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 	enum pci_barno barno;
412 	struct epf_ntb_ctrl *ctrl;
413 	u32 spad_size, ctrl_size;
414 	struct pci_epf *epf = ntb->epf;
415 	struct device *dev = &epf->dev;
416 	u32 spad_count;
417 	void *base;
418 	int i;
419 	const struct pci_epc_features *epc_features = pci_epc_get_features(epf->epc,
420 								epf->func_no,
421 								epf->vfunc_no);
422 	barno = ntb->epf_ntb_bar[BAR_CONFIG];
423 	spad_count = ntb->spad_count;
424 
425 	ctrl_size = ALIGN(sizeof(struct epf_ntb_ctrl), sizeof(u32));
426 	spad_size = 2 * spad_count * sizeof(u32);
427 
428 	base = pci_epf_alloc_space(epf, ctrl_size + spad_size,
429 				   barno, epc_features, 0);
430 	if (!base) {
431 		dev_err(dev, "Config/Status/SPAD alloc region fail\n");
432 		return -ENOMEM;
433 	}
434 
435 	ntb->reg = base;
436 
437 	ctrl = ntb->reg;
438 	ctrl->spad_offset = ctrl_size;
439 
440 	ctrl->spad_count = spad_count;
441 	ctrl->num_mws = ntb->num_mws;
442 	ntb->spad_size = spad_size;
443 
444 	ctrl->db_entry_size = sizeof(u32);
445 
446 	for (i = 0; i < ntb->db_count; i++) {
447 		ntb->reg->db_data[i] = 1 + i;
448 		ntb->reg->db_offset[i] = 0;
449 	}
450 
451 	return 0;
452 }
453 
454 /**
455  * epf_ntb_configure_interrupt() - Configure MSI/MSI-X capability
456  * @ntb: NTB device that facilitates communication between HOST and VHOST
457  *
458  * Configure MSI/MSI-X capability for each interface with number of
459  * interrupts equal to "db_count" configfs entry.
460  *
461  * Returns: Zero for success, or an error code in case of failure
462  */
463 static int epf_ntb_configure_interrupt(struct epf_ntb *ntb)
464 {
465 	const struct pci_epc_features *epc_features;
466 	struct device *dev;
467 	u32 db_count;
468 	int ret;
469 
470 	dev = &ntb->epf->dev;
471 
472 	epc_features = pci_epc_get_features(ntb->epf->epc, ntb->epf->func_no, ntb->epf->vfunc_no);
473 
474 	if (!(epc_features->msix_capable || epc_features->msi_capable)) {
475 		dev_err(dev, "MSI or MSI-X is required for doorbell\n");
476 		return -EINVAL;
477 	}
478 
479 	db_count = ntb->db_count;
480 	if (db_count > MAX_DB_COUNT) {
481 		dev_err(dev, "DB count cannot be more than %d\n", MAX_DB_COUNT);
482 		return -EINVAL;
483 	}
484 
485 	ntb->db_count = db_count;
486 
487 	if (epc_features->msi_capable) {
488 		ret = pci_epc_set_msi(ntb->epf->epc,
489 				      ntb->epf->func_no,
490 				      ntb->epf->vfunc_no,
491 				      16);
492 		if (ret) {
493 			dev_err(dev, "MSI configuration failed\n");
494 			return ret;
495 		}
496 	}
497 
498 	return 0;
499 }
500 
501 /**
502  * epf_ntb_db_bar_init() - Configure Doorbell window BARs
503  * @ntb: NTB device that facilitates communication between HOST and VHOST
504  *
505  * Returns: Zero for success, or an error code in case of failure
506  */
507 static int epf_ntb_db_bar_init(struct epf_ntb *ntb)
508 {
509 	const struct pci_epc_features *epc_features;
510 	struct device *dev = &ntb->epf->dev;
511 	int ret;
512 	struct pci_epf_bar *epf_bar;
513 	void __iomem *mw_addr;
514 	enum pci_barno barno;
515 	size_t size = sizeof(u32) * ntb->db_count;
516 
517 	epc_features = pci_epc_get_features(ntb->epf->epc,
518 					    ntb->epf->func_no,
519 					    ntb->epf->vfunc_no);
520 	barno = ntb->epf_ntb_bar[BAR_DB];
521 
522 	mw_addr = pci_epf_alloc_space(ntb->epf, size, barno, epc_features, 0);
523 	if (!mw_addr) {
524 		dev_err(dev, "Failed to allocate OB address\n");
525 		return -ENOMEM;
526 	}
527 
528 	ntb->epf_db = mw_addr;
529 
530 	epf_bar = &ntb->epf->bar[barno];
531 
532 	ret = pci_epc_set_bar(ntb->epf->epc, ntb->epf->func_no, ntb->epf->vfunc_no, epf_bar);
533 	if (ret) {
534 		dev_err(dev, "Doorbell BAR set failed\n");
535 			goto err_alloc_peer_mem;
536 	}
537 	return ret;
538 
539 err_alloc_peer_mem:
540 	pci_epf_free_space(ntb->epf, mw_addr, barno, 0);
541 	return -1;
542 }
543 
544 static void epf_ntb_mw_bar_clear(struct epf_ntb *ntb, int num_mws);
545 
546 /**
547  * epf_ntb_db_bar_clear() - Clear doorbell BAR and free memory
548  *   allocated in peer's outbound address space
549  * @ntb: NTB device that facilitates communication between HOST and VHOST
550  */
551 static void epf_ntb_db_bar_clear(struct epf_ntb *ntb)
552 {
553 	enum pci_barno barno;
554 
555 	barno = ntb->epf_ntb_bar[BAR_DB];
556 	pci_epf_free_space(ntb->epf, ntb->epf_db, barno, 0);
557 	pci_epc_clear_bar(ntb->epf->epc,
558 			  ntb->epf->func_no,
559 			  ntb->epf->vfunc_no,
560 			  &ntb->epf->bar[barno]);
561 }
562 
563 /**
564  * epf_ntb_mw_bar_init() - Configure Memory window BARs
565  * @ntb: NTB device that facilitates communication between HOST and VHOST
566  *
567  * Returns: Zero for success, or an error code in case of failure
568  */
569 static int epf_ntb_mw_bar_init(struct epf_ntb *ntb)
570 {
571 	int ret = 0;
572 	int i;
573 	u64 size;
574 	enum pci_barno barno;
575 	struct device *dev = &ntb->epf->dev;
576 
577 	for (i = 0; i < ntb->num_mws; i++) {
578 		size = ntb->mws_size[i];
579 		barno = ntb->epf_ntb_bar[BAR_MW0 + i];
580 
581 		ntb->epf->bar[barno].barno = barno;
582 		ntb->epf->bar[barno].size = size;
583 		ntb->epf->bar[barno].addr = NULL;
584 		ntb->epf->bar[barno].phys_addr = 0;
585 		ntb->epf->bar[barno].flags |= upper_32_bits(size) ?
586 				PCI_BASE_ADDRESS_MEM_TYPE_64 :
587 				PCI_BASE_ADDRESS_MEM_TYPE_32;
588 
589 		ret = pci_epc_set_bar(ntb->epf->epc,
590 				      ntb->epf->func_no,
591 				      ntb->epf->vfunc_no,
592 				      &ntb->epf->bar[barno]);
593 		if (ret) {
594 			dev_err(dev, "MW set failed\n");
595 			goto err_alloc_mem;
596 		}
597 
598 		/* Allocate EPC outbound memory windows to vpci vntb device */
599 		ntb->vpci_mw_addr[i] = pci_epc_mem_alloc_addr(ntb->epf->epc,
600 							      &ntb->vpci_mw_phy[i],
601 							      size);
602 		if (!ntb->vpci_mw_addr[i]) {
603 			ret = -ENOMEM;
604 			dev_err(dev, "Failed to allocate source address\n");
605 			goto err_set_bar;
606 		}
607 	}
608 
609 	return ret;
610 
611 err_set_bar:
612 	pci_epc_clear_bar(ntb->epf->epc,
613 			  ntb->epf->func_no,
614 			  ntb->epf->vfunc_no,
615 			  &ntb->epf->bar[barno]);
616 err_alloc_mem:
617 	epf_ntb_mw_bar_clear(ntb, i);
618 	return ret;
619 }
620 
621 /**
622  * epf_ntb_mw_bar_clear() - Clear Memory window BARs
623  * @ntb: NTB device that facilitates communication between HOST and VHOST
624  * @num_mws: the number of Memory window BARs that to be cleared
625  */
626 static void epf_ntb_mw_bar_clear(struct epf_ntb *ntb, int num_mws)
627 {
628 	enum pci_barno barno;
629 	int i;
630 
631 	for (i = 0; i < num_mws; i++) {
632 		barno = ntb->epf_ntb_bar[BAR_MW0 + i];
633 		pci_epc_clear_bar(ntb->epf->epc,
634 				  ntb->epf->func_no,
635 				  ntb->epf->vfunc_no,
636 				  &ntb->epf->bar[barno]);
637 
638 		pci_epc_mem_free_addr(ntb->epf->epc,
639 				      ntb->vpci_mw_phy[i],
640 				      ntb->vpci_mw_addr[i],
641 				      ntb->mws_size[i]);
642 	}
643 }
644 
645 /**
646  * epf_ntb_epc_destroy() - Cleanup NTB EPC interface
647  * @ntb: NTB device that facilitates communication between HOST and VHOST
648  *
649  * Wrapper for epf_ntb_epc_destroy_interface() to cleanup all the NTB interfaces
650  */
651 static void epf_ntb_epc_destroy(struct epf_ntb *ntb)
652 {
653 	pci_epc_remove_epf(ntb->epf->epc, ntb->epf, 0);
654 	pci_epc_put(ntb->epf->epc);
655 }
656 
657 /**
658  * epf_ntb_init_epc_bar() - Identify BARs to be used for each of the NTB
659  * constructs (scratchpad region, doorbell, memorywindow)
660  * @ntb: NTB device that facilitates communication between HOST and VHOST
661  *
662  * Returns: Zero for success, or an error code in case of failure
663  */
664 static int epf_ntb_init_epc_bar(struct epf_ntb *ntb)
665 {
666 	const struct pci_epc_features *epc_features;
667 	enum pci_barno barno;
668 	enum epf_ntb_bar bar;
669 	struct device *dev;
670 	u32 num_mws;
671 	int i;
672 
673 	barno = BAR_0;
674 	num_mws = ntb->num_mws;
675 	dev = &ntb->epf->dev;
676 	epc_features = pci_epc_get_features(ntb->epf->epc, ntb->epf->func_no, ntb->epf->vfunc_no);
677 
678 	/* These are required BARs which are mandatory for NTB functionality */
679 	for (bar = BAR_CONFIG; bar <= BAR_MW0; bar++, barno++) {
680 		barno = pci_epc_get_next_free_bar(epc_features, barno);
681 		if (barno < 0) {
682 			dev_err(dev, "Fail to get NTB function BAR\n");
683 			return barno;
684 		}
685 		ntb->epf_ntb_bar[bar] = barno;
686 	}
687 
688 	/* These are optional BARs which don't impact NTB functionality */
689 	for (bar = BAR_MW1, i = 1; i < num_mws; bar++, barno++, i++) {
690 		barno = pci_epc_get_next_free_bar(epc_features, barno);
691 		if (barno < 0) {
692 			ntb->num_mws = i;
693 			dev_dbg(dev, "BAR not available for > MW%d\n", i + 1);
694 		}
695 		ntb->epf_ntb_bar[bar] = barno;
696 	}
697 
698 	return 0;
699 }
700 
701 /**
702  * epf_ntb_epc_init() - Initialize NTB interface
703  * @ntb: NTB device that facilitates communication between HOST and VHOST
704  *
705  * Wrapper to initialize a particular EPC interface and start the workqueue
706  * to check for commands from HOST. This function will write to the
707  * EP controller HW for configuring it.
708  *
709  * Returns: Zero for success, or an error code in case of failure
710  */
711 static int epf_ntb_epc_init(struct epf_ntb *ntb)
712 {
713 	u8 func_no, vfunc_no;
714 	struct pci_epc *epc;
715 	struct pci_epf *epf;
716 	struct device *dev;
717 	int ret;
718 
719 	epf = ntb->epf;
720 	dev = &epf->dev;
721 	epc = epf->epc;
722 	func_no = ntb->epf->func_no;
723 	vfunc_no = ntb->epf->vfunc_no;
724 
725 	ret = epf_ntb_config_sspad_bar_set(ntb);
726 	if (ret) {
727 		dev_err(dev, "Config/self SPAD BAR init failed");
728 		return ret;
729 	}
730 
731 	ret = epf_ntb_configure_interrupt(ntb);
732 	if (ret) {
733 		dev_err(dev, "Interrupt configuration failed\n");
734 		goto err_config_interrupt;
735 	}
736 
737 	ret = epf_ntb_db_bar_init(ntb);
738 	if (ret) {
739 		dev_err(dev, "DB BAR init failed\n");
740 		goto err_db_bar_init;
741 	}
742 
743 	ret = epf_ntb_mw_bar_init(ntb);
744 	if (ret) {
745 		dev_err(dev, "MW BAR init failed\n");
746 		goto err_mw_bar_init;
747 	}
748 
749 	if (vfunc_no <= 1) {
750 		ret = pci_epc_write_header(epc, func_no, vfunc_no, epf->header);
751 		if (ret) {
752 			dev_err(dev, "Configuration header write failed\n");
753 			goto err_write_header;
754 		}
755 	}
756 
757 	INIT_DELAYED_WORK(&ntb->cmd_handler, epf_ntb_cmd_handler);
758 	queue_work(kpcintb_workqueue, &ntb->cmd_handler.work);
759 
760 	return 0;
761 
762 err_write_header:
763 	epf_ntb_mw_bar_clear(ntb, ntb->num_mws);
764 err_mw_bar_init:
765 	epf_ntb_db_bar_clear(ntb);
766 err_db_bar_init:
767 err_config_interrupt:
768 	epf_ntb_config_sspad_bar_clear(ntb);
769 
770 	return ret;
771 }
772 
773 
774 /**
775  * epf_ntb_epc_cleanup() - Cleanup all NTB interfaces
776  * @ntb: NTB device that facilitates communication between HOST and VHOST
777  *
778  * Wrapper to cleanup all NTB interfaces.
779  */
780 static void epf_ntb_epc_cleanup(struct epf_ntb *ntb)
781 {
782 	epf_ntb_mw_bar_clear(ntb, ntb->num_mws);
783 	epf_ntb_db_bar_clear(ntb);
784 	epf_ntb_config_sspad_bar_clear(ntb);
785 }
786 
787 #define EPF_NTB_R(_name)						\
788 static ssize_t epf_ntb_##_name##_show(struct config_item *item,		\
789 				      char *page)			\
790 {									\
791 	struct config_group *group = to_config_group(item);		\
792 	struct epf_ntb *ntb = to_epf_ntb(group);			\
793 									\
794 	return sprintf(page, "%d\n", ntb->_name);			\
795 }
796 
797 #define EPF_NTB_W(_name)						\
798 static ssize_t epf_ntb_##_name##_store(struct config_item *item,	\
799 				       const char *page, size_t len)	\
800 {									\
801 	struct config_group *group = to_config_group(item);		\
802 	struct epf_ntb *ntb = to_epf_ntb(group);			\
803 	u32 val;							\
804 	int ret;							\
805 									\
806 	ret = kstrtou32(page, 0, &val);					\
807 	if (ret)							\
808 		return ret;						\
809 									\
810 	ntb->_name = val;						\
811 									\
812 	return len;							\
813 }
814 
815 #define EPF_NTB_MW_R(_name)						\
816 static ssize_t epf_ntb_##_name##_show(struct config_item *item,		\
817 				      char *page)			\
818 {									\
819 	struct config_group *group = to_config_group(item);		\
820 	struct epf_ntb *ntb = to_epf_ntb(group);			\
821 	struct device *dev = &ntb->epf->dev;				\
822 	int win_no;							\
823 									\
824 	if (sscanf(#_name, "mw%d", &win_no) != 1)			\
825 		return -EINVAL;						\
826 									\
827 	if (win_no <= 0 || win_no > ntb->num_mws) {			\
828 		dev_err(dev, "Invalid num_nws: %d value\n", ntb->num_mws); \
829 		return -EINVAL;						\
830 	}								\
831 									\
832 	return sprintf(page, "%lld\n", ntb->mws_size[win_no - 1]);	\
833 }
834 
835 #define EPF_NTB_MW_W(_name)						\
836 static ssize_t epf_ntb_##_name##_store(struct config_item *item,	\
837 				       const char *page, size_t len)	\
838 {									\
839 	struct config_group *group = to_config_group(item);		\
840 	struct epf_ntb *ntb = to_epf_ntb(group);			\
841 	struct device *dev = &ntb->epf->dev;				\
842 	int win_no;							\
843 	u64 val;							\
844 	int ret;							\
845 									\
846 	ret = kstrtou64(page, 0, &val);					\
847 	if (ret)							\
848 		return ret;						\
849 									\
850 	if (sscanf(#_name, "mw%d", &win_no) != 1)			\
851 		return -EINVAL;						\
852 									\
853 	if (win_no <= 0 || win_no > ntb->num_mws) {			\
854 		dev_err(dev, "Invalid num_nws: %d value\n", ntb->num_mws); \
855 		return -EINVAL;						\
856 	}								\
857 									\
858 	ntb->mws_size[win_no - 1] = val;				\
859 									\
860 	return len;							\
861 }
862 
863 static ssize_t epf_ntb_num_mws_store(struct config_item *item,
864 				     const char *page, size_t len)
865 {
866 	struct config_group *group = to_config_group(item);
867 	struct epf_ntb *ntb = to_epf_ntb(group);
868 	u32 val;
869 	int ret;
870 
871 	ret = kstrtou32(page, 0, &val);
872 	if (ret)
873 		return ret;
874 
875 	if (val > MAX_MW)
876 		return -EINVAL;
877 
878 	ntb->num_mws = val;
879 
880 	return len;
881 }
882 
883 EPF_NTB_R(spad_count)
884 EPF_NTB_W(spad_count)
885 EPF_NTB_R(db_count)
886 EPF_NTB_W(db_count)
887 EPF_NTB_R(num_mws)
888 EPF_NTB_R(vbus_number)
889 EPF_NTB_W(vbus_number)
890 EPF_NTB_R(vntb_pid)
891 EPF_NTB_W(vntb_pid)
892 EPF_NTB_R(vntb_vid)
893 EPF_NTB_W(vntb_vid)
894 EPF_NTB_MW_R(mw1)
895 EPF_NTB_MW_W(mw1)
896 EPF_NTB_MW_R(mw2)
897 EPF_NTB_MW_W(mw2)
898 EPF_NTB_MW_R(mw3)
899 EPF_NTB_MW_W(mw3)
900 EPF_NTB_MW_R(mw4)
901 EPF_NTB_MW_W(mw4)
902 
903 CONFIGFS_ATTR(epf_ntb_, spad_count);
904 CONFIGFS_ATTR(epf_ntb_, db_count);
905 CONFIGFS_ATTR(epf_ntb_, num_mws);
906 CONFIGFS_ATTR(epf_ntb_, mw1);
907 CONFIGFS_ATTR(epf_ntb_, mw2);
908 CONFIGFS_ATTR(epf_ntb_, mw3);
909 CONFIGFS_ATTR(epf_ntb_, mw4);
910 CONFIGFS_ATTR(epf_ntb_, vbus_number);
911 CONFIGFS_ATTR(epf_ntb_, vntb_pid);
912 CONFIGFS_ATTR(epf_ntb_, vntb_vid);
913 
914 static struct configfs_attribute *epf_ntb_attrs[] = {
915 	&epf_ntb_attr_spad_count,
916 	&epf_ntb_attr_db_count,
917 	&epf_ntb_attr_num_mws,
918 	&epf_ntb_attr_mw1,
919 	&epf_ntb_attr_mw2,
920 	&epf_ntb_attr_mw3,
921 	&epf_ntb_attr_mw4,
922 	&epf_ntb_attr_vbus_number,
923 	&epf_ntb_attr_vntb_pid,
924 	&epf_ntb_attr_vntb_vid,
925 	NULL,
926 };
927 
928 static const struct config_item_type ntb_group_type = {
929 	.ct_attrs	= epf_ntb_attrs,
930 	.ct_owner	= THIS_MODULE,
931 };
932 
933 /**
934  * epf_ntb_add_cfs() - Add configfs directory specific to NTB
935  * @epf: NTB endpoint function device
936  * @group: A pointer to the config_group structure referencing a group of
937  *	   config_items of a specific type that belong to a specific sub-system.
938  *
939  * Add configfs directory specific to NTB. This directory will hold
940  * NTB specific properties like db_count, spad_count, num_mws etc.,
941  *
942  * Returns: Pointer to config_group
943  */
944 static struct config_group *epf_ntb_add_cfs(struct pci_epf *epf,
945 					    struct config_group *group)
946 {
947 	struct epf_ntb *ntb = epf_get_drvdata(epf);
948 	struct config_group *ntb_group = &ntb->group;
949 	struct device *dev = &epf->dev;
950 
951 	config_group_init_type_name(ntb_group, dev_name(dev), &ntb_group_type);
952 
953 	return ntb_group;
954 }
955 
956 /*==== virtual PCI bus driver, which only load virtual NTB PCI driver ====*/
957 
958 static u32 pci_space[] = {
959 	0xffffffff,	/* Device ID, Vendor ID */
960 	0,		/* Status, Command */
961 	0xffffffff,	/* Base Class, Subclass, Prog Intf, Revision ID */
962 	0x40,		/* BIST, Header Type, Latency Timer, Cache Line Size */
963 	0,		/* BAR 0 */
964 	0,		/* BAR 1 */
965 	0,		/* BAR 2 */
966 	0,		/* BAR 3 */
967 	0,		/* BAR 4 */
968 	0,		/* BAR 5 */
969 	0,		/* Cardbus CIS Pointer */
970 	0,		/* Subsystem ID, Subsystem Vendor ID */
971 	0,		/* ROM Base Address */
972 	0,		/* Reserved, Capabilities Pointer */
973 	0,		/* Reserved */
974 	0,		/* Max_Lat, Min_Gnt, Interrupt Pin, Interrupt Line */
975 };
976 
977 static int pci_read(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *val)
978 {
979 	if (devfn == 0) {
980 		memcpy(val, ((u8 *)pci_space) + where, size);
981 		return PCIBIOS_SUCCESSFUL;
982 	}
983 	return PCIBIOS_DEVICE_NOT_FOUND;
984 }
985 
986 static int pci_write(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 val)
987 {
988 	return 0;
989 }
990 
991 static struct pci_ops vpci_ops = {
992 	.read = pci_read,
993 	.write = pci_write,
994 };
995 
996 static int vpci_scan_bus(void *sysdata)
997 {
998 	struct pci_bus *vpci_bus;
999 	struct epf_ntb *ndev = sysdata;
1000 
1001 	vpci_bus = pci_scan_bus(ndev->vbus_number, &vpci_ops, sysdata);
1002 	if (!vpci_bus) {
1003 		pr_err("create pci bus failed\n");
1004 		return -EINVAL;
1005 	}
1006 
1007 	pci_bus_add_devices(vpci_bus);
1008 
1009 	return 0;
1010 }
1011 
1012 /*==================== Virtual PCIe NTB driver ==========================*/
1013 
1014 static int vntb_epf_mw_count(struct ntb_dev *ntb, int pidx)
1015 {
1016 	struct epf_ntb *ndev = ntb_ndev(ntb);
1017 
1018 	return ndev->num_mws;
1019 }
1020 
1021 static int vntb_epf_spad_count(struct ntb_dev *ntb)
1022 {
1023 	return ntb_ndev(ntb)->spad_count;
1024 }
1025 
1026 static int vntb_epf_peer_mw_count(struct ntb_dev *ntb)
1027 {
1028 	return ntb_ndev(ntb)->num_mws;
1029 }
1030 
1031 static u64 vntb_epf_db_valid_mask(struct ntb_dev *ntb)
1032 {
1033 	return BIT_ULL(ntb_ndev(ntb)->db_count) - 1;
1034 }
1035 
1036 static int vntb_epf_db_set_mask(struct ntb_dev *ntb, u64 db_bits)
1037 {
1038 	return 0;
1039 }
1040 
1041 static int vntb_epf_mw_set_trans(struct ntb_dev *ndev, int pidx, int idx,
1042 		dma_addr_t addr, resource_size_t size)
1043 {
1044 	struct epf_ntb *ntb = ntb_ndev(ndev);
1045 	struct pci_epf_bar *epf_bar;
1046 	enum pci_barno barno;
1047 	int ret;
1048 	struct device *dev;
1049 
1050 	dev = &ntb->ntb.dev;
1051 	barno = ntb->epf_ntb_bar[BAR_MW0 + idx];
1052 	epf_bar = &ntb->epf->bar[barno];
1053 	epf_bar->phys_addr = addr;
1054 	epf_bar->barno = barno;
1055 	epf_bar->size = size;
1056 
1057 	ret = pci_epc_set_bar(ntb->epf->epc, 0, 0, epf_bar);
1058 	if (ret) {
1059 		dev_err(dev, "failure set mw trans\n");
1060 		return ret;
1061 	}
1062 	return 0;
1063 }
1064 
1065 static int vntb_epf_mw_clear_trans(struct ntb_dev *ntb, int pidx, int idx)
1066 {
1067 	return 0;
1068 }
1069 
1070 static int vntb_epf_peer_mw_get_addr(struct ntb_dev *ndev, int idx,
1071 				phys_addr_t *base, resource_size_t *size)
1072 {
1073 
1074 	struct epf_ntb *ntb = ntb_ndev(ndev);
1075 
1076 	if (base)
1077 		*base = ntb->vpci_mw_phy[idx];
1078 
1079 	if (size)
1080 		*size = ntb->mws_size[idx];
1081 
1082 	return 0;
1083 }
1084 
1085 static int vntb_epf_link_enable(struct ntb_dev *ntb,
1086 			enum ntb_speed max_speed,
1087 			enum ntb_width max_width)
1088 {
1089 	return 0;
1090 }
1091 
1092 static u32 vntb_epf_spad_read(struct ntb_dev *ndev, int idx)
1093 {
1094 	struct epf_ntb *ntb = ntb_ndev(ndev);
1095 	int off = ntb->reg->spad_offset, ct = ntb->reg->spad_count * sizeof(u32);
1096 	u32 val;
1097 	void __iomem *base = (void __iomem *)ntb->reg;
1098 
1099 	val = readl(base + off + ct + idx * sizeof(u32));
1100 	return val;
1101 }
1102 
1103 static int vntb_epf_spad_write(struct ntb_dev *ndev, int idx, u32 val)
1104 {
1105 	struct epf_ntb *ntb = ntb_ndev(ndev);
1106 	struct epf_ntb_ctrl *ctrl = ntb->reg;
1107 	int off = ctrl->spad_offset, ct = ctrl->spad_count * sizeof(u32);
1108 	void __iomem *base = (void __iomem *)ntb->reg;
1109 
1110 	writel(val, base + off + ct + idx * sizeof(u32));
1111 	return 0;
1112 }
1113 
1114 static u32 vntb_epf_peer_spad_read(struct ntb_dev *ndev, int pidx, int idx)
1115 {
1116 	struct epf_ntb *ntb = ntb_ndev(ndev);
1117 	struct epf_ntb_ctrl *ctrl = ntb->reg;
1118 	int off = ctrl->spad_offset;
1119 	void __iomem *base = (void __iomem *)ntb->reg;
1120 	u32 val;
1121 
1122 	val = readl(base + off + idx * sizeof(u32));
1123 	return val;
1124 }
1125 
1126 static int vntb_epf_peer_spad_write(struct ntb_dev *ndev, int pidx, int idx, u32 val)
1127 {
1128 	struct epf_ntb *ntb = ntb_ndev(ndev);
1129 	struct epf_ntb_ctrl *ctrl = ntb->reg;
1130 	int off = ctrl->spad_offset;
1131 	void __iomem *base = (void __iomem *)ntb->reg;
1132 
1133 	writel(val, base + off + idx * sizeof(u32));
1134 	return 0;
1135 }
1136 
1137 static int vntb_epf_peer_db_set(struct ntb_dev *ndev, u64 db_bits)
1138 {
1139 	u32 interrupt_num = ffs(db_bits) + 1;
1140 	struct epf_ntb *ntb = ntb_ndev(ndev);
1141 	u8 func_no, vfunc_no;
1142 	int ret;
1143 
1144 	func_no = ntb->epf->func_no;
1145 	vfunc_no = ntb->epf->vfunc_no;
1146 
1147 	ret = pci_epc_raise_irq(ntb->epf->epc, func_no, vfunc_no,
1148 				PCI_IRQ_MSI, interrupt_num + 1);
1149 	if (ret)
1150 		dev_err(&ntb->ntb.dev, "Failed to raise IRQ\n");
1151 
1152 	return ret;
1153 }
1154 
1155 static u64 vntb_epf_db_read(struct ntb_dev *ndev)
1156 {
1157 	struct epf_ntb *ntb = ntb_ndev(ndev);
1158 
1159 	return ntb->db;
1160 }
1161 
1162 static int vntb_epf_mw_get_align(struct ntb_dev *ndev, int pidx, int idx,
1163 			resource_size_t *addr_align,
1164 			resource_size_t *size_align,
1165 			resource_size_t *size_max)
1166 {
1167 	struct epf_ntb *ntb = ntb_ndev(ndev);
1168 
1169 	if (addr_align)
1170 		*addr_align = SZ_4K;
1171 
1172 	if (size_align)
1173 		*size_align = 1;
1174 
1175 	if (size_max)
1176 		*size_max = ntb->mws_size[idx];
1177 
1178 	return 0;
1179 }
1180 
1181 static u64 vntb_epf_link_is_up(struct ntb_dev *ndev,
1182 			enum ntb_speed *speed,
1183 			enum ntb_width *width)
1184 {
1185 	struct epf_ntb *ntb = ntb_ndev(ndev);
1186 
1187 	return ntb->reg->link_status;
1188 }
1189 
1190 static int vntb_epf_db_clear_mask(struct ntb_dev *ndev, u64 db_bits)
1191 {
1192 	return 0;
1193 }
1194 
1195 static int vntb_epf_db_clear(struct ntb_dev *ndev, u64 db_bits)
1196 {
1197 	struct epf_ntb *ntb = ntb_ndev(ndev);
1198 
1199 	ntb->db &= ~db_bits;
1200 	return 0;
1201 }
1202 
1203 static int vntb_epf_link_disable(struct ntb_dev *ntb)
1204 {
1205 	return 0;
1206 }
1207 
1208 static const struct ntb_dev_ops vntb_epf_ops = {
1209 	.mw_count		= vntb_epf_mw_count,
1210 	.spad_count		= vntb_epf_spad_count,
1211 	.peer_mw_count		= vntb_epf_peer_mw_count,
1212 	.db_valid_mask		= vntb_epf_db_valid_mask,
1213 	.db_set_mask		= vntb_epf_db_set_mask,
1214 	.mw_set_trans		= vntb_epf_mw_set_trans,
1215 	.mw_clear_trans		= vntb_epf_mw_clear_trans,
1216 	.peer_mw_get_addr	= vntb_epf_peer_mw_get_addr,
1217 	.link_enable		= vntb_epf_link_enable,
1218 	.spad_read		= vntb_epf_spad_read,
1219 	.spad_write		= vntb_epf_spad_write,
1220 	.peer_spad_read		= vntb_epf_peer_spad_read,
1221 	.peer_spad_write	= vntb_epf_peer_spad_write,
1222 	.peer_db_set		= vntb_epf_peer_db_set,
1223 	.db_read		= vntb_epf_db_read,
1224 	.mw_get_align		= vntb_epf_mw_get_align,
1225 	.link_is_up		= vntb_epf_link_is_up,
1226 	.db_clear_mask		= vntb_epf_db_clear_mask,
1227 	.db_clear		= vntb_epf_db_clear,
1228 	.link_disable		= vntb_epf_link_disable,
1229 };
1230 
1231 static int pci_vntb_probe(struct pci_dev *pdev, const struct pci_device_id *id)
1232 {
1233 	int ret;
1234 	struct epf_ntb *ndev = (struct epf_ntb *)pdev->sysdata;
1235 	struct device *dev = &pdev->dev;
1236 
1237 	ndev->ntb.pdev = pdev;
1238 	ndev->ntb.topo = NTB_TOPO_NONE;
1239 	ndev->ntb.ops =  &vntb_epf_ops;
1240 
1241 	ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
1242 	if (ret) {
1243 		dev_err(dev, "Cannot set DMA mask\n");
1244 		return ret;
1245 	}
1246 
1247 	ret = ntb_register_device(&ndev->ntb);
1248 	if (ret) {
1249 		dev_err(dev, "Failed to register NTB device\n");
1250 		return ret;
1251 	}
1252 
1253 	dev_dbg(dev, "PCI Virtual NTB driver loaded\n");
1254 	return 0;
1255 }
1256 
1257 static struct pci_device_id pci_vntb_table[] = {
1258 	{
1259 		PCI_DEVICE(0xffff, 0xffff),
1260 	},
1261 	{},
1262 };
1263 
1264 static struct pci_driver vntb_pci_driver = {
1265 	.name           = "pci-vntb",
1266 	.id_table       = pci_vntb_table,
1267 	.probe          = pci_vntb_probe,
1268 };
1269 
1270 /* ============ PCIe EPF Driver Bind ====================*/
1271 
1272 /**
1273  * epf_ntb_bind() - Initialize endpoint controller to provide NTB functionality
1274  * @epf: NTB endpoint function device
1275  *
1276  * Initialize both the endpoint controllers associated with NTB function device.
1277  * Invoked when a primary interface or secondary interface is bound to EPC
1278  * device. This function will succeed only when EPC is bound to both the
1279  * interfaces.
1280  *
1281  * Returns: Zero for success, or an error code in case of failure
1282  */
1283 static int epf_ntb_bind(struct pci_epf *epf)
1284 {
1285 	struct epf_ntb *ntb = epf_get_drvdata(epf);
1286 	struct device *dev = &epf->dev;
1287 	int ret;
1288 
1289 	if (!epf->epc) {
1290 		dev_dbg(dev, "PRIMARY EPC interface not yet bound\n");
1291 		return 0;
1292 	}
1293 
1294 	ret = epf_ntb_init_epc_bar(ntb);
1295 	if (ret) {
1296 		dev_err(dev, "Failed to create NTB EPC\n");
1297 		goto err_bar_init;
1298 	}
1299 
1300 	ret = epf_ntb_config_spad_bar_alloc(ntb);
1301 	if (ret) {
1302 		dev_err(dev, "Failed to allocate BAR memory\n");
1303 		goto err_bar_alloc;
1304 	}
1305 
1306 	ret = epf_ntb_epc_init(ntb);
1307 	if (ret) {
1308 		dev_err(dev, "Failed to initialize EPC\n");
1309 		goto err_bar_alloc;
1310 	}
1311 
1312 	epf_set_drvdata(epf, ntb);
1313 
1314 	pci_space[0] = (ntb->vntb_pid << 16) | ntb->vntb_vid;
1315 	pci_vntb_table[0].vendor = ntb->vntb_vid;
1316 	pci_vntb_table[0].device = ntb->vntb_pid;
1317 
1318 	ret = pci_register_driver(&vntb_pci_driver);
1319 	if (ret) {
1320 		dev_err(dev, "failure register vntb pci driver\n");
1321 		goto err_epc_cleanup;
1322 	}
1323 
1324 	ret = vpci_scan_bus(ntb);
1325 	if (ret)
1326 		goto err_unregister;
1327 
1328 	return 0;
1329 
1330 err_unregister:
1331 	pci_unregister_driver(&vntb_pci_driver);
1332 err_epc_cleanup:
1333 	epf_ntb_epc_cleanup(ntb);
1334 err_bar_alloc:
1335 	epf_ntb_config_spad_bar_free(ntb);
1336 
1337 err_bar_init:
1338 	epf_ntb_epc_destroy(ntb);
1339 
1340 	return ret;
1341 }
1342 
1343 /**
1344  * epf_ntb_unbind() - Cleanup the initialization from epf_ntb_bind()
1345  * @epf: NTB endpoint function device
1346  *
1347  * Cleanup the initialization from epf_ntb_bind()
1348  */
1349 static void epf_ntb_unbind(struct pci_epf *epf)
1350 {
1351 	struct epf_ntb *ntb = epf_get_drvdata(epf);
1352 
1353 	epf_ntb_epc_cleanup(ntb);
1354 	epf_ntb_config_spad_bar_free(ntb);
1355 	epf_ntb_epc_destroy(ntb);
1356 
1357 	pci_unregister_driver(&vntb_pci_driver);
1358 }
1359 
1360 // EPF driver probe
1361 static const struct pci_epf_ops epf_ntb_ops = {
1362 	.bind   = epf_ntb_bind,
1363 	.unbind = epf_ntb_unbind,
1364 	.add_cfs = epf_ntb_add_cfs,
1365 };
1366 
1367 /**
1368  * epf_ntb_probe() - Probe NTB function driver
1369  * @epf: NTB endpoint function device
1370  * @id: NTB endpoint function device ID
1371  *
1372  * Probe NTB function driver when endpoint function bus detects a NTB
1373  * endpoint function.
1374  *
1375  * Returns: Zero for success, or an error code in case of failure
1376  */
1377 static int epf_ntb_probe(struct pci_epf *epf,
1378 			 const struct pci_epf_device_id *id)
1379 {
1380 	struct epf_ntb *ntb;
1381 	struct device *dev;
1382 
1383 	dev = &epf->dev;
1384 
1385 	ntb = devm_kzalloc(dev, sizeof(*ntb), GFP_KERNEL);
1386 	if (!ntb)
1387 		return -ENOMEM;
1388 
1389 	epf->header = &epf_ntb_header;
1390 	ntb->epf = epf;
1391 	ntb->vbus_number = 0xff;
1392 	epf_set_drvdata(epf, ntb);
1393 
1394 	dev_info(dev, "pci-ep epf driver loaded\n");
1395 	return 0;
1396 }
1397 
1398 static const struct pci_epf_device_id epf_ntb_ids[] = {
1399 	{
1400 		.name = "pci_epf_vntb",
1401 	},
1402 	{},
1403 };
1404 
1405 static struct pci_epf_driver epf_ntb_driver = {
1406 	.driver.name    = "pci_epf_vntb",
1407 	.probe          = epf_ntb_probe,
1408 	.id_table       = epf_ntb_ids,
1409 	.ops            = &epf_ntb_ops,
1410 	.owner          = THIS_MODULE,
1411 };
1412 
1413 static int __init epf_ntb_init(void)
1414 {
1415 	int ret;
1416 
1417 	kpcintb_workqueue = alloc_workqueue("kpcintb", WQ_MEM_RECLAIM |
1418 					    WQ_HIGHPRI, 0);
1419 	ret = pci_epf_register_driver(&epf_ntb_driver);
1420 	if (ret) {
1421 		destroy_workqueue(kpcintb_workqueue);
1422 		pr_err("Failed to register pci epf ntb driver --> %d\n", ret);
1423 		return ret;
1424 	}
1425 
1426 	return 0;
1427 }
1428 module_init(epf_ntb_init);
1429 
1430 static void __exit epf_ntb_exit(void)
1431 {
1432 	pci_epf_unregister_driver(&epf_ntb_driver);
1433 	destroy_workqueue(kpcintb_workqueue);
1434 }
1435 module_exit(epf_ntb_exit);
1436 
1437 MODULE_DESCRIPTION("PCI EPF NTB DRIVER");
1438 MODULE_AUTHOR("Frank Li <Frank.li@nxp.com>");
1439 MODULE_LICENSE("GPL v2");
1440