xref: /openbmc/linux/drivers/thunderbolt/nhi.c (revision 97d5f2e9)
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 static void nhi_mask_interrupt(struct tb_nhi *nhi, int mask, int ring)
58 {
59 	if (nhi->quirks & QUIRK_AUTO_CLEAR_INT)
60 		return;
61 	iowrite32(mask, nhi->iobase + REG_RING_INTERRUPT_MASK_CLEAR_BASE + ring);
62 }
63 
64 static void nhi_clear_interrupt(struct tb_nhi *nhi, int ring)
65 {
66 	if (nhi->quirks & QUIRK_AUTO_CLEAR_INT)
67 		ioread32(nhi->iobase + REG_RING_NOTIFY_BASE + ring);
68 	else
69 		iowrite32(~0, nhi->iobase + REG_RING_INT_CLEAR + ring);
70 }
71 
72 /*
73  * ring_interrupt_active() - activate/deactivate interrupts for a single ring
74  *
75  * ring->nhi->lock must be held.
76  */
77 static void ring_interrupt_active(struct tb_ring *ring, bool active)
78 {
79 	int index = ring_interrupt_index(ring) / 32 * 4;
80 	int reg = REG_RING_INTERRUPT_BASE + index;
81 	int interrupt_bit = ring_interrupt_index(ring) & 31;
82 	int mask = 1 << interrupt_bit;
83 	u32 old, new;
84 
85 	if (ring->irq > 0) {
86 		u32 step, shift, ivr, misc;
87 		void __iomem *ivr_base;
88 		int auto_clear_bit;
89 		int index;
90 
91 		if (ring->is_tx)
92 			index = ring->hop;
93 		else
94 			index = ring->hop + ring->nhi->hop_count;
95 
96 		/*
97 		 * Intel routers support a bit that isn't part of
98 		 * the USB4 spec to ask the hardware to clear
99 		 * interrupt status bits automatically since
100 		 * we already know which interrupt was triggered.
101 		 *
102 		 * Other routers explicitly disable auto-clear
103 		 * to prevent conditions that may occur where two
104 		 * MSIX interrupts are simultaneously active and
105 		 * reading the register clears both of them.
106 		 */
107 		misc = ioread32(ring->nhi->iobase + REG_DMA_MISC);
108 		if (ring->nhi->quirks & QUIRK_AUTO_CLEAR_INT)
109 			auto_clear_bit = REG_DMA_MISC_INT_AUTO_CLEAR;
110 		else
111 			auto_clear_bit = REG_DMA_MISC_DISABLE_AUTO_CLEAR;
112 		if (!(misc & auto_clear_bit))
113 			iowrite32(misc | auto_clear_bit,
114 				  ring->nhi->iobase + REG_DMA_MISC);
115 
116 		ivr_base = ring->nhi->iobase + REG_INT_VEC_ALLOC_BASE;
117 		step = index / REG_INT_VEC_ALLOC_REGS * REG_INT_VEC_ALLOC_BITS;
118 		shift = index % REG_INT_VEC_ALLOC_REGS * REG_INT_VEC_ALLOC_BITS;
119 		ivr = ioread32(ivr_base + step);
120 		ivr &= ~(REG_INT_VEC_ALLOC_MASK << shift);
121 		if (active)
122 			ivr |= ring->vector << shift;
123 		iowrite32(ivr, ivr_base + step);
124 	}
125 
126 	old = ioread32(ring->nhi->iobase + reg);
127 	if (active)
128 		new = old | mask;
129 	else
130 		new = old & ~mask;
131 
132 	dev_dbg(&ring->nhi->pdev->dev,
133 		"%s interrupt at register %#x bit %d (%#x -> %#x)\n",
134 		active ? "enabling" : "disabling", reg, interrupt_bit, old, new);
135 
136 	if (new == old)
137 		dev_WARN(&ring->nhi->pdev->dev,
138 					 "interrupt for %s %d is already %s\n",
139 					 RING_TYPE(ring), ring->hop,
140 					 active ? "enabled" : "disabled");
141 
142 	if (active)
143 		iowrite32(new, ring->nhi->iobase + reg);
144 	else
145 		nhi_mask_interrupt(ring->nhi, mask, index);
146 }
147 
148 /*
149  * nhi_disable_interrupts() - disable interrupts for all rings
150  *
151  * Use only during init and shutdown.
152  */
153 static void nhi_disable_interrupts(struct tb_nhi *nhi)
154 {
155 	int i = 0;
156 	/* disable interrupts */
157 	for (i = 0; i < RING_INTERRUPT_REG_COUNT(nhi); i++)
158 		nhi_mask_interrupt(nhi, ~0, 4 * i);
159 
160 	/* clear interrupt status bits */
161 	for (i = 0; i < RING_NOTIFY_REG_COUNT(nhi); i++)
162 		nhi_clear_interrupt(nhi, 4 * i);
163 }
164 
165 /* ring helper methods */
166 
167 static void __iomem *ring_desc_base(struct tb_ring *ring)
168 {
169 	void __iomem *io = ring->nhi->iobase;
170 	io += ring->is_tx ? REG_TX_RING_BASE : REG_RX_RING_BASE;
171 	io += ring->hop * 16;
172 	return io;
173 }
174 
175 static void __iomem *ring_options_base(struct tb_ring *ring)
176 {
177 	void __iomem *io = ring->nhi->iobase;
178 	io += ring->is_tx ? REG_TX_OPTIONS_BASE : REG_RX_OPTIONS_BASE;
179 	io += ring->hop * 32;
180 	return io;
181 }
182 
183 static void ring_iowrite_cons(struct tb_ring *ring, u16 cons)
184 {
185 	/*
186 	 * The other 16-bits in the register is read-only and writes to it
187 	 * are ignored by the hardware so we can save one ioread32() by
188 	 * filling the read-only bits with zeroes.
189 	 */
190 	iowrite32(cons, ring_desc_base(ring) + 8);
191 }
192 
193 static void ring_iowrite_prod(struct tb_ring *ring, u16 prod)
194 {
195 	/* See ring_iowrite_cons() above for explanation */
196 	iowrite32(prod << 16, ring_desc_base(ring) + 8);
197 }
198 
199 static void ring_iowrite32desc(struct tb_ring *ring, u32 value, u32 offset)
200 {
201 	iowrite32(value, ring_desc_base(ring) + offset);
202 }
203 
204 static void ring_iowrite64desc(struct tb_ring *ring, u64 value, u32 offset)
205 {
206 	iowrite32(value, ring_desc_base(ring) + offset);
207 	iowrite32(value >> 32, ring_desc_base(ring) + offset + 4);
208 }
209 
210 static void ring_iowrite32options(struct tb_ring *ring, u32 value, u32 offset)
211 {
212 	iowrite32(value, ring_options_base(ring) + offset);
213 }
214 
215 static bool ring_full(struct tb_ring *ring)
216 {
217 	return ((ring->head + 1) % ring->size) == ring->tail;
218 }
219 
220 static bool ring_empty(struct tb_ring *ring)
221 {
222 	return ring->head == ring->tail;
223 }
224 
225 /*
226  * ring_write_descriptors() - post frames from ring->queue to the controller
227  *
228  * ring->lock is held.
229  */
230 static void ring_write_descriptors(struct tb_ring *ring)
231 {
232 	struct ring_frame *frame, *n;
233 	struct ring_desc *descriptor;
234 	list_for_each_entry_safe(frame, n, &ring->queue, list) {
235 		if (ring_full(ring))
236 			break;
237 		list_move_tail(&frame->list, &ring->in_flight);
238 		descriptor = &ring->descriptors[ring->head];
239 		descriptor->phys = frame->buffer_phy;
240 		descriptor->time = 0;
241 		descriptor->flags = RING_DESC_POSTED | RING_DESC_INTERRUPT;
242 		if (ring->is_tx) {
243 			descriptor->length = frame->size;
244 			descriptor->eof = frame->eof;
245 			descriptor->sof = frame->sof;
246 		}
247 		ring->head = (ring->head + 1) % ring->size;
248 		if (ring->is_tx)
249 			ring_iowrite_prod(ring, ring->head);
250 		else
251 			ring_iowrite_cons(ring, ring->head);
252 	}
253 }
254 
255 /*
256  * ring_work() - progress completed frames
257  *
258  * If the ring is shutting down then all frames are marked as canceled and
259  * their callbacks are invoked.
260  *
261  * Otherwise we collect all completed frame from the ring buffer, write new
262  * frame to the ring buffer and invoke the callbacks for the completed frames.
263  */
264 static void ring_work(struct work_struct *work)
265 {
266 	struct tb_ring *ring = container_of(work, typeof(*ring), work);
267 	struct ring_frame *frame;
268 	bool canceled = false;
269 	unsigned long flags;
270 	LIST_HEAD(done);
271 
272 	spin_lock_irqsave(&ring->lock, flags);
273 
274 	if (!ring->running) {
275 		/*  Move all frames to done and mark them as canceled. */
276 		list_splice_tail_init(&ring->in_flight, &done);
277 		list_splice_tail_init(&ring->queue, &done);
278 		canceled = true;
279 		goto invoke_callback;
280 	}
281 
282 	while (!ring_empty(ring)) {
283 		if (!(ring->descriptors[ring->tail].flags
284 				& RING_DESC_COMPLETED))
285 			break;
286 		frame = list_first_entry(&ring->in_flight, typeof(*frame),
287 					 list);
288 		list_move_tail(&frame->list, &done);
289 		if (!ring->is_tx) {
290 			frame->size = ring->descriptors[ring->tail].length;
291 			frame->eof = ring->descriptors[ring->tail].eof;
292 			frame->sof = ring->descriptors[ring->tail].sof;
293 			frame->flags = ring->descriptors[ring->tail].flags;
294 		}
295 		ring->tail = (ring->tail + 1) % ring->size;
296 	}
297 	ring_write_descriptors(ring);
298 
299 invoke_callback:
300 	/* allow callbacks to schedule new work */
301 	spin_unlock_irqrestore(&ring->lock, flags);
302 	while (!list_empty(&done)) {
303 		frame = list_first_entry(&done, typeof(*frame), list);
304 		/*
305 		 * The callback may reenqueue or delete frame.
306 		 * Do not hold on to it.
307 		 */
308 		list_del_init(&frame->list);
309 		if (frame->callback)
310 			frame->callback(ring, frame, canceled);
311 	}
312 }
313 
314 int __tb_ring_enqueue(struct tb_ring *ring, struct ring_frame *frame)
315 {
316 	unsigned long flags;
317 	int ret = 0;
318 
319 	spin_lock_irqsave(&ring->lock, flags);
320 	if (ring->running) {
321 		list_add_tail(&frame->list, &ring->queue);
322 		ring_write_descriptors(ring);
323 	} else {
324 		ret = -ESHUTDOWN;
325 	}
326 	spin_unlock_irqrestore(&ring->lock, flags);
327 	return ret;
328 }
329 EXPORT_SYMBOL_GPL(__tb_ring_enqueue);
330 
331 /**
332  * tb_ring_poll() - Poll one completed frame from the ring
333  * @ring: Ring to poll
334  *
335  * This function can be called when @start_poll callback of the @ring
336  * has been called. It will read one completed frame from the ring and
337  * return it to the caller. Returns %NULL if there is no more completed
338  * frames.
339  */
340 struct ring_frame *tb_ring_poll(struct tb_ring *ring)
341 {
342 	struct ring_frame *frame = NULL;
343 	unsigned long flags;
344 
345 	spin_lock_irqsave(&ring->lock, flags);
346 	if (!ring->running)
347 		goto unlock;
348 	if (ring_empty(ring))
349 		goto unlock;
350 
351 	if (ring->descriptors[ring->tail].flags & RING_DESC_COMPLETED) {
352 		frame = list_first_entry(&ring->in_flight, typeof(*frame),
353 					 list);
354 		list_del_init(&frame->list);
355 
356 		if (!ring->is_tx) {
357 			frame->size = ring->descriptors[ring->tail].length;
358 			frame->eof = ring->descriptors[ring->tail].eof;
359 			frame->sof = ring->descriptors[ring->tail].sof;
360 			frame->flags = ring->descriptors[ring->tail].flags;
361 		}
362 
363 		ring->tail = (ring->tail + 1) % ring->size;
364 	}
365 
366 unlock:
367 	spin_unlock_irqrestore(&ring->lock, flags);
368 	return frame;
369 }
370 EXPORT_SYMBOL_GPL(tb_ring_poll);
371 
372 static void __ring_interrupt_mask(struct tb_ring *ring, bool mask)
373 {
374 	int idx = ring_interrupt_index(ring);
375 	int reg = REG_RING_INTERRUPT_BASE + idx / 32 * 4;
376 	int bit = idx % 32;
377 	u32 val;
378 
379 	val = ioread32(ring->nhi->iobase + reg);
380 	if (mask)
381 		val &= ~BIT(bit);
382 	else
383 		val |= BIT(bit);
384 	iowrite32(val, ring->nhi->iobase + reg);
385 }
386 
387 /* Both @nhi->lock and @ring->lock should be held */
388 static void __ring_interrupt(struct tb_ring *ring)
389 {
390 	if (!ring->running)
391 		return;
392 
393 	if (ring->start_poll) {
394 		__ring_interrupt_mask(ring, true);
395 		ring->start_poll(ring->poll_data);
396 	} else {
397 		schedule_work(&ring->work);
398 	}
399 }
400 
401 /**
402  * tb_ring_poll_complete() - Re-start interrupt for the ring
403  * @ring: Ring to re-start the interrupt
404  *
405  * This will re-start (unmask) the ring interrupt once the user is done
406  * with polling.
407  */
408 void tb_ring_poll_complete(struct tb_ring *ring)
409 {
410 	unsigned long flags;
411 
412 	spin_lock_irqsave(&ring->nhi->lock, flags);
413 	spin_lock(&ring->lock);
414 	if (ring->start_poll)
415 		__ring_interrupt_mask(ring, false);
416 	spin_unlock(&ring->lock);
417 	spin_unlock_irqrestore(&ring->nhi->lock, flags);
418 }
419 EXPORT_SYMBOL_GPL(tb_ring_poll_complete);
420 
421 static void ring_clear_msix(const struct tb_ring *ring)
422 {
423 	int bit;
424 
425 	if (ring->nhi->quirks & QUIRK_AUTO_CLEAR_INT)
426 		return;
427 
428 	bit = ring_interrupt_index(ring) & 31;
429 	if (ring->is_tx)
430 		iowrite32(BIT(bit), ring->nhi->iobase + REG_RING_INT_CLEAR);
431 	else
432 		iowrite32(BIT(bit), ring->nhi->iobase + REG_RING_INT_CLEAR +
433 			  4 * (ring->nhi->hop_count / 32));
434 }
435 
436 static irqreturn_t ring_msix(int irq, void *data)
437 {
438 	struct tb_ring *ring = data;
439 
440 	spin_lock(&ring->nhi->lock);
441 	ring_clear_msix(ring);
442 	spin_lock(&ring->lock);
443 	__ring_interrupt(ring);
444 	spin_unlock(&ring->lock);
445 	spin_unlock(&ring->nhi->lock);
446 
447 	return IRQ_HANDLED;
448 }
449 
450 static int ring_request_msix(struct tb_ring *ring, bool no_suspend)
451 {
452 	struct tb_nhi *nhi = ring->nhi;
453 	unsigned long irqflags;
454 	int ret;
455 
456 	if (!nhi->pdev->msix_enabled)
457 		return 0;
458 
459 	ret = ida_simple_get(&nhi->msix_ida, 0, MSIX_MAX_VECS, GFP_KERNEL);
460 	if (ret < 0)
461 		return ret;
462 
463 	ring->vector = ret;
464 
465 	ret = pci_irq_vector(ring->nhi->pdev, ring->vector);
466 	if (ret < 0)
467 		goto err_ida_remove;
468 
469 	ring->irq = ret;
470 
471 	irqflags = no_suspend ? IRQF_NO_SUSPEND : 0;
472 	ret = request_irq(ring->irq, ring_msix, irqflags, "thunderbolt", ring);
473 	if (ret)
474 		goto err_ida_remove;
475 
476 	return 0;
477 
478 err_ida_remove:
479 	ida_simple_remove(&nhi->msix_ida, ring->vector);
480 
481 	return ret;
482 }
483 
484 static void ring_release_msix(struct tb_ring *ring)
485 {
486 	if (ring->irq <= 0)
487 		return;
488 
489 	free_irq(ring->irq, ring);
490 	ida_simple_remove(&ring->nhi->msix_ida, ring->vector);
491 	ring->vector = 0;
492 	ring->irq = 0;
493 }
494 
495 static int nhi_alloc_hop(struct tb_nhi *nhi, struct tb_ring *ring)
496 {
497 	unsigned int start_hop = RING_FIRST_USABLE_HOPID;
498 	int ret = 0;
499 
500 	if (nhi->quirks & QUIRK_E2E) {
501 		start_hop = RING_FIRST_USABLE_HOPID + 1;
502 		if (ring->flags & RING_FLAG_E2E && !ring->is_tx) {
503 			dev_dbg(&nhi->pdev->dev, "quirking E2E TX HopID %u -> %u\n",
504 				ring->e2e_tx_hop, RING_E2E_RESERVED_HOPID);
505 			ring->e2e_tx_hop = RING_E2E_RESERVED_HOPID;
506 		}
507 	}
508 
509 	spin_lock_irq(&nhi->lock);
510 
511 	if (ring->hop < 0) {
512 		unsigned int i;
513 
514 		/*
515 		 * Automatically allocate HopID from the non-reserved
516 		 * range 1 .. hop_count - 1.
517 		 */
518 		for (i = start_hop; i < nhi->hop_count; i++) {
519 			if (ring->is_tx) {
520 				if (!nhi->tx_rings[i]) {
521 					ring->hop = i;
522 					break;
523 				}
524 			} else {
525 				if (!nhi->rx_rings[i]) {
526 					ring->hop = i;
527 					break;
528 				}
529 			}
530 		}
531 	}
532 
533 	if (ring->hop > 0 && ring->hop < start_hop) {
534 		dev_warn(&nhi->pdev->dev, "invalid hop: %d\n", ring->hop);
535 		ret = -EINVAL;
536 		goto err_unlock;
537 	}
538 	if (ring->hop < 0 || ring->hop >= nhi->hop_count) {
539 		dev_warn(&nhi->pdev->dev, "invalid hop: %d\n", ring->hop);
540 		ret = -EINVAL;
541 		goto err_unlock;
542 	}
543 	if (ring->is_tx && nhi->tx_rings[ring->hop]) {
544 		dev_warn(&nhi->pdev->dev, "TX hop %d already allocated\n",
545 			 ring->hop);
546 		ret = -EBUSY;
547 		goto err_unlock;
548 	}
549 	if (!ring->is_tx && nhi->rx_rings[ring->hop]) {
550 		dev_warn(&nhi->pdev->dev, "RX hop %d already allocated\n",
551 			 ring->hop);
552 		ret = -EBUSY;
553 		goto err_unlock;
554 	}
555 
556 	if (ring->is_tx)
557 		nhi->tx_rings[ring->hop] = ring;
558 	else
559 		nhi->rx_rings[ring->hop] = ring;
560 
561 err_unlock:
562 	spin_unlock_irq(&nhi->lock);
563 
564 	return ret;
565 }
566 
567 static struct tb_ring *tb_ring_alloc(struct tb_nhi *nhi, u32 hop, int size,
568 				     bool transmit, unsigned int flags,
569 				     int e2e_tx_hop, u16 sof_mask, u16 eof_mask,
570 				     void (*start_poll)(void *),
571 				     void *poll_data)
572 {
573 	struct tb_ring *ring = NULL;
574 
575 	dev_dbg(&nhi->pdev->dev, "allocating %s ring %d of size %d\n",
576 		transmit ? "TX" : "RX", hop, size);
577 
578 	ring = kzalloc(sizeof(*ring), GFP_KERNEL);
579 	if (!ring)
580 		return NULL;
581 
582 	spin_lock_init(&ring->lock);
583 	INIT_LIST_HEAD(&ring->queue);
584 	INIT_LIST_HEAD(&ring->in_flight);
585 	INIT_WORK(&ring->work, ring_work);
586 
587 	ring->nhi = nhi;
588 	ring->hop = hop;
589 	ring->is_tx = transmit;
590 	ring->size = size;
591 	ring->flags = flags;
592 	ring->e2e_tx_hop = e2e_tx_hop;
593 	ring->sof_mask = sof_mask;
594 	ring->eof_mask = eof_mask;
595 	ring->head = 0;
596 	ring->tail = 0;
597 	ring->running = false;
598 	ring->start_poll = start_poll;
599 	ring->poll_data = poll_data;
600 
601 	ring->descriptors = dma_alloc_coherent(&ring->nhi->pdev->dev,
602 			size * sizeof(*ring->descriptors),
603 			&ring->descriptors_dma, GFP_KERNEL | __GFP_ZERO);
604 	if (!ring->descriptors)
605 		goto err_free_ring;
606 
607 	if (ring_request_msix(ring, flags & RING_FLAG_NO_SUSPEND))
608 		goto err_free_descs;
609 
610 	if (nhi_alloc_hop(nhi, ring))
611 		goto err_release_msix;
612 
613 	return ring;
614 
615 err_release_msix:
616 	ring_release_msix(ring);
617 err_free_descs:
618 	dma_free_coherent(&ring->nhi->pdev->dev,
619 			  ring->size * sizeof(*ring->descriptors),
620 			  ring->descriptors, ring->descriptors_dma);
621 err_free_ring:
622 	kfree(ring);
623 
624 	return NULL;
625 }
626 
627 /**
628  * tb_ring_alloc_tx() - Allocate DMA ring for transmit
629  * @nhi: Pointer to the NHI the ring is to be allocated
630  * @hop: HopID (ring) to allocate
631  * @size: Number of entries in the ring
632  * @flags: Flags for the ring
633  */
634 struct tb_ring *tb_ring_alloc_tx(struct tb_nhi *nhi, int hop, int size,
635 				 unsigned int flags)
636 {
637 	return tb_ring_alloc(nhi, hop, size, true, flags, 0, 0, 0, NULL, NULL);
638 }
639 EXPORT_SYMBOL_GPL(tb_ring_alloc_tx);
640 
641 /**
642  * tb_ring_alloc_rx() - Allocate DMA ring for receive
643  * @nhi: Pointer to the NHI the ring is to be allocated
644  * @hop: HopID (ring) to allocate. Pass %-1 for automatic allocation.
645  * @size: Number of entries in the ring
646  * @flags: Flags for the ring
647  * @e2e_tx_hop: Transmit HopID when E2E is enabled in @flags
648  * @sof_mask: Mask of PDF values that start a frame
649  * @eof_mask: Mask of PDF values that end a frame
650  * @start_poll: If not %NULL the ring will call this function when an
651  *		interrupt is triggered and masked, instead of callback
652  *		in each Rx frame.
653  * @poll_data: Optional data passed to @start_poll
654  */
655 struct tb_ring *tb_ring_alloc_rx(struct tb_nhi *nhi, int hop, int size,
656 				 unsigned int flags, int e2e_tx_hop,
657 				 u16 sof_mask, u16 eof_mask,
658 				 void (*start_poll)(void *), void *poll_data)
659 {
660 	return tb_ring_alloc(nhi, hop, size, false, flags, e2e_tx_hop, sof_mask, eof_mask,
661 			     start_poll, poll_data);
662 }
663 EXPORT_SYMBOL_GPL(tb_ring_alloc_rx);
664 
665 /**
666  * tb_ring_start() - enable a ring
667  * @ring: Ring to start
668  *
669  * Must not be invoked in parallel with tb_ring_stop().
670  */
671 void tb_ring_start(struct tb_ring *ring)
672 {
673 	u16 frame_size;
674 	u32 flags;
675 
676 	spin_lock_irq(&ring->nhi->lock);
677 	spin_lock(&ring->lock);
678 	if (ring->nhi->going_away)
679 		goto err;
680 	if (ring->running) {
681 		dev_WARN(&ring->nhi->pdev->dev, "ring already started\n");
682 		goto err;
683 	}
684 	dev_dbg(&ring->nhi->pdev->dev, "starting %s %d\n",
685 		RING_TYPE(ring), ring->hop);
686 
687 	if (ring->flags & RING_FLAG_FRAME) {
688 		/* Means 4096 */
689 		frame_size = 0;
690 		flags = RING_FLAG_ENABLE;
691 	} else {
692 		frame_size = TB_FRAME_SIZE;
693 		flags = RING_FLAG_ENABLE | RING_FLAG_RAW;
694 	}
695 
696 	ring_iowrite64desc(ring, ring->descriptors_dma, 0);
697 	if (ring->is_tx) {
698 		ring_iowrite32desc(ring, ring->size, 12);
699 		ring_iowrite32options(ring, 0, 4); /* time releated ? */
700 		ring_iowrite32options(ring, flags, 0);
701 	} else {
702 		u32 sof_eof_mask = ring->sof_mask << 16 | ring->eof_mask;
703 
704 		ring_iowrite32desc(ring, (frame_size << 16) | ring->size, 12);
705 		ring_iowrite32options(ring, sof_eof_mask, 4);
706 		ring_iowrite32options(ring, flags, 0);
707 	}
708 
709 	/*
710 	 * Now that the ring valid bit is set we can configure E2E if
711 	 * enabled for the ring.
712 	 */
713 	if (ring->flags & RING_FLAG_E2E) {
714 		if (!ring->is_tx) {
715 			u32 hop;
716 
717 			hop = ring->e2e_tx_hop << REG_RX_OPTIONS_E2E_HOP_SHIFT;
718 			hop &= REG_RX_OPTIONS_E2E_HOP_MASK;
719 			flags |= hop;
720 
721 			dev_dbg(&ring->nhi->pdev->dev,
722 				"enabling E2E for %s %d with TX HopID %d\n",
723 				RING_TYPE(ring), ring->hop, ring->e2e_tx_hop);
724 		} else {
725 			dev_dbg(&ring->nhi->pdev->dev, "enabling E2E for %s %d\n",
726 				RING_TYPE(ring), ring->hop);
727 		}
728 
729 		flags |= RING_FLAG_E2E_FLOW_CONTROL;
730 		ring_iowrite32options(ring, flags, 0);
731 	}
732 
733 	ring_interrupt_active(ring, true);
734 	ring->running = true;
735 err:
736 	spin_unlock(&ring->lock);
737 	spin_unlock_irq(&ring->nhi->lock);
738 }
739 EXPORT_SYMBOL_GPL(tb_ring_start);
740 
741 /**
742  * tb_ring_stop() - shutdown a ring
743  * @ring: Ring to stop
744  *
745  * Must not be invoked from a callback.
746  *
747  * This method will disable the ring. Further calls to
748  * tb_ring_tx/tb_ring_rx will return -ESHUTDOWN until ring_stop has been
749  * called.
750  *
751  * All enqueued frames will be canceled and their callbacks will be executed
752  * with frame->canceled set to true (on the callback thread). This method
753  * returns only after all callback invocations have finished.
754  */
755 void tb_ring_stop(struct tb_ring *ring)
756 {
757 	spin_lock_irq(&ring->nhi->lock);
758 	spin_lock(&ring->lock);
759 	dev_dbg(&ring->nhi->pdev->dev, "stopping %s %d\n",
760 		RING_TYPE(ring), ring->hop);
761 	if (ring->nhi->going_away)
762 		goto err;
763 	if (!ring->running) {
764 		dev_WARN(&ring->nhi->pdev->dev, "%s %d already stopped\n",
765 			 RING_TYPE(ring), ring->hop);
766 		goto err;
767 	}
768 	ring_interrupt_active(ring, false);
769 
770 	ring_iowrite32options(ring, 0, 0);
771 	ring_iowrite64desc(ring, 0, 0);
772 	ring_iowrite32desc(ring, 0, 8);
773 	ring_iowrite32desc(ring, 0, 12);
774 	ring->head = 0;
775 	ring->tail = 0;
776 	ring->running = false;
777 
778 err:
779 	spin_unlock(&ring->lock);
780 	spin_unlock_irq(&ring->nhi->lock);
781 
782 	/*
783 	 * schedule ring->work to invoke callbacks on all remaining frames.
784 	 */
785 	schedule_work(&ring->work);
786 	flush_work(&ring->work);
787 }
788 EXPORT_SYMBOL_GPL(tb_ring_stop);
789 
790 /*
791  * tb_ring_free() - free ring
792  *
793  * When this method returns all invocations of ring->callback will have
794  * finished.
795  *
796  * Ring must be stopped.
797  *
798  * Must NOT be called from ring_frame->callback!
799  */
800 void tb_ring_free(struct tb_ring *ring)
801 {
802 	spin_lock_irq(&ring->nhi->lock);
803 	/*
804 	 * Dissociate the ring from the NHI. This also ensures that
805 	 * nhi_interrupt_work cannot reschedule ring->work.
806 	 */
807 	if (ring->is_tx)
808 		ring->nhi->tx_rings[ring->hop] = NULL;
809 	else
810 		ring->nhi->rx_rings[ring->hop] = NULL;
811 
812 	if (ring->running) {
813 		dev_WARN(&ring->nhi->pdev->dev, "%s %d still running\n",
814 			 RING_TYPE(ring), ring->hop);
815 	}
816 	spin_unlock_irq(&ring->nhi->lock);
817 
818 	ring_release_msix(ring);
819 
820 	dma_free_coherent(&ring->nhi->pdev->dev,
821 			  ring->size * sizeof(*ring->descriptors),
822 			  ring->descriptors, ring->descriptors_dma);
823 
824 	ring->descriptors = NULL;
825 	ring->descriptors_dma = 0;
826 
827 
828 	dev_dbg(&ring->nhi->pdev->dev, "freeing %s %d\n", RING_TYPE(ring),
829 		ring->hop);
830 
831 	/*
832 	 * ring->work can no longer be scheduled (it is scheduled only
833 	 * by nhi_interrupt_work, ring_stop and ring_msix). Wait for it
834 	 * to finish before freeing the ring.
835 	 */
836 	flush_work(&ring->work);
837 	kfree(ring);
838 }
839 EXPORT_SYMBOL_GPL(tb_ring_free);
840 
841 /**
842  * nhi_mailbox_cmd() - Send a command through NHI mailbox
843  * @nhi: Pointer to the NHI structure
844  * @cmd: Command to send
845  * @data: Data to be send with the command
846  *
847  * Sends mailbox command to the firmware running on NHI. Returns %0 in
848  * case of success and negative errno in case of failure.
849  */
850 int nhi_mailbox_cmd(struct tb_nhi *nhi, enum nhi_mailbox_cmd cmd, u32 data)
851 {
852 	ktime_t timeout;
853 	u32 val;
854 
855 	iowrite32(data, nhi->iobase + REG_INMAIL_DATA);
856 
857 	val = ioread32(nhi->iobase + REG_INMAIL_CMD);
858 	val &= ~(REG_INMAIL_CMD_MASK | REG_INMAIL_ERROR);
859 	val |= REG_INMAIL_OP_REQUEST | cmd;
860 	iowrite32(val, nhi->iobase + REG_INMAIL_CMD);
861 
862 	timeout = ktime_add_ms(ktime_get(), NHI_MAILBOX_TIMEOUT);
863 	do {
864 		val = ioread32(nhi->iobase + REG_INMAIL_CMD);
865 		if (!(val & REG_INMAIL_OP_REQUEST))
866 			break;
867 		usleep_range(10, 20);
868 	} while (ktime_before(ktime_get(), timeout));
869 
870 	if (val & REG_INMAIL_OP_REQUEST)
871 		return -ETIMEDOUT;
872 	if (val & REG_INMAIL_ERROR)
873 		return -EIO;
874 
875 	return 0;
876 }
877 
878 /**
879  * nhi_mailbox_mode() - Return current firmware operation mode
880  * @nhi: Pointer to the NHI structure
881  *
882  * The function reads current firmware operation mode using NHI mailbox
883  * registers and returns it to the caller.
884  */
885 enum nhi_fw_mode nhi_mailbox_mode(struct tb_nhi *nhi)
886 {
887 	u32 val;
888 
889 	val = ioread32(nhi->iobase + REG_OUTMAIL_CMD);
890 	val &= REG_OUTMAIL_CMD_OPMODE_MASK;
891 	val >>= REG_OUTMAIL_CMD_OPMODE_SHIFT;
892 
893 	return (enum nhi_fw_mode)val;
894 }
895 
896 static void nhi_interrupt_work(struct work_struct *work)
897 {
898 	struct tb_nhi *nhi = container_of(work, typeof(*nhi), interrupt_work);
899 	int value = 0; /* Suppress uninitialized usage warning. */
900 	int bit;
901 	int hop = -1;
902 	int type = 0; /* current interrupt type 0: TX, 1: RX, 2: RX overflow */
903 	struct tb_ring *ring;
904 
905 	spin_lock_irq(&nhi->lock);
906 
907 	/*
908 	 * Starting at REG_RING_NOTIFY_BASE there are three status bitfields
909 	 * (TX, RX, RX overflow). We iterate over the bits and read a new
910 	 * dwords as required. The registers are cleared on read.
911 	 */
912 	for (bit = 0; bit < 3 * nhi->hop_count; bit++) {
913 		if (bit % 32 == 0)
914 			value = ioread32(nhi->iobase
915 					 + REG_RING_NOTIFY_BASE
916 					 + 4 * (bit / 32));
917 		if (++hop == nhi->hop_count) {
918 			hop = 0;
919 			type++;
920 		}
921 		if ((value & (1 << (bit % 32))) == 0)
922 			continue;
923 		if (type == 2) {
924 			dev_warn(&nhi->pdev->dev,
925 				 "RX overflow for ring %d\n",
926 				 hop);
927 			continue;
928 		}
929 		if (type == 0)
930 			ring = nhi->tx_rings[hop];
931 		else
932 			ring = nhi->rx_rings[hop];
933 		if (ring == NULL) {
934 			dev_warn(&nhi->pdev->dev,
935 				 "got interrupt for inactive %s ring %d\n",
936 				 type ? "RX" : "TX",
937 				 hop);
938 			continue;
939 		}
940 
941 		spin_lock(&ring->lock);
942 		__ring_interrupt(ring);
943 		spin_unlock(&ring->lock);
944 	}
945 	spin_unlock_irq(&nhi->lock);
946 }
947 
948 static irqreturn_t nhi_msi(int irq, void *data)
949 {
950 	struct tb_nhi *nhi = data;
951 	schedule_work(&nhi->interrupt_work);
952 	return IRQ_HANDLED;
953 }
954 
955 static int __nhi_suspend_noirq(struct device *dev, bool wakeup)
956 {
957 	struct pci_dev *pdev = to_pci_dev(dev);
958 	struct tb *tb = pci_get_drvdata(pdev);
959 	struct tb_nhi *nhi = tb->nhi;
960 	int ret;
961 
962 	ret = tb_domain_suspend_noirq(tb);
963 	if (ret)
964 		return ret;
965 
966 	if (nhi->ops && nhi->ops->suspend_noirq) {
967 		ret = nhi->ops->suspend_noirq(tb->nhi, wakeup);
968 		if (ret)
969 			return ret;
970 	}
971 
972 	return 0;
973 }
974 
975 static int nhi_suspend_noirq(struct device *dev)
976 {
977 	return __nhi_suspend_noirq(dev, device_may_wakeup(dev));
978 }
979 
980 static int nhi_freeze_noirq(struct device *dev)
981 {
982 	struct pci_dev *pdev = to_pci_dev(dev);
983 	struct tb *tb = pci_get_drvdata(pdev);
984 
985 	return tb_domain_freeze_noirq(tb);
986 }
987 
988 static int nhi_thaw_noirq(struct device *dev)
989 {
990 	struct pci_dev *pdev = to_pci_dev(dev);
991 	struct tb *tb = pci_get_drvdata(pdev);
992 
993 	return tb_domain_thaw_noirq(tb);
994 }
995 
996 static bool nhi_wake_supported(struct pci_dev *pdev)
997 {
998 	u8 val;
999 
1000 	/*
1001 	 * If power rails are sustainable for wakeup from S4 this
1002 	 * property is set by the BIOS.
1003 	 */
1004 	if (device_property_read_u8(&pdev->dev, "WAKE_SUPPORTED", &val))
1005 		return !!val;
1006 
1007 	return true;
1008 }
1009 
1010 static int nhi_poweroff_noirq(struct device *dev)
1011 {
1012 	struct pci_dev *pdev = to_pci_dev(dev);
1013 	bool wakeup;
1014 
1015 	wakeup = device_may_wakeup(dev) && nhi_wake_supported(pdev);
1016 	return __nhi_suspend_noirq(dev, wakeup);
1017 }
1018 
1019 static void nhi_enable_int_throttling(struct tb_nhi *nhi)
1020 {
1021 	/* Throttling is specified in 256ns increments */
1022 	u32 throttle = DIV_ROUND_UP(128 * NSEC_PER_USEC, 256);
1023 	unsigned int i;
1024 
1025 	/*
1026 	 * Configure interrupt throttling for all vectors even if we
1027 	 * only use few.
1028 	 */
1029 	for (i = 0; i < MSIX_MAX_VECS; i++) {
1030 		u32 reg = REG_INT_THROTTLING_RATE + i * 4;
1031 		iowrite32(throttle, nhi->iobase + reg);
1032 	}
1033 }
1034 
1035 static int nhi_resume_noirq(struct device *dev)
1036 {
1037 	struct pci_dev *pdev = to_pci_dev(dev);
1038 	struct tb *tb = pci_get_drvdata(pdev);
1039 	struct tb_nhi *nhi = tb->nhi;
1040 	int ret;
1041 
1042 	/*
1043 	 * Check that the device is still there. It may be that the user
1044 	 * unplugged last device which causes the host controller to go
1045 	 * away on PCs.
1046 	 */
1047 	if (!pci_device_is_present(pdev)) {
1048 		nhi->going_away = true;
1049 	} else {
1050 		if (nhi->ops && nhi->ops->resume_noirq) {
1051 			ret = nhi->ops->resume_noirq(nhi);
1052 			if (ret)
1053 				return ret;
1054 		}
1055 		nhi_enable_int_throttling(tb->nhi);
1056 	}
1057 
1058 	return tb_domain_resume_noirq(tb);
1059 }
1060 
1061 static int nhi_suspend(struct device *dev)
1062 {
1063 	struct pci_dev *pdev = to_pci_dev(dev);
1064 	struct tb *tb = pci_get_drvdata(pdev);
1065 
1066 	return tb_domain_suspend(tb);
1067 }
1068 
1069 static void nhi_complete(struct device *dev)
1070 {
1071 	struct pci_dev *pdev = to_pci_dev(dev);
1072 	struct tb *tb = pci_get_drvdata(pdev);
1073 
1074 	/*
1075 	 * If we were runtime suspended when system suspend started,
1076 	 * schedule runtime resume now. It should bring the domain back
1077 	 * to functional state.
1078 	 */
1079 	if (pm_runtime_suspended(&pdev->dev))
1080 		pm_runtime_resume(&pdev->dev);
1081 	else
1082 		tb_domain_complete(tb);
1083 }
1084 
1085 static int nhi_runtime_suspend(struct device *dev)
1086 {
1087 	struct pci_dev *pdev = to_pci_dev(dev);
1088 	struct tb *tb = pci_get_drvdata(pdev);
1089 	struct tb_nhi *nhi = tb->nhi;
1090 	int ret;
1091 
1092 	ret = tb_domain_runtime_suspend(tb);
1093 	if (ret)
1094 		return ret;
1095 
1096 	if (nhi->ops && nhi->ops->runtime_suspend) {
1097 		ret = nhi->ops->runtime_suspend(tb->nhi);
1098 		if (ret)
1099 			return ret;
1100 	}
1101 	return 0;
1102 }
1103 
1104 static int nhi_runtime_resume(struct device *dev)
1105 {
1106 	struct pci_dev *pdev = to_pci_dev(dev);
1107 	struct tb *tb = pci_get_drvdata(pdev);
1108 	struct tb_nhi *nhi = tb->nhi;
1109 	int ret;
1110 
1111 	if (nhi->ops && nhi->ops->runtime_resume) {
1112 		ret = nhi->ops->runtime_resume(nhi);
1113 		if (ret)
1114 			return ret;
1115 	}
1116 
1117 	nhi_enable_int_throttling(nhi);
1118 	return tb_domain_runtime_resume(tb);
1119 }
1120 
1121 static void nhi_shutdown(struct tb_nhi *nhi)
1122 {
1123 	int i;
1124 
1125 	dev_dbg(&nhi->pdev->dev, "shutdown\n");
1126 
1127 	for (i = 0; i < nhi->hop_count; i++) {
1128 		if (nhi->tx_rings[i])
1129 			dev_WARN(&nhi->pdev->dev,
1130 				 "TX ring %d is still active\n", i);
1131 		if (nhi->rx_rings[i])
1132 			dev_WARN(&nhi->pdev->dev,
1133 				 "RX ring %d is still active\n", i);
1134 	}
1135 	nhi_disable_interrupts(nhi);
1136 	/*
1137 	 * We have to release the irq before calling flush_work. Otherwise an
1138 	 * already executing IRQ handler could call schedule_work again.
1139 	 */
1140 	if (!nhi->pdev->msix_enabled) {
1141 		devm_free_irq(&nhi->pdev->dev, nhi->pdev->irq, nhi);
1142 		flush_work(&nhi->interrupt_work);
1143 	}
1144 	ida_destroy(&nhi->msix_ida);
1145 
1146 	if (nhi->ops && nhi->ops->shutdown)
1147 		nhi->ops->shutdown(nhi);
1148 }
1149 
1150 static void nhi_check_quirks(struct tb_nhi *nhi)
1151 {
1152 	if (nhi->pdev->vendor == PCI_VENDOR_ID_INTEL) {
1153 		/*
1154 		 * Intel hardware supports auto clear of the interrupt
1155 		 * status register right after interrupt is being
1156 		 * issued.
1157 		 */
1158 		nhi->quirks |= QUIRK_AUTO_CLEAR_INT;
1159 
1160 		switch (nhi->pdev->device) {
1161 		case PCI_DEVICE_ID_INTEL_FALCON_RIDGE_2C_NHI:
1162 		case PCI_DEVICE_ID_INTEL_FALCON_RIDGE_4C_NHI:
1163 			/*
1164 			 * Falcon Ridge controller needs the end-to-end
1165 			 * flow control workaround to avoid losing Rx
1166 			 * packets when RING_FLAG_E2E is set.
1167 			 */
1168 			nhi->quirks |= QUIRK_E2E;
1169 			break;
1170 		}
1171 	}
1172 }
1173 
1174 static int nhi_check_iommu_pdev(struct pci_dev *pdev, void *data)
1175 {
1176 	if (!pdev->external_facing ||
1177 	    !device_iommu_capable(&pdev->dev, IOMMU_CAP_PRE_BOOT_PROTECTION))
1178 		return 0;
1179 	*(bool *)data = true;
1180 	return 1; /* Stop walking */
1181 }
1182 
1183 static void nhi_check_iommu(struct tb_nhi *nhi)
1184 {
1185 	struct pci_bus *bus = nhi->pdev->bus;
1186 	bool port_ok = false;
1187 
1188 	/*
1189 	 * Ideally what we'd do here is grab every PCI device that
1190 	 * represents a tunnelling adapter for this NHI and check their
1191 	 * status directly, but unfortunately USB4 seems to make it
1192 	 * obnoxiously difficult to reliably make any correlation.
1193 	 *
1194 	 * So for now we'll have to bodge it... Hoping that the system
1195 	 * is at least sane enough that an adapter is in the same PCI
1196 	 * segment as its NHI, if we can find *something* on that segment
1197 	 * which meets the requirements for Kernel DMA Protection, we'll
1198 	 * take that to imply that firmware is aware and has (hopefully)
1199 	 * done the right thing in general. We need to know that the PCI
1200 	 * layer has seen the ExternalFacingPort property which will then
1201 	 * inform the IOMMU layer to enforce the complete "untrusted DMA"
1202 	 * flow, but also that the IOMMU driver itself can be trusted not
1203 	 * to have been subverted by a pre-boot DMA attack.
1204 	 */
1205 	while (bus->parent)
1206 		bus = bus->parent;
1207 
1208 	pci_walk_bus(bus, nhi_check_iommu_pdev, &port_ok);
1209 
1210 	nhi->iommu_dma_protection = port_ok;
1211 	dev_dbg(&nhi->pdev->dev, "IOMMU DMA protection is %s\n",
1212 		str_enabled_disabled(port_ok));
1213 }
1214 
1215 static int nhi_init_msi(struct tb_nhi *nhi)
1216 {
1217 	struct pci_dev *pdev = nhi->pdev;
1218 	struct device *dev = &pdev->dev;
1219 	int res, irq, nvec;
1220 
1221 	/* In case someone left them on. */
1222 	nhi_disable_interrupts(nhi);
1223 
1224 	nhi_enable_int_throttling(nhi);
1225 
1226 	ida_init(&nhi->msix_ida);
1227 
1228 	/*
1229 	 * The NHI has 16 MSI-X vectors or a single MSI. We first try to
1230 	 * get all MSI-X vectors and if we succeed, each ring will have
1231 	 * one MSI-X. If for some reason that does not work out, we
1232 	 * fallback to a single MSI.
1233 	 */
1234 	nvec = pci_alloc_irq_vectors(pdev, MSIX_MIN_VECS, MSIX_MAX_VECS,
1235 				     PCI_IRQ_MSIX);
1236 	if (nvec < 0) {
1237 		nvec = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSI);
1238 		if (nvec < 0)
1239 			return nvec;
1240 
1241 		INIT_WORK(&nhi->interrupt_work, nhi_interrupt_work);
1242 
1243 		irq = pci_irq_vector(nhi->pdev, 0);
1244 		if (irq < 0)
1245 			return irq;
1246 
1247 		res = devm_request_irq(&pdev->dev, irq, nhi_msi,
1248 				       IRQF_NO_SUSPEND, "thunderbolt", nhi);
1249 		if (res)
1250 			return dev_err_probe(dev, res, "request_irq failed, aborting\n");
1251 	}
1252 
1253 	return 0;
1254 }
1255 
1256 static bool nhi_imr_valid(struct pci_dev *pdev)
1257 {
1258 	u8 val;
1259 
1260 	if (!device_property_read_u8(&pdev->dev, "IMR_VALID", &val))
1261 		return !!val;
1262 
1263 	return true;
1264 }
1265 
1266 static struct tb *nhi_select_cm(struct tb_nhi *nhi)
1267 {
1268 	struct tb *tb;
1269 
1270 	/*
1271 	 * USB4 case is simple. If we got control of any of the
1272 	 * capabilities, we use software CM.
1273 	 */
1274 	if (tb_acpi_is_native())
1275 		return tb_probe(nhi);
1276 
1277 	/*
1278 	 * Either firmware based CM is running (we did not get control
1279 	 * from the firmware) or this is pre-USB4 PC so try first
1280 	 * firmware CM and then fallback to software CM.
1281 	 */
1282 	tb = icm_probe(nhi);
1283 	if (!tb)
1284 		tb = tb_probe(nhi);
1285 
1286 	return tb;
1287 }
1288 
1289 static int nhi_probe(struct pci_dev *pdev, const struct pci_device_id *id)
1290 {
1291 	struct device *dev = &pdev->dev;
1292 	struct tb_nhi *nhi;
1293 	struct tb *tb;
1294 	int res;
1295 
1296 	if (!nhi_imr_valid(pdev))
1297 		return dev_err_probe(dev, -ENODEV, "firmware image not valid, aborting\n");
1298 
1299 	res = pcim_enable_device(pdev);
1300 	if (res)
1301 		return dev_err_probe(dev, res, "cannot enable PCI device, aborting\n");
1302 
1303 	res = pcim_iomap_regions(pdev, 1 << 0, "thunderbolt");
1304 	if (res)
1305 		return dev_err_probe(dev, res, "cannot obtain PCI resources, aborting\n");
1306 
1307 	nhi = devm_kzalloc(&pdev->dev, sizeof(*nhi), GFP_KERNEL);
1308 	if (!nhi)
1309 		return -ENOMEM;
1310 
1311 	nhi->pdev = pdev;
1312 	nhi->ops = (const struct tb_nhi_ops *)id->driver_data;
1313 	/* cannot fail - table is allocated in pcim_iomap_regions */
1314 	nhi->iobase = pcim_iomap_table(pdev)[0];
1315 	nhi->hop_count = ioread32(nhi->iobase + REG_HOP_COUNT) & 0x3ff;
1316 	dev_dbg(dev, "total paths: %d\n", nhi->hop_count);
1317 
1318 	nhi->tx_rings = devm_kcalloc(&pdev->dev, nhi->hop_count,
1319 				     sizeof(*nhi->tx_rings), GFP_KERNEL);
1320 	nhi->rx_rings = devm_kcalloc(&pdev->dev, nhi->hop_count,
1321 				     sizeof(*nhi->rx_rings), GFP_KERNEL);
1322 	if (!nhi->tx_rings || !nhi->rx_rings)
1323 		return -ENOMEM;
1324 
1325 	nhi_check_quirks(nhi);
1326 	nhi_check_iommu(nhi);
1327 
1328 	res = nhi_init_msi(nhi);
1329 	if (res)
1330 		return dev_err_probe(dev, res, "cannot enable MSI, aborting\n");
1331 
1332 	spin_lock_init(&nhi->lock);
1333 
1334 	res = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
1335 	if (res)
1336 		return dev_err_probe(dev, res, "failed to set DMA mask\n");
1337 
1338 	pci_set_master(pdev);
1339 
1340 	if (nhi->ops && nhi->ops->init) {
1341 		res = nhi->ops->init(nhi);
1342 		if (res)
1343 			return res;
1344 	}
1345 
1346 	tb = nhi_select_cm(nhi);
1347 	if (!tb)
1348 		return dev_err_probe(dev, -ENODEV,
1349 			"failed to determine connection manager, aborting\n");
1350 
1351 	dev_dbg(dev, "NHI initialized, starting thunderbolt\n");
1352 
1353 	res = tb_domain_add(tb);
1354 	if (res) {
1355 		/*
1356 		 * At this point the RX/TX rings might already have been
1357 		 * activated. Do a proper shutdown.
1358 		 */
1359 		tb_domain_put(tb);
1360 		nhi_shutdown(nhi);
1361 		return res;
1362 	}
1363 	pci_set_drvdata(pdev, tb);
1364 
1365 	device_wakeup_enable(&pdev->dev);
1366 
1367 	pm_runtime_allow(&pdev->dev);
1368 	pm_runtime_set_autosuspend_delay(&pdev->dev, TB_AUTOSUSPEND_DELAY);
1369 	pm_runtime_use_autosuspend(&pdev->dev);
1370 	pm_runtime_put_autosuspend(&pdev->dev);
1371 
1372 	return 0;
1373 }
1374 
1375 static void nhi_remove(struct pci_dev *pdev)
1376 {
1377 	struct tb *tb = pci_get_drvdata(pdev);
1378 	struct tb_nhi *nhi = tb->nhi;
1379 
1380 	pm_runtime_get_sync(&pdev->dev);
1381 	pm_runtime_dont_use_autosuspend(&pdev->dev);
1382 	pm_runtime_forbid(&pdev->dev);
1383 
1384 	tb_domain_remove(tb);
1385 	nhi_shutdown(nhi);
1386 }
1387 
1388 /*
1389  * The tunneled pci bridges are siblings of us. Use resume_noirq to reenable
1390  * the tunnels asap. A corresponding pci quirk blocks the downstream bridges
1391  * resume_noirq until we are done.
1392  */
1393 static const struct dev_pm_ops nhi_pm_ops = {
1394 	.suspend_noirq = nhi_suspend_noirq,
1395 	.resume_noirq = nhi_resume_noirq,
1396 	.freeze_noirq = nhi_freeze_noirq,  /*
1397 					    * we just disable hotplug, the
1398 					    * pci-tunnels stay alive.
1399 					    */
1400 	.thaw_noirq = nhi_thaw_noirq,
1401 	.restore_noirq = nhi_resume_noirq,
1402 	.suspend = nhi_suspend,
1403 	.poweroff_noirq = nhi_poweroff_noirq,
1404 	.poweroff = nhi_suspend,
1405 	.complete = nhi_complete,
1406 	.runtime_suspend = nhi_runtime_suspend,
1407 	.runtime_resume = nhi_runtime_resume,
1408 };
1409 
1410 static struct pci_device_id nhi_ids[] = {
1411 	/*
1412 	 * We have to specify class, the TB bridges use the same device and
1413 	 * vendor (sub)id on gen 1 and gen 2 controllers.
1414 	 */
1415 	{
1416 		.class = PCI_CLASS_SYSTEM_OTHER << 8, .class_mask = ~0,
1417 		.vendor = PCI_VENDOR_ID_INTEL,
1418 		.device = PCI_DEVICE_ID_INTEL_LIGHT_RIDGE,
1419 		.subvendor = 0x2222, .subdevice = 0x1111,
1420 	},
1421 	{
1422 		.class = PCI_CLASS_SYSTEM_OTHER << 8, .class_mask = ~0,
1423 		.vendor = PCI_VENDOR_ID_INTEL,
1424 		.device = PCI_DEVICE_ID_INTEL_CACTUS_RIDGE_4C,
1425 		.subvendor = 0x2222, .subdevice = 0x1111,
1426 	},
1427 	{
1428 		.class = PCI_CLASS_SYSTEM_OTHER << 8, .class_mask = ~0,
1429 		.vendor = PCI_VENDOR_ID_INTEL,
1430 		.device = PCI_DEVICE_ID_INTEL_FALCON_RIDGE_2C_NHI,
1431 		.subvendor = PCI_ANY_ID, .subdevice = PCI_ANY_ID,
1432 	},
1433 	{
1434 		.class = PCI_CLASS_SYSTEM_OTHER << 8, .class_mask = ~0,
1435 		.vendor = PCI_VENDOR_ID_INTEL,
1436 		.device = PCI_DEVICE_ID_INTEL_FALCON_RIDGE_4C_NHI,
1437 		.subvendor = PCI_ANY_ID, .subdevice = PCI_ANY_ID,
1438 	},
1439 
1440 	/* Thunderbolt 3 */
1441 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_2C_NHI) },
1442 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_4C_NHI) },
1443 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_USBONLY_NHI) },
1444 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_LP_NHI) },
1445 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_LP_USBONLY_NHI) },
1446 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_C_2C_NHI) },
1447 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_C_4C_NHI) },
1448 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_C_USBONLY_NHI) },
1449 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_TITAN_RIDGE_2C_NHI) },
1450 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_TITAN_RIDGE_4C_NHI) },
1451 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ICL_NHI0),
1452 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1453 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ICL_NHI1),
1454 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1455 	/* Thunderbolt 4 */
1456 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_TGL_NHI0),
1457 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1458 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_TGL_NHI1),
1459 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1460 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_TGL_H_NHI0),
1461 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1462 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_TGL_H_NHI1),
1463 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1464 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ADL_NHI0),
1465 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1466 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ADL_NHI1),
1467 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1468 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_RPL_NHI0),
1469 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1470 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_RPL_NHI1),
1471 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1472 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_MTL_M_NHI0),
1473 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1474 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_MTL_P_NHI0),
1475 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1476 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_MTL_P_NHI1),
1477 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1478 
1479 	/* Any USB4 compliant host */
1480 	{ PCI_DEVICE_CLASS(PCI_CLASS_SERIAL_USB_USB4, ~0) },
1481 
1482 	{ 0,}
1483 };
1484 
1485 MODULE_DEVICE_TABLE(pci, nhi_ids);
1486 MODULE_LICENSE("GPL");
1487 
1488 static struct pci_driver nhi_driver = {
1489 	.name = "thunderbolt",
1490 	.id_table = nhi_ids,
1491 	.probe = nhi_probe,
1492 	.remove = nhi_remove,
1493 	.shutdown = nhi_remove,
1494 	.driver.pm = &nhi_pm_ops,
1495 };
1496 
1497 static int __init nhi_init(void)
1498 {
1499 	int ret;
1500 
1501 	ret = tb_domain_init();
1502 	if (ret)
1503 		return ret;
1504 	ret = pci_register_driver(&nhi_driver);
1505 	if (ret)
1506 		tb_domain_exit();
1507 	return ret;
1508 }
1509 
1510 static void __exit nhi_unload(void)
1511 {
1512 	pci_unregister_driver(&nhi_driver);
1513 	tb_domain_exit();
1514 }
1515 
1516 rootfs_initcall(nhi_init);
1517 module_exit(nhi_unload);
1518