xref: /linux/drivers/pci/endpoint/functions/pci-epf-vntb.c (revision ab93e0dd72c37d378dd936f031ffb83ff2bd87ce)
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_MW1,
74 	BAR_MW2,
75 	BAR_MW3,
76 	BAR_MW4,
77 	VNTB_BAR_NUM,
78 };
79 
80 /*
81  * +--------------------------------------------------+ Base
82  * |                                                  |
83  * |                                                  |
84  * |                                                  |
85  * |          Common Control Register                 |
86  * |                                                  |
87  * |                                                  |
88  * |                                                  |
89  * +-----------------------+--------------------------+ Base+spad_offset
90  * |                       |                          |
91  * |    Peer Spad Space    |    Spad Space            |
92  * |                       |                          |
93  * |                       |                          |
94  * +-----------------------+--------------------------+ Base+spad_offset
95  * |                       |                          |     +spad_count * 4
96  * |                       |                          |
97  * |     Spad Space        |   Peer Spad Space        |
98  * |                       |                          |
99  * +-----------------------+--------------------------+
100  *       Virtual PCI             PCIe Endpoint
101  *       NTB Driver               NTB Driver
102  */
103 struct epf_ntb_ctrl {
104 	u32 command;
105 	u32 argument;
106 	u16 command_status;
107 	u16 link_status;
108 	u32 topology;
109 	u64 addr;
110 	u64 size;
111 	u32 num_mws;
112 	u32 reserved;
113 	u32 spad_offset;
114 	u32 spad_count;
115 	u32 db_entry_size;
116 	u32 db_data[MAX_DB_COUNT];
117 	u32 db_offset[MAX_DB_COUNT];
118 } __packed;
119 
120 struct epf_ntb {
121 	struct ntb_dev ntb;
122 	struct pci_epf *epf;
123 	struct config_group group;
124 
125 	u32 num_mws;
126 	u32 db_count;
127 	u32 spad_count;
128 	u64 mws_size[MAX_MW];
129 	u64 db;
130 	u32 vbus_number;
131 	u16 vntb_pid;
132 	u16 vntb_vid;
133 
134 	bool linkup;
135 	u32 spad_size;
136 
137 	enum pci_barno epf_ntb_bar[VNTB_BAR_NUM];
138 
139 	struct epf_ntb_ctrl *reg;
140 
141 	u32 *epf_db;
142 
143 	phys_addr_t vpci_mw_phy[MAX_MW];
144 	void __iomem *vpci_mw_addr[MAX_MW];
145 
146 	struct delayed_work cmd_handler;
147 };
148 
149 #define to_epf_ntb(epf_group) container_of((epf_group), struct epf_ntb, group)
150 #define ntb_ndev(__ntb) container_of(__ntb, struct epf_ntb, ntb)
151 
152 static struct pci_epf_header epf_ntb_header = {
153 	.vendorid	= PCI_ANY_ID,
154 	.deviceid	= PCI_ANY_ID,
155 	.baseclass_code	= PCI_BASE_CLASS_MEMORY,
156 	.interrupt_pin	= PCI_INTERRUPT_INTA,
157 };
158 
159 /**
160  * epf_ntb_link_up() - Raise link_up interrupt to Virtual Host (VHOST)
161  * @ntb: NTB device that facilitates communication between HOST and VHOST
162  * @link_up: true or false indicating Link is UP or Down
163  *
164  * Once NTB function in HOST invoke ntb_link_enable(),
165  * this NTB function driver will trigger a link event to VHOST.
166  *
167  * Returns: Zero for success, or an error code in case of failure
168  */
epf_ntb_link_up(struct epf_ntb * ntb,bool link_up)169 static int epf_ntb_link_up(struct epf_ntb *ntb, bool link_up)
170 {
171 	if (link_up)
172 		ntb->reg->link_status |= LINK_STATUS_UP;
173 	else
174 		ntb->reg->link_status &= ~LINK_STATUS_UP;
175 
176 	ntb_link_event(&ntb->ntb);
177 	return 0;
178 }
179 
180 /**
181  * epf_ntb_configure_mw() - Configure the Outbound Address Space for VHOST
182  *   to access the memory window of HOST
183  * @ntb: NTB device that facilitates communication between HOST and VHOST
184  * @mw: Index of the memory window (either 0, 1, 2 or 3)
185  *
186  *                          EP Outbound Window
187  * +--------+              +-----------+
188  * |        |              |           |
189  * |        |              |           |
190  * |        |              |           |
191  * |        |              |           |
192  * |        |              +-----------+
193  * | Virtual|              | Memory Win|
194  * | NTB    | -----------> |           |
195  * | Driver |              |           |
196  * |        |              +-----------+
197  * |        |              |           |
198  * |        |              |           |
199  * +--------+              +-----------+
200  *  VHOST                   PCI EP
201  *
202  * Returns: Zero for success, or an error code in case of failure
203  */
epf_ntb_configure_mw(struct epf_ntb * ntb,u32 mw)204 static int epf_ntb_configure_mw(struct epf_ntb *ntb, u32 mw)
205 {
206 	phys_addr_t phys_addr;
207 	u8 func_no, vfunc_no;
208 	u64 addr, size;
209 	int ret = 0;
210 
211 	phys_addr = ntb->vpci_mw_phy[mw];
212 	addr = ntb->reg->addr;
213 	size = ntb->reg->size;
214 
215 	func_no = ntb->epf->func_no;
216 	vfunc_no = ntb->epf->vfunc_no;
217 
218 	ret = pci_epc_map_addr(ntb->epf->epc, func_no, vfunc_no, phys_addr, addr, size);
219 	if (ret)
220 		dev_err(&ntb->epf->epc->dev,
221 			"Failed to map memory window %d address\n", mw);
222 	return ret;
223 }
224 
225 /**
226  * epf_ntb_teardown_mw() - Teardown the configured OB ATU
227  * @ntb: NTB device that facilitates communication between HOST and VHOST
228  * @mw: Index of the memory window (either 0, 1, 2 or 3)
229  *
230  * Teardown the configured OB ATU configured in epf_ntb_configure_mw() using
231  * pci_epc_unmap_addr()
232  */
epf_ntb_teardown_mw(struct epf_ntb * ntb,u32 mw)233 static void epf_ntb_teardown_mw(struct epf_ntb *ntb, u32 mw)
234 {
235 	pci_epc_unmap_addr(ntb->epf->epc,
236 			   ntb->epf->func_no,
237 			   ntb->epf->vfunc_no,
238 			   ntb->vpci_mw_phy[mw]);
239 }
240 
241 /**
242  * epf_ntb_cmd_handler() - Handle commands provided by the NTB HOST
243  * @work: work_struct for the epf_ntb_epc
244  *
245  * Workqueue function that gets invoked for the two epf_ntb_epc
246  * periodically (once every 5ms) to see if it has received any commands
247  * from NTB HOST. The HOST can send commands to configure doorbell or
248  * configure memory window or to update link status.
249  */
epf_ntb_cmd_handler(struct work_struct * work)250 static void epf_ntb_cmd_handler(struct work_struct *work)
251 {
252 	struct epf_ntb_ctrl *ctrl;
253 	u32 command, argument;
254 	struct epf_ntb *ntb;
255 	struct device *dev;
256 	int ret;
257 	int i;
258 
259 	ntb = container_of(work, struct epf_ntb, cmd_handler.work);
260 
261 	for (i = 1; i < ntb->db_count; i++) {
262 		if (ntb->epf_db[i]) {
263 			ntb->db |= 1 << (i - 1);
264 			ntb_db_event(&ntb->ntb, i);
265 			ntb->epf_db[i] = 0;
266 		}
267 	}
268 
269 	ctrl = ntb->reg;
270 	command = ctrl->command;
271 	if (!command)
272 		goto reset_handler;
273 	argument = ctrl->argument;
274 
275 	ctrl->command = 0;
276 	ctrl->argument = 0;
277 
278 	ctrl = ntb->reg;
279 	dev = &ntb->epf->dev;
280 
281 	switch (command) {
282 	case COMMAND_CONFIGURE_DOORBELL:
283 		ctrl->command_status = COMMAND_STATUS_OK;
284 		break;
285 	case COMMAND_TEARDOWN_DOORBELL:
286 		ctrl->command_status = COMMAND_STATUS_OK;
287 		break;
288 	case COMMAND_CONFIGURE_MW:
289 		ret = epf_ntb_configure_mw(ntb, argument);
290 		if (ret < 0)
291 			ctrl->command_status = COMMAND_STATUS_ERROR;
292 		else
293 			ctrl->command_status = COMMAND_STATUS_OK;
294 		break;
295 	case COMMAND_TEARDOWN_MW:
296 		epf_ntb_teardown_mw(ntb, argument);
297 		ctrl->command_status = COMMAND_STATUS_OK;
298 		break;
299 	case COMMAND_LINK_UP:
300 		ntb->linkup = true;
301 		ret = epf_ntb_link_up(ntb, true);
302 		if (ret < 0)
303 			ctrl->command_status = COMMAND_STATUS_ERROR;
304 		else
305 			ctrl->command_status = COMMAND_STATUS_OK;
306 		goto reset_handler;
307 	case COMMAND_LINK_DOWN:
308 		ntb->linkup = false;
309 		ret = epf_ntb_link_up(ntb, false);
310 		if (ret < 0)
311 			ctrl->command_status = COMMAND_STATUS_ERROR;
312 		else
313 			ctrl->command_status = COMMAND_STATUS_OK;
314 		break;
315 	default:
316 		dev_err(dev, "UNKNOWN command: %d\n", command);
317 		break;
318 	}
319 
320 reset_handler:
321 	queue_delayed_work(kpcintb_workqueue, &ntb->cmd_handler,
322 			   msecs_to_jiffies(5));
323 }
324 
325 /**
326  * epf_ntb_config_sspad_bar_clear() - Clear Config + Self scratchpad BAR
327  * @ntb: EPC associated with one of the HOST which holds peer's outbound
328  *	 address.
329  *
330  * Clear BAR0 of EP CONTROLLER 1 which contains the HOST1's config and
331  * self scratchpad region (removes inbound ATU configuration). While BAR0 is
332  * the default self scratchpad BAR, an NTB could have other BARs for self
333  * scratchpad (because of reserved BARs). This function can get the exact BAR
334  * used for self scratchpad from epf_ntb_bar[BAR_CONFIG].
335  *
336  * Please note the self scratchpad region and config region is combined to
337  * a single region and mapped using the same BAR. Also note VHOST's peer
338  * scratchpad is HOST's self scratchpad.
339  *
340  * Returns: void
341  */
epf_ntb_config_sspad_bar_clear(struct epf_ntb * ntb)342 static void epf_ntb_config_sspad_bar_clear(struct epf_ntb *ntb)
343 {
344 	struct pci_epf_bar *epf_bar;
345 	enum pci_barno barno;
346 
347 	barno = ntb->epf_ntb_bar[BAR_CONFIG];
348 	epf_bar = &ntb->epf->bar[barno];
349 
350 	pci_epc_clear_bar(ntb->epf->epc, ntb->epf->func_no, ntb->epf->vfunc_no, epf_bar);
351 }
352 
353 /**
354  * epf_ntb_config_sspad_bar_set() - Set Config + Self scratchpad BAR
355  * @ntb: NTB device that facilitates communication between HOST and VHOST
356  *
357  * Map BAR0 of EP CONTROLLER which contains the VHOST's config and
358  * self scratchpad region.
359  *
360  * Please note the self scratchpad region and config region is combined to
361  * a single region and mapped using the same BAR.
362  *
363  * Returns: Zero for success, or an error code in case of failure
364  */
epf_ntb_config_sspad_bar_set(struct epf_ntb * ntb)365 static int epf_ntb_config_sspad_bar_set(struct epf_ntb *ntb)
366 {
367 	struct pci_epf_bar *epf_bar;
368 	enum pci_barno barno;
369 	u8 func_no, vfunc_no;
370 	struct device *dev;
371 	int ret;
372 
373 	dev = &ntb->epf->dev;
374 	func_no = ntb->epf->func_no;
375 	vfunc_no = ntb->epf->vfunc_no;
376 	barno = ntb->epf_ntb_bar[BAR_CONFIG];
377 	epf_bar = &ntb->epf->bar[barno];
378 
379 	ret = pci_epc_set_bar(ntb->epf->epc, func_no, vfunc_no, epf_bar);
380 	if (ret) {
381 		dev_err(dev, "inft: Config/Status/SPAD BAR set failed\n");
382 		return ret;
383 	}
384 	return 0;
385 }
386 
387 /**
388  * epf_ntb_config_spad_bar_free() - Free the physical memory associated with
389  *   config + scratchpad region
390  * @ntb: NTB device that facilitates communication between HOST and VHOST
391  */
epf_ntb_config_spad_bar_free(struct epf_ntb * ntb)392 static void epf_ntb_config_spad_bar_free(struct epf_ntb *ntb)
393 {
394 	enum pci_barno barno;
395 
396 	barno = ntb->epf_ntb_bar[BAR_CONFIG];
397 	pci_epf_free_space(ntb->epf, ntb->reg, barno, 0);
398 }
399 
400 /**
401  * epf_ntb_config_spad_bar_alloc() - Allocate memory for config + scratchpad
402  *   region
403  * @ntb: NTB device that facilitates communication between HOST and VHOST
404  *
405  * Allocate the Local Memory mentioned in the above diagram. The size of
406  * CONFIG REGION is sizeof(struct epf_ntb_ctrl) and size of SCRATCHPAD REGION
407  * is obtained from "spad-count" configfs entry.
408  *
409  * Returns: Zero for success, or an error code in case of failure
410  */
epf_ntb_config_spad_bar_alloc(struct epf_ntb * ntb)411 static int epf_ntb_config_spad_bar_alloc(struct epf_ntb *ntb)
412 {
413 	enum pci_barno barno;
414 	struct epf_ntb_ctrl *ctrl;
415 	u32 spad_size, ctrl_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 	spad_count = ntb->spad_count;
426 
427 	ctrl_size = ALIGN(sizeof(struct epf_ntb_ctrl), sizeof(u32));
428 	spad_size = 2 * spad_count * sizeof(u32);
429 
430 	base = pci_epf_alloc_space(epf, ctrl_size + spad_size,
431 				   barno, epc_features, 0);
432 	if (!base) {
433 		dev_err(dev, "Config/Status/SPAD alloc region fail\n");
434 		return -ENOMEM;
435 	}
436 
437 	ntb->reg = base;
438 
439 	ctrl = ntb->reg;
440 	ctrl->spad_offset = ctrl_size;
441 
442 	ctrl->spad_count = spad_count;
443 	ctrl->num_mws = ntb->num_mws;
444 	ntb->spad_size = spad_size;
445 
446 	ctrl->db_entry_size = sizeof(u32);
447 
448 	for (i = 0; i < ntb->db_count; i++) {
449 		ntb->reg->db_data[i] = 1 + i;
450 		ntb->reg->db_offset[i] = 0;
451 	}
452 
453 	return 0;
454 }
455 
456 /**
457  * epf_ntb_configure_interrupt() - Configure MSI/MSI-X capability
458  * @ntb: NTB device that facilitates communication between HOST and VHOST
459  *
460  * Configure MSI/MSI-X capability for each interface with number of
461  * interrupts equal to "db_count" configfs entry.
462  *
463  * Returns: Zero for success, or an error code in case of failure
464  */
epf_ntb_configure_interrupt(struct epf_ntb * ntb)465 static int epf_ntb_configure_interrupt(struct epf_ntb *ntb)
466 {
467 	const struct pci_epc_features *epc_features;
468 	struct device *dev;
469 	u32 db_count;
470 	int ret;
471 
472 	dev = &ntb->epf->dev;
473 
474 	epc_features = pci_epc_get_features(ntb->epf->epc, ntb->epf->func_no, ntb->epf->vfunc_no);
475 
476 	if (!(epc_features->msix_capable || epc_features->msi_capable)) {
477 		dev_err(dev, "MSI or MSI-X is required for doorbell\n");
478 		return -EINVAL;
479 	}
480 
481 	db_count = ntb->db_count;
482 	if (db_count > MAX_DB_COUNT) {
483 		dev_err(dev, "DB count cannot be more than %d\n", MAX_DB_COUNT);
484 		return -EINVAL;
485 	}
486 
487 	ntb->db_count = db_count;
488 
489 	if (epc_features->msi_capable) {
490 		ret = pci_epc_set_msi(ntb->epf->epc,
491 				      ntb->epf->func_no,
492 				      ntb->epf->vfunc_no,
493 				      16);
494 		if (ret) {
495 			dev_err(dev, "MSI configuration failed\n");
496 			return ret;
497 		}
498 	}
499 
500 	return 0;
501 }
502 
503 /**
504  * epf_ntb_db_bar_init() - Configure Doorbell window BARs
505  * @ntb: NTB device that facilitates communication between HOST and VHOST
506  *
507  * Returns: Zero for success, or an error code in case of failure
508  */
epf_ntb_db_bar_init(struct epf_ntb * ntb)509 static int epf_ntb_db_bar_init(struct epf_ntb *ntb)
510 {
511 	const struct pci_epc_features *epc_features;
512 	struct device *dev = &ntb->epf->dev;
513 	int ret;
514 	struct pci_epf_bar *epf_bar;
515 	void *mw_addr;
516 	enum pci_barno barno;
517 	size_t size = sizeof(u32) * ntb->db_count;
518 
519 	epc_features = pci_epc_get_features(ntb->epf->epc,
520 					    ntb->epf->func_no,
521 					    ntb->epf->vfunc_no);
522 	barno = ntb->epf_ntb_bar[BAR_DB];
523 
524 	mw_addr = pci_epf_alloc_space(ntb->epf, size, barno, epc_features, 0);
525 	if (!mw_addr) {
526 		dev_err(dev, "Failed to allocate OB address\n");
527 		return -ENOMEM;
528 	}
529 
530 	ntb->epf_db = mw_addr;
531 
532 	epf_bar = &ntb->epf->bar[barno];
533 
534 	ret = pci_epc_set_bar(ntb->epf->epc, ntb->epf->func_no, ntb->epf->vfunc_no, epf_bar);
535 	if (ret) {
536 		dev_err(dev, "Doorbell BAR set failed\n");
537 			goto err_alloc_peer_mem;
538 	}
539 	return ret;
540 
541 err_alloc_peer_mem:
542 	pci_epf_free_space(ntb->epf, mw_addr, barno, 0);
543 	return -1;
544 }
545 
546 static void epf_ntb_mw_bar_clear(struct epf_ntb *ntb, int num_mws);
547 
548 /**
549  * epf_ntb_db_bar_clear() - Clear doorbell BAR and free memory
550  *   allocated in peer's outbound address space
551  * @ntb: NTB device that facilitates communication between HOST and VHOST
552  */
epf_ntb_db_bar_clear(struct epf_ntb * ntb)553 static void epf_ntb_db_bar_clear(struct epf_ntb *ntb)
554 {
555 	enum pci_barno barno;
556 
557 	barno = ntb->epf_ntb_bar[BAR_DB];
558 	pci_epf_free_space(ntb->epf, ntb->epf_db, barno, 0);
559 	pci_epc_clear_bar(ntb->epf->epc,
560 			  ntb->epf->func_no,
561 			  ntb->epf->vfunc_no,
562 			  &ntb->epf->bar[barno]);
563 }
564 
565 /**
566  * epf_ntb_mw_bar_init() - Configure Memory window BARs
567  * @ntb: NTB device that facilitates communication between HOST and VHOST
568  *
569  * Returns: Zero for success, or an error code in case of failure
570  */
epf_ntb_mw_bar_init(struct epf_ntb * ntb)571 static int epf_ntb_mw_bar_init(struct epf_ntb *ntb)
572 {
573 	int ret = 0;
574 	int i;
575 	u64 size;
576 	enum pci_barno barno;
577 	struct device *dev = &ntb->epf->dev;
578 
579 	for (i = 0; i < ntb->num_mws; i++) {
580 		size = ntb->mws_size[i];
581 		barno = ntb->epf_ntb_bar[BAR_MW1 + i];
582 
583 		ntb->epf->bar[barno].barno = barno;
584 		ntb->epf->bar[barno].size = size;
585 		ntb->epf->bar[barno].addr = NULL;
586 		ntb->epf->bar[barno].phys_addr = 0;
587 		ntb->epf->bar[barno].flags |= upper_32_bits(size) ?
588 				PCI_BASE_ADDRESS_MEM_TYPE_64 :
589 				PCI_BASE_ADDRESS_MEM_TYPE_32;
590 
591 		ret = pci_epc_set_bar(ntb->epf->epc,
592 				      ntb->epf->func_no,
593 				      ntb->epf->vfunc_no,
594 				      &ntb->epf->bar[barno]);
595 		if (ret) {
596 			dev_err(dev, "MW set failed\n");
597 			goto err_alloc_mem;
598 		}
599 
600 		/* Allocate EPC outbound memory windows to vpci vntb device */
601 		ntb->vpci_mw_addr[i] = pci_epc_mem_alloc_addr(ntb->epf->epc,
602 							      &ntb->vpci_mw_phy[i],
603 							      size);
604 		if (!ntb->vpci_mw_addr[i]) {
605 			ret = -ENOMEM;
606 			dev_err(dev, "Failed to allocate source address\n");
607 			goto err_set_bar;
608 		}
609 	}
610 
611 	return ret;
612 
613 err_set_bar:
614 	pci_epc_clear_bar(ntb->epf->epc,
615 			  ntb->epf->func_no,
616 			  ntb->epf->vfunc_no,
617 			  &ntb->epf->bar[barno]);
618 err_alloc_mem:
619 	epf_ntb_mw_bar_clear(ntb, i);
620 	return ret;
621 }
622 
623 /**
624  * epf_ntb_mw_bar_clear() - Clear Memory window BARs
625  * @ntb: NTB device that facilitates communication between HOST and VHOST
626  * @num_mws: the number of Memory window BARs that to be cleared
627  */
epf_ntb_mw_bar_clear(struct epf_ntb * ntb,int num_mws)628 static void epf_ntb_mw_bar_clear(struct epf_ntb *ntb, int num_mws)
629 {
630 	enum pci_barno barno;
631 	int i;
632 
633 	for (i = 0; i < num_mws; i++) {
634 		barno = ntb->epf_ntb_bar[BAR_MW1 + i];
635 		pci_epc_clear_bar(ntb->epf->epc,
636 				  ntb->epf->func_no,
637 				  ntb->epf->vfunc_no,
638 				  &ntb->epf->bar[barno]);
639 
640 		pci_epc_mem_free_addr(ntb->epf->epc,
641 				      ntb->vpci_mw_phy[i],
642 				      ntb->vpci_mw_addr[i],
643 				      ntb->mws_size[i]);
644 	}
645 }
646 
647 /**
648  * epf_ntb_epc_destroy() - Cleanup NTB EPC interface
649  * @ntb: NTB device that facilitates communication between HOST and VHOST
650  *
651  * Wrapper for epf_ntb_epc_destroy_interface() to cleanup all the NTB interfaces
652  */
epf_ntb_epc_destroy(struct epf_ntb * ntb)653 static void epf_ntb_epc_destroy(struct epf_ntb *ntb)
654 {
655 	pci_epc_remove_epf(ntb->epf->epc, ntb->epf, 0);
656 	pci_epc_put(ntb->epf->epc);
657 }
658 
659 
660 /**
661  * epf_ntb_is_bar_used() - Check if a bar is used in the ntb configuration
662  * @ntb: NTB device that facilitates communication between HOST and VHOST
663  * @barno: Checked bar number
664  *
665  * Returns: true if used, false if free.
666  */
epf_ntb_is_bar_used(struct epf_ntb * ntb,enum pci_barno barno)667 static bool epf_ntb_is_bar_used(struct epf_ntb *ntb,
668 				enum pci_barno barno)
669 {
670 	int i;
671 
672 	for (i = 0; i < VNTB_BAR_NUM; i++) {
673 		if (ntb->epf_ntb_bar[i] == barno)
674 			return true;
675 	}
676 
677 	return false;
678 }
679 
680 /**
681  * epf_ntb_find_bar() - Assign BAR number when no configuration is provided
682  * @ntb: NTB device that facilitates communication between HOST and VHOST
683  * @epc_features: The features provided by the EPC specific to this EPF
684  * @bar: NTB BAR index
685  * @barno: Bar start index
686  *
687  * When the BAR configuration was not provided through the userspace
688  * configuration, automatically assign BAR as it has been historically
689  * done by this endpoint function.
690  *
691  * Returns: the BAR number found, if any. -1 otherwise
692  */
epf_ntb_find_bar(struct epf_ntb * ntb,const struct pci_epc_features * epc_features,enum epf_ntb_bar bar,enum pci_barno barno)693 static int epf_ntb_find_bar(struct epf_ntb *ntb,
694 			    const struct pci_epc_features *epc_features,
695 			    enum epf_ntb_bar bar,
696 			    enum pci_barno barno)
697 {
698 	while (ntb->epf_ntb_bar[bar] < 0) {
699 		barno = pci_epc_get_next_free_bar(epc_features, barno);
700 		if (barno < 0)
701 			break; /* No more BAR available */
702 
703 		/*
704 		 * Verify if the BAR found is not already assigned
705 		 * through the provided configuration
706 		 */
707 		if (!epf_ntb_is_bar_used(ntb, barno))
708 			ntb->epf_ntb_bar[bar] = barno;
709 
710 		barno += 1;
711 	}
712 
713 	return barno;
714 }
715 
716 /**
717  * epf_ntb_init_epc_bar() - Identify BARs to be used for each of the NTB
718  * constructs (scratchpad region, doorbell, memorywindow)
719  * @ntb: NTB device that facilitates communication between HOST and VHOST
720  *
721  * Returns: Zero for success, or an error code in case of failure
722  */
epf_ntb_init_epc_bar(struct epf_ntb * ntb)723 static int epf_ntb_init_epc_bar(struct epf_ntb *ntb)
724 {
725 	const struct pci_epc_features *epc_features;
726 	enum pci_barno barno;
727 	enum epf_ntb_bar bar;
728 	struct device *dev;
729 	u32 num_mws;
730 	int i;
731 
732 	barno = BAR_0;
733 	num_mws = ntb->num_mws;
734 	dev = &ntb->epf->dev;
735 	epc_features = pci_epc_get_features(ntb->epf->epc, ntb->epf->func_no, ntb->epf->vfunc_no);
736 
737 	/* These are required BARs which are mandatory for NTB functionality */
738 	for (bar = BAR_CONFIG; bar <= BAR_MW1; bar++) {
739 		barno = epf_ntb_find_bar(ntb, epc_features, bar, barno);
740 		if (barno < 0) {
741 			dev_err(dev, "Fail to get NTB function BAR\n");
742 			return -ENOENT;
743 		}
744 	}
745 
746 	/* These are optional BARs which don't impact NTB functionality */
747 	for (bar = BAR_MW1, i = 1; i < num_mws; bar++, i++) {
748 		barno = epf_ntb_find_bar(ntb, epc_features, bar, barno);
749 		if (barno < 0) {
750 			ntb->num_mws = i;
751 			dev_dbg(dev, "BAR not available for > MW%d\n", i + 1);
752 		}
753 	}
754 
755 	return 0;
756 }
757 
758 /**
759  * epf_ntb_epc_init() - Initialize NTB interface
760  * @ntb: NTB device that facilitates communication between HOST and VHOST
761  *
762  * Wrapper to initialize a particular EPC interface and start the workqueue
763  * to check for commands from HOST. This function will write to the
764  * EP controller HW for configuring it.
765  *
766  * Returns: Zero for success, or an error code in case of failure
767  */
epf_ntb_epc_init(struct epf_ntb * ntb)768 static int epf_ntb_epc_init(struct epf_ntb *ntb)
769 {
770 	u8 func_no, vfunc_no;
771 	struct pci_epc *epc;
772 	struct pci_epf *epf;
773 	struct device *dev;
774 	int ret;
775 
776 	epf = ntb->epf;
777 	dev = &epf->dev;
778 	epc = epf->epc;
779 	func_no = ntb->epf->func_no;
780 	vfunc_no = ntb->epf->vfunc_no;
781 
782 	ret = epf_ntb_config_sspad_bar_set(ntb);
783 	if (ret) {
784 		dev_err(dev, "Config/self SPAD BAR init failed");
785 		return ret;
786 	}
787 
788 	ret = epf_ntb_configure_interrupt(ntb);
789 	if (ret) {
790 		dev_err(dev, "Interrupt configuration failed\n");
791 		goto err_config_interrupt;
792 	}
793 
794 	ret = epf_ntb_db_bar_init(ntb);
795 	if (ret) {
796 		dev_err(dev, "DB BAR init failed\n");
797 		goto err_db_bar_init;
798 	}
799 
800 	ret = epf_ntb_mw_bar_init(ntb);
801 	if (ret) {
802 		dev_err(dev, "MW BAR init failed\n");
803 		goto err_mw_bar_init;
804 	}
805 
806 	if (vfunc_no <= 1) {
807 		ret = pci_epc_write_header(epc, func_no, vfunc_no, epf->header);
808 		if (ret) {
809 			dev_err(dev, "Configuration header write failed\n");
810 			goto err_write_header;
811 		}
812 	}
813 
814 	INIT_DELAYED_WORK(&ntb->cmd_handler, epf_ntb_cmd_handler);
815 	queue_work(kpcintb_workqueue, &ntb->cmd_handler.work);
816 
817 	return 0;
818 
819 err_write_header:
820 	epf_ntb_mw_bar_clear(ntb, ntb->num_mws);
821 err_mw_bar_init:
822 	epf_ntb_db_bar_clear(ntb);
823 err_db_bar_init:
824 err_config_interrupt:
825 	epf_ntb_config_sspad_bar_clear(ntb);
826 
827 	return ret;
828 }
829 
830 
831 /**
832  * epf_ntb_epc_cleanup() - Cleanup all NTB interfaces
833  * @ntb: NTB device that facilitates communication between HOST and VHOST
834  *
835  * Wrapper to cleanup all NTB interfaces.
836  */
epf_ntb_epc_cleanup(struct epf_ntb * ntb)837 static void epf_ntb_epc_cleanup(struct epf_ntb *ntb)
838 {
839 	epf_ntb_mw_bar_clear(ntb, ntb->num_mws);
840 	epf_ntb_db_bar_clear(ntb);
841 	epf_ntb_config_sspad_bar_clear(ntb);
842 }
843 
844 #define EPF_NTB_R(_name)						\
845 static ssize_t epf_ntb_##_name##_show(struct config_item *item,		\
846 				      char *page)			\
847 {									\
848 	struct config_group *group = to_config_group(item);		\
849 	struct epf_ntb *ntb = to_epf_ntb(group);			\
850 									\
851 	return sprintf(page, "%d\n", ntb->_name);			\
852 }
853 
854 #define EPF_NTB_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 	u32 val;							\
861 	int ret;							\
862 									\
863 	ret = kstrtou32(page, 0, &val);					\
864 	if (ret)							\
865 		return ret;						\
866 									\
867 	ntb->_name = val;						\
868 									\
869 	return len;							\
870 }
871 
872 #define EPF_NTB_MW_R(_name)						\
873 static ssize_t epf_ntb_##_name##_show(struct config_item *item,		\
874 				      char *page)			\
875 {									\
876 	struct config_group *group = to_config_group(item);		\
877 	struct epf_ntb *ntb = to_epf_ntb(group);			\
878 	struct device *dev = &ntb->epf->dev;				\
879 	int win_no;							\
880 									\
881 	if (sscanf(#_name, "mw%d", &win_no) != 1)			\
882 		return -EINVAL;						\
883 									\
884 	if (win_no <= 0 || win_no > ntb->num_mws) {			\
885 		dev_err(dev, "Invalid num_nws: %d value\n", ntb->num_mws); \
886 		return -EINVAL;						\
887 	}								\
888 									\
889 	return sprintf(page, "%lld\n", ntb->mws_size[win_no - 1]);	\
890 }
891 
892 #define EPF_NTB_MW_W(_name)						\
893 static ssize_t epf_ntb_##_name##_store(struct config_item *item,	\
894 				       const char *page, size_t len)	\
895 {									\
896 	struct config_group *group = to_config_group(item);		\
897 	struct epf_ntb *ntb = to_epf_ntb(group);			\
898 	struct device *dev = &ntb->epf->dev;				\
899 	int win_no;							\
900 	u64 val;							\
901 	int ret;							\
902 									\
903 	ret = kstrtou64(page, 0, &val);					\
904 	if (ret)							\
905 		return ret;						\
906 									\
907 	if (sscanf(#_name, "mw%d", &win_no) != 1)			\
908 		return -EINVAL;						\
909 									\
910 	if (win_no <= 0 || win_no > ntb->num_mws) {			\
911 		dev_err(dev, "Invalid num_nws: %d value\n", ntb->num_mws); \
912 		return -EINVAL;						\
913 	}								\
914 									\
915 	ntb->mws_size[win_no - 1] = val;				\
916 									\
917 	return len;							\
918 }
919 
920 #define EPF_NTB_BAR_R(_name, _id)					\
921 	static ssize_t epf_ntb_##_name##_show(struct config_item *item,	\
922 					      char *page)		\
923 	{								\
924 		struct config_group *group = to_config_group(item);	\
925 		struct epf_ntb *ntb = to_epf_ntb(group);		\
926 									\
927 		return sprintf(page, "%d\n", ntb->epf_ntb_bar[_id]);	\
928 	}
929 
930 #define EPF_NTB_BAR_W(_name, _id)					\
931 	static ssize_t epf_ntb_##_name##_store(struct config_item *item, \
932 					       const char *page, size_t len) \
933 	{								\
934 		struct config_group *group = to_config_group(item);	\
935 		struct epf_ntb *ntb = to_epf_ntb(group);		\
936 		int val;						\
937 		int ret;						\
938 									\
939 		ret = kstrtoint(page, 0, &val);				\
940 		if (ret)						\
941 			return ret;					\
942 									\
943 		if (val < NO_BAR || val > BAR_5)			\
944 			return -EINVAL;					\
945 									\
946 		ntb->epf_ntb_bar[_id] = val;				\
947 									\
948 		return len;						\
949 	}
950 
epf_ntb_num_mws_store(struct config_item * item,const char * page,size_t len)951 static ssize_t epf_ntb_num_mws_store(struct config_item *item,
952 				     const char *page, size_t len)
953 {
954 	struct config_group *group = to_config_group(item);
955 	struct epf_ntb *ntb = to_epf_ntb(group);
956 	u32 val;
957 	int ret;
958 
959 	ret = kstrtou32(page, 0, &val);
960 	if (ret)
961 		return ret;
962 
963 	if (val > MAX_MW)
964 		return -EINVAL;
965 
966 	ntb->num_mws = val;
967 
968 	return len;
969 }
970 
971 EPF_NTB_R(spad_count)
972 EPF_NTB_W(spad_count)
973 EPF_NTB_R(db_count)
974 EPF_NTB_W(db_count)
975 EPF_NTB_R(num_mws)
976 EPF_NTB_R(vbus_number)
977 EPF_NTB_W(vbus_number)
978 EPF_NTB_R(vntb_pid)
979 EPF_NTB_W(vntb_pid)
980 EPF_NTB_R(vntb_vid)
981 EPF_NTB_W(vntb_vid)
982 EPF_NTB_MW_R(mw1)
983 EPF_NTB_MW_W(mw1)
984 EPF_NTB_MW_R(mw2)
985 EPF_NTB_MW_W(mw2)
986 EPF_NTB_MW_R(mw3)
987 EPF_NTB_MW_W(mw3)
988 EPF_NTB_MW_R(mw4)
989 EPF_NTB_MW_W(mw4)
990 EPF_NTB_BAR_R(ctrl_bar, BAR_CONFIG)
991 EPF_NTB_BAR_W(ctrl_bar, BAR_CONFIG)
992 EPF_NTB_BAR_R(db_bar, BAR_DB)
993 EPF_NTB_BAR_W(db_bar, BAR_DB)
994 EPF_NTB_BAR_R(mw1_bar, BAR_MW1)
995 EPF_NTB_BAR_W(mw1_bar, BAR_MW1)
996 EPF_NTB_BAR_R(mw2_bar, BAR_MW2)
997 EPF_NTB_BAR_W(mw2_bar, BAR_MW2)
998 EPF_NTB_BAR_R(mw3_bar, BAR_MW3)
999 EPF_NTB_BAR_W(mw3_bar, BAR_MW3)
1000 EPF_NTB_BAR_R(mw4_bar, BAR_MW4)
1001 EPF_NTB_BAR_W(mw4_bar, BAR_MW4)
1002 
1003 CONFIGFS_ATTR(epf_ntb_, spad_count);
1004 CONFIGFS_ATTR(epf_ntb_, db_count);
1005 CONFIGFS_ATTR(epf_ntb_, num_mws);
1006 CONFIGFS_ATTR(epf_ntb_, mw1);
1007 CONFIGFS_ATTR(epf_ntb_, mw2);
1008 CONFIGFS_ATTR(epf_ntb_, mw3);
1009 CONFIGFS_ATTR(epf_ntb_, mw4);
1010 CONFIGFS_ATTR(epf_ntb_, vbus_number);
1011 CONFIGFS_ATTR(epf_ntb_, vntb_pid);
1012 CONFIGFS_ATTR(epf_ntb_, vntb_vid);
1013 CONFIGFS_ATTR(epf_ntb_, ctrl_bar);
1014 CONFIGFS_ATTR(epf_ntb_, db_bar);
1015 CONFIGFS_ATTR(epf_ntb_, mw1_bar);
1016 CONFIGFS_ATTR(epf_ntb_, mw2_bar);
1017 CONFIGFS_ATTR(epf_ntb_, mw3_bar);
1018 CONFIGFS_ATTR(epf_ntb_, mw4_bar);
1019 
1020 static struct configfs_attribute *epf_ntb_attrs[] = {
1021 	&epf_ntb_attr_spad_count,
1022 	&epf_ntb_attr_db_count,
1023 	&epf_ntb_attr_num_mws,
1024 	&epf_ntb_attr_mw1,
1025 	&epf_ntb_attr_mw2,
1026 	&epf_ntb_attr_mw3,
1027 	&epf_ntb_attr_mw4,
1028 	&epf_ntb_attr_vbus_number,
1029 	&epf_ntb_attr_vntb_pid,
1030 	&epf_ntb_attr_vntb_vid,
1031 	&epf_ntb_attr_ctrl_bar,
1032 	&epf_ntb_attr_db_bar,
1033 	&epf_ntb_attr_mw1_bar,
1034 	&epf_ntb_attr_mw2_bar,
1035 	&epf_ntb_attr_mw3_bar,
1036 	&epf_ntb_attr_mw4_bar,
1037 	NULL,
1038 };
1039 
1040 static const struct config_item_type ntb_group_type = {
1041 	.ct_attrs	= epf_ntb_attrs,
1042 	.ct_owner	= THIS_MODULE,
1043 };
1044 
1045 /**
1046  * epf_ntb_add_cfs() - Add configfs directory specific to NTB
1047  * @epf: NTB endpoint function device
1048  * @group: A pointer to the config_group structure referencing a group of
1049  *	   config_items of a specific type that belong to a specific sub-system.
1050  *
1051  * Add configfs directory specific to NTB. This directory will hold
1052  * NTB specific properties like db_count, spad_count, num_mws etc.,
1053  *
1054  * Returns: Pointer to config_group
1055  */
epf_ntb_add_cfs(struct pci_epf * epf,struct config_group * group)1056 static struct config_group *epf_ntb_add_cfs(struct pci_epf *epf,
1057 					    struct config_group *group)
1058 {
1059 	struct epf_ntb *ntb = epf_get_drvdata(epf);
1060 	struct config_group *ntb_group = &ntb->group;
1061 	struct device *dev = &epf->dev;
1062 
1063 	config_group_init_type_name(ntb_group, dev_name(dev), &ntb_group_type);
1064 
1065 	return ntb_group;
1066 }
1067 
1068 /*==== virtual PCI bus driver, which only load virtual NTB PCI driver ====*/
1069 
1070 static u32 pci_space[] = {
1071 	0xffffffff,	/* Device ID, Vendor ID */
1072 	0,		/* Status, Command */
1073 	0xffffffff,	/* Base Class, Subclass, Prog Intf, Revision ID */
1074 	0x40,		/* BIST, Header Type, Latency Timer, Cache Line Size */
1075 	0,		/* BAR 0 */
1076 	0,		/* BAR 1 */
1077 	0,		/* BAR 2 */
1078 	0,		/* BAR 3 */
1079 	0,		/* BAR 4 */
1080 	0,		/* BAR 5 */
1081 	0,		/* Cardbus CIS Pointer */
1082 	0,		/* Subsystem ID, Subsystem Vendor ID */
1083 	0,		/* ROM Base Address */
1084 	0,		/* Reserved, Capabilities Pointer */
1085 	0,		/* Reserved */
1086 	0,		/* Max_Lat, Min_Gnt, Interrupt Pin, Interrupt Line */
1087 };
1088 
pci_read(struct pci_bus * bus,unsigned int devfn,int where,int size,u32 * val)1089 static int pci_read(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *val)
1090 {
1091 	if (devfn == 0) {
1092 		memcpy(val, ((u8 *)pci_space) + where, size);
1093 		return PCIBIOS_SUCCESSFUL;
1094 	}
1095 	return PCIBIOS_DEVICE_NOT_FOUND;
1096 }
1097 
pci_write(struct pci_bus * bus,unsigned int devfn,int where,int size,u32 val)1098 static int pci_write(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 val)
1099 {
1100 	return 0;
1101 }
1102 
1103 static struct pci_ops vpci_ops = {
1104 	.read = pci_read,
1105 	.write = pci_write,
1106 };
1107 
vpci_scan_bus(void * sysdata)1108 static int vpci_scan_bus(void *sysdata)
1109 {
1110 	struct pci_bus *vpci_bus;
1111 	struct epf_ntb *ndev = sysdata;
1112 
1113 	vpci_bus = pci_scan_bus(ndev->vbus_number, &vpci_ops, sysdata);
1114 	if (!vpci_bus) {
1115 		pr_err("create pci bus failed\n");
1116 		return -EINVAL;
1117 	}
1118 
1119 	pci_bus_add_devices(vpci_bus);
1120 
1121 	return 0;
1122 }
1123 
1124 /*==================== Virtual PCIe NTB driver ==========================*/
1125 
vntb_epf_mw_count(struct ntb_dev * ntb,int pidx)1126 static int vntb_epf_mw_count(struct ntb_dev *ntb, int pidx)
1127 {
1128 	struct epf_ntb *ndev = ntb_ndev(ntb);
1129 
1130 	return ndev->num_mws;
1131 }
1132 
vntb_epf_spad_count(struct ntb_dev * ntb)1133 static int vntb_epf_spad_count(struct ntb_dev *ntb)
1134 {
1135 	return ntb_ndev(ntb)->spad_count;
1136 }
1137 
vntb_epf_peer_mw_count(struct ntb_dev * ntb)1138 static int vntb_epf_peer_mw_count(struct ntb_dev *ntb)
1139 {
1140 	return ntb_ndev(ntb)->num_mws;
1141 }
1142 
vntb_epf_db_valid_mask(struct ntb_dev * ntb)1143 static u64 vntb_epf_db_valid_mask(struct ntb_dev *ntb)
1144 {
1145 	return BIT_ULL(ntb_ndev(ntb)->db_count) - 1;
1146 }
1147 
vntb_epf_db_set_mask(struct ntb_dev * ntb,u64 db_bits)1148 static int vntb_epf_db_set_mask(struct ntb_dev *ntb, u64 db_bits)
1149 {
1150 	return 0;
1151 }
1152 
vntb_epf_mw_set_trans(struct ntb_dev * ndev,int pidx,int idx,dma_addr_t addr,resource_size_t size)1153 static int vntb_epf_mw_set_trans(struct ntb_dev *ndev, int pidx, int idx,
1154 		dma_addr_t addr, resource_size_t size)
1155 {
1156 	struct epf_ntb *ntb = ntb_ndev(ndev);
1157 	struct pci_epf_bar *epf_bar;
1158 	enum pci_barno barno;
1159 	int ret;
1160 	struct device *dev;
1161 
1162 	dev = &ntb->ntb.dev;
1163 	barno = ntb->epf_ntb_bar[BAR_MW1 + idx];
1164 	epf_bar = &ntb->epf->bar[barno];
1165 	epf_bar->phys_addr = addr;
1166 	epf_bar->barno = barno;
1167 	epf_bar->size = size;
1168 
1169 	ret = pci_epc_set_bar(ntb->epf->epc, 0, 0, epf_bar);
1170 	if (ret) {
1171 		dev_err(dev, "failure set mw trans\n");
1172 		return ret;
1173 	}
1174 	return 0;
1175 }
1176 
vntb_epf_mw_clear_trans(struct ntb_dev * ntb,int pidx,int idx)1177 static int vntb_epf_mw_clear_trans(struct ntb_dev *ntb, int pidx, int idx)
1178 {
1179 	return 0;
1180 }
1181 
vntb_epf_peer_mw_get_addr(struct ntb_dev * ndev,int idx,phys_addr_t * base,resource_size_t * size)1182 static int vntb_epf_peer_mw_get_addr(struct ntb_dev *ndev, int idx,
1183 				phys_addr_t *base, resource_size_t *size)
1184 {
1185 
1186 	struct epf_ntb *ntb = ntb_ndev(ndev);
1187 
1188 	if (base)
1189 		*base = ntb->vpci_mw_phy[idx];
1190 
1191 	if (size)
1192 		*size = ntb->mws_size[idx];
1193 
1194 	return 0;
1195 }
1196 
vntb_epf_link_enable(struct ntb_dev * ntb,enum ntb_speed max_speed,enum ntb_width max_width)1197 static int vntb_epf_link_enable(struct ntb_dev *ntb,
1198 			enum ntb_speed max_speed,
1199 			enum ntb_width max_width)
1200 {
1201 	return 0;
1202 }
1203 
vntb_epf_spad_read(struct ntb_dev * ndev,int idx)1204 static u32 vntb_epf_spad_read(struct ntb_dev *ndev, int idx)
1205 {
1206 	struct epf_ntb *ntb = ntb_ndev(ndev);
1207 	int off = ntb->reg->spad_offset, ct = ntb->reg->spad_count * sizeof(u32);
1208 	u32 val;
1209 	void __iomem *base = (void __iomem *)ntb->reg;
1210 
1211 	val = readl(base + off + ct + idx * sizeof(u32));
1212 	return val;
1213 }
1214 
vntb_epf_spad_write(struct ntb_dev * ndev,int idx,u32 val)1215 static int vntb_epf_spad_write(struct ntb_dev *ndev, int idx, u32 val)
1216 {
1217 	struct epf_ntb *ntb = ntb_ndev(ndev);
1218 	struct epf_ntb_ctrl *ctrl = ntb->reg;
1219 	int off = ctrl->spad_offset, ct = ctrl->spad_count * sizeof(u32);
1220 	void __iomem *base = (void __iomem *)ntb->reg;
1221 
1222 	writel(val, base + off + ct + idx * sizeof(u32));
1223 	return 0;
1224 }
1225 
vntb_epf_peer_spad_read(struct ntb_dev * ndev,int pidx,int idx)1226 static u32 vntb_epf_peer_spad_read(struct ntb_dev *ndev, int pidx, int idx)
1227 {
1228 	struct epf_ntb *ntb = ntb_ndev(ndev);
1229 	struct epf_ntb_ctrl *ctrl = ntb->reg;
1230 	int off = ctrl->spad_offset;
1231 	void __iomem *base = (void __iomem *)ntb->reg;
1232 	u32 val;
1233 
1234 	val = readl(base + off + idx * sizeof(u32));
1235 	return val;
1236 }
1237 
vntb_epf_peer_spad_write(struct ntb_dev * ndev,int pidx,int idx,u32 val)1238 static int vntb_epf_peer_spad_write(struct ntb_dev *ndev, int pidx, int idx, u32 val)
1239 {
1240 	struct epf_ntb *ntb = ntb_ndev(ndev);
1241 	struct epf_ntb_ctrl *ctrl = ntb->reg;
1242 	int off = ctrl->spad_offset;
1243 	void __iomem *base = (void __iomem *)ntb->reg;
1244 
1245 	writel(val, base + off + idx * sizeof(u32));
1246 	return 0;
1247 }
1248 
vntb_epf_peer_db_set(struct ntb_dev * ndev,u64 db_bits)1249 static int vntb_epf_peer_db_set(struct ntb_dev *ndev, u64 db_bits)
1250 {
1251 	u32 interrupt_num = ffs(db_bits) + 1;
1252 	struct epf_ntb *ntb = ntb_ndev(ndev);
1253 	u8 func_no, vfunc_no;
1254 	int ret;
1255 
1256 	func_no = ntb->epf->func_no;
1257 	vfunc_no = ntb->epf->vfunc_no;
1258 
1259 	ret = pci_epc_raise_irq(ntb->epf->epc, func_no, vfunc_no,
1260 				PCI_IRQ_MSI, interrupt_num + 1);
1261 	if (ret)
1262 		dev_err(&ntb->ntb.dev, "Failed to raise IRQ\n");
1263 
1264 	return ret;
1265 }
1266 
vntb_epf_db_read(struct ntb_dev * ndev)1267 static u64 vntb_epf_db_read(struct ntb_dev *ndev)
1268 {
1269 	struct epf_ntb *ntb = ntb_ndev(ndev);
1270 
1271 	return ntb->db;
1272 }
1273 
vntb_epf_mw_get_align(struct ntb_dev * ndev,int pidx,int idx,resource_size_t * addr_align,resource_size_t * size_align,resource_size_t * size_max)1274 static int vntb_epf_mw_get_align(struct ntb_dev *ndev, int pidx, int idx,
1275 			resource_size_t *addr_align,
1276 			resource_size_t *size_align,
1277 			resource_size_t *size_max)
1278 {
1279 	struct epf_ntb *ntb = ntb_ndev(ndev);
1280 
1281 	if (addr_align)
1282 		*addr_align = SZ_4K;
1283 
1284 	if (size_align)
1285 		*size_align = 1;
1286 
1287 	if (size_max)
1288 		*size_max = ntb->mws_size[idx];
1289 
1290 	return 0;
1291 }
1292 
vntb_epf_link_is_up(struct ntb_dev * ndev,enum ntb_speed * speed,enum ntb_width * width)1293 static u64 vntb_epf_link_is_up(struct ntb_dev *ndev,
1294 			enum ntb_speed *speed,
1295 			enum ntb_width *width)
1296 {
1297 	struct epf_ntb *ntb = ntb_ndev(ndev);
1298 
1299 	return ntb->reg->link_status;
1300 }
1301 
vntb_epf_db_clear_mask(struct ntb_dev * ndev,u64 db_bits)1302 static int vntb_epf_db_clear_mask(struct ntb_dev *ndev, u64 db_bits)
1303 {
1304 	return 0;
1305 }
1306 
vntb_epf_db_clear(struct ntb_dev * ndev,u64 db_bits)1307 static int vntb_epf_db_clear(struct ntb_dev *ndev, u64 db_bits)
1308 {
1309 	struct epf_ntb *ntb = ntb_ndev(ndev);
1310 
1311 	ntb->db &= ~db_bits;
1312 	return 0;
1313 }
1314 
vntb_epf_link_disable(struct ntb_dev * ntb)1315 static int vntb_epf_link_disable(struct ntb_dev *ntb)
1316 {
1317 	return 0;
1318 }
1319 
1320 static const struct ntb_dev_ops vntb_epf_ops = {
1321 	.mw_count		= vntb_epf_mw_count,
1322 	.spad_count		= vntb_epf_spad_count,
1323 	.peer_mw_count		= vntb_epf_peer_mw_count,
1324 	.db_valid_mask		= vntb_epf_db_valid_mask,
1325 	.db_set_mask		= vntb_epf_db_set_mask,
1326 	.mw_set_trans		= vntb_epf_mw_set_trans,
1327 	.mw_clear_trans		= vntb_epf_mw_clear_trans,
1328 	.peer_mw_get_addr	= vntb_epf_peer_mw_get_addr,
1329 	.link_enable		= vntb_epf_link_enable,
1330 	.spad_read		= vntb_epf_spad_read,
1331 	.spad_write		= vntb_epf_spad_write,
1332 	.peer_spad_read		= vntb_epf_peer_spad_read,
1333 	.peer_spad_write	= vntb_epf_peer_spad_write,
1334 	.peer_db_set		= vntb_epf_peer_db_set,
1335 	.db_read		= vntb_epf_db_read,
1336 	.mw_get_align		= vntb_epf_mw_get_align,
1337 	.link_is_up		= vntb_epf_link_is_up,
1338 	.db_clear_mask		= vntb_epf_db_clear_mask,
1339 	.db_clear		= vntb_epf_db_clear,
1340 	.link_disable		= vntb_epf_link_disable,
1341 };
1342 
pci_vntb_probe(struct pci_dev * pdev,const struct pci_device_id * id)1343 static int pci_vntb_probe(struct pci_dev *pdev, const struct pci_device_id *id)
1344 {
1345 	int ret;
1346 	struct epf_ntb *ndev = (struct epf_ntb *)pdev->sysdata;
1347 	struct device *dev = &pdev->dev;
1348 
1349 	ndev->ntb.pdev = pdev;
1350 	ndev->ntb.topo = NTB_TOPO_NONE;
1351 	ndev->ntb.ops =  &vntb_epf_ops;
1352 
1353 	ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
1354 	if (ret) {
1355 		dev_err(dev, "Cannot set DMA mask\n");
1356 		return ret;
1357 	}
1358 
1359 	ret = ntb_register_device(&ndev->ntb);
1360 	if (ret) {
1361 		dev_err(dev, "Failed to register NTB device\n");
1362 		return ret;
1363 	}
1364 
1365 	dev_dbg(dev, "PCI Virtual NTB driver loaded\n");
1366 	return 0;
1367 }
1368 
1369 static struct pci_device_id pci_vntb_table[] = {
1370 	{
1371 		PCI_DEVICE(0xffff, 0xffff),
1372 	},
1373 	{},
1374 };
1375 
1376 static struct pci_driver vntb_pci_driver = {
1377 	.name           = "pci-vntb",
1378 	.id_table       = pci_vntb_table,
1379 	.probe          = pci_vntb_probe,
1380 };
1381 
1382 /* ============ PCIe EPF Driver Bind ====================*/
1383 
1384 /**
1385  * epf_ntb_bind() - Initialize endpoint controller to provide NTB functionality
1386  * @epf: NTB endpoint function device
1387  *
1388  * Initialize both the endpoint controllers associated with NTB function device.
1389  * Invoked when a primary interface or secondary interface is bound to EPC
1390  * device. This function will succeed only when EPC is bound to both the
1391  * interfaces.
1392  *
1393  * Returns: Zero for success, or an error code in case of failure
1394  */
epf_ntb_bind(struct pci_epf * epf)1395 static int epf_ntb_bind(struct pci_epf *epf)
1396 {
1397 	struct epf_ntb *ntb = epf_get_drvdata(epf);
1398 	struct device *dev = &epf->dev;
1399 	int ret;
1400 
1401 	if (!epf->epc) {
1402 		dev_dbg(dev, "PRIMARY EPC interface not yet bound\n");
1403 		return 0;
1404 	}
1405 
1406 	ret = epf_ntb_init_epc_bar(ntb);
1407 	if (ret) {
1408 		dev_err(dev, "Failed to create NTB EPC\n");
1409 		goto err_bar_init;
1410 	}
1411 
1412 	ret = epf_ntb_config_spad_bar_alloc(ntb);
1413 	if (ret) {
1414 		dev_err(dev, "Failed to allocate BAR memory\n");
1415 		goto err_bar_alloc;
1416 	}
1417 
1418 	ret = epf_ntb_epc_init(ntb);
1419 	if (ret) {
1420 		dev_err(dev, "Failed to initialize EPC\n");
1421 		goto err_bar_alloc;
1422 	}
1423 
1424 	epf_set_drvdata(epf, ntb);
1425 
1426 	pci_space[0] = (ntb->vntb_pid << 16) | ntb->vntb_vid;
1427 	pci_vntb_table[0].vendor = ntb->vntb_vid;
1428 	pci_vntb_table[0].device = ntb->vntb_pid;
1429 
1430 	ret = pci_register_driver(&vntb_pci_driver);
1431 	if (ret) {
1432 		dev_err(dev, "failure register vntb pci driver\n");
1433 		goto err_epc_cleanup;
1434 	}
1435 
1436 	ret = vpci_scan_bus(ntb);
1437 	if (ret)
1438 		goto err_unregister;
1439 
1440 	return 0;
1441 
1442 err_unregister:
1443 	pci_unregister_driver(&vntb_pci_driver);
1444 err_epc_cleanup:
1445 	epf_ntb_epc_cleanup(ntb);
1446 err_bar_alloc:
1447 	epf_ntb_config_spad_bar_free(ntb);
1448 
1449 err_bar_init:
1450 	epf_ntb_epc_destroy(ntb);
1451 
1452 	return ret;
1453 }
1454 
1455 /**
1456  * epf_ntb_unbind() - Cleanup the initialization from epf_ntb_bind()
1457  * @epf: NTB endpoint function device
1458  *
1459  * Cleanup the initialization from epf_ntb_bind()
1460  */
epf_ntb_unbind(struct pci_epf * epf)1461 static void epf_ntb_unbind(struct pci_epf *epf)
1462 {
1463 	struct epf_ntb *ntb = epf_get_drvdata(epf);
1464 
1465 	epf_ntb_epc_cleanup(ntb);
1466 	epf_ntb_config_spad_bar_free(ntb);
1467 	epf_ntb_epc_destroy(ntb);
1468 
1469 	pci_unregister_driver(&vntb_pci_driver);
1470 }
1471 
1472 // EPF driver probe
1473 static const struct pci_epf_ops epf_ntb_ops = {
1474 	.bind   = epf_ntb_bind,
1475 	.unbind = epf_ntb_unbind,
1476 	.add_cfs = epf_ntb_add_cfs,
1477 };
1478 
1479 /**
1480  * epf_ntb_probe() - Probe NTB function driver
1481  * @epf: NTB endpoint function device
1482  * @id: NTB endpoint function device ID
1483  *
1484  * Probe NTB function driver when endpoint function bus detects a NTB
1485  * endpoint function.
1486  *
1487  * Returns: Zero for success, or an error code in case of failure
1488  */
epf_ntb_probe(struct pci_epf * epf,const struct pci_epf_device_id * id)1489 static int epf_ntb_probe(struct pci_epf *epf,
1490 			 const struct pci_epf_device_id *id)
1491 {
1492 	struct epf_ntb *ntb;
1493 	struct device *dev;
1494 	int i;
1495 
1496 	dev = &epf->dev;
1497 
1498 	ntb = devm_kzalloc(dev, sizeof(*ntb), GFP_KERNEL);
1499 	if (!ntb)
1500 		return -ENOMEM;
1501 
1502 	epf->header = &epf_ntb_header;
1503 	ntb->epf = epf;
1504 	ntb->vbus_number = 0xff;
1505 
1506 	/* Initially, no bar is assigned */
1507 	for (i = 0; i < VNTB_BAR_NUM; i++)
1508 		ntb->epf_ntb_bar[i] = NO_BAR;
1509 
1510 	epf_set_drvdata(epf, ntb);
1511 
1512 	dev_info(dev, "pci-ep epf driver loaded\n");
1513 	return 0;
1514 }
1515 
1516 static const struct pci_epf_device_id epf_ntb_ids[] = {
1517 	{
1518 		.name = "pci_epf_vntb",
1519 	},
1520 	{},
1521 };
1522 
1523 static struct pci_epf_driver epf_ntb_driver = {
1524 	.driver.name    = "pci_epf_vntb",
1525 	.probe          = epf_ntb_probe,
1526 	.id_table       = epf_ntb_ids,
1527 	.ops            = &epf_ntb_ops,
1528 	.owner          = THIS_MODULE,
1529 };
1530 
epf_ntb_init(void)1531 static int __init epf_ntb_init(void)
1532 {
1533 	int ret;
1534 
1535 	kpcintb_workqueue = alloc_workqueue("kpcintb", WQ_MEM_RECLAIM |
1536 					    WQ_HIGHPRI, 0);
1537 	ret = pci_epf_register_driver(&epf_ntb_driver);
1538 	if (ret) {
1539 		destroy_workqueue(kpcintb_workqueue);
1540 		pr_err("Failed to register pci epf ntb driver --> %d\n", ret);
1541 		return ret;
1542 	}
1543 
1544 	return 0;
1545 }
1546 module_init(epf_ntb_init);
1547 
epf_ntb_exit(void)1548 static void __exit epf_ntb_exit(void)
1549 {
1550 	pci_epf_unregister_driver(&epf_ntb_driver);
1551 	destroy_workqueue(kpcintb_workqueue);
1552 }
1553 module_exit(epf_ntb_exit);
1554 
1555 MODULE_DESCRIPTION("PCI EPF NTB DRIVER");
1556 MODULE_AUTHOR("Frank Li <Frank.li@nxp.com>");
1557 MODULE_LICENSE("GPL v2");
1558