xref: /linux/drivers/thunderbolt/nhi.c (revision 6093a688a07da07808f0122f9aa2a3eed250d853)
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_choices.h>
23 #include <linux/string_helpers.h>
24 
25 #include "nhi.h"
26 #include "nhi_regs.h"
27 #include "tb.h"
28 
29 #define RING_TYPE(ring) ((ring)->is_tx ? "TX ring" : "RX ring")
30 
31 #define RING_FIRST_USABLE_HOPID	1
32 /*
33  * Used with QUIRK_E2E to specify an unused HopID the Rx credits are
34  * transferred.
35  */
36 #define RING_E2E_RESERVED_HOPID	RING_FIRST_USABLE_HOPID
37 /*
38  * Minimal number of vectors when we use MSI-X. Two for control channel
39  * Rx/Tx and the rest four are for cross domain DMA paths.
40  */
41 #define MSIX_MIN_VECS		6
42 #define MSIX_MAX_VECS		16
43 
44 #define NHI_MAILBOX_TIMEOUT	500 /* ms */
45 
46 /* Host interface quirks */
47 #define QUIRK_AUTO_CLEAR_INT	BIT(0)
48 #define QUIRK_E2E		BIT(1)
49 
50 static bool host_reset = true;
51 module_param(host_reset, bool, 0444);
52 MODULE_PARM_DESC(host_reset, "reset USB4 host router (default: true)");
53 
54 static int ring_interrupt_index(const struct tb_ring *ring)
55 {
56 	int bit = ring->hop;
57 	if (!ring->is_tx)
58 		bit += ring->nhi->hop_count;
59 	return bit;
60 }
61 
62 static void nhi_mask_interrupt(struct tb_nhi *nhi, int mask, int ring)
63 {
64 	if (nhi->quirks & QUIRK_AUTO_CLEAR_INT) {
65 		u32 val;
66 
67 		val = ioread32(nhi->iobase + REG_RING_INTERRUPT_BASE + ring);
68 		iowrite32(val & ~mask, nhi->iobase + REG_RING_INTERRUPT_BASE + ring);
69 	} else {
70 		iowrite32(mask, nhi->iobase + REG_RING_INTERRUPT_MASK_CLEAR_BASE + ring);
71 	}
72 }
73 
74 static void nhi_clear_interrupt(struct tb_nhi *nhi, int ring)
75 {
76 	if (nhi->quirks & QUIRK_AUTO_CLEAR_INT)
77 		ioread32(nhi->iobase + REG_RING_NOTIFY_BASE + ring);
78 	else
79 		iowrite32(~0, nhi->iobase + REG_RING_INT_CLEAR + ring);
80 }
81 
82 /*
83  * ring_interrupt_active() - activate/deactivate interrupts for a single ring
84  *
85  * ring->nhi->lock must be held.
86  */
87 static void ring_interrupt_active(struct tb_ring *ring, bool active)
88 {
89 	int index = ring_interrupt_index(ring) / 32 * 4;
90 	int reg = REG_RING_INTERRUPT_BASE + index;
91 	int interrupt_bit = ring_interrupt_index(ring) & 31;
92 	int mask = 1 << interrupt_bit;
93 	u32 old, new;
94 
95 	if (ring->irq > 0) {
96 		u32 step, shift, ivr, misc;
97 		void __iomem *ivr_base;
98 		int auto_clear_bit;
99 		int index;
100 
101 		if (ring->is_tx)
102 			index = ring->hop;
103 		else
104 			index = ring->hop + ring->nhi->hop_count;
105 
106 		/*
107 		 * Intel routers support a bit that isn't part of
108 		 * the USB4 spec to ask the hardware to clear
109 		 * interrupt status bits automatically since
110 		 * we already know which interrupt was triggered.
111 		 *
112 		 * Other routers explicitly disable auto-clear
113 		 * to prevent conditions that may occur where two
114 		 * MSIX interrupts are simultaneously active and
115 		 * reading the register clears both of them.
116 		 */
117 		misc = ioread32(ring->nhi->iobase + REG_DMA_MISC);
118 		if (ring->nhi->quirks & QUIRK_AUTO_CLEAR_INT)
119 			auto_clear_bit = REG_DMA_MISC_INT_AUTO_CLEAR;
120 		else
121 			auto_clear_bit = REG_DMA_MISC_DISABLE_AUTO_CLEAR;
122 		if (!(misc & auto_clear_bit))
123 			iowrite32(misc | auto_clear_bit,
124 				  ring->nhi->iobase + REG_DMA_MISC);
125 
126 		ivr_base = ring->nhi->iobase + REG_INT_VEC_ALLOC_BASE;
127 		step = index / REG_INT_VEC_ALLOC_REGS * REG_INT_VEC_ALLOC_BITS;
128 		shift = index % REG_INT_VEC_ALLOC_REGS * REG_INT_VEC_ALLOC_BITS;
129 		ivr = ioread32(ivr_base + step);
130 		ivr &= ~(REG_INT_VEC_ALLOC_MASK << shift);
131 		if (active)
132 			ivr |= ring->vector << shift;
133 		iowrite32(ivr, ivr_base + step);
134 	}
135 
136 	old = ioread32(ring->nhi->iobase + reg);
137 	if (active)
138 		new = old | mask;
139 	else
140 		new = old & ~mask;
141 
142 	dev_dbg(&ring->nhi->pdev->dev,
143 		"%s interrupt at register %#x bit %d (%#x -> %#x)\n",
144 		active ? "enabling" : "disabling", reg, interrupt_bit, old, new);
145 
146 	if (new == old)
147 		dev_WARN(&ring->nhi->pdev->dev,
148 					 "interrupt for %s %d is already %s\n",
149 					 RING_TYPE(ring), ring->hop,
150 					 str_enabled_disabled(active));
151 
152 	if (active)
153 		iowrite32(new, ring->nhi->iobase + reg);
154 	else
155 		nhi_mask_interrupt(ring->nhi, mask, index);
156 }
157 
158 /*
159  * nhi_disable_interrupts() - disable interrupts for all rings
160  *
161  * Use only during init and shutdown.
162  */
163 static void nhi_disable_interrupts(struct tb_nhi *nhi)
164 {
165 	int i = 0;
166 	/* disable interrupts */
167 	for (i = 0; i < RING_INTERRUPT_REG_COUNT(nhi); i++)
168 		nhi_mask_interrupt(nhi, ~0, 4 * i);
169 
170 	/* clear interrupt status bits */
171 	for (i = 0; i < RING_NOTIFY_REG_COUNT(nhi); i++)
172 		nhi_clear_interrupt(nhi, 4 * i);
173 }
174 
175 /* ring helper methods */
176 
177 static void __iomem *ring_desc_base(struct tb_ring *ring)
178 {
179 	void __iomem *io = ring->nhi->iobase;
180 	io += ring->is_tx ? REG_TX_RING_BASE : REG_RX_RING_BASE;
181 	io += ring->hop * 16;
182 	return io;
183 }
184 
185 static void __iomem *ring_options_base(struct tb_ring *ring)
186 {
187 	void __iomem *io = ring->nhi->iobase;
188 	io += ring->is_tx ? REG_TX_OPTIONS_BASE : REG_RX_OPTIONS_BASE;
189 	io += ring->hop * 32;
190 	return io;
191 }
192 
193 static void ring_iowrite_cons(struct tb_ring *ring, u16 cons)
194 {
195 	/*
196 	 * The other 16-bits in the register is read-only and writes to it
197 	 * are ignored by the hardware so we can save one ioread32() by
198 	 * filling the read-only bits with zeroes.
199 	 */
200 	iowrite32(cons, ring_desc_base(ring) + 8);
201 }
202 
203 static void ring_iowrite_prod(struct tb_ring *ring, u16 prod)
204 {
205 	/* See ring_iowrite_cons() above for explanation */
206 	iowrite32(prod << 16, ring_desc_base(ring) + 8);
207 }
208 
209 static void ring_iowrite32desc(struct tb_ring *ring, u32 value, u32 offset)
210 {
211 	iowrite32(value, ring_desc_base(ring) + offset);
212 }
213 
214 static void ring_iowrite64desc(struct tb_ring *ring, u64 value, u32 offset)
215 {
216 	iowrite32(value, ring_desc_base(ring) + offset);
217 	iowrite32(value >> 32, ring_desc_base(ring) + offset + 4);
218 }
219 
220 static void ring_iowrite32options(struct tb_ring *ring, u32 value, u32 offset)
221 {
222 	iowrite32(value, ring_options_base(ring) + offset);
223 }
224 
225 static bool ring_full(struct tb_ring *ring)
226 {
227 	return ((ring->head + 1) % ring->size) == ring->tail;
228 }
229 
230 static bool ring_empty(struct tb_ring *ring)
231 {
232 	return ring->head == ring->tail;
233 }
234 
235 /*
236  * ring_write_descriptors() - post frames from ring->queue to the controller
237  *
238  * ring->lock is held.
239  */
240 static void ring_write_descriptors(struct tb_ring *ring)
241 {
242 	struct ring_frame *frame, *n;
243 	struct ring_desc *descriptor;
244 	list_for_each_entry_safe(frame, n, &ring->queue, list) {
245 		if (ring_full(ring))
246 			break;
247 		list_move_tail(&frame->list, &ring->in_flight);
248 		descriptor = &ring->descriptors[ring->head];
249 		descriptor->phys = frame->buffer_phy;
250 		descriptor->time = 0;
251 		descriptor->flags = RING_DESC_POSTED | RING_DESC_INTERRUPT;
252 		if (ring->is_tx) {
253 			descriptor->length = frame->size;
254 			descriptor->eof = frame->eof;
255 			descriptor->sof = frame->sof;
256 		}
257 		ring->head = (ring->head + 1) % ring->size;
258 		if (ring->is_tx)
259 			ring_iowrite_prod(ring, ring->head);
260 		else
261 			ring_iowrite_cons(ring, ring->head);
262 	}
263 }
264 
265 /*
266  * ring_work() - progress completed frames
267  *
268  * If the ring is shutting down then all frames are marked as canceled and
269  * their callbacks are invoked.
270  *
271  * Otherwise we collect all completed frame from the ring buffer, write new
272  * frame to the ring buffer and invoke the callbacks for the completed frames.
273  */
274 static void ring_work(struct work_struct *work)
275 {
276 	struct tb_ring *ring = container_of(work, typeof(*ring), work);
277 	struct ring_frame *frame;
278 	bool canceled = false;
279 	unsigned long flags;
280 	LIST_HEAD(done);
281 
282 	spin_lock_irqsave(&ring->lock, flags);
283 
284 	if (!ring->running) {
285 		/*  Move all frames to done and mark them as canceled. */
286 		list_splice_tail_init(&ring->in_flight, &done);
287 		list_splice_tail_init(&ring->queue, &done);
288 		canceled = true;
289 		goto invoke_callback;
290 	}
291 
292 	while (!ring_empty(ring)) {
293 		if (!(ring->descriptors[ring->tail].flags
294 				& RING_DESC_COMPLETED))
295 			break;
296 		frame = list_first_entry(&ring->in_flight, typeof(*frame),
297 					 list);
298 		list_move_tail(&frame->list, &done);
299 		if (!ring->is_tx) {
300 			frame->size = ring->descriptors[ring->tail].length;
301 			frame->eof = ring->descriptors[ring->tail].eof;
302 			frame->sof = ring->descriptors[ring->tail].sof;
303 			frame->flags = ring->descriptors[ring->tail].flags;
304 		}
305 		ring->tail = (ring->tail + 1) % ring->size;
306 	}
307 	ring_write_descriptors(ring);
308 
309 invoke_callback:
310 	/* allow callbacks to schedule new work */
311 	spin_unlock_irqrestore(&ring->lock, flags);
312 	while (!list_empty(&done)) {
313 		frame = list_first_entry(&done, typeof(*frame), list);
314 		/*
315 		 * The callback may reenqueue or delete frame.
316 		 * Do not hold on to it.
317 		 */
318 		list_del_init(&frame->list);
319 		if (frame->callback)
320 			frame->callback(ring, frame, canceled);
321 	}
322 }
323 
324 int __tb_ring_enqueue(struct tb_ring *ring, struct ring_frame *frame)
325 {
326 	unsigned long flags;
327 	int ret = 0;
328 
329 	spin_lock_irqsave(&ring->lock, flags);
330 	if (ring->running) {
331 		list_add_tail(&frame->list, &ring->queue);
332 		ring_write_descriptors(ring);
333 	} else {
334 		ret = -ESHUTDOWN;
335 	}
336 	spin_unlock_irqrestore(&ring->lock, flags);
337 	return ret;
338 }
339 EXPORT_SYMBOL_GPL(__tb_ring_enqueue);
340 
341 /**
342  * tb_ring_poll() - Poll one completed frame from the ring
343  * @ring: Ring to poll
344  *
345  * This function can be called when @start_poll callback of the @ring
346  * has been called. It will read one completed frame from the ring and
347  * return it to the caller.
348  *
349  * Return: Pointer to &struct ring_frame, %NULL if there is no more
350  * completed frames.
351  */
352 struct ring_frame *tb_ring_poll(struct tb_ring *ring)
353 {
354 	struct ring_frame *frame = NULL;
355 	unsigned long flags;
356 
357 	spin_lock_irqsave(&ring->lock, flags);
358 	if (!ring->running)
359 		goto unlock;
360 	if (ring_empty(ring))
361 		goto unlock;
362 
363 	if (ring->descriptors[ring->tail].flags & RING_DESC_COMPLETED) {
364 		frame = list_first_entry(&ring->in_flight, typeof(*frame),
365 					 list);
366 		list_del_init(&frame->list);
367 
368 		if (!ring->is_tx) {
369 			frame->size = ring->descriptors[ring->tail].length;
370 			frame->eof = ring->descriptors[ring->tail].eof;
371 			frame->sof = ring->descriptors[ring->tail].sof;
372 			frame->flags = ring->descriptors[ring->tail].flags;
373 		}
374 
375 		ring->tail = (ring->tail + 1) % ring->size;
376 	}
377 
378 unlock:
379 	spin_unlock_irqrestore(&ring->lock, flags);
380 	return frame;
381 }
382 EXPORT_SYMBOL_GPL(tb_ring_poll);
383 
384 static void __ring_interrupt_mask(struct tb_ring *ring, bool mask)
385 {
386 	int idx = ring_interrupt_index(ring);
387 	int reg = REG_RING_INTERRUPT_BASE + idx / 32 * 4;
388 	int bit = idx % 32;
389 	u32 val;
390 
391 	val = ioread32(ring->nhi->iobase + reg);
392 	if (mask)
393 		val &= ~BIT(bit);
394 	else
395 		val |= BIT(bit);
396 	iowrite32(val, ring->nhi->iobase + reg);
397 }
398 
399 /* Both @nhi->lock and @ring->lock should be held */
400 static void __ring_interrupt(struct tb_ring *ring)
401 {
402 	if (!ring->running)
403 		return;
404 
405 	if (ring->start_poll) {
406 		__ring_interrupt_mask(ring, true);
407 		ring->start_poll(ring->poll_data);
408 	} else {
409 		schedule_work(&ring->work);
410 	}
411 }
412 
413 /**
414  * tb_ring_poll_complete() - Re-start interrupt for the ring
415  * @ring: Ring to re-start the interrupt
416  *
417  * This will re-start (unmask) the ring interrupt once the user is done
418  * with polling.
419  */
420 void tb_ring_poll_complete(struct tb_ring *ring)
421 {
422 	unsigned long flags;
423 
424 	spin_lock_irqsave(&ring->nhi->lock, flags);
425 	spin_lock(&ring->lock);
426 	if (ring->start_poll)
427 		__ring_interrupt_mask(ring, false);
428 	spin_unlock(&ring->lock);
429 	spin_unlock_irqrestore(&ring->nhi->lock, flags);
430 }
431 EXPORT_SYMBOL_GPL(tb_ring_poll_complete);
432 
433 static void ring_clear_msix(const struct tb_ring *ring)
434 {
435 	int bit;
436 
437 	if (ring->nhi->quirks & QUIRK_AUTO_CLEAR_INT)
438 		return;
439 
440 	bit = ring_interrupt_index(ring) & 31;
441 	if (ring->is_tx)
442 		iowrite32(BIT(bit), ring->nhi->iobase + REG_RING_INT_CLEAR);
443 	else
444 		iowrite32(BIT(bit), ring->nhi->iobase + REG_RING_INT_CLEAR +
445 			  4 * (ring->nhi->hop_count / 32));
446 }
447 
448 static irqreturn_t ring_msix(int irq, void *data)
449 {
450 	struct tb_ring *ring = data;
451 
452 	spin_lock(&ring->nhi->lock);
453 	ring_clear_msix(ring);
454 	spin_lock(&ring->lock);
455 	__ring_interrupt(ring);
456 	spin_unlock(&ring->lock);
457 	spin_unlock(&ring->nhi->lock);
458 
459 	return IRQ_HANDLED;
460 }
461 
462 static int ring_request_msix(struct tb_ring *ring, bool no_suspend)
463 {
464 	struct tb_nhi *nhi = ring->nhi;
465 	unsigned long irqflags;
466 	int ret;
467 
468 	if (!nhi->pdev->msix_enabled)
469 		return 0;
470 
471 	ret = ida_alloc_max(&nhi->msix_ida, MSIX_MAX_VECS - 1, GFP_KERNEL);
472 	if (ret < 0)
473 		return ret;
474 
475 	ring->vector = ret;
476 
477 	ret = pci_irq_vector(ring->nhi->pdev, ring->vector);
478 	if (ret < 0)
479 		goto err_ida_remove;
480 
481 	ring->irq = ret;
482 
483 	irqflags = no_suspend ? IRQF_NO_SUSPEND : 0;
484 	ret = request_irq(ring->irq, ring_msix, irqflags, "thunderbolt", ring);
485 	if (ret)
486 		goto err_ida_remove;
487 
488 	return 0;
489 
490 err_ida_remove:
491 	ida_free(&nhi->msix_ida, ring->vector);
492 
493 	return ret;
494 }
495 
496 static void ring_release_msix(struct tb_ring *ring)
497 {
498 	if (ring->irq <= 0)
499 		return;
500 
501 	free_irq(ring->irq, ring);
502 	ida_free(&ring->nhi->msix_ida, ring->vector);
503 	ring->vector = 0;
504 	ring->irq = 0;
505 }
506 
507 static int nhi_alloc_hop(struct tb_nhi *nhi, struct tb_ring *ring)
508 {
509 	unsigned int start_hop = RING_FIRST_USABLE_HOPID;
510 	int ret = 0;
511 
512 	if (nhi->quirks & QUIRK_E2E) {
513 		start_hop = RING_FIRST_USABLE_HOPID + 1;
514 		if (ring->flags & RING_FLAG_E2E && !ring->is_tx) {
515 			dev_dbg(&nhi->pdev->dev, "quirking E2E TX HopID %u -> %u\n",
516 				ring->e2e_tx_hop, RING_E2E_RESERVED_HOPID);
517 			ring->e2e_tx_hop = RING_E2E_RESERVED_HOPID;
518 		}
519 	}
520 
521 	spin_lock_irq(&nhi->lock);
522 
523 	if (ring->hop < 0) {
524 		unsigned int i;
525 
526 		/*
527 		 * Automatically allocate HopID from the non-reserved
528 		 * range 1 .. hop_count - 1.
529 		 */
530 		for (i = start_hop; i < nhi->hop_count; i++) {
531 			if (ring->is_tx) {
532 				if (!nhi->tx_rings[i]) {
533 					ring->hop = i;
534 					break;
535 				}
536 			} else {
537 				if (!nhi->rx_rings[i]) {
538 					ring->hop = i;
539 					break;
540 				}
541 			}
542 		}
543 	}
544 
545 	if (ring->hop > 0 && ring->hop < start_hop) {
546 		dev_warn(&nhi->pdev->dev, "invalid hop: %d\n", ring->hop);
547 		ret = -EINVAL;
548 		goto err_unlock;
549 	}
550 	if (ring->hop < 0 || ring->hop >= nhi->hop_count) {
551 		dev_warn(&nhi->pdev->dev, "invalid hop: %d\n", ring->hop);
552 		ret = -EINVAL;
553 		goto err_unlock;
554 	}
555 	if (ring->is_tx && nhi->tx_rings[ring->hop]) {
556 		dev_warn(&nhi->pdev->dev, "TX hop %d already allocated\n",
557 			 ring->hop);
558 		ret = -EBUSY;
559 		goto err_unlock;
560 	}
561 	if (!ring->is_tx && nhi->rx_rings[ring->hop]) {
562 		dev_warn(&nhi->pdev->dev, "RX hop %d already allocated\n",
563 			 ring->hop);
564 		ret = -EBUSY;
565 		goto err_unlock;
566 	}
567 
568 	if (ring->is_tx)
569 		nhi->tx_rings[ring->hop] = ring;
570 	else
571 		nhi->rx_rings[ring->hop] = ring;
572 
573 err_unlock:
574 	spin_unlock_irq(&nhi->lock);
575 
576 	return ret;
577 }
578 
579 static struct tb_ring *tb_ring_alloc(struct tb_nhi *nhi, u32 hop, int size,
580 				     bool transmit, unsigned int flags,
581 				     int e2e_tx_hop, u16 sof_mask, u16 eof_mask,
582 				     void (*start_poll)(void *),
583 				     void *poll_data)
584 {
585 	struct tb_ring *ring = NULL;
586 
587 	dev_dbg(&nhi->pdev->dev, "allocating %s ring %d of size %d\n",
588 		transmit ? "TX" : "RX", hop, size);
589 
590 	ring = kzalloc(sizeof(*ring), GFP_KERNEL);
591 	if (!ring)
592 		return NULL;
593 
594 	spin_lock_init(&ring->lock);
595 	INIT_LIST_HEAD(&ring->queue);
596 	INIT_LIST_HEAD(&ring->in_flight);
597 	INIT_WORK(&ring->work, ring_work);
598 
599 	ring->nhi = nhi;
600 	ring->hop = hop;
601 	ring->is_tx = transmit;
602 	ring->size = size;
603 	ring->flags = flags;
604 	ring->e2e_tx_hop = e2e_tx_hop;
605 	ring->sof_mask = sof_mask;
606 	ring->eof_mask = eof_mask;
607 	ring->head = 0;
608 	ring->tail = 0;
609 	ring->running = false;
610 	ring->start_poll = start_poll;
611 	ring->poll_data = poll_data;
612 
613 	ring->descriptors = dma_alloc_coherent(&ring->nhi->pdev->dev,
614 			size * sizeof(*ring->descriptors),
615 			&ring->descriptors_dma, GFP_KERNEL | __GFP_ZERO);
616 	if (!ring->descriptors)
617 		goto err_free_ring;
618 
619 	if (ring_request_msix(ring, flags & RING_FLAG_NO_SUSPEND))
620 		goto err_free_descs;
621 
622 	if (nhi_alloc_hop(nhi, ring))
623 		goto err_release_msix;
624 
625 	return ring;
626 
627 err_release_msix:
628 	ring_release_msix(ring);
629 err_free_descs:
630 	dma_free_coherent(&ring->nhi->pdev->dev,
631 			  ring->size * sizeof(*ring->descriptors),
632 			  ring->descriptors, ring->descriptors_dma);
633 err_free_ring:
634 	kfree(ring);
635 
636 	return NULL;
637 }
638 
639 /**
640  * tb_ring_alloc_tx() - Allocate DMA ring for transmit
641  * @nhi: Pointer to the NHI the ring is to be allocated
642  * @hop: HopID (ring) to allocate
643  * @size: Number of entries in the ring
644  * @flags: Flags for the ring
645  *
646  * Return: Pointer to &struct tb_ring, %NULL otherwise.
647  */
648 struct tb_ring *tb_ring_alloc_tx(struct tb_nhi *nhi, int hop, int size,
649 				 unsigned int flags)
650 {
651 	return tb_ring_alloc(nhi, hop, size, true, flags, 0, 0, 0, NULL, NULL);
652 }
653 EXPORT_SYMBOL_GPL(tb_ring_alloc_tx);
654 
655 /**
656  * tb_ring_alloc_rx() - Allocate DMA ring for receive
657  * @nhi: Pointer to the NHI the ring is to be allocated
658  * @hop: HopID (ring) to allocate. Pass %-1 for automatic allocation.
659  * @size: Number of entries in the ring
660  * @flags: Flags for the ring
661  * @e2e_tx_hop: Transmit HopID when E2E is enabled in @flags
662  * @sof_mask: Mask of PDF values that start a frame
663  * @eof_mask: Mask of PDF values that end a frame
664  * @start_poll: If not %NULL the ring will call this function when an
665  *		interrupt is triggered and masked, instead of callback
666  *		in each Rx frame.
667  * @poll_data: Optional data passed to @start_poll
668  *
669  * Return: Pointer to &struct tb_ring, %NULL otherwise.
670  */
671 struct tb_ring *tb_ring_alloc_rx(struct tb_nhi *nhi, int hop, int size,
672 				 unsigned int flags, int e2e_tx_hop,
673 				 u16 sof_mask, u16 eof_mask,
674 				 void (*start_poll)(void *), void *poll_data)
675 {
676 	return tb_ring_alloc(nhi, hop, size, false, flags, e2e_tx_hop, sof_mask, eof_mask,
677 			     start_poll, poll_data);
678 }
679 EXPORT_SYMBOL_GPL(tb_ring_alloc_rx);
680 
681 /**
682  * tb_ring_start() - enable a ring
683  * @ring: Ring to start
684  *
685  * Must not be invoked in parallel with tb_ring_stop().
686  */
687 void tb_ring_start(struct tb_ring *ring)
688 {
689 	u16 frame_size;
690 	u32 flags;
691 
692 	spin_lock_irq(&ring->nhi->lock);
693 	spin_lock(&ring->lock);
694 	if (ring->nhi->going_away)
695 		goto err;
696 	if (ring->running) {
697 		dev_WARN(&ring->nhi->pdev->dev, "ring already started\n");
698 		goto err;
699 	}
700 	dev_dbg(&ring->nhi->pdev->dev, "starting %s %d\n",
701 		RING_TYPE(ring), ring->hop);
702 
703 	if (ring->flags & RING_FLAG_FRAME) {
704 		/* Means 4096 */
705 		frame_size = 0;
706 		flags = RING_FLAG_ENABLE;
707 	} else {
708 		frame_size = TB_FRAME_SIZE;
709 		flags = RING_FLAG_ENABLE | RING_FLAG_RAW;
710 	}
711 
712 	ring_iowrite64desc(ring, ring->descriptors_dma, 0);
713 	if (ring->is_tx) {
714 		ring_iowrite32desc(ring, ring->size, 12);
715 		ring_iowrite32options(ring, 0, 4); /* time releated ? */
716 		ring_iowrite32options(ring, flags, 0);
717 	} else {
718 		u32 sof_eof_mask = ring->sof_mask << 16 | ring->eof_mask;
719 
720 		ring_iowrite32desc(ring, (frame_size << 16) | ring->size, 12);
721 		ring_iowrite32options(ring, sof_eof_mask, 4);
722 		ring_iowrite32options(ring, flags, 0);
723 	}
724 
725 	/*
726 	 * Now that the ring valid bit is set we can configure E2E if
727 	 * enabled for the ring.
728 	 */
729 	if (ring->flags & RING_FLAG_E2E) {
730 		if (!ring->is_tx) {
731 			u32 hop;
732 
733 			hop = ring->e2e_tx_hop << REG_RX_OPTIONS_E2E_HOP_SHIFT;
734 			hop &= REG_RX_OPTIONS_E2E_HOP_MASK;
735 			flags |= hop;
736 
737 			dev_dbg(&ring->nhi->pdev->dev,
738 				"enabling E2E for %s %d with TX HopID %d\n",
739 				RING_TYPE(ring), ring->hop, ring->e2e_tx_hop);
740 		} else {
741 			dev_dbg(&ring->nhi->pdev->dev, "enabling E2E for %s %d\n",
742 				RING_TYPE(ring), ring->hop);
743 		}
744 
745 		flags |= RING_FLAG_E2E_FLOW_CONTROL;
746 		ring_iowrite32options(ring, flags, 0);
747 	}
748 
749 	ring_interrupt_active(ring, true);
750 	ring->running = true;
751 err:
752 	spin_unlock(&ring->lock);
753 	spin_unlock_irq(&ring->nhi->lock);
754 }
755 EXPORT_SYMBOL_GPL(tb_ring_start);
756 
757 /**
758  * tb_ring_stop() - shutdown a ring
759  * @ring: Ring to stop
760  *
761  * Must not be invoked from a callback.
762  *
763  * This method will disable the ring. Further calls to
764  * tb_ring_tx/tb_ring_rx will return -ESHUTDOWN until ring_stop has been
765  * called.
766  *
767  * All enqueued frames will be canceled and their callbacks will be executed
768  * with frame->canceled set to true (on the callback thread). This method
769  * returns only after all callback invocations have finished.
770  */
771 void tb_ring_stop(struct tb_ring *ring)
772 {
773 	spin_lock_irq(&ring->nhi->lock);
774 	spin_lock(&ring->lock);
775 	dev_dbg(&ring->nhi->pdev->dev, "stopping %s %d\n",
776 		RING_TYPE(ring), ring->hop);
777 	if (ring->nhi->going_away)
778 		goto err;
779 	if (!ring->running) {
780 		dev_WARN(&ring->nhi->pdev->dev, "%s %d already stopped\n",
781 			 RING_TYPE(ring), ring->hop);
782 		goto err;
783 	}
784 	ring_interrupt_active(ring, false);
785 
786 	ring_iowrite32options(ring, 0, 0);
787 	ring_iowrite64desc(ring, 0, 0);
788 	ring_iowrite32desc(ring, 0, 8);
789 	ring_iowrite32desc(ring, 0, 12);
790 	ring->head = 0;
791 	ring->tail = 0;
792 	ring->running = false;
793 
794 err:
795 	spin_unlock(&ring->lock);
796 	spin_unlock_irq(&ring->nhi->lock);
797 
798 	/*
799 	 * schedule ring->work to invoke callbacks on all remaining frames.
800 	 */
801 	schedule_work(&ring->work);
802 	flush_work(&ring->work);
803 }
804 EXPORT_SYMBOL_GPL(tb_ring_stop);
805 
806 /*
807  * tb_ring_free() - free ring
808  *
809  * When this method returns all invocations of ring->callback will have
810  * finished.
811  *
812  * Ring must be stopped.
813  *
814  * Must NOT be called from ring_frame->callback!
815  */
816 void tb_ring_free(struct tb_ring *ring)
817 {
818 	spin_lock_irq(&ring->nhi->lock);
819 	/*
820 	 * Dissociate the ring from the NHI. This also ensures that
821 	 * nhi_interrupt_work cannot reschedule ring->work.
822 	 */
823 	if (ring->is_tx)
824 		ring->nhi->tx_rings[ring->hop] = NULL;
825 	else
826 		ring->nhi->rx_rings[ring->hop] = NULL;
827 
828 	if (ring->running) {
829 		dev_WARN(&ring->nhi->pdev->dev, "%s %d still running\n",
830 			 RING_TYPE(ring), ring->hop);
831 	}
832 	spin_unlock_irq(&ring->nhi->lock);
833 
834 	ring_release_msix(ring);
835 
836 	dma_free_coherent(&ring->nhi->pdev->dev,
837 			  ring->size * sizeof(*ring->descriptors),
838 			  ring->descriptors, ring->descriptors_dma);
839 
840 	ring->descriptors = NULL;
841 	ring->descriptors_dma = 0;
842 
843 
844 	dev_dbg(&ring->nhi->pdev->dev, "freeing %s %d\n", RING_TYPE(ring),
845 		ring->hop);
846 
847 	/*
848 	 * ring->work can no longer be scheduled (it is scheduled only
849 	 * by nhi_interrupt_work, ring_stop and ring_msix). Wait for it
850 	 * to finish before freeing the ring.
851 	 */
852 	flush_work(&ring->work);
853 	kfree(ring);
854 }
855 EXPORT_SYMBOL_GPL(tb_ring_free);
856 
857 /**
858  * nhi_mailbox_cmd() - Send a command through NHI mailbox
859  * @nhi: Pointer to the NHI structure
860  * @cmd: Command to send
861  * @data: Data to be send with the command
862  *
863  * Sends mailbox command to the firmware running on NHI.
864  *
865  * Return: %0 on success, negative errno otherwise.
866  */
867 int nhi_mailbox_cmd(struct tb_nhi *nhi, enum nhi_mailbox_cmd cmd, u32 data)
868 {
869 	ktime_t timeout;
870 	u32 val;
871 
872 	iowrite32(data, nhi->iobase + REG_INMAIL_DATA);
873 
874 	val = ioread32(nhi->iobase + REG_INMAIL_CMD);
875 	val &= ~(REG_INMAIL_CMD_MASK | REG_INMAIL_ERROR);
876 	val |= REG_INMAIL_OP_REQUEST | cmd;
877 	iowrite32(val, nhi->iobase + REG_INMAIL_CMD);
878 
879 	timeout = ktime_add_ms(ktime_get(), NHI_MAILBOX_TIMEOUT);
880 	do {
881 		val = ioread32(nhi->iobase + REG_INMAIL_CMD);
882 		if (!(val & REG_INMAIL_OP_REQUEST))
883 			break;
884 		usleep_range(10, 20);
885 	} while (ktime_before(ktime_get(), timeout));
886 
887 	if (val & REG_INMAIL_OP_REQUEST)
888 		return -ETIMEDOUT;
889 	if (val & REG_INMAIL_ERROR)
890 		return -EIO;
891 
892 	return 0;
893 }
894 
895 /**
896  * nhi_mailbox_mode() - Return current firmware operation mode
897  * @nhi: Pointer to the NHI structure
898  *
899  * The function reads current firmware operation mode using NHI mailbox
900  * registers and returns it to the caller.
901  *
902  * Return: &enum nhi_fw_mode.
903  */
904 enum nhi_fw_mode nhi_mailbox_mode(struct tb_nhi *nhi)
905 {
906 	u32 val;
907 
908 	val = ioread32(nhi->iobase + REG_OUTMAIL_CMD);
909 	val &= REG_OUTMAIL_CMD_OPMODE_MASK;
910 	val >>= REG_OUTMAIL_CMD_OPMODE_SHIFT;
911 
912 	return (enum nhi_fw_mode)val;
913 }
914 
915 static void nhi_interrupt_work(struct work_struct *work)
916 {
917 	struct tb_nhi *nhi = container_of(work, typeof(*nhi), interrupt_work);
918 	int value = 0; /* Suppress uninitialized usage warning. */
919 	int bit;
920 	int hop = -1;
921 	int type = 0; /* current interrupt type 0: TX, 1: RX, 2: RX overflow */
922 	struct tb_ring *ring;
923 
924 	spin_lock_irq(&nhi->lock);
925 
926 	/*
927 	 * Starting at REG_RING_NOTIFY_BASE there are three status bitfields
928 	 * (TX, RX, RX overflow). We iterate over the bits and read a new
929 	 * dwords as required. The registers are cleared on read.
930 	 */
931 	for (bit = 0; bit < 3 * nhi->hop_count; bit++) {
932 		if (bit % 32 == 0)
933 			value = ioread32(nhi->iobase
934 					 + REG_RING_NOTIFY_BASE
935 					 + 4 * (bit / 32));
936 		if (++hop == nhi->hop_count) {
937 			hop = 0;
938 			type++;
939 		}
940 		if ((value & (1 << (bit % 32))) == 0)
941 			continue;
942 		if (type == 2) {
943 			dev_warn(&nhi->pdev->dev,
944 				 "RX overflow for ring %d\n",
945 				 hop);
946 			continue;
947 		}
948 		if (type == 0)
949 			ring = nhi->tx_rings[hop];
950 		else
951 			ring = nhi->rx_rings[hop];
952 		if (ring == NULL) {
953 			dev_warn(&nhi->pdev->dev,
954 				 "got interrupt for inactive %s ring %d\n",
955 				 type ? "RX" : "TX",
956 				 hop);
957 			continue;
958 		}
959 
960 		spin_lock(&ring->lock);
961 		__ring_interrupt(ring);
962 		spin_unlock(&ring->lock);
963 	}
964 	spin_unlock_irq(&nhi->lock);
965 }
966 
967 static irqreturn_t nhi_msi(int irq, void *data)
968 {
969 	struct tb_nhi *nhi = data;
970 	schedule_work(&nhi->interrupt_work);
971 	return IRQ_HANDLED;
972 }
973 
974 static int __nhi_suspend_noirq(struct device *dev, bool wakeup)
975 {
976 	struct pci_dev *pdev = to_pci_dev(dev);
977 	struct tb *tb = pci_get_drvdata(pdev);
978 	struct tb_nhi *nhi = tb->nhi;
979 	int ret;
980 
981 	ret = tb_domain_suspend_noirq(tb);
982 	if (ret)
983 		return ret;
984 
985 	if (nhi->ops && nhi->ops->suspend_noirq) {
986 		ret = nhi->ops->suspend_noirq(tb->nhi, wakeup);
987 		if (ret)
988 			return ret;
989 	}
990 
991 	return 0;
992 }
993 
994 static int nhi_suspend_noirq(struct device *dev)
995 {
996 	return __nhi_suspend_noirq(dev, device_may_wakeup(dev));
997 }
998 
999 static int nhi_freeze_noirq(struct device *dev)
1000 {
1001 	struct pci_dev *pdev = to_pci_dev(dev);
1002 	struct tb *tb = pci_get_drvdata(pdev);
1003 
1004 	return tb_domain_freeze_noirq(tb);
1005 }
1006 
1007 static int nhi_thaw_noirq(struct device *dev)
1008 {
1009 	struct pci_dev *pdev = to_pci_dev(dev);
1010 	struct tb *tb = pci_get_drvdata(pdev);
1011 
1012 	return tb_domain_thaw_noirq(tb);
1013 }
1014 
1015 static bool nhi_wake_supported(struct pci_dev *pdev)
1016 {
1017 	u8 val;
1018 
1019 	/*
1020 	 * If power rails are sustainable for wakeup from S4 this
1021 	 * property is set by the BIOS.
1022 	 */
1023 	if (device_property_read_u8(&pdev->dev, "WAKE_SUPPORTED", &val))
1024 		return !!val;
1025 
1026 	return true;
1027 }
1028 
1029 static int nhi_poweroff_noirq(struct device *dev)
1030 {
1031 	struct pci_dev *pdev = to_pci_dev(dev);
1032 	bool wakeup;
1033 
1034 	wakeup = device_may_wakeup(dev) && nhi_wake_supported(pdev);
1035 	return __nhi_suspend_noirq(dev, wakeup);
1036 }
1037 
1038 static void nhi_enable_int_throttling(struct tb_nhi *nhi)
1039 {
1040 	/* Throttling is specified in 256ns increments */
1041 	u32 throttle = DIV_ROUND_UP(128 * NSEC_PER_USEC, 256);
1042 	unsigned int i;
1043 
1044 	/*
1045 	 * Configure interrupt throttling for all vectors even if we
1046 	 * only use few.
1047 	 */
1048 	for (i = 0; i < MSIX_MAX_VECS; i++) {
1049 		u32 reg = REG_INT_THROTTLING_RATE + i * 4;
1050 		iowrite32(throttle, nhi->iobase + reg);
1051 	}
1052 }
1053 
1054 static int nhi_resume_noirq(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 	/*
1062 	 * Check that the device is still there. It may be that the user
1063 	 * unplugged last device which causes the host controller to go
1064 	 * away on PCs.
1065 	 */
1066 	if (!pci_device_is_present(pdev)) {
1067 		nhi->going_away = true;
1068 	} else {
1069 		if (nhi->ops && nhi->ops->resume_noirq) {
1070 			ret = nhi->ops->resume_noirq(nhi);
1071 			if (ret)
1072 				return ret;
1073 		}
1074 		nhi_enable_int_throttling(tb->nhi);
1075 	}
1076 
1077 	return tb_domain_resume_noirq(tb);
1078 }
1079 
1080 static int nhi_suspend(struct device *dev)
1081 {
1082 	struct pci_dev *pdev = to_pci_dev(dev);
1083 	struct tb *tb = pci_get_drvdata(pdev);
1084 
1085 	return tb_domain_suspend(tb);
1086 }
1087 
1088 static void nhi_complete(struct device *dev)
1089 {
1090 	struct pci_dev *pdev = to_pci_dev(dev);
1091 	struct tb *tb = pci_get_drvdata(pdev);
1092 
1093 	/*
1094 	 * If we were runtime suspended when system suspend started,
1095 	 * schedule runtime resume now. It should bring the domain back
1096 	 * to functional state.
1097 	 */
1098 	if (pm_runtime_suspended(&pdev->dev))
1099 		pm_runtime_resume(&pdev->dev);
1100 	else
1101 		tb_domain_complete(tb);
1102 }
1103 
1104 static int nhi_runtime_suspend(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 	ret = tb_domain_runtime_suspend(tb);
1112 	if (ret)
1113 		return ret;
1114 
1115 	if (nhi->ops && nhi->ops->runtime_suspend) {
1116 		ret = nhi->ops->runtime_suspend(tb->nhi);
1117 		if (ret)
1118 			return ret;
1119 	}
1120 	return 0;
1121 }
1122 
1123 static int nhi_runtime_resume(struct device *dev)
1124 {
1125 	struct pci_dev *pdev = to_pci_dev(dev);
1126 	struct tb *tb = pci_get_drvdata(pdev);
1127 	struct tb_nhi *nhi = tb->nhi;
1128 	int ret;
1129 
1130 	if (nhi->ops && nhi->ops->runtime_resume) {
1131 		ret = nhi->ops->runtime_resume(nhi);
1132 		if (ret)
1133 			return ret;
1134 	}
1135 
1136 	nhi_enable_int_throttling(nhi);
1137 	return tb_domain_runtime_resume(tb);
1138 }
1139 
1140 static void nhi_shutdown(struct tb_nhi *nhi)
1141 {
1142 	int i;
1143 
1144 	dev_dbg(&nhi->pdev->dev, "shutdown\n");
1145 
1146 	for (i = 0; i < nhi->hop_count; i++) {
1147 		if (nhi->tx_rings[i])
1148 			dev_WARN(&nhi->pdev->dev,
1149 				 "TX ring %d is still active\n", i);
1150 		if (nhi->rx_rings[i])
1151 			dev_WARN(&nhi->pdev->dev,
1152 				 "RX ring %d is still active\n", i);
1153 	}
1154 	nhi_disable_interrupts(nhi);
1155 	/*
1156 	 * We have to release the irq before calling flush_work. Otherwise an
1157 	 * already executing IRQ handler could call schedule_work again.
1158 	 */
1159 	if (!nhi->pdev->msix_enabled) {
1160 		devm_free_irq(&nhi->pdev->dev, nhi->pdev->irq, nhi);
1161 		flush_work(&nhi->interrupt_work);
1162 	}
1163 	ida_destroy(&nhi->msix_ida);
1164 
1165 	if (nhi->ops && nhi->ops->shutdown)
1166 		nhi->ops->shutdown(nhi);
1167 }
1168 
1169 static void nhi_check_quirks(struct tb_nhi *nhi)
1170 {
1171 	if (nhi->pdev->vendor == PCI_VENDOR_ID_INTEL) {
1172 		/*
1173 		 * Intel hardware supports auto clear of the interrupt
1174 		 * status register right after interrupt is being
1175 		 * issued.
1176 		 */
1177 		nhi->quirks |= QUIRK_AUTO_CLEAR_INT;
1178 
1179 		switch (nhi->pdev->device) {
1180 		case PCI_DEVICE_ID_INTEL_FALCON_RIDGE_2C_NHI:
1181 		case PCI_DEVICE_ID_INTEL_FALCON_RIDGE_4C_NHI:
1182 			/*
1183 			 * Falcon Ridge controller needs the end-to-end
1184 			 * flow control workaround to avoid losing Rx
1185 			 * packets when RING_FLAG_E2E is set.
1186 			 */
1187 			nhi->quirks |= QUIRK_E2E;
1188 			break;
1189 		}
1190 	}
1191 }
1192 
1193 static int nhi_check_iommu_pdev(struct pci_dev *pdev, void *data)
1194 {
1195 	if (!pdev->external_facing ||
1196 	    !device_iommu_capable(&pdev->dev, IOMMU_CAP_PRE_BOOT_PROTECTION))
1197 		return 0;
1198 	*(bool *)data = true;
1199 	return 1; /* Stop walking */
1200 }
1201 
1202 static void nhi_check_iommu(struct tb_nhi *nhi)
1203 {
1204 	struct pci_bus *bus = nhi->pdev->bus;
1205 	bool port_ok = false;
1206 
1207 	/*
1208 	 * Ideally what we'd do here is grab every PCI device that
1209 	 * represents a tunnelling adapter for this NHI and check their
1210 	 * status directly, but unfortunately USB4 seems to make it
1211 	 * obnoxiously difficult to reliably make any correlation.
1212 	 *
1213 	 * So for now we'll have to bodge it... Hoping that the system
1214 	 * is at least sane enough that an adapter is in the same PCI
1215 	 * segment as its NHI, if we can find *something* on that segment
1216 	 * which meets the requirements for Kernel DMA Protection, we'll
1217 	 * take that to imply that firmware is aware and has (hopefully)
1218 	 * done the right thing in general. We need to know that the PCI
1219 	 * layer has seen the ExternalFacingPort property which will then
1220 	 * inform the IOMMU layer to enforce the complete "untrusted DMA"
1221 	 * flow, but also that the IOMMU driver itself can be trusted not
1222 	 * to have been subverted by a pre-boot DMA attack.
1223 	 */
1224 	while (bus->parent)
1225 		bus = bus->parent;
1226 
1227 	pci_walk_bus(bus, nhi_check_iommu_pdev, &port_ok);
1228 
1229 	nhi->iommu_dma_protection = port_ok;
1230 	dev_dbg(&nhi->pdev->dev, "IOMMU DMA protection is %s\n",
1231 		str_enabled_disabled(port_ok));
1232 }
1233 
1234 static void nhi_reset(struct tb_nhi *nhi)
1235 {
1236 	ktime_t timeout;
1237 	u32 val;
1238 
1239 	val = ioread32(nhi->iobase + REG_CAPS);
1240 	/* Reset only v2 and later routers */
1241 	if (FIELD_GET(REG_CAPS_VERSION_MASK, val) < REG_CAPS_VERSION_2)
1242 		return;
1243 
1244 	if (!host_reset) {
1245 		dev_dbg(&nhi->pdev->dev, "skipping host router reset\n");
1246 		return;
1247 	}
1248 
1249 	iowrite32(REG_RESET_HRR, nhi->iobase + REG_RESET);
1250 	msleep(100);
1251 
1252 	timeout = ktime_add_ms(ktime_get(), 500);
1253 	do {
1254 		val = ioread32(nhi->iobase + REG_RESET);
1255 		if (!(val & REG_RESET_HRR)) {
1256 			dev_warn(&nhi->pdev->dev, "host router reset successful\n");
1257 			return;
1258 		}
1259 		usleep_range(10, 20);
1260 	} while (ktime_before(ktime_get(), timeout));
1261 
1262 	dev_warn(&nhi->pdev->dev, "timeout resetting host router\n");
1263 }
1264 
1265 static int nhi_init_msi(struct tb_nhi *nhi)
1266 {
1267 	struct pci_dev *pdev = nhi->pdev;
1268 	struct device *dev = &pdev->dev;
1269 	int res, irq, nvec;
1270 
1271 	/* In case someone left them on. */
1272 	nhi_disable_interrupts(nhi);
1273 
1274 	nhi_enable_int_throttling(nhi);
1275 
1276 	ida_init(&nhi->msix_ida);
1277 
1278 	/*
1279 	 * The NHI has 16 MSI-X vectors or a single MSI. We first try to
1280 	 * get all MSI-X vectors and if we succeed, each ring will have
1281 	 * one MSI-X. If for some reason that does not work out, we
1282 	 * fallback to a single MSI.
1283 	 */
1284 	nvec = pci_alloc_irq_vectors(pdev, MSIX_MIN_VECS, MSIX_MAX_VECS,
1285 				     PCI_IRQ_MSIX);
1286 	if (nvec < 0) {
1287 		nvec = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSI);
1288 		if (nvec < 0)
1289 			return nvec;
1290 
1291 		INIT_WORK(&nhi->interrupt_work, nhi_interrupt_work);
1292 
1293 		irq = pci_irq_vector(nhi->pdev, 0);
1294 		if (irq < 0)
1295 			return irq;
1296 
1297 		res = devm_request_irq(&pdev->dev, irq, nhi_msi,
1298 				       IRQF_NO_SUSPEND, "thunderbolt", nhi);
1299 		if (res)
1300 			return dev_err_probe(dev, res, "request_irq failed, aborting\n");
1301 	}
1302 
1303 	return 0;
1304 }
1305 
1306 static bool nhi_imr_valid(struct pci_dev *pdev)
1307 {
1308 	u8 val;
1309 
1310 	if (!device_property_read_u8(&pdev->dev, "IMR_VALID", &val))
1311 		return !!val;
1312 
1313 	return true;
1314 }
1315 
1316 static struct tb *nhi_select_cm(struct tb_nhi *nhi)
1317 {
1318 	struct tb *tb;
1319 
1320 	/*
1321 	 * USB4 case is simple. If we got control of any of the
1322 	 * capabilities, we use software CM.
1323 	 */
1324 	if (tb_acpi_is_native())
1325 		return tb_probe(nhi);
1326 
1327 	/*
1328 	 * Either firmware based CM is running (we did not get control
1329 	 * from the firmware) or this is pre-USB4 PC so try first
1330 	 * firmware CM and then fallback to software CM.
1331 	 */
1332 	tb = icm_probe(nhi);
1333 	if (!tb)
1334 		tb = tb_probe(nhi);
1335 
1336 	return tb;
1337 }
1338 
1339 static int nhi_probe(struct pci_dev *pdev, const struct pci_device_id *id)
1340 {
1341 	struct device *dev = &pdev->dev;
1342 	struct tb_nhi *nhi;
1343 	struct tb *tb;
1344 	int res;
1345 
1346 	if (!nhi_imr_valid(pdev))
1347 		return dev_err_probe(dev, -ENODEV, "firmware image not valid, aborting\n");
1348 
1349 	res = pcim_enable_device(pdev);
1350 	if (res)
1351 		return dev_err_probe(dev, res, "cannot enable PCI device, aborting\n");
1352 
1353 	nhi = devm_kzalloc(&pdev->dev, sizeof(*nhi), GFP_KERNEL);
1354 	if (!nhi)
1355 		return -ENOMEM;
1356 
1357 	nhi->pdev = pdev;
1358 	nhi->ops = (const struct tb_nhi_ops *)id->driver_data;
1359 
1360 	nhi->iobase = pcim_iomap_region(pdev, 0, "thunderbolt");
1361 	res = PTR_ERR_OR_ZERO(nhi->iobase);
1362 	if (res)
1363 		return dev_err_probe(dev, res, "cannot obtain PCI resources, aborting\n");
1364 
1365 	nhi->hop_count = ioread32(nhi->iobase + REG_CAPS) & 0x3ff;
1366 	dev_dbg(dev, "total paths: %d\n", nhi->hop_count);
1367 
1368 	nhi->tx_rings = devm_kcalloc(&pdev->dev, nhi->hop_count,
1369 				     sizeof(*nhi->tx_rings), GFP_KERNEL);
1370 	nhi->rx_rings = devm_kcalloc(&pdev->dev, nhi->hop_count,
1371 				     sizeof(*nhi->rx_rings), GFP_KERNEL);
1372 	if (!nhi->tx_rings || !nhi->rx_rings)
1373 		return -ENOMEM;
1374 
1375 	nhi_check_quirks(nhi);
1376 	nhi_check_iommu(nhi);
1377 	nhi_reset(nhi);
1378 
1379 	res = nhi_init_msi(nhi);
1380 	if (res)
1381 		return dev_err_probe(dev, res, "cannot enable MSI, aborting\n");
1382 
1383 	spin_lock_init(&nhi->lock);
1384 
1385 	res = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
1386 	if (res)
1387 		return dev_err_probe(dev, res, "failed to set DMA mask\n");
1388 
1389 	pci_set_master(pdev);
1390 
1391 	if (nhi->ops && nhi->ops->init) {
1392 		res = nhi->ops->init(nhi);
1393 		if (res)
1394 			return res;
1395 	}
1396 
1397 	tb = nhi_select_cm(nhi);
1398 	if (!tb)
1399 		return dev_err_probe(dev, -ENODEV,
1400 			"failed to determine connection manager, aborting\n");
1401 
1402 	dev_dbg(dev, "NHI initialized, starting thunderbolt\n");
1403 
1404 	res = tb_domain_add(tb, host_reset);
1405 	if (res) {
1406 		/*
1407 		 * At this point the RX/TX rings might already have been
1408 		 * activated. Do a proper shutdown.
1409 		 */
1410 		tb_domain_put(tb);
1411 		nhi_shutdown(nhi);
1412 		return res;
1413 	}
1414 	pci_set_drvdata(pdev, tb);
1415 
1416 	device_wakeup_enable(&pdev->dev);
1417 
1418 	pm_runtime_allow(&pdev->dev);
1419 	pm_runtime_set_autosuspend_delay(&pdev->dev, TB_AUTOSUSPEND_DELAY);
1420 	pm_runtime_use_autosuspend(&pdev->dev);
1421 	pm_runtime_put_autosuspend(&pdev->dev);
1422 
1423 	return 0;
1424 }
1425 
1426 static void nhi_remove(struct pci_dev *pdev)
1427 {
1428 	struct tb *tb = pci_get_drvdata(pdev);
1429 	struct tb_nhi *nhi = tb->nhi;
1430 
1431 	pm_runtime_get_sync(&pdev->dev);
1432 	pm_runtime_dont_use_autosuspend(&pdev->dev);
1433 	pm_runtime_forbid(&pdev->dev);
1434 
1435 	tb_domain_remove(tb);
1436 	nhi_shutdown(nhi);
1437 }
1438 
1439 /*
1440  * The tunneled pci bridges are siblings of us. Use resume_noirq to reenable
1441  * the tunnels asap. A corresponding pci quirk blocks the downstream bridges
1442  * resume_noirq until we are done.
1443  */
1444 static const struct dev_pm_ops nhi_pm_ops = {
1445 	.suspend_noirq = nhi_suspend_noirq,
1446 	.resume_noirq = nhi_resume_noirq,
1447 	.freeze_noirq = nhi_freeze_noirq,  /*
1448 					    * we just disable hotplug, the
1449 					    * pci-tunnels stay alive.
1450 					    */
1451 	.thaw_noirq = nhi_thaw_noirq,
1452 	.restore_noirq = nhi_resume_noirq,
1453 	.suspend = nhi_suspend,
1454 	.poweroff_noirq = nhi_poweroff_noirq,
1455 	.poweroff = nhi_suspend,
1456 	.complete = nhi_complete,
1457 	.runtime_suspend = nhi_runtime_suspend,
1458 	.runtime_resume = nhi_runtime_resume,
1459 };
1460 
1461 static struct pci_device_id nhi_ids[] = {
1462 	/*
1463 	 * We have to specify class, the TB bridges use the same device and
1464 	 * vendor (sub)id on gen 1 and gen 2 controllers.
1465 	 */
1466 	{
1467 		.class = PCI_CLASS_SYSTEM_OTHER << 8, .class_mask = ~0,
1468 		.vendor = PCI_VENDOR_ID_INTEL,
1469 		.device = PCI_DEVICE_ID_INTEL_LIGHT_RIDGE,
1470 		.subvendor = 0x2222, .subdevice = 0x1111,
1471 	},
1472 	{
1473 		.class = PCI_CLASS_SYSTEM_OTHER << 8, .class_mask = ~0,
1474 		.vendor = PCI_VENDOR_ID_INTEL,
1475 		.device = PCI_DEVICE_ID_INTEL_CACTUS_RIDGE_4C,
1476 		.subvendor = 0x2222, .subdevice = 0x1111,
1477 	},
1478 	{
1479 		.class = PCI_CLASS_SYSTEM_OTHER << 8, .class_mask = ~0,
1480 		.vendor = PCI_VENDOR_ID_INTEL,
1481 		.device = PCI_DEVICE_ID_INTEL_FALCON_RIDGE_2C_NHI,
1482 		.subvendor = PCI_ANY_ID, .subdevice = PCI_ANY_ID,
1483 	},
1484 	{
1485 		.class = PCI_CLASS_SYSTEM_OTHER << 8, .class_mask = ~0,
1486 		.vendor = PCI_VENDOR_ID_INTEL,
1487 		.device = PCI_DEVICE_ID_INTEL_FALCON_RIDGE_4C_NHI,
1488 		.subvendor = PCI_ANY_ID, .subdevice = PCI_ANY_ID,
1489 	},
1490 
1491 	/* Thunderbolt 3 */
1492 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_2C_NHI) },
1493 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_4C_NHI) },
1494 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_USBONLY_NHI) },
1495 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_LP_NHI) },
1496 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_LP_USBONLY_NHI) },
1497 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_C_2C_NHI) },
1498 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_C_4C_NHI) },
1499 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_C_USBONLY_NHI) },
1500 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_TITAN_RIDGE_2C_NHI) },
1501 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_TITAN_RIDGE_4C_NHI) },
1502 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ICL_NHI0),
1503 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1504 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ICL_NHI1),
1505 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1506 	/* Thunderbolt 4 */
1507 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_TGL_NHI0),
1508 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1509 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_TGL_NHI1),
1510 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1511 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_TGL_H_NHI0),
1512 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1513 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_TGL_H_NHI1),
1514 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1515 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ADL_NHI0),
1516 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1517 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ADL_NHI1),
1518 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1519 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_RPL_NHI0),
1520 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1521 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_RPL_NHI1),
1522 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1523 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_MTL_M_NHI0),
1524 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1525 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_MTL_P_NHI0),
1526 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1527 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_MTL_P_NHI1),
1528 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1529 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_LNL_NHI0),
1530 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1531 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_LNL_NHI1),
1532 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1533 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_PTL_M_NHI0),
1534 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1535 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_PTL_M_NHI1),
1536 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1537 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_PTL_P_NHI0),
1538 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1539 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_PTL_P_NHI1),
1540 	  .driver_data = (kernel_ulong_t)&icl_nhi_ops },
1541 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_BARLOW_RIDGE_HOST_80G_NHI) },
1542 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_BARLOW_RIDGE_HOST_40G_NHI) },
1543 
1544 	/* Any USB4 compliant host */
1545 	{ PCI_DEVICE_CLASS(PCI_CLASS_SERIAL_USB_USB4, ~0) },
1546 
1547 	{ 0,}
1548 };
1549 
1550 MODULE_DEVICE_TABLE(pci, nhi_ids);
1551 MODULE_DESCRIPTION("Thunderbolt/USB4 core driver");
1552 MODULE_LICENSE("GPL");
1553 
1554 static struct pci_driver nhi_driver = {
1555 	.name = "thunderbolt",
1556 	.id_table = nhi_ids,
1557 	.probe = nhi_probe,
1558 	.remove = nhi_remove,
1559 	.shutdown = nhi_remove,
1560 	.driver.pm = &nhi_pm_ops,
1561 };
1562 
1563 static int __init nhi_init(void)
1564 {
1565 	int ret;
1566 
1567 	ret = tb_domain_init();
1568 	if (ret)
1569 		return ret;
1570 	ret = pci_register_driver(&nhi_driver);
1571 	if (ret)
1572 		tb_domain_exit();
1573 	return ret;
1574 }
1575 
1576 static void __exit nhi_unload(void)
1577 {
1578 	pci_unregister_driver(&nhi_driver);
1579 	tb_domain_exit();
1580 }
1581 
1582 rootfs_initcall(nhi_init);
1583 module_exit(nhi_unload);
1584