "DB BAR init failed\n");
760 		goto err_db_bar_init;
761 	}
762 
763 	ret = epf_ntb_mw_bar_init(ntb);
764 	if (ret) {
765 		dev_err(dev, "MW BAR init failed\n");
766 		goto err_mw_bar_init;
767 	}
768 
769 	if (vfunc_no <= 1) {
770 		ret = pci_epc_write_header(epc, func_no, vfunc_no, epf->header);
771 		if (ret) {
772 			dev_err(dev, "Configuration header write failed\n");
773 			goto err_write_header;
774 		}
775 	}
776 
777 	INIT_DELAYED_WORK(&ntb->cmd_handler, epf_ntb_cmd_handler);
778 	queue_work(kpcintb_workqueue, &ntb->cmd_handler.work);
779 
780 	return 0;
781 
782 err_write_header:
783 	epf_ntb_mw_bar_clear(ntb, ntb->num_mws);
784 err_mw_bar_init:
785 	epf_ntb_db_bar_clear(ntb);
786 err_db_bar_init:
787 err_config_interrupt:
788 	epf_ntb_config_sspad_bar_clear(ntb);
789 
790 	return ret;
791 }
792 
793 
794 /**
795  * epf_ntb_epc_cleanup() - Cleanup all NTB interfaces
796  * @ntb: NTB device that facilitates communication between HOST and VHOST
797  *
798  * Wrapper to cleanup all NTB interfaces.
799  */
800 static void epf_ntb_epc_cleanup(struct epf_ntb *ntb)
801 {
802 	epf_ntb_db_bar_clear(ntb);
803 	epf_ntb_mw_bar_clear(ntb, ntb->num_mws);
804 }
805 
806 #define EPF_NTB_R(_name)						\
807 static ssize_t epf_ntb_##_name##_show(struct config_item *item,		\
808 				      char *page)			\
809 {									\
810 	struct config_group *group = to_config_group(item);		\
811 	struct epf_ntb *ntb = to_epf_ntb(group);			\
812 									\
813 	return sprintf(page, "%d\n", ntb->_name);			\
814 }
815 
816 #define EPF_NTB_W(_name)						\
817 static ssize_t epf_ntb_##_name##_store(struct config_item *item,	\
818 				       const char *page, size_t len)	\
819 {									\
820 	struct config_group *group = to_config_group(item);		\
821 	struct epf_ntb *ntb = to_epf_ntb(group);			\
822 	u32 val;							\
823 	int ret;							\
824 									\
825 	ret = kstrtou32(page, 0, &val);					\
826 	if (ret)							\
827 		return ret;						\
828 									\
829 	ntb->_name = val;						\
830 									\
831 	return len;							\
832 }
833 
834 #define EPF_NTB_MW_R(_name)						\
835 static ssize_t epf_ntb_##_name##_show(struct config_item *item,		\
836 				      char *page)			\
837 {									\
838 	struct config_group *group = to_config_group(item);		\
839 	struct epf_ntb *ntb = to_epf_ntb(group);			\
840 	struct device *dev = &ntb->epf->dev;				\
841 	int win_no;							\
842 									\
843 	if (sscanf(#_name, "mw%d", &win_no) != 1)			\
844 		return -EINVAL;						\
845 									\
846 	if (win_no <= 0 || win_no > ntb->num_mws) {			\
847 		dev_err(dev, "Invalid num_nws: %d value\n", ntb->num_mws); \
848 		return -EINVAL;						\
849 	}								\
850 									\
851 	return sprintf(page, "%lld\n", ntb->mws_size[win_no - 1]);	\
852 }
853 
854 #define EPF_NTB_MW_W(_name)						\
855 static ssize_t epf_ntb_##_name##_store(struct config_item *item,	\
856 				       const char *page, size_t len)	\
857 {									\
858 	struct config_group *group = to_config_group(item);		\
859 	struct epf_ntb *ntb = to_epf_ntb(group);			\
860 	struct device *dev = &ntb->epf->dev;				\
861 	int win_no;							\
862 	u64 val;							\
863 	int ret;							\
864 									\
865 	ret = kstrtou64(page, 0, &val);					\
866 	if (ret)							\
867 		return ret;						\
868 									\
869 	if (sscanf(#_name, "mw%d", &win_no) != 1)			\
870 		return -EINVAL;						\
871 									\
872 	if (win_no <= 0 || win_no > ntb->num_mws) {			\
873 		dev_err(dev, "Invalid num_nws: %d value\n", ntb->num_mws); \
874 		return -EINVAL;						\
875 	}								\
876 									\
877 	ntb->mws_size[win_no - 1] = val;				\
878 									\
879 	return len;							\
880 }
881 
882 static ssize_t epf_ntb_num_mws_store(struct config_item *item,
883 				     const char *page, size_t len)
884 {
885 	struct config_group *group = to_config_group(item);
886 	struct epf_ntb *ntb = to_epf_ntb(group);
887 	u32 val;
888 	int ret;
889 
890 	ret = kstrtou32(page, 0, &val);
891 	if (ret)
892 		return ret;
893 
894 	if (val > MAX_MW)
895 		return -EINVAL;
896 
897 	ntb->num_mws = val;
898 
899 	return len;
900 }
901 
902 EPF_NTB_R(spad_count)
903 EPF_NTB_W(spad_count)
904 EPF_NTB_R(db_count)
905 EPF_NTB_W(db_count)
906 EPF_NTB_R(num_mws)
907 EPF_NTB_R(vbus_number)
908 EPF_NTB_W(vbus_number)
909 EPF_NTB_R(vntb_pid)
910 EPF_NTB_W(vntb_pid)
911 EPF_NTB_R(vntb_vid)
912 EPF_NTB_W(vntb_vid)
913 EPF_NTB_MW_R(mw1)
914 EPF_NTB_MW_W(mw1)
915 EPF_NTB_MW_R(mw2)
916 EPF_NTB_MW_W(mw2)
917 EPF_NTB_MW_R(mw3)
918 EPF_NTB_MW_W(mw3)
919 EPF_NTB_MW_R(mw4)
920 EPF_NTB_MW_W(mw4)
921 
922 CONFIGFS_ATTR(epf_ntb_, spad_count);
923 CONFIGFS_ATTR(epf_ntb_, db_count);
924 CONFIGFS_ATTR(epf_ntb_, num_mws);
925 CONFIGFS_ATTR(epf_ntb_, mw1);
926 CONFIGFS_ATTR(epf_ntb_, mw2);
927 CONFIGFS_ATTR(epf_ntb_, mw3);
928 CONFIGFS_ATTR(epf_ntb_, mw4);
929 CONFIGFS_ATTR(epf_ntb_, vbus_number);
930 CONFIGFS_ATTR(epf_ntb_, vntb_pid);
931 CONFIGFS_ATTR(epf_ntb_, vntb_vid);
932 
933 static struct configfs_attribute *epf_ntb_attrs[] = {
934 	&epf_ntb_attr_spad_count,
935 	&epf_ntb_attr_db_count,
936 	&epf_ntb_attr_num_mws,
937 	&epf_ntb_attr_mw1,
938 	&epf_ntb_attr_mw2,
939 	&epf_ntb_attr_mw3,
940 	&epf_ntb_attr_mw4,
941 	&epf_ntb_attr_vbus_number,
942 	&epf_ntb_attr_vntb_pid,
943 	&epf_ntb_attr_vntb_vid,
944 	NULL,
945 };
946 
947 static const struct config_item_type ntb_group_type = {
948 	.ct_attrs	= epf_ntb_attrs,
949 	.ct_owner	= THIS_MODULE,
950 };
951 
952 /**
953  * epf_ntb_add_cfs() - Add configfs directory specific to NTB
954  * @epf: NTB endpoint function device
955  * @group: A pointer to the config_group structure referencing a group of
956  *	   config_items of a specific type that belong to a specific sub-system.
957  *
958  * Add configfs directory specific to NTB. This directory will hold
959  * NTB specific properties like db_count, spad_count, num_mws etc.,
960  *
961  * Returns: Pointer to config_group
962  */
963 static struct config_group *epf_ntb_add_cfs(struct pci_epf *epf,
964 					    struct config_group *group)
965 {
966 	struct epf_ntb *ntb = epf_get_drvdata(epf);
967 	struct config_group *ntb_group = &ntb->group;
968 	struct device *dev = &epf->dev;
969 
970 	config_group_init_type_name(ntb_group, dev_name(dev), &ntb_group_type);
971 
972 	return ntb_group;
973 }
974 
975 /*==== virtual PCI bus driver, which only load virtual NTB PCI driver ====*/
976 
977 static u32 pci_space[] = {
978 	0xffffffff,	/* Device ID, Vendor ID */
979 	0,		/* Status, Command */
980 	0xffffffff,	/* Base Class, Subclass, Prog Intf, Revision ID */
981 	0x40,		/* BIST, Header Type, Latency Timer, Cache Line Size */
982 	0,		/* BAR 0 */
983 	0,		/* BAR 1 */
984 	0,		/* BAR 2 */
985 	0,		/* BAR 3 */
986 	0,		/* BAR 4 */
987 	0,		/* BAR 5 */
988 	0,		/* Cardbus CIS Pointer */
989 	0,		/* Subsystem ID, Subsystem Vendor ID */
990 	0,		/* ROM Base Address */
991 	0,		/* Reserved, Capabilities Pointer */
992 	0,		/* Reserved */
993 	0,		/* Max_Lat, Min_Gnt, Interrupt Pin, Interrupt Line */
994 };
995 
996 static int pci_read(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *val)
997 {
998 	if (devfn == 0) {
999 		memcpy(val, ((u8 *)pci_space) + where, size);
1000 		return PCIBIOS_SUCCESSFUL;
1001 	}
1002 	return PCIBIOS_DEVICE_NOT_FOUND;
1003 }
1004 
1005 static int pci_write(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 val)
1006 {
1007 	return 0;
1008 }
1009 
1010 static struct pci_ops vpci_ops = {
1011 	.read = pci_read,
1012 	.write = pci_write,
1013 };
1014 
1015 static int vpci_scan_bus(void *sysdata)
1016 {
1017 	struct pci_bus *vpci_bus;
1018 	struct epf_ntb *ndev = sysdata;
1019 
1020 	vpci_bus = pci_scan_bus(ndev->vbus_number, &vpci_ops, sysdata);
1021 	if (vpci_bus)
1022 		pr_err("create pci bus\n");
1023 
1024 	pci_bus_add_devices(vpci_bus);
1025 
1026 	return 0;
1027 }
1028 
1029 /*==================== Virtual PCIe NTB driver ==========================*/
1030 
1031 static int vntb_epf_mw_count(struct ntb_dev *ntb, int pidx)
1032 {
1033 	struct epf_ntb *ndev = ntb_ndev(ntb);
1034 
1035 	return ndev->num_mws;
1036 }
1037 
1038 static int vntb_epf_spad_count(struct ntb_dev *ntb)
1039 {
1040 	return ntb_ndev(ntb)->spad_count;
1041 }
1042 
1043 static int vntb_epf_peer_mw_count(struct ntb_dev *ntb)
1044 {
1045 	return ntb_ndev(ntb)->num_mws;
1046 }
1047 
1048 static u64 vntb_epf_db_valid_mask(struct ntb_dev *ntb)
1049 {
1050 	return BIT_ULL(ntb_ndev(ntb)->db_count) - 1;
1051 }
1052 
1053 static int vntb_epf_db_set_mask(struct ntb_dev *ntb, u64 db_bits)
1054 {
1055 	return 0;
1056 }
1057 
1058 static int vntb_epf_mw_set_trans(struct ntb_dev *ndev, int pidx, int idx,
1059 		dma_addr_t addr, resource_size_t size)
1060 {
1061 	struct epf_ntb *ntb = ntb_ndev(ndev);
1062 	struct pci_epf_bar *epf_bar;
1063 	enum pci_barno barno;
1064 	int ret;
1065 	struct device *dev;
1066 
1067 	dev = &ntb->ntb.dev;
1068 	barno = ntb->epf_ntb_bar[BAR_MW0 + idx];
1069 	epf_bar = &ntb->epf->bar[barno];
1070 	epf_bar->phys_addr = addr;
1071 	epf_bar->barno = barno;
1072 	epf_bar->size = size;
1073 
1074 	ret = pci_epc_set_bar(ntb->epf->epc, 0, 0, epf_bar);
1075 	if (ret) {
1076 		dev_err(dev, "failure set mw trans\n");
1077 		return ret;
1078 	}
1079 	return 0;
1080 }
1081 
1082 static int vntb_epf_mw_clear_trans(struct ntb_dev *ntb, int pidx, int idx)
1083 {
1084 	return 0;
1085 }
1086 
1087 static int vntb_epf_peer_mw_get_addr(struct ntb_dev *ndev, int idx,
1088 				phys_addr_t *base, resource_size_t *size)
1089 {
1090 
1091 	struct epf_ntb *ntb = ntb_ndev(ndev);
1092 
1093 	if (base)
1094 		*base = ntb->vpci_mw_phy[idx];
1095 
1096 	if (size)
1097 		*size = ntb->mws_size[idx];
1098 
1099 	return 0;
1100 }
1101 
1102 static int vntb_epf_link_enable(struct ntb_dev *ntb,
1103 			enum ntb_speed max_speed,
1104 			enum ntb_width max_width)
1105 {
1106 	return 0;
1107 }
1108 
1109 static u32 vntb_epf_spad_read(struct ntb_dev *ndev, int idx)
1110 {
1111 	struct epf_ntb *ntb = ntb_ndev(ndev);
1112 	int off = ntb->reg->spad_offset, ct = ntb->reg->spad_count * sizeof(u32);
1113 	u32 val;
1114 	void __iomem *base = (void __iomem *)ntb->reg;
1115 
1116 	val = readl(base + off + ct + idx * sizeof(u32));
1117 	return val;
1118 }
1119 
1120 static int vntb_epf_spad_write(struct ntb_dev *ndev, int idx, u32 val)
1121 {
1122 	struct epf_ntb *ntb = ntb_ndev(ndev);
1123 	struct epf_ntb_ctrl *ctrl = ntb->reg;
1124 	int off = ctrl->spad_offset, ct = ctrl->spad_count * sizeof(u32);
1125 	void __iomem *base = (void __iomem *)ntb->reg;
1126 
1127 	writel(val, base + off + ct + idx * sizeof(u32));
1128 	return 0;
1129 }
1130 
1131 static u32 vntb_epf_peer_spad_read(struct ntb_dev *ndev, int pidx, int idx)
1132 {
1133 	struct epf_ntb *ntb = ntb_ndev(ndev);
1134 	struct epf_ntb_ctrl *ctrl = ntb->reg;
1135 	int off = ctrl->spad_offset;
1136 	void __iomem *base = (void __iomem *)ntb->reg;
1137 	u32 val;
1138 
1139 	val = readl(base + off + idx * sizeof(u32));
1140 	return val;
1141 }
1142 
1143 static int vntb_epf_peer_spad_write(struct ntb_dev *ndev, int pidx, int idx, u32 val)
1144 {
1145 	struct epf_ntb *ntb = ntb_ndev(ndev);
1146 	struct epf_ntb_ctrl *ctrl = ntb->reg;
1147 	int off = ctrl->spad_offset;
1148 	void __iomem *base = (void __iomem *)ntb->reg;
1149 
1150 	writel(val, base + off + idx * sizeof(u32));
1151 	return 0;
1152 }
1153 
1154 static int vntb_epf_peer_db_set(struct ntb_dev *ndev, u64 db_bits)
1155 {
1156 	u32 interrupt_num = ffs(db_bits) + 1;
1157 	struct epf_ntb *ntb = ntb_ndev(ndev);
1158 	u8 func_no, vfunc_no;
1159 	int ret;
1160 
1161 	func_no = ntb->epf->func_no;
1162 	vfunc_no = ntb->epf->vfunc_no;
1163 
1164 	ret = pci_epc_raise_irq(ntb->epf->epc, func_no, vfunc_no,
1165 				PCI_IRQ_MSI, interrupt_num + 1);
1166 	if (ret)
1167 		dev_err(&ntb->ntb.dev, "Failed to raise IRQ\n");
1168 
1169 	return ret;
1170 }
1171 
1172 static u64 vntb_epf_db_read(struct ntb_dev *ndev)
1173 {
1174 	struct epf_ntb *ntb = ntb_ndev(ndev);
1175 
1176 	return ntb->db;
1177 }
1178 
1179 static int vntb_epf_mw_get_align(struct ntb_dev *ndev, int pidx, int idx,
1180 			resource_size_t *addr_align,
1181 			resource_size_t *size_align,
1182 			resource_size_t *size_max)
1183 {
1184 	struct epf_ntb *ntb = ntb_ndev(ndev);
1185 
1186 	if (addr_align)
1187 		*addr_align = SZ_4K;
1188 
1189 	if (size_align)
1190 		*size_align = 1;
1191 
1192 	if (size_max)
1193 		*size_max = ntb->mws_size[idx];
1194 
1195 	return 0;
1196 }
1197 
1198 static u64 vntb_epf_link_is_up(struct ntb_dev *ndev,
1199 			enum ntb_speed *speed,
1200 			enum ntb_width *width)
1201 {
1202 	struct epf_ntb *ntb = ntb_ndev(ndev);
1203 
1204 	return ntb->reg->link_status;
1205 }
1206 
1207 static int vntb_epf_db_clear_mask(struct ntb_dev *ndev, u64 db_bits)
1208 {
1209 	return 0;
1210 }
1211 
1212 static int vntb_epf_db_clear(struct ntb_dev *ndev, u64 db_bits)
1213 {
1214 	struct epf_ntb *ntb = ntb_ndev(ndev);
1215 
1216 	ntb->db &= ~db_bits;
1217 	return 0;
1218 }
1219 
1220 static int vntb_epf_link_disable(struct ntb_dev *ntb)
1221 {
1222 	return 0;
1223 }
1224 
1225 static const struct ntb_dev_ops vntb_epf_ops = {
1226 	.mw_count		= vntb_epf_mw_count,
1227 	.spad_count		= vntb_epf_spad_count,
1228 	.peer_mw_count		= vntb_epf_peer_mw_count,
1229 	.db_valid_mask		= vntb_epf_db_valid_mask,
1230 	.db_set_mask		= vntb_epf_db_set_mask,
1231 	.mw_set_trans		= vntb_epf_mw_set_trans,
1232 	.mw_clear_trans		= vntb_epf_mw_clear_trans,
1233 	.peer_mw_get_addr	= vntb_epf_peer_mw_get_addr,
1234 	.link_enable		= vntb_epf_link_enable,
1235 	.spad_read		= vntb_epf_spad_read,
1236 	.spad_write		= vntb_epf_spad_write,
1237 	.peer_spad_read		= vntb_epf_peer_spad_read,
1238 	.peer_spad_write	= vntb_epf_peer_spad_write,
1239 	.peer_db_set		= vntb_epf_peer_db_set,
1240 	.db_read		= vntb_epf_db_read,
1241 	.mw_get_align		= vntb_epf_mw_get_align,
1242 	.link_is_up		= vntb_epf_link_is_up,
1243 	.db_clear_mask		= vntb_epf_db_clear_mask,
1244 	.db_clear		= vntb_epf_db_clear,
1245 	.link_disable		= vntb_epf_link_disable,
1246 };
1247 
1248 static int pci_vntb_probe(struct pci_dev *pdev, const struct pci_device_id *id)
1249 {
1250 	int ret;
1251 	struct epf_ntb *ndev = (struct epf_ntb *)pdev->sysdata;
1252 	struct device *dev = &pdev->dev;
1253 
1254 	ndev->ntb.pdev = pdev;
1255 	ndev->ntb.topo = NTB_TOPO_NONE;
1256 	ndev->ntb.ops =  &vntb_epf_ops;
1257 
1258 	ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
1259 	if (ret) {
1260 		dev_err(dev, "Cannot set DMA mask\n");
1261 		return ret;
1262 	}
1263 
1264 	ret = ntb_register_device(&ndev->ntb);
1265 	if (ret) {
1266 		dev_err(dev, "Failed to register NTB device\n");
1267 		return ret;
1268 	}
1269 
1270 	dev_dbg(dev, "PCI Virtual NTB driver loaded\n");
1271 	return 0;
1272 }
1273 
1274 static struct pci_device_id pci_vntb_table[] = {
1275 	{
1276 		PCI_DEVICE(0xffff, 0xffff),
1277 	},
1278 	{},
1279 };
1280 
1281 static struct pci_driver vntb_pci_driver = {
1282 	.name           = "pci-vntb",
1283 	.id_table       = pci_vntb_table,
1284 	.probe          = pci_vntb_probe,
1285 };
1286 
1287 /* ============ PCIe EPF Driver Bind ====================*/
1288 
1289 /**
1290  * epf_ntb_bind() - Initialize endpoint controller to provide NTB functionality
1291  * @epf: NTB endpoint function device
1292  *
1293  * Initialize both the endpoint controllers associated with NTB function device.
1294  * Invoked when a primary interface or secondary interface is bound to EPC
1295  * device. This function will succeed only when EPC is bound to both the
1296  * interfaces.
1297  *
1298  * Returns: Zero for success, or an error code in case of failure
1299  */
1300 static int epf_ntb_bind(struct pci_epf *epf)
1301 {
1302 	struct epf_ntb *ntb = epf_get_drvdata(epf);
1303 	struct device *dev = &epf->dev;
1304 	int ret;
1305 
1306 	if (!epf->epc) {
1307 		dev_dbg(dev, "PRIMARY EPC interface not yet bound\n");
1308 		return 0;
1309 	}
1310 
1311 	ret = epf_ntb_init_epc_bar(ntb);
1312 	if (ret) {
1313 		dev_err(dev, "Failed to create NTB EPC\n");
1314 		goto err_bar_init;
1315 	}
1316 
1317 	ret = epf_ntb_config_spad_bar_alloc(ntb);
1318 	if (ret) {
1319 		dev_err(dev, "Failed to allocate BAR memory\n");
1320 		goto err_bar_alloc;
1321 	}
1322 
1323 	ret = epf_ntb_epc_init(ntb);
1324 	if (ret) {
1325 		dev_err(dev, "Failed to initialize EPC\n");
1326 		goto err_bar_alloc;
1327 	}
1328 
1329 	epf_set_drvdata(epf, ntb);
1330 
1331 	pci_space[0] = (ntb->vntb_pid << 16) | ntb->vntb_vid;
1332 	pci_vntb_table[0].vendor = ntb->vntb_vid;
1333 	pci_vntb_table[0].device = ntb->vntb_pid;
1334 
1335 	ret = pci_register_driver(&vntb_pci_driver);
1336 	if (ret) {
1337 		dev_err(dev, "failure register vntb pci driver\n");
1338 		goto err_bar_alloc;
1339 	}
1340 
1341 	vpci_scan_bus(ntb);
1342 
1343 	return 0;
1344 
1345 err_bar_alloc:
1346 	epf_ntb_config_spad_bar_free(ntb);
1347 
1348 err_bar_init:
1349 	epf_ntb_epc_destroy(ntb);
1350 
1351 	return ret;
1352 }
1353 
1354 /**
1355  * epf_ntb_unbind() - Cleanup the initialization from epf_ntb_bind()
1356  * @epf: NTB endpoint function device
1357  *
1358  * Cleanup the initialization from epf_ntb_bind()
1359  */
1360 static void epf_ntb_unbind(struct pci_epf *epf)
1361 {
1362 	struct epf_ntb *ntb = epf_get_drvdata(epf);
1363 
1364 	epf_ntb_epc_cleanup(ntb);
1365 	epf_ntb_config_spad_bar_free(ntb);
1366 	epf_ntb_epc_destroy(ntb);
1367 
1368 	pci_unregister_driver(&vntb_pci_driver);
1369 }
1370 
1371 // EPF driver probe
1372 static const struct pci_epf_ops epf_ntb_ops = {
1373 	.bind   = epf_ntb_bind,
1374 	.unbind = epf_ntb_unbind,
1375 	.add_cfs = epf_ntb_add_cfs,
1376 };
1377 
1378 /**
1379  * epf_ntb_probe() - Probe NTB function driver
1380  * @epf: NTB endpoint function device
1381  * @id: NTB endpoint function device ID
1382  *
1383  * Probe NTB function driver when endpoint function bus detects a NTB
1384  * endpoint function.
1385  *
1386  * Returns: Zero for success, or an error code in case of failure
1387  */
1388 static int epf_ntb_probe(struct pci_epf *epf,
1389 			 const struct pci_epf_device_id *id)
1390 {
1391 	struct epf_ntb *ntb;
1392 	struct device *dev;
1393 
1394 	dev = &epf->dev;
1395 
1396 	ntb = devm_kzalloc(dev, sizeof(*ntb), GFP_KERNEL);
1397 	if (!ntb)
1398 		return -ENOMEM;
1399 
1400 	epf->header = &epf_ntb_header;
1401 	ntb->epf = epf;
1402 	ntb->vbus_number = 0xff;
1403 	epf_set_drvdata(epf, ntb);
1404 
1405 	dev_info(dev, "pci-ep epf driver loaded\n");
1406 	return 0;
1407 }
1408 
1409 static const struct pci_epf_device_id epf_ntb_ids[] = {
1410 	{
1411 		.name = "pci_epf_vntb",
1412 	},
1413 	{},
1414 };
1415 
1416 static struct pci_epf_driver epf_ntb_driver = {
1417 	.driver.name    = "pci_epf_vntb",
1418 	.probe          = epf_ntb_probe,
1419 	.id_table       = epf_ntb_ids,
1420 	.ops            = &epf_ntb_ops,
1421 	.owner          = THIS_MODULE,
1422 };
1423 
1424 static int __init epf_ntb_init(void)
1425 {
1426 	int ret;
1427 
1428 	kpcintb_workqueue = alloc_workqueue("kpcintb", WQ_MEM_RECLAIM |
1429 					    WQ_HIGHPRI, 0);
1430 	ret = pci_epf_register_driver(&epf_ntb_driver);
1431 	if (ret) {
1432 		destroy_workqueue(kpcintb_workqueue);
1433 		pr_err("Failed to register pci epf ntb driver --> %d\n", ret);
1434 		return ret;
1435 	}
1436 
1437 	return 0;
1438 }
1439 module_init(epf_ntb_init);
1440 
1441 static void __exit epf_ntb_exit(void)
1442 {
1443 	pci_epf_unregister_driver(&epf_ntb_driver);
1444 	destroy_workqueue(kpcintb_workqueue);
1445 }
1446 module_exit(epf_ntb_exit);
1447 
1448 MODULE_DESCRIPTION("PCI EPF NTB DRIVER");
1449 MODULE_AUTHOR("Frank Li <Frank.li@nxp.com>");
1450 MODULE_LICENSE("GPL v2");
1451