xref: /linux/drivers/ntb/hw/mscc/ntb_hw_switchtec.c (revision e9f0878c4b2004ac19581274c1ae4c61ae3ca70e)
1 /*
2  * Microsemi Switchtec(tm) PCIe Management Driver
3  * Copyright (c) 2017, Microsemi Corporation
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms and conditions of the GNU General Public License,
7  * version 2, as published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12  * more details.
13  *
14  */
15 
16 #include <linux/switchtec.h>
17 #include <linux/module.h>
18 #include <linux/delay.h>
19 #include <linux/kthread.h>
20 #include <linux/interrupt.h>
21 #include <linux/ntb.h>
22 #include <linux/pci.h>
23 
24 MODULE_DESCRIPTION("Microsemi Switchtec(tm) NTB Driver");
25 MODULE_VERSION("0.1");
26 MODULE_LICENSE("GPL");
27 MODULE_AUTHOR("Microsemi Corporation");
28 
29 static ulong max_mw_size = SZ_2M;
30 module_param(max_mw_size, ulong, 0644);
31 MODULE_PARM_DESC(max_mw_size,
32 	"Max memory window size reported to the upper layer");
33 
34 static bool use_lut_mws;
35 module_param(use_lut_mws, bool, 0644);
36 MODULE_PARM_DESC(use_lut_mws,
37 		 "Enable the use of the LUT based memory windows");
38 
39 #ifndef ioread64
40 #ifdef readq
41 #define ioread64 readq
42 #else
43 #define ioread64 _ioread64
44 static inline u64 _ioread64(void __iomem *mmio)
45 {
46 	u64 low, high;
47 
48 	low = ioread32(mmio);
49 	high = ioread32(mmio + sizeof(u32));
50 	return low | (high << 32);
51 }
52 #endif
53 #endif
54 
55 #ifndef iowrite64
56 #ifdef writeq
57 #define iowrite64 writeq
58 #else
59 #define iowrite64 _iowrite64
60 static inline void _iowrite64(u64 val, void __iomem *mmio)
61 {
62 	iowrite32(val, mmio);
63 	iowrite32(val >> 32, mmio + sizeof(u32));
64 }
65 #endif
66 #endif
67 
68 #define SWITCHTEC_NTB_MAGIC 0x45CC0001
69 #define MAX_MWS     128
70 
71 struct shared_mw {
72 	u32 magic;
73 	u32 link_sta;
74 	u32 partition_id;
75 	u64 mw_sizes[MAX_MWS];
76 	u32 spad[128];
77 };
78 
79 #define MAX_DIRECT_MW ARRAY_SIZE(((struct ntb_ctrl_regs *)(0))->bar_entry)
80 #define LUT_SIZE SZ_64K
81 
82 struct switchtec_ntb {
83 	struct ntb_dev ntb;
84 	struct switchtec_dev *stdev;
85 
86 	int self_partition;
87 	int peer_partition;
88 
89 	int doorbell_irq;
90 	int message_irq;
91 
92 	struct ntb_info_regs __iomem *mmio_ntb;
93 	struct ntb_ctrl_regs __iomem *mmio_ctrl;
94 	struct ntb_dbmsg_regs __iomem *mmio_dbmsg;
95 	struct ntb_ctrl_regs __iomem *mmio_self_ctrl;
96 	struct ntb_ctrl_regs __iomem *mmio_peer_ctrl;
97 	struct ntb_dbmsg_regs __iomem *mmio_self_dbmsg;
98 	struct ntb_dbmsg_regs __iomem *mmio_peer_dbmsg;
99 
100 	void __iomem *mmio_xlink_win;
101 
102 	struct shared_mw *self_shared;
103 	struct shared_mw __iomem *peer_shared;
104 	dma_addr_t self_shared_dma;
105 
106 	u64 db_mask;
107 	u64 db_valid_mask;
108 	int db_shift;
109 	int db_peer_shift;
110 
111 	/* synchronize rmw access of db_mask and hw reg */
112 	spinlock_t db_mask_lock;
113 
114 	int nr_direct_mw;
115 	int nr_lut_mw;
116 	int nr_rsvd_luts;
117 	int direct_mw_to_bar[MAX_DIRECT_MW];
118 
119 	int peer_nr_direct_mw;
120 	int peer_nr_lut_mw;
121 	int peer_direct_mw_to_bar[MAX_DIRECT_MW];
122 
123 	bool link_is_up;
124 	enum ntb_speed link_speed;
125 	enum ntb_width link_width;
126 	struct work_struct link_reinit_work;
127 };
128 
129 static struct switchtec_ntb *ntb_sndev(struct ntb_dev *ntb)
130 {
131 	return container_of(ntb, struct switchtec_ntb, ntb);
132 }
133 
134 static int switchtec_ntb_part_op(struct switchtec_ntb *sndev,
135 				 struct ntb_ctrl_regs __iomem *ctl,
136 				 u32 op, int wait_status)
137 {
138 	static const char * const op_text[] = {
139 		[NTB_CTRL_PART_OP_LOCK] = "lock",
140 		[NTB_CTRL_PART_OP_CFG] = "configure",
141 		[NTB_CTRL_PART_OP_RESET] = "reset",
142 	};
143 
144 	int i;
145 	u32 ps;
146 	int status;
147 
148 	switch (op) {
149 	case NTB_CTRL_PART_OP_LOCK:
150 		status = NTB_CTRL_PART_STATUS_LOCKING;
151 		break;
152 	case NTB_CTRL_PART_OP_CFG:
153 		status = NTB_CTRL_PART_STATUS_CONFIGURING;
154 		break;
155 	case NTB_CTRL_PART_OP_RESET:
156 		status = NTB_CTRL_PART_STATUS_RESETTING;
157 		break;
158 	default:
159 		return -EINVAL;
160 	}
161 
162 	iowrite32(op, &ctl->partition_op);
163 
164 	for (i = 0; i < 1000; i++) {
165 		if (msleep_interruptible(50) != 0) {
166 			iowrite32(NTB_CTRL_PART_OP_RESET, &ctl->partition_op);
167 			return -EINTR;
168 		}
169 
170 		ps = ioread32(&ctl->partition_status) & 0xFFFF;
171 
172 		if (ps != status)
173 			break;
174 	}
175 
176 	if (ps == wait_status)
177 		return 0;
178 
179 	if (ps == status) {
180 		dev_err(&sndev->stdev->dev,
181 			"Timed out while performing %s (%d). (%08x)\n",
182 			op_text[op], op,
183 			ioread32(&ctl->partition_status));
184 
185 		return -ETIMEDOUT;
186 	}
187 
188 	return -EIO;
189 }
190 
191 static int switchtec_ntb_send_msg(struct switchtec_ntb *sndev, int idx,
192 				  u32 val)
193 {
194 	if (idx < 0 || idx >= ARRAY_SIZE(sndev->mmio_peer_dbmsg->omsg))
195 		return -EINVAL;
196 
197 	iowrite32(val, &sndev->mmio_peer_dbmsg->omsg[idx].msg);
198 
199 	return 0;
200 }
201 
202 static int switchtec_ntb_mw_count(struct ntb_dev *ntb, int pidx)
203 {
204 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
205 	int nr_direct_mw = sndev->peer_nr_direct_mw;
206 	int nr_lut_mw = sndev->peer_nr_lut_mw - sndev->nr_rsvd_luts;
207 
208 	if (pidx != NTB_DEF_PEER_IDX)
209 		return -EINVAL;
210 
211 	if (!use_lut_mws)
212 		nr_lut_mw = 0;
213 
214 	return nr_direct_mw + nr_lut_mw;
215 }
216 
217 static int lut_index(struct switchtec_ntb *sndev, int mw_idx)
218 {
219 	return mw_idx - sndev->nr_direct_mw + sndev->nr_rsvd_luts;
220 }
221 
222 static int peer_lut_index(struct switchtec_ntb *sndev, int mw_idx)
223 {
224 	return mw_idx - sndev->peer_nr_direct_mw + sndev->nr_rsvd_luts;
225 }
226 
227 static int switchtec_ntb_mw_get_align(struct ntb_dev *ntb, int pidx,
228 				      int widx, resource_size_t *addr_align,
229 				      resource_size_t *size_align,
230 				      resource_size_t *size_max)
231 {
232 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
233 	int lut;
234 	resource_size_t size;
235 
236 	if (pidx != NTB_DEF_PEER_IDX)
237 		return -EINVAL;
238 
239 	lut = widx >= sndev->peer_nr_direct_mw;
240 	size = ioread64(&sndev->peer_shared->mw_sizes[widx]);
241 
242 	if (size == 0)
243 		return -EINVAL;
244 
245 	if (addr_align)
246 		*addr_align = lut ? size : SZ_4K;
247 
248 	if (size_align)
249 		*size_align = lut ? size : SZ_4K;
250 
251 	if (size_max)
252 		*size_max = size;
253 
254 	return 0;
255 }
256 
257 static void switchtec_ntb_mw_clr_direct(struct switchtec_ntb *sndev, int idx)
258 {
259 	struct ntb_ctrl_regs __iomem *ctl = sndev->mmio_peer_ctrl;
260 	int bar = sndev->peer_direct_mw_to_bar[idx];
261 	u32 ctl_val;
262 
263 	ctl_val = ioread32(&ctl->bar_entry[bar].ctl);
264 	ctl_val &= ~NTB_CTRL_BAR_DIR_WIN_EN;
265 	iowrite32(ctl_val, &ctl->bar_entry[bar].ctl);
266 	iowrite32(0, &ctl->bar_entry[bar].win_size);
267 	iowrite64(sndev->self_partition, &ctl->bar_entry[bar].xlate_addr);
268 }
269 
270 static void switchtec_ntb_mw_clr_lut(struct switchtec_ntb *sndev, int idx)
271 {
272 	struct ntb_ctrl_regs __iomem *ctl = sndev->mmio_peer_ctrl;
273 
274 	iowrite64(0, &ctl->lut_entry[peer_lut_index(sndev, idx)]);
275 }
276 
277 static void switchtec_ntb_mw_set_direct(struct switchtec_ntb *sndev, int idx,
278 					dma_addr_t addr, resource_size_t size)
279 {
280 	int xlate_pos = ilog2(size);
281 	int bar = sndev->peer_direct_mw_to_bar[idx];
282 	struct ntb_ctrl_regs __iomem *ctl = sndev->mmio_peer_ctrl;
283 	u32 ctl_val;
284 
285 	ctl_val = ioread32(&ctl->bar_entry[bar].ctl);
286 	ctl_val |= NTB_CTRL_BAR_DIR_WIN_EN;
287 
288 	iowrite32(ctl_val, &ctl->bar_entry[bar].ctl);
289 	iowrite32(xlate_pos | size, &ctl->bar_entry[bar].win_size);
290 	iowrite64(sndev->self_partition | addr,
291 		  &ctl->bar_entry[bar].xlate_addr);
292 }
293 
294 static void switchtec_ntb_mw_set_lut(struct switchtec_ntb *sndev, int idx,
295 				     dma_addr_t addr, resource_size_t size)
296 {
297 	struct ntb_ctrl_regs __iomem *ctl = sndev->mmio_peer_ctrl;
298 
299 	iowrite64((NTB_CTRL_LUT_EN | (sndev->self_partition << 1) | addr),
300 		  &ctl->lut_entry[peer_lut_index(sndev, idx)]);
301 }
302 
303 static int switchtec_ntb_mw_set_trans(struct ntb_dev *ntb, int pidx, int widx,
304 				      dma_addr_t addr, resource_size_t size)
305 {
306 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
307 	struct ntb_ctrl_regs __iomem *ctl = sndev->mmio_peer_ctrl;
308 	int xlate_pos = ilog2(size);
309 	int nr_direct_mw = sndev->peer_nr_direct_mw;
310 	int rc;
311 
312 	if (pidx != NTB_DEF_PEER_IDX)
313 		return -EINVAL;
314 
315 	dev_dbg(&sndev->stdev->dev, "MW %d: part %d addr %pad size %pap\n",
316 		widx, pidx, &addr, &size);
317 
318 	if (widx >= switchtec_ntb_mw_count(ntb, pidx))
319 		return -EINVAL;
320 
321 	if (xlate_pos < 12)
322 		return -EINVAL;
323 
324 	if (!IS_ALIGNED(addr, BIT_ULL(xlate_pos))) {
325 		/*
326 		 * In certain circumstances we can get a buffer that is
327 		 * not aligned to its size. (Most of the time
328 		 * dma_alloc_coherent ensures this). This can happen when
329 		 * using large buffers allocated by the CMA
330 		 * (see CMA_CONFIG_ALIGNMENT)
331 		 */
332 		dev_err(&sndev->stdev->dev,
333 			"ERROR: Memory window address is not aligned to it's size!\n");
334 		return -EINVAL;
335 	}
336 
337 	rc = switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_LOCK,
338 				   NTB_CTRL_PART_STATUS_LOCKED);
339 	if (rc)
340 		return rc;
341 
342 	if (addr == 0 || size == 0) {
343 		if (widx < nr_direct_mw)
344 			switchtec_ntb_mw_clr_direct(sndev, widx);
345 		else
346 			switchtec_ntb_mw_clr_lut(sndev, widx);
347 	} else {
348 		if (widx < nr_direct_mw)
349 			switchtec_ntb_mw_set_direct(sndev, widx, addr, size);
350 		else
351 			switchtec_ntb_mw_set_lut(sndev, widx, addr, size);
352 	}
353 
354 	rc = switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_CFG,
355 				   NTB_CTRL_PART_STATUS_NORMAL);
356 
357 	if (rc == -EIO) {
358 		dev_err(&sndev->stdev->dev,
359 			"Hardware reported an error configuring mw %d: %08x\n",
360 			widx, ioread32(&ctl->bar_error));
361 
362 		if (widx < nr_direct_mw)
363 			switchtec_ntb_mw_clr_direct(sndev, widx);
364 		else
365 			switchtec_ntb_mw_clr_lut(sndev, widx);
366 
367 		switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_CFG,
368 				      NTB_CTRL_PART_STATUS_NORMAL);
369 	}
370 
371 	return rc;
372 }
373 
374 static int switchtec_ntb_peer_mw_count(struct ntb_dev *ntb)
375 {
376 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
377 	int nr_lut_mw = sndev->nr_lut_mw - sndev->nr_rsvd_luts;
378 
379 	return sndev->nr_direct_mw + (use_lut_mws ? nr_lut_mw : 0);
380 }
381 
382 static int switchtec_ntb_direct_get_addr(struct switchtec_ntb *sndev,
383 					 int idx, phys_addr_t *base,
384 					 resource_size_t *size)
385 {
386 	int bar = sndev->direct_mw_to_bar[idx];
387 	size_t offset = 0;
388 
389 	if (bar < 0)
390 		return -EINVAL;
391 
392 	if (idx == 0) {
393 		/*
394 		 * This is the direct BAR shared with the LUTs
395 		 * which means the actual window will be offset
396 		 * by the size of all the LUT entries.
397 		 */
398 
399 		offset = LUT_SIZE * sndev->nr_lut_mw;
400 	}
401 
402 	if (base)
403 		*base = pci_resource_start(sndev->ntb.pdev, bar) + offset;
404 
405 	if (size) {
406 		*size = pci_resource_len(sndev->ntb.pdev, bar) - offset;
407 		if (offset && *size > offset)
408 			*size = offset;
409 
410 		if (*size > max_mw_size)
411 			*size = max_mw_size;
412 	}
413 
414 	return 0;
415 }
416 
417 static int switchtec_ntb_lut_get_addr(struct switchtec_ntb *sndev,
418 				      int idx, phys_addr_t *base,
419 				      resource_size_t *size)
420 {
421 	int bar = sndev->direct_mw_to_bar[0];
422 	int offset;
423 
424 	offset = LUT_SIZE * lut_index(sndev, idx);
425 
426 	if (base)
427 		*base = pci_resource_start(sndev->ntb.pdev, bar) + offset;
428 
429 	if (size)
430 		*size = LUT_SIZE;
431 
432 	return 0;
433 }
434 
435 static int switchtec_ntb_peer_mw_get_addr(struct ntb_dev *ntb, int idx,
436 					  phys_addr_t *base,
437 					  resource_size_t *size)
438 {
439 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
440 
441 	if (idx < sndev->nr_direct_mw)
442 		return switchtec_ntb_direct_get_addr(sndev, idx, base, size);
443 	else if (idx < switchtec_ntb_peer_mw_count(ntb))
444 		return switchtec_ntb_lut_get_addr(sndev, idx, base, size);
445 	else
446 		return -EINVAL;
447 }
448 
449 static void switchtec_ntb_part_link_speed(struct switchtec_ntb *sndev,
450 					  int partition,
451 					  enum ntb_speed *speed,
452 					  enum ntb_width *width)
453 {
454 	struct switchtec_dev *stdev = sndev->stdev;
455 
456 	u32 pff = ioread32(&stdev->mmio_part_cfg[partition].vep_pff_inst_id);
457 	u32 linksta = ioread32(&stdev->mmio_pff_csr[pff].pci_cap_region[13]);
458 
459 	if (speed)
460 		*speed = (linksta >> 16) & 0xF;
461 
462 	if (width)
463 		*width = (linksta >> 20) & 0x3F;
464 }
465 
466 static void switchtec_ntb_set_link_speed(struct switchtec_ntb *sndev)
467 {
468 	enum ntb_speed self_speed, peer_speed;
469 	enum ntb_width self_width, peer_width;
470 
471 	if (!sndev->link_is_up) {
472 		sndev->link_speed = NTB_SPEED_NONE;
473 		sndev->link_width = NTB_WIDTH_NONE;
474 		return;
475 	}
476 
477 	switchtec_ntb_part_link_speed(sndev, sndev->self_partition,
478 				      &self_speed, &self_width);
479 	switchtec_ntb_part_link_speed(sndev, sndev->peer_partition,
480 				      &peer_speed, &peer_width);
481 
482 	sndev->link_speed = min(self_speed, peer_speed);
483 	sndev->link_width = min(self_width, peer_width);
484 }
485 
486 static int crosslink_is_enabled(struct switchtec_ntb *sndev)
487 {
488 	struct ntb_info_regs __iomem *inf = sndev->mmio_ntb;
489 
490 	return ioread8(&inf->ntp_info[sndev->peer_partition].xlink_enabled);
491 }
492 
493 static void crosslink_init_dbmsgs(struct switchtec_ntb *sndev)
494 {
495 	int i;
496 	u32 msg_map = 0;
497 
498 	if (!crosslink_is_enabled(sndev))
499 		return;
500 
501 	for (i = 0; i < ARRAY_SIZE(sndev->mmio_peer_dbmsg->imsg); i++) {
502 		int m = i | sndev->self_partition << 2;
503 
504 		msg_map |= m << i * 8;
505 	}
506 
507 	iowrite32(msg_map, &sndev->mmio_peer_dbmsg->msg_map);
508 	iowrite64(sndev->db_valid_mask << sndev->db_peer_shift,
509 		  &sndev->mmio_peer_dbmsg->odb_mask);
510 }
511 
512 enum switchtec_msg {
513 	LINK_MESSAGE = 0,
514 	MSG_LINK_UP = 1,
515 	MSG_LINK_DOWN = 2,
516 	MSG_CHECK_LINK = 3,
517 	MSG_LINK_FORCE_DOWN = 4,
518 };
519 
520 static int switchtec_ntb_reinit_peer(struct switchtec_ntb *sndev);
521 
522 static void link_reinit_work(struct work_struct *work)
523 {
524 	struct switchtec_ntb *sndev;
525 
526 	sndev = container_of(work, struct switchtec_ntb, link_reinit_work);
527 
528 	switchtec_ntb_reinit_peer(sndev);
529 }
530 
531 static void switchtec_ntb_check_link(struct switchtec_ntb *sndev,
532 				     enum switchtec_msg msg)
533 {
534 	int link_sta;
535 	int old = sndev->link_is_up;
536 
537 	if (msg == MSG_LINK_FORCE_DOWN) {
538 		schedule_work(&sndev->link_reinit_work);
539 
540 		if (sndev->link_is_up) {
541 			sndev->link_is_up = 0;
542 			ntb_link_event(&sndev->ntb);
543 			dev_info(&sndev->stdev->dev, "ntb link forced down\n");
544 		}
545 
546 		return;
547 	}
548 
549 	link_sta = sndev->self_shared->link_sta;
550 	if (link_sta) {
551 		u64 peer = ioread64(&sndev->peer_shared->magic);
552 
553 		if ((peer & 0xFFFFFFFF) == SWITCHTEC_NTB_MAGIC)
554 			link_sta = peer >> 32;
555 		else
556 			link_sta = 0;
557 	}
558 
559 	sndev->link_is_up = link_sta;
560 	switchtec_ntb_set_link_speed(sndev);
561 
562 	if (link_sta != old) {
563 		switchtec_ntb_send_msg(sndev, LINK_MESSAGE, MSG_CHECK_LINK);
564 		ntb_link_event(&sndev->ntb);
565 		dev_info(&sndev->stdev->dev, "ntb link %s\n",
566 			 link_sta ? "up" : "down");
567 
568 		if (link_sta)
569 			crosslink_init_dbmsgs(sndev);
570 	}
571 }
572 
573 static void switchtec_ntb_link_notification(struct switchtec_dev *stdev)
574 {
575 	struct switchtec_ntb *sndev = stdev->sndev;
576 
577 	switchtec_ntb_check_link(sndev, MSG_CHECK_LINK);
578 }
579 
580 static u64 switchtec_ntb_link_is_up(struct ntb_dev *ntb,
581 				    enum ntb_speed *speed,
582 				    enum ntb_width *width)
583 {
584 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
585 
586 	if (speed)
587 		*speed = sndev->link_speed;
588 	if (width)
589 		*width = sndev->link_width;
590 
591 	return sndev->link_is_up;
592 }
593 
594 static int switchtec_ntb_link_enable(struct ntb_dev *ntb,
595 				     enum ntb_speed max_speed,
596 				     enum ntb_width max_width)
597 {
598 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
599 
600 	dev_dbg(&sndev->stdev->dev, "enabling link\n");
601 
602 	sndev->self_shared->link_sta = 1;
603 	switchtec_ntb_send_msg(sndev, LINK_MESSAGE, MSG_LINK_UP);
604 
605 	switchtec_ntb_check_link(sndev, MSG_CHECK_LINK);
606 
607 	return 0;
608 }
609 
610 static int switchtec_ntb_link_disable(struct ntb_dev *ntb)
611 {
612 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
613 
614 	dev_dbg(&sndev->stdev->dev, "disabling link\n");
615 
616 	sndev->self_shared->link_sta = 0;
617 	switchtec_ntb_send_msg(sndev, LINK_MESSAGE, MSG_LINK_DOWN);
618 
619 	switchtec_ntb_check_link(sndev, MSG_CHECK_LINK);
620 
621 	return 0;
622 }
623 
624 static u64 switchtec_ntb_db_valid_mask(struct ntb_dev *ntb)
625 {
626 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
627 
628 	return sndev->db_valid_mask;
629 }
630 
631 static int switchtec_ntb_db_vector_count(struct ntb_dev *ntb)
632 {
633 	return 1;
634 }
635 
636 static u64 switchtec_ntb_db_vector_mask(struct ntb_dev *ntb, int db_vector)
637 {
638 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
639 
640 	if (db_vector < 0 || db_vector > 1)
641 		return 0;
642 
643 	return sndev->db_valid_mask;
644 }
645 
646 static u64 switchtec_ntb_db_read(struct ntb_dev *ntb)
647 {
648 	u64 ret;
649 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
650 
651 	ret = ioread64(&sndev->mmio_self_dbmsg->idb) >> sndev->db_shift;
652 
653 	return ret & sndev->db_valid_mask;
654 }
655 
656 static int switchtec_ntb_db_clear(struct ntb_dev *ntb, u64 db_bits)
657 {
658 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
659 
660 	iowrite64(db_bits << sndev->db_shift, &sndev->mmio_self_dbmsg->idb);
661 
662 	return 0;
663 }
664 
665 static int switchtec_ntb_db_set_mask(struct ntb_dev *ntb, u64 db_bits)
666 {
667 	unsigned long irqflags;
668 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
669 
670 	if (db_bits & ~sndev->db_valid_mask)
671 		return -EINVAL;
672 
673 	spin_lock_irqsave(&sndev->db_mask_lock, irqflags);
674 
675 	sndev->db_mask |= db_bits << sndev->db_shift;
676 	iowrite64(~sndev->db_mask, &sndev->mmio_self_dbmsg->idb_mask);
677 
678 	spin_unlock_irqrestore(&sndev->db_mask_lock, irqflags);
679 
680 	return 0;
681 }
682 
683 static int switchtec_ntb_db_clear_mask(struct ntb_dev *ntb, u64 db_bits)
684 {
685 	unsigned long irqflags;
686 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
687 
688 	if (db_bits & ~sndev->db_valid_mask)
689 		return -EINVAL;
690 
691 	spin_lock_irqsave(&sndev->db_mask_lock, irqflags);
692 
693 	sndev->db_mask &= ~(db_bits << sndev->db_shift);
694 	iowrite64(~sndev->db_mask, &sndev->mmio_self_dbmsg->idb_mask);
695 
696 	spin_unlock_irqrestore(&sndev->db_mask_lock, irqflags);
697 
698 	return 0;
699 }
700 
701 static u64 switchtec_ntb_db_read_mask(struct ntb_dev *ntb)
702 {
703 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
704 
705 	return (sndev->db_mask >> sndev->db_shift) & sndev->db_valid_mask;
706 }
707 
708 static int switchtec_ntb_peer_db_addr(struct ntb_dev *ntb,
709 				      phys_addr_t *db_addr,
710 				      resource_size_t *db_size)
711 {
712 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
713 	unsigned long offset;
714 
715 	offset = (unsigned long)sndev->mmio_peer_dbmsg->odb -
716 		(unsigned long)sndev->stdev->mmio;
717 
718 	offset += sndev->db_shift / 8;
719 
720 	if (db_addr)
721 		*db_addr = pci_resource_start(ntb->pdev, 0) + offset;
722 	if (db_size)
723 		*db_size = sizeof(u32);
724 
725 	return 0;
726 }
727 
728 static int switchtec_ntb_peer_db_set(struct ntb_dev *ntb, u64 db_bits)
729 {
730 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
731 
732 	iowrite64(db_bits << sndev->db_peer_shift,
733 		  &sndev->mmio_peer_dbmsg->odb);
734 
735 	return 0;
736 }
737 
738 static int switchtec_ntb_spad_count(struct ntb_dev *ntb)
739 {
740 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
741 
742 	return ARRAY_SIZE(sndev->self_shared->spad);
743 }
744 
745 static u32 switchtec_ntb_spad_read(struct ntb_dev *ntb, int idx)
746 {
747 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
748 
749 	if (idx < 0 || idx >= ARRAY_SIZE(sndev->self_shared->spad))
750 		return 0;
751 
752 	if (!sndev->self_shared)
753 		return 0;
754 
755 	return sndev->self_shared->spad[idx];
756 }
757 
758 static int switchtec_ntb_spad_write(struct ntb_dev *ntb, int idx, u32 val)
759 {
760 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
761 
762 	if (idx < 0 || idx >= ARRAY_SIZE(sndev->self_shared->spad))
763 		return -EINVAL;
764 
765 	if (!sndev->self_shared)
766 		return -EIO;
767 
768 	sndev->self_shared->spad[idx] = val;
769 
770 	return 0;
771 }
772 
773 static u32 switchtec_ntb_peer_spad_read(struct ntb_dev *ntb, int pidx,
774 					int sidx)
775 {
776 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
777 
778 	if (pidx != NTB_DEF_PEER_IDX)
779 		return -EINVAL;
780 
781 	if (sidx < 0 || sidx >= ARRAY_SIZE(sndev->peer_shared->spad))
782 		return 0;
783 
784 	if (!sndev->peer_shared)
785 		return 0;
786 
787 	return ioread32(&sndev->peer_shared->spad[sidx]);
788 }
789 
790 static int switchtec_ntb_peer_spad_write(struct ntb_dev *ntb, int pidx,
791 					 int sidx, u32 val)
792 {
793 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
794 
795 	if (pidx != NTB_DEF_PEER_IDX)
796 		return -EINVAL;
797 
798 	if (sidx < 0 || sidx >= ARRAY_SIZE(sndev->peer_shared->spad))
799 		return -EINVAL;
800 
801 	if (!sndev->peer_shared)
802 		return -EIO;
803 
804 	iowrite32(val, &sndev->peer_shared->spad[sidx]);
805 
806 	return 0;
807 }
808 
809 static int switchtec_ntb_peer_spad_addr(struct ntb_dev *ntb, int pidx,
810 					int sidx, phys_addr_t *spad_addr)
811 {
812 	struct switchtec_ntb *sndev = ntb_sndev(ntb);
813 	unsigned long offset;
814 
815 	if (pidx != NTB_DEF_PEER_IDX)
816 		return -EINVAL;
817 
818 	offset = (unsigned long)&sndev->peer_shared->spad[sidx] -
819 		(unsigned long)sndev->stdev->mmio;
820 
821 	if (spad_addr)
822 		*spad_addr = pci_resource_start(ntb->pdev, 0) + offset;
823 
824 	return 0;
825 }
826 
827 static const struct ntb_dev_ops switchtec_ntb_ops = {
828 	.mw_count		= switchtec_ntb_mw_count,
829 	.mw_get_align		= switchtec_ntb_mw_get_align,
830 	.mw_set_trans		= switchtec_ntb_mw_set_trans,
831 	.peer_mw_count		= switchtec_ntb_peer_mw_count,
832 	.peer_mw_get_addr	= switchtec_ntb_peer_mw_get_addr,
833 	.link_is_up		= switchtec_ntb_link_is_up,
834 	.link_enable		= switchtec_ntb_link_enable,
835 	.link_disable		= switchtec_ntb_link_disable,
836 	.db_valid_mask		= switchtec_ntb_db_valid_mask,
837 	.db_vector_count	= switchtec_ntb_db_vector_count,
838 	.db_vector_mask		= switchtec_ntb_db_vector_mask,
839 	.db_read		= switchtec_ntb_db_read,
840 	.db_clear		= switchtec_ntb_db_clear,
841 	.db_set_mask		= switchtec_ntb_db_set_mask,
842 	.db_clear_mask		= switchtec_ntb_db_clear_mask,
843 	.db_read_mask		= switchtec_ntb_db_read_mask,
844 	.peer_db_addr		= switchtec_ntb_peer_db_addr,
845 	.peer_db_set		= switchtec_ntb_peer_db_set,
846 	.spad_count		= switchtec_ntb_spad_count,
847 	.spad_read		= switchtec_ntb_spad_read,
848 	.spad_write		= switchtec_ntb_spad_write,
849 	.peer_spad_read		= switchtec_ntb_peer_spad_read,
850 	.peer_spad_write	= switchtec_ntb_peer_spad_write,
851 	.peer_spad_addr		= switchtec_ntb_peer_spad_addr,
852 };
853 
854 static int switchtec_ntb_init_sndev(struct switchtec_ntb *sndev)
855 {
856 	u64 tpart_vec;
857 	int self;
858 	u64 part_map;
859 	int bit;
860 
861 	sndev->ntb.pdev = sndev->stdev->pdev;
862 	sndev->ntb.topo = NTB_TOPO_SWITCH;
863 	sndev->ntb.ops = &switchtec_ntb_ops;
864 
865 	INIT_WORK(&sndev->link_reinit_work, link_reinit_work);
866 
867 	sndev->self_partition = sndev->stdev->partition;
868 
869 	sndev->mmio_ntb = sndev->stdev->mmio_ntb;
870 
871 	self = sndev->self_partition;
872 	tpart_vec = ioread32(&sndev->mmio_ntb->ntp_info[self].target_part_high);
873 	tpart_vec <<= 32;
874 	tpart_vec |= ioread32(&sndev->mmio_ntb->ntp_info[self].target_part_low);
875 
876 	part_map = ioread64(&sndev->mmio_ntb->ep_map);
877 	part_map &= ~(1 << sndev->self_partition);
878 
879 	if (!ffs(tpart_vec)) {
880 		if (sndev->stdev->partition_count != 2) {
881 			dev_err(&sndev->stdev->dev,
882 				"ntb target partition not defined\n");
883 			return -ENODEV;
884 		}
885 
886 		bit = ffs(part_map);
887 		if (!bit) {
888 			dev_err(&sndev->stdev->dev,
889 				"peer partition is not NT partition\n");
890 			return -ENODEV;
891 		}
892 
893 		sndev->peer_partition = bit - 1;
894 	} else {
895 		if (ffs(tpart_vec) != fls(tpart_vec)) {
896 			dev_err(&sndev->stdev->dev,
897 				"ntb driver only supports 1 pair of 1-1 ntb mapping\n");
898 			return -ENODEV;
899 		}
900 
901 		sndev->peer_partition = ffs(tpart_vec) - 1;
902 		if (!(part_map & (1 << sndev->peer_partition))) {
903 			dev_err(&sndev->stdev->dev,
904 				"ntb target partition is not NT partition\n");
905 			return -ENODEV;
906 		}
907 	}
908 
909 	dev_dbg(&sndev->stdev->dev, "Partition ID %d of %d\n",
910 		sndev->self_partition, sndev->stdev->partition_count);
911 
912 	sndev->mmio_ctrl = (void * __iomem)sndev->mmio_ntb +
913 		SWITCHTEC_NTB_REG_CTRL_OFFSET;
914 	sndev->mmio_dbmsg = (void * __iomem)sndev->mmio_ntb +
915 		SWITCHTEC_NTB_REG_DBMSG_OFFSET;
916 
917 	sndev->mmio_self_ctrl = &sndev->mmio_ctrl[sndev->self_partition];
918 	sndev->mmio_peer_ctrl = &sndev->mmio_ctrl[sndev->peer_partition];
919 	sndev->mmio_self_dbmsg = &sndev->mmio_dbmsg[sndev->self_partition];
920 	sndev->mmio_peer_dbmsg = sndev->mmio_self_dbmsg;
921 
922 	return 0;
923 }
924 
925 static int config_rsvd_lut_win(struct switchtec_ntb *sndev,
926 			       struct ntb_ctrl_regs __iomem *ctl,
927 			       int lut_idx, int partition, u64 addr)
928 {
929 	int peer_bar = sndev->peer_direct_mw_to_bar[0];
930 	u32 ctl_val;
931 	int rc;
932 
933 	rc = switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_LOCK,
934 				   NTB_CTRL_PART_STATUS_LOCKED);
935 	if (rc)
936 		return rc;
937 
938 	ctl_val = ioread32(&ctl->bar_entry[peer_bar].ctl);
939 	ctl_val &= 0xFF;
940 	ctl_val |= NTB_CTRL_BAR_LUT_WIN_EN;
941 	ctl_val |= ilog2(LUT_SIZE) << 8;
942 	ctl_val |= (sndev->nr_lut_mw - 1) << 14;
943 	iowrite32(ctl_val, &ctl->bar_entry[peer_bar].ctl);
944 
945 	iowrite64((NTB_CTRL_LUT_EN | (partition << 1) | addr),
946 		  &ctl->lut_entry[lut_idx]);
947 
948 	rc = switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_CFG,
949 				   NTB_CTRL_PART_STATUS_NORMAL);
950 	if (rc) {
951 		u32 bar_error, lut_error;
952 
953 		bar_error = ioread32(&ctl->bar_error);
954 		lut_error = ioread32(&ctl->lut_error);
955 		dev_err(&sndev->stdev->dev,
956 			"Error setting up reserved lut window: %08x / %08x\n",
957 			bar_error, lut_error);
958 		return rc;
959 	}
960 
961 	return 0;
962 }
963 
964 static int config_req_id_table(struct switchtec_ntb *sndev,
965 			       struct ntb_ctrl_regs __iomem *mmio_ctrl,
966 			       int *req_ids, int count)
967 {
968 	int i, rc = 0;
969 	u32 error;
970 	u32 proxy_id;
971 
972 	if (ioread32(&mmio_ctrl->req_id_table_size) < count) {
973 		dev_err(&sndev->stdev->dev,
974 			"Not enough requester IDs available.\n");
975 		return -EFAULT;
976 	}
977 
978 	rc = switchtec_ntb_part_op(sndev, mmio_ctrl,
979 				   NTB_CTRL_PART_OP_LOCK,
980 				   NTB_CTRL_PART_STATUS_LOCKED);
981 	if (rc)
982 		return rc;
983 
984 	iowrite32(NTB_PART_CTRL_ID_PROT_DIS,
985 		  &mmio_ctrl->partition_ctrl);
986 
987 	for (i = 0; i < count; i++) {
988 		iowrite32(req_ids[i] << 16 | NTB_CTRL_REQ_ID_EN,
989 			  &mmio_ctrl->req_id_table[i]);
990 
991 		proxy_id = ioread32(&mmio_ctrl->req_id_table[i]);
992 		dev_dbg(&sndev->stdev->dev,
993 			"Requester ID %02X:%02X.%X -> BB:%02X.%X\n",
994 			req_ids[i] >> 8, (req_ids[i] >> 3) & 0x1F,
995 			req_ids[i] & 0x7, (proxy_id >> 4) & 0x1F,
996 			(proxy_id >> 1) & 0x7);
997 	}
998 
999 	rc = switchtec_ntb_part_op(sndev, mmio_ctrl,
1000 				   NTB_CTRL_PART_OP_CFG,
1001 				   NTB_CTRL_PART_STATUS_NORMAL);
1002 
1003 	if (rc == -EIO) {
1004 		error = ioread32(&mmio_ctrl->req_id_error);
1005 		dev_err(&sndev->stdev->dev,
1006 			"Error setting up the requester ID table: %08x\n",
1007 			error);
1008 	}
1009 
1010 	return 0;
1011 }
1012 
1013 static int crosslink_setup_mws(struct switchtec_ntb *sndev, int ntb_lut_idx,
1014 			       u64 *mw_addrs, int mw_count)
1015 {
1016 	int rc, i;
1017 	struct ntb_ctrl_regs __iomem *ctl = sndev->mmio_self_ctrl;
1018 	u64 addr;
1019 	size_t size, offset;
1020 	int bar;
1021 	int xlate_pos;
1022 	u32 ctl_val;
1023 
1024 	rc = switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_LOCK,
1025 				   NTB_CTRL_PART_STATUS_LOCKED);
1026 	if (rc)
1027 		return rc;
1028 
1029 	for (i = 0; i < sndev->nr_lut_mw; i++) {
1030 		if (i == ntb_lut_idx)
1031 			continue;
1032 
1033 		addr = mw_addrs[0] + LUT_SIZE * i;
1034 
1035 		iowrite64((NTB_CTRL_LUT_EN | (sndev->peer_partition << 1) |
1036 			   addr),
1037 			  &ctl->lut_entry[i]);
1038 	}
1039 
1040 	sndev->nr_direct_mw = min_t(int, sndev->nr_direct_mw, mw_count);
1041 
1042 	for (i = 0; i < sndev->nr_direct_mw; i++) {
1043 		bar = sndev->direct_mw_to_bar[i];
1044 		offset = (i == 0) ? LUT_SIZE * sndev->nr_lut_mw : 0;
1045 		addr = mw_addrs[i] + offset;
1046 		size = pci_resource_len(sndev->ntb.pdev, bar) - offset;
1047 		xlate_pos = ilog2(size);
1048 
1049 		if (offset && size > offset)
1050 			size = offset;
1051 
1052 		ctl_val = ioread32(&ctl->bar_entry[bar].ctl);
1053 		ctl_val |= NTB_CTRL_BAR_DIR_WIN_EN;
1054 
1055 		iowrite32(ctl_val, &ctl->bar_entry[bar].ctl);
1056 		iowrite32(xlate_pos | size, &ctl->bar_entry[bar].win_size);
1057 		iowrite64(sndev->peer_partition | addr,
1058 			  &ctl->bar_entry[bar].xlate_addr);
1059 	}
1060 
1061 	rc = switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_CFG,
1062 				   NTB_CTRL_PART_STATUS_NORMAL);
1063 	if (rc) {
1064 		u32 bar_error, lut_error;
1065 
1066 		bar_error = ioread32(&ctl->bar_error);
1067 		lut_error = ioread32(&ctl->lut_error);
1068 		dev_err(&sndev->stdev->dev,
1069 			"Error setting up cross link windows: %08x / %08x\n",
1070 			bar_error, lut_error);
1071 		return rc;
1072 	}
1073 
1074 	return 0;
1075 }
1076 
1077 static int crosslink_setup_req_ids(struct switchtec_ntb *sndev,
1078 	struct ntb_ctrl_regs __iomem *mmio_ctrl)
1079 {
1080 	int req_ids[16];
1081 	int i;
1082 	u32 proxy_id;
1083 
1084 	for (i = 0; i < ARRAY_SIZE(req_ids); i++) {
1085 		proxy_id = ioread32(&sndev->mmio_self_ctrl->req_id_table[i]);
1086 
1087 		if (!(proxy_id & NTB_CTRL_REQ_ID_EN))
1088 			break;
1089 
1090 		req_ids[i] = ((proxy_id >> 1) & 0xFF);
1091 	}
1092 
1093 	return config_req_id_table(sndev, mmio_ctrl, req_ids, i);
1094 }
1095 
1096 /*
1097  * In crosslink configuration there is a virtual partition in the
1098  * middle of the two switches. The BARs in this partition have to be
1099  * enumerated and assigned addresses.
1100  */
1101 static int crosslink_enum_partition(struct switchtec_ntb *sndev,
1102 				    u64 *bar_addrs)
1103 {
1104 	struct part_cfg_regs __iomem *part_cfg =
1105 		&sndev->stdev->mmio_part_cfg_all[sndev->peer_partition];
1106 	u32 pff = ioread32(&part_cfg->vep_pff_inst_id);
1107 	struct pff_csr_regs __iomem *mmio_pff =
1108 		&sndev->stdev->mmio_pff_csr[pff];
1109 	const u64 bar_space = 0x1000000000LL;
1110 	u64 bar_addr;
1111 	int bar_cnt = 0;
1112 	int i;
1113 
1114 	iowrite16(0x6, &mmio_pff->pcicmd);
1115 
1116 	for (i = 0; i < ARRAY_SIZE(mmio_pff->pci_bar64); i++) {
1117 		iowrite64(bar_space * i, &mmio_pff->pci_bar64[i]);
1118 		bar_addr = ioread64(&mmio_pff->pci_bar64[i]);
1119 		bar_addr &= ~0xf;
1120 
1121 		dev_dbg(&sndev->stdev->dev,
1122 			"Crosslink BAR%d addr: %llx\n",
1123 			i, bar_addr);
1124 
1125 		if (bar_addr != bar_space * i)
1126 			continue;
1127 
1128 		bar_addrs[bar_cnt++] = bar_addr;
1129 	}
1130 
1131 	return bar_cnt;
1132 }
1133 
1134 static int switchtec_ntb_init_crosslink(struct switchtec_ntb *sndev)
1135 {
1136 	int rc;
1137 	int bar = sndev->direct_mw_to_bar[0];
1138 	const int ntb_lut_idx = 1;
1139 	u64 bar_addrs[6];
1140 	u64 addr;
1141 	int offset;
1142 	int bar_cnt;
1143 
1144 	if (!crosslink_is_enabled(sndev))
1145 		return 0;
1146 
1147 	dev_info(&sndev->stdev->dev, "Using crosslink configuration\n");
1148 	sndev->ntb.topo = NTB_TOPO_CROSSLINK;
1149 
1150 	bar_cnt = crosslink_enum_partition(sndev, bar_addrs);
1151 	if (bar_cnt < sndev->nr_direct_mw + 1) {
1152 		dev_err(&sndev->stdev->dev,
1153 			"Error enumerating crosslink partition\n");
1154 		return -EINVAL;
1155 	}
1156 
1157 	addr = (bar_addrs[0] + SWITCHTEC_GAS_NTB_OFFSET +
1158 		SWITCHTEC_NTB_REG_DBMSG_OFFSET +
1159 		sizeof(struct ntb_dbmsg_regs) * sndev->peer_partition);
1160 
1161 	offset = addr & (LUT_SIZE - 1);
1162 	addr -= offset;
1163 
1164 	rc = config_rsvd_lut_win(sndev, sndev->mmio_self_ctrl, ntb_lut_idx,
1165 				 sndev->peer_partition, addr);
1166 	if (rc)
1167 		return rc;
1168 
1169 	rc = crosslink_setup_mws(sndev, ntb_lut_idx, &bar_addrs[1],
1170 				 bar_cnt - 1);
1171 	if (rc)
1172 		return rc;
1173 
1174 	rc = crosslink_setup_req_ids(sndev, sndev->mmio_peer_ctrl);
1175 	if (rc)
1176 		return rc;
1177 
1178 	sndev->mmio_xlink_win = pci_iomap_range(sndev->stdev->pdev, bar,
1179 						LUT_SIZE, LUT_SIZE);
1180 	if (!sndev->mmio_xlink_win) {
1181 		rc = -ENOMEM;
1182 		return rc;
1183 	}
1184 
1185 	sndev->mmio_peer_dbmsg = sndev->mmio_xlink_win + offset;
1186 	sndev->nr_rsvd_luts++;
1187 
1188 	crosslink_init_dbmsgs(sndev);
1189 
1190 	return 0;
1191 }
1192 
1193 static void switchtec_ntb_deinit_crosslink(struct switchtec_ntb *sndev)
1194 {
1195 	if (sndev->mmio_xlink_win)
1196 		pci_iounmap(sndev->stdev->pdev, sndev->mmio_xlink_win);
1197 }
1198 
1199 static int map_bars(int *map, struct ntb_ctrl_regs __iomem *ctrl)
1200 {
1201 	int i;
1202 	int cnt = 0;
1203 
1204 	for (i = 0; i < ARRAY_SIZE(ctrl->bar_entry); i++) {
1205 		u32 r = ioread32(&ctrl->bar_entry[i].ctl);
1206 
1207 		if (r & NTB_CTRL_BAR_VALID)
1208 			map[cnt++] = i;
1209 	}
1210 
1211 	return cnt;
1212 }
1213 
1214 static void switchtec_ntb_init_mw(struct switchtec_ntb *sndev)
1215 {
1216 	sndev->nr_direct_mw = map_bars(sndev->direct_mw_to_bar,
1217 				       sndev->mmio_self_ctrl);
1218 
1219 	sndev->nr_lut_mw = ioread16(&sndev->mmio_self_ctrl->lut_table_entries);
1220 	sndev->nr_lut_mw = rounddown_pow_of_two(sndev->nr_lut_mw);
1221 
1222 	dev_dbg(&sndev->stdev->dev, "MWs: %d direct, %d lut\n",
1223 		sndev->nr_direct_mw, sndev->nr_lut_mw);
1224 
1225 	sndev->peer_nr_direct_mw = map_bars(sndev->peer_direct_mw_to_bar,
1226 					    sndev->mmio_peer_ctrl);
1227 
1228 	sndev->peer_nr_lut_mw =
1229 		ioread16(&sndev->mmio_peer_ctrl->lut_table_entries);
1230 	sndev->peer_nr_lut_mw = rounddown_pow_of_two(sndev->peer_nr_lut_mw);
1231 
1232 	dev_dbg(&sndev->stdev->dev, "Peer MWs: %d direct, %d lut\n",
1233 		sndev->peer_nr_direct_mw, sndev->peer_nr_lut_mw);
1234 
1235 }
1236 
1237 /*
1238  * There are 64 doorbells in the switch hardware but this is
1239  * shared among all partitions. So we must split them in half
1240  * (32 for each partition). However, the message interrupts are
1241  * also shared with the top 4 doorbells so we just limit this to
1242  * 28 doorbells per partition.
1243  *
1244  * In crosslink mode, each side has it's own dbmsg register so
1245  * they can each use all 60 of the available doorbells.
1246  */
1247 static void switchtec_ntb_init_db(struct switchtec_ntb *sndev)
1248 {
1249 	sndev->db_mask = 0x0FFFFFFFFFFFFFFFULL;
1250 
1251 	if (sndev->mmio_peer_dbmsg != sndev->mmio_self_dbmsg) {
1252 		sndev->db_shift = 0;
1253 		sndev->db_peer_shift = 0;
1254 		sndev->db_valid_mask = sndev->db_mask;
1255 	} else if (sndev->self_partition < sndev->peer_partition) {
1256 		sndev->db_shift = 0;
1257 		sndev->db_peer_shift = 32;
1258 		sndev->db_valid_mask = 0x0FFFFFFF;
1259 	} else {
1260 		sndev->db_shift = 32;
1261 		sndev->db_peer_shift = 0;
1262 		sndev->db_valid_mask = 0x0FFFFFFF;
1263 	}
1264 
1265 	iowrite64(~sndev->db_mask, &sndev->mmio_self_dbmsg->idb_mask);
1266 	iowrite64(sndev->db_valid_mask << sndev->db_peer_shift,
1267 		  &sndev->mmio_peer_dbmsg->odb_mask);
1268 
1269 	dev_dbg(&sndev->stdev->dev, "dbs: shift %d/%d, mask %016llx\n",
1270 		sndev->db_shift, sndev->db_peer_shift, sndev->db_valid_mask);
1271 }
1272 
1273 static void switchtec_ntb_init_msgs(struct switchtec_ntb *sndev)
1274 {
1275 	int i;
1276 	u32 msg_map = 0;
1277 
1278 	for (i = 0; i < ARRAY_SIZE(sndev->mmio_self_dbmsg->imsg); i++) {
1279 		int m = i | sndev->peer_partition << 2;
1280 
1281 		msg_map |= m << i * 8;
1282 	}
1283 
1284 	iowrite32(msg_map, &sndev->mmio_self_dbmsg->msg_map);
1285 
1286 	for (i = 0; i < ARRAY_SIZE(sndev->mmio_self_dbmsg->imsg); i++)
1287 		iowrite64(NTB_DBMSG_IMSG_STATUS | NTB_DBMSG_IMSG_MASK,
1288 			  &sndev->mmio_self_dbmsg->imsg[i]);
1289 }
1290 
1291 static int
1292 switchtec_ntb_init_req_id_table(struct switchtec_ntb *sndev)
1293 {
1294 	int req_ids[2];
1295 
1296 	/*
1297 	 * Root Complex Requester ID (which is 0:00.0)
1298 	 */
1299 	req_ids[0] = 0;
1300 
1301 	/*
1302 	 * Host Bridge Requester ID (as read from the mmap address)
1303 	 */
1304 	req_ids[1] = ioread16(&sndev->mmio_ntb->requester_id);
1305 
1306 	return config_req_id_table(sndev, sndev->mmio_self_ctrl, req_ids,
1307 				   ARRAY_SIZE(req_ids));
1308 }
1309 
1310 static void switchtec_ntb_init_shared(struct switchtec_ntb *sndev)
1311 {
1312 	int i;
1313 
1314 	memset(sndev->self_shared, 0, LUT_SIZE);
1315 	sndev->self_shared->magic = SWITCHTEC_NTB_MAGIC;
1316 	sndev->self_shared->partition_id = sndev->stdev->partition;
1317 
1318 	for (i = 0; i < sndev->nr_direct_mw; i++) {
1319 		int bar = sndev->direct_mw_to_bar[i];
1320 		resource_size_t sz = pci_resource_len(sndev->stdev->pdev, bar);
1321 
1322 		if (i == 0)
1323 			sz = min_t(resource_size_t, sz,
1324 				   LUT_SIZE * sndev->nr_lut_mw);
1325 
1326 		sndev->self_shared->mw_sizes[i] = sz;
1327 	}
1328 
1329 	for (i = 0; i < sndev->nr_lut_mw; i++) {
1330 		int idx = sndev->nr_direct_mw + i;
1331 
1332 		sndev->self_shared->mw_sizes[idx] = LUT_SIZE;
1333 	}
1334 }
1335 
1336 static int switchtec_ntb_init_shared_mw(struct switchtec_ntb *sndev)
1337 {
1338 	int self_bar = sndev->direct_mw_to_bar[0];
1339 	int rc;
1340 
1341 	sndev->nr_rsvd_luts++;
1342 	sndev->self_shared = dma_zalloc_coherent(&sndev->stdev->pdev->dev,
1343 						 LUT_SIZE,
1344 						 &sndev->self_shared_dma,
1345 						 GFP_KERNEL);
1346 	if (!sndev->self_shared) {
1347 		dev_err(&sndev->stdev->dev,
1348 			"unable to allocate memory for shared mw\n");
1349 		return -ENOMEM;
1350 	}
1351 
1352 	switchtec_ntb_init_shared(sndev);
1353 
1354 	rc = config_rsvd_lut_win(sndev, sndev->mmio_peer_ctrl, 0,
1355 				 sndev->self_partition,
1356 				 sndev->self_shared_dma);
1357 	if (rc)
1358 		goto unalloc_and_exit;
1359 
1360 	sndev->peer_shared = pci_iomap(sndev->stdev->pdev, self_bar, LUT_SIZE);
1361 	if (!sndev->peer_shared) {
1362 		rc = -ENOMEM;
1363 		goto unalloc_and_exit;
1364 	}
1365 
1366 	dev_dbg(&sndev->stdev->dev, "Shared MW Ready\n");
1367 	return 0;
1368 
1369 unalloc_and_exit:
1370 	dma_free_coherent(&sndev->stdev->pdev->dev, LUT_SIZE,
1371 			  sndev->self_shared, sndev->self_shared_dma);
1372 
1373 	return rc;
1374 }
1375 
1376 static void switchtec_ntb_deinit_shared_mw(struct switchtec_ntb *sndev)
1377 {
1378 	if (sndev->peer_shared)
1379 		pci_iounmap(sndev->stdev->pdev, sndev->peer_shared);
1380 
1381 	if (sndev->self_shared)
1382 		dma_free_coherent(&sndev->stdev->pdev->dev, LUT_SIZE,
1383 				  sndev->self_shared,
1384 				  sndev->self_shared_dma);
1385 	sndev->nr_rsvd_luts--;
1386 }
1387 
1388 static irqreturn_t switchtec_ntb_doorbell_isr(int irq, void *dev)
1389 {
1390 	struct switchtec_ntb *sndev = dev;
1391 
1392 	dev_dbg(&sndev->stdev->dev, "doorbell\n");
1393 
1394 	ntb_db_event(&sndev->ntb, 0);
1395 
1396 	return IRQ_HANDLED;
1397 }
1398 
1399 static irqreturn_t switchtec_ntb_message_isr(int irq, void *dev)
1400 {
1401 	int i;
1402 	struct switchtec_ntb *sndev = dev;
1403 
1404 	for (i = 0; i < ARRAY_SIZE(sndev->mmio_self_dbmsg->imsg); i++) {
1405 		u64 msg = ioread64(&sndev->mmio_self_dbmsg->imsg[i]);
1406 
1407 		if (msg & NTB_DBMSG_IMSG_STATUS) {
1408 			dev_dbg(&sndev->stdev->dev, "message: %d %08x\n",
1409 				i, (u32)msg);
1410 			iowrite8(1, &sndev->mmio_self_dbmsg->imsg[i].status);
1411 
1412 			if (i == LINK_MESSAGE)
1413 				switchtec_ntb_check_link(sndev, msg);
1414 		}
1415 	}
1416 
1417 	return IRQ_HANDLED;
1418 }
1419 
1420 static int switchtec_ntb_init_db_msg_irq(struct switchtec_ntb *sndev)
1421 {
1422 	int i;
1423 	int rc;
1424 	int doorbell_irq = 0;
1425 	int message_irq = 0;
1426 	int event_irq;
1427 	int idb_vecs = sizeof(sndev->mmio_self_dbmsg->idb_vec_map);
1428 
1429 	event_irq = ioread32(&sndev->stdev->mmio_part_cfg->vep_vector_number);
1430 
1431 	while (doorbell_irq == event_irq)
1432 		doorbell_irq++;
1433 	while (message_irq == doorbell_irq ||
1434 	       message_irq == event_irq)
1435 		message_irq++;
1436 
1437 	dev_dbg(&sndev->stdev->dev, "irqs - event: %d, db: %d, msgs: %d\n",
1438 		event_irq, doorbell_irq, message_irq);
1439 
1440 	for (i = 0; i < idb_vecs - 4; i++)
1441 		iowrite8(doorbell_irq,
1442 			 &sndev->mmio_self_dbmsg->idb_vec_map[i]);
1443 
1444 	for (; i < idb_vecs; i++)
1445 		iowrite8(message_irq,
1446 			 &sndev->mmio_self_dbmsg->idb_vec_map[i]);
1447 
1448 	sndev->doorbell_irq = pci_irq_vector(sndev->stdev->pdev, doorbell_irq);
1449 	sndev->message_irq = pci_irq_vector(sndev->stdev->pdev, message_irq);
1450 
1451 	rc = request_irq(sndev->doorbell_irq,
1452 			 switchtec_ntb_doorbell_isr, 0,
1453 			 "switchtec_ntb_doorbell", sndev);
1454 	if (rc)
1455 		return rc;
1456 
1457 	rc = request_irq(sndev->message_irq,
1458 			 switchtec_ntb_message_isr, 0,
1459 			 "switchtec_ntb_message", sndev);
1460 	if (rc) {
1461 		free_irq(sndev->doorbell_irq, sndev);
1462 		return rc;
1463 	}
1464 
1465 	return 0;
1466 }
1467 
1468 static void switchtec_ntb_deinit_db_msg_irq(struct switchtec_ntb *sndev)
1469 {
1470 	free_irq(sndev->doorbell_irq, sndev);
1471 	free_irq(sndev->message_irq, sndev);
1472 }
1473 
1474 static int switchtec_ntb_reinit_peer(struct switchtec_ntb *sndev)
1475 {
1476 	dev_info(&sndev->stdev->dev, "peer reinitialized\n");
1477 	switchtec_ntb_deinit_shared_mw(sndev);
1478 	switchtec_ntb_init_mw(sndev);
1479 	return switchtec_ntb_init_shared_mw(sndev);
1480 }
1481 
1482 static int switchtec_ntb_add(struct device *dev,
1483 			     struct class_interface *class_intf)
1484 {
1485 	struct switchtec_dev *stdev = to_stdev(dev);
1486 	struct switchtec_ntb *sndev;
1487 	int rc;
1488 
1489 	stdev->sndev = NULL;
1490 
1491 	if (stdev->pdev->class != (PCI_CLASS_BRIDGE_OTHER << 8))
1492 		return -ENODEV;
1493 
1494 	sndev = kzalloc_node(sizeof(*sndev), GFP_KERNEL, dev_to_node(dev));
1495 	if (!sndev)
1496 		return -ENOMEM;
1497 
1498 	sndev->stdev = stdev;
1499 	rc = switchtec_ntb_init_sndev(sndev);
1500 	if (rc)
1501 		goto free_and_exit;
1502 
1503 	switchtec_ntb_init_mw(sndev);
1504 
1505 	rc = switchtec_ntb_init_req_id_table(sndev);
1506 	if (rc)
1507 		goto free_and_exit;
1508 
1509 	rc = switchtec_ntb_init_crosslink(sndev);
1510 	if (rc)
1511 		goto free_and_exit;
1512 
1513 	switchtec_ntb_init_db(sndev);
1514 	switchtec_ntb_init_msgs(sndev);
1515 
1516 	rc = switchtec_ntb_init_shared_mw(sndev);
1517 	if (rc)
1518 		goto deinit_crosslink;
1519 
1520 	rc = switchtec_ntb_init_db_msg_irq(sndev);
1521 	if (rc)
1522 		goto deinit_shared_and_exit;
1523 
1524 	/*
1525 	 * If this host crashed, the other host may think the link is
1526 	 * still up. Tell them to force it down (it will go back up
1527 	 * once we register the ntb device).
1528 	 */
1529 	switchtec_ntb_send_msg(sndev, LINK_MESSAGE, MSG_LINK_FORCE_DOWN);
1530 
1531 	rc = ntb_register_device(&sndev->ntb);
1532 	if (rc)
1533 		goto deinit_and_exit;
1534 
1535 	stdev->sndev = sndev;
1536 	stdev->link_notifier = switchtec_ntb_link_notification;
1537 	dev_info(dev, "NTB device registered\n");
1538 
1539 	return 0;
1540 
1541 deinit_and_exit:
1542 	switchtec_ntb_deinit_db_msg_irq(sndev);
1543 deinit_shared_and_exit:
1544 	switchtec_ntb_deinit_shared_mw(sndev);
1545 deinit_crosslink:
1546 	switchtec_ntb_deinit_crosslink(sndev);
1547 free_and_exit:
1548 	kfree(sndev);
1549 	dev_err(dev, "failed to register ntb device: %d\n", rc);
1550 	return rc;
1551 }
1552 
1553 static void switchtec_ntb_remove(struct device *dev,
1554 				 struct class_interface *class_intf)
1555 {
1556 	struct switchtec_dev *stdev = to_stdev(dev);
1557 	struct switchtec_ntb *sndev = stdev->sndev;
1558 
1559 	if (!sndev)
1560 		return;
1561 
1562 	stdev->link_notifier = NULL;
1563 	stdev->sndev = NULL;
1564 	ntb_unregister_device(&sndev->ntb);
1565 	switchtec_ntb_deinit_db_msg_irq(sndev);
1566 	switchtec_ntb_deinit_shared_mw(sndev);
1567 	switchtec_ntb_deinit_crosslink(sndev);
1568 	kfree(sndev);
1569 	dev_info(dev, "ntb device unregistered\n");
1570 }
1571 
1572 static struct class_interface switchtec_interface  = {
1573 	.add_dev = switchtec_ntb_add,
1574 	.remove_dev = switchtec_ntb_remove,
1575 };
1576 
1577 static int __init switchtec_ntb_init(void)
1578 {
1579 	switchtec_interface.class = switchtec_class;
1580 	return class_interface_register(&switchtec_interface);
1581 }
1582 module_init(switchtec_ntb_init);
1583 
1584 static void __exit switchtec_ntb_exit(void)
1585 {
1586 	class_interface_unregister(&switchtec_interface);
1587 }
1588 module_exit(switchtec_ntb_exit);
1589