xref: /openbmc/linux/drivers/thunderbolt/nhi.c (revision f0417e72)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Thunderbolt driver - NHI driver
4  *
5  * The NHI (native host interface) is the pci device that allows us to send and
6  * receive frames from the thunderbolt bus.
7  *
8  * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
9  * Copyright (C) 2018, Intel Corporation
10  */
11 
12 #include <linux/pm_runtime.h>
13 #include <linux/slab.h>
14 #include <linux/errno.h>
15 #include <linux/pci.h>
16 #include <linux/dma-mapping.h>
17 #include <linux/interrupt.h>
18 #include <linux/iommu.h>
19 #include <linux/module.h>
20 #include <linux/delay.h>
21 #include <linux/property.h>
22 #include <linux/string_helpers.h>
23 
24 #include "nhi.h"
25 #include "nhi_regs.h"
26 #include "tb.h"
27 
28 #define RING_TYPE(ring) ((ring)->is_tx ? "TX ring" : "RX ring")
29 
30 #define RING_FIRST_USABLE_HOPID	1
31 /*
32  * Used with QUIRK_E2E to specify an unused HopID the Rx credits are
33  * transferred.
34  */
35 #define RING_E2E_RESERVED_HOPID	RING_FIRST_USABLE_HOPID
36 /*
37  * Minimal number of vectors when we use MSI-X. Two for control channel
38  * Rx/Tx and the rest four are for cross domain DMA paths.
39  */
40 #define MSIX_MIN_VECS		6
41 #define MSIX_MAX_VECS		16
42 
43 #define NHI_MAILBOX_TIMEOUT	500 /* ms */
44 
45 /* Host interface quirks */
46 #define QUIRK_AUTO_CLEAR_INT	BIT(0)
47 #define QUIRK_E2E		BIT(1)
48 
49 static int ring_interrupt_index(const struct tb_ring *ring)
50 {
51 	int bit = ring->hop;
52 	if (!ring->is_tx)
53 		bit += ring->nhi->hop_count;
54 	return bit;
55 }
56 
57 /*
58  * ring_interrupt_active() - activate/deactivate interrupts for a single ring
59  *
60  * ring->nhi->lock must be held.
61  */
62 static void ring_interrupt_active(struct tb_ring *ring, bool active)
63 {
64 	int reg = REG_RING_INTERRUPT_BASE +
65 		  ring_interrupt_index(ring) / 32 * 4;
66 	int interrupt_bit = ring_interrupt_index(ring) & 31;
67 	int mask = 1 << interrupt_bit;
68 	u32 old, new;
69 
70 	if (ring->irq > 0) {
71 		u32 step, shift, ivr, misc;
72 		void __iomem *ivr_base;
73 		int auto_clear_bit;
74 		int index;
75 
76 		if (ring->is_tx)
77 			index = ring->hop;
78 		else
79 			index = ring->hop + ring->nhi->hop_count;
80 
81 		/*
82 		 * Intel routers support a bit that isn't part of
83 		 * the USB4 spec to ask the hardware to clear
84 		 * interrupt status bits automatically since
85 		 * we already know which interrupt was triggered.
86 		 *
87 		 * Other routers explicitly disable auto-clear
88 		 * to prevent conditions that may occur where two
89 		 * MSIX interrupts are simultaneously active and
90 		 * reading the register clears both of them.
91 		 */
92 		misc = ioread32(ring->nhi->iobase + REG_DMA_MISC);
93 		if (ring->nhi->quirks & QUIRK_AUTO_CLEAR_INT)
94 			auto_clear_bit = REG_DMA_MISC_INT_AUTO_CLEAR;
95 		else
96 			auto_clear_bit = REG_DMA_MISC_DISABLE_AUTO_CLEAR;
97 		if (!(misc & auto_clear_bit))
98 			iowrite32(misc | auto_clear_bit,
99 				  ring->nhi->iobase + REG_DMA_MISC);
100 
101 		ivr_base = ring->nhi->iobase + REG_INT_VEC_ALLOC_BASE;
102 		step = index / REG_INT_VEC_ALLOC_REGS * REG_INT_VEC_ALLOC_BITS;
103 		shift = index % REG_INT_VEC_ALLOC_REGS * REG_INT_VEC_ALLOC_BITS;
104 		ivr = ioread32(ivr_base + step);
105 		ivr &= ~(REG_INT_VEC_ALLOC_MASK << shift);
106 		if (active)
107 			ivr |= ring->vector << shift;
108 		iowrite32(ivr, ivr_base + step);
109 	}
110 
111 	old = ioread32(ring->nhi->iobase + reg);
112 	if (active)
113 		new = old | mask;
114 	else
115 		new = old & ~mask;
116 
117 	dev_dbg(&ring->nhi->pdev->dev,
118 		"%s interrupt at register %#x bit %d (%#x -> %#x)\n",
119 		active ? "enabling" : "disabling", reg, interrupt_bit, old, new);
120 
121 	if (new == old)
122 		dev_WARN(&ring->nhi->pdev->dev,
123 					 "interrupt for %s %d is already %s\n",
124 					 RING_TYPE(ring), ring->hop,
125 					 active ? "enabled" : "disabled");
126 	iowrite32(new, ring->nhi->iobase + reg);
127 }
128 
129 /*
130  * nhi_disable_interrupts() - disable interrupts for all rings
131  *
132  * Use only during init and shutdown.
133  */
134 static void nhi_disable_interrupts(struct tb_nhi *nhi)
135 {
136 	int i = 0;
137 	/* disable interrupts */
138 	for (i = 0; i < RING_INTERRUPT_REG_COUNT(nhi); i++)
139 		iowrite32(0, nhi->iobase + REG_RING_INTERRUPT_BASE + 4 * i);
140 
141 	/* clear interrupt status bits */
142 	for (i = 0; i < RING_NOTIFY_REG_COUNT(nhi); i++)
143 		ioread32(nhi->iobase + REG_RING_NOTIFY_BASE + 4 * i);
144 }
145 
146 /* ring helper methods */
147 
148 static void __iomem *ring_desc_base(struct tb_ring *ring)
149 {
150 	void __iomem *io = ring->nhi->iobase;
151 	io += ring->is_tx ? REG_TX_RING_BASE : REG_RX_RING_BASE;
152 	io += ring->hop * 16;
153 	return io;
154 }
155 
156 static void __iomem *ring_options_base(struct tb_ring *ring)
157 {
158 	void __iomem *io = ring->nhi->iobase;
159 	io += ring->is_tx ? REG_TX_OPTIONS_BASE : REG_RX_OPTIONS_BASE;
160 	io += ring->hop * 32;
161 	return io;
162 }
163 
164 static void ring_iowrite_cons(struct tb_ring *ring, u16 cons)
165 {
166 	/*
167 	 * The other 16-bits in the register is read-only and writes to it
168 	 * are ignored by the hardware so we can save one ioread32() by
169 	 * filling the read-only bits with zeroes.
170 	 */
171 	iowrite32(cons, ring_desc_base(ring) + 8);
172 }
173 
174 static void ring_iowrite_prod(struct tb_ring *ring, u16 prod)
175 {
176 	/* See ring_iowrite_cons() above for explanation */
177 	iowrite32(prod << 16, ring_desc_base(ring) + 8);
178 }
179 
180 static void ring_iowrite32desc(struct tb_ring *ring, u32 value, u32 offset)
181 {
182 	iowrite32(value, ring_desc_base(ring) + offset);
183 }
184 
185 static void ring_iowrite64desc(struct tb_ring *ring, u64 value, u32 offset)
186 {
187 	iowrite32(value, ring_desc_base(ring) + offset);
188 	iowrite32(value >> 32, ring_desc_base(ring) + offset + 4);
189 }
190 
191 static void ring_iowrite32options(struct tb_ring *ring, u32 value, u32 offset)
192 {
193 	iowrite32(value, ring_options_base(ring) + offset);
194 }
195 
196 static bool ring_full(struct tb_ring *ring)
197 {
198 	return ((ring->head + 1) % ring->size) == ring->tail;
199 }
200 
201 static bool ring_empty(struct tb_ring *ring)
202 {
203 	return ring->head == ring->tail;
204 }
205 
206 /*
207  * ring_write_descriptors() - post frames from ring->queue to the controller
208  *
209  * ring->lock is held.
210  */
211 static void ring_write_descriptors(struct tb_ring *ring)
212 {
213 	struct ring_frame *frame, *n;
214 	struct ring_desc *descriptor;
215 	list_for_each_entry_safe(frame, n, &ring->queue, list) {
216 		if (ring_full(ring))
217 			break;
218 		list_move_tail(&frame->list, &ring->in_flight);
219 		descriptor = &ring->descriptors[ring->head];
220 		descriptor->phys = frame->buffer_phy;
221 		descriptor->time = 0;
222 		descriptor->flags = RING_DESC_POSTED | RING_DESC_INTERRUPT;
223 		if (ring->is_tx) {
224 			descriptor->length = frame->size;
225 			descriptor->eof = frame->eof;
226 			descriptor->sof = frame->sof;
227 		}
228 		ring->head = (ring->head + 1) % ring->size;
229 		if (ring->is_tx)
230 			ring_iowrite_prod(ring, ring->head);
231 		else
232 			ring_iowrite_cons(ring, ring->head);
233 	}
234 }
235 
236 /*
237  * ring_work() - progress completed frames
238  *
239  * If the ring is shutting down then all frames are marked as canceled and
240  * their callbacks are invoked.
241  *
242  * Otherwise we collect all completed frame from the ring buffer, write new
243  * frame to the ring buffer and invoke the callbacks for the completed frames.
244  */
245 static void ring_work(struct work_struct *work)
246 {
247 	struct tb_ring *ring = container_of(work, typeof(*ring), work);
248 	struct ring_frame *frame;
249 	bool canceled = false;
250 	unsigned long flags;
251 	LIST_HEAD(done);
252 
253 	spin_lock_irqsave(&ring->lock, flags);
254 
255 	if (!ring->running) {
256 		/*  Move all frames to done and mark them as canceled. */
257 		list_splice_tail_init(&ring->in_flight, &done);
258 		list_splice_tail_init(&ring->queue, &done);
259 		canceled = true;
260 		goto invoke_callback;
261 	}
262 
263 	while (!ring_empty(ring)) {
264 		if (!(ring->descriptors[ring->tail].flags
265 				& RING_DESC_COMPLETED))
266 			break;
267 		frame = list_first_entry(&ring->in_flight, typeof(*frame),
268 					 list);
269 		list_move_tail(&frame->list, &done);
270 		if (!ring->is_tx) {
271 			frame->size = ring->descriptors[ring->tail].length;
272 			frame->eof = ring->descriptors[ring->tail].eof;
273 			frame->sof = ring->descriptors[ring->tail].sof;
274 			frame->flags = ring->descriptors[ring->tail].flags;
275 		}
276 		ring->tail = (ring->tail + 1) % ring->size;
277 	}
278 	ring_write_descriptors(ring);
279 
280 invoke_callback:
281 	/* allow callbacks to schedule new work */
282 	spin_unlock_irqrestore(&ring->lock, flags);
283 	while (!list_empty(&done)) {
284 		frame = list_first_entry(&done, typeof(*frame), list);
285 		/*
286 		 * The callback may reenqueue or delete frame.
287 		 * Do not hold on to it.
288 		 */
289 		list_del_init(&frame->list);
290 		if (frame->callback)
291 			frame->callback(ring, frame, canceled);
292 	}
293 }
294 
295 int __tb_ring_enqueue(struct tb_ring *ring, struct ring_frame *frame)
296 {
297 	unsigned long flags;
298 	int ret = 0;
299 
300 	spin_lock_irqsave(&ring->lock, flags);
301 	if (ring->running) {
302 		list_add_tail(&frame->list, &ring->queue);
303 		ring_write_descriptors(ring);
304 	} else {
305 		ret = -ESHUTDOWN;
306 	}
307 	spin_unlock_irqrestore(&ring->lock, flags);
308 	return ret;
309 }
310 EXPORT_SYMBOL_GPL(__tb_ring_enqueue);
311 
312 /**
313  * tb_ring_poll() - Poll one completed frame from the ring
314  * @ring: Ring to poll
315  *
316  * This function can be called when @start_poll callback of the @ring
317  * has been called. It will read one completed frame from the ring and
318  * return it to the caller. Returns %NULL if there is no more completed
319  * frames.
320  */
321 struct ring_frame *tb_ring_poll(struct tb_ring *ring)
322 {
323 	struct ring_frame *frame = NULL;
324 	unsigned long flags;
325 
326 	spin_lock_irqsave(&ring->lock, flags);
327 	if (!ring->running)
328 		goto unlock;
329 	if (ring_empty(ring))
330 		goto unlock;
331 
332 	if (ring->descriptors[ring->tail].flags & RING_DESC_COMPLETED) {
333 		frame = list_first_entry(&ring->in_flight, typeof(*frame),
334 					 list);
335 		list_del_init(&frame->list);
336 
337 		if (!ring->is_tx) {
338 			frame->size = ring->descriptors[ring->tail].length;
339 			frame->eof = ring->descriptors[ring->tail].eof;
340 			frame->sof = ring->descriptors[ring->tail].sof;
341 			frame->flags = ring->descriptors[ring->tail].flags;
342 		}
343 
344 		ring->tail = (ring->tail + 1) % ring->size;
345 	}
346 
347 unlock:
348 	spin_unlock_irqrestore(&ring->lock, flags);
349 	return frame;
350 }
351 EXPORT_SYMBOL_GPL(tb_ring_poll);
352 
353 static void __ring_interrupt_mask(struct tb_ring *ring, bool mask)
354 {
355 	int idx = ring_interrupt_index(ring);
356 	int reg = REG_RING_INTERRUPT_BASE + idx / 32 * 4;
357 	int bit = idx % 32;
358 	u32 val;
359 
360 	val = ioread32(ring->nhi->iobase + reg);
361 	if (mask)
362 		val &= ~BIT(bit);
363 	else
364 		val |= BIT(bit);
365 	iowrite32(val, ring->nhi->iobase + reg);
366 }
367 
368 /* Both @nhi->lock and @ring->lock should be held */
369 static void __ring_interrupt(struct tb_ring *ring)
370 {
371 	if (!ring->running)
372 		return;
373 
374 	if (ring->start_poll) {
375 		__ring_interrupt_mask(ring, true);
376 		ring->start_poll(ring->poll_data);
377 	} else {
378 		schedule_work(&ring->work);
379 	}
380 }
381 
382 /**
383  * tb_ring_poll_complete() - Re-start interrupt for the ring
384  * @ring: Ring to re-start the interrupt
385  *
386  * This will re-start (unmask) the ring interrupt once the user is done
387  * with polling.
388  */
389 void tb_ring_poll_complete(struct tb_ring *ring)
390 {
391 	unsigned long flags;
392 
393 	spin_lock_irqsave(&ring->nhi->lock, flags);
394 	spin_lock(&ring->lock);
395 	if (ring->start_poll)
396 		__ring_interrupt_mask(ring, false);
397 	spin_unlock(&ring->lock);
398 	spin_unlock_irqrestore(&ring->nhi->lock, flags);
399 }
400 EXPORT_SYMBOL_GPL(tb_ring_poll_complete);
401 
402 static void ring_clear_msix(const struct tb_ring *ring)
403 {
404 	int bit;
405 
406 	if (ring->nhi->quirks & QUIRK_AUTO_CLEAR_INT)
407 		return;
408 
409 	bit = ring_interrupt_index(ring) & 31;
410 	if (ring->is_tx)
411 		iowrite32(BIT(bit), ring->nhi->iobase + REG_RING_INT_CLEAR);
412 	else
413 		iowrite32(BIT(bit), ring->nhi->iobase + REG_RING_INT_CLEAR +
414 			  4 * (ring->nhi->hop_count / 32));
415 }
416 
417 static irqreturn_t ring_msix(int irq, void *data)
418 {
419 	struct tb_ring *ring = data;
420 
421 	spin_lock(&ring->nhi->lock);
422 	ring_clear_msix(ring);
423 	spin_lock(&ring->lock);
424 	__ring_interrupt(ring);
425 	spin_unlock(&ring->lock);
426 	spin_unlock(&ring->nhi->lock);
427 
428 	return IRQ_HANDLED;
429 }
430 
431 static int ring_request_msix(struct tb_ring *ring, bool no_suspend)
432 {
433 	struct tb_nhi *nhi = ring->nhi;
434 	unsigned long irqflags;
435 	int ret;
436 
437 	if (!nhi->pdev->msix_enabled)
438 		return 0;
439 
440 	ret = ida_simple_get(&nhi->msix_ida, 0, MSIX_MAX_VECS, GFP_KERNEL);
441 	if (ret < 0)
442 		return ret;
443 
444 	ring->vector = ret;
445 
446 	ret = pci_irq_vector(ring->nhi->pdev, ring->vector);
447 	if (ret < 0)
448 		goto err_ida_remove;
449 
450 	ring->irq = ret;
451 
452 	irqflags = no_suspend ? IRQF_NO_SUSPEND : 0;
453 	ret = request_irq(ring->irq, ring_msix, irqflags, "thunderbolt", ring);
454 	if (ret)
455 		goto err_ida_remove;
456 
457 	return 0;
458 
459 err_ida_remove:
460 	ida_simple_remove(&nhi->msix_ida, ring->vector);
461 
462 	return ret;
463 }
464 
465 static void ring_release_msix(struct tb_ring *ring)
466 {
467 	if (ring->irq <= 0)
468 		return;
469 
470 	free_irq(ring->irq, ring);
471 	ida_simple_remove(&ring->nhi->msix_ida, ring->vector);
472 	ring->vector = 0;
473 	ring->irq = 0;
474 }
475 
476 static int nhi_alloc_hop(struct tb_nhi *nhi, struct tb_ring *ring)
477 {
478 	unsigned int start_hop = RING_FIRST_USABLE_HOPID;
479 	int ret = 0;
480 
481 	if (nhi->quirks & QUIRK_E2E) {
482 		start_hop = RING_FIRST_USABLE_HOPID + 1;
483 		if (ring->flags & RING_FLAG_E2E && !ring->is_tx) {
484 			dev_dbg(&nhi->pdev->dev, "quirking E2E TX HopID %u -> %u\n",
485 				ring->e2e_tx_hop, RING_E2E_RESERVED_HOPID);
486 			ring->e2e_tx_hop = RING_E2E_RESERVED_HOPID;
487 		}
488 	}
489 
490 	spin_lock_irq(&nhi->lock);
491 
492 	if (ring->hop < 0) {
493 		unsigned int i;
494 
495 		/*
496 		 * Automatically allocate HopID from the non-reserved
497 		 * range 1 .. hop_count - 1.
498 		 */
499 		for (i = start_hop; i < nhi->hop_count; i++) {
500 			if (ring->is_tx) {
501 				if (!nhi->tx_rings[i]) {
502 					ring->hop = i;
503 					break;
504 				}
505 			} else {
506 				if (!nhi->rx_rings[i]) {
507 					ring->hop = i;
508 					break;
509 				}
510 			}
511 		}
512 	}
513 
514 	if (ring->hop > 0 && ring->hop < start_hop) {
515 		dev_warn(&nhi->pdev->dev, "invalid hop: %d\n", ring->hop);
516 		ret = -EINVAL;
517 		goto err_unlock;
518 	}
519 	if (ring->hop < 0 || ring->hop >= nhi->hop_count) {
520 		dev_warn(&nhi->pdev->dev, "invalid hop: %d\n", ring->hop);
521 		ret = -EINVAL;
522 		goto err_unlock;
523 	}
524 	if (ring->is_tx && nhi->tx_rings[ring->hop]) {
525 		dev_warn(&nhi->pdev->dev, "TX hop %d already allocated\n",
526 			 ring->hop);
527 		ret = -EBUSY;
528 		goto err_unlock;
529 	} else if (!ring->is_tx && nhi->rx_rings[ring->hop]) {
530 		dev_warn(&nhi->pdev->dev, "RX hop %d already allocated\n",
531 			 ring->hop);
532 		ret = -EBUSY;
533 		goto err_unlock;
534 	}
535 
536 	if (ring->is_tx)
537 		nhi->tx_rings[ring->hop] = ring;
538 	else
539 		nhi->rx_rings[ring->hop] = ring;
540 
541 err_unlock:
542 	spin_unlock_irq(&nhi->lock);
543 
544 	return ret;
545 }
546 
547 static struct tb_ring *tb_ring_alloc(struct tb_nhi *nhi, u32 hop, int size,
548 				     bool transmit, unsigned int flags,
549 				     int e2e_tx_hop, u16 sof_mask, u16 eof_mask,
550 				     void (*start_poll)(void *),
551 				     void *poll_data)
552 {
553 	struct tb_ring *ring = NULL;
554 
555 	dev_dbg(&nhi->pdev->dev, "allocating %s ring %d of size %d\n",
556 		transmit ? "TX" : "RX", hop, size);
557 
558 	ring = kzalloc(sizeof(*ring), GFP_KERNEL);
559 	if (!ring)
560 		return NULL;
561 
562 	spin_lock_init(&ring->lock);
563 	INIT_LIST_HEAD(&ring->queue);
564 	INIT_LIST_HEAD(&ring->in_flight);
565 	INIT_WORK(&ring->work, ring_work);
566 
567 	ring->nhi = nhi;
568 	ring->hop = hop;
569 	ring->is_tx = transmit;
570 	ring->size = size;
571 	ring->flags = flags;
572 	ring->e2e_tx_hop = e2e_tx_hop;
573 	ring->sof_mask = sof_mask;
574 	ring->eof_mask = eof_mask;
575 	ring->head = 0;
576 	ring->tail = 0;
577 	ring->running = false;
578 	ring->start_poll = start_poll;
579 	ring->poll_data = poll_data;
580 
581 	ring->descriptors = dma_alloc_coherent(&ring->nhi->pdev->dev,
582 			size * sizeof(*ring->descriptors),
583 			&ring->descriptors_dma, GFP_KERNEL | __GFP_ZERO);
584 	if (!ring->descriptors)
585 		goto err_free_ring;
586 
587 	if (ring_request_msix(ring, flags & RING_FLAG_NO_SUSPEND))
588 		goto err_free_descs;
589 
590 	if (nhi_alloc_hop(nhi, ring))
591 		goto err_release_msix;
592 
593 	return ring;
594 
595 err_release_msix:
596 	ring_release_msix(ring);
597 err_free_descs:
598 	dma_free_coherent(&ring->nhi->pdev->dev,
599 			  ring->size * sizeof(*ring->descriptors),
600 			  ring->descriptors, ring->descriptors_dma);
601 err_free_ring:
602 	kfree(ring);
603 
604 	return NULL;
605 }
606 
607 /**
608  * tb_ring_alloc_tx() - Allocate DMA ring for transmit
609  * @nhi: Pointer to the NHI the ring is to be allocated
610  * @hop: HopID (ring) to allocate
611  * @size: Number of entries in the ring
612  * @flags: Flags for the ring
613  */
614 struct tb_ring *tb_ring_alloc_tx(struct tb_nhi *nhi, int hop, int size,
615 				 unsigned int flags)
616 {
617 	return tb_ring_alloc(nhi, hop, size, true, flags, 0, 0, 0, NULL, NULL);
618 }
619 EXPORT_SYMBOL_GPL(tb_ring_alloc_tx);
620 
621 /**
622  * tb_ring_alloc_rx() - Allocate DMA ring for receive
623  * @nhi: Pointer to the NHI the ring is to be allocated
624  * @hop: HopID (ring) to allocate. Pass %-1 for automatic allocation.
625  * @size: Number of entries in the ring
626  * @flags: Flags for the ring
627  * @e2e_tx_hop: Transmit HopID when E2E is enabled in @flags
628  * @sof_mask: Mask of PDF values that start a frame
629  * @eof_mask: Mask of PDF values that end a frame
630  * @start_poll: If not %NULL the ring will call this function when an
631  *		interrupt is triggered and masked, instead of callback
632  *		in each Rx frame.
633  * @poll_data: Optional data passed to @start_poll
634  */
635 struct tb_ring *tb_ring_alloc_rx(struct tb_nhi *nhi, int hop, int size,
636 				 unsigned int flags, int e2e_tx_hop,
637 				 u16 sof_mask, u16 eof_mask,
638 				 void (*start_poll)(void *), void *poll_data)
639 {
640 	return tb_ring_alloc(nhi, hop, size, false, flags, e2e_tx_hop, sof_mask, eof_mask,
641 			     start_poll, poll_data);
642 }
643 EXPORT_SYMBOL_GPL(tb_ring_alloc_rx);
644 
645 /**
646  * tb_ring_start() - enable a ring
647  * @ring: Ring to start
648  *
649  * Must not be invoked in parallel with tb_ring_stop().
650  */
651 void tb_ring_start(struct tb_ring *ring)
652 {
653 	u16 frame_size;
654 	u32 flags;
655 
656 	spin_lock_irq(&ring->nhi->lock);
657 	spin_lock(&ring->lock);
658 	if (ring->nhi->going_away)
659 		goto err;
660 	if (ring->running) {
661 		dev_WARN(&ring->nhi->pdev->dev, "ring already started\n");
662 		goto err;
663 	}
664 	dev_dbg(&ring->nhi->pdev->dev, "starting %s %d\n",
665 		RING_TYPE(ring), ring->hop);
666 
667 	if (ring->flags & RING_FLAG_FRAME) {
668 		/* Means 4096 */
669 		frame_size = 0;
670 		flags = RING_FLAG_ENABLE;
671 	} else {
672 		frame_size = TB_FRAME_SIZE;
673 		flags = RING_FLAG_ENABLE | RING_FLAG_RAW;
674 	}
675 
676 	ring_iowrite64desc(ring, ring->descriptors_dma, 0);
677 	if (ring->is_tx) {
678 		ring_iowrite32desc(ring, ring->size, 12);
679 		ring_iowrite32options(ring, 0, 4); /* time releated ? */
680 		ring_iowrite32options(ring, flags, 0);
681 	} else {
682 		u32 sof_eof_mask = ring->sof_mask << 16 | ring->eof_mask;
683 
684 		ring_iowrite32desc(ring, (frame_size << 16) | ring->size, 12);
685 		ring_iowrite32options(ring, sof_eof_mask, 4);
686 		ring_iowrite32options(ring, flags, 0);
687 	}
688 
689 	/*
690 	 * Now that the ring valid bit is set we can configure E2E if
691 	 * enabled for the ring.
692 	 */
693 	if (ring->flags & RING_FLAG_E2E) {
694 		if (!ring->is_tx) {
695 			u32 hop;
696 
697 			hop = ring->e2e_tx_hop << REG_RX_OPTIONS_E2E_HOP_SHIFT;
698 			hop &= REG_RX_OPTIONS_E2E_HOP_MASK;
699 			flags |= hop;
700 
701 			dev_dbg(&ring->nhi->pdev->dev,
702 				"enabling E2E for %s %d with TX HopID %d\n",
703 				RING_TYPE(ring), ring->hop, ring->e2e_tx_hop);
704 		} else {
705 			dev_dbg(&ring->nhi->pdev->dev, "enabling E2E for %s %d\n",
706 				RING_TYPE(ring), ring->hop);
707 		}
708 
709 		flags |= RING_FLAG_E2E_FLOW_CONTROL;
710 		ring_iowrite32options(ring, flags, 0);
711 	}
712 
713 	ring_interrupt_active(ring, true);
714 	ring->running = true;
715 err:
716 	spin_unlock(&ring->lock);
717 	spin_unlock_irq(&ring->nhi->lock);
718 }
719 EXPORT_SYMBOL_GPL(tb_ring_start);
720 
721 /**
722  * tb_ring_stop() - shutdown a ring
723  * @ring: Ring to stop
724  *
725  * Must not be invoked from a callback.
726  *
727  * This method will disable the ring. Further calls to
728  * tb_ring_tx/tb_ring_rx will return -ESHUTDOWN until ring_stop has been
729  * called.
730  *
731  * All enqueued frames will be canceled and their callbacks will be executed
732  * with frame->canceled set to true (on the callback thread). This method
733  * returns only after all callback invocations have finished.
734  */
735 void tb_ring_stop(struct tb_ring *ring)
736 {
737 	spin_lock_irq(&ring->nhi->lock);
738 	spin_lock(&ring->lock);
739 	dev_dbg(&ring->nhi->pdev->dev, "stopping %s %d\n",
740 		RING_TYPE(ring), ring->hop);
741 	if (ring->nhi->going_away)
742 		goto err;
743 	if (!ring->running) {
744 		dev_WARN(&ring->nhi->pdev->dev, "%s %d already stopped\n",
745 			 RING_TYPE(ring), ring->hop);
746 		goto err;
747 	}
748 	ring_interrupt_active(ring, false);
749 
750 	ring_iowrite32options(ring, 0, 0);
751 	ring_iowrite64desc(ring, 0, 0);
752 	ring_iowrite32desc(ring, 0, 8);
753 	ring_iowrite32desc(ring, 0, 12);
754 	ring->head = 0;
755 	ring->tail = 0;
756 	ring->running = false;
757 
758 err:
759 	spin_unlock(&ring->lock);
760 	spin_unlock_irq(&ring->nhi->lock);
761 
762 	/*
763 	 * schedule ring->work to invoke callbacks on all remaining frames.
764 	 */
765 	schedule_work(&ring->work);
766 	flush_work(&ring->work);
767 }
768 EXPORT_SYMBOL_GPL(tb_ring_stop);
769 
770 /*
771  * tb_ring_free() - free ring
772  *
773  * When this method returns all invocations of ring->callback will have
774  * finished.
775  *
776  * Ring must be stopped.
777  *
778  * Must NOT be called from ring_frame->callback!
779  */
780 void tb_ring_free(struct tb_ring *ring)
781 {
782 	spin_lock_irq(&ring->nhi->lock);
783 	/*
784 	 * Dissociate the ring from the NHI. This also ensures that
785 	 * nhi_interrupt_work cannot reschedule ring->work.
786 	 */
787 	if (ring->is_tx)
788 		ring->nhi->tx_rings[ring->hop] = NULL;
789 	else
790 		ring->nhi->rx_rings[ring->hop] = NULL;
791 
792 	if (ring->running) {
793 		dev_WARN(&ring->nhi->pdev->dev, "%s %d still running\n",
794 			 RING_TYPE(ring), ring->hop);
795 	}
796 	spin_unlock_irq(&ring->nhi->lock);
797 
798 	ring_release_msix(ring);
799 
800 	dma_free_coherent(&ring->nhi->pdev->dev,
801 			  ring->size * sizeof(*ring->descriptors),
802 			  ring->descriptors, ring->descriptors_dma);
803 
804 	ring->descriptors = NULL;
805 	ring->descriptors_dma = 0;
806 
807 
808 	dev_dbg(&ring->nhi->pdev->dev, "freeing %s %d\n", RING_TYPE(ring),
809 		ring->hop);
810 
811 	/*
812 	 * ring->work can no longer be scheduled (it is scheduled only
813 	 * by nhi_interrupt_work, ring_stop and ring_msix). Wait for it
814 	 * to finish before freeing the ring.
815 	 */
816 	flush_work(&ring->work);
817 	kfree(ring);
818 }
819 EXPORT_SYMBOL_GPL(tb_ring_free);
820 
821 /**
822  * nhi_mailbox_cmd() - Send a command through NHI mailbox
823  * @nhi: Pointer to the NHI structure
824  * @cmd: Command to send
825  * @data: Data to be send with the command
826  *
827  * Sends mailbox command to the firmware running on NHI. Returns %0 in
828  * case of success and negative errno in case of failure.
829  */
830 int nhi_mailbox_cmd(struct tb_nhi *nhi, enum nhi_mailbox_cmd cmd, u32 data)
831 {
832 	ktime_t timeout;
833 	u32 val;
834 
835 	iowrite32(data, nhi->iobase + REG_INMAIL_DATA);
836 
837 	val = ioread32(nhi->iobase + REG_INMAIL_CMD);
838 	val &= ~(REG_INMAIL_CMD_MASK | REG_INMAIL_ERROR);
839 	val |= REG_INMAIL_OP_REQUEST | cmd;
840 	iowrite32(val, nhi->iobase + REG_INMAIL_CMD);
841 
842 	timeout = ktime_add_ms(ktime_get(), NHI_MAILBOX_TIMEOUT);
843 	do {
844 		val = ioread32(nhi->iobase + REG_INMAIL_CMD);
845 		if (!(val & REG_INMAIL_OP_REQUEST))
846 			break;
847 		usleep_range(10, 20);
848 	} while (ktime_before(ktime_get(), timeout));
849 
850 	if (val & REG_INMAIL_OP_REQUEST)
851 		return -ETIMEDOUT;
852 	if (val & REG_INMAIL_ERROR)
853 		return -EIO;
854 
855 	return 0;
856 }
857 
858 /**
859  * nhi_mailbox_mode() - Return current firmware operation mode
860  * @nhi: Pointer to the NHI structure
861  *
862  * The function reads current firmware operation mode using NHI mailbox
863  * registers and returns it to the caller.
864  */
865 enum nhi_fw_mode nhi_mailbox_mode(struct tb_nhi *nhi)
866 {
867 	u32 val;
868 
869 	val = ioread32(nhi->iobase + REG_OUTMAIL_CMD);
870 	val &= REG_OUTMAIL_CMD_OPMODE_MASK;
871 	val >>= REG_OUTMAIL_CMD_OPMODE_SHIFT;
872 
873 	return (enum nhi_fw_mode)val;
874 }
875 
876 static void nhi_interrupt_work(struct work_struct *work)
877 {
878 	struct tb_nhi *nhi = container_of(work, typeof(*nhi), interrupt_work);
879 	int value = 0; /* Suppress uninitialized usage warning. */
880 	int bit;
881 	int hop = -1;
882 	int type = 0; /* current interrupt type 0: TX, 1: RX, 2: RX overflow */
883 	struct tb_ring *ring;
884 
885 	spin_lock_irq(&nhi->lock);
886 
887 	/*
888 	 * Starting at REG_RING_NOTIFY_BASE there are three status bitfields
889 	 * (TX, RX, RX overflow). We iterate over the bits and read a new
890 	 * dwords as required. The registers are cleared on read.
891 	 */
892 	for (bit = 0; bit < 3 * nhi->hop_count; bit++) {
893 		if (bit % 32 == 0)
894 			value = ioread32(nhi->iobase
895 					 + REG_RING_NOTIFY_BASE
896 					 + 4 * (bit / 32));
897 		if (++hop == nhi->hop_count) {
898 			hop = 0;
899 			type++;
900 		}
901 		if ((value & (1 << (bit % 32))) == 0)
902 			continue;
903 		if (type == 2) {
904 			dev_warn(&nhi->pdev->dev,
905 				 "RX overflow for ring %d\n",
906 				 hop);
907 			continue;
908 		}
909 		if (type == 0)
910 			ring = nhi->tx_rings[hop];
911 		else
912 			ring = nhi->rx_rings[hop];
913 		if (ring == NULL) {
914 			dev_warn(&nhi->pdev->dev,
915 				 "got interrupt for inactive %s ring %d\n",
916 				 type ? "RX" : "TX",
917 				 hop);
918 			continue;
919 		}
920 
921 		spin_lock(&ring->lock);
922 		__ring_interrupt(ring);
923 		spin_unlock(&ring->lock);
924 	}
925 	spin_unlock_irq(&nhi->lock);
926 }
927 
928 static irqreturn_t nhi_msi(int irq, void *data)
929 {
930 	struct tb_nhi *nhi = data;
931 	schedule_work(&nhi->interrupt_work);
932 	return IRQ_HANDLED;
933 }
934 
935 static int __nhi_suspend_noirq(struct device *dev, bool wakeup)
936 {
937 	struct pci_dev *pdev = to_pci_dev(dev);
938 	struct tb *tb = pci_get_drvdata(pdev);
939 	struct tb_nhi *nhi = tb->nhi;
940 	int ret;
941 
942 	ret = tb_domain_suspend_noirq(tb);
943 	if (ret)
944 		return ret;
945 
946 	if (nhi->ops && nhi->ops->suspend_noirq) {
947 		ret = nhi->ops->suspend_noirq(tb->nhi, wakeup);
948 		if (ret)
949 			return ret;
950 	}
951 
952 	return 0;
953 }
954 
955 static int nhi_suspend_noirq(struct device *dev)
956 {
957 	return __nhi_suspend_noirq(dev, device_may_wakeup(dev));
958 }
959 
960 static int nhi_freeze_noirq(struct device *dev)
961 {
962 	struct pci_dev *pdev = to_pci_dev(dev);
963 	struct tb *tb = pci_get_drvdata(pdev);
964 
965 	return tb_domain_freeze_noirq(tb);
966 }
967 
968 static int nhi_thaw_noirq(struct device *dev)
969 {
970 	struct pci_dev *pdev = to_pci_dev(dev);
971 	struct tb *tb = pci_get_drvdata(pdev);
972 
973 	return tb_domain_thaw_noirq(tb);
974 }
975 
976 static bool nhi_wake_supported(struct pci_dev *pdev)
977 {
978 	u8 val;
979 
980 	/*
981 	 * If power rails are sustainable for wakeup from S4 this
982 	 * property is set by the BIOS.
983 	 */
984 	if (device_property_read_u8(&pdev->dev, "WAKE_SUPPORTED", &val))
985 		return !!val;
986 
987 	return true;
988 }
989 
990 static int nhi_poweroff_noirq(struct device *dev)
991 {
992 	struct pci_dev *pdev = to_pci_dev(dev);
993 	bool wakeup;
994 
995 	wakeup = device_may_wakeup(dev) && nhi_wake_supported(pdev);
996 	return __nhi_suspend_noirq(dev, wakeup);
997 }
998 
999 static void nhi_enable_int_throttling(struct tb_nhi *nhi)
1000 {
1001 	/* Throttling is specified in 256ns increments */
1002 	u32 throttle = DIV_ROUND_UP(128 * NSEC_PER_USEC, 256);
1003 	unsigned int i;
1004 
1005 	/*
1006 	 * Configure interrupt throttling for all vectors even if we
1007 	 * only use few.
1008 	 */
1009 	for (i = 0; i < MSIX_MAX_VECS; i++) {
1010 		u32 reg = REG_INT_THROTTLING_RATE + i * 4;
1011 		iowrite32(throttle, nhi->iobase + reg);
1012 	}
1013 }
1014 
1015 static int nhi_resume_noirq(struct device *dev)
1016 {
1017 	struct pci_dev *pdev = to_pci_dev(dev);
1018 	struct tb *tb = pci_get_drvdata(pdev);
1019 	struct tb_nhi *nhi = tb->nhi;
1020 	int ret;
1021 
1022 	/*
1023 	 * Check that the device is still there. It may be that the user
1024 	 * unplugged last device which causes the host controller to go
1025 	 * away on PCs.
1026 	 */
1027 	if (!pci_device_is_present(pdev)) {
1028 		nhi->going_away = true;
1029 	} else {
1030 		if (nhi->ops && nhi->ops->resume_noirq) {
1031 			ret = nhi->ops->resume_noirq(nhi);
1032 			if (ret)
1033 				return ret;
1034 		}
1035 		nhi_enable_int_throttling(tb->nhi);
1036 	}
1037 
1038 	return tb_domain_resume_noirq(tb);
1039 }
1040 
1041 static int nhi_suspend(struct device *dev)
1042 {
1043 	struct pci_dev *pdev = to_pci_dev(dev);
1044 	struct tb *tb = pci_get_drvdata(pdev);
1045 
1046 	return tb_domain_suspend(tb);
1047 }
1048 
1049 static void nhi_complete(struct device *dev)
1050 {
1051 	struct pci_dev *pdev = to_pci_dev(dev);
1052 	struct tb *tb = pci_get_drvdata(pdev);
1053 
1054 	/*
1055 	 * If we were runtime suspended when system suspend started,
1056 	 * schedule runtime resume now. It should bring the domain back
1057 	 * to functional state.
1058 	 */
1059 	if (pm_runtime_suspended(&pdev->dev))
1060 		pm_runtime_resume(&pdev->dev);
1061 	else
1062 		tb_domain_complete(tb);
1063 }
1064 
1065 static int nhi_runtime_suspend(struct device *dev)
1066 {
1067 	struct pci_dev *pdev = to_pci_dev(dev);
1068 	struct tb *tb = pci_get_drvdata(pdev);
1069 	struct tb_nhi *nhi = tb->nhi;
1070 	int ret;
1071 
1072 	ret = tb_domain_runtime_suspend(tb);
1073 	if (ret)
1074 		return ret;
1075 
1076 	if (nhi->ops && nhi->ops->runtime_suspend) {
1077 		ret = nhi->ops->runtime_suspend(tb->nhi);
1078 		if (ret)
1079 			return ret;
1080 	}
1081 	return 0;
1082 }
1083 
1084 static int nhi_runtime_resume(struct device *dev)
1085 {
1086 	struct pci_dev *pdev = to_pci_dev(dev);
1087 	struct tb *tb = pci_get_drvdata(pdev);
1088 	struct tb_nhi *nhi = tb->nhi;
1089 	int ret;
1090 
1091 	if (nhi->ops && nhi->ops->runtime_resume) {
1092 		ret = nhi->ops->runtime_resume(nhi);
1093 		if (ret)
1094 			return ret;
1095 	}
1096 
1097 	nhi_enable_int_throttling(nhi);
1098 	return tb_domain_runtime_resume(tb);
1099 }
1100 
1101 static void nhi_shutdown(struct tb_nhi *nhi)
1102 {
1103 	int i;
1104 
1105 	dev_dbg(&nhi->pdev->dev, "shutdown\n");
1106 
1107 	for (i = 0; i < nhi->hop_count; i++) {
1108 		if (nhi->tx_rings[i])
1109 			dev_WARN(&nhi->pdev->dev,
1110 				 "TX ring %d is still active\n", i);
1111 		if (nhi->rx_rings[i])
1112 			dev_WARN(&nhi->pdev->dev,
1113 				 "RX ring %d is still active\n", i);
1114 	}
1115 	nhi_disable_interrupts(nhi);
1116 	/*
1117 	 * We have to release the irq before calling flush_work. Otherwise an
1118 	 * already executing IRQ handler could call schedule_work again.
1119 	 */
1120 	if (!nhi->pdev->msix_enabled) {
1121 		devm_free_irq(&nhi->pdev->dev, nhi->pdev->irq, nhi);
1122 		flush_work(&nhi->interrupt_work);
1123 	}
1124 	ida_destroy(&nhi->msix_ida);
1125 
1126 	if (nhi->ops && nhi->ops->shutdown)
1127 		nhi->ops->shutdown(nhi);
1128 }
1129 
1130 static void nhi_check_quirks(struct tb_nhi *nhi)
1131 {
1132 	if (nhi->pdev->vendor == PCI_VENDOR_ID_INTEL) {
1133 		/*
1134 		 * Intel hardware supports auto clear of the interrupt
1135 		 * status register right after interrupt is being
1136 		 * issued.
1137 		 */
1138 		nhi->quirks |= QUIRK_AUTO_CLEAR_INT;
1139 
1140 		switch (nhi->pdev->device) {
1141 		case PCI_DEVICE_ID_INTEL_FALCON_RIDGE_2C_NHI:
1142 		case PCI_DEVICE_ID_INTEL_FALCON_RIDGE_4C_NHI:
1143 			/*
1144 			 * Falcon Ridge controller needs the end-to-end
1145 			 * flow control workaround to avoid losing Rx
1146 			 * packets when RING_FLAG_E2E is set.
1147 			 */
1148 			nhi->quirks |= QUIRK_E2E;
1149 			break;
1150 		}
1151 	}
1152 }
1153 
1154 static int nhi_check_iommu_pdev(struct pci_dev *pdev, void *data)
1155 {
1156 	if (!pdev->external_facing ||
1157 	    !device_iommu_capable(&pdev->dev, IOMMU_CAP_PRE_BOOT_PROTECTION))
1158 		return 0;
1159 	*(bool *)data = true;
1160 	return 1; /* Stop walking */
1161 }
1162 
1163 static void nhi_check_iommu(struct tb_nhi *nhi)
1164 {
1165 	struct pci_bus *bus = nhi->pdev->bus;
1166 	bool port_ok = false;
1167 
1168 	/*
1169 	 * Ideally what we'd do here is grab every PCI device that
1170 	 * represents a tunnelling adapter for this NHI and check their
1171 	 * status directly, but unfortunately USB4 seems to make it
1172 	 * obnoxiously difficult to reliably make any correlation.
1173 	 *
1174 	 * So for now we'll have to bodge it... Hoping that the system
1175 	 * is at least sane enough that an adapter is in the same PCI
1176 	 * segment as its NHI, if we can find *something* on that segment
1177 	 * which meets the requirements for Kernel DMA Protection, we'll
1178 	 * take that to imply that firmware is aware and has (hopefully)
1179 	 * done the right thing in general. We need to know that the PCI
1180 	 * layer has seen the ExternalFacingPort property which will then
1181 	 * inform the IOMMU layer to enforce the complete "untrusted DMA"
1182 	 * flow, but also that the IOMMU driver itself can be trusted not
1183 	 * to have been subverted by a pre-boot DMA attack.
1184 	 */
1185 	while (bus->parent)
1186 		bus = bus->parent;
1187 
1188 	pci_walk_bus(bus, nhi_check_iommu_pdev, &port_ok);
1189 
1190 	nhi->iommu_dma_protection = port_ok;
1191 	dev_dbg(&nhi->pdev->dev, "IOMMU DMA protection is %s\n",
1192 		str_enabled_disabled(port_ok));
1193 }
1194 
1195 static int nhi_init_msi(struct tb_nhi *nhi)
1196 {
1197 	struct pci_dev *pdev = nhi->pdev;
1198 	struct device *dev = &pdev->dev;
1199 	int res, irq, nvec;
1200 
1201 	/* In case someone left them on. */
1202 	nhi_disable_interrupts(nhi);
1203 
1204 	nhi_enable_int_throttling(nhi);
1205 
1206 	ida_init(&nhi->msix_ida);
1207 
1208 	/*
1209 	 * The NHI has 16 MSI-X vectors or a single MSI. We first try to
1210 	 * get all MSI-X vectors and if we succeed, each ring will have
1211 	 * one MSI-X. If for some reason that does not work out, we
1212 	 * fallback to a single MSI.
1213 	 */
1214 	nvec = pci_alloc_irq_vectors(pdev, MSIX_MIN_VECS, MSIX_MAX_VECS,
1215 				     PCI_IRQ_MSIX);
1216 	if (nvec < 0) {
1217 		nvec = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSI);
1218 		if (nvec < 0)
1219 			return nvec;
1220 
1221 		INIT_WORK(&nhi->interrupt_work, nhi_interrupt_work);
1222 
1223 		irq = pci_irq_vector(nhi->pdev, 0);
1224 		if (irq < 0)
1225 			return irq;
1226 
1227 		res = devm_request_irq(&pdev->dev, irq, nhi_msi,
1228 				       IRQF_NO_SUSPEND, "thunderbolt", nhi);
1229 		if (res)
1230 			return dev_err_probe(dev, res, "request_irq failed, aborting\n");
1231 	}
1232 
1233 	return 0;
1234 }
1235 
1236 static bool nhi_imr_valid(struct pci_dev *pdev)
1237 {
1238 	u8 val;
1239 
1240 	if (!device_property_read_u8(&pdev->dev, "IMR_VALID", &val))
1241 		return !!val;
1242 
1243 	return true;
1244 }
1245 
1246 static struct tb *nhi_select_cm(struct tb_nhi *nhi)
1247 {
1248 	struct tb *tb;
1249 
1250 	/*
1251 	 * USB4 case is simple. If we got control of any of the
1252 	 * capabilities, we use software CM.
1253 	 */
1254 	if (tb_acpi_is_native())
1255 		return tb_probe(nhi);
1256 
1257 	/*
1258 	 * Either firmware based CM is running (we did not get control
1259 	 * from the firmware) or this is pre-USB4 PC so try first
1260 	 * firmware CM and then fallback to software CM.
1261 	 */
1262 	tb = icm_probe(nhi);
1263 	if (!tb)
1264 		tb = tb_probe(nhi);
1265 
1266 	return tb;
1267 }
1268 
1269 static int nhi_probe(struct pci_dev *pdev, const struct pci_device_id *id)
1270 {
1271 	struct device *dev = &pdev->dev;
1272 	struct tb_nhi *nhi;
1273 	struct tb *tb;
1274 	int res;
1275 
1276 	if (!nhi_imr_valid(pdev))
1277 		return dev_err_probe(dev, -ENODEV, "firmware image not valid, aborting\n");
1278 
1279 	res = pcim_enable_device(pdev);
1280 	if (res)
1281 		return dev_err_probe(dev, res, "cannot enable PCI device, aborting\n");
1282 
1283 	res = pcim_iomap_regions(pdev, 1 << 0, "thunderbolt");
1284 	if (res)
1285 		return dev_err_probe(dev, res, "cannot obtain PCI resources, aborting\n");
1286 
1287 	nhi = devm_kzalloc(&pdev->dev, sizeof(*nhi), GFP_KERNEL);
1288 	if (!nhi)
1289 		return -ENOMEM;
1290 
1291 	nhi->pdev = pdev;
1292 	nhi->ops = (const struct tb_nhi_ops *)id->driver_data;
1293 	/* cannot fail - table is allocated in pcim_iomap_regions */
1294 	nhi->iobase = pcim_iomap_table(pdev)[0];
1295 	nhi->hop_count = ioread32(nhi->iobase + REG_HOP_COUNT) & 0x3ff;
1296 	dev_dbg(dev, "total paths: %d\n", nhi->hop_count);
1297 
1298 	nhi->tx_rings = devm_kcalloc(&pdev->dev, nhi->hop_count,
1299 				     sizeof(*nhi->tx_rings), GFP_KERNEL);
1300 	nhi->rx_rings = devm_kcalloc(&pdev->dev, nhi->hop_count,
1301 				     sizeof(*nhi->rx_rings), GFP_KERNEL);
1302 	if (!nhi->tx_rings || !nhi->rx_rings)
1303 		return -ENOMEM;
1304 
1305 	nhi_check_quirks(nhi);
1306 	nhi_check_iommu(nhi);
1307 
1308 	res = nhi_init_msi(nhi);
1309 	if (res)
1310 		return dev_err_probe(dev, res, "cannot enable MSI, aborting\n");
1311 
1312 	spin_lock_init(&nhi->lock);
1313 
1314 	res = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
1315 	if (res)
1316 		return dev_err_probe(dev, res, "failed to set DMA mask\n");
1317 
1318 	pci_set_master(pdev);
1319 
1320 	if (nhi->ops && nhi->ops->init) {
1321 		res = nhi->ops->init(nhi);
1322 		if (res)
1323 			return res;
1324 	}
1325 
1326 	tb = nhi_select_cm(nhi);
1327 	if (!tb)
1328 		return dev_err_probe(dev, -ENODEV,
1329 			"failed to determine connection manager, aborting\n");
1330 
1331 	dev_dbg(dev, "NHI initialized, starting thunderbolt\n");
1332 
1333 	res = tb_domain_add(tb);
1334 	if (res) {
1335 		/*
1336 		 * At this point the RX/TX rings might already have been
1337 		 * activated. Do a proper shutdown.
1338 		 */
1339 		tb_domain_put(tb);
1340 		nhi_shutdown(nhi);
1341 		return res;
1342 	}
1343 	pci_set_drvdata(pdev, tb);
1344 
1345 	device_wakeup_enable(&pdev->dev);
1346 
1347 	pm_runtime_allow(&pdev->dev);
1348 	pm_runtime_set_autosuspend_delay(&pdev->dev, TB_AUTOSUSPEND_DELAY);
1349 	pm_runtime_use_autosuspend(&pdev->dev);
1350 	pm_runtime_put_autosuspend(&pdev->dev);
1351 
1352 	return 0;
1353 }
1354 
1355 static void nhi_remove(struct pci_dev *pdev)
1356 {
1357 	struct tb *tb = pci_get_drvdata(pdev);
1358 	struct tb_nhi *nhi = tb->nhi;
1359 
1360 	pm_runtime_get_sync(&pdev->dev);
1361 	pm_runtime_dont_use_autosuspend(&pdev->dev);
1362 	pm_runtime_forbid(&pdev->dev);
1363 
1364 	tb_domain_remove(tb);
1365 	nhi_shutdown(nhi);
1366 }
1367 
1368 /*
1369  * The tunneled pci bridges are siblings of us. Use resume_noirq to reenable
1370  * the tunnels asap. A corresponding pci quirk blocks the downstream bridges
1371  * resume_noirq until we are done.
1372  */
1373 static const struct dev_pm_ops nhi_pm_ops = {
1374 	.suspend_noirq = nhi_suspend_noirq,
1375 	.resume_noirq = nhi_resume_noirq,
1376 	.freeze_noirq = nhi_freeze_noirq,  /*
1377 					    * we just disable hotplug, the
1378 					    * pci-tunnels stay alive.
1379 					    */
1380 	.thaw_noirq = nhi_thaw_noirq,
1381 	.restore_noirq = nhi_resume_noirq,
1382 	.suspend = nhi_suspend,
1383 	.poweroff_noirq = nhi_poweroff_noirq,
1384 	.poweroff = nhi_suspend,
1385 	.complete = nhi_complete,
1386 	.runtime_suspend = nhi_runtime_suspend,
1387 	.runtime_resume = nhi_runtime_resume,
1388 };
1389 
1390 static struct pci_device_id nhi_ids[] = {
1391 	/*
1392 	 * We have to specify class, the TB bridges use the same device and
1393 	 * vendor (sub)id on gen 1 and gen 2 controllers.
1394 	 */
1395 	{
1396 		.class = PCI_CLASS_SYSTEM_OTHER << 8, .class_mask = ~0,
1397 		.vendor = PCI_VENDOR_ID_INTEL,
1398 		.device = PCI_DEVICE_ID_INTEL_LIGHT_RIDGE,
1399 		.subvendor = 0x2222, .subdevice = 0x1111,
1400 	},
1401 	{
1402 		.class = PCI_CLASS_SYSTEM_OTHER << 8, .class_mask = ~0,
1403 		.vendor = PCI_VENDOR_ID_INTEL,
1404 		.device = PCI_DEVICE_ID_INTEL_CACTUS_RIDGE_4C,
1405 		.subvendor = 0x2222, .subdevice = 0x1111,
1406 	},
1407 	{
1408 		.class = PCI_CLASS_SYSTEM_OTHER << 8, .class_mask = ~0,
1409 		.vendor = PCI_VENDOR_ID_INTEL,
1410 		.device = PCI_DEVICE_ID_INTEL_FALCON_RIDGE_2C_NHI,
1411 		.subvendor = PCI_ANY_ID, .subdevice = PCI_ANY_ID,
1412 	},
1413 	{
1414 		.class = PCI_CLASS_SYSTEM_OTHER << 8, .class_mask = ~0,
1415 		.vendor = PCI_VENDOR_ID_INTEL,
1416 		.device = PCI_DEVICE_ID_INTEL_FALCON_RIDGE_4C_NHI,
1417 		.subvendor = PCI_ANY_ID, .subdevice = PCI_ANY_ID,
1418 	},
1419 
1420 	/* Thunderbolt 3 */
1421 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_2C_NHI) },
1422 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_4C_NHI) },
1423 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_USBONLY_NHI) },
1424 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_LP_NHI) },
1425 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_LP_USBONLY_NHI) },
1426 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_C_2C_NHI) },
1427 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_C_4C_NHI) },
1428 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_C_USBONLY_NHI) },
1429 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_TITAN_RIDGE_2C_NHI) },
1430 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_TITAN_RIDGE_4C_NHI) },
1431 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ICL_NHI0),
1432 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1433 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ICL_NHI1),
1434 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1435 	/* Thunderbolt 4 */
1436 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_TGL_NHI0),
1437 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1438 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_TGL_NHI1),
1439 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1440 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_TGL_H_NHI0),
1441 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1442 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_TGL_H_NHI1),
1443 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1444 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ADL_NHI0),
1445 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1446 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ADL_NHI1),
1447 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1448 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_RPL_NHI0),
1449 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1450 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_RPL_NHI1),
1451 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1452 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_MTL_M_NHI0),
1453 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1454 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_MTL_P_NHI0),
1455 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1456 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_MTL_P_NHI1),
1457 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1458 
1459 	/* Any USB4 compliant host */
1460 	{ PCI_DEVICE_CLASS(PCI_CLASS_SERIAL_USB_USB4, ~0) },
1461 
1462 	{ 0,}
1463 };
1464 
1465 MODULE_DEVICE_TABLE(pci, nhi_ids);
1466 MODULE_LICENSE("GPL");
1467 
1468 static struct pci_driver nhi_driver = {
1469 	.name = "thunderbolt",
1470 	.id_table = nhi_ids,
1471 	.probe = nhi_probe,
1472 	.remove = nhi_remove,
1473 	.shutdown = nhi_remove,
1474 	.driver.pm = &nhi_pm_ops,
1475 };
1476 
1477 static int __init nhi_init(void)
1478 {
1479 	int ret;
1480 
1481 	ret = tb_domain_init();
1482 	if (ret)
1483 		return ret;
1484 	ret = pci_register_driver(&nhi_driver);
1485 	if (ret)
1486 		tb_domain_exit();
1487 	return ret;
1488 }
1489 
1490 static void __exit nhi_unload(void)
1491 {
1492 	pci_unregister_driver(&nhi_driver);
1493 	tb_domain_exit();
1494 }
1495 
1496 rootfs_initcall(nhi_init);
1497 module_exit(nhi_unload);
1498