xref: /linux/drivers/thunderbolt/nhi.c (revision 320fefa9e2edc67011e235ea1d50f0d00ddfe004)
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(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 bit = ring_interrupt_index(ring) & 31;
67 	int mask = 1 << bit;
68 	u32 old, new;
69 
70 	if (ring->irq > 0) {
71 		u32 step, shift, ivr, misc;
72 		void __iomem *ivr_base;
73 		int index;
74 
75 		if (ring->is_tx)
76 			index = ring->hop;
77 		else
78 			index = ring->hop + ring->nhi->hop_count;
79 
80 		if (ring->nhi->quirks & QUIRK_AUTO_CLEAR_INT) {
81 			/*
82 			 * Ask the hardware to clear interrupt status
83 			 * bits automatically since we already know
84 			 * which interrupt was triggered.
85 			 */
86 			misc = ioread32(ring->nhi->iobase + REG_DMA_MISC);
87 			if (!(misc & REG_DMA_MISC_INT_AUTO_CLEAR)) {
88 				misc |= REG_DMA_MISC_INT_AUTO_CLEAR;
89 				iowrite32(misc, ring->nhi->iobase + REG_DMA_MISC);
90 			}
91 		}
92 
93 		ivr_base = ring->nhi->iobase + REG_INT_VEC_ALLOC_BASE;
94 		step = index / REG_INT_VEC_ALLOC_REGS * REG_INT_VEC_ALLOC_BITS;
95 		shift = index % REG_INT_VEC_ALLOC_REGS * REG_INT_VEC_ALLOC_BITS;
96 		ivr = ioread32(ivr_base + step);
97 		ivr &= ~(REG_INT_VEC_ALLOC_MASK << shift);
98 		if (active)
99 			ivr |= ring->vector << shift;
100 		iowrite32(ivr, ivr_base + step);
101 	}
102 
103 	old = ioread32(ring->nhi->iobase + reg);
104 	if (active)
105 		new = old | mask;
106 	else
107 		new = old & ~mask;
108 
109 	dev_dbg(&ring->nhi->pdev->dev,
110 		"%s interrupt at register %#x bit %d (%#x -> %#x)\n",
111 		active ? "enabling" : "disabling", reg, bit, old, new);
112 
113 	if (new == old)
114 		dev_WARN(&ring->nhi->pdev->dev,
115 					 "interrupt for %s %d is already %s\n",
116 					 RING_TYPE(ring), ring->hop,
117 					 active ? "enabled" : "disabled");
118 	iowrite32(new, ring->nhi->iobase + reg);
119 }
120 
121 /*
122  * nhi_disable_interrupts() - disable interrupts for all rings
123  *
124  * Use only during init and shutdown.
125  */
126 static void nhi_disable_interrupts(struct tb_nhi *nhi)
127 {
128 	int i = 0;
129 	/* disable interrupts */
130 	for (i = 0; i < RING_INTERRUPT_REG_COUNT(nhi); i++)
131 		iowrite32(0, nhi->iobase + REG_RING_INTERRUPT_BASE + 4 * i);
132 
133 	/* clear interrupt status bits */
134 	for (i = 0; i < RING_NOTIFY_REG_COUNT(nhi); i++)
135 		ioread32(nhi->iobase + REG_RING_NOTIFY_BASE + 4 * i);
136 }
137 
138 /* ring helper methods */
139 
140 static void __iomem *ring_desc_base(struct tb_ring *ring)
141 {
142 	void __iomem *io = ring->nhi->iobase;
143 	io += ring->is_tx ? REG_TX_RING_BASE : REG_RX_RING_BASE;
144 	io += ring->hop * 16;
145 	return io;
146 }
147 
148 static void __iomem *ring_options_base(struct tb_ring *ring)
149 {
150 	void __iomem *io = ring->nhi->iobase;
151 	io += ring->is_tx ? REG_TX_OPTIONS_BASE : REG_RX_OPTIONS_BASE;
152 	io += ring->hop * 32;
153 	return io;
154 }
155 
156 static void ring_iowrite_cons(struct tb_ring *ring, u16 cons)
157 {
158 	/*
159 	 * The other 16-bits in the register is read-only and writes to it
160 	 * are ignored by the hardware so we can save one ioread32() by
161 	 * filling the read-only bits with zeroes.
162 	 */
163 	iowrite32(cons, ring_desc_base(ring) + 8);
164 }
165 
166 static void ring_iowrite_prod(struct tb_ring *ring, u16 prod)
167 {
168 	/* See ring_iowrite_cons() above for explanation */
169 	iowrite32(prod << 16, ring_desc_base(ring) + 8);
170 }
171 
172 static void ring_iowrite32desc(struct tb_ring *ring, u32 value, u32 offset)
173 {
174 	iowrite32(value, ring_desc_base(ring) + offset);
175 }
176 
177 static void ring_iowrite64desc(struct tb_ring *ring, u64 value, u32 offset)
178 {
179 	iowrite32(value, ring_desc_base(ring) + offset);
180 	iowrite32(value >> 32, ring_desc_base(ring) + offset + 4);
181 }
182 
183 static void ring_iowrite32options(struct tb_ring *ring, u32 value, u32 offset)
184 {
185 	iowrite32(value, ring_options_base(ring) + offset);
186 }
187 
188 static bool ring_full(struct tb_ring *ring)
189 {
190 	return ((ring->head + 1) % ring->size) == ring->tail;
191 }
192 
193 static bool ring_empty(struct tb_ring *ring)
194 {
195 	return ring->head == ring->tail;
196 }
197 
198 /*
199  * ring_write_descriptors() - post frames from ring->queue to the controller
200  *
201  * ring->lock is held.
202  */
203 static void ring_write_descriptors(struct tb_ring *ring)
204 {
205 	struct ring_frame *frame, *n;
206 	struct ring_desc *descriptor;
207 	list_for_each_entry_safe(frame, n, &ring->queue, list) {
208 		if (ring_full(ring))
209 			break;
210 		list_move_tail(&frame->list, &ring->in_flight);
211 		descriptor = &ring->descriptors[ring->head];
212 		descriptor->phys = frame->buffer_phy;
213 		descriptor->time = 0;
214 		descriptor->flags = RING_DESC_POSTED | RING_DESC_INTERRUPT;
215 		if (ring->is_tx) {
216 			descriptor->length = frame->size;
217 			descriptor->eof = frame->eof;
218 			descriptor->sof = frame->sof;
219 		}
220 		ring->head = (ring->head + 1) % ring->size;
221 		if (ring->is_tx)
222 			ring_iowrite_prod(ring, ring->head);
223 		else
224 			ring_iowrite_cons(ring, ring->head);
225 	}
226 }
227 
228 /*
229  * ring_work() - progress completed frames
230  *
231  * If the ring is shutting down then all frames are marked as canceled and
232  * their callbacks are invoked.
233  *
234  * Otherwise we collect all completed frame from the ring buffer, write new
235  * frame to the ring buffer and invoke the callbacks for the completed frames.
236  */
237 static void ring_work(struct work_struct *work)
238 {
239 	struct tb_ring *ring = container_of(work, typeof(*ring), work);
240 	struct ring_frame *frame;
241 	bool canceled = false;
242 	unsigned long flags;
243 	LIST_HEAD(done);
244 
245 	spin_lock_irqsave(&ring->lock, flags);
246 
247 	if (!ring->running) {
248 		/*  Move all frames to done and mark them as canceled. */
249 		list_splice_tail_init(&ring->in_flight, &done);
250 		list_splice_tail_init(&ring->queue, &done);
251 		canceled = true;
252 		goto invoke_callback;
253 	}
254 
255 	while (!ring_empty(ring)) {
256 		if (!(ring->descriptors[ring->tail].flags
257 				& RING_DESC_COMPLETED))
258 			break;
259 		frame = list_first_entry(&ring->in_flight, typeof(*frame),
260 					 list);
261 		list_move_tail(&frame->list, &done);
262 		if (!ring->is_tx) {
263 			frame->size = ring->descriptors[ring->tail].length;
264 			frame->eof = ring->descriptors[ring->tail].eof;
265 			frame->sof = ring->descriptors[ring->tail].sof;
266 			frame->flags = ring->descriptors[ring->tail].flags;
267 		}
268 		ring->tail = (ring->tail + 1) % ring->size;
269 	}
270 	ring_write_descriptors(ring);
271 
272 invoke_callback:
273 	/* allow callbacks to schedule new work */
274 	spin_unlock_irqrestore(&ring->lock, flags);
275 	while (!list_empty(&done)) {
276 		frame = list_first_entry(&done, typeof(*frame), list);
277 		/*
278 		 * The callback may reenqueue or delete frame.
279 		 * Do not hold on to it.
280 		 */
281 		list_del_init(&frame->list);
282 		if (frame->callback)
283 			frame->callback(ring, frame, canceled);
284 	}
285 }
286 
287 int __tb_ring_enqueue(struct tb_ring *ring, struct ring_frame *frame)
288 {
289 	unsigned long flags;
290 	int ret = 0;
291 
292 	spin_lock_irqsave(&ring->lock, flags);
293 	if (ring->running) {
294 		list_add_tail(&frame->list, &ring->queue);
295 		ring_write_descriptors(ring);
296 	} else {
297 		ret = -ESHUTDOWN;
298 	}
299 	spin_unlock_irqrestore(&ring->lock, flags);
300 	return ret;
301 }
302 EXPORT_SYMBOL_GPL(__tb_ring_enqueue);
303 
304 /**
305  * tb_ring_poll() - Poll one completed frame from the ring
306  * @ring: Ring to poll
307  *
308  * This function can be called when @start_poll callback of the @ring
309  * has been called. It will read one completed frame from the ring and
310  * return it to the caller. Returns %NULL if there is no more completed
311  * frames.
312  */
313 struct ring_frame *tb_ring_poll(struct tb_ring *ring)
314 {
315 	struct ring_frame *frame = NULL;
316 	unsigned long flags;
317 
318 	spin_lock_irqsave(&ring->lock, flags);
319 	if (!ring->running)
320 		goto unlock;
321 	if (ring_empty(ring))
322 		goto unlock;
323 
324 	if (ring->descriptors[ring->tail].flags & RING_DESC_COMPLETED) {
325 		frame = list_first_entry(&ring->in_flight, typeof(*frame),
326 					 list);
327 		list_del_init(&frame->list);
328 
329 		if (!ring->is_tx) {
330 			frame->size = ring->descriptors[ring->tail].length;
331 			frame->eof = ring->descriptors[ring->tail].eof;
332 			frame->sof = ring->descriptors[ring->tail].sof;
333 			frame->flags = ring->descriptors[ring->tail].flags;
334 		}
335 
336 		ring->tail = (ring->tail + 1) % ring->size;
337 	}
338 
339 unlock:
340 	spin_unlock_irqrestore(&ring->lock, flags);
341 	return frame;
342 }
343 EXPORT_SYMBOL_GPL(tb_ring_poll);
344 
345 static void __ring_interrupt_mask(struct tb_ring *ring, bool mask)
346 {
347 	int idx = ring_interrupt_index(ring);
348 	int reg = REG_RING_INTERRUPT_BASE + idx / 32 * 4;
349 	int bit = idx % 32;
350 	u32 val;
351 
352 	val = ioread32(ring->nhi->iobase + reg);
353 	if (mask)
354 		val &= ~BIT(bit);
355 	else
356 		val |= BIT(bit);
357 	iowrite32(val, ring->nhi->iobase + reg);
358 }
359 
360 /* Both @nhi->lock and @ring->lock should be held */
361 static void __ring_interrupt(struct tb_ring *ring)
362 {
363 	if (!ring->running)
364 		return;
365 
366 	if (ring->start_poll) {
367 		__ring_interrupt_mask(ring, true);
368 		ring->start_poll(ring->poll_data);
369 	} else {
370 		schedule_work(&ring->work);
371 	}
372 }
373 
374 /**
375  * tb_ring_poll_complete() - Re-start interrupt for the ring
376  * @ring: Ring to re-start the interrupt
377  *
378  * This will re-start (unmask) the ring interrupt once the user is done
379  * with polling.
380  */
381 void tb_ring_poll_complete(struct tb_ring *ring)
382 {
383 	unsigned long flags;
384 
385 	spin_lock_irqsave(&ring->nhi->lock, flags);
386 	spin_lock(&ring->lock);
387 	if (ring->start_poll)
388 		__ring_interrupt_mask(ring, false);
389 	spin_unlock(&ring->lock);
390 	spin_unlock_irqrestore(&ring->nhi->lock, flags);
391 }
392 EXPORT_SYMBOL_GPL(tb_ring_poll_complete);
393 
394 static void ring_clear_msix(const struct tb_ring *ring)
395 {
396 	if (ring->nhi->quirks & QUIRK_AUTO_CLEAR_INT)
397 		return;
398 
399 	if (ring->is_tx)
400 		ioread32(ring->nhi->iobase + REG_RING_NOTIFY_BASE);
401 	else
402 		ioread32(ring->nhi->iobase + REG_RING_NOTIFY_BASE +
403 			 4 * (ring->nhi->hop_count / 32));
404 }
405 
406 static irqreturn_t ring_msix(int irq, void *data)
407 {
408 	struct tb_ring *ring = data;
409 
410 	spin_lock(&ring->nhi->lock);
411 	ring_clear_msix(ring);
412 	spin_lock(&ring->lock);
413 	__ring_interrupt(ring);
414 	spin_unlock(&ring->lock);
415 	spin_unlock(&ring->nhi->lock);
416 
417 	return IRQ_HANDLED;
418 }
419 
420 static int ring_request_msix(struct tb_ring *ring, bool no_suspend)
421 {
422 	struct tb_nhi *nhi = ring->nhi;
423 	unsigned long irqflags;
424 	int ret;
425 
426 	if (!nhi->pdev->msix_enabled)
427 		return 0;
428 
429 	ret = ida_simple_get(&nhi->msix_ida, 0, MSIX_MAX_VECS, GFP_KERNEL);
430 	if (ret < 0)
431 		return ret;
432 
433 	ring->vector = ret;
434 
435 	ret = pci_irq_vector(ring->nhi->pdev, ring->vector);
436 	if (ret < 0)
437 		goto err_ida_remove;
438 
439 	ring->irq = ret;
440 
441 	irqflags = no_suspend ? IRQF_NO_SUSPEND : 0;
442 	ret = request_irq(ring->irq, ring_msix, irqflags, "thunderbolt", ring);
443 	if (ret)
444 		goto err_ida_remove;
445 
446 	return 0;
447 
448 err_ida_remove:
449 	ida_simple_remove(&nhi->msix_ida, ring->vector);
450 
451 	return ret;
452 }
453 
454 static void ring_release_msix(struct tb_ring *ring)
455 {
456 	if (ring->irq <= 0)
457 		return;
458 
459 	free_irq(ring->irq, ring);
460 	ida_simple_remove(&ring->nhi->msix_ida, ring->vector);
461 	ring->vector = 0;
462 	ring->irq = 0;
463 }
464 
465 static int nhi_alloc_hop(struct tb_nhi *nhi, struct tb_ring *ring)
466 {
467 	unsigned int start_hop = RING_FIRST_USABLE_HOPID;
468 	int ret = 0;
469 
470 	if (nhi->quirks & QUIRK_E2E) {
471 		start_hop = RING_FIRST_USABLE_HOPID + 1;
472 		if (ring->flags & RING_FLAG_E2E && !ring->is_tx) {
473 			dev_dbg(&nhi->pdev->dev, "quirking E2E TX HopID %u -> %u\n",
474 				ring->e2e_tx_hop, RING_E2E_RESERVED_HOPID);
475 			ring->e2e_tx_hop = RING_E2E_RESERVED_HOPID;
476 		}
477 	}
478 
479 	spin_lock_irq(&nhi->lock);
480 
481 	if (ring->hop < 0) {
482 		unsigned int i;
483 
484 		/*
485 		 * Automatically allocate HopID from the non-reserved
486 		 * range 1 .. hop_count - 1.
487 		 */
488 		for (i = start_hop; i < nhi->hop_count; i++) {
489 			if (ring->is_tx) {
490 				if (!nhi->tx_rings[i]) {
491 					ring->hop = i;
492 					break;
493 				}
494 			} else {
495 				if (!nhi->rx_rings[i]) {
496 					ring->hop = i;
497 					break;
498 				}
499 			}
500 		}
501 	}
502 
503 	if (ring->hop > 0 && ring->hop < start_hop) {
504 		dev_warn(&nhi->pdev->dev, "invalid hop: %d\n", ring->hop);
505 		ret = -EINVAL;
506 		goto err_unlock;
507 	}
508 	if (ring->hop < 0 || ring->hop >= nhi->hop_count) {
509 		dev_warn(&nhi->pdev->dev, "invalid hop: %d\n", ring->hop);
510 		ret = -EINVAL;
511 		goto err_unlock;
512 	}
513 	if (ring->is_tx && nhi->tx_rings[ring->hop]) {
514 		dev_warn(&nhi->pdev->dev, "TX hop %d already allocated\n",
515 			 ring->hop);
516 		ret = -EBUSY;
517 		goto err_unlock;
518 	} else if (!ring->is_tx && nhi->rx_rings[ring->hop]) {
519 		dev_warn(&nhi->pdev->dev, "RX hop %d already allocated\n",
520 			 ring->hop);
521 		ret = -EBUSY;
522 		goto err_unlock;
523 	}
524 
525 	if (ring->is_tx)
526 		nhi->tx_rings[ring->hop] = ring;
527 	else
528 		nhi->rx_rings[ring->hop] = ring;
529 
530 err_unlock:
531 	spin_unlock_irq(&nhi->lock);
532 
533 	return ret;
534 }
535 
536 static struct tb_ring *tb_ring_alloc(struct tb_nhi *nhi, u32 hop, int size,
537 				     bool transmit, unsigned int flags,
538 				     int e2e_tx_hop, u16 sof_mask, u16 eof_mask,
539 				     void (*start_poll)(void *),
540 				     void *poll_data)
541 {
542 	struct tb_ring *ring = NULL;
543 
544 	dev_dbg(&nhi->pdev->dev, "allocating %s ring %d of size %d\n",
545 		transmit ? "TX" : "RX", hop, size);
546 
547 	ring = kzalloc(sizeof(*ring), GFP_KERNEL);
548 	if (!ring)
549 		return NULL;
550 
551 	spin_lock_init(&ring->lock);
552 	INIT_LIST_HEAD(&ring->queue);
553 	INIT_LIST_HEAD(&ring->in_flight);
554 	INIT_WORK(&ring->work, ring_work);
555 
556 	ring->nhi = nhi;
557 	ring->hop = hop;
558 	ring->is_tx = transmit;
559 	ring->size = size;
560 	ring->flags = flags;
561 	ring->e2e_tx_hop = e2e_tx_hop;
562 	ring->sof_mask = sof_mask;
563 	ring->eof_mask = eof_mask;
564 	ring->head = 0;
565 	ring->tail = 0;
566 	ring->running = false;
567 	ring->start_poll = start_poll;
568 	ring->poll_data = poll_data;
569 
570 	ring->descriptors = dma_alloc_coherent(&ring->nhi->pdev->dev,
571 			size * sizeof(*ring->descriptors),
572 			&ring->descriptors_dma, GFP_KERNEL | __GFP_ZERO);
573 	if (!ring->descriptors)
574 		goto err_free_ring;
575 
576 	if (ring_request_msix(ring, flags & RING_FLAG_NO_SUSPEND))
577 		goto err_free_descs;
578 
579 	if (nhi_alloc_hop(nhi, ring))
580 		goto err_release_msix;
581 
582 	return ring;
583 
584 err_release_msix:
585 	ring_release_msix(ring);
586 err_free_descs:
587 	dma_free_coherent(&ring->nhi->pdev->dev,
588 			  ring->size * sizeof(*ring->descriptors),
589 			  ring->descriptors, ring->descriptors_dma);
590 err_free_ring:
591 	kfree(ring);
592 
593 	return NULL;
594 }
595 
596 /**
597  * tb_ring_alloc_tx() - Allocate DMA ring for transmit
598  * @nhi: Pointer to the NHI the ring is to be allocated
599  * @hop: HopID (ring) to allocate
600  * @size: Number of entries in the ring
601  * @flags: Flags for the ring
602  */
603 struct tb_ring *tb_ring_alloc_tx(struct tb_nhi *nhi, int hop, int size,
604 				 unsigned int flags)
605 {
606 	return tb_ring_alloc(nhi, hop, size, true, flags, 0, 0, 0, NULL, NULL);
607 }
608 EXPORT_SYMBOL_GPL(tb_ring_alloc_tx);
609 
610 /**
611  * tb_ring_alloc_rx() - Allocate DMA ring for receive
612  * @nhi: Pointer to the NHI the ring is to be allocated
613  * @hop: HopID (ring) to allocate. Pass %-1 for automatic allocation.
614  * @size: Number of entries in the ring
615  * @flags: Flags for the ring
616  * @e2e_tx_hop: Transmit HopID when E2E is enabled in @flags
617  * @sof_mask: Mask of PDF values that start a frame
618  * @eof_mask: Mask of PDF values that end a frame
619  * @start_poll: If not %NULL the ring will call this function when an
620  *		interrupt is triggered and masked, instead of callback
621  *		in each Rx frame.
622  * @poll_data: Optional data passed to @start_poll
623  */
624 struct tb_ring *tb_ring_alloc_rx(struct tb_nhi *nhi, int hop, int size,
625 				 unsigned int flags, int e2e_tx_hop,
626 				 u16 sof_mask, u16 eof_mask,
627 				 void (*start_poll)(void *), void *poll_data)
628 {
629 	return tb_ring_alloc(nhi, hop, size, false, flags, e2e_tx_hop, sof_mask, eof_mask,
630 			     start_poll, poll_data);
631 }
632 EXPORT_SYMBOL_GPL(tb_ring_alloc_rx);
633 
634 /**
635  * tb_ring_start() - enable a ring
636  * @ring: Ring to start
637  *
638  * Must not be invoked in parallel with tb_ring_stop().
639  */
640 void tb_ring_start(struct tb_ring *ring)
641 {
642 	u16 frame_size;
643 	u32 flags;
644 
645 	spin_lock_irq(&ring->nhi->lock);
646 	spin_lock(&ring->lock);
647 	if (ring->nhi->going_away)
648 		goto err;
649 	if (ring->running) {
650 		dev_WARN(&ring->nhi->pdev->dev, "ring already started\n");
651 		goto err;
652 	}
653 	dev_dbg(&ring->nhi->pdev->dev, "starting %s %d\n",
654 		RING_TYPE(ring), ring->hop);
655 
656 	if (ring->flags & RING_FLAG_FRAME) {
657 		/* Means 4096 */
658 		frame_size = 0;
659 		flags = RING_FLAG_ENABLE;
660 	} else {
661 		frame_size = TB_FRAME_SIZE;
662 		flags = RING_FLAG_ENABLE | RING_FLAG_RAW;
663 	}
664 
665 	ring_iowrite64desc(ring, ring->descriptors_dma, 0);
666 	if (ring->is_tx) {
667 		ring_iowrite32desc(ring, ring->size, 12);
668 		ring_iowrite32options(ring, 0, 4); /* time releated ? */
669 		ring_iowrite32options(ring, flags, 0);
670 	} else {
671 		u32 sof_eof_mask = ring->sof_mask << 16 | ring->eof_mask;
672 
673 		ring_iowrite32desc(ring, (frame_size << 16) | ring->size, 12);
674 		ring_iowrite32options(ring, sof_eof_mask, 4);
675 		ring_iowrite32options(ring, flags, 0);
676 	}
677 
678 	/*
679 	 * Now that the ring valid bit is set we can configure E2E if
680 	 * enabled for the ring.
681 	 */
682 	if (ring->flags & RING_FLAG_E2E) {
683 		if (!ring->is_tx) {
684 			u32 hop;
685 
686 			hop = ring->e2e_tx_hop << REG_RX_OPTIONS_E2E_HOP_SHIFT;
687 			hop &= REG_RX_OPTIONS_E2E_HOP_MASK;
688 			flags |= hop;
689 
690 			dev_dbg(&ring->nhi->pdev->dev,
691 				"enabling E2E for %s %d with TX HopID %d\n",
692 				RING_TYPE(ring), ring->hop, ring->e2e_tx_hop);
693 		} else {
694 			dev_dbg(&ring->nhi->pdev->dev, "enabling E2E for %s %d\n",
695 				RING_TYPE(ring), ring->hop);
696 		}
697 
698 		flags |= RING_FLAG_E2E_FLOW_CONTROL;
699 		ring_iowrite32options(ring, flags, 0);
700 	}
701 
702 	ring_interrupt_active(ring, true);
703 	ring->running = true;
704 err:
705 	spin_unlock(&ring->lock);
706 	spin_unlock_irq(&ring->nhi->lock);
707 }
708 EXPORT_SYMBOL_GPL(tb_ring_start);
709 
710 /**
711  * tb_ring_stop() - shutdown a ring
712  * @ring: Ring to stop
713  *
714  * Must not be invoked from a callback.
715  *
716  * This method will disable the ring. Further calls to
717  * tb_ring_tx/tb_ring_rx will return -ESHUTDOWN until ring_stop has been
718  * called.
719  *
720  * All enqueued frames will be canceled and their callbacks will be executed
721  * with frame->canceled set to true (on the callback thread). This method
722  * returns only after all callback invocations have finished.
723  */
724 void tb_ring_stop(struct tb_ring *ring)
725 {
726 	spin_lock_irq(&ring->nhi->lock);
727 	spin_lock(&ring->lock);
728 	dev_dbg(&ring->nhi->pdev->dev, "stopping %s %d\n",
729 		RING_TYPE(ring), ring->hop);
730 	if (ring->nhi->going_away)
731 		goto err;
732 	if (!ring->running) {
733 		dev_WARN(&ring->nhi->pdev->dev, "%s %d already stopped\n",
734 			 RING_TYPE(ring), ring->hop);
735 		goto err;
736 	}
737 	ring_interrupt_active(ring, false);
738 
739 	ring_iowrite32options(ring, 0, 0);
740 	ring_iowrite64desc(ring, 0, 0);
741 	ring_iowrite32desc(ring, 0, 8);
742 	ring_iowrite32desc(ring, 0, 12);
743 	ring->head = 0;
744 	ring->tail = 0;
745 	ring->running = false;
746 
747 err:
748 	spin_unlock(&ring->lock);
749 	spin_unlock_irq(&ring->nhi->lock);
750 
751 	/*
752 	 * schedule ring->work to invoke callbacks on all remaining frames.
753 	 */
754 	schedule_work(&ring->work);
755 	flush_work(&ring->work);
756 }
757 EXPORT_SYMBOL_GPL(tb_ring_stop);
758 
759 /*
760  * tb_ring_free() - free ring
761  *
762  * When this method returns all invocations of ring->callback will have
763  * finished.
764  *
765  * Ring must be stopped.
766  *
767  * Must NOT be called from ring_frame->callback!
768  */
769 void tb_ring_free(struct tb_ring *ring)
770 {
771 	spin_lock_irq(&ring->nhi->lock);
772 	/*
773 	 * Dissociate the ring from the NHI. This also ensures that
774 	 * nhi_interrupt_work cannot reschedule ring->work.
775 	 */
776 	if (ring->is_tx)
777 		ring->nhi->tx_rings[ring->hop] = NULL;
778 	else
779 		ring->nhi->rx_rings[ring->hop] = NULL;
780 
781 	if (ring->running) {
782 		dev_WARN(&ring->nhi->pdev->dev, "%s %d still running\n",
783 			 RING_TYPE(ring), ring->hop);
784 	}
785 	spin_unlock_irq(&ring->nhi->lock);
786 
787 	ring_release_msix(ring);
788 
789 	dma_free_coherent(&ring->nhi->pdev->dev,
790 			  ring->size * sizeof(*ring->descriptors),
791 			  ring->descriptors, ring->descriptors_dma);
792 
793 	ring->descriptors = NULL;
794 	ring->descriptors_dma = 0;
795 
796 
797 	dev_dbg(&ring->nhi->pdev->dev, "freeing %s %d\n", RING_TYPE(ring),
798 		ring->hop);
799 
800 	/*
801 	 * ring->work can no longer be scheduled (it is scheduled only
802 	 * by nhi_interrupt_work, ring_stop and ring_msix). Wait for it
803 	 * to finish before freeing the ring.
804 	 */
805 	flush_work(&ring->work);
806 	kfree(ring);
807 }
808 EXPORT_SYMBOL_GPL(tb_ring_free);
809 
810 /**
811  * nhi_mailbox_cmd() - Send a command through NHI mailbox
812  * @nhi: Pointer to the NHI structure
813  * @cmd: Command to send
814  * @data: Data to be send with the command
815  *
816  * Sends mailbox command to the firmware running on NHI. Returns %0 in
817  * case of success and negative errno in case of failure.
818  */
819 int nhi_mailbox_cmd(struct tb_nhi *nhi, enum nhi_mailbox_cmd cmd, u32 data)
820 {
821 	ktime_t timeout;
822 	u32 val;
823 
824 	iowrite32(data, nhi->iobase + REG_INMAIL_DATA);
825 
826 	val = ioread32(nhi->iobase + REG_INMAIL_CMD);
827 	val &= ~(REG_INMAIL_CMD_MASK | REG_INMAIL_ERROR);
828 	val |= REG_INMAIL_OP_REQUEST | cmd;
829 	iowrite32(val, nhi->iobase + REG_INMAIL_CMD);
830 
831 	timeout = ktime_add_ms(ktime_get(), NHI_MAILBOX_TIMEOUT);
832 	do {
833 		val = ioread32(nhi->iobase + REG_INMAIL_CMD);
834 		if (!(val & REG_INMAIL_OP_REQUEST))
835 			break;
836 		usleep_range(10, 20);
837 	} while (ktime_before(ktime_get(), timeout));
838 
839 	if (val & REG_INMAIL_OP_REQUEST)
840 		return -ETIMEDOUT;
841 	if (val & REG_INMAIL_ERROR)
842 		return -EIO;
843 
844 	return 0;
845 }
846 
847 /**
848  * nhi_mailbox_mode() - Return current firmware operation mode
849  * @nhi: Pointer to the NHI structure
850  *
851  * The function reads current firmware operation mode using NHI mailbox
852  * registers and returns it to the caller.
853  */
854 enum nhi_fw_mode nhi_mailbox_mode(struct tb_nhi *nhi)
855 {
856 	u32 val;
857 
858 	val = ioread32(nhi->iobase + REG_OUTMAIL_CMD);
859 	val &= REG_OUTMAIL_CMD_OPMODE_MASK;
860 	val >>= REG_OUTMAIL_CMD_OPMODE_SHIFT;
861 
862 	return (enum nhi_fw_mode)val;
863 }
864 
865 static void nhi_interrupt_work(struct work_struct *work)
866 {
867 	struct tb_nhi *nhi = container_of(work, typeof(*nhi), interrupt_work);
868 	int value = 0; /* Suppress uninitialized usage warning. */
869 	int bit;
870 	int hop = -1;
871 	int type = 0; /* current interrupt type 0: TX, 1: RX, 2: RX overflow */
872 	struct tb_ring *ring;
873 
874 	spin_lock_irq(&nhi->lock);
875 
876 	/*
877 	 * Starting at REG_RING_NOTIFY_BASE there are three status bitfields
878 	 * (TX, RX, RX overflow). We iterate over the bits and read a new
879 	 * dwords as required. The registers are cleared on read.
880 	 */
881 	for (bit = 0; bit < 3 * nhi->hop_count; bit++) {
882 		if (bit % 32 == 0)
883 			value = ioread32(nhi->iobase
884 					 + REG_RING_NOTIFY_BASE
885 					 + 4 * (bit / 32));
886 		if (++hop == nhi->hop_count) {
887 			hop = 0;
888 			type++;
889 		}
890 		if ((value & (1 << (bit % 32))) == 0)
891 			continue;
892 		if (type == 2) {
893 			dev_warn(&nhi->pdev->dev,
894 				 "RX overflow for ring %d\n",
895 				 hop);
896 			continue;
897 		}
898 		if (type == 0)
899 			ring = nhi->tx_rings[hop];
900 		else
901 			ring = nhi->rx_rings[hop];
902 		if (ring == NULL) {
903 			dev_warn(&nhi->pdev->dev,
904 				 "got interrupt for inactive %s ring %d\n",
905 				 type ? "RX" : "TX",
906 				 hop);
907 			continue;
908 		}
909 
910 		spin_lock(&ring->lock);
911 		__ring_interrupt(ring);
912 		spin_unlock(&ring->lock);
913 	}
914 	spin_unlock_irq(&nhi->lock);
915 }
916 
917 static irqreturn_t nhi_msi(int irq, void *data)
918 {
919 	struct tb_nhi *nhi = data;
920 	schedule_work(&nhi->interrupt_work);
921 	return IRQ_HANDLED;
922 }
923 
924 static int __nhi_suspend_noirq(struct device *dev, bool wakeup)
925 {
926 	struct pci_dev *pdev = to_pci_dev(dev);
927 	struct tb *tb = pci_get_drvdata(pdev);
928 	struct tb_nhi *nhi = tb->nhi;
929 	int ret;
930 
931 	ret = tb_domain_suspend_noirq(tb);
932 	if (ret)
933 		return ret;
934 
935 	if (nhi->ops && nhi->ops->suspend_noirq) {
936 		ret = nhi->ops->suspend_noirq(tb->nhi, wakeup);
937 		if (ret)
938 			return ret;
939 	}
940 
941 	return 0;
942 }
943 
944 static int nhi_suspend_noirq(struct device *dev)
945 {
946 	return __nhi_suspend_noirq(dev, device_may_wakeup(dev));
947 }
948 
949 static int nhi_freeze_noirq(struct device *dev)
950 {
951 	struct pci_dev *pdev = to_pci_dev(dev);
952 	struct tb *tb = pci_get_drvdata(pdev);
953 
954 	return tb_domain_freeze_noirq(tb);
955 }
956 
957 static int nhi_thaw_noirq(struct device *dev)
958 {
959 	struct pci_dev *pdev = to_pci_dev(dev);
960 	struct tb *tb = pci_get_drvdata(pdev);
961 
962 	return tb_domain_thaw_noirq(tb);
963 }
964 
965 static bool nhi_wake_supported(struct pci_dev *pdev)
966 {
967 	u8 val;
968 
969 	/*
970 	 * If power rails are sustainable for wakeup from S4 this
971 	 * property is set by the BIOS.
972 	 */
973 	if (device_property_read_u8(&pdev->dev, "WAKE_SUPPORTED", &val))
974 		return !!val;
975 
976 	return true;
977 }
978 
979 static int nhi_poweroff_noirq(struct device *dev)
980 {
981 	struct pci_dev *pdev = to_pci_dev(dev);
982 	bool wakeup;
983 
984 	wakeup = device_may_wakeup(dev) && nhi_wake_supported(pdev);
985 	return __nhi_suspend_noirq(dev, wakeup);
986 }
987 
988 static void nhi_enable_int_throttling(struct tb_nhi *nhi)
989 {
990 	/* Throttling is specified in 256ns increments */
991 	u32 throttle = DIV_ROUND_UP(128 * NSEC_PER_USEC, 256);
992 	unsigned int i;
993 
994 	/*
995 	 * Configure interrupt throttling for all vectors even if we
996 	 * only use few.
997 	 */
998 	for (i = 0; i < MSIX_MAX_VECS; i++) {
999 		u32 reg = REG_INT_THROTTLING_RATE + i * 4;
1000 		iowrite32(throttle, nhi->iobase + reg);
1001 	}
1002 }
1003 
1004 static int nhi_resume_noirq(struct device *dev)
1005 {
1006 	struct pci_dev *pdev = to_pci_dev(dev);
1007 	struct tb *tb = pci_get_drvdata(pdev);
1008 	struct tb_nhi *nhi = tb->nhi;
1009 	int ret;
1010 
1011 	/*
1012 	 * Check that the device is still there. It may be that the user
1013 	 * unplugged last device which causes the host controller to go
1014 	 * away on PCs.
1015 	 */
1016 	if (!pci_device_is_present(pdev)) {
1017 		nhi->going_away = true;
1018 	} else {
1019 		if (nhi->ops && nhi->ops->resume_noirq) {
1020 			ret = nhi->ops->resume_noirq(nhi);
1021 			if (ret)
1022 				return ret;
1023 		}
1024 		nhi_enable_int_throttling(tb->nhi);
1025 	}
1026 
1027 	return tb_domain_resume_noirq(tb);
1028 }
1029 
1030 static int nhi_suspend(struct device *dev)
1031 {
1032 	struct pci_dev *pdev = to_pci_dev(dev);
1033 	struct tb *tb = pci_get_drvdata(pdev);
1034 
1035 	return tb_domain_suspend(tb);
1036 }
1037 
1038 static void nhi_complete(struct device *dev)
1039 {
1040 	struct pci_dev *pdev = to_pci_dev(dev);
1041 	struct tb *tb = pci_get_drvdata(pdev);
1042 
1043 	/*
1044 	 * If we were runtime suspended when system suspend started,
1045 	 * schedule runtime resume now. It should bring the domain back
1046 	 * to functional state.
1047 	 */
1048 	if (pm_runtime_suspended(&pdev->dev))
1049 		pm_runtime_resume(&pdev->dev);
1050 	else
1051 		tb_domain_complete(tb);
1052 }
1053 
1054 static int nhi_runtime_suspend(struct device *dev)
1055 {
1056 	struct pci_dev *pdev = to_pci_dev(dev);
1057 	struct tb *tb = pci_get_drvdata(pdev);
1058 	struct tb_nhi *nhi = tb->nhi;
1059 	int ret;
1060 
1061 	ret = tb_domain_runtime_suspend(tb);
1062 	if (ret)
1063 		return ret;
1064 
1065 	if (nhi->ops && nhi->ops->runtime_suspend) {
1066 		ret = nhi->ops->runtime_suspend(tb->nhi);
1067 		if (ret)
1068 			return ret;
1069 	}
1070 	return 0;
1071 }
1072 
1073 static int nhi_runtime_resume(struct device *dev)
1074 {
1075 	struct pci_dev *pdev = to_pci_dev(dev);
1076 	struct tb *tb = pci_get_drvdata(pdev);
1077 	struct tb_nhi *nhi = tb->nhi;
1078 	int ret;
1079 
1080 	if (nhi->ops && nhi->ops->runtime_resume) {
1081 		ret = nhi->ops->runtime_resume(nhi);
1082 		if (ret)
1083 			return ret;
1084 	}
1085 
1086 	nhi_enable_int_throttling(nhi);
1087 	return tb_domain_runtime_resume(tb);
1088 }
1089 
1090 static void nhi_shutdown(struct tb_nhi *nhi)
1091 {
1092 	int i;
1093 
1094 	dev_dbg(&nhi->pdev->dev, "shutdown\n");
1095 
1096 	for (i = 0; i < nhi->hop_count; i++) {
1097 		if (nhi->tx_rings[i])
1098 			dev_WARN(&nhi->pdev->dev,
1099 				 "TX ring %d is still active\n", i);
1100 		if (nhi->rx_rings[i])
1101 			dev_WARN(&nhi->pdev->dev,
1102 				 "RX ring %d is still active\n", i);
1103 	}
1104 	nhi_disable_interrupts(nhi);
1105 	/*
1106 	 * We have to release the irq before calling flush_work. Otherwise an
1107 	 * already executing IRQ handler could call schedule_work again.
1108 	 */
1109 	if (!nhi->pdev->msix_enabled) {
1110 		devm_free_irq(&nhi->pdev->dev, nhi->pdev->irq, nhi);
1111 		flush_work(&nhi->interrupt_work);
1112 	}
1113 	ida_destroy(&nhi->msix_ida);
1114 
1115 	if (nhi->ops && nhi->ops->shutdown)
1116 		nhi->ops->shutdown(nhi);
1117 }
1118 
1119 static void nhi_check_quirks(struct tb_nhi *nhi)
1120 {
1121 	if (nhi->pdev->vendor == PCI_VENDOR_ID_INTEL) {
1122 		/*
1123 		 * Intel hardware supports auto clear of the interrupt
1124 		 * status register right after interrupt is being
1125 		 * issued.
1126 		 */
1127 		nhi->quirks |= QUIRK_AUTO_CLEAR_INT;
1128 
1129 		switch (nhi->pdev->device) {
1130 		case PCI_DEVICE_ID_INTEL_FALCON_RIDGE_2C_NHI:
1131 		case PCI_DEVICE_ID_INTEL_FALCON_RIDGE_4C_NHI:
1132 			/*
1133 			 * Falcon Ridge controller needs the end-to-end
1134 			 * flow control workaround to avoid losing Rx
1135 			 * packets when RING_FLAG_E2E is set.
1136 			 */
1137 			nhi->quirks |= QUIRK_E2E;
1138 			break;
1139 		}
1140 	}
1141 }
1142 
1143 static int nhi_check_iommu_pdev(struct pci_dev *pdev, void *data)
1144 {
1145 	if (!pdev->external_facing ||
1146 	    !device_iommu_capable(&pdev->dev, IOMMU_CAP_PRE_BOOT_PROTECTION))
1147 		return 0;
1148 	*(bool *)data = true;
1149 	return 1; /* Stop walking */
1150 }
1151 
1152 static void nhi_check_iommu(struct tb_nhi *nhi)
1153 {
1154 	struct pci_bus *bus = nhi->pdev->bus;
1155 	bool port_ok = false;
1156 
1157 	/*
1158 	 * Ideally what we'd do here is grab every PCI device that
1159 	 * represents a tunnelling adapter for this NHI and check their
1160 	 * status directly, but unfortunately USB4 seems to make it
1161 	 * obnoxiously difficult to reliably make any correlation.
1162 	 *
1163 	 * So for now we'll have to bodge it... Hoping that the system
1164 	 * is at least sane enough that an adapter is in the same PCI
1165 	 * segment as its NHI, if we can find *something* on that segment
1166 	 * which meets the requirements for Kernel DMA Protection, we'll
1167 	 * take that to imply that firmware is aware and has (hopefully)
1168 	 * done the right thing in general. We need to know that the PCI
1169 	 * layer has seen the ExternalFacingPort property which will then
1170 	 * inform the IOMMU layer to enforce the complete "untrusted DMA"
1171 	 * flow, but also that the IOMMU driver itself can be trusted not
1172 	 * to have been subverted by a pre-boot DMA attack.
1173 	 */
1174 	while (bus->parent)
1175 		bus = bus->parent;
1176 
1177 	pci_walk_bus(bus, nhi_check_iommu_pdev, &port_ok);
1178 
1179 	nhi->iommu_dma_protection = port_ok;
1180 	dev_dbg(&nhi->pdev->dev, "IOMMU DMA protection is %s\n",
1181 		str_enabled_disabled(port_ok));
1182 }
1183 
1184 static int nhi_init_msi(struct tb_nhi *nhi)
1185 {
1186 	struct pci_dev *pdev = nhi->pdev;
1187 	struct device *dev = &pdev->dev;
1188 	int res, irq, nvec;
1189 
1190 	/* In case someone left them on. */
1191 	nhi_disable_interrupts(nhi);
1192 
1193 	nhi_enable_int_throttling(nhi);
1194 
1195 	ida_init(&nhi->msix_ida);
1196 
1197 	/*
1198 	 * The NHI has 16 MSI-X vectors or a single MSI. We first try to
1199 	 * get all MSI-X vectors and if we succeed, each ring will have
1200 	 * one MSI-X. If for some reason that does not work out, we
1201 	 * fallback to a single MSI.
1202 	 */
1203 	nvec = pci_alloc_irq_vectors(pdev, MSIX_MIN_VECS, MSIX_MAX_VECS,
1204 				     PCI_IRQ_MSIX);
1205 	if (nvec < 0) {
1206 		nvec = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSI);
1207 		if (nvec < 0)
1208 			return nvec;
1209 
1210 		INIT_WORK(&nhi->interrupt_work, nhi_interrupt_work);
1211 
1212 		irq = pci_irq_vector(nhi->pdev, 0);
1213 		if (irq < 0)
1214 			return irq;
1215 
1216 		res = devm_request_irq(&pdev->dev, irq, nhi_msi,
1217 				       IRQF_NO_SUSPEND, "thunderbolt", nhi);
1218 		if (res)
1219 			return dev_err_probe(dev, res, "request_irq failed, aborting\n");
1220 	}
1221 
1222 	return 0;
1223 }
1224 
1225 static bool nhi_imr_valid(struct pci_dev *pdev)
1226 {
1227 	u8 val;
1228 
1229 	if (!device_property_read_u8(&pdev->dev, "IMR_VALID", &val))
1230 		return !!val;
1231 
1232 	return true;
1233 }
1234 
1235 static struct tb *nhi_select_cm(struct tb_nhi *nhi)
1236 {
1237 	struct tb *tb;
1238 
1239 	/*
1240 	 * USB4 case is simple. If we got control of any of the
1241 	 * capabilities, we use software CM.
1242 	 */
1243 	if (tb_acpi_is_native())
1244 		return tb_probe(nhi);
1245 
1246 	/*
1247 	 * Either firmware based CM is running (we did not get control
1248 	 * from the firmware) or this is pre-USB4 PC so try first
1249 	 * firmware CM and then fallback to software CM.
1250 	 */
1251 	tb = icm_probe(nhi);
1252 	if (!tb)
1253 		tb = tb_probe(nhi);
1254 
1255 	return tb;
1256 }
1257 
1258 static int nhi_probe(struct pci_dev *pdev, const struct pci_device_id *id)
1259 {
1260 	struct device *dev = &pdev->dev;
1261 	struct tb_nhi *nhi;
1262 	struct tb *tb;
1263 	int res;
1264 
1265 	if (!nhi_imr_valid(pdev))
1266 		return dev_err_probe(dev, -ENODEV, "firmware image not valid, aborting\n");
1267 
1268 	res = pcim_enable_device(pdev);
1269 	if (res)
1270 		return dev_err_probe(dev, res, "cannot enable PCI device, aborting\n");
1271 
1272 	res = pcim_iomap_regions(pdev, 1 << 0, "thunderbolt");
1273 	if (res)
1274 		return dev_err_probe(dev, res, "cannot obtain PCI resources, aborting\n");
1275 
1276 	nhi = devm_kzalloc(&pdev->dev, sizeof(*nhi), GFP_KERNEL);
1277 	if (!nhi)
1278 		return -ENOMEM;
1279 
1280 	nhi->pdev = pdev;
1281 	nhi->ops = (const struct tb_nhi_ops *)id->driver_data;
1282 	/* cannot fail - table is allocated in pcim_iomap_regions */
1283 	nhi->iobase = pcim_iomap_table(pdev)[0];
1284 	nhi->hop_count = ioread32(nhi->iobase + REG_HOP_COUNT) & 0x3ff;
1285 	dev_dbg(dev, "total paths: %d\n", nhi->hop_count);
1286 
1287 	nhi->tx_rings = devm_kcalloc(&pdev->dev, nhi->hop_count,
1288 				     sizeof(*nhi->tx_rings), GFP_KERNEL);
1289 	nhi->rx_rings = devm_kcalloc(&pdev->dev, nhi->hop_count,
1290 				     sizeof(*nhi->rx_rings), GFP_KERNEL);
1291 	if (!nhi->tx_rings || !nhi->rx_rings)
1292 		return -ENOMEM;
1293 
1294 	nhi_check_quirks(nhi);
1295 	nhi_check_iommu(nhi);
1296 
1297 	res = nhi_init_msi(nhi);
1298 	if (res)
1299 		return dev_err_probe(dev, res, "cannot enable MSI, aborting\n");
1300 
1301 	spin_lock_init(&nhi->lock);
1302 
1303 	res = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
1304 	if (res)
1305 		return dev_err_probe(dev, res, "failed to set DMA mask\n");
1306 
1307 	pci_set_master(pdev);
1308 
1309 	if (nhi->ops && nhi->ops->init) {
1310 		res = nhi->ops->init(nhi);
1311 		if (res)
1312 			return res;
1313 	}
1314 
1315 	tb = nhi_select_cm(nhi);
1316 	if (!tb)
1317 		return dev_err_probe(dev, -ENODEV,
1318 			"failed to determine connection manager, aborting\n");
1319 
1320 	dev_dbg(dev, "NHI initialized, starting thunderbolt\n");
1321 
1322 	res = tb_domain_add(tb);
1323 	if (res) {
1324 		/*
1325 		 * At this point the RX/TX rings might already have been
1326 		 * activated. Do a proper shutdown.
1327 		 */
1328 		tb_domain_put(tb);
1329 		nhi_shutdown(nhi);
1330 		return res;
1331 	}
1332 	pci_set_drvdata(pdev, tb);
1333 
1334 	device_wakeup_enable(&pdev->dev);
1335 
1336 	pm_runtime_allow(&pdev->dev);
1337 	pm_runtime_set_autosuspend_delay(&pdev->dev, TB_AUTOSUSPEND_DELAY);
1338 	pm_runtime_use_autosuspend(&pdev->dev);
1339 	pm_runtime_put_autosuspend(&pdev->dev);
1340 
1341 	return 0;
1342 }
1343 
1344 static void nhi_remove(struct pci_dev *pdev)
1345 {
1346 	struct tb *tb = pci_get_drvdata(pdev);
1347 	struct tb_nhi *nhi = tb->nhi;
1348 
1349 	pm_runtime_get_sync(&pdev->dev);
1350 	pm_runtime_dont_use_autosuspend(&pdev->dev);
1351 	pm_runtime_forbid(&pdev->dev);
1352 
1353 	tb_domain_remove(tb);
1354 	nhi_shutdown(nhi);
1355 }
1356 
1357 /*
1358  * The tunneled pci bridges are siblings of us. Use resume_noirq to reenable
1359  * the tunnels asap. A corresponding pci quirk blocks the downstream bridges
1360  * resume_noirq until we are done.
1361  */
1362 static const struct dev_pm_ops nhi_pm_ops = {
1363 	.suspend_noirq = nhi_suspend_noirq,
1364 	.resume_noirq = nhi_resume_noirq,
1365 	.freeze_noirq = nhi_freeze_noirq,  /*
1366 					    * we just disable hotplug, the
1367 					    * pci-tunnels stay alive.
1368 					    */
1369 	.thaw_noirq = nhi_thaw_noirq,
1370 	.restore_noirq = nhi_resume_noirq,
1371 	.suspend = nhi_suspend,
1372 	.poweroff_noirq = nhi_poweroff_noirq,
1373 	.poweroff = nhi_suspend,
1374 	.complete = nhi_complete,
1375 	.runtime_suspend = nhi_runtime_suspend,
1376 	.runtime_resume = nhi_runtime_resume,
1377 };
1378 
1379 static struct pci_device_id nhi_ids[] = {
1380 	/*
1381 	 * We have to specify class, the TB bridges use the same device and
1382 	 * vendor (sub)id on gen 1 and gen 2 controllers.
1383 	 */
1384 	{
1385 		.class = PCI_CLASS_SYSTEM_OTHER << 8, .class_mask = ~0,
1386 		.vendor = PCI_VENDOR_ID_INTEL,
1387 		.device = PCI_DEVICE_ID_INTEL_LIGHT_RIDGE,
1388 		.subvendor = 0x2222, .subdevice = 0x1111,
1389 	},
1390 	{
1391 		.class = PCI_CLASS_SYSTEM_OTHER << 8, .class_mask = ~0,
1392 		.vendor = PCI_VENDOR_ID_INTEL,
1393 		.device = PCI_DEVICE_ID_INTEL_CACTUS_RIDGE_4C,
1394 		.subvendor = 0x2222, .subdevice = 0x1111,
1395 	},
1396 	{
1397 		.class = PCI_CLASS_SYSTEM_OTHER << 8, .class_mask = ~0,
1398 		.vendor = PCI_VENDOR_ID_INTEL,
1399 		.device = PCI_DEVICE_ID_INTEL_FALCON_RIDGE_2C_NHI,
1400 		.subvendor = PCI_ANY_ID, .subdevice = PCI_ANY_ID,
1401 	},
1402 	{
1403 		.class = PCI_CLASS_SYSTEM_OTHER << 8, .class_mask = ~0,
1404 		.vendor = PCI_VENDOR_ID_INTEL,
1405 		.device = PCI_DEVICE_ID_INTEL_FALCON_RIDGE_4C_NHI,
1406 		.subvendor = PCI_ANY_ID, .subdevice = PCI_ANY_ID,
1407 	},
1408 
1409 	/* Thunderbolt 3 */
1410 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_2C_NHI) },
1411 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_4C_NHI) },
1412 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_USBONLY_NHI) },
1413 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_LP_NHI) },
1414 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_LP_USBONLY_NHI) },
1415 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_C_2C_NHI) },
1416 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_C_4C_NHI) },
1417 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_C_USBONLY_NHI) },
1418 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_TITAN_RIDGE_2C_NHI) },
1419 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_TITAN_RIDGE_4C_NHI) },
1420 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ICL_NHI0),
1421 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1422 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ICL_NHI1),
1423 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1424 	/* Thunderbolt 4 */
1425 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_TGL_NHI0),
1426 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1427 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_TGL_NHI1),
1428 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1429 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_TGL_H_NHI0),
1430 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1431 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_TGL_H_NHI1),
1432 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1433 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ADL_NHI0),
1434 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1435 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ADL_NHI1),
1436 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1437 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_RPL_NHI0),
1438 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1439 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_RPL_NHI1),
1440 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1441 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_MTL_M_NHI0),
1442 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1443 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_MTL_P_NHI0),
1444 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1445 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_MTL_P_NHI1),
1446 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1447 
1448 	/* Any USB4 compliant host */
1449 	{ PCI_DEVICE_CLASS(PCI_CLASS_SERIAL_USB_USB4, ~0) },
1450 
1451 	{ 0,}
1452 };
1453 
1454 MODULE_DEVICE_TABLE(pci, nhi_ids);
1455 MODULE_LICENSE("GPL");
1456 
1457 static struct pci_driver nhi_driver = {
1458 	.name = "thunderbolt",
1459 	.id_table = nhi_ids,
1460 	.probe = nhi_probe,
1461 	.remove = nhi_remove,
1462 	.shutdown = nhi_remove,
1463 	.driver.pm = &nhi_pm_ops,
1464 };
1465 
1466 static int __init nhi_init(void)
1467 {
1468 	int ret;
1469 
1470 	ret = tb_domain_init();
1471 	if (ret)
1472 		return ret;
1473 	ret = pci_register_driver(&nhi_driver);
1474 	if (ret)
1475 		tb_domain_exit();
1476 	return ret;
1477 }
1478 
1479 static void __exit nhi_unload(void)
1480 {
1481 	pci_unregister_driver(&nhi_driver);
1482 	tb_domain_exit();
1483 }
1484 
1485 rootfs_initcall(nhi_init);
1486 module_exit(nhi_unload);
1487