1	// SPDX-License-Identifier: GPL-2.0
2	/*
3	* Thunderbolt driver - Tunneling support
4	*
5	* Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
6	* Copyright (C) 2019, Intel Corporation
7	*/
8
9	#include <linux/delay.h>
10	#include <linux/slab.h>
11	#include <linux/list.h>
12	#include <linux/ktime.h>
13	#include <linux/string_helpers.h>
14
15	#include "tunnel.h"
16	#include "tb.h"
17
18	/* PCIe adapters use always HopID of 8 for both directions */
19	#define TB_PCI_HOPID 8
20
21	#define TB_PCI_PATH_DOWN 0
22	#define TB_PCI_PATH_UP 1
23
24	#define TB_PCI_PRIORITY 3
25	#define TB_PCI_WEIGHT 1
26
27	/* USB3 adapters use always HopID of 8 for both directions */
28	#define TB_USB3_HOPID 8
29
30	#define TB_USB3_PATH_DOWN 0
31	#define TB_USB3_PATH_UP 1
32
33	#define TB_USB3_PRIORITY 3
34	#define TB_USB3_WEIGHT 2
35
36	/* DP adapters use HopID 8 for AUX and 9 for Video */
37	#define TB_DP_AUX_TX_HOPID 8
38	#define TB_DP_AUX_RX_HOPID 8
39	#define TB_DP_VIDEO_HOPID 9
40
41	#define TB_DP_VIDEO_PATH_OUT 0
42	#define TB_DP_AUX_PATH_OUT 1
43	#define TB_DP_AUX_PATH_IN 2
44
45	#define TB_DP_VIDEO_PRIORITY 1
46	#define TB_DP_VIDEO_WEIGHT 1
47
48	#define TB_DP_AUX_PRIORITY 2
49	#define TB_DP_AUX_WEIGHT 1
50
51	/* Minimum number of credits needed for PCIe path */
52	#define TB_MIN_PCIE_CREDITS 6U
53	/*
54	* Number of credits we try to allocate for each DMA path if not limited
55	* by the host router baMaxHI.
56	*/
57	#define TB_DMA_CREDITS 14
58	/* Minimum number of credits for DMA path */
59	#define TB_MIN_DMA_CREDITS 1
60
61	#define TB_DMA_PRIORITY 5
62	#define TB_DMA_WEIGHT 1
63
64	/*
65	* Reserve additional bandwidth for USB 3.x and PCIe bulk traffic
66	* according to USB4 v2 Connection Manager guide. This ends up reserving
67	* 1500 Mb/s for PCIe and 3000 Mb/s for USB 3.x taking weights into
68	* account.
69	*/
70	#define USB4_V2_PCI_MIN_BANDWIDTH (1500 * TB_PCI_WEIGHT)
71	#define USB4_V2_USB3_MIN_BANDWIDTH (1500 * TB_USB3_WEIGHT)
72
73	static unsigned int dma_credits = TB_DMA_CREDITS;
74	module_param(dma_credits, uint, 0444);
75	MODULE_PARM_DESC(dma_credits, "specify custom credits for DMA tunnels (default: "
76	__MODULE_STRING(TB_DMA_CREDITS) ")");
77
78	static bool bw_alloc_mode = true;
79	module_param(bw_alloc_mode, bool, 0444);
80	MODULE_PARM_DESC(bw_alloc_mode,
81	"enable bandwidth allocation mode if supported (default: true)");
82
83	static const char * const tb_tunnel_names[] = { "PCI", "DP", "DMA", "USB3" };
84
85	static inline unsigned int tb_usable_credits(const struct tb_port *port)
86	{
87	return port->total_credits - port->ctl_credits;
88	}
89
90	/**
91	* tb_available_credits() - Available credits for PCIe and DMA
92	* @port: Lane adapter to check
93	* @max_dp_streams: If non-%NULL stores maximum number of simultaneous DP
94	* streams possible through this lane adapter
95	*/
96	static unsigned int tb_available_credits(const struct tb_port *port,
97	size_t *max_dp_streams)
98	{
99	const struct tb_switch *sw = port->sw;
100	int credits, usb3, pcie, spare;
101	size_t ndp;
102
103	usb3 = tb_acpi_may_tunnel_usb3() ? sw->max_usb3_credits : 0;
104	pcie = tb_acpi_may_tunnel_pcie() ? sw->max_pcie_credits : 0;
105
106	if (tb_acpi_is_xdomain_allowed()) {
107	spare = min_not_zero(sw->max_dma_credits, dma_credits);
108	/* Add some credits for potential second DMA tunnel */
109	spare += TB_MIN_DMA_CREDITS;
110	} else {
111	spare = 0;
112	}
113
114	credits = tb_usable_credits(port);
115	if (tb_acpi_may_tunnel_dp()) {
116	/*
117	* Maximum number of DP streams possible through the
118	* lane adapter.
119	*/
120	if (sw->min_dp_aux_credits + sw->min_dp_main_credits)
121	ndp = (credits - (usb3 + pcie + spare)) /
122	(sw->min_dp_aux_credits + sw->min_dp_main_credits);
123	else
124	ndp = 0;
125	} else {
126	ndp = 0;
127	}
128	credits -= ndp * (sw->min_dp_aux_credits + sw->min_dp_main_credits);
129	credits -= usb3;
130
131	if (max_dp_streams)
132	*max_dp_streams = ndp;
133
134	return credits > 0 ? credits : 0;
135	}
136
137	static void tb_init_pm_support(struct tb_path_hop *hop)
138	{
139	struct tb_port *out_port = hop->out_port;
140	struct tb_port *in_port = hop->in_port;
141
142	if (tb_port_is_null(port: in_port) && tb_port_is_null(port: out_port) &&
143	usb4_switch_version(sw: in_port->sw) >= 2)
144	hop->pm_support = true;
145	}
146
147	static struct tb_tunnel *tb_tunnel_alloc(struct tb *tb, size_t npaths,
148	enum tb_tunnel_type type)
149	{
150	struct tb_tunnel *tunnel;
151
152	tunnel = kzalloc(size: sizeof(*tunnel), GFP_KERNEL);
153	if (!tunnel)
154	return NULL;
155
156	tunnel->paths = kcalloc(n: npaths, size: sizeof(tunnel->paths[0]), GFP_KERNEL);
157	if (!tunnel->paths) {
158	tb_tunnel_free(tunnel);
159	return NULL;
160	}
161
162	INIT_LIST_HEAD(list: &tunnel->list);
163	tunnel->tb = tb;
164	tunnel->npaths = npaths;
165	tunnel->type = type;
166
167	return tunnel;
168	}
169
170	static int tb_pci_set_ext_encapsulation(struct tb_tunnel *tunnel, bool enable)
171	{
172	struct tb_port *port = tb_upstream_port(sw: tunnel->dst_port->sw);
173	int ret;
174
175	/* Only supported of both routers are at least USB4 v2 */
176	if ((usb4_switch_version(sw: tunnel->src_port->sw) < 2) ||
177	(usb4_switch_version(sw: tunnel->dst_port->sw) < 2))
178	return 0;
179
180	if (enable && tb_port_get_link_generation(port) < 4)
181	return 0;
182
183	ret = usb4_pci_port_set_ext_encapsulation(port: tunnel->src_port, enable);
184	if (ret)
185	return ret;
186
187	/*
188	* Downstream router could be unplugged so disable of encapsulation
189	* in upstream router is still possible.
190	*/
191	ret = usb4_pci_port_set_ext_encapsulation(port: tunnel->dst_port, enable);
192	if (ret) {
193	if (enable)
194	return ret;
195	if (ret != -ENODEV)
196	return ret;
197	}
198
199	tb_tunnel_dbg(tunnel, "extended encapsulation %s\n",
200	str_enabled_disabled(enable));
201	return 0;
202	}
203
204	static int tb_pci_activate(struct tb_tunnel *tunnel, bool activate)
205	{
206	int res;
207
208	if (activate) {
209	res = tb_pci_set_ext_encapsulation(tunnel, enable: activate);
210	if (res)
211	return res;
212	}
213
214	if (activate)
215	res = tb_pci_port_enable(port: tunnel->dst_port, enable: activate);
216	else
217	res = tb_pci_port_enable(port: tunnel->src_port, enable: activate);
218	if (res)
219	return res;
220
221
222	if (activate) {
223	res = tb_pci_port_enable(port: tunnel->src_port, enable: activate);
224	if (res)
225	return res;
226	} else {
227	/* Downstream router could be unplugged */
228	tb_pci_port_enable(port: tunnel->dst_port, enable: activate);
229	}
230
231	return activate ? 0 : tb_pci_set_ext_encapsulation(tunnel, enable: activate);
232	}
233
234	static int tb_pci_init_credits(struct tb_path_hop *hop)
235	{
236	struct tb_port *port = hop->in_port;
237	struct tb_switch *sw = port->sw;
238	unsigned int credits;
239
240	if (tb_port_use_credit_allocation(port)) {
241	unsigned int available;
242
243	available = tb_available_credits(port, NULL);
244	credits = min(sw->max_pcie_credits, available);
245
246	if (credits < TB_MIN_PCIE_CREDITS)
247	return -ENOSPC;
248
249	credits = max(TB_MIN_PCIE_CREDITS, credits);
250	} else {
251	if (tb_port_is_null(port))
252	credits = port->bonded ? 32 : 16;
253	else
254	credits = 7;
255	}
256
257	hop->initial_credits = credits;
258	return 0;
259	}
260
261	static int tb_pci_init_path(struct tb_path *path)
262	{
263	struct tb_path_hop *hop;
264
265	path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
266	path->egress_shared_buffer = TB_PATH_NONE;
267	path->ingress_fc_enable = TB_PATH_ALL;
268	path->ingress_shared_buffer = TB_PATH_NONE;
269	path->priority = TB_PCI_PRIORITY;
270	path->weight = TB_PCI_WEIGHT;
271	path->drop_packages = 0;
272
273	tb_path_for_each_hop(path, hop) {
274	int ret;
275
276	ret = tb_pci_init_credits(hop);
277	if (ret)
278	return ret;
279	}
280
281	return 0;
282	}
283
284	/**
285	* tb_tunnel_discover_pci() - Discover existing PCIe tunnels
286	* @tb: Pointer to the domain structure
287	* @down: PCIe downstream adapter
288	* @alloc_hopid: Allocate HopIDs from visited ports
289	*
290	* If @down adapter is active, follows the tunnel to the PCIe upstream
291	* adapter and back. Returns the discovered tunnel or %NULL if there was
292	* no tunnel.
293	*/
294	struct tb_tunnel *tb_tunnel_discover_pci(struct tb *tb, struct tb_port *down,
295	bool alloc_hopid)
296	{
297	struct tb_tunnel *tunnel;
298	struct tb_path *path;
299
300	if (!tb_pci_port_is_enabled(port: down))
301	return NULL;
302
303	tunnel = tb_tunnel_alloc(tb, npaths: 2, type: TB_TUNNEL_PCI);
304	if (!tunnel)
305	return NULL;
306
307	tunnel->activate = tb_pci_activate;
308	tunnel->src_port = down;
309
310	/*
311	* Discover both paths even if they are not complete. We will
312	* clean them up by calling tb_tunnel_deactivate() below in that
313	* case.
314	*/
315	path = tb_path_discover(src: down, TB_PCI_HOPID, NULL, dst_hopid: -1,
316	last: &tunnel->dst_port, name: "PCIe Up", alloc_hopid);
317	if (!path) {
318	/* Just disable the downstream port */
319	tb_pci_port_enable(port: down, enable: false);
320	goto err_free;
321	}
322	tunnel->paths[TB_PCI_PATH_UP] = path;
323	if (tb_pci_init_path(path: tunnel->paths[TB_PCI_PATH_UP]))
324	goto err_free;
325
326	path = tb_path_discover(src: tunnel->dst_port, src_hopid: -1, dst: down, TB_PCI_HOPID, NULL,
327	name: "PCIe Down", alloc_hopid);
328	if (!path)
329	goto err_deactivate;
330	tunnel->paths[TB_PCI_PATH_DOWN] = path;
331	if (tb_pci_init_path(path: tunnel->paths[TB_PCI_PATH_DOWN]))
332	goto err_deactivate;
333
334	/* Validate that the tunnel is complete */
335	if (!tb_port_is_pcie_up(port: tunnel->dst_port)) {
336	tb_port_warn(tunnel->dst_port,
337	"path does not end on a PCIe adapter, cleaning up\n");
338	goto err_deactivate;
339	}
340
341	if (down != tunnel->src_port) {
342	tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");
343	goto err_deactivate;
344	}
345
346	if (!tb_pci_port_is_enabled(port: tunnel->dst_port)) {
347	tb_tunnel_warn(tunnel,
348	"tunnel is not fully activated, cleaning up\n");
349	goto err_deactivate;
350	}
351
352	tb_tunnel_dbg(tunnel, "discovered\n");
353	return tunnel;
354
355	err_deactivate:
356	tb_tunnel_deactivate(tunnel);
357	err_free:
358	tb_tunnel_free(tunnel);
359
360	return NULL;
361	}
362
363	/**
364	* tb_tunnel_alloc_pci() - allocate a pci tunnel
365	* @tb: Pointer to the domain structure
366	* @up: PCIe upstream adapter port
367	* @down: PCIe downstream adapter port
368	*
369	* Allocate a PCI tunnel. The ports must be of type TB_TYPE_PCIE_UP and
370	* TB_TYPE_PCIE_DOWN.
371	*
372	* Return: Returns a tb_tunnel on success or NULL on failure.
373	*/
374	struct tb_tunnel *tb_tunnel_alloc_pci(struct tb *tb, struct tb_port *up,
375	struct tb_port *down)
376	{
377	struct tb_tunnel *tunnel;
378	struct tb_path *path;
379
380	tunnel = tb_tunnel_alloc(tb, npaths: 2, type: TB_TUNNEL_PCI);
381	if (!tunnel)
382	return NULL;
383
384	tunnel->activate = tb_pci_activate;
385	tunnel->src_port = down;
386	tunnel->dst_port = up;
387
388	path = tb_path_alloc(tb, src: down, TB_PCI_HOPID, dst: up, TB_PCI_HOPID, link_nr: 0,
389	name: "PCIe Down");
390	if (!path)
391	goto err_free;
392	tunnel->paths[TB_PCI_PATH_DOWN] = path;
393	if (tb_pci_init_path(path))
394	goto err_free;
395
396	path = tb_path_alloc(tb, src: up, TB_PCI_HOPID, dst: down, TB_PCI_HOPID, link_nr: 0,
397	name: "PCIe Up");
398	if (!path)
399	goto err_free;
400	tunnel->paths[TB_PCI_PATH_UP] = path;
401	if (tb_pci_init_path(path))
402	goto err_free;
403
404	return tunnel;
405
406	err_free:
407	tb_tunnel_free(tunnel);
408	return NULL;
409	}
410
411	/**
412	* tb_tunnel_reserved_pci() - Amount of bandwidth to reserve for PCIe
413	* @port: Lane 0 adapter
414	* @reserved_up: Upstream bandwidth in Mb/s to reserve
415	* @reserved_down: Downstream bandwidth in Mb/s to reserve
416	*
417	* Can be called to any connected lane 0 adapter to find out how much
418	* bandwidth needs to be left in reserve for possible PCIe bulk traffic.
419	* Returns true if there is something to be reserved and writes the
420	* amount to @reserved_down/@reserved_up. Otherwise returns false and
421	* does not touch the parameters.
422	*/
423	bool tb_tunnel_reserved_pci(struct tb_port *port, int *reserved_up,
424	int *reserved_down)
425	{
426	if (WARN_ON_ONCE(!port->remote))
427	return false;
428
429	if (!tb_acpi_may_tunnel_pcie())
430	return false;
431
432	if (tb_port_get_link_generation(port) < 4)
433	return false;
434
435	/* Must have PCIe adapters */
436	if (tb_is_upstream_port(port)) {
437	if (!tb_switch_find_port(sw: port->sw, type: TB_TYPE_PCIE_UP))
438	return false;
439	if (!tb_switch_find_port(sw: port->remote->sw, type: TB_TYPE_PCIE_DOWN))
440	return false;
441	} else {
442	if (!tb_switch_find_port(sw: port->sw, type: TB_TYPE_PCIE_DOWN))
443	return false;
444	if (!tb_switch_find_port(sw: port->remote->sw, type: TB_TYPE_PCIE_UP))
445	return false;
446	}
447
448	*reserved_up = USB4_V2_PCI_MIN_BANDWIDTH;
449	*reserved_down = USB4_V2_PCI_MIN_BANDWIDTH;
450
451	tb_port_dbg(port, "reserving %u/%u Mb/s for PCIe\n", *reserved_up,
452	*reserved_down);
453	return true;
454	}
455
456	static bool tb_dp_is_usb4(const struct tb_switch *sw)
457	{
458	/* Titan Ridge DP adapters need the same treatment as USB4 */
459	return tb_switch_is_usb4(sw) || tb_switch_is_titan_ridge(sw);
460	}
461
462	static int tb_dp_cm_handshake(struct tb_port *in, struct tb_port *out,
463	int timeout_msec)
464	{
465	ktime_t timeout = ktime_add_ms(kt: ktime_get(), msec: timeout_msec);
466	u32 val;
467	int ret;
468
469	/* Both ends need to support this */
470	if (!tb_dp_is_usb4(sw: in->sw) || !tb_dp_is_usb4(sw: out->sw))
471	return 0;
472
473	ret = tb_port_read(port: out, buffer: &val, space: TB_CFG_PORT,
474	offset: out->cap_adap + DP_STATUS_CTRL, length: 1);
475	if (ret)
476	return ret;
477
478	val |= DP_STATUS_CTRL_UF | DP_STATUS_CTRL_CMHS;
479
480	ret = tb_port_write(port: out, buffer: &val, space: TB_CFG_PORT,
481	offset: out->cap_adap + DP_STATUS_CTRL, length: 1);
482	if (ret)
483	return ret;
484
485	do {
486	ret = tb_port_read(port: out, buffer: &val, space: TB_CFG_PORT,
487	offset: out->cap_adap + DP_STATUS_CTRL, length: 1);
488	if (ret)
489	return ret;
490	if (!(val & DP_STATUS_CTRL_CMHS))
491	return 0;
492	usleep_range(min: 100, max: 150);
493	} while (ktime_before(cmp1: ktime_get(), cmp2: timeout));
494
495	return -ETIMEDOUT;
496	}
497
498	/*
499	* Returns maximum possible rate from capability supporting only DP 2.0
500	* and below. Used when DP BW allocation mode is not enabled.
501	*/
502	static inline u32 tb_dp_cap_get_rate(u32 val)
503	{
504	u32 rate = (val & DP_COMMON_CAP_RATE_MASK) >> DP_COMMON_CAP_RATE_SHIFT;
505
506	switch (rate) {
507	case DP_COMMON_CAP_RATE_RBR:
508	return 1620;
509	case DP_COMMON_CAP_RATE_HBR:
510	return 2700;
511	case DP_COMMON_CAP_RATE_HBR2:
512	return 5400;
513	case DP_COMMON_CAP_RATE_HBR3:
514	return 8100;
515	default:
516	return 0;
517	}
518	}
519
520	/*
521	* Returns maximum possible rate from capability supporting DP 2.1
522	* UHBR20, 13.5 and 10 rates as well. Use only when DP BW allocation
523	* mode is enabled.
524	*/
525	static inline u32 tb_dp_cap_get_rate_ext(u32 val)
526	{
527	if (val & DP_COMMON_CAP_UHBR20)
528	return 20000;
529	else if (val & DP_COMMON_CAP_UHBR13_5)
530	return 13500;
531	else if (val & DP_COMMON_CAP_UHBR10)
532	return 10000;
533
534	return tb_dp_cap_get_rate(val);
535	}
536
537	static inline bool tb_dp_is_uhbr_rate(unsigned int rate)
538	{
539	return rate >= 10000;
540	}
541
542	static inline u32 tb_dp_cap_set_rate(u32 val, u32 rate)
543	{
544	val &= ~DP_COMMON_CAP_RATE_MASK;
545	switch (rate) {
546	default:
547	WARN(1, "invalid rate %u passed, defaulting to 1620 MB/s\n", rate);
548	fallthrough;
549	case 1620:
550	val |= DP_COMMON_CAP_RATE_RBR << DP_COMMON_CAP_RATE_SHIFT;
551	break;
552	case 2700:
553	val |= DP_COMMON_CAP_RATE_HBR << DP_COMMON_CAP_RATE_SHIFT;
554	break;
555	case 5400:
556	val |= DP_COMMON_CAP_RATE_HBR2 << DP_COMMON_CAP_RATE_SHIFT;
557	break;
558	case 8100:
559	val |= DP_COMMON_CAP_RATE_HBR3 << DP_COMMON_CAP_RATE_SHIFT;
560	break;
561	}
562	return val;
563	}
564
565	static inline u32 tb_dp_cap_get_lanes(u32 val)
566	{
567	u32 lanes = (val & DP_COMMON_CAP_LANES_MASK) >> DP_COMMON_CAP_LANES_SHIFT;
568
569	switch (lanes) {
570	case DP_COMMON_CAP_1_LANE:
571	return 1;
572	case DP_COMMON_CAP_2_LANES:
573	return 2;
574	case DP_COMMON_CAP_4_LANES:
575	return 4;
576	default:
577	return 0;
578	}
579	}
580
581	static inline u32 tb_dp_cap_set_lanes(u32 val, u32 lanes)
582	{
583	val &= ~DP_COMMON_CAP_LANES_MASK;
584	switch (lanes) {
585	default:
586	WARN(1, "invalid number of lanes %u passed, defaulting to 1\n",
587	lanes);
588	fallthrough;
589	case 1:
590	val |= DP_COMMON_CAP_1_LANE << DP_COMMON_CAP_LANES_SHIFT;
591	break;
592	case 2:
593	val |= DP_COMMON_CAP_2_LANES << DP_COMMON_CAP_LANES_SHIFT;
594	break;
595	case 4:
596	val |= DP_COMMON_CAP_4_LANES << DP_COMMON_CAP_LANES_SHIFT;
597	break;
598	}
599	return val;
600	}
601
602	static unsigned int tb_dp_bandwidth(unsigned int rate, unsigned int lanes)
603	{
604	/* Tunneling removes the DP 8b/10b 128/132b encoding */
605	if (tb_dp_is_uhbr_rate(rate))
606	return rate * lanes * 128 / 132;
607	return rate * lanes * 8 / 10;
608	}
609
610	static int tb_dp_reduce_bandwidth(int max_bw, u32 in_rate, u32 in_lanes,
611	u32 out_rate, u32 out_lanes, u32 *new_rate,
612	u32 *new_lanes)
613	{
614	static const u32 dp_bw[][2] = {
615	/* Mb/s, lanes */
616	{ 8100, 4 }, /* 25920 Mb/s */
617	{ 5400, 4 }, /* 17280 Mb/s */
618	{ 8100, 2 }, /* 12960 Mb/s */
619	{ 2700, 4 }, /* 8640 Mb/s */
620	{ 5400, 2 }, /* 8640 Mb/s */
621	{ 8100, 1 }, /* 6480 Mb/s */
622	{ 1620, 4 }, /* 5184 Mb/s */
623	{ 5400, 1 }, /* 4320 Mb/s */
624	{ 2700, 2 }, /* 4320 Mb/s */
625	{ 1620, 2 }, /* 2592 Mb/s */
626	{ 2700, 1 }, /* 2160 Mb/s */
627	{ 1620, 1 }, /* 1296 Mb/s */
628	};
629	unsigned int i;
630
631	/*
632	* Find a combination that can fit into max_bw and does not
633	* exceed the maximum rate and lanes supported by the DP OUT and
634	* DP IN adapters.
635	*/
636	for (i = 0; i < ARRAY_SIZE(dp_bw); i++) {
637	if (dp_bw[i][0] > out_rate || dp_bw[i][1] > out_lanes)
638	continue;
639
640	if (dp_bw[i][0] > in_rate || dp_bw[i][1] > in_lanes)
641	continue;
642
643	if (tb_dp_bandwidth(rate: dp_bw[i][0], lanes: dp_bw[i][1]) <= max_bw) {
644	*new_rate = dp_bw[i][0];
645	*new_lanes = dp_bw[i][1];
646	return 0;
647	}
648	}
649
650	return -ENOSR;
651	}
652
653	static int tb_dp_xchg_caps(struct tb_tunnel *tunnel)
654	{
655	u32 out_dp_cap, out_rate, out_lanes, in_dp_cap, in_rate, in_lanes, bw;
656	struct tb_port *out = tunnel->dst_port;
657	struct tb_port *in = tunnel->src_port;
658	int ret, max_bw;
659
660	/*
661	* Copy DP_LOCAL_CAP register to DP_REMOTE_CAP register for
662	* newer generation hardware.
663	*/
664	if (in->sw->generation < 2 || out->sw->generation < 2)
665	return 0;
666
667	/*
668	* Perform connection manager handshake between IN and OUT ports
669	* before capabilities exchange can take place.
670	*/
671	ret = tb_dp_cm_handshake(in, out, timeout_msec: 3000);
672	if (ret)
673	return ret;
674
675	/* Read both DP_LOCAL_CAP registers */
676	ret = tb_port_read(port: in, buffer: &in_dp_cap, space: TB_CFG_PORT,
677	offset: in->cap_adap + DP_LOCAL_CAP, length: 1);
678	if (ret)
679	return ret;
680
681	ret = tb_port_read(port: out, buffer: &out_dp_cap, space: TB_CFG_PORT,
682	offset: out->cap_adap + DP_LOCAL_CAP, length: 1);
683	if (ret)
684	return ret;
685
686	/* Write IN local caps to OUT remote caps */
687	ret = tb_port_write(port: out, buffer: &in_dp_cap, space: TB_CFG_PORT,
688	offset: out->cap_adap + DP_REMOTE_CAP, length: 1);
689	if (ret)
690	return ret;
691
692	in_rate = tb_dp_cap_get_rate(val: in_dp_cap);
693	in_lanes = tb_dp_cap_get_lanes(val: in_dp_cap);
694	tb_tunnel_dbg(tunnel,
695	"DP IN maximum supported bandwidth %u Mb/s x%u = %u Mb/s\n",
696	in_rate, in_lanes, tb_dp_bandwidth(in_rate, in_lanes));
697
698	/*
699	* If the tunnel bandwidth is limited (max_bw is set) then see
700	* if we need to reduce bandwidth to fit there.
701	*/
702	out_rate = tb_dp_cap_get_rate(val: out_dp_cap);
703	out_lanes = tb_dp_cap_get_lanes(val: out_dp_cap);
704	bw = tb_dp_bandwidth(rate: out_rate, lanes: out_lanes);
705	tb_tunnel_dbg(tunnel,
706	"DP OUT maximum supported bandwidth %u Mb/s x%u = %u Mb/s\n",
707	out_rate, out_lanes, bw);
708
709	if (tb_tunnel_direction_downstream(tunnel))
710	max_bw = tunnel->max_down;
711	else
712	max_bw = tunnel->max_up;
713
714	if (max_bw && bw > max_bw) {
715	u32 new_rate, new_lanes, new_bw;
716
717	ret = tb_dp_reduce_bandwidth(max_bw, in_rate, in_lanes,
718	out_rate, out_lanes, new_rate: &new_rate,
719	new_lanes: &new_lanes);
720	if (ret) {
721	tb_tunnel_info(tunnel, "not enough bandwidth\n");
722	return ret;
723	}
724
725	new_bw = tb_dp_bandwidth(rate: new_rate, lanes: new_lanes);
726	tb_tunnel_dbg(tunnel,
727	"bandwidth reduced to %u Mb/s x%u = %u Mb/s\n",
728	new_rate, new_lanes, new_bw);
729
730	/*
731	* Set new rate and number of lanes before writing it to
732	* the IN port remote caps.
733	*/
734	out_dp_cap = tb_dp_cap_set_rate(val: out_dp_cap, rate: new_rate);
735	out_dp_cap = tb_dp_cap_set_lanes(val: out_dp_cap, lanes: new_lanes);
736	}
737
738	/*
739	* Titan Ridge does not disable AUX timers when it gets
740	* SET_CONFIG with SET_LTTPR_MODE set. This causes problems with
741	* DP tunneling.
742	*/
743	if (tb_route(sw: out->sw) && tb_switch_is_titan_ridge(sw: out->sw)) {
744	out_dp_cap |= DP_COMMON_CAP_LTTPR_NS;
745	tb_tunnel_dbg(tunnel, "disabling LTTPR\n");
746	}
747
748	return tb_port_write(port: in, buffer: &out_dp_cap, space: TB_CFG_PORT,
749	offset: in->cap_adap + DP_REMOTE_CAP, length: 1);
750	}
751
752	static int tb_dp_bandwidth_alloc_mode_enable(struct tb_tunnel *tunnel)
753	{
754	int ret, estimated_bw, granularity, tmp;
755	struct tb_port *out = tunnel->dst_port;
756	struct tb_port *in = tunnel->src_port;
757	u32 out_dp_cap, out_rate, out_lanes;
758	u32 in_dp_cap, in_rate, in_lanes;
759	u32 rate, lanes;
760
761	if (!bw_alloc_mode)
762	return 0;
763
764	ret = usb4_dp_port_set_cm_bandwidth_mode_supported(port: in, supported: true);
765	if (ret)
766	return ret;
767
768	ret = usb4_dp_port_set_group_id(port: in, group_id: in->group->index);
769	if (ret)
770	return ret;
771
772	/*
773	* Get the non-reduced rate and lanes based on the lowest
774	* capability of both adapters.
775	*/
776	ret = tb_port_read(port: in, buffer: &in_dp_cap, space: TB_CFG_PORT,
777	offset: in->cap_adap + DP_LOCAL_CAP, length: 1);
778	if (ret)
779	return ret;
780
781	ret = tb_port_read(port: out, buffer: &out_dp_cap, space: TB_CFG_PORT,
782	offset: out->cap_adap + DP_LOCAL_CAP, length: 1);
783	if (ret)
784	return ret;
785
786	in_rate = tb_dp_cap_get_rate(val: in_dp_cap);
787	in_lanes = tb_dp_cap_get_lanes(val: in_dp_cap);
788	out_rate = tb_dp_cap_get_rate(val: out_dp_cap);
789	out_lanes = tb_dp_cap_get_lanes(val: out_dp_cap);
790
791	rate = min(in_rate, out_rate);
792	lanes = min(in_lanes, out_lanes);
793	tmp = tb_dp_bandwidth(rate, lanes);
794
795	tb_tunnel_dbg(tunnel, "non-reduced bandwidth %u Mb/s x%u = %u Mb/s\n",
796	rate, lanes, tmp);
797
798	ret = usb4_dp_port_set_nrd(port: in, rate, lanes);
799	if (ret)
800	return ret;
801
802	/*
803	* Pick up granularity that supports maximum possible bandwidth.
804	* For that we use the UHBR rates too.
805	*/
806	in_rate = tb_dp_cap_get_rate_ext(val: in_dp_cap);
807	out_rate = tb_dp_cap_get_rate_ext(val: out_dp_cap);
808	rate = min(in_rate, out_rate);
809	tmp = tb_dp_bandwidth(rate, lanes);
810
811	tb_tunnel_dbg(tunnel,
812	"maximum bandwidth through allocation mode %u Mb/s x%u = %u Mb/s\n",
813	rate, lanes, tmp);
814
815	for (granularity = 250; tmp / granularity > 255 && granularity <= 1000;
816	granularity *= 2)
817	;
818
819	tb_tunnel_dbg(tunnel, "granularity %d Mb/s\n", granularity);
820
821	/*
822	* Returns -EINVAL if granularity above is outside of the
823	* accepted ranges.
824	*/
825	ret = usb4_dp_port_set_granularity(port: in, granularity);
826	if (ret)
827	return ret;
828
829	/*
830	* Bandwidth estimation is pretty much what we have in
831	* max_up/down fields. For discovery we just read what the
832	* estimation was set to.
833	*/
834	if (tb_tunnel_direction_downstream(tunnel))
835	estimated_bw = tunnel->max_down;
836	else
837	estimated_bw = tunnel->max_up;
838
839	tb_tunnel_dbg(tunnel, "estimated bandwidth %d Mb/s\n", estimated_bw);
840
841	ret = usb4_dp_port_set_estimated_bandwidth(port: in, bw: estimated_bw);
842	if (ret)
843	return ret;
844
845	/* Initial allocation should be 0 according the spec */
846	ret = usb4_dp_port_allocate_bandwidth(port: in, bw: 0);
847	if (ret)
848	return ret;
849
850	tb_tunnel_dbg(tunnel, "bandwidth allocation mode enabled\n");
851	return 0;
852	}
853
854	static int tb_dp_init(struct tb_tunnel *tunnel)
855	{
856	struct tb_port *in = tunnel->src_port;
857	struct tb_switch *sw = in->sw;
858	struct tb *tb = in->sw->tb;
859	int ret;
860
861	ret = tb_dp_xchg_caps(tunnel);
862	if (ret)
863	return ret;
864
865	if (!tb_switch_is_usb4(sw))
866	return 0;
867
868	if (!usb4_dp_port_bandwidth_mode_supported(port: in))
869	return 0;
870
871	tb_tunnel_dbg(tunnel, "bandwidth allocation mode supported\n");
872
873	ret = usb4_dp_port_set_cm_id(port: in, cm_id: tb->index);
874	if (ret)
875	return ret;
876
877	return tb_dp_bandwidth_alloc_mode_enable(tunnel);
878	}
879
880	static void tb_dp_deinit(struct tb_tunnel *tunnel)
881	{
882	struct tb_port *in = tunnel->src_port;
883
884	if (!usb4_dp_port_bandwidth_mode_supported(port: in))
885	return;
886	if (usb4_dp_port_bandwidth_mode_enabled(port: in)) {
887	usb4_dp_port_set_cm_bandwidth_mode_supported(port: in, supported: false);
888	tb_tunnel_dbg(tunnel, "bandwidth allocation mode disabled\n");
889	}
890	}
891
892	static int tb_dp_activate(struct tb_tunnel *tunnel, bool active)
893	{
894	int ret;
895
896	if (active) {
897	struct tb_path **paths;
898	int last;
899
900	paths = tunnel->paths;
901	last = paths[TB_DP_VIDEO_PATH_OUT]->path_length - 1;
902
903	tb_dp_port_set_hops(port: tunnel->src_port,
904	video: paths[TB_DP_VIDEO_PATH_OUT]->hops[0].in_hop_index,
905	aux_tx: paths[TB_DP_AUX_PATH_OUT]->hops[0].in_hop_index,
906	aux_rx: paths[TB_DP_AUX_PATH_IN]->hops[last].next_hop_index);
907
908	tb_dp_port_set_hops(port: tunnel->dst_port,
909	video: paths[TB_DP_VIDEO_PATH_OUT]->hops[last].next_hop_index,
910	aux_tx: paths[TB_DP_AUX_PATH_IN]->hops[0].in_hop_index,
911	aux_rx: paths[TB_DP_AUX_PATH_OUT]->hops[last].next_hop_index);
912	} else {
913	tb_dp_port_hpd_clear(port: tunnel->src_port);
914	tb_dp_port_set_hops(port: tunnel->src_port, video: 0, aux_tx: 0, aux_rx: 0);
915	if (tb_port_is_dpout(port: tunnel->dst_port))
916	tb_dp_port_set_hops(port: tunnel->dst_port, video: 0, aux_tx: 0, aux_rx: 0);
917	}
918
919	ret = tb_dp_port_enable(port: tunnel->src_port, enable: active);
920	if (ret)
921	return ret;
922
923	if (tb_port_is_dpout(port: tunnel->dst_port))
924	return tb_dp_port_enable(port: tunnel->dst_port, enable: active);
925
926	return 0;
927	}
928
929	/**
930	* tb_dp_bandwidth_mode_maximum_bandwidth() - Maximum possible bandwidth
931	* @tunnel: DP tunnel to check
932	* @max_bw_rounded: Maximum bandwidth in Mb/s rounded up to the next granularity
933	*
934	* Returns maximum possible bandwidth for this tunnel in Mb/s.
935	*/
936	static int tb_dp_bandwidth_mode_maximum_bandwidth(struct tb_tunnel *tunnel,
937	int *max_bw_rounded)
938	{
939	struct tb_port *in = tunnel->src_port;
940	int ret, rate, lanes, max_bw;
941	u32 cap;
942
943	/*
944	* DP IN adapter DP_LOCAL_CAP gets updated to the lowest AUX
945	* read parameter values so this so we can use this to determine
946	* the maximum possible bandwidth over this link.
947	*
948	* See USB4 v2 spec 1.0 10.4.4.5.
949	*/
950	ret = tb_port_read(port: in, buffer: &cap, space: TB_CFG_PORT,
951	offset: in->cap_adap + DP_LOCAL_CAP, length: 1);
952	if (ret)
953	return ret;
954
955	rate = tb_dp_cap_get_rate_ext(val: cap);
956	lanes = tb_dp_cap_get_lanes(val: cap);
957
958	max_bw = tb_dp_bandwidth(rate, lanes);
959
960	if (max_bw_rounded) {
961	ret = usb4_dp_port_granularity(port: in);
962	if (ret < 0)
963	return ret;
964	*max_bw_rounded = roundup(max_bw, ret);
965	}
966
967	return max_bw;
968	}
969
970	static int tb_dp_bandwidth_mode_consumed_bandwidth(struct tb_tunnel *tunnel,
971	int *consumed_up,
972	int *consumed_down)
973	{
974	struct tb_port *in = tunnel->src_port;
975	int ret, allocated_bw, max_bw_rounded;
976
977	if (!usb4_dp_port_bandwidth_mode_enabled(port: in))
978	return -EOPNOTSUPP;
979
980	if (!tunnel->bw_mode)
981	return -EOPNOTSUPP;
982
983	/* Read what was allocated previously if any */
984	ret = usb4_dp_port_allocated_bandwidth(port: in);
985	if (ret < 0)
986	return ret;
987	allocated_bw = ret;
988
989	ret = tb_dp_bandwidth_mode_maximum_bandwidth(tunnel, max_bw_rounded: &max_bw_rounded);
990	if (ret < 0)
991	return ret;
992	if (allocated_bw == max_bw_rounded)
993	allocated_bw = ret;
994
995	if (tb_tunnel_direction_downstream(tunnel)) {
996	*consumed_up = 0;
997	*consumed_down = allocated_bw;
998	} else {
999	*consumed_up = allocated_bw;
1000	*consumed_down = 0;
1001	}
1002
1003	return 0;
1004	}
1005
1006	static int tb_dp_allocated_bandwidth(struct tb_tunnel *tunnel, int *allocated_up,
1007	int *allocated_down)
1008	{
1009	struct tb_port *in = tunnel->src_port;
1010
1011	/*
1012	* If we have already set the allocated bandwidth then use that.
1013	* Otherwise we read it from the DPRX.
1014	*/
1015	if (usb4_dp_port_bandwidth_mode_enabled(port: in) && tunnel->bw_mode) {
1016	int ret, allocated_bw, max_bw_rounded;
1017
1018	ret = usb4_dp_port_allocated_bandwidth(port: in);
1019	if (ret < 0)
1020	return ret;
1021	allocated_bw = ret;
1022
1023	ret = tb_dp_bandwidth_mode_maximum_bandwidth(tunnel,
1024	max_bw_rounded: &max_bw_rounded);
1025	if (ret < 0)
1026	return ret;
1027	if (allocated_bw == max_bw_rounded)
1028	allocated_bw = ret;
1029
1030	if (tb_tunnel_direction_downstream(tunnel)) {
1031	*allocated_up = 0;
1032	*allocated_down = allocated_bw;
1033	} else {
1034	*allocated_up = allocated_bw;
1035	*allocated_down = 0;
1036	}
1037	return 0;
1038	}
1039
1040	return tunnel->consumed_bandwidth(tunnel, allocated_up,
1041	allocated_down);
1042	}
1043
1044	static int tb_dp_alloc_bandwidth(struct tb_tunnel *tunnel, int *alloc_up,
1045	int *alloc_down)
1046	{
1047	struct tb_port *in = tunnel->src_port;
1048	int max_bw_rounded, ret, tmp;
1049
1050	if (!usb4_dp_port_bandwidth_mode_enabled(port: in))
1051	return -EOPNOTSUPP;
1052
1053	ret = tb_dp_bandwidth_mode_maximum_bandwidth(tunnel, max_bw_rounded: &max_bw_rounded);
1054	if (ret < 0)
1055	return ret;
1056
1057	if (tb_tunnel_direction_downstream(tunnel)) {
1058	tmp = min(*alloc_down, max_bw_rounded);
1059	ret = usb4_dp_port_allocate_bandwidth(port: in, bw: tmp);
1060	if (ret)
1061	return ret;
1062	*alloc_down = tmp;
1063	*alloc_up = 0;
1064	} else {
1065	tmp = min(*alloc_up, max_bw_rounded);
1066	ret = usb4_dp_port_allocate_bandwidth(port: in, bw: tmp);
1067	if (ret)
1068	return ret;
1069	*alloc_down = 0;
1070	*alloc_up = tmp;
1071	}
1072
1073	/* Now we can use BW mode registers to figure out the bandwidth */
1074	/* TODO: need to handle discovery too */
1075	tunnel->bw_mode = true;
1076	return 0;
1077	}
1078
1079	static int tb_dp_wait_dprx(struct tb_tunnel *tunnel, int timeout_msec)
1080	{
1081	ktime_t timeout = ktime_add_ms(kt: ktime_get(), msec: timeout_msec);
1082	struct tb_port *in = tunnel->src_port;
1083
1084	/*
1085	* Wait for DPRX done. Normally it should be already set for
1086	* active tunnel.
1087	*/
1088	do {
1089	u32 val;
1090	int ret;
1091
1092	ret = tb_port_read(port: in, buffer: &val, space: TB_CFG_PORT,
1093	offset: in->cap_adap + DP_COMMON_CAP, length: 1);
1094	if (ret)
1095	return ret;
1096
1097	if (val & DP_COMMON_CAP_DPRX_DONE) {
1098	tb_tunnel_dbg(tunnel, "DPRX read done\n");
1099	return 0;
1100	}
1101	usleep_range(min: 100, max: 150);
1102	} while (ktime_before(cmp1: ktime_get(), cmp2: timeout));
1103
1104	tb_tunnel_dbg(tunnel, "DPRX read timeout\n");
1105	return -ETIMEDOUT;
1106	}
1107
1108	/* Read cap from tunnel DP IN */
1109	static int tb_dp_read_cap(struct tb_tunnel *tunnel, unsigned int cap, u32 *rate,
1110	u32 *lanes)
1111	{
1112	struct tb_port *in = tunnel->src_port;
1113	u32 val;
1114	int ret;
1115
1116	switch (cap) {
1117	case DP_LOCAL_CAP:
1118	case DP_REMOTE_CAP:
1119	case DP_COMMON_CAP:
1120	break;
1121
1122	default:
1123	tb_tunnel_WARN(tunnel, "invalid capability index %#x\n", cap);
1124	return -EINVAL;
1125	}
1126
1127	/*
1128	* Read from the copied remote cap so that we take into account
1129	* if capabilities were reduced during exchange.
1130	*/
1131	ret = tb_port_read(port: in, buffer: &val, space: TB_CFG_PORT, offset: in->cap_adap + cap, length: 1);
1132	if (ret)
1133	return ret;
1134
1135	*rate = tb_dp_cap_get_rate(val);
1136	*lanes = tb_dp_cap_get_lanes(val);
1137	return 0;
1138	}
1139
1140	static int tb_dp_maximum_bandwidth(struct tb_tunnel *tunnel, int *max_up,
1141	int *max_down)
1142	{
1143	int ret;
1144
1145	if (!usb4_dp_port_bandwidth_mode_enabled(port: tunnel->src_port))
1146	return -EOPNOTSUPP;
1147
1148	ret = tb_dp_bandwidth_mode_maximum_bandwidth(tunnel, NULL);
1149	if (ret < 0)
1150	return ret;
1151
1152	if (tb_tunnel_direction_downstream(tunnel)) {
1153	*max_up = 0;
1154	*max_down = ret;
1155	} else {
1156	*max_up = ret;
1157	*max_down = 0;
1158	}
1159
1160	return 0;
1161	}
1162
1163	static int tb_dp_consumed_bandwidth(struct tb_tunnel *tunnel, int *consumed_up,
1164	int *consumed_down)
1165	{
1166	const struct tb_switch *sw = tunnel->src_port->sw;
1167	u32 rate = 0, lanes = 0;
1168	int ret;
1169
1170	if (tb_dp_is_usb4(sw)) {
1171	/*
1172	* On USB4 routers check if the bandwidth allocation
1173	* mode is enabled first and then read the bandwidth
1174	* through those registers.
1175	*/
1176	ret = tb_dp_bandwidth_mode_consumed_bandwidth(tunnel, consumed_up,
1177	consumed_down);
1178	if (ret < 0) {
1179	if (ret != -EOPNOTSUPP)
1180	return ret;
1181	} else if (!ret) {
1182	return 0;
1183	}
1184	/*
1185	* Then see if the DPRX negotiation is ready and if yes
1186	* return that bandwidth (it may be smaller than the
1187	* reduced one). According to VESA spec, the DPRX
1188	* negotiation shall compete in 5 seconds after tunnel
1189	* established. We give it 100ms extra just in case.
1190	*/
1191	ret = tb_dp_wait_dprx(tunnel, timeout_msec: 5100);
1192	if (ret)
1193	return ret;
1194	ret = tb_dp_read_cap(tunnel, DP_COMMON_CAP, rate: &rate, lanes: &lanes);
1195	if (ret)
1196	return ret;
1197	} else if (sw->generation >= 2) {
1198	ret = tb_dp_read_cap(tunnel, DP_REMOTE_CAP, rate: &rate, lanes: &lanes);
1199	if (ret)
1200	return ret;
1201	} else {
1202	/* No bandwidth management for legacy devices */
1203	*consumed_up = 0;
1204	*consumed_down = 0;
1205	return 0;
1206	}
1207
1208	if (tb_tunnel_direction_downstream(tunnel)) {
1209	*consumed_up = 0;
1210	*consumed_down = tb_dp_bandwidth(rate, lanes);
1211	} else {
1212	*consumed_up = tb_dp_bandwidth(rate, lanes);
1213	*consumed_down = 0;
1214	}
1215
1216	return 0;
1217	}
1218
1219	static void tb_dp_init_aux_credits(struct tb_path_hop *hop)
1220	{
1221	struct tb_port *port = hop->in_port;
1222	struct tb_switch *sw = port->sw;
1223
1224	if (tb_port_use_credit_allocation(port))
1225	hop->initial_credits = sw->min_dp_aux_credits;
1226	else
1227	hop->initial_credits = 1;
1228	}
1229
1230	static void tb_dp_init_aux_path(struct tb_path *path, bool pm_support)
1231	{
1232	struct tb_path_hop *hop;
1233
1234	path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
1235	path->egress_shared_buffer = TB_PATH_NONE;
1236	path->ingress_fc_enable = TB_PATH_ALL;
1237	path->ingress_shared_buffer = TB_PATH_NONE;
1238	path->priority = TB_DP_AUX_PRIORITY;
1239	path->weight = TB_DP_AUX_WEIGHT;
1240
1241	tb_path_for_each_hop(path, hop) {
1242	tb_dp_init_aux_credits(hop);
1243	if (pm_support)
1244	tb_init_pm_support(hop);
1245	}
1246	}
1247
1248	static int tb_dp_init_video_credits(struct tb_path_hop *hop)
1249	{
1250	struct tb_port *port = hop->in_port;
1251	struct tb_switch *sw = port->sw;
1252
1253	if (tb_port_use_credit_allocation(port)) {
1254	unsigned int nfc_credits;
1255	size_t max_dp_streams;
1256
1257	tb_available_credits(port, max_dp_streams: &max_dp_streams);
1258	/*
1259	* Read the number of currently allocated NFC credits
1260	* from the lane adapter. Since we only use them for DP
1261	* tunneling we can use that to figure out how many DP
1262	* tunnels already go through the lane adapter.
1263	*/
1264	nfc_credits = port->config.nfc_credits &
1265	ADP_CS_4_NFC_BUFFERS_MASK;
1266	if (nfc_credits / sw->min_dp_main_credits > max_dp_streams)
1267	return -ENOSPC;
1268
1269	hop->nfc_credits = sw->min_dp_main_credits;
1270	} else {
1271	hop->nfc_credits = min(port->total_credits - 2, 12U);
1272	}
1273
1274	return 0;
1275	}
1276
1277	static int tb_dp_init_video_path(struct tb_path *path, bool pm_support)
1278	{
1279	struct tb_path_hop *hop;
1280
1281	path->egress_fc_enable = TB_PATH_NONE;
1282	path->egress_shared_buffer = TB_PATH_NONE;
1283	path->ingress_fc_enable = TB_PATH_NONE;
1284	path->ingress_shared_buffer = TB_PATH_NONE;
1285	path->priority = TB_DP_VIDEO_PRIORITY;
1286	path->weight = TB_DP_VIDEO_WEIGHT;
1287
1288	tb_path_for_each_hop(path, hop) {
1289	int ret;
1290
1291	ret = tb_dp_init_video_credits(hop);
1292	if (ret)
1293	return ret;
1294	if (pm_support)
1295	tb_init_pm_support(hop);
1296	}
1297
1298	return 0;
1299	}
1300
1301	static void tb_dp_dump(struct tb_tunnel *tunnel)
1302	{
1303	struct tb_port *in, *out;
1304	u32 dp_cap, rate, lanes;
1305
1306	in = tunnel->src_port;
1307	out = tunnel->dst_port;
1308
1309	if (tb_port_read(port: in, buffer: &dp_cap, space: TB_CFG_PORT,
1310	offset: in->cap_adap + DP_LOCAL_CAP, length: 1))
1311	return;
1312
1313	rate = tb_dp_cap_get_rate(val: dp_cap);
1314	lanes = tb_dp_cap_get_lanes(val: dp_cap);
1315
1316	tb_tunnel_dbg(tunnel,
1317	"DP IN maximum supported bandwidth %u Mb/s x%u = %u Mb/s\n",
1318	rate, lanes, tb_dp_bandwidth(rate, lanes));
1319
1320	if (tb_port_read(port: out, buffer: &dp_cap, space: TB_CFG_PORT,
1321	offset: out->cap_adap + DP_LOCAL_CAP, length: 1))
1322	return;
1323
1324	rate = tb_dp_cap_get_rate(val: dp_cap);
1325	lanes = tb_dp_cap_get_lanes(val: dp_cap);
1326
1327	tb_tunnel_dbg(tunnel,
1328	"DP OUT maximum supported bandwidth %u Mb/s x%u = %u Mb/s\n",
1329	rate, lanes, tb_dp_bandwidth(rate, lanes));
1330
1331	if (tb_port_read(port: in, buffer: &dp_cap, space: TB_CFG_PORT,
1332	offset: in->cap_adap + DP_REMOTE_CAP, length: 1))
1333	return;
1334
1335	rate = tb_dp_cap_get_rate(val: dp_cap);
1336	lanes = tb_dp_cap_get_lanes(val: dp_cap);
1337
1338	tb_tunnel_dbg(tunnel, "reduced bandwidth %u Mb/s x%u = %u Mb/s\n",
1339	rate, lanes, tb_dp_bandwidth(rate, lanes));
1340	}
1341
1342	/**
1343	* tb_tunnel_discover_dp() - Discover existing Display Port tunnels
1344	* @tb: Pointer to the domain structure
1345	* @in: DP in adapter
1346	* @alloc_hopid: Allocate HopIDs from visited ports
1347	*
1348	* If @in adapter is active, follows the tunnel to the DP out adapter
1349	* and back. Returns the discovered tunnel or %NULL if there was no
1350	* tunnel.
1351	*
1352	* Return: DP tunnel or %NULL if no tunnel found.
1353	*/
1354	struct tb_tunnel *tb_tunnel_discover_dp(struct tb *tb, struct tb_port *in,
1355	bool alloc_hopid)
1356	{
1357	struct tb_tunnel *tunnel;
1358	struct tb_port *port;
1359	struct tb_path *path;
1360
1361	if (!tb_dp_port_is_enabled(port: in))
1362	return NULL;
1363
1364	tunnel = tb_tunnel_alloc(tb, npaths: 3, type: TB_TUNNEL_DP);
1365	if (!tunnel)
1366	return NULL;
1367
1368	tunnel->init = tb_dp_init;
1369	tunnel->deinit = tb_dp_deinit;
1370	tunnel->activate = tb_dp_activate;
1371	tunnel->maximum_bandwidth = tb_dp_maximum_bandwidth;
1372	tunnel->allocated_bandwidth = tb_dp_allocated_bandwidth;
1373	tunnel->alloc_bandwidth = tb_dp_alloc_bandwidth;
1374	tunnel->consumed_bandwidth = tb_dp_consumed_bandwidth;
1375	tunnel->src_port = in;
1376
1377	path = tb_path_discover(src: in, TB_DP_VIDEO_HOPID, NULL, dst_hopid: -1,
1378	last: &tunnel->dst_port, name: "Video", alloc_hopid);
1379	if (!path) {
1380	/* Just disable the DP IN port */
1381	tb_dp_port_enable(port: in, enable: false);
1382	goto err_free;
1383	}
1384	tunnel->paths[TB_DP_VIDEO_PATH_OUT] = path;
1385	if (tb_dp_init_video_path(path: tunnel->paths[TB_DP_VIDEO_PATH_OUT], pm_support: false))
1386	goto err_free;
1387
1388	path = tb_path_discover(src: in, TB_DP_AUX_TX_HOPID, NULL, dst_hopid: -1, NULL, name: "AUX TX",
1389	alloc_hopid);
1390	if (!path)
1391	goto err_deactivate;
1392	tunnel->paths[TB_DP_AUX_PATH_OUT] = path;
1393	tb_dp_init_aux_path(path: tunnel->paths[TB_DP_AUX_PATH_OUT], pm_support: false);
1394
1395	path = tb_path_discover(src: tunnel->dst_port, src_hopid: -1, dst: in, TB_DP_AUX_RX_HOPID,
1396	last: &port, name: "AUX RX", alloc_hopid);
1397	if (!path)
1398	goto err_deactivate;
1399	tunnel->paths[TB_DP_AUX_PATH_IN] = path;
1400	tb_dp_init_aux_path(path: tunnel->paths[TB_DP_AUX_PATH_IN], pm_support: false);
1401
1402	/* Validate that the tunnel is complete */
1403	if (!tb_port_is_dpout(port: tunnel->dst_port)) {
1404	tb_port_warn(in, "path does not end on a DP adapter, cleaning up\n");
1405	goto err_deactivate;
1406	}
1407
1408	if (!tb_dp_port_is_enabled(port: tunnel->dst_port))
1409	goto err_deactivate;
1410
1411	if (!tb_dp_port_hpd_is_active(port: tunnel->dst_port))
1412	goto err_deactivate;
1413
1414	if (port != tunnel->src_port) {
1415	tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");
1416	goto err_deactivate;
1417	}
1418
1419	tb_dp_dump(tunnel);
1420
1421	tb_tunnel_dbg(tunnel, "discovered\n");
1422	return tunnel;
1423
1424	err_deactivate:
1425	tb_tunnel_deactivate(tunnel);
1426	err_free:
1427	tb_tunnel_free(tunnel);
1428
1429	return NULL;
1430	}
1431
1432	/**
1433	* tb_tunnel_alloc_dp() - allocate a Display Port tunnel
1434	* @tb: Pointer to the domain structure
1435	* @in: DP in adapter port
1436	* @out: DP out adapter port
1437	* @link_nr: Preferred lane adapter when the link is not bonded
1438	* @max_up: Maximum available upstream bandwidth for the DP tunnel (%0
1439	* if not limited)
1440	* @max_down: Maximum available downstream bandwidth for the DP tunnel
1441	* (%0 if not limited)
1442	*
1443	* Allocates a tunnel between @in and @out that is capable of tunneling
1444	* Display Port traffic.
1445	*
1446	* Return: Returns a tb_tunnel on success or NULL on failure.
1447	*/
1448	struct tb_tunnel *tb_tunnel_alloc_dp(struct tb *tb, struct tb_port *in,
1449	struct tb_port *out, int link_nr,
1450	int max_up, int max_down)
1451	{
1452	struct tb_tunnel *tunnel;
1453	struct tb_path **paths;
1454	struct tb_path *path;
1455	bool pm_support;
1456
1457	if (WARN_ON(!in->cap_adap || !out->cap_adap))
1458	return NULL;
1459
1460	tunnel = tb_tunnel_alloc(tb, npaths: 3, type: TB_TUNNEL_DP);
1461	if (!tunnel)
1462	return NULL;
1463
1464	tunnel->init = tb_dp_init;
1465	tunnel->deinit = tb_dp_deinit;
1466	tunnel->activate = tb_dp_activate;
1467	tunnel->maximum_bandwidth = tb_dp_maximum_bandwidth;
1468	tunnel->allocated_bandwidth = tb_dp_allocated_bandwidth;
1469	tunnel->alloc_bandwidth = tb_dp_alloc_bandwidth;
1470	tunnel->consumed_bandwidth = tb_dp_consumed_bandwidth;
1471	tunnel->src_port = in;
1472	tunnel->dst_port = out;
1473	tunnel->max_up = max_up;
1474	tunnel->max_down = max_down;
1475
1476	paths = tunnel->paths;
1477	pm_support = usb4_switch_version(sw: in->sw) >= 2;
1478
1479	path = tb_path_alloc(tb, src: in, TB_DP_VIDEO_HOPID, dst: out, TB_DP_VIDEO_HOPID,
1480	link_nr, name: "Video");
1481	if (!path)
1482	goto err_free;
1483	tb_dp_init_video_path(path, pm_support);
1484	paths[TB_DP_VIDEO_PATH_OUT] = path;
1485
1486	path = tb_path_alloc(tb, src: in, TB_DP_AUX_TX_HOPID, dst: out,
1487	TB_DP_AUX_TX_HOPID, link_nr, name: "AUX TX");
1488	if (!path)
1489	goto err_free;
1490	tb_dp_init_aux_path(path, pm_support);
1491	paths[TB_DP_AUX_PATH_OUT] = path;
1492
1493	path = tb_path_alloc(tb, src: out, TB_DP_AUX_RX_HOPID, dst: in,
1494	TB_DP_AUX_RX_HOPID, link_nr, name: "AUX RX");
1495	if (!path)
1496	goto err_free;
1497	tb_dp_init_aux_path(path, pm_support);
1498	paths[TB_DP_AUX_PATH_IN] = path;
1499
1500	return tunnel;
1501
1502	err_free:
1503	tb_tunnel_free(tunnel);
1504	return NULL;
1505	}
1506
1507	static unsigned int tb_dma_available_credits(const struct tb_port *port)
1508	{
1509	const struct tb_switch *sw = port->sw;
1510	int credits;
1511
1512	credits = tb_available_credits(port, NULL);
1513	if (tb_acpi_may_tunnel_pcie())
1514	credits -= sw->max_pcie_credits;
1515	credits -= port->dma_credits;
1516
1517	return credits > 0 ? credits : 0;
1518	}
1519
1520	static int tb_dma_reserve_credits(struct tb_path_hop *hop, unsigned int credits)
1521	{
1522	struct tb_port *port = hop->in_port;
1523
1524	if (tb_port_use_credit_allocation(port)) {
1525	unsigned int available = tb_dma_available_credits(port);
1526
1527	/*
1528	* Need to have at least TB_MIN_DMA_CREDITS, otherwise
1529	* DMA path cannot be established.
1530	*/
1531	if (available < TB_MIN_DMA_CREDITS)
1532	return -ENOSPC;
1533
1534	while (credits > available)
1535	credits--;
1536
1537	tb_port_dbg(port, "reserving %u credits for DMA path\n",
1538	credits);
1539
1540	port->dma_credits += credits;
1541	} else {
1542	if (tb_port_is_null(port))
1543	credits = port->bonded ? 14 : 6;
1544	else
1545	credits = min(port->total_credits, credits);
1546	}
1547
1548	hop->initial_credits = credits;
1549	return 0;
1550	}
1551
1552	/* Path from lane adapter to NHI */
1553	static int tb_dma_init_rx_path(struct tb_path *path, unsigned int credits)
1554	{
1555	struct tb_path_hop *hop;
1556	unsigned int i, tmp;
1557
1558	path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
1559	path->ingress_fc_enable = TB_PATH_ALL;
1560	path->egress_shared_buffer = TB_PATH_NONE;
1561	path->ingress_shared_buffer = TB_PATH_NONE;
1562	path->priority = TB_DMA_PRIORITY;
1563	path->weight = TB_DMA_WEIGHT;
1564	path->clear_fc = true;
1565
1566	/*
1567	* First lane adapter is the one connected to the remote host.
1568	* We don't tunnel other traffic over this link so can use all
1569	* the credits (except the ones reserved for control traffic).
1570	*/
1571	hop = &path->hops[0];
1572	tmp = min(tb_usable_credits(hop->in_port), credits);
1573	hop->initial_credits = tmp;
1574	hop->in_port->dma_credits += tmp;
1575
1576	for (i = 1; i < path->path_length; i++) {
1577	int ret;
1578
1579	ret = tb_dma_reserve_credits(hop: &path->hops[i], credits);
1580	if (ret)
1581	return ret;
1582	}
1583
1584	return 0;
1585	}
1586
1587	/* Path from NHI to lane adapter */
1588	static int tb_dma_init_tx_path(struct tb_path *path, unsigned int credits)
1589	{
1590	struct tb_path_hop *hop;
1591
1592	path->egress_fc_enable = TB_PATH_ALL;
1593	path->ingress_fc_enable = TB_PATH_ALL;
1594	path->egress_shared_buffer = TB_PATH_NONE;
1595	path->ingress_shared_buffer = TB_PATH_NONE;
1596	path->priority = TB_DMA_PRIORITY;
1597	path->weight = TB_DMA_WEIGHT;
1598	path->clear_fc = true;
1599
1600	tb_path_for_each_hop(path, hop) {
1601	int ret;
1602
1603	ret = tb_dma_reserve_credits(hop, credits);
1604	if (ret)
1605	return ret;
1606	}
1607
1608	return 0;
1609	}
1610
1611	static void tb_dma_release_credits(struct tb_path_hop *hop)
1612	{
1613	struct tb_port *port = hop->in_port;
1614
1615	if (tb_port_use_credit_allocation(port)) {
1616	port->dma_credits -= hop->initial_credits;
1617
1618	tb_port_dbg(port, "released %u DMA path credits\n",
1619	hop->initial_credits);
1620	}
1621	}
1622
1623	static void tb_dma_deinit_path(struct tb_path *path)
1624	{
1625	struct tb_path_hop *hop;
1626
1627	tb_path_for_each_hop(path, hop)
1628	tb_dma_release_credits(hop);
1629	}
1630
1631	static void tb_dma_deinit(struct tb_tunnel *tunnel)
1632	{
1633	int i;
1634
1635	for (i = 0; i < tunnel->npaths; i++) {
1636	if (!tunnel->paths[i])
1637	continue;
1638	tb_dma_deinit_path(path: tunnel->paths[i]);
1639	}
1640	}
1641
1642	/**
1643	* tb_tunnel_alloc_dma() - allocate a DMA tunnel
1644	* @tb: Pointer to the domain structure
1645	* @nhi: Host controller port
1646	* @dst: Destination null port which the other domain is connected to
1647	* @transmit_path: HopID used for transmitting packets
1648	* @transmit_ring: NHI ring number used to send packets towards the
1649	* other domain. Set to %-1 if TX path is not needed.
1650	* @receive_path: HopID used for receiving packets
1651	* @receive_ring: NHI ring number used to receive packets from the
1652	* other domain. Set to %-1 if RX path is not needed.
1653	*
1654	* Return: Returns a tb_tunnel on success or NULL on failure.
1655	*/
1656	struct tb_tunnel *tb_tunnel_alloc_dma(struct tb *tb, struct tb_port *nhi,
1657	struct tb_port *dst, int transmit_path,
1658	int transmit_ring, int receive_path,
1659	int receive_ring)
1660	{
1661	struct tb_tunnel *tunnel;
1662	size_t npaths = 0, i = 0;
1663	struct tb_path *path;
1664	int credits;
1665
1666	/* Ring 0 is reserved for control channel */
1667	if (WARN_ON(!receive_ring || !transmit_ring))
1668	return NULL;
1669
1670	if (receive_ring > 0)
1671	npaths++;
1672	if (transmit_ring > 0)
1673	npaths++;
1674
1675	if (WARN_ON(!npaths))
1676	return NULL;
1677
1678	tunnel = tb_tunnel_alloc(tb, npaths, type: TB_TUNNEL_DMA);
1679	if (!tunnel)
1680	return NULL;
1681
1682	tunnel->src_port = nhi;
1683	tunnel->dst_port = dst;
1684	tunnel->deinit = tb_dma_deinit;
1685
1686	credits = min_not_zero(dma_credits, nhi->sw->max_dma_credits);
1687
1688	if (receive_ring > 0) {
1689	path = tb_path_alloc(tb, src: dst, src_hopid: receive_path, dst: nhi, dst_hopid: receive_ring, link_nr: 0,
1690	name: "DMA RX");
1691	if (!path)
1692	goto err_free;
1693	tunnel->paths[i++] = path;
1694	if (tb_dma_init_rx_path(path, credits)) {
1695	tb_tunnel_dbg(tunnel, "not enough buffers for RX path\n");
1696	goto err_free;
1697	}
1698	}
1699
1700	if (transmit_ring > 0) {
1701	path = tb_path_alloc(tb, src: nhi, src_hopid: transmit_ring, dst, dst_hopid: transmit_path, link_nr: 0,
1702	name: "DMA TX");
1703	if (!path)
1704	goto err_free;
1705	tunnel->paths[i++] = path;
1706	if (tb_dma_init_tx_path(path, credits)) {
1707	tb_tunnel_dbg(tunnel, "not enough buffers for TX path\n");
1708	goto err_free;
1709	}
1710	}
1711
1712	return tunnel;
1713
1714	err_free:
1715	tb_tunnel_free(tunnel);
1716	return NULL;
1717	}
1718
1719	/**
1720	* tb_tunnel_match_dma() - Match DMA tunnel
1721	* @tunnel: Tunnel to match
1722	* @transmit_path: HopID used for transmitting packets. Pass %-1 to ignore.
1723	* @transmit_ring: NHI ring number used to send packets towards the
1724	* other domain. Pass %-1 to ignore.
1725	* @receive_path: HopID used for receiving packets. Pass %-1 to ignore.
1726	* @receive_ring: NHI ring number used to receive packets from the
1727	* other domain. Pass %-1 to ignore.
1728	*
1729	* This function can be used to match specific DMA tunnel, if there are
1730	* multiple DMA tunnels going through the same XDomain connection.
1731	* Returns true if there is match and false otherwise.
1732	*/
1733	bool tb_tunnel_match_dma(const struct tb_tunnel *tunnel, int transmit_path,
1734	int transmit_ring, int receive_path, int receive_ring)
1735	{
1736	const struct tb_path *tx_path = NULL, *rx_path = NULL;
1737	int i;
1738
1739	if (!receive_ring || !transmit_ring)
1740	return false;
1741
1742	for (i = 0; i < tunnel->npaths; i++) {
1743	const struct tb_path *path = tunnel->paths[i];
1744
1745	if (!path)
1746	continue;
1747
1748	if (tb_port_is_nhi(port: path->hops[0].in_port))
1749	tx_path = path;
1750	else if (tb_port_is_nhi(port: path->hops[path->path_length - 1].out_port))
1751	rx_path = path;
1752	}
1753
1754	if (transmit_ring > 0 || transmit_path > 0) {
1755	if (!tx_path)
1756	return false;
1757	if (transmit_ring > 0 &&
1758	(tx_path->hops[0].in_hop_index != transmit_ring))
1759	return false;
1760	if (transmit_path > 0 &&
1761	(tx_path->hops[tx_path->path_length - 1].next_hop_index != transmit_path))
1762	return false;
1763	}
1764
1765	if (receive_ring > 0 || receive_path > 0) {
1766	if (!rx_path)
1767	return false;
1768	if (receive_path > 0 &&
1769	(rx_path->hops[0].in_hop_index != receive_path))
1770	return false;
1771	if (receive_ring > 0 &&
1772	(rx_path->hops[rx_path->path_length - 1].next_hop_index != receive_ring))
1773	return false;
1774	}
1775
1776	return true;
1777	}
1778
1779	static int tb_usb3_max_link_rate(struct tb_port *up, struct tb_port *down)
1780	{
1781	int ret, up_max_rate, down_max_rate;
1782
1783	ret = usb4_usb3_port_max_link_rate(port: up);
1784	if (ret < 0)
1785	return ret;
1786	up_max_rate = ret;
1787
1788	ret = usb4_usb3_port_max_link_rate(port: down);
1789	if (ret < 0)
1790	return ret;
1791	down_max_rate = ret;
1792
1793	return min(up_max_rate, down_max_rate);
1794	}
1795
1796	static int tb_usb3_init(struct tb_tunnel *tunnel)
1797	{
1798	tb_tunnel_dbg(tunnel, "allocating initial bandwidth %d/%d Mb/s\n",
1799	tunnel->allocated_up, tunnel->allocated_down);
1800
1801	return usb4_usb3_port_allocate_bandwidth(port: tunnel->src_port,
1802	upstream_bw: &tunnel->allocated_up,
1803	downstream_bw: &tunnel->allocated_down);
1804	}
1805
1806	static int tb_usb3_activate(struct tb_tunnel *tunnel, bool activate)
1807	{
1808	int res;
1809
1810	res = tb_usb3_port_enable(port: tunnel->src_port, enable: activate);
1811	if (res)
1812	return res;
1813
1814	if (tb_port_is_usb3_up(port: tunnel->dst_port))
1815	return tb_usb3_port_enable(port: tunnel->dst_port, enable: activate);
1816
1817	return 0;
1818	}
1819
1820	static int tb_usb3_consumed_bandwidth(struct tb_tunnel *tunnel,
1821	int *consumed_up, int *consumed_down)
1822	{
1823	struct tb_port *port = tb_upstream_port(sw: tunnel->dst_port->sw);
1824	int pcie_weight = tb_acpi_may_tunnel_pcie() ? TB_PCI_WEIGHT : 0;
1825
1826	/*
1827	* PCIe tunneling, if enabled, affects the USB3 bandwidth so
1828	* take that it into account here.
1829	*/
1830	*consumed_up = tunnel->allocated_up *
1831	(TB_USB3_WEIGHT + pcie_weight) / TB_USB3_WEIGHT;
1832	*consumed_down = tunnel->allocated_down *
1833	(TB_USB3_WEIGHT + pcie_weight) / TB_USB3_WEIGHT;
1834
1835	if (tb_port_get_link_generation(port) >= 4) {
1836	*consumed_up = max(*consumed_up, USB4_V2_USB3_MIN_BANDWIDTH);
1837	*consumed_down = max(*consumed_down, USB4_V2_USB3_MIN_BANDWIDTH);
1838	}
1839
1840	return 0;
1841	}
1842
1843	static int tb_usb3_release_unused_bandwidth(struct tb_tunnel *tunnel)
1844	{
1845	int ret;
1846
1847	ret = usb4_usb3_port_release_bandwidth(port: tunnel->src_port,
1848	upstream_bw: &tunnel->allocated_up,
1849	downstream_bw: &tunnel->allocated_down);
1850	if (ret)
1851	return ret;
1852
1853	tb_tunnel_dbg(tunnel, "decreased bandwidth allocation to %d/%d Mb/s\n",
1854	tunnel->allocated_up, tunnel->allocated_down);
1855	return 0;
1856	}
1857
1858	static void tb_usb3_reclaim_available_bandwidth(struct tb_tunnel *tunnel,
1859	int *available_up,
1860	int *available_down)
1861	{
1862	int ret, max_rate, allocate_up, allocate_down;
1863
1864	ret = tb_usb3_max_link_rate(up: tunnel->dst_port, down: tunnel->src_port);
1865	if (ret < 0) {
1866	tb_tunnel_warn(tunnel, "failed to read maximum link rate\n");
1867	return;
1868	}
1869
1870	/*
1871	* 90% of the max rate can be allocated for isochronous
1872	* transfers.
1873	*/
1874	max_rate = ret * 90 / 100;
1875
1876	/* No need to reclaim if already at maximum */
1877	if (tunnel->allocated_up >= max_rate &&
1878	tunnel->allocated_down >= max_rate)
1879	return;
1880
1881	/* Don't go lower than what is already allocated */
1882	allocate_up = min(max_rate, *available_up);
1883	if (allocate_up < tunnel->allocated_up)
1884	allocate_up = tunnel->allocated_up;
1885
1886	allocate_down = min(max_rate, *available_down);
1887	if (allocate_down < tunnel->allocated_down)
1888	allocate_down = tunnel->allocated_down;
1889
1890	/* If no changes no need to do more */
1891	if (allocate_up == tunnel->allocated_up &&
1892	allocate_down == tunnel->allocated_down)
1893	return;
1894
1895	ret = usb4_usb3_port_allocate_bandwidth(port: tunnel->src_port, upstream_bw: &allocate_up,
1896	downstream_bw: &allocate_down);
1897	if (ret) {
1898	tb_tunnel_info(tunnel, "failed to allocate bandwidth\n");
1899	return;
1900	}
1901
1902	tunnel->allocated_up = allocate_up;
1903	*available_up -= tunnel->allocated_up;
1904
1905	tunnel->allocated_down = allocate_down;
1906	*available_down -= tunnel->allocated_down;
1907
1908	tb_tunnel_dbg(tunnel, "increased bandwidth allocation to %d/%d Mb/s\n",
1909	tunnel->allocated_up, tunnel->allocated_down);
1910	}
1911
1912	static void tb_usb3_init_credits(struct tb_path_hop *hop)
1913	{
1914	struct tb_port *port = hop->in_port;
1915	struct tb_switch *sw = port->sw;
1916	unsigned int credits;
1917
1918	if (tb_port_use_credit_allocation(port)) {
1919	credits = sw->max_usb3_credits;
1920	} else {
1921	if (tb_port_is_null(port))
1922	credits = port->bonded ? 32 : 16;
1923	else
1924	credits = 7;
1925	}
1926
1927	hop->initial_credits = credits;
1928	}
1929
1930	static void tb_usb3_init_path(struct tb_path *path)
1931	{
1932	struct tb_path_hop *hop;
1933
1934	path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
1935	path->egress_shared_buffer = TB_PATH_NONE;
1936	path->ingress_fc_enable = TB_PATH_ALL;
1937	path->ingress_shared_buffer = TB_PATH_NONE;
1938	path->priority = TB_USB3_PRIORITY;
1939	path->weight = TB_USB3_WEIGHT;
1940	path->drop_packages = 0;
1941
1942	tb_path_for_each_hop(path, hop)
1943	tb_usb3_init_credits(hop);
1944	}
1945
1946	/**
1947	* tb_tunnel_discover_usb3() - Discover existing USB3 tunnels
1948	* @tb: Pointer to the domain structure
1949	* @down: USB3 downstream adapter
1950	* @alloc_hopid: Allocate HopIDs from visited ports
1951	*
1952	* If @down adapter is active, follows the tunnel to the USB3 upstream
1953	* adapter and back. Returns the discovered tunnel or %NULL if there was
1954	* no tunnel.
1955	*/
1956	struct tb_tunnel *tb_tunnel_discover_usb3(struct tb *tb, struct tb_port *down,
1957	bool alloc_hopid)
1958	{
1959	struct tb_tunnel *tunnel;
1960	struct tb_path *path;
1961
1962	if (!tb_usb3_port_is_enabled(port: down))
1963	return NULL;
1964
1965	tunnel = tb_tunnel_alloc(tb, npaths: 2, type: TB_TUNNEL_USB3);
1966	if (!tunnel)
1967	return NULL;
1968
1969	tunnel->activate = tb_usb3_activate;
1970	tunnel->src_port = down;
1971
1972	/*
1973	* Discover both paths even if they are not complete. We will
1974	* clean them up by calling tb_tunnel_deactivate() below in that
1975	* case.
1976	*/
1977	path = tb_path_discover(src: down, TB_USB3_HOPID, NULL, dst_hopid: -1,
1978	last: &tunnel->dst_port, name: "USB3 Down", alloc_hopid);
1979	if (!path) {
1980	/* Just disable the downstream port */
1981	tb_usb3_port_enable(port: down, enable: false);
1982	goto err_free;
1983	}
1984	tunnel->paths[TB_USB3_PATH_DOWN] = path;
1985	tb_usb3_init_path(path: tunnel->paths[TB_USB3_PATH_DOWN]);
1986
1987	path = tb_path_discover(src: tunnel->dst_port, src_hopid: -1, dst: down, TB_USB3_HOPID, NULL,
1988	name: "USB3 Up", alloc_hopid);
1989	if (!path)
1990	goto err_deactivate;
1991	tunnel->paths[TB_USB3_PATH_UP] = path;
1992	tb_usb3_init_path(path: tunnel->paths[TB_USB3_PATH_UP]);
1993
1994	/* Validate that the tunnel is complete */
1995	if (!tb_port_is_usb3_up(port: tunnel->dst_port)) {
1996	tb_port_warn(tunnel->dst_port,
1997	"path does not end on an USB3 adapter, cleaning up\n");
1998	goto err_deactivate;
1999	}
2000
2001	if (down != tunnel->src_port) {
2002	tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");
2003	goto err_deactivate;
2004	}
2005
2006	if (!tb_usb3_port_is_enabled(port: tunnel->dst_port)) {
2007	tb_tunnel_warn(tunnel,
2008	"tunnel is not fully activated, cleaning up\n");
2009	goto err_deactivate;
2010	}
2011
2012	if (!tb_route(sw: down->sw)) {
2013	int ret;
2014
2015	/*
2016	* Read the initial bandwidth allocation for the first
2017	* hop tunnel.
2018	*/
2019	ret = usb4_usb3_port_allocated_bandwidth(port: down,
2020	upstream_bw: &tunnel->allocated_up, downstream_bw: &tunnel->allocated_down);
2021	if (ret)
2022	goto err_deactivate;
2023
2024	tb_tunnel_dbg(tunnel, "currently allocated bandwidth %d/%d Mb/s\n",
2025	tunnel->allocated_up, tunnel->allocated_down);
2026
2027	tunnel->init = tb_usb3_init;
2028	tunnel->consumed_bandwidth = tb_usb3_consumed_bandwidth;
2029	tunnel->release_unused_bandwidth =
2030	tb_usb3_release_unused_bandwidth;
2031	tunnel->reclaim_available_bandwidth =
2032	tb_usb3_reclaim_available_bandwidth;
2033	}
2034
2035	tb_tunnel_dbg(tunnel, "discovered\n");
2036	return tunnel;
2037
2038	err_deactivate:
2039	tb_tunnel_deactivate(tunnel);
2040	err_free:
2041	tb_tunnel_free(tunnel);
2042
2043	return NULL;
2044	}
2045
2046	/**
2047	* tb_tunnel_alloc_usb3() - allocate a USB3 tunnel
2048	* @tb: Pointer to the domain structure
2049	* @up: USB3 upstream adapter port
2050	* @down: USB3 downstream adapter port
2051	* @max_up: Maximum available upstream bandwidth for the USB3 tunnel (%0
2052	* if not limited).
2053	* @max_down: Maximum available downstream bandwidth for the USB3 tunnel
2054	* (%0 if not limited).
2055	*
2056	* Allocate an USB3 tunnel. The ports must be of type @TB_TYPE_USB3_UP and
2057	* @TB_TYPE_USB3_DOWN.
2058	*
2059	* Return: Returns a tb_tunnel on success or %NULL on failure.
2060	*/
2061	struct tb_tunnel *tb_tunnel_alloc_usb3(struct tb *tb, struct tb_port *up,
2062	struct tb_port *down, int max_up,
2063	int max_down)
2064	{
2065	struct tb_tunnel *tunnel;
2066	struct tb_path *path;
2067	int max_rate = 0;
2068
2069	/*
2070	* Check that we have enough bandwidth available for the new
2071	* USB3 tunnel.
2072	*/
2073	if (max_up > 0 || max_down > 0) {
2074	max_rate = tb_usb3_max_link_rate(up: down, down: up);
2075	if (max_rate < 0)
2076	return NULL;
2077
2078	/* Only 90% can be allocated for USB3 isochronous transfers */
2079	max_rate = max_rate * 90 / 100;
2080	tb_port_dbg(up, "required bandwidth for USB3 tunnel %d Mb/s\n",
2081	max_rate);
2082
2083	if (max_rate > max_up || max_rate > max_down) {
2084	tb_port_warn(up, "not enough bandwidth for USB3 tunnel\n");
2085	return NULL;
2086	}
2087	}
2088
2089	tunnel = tb_tunnel_alloc(tb, npaths: 2, type: TB_TUNNEL_USB3);
2090	if (!tunnel)
2091	return NULL;
2092
2093	tunnel->activate = tb_usb3_activate;
2094	tunnel->src_port = down;
2095	tunnel->dst_port = up;
2096	tunnel->max_up = max_up;
2097	tunnel->max_down = max_down;
2098
2099	path = tb_path_alloc(tb, src: down, TB_USB3_HOPID, dst: up, TB_USB3_HOPID, link_nr: 0,
2100	name: "USB3 Down");
2101	if (!path) {
2102	tb_tunnel_free(tunnel);
2103	return NULL;
2104	}
2105	tb_usb3_init_path(path);
2106	tunnel->paths[TB_USB3_PATH_DOWN] = path;
2107
2108	path = tb_path_alloc(tb, src: up, TB_USB3_HOPID, dst: down, TB_USB3_HOPID, link_nr: 0,
2109	name: "USB3 Up");
2110	if (!path) {
2111	tb_tunnel_free(tunnel);
2112	return NULL;
2113	}
2114	tb_usb3_init_path(path);
2115	tunnel->paths[TB_USB3_PATH_UP] = path;
2116
2117	if (!tb_route(sw: down->sw)) {
2118	tunnel->allocated_up = max_rate;
2119	tunnel->allocated_down = max_rate;
2120
2121	tunnel->init = tb_usb3_init;
2122	tunnel->consumed_bandwidth = tb_usb3_consumed_bandwidth;
2123	tunnel->release_unused_bandwidth =
2124	tb_usb3_release_unused_bandwidth;
2125	tunnel->reclaim_available_bandwidth =
2126	tb_usb3_reclaim_available_bandwidth;
2127	}
2128
2129	return tunnel;
2130	}
2131
2132	/**
2133	* tb_tunnel_free() - free a tunnel
2134	* @tunnel: Tunnel to be freed
2135	*
2136	* Frees a tunnel. The tunnel does not need to be deactivated.
2137	*/
2138	void tb_tunnel_free(struct tb_tunnel *tunnel)
2139	{
2140	int i;
2141
2142	if (!tunnel)
2143	return;
2144
2145	if (tunnel->deinit)
2146	tunnel->deinit(tunnel);
2147
2148	for (i = 0; i < tunnel->npaths; i++) {
2149	if (tunnel->paths[i])
2150	tb_path_free(path: tunnel->paths[i]);
2151	}
2152
2153	kfree(objp: tunnel->paths);
2154	kfree(objp: tunnel);
2155	}
2156
2157	/**
2158	* tb_tunnel_is_invalid - check whether an activated path is still valid
2159	* @tunnel: Tunnel to check
2160	*/
2161	bool tb_tunnel_is_invalid(struct tb_tunnel *tunnel)
2162	{
2163	int i;
2164
2165	for (i = 0; i < tunnel->npaths; i++) {
2166	WARN_ON(!tunnel->paths[i]->activated);
2167	if (tb_path_is_invalid(path: tunnel->paths[i]))
2168	return true;
2169	}
2170
2171	return false;
2172	}
2173
2174	/**
2175	* tb_tunnel_restart() - activate a tunnel after a hardware reset
2176	* @tunnel: Tunnel to restart
2177	*
2178	* Return: 0 on success and negative errno in case if failure
2179	*/
2180	int tb_tunnel_restart(struct tb_tunnel *tunnel)
2181	{
2182	int res, i;
2183
2184	tb_tunnel_dbg(tunnel, "activating\n");
2185
2186	/*
2187	* Make sure all paths are properly disabled before enabling
2188	* them again.
2189	*/
2190	for (i = 0; i < tunnel->npaths; i++) {
2191	if (tunnel->paths[i]->activated) {
2192	tb_path_deactivate(path: tunnel->paths[i]);
2193	tunnel->paths[i]->activated = false;
2194	}
2195	}
2196
2197	if (tunnel->init) {
2198	res = tunnel->init(tunnel);
2199	if (res)
2200	return res;
2201	}
2202
2203	for (i = 0; i < tunnel->npaths; i++) {
2204	res = tb_path_activate(path: tunnel->paths[i]);
2205	if (res)
2206	goto err;
2207	}
2208
2209	if (tunnel->activate) {
2210	res = tunnel->activate(tunnel, true);
2211	if (res)
2212	goto err;
2213	}
2214
2215	return 0;
2216
2217	err:
2218	tb_tunnel_warn(tunnel, "activation failed\n");
2219	tb_tunnel_deactivate(tunnel);
2220	return res;
2221	}
2222
2223	/**
2224	* tb_tunnel_activate() - activate a tunnel
2225	* @tunnel: Tunnel to activate
2226	*
2227	* Return: Returns 0 on success or an error code on failure.
2228	*/
2229	int tb_tunnel_activate(struct tb_tunnel *tunnel)
2230	{
2231	int i;
2232
2233	for (i = 0; i < tunnel->npaths; i++) {
2234	if (tunnel->paths[i]->activated) {
2235	tb_tunnel_WARN(tunnel,
2236	"trying to activate an already activated tunnel\n");
2237	return -EINVAL;
2238	}
2239	}
2240
2241	return tb_tunnel_restart(tunnel);
2242	}
2243
2244	/**
2245	* tb_tunnel_deactivate() - deactivate a tunnel
2246	* @tunnel: Tunnel to deactivate
2247	*/
2248	void tb_tunnel_deactivate(struct tb_tunnel *tunnel)
2249	{
2250	int i;
2251
2252	tb_tunnel_dbg(tunnel, "deactivating\n");
2253
2254	if (tunnel->activate)
2255	tunnel->activate(tunnel, false);
2256
2257	for (i = 0; i < tunnel->npaths; i++) {
2258	if (tunnel->paths[i] && tunnel->paths[i]->activated)
2259	tb_path_deactivate(path: tunnel->paths[i]);
2260	}
2261	}
2262
2263	/**
2264	* tb_tunnel_port_on_path() - Does the tunnel go through port
2265	* @tunnel: Tunnel to check
2266	* @port: Port to check
2267	*
2268	* Returns true if @tunnel goes through @port (direction does not matter),
2269	* false otherwise.
2270	*/
2271	bool tb_tunnel_port_on_path(const struct tb_tunnel *tunnel,
2272	const struct tb_port *port)
2273	{
2274	int i;
2275
2276	for (i = 0; i < tunnel->npaths; i++) {
2277	if (!tunnel->paths[i])
2278	continue;
2279
2280	if (tb_path_port_on_path(path: tunnel->paths[i], port))
2281	return true;
2282	}
2283
2284	return false;
2285	}
2286
2287	static bool tb_tunnel_is_active(const struct tb_tunnel *tunnel)
2288	{
2289	int i;
2290
2291	for (i = 0; i < tunnel->npaths; i++) {
2292	if (!tunnel->paths[i])
2293	return false;
2294	if (!tunnel->paths[i]->activated)
2295	return false;
2296	}
2297
2298	return true;
2299	}
2300
2301	/**
2302	* tb_tunnel_maximum_bandwidth() - Return maximum possible bandwidth
2303	* @tunnel: Tunnel to check
2304	* @max_up: Maximum upstream bandwidth in Mb/s
2305	* @max_down: Maximum downstream bandwidth in Mb/s
2306	*
2307	* Returns maximum possible bandwidth this tunnel can go if not limited
2308	* by other bandwidth clients. If the tunnel does not support this
2309	* returns %-EOPNOTSUPP.
2310	*/
2311	int tb_tunnel_maximum_bandwidth(struct tb_tunnel *tunnel, int *max_up,
2312	int *max_down)
2313	{
2314	if (!tb_tunnel_is_active(tunnel))
2315	return -EINVAL;
2316
2317	if (tunnel->maximum_bandwidth)
2318	return tunnel->maximum_bandwidth(tunnel, max_up, max_down);
2319	return -EOPNOTSUPP;
2320	}
2321
2322	/**
2323	* tb_tunnel_allocated_bandwidth() - Return bandwidth allocated for the tunnel
2324	* @tunnel: Tunnel to check
2325	* @allocated_up: Currently allocated upstream bandwidth in Mb/s is stored here
2326	* @allocated_down: Currently allocated downstream bandwidth in Mb/s is
2327	* stored here
2328	*
2329	* Returns the bandwidth allocated for the tunnel. This may be higher
2330	* than what the tunnel actually consumes.
2331	*/
2332	int tb_tunnel_allocated_bandwidth(struct tb_tunnel *tunnel, int *allocated_up,
2333	int *allocated_down)
2334	{
2335	if (!tb_tunnel_is_active(tunnel))
2336	return -EINVAL;
2337
2338	if (tunnel->allocated_bandwidth)
2339	return tunnel->allocated_bandwidth(tunnel, allocated_up,
2340	allocated_down);
2341	return -EOPNOTSUPP;
2342	}
2343
2344	/**
2345	* tb_tunnel_alloc_bandwidth() - Change tunnel bandwidth allocation
2346	* @tunnel: Tunnel whose bandwidth allocation to change
2347	* @alloc_up: New upstream bandwidth in Mb/s
2348	* @alloc_down: New downstream bandwidth in Mb/s
2349	*
2350	* Tries to change tunnel bandwidth allocation. If succeeds returns %0
2351	* and updates @alloc_up and @alloc_down to that was actually allocated
2352	* (it may not be the same as passed originally). Returns negative errno
2353	* in case of failure.
2354	*/
2355	int tb_tunnel_alloc_bandwidth(struct tb_tunnel *tunnel, int *alloc_up,
2356	int *alloc_down)
2357	{
2358	if (!tb_tunnel_is_active(tunnel))
2359	return -EINVAL;
2360
2361	if (tunnel->alloc_bandwidth)
2362	return tunnel->alloc_bandwidth(tunnel, alloc_up, alloc_down);
2363
2364	return -EOPNOTSUPP;
2365	}
2366
2367	/**
2368	* tb_tunnel_consumed_bandwidth() - Return bandwidth consumed by the tunnel
2369	* @tunnel: Tunnel to check
2370	* @consumed_up: Consumed bandwidth in Mb/s from @dst_port to @src_port.
2371	* Can be %NULL.
2372	* @consumed_down: Consumed bandwidth in Mb/s from @src_port to @dst_port.
2373	* Can be %NULL.
2374	*
2375	* Stores the amount of isochronous bandwidth @tunnel consumes in
2376	* @consumed_up and @consumed_down. In case of success returns %0,
2377	* negative errno otherwise.
2378	*/
2379	int tb_tunnel_consumed_bandwidth(struct tb_tunnel *tunnel, int *consumed_up,
2380	int *consumed_down)
2381	{
2382	int up_bw = 0, down_bw = 0;
2383
2384	if (!tb_tunnel_is_active(tunnel))
2385	goto out;
2386
2387	if (tunnel->consumed_bandwidth) {
2388	int ret;
2389
2390	ret = tunnel->consumed_bandwidth(tunnel, &up_bw, &down_bw);
2391	if (ret)
2392	return ret;
2393
2394	tb_tunnel_dbg(tunnel, "consumed bandwidth %d/%d Mb/s\n", up_bw,
2395	down_bw);
2396	}
2397
2398	out:
2399	if (consumed_up)
2400	*consumed_up = up_bw;
2401	if (consumed_down)
2402	*consumed_down = down_bw;
2403
2404	return 0;
2405	}
2406
2407	/**
2408	* tb_tunnel_release_unused_bandwidth() - Release unused bandwidth
2409	* @tunnel: Tunnel whose unused bandwidth to release
2410	*
2411	* If tunnel supports dynamic bandwidth management (USB3 tunnels at the
2412	* moment) this function makes it to release all the unused bandwidth.
2413	*
2414	* Returns %0 in case of success and negative errno otherwise.
2415	*/
2416	int tb_tunnel_release_unused_bandwidth(struct tb_tunnel *tunnel)
2417	{
2418	if (!tb_tunnel_is_active(tunnel))
2419	return 0;
2420
2421	if (tunnel->release_unused_bandwidth) {
2422	int ret;
2423
2424	ret = tunnel->release_unused_bandwidth(tunnel);
2425	if (ret)
2426	return ret;
2427	}
2428
2429	return 0;
2430	}
2431
2432	/**
2433	* tb_tunnel_reclaim_available_bandwidth() - Reclaim available bandwidth
2434	* @tunnel: Tunnel reclaiming available bandwidth
2435	* @available_up: Available upstream bandwidth (in Mb/s)
2436	* @available_down: Available downstream bandwidth (in Mb/s)
2437	*
2438	* Reclaims bandwidth from @available_up and @available_down and updates
2439	* the variables accordingly (e.g decreases both according to what was
2440	* reclaimed by the tunnel). If nothing was reclaimed the values are
2441	* kept as is.
2442	*/
2443	void tb_tunnel_reclaim_available_bandwidth(struct tb_tunnel *tunnel,
2444	int *available_up,
2445	int *available_down)
2446	{
2447	if (!tb_tunnel_is_active(tunnel))
2448	return;
2449
2450	if (tunnel->reclaim_available_bandwidth)
2451	tunnel->reclaim_available_bandwidth(tunnel, available_up,
2452	available_down);
2453	}
2454
2455	const char *tb_tunnel_type_name(const struct tb_tunnel *tunnel)
2456	{
2457	return tb_tunnel_names[tunnel->type];
2458	}
2459