1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Microsemi Switchtec(tm) PCIe Management Driver
4  * Copyright (c) 2017, Microsemi Corporation
5  */
6 
7 #include <linux/interrupt.h>
8 #include <linux/io-64-nonatomic-lo-hi.h>
9 #include <linux/delay.h>
10 #include <linux/kthread.h>
11 #include <linux/module.h>
12 #include <linux/ntb.h>
13 #include <linux/pci.h>
14 #include <linux/switchtec.h>
15 
16 MODULE_DESCRIPTION("Microsemi Switchtec(tm) NTB Driver");
17 MODULE_VERSION("0.1");
18 MODULE_LICENSE("GPL");
19 MODULE_AUTHOR("Microsemi Corporation");
20 
21 static ulong max_mw_size = SZ_2M;
22 module_param(max_mw_size, ulong, 0644);
23 MODULE_PARM_DESC(max_mw_size,
24 	"Max memory window size reported to the upper layer");
25 
26 static bool use_lut_mws;
27 module_param(use_lut_mws, bool, 0644);
28 MODULE_PARM_DESC(use_lut_mws,
29 		 "Enable the use of the LUT based memory windows");
30 
31 #define SWITCHTEC_NTB_MAGIC 0x45CC0001
32 #define MAX_MWS     128
33 
34 struct shared_mw {
35 	u32 magic;
36 	u32 link_sta;
37 	u32 partition_id;
38 	u64 mw_sizes[MAX_MWS];
39 	u32 spad[128];
40 };
41 
42 #define MAX_DIRECT_MW ARRAY_SIZE(((struct ntb_ctrl_regs *)(0))->bar_entry)
43 #define LUT_SIZE SZ_64K
44 
45 struct switchtec_ntb {
46 	struct ntb_dev ntb;
47 	struct switchtec_dev *stdev;
48 
49 	int self_partition;
50 	int peer_partition;
51 
52 	int doorbell_irq;
53 	int message_irq;
54 
55 	struct ntb_info_regs __iomem *mmio_ntb;
56 	struct ntb_ctrl_regs __iomem *mmio_ctrl;
57 	struct ntb_dbmsg_regs __iomem *mmio_dbmsg;
58 	struct ntb_ctrl_regs __iomem *mmio_self_ctrl;
59 	struct ntb_ctrl_regs __iomem *mmio_peer_ctrl;
60 	struct ntb_dbmsg_regs __iomem *mmio_self_dbmsg;
61 	struct ntb_dbmsg_regs __iomem *mmio_peer_dbmsg;
62 
63 	void __iomem *mmio_xlink_win;
64 
65 	struct shared_mw *self_shared;
66 	struct shared_mw __iomem *peer_shared;
67 	dma_addr_t self_shared_dma;
68 
69 	u64 db_mask;
70 	u64 db_valid_mask;
71 	int db_shift;
72 	int db_peer_shift;
73 
74 	/* synchronize rmw access of db_mask and hw reg */
75 	spinlock_t db_mask_lock;
76 
77 	int nr_direct_mw;
78 	int nr_lut_mw;
79 	int nr_rsvd_luts;
80 	int direct_mw_to_bar[MAX_DIRECT_MW];
81 
82 	int peer_nr_direct_mw;
83 	int peer_nr_lut_mw;
84 	int peer_direct_mw_to_bar[MAX_DIRECT_MW];
85 
86 	bool link_is_up;
87 	enum ntb_speed link_speed;
88 	enum ntb_width link_width;
89 	struct work_struct check_link_status_work;
90 	bool link_force_down;
91 };
92 
93 static struct switchtec_ntb *ntb_sndev(struct ntb_dev *ntb)
94 {
95 	return container_of(ntb, struct switchtec_ntb, ntb);
96 }
97 
98 static int switchtec_ntb_part_op(struct switchtec_ntb *sndev,
99 				 struct ntb_ctrl_regs __iomem *ctl,
100 				 u32 op, int wait_status)
101 {
102 	static const char * const op_text[] = {
103 		[NTB_CTRL_PART_OP_LOCK] = "lock",
104 		[NTB_CTRL_PART_OP_CFG] = "configure",
105 		[NTB_CTRL_PART_OP_RESET] = "reset",
106 	};
107 
108 	int i;
109 	u32 ps;
110 	int status;
111 
112 	switch (op) {
113 	case NTB_CTRL_PART_OP_LOCK:
114 		status = NTB_CTRL_PART_STATUS_LOCKING;
115 		break;
116 	case NTB_CTRL_PART_OP_CFG:
117 		status = NTB_CTRL_PART_STATUS_CONFIGURING;
118 		break;
119 	case NTB_CTRL_PART_OP_RESET:
120 		status = NTB_CTRL_PART_STATUS_RESETTING;
121 		break;
122 	default:
123 		return -EINVAL;
124 	}
125 
126 	iowrite32(op, &ctl->partition_op);
127 
128 	for (i = 0; i < 1000; i++) {
129 		if (msleep_interruptible(50) != 0) {
130 			iowrite32(NTB_CTRL_PART_OP_RESET, &ctl->partition_op);
131 			return -EINTR;
132 		}
133 
134 		ps = ioread32(&ctl->partition_status) & 0xFFFF;
135 
136 		if (ps != status)
137 			break;
138 	}
139 
140 	if (ps == wait_status)
141 		return 0;
142 
143 	if (ps == status) {
144 		dev_err(&sndev->stdev->dev,
145 			"Timed out while performing %s (%d). (%08x)\n",
146 			op_text[op], op,
147 			ioread32(&ctl->partition_status));
148 
149 		return -ETIMEDOUT;
150 	}
151 
152 	return -EIO;
153 }
154 
155 static int switchtec_ntb_send_msg(struct switchtec_ntb *sndev, int idx,
156 				  u32 val)
157 {
158 	if (idx < 0 || idx >= ARRAY_SIZE(sndev->mmio_peer_dbmsg->omsg))
159 		return -EINVAL;
160 
161 	iowrite32(val, &sndev->mmio_peer_dbmsg->omsg[idx].msg);
162 
163 	return 0;
164 }
165 
166 static int switchtec_ntb_mw_count(struct ntb_dev *ntb, int pidx)
167 {
168 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
169 	int nr_direct_mw = sndev->peer_nr_direct_mw;
170 	int nr_lut_mw = sndev->peer_nr_lut_mw - sndev->nr_rsvd_luts;
171 
172 	if (pidx != NTB_DEF_PEER_IDX)
173 		return -EINVAL;
174 
175 	if (!use_lut_mws)
176 		nr_lut_mw = 0;
177 
178 	return nr_direct_mw + nr_lut_mw;
179 }
180 
181 static int lut_index(struct switchtec_ntb *sndev, int mw_idx)
182 {
183 	return mw_idx - sndev->nr_direct_mw + sndev->nr_rsvd_luts;
184 }
185 
186 static int peer_lut_index(struct switchtec_ntb *sndev, int mw_idx)
187 {
188 	return mw_idx - sndev->peer_nr_direct_mw + sndev->nr_rsvd_luts;
189 }
190 
191 static int switchtec_ntb_mw_get_align(struct ntb_dev *ntb, int pidx,
192 				      int widx, resource_size_t *addr_align,
193 				      resource_size_t *size_align,
194 				      resource_size_t *size_max)
195 {
196 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
197 	int lut;
198 	resource_size_t size;
199 
200 	if (pidx != NTB_DEF_PEER_IDX)
201 		return -EINVAL;
202 
203 	lut = widx >= sndev->peer_nr_direct_mw;
204 	size = ioread64(&sndev->peer_shared->mw_sizes[widx]);
205 
206 	if (size == 0)
207 		return -EINVAL;
208 
209 	if (addr_align)
210 		*addr_align = lut ? size : SZ_4K;
211 
212 	if (size_align)
213 		*size_align = lut ? size : SZ_4K;
214 
215 	if (size_max)
216 		*size_max = size;
217 
218 	return 0;
219 }
220 
221 static void switchtec_ntb_mw_clr_direct(struct switchtec_ntb *sndev, int idx)
222 {
223 	struct ntb_ctrl_regs __iomem *ctl = sndev->mmio_peer_ctrl;
224 	int bar = sndev->peer_direct_mw_to_bar[idx];
225 	u32 ctl_val;
226 
227 	ctl_val = ioread32(&ctl->bar_entry[bar].ctl);
228 	ctl_val &= ~NTB_CTRL_BAR_DIR_WIN_EN;
229 	iowrite32(ctl_val, &ctl->bar_entry[bar].ctl);
230 	iowrite32(0, &ctl->bar_entry[bar].win_size);
231 	iowrite32(0, &ctl->bar_ext_entry[bar].win_size);
232 	iowrite64(sndev->self_partition, &ctl->bar_entry[bar].xlate_addr);
233 }
234 
235 static void switchtec_ntb_mw_clr_lut(struct switchtec_ntb *sndev, int idx)
236 {
237 	struct ntb_ctrl_regs __iomem *ctl = sndev->mmio_peer_ctrl;
238 
239 	iowrite64(0, &ctl->lut_entry[peer_lut_index(sndev, idx)]);
240 }
241 
242 static void switchtec_ntb_mw_set_direct(struct switchtec_ntb *sndev, int idx,
243 					dma_addr_t addr, resource_size_t size)
244 {
245 	int xlate_pos = ilog2(size);
246 	int bar = sndev->peer_direct_mw_to_bar[idx];
247 	struct ntb_ctrl_regs __iomem *ctl = sndev->mmio_peer_ctrl;
248 	u32 ctl_val;
249 
250 	ctl_val = ioread32(&ctl->bar_entry[bar].ctl);
251 	ctl_val |= NTB_CTRL_BAR_DIR_WIN_EN;
252 
253 	iowrite32(ctl_val, &ctl->bar_entry[bar].ctl);
254 	iowrite32(xlate_pos | (lower_32_bits(size) & 0xFFFFF000),
255 		  &ctl->bar_entry[bar].win_size);
256 	iowrite32(upper_32_bits(size), &ctl->bar_ext_entry[bar].win_size);
257 	iowrite64(sndev->self_partition | addr,
258 		  &ctl->bar_entry[bar].xlate_addr);
259 }
260 
261 static void switchtec_ntb_mw_set_lut(struct switchtec_ntb *sndev, int idx,
262 				     dma_addr_t addr, resource_size_t size)
263 {
264 	struct ntb_ctrl_regs __iomem *ctl = sndev->mmio_peer_ctrl;
265 
266 	iowrite64((NTB_CTRL_LUT_EN | (sndev->self_partition << 1) | addr),
267 		  &ctl->lut_entry[peer_lut_index(sndev, idx)]);
268 }
269 
270 static int switchtec_ntb_mw_set_trans(struct ntb_dev *ntb, int pidx, int widx,
271 				      dma_addr_t addr, resource_size_t size)
272 {
273 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
274 	struct ntb_ctrl_regs __iomem *ctl = sndev->mmio_peer_ctrl;
275 	int xlate_pos = ilog2(size);
276 	int nr_direct_mw = sndev->peer_nr_direct_mw;
277 	int rc;
278 
279 	if (pidx != NTB_DEF_PEER_IDX)
280 		return -EINVAL;
281 
282 	dev_dbg(&sndev->stdev->dev, "MW %d: part %d addr %pad size %pap\n",
283 		widx, pidx, &addr, &size);
284 
285 	if (widx >= switchtec_ntb_mw_count(ntb, pidx))
286 		return -EINVAL;
287 
288 	if (size != 0 && xlate_pos < 12)
289 		return -EINVAL;
290 
291 	if (!IS_ALIGNED(addr, BIT_ULL(xlate_pos))) {
292 		/*
293 		 * In certain circumstances we can get a buffer that is
294 		 * not aligned to its size. (Most of the time
295 		 * dma_alloc_coherent ensures this). This can happen when
296 		 * using large buffers allocated by the CMA
297 		 * (see CMA_CONFIG_ALIGNMENT)
298 		 */
299 		dev_err(&sndev->stdev->dev,
300 			"ERROR: Memory window address is not aligned to its size!\n");
301 		return -EINVAL;
302 	}
303 
304 	rc = switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_LOCK,
305 				   NTB_CTRL_PART_STATUS_LOCKED);
306 	if (rc)
307 		return rc;
308 
309 	if (size == 0) {
310 		if (widx < nr_direct_mw)
311 			switchtec_ntb_mw_clr_direct(sndev, widx);
312 		else
313 			switchtec_ntb_mw_clr_lut(sndev, widx);
314 	} else {
315 		if (widx < nr_direct_mw)
316 			switchtec_ntb_mw_set_direct(sndev, widx, addr, size);
317 		else
318 			switchtec_ntb_mw_set_lut(sndev, widx, addr, size);
319 	}
320 
321 	rc = switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_CFG,
322 				   NTB_CTRL_PART_STATUS_NORMAL);
323 
324 	if (rc == -EIO) {
325 		dev_err(&sndev->stdev->dev,
326 			"Hardware reported an error configuring mw %d: %08x\n",
327 			widx, ioread32(&ctl->bar_error));
328 
329 		if (widx < nr_direct_mw)
330 			switchtec_ntb_mw_clr_direct(sndev, widx);
331 		else
332 			switchtec_ntb_mw_clr_lut(sndev, widx);
333 
334 		switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_CFG,
335 				      NTB_CTRL_PART_STATUS_NORMAL);
336 	}
337 
338 	return rc;
339 }
340 
341 static int switchtec_ntb_peer_mw_count(struct ntb_dev *ntb)
342 {
343 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
344 	int nr_lut_mw = sndev->nr_lut_mw - sndev->nr_rsvd_luts;
345 
346 	return sndev->nr_direct_mw + (use_lut_mws ? nr_lut_mw : 0);
347 }
348 
349 static int switchtec_ntb_direct_get_addr(struct switchtec_ntb *sndev,
350 					 int idx, phys_addr_t *base,
351 					 resource_size_t *size)
352 {
353 	int bar = sndev->direct_mw_to_bar[idx];
354 	size_t offset = 0;
355 
356 	if (bar < 0)
357 		return -EINVAL;
358 
359 	if (idx == 0) {
360 		/*
361 		 * This is the direct BAR shared with the LUTs
362 		 * which means the actual window will be offset
363 		 * by the size of all the LUT entries.
364 		 */
365 
366 		offset = LUT_SIZE * sndev->nr_lut_mw;
367 	}
368 
369 	if (base)
370 		*base = pci_resource_start(sndev->ntb.pdev, bar) + offset;
371 
372 	if (size) {
373 		*size = pci_resource_len(sndev->ntb.pdev, bar) - offset;
374 		if (offset && *size > offset)
375 			*size = offset;
376 
377 		if (*size > max_mw_size)
378 			*size = max_mw_size;
379 	}
380 
381 	return 0;
382 }
383 
384 static int switchtec_ntb_lut_get_addr(struct switchtec_ntb *sndev,
385 				      int idx, phys_addr_t *base,
386 				      resource_size_t *size)
387 {
388 	int bar = sndev->direct_mw_to_bar[0];
389 	int offset;
390 
391 	offset = LUT_SIZE * lut_index(sndev, idx);
392 
393 	if (base)
394 		*base = pci_resource_start(sndev->ntb.pdev, bar) + offset;
395 
396 	if (size)
397 		*size = LUT_SIZE;
398 
399 	return 0;
400 }
401 
402 static int switchtec_ntb_peer_mw_get_addr(struct ntb_dev *ntb, int idx,
403 					  phys_addr_t *base,
404 					  resource_size_t *size)
405 {
406 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
407 
408 	if (idx < sndev->nr_direct_mw)
409 		return switchtec_ntb_direct_get_addr(sndev, idx, base, size);
410 	else if (idx < switchtec_ntb_peer_mw_count(ntb))
411 		return switchtec_ntb_lut_get_addr(sndev, idx, base, size);
412 	else
413 		return -EINVAL;
414 }
415 
416 static void switchtec_ntb_part_link_speed(struct switchtec_ntb *sndev,
417 					  int partition,
418 					  enum ntb_speed *speed,
419 					  enum ntb_width *width)
420 {
421 	struct switchtec_dev *stdev = sndev->stdev;
422 	struct part_cfg_regs __iomem *part_cfg =
423 		&stdev->mmio_part_cfg_all[partition];
424 
425 	u32 pff = ioread32(&part_cfg->vep_pff_inst_id) & 0xFF;
426 	u32 linksta = ioread32(&stdev->mmio_pff_csr[pff].pci_cap_region[13]);
427 
428 	if (speed)
429 		*speed = (linksta >> 16) & 0xF;
430 
431 	if (width)
432 		*width = (linksta >> 20) & 0x3F;
433 }
434 
435 static void switchtec_ntb_set_link_speed(struct switchtec_ntb *sndev)
436 {
437 	enum ntb_speed self_speed, peer_speed;
438 	enum ntb_width self_width, peer_width;
439 
440 	if (!sndev->link_is_up) {
441 		sndev->link_speed = NTB_SPEED_NONE;
442 		sndev->link_width = NTB_WIDTH_NONE;
443 		return;
444 	}
445 
446 	switchtec_ntb_part_link_speed(sndev, sndev->self_partition,
447 				      &self_speed, &self_width);
448 	switchtec_ntb_part_link_speed(sndev, sndev->peer_partition,
449 				      &peer_speed, &peer_width);
450 
451 	sndev->link_speed = min(self_speed, peer_speed);
452 	sndev->link_width = min(self_width, peer_width);
453 }
454 
455 static int crosslink_is_enabled(struct switchtec_ntb *sndev)
456 {
457 	struct ntb_info_regs __iomem *inf = sndev->mmio_ntb;
458 
459 	return ioread8(&inf->ntp_info[sndev->peer_partition].xlink_enabled);
460 }
461 
462 static void crosslink_init_dbmsgs(struct switchtec_ntb *sndev)
463 {
464 	int i;
465 	u32 msg_map = 0;
466 
467 	if (!crosslink_is_enabled(sndev))
468 		return;
469 
470 	for (i = 0; i < ARRAY_SIZE(sndev->mmio_peer_dbmsg->imsg); i++) {
471 		int m = i | sndev->self_partition << 2;
472 
473 		msg_map |= m << i * 8;
474 	}
475 
476 	iowrite32(msg_map, &sndev->mmio_peer_dbmsg->msg_map);
477 	iowrite64(sndev->db_valid_mask << sndev->db_peer_shift,
478 		  &sndev->mmio_peer_dbmsg->odb_mask);
479 }
480 
481 enum switchtec_msg {
482 	LINK_MESSAGE = 0,
483 	MSG_LINK_UP = 1,
484 	MSG_LINK_DOWN = 2,
485 	MSG_CHECK_LINK = 3,
486 	MSG_LINK_FORCE_DOWN = 4,
487 };
488 
489 static int switchtec_ntb_reinit_peer(struct switchtec_ntb *sndev);
490 
491 static void switchtec_ntb_link_status_update(struct switchtec_ntb *sndev)
492 {
493 	int link_sta;
494 	int old = sndev->link_is_up;
495 
496 	link_sta = sndev->self_shared->link_sta;
497 	if (link_sta) {
498 		u64 peer = ioread64(&sndev->peer_shared->magic);
499 
500 		if ((peer & 0xFFFFFFFF) == SWITCHTEC_NTB_MAGIC)
501 			link_sta = peer >> 32;
502 		else
503 			link_sta = 0;
504 	}
505 
506 	sndev->link_is_up = link_sta;
507 	switchtec_ntb_set_link_speed(sndev);
508 
509 	if (link_sta != old) {
510 		switchtec_ntb_send_msg(sndev, LINK_MESSAGE, MSG_CHECK_LINK);
511 		ntb_link_event(&sndev->ntb);
512 		dev_info(&sndev->stdev->dev, "ntb link %s\n",
513 			 link_sta ? "up" : "down");
514 
515 		if (link_sta)
516 			crosslink_init_dbmsgs(sndev);
517 	}
518 }
519 
520 static void check_link_status_work(struct work_struct *work)
521 {
522 	struct switchtec_ntb *sndev;
523 
524 	sndev = container_of(work, struct switchtec_ntb,
525 			     check_link_status_work);
526 
527 	if (sndev->link_force_down) {
528 		sndev->link_force_down = false;
529 		switchtec_ntb_reinit_peer(sndev);
530 
531 		if (sndev->link_is_up) {
532 			sndev->link_is_up = 0;
533 			ntb_link_event(&sndev->ntb);
534 			dev_info(&sndev->stdev->dev, "ntb link forced down\n");
535 		}
536 
537 		return;
538 	}
539 
540 	switchtec_ntb_link_status_update(sndev);
541 }
542 
543 static void switchtec_ntb_check_link(struct switchtec_ntb *sndev,
544 				      enum switchtec_msg msg)
545 {
546 	if (msg == MSG_LINK_FORCE_DOWN)
547 		sndev->link_force_down = true;
548 
549 	schedule_work(&sndev->check_link_status_work);
550 }
551 
552 static void switchtec_ntb_link_notification(struct switchtec_dev *stdev)
553 {
554 	struct switchtec_ntb *sndev = stdev->sndev;
555 
556 	switchtec_ntb_check_link(sndev, MSG_CHECK_LINK);
557 }
558 
559 static u64 switchtec_ntb_link_is_up(struct ntb_dev *ntb,
560 				    enum ntb_speed *speed,
561 				    enum ntb_width *width)
562 {
563 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
564 
565 	if (speed)
566 		*speed = sndev->link_speed;
567 	if (width)
568 		*width = sndev->link_width;
569 
570 	return sndev->link_is_up;
571 }
572 
573 static int switchtec_ntb_link_enable(struct ntb_dev *ntb,
574 				     enum ntb_speed max_speed,
575 				     enum ntb_width max_width)
576 {
577 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
578 
579 	dev_dbg(&sndev->stdev->dev, "enabling link\n");
580 
581 	sndev->self_shared->link_sta = 1;
582 	switchtec_ntb_send_msg(sndev, LINK_MESSAGE, MSG_LINK_UP);
583 
584 	switchtec_ntb_link_status_update(sndev);
585 
586 	return 0;
587 }
588 
589 static int switchtec_ntb_link_disable(struct ntb_dev *ntb)
590 {
591 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
592 
593 	dev_dbg(&sndev->stdev->dev, "disabling link\n");
594 
595 	sndev->self_shared->link_sta = 0;
596 	switchtec_ntb_send_msg(sndev, LINK_MESSAGE, MSG_LINK_DOWN);
597 
598 	switchtec_ntb_link_status_update(sndev);
599 
600 	return 0;
601 }
602 
603 static u64 switchtec_ntb_db_valid_mask(struct ntb_dev *ntb)
604 {
605 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
606 
607 	return sndev->db_valid_mask;
608 }
609 
610 static int switchtec_ntb_db_vector_count(struct ntb_dev *ntb)
611 {
612 	return 1;
613 }
614 
615 static u64 switchtec_ntb_db_vector_mask(struct ntb_dev *ntb, int db_vector)
616 {
617 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
618 
619 	if (db_vector < 0 || db_vector > 1)
620 		return 0;
621 
622 	return sndev->db_valid_mask;
623 }
624 
625 static u64 switchtec_ntb_db_read(struct ntb_dev *ntb)
626 {
627 	u64 ret;
628 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
629 
630 	ret = ioread64(&sndev->mmio_self_dbmsg->idb) >> sndev->db_shift;
631 
632 	return ret & sndev->db_valid_mask;
633 }
634 
635 static int switchtec_ntb_db_clear(struct ntb_dev *ntb, u64 db_bits)
636 {
637 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
638 
639 	iowrite64(db_bits << sndev->db_shift, &sndev->mmio_self_dbmsg->idb);
640 
641 	return 0;
642 }
643 
644 static int switchtec_ntb_db_set_mask(struct ntb_dev *ntb, u64 db_bits)
645 {
646 	unsigned long irqflags;
647 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
648 
649 	if (db_bits & ~sndev->db_valid_mask)
650 		return -EINVAL;
651 
652 	spin_lock_irqsave(&sndev->db_mask_lock, irqflags);
653 
654 	sndev->db_mask |= db_bits << sndev->db_shift;
655 	iowrite64(~sndev->db_mask, &sndev->mmio_self_dbmsg->idb_mask);
656 
657 	spin_unlock_irqrestore(&sndev->db_mask_lock, irqflags);
658 
659 	return 0;
660 }
661 
662 static int switchtec_ntb_db_clear_mask(struct ntb_dev *ntb, u64 db_bits)
663 {
664 	unsigned long irqflags;
665 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
666 
667 	if (db_bits & ~sndev->db_valid_mask)
668 		return -EINVAL;
669 
670 	spin_lock_irqsave(&sndev->db_mask_lock, irqflags);
671 
672 	sndev->db_mask &= ~(db_bits << sndev->db_shift);
673 	iowrite64(~sndev->db_mask, &sndev->mmio_self_dbmsg->idb_mask);
674 
675 	spin_unlock_irqrestore(&sndev->db_mask_lock, irqflags);
676 
677 	return 0;
678 }
679 
680 static u64 switchtec_ntb_db_read_mask(struct ntb_dev *ntb)
681 {
682 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
683 
684 	return (sndev->db_mask >> sndev->db_shift) & sndev->db_valid_mask;
685 }
686 
687 static int switchtec_ntb_peer_db_addr(struct ntb_dev *ntb,
688 				      phys_addr_t *db_addr,
689 				      resource_size_t *db_size,
690 				      u64 *db_data,
691 				      int db_bit)
692 {
693 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
694 	unsigned long offset;
695 
696 	if (unlikely(db_bit >= BITS_PER_LONG_LONG))
697 		return -EINVAL;
698 
699 	offset = (unsigned long)sndev->mmio_peer_dbmsg->odb -
700 		(unsigned long)sndev->stdev->mmio;
701 
702 	offset += sndev->db_shift / 8;
703 
704 	if (db_addr)
705 		*db_addr = pci_resource_start(ntb->pdev, 0) + offset;
706 	if (db_size)
707 		*db_size = sizeof(u32);
708 	if (db_data)
709 		*db_data = BIT_ULL(db_bit) << sndev->db_peer_shift;
710 
711 	return 0;
712 }
713 
714 static int switchtec_ntb_peer_db_set(struct ntb_dev *ntb, u64 db_bits)
715 {
716 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
717 
718 	iowrite64(db_bits << sndev->db_peer_shift,
719 		  &sndev->mmio_peer_dbmsg->odb);
720 
721 	return 0;
722 }
723 
724 static int switchtec_ntb_spad_count(struct ntb_dev *ntb)
725 {
726 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
727 
728 	return ARRAY_SIZE(sndev->self_shared->spad);
729 }
730 
731 static u32 switchtec_ntb_spad_read(struct ntb_dev *ntb, int idx)
732 {
733 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
734 
735 	if (idx < 0 || idx >= ARRAY_SIZE(sndev->self_shared->spad))
736 		return 0;
737 
738 	if (!sndev->self_shared)
739 		return 0;
740 
741 	return sndev->self_shared->spad[idx];
742 }
743 
744 static int switchtec_ntb_spad_write(struct ntb_dev *ntb, int idx, u32 val)
745 {
746 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
747 
748 	if (idx < 0 || idx >= ARRAY_SIZE(sndev->self_shared->spad))
749 		return -EINVAL;
750 
751 	if (!sndev->self_shared)
752 		return -EIO;
753 
754 	sndev->self_shared->spad[idx] = val;
755 
756 	return 0;
757 }
758 
759 static u32 switchtec_ntb_peer_spad_read(struct ntb_dev *ntb, int pidx,
760 					int sidx)
761 {
762 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
763 
764 	if (pidx != NTB_DEF_PEER_IDX)
765 		return -EINVAL;
766 
767 	if (sidx < 0 || sidx >= ARRAY_SIZE(sndev->peer_shared->spad))
768 		return 0;
769 
770 	if (!sndev->peer_shared)
771 		return 0;
772 
773 	return ioread32(&sndev->peer_shared->spad[sidx]);
774 }
775 
776 static int switchtec_ntb_peer_spad_write(struct ntb_dev *ntb, int pidx,
777 					 int sidx, u32 val)
778 {
779 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
780 
781 	if (pidx != NTB_DEF_PEER_IDX)
782 		return -EINVAL;
783 
784 	if (sidx < 0 || sidx >= ARRAY_SIZE(sndev->peer_shared->spad))
785 		return -EINVAL;
786 
787 	if (!sndev->peer_shared)
788 		return -EIO;
789 
790 	iowrite32(val, &sndev->peer_shared->spad[sidx]);
791 
792 	return 0;
793 }
794 
795 static int switchtec_ntb_peer_spad_addr(struct ntb_dev *ntb, int pidx,
796 					int sidx, phys_addr_t *spad_addr)
797 {
798 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
799 	unsigned long offset;
800 
801 	if (pidx != NTB_DEF_PEER_IDX)
802 		return -EINVAL;
803 
804 	offset = (unsigned long)&sndev->peer_shared->spad[sidx] -
805 		(unsigned long)sndev->stdev->mmio;
806 
807 	if (spad_addr)
808 		*spad_addr = pci_resource_start(ntb->pdev, 0) + offset;
809 
810 	return 0;
811 }
812 
813 static const struct ntb_dev_ops switchtec_ntb_ops = {
814 	.mw_count		= switchtec_ntb_mw_count,
815 	.mw_get_align		= switchtec_ntb_mw_get_align,
816 	.mw_set_trans		= switchtec_ntb_mw_set_trans,
817 	.peer_mw_count		= switchtec_ntb_peer_mw_count,
818 	.peer_mw_get_addr	= switchtec_ntb_peer_mw_get_addr,
819 	.link_is_up		= switchtec_ntb_link_is_up,
820 	.link_enable		= switchtec_ntb_link_enable,
821 	.link_disable		= switchtec_ntb_link_disable,
822 	.db_valid_mask		= switchtec_ntb_db_valid_mask,
823 	.db_vector_count	= switchtec_ntb_db_vector_count,
824 	.db_vector_mask		= switchtec_ntb_db_vector_mask,
825 	.db_read		= switchtec_ntb_db_read,
826 	.db_clear		= switchtec_ntb_db_clear,
827 	.db_set_mask		= switchtec_ntb_db_set_mask,
828 	.db_clear_mask		= switchtec_ntb_db_clear_mask,
829 	.db_read_mask		= switchtec_ntb_db_read_mask,
830 	.peer_db_addr		= switchtec_ntb_peer_db_addr,
831 	.peer_db_set		= switchtec_ntb_peer_db_set,
832 	.spad_count		= switchtec_ntb_spad_count,
833 	.spad_read		= switchtec_ntb_spad_read,
834 	.spad_write		= switchtec_ntb_spad_write,
835 	.peer_spad_read		= switchtec_ntb_peer_spad_read,
836 	.peer_spad_write	= switchtec_ntb_peer_spad_write,
837 	.peer_spad_addr		= switchtec_ntb_peer_spad_addr,
838 };
839 
840 static int switchtec_ntb_init_sndev(struct switchtec_ntb *sndev)
841 {
842 	u64 tpart_vec;
843 	int self;
844 	u64 part_map;
845 
846 	sndev->ntb.pdev = sndev->stdev->pdev;
847 	sndev->ntb.topo = NTB_TOPO_SWITCH;
848 	sndev->ntb.ops = &switchtec_ntb_ops;
849 
850 	INIT_WORK(&sndev->check_link_status_work, check_link_status_work);
851 	sndev->link_force_down = false;
852 
853 	sndev->self_partition = sndev->stdev->partition;
854 
855 	sndev->mmio_ntb = sndev->stdev->mmio_ntb;
856 
857 	self = sndev->self_partition;
858 	tpart_vec = ioread32(&sndev->mmio_ntb->ntp_info[self].target_part_high);
859 	tpart_vec <<= 32;
860 	tpart_vec |= ioread32(&sndev->mmio_ntb->ntp_info[self].target_part_low);
861 
862 	part_map = ioread64(&sndev->mmio_ntb->ep_map);
863 	tpart_vec &= part_map;
864 	part_map &= ~(1 << sndev->self_partition);
865 
866 	if (!tpart_vec) {
867 		if (sndev->stdev->partition_count != 2) {
868 			dev_err(&sndev->stdev->dev,
869 				"ntb target partition not defined\n");
870 			return -ENODEV;
871 		}
872 
873 		if (!part_map) {
874 			dev_err(&sndev->stdev->dev,
875 				"peer partition is not NT partition\n");
876 			return -ENODEV;
877 		}
878 
879 		sndev->peer_partition = __ffs64(part_map);
880 	} else {
881 		if (__ffs64(tpart_vec) != (fls64(tpart_vec) - 1)) {
882 			dev_err(&sndev->stdev->dev,
883 				"ntb driver only supports 1 pair of 1-1 ntb mapping\n");
884 			return -ENODEV;
885 		}
886 
887 		sndev->peer_partition = __ffs64(tpart_vec);
888 		if (!(part_map & (1ULL << sndev->peer_partition))) {
889 			dev_err(&sndev->stdev->dev,
890 				"ntb target partition is not NT partition\n");
891 			return -ENODEV;
892 		}
893 	}
894 
895 	dev_dbg(&sndev->stdev->dev, "Partition ID %d of %d\n",
896 		sndev->self_partition, sndev->stdev->partition_count);
897 
898 	sndev->mmio_ctrl = (void * __iomem)sndev->mmio_ntb +
899 		SWITCHTEC_NTB_REG_CTRL_OFFSET;
900 	sndev->mmio_dbmsg = (void * __iomem)sndev->mmio_ntb +
901 		SWITCHTEC_NTB_REG_DBMSG_OFFSET;
902 
903 	sndev->mmio_self_ctrl = &sndev->mmio_ctrl[sndev->self_partition];
904 	sndev->mmio_peer_ctrl = &sndev->mmio_ctrl[sndev->peer_partition];
905 	sndev->mmio_self_dbmsg = &sndev->mmio_dbmsg[sndev->self_partition];
906 	sndev->mmio_peer_dbmsg = sndev->mmio_self_dbmsg;
907 
908 	return 0;
909 }
910 
911 static int config_rsvd_lut_win(struct switchtec_ntb *sndev,
912 			       struct ntb_ctrl_regs __iomem *ctl,
913 			       int lut_idx, int partition, u64 addr)
914 {
915 	int peer_bar = sndev->peer_direct_mw_to_bar[0];
916 	u32 ctl_val;
917 	int rc;
918 
919 	rc = switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_LOCK,
920 				   NTB_CTRL_PART_STATUS_LOCKED);
921 	if (rc)
922 		return rc;
923 
924 	ctl_val = ioread32(&ctl->bar_entry[peer_bar].ctl);
925 	ctl_val &= 0xFF;
926 	ctl_val |= NTB_CTRL_BAR_LUT_WIN_EN;
927 	ctl_val |= ilog2(LUT_SIZE) << 8;
928 	ctl_val |= (sndev->nr_lut_mw - 1) << 14;
929 	iowrite32(ctl_val, &ctl->bar_entry[peer_bar].ctl);
930 
931 	iowrite64((NTB_CTRL_LUT_EN | (partition << 1) | addr),
932 		  &ctl->lut_entry[lut_idx]);
933 
934 	rc = switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_CFG,
935 				   NTB_CTRL_PART_STATUS_NORMAL);
936 	if (rc) {
937 		u32 bar_error, lut_error;
938 
939 		bar_error = ioread32(&ctl->bar_error);
940 		lut_error = ioread32(&ctl->lut_error);
941 		dev_err(&sndev->stdev->dev,
942 			"Error setting up reserved lut window: %08x / %08x\n",
943 			bar_error, lut_error);
944 		return rc;
945 	}
946 
947 	return 0;
948 }
949 
950 static int config_req_id_table(struct switchtec_ntb *sndev,
951 			       struct ntb_ctrl_regs __iomem *mmio_ctrl,
952 			       int *req_ids, int count)
953 {
954 	int i, rc = 0;
955 	u32 error;
956 	u32 proxy_id;
957 
958 	if (ioread16(&mmio_ctrl->req_id_table_size) < count) {
959 		dev_err(&sndev->stdev->dev,
960 			"Not enough requester IDs available.\n");
961 		return -EFAULT;
962 	}
963 
964 	rc = switchtec_ntb_part_op(sndev, mmio_ctrl,
965 				   NTB_CTRL_PART_OP_LOCK,
966 				   NTB_CTRL_PART_STATUS_LOCKED);
967 	if (rc)
968 		return rc;
969 
970 	for (i = 0; i < count; i++) {
971 		iowrite32(req_ids[i] << 16 | NTB_CTRL_REQ_ID_EN,
972 			  &mmio_ctrl->req_id_table[i]);
973 
974 		proxy_id = ioread32(&mmio_ctrl->req_id_table[i]);
975 		dev_dbg(&sndev->stdev->dev,
976 			"Requester ID %02X:%02X.%X -> BB:%02X.%X\n",
977 			req_ids[i] >> 8, (req_ids[i] >> 3) & 0x1F,
978 			req_ids[i] & 0x7, (proxy_id >> 4) & 0x1F,
979 			(proxy_id >> 1) & 0x7);
980 	}
981 
982 	rc = switchtec_ntb_part_op(sndev, mmio_ctrl,
983 				   NTB_CTRL_PART_OP_CFG,
984 				   NTB_CTRL_PART_STATUS_NORMAL);
985 
986 	if (rc == -EIO) {
987 		error = ioread32(&mmio_ctrl->req_id_error);
988 		dev_err(&sndev->stdev->dev,
989 			"Error setting up the requester ID table: %08x\n",
990 			error);
991 	}
992 
993 	return 0;
994 }
995 
996 static int crosslink_setup_mws(struct switchtec_ntb *sndev, int ntb_lut_idx,
997 			       u64 *mw_addrs, int mw_count)
998 {
999 	int rc, i;
1000 	struct ntb_ctrl_regs __iomem *ctl = sndev->mmio_self_ctrl;
1001 	u64 addr;
1002 	size_t size, offset;
1003 	int bar;
1004 	int xlate_pos;
1005 	u32 ctl_val;
1006 
1007 	rc = switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_LOCK,
1008 				   NTB_CTRL_PART_STATUS_LOCKED);
1009 	if (rc)
1010 		return rc;
1011 
1012 	for (i = 0; i < sndev->nr_lut_mw; i++) {
1013 		if (i == ntb_lut_idx)
1014 			continue;
1015 
1016 		addr = mw_addrs[0] + LUT_SIZE * i;
1017 
1018 		iowrite64((NTB_CTRL_LUT_EN | (sndev->peer_partition << 1) |
1019 			   addr),
1020 			  &ctl->lut_entry[i]);
1021 	}
1022 
1023 	sndev->nr_direct_mw = min_t(int, sndev->nr_direct_mw, mw_count);
1024 
1025 	for (i = 0; i < sndev->nr_direct_mw; i++) {
1026 		bar = sndev->direct_mw_to_bar[i];
1027 		offset = (i == 0) ? LUT_SIZE * sndev->nr_lut_mw : 0;
1028 		addr = mw_addrs[i] + offset;
1029 		size = pci_resource_len(sndev->ntb.pdev, bar) - offset;
1030 		xlate_pos = ilog2(size);
1031 
1032 		if (offset && size > offset)
1033 			size = offset;
1034 
1035 		ctl_val = ioread32(&ctl->bar_entry[bar].ctl);
1036 		ctl_val |= NTB_CTRL_BAR_DIR_WIN_EN;
1037 
1038 		iowrite32(ctl_val, &ctl->bar_entry[bar].ctl);
1039 		iowrite32(xlate_pos | (lower_32_bits(size) & 0xFFFFF000),
1040 			  &ctl->bar_entry[bar].win_size);
1041 		iowrite32(upper_32_bits(size), &ctl->bar_ext_entry[bar].win_size);
1042 		iowrite64(sndev->peer_partition | addr,
1043 			  &ctl->bar_entry[bar].xlate_addr);
1044 	}
1045 
1046 	rc = switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_CFG,
1047 				   NTB_CTRL_PART_STATUS_NORMAL);
1048 	if (rc) {
1049 		u32 bar_error, lut_error;
1050 
1051 		bar_error = ioread32(&ctl->bar_error);
1052 		lut_error = ioread32(&ctl->lut_error);
1053 		dev_err(&sndev->stdev->dev,
1054 			"Error setting up cross link windows: %08x / %08x\n",
1055 			bar_error, lut_error);
1056 		return rc;
1057 	}
1058 
1059 	return 0;
1060 }
1061 
1062 static int crosslink_setup_req_ids(struct switchtec_ntb *sndev,
1063 	struct ntb_ctrl_regs __iomem *mmio_ctrl)
1064 {
1065 	int req_ids[16];
1066 	int i;
1067 	u32 proxy_id;
1068 
1069 	for (i = 0; i < ARRAY_SIZE(req_ids); i++) {
1070 		proxy_id = ioread32(&sndev->mmio_self_ctrl->req_id_table[i]);
1071 
1072 		if (!(proxy_id & NTB_CTRL_REQ_ID_EN))
1073 			break;
1074 
1075 		req_ids[i] = ((proxy_id >> 1) & 0xFF);
1076 	}
1077 
1078 	return config_req_id_table(sndev, mmio_ctrl, req_ids, i);
1079 }
1080 
1081 /*
1082  * In crosslink configuration there is a virtual partition in the
1083  * middle of the two switches. The BARs in this partition have to be
1084  * enumerated and assigned addresses.
1085  */
1086 static int crosslink_enum_partition(struct switchtec_ntb *sndev,
1087 				    u64 *bar_addrs)
1088 {
1089 	struct part_cfg_regs __iomem *part_cfg =
1090 		&sndev->stdev->mmio_part_cfg_all[sndev->peer_partition];
1091 	u32 pff = ioread32(&part_cfg->vep_pff_inst_id) & 0xFF;
1092 	struct pff_csr_regs __iomem *mmio_pff =
1093 		&sndev->stdev->mmio_pff_csr[pff];
1094 	const u64 bar_space = 0x1000000000LL;
1095 	u64 bar_addr;
1096 	int bar_cnt = 0;
1097 	int i;
1098 
1099 	iowrite16(0x6, &mmio_pff->pcicmd);
1100 
1101 	for (i = 0; i < ARRAY_SIZE(mmio_pff->pci_bar64); i++) {
1102 		iowrite64(bar_space * i, &mmio_pff->pci_bar64[i]);
1103 		bar_addr = ioread64(&mmio_pff->pci_bar64[i]);
1104 		bar_addr &= ~0xf;
1105 
1106 		dev_dbg(&sndev->stdev->dev,
1107 			"Crosslink BAR%d addr: %llx\n",
1108 			i*2, bar_addr);
1109 
1110 		if (bar_addr != bar_space * i)
1111 			continue;
1112 
1113 		bar_addrs[bar_cnt++] = bar_addr;
1114 	}
1115 
1116 	return bar_cnt;
1117 }
1118 
1119 static int switchtec_ntb_init_crosslink(struct switchtec_ntb *sndev)
1120 {
1121 	int rc;
1122 	int bar = sndev->direct_mw_to_bar[0];
1123 	const int ntb_lut_idx = 1;
1124 	u64 bar_addrs[6];
1125 	u64 addr;
1126 	int offset;
1127 	int bar_cnt;
1128 
1129 	if (!crosslink_is_enabled(sndev))
1130 		return 0;
1131 
1132 	dev_info(&sndev->stdev->dev, "Using crosslink configuration\n");
1133 	sndev->ntb.topo = NTB_TOPO_CROSSLINK;
1134 
1135 	bar_cnt = crosslink_enum_partition(sndev, bar_addrs);
1136 	if (bar_cnt < sndev->nr_direct_mw + 1) {
1137 		dev_err(&sndev->stdev->dev,
1138 			"Error enumerating crosslink partition\n");
1139 		return -EINVAL;
1140 	}
1141 
1142 	addr = (bar_addrs[0] + SWITCHTEC_GAS_NTB_OFFSET +
1143 		SWITCHTEC_NTB_REG_DBMSG_OFFSET +
1144 		sizeof(struct ntb_dbmsg_regs) * sndev->peer_partition);
1145 
1146 	offset = addr & (LUT_SIZE - 1);
1147 	addr -= offset;
1148 
1149 	rc = config_rsvd_lut_win(sndev, sndev->mmio_self_ctrl, ntb_lut_idx,
1150 				 sndev->peer_partition, addr);
1151 	if (rc)
1152 		return rc;
1153 
1154 	rc = crosslink_setup_mws(sndev, ntb_lut_idx, &bar_addrs[1],
1155 				 bar_cnt - 1);
1156 	if (rc)
1157 		return rc;
1158 
1159 	rc = crosslink_setup_req_ids(sndev, sndev->mmio_peer_ctrl);
1160 	if (rc)
1161 		return rc;
1162 
1163 	sndev->mmio_xlink_win = pci_iomap_range(sndev->stdev->pdev, bar,
1164 						LUT_SIZE, LUT_SIZE);
1165 	if (!sndev->mmio_xlink_win) {
1166 		rc = -ENOMEM;
1167 		return rc;
1168 	}
1169 
1170 	sndev->mmio_peer_dbmsg = sndev->mmio_xlink_win + offset;
1171 	sndev->nr_rsvd_luts++;
1172 
1173 	crosslink_init_dbmsgs(sndev);
1174 
1175 	return 0;
1176 }
1177 
1178 static void switchtec_ntb_deinit_crosslink(struct switchtec_ntb *sndev)
1179 {
1180 	if (sndev->mmio_xlink_win)
1181 		pci_iounmap(sndev->stdev->pdev, sndev->mmio_xlink_win);
1182 }
1183 
1184 static int map_bars(int *map, struct ntb_ctrl_regs __iomem *ctrl)
1185 {
1186 	int i;
1187 	int cnt = 0;
1188 
1189 	for (i = 0; i < ARRAY_SIZE(ctrl->bar_entry); i++) {
1190 		u32 r = ioread32(&ctrl->bar_entry[i].ctl);
1191 
1192 		if (r & NTB_CTRL_BAR_VALID)
1193 			map[cnt++] = i;
1194 	}
1195 
1196 	return cnt;
1197 }
1198 
1199 static void switchtec_ntb_init_mw(struct switchtec_ntb *sndev)
1200 {
1201 	sndev->nr_direct_mw = map_bars(sndev->direct_mw_to_bar,
1202 				       sndev->mmio_self_ctrl);
1203 
1204 	sndev->nr_lut_mw = ioread16(&sndev->mmio_self_ctrl->lut_table_entries);
1205 	sndev->nr_lut_mw = rounddown_pow_of_two(sndev->nr_lut_mw);
1206 
1207 	dev_dbg(&sndev->stdev->dev, "MWs: %d direct, %d lut\n",
1208 		sndev->nr_direct_mw, sndev->nr_lut_mw);
1209 
1210 	sndev->peer_nr_direct_mw = map_bars(sndev->peer_direct_mw_to_bar,
1211 					    sndev->mmio_peer_ctrl);
1212 
1213 	sndev->peer_nr_lut_mw =
1214 		ioread16(&sndev->mmio_peer_ctrl->lut_table_entries);
1215 	sndev->peer_nr_lut_mw = rounddown_pow_of_two(sndev->peer_nr_lut_mw);
1216 
1217 	dev_dbg(&sndev->stdev->dev, "Peer MWs: %d direct, %d lut\n",
1218 		sndev->peer_nr_direct_mw, sndev->peer_nr_lut_mw);
1219 
1220 }
1221 
1222 /*
1223  * There are 64 doorbells in the switch hardware but this is
1224  * shared among all partitions. So we must split them in half
1225  * (32 for each partition). However, the message interrupts are
1226  * also shared with the top 4 doorbells so we just limit this to
1227  * 28 doorbells per partition.
1228  *
1229  * In crosslink mode, each side has it's own dbmsg register so
1230  * they can each use all 60 of the available doorbells.
1231  */
1232 static void switchtec_ntb_init_db(struct switchtec_ntb *sndev)
1233 {
1234 	sndev->db_mask = 0x0FFFFFFFFFFFFFFFULL;
1235 
1236 	if (sndev->mmio_peer_dbmsg != sndev->mmio_self_dbmsg) {
1237 		sndev->db_shift = 0;
1238 		sndev->db_peer_shift = 0;
1239 		sndev->db_valid_mask = sndev->db_mask;
1240 	} else if (sndev->self_partition < sndev->peer_partition) {
1241 		sndev->db_shift = 0;
1242 		sndev->db_peer_shift = 32;
1243 		sndev->db_valid_mask = 0x0FFFFFFF;
1244 	} else {
1245 		sndev->db_shift = 32;
1246 		sndev->db_peer_shift = 0;
1247 		sndev->db_valid_mask = 0x0FFFFFFF;
1248 	}
1249 
1250 	iowrite64(~sndev->db_mask, &sndev->mmio_self_dbmsg->idb_mask);
1251 	iowrite64(sndev->db_valid_mask << sndev->db_peer_shift,
1252 		  &sndev->mmio_peer_dbmsg->odb_mask);
1253 
1254 	dev_dbg(&sndev->stdev->dev, "dbs: shift %d/%d, mask %016llx\n",
1255 		sndev->db_shift, sndev->db_peer_shift, sndev->db_valid_mask);
1256 }
1257 
1258 static void switchtec_ntb_init_msgs(struct switchtec_ntb *sndev)
1259 {
1260 	int i;
1261 	u32 msg_map = 0;
1262 
1263 	for (i = 0; i < ARRAY_SIZE(sndev->mmio_self_dbmsg->imsg); i++) {
1264 		int m = i | sndev->peer_partition << 2;
1265 
1266 		msg_map |= m << i * 8;
1267 	}
1268 
1269 	iowrite32(msg_map, &sndev->mmio_self_dbmsg->msg_map);
1270 
1271 	for (i = 0; i < ARRAY_SIZE(sndev->mmio_self_dbmsg->imsg); i++)
1272 		iowrite64(NTB_DBMSG_IMSG_STATUS | NTB_DBMSG_IMSG_MASK,
1273 			  &sndev->mmio_self_dbmsg->imsg[i]);
1274 }
1275 
1276 static int
1277 switchtec_ntb_init_req_id_table(struct switchtec_ntb *sndev)
1278 {
1279 	int req_ids[2];
1280 
1281 	/*
1282 	 * Root Complex Requester ID (which is 0:00.0)
1283 	 */
1284 	req_ids[0] = 0;
1285 
1286 	/*
1287 	 * Host Bridge Requester ID (as read from the mmap address)
1288 	 */
1289 	req_ids[1] = ioread16(&sndev->mmio_ntb->requester_id);
1290 
1291 	return config_req_id_table(sndev, sndev->mmio_self_ctrl, req_ids,
1292 				   ARRAY_SIZE(req_ids));
1293 }
1294 
1295 static void switchtec_ntb_init_shared(struct switchtec_ntb *sndev)
1296 {
1297 	int i;
1298 
1299 	memset(sndev->self_shared, 0, LUT_SIZE);
1300 	sndev->self_shared->magic = SWITCHTEC_NTB_MAGIC;
1301 	sndev->self_shared->partition_id = sndev->stdev->partition;
1302 
1303 	for (i = 0; i < sndev->nr_direct_mw; i++) {
1304 		int bar = sndev->direct_mw_to_bar[i];
1305 		resource_size_t sz = pci_resource_len(sndev->stdev->pdev, bar);
1306 
1307 		if (i == 0)
1308 			sz = min_t(resource_size_t, sz,
1309 				   LUT_SIZE * sndev->nr_lut_mw);
1310 
1311 		sndev->self_shared->mw_sizes[i] = sz;
1312 	}
1313 
1314 	for (i = 0; i < sndev->nr_lut_mw; i++) {
1315 		int idx = sndev->nr_direct_mw + i;
1316 
1317 		sndev->self_shared->mw_sizes[idx] = LUT_SIZE;
1318 	}
1319 }
1320 
1321 static int switchtec_ntb_init_shared_mw(struct switchtec_ntb *sndev)
1322 {
1323 	int self_bar = sndev->direct_mw_to_bar[0];
1324 	int rc;
1325 
1326 	sndev->nr_rsvd_luts++;
1327 	sndev->self_shared = dma_alloc_coherent(&sndev->stdev->pdev->dev,
1328 						LUT_SIZE,
1329 						&sndev->self_shared_dma,
1330 						GFP_KERNEL);
1331 	if (!sndev->self_shared) {
1332 		dev_err(&sndev->stdev->dev,
1333 			"unable to allocate memory for shared mw\n");
1334 		return -ENOMEM;
1335 	}
1336 
1337 	switchtec_ntb_init_shared(sndev);
1338 
1339 	rc = config_rsvd_lut_win(sndev, sndev->mmio_peer_ctrl, 0,
1340 				 sndev->self_partition,
1341 				 sndev->self_shared_dma);
1342 	if (rc)
1343 		goto unalloc_and_exit;
1344 
1345 	sndev->peer_shared = pci_iomap(sndev->stdev->pdev, self_bar, LUT_SIZE);
1346 	if (!sndev->peer_shared) {
1347 		rc = -ENOMEM;
1348 		goto unalloc_and_exit;
1349 	}
1350 
1351 	dev_dbg(&sndev->stdev->dev, "Shared MW Ready\n");
1352 	return 0;
1353 
1354 unalloc_and_exit:
1355 	dma_free_coherent(&sndev->stdev->pdev->dev, LUT_SIZE,
1356 			  sndev->self_shared, sndev->self_shared_dma);
1357 
1358 	return rc;
1359 }
1360 
1361 static void switchtec_ntb_deinit_shared_mw(struct switchtec_ntb *sndev)
1362 {
1363 	if (sndev->peer_shared)
1364 		pci_iounmap(sndev->stdev->pdev, sndev->peer_shared);
1365 
1366 	if (sndev->self_shared)
1367 		dma_free_coherent(&sndev->stdev->pdev->dev, LUT_SIZE,
1368 				  sndev->self_shared,
1369 				  sndev->self_shared_dma);
1370 	sndev->nr_rsvd_luts--;
1371 }
1372 
1373 static irqreturn_t switchtec_ntb_doorbell_isr(int irq, void *dev)
1374 {
1375 	struct switchtec_ntb *sndev = dev;
1376 
1377 	dev_dbg(&sndev->stdev->dev, "doorbell\n");
1378 
1379 	ntb_db_event(&sndev->ntb, 0);
1380 
1381 	return IRQ_HANDLED;
1382 }
1383 
1384 static irqreturn_t switchtec_ntb_message_isr(int irq, void *dev)
1385 {
1386 	int i;
1387 	struct switchtec_ntb *sndev = dev;
1388 
1389 	for (i = 0; i < ARRAY_SIZE(sndev->mmio_self_dbmsg->imsg); i++) {
1390 		u64 msg = ioread64(&sndev->mmio_self_dbmsg->imsg[i]);
1391 
1392 		if (msg & NTB_DBMSG_IMSG_STATUS) {
1393 			dev_dbg(&sndev->stdev->dev, "message: %d %08x\n",
1394 				i, (u32)msg);
1395 			iowrite8(1, &sndev->mmio_self_dbmsg->imsg[i].status);
1396 
1397 			if (i == LINK_MESSAGE)
1398 				switchtec_ntb_check_link(sndev, msg);
1399 		}
1400 	}
1401 
1402 	return IRQ_HANDLED;
1403 }
1404 
1405 static int switchtec_ntb_init_db_msg_irq(struct switchtec_ntb *sndev)
1406 {
1407 	int i;
1408 	int rc;
1409 	int doorbell_irq = 0;
1410 	int message_irq = 0;
1411 	int event_irq;
1412 	int idb_vecs = sizeof(sndev->mmio_self_dbmsg->idb_vec_map);
1413 
1414 	event_irq = ioread32(&sndev->stdev->mmio_part_cfg->vep_vector_number);
1415 
1416 	while (doorbell_irq == event_irq)
1417 		doorbell_irq++;
1418 	while (message_irq == doorbell_irq ||
1419 	       message_irq == event_irq)
1420 		message_irq++;
1421 
1422 	dev_dbg(&sndev->stdev->dev, "irqs - event: %d, db: %d, msgs: %d\n",
1423 		event_irq, doorbell_irq, message_irq);
1424 
1425 	for (i = 0; i < idb_vecs - 4; i++)
1426 		iowrite8(doorbell_irq,
1427 			 &sndev->mmio_self_dbmsg->idb_vec_map[i]);
1428 
1429 	for (; i < idb_vecs; i++)
1430 		iowrite8(message_irq,
1431 			 &sndev->mmio_self_dbmsg->idb_vec_map[i]);
1432 
1433 	sndev->doorbell_irq = pci_irq_vector(sndev->stdev->pdev, doorbell_irq);
1434 	sndev->message_irq = pci_irq_vector(sndev->stdev->pdev, message_irq);
1435 
1436 	rc = request_irq(sndev->doorbell_irq,
1437 			 switchtec_ntb_doorbell_isr, 0,
1438 			 "switchtec_ntb_doorbell", sndev);
1439 	if (rc)
1440 		return rc;
1441 
1442 	rc = request_irq(sndev->message_irq,
1443 			 switchtec_ntb_message_isr, 0,
1444 			 "switchtec_ntb_message", sndev);
1445 	if (rc) {
1446 		free_irq(sndev->doorbell_irq, sndev);
1447 		return rc;
1448 	}
1449 
1450 	return 0;
1451 }
1452 
1453 static void switchtec_ntb_deinit_db_msg_irq(struct switchtec_ntb *sndev)
1454 {
1455 	free_irq(sndev->doorbell_irq, sndev);
1456 	free_irq(sndev->message_irq, sndev);
1457 }
1458 
1459 static int switchtec_ntb_reinit_peer(struct switchtec_ntb *sndev)
1460 {
1461 	int rc;
1462 
1463 	if (crosslink_is_enabled(sndev))
1464 		return 0;
1465 
1466 	dev_info(&sndev->stdev->dev, "reinitialize shared memory window\n");
1467 	rc = config_rsvd_lut_win(sndev, sndev->mmio_peer_ctrl, 0,
1468 				 sndev->self_partition,
1469 				 sndev->self_shared_dma);
1470 	return rc;
1471 }
1472 
1473 static int switchtec_ntb_add(struct device *dev)
1474 {
1475 	struct switchtec_dev *stdev = to_stdev(dev);
1476 	struct switchtec_ntb *sndev;
1477 	int rc;
1478 
1479 	stdev->sndev = NULL;
1480 
1481 	if (stdev->pdev->class != (PCI_CLASS_BRIDGE_OTHER << 8))
1482 		return -ENODEV;
1483 
1484 	sndev = kzalloc_node(sizeof(*sndev), GFP_KERNEL, dev_to_node(dev));
1485 	if (!sndev)
1486 		return -ENOMEM;
1487 
1488 	sndev->stdev = stdev;
1489 	rc = switchtec_ntb_init_sndev(sndev);
1490 	if (rc)
1491 		goto free_and_exit;
1492 
1493 	switchtec_ntb_init_mw(sndev);
1494 
1495 	rc = switchtec_ntb_init_req_id_table(sndev);
1496 	if (rc)
1497 		goto free_and_exit;
1498 
1499 	rc = switchtec_ntb_init_crosslink(sndev);
1500 	if (rc)
1501 		goto free_and_exit;
1502 
1503 	switchtec_ntb_init_db(sndev);
1504 	switchtec_ntb_init_msgs(sndev);
1505 
1506 	rc = switchtec_ntb_init_shared_mw(sndev);
1507 	if (rc)
1508 		goto deinit_crosslink;
1509 
1510 	rc = switchtec_ntb_init_db_msg_irq(sndev);
1511 	if (rc)
1512 		goto deinit_shared_and_exit;
1513 
1514 	/*
1515 	 * If this host crashed, the other host may think the link is
1516 	 * still up. Tell them to force it down (it will go back up
1517 	 * once we register the ntb device).
1518 	 */
1519 	switchtec_ntb_send_msg(sndev, LINK_MESSAGE, MSG_LINK_FORCE_DOWN);
1520 
1521 	rc = ntb_register_device(&sndev->ntb);
1522 	if (rc)
1523 		goto deinit_and_exit;
1524 
1525 	stdev->sndev = sndev;
1526 	stdev->link_notifier = switchtec_ntb_link_notification;
1527 	dev_info(dev, "NTB device registered\n");
1528 
1529 	return 0;
1530 
1531 deinit_and_exit:
1532 	switchtec_ntb_deinit_db_msg_irq(sndev);
1533 deinit_shared_and_exit:
1534 	switchtec_ntb_deinit_shared_mw(sndev);
1535 deinit_crosslink:
1536 	switchtec_ntb_deinit_crosslink(sndev);
1537 free_and_exit:
1538 	kfree(sndev);
1539 	dev_err(dev, "failed to register ntb device: %d\n", rc);
1540 	return rc;
1541 }
1542 
1543 static void switchtec_ntb_remove(struct device *dev)
1544 {
1545 	struct switchtec_dev *stdev = to_stdev(dev);
1546 	struct switchtec_ntb *sndev = stdev->sndev;
1547 
1548 	if (!sndev)
1549 		return;
1550 
1551 	stdev->link_notifier = NULL;
1552 	stdev->sndev = NULL;
1553 	ntb_unregister_device(&sndev->ntb);
1554 	switchtec_ntb_deinit_db_msg_irq(sndev);
1555 	switchtec_ntb_deinit_shared_mw(sndev);
1556 	switchtec_ntb_deinit_crosslink(sndev);
1557 	cancel_work_sync(&sndev->check_link_status_work);
1558 	kfree(sndev);
1559 	dev_info(dev, "ntb device unregistered\n");
1560 }
1561 
1562 static struct class_interface switchtec_interface  = {
1563 	.add_dev = switchtec_ntb_add,
1564 	.remove_dev = switchtec_ntb_remove,
1565 };
1566 
1567 static int __init switchtec_ntb_init(void)
1568 {
1569 	switchtec_interface.class = switchtec_class;
1570 	return class_interface_register(&switchtec_interface);
1571 }
1572 module_init(switchtec_ntb_init);
1573 
1574 static void __exit switchtec_ntb_exit(void)
1575 {
1576 	class_interface_unregister(&switchtec_interface);
1577 }
1578 module_exit(switchtec_ntb_exit);
1579