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 /* USB3 adapters use always HopID of 8 for both directions */
25 #define TB_USB3_HOPID			8
26 
27 #define TB_USB3_PATH_DOWN		0
28 #define TB_USB3_PATH_UP			1
29 
30 /* DP adapters use HopID 8 for AUX and 9 for Video */
31 #define TB_DP_AUX_TX_HOPID		8
32 #define TB_DP_AUX_RX_HOPID		8
33 #define TB_DP_VIDEO_HOPID		9
34 
35 #define TB_DP_VIDEO_PATH_OUT		0
36 #define TB_DP_AUX_PATH_OUT		1
37 #define TB_DP_AUX_PATH_IN		2
38 
39 /* Minimum number of credits needed for PCIe path */
40 #define TB_MIN_PCIE_CREDITS		6U
41 /*
42  * Number of credits we try to allocate for each DMA path if not limited
43  * by the host router baMaxHI.
44  */
45 #define TB_DMA_CREDITS			14
46 /* Minimum number of credits for DMA path */
47 #define TB_MIN_DMA_CREDITS		1
48 
49 static unsigned int dma_credits = TB_DMA_CREDITS;
50 module_param(dma_credits, uint, 0444);
51 MODULE_PARM_DESC(dma_credits, "specify custom credits for DMA tunnels (default: "
52                 __MODULE_STRING(TB_DMA_CREDITS) ")");
53 
54 static bool bw_alloc_mode = true;
55 module_param(bw_alloc_mode, bool, 0444);
56 MODULE_PARM_DESC(bw_alloc_mode,
57 		 "enable bandwidth allocation mode if supported (default: true)");
58 
59 static const char * const tb_tunnel_names[] = { "PCI", "DP", "DMA", "USB3" };
60 
61 #define __TB_TUNNEL_PRINT(level, tunnel, fmt, arg...)                   \
62 	do {                                                            \
63 		struct tb_tunnel *__tunnel = (tunnel);                  \
64 		level(__tunnel->tb, "%llx:%u <-> %llx:%u (%s): " fmt,   \
65 		      tb_route(__tunnel->src_port->sw),                 \
66 		      __tunnel->src_port->port,                         \
67 		      tb_route(__tunnel->dst_port->sw),                 \
68 		      __tunnel->dst_port->port,                         \
69 		      tb_tunnel_names[__tunnel->type],			\
70 		      ## arg);                                          \
71 	} while (0)
72 
73 #define tb_tunnel_WARN(tunnel, fmt, arg...) \
74 	__TB_TUNNEL_PRINT(tb_WARN, tunnel, fmt, ##arg)
75 #define tb_tunnel_warn(tunnel, fmt, arg...) \
76 	__TB_TUNNEL_PRINT(tb_warn, tunnel, fmt, ##arg)
77 #define tb_tunnel_info(tunnel, fmt, arg...) \
78 	__TB_TUNNEL_PRINT(tb_info, tunnel, fmt, ##arg)
79 #define tb_tunnel_dbg(tunnel, fmt, arg...) \
80 	__TB_TUNNEL_PRINT(tb_dbg, tunnel, fmt, ##arg)
81 
tb_usable_credits(const struct tb_port * port)82 static inline unsigned int tb_usable_credits(const struct tb_port *port)
83 {
84 	return port->total_credits - port->ctl_credits;
85 }
86 
87 /**
88  * tb_available_credits() - Available credits for PCIe and DMA
89  * @port: Lane adapter to check
90  * @max_dp_streams: If non-%NULL stores maximum number of simultaneous DP
91  *		    streams possible through this lane adapter
92  */
tb_available_credits(const struct tb_port * port,size_t * max_dp_streams)93 static unsigned int tb_available_credits(const struct tb_port *port,
94 					 size_t *max_dp_streams)
95 {
96 	const struct tb_switch *sw = port->sw;
97 	int credits, usb3, pcie, spare;
98 	size_t ndp;
99 
100 	usb3 = tb_acpi_may_tunnel_usb3() ? sw->max_usb3_credits : 0;
101 	pcie = tb_acpi_may_tunnel_pcie() ? sw->max_pcie_credits : 0;
102 
103 	if (tb_acpi_is_xdomain_allowed()) {
104 		spare = min_not_zero(sw->max_dma_credits, dma_credits);
105 		/* Add some credits for potential second DMA tunnel */
106 		spare += TB_MIN_DMA_CREDITS;
107 	} else {
108 		spare = 0;
109 	}
110 
111 	credits = tb_usable_credits(port);
112 	if (tb_acpi_may_tunnel_dp()) {
113 		/*
114 		 * Maximum number of DP streams possible through the
115 		 * lane adapter.
116 		 */
117 		if (sw->min_dp_aux_credits + sw->min_dp_main_credits)
118 			ndp = (credits - (usb3 + pcie + spare)) /
119 			      (sw->min_dp_aux_credits + sw->min_dp_main_credits);
120 		else
121 			ndp = 0;
122 	} else {
123 		ndp = 0;
124 	}
125 	credits -= ndp * (sw->min_dp_aux_credits + sw->min_dp_main_credits);
126 	credits -= usb3;
127 
128 	if (max_dp_streams)
129 		*max_dp_streams = ndp;
130 
131 	return credits > 0 ? credits : 0;
132 }
133 
tb_tunnel_alloc(struct tb * tb,size_t npaths,enum tb_tunnel_type type)134 static struct tb_tunnel *tb_tunnel_alloc(struct tb *tb, size_t npaths,
135 					 enum tb_tunnel_type type)
136 {
137 	struct tb_tunnel *tunnel;
138 
139 	tunnel = kzalloc(sizeof(*tunnel), GFP_KERNEL);
140 	if (!tunnel)
141 		return NULL;
142 
143 	tunnel->paths = kcalloc(npaths, sizeof(tunnel->paths[0]), GFP_KERNEL);
144 	if (!tunnel->paths) {
145 		tb_tunnel_free(tunnel);
146 		return NULL;
147 	}
148 
149 	INIT_LIST_HEAD(&tunnel->list);
150 	tunnel->tb = tb;
151 	tunnel->npaths = npaths;
152 	tunnel->type = type;
153 
154 	return tunnel;
155 }
156 
tb_pci_set_ext_encapsulation(struct tb_tunnel * tunnel,bool enable)157 static int tb_pci_set_ext_encapsulation(struct tb_tunnel *tunnel, bool enable)
158 {
159 	int ret;
160 
161 	/* Only supported of both routers are at least USB4 v2 */
162 	if (usb4_switch_version(tunnel->src_port->sw) < 2 ||
163 	    usb4_switch_version(tunnel->dst_port->sw) < 2)
164 		return 0;
165 
166 	ret = usb4_pci_port_set_ext_encapsulation(tunnel->src_port, enable);
167 	if (ret)
168 		return ret;
169 
170 	ret = usb4_pci_port_set_ext_encapsulation(tunnel->dst_port, enable);
171 	if (ret)
172 		return ret;
173 
174 	tb_tunnel_dbg(tunnel, "extended encapsulation %s\n",
175 		      str_enabled_disabled(enable));
176 	return 0;
177 }
178 
tb_pci_activate(struct tb_tunnel * tunnel,bool activate)179 static int tb_pci_activate(struct tb_tunnel *tunnel, bool activate)
180 {
181 	int res;
182 
183 	if (activate) {
184 		res = tb_pci_set_ext_encapsulation(tunnel, activate);
185 		if (res)
186 			return res;
187 	}
188 
189 	res = tb_pci_port_enable(tunnel->src_port, activate);
190 	if (res)
191 		return res;
192 
193 	if (tb_port_is_pcie_up(tunnel->dst_port)) {
194 		res = tb_pci_port_enable(tunnel->dst_port, activate);
195 		if (res)
196 			return res;
197 	}
198 
199 	return activate ? 0 : tb_pci_set_ext_encapsulation(tunnel, activate);
200 }
201 
tb_pci_init_credits(struct tb_path_hop * hop)202 static int tb_pci_init_credits(struct tb_path_hop *hop)
203 {
204 	struct tb_port *port = hop->in_port;
205 	struct tb_switch *sw = port->sw;
206 	unsigned int credits;
207 
208 	if (tb_port_use_credit_allocation(port)) {
209 		unsigned int available;
210 
211 		available = tb_available_credits(port, NULL);
212 		credits = min(sw->max_pcie_credits, available);
213 
214 		if (credits < TB_MIN_PCIE_CREDITS)
215 			return -ENOSPC;
216 
217 		credits = max(TB_MIN_PCIE_CREDITS, credits);
218 	} else {
219 		if (tb_port_is_null(port))
220 			credits = port->bonded ? 32 : 16;
221 		else
222 			credits = 7;
223 	}
224 
225 	hop->initial_credits = credits;
226 	return 0;
227 }
228 
tb_pci_init_path(struct tb_path * path)229 static int tb_pci_init_path(struct tb_path *path)
230 {
231 	struct tb_path_hop *hop;
232 
233 	path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
234 	path->egress_shared_buffer = TB_PATH_NONE;
235 	path->ingress_fc_enable = TB_PATH_ALL;
236 	path->ingress_shared_buffer = TB_PATH_NONE;
237 	path->priority = 3;
238 	path->weight = 1;
239 	path->drop_packages = 0;
240 
241 	tb_path_for_each_hop(path, hop) {
242 		int ret;
243 
244 		ret = tb_pci_init_credits(hop);
245 		if (ret)
246 			return ret;
247 	}
248 
249 	return 0;
250 }
251 
252 /**
253  * tb_tunnel_discover_pci() - Discover existing PCIe tunnels
254  * @tb: Pointer to the domain structure
255  * @down: PCIe downstream adapter
256  * @alloc_hopid: Allocate HopIDs from visited ports
257  *
258  * If @down adapter is active, follows the tunnel to the PCIe upstream
259  * adapter and back. Returns the discovered tunnel or %NULL if there was
260  * no tunnel.
261  */
tb_tunnel_discover_pci(struct tb * tb,struct tb_port * down,bool alloc_hopid)262 struct tb_tunnel *tb_tunnel_discover_pci(struct tb *tb, struct tb_port *down,
263 					 bool alloc_hopid)
264 {
265 	struct tb_tunnel *tunnel;
266 	struct tb_path *path;
267 
268 	if (!tb_pci_port_is_enabled(down))
269 		return NULL;
270 
271 	tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_PCI);
272 	if (!tunnel)
273 		return NULL;
274 
275 	tunnel->activate = tb_pci_activate;
276 	tunnel->src_port = down;
277 
278 	/*
279 	 * Discover both paths even if they are not complete. We will
280 	 * clean them up by calling tb_tunnel_deactivate() below in that
281 	 * case.
282 	 */
283 	path = tb_path_discover(down, TB_PCI_HOPID, NULL, -1,
284 				&tunnel->dst_port, "PCIe Up", alloc_hopid);
285 	if (!path) {
286 		/* Just disable the downstream port */
287 		tb_pci_port_enable(down, false);
288 		goto err_free;
289 	}
290 	tunnel->paths[TB_PCI_PATH_UP] = path;
291 	if (tb_pci_init_path(tunnel->paths[TB_PCI_PATH_UP]))
292 		goto err_free;
293 
294 	path = tb_path_discover(tunnel->dst_port, -1, down, TB_PCI_HOPID, NULL,
295 				"PCIe Down", alloc_hopid);
296 	if (!path)
297 		goto err_deactivate;
298 	tunnel->paths[TB_PCI_PATH_DOWN] = path;
299 	if (tb_pci_init_path(tunnel->paths[TB_PCI_PATH_DOWN]))
300 		goto err_deactivate;
301 
302 	/* Validate that the tunnel is complete */
303 	if (!tb_port_is_pcie_up(tunnel->dst_port)) {
304 		tb_port_warn(tunnel->dst_port,
305 			     "path does not end on a PCIe adapter, cleaning up\n");
306 		goto err_deactivate;
307 	}
308 
309 	if (down != tunnel->src_port) {
310 		tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");
311 		goto err_deactivate;
312 	}
313 
314 	if (!tb_pci_port_is_enabled(tunnel->dst_port)) {
315 		tb_tunnel_warn(tunnel,
316 			       "tunnel is not fully activated, cleaning up\n");
317 		goto err_deactivate;
318 	}
319 
320 	tb_tunnel_dbg(tunnel, "discovered\n");
321 	return tunnel;
322 
323 err_deactivate:
324 	tb_tunnel_deactivate(tunnel);
325 err_free:
326 	tb_tunnel_free(tunnel);
327 
328 	return NULL;
329 }
330 
331 /**
332  * tb_tunnel_alloc_pci() - allocate a pci tunnel
333  * @tb: Pointer to the domain structure
334  * @up: PCIe upstream adapter port
335  * @down: PCIe downstream adapter port
336  *
337  * Allocate a PCI tunnel. The ports must be of type TB_TYPE_PCIE_UP and
338  * TB_TYPE_PCIE_DOWN.
339  *
340  * Return: Returns a tb_tunnel on success or NULL on failure.
341  */
tb_tunnel_alloc_pci(struct tb * tb,struct tb_port * up,struct tb_port * down)342 struct tb_tunnel *tb_tunnel_alloc_pci(struct tb *tb, struct tb_port *up,
343 				      struct tb_port *down)
344 {
345 	struct tb_tunnel *tunnel;
346 	struct tb_path *path;
347 
348 	tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_PCI);
349 	if (!tunnel)
350 		return NULL;
351 
352 	tunnel->activate = tb_pci_activate;
353 	tunnel->src_port = down;
354 	tunnel->dst_port = up;
355 
356 	path = tb_path_alloc(tb, down, TB_PCI_HOPID, up, TB_PCI_HOPID, 0,
357 			     "PCIe Down");
358 	if (!path)
359 		goto err_free;
360 	tunnel->paths[TB_PCI_PATH_DOWN] = path;
361 	if (tb_pci_init_path(path))
362 		goto err_free;
363 
364 	path = tb_path_alloc(tb, up, TB_PCI_HOPID, down, TB_PCI_HOPID, 0,
365 			     "PCIe Up");
366 	if (!path)
367 		goto err_free;
368 	tunnel->paths[TB_PCI_PATH_UP] = path;
369 	if (tb_pci_init_path(path))
370 		goto err_free;
371 
372 	return tunnel;
373 
374 err_free:
375 	tb_tunnel_free(tunnel);
376 	return NULL;
377 }
378 
tb_dp_is_usb4(const struct tb_switch * sw)379 static bool tb_dp_is_usb4(const struct tb_switch *sw)
380 {
381 	/* Titan Ridge DP adapters need the same treatment as USB4 */
382 	return tb_switch_is_usb4(sw) || tb_switch_is_titan_ridge(sw);
383 }
384 
tb_dp_cm_handshake(struct tb_port * in,struct tb_port * out,int timeout_msec)385 static int tb_dp_cm_handshake(struct tb_port *in, struct tb_port *out,
386 			      int timeout_msec)
387 {
388 	ktime_t timeout = ktime_add_ms(ktime_get(), timeout_msec);
389 	u32 val;
390 	int ret;
391 
392 	/* Both ends need to support this */
393 	if (!tb_dp_is_usb4(in->sw) || !tb_dp_is_usb4(out->sw))
394 		return 0;
395 
396 	ret = tb_port_read(out, &val, TB_CFG_PORT,
397 			   out->cap_adap + DP_STATUS_CTRL, 1);
398 	if (ret)
399 		return ret;
400 
401 	val |= DP_STATUS_CTRL_UF | DP_STATUS_CTRL_CMHS;
402 
403 	ret = tb_port_write(out, &val, TB_CFG_PORT,
404 			    out->cap_adap + DP_STATUS_CTRL, 1);
405 	if (ret)
406 		return ret;
407 
408 	do {
409 		ret = tb_port_read(out, &val, TB_CFG_PORT,
410 				   out->cap_adap + DP_STATUS_CTRL, 1);
411 		if (ret)
412 			return ret;
413 		if (!(val & DP_STATUS_CTRL_CMHS))
414 			return 0;
415 		usleep_range(100, 150);
416 	} while (ktime_before(ktime_get(), timeout));
417 
418 	return -ETIMEDOUT;
419 }
420 
421 /*
422  * Returns maximum possible rate from capability supporting only DP 2.0
423  * and below. Used when DP BW allocation mode is not enabled.
424  */
tb_dp_cap_get_rate(u32 val)425 static inline u32 tb_dp_cap_get_rate(u32 val)
426 {
427 	u32 rate = (val & DP_COMMON_CAP_RATE_MASK) >> DP_COMMON_CAP_RATE_SHIFT;
428 
429 	switch (rate) {
430 	case DP_COMMON_CAP_RATE_RBR:
431 		return 1620;
432 	case DP_COMMON_CAP_RATE_HBR:
433 		return 2700;
434 	case DP_COMMON_CAP_RATE_HBR2:
435 		return 5400;
436 	case DP_COMMON_CAP_RATE_HBR3:
437 		return 8100;
438 	default:
439 		return 0;
440 	}
441 }
442 
443 /*
444  * Returns maximum possible rate from capability supporting DP 2.1
445  * UHBR20, 13.5 and 10 rates as well. Use only when DP BW allocation
446  * mode is enabled.
447  */
tb_dp_cap_get_rate_ext(u32 val)448 static inline u32 tb_dp_cap_get_rate_ext(u32 val)
449 {
450 	if (val & DP_COMMON_CAP_UHBR20)
451 		return 20000;
452 	else if (val & DP_COMMON_CAP_UHBR13_5)
453 		return 13500;
454 	else if (val & DP_COMMON_CAP_UHBR10)
455 		return 10000;
456 
457 	return tb_dp_cap_get_rate(val);
458 }
459 
tb_dp_is_uhbr_rate(unsigned int rate)460 static inline bool tb_dp_is_uhbr_rate(unsigned int rate)
461 {
462 	return rate >= 10000;
463 }
464 
tb_dp_cap_set_rate(u32 val,u32 rate)465 static inline u32 tb_dp_cap_set_rate(u32 val, u32 rate)
466 {
467 	val &= ~DP_COMMON_CAP_RATE_MASK;
468 	switch (rate) {
469 	default:
470 		WARN(1, "invalid rate %u passed, defaulting to 1620 MB/s\n", rate);
471 		fallthrough;
472 	case 1620:
473 		val |= DP_COMMON_CAP_RATE_RBR << DP_COMMON_CAP_RATE_SHIFT;
474 		break;
475 	case 2700:
476 		val |= DP_COMMON_CAP_RATE_HBR << DP_COMMON_CAP_RATE_SHIFT;
477 		break;
478 	case 5400:
479 		val |= DP_COMMON_CAP_RATE_HBR2 << DP_COMMON_CAP_RATE_SHIFT;
480 		break;
481 	case 8100:
482 		val |= DP_COMMON_CAP_RATE_HBR3 << DP_COMMON_CAP_RATE_SHIFT;
483 		break;
484 	}
485 	return val;
486 }
487 
tb_dp_cap_get_lanes(u32 val)488 static inline u32 tb_dp_cap_get_lanes(u32 val)
489 {
490 	u32 lanes = (val & DP_COMMON_CAP_LANES_MASK) >> DP_COMMON_CAP_LANES_SHIFT;
491 
492 	switch (lanes) {
493 	case DP_COMMON_CAP_1_LANE:
494 		return 1;
495 	case DP_COMMON_CAP_2_LANES:
496 		return 2;
497 	case DP_COMMON_CAP_4_LANES:
498 		return 4;
499 	default:
500 		return 0;
501 	}
502 }
503 
tb_dp_cap_set_lanes(u32 val,u32 lanes)504 static inline u32 tb_dp_cap_set_lanes(u32 val, u32 lanes)
505 {
506 	val &= ~DP_COMMON_CAP_LANES_MASK;
507 	switch (lanes) {
508 	default:
509 		WARN(1, "invalid number of lanes %u passed, defaulting to 1\n",
510 		     lanes);
511 		fallthrough;
512 	case 1:
513 		val |= DP_COMMON_CAP_1_LANE << DP_COMMON_CAP_LANES_SHIFT;
514 		break;
515 	case 2:
516 		val |= DP_COMMON_CAP_2_LANES << DP_COMMON_CAP_LANES_SHIFT;
517 		break;
518 	case 4:
519 		val |= DP_COMMON_CAP_4_LANES << DP_COMMON_CAP_LANES_SHIFT;
520 		break;
521 	}
522 	return val;
523 }
524 
tb_dp_bandwidth(unsigned int rate,unsigned int lanes)525 static unsigned int tb_dp_bandwidth(unsigned int rate, unsigned int lanes)
526 {
527 	/* Tunneling removes the DP 8b/10b 128/132b encoding */
528 	if (tb_dp_is_uhbr_rate(rate))
529 		return rate * lanes * 128 / 132;
530 	return rate * lanes * 8 / 10;
531 }
532 
tb_dp_reduce_bandwidth(int max_bw,u32 in_rate,u32 in_lanes,u32 out_rate,u32 out_lanes,u32 * new_rate,u32 * new_lanes)533 static int tb_dp_reduce_bandwidth(int max_bw, u32 in_rate, u32 in_lanes,
534 				  u32 out_rate, u32 out_lanes, u32 *new_rate,
535 				  u32 *new_lanes)
536 {
537 	static const u32 dp_bw[][2] = {
538 		/* Mb/s, lanes */
539 		{ 8100, 4 }, /* 25920 Mb/s */
540 		{ 5400, 4 }, /* 17280 Mb/s */
541 		{ 8100, 2 }, /* 12960 Mb/s */
542 		{ 2700, 4 }, /* 8640 Mb/s */
543 		{ 5400, 2 }, /* 8640 Mb/s */
544 		{ 8100, 1 }, /* 6480 Mb/s */
545 		{ 1620, 4 }, /* 5184 Mb/s */
546 		{ 5400, 1 }, /* 4320 Mb/s */
547 		{ 2700, 2 }, /* 4320 Mb/s */
548 		{ 1620, 2 }, /* 2592 Mb/s */
549 		{ 2700, 1 }, /* 2160 Mb/s */
550 		{ 1620, 1 }, /* 1296 Mb/s */
551 	};
552 	unsigned int i;
553 
554 	/*
555 	 * Find a combination that can fit into max_bw and does not
556 	 * exceed the maximum rate and lanes supported by the DP OUT and
557 	 * DP IN adapters.
558 	 */
559 	for (i = 0; i < ARRAY_SIZE(dp_bw); i++) {
560 		if (dp_bw[i][0] > out_rate || dp_bw[i][1] > out_lanes)
561 			continue;
562 
563 		if (dp_bw[i][0] > in_rate || dp_bw[i][1] > in_lanes)
564 			continue;
565 
566 		if (tb_dp_bandwidth(dp_bw[i][0], dp_bw[i][1]) <= max_bw) {
567 			*new_rate = dp_bw[i][0];
568 			*new_lanes = dp_bw[i][1];
569 			return 0;
570 		}
571 	}
572 
573 	return -ENOSR;
574 }
575 
tb_dp_xchg_caps(struct tb_tunnel * tunnel)576 static int tb_dp_xchg_caps(struct tb_tunnel *tunnel)
577 {
578 	u32 out_dp_cap, out_rate, out_lanes, in_dp_cap, in_rate, in_lanes, bw;
579 	struct tb_port *out = tunnel->dst_port;
580 	struct tb_port *in = tunnel->src_port;
581 	int ret, max_bw;
582 
583 	/*
584 	 * Copy DP_LOCAL_CAP register to DP_REMOTE_CAP register for
585 	 * newer generation hardware.
586 	 */
587 	if (in->sw->generation < 2 || out->sw->generation < 2)
588 		return 0;
589 
590 	/*
591 	 * Perform connection manager handshake between IN and OUT ports
592 	 * before capabilities exchange can take place.
593 	 */
594 	ret = tb_dp_cm_handshake(in, out, 3000);
595 	if (ret)
596 		return ret;
597 
598 	/* Read both DP_LOCAL_CAP registers */
599 	ret = tb_port_read(in, &in_dp_cap, TB_CFG_PORT,
600 			   in->cap_adap + DP_LOCAL_CAP, 1);
601 	if (ret)
602 		return ret;
603 
604 	ret = tb_port_read(out, &out_dp_cap, TB_CFG_PORT,
605 			   out->cap_adap + DP_LOCAL_CAP, 1);
606 	if (ret)
607 		return ret;
608 
609 	/* Write IN local caps to OUT remote caps */
610 	ret = tb_port_write(out, &in_dp_cap, TB_CFG_PORT,
611 			    out->cap_adap + DP_REMOTE_CAP, 1);
612 	if (ret)
613 		return ret;
614 
615 	in_rate = tb_dp_cap_get_rate(in_dp_cap);
616 	in_lanes = tb_dp_cap_get_lanes(in_dp_cap);
617 	tb_port_dbg(in, "maximum supported bandwidth %u Mb/s x%u = %u Mb/s\n",
618 		    in_rate, in_lanes, tb_dp_bandwidth(in_rate, in_lanes));
619 
620 	/*
621 	 * If the tunnel bandwidth is limited (max_bw is set) then see
622 	 * if we need to reduce bandwidth to fit there.
623 	 */
624 	out_rate = tb_dp_cap_get_rate(out_dp_cap);
625 	out_lanes = tb_dp_cap_get_lanes(out_dp_cap);
626 	bw = tb_dp_bandwidth(out_rate, out_lanes);
627 	tb_port_dbg(out, "maximum supported bandwidth %u Mb/s x%u = %u Mb/s\n",
628 		    out_rate, out_lanes, bw);
629 
630 	if (in->sw->config.depth < out->sw->config.depth)
631 		max_bw = tunnel->max_down;
632 	else
633 		max_bw = tunnel->max_up;
634 
635 	if (max_bw && bw > max_bw) {
636 		u32 new_rate, new_lanes, new_bw;
637 
638 		ret = tb_dp_reduce_bandwidth(max_bw, in_rate, in_lanes,
639 					     out_rate, out_lanes, &new_rate,
640 					     &new_lanes);
641 		if (ret) {
642 			tb_port_info(out, "not enough bandwidth for DP tunnel\n");
643 			return ret;
644 		}
645 
646 		new_bw = tb_dp_bandwidth(new_rate, new_lanes);
647 		tb_port_dbg(out, "bandwidth reduced to %u Mb/s x%u = %u Mb/s\n",
648 			    new_rate, new_lanes, new_bw);
649 
650 		/*
651 		 * Set new rate and number of lanes before writing it to
652 		 * the IN port remote caps.
653 		 */
654 		out_dp_cap = tb_dp_cap_set_rate(out_dp_cap, new_rate);
655 		out_dp_cap = tb_dp_cap_set_lanes(out_dp_cap, new_lanes);
656 	}
657 
658 	/*
659 	 * Titan Ridge does not disable AUX timers when it gets
660 	 * SET_CONFIG with SET_LTTPR_MODE set. This causes problems with
661 	 * DP tunneling.
662 	 */
663 	if (tb_route(out->sw) && tb_switch_is_titan_ridge(out->sw)) {
664 		out_dp_cap |= DP_COMMON_CAP_LTTPR_NS;
665 		tb_port_dbg(out, "disabling LTTPR\n");
666 	}
667 
668 	return tb_port_write(in, &out_dp_cap, TB_CFG_PORT,
669 			     in->cap_adap + DP_REMOTE_CAP, 1);
670 }
671 
tb_dp_bandwidth_alloc_mode_enable(struct tb_tunnel * tunnel)672 static int tb_dp_bandwidth_alloc_mode_enable(struct tb_tunnel *tunnel)
673 {
674 	int ret, estimated_bw, granularity, tmp;
675 	struct tb_port *out = tunnel->dst_port;
676 	struct tb_port *in = tunnel->src_port;
677 	u32 out_dp_cap, out_rate, out_lanes;
678 	u32 in_dp_cap, in_rate, in_lanes;
679 	u32 rate, lanes;
680 
681 	if (!bw_alloc_mode)
682 		return 0;
683 
684 	ret = usb4_dp_port_set_cm_bandwidth_mode_supported(in, true);
685 	if (ret)
686 		return ret;
687 
688 	ret = usb4_dp_port_set_group_id(in, in->group->index);
689 	if (ret)
690 		return ret;
691 
692 	/*
693 	 * Get the non-reduced rate and lanes based on the lowest
694 	 * capability of both adapters.
695 	 */
696 	ret = tb_port_read(in, &in_dp_cap, TB_CFG_PORT,
697 			   in->cap_adap + DP_LOCAL_CAP, 1);
698 	if (ret)
699 		return ret;
700 
701 	ret = tb_port_read(out, &out_dp_cap, TB_CFG_PORT,
702 			   out->cap_adap + DP_LOCAL_CAP, 1);
703 	if (ret)
704 		return ret;
705 
706 	in_rate = tb_dp_cap_get_rate(in_dp_cap);
707 	in_lanes = tb_dp_cap_get_lanes(in_dp_cap);
708 	out_rate = tb_dp_cap_get_rate(out_dp_cap);
709 	out_lanes = tb_dp_cap_get_lanes(out_dp_cap);
710 
711 	rate = min(in_rate, out_rate);
712 	lanes = min(in_lanes, out_lanes);
713 	tmp = tb_dp_bandwidth(rate, lanes);
714 
715 	tb_port_dbg(in, "non-reduced bandwidth %u Mb/s x%u = %u Mb/s\n", rate,
716 		    lanes, tmp);
717 
718 	ret = usb4_dp_port_set_nrd(in, rate, lanes);
719 	if (ret)
720 		return ret;
721 
722 	/*
723 	 * Pick up granularity that supports maximum possible bandwidth.
724 	 * For that we use the UHBR rates too.
725 	 */
726 	in_rate = tb_dp_cap_get_rate_ext(in_dp_cap);
727 	out_rate = tb_dp_cap_get_rate_ext(out_dp_cap);
728 	rate = min(in_rate, out_rate);
729 	tmp = tb_dp_bandwidth(rate, lanes);
730 
731 	tb_port_dbg(in,
732 		    "maximum bandwidth through allocation mode %u Mb/s x%u = %u Mb/s\n",
733 		    rate, lanes, tmp);
734 
735 	for (granularity = 250; tmp / granularity > 255 && granularity <= 1000;
736 	     granularity *= 2)
737 		;
738 
739 	tb_port_dbg(in, "granularity %d Mb/s\n", granularity);
740 
741 	/*
742 	 * Returns -EINVAL if granularity above is outside of the
743 	 * accepted ranges.
744 	 */
745 	ret = usb4_dp_port_set_granularity(in, granularity);
746 	if (ret)
747 		return ret;
748 
749 	/*
750 	 * Bandwidth estimation is pretty much what we have in
751 	 * max_up/down fields. For discovery we just read what the
752 	 * estimation was set to.
753 	 */
754 	if (in->sw->config.depth < out->sw->config.depth)
755 		estimated_bw = tunnel->max_down;
756 	else
757 		estimated_bw = tunnel->max_up;
758 
759 	tb_port_dbg(in, "estimated bandwidth %d Mb/s\n", estimated_bw);
760 
761 	ret = usb4_dp_port_set_estimated_bandwidth(in, estimated_bw);
762 	if (ret)
763 		return ret;
764 
765 	/* Initial allocation should be 0 according the spec */
766 	ret = usb4_dp_port_allocate_bandwidth(in, 0);
767 	if (ret)
768 		return ret;
769 
770 	tb_port_dbg(in, "bandwidth allocation mode enabled\n");
771 	return 0;
772 }
773 
tb_dp_init(struct tb_tunnel * tunnel)774 static int tb_dp_init(struct tb_tunnel *tunnel)
775 {
776 	struct tb_port *in = tunnel->src_port;
777 	struct tb_switch *sw = in->sw;
778 	struct tb *tb = in->sw->tb;
779 	int ret;
780 
781 	ret = tb_dp_xchg_caps(tunnel);
782 	if (ret)
783 		return ret;
784 
785 	if (!tb_switch_is_usb4(sw))
786 		return 0;
787 
788 	if (!usb4_dp_port_bandwidth_mode_supported(in))
789 		return 0;
790 
791 	tb_port_dbg(in, "bandwidth allocation mode supported\n");
792 
793 	ret = usb4_dp_port_set_cm_id(in, tb->index);
794 	if (ret)
795 		return ret;
796 
797 	return tb_dp_bandwidth_alloc_mode_enable(tunnel);
798 }
799 
tb_dp_deinit(struct tb_tunnel * tunnel)800 static void tb_dp_deinit(struct tb_tunnel *tunnel)
801 {
802 	struct tb_port *in = tunnel->src_port;
803 
804 	if (!usb4_dp_port_bandwidth_mode_supported(in))
805 		return;
806 	if (usb4_dp_port_bandwidth_mode_enabled(in)) {
807 		usb4_dp_port_set_cm_bandwidth_mode_supported(in, false);
808 		tb_port_dbg(in, "bandwidth allocation mode disabled\n");
809 	}
810 }
811 
tb_dp_activate(struct tb_tunnel * tunnel,bool active)812 static int tb_dp_activate(struct tb_tunnel *tunnel, bool active)
813 {
814 	int ret;
815 
816 	if (active) {
817 		struct tb_path **paths;
818 		int last;
819 
820 		paths = tunnel->paths;
821 		last = paths[TB_DP_VIDEO_PATH_OUT]->path_length - 1;
822 
823 		tb_dp_port_set_hops(tunnel->src_port,
824 			paths[TB_DP_VIDEO_PATH_OUT]->hops[0].in_hop_index,
825 			paths[TB_DP_AUX_PATH_OUT]->hops[0].in_hop_index,
826 			paths[TB_DP_AUX_PATH_IN]->hops[last].next_hop_index);
827 
828 		tb_dp_port_set_hops(tunnel->dst_port,
829 			paths[TB_DP_VIDEO_PATH_OUT]->hops[last].next_hop_index,
830 			paths[TB_DP_AUX_PATH_IN]->hops[0].in_hop_index,
831 			paths[TB_DP_AUX_PATH_OUT]->hops[last].next_hop_index);
832 	} else {
833 		tb_dp_port_hpd_clear(tunnel->src_port);
834 		tb_dp_port_set_hops(tunnel->src_port, 0, 0, 0);
835 		if (tb_port_is_dpout(tunnel->dst_port))
836 			tb_dp_port_set_hops(tunnel->dst_port, 0, 0, 0);
837 	}
838 
839 	ret = tb_dp_port_enable(tunnel->src_port, active);
840 	if (ret)
841 		return ret;
842 
843 	if (tb_port_is_dpout(tunnel->dst_port))
844 		return tb_dp_port_enable(tunnel->dst_port, active);
845 
846 	return 0;
847 }
848 
849 /* max_bw is rounded up to next granularity */
tb_dp_bandwidth_mode_maximum_bandwidth(struct tb_tunnel * tunnel,int * max_bw)850 static int tb_dp_bandwidth_mode_maximum_bandwidth(struct tb_tunnel *tunnel,
851 						  int *max_bw)
852 {
853 	struct tb_port *in = tunnel->src_port;
854 	int ret, rate, lanes, nrd_bw;
855 	u32 cap;
856 
857 	/*
858 	 * DP IN adapter DP_LOCAL_CAP gets updated to the lowest AUX
859 	 * read parameter values so this so we can use this to determine
860 	 * the maximum possible bandwidth over this link.
861 	 *
862 	 * See USB4 v2 spec 1.0 10.4.4.5.
863 	 */
864 	ret = tb_port_read(in, &cap, TB_CFG_PORT,
865 			   in->cap_adap + DP_LOCAL_CAP, 1);
866 	if (ret)
867 		return ret;
868 
869 	rate = tb_dp_cap_get_rate_ext(cap);
870 	if (tb_dp_is_uhbr_rate(rate)) {
871 		/*
872 		 * When UHBR is used there is no reduction in lanes so
873 		 * we can use this directly.
874 		 */
875 		lanes = tb_dp_cap_get_lanes(cap);
876 	} else {
877 		/*
878 		 * If there is no UHBR supported then check the
879 		 * non-reduced rate and lanes.
880 		 */
881 		ret = usb4_dp_port_nrd(in, &rate, &lanes);
882 		if (ret)
883 			return ret;
884 	}
885 
886 	nrd_bw = tb_dp_bandwidth(rate, lanes);
887 
888 	if (max_bw) {
889 		ret = usb4_dp_port_granularity(in);
890 		if (ret < 0)
891 			return ret;
892 		*max_bw = roundup(nrd_bw, ret);
893 	}
894 
895 	return nrd_bw;
896 }
897 
tb_dp_bandwidth_mode_consumed_bandwidth(struct tb_tunnel * tunnel,int * consumed_up,int * consumed_down)898 static int tb_dp_bandwidth_mode_consumed_bandwidth(struct tb_tunnel *tunnel,
899 						   int *consumed_up,
900 						   int *consumed_down)
901 {
902 	struct tb_port *out = tunnel->dst_port;
903 	struct tb_port *in = tunnel->src_port;
904 	int ret, allocated_bw, max_bw;
905 
906 	if (!usb4_dp_port_bandwidth_mode_enabled(in))
907 		return -EOPNOTSUPP;
908 
909 	if (!tunnel->bw_mode)
910 		return -EOPNOTSUPP;
911 
912 	/* Read what was allocated previously if any */
913 	ret = usb4_dp_port_allocated_bandwidth(in);
914 	if (ret < 0)
915 		return ret;
916 	allocated_bw = ret;
917 
918 	ret = tb_dp_bandwidth_mode_maximum_bandwidth(tunnel, &max_bw);
919 	if (ret < 0)
920 		return ret;
921 	if (allocated_bw == max_bw)
922 		allocated_bw = ret;
923 
924 	tb_port_dbg(in, "consumed bandwidth through allocation mode %d Mb/s\n",
925 		    allocated_bw);
926 
927 	if (in->sw->config.depth < out->sw->config.depth) {
928 		*consumed_up = 0;
929 		*consumed_down = allocated_bw;
930 	} else {
931 		*consumed_up = allocated_bw;
932 		*consumed_down = 0;
933 	}
934 
935 	return 0;
936 }
937 
tb_dp_allocated_bandwidth(struct tb_tunnel * tunnel,int * allocated_up,int * allocated_down)938 static int tb_dp_allocated_bandwidth(struct tb_tunnel *tunnel, int *allocated_up,
939 				     int *allocated_down)
940 {
941 	struct tb_port *out = tunnel->dst_port;
942 	struct tb_port *in = tunnel->src_port;
943 
944 	/*
945 	 * If we have already set the allocated bandwidth then use that.
946 	 * Otherwise we read it from the DPRX.
947 	 */
948 	if (usb4_dp_port_bandwidth_mode_enabled(in) && tunnel->bw_mode) {
949 		int ret, allocated_bw, max_bw;
950 
951 		ret = usb4_dp_port_allocated_bandwidth(in);
952 		if (ret < 0)
953 			return ret;
954 		allocated_bw = ret;
955 
956 		ret = tb_dp_bandwidth_mode_maximum_bandwidth(tunnel, &max_bw);
957 		if (ret < 0)
958 			return ret;
959 		if (allocated_bw == max_bw)
960 			allocated_bw = ret;
961 
962 		if (in->sw->config.depth < out->sw->config.depth) {
963 			*allocated_up = 0;
964 			*allocated_down = allocated_bw;
965 		} else {
966 			*allocated_up = allocated_bw;
967 			*allocated_down = 0;
968 		}
969 		return 0;
970 	}
971 
972 	return tunnel->consumed_bandwidth(tunnel, allocated_up,
973 					  allocated_down);
974 }
975 
tb_dp_alloc_bandwidth(struct tb_tunnel * tunnel,int * alloc_up,int * alloc_down)976 static int tb_dp_alloc_bandwidth(struct tb_tunnel *tunnel, int *alloc_up,
977 				 int *alloc_down)
978 {
979 	struct tb_port *out = tunnel->dst_port;
980 	struct tb_port *in = tunnel->src_port;
981 	int max_bw, ret, tmp;
982 
983 	if (!usb4_dp_port_bandwidth_mode_enabled(in))
984 		return -EOPNOTSUPP;
985 
986 	ret = tb_dp_bandwidth_mode_maximum_bandwidth(tunnel, &max_bw);
987 	if (ret < 0)
988 		return ret;
989 
990 	if (in->sw->config.depth < out->sw->config.depth) {
991 		tmp = min(*alloc_down, max_bw);
992 		ret = usb4_dp_port_allocate_bandwidth(in, tmp);
993 		if (ret)
994 			return ret;
995 		*alloc_down = tmp;
996 		*alloc_up = 0;
997 	} else {
998 		tmp = min(*alloc_up, max_bw);
999 		ret = usb4_dp_port_allocate_bandwidth(in, tmp);
1000 		if (ret)
1001 			return ret;
1002 		*alloc_down = 0;
1003 		*alloc_up = tmp;
1004 	}
1005 
1006 	/* Now we can use BW mode registers to figure out the bandwidth */
1007 	/* TODO: need to handle discovery too */
1008 	tunnel->bw_mode = true;
1009 
1010 	tb_port_dbg(in, "allocated bandwidth through allocation mode %d Mb/s\n",
1011 		    tmp);
1012 	return 0;
1013 }
1014 
tb_dp_read_dprx(struct tb_tunnel * tunnel,u32 * rate,u32 * lanes,int timeout_msec)1015 static int tb_dp_read_dprx(struct tb_tunnel *tunnel, u32 *rate, u32 *lanes,
1016 			   int timeout_msec)
1017 {
1018 	ktime_t timeout = ktime_add_ms(ktime_get(), timeout_msec);
1019 	struct tb_port *in = tunnel->src_port;
1020 
1021 	/*
1022 	 * Wait for DPRX done. Normally it should be already set for
1023 	 * active tunnel.
1024 	 */
1025 	do {
1026 		u32 val;
1027 		int ret;
1028 
1029 		ret = tb_port_read(in, &val, TB_CFG_PORT,
1030 				   in->cap_adap + DP_COMMON_CAP, 1);
1031 		if (ret)
1032 			return ret;
1033 
1034 		if (val & DP_COMMON_CAP_DPRX_DONE) {
1035 			*rate = tb_dp_cap_get_rate(val);
1036 			*lanes = tb_dp_cap_get_lanes(val);
1037 
1038 			tb_port_dbg(in, "consumed bandwidth through DPRX %d Mb/s\n",
1039 				    tb_dp_bandwidth(*rate, *lanes));
1040 			return 0;
1041 		}
1042 		usleep_range(100, 150);
1043 	} while (ktime_before(ktime_get(), timeout));
1044 
1045 	return -ETIMEDOUT;
1046 }
1047 
1048 /* Read cap from tunnel DP IN */
tb_dp_read_cap(struct tb_tunnel * tunnel,unsigned int cap,u32 * rate,u32 * lanes)1049 static int tb_dp_read_cap(struct tb_tunnel *tunnel, unsigned int cap, u32 *rate,
1050 			  u32 *lanes)
1051 {
1052 	struct tb_port *in = tunnel->src_port;
1053 	u32 val;
1054 	int ret;
1055 
1056 	switch (cap) {
1057 	case DP_LOCAL_CAP:
1058 	case DP_REMOTE_CAP:
1059 		break;
1060 
1061 	default:
1062 		tb_tunnel_WARN(tunnel, "invalid capability index %#x\n", cap);
1063 		return -EINVAL;
1064 	}
1065 
1066 	/*
1067 	 * Read from the copied remote cap so that we take into account
1068 	 * if capabilities were reduced during exchange.
1069 	 */
1070 	ret = tb_port_read(in, &val, TB_CFG_PORT, in->cap_adap + cap, 1);
1071 	if (ret)
1072 		return ret;
1073 
1074 	*rate = tb_dp_cap_get_rate(val);
1075 	*lanes = tb_dp_cap_get_lanes(val);
1076 
1077 	tb_port_dbg(in, "bandwidth from %#x capability %d Mb/s\n", cap,
1078 		    tb_dp_bandwidth(*rate, *lanes));
1079 	return 0;
1080 }
1081 
tb_dp_maximum_bandwidth(struct tb_tunnel * tunnel,int * max_up,int * max_down)1082 static int tb_dp_maximum_bandwidth(struct tb_tunnel *tunnel, int *max_up,
1083 				   int *max_down)
1084 {
1085 	struct tb_port *in = tunnel->src_port;
1086 	int ret;
1087 
1088 	if (!usb4_dp_port_bandwidth_mode_enabled(in))
1089 		return -EOPNOTSUPP;
1090 
1091 	ret = tb_dp_bandwidth_mode_maximum_bandwidth(tunnel, NULL);
1092 	if (ret < 0)
1093 		return ret;
1094 
1095 	if (in->sw->config.depth < tunnel->dst_port->sw->config.depth) {
1096 		*max_up = 0;
1097 		*max_down = ret;
1098 	} else {
1099 		*max_up = ret;
1100 		*max_down = 0;
1101 	}
1102 
1103 	return 0;
1104 }
1105 
tb_dp_consumed_bandwidth(struct tb_tunnel * tunnel,int * consumed_up,int * consumed_down)1106 static int tb_dp_consumed_bandwidth(struct tb_tunnel *tunnel, int *consumed_up,
1107 				    int *consumed_down)
1108 {
1109 	struct tb_port *in = tunnel->src_port;
1110 	const struct tb_switch *sw = in->sw;
1111 	u32 rate = 0, lanes = 0;
1112 	int ret;
1113 
1114 	if (tb_dp_is_usb4(sw)) {
1115 		/*
1116 		 * On USB4 routers check if the bandwidth allocation
1117 		 * mode is enabled first and then read the bandwidth
1118 		 * through those registers.
1119 		 */
1120 		ret = tb_dp_bandwidth_mode_consumed_bandwidth(tunnel, consumed_up,
1121 							      consumed_down);
1122 		if (ret < 0) {
1123 			if (ret != -EOPNOTSUPP)
1124 				return ret;
1125 		} else if (!ret) {
1126 			return 0;
1127 		}
1128 		/*
1129 		 * Then see if the DPRX negotiation is ready and if yes
1130 		 * return that bandwidth (it may be smaller than the
1131 		 * reduced one). Otherwise return the remote (possibly
1132 		 * reduced) caps.
1133 		 */
1134 		ret = tb_dp_read_dprx(tunnel, &rate, &lanes, 150);
1135 		if (ret) {
1136 			if (ret == -ETIMEDOUT)
1137 				ret = tb_dp_read_cap(tunnel, DP_REMOTE_CAP,
1138 						     &rate, &lanes);
1139 			if (ret)
1140 				return ret;
1141 		}
1142 	} else if (sw->generation >= 2) {
1143 		ret = tb_dp_read_cap(tunnel, DP_REMOTE_CAP, &rate, &lanes);
1144 		if (ret)
1145 			return ret;
1146 	} else {
1147 		/* No bandwidth management for legacy devices  */
1148 		*consumed_up = 0;
1149 		*consumed_down = 0;
1150 		return 0;
1151 	}
1152 
1153 	if (in->sw->config.depth < tunnel->dst_port->sw->config.depth) {
1154 		*consumed_up = 0;
1155 		*consumed_down = tb_dp_bandwidth(rate, lanes);
1156 	} else {
1157 		*consumed_up = tb_dp_bandwidth(rate, lanes);
1158 		*consumed_down = 0;
1159 	}
1160 
1161 	return 0;
1162 }
1163 
tb_dp_init_aux_credits(struct tb_path_hop * hop)1164 static void tb_dp_init_aux_credits(struct tb_path_hop *hop)
1165 {
1166 	struct tb_port *port = hop->in_port;
1167 	struct tb_switch *sw = port->sw;
1168 
1169 	if (tb_port_use_credit_allocation(port))
1170 		hop->initial_credits = sw->min_dp_aux_credits;
1171 	else
1172 		hop->initial_credits = 1;
1173 }
1174 
tb_dp_init_aux_path(struct tb_path * path)1175 static void tb_dp_init_aux_path(struct tb_path *path)
1176 {
1177 	struct tb_path_hop *hop;
1178 
1179 	path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
1180 	path->egress_shared_buffer = TB_PATH_NONE;
1181 	path->ingress_fc_enable = TB_PATH_ALL;
1182 	path->ingress_shared_buffer = TB_PATH_NONE;
1183 	path->priority = 2;
1184 	path->weight = 1;
1185 
1186 	tb_path_for_each_hop(path, hop)
1187 		tb_dp_init_aux_credits(hop);
1188 }
1189 
tb_dp_init_video_credits(struct tb_path_hop * hop)1190 static int tb_dp_init_video_credits(struct tb_path_hop *hop)
1191 {
1192 	struct tb_port *port = hop->in_port;
1193 	struct tb_switch *sw = port->sw;
1194 
1195 	if (tb_port_use_credit_allocation(port)) {
1196 		unsigned int nfc_credits;
1197 		size_t max_dp_streams;
1198 
1199 		tb_available_credits(port, &max_dp_streams);
1200 		/*
1201 		 * Read the number of currently allocated NFC credits
1202 		 * from the lane adapter. Since we only use them for DP
1203 		 * tunneling we can use that to figure out how many DP
1204 		 * tunnels already go through the lane adapter.
1205 		 */
1206 		nfc_credits = port->config.nfc_credits &
1207 				ADP_CS_4_NFC_BUFFERS_MASK;
1208 		if (nfc_credits / sw->min_dp_main_credits > max_dp_streams)
1209 			return -ENOSPC;
1210 
1211 		hop->nfc_credits = sw->min_dp_main_credits;
1212 	} else {
1213 		hop->nfc_credits = min(port->total_credits - 2, 12U);
1214 	}
1215 
1216 	return 0;
1217 }
1218 
tb_dp_init_video_path(struct tb_path * path)1219 static int tb_dp_init_video_path(struct tb_path *path)
1220 {
1221 	struct tb_path_hop *hop;
1222 
1223 	path->egress_fc_enable = TB_PATH_NONE;
1224 	path->egress_shared_buffer = TB_PATH_NONE;
1225 	path->ingress_fc_enable = TB_PATH_NONE;
1226 	path->ingress_shared_buffer = TB_PATH_NONE;
1227 	path->priority = 1;
1228 	path->weight = 1;
1229 
1230 	tb_path_for_each_hop(path, hop) {
1231 		int ret;
1232 
1233 		ret = tb_dp_init_video_credits(hop);
1234 		if (ret)
1235 			return ret;
1236 	}
1237 
1238 	return 0;
1239 }
1240 
tb_dp_dump(struct tb_tunnel * tunnel)1241 static void tb_dp_dump(struct tb_tunnel *tunnel)
1242 {
1243 	struct tb_port *in, *out;
1244 	u32 dp_cap, rate, lanes;
1245 
1246 	in = tunnel->src_port;
1247 	out = tunnel->dst_port;
1248 
1249 	if (tb_port_read(in, &dp_cap, TB_CFG_PORT,
1250 			 in->cap_adap + DP_LOCAL_CAP, 1))
1251 		return;
1252 
1253 	rate = tb_dp_cap_get_rate(dp_cap);
1254 	lanes = tb_dp_cap_get_lanes(dp_cap);
1255 
1256 	tb_port_dbg(in, "maximum supported bandwidth %u Mb/s x%u = %u Mb/s\n",
1257 		    rate, lanes, tb_dp_bandwidth(rate, lanes));
1258 
1259 	out = tunnel->dst_port;
1260 
1261 	if (tb_port_read(out, &dp_cap, TB_CFG_PORT,
1262 			 out->cap_adap + DP_LOCAL_CAP, 1))
1263 		return;
1264 
1265 	rate = tb_dp_cap_get_rate(dp_cap);
1266 	lanes = tb_dp_cap_get_lanes(dp_cap);
1267 
1268 	tb_port_dbg(out, "maximum supported bandwidth %u Mb/s x%u = %u Mb/s\n",
1269 		    rate, lanes, tb_dp_bandwidth(rate, lanes));
1270 
1271 	if (tb_port_read(in, &dp_cap, TB_CFG_PORT,
1272 			 in->cap_adap + DP_REMOTE_CAP, 1))
1273 		return;
1274 
1275 	rate = tb_dp_cap_get_rate(dp_cap);
1276 	lanes = tb_dp_cap_get_lanes(dp_cap);
1277 
1278 	tb_port_dbg(in, "reduced bandwidth %u Mb/s x%u = %u Mb/s\n",
1279 		    rate, lanes, tb_dp_bandwidth(rate, lanes));
1280 }
1281 
1282 /**
1283  * tb_tunnel_discover_dp() - Discover existing Display Port tunnels
1284  * @tb: Pointer to the domain structure
1285  * @in: DP in adapter
1286  * @alloc_hopid: Allocate HopIDs from visited ports
1287  *
1288  * If @in adapter is active, follows the tunnel to the DP out adapter
1289  * and back. Returns the discovered tunnel or %NULL if there was no
1290  * tunnel.
1291  *
1292  * Return: DP tunnel or %NULL if no tunnel found.
1293  */
tb_tunnel_discover_dp(struct tb * tb,struct tb_port * in,bool alloc_hopid)1294 struct tb_tunnel *tb_tunnel_discover_dp(struct tb *tb, struct tb_port *in,
1295 					bool alloc_hopid)
1296 {
1297 	struct tb_tunnel *tunnel;
1298 	struct tb_port *port;
1299 	struct tb_path *path;
1300 
1301 	if (!tb_dp_port_is_enabled(in))
1302 		return NULL;
1303 
1304 	tunnel = tb_tunnel_alloc(tb, 3, TB_TUNNEL_DP);
1305 	if (!tunnel)
1306 		return NULL;
1307 
1308 	tunnel->init = tb_dp_init;
1309 	tunnel->deinit = tb_dp_deinit;
1310 	tunnel->activate = tb_dp_activate;
1311 	tunnel->maximum_bandwidth = tb_dp_maximum_bandwidth;
1312 	tunnel->allocated_bandwidth = tb_dp_allocated_bandwidth;
1313 	tunnel->alloc_bandwidth = tb_dp_alloc_bandwidth;
1314 	tunnel->consumed_bandwidth = tb_dp_consumed_bandwidth;
1315 	tunnel->src_port = in;
1316 
1317 	path = tb_path_discover(in, TB_DP_VIDEO_HOPID, NULL, -1,
1318 				&tunnel->dst_port, "Video", alloc_hopid);
1319 	if (!path) {
1320 		/* Just disable the DP IN port */
1321 		tb_dp_port_enable(in, false);
1322 		goto err_free;
1323 	}
1324 	tunnel->paths[TB_DP_VIDEO_PATH_OUT] = path;
1325 	if (tb_dp_init_video_path(tunnel->paths[TB_DP_VIDEO_PATH_OUT]))
1326 		goto err_free;
1327 
1328 	path = tb_path_discover(in, TB_DP_AUX_TX_HOPID, NULL, -1, NULL, "AUX TX",
1329 				alloc_hopid);
1330 	if (!path)
1331 		goto err_deactivate;
1332 	tunnel->paths[TB_DP_AUX_PATH_OUT] = path;
1333 	tb_dp_init_aux_path(tunnel->paths[TB_DP_AUX_PATH_OUT]);
1334 
1335 	path = tb_path_discover(tunnel->dst_port, -1, in, TB_DP_AUX_RX_HOPID,
1336 				&port, "AUX RX", alloc_hopid);
1337 	if (!path)
1338 		goto err_deactivate;
1339 	tunnel->paths[TB_DP_AUX_PATH_IN] = path;
1340 	tb_dp_init_aux_path(tunnel->paths[TB_DP_AUX_PATH_IN]);
1341 
1342 	/* Validate that the tunnel is complete */
1343 	if (!tb_port_is_dpout(tunnel->dst_port)) {
1344 		tb_port_warn(in, "path does not end on a DP adapter, cleaning up\n");
1345 		goto err_deactivate;
1346 	}
1347 
1348 	if (!tb_dp_port_is_enabled(tunnel->dst_port))
1349 		goto err_deactivate;
1350 
1351 	if (!tb_dp_port_hpd_is_active(tunnel->dst_port))
1352 		goto err_deactivate;
1353 
1354 	if (port != tunnel->src_port) {
1355 		tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");
1356 		goto err_deactivate;
1357 	}
1358 
1359 	tb_dp_dump(tunnel);
1360 
1361 	tb_tunnel_dbg(tunnel, "discovered\n");
1362 	return tunnel;
1363 
1364 err_deactivate:
1365 	tb_tunnel_deactivate(tunnel);
1366 err_free:
1367 	tb_tunnel_free(tunnel);
1368 
1369 	return NULL;
1370 }
1371 
1372 /**
1373  * tb_tunnel_alloc_dp() - allocate a Display Port tunnel
1374  * @tb: Pointer to the domain structure
1375  * @in: DP in adapter port
1376  * @out: DP out adapter port
1377  * @link_nr: Preferred lane adapter when the link is not bonded
1378  * @max_up: Maximum available upstream bandwidth for the DP tunnel (%0
1379  *	    if not limited)
1380  * @max_down: Maximum available downstream bandwidth for the DP tunnel
1381  *	      (%0 if not limited)
1382  *
1383  * Allocates a tunnel between @in and @out that is capable of tunneling
1384  * Display Port traffic.
1385  *
1386  * Return: Returns a tb_tunnel on success or NULL on failure.
1387  */
tb_tunnel_alloc_dp(struct tb * tb,struct tb_port * in,struct tb_port * out,int link_nr,int max_up,int max_down)1388 struct tb_tunnel *tb_tunnel_alloc_dp(struct tb *tb, struct tb_port *in,
1389 				     struct tb_port *out, int link_nr,
1390 				     int max_up, int max_down)
1391 {
1392 	struct tb_tunnel *tunnel;
1393 	struct tb_path **paths;
1394 	struct tb_path *path;
1395 
1396 	if (WARN_ON(!in->cap_adap || !out->cap_adap))
1397 		return NULL;
1398 
1399 	tunnel = tb_tunnel_alloc(tb, 3, TB_TUNNEL_DP);
1400 	if (!tunnel)
1401 		return NULL;
1402 
1403 	tunnel->init = tb_dp_init;
1404 	tunnel->deinit = tb_dp_deinit;
1405 	tunnel->activate = tb_dp_activate;
1406 	tunnel->maximum_bandwidth = tb_dp_maximum_bandwidth;
1407 	tunnel->allocated_bandwidth = tb_dp_allocated_bandwidth;
1408 	tunnel->alloc_bandwidth = tb_dp_alloc_bandwidth;
1409 	tunnel->consumed_bandwidth = tb_dp_consumed_bandwidth;
1410 	tunnel->src_port = in;
1411 	tunnel->dst_port = out;
1412 	tunnel->max_up = max_up;
1413 	tunnel->max_down = max_down;
1414 
1415 	paths = tunnel->paths;
1416 
1417 	path = tb_path_alloc(tb, in, TB_DP_VIDEO_HOPID, out, TB_DP_VIDEO_HOPID,
1418 			     link_nr, "Video");
1419 	if (!path)
1420 		goto err_free;
1421 	tb_dp_init_video_path(path);
1422 	paths[TB_DP_VIDEO_PATH_OUT] = path;
1423 
1424 	path = tb_path_alloc(tb, in, TB_DP_AUX_TX_HOPID, out,
1425 			     TB_DP_AUX_TX_HOPID, link_nr, "AUX TX");
1426 	if (!path)
1427 		goto err_free;
1428 	tb_dp_init_aux_path(path);
1429 	paths[TB_DP_AUX_PATH_OUT] = path;
1430 
1431 	path = tb_path_alloc(tb, out, TB_DP_AUX_RX_HOPID, in,
1432 			     TB_DP_AUX_RX_HOPID, link_nr, "AUX RX");
1433 	if (!path)
1434 		goto err_free;
1435 	tb_dp_init_aux_path(path);
1436 	paths[TB_DP_AUX_PATH_IN] = path;
1437 
1438 	return tunnel;
1439 
1440 err_free:
1441 	tb_tunnel_free(tunnel);
1442 	return NULL;
1443 }
1444 
tb_dma_available_credits(const struct tb_port * port)1445 static unsigned int tb_dma_available_credits(const struct tb_port *port)
1446 {
1447 	const struct tb_switch *sw = port->sw;
1448 	int credits;
1449 
1450 	credits = tb_available_credits(port, NULL);
1451 	if (tb_acpi_may_tunnel_pcie())
1452 		credits -= sw->max_pcie_credits;
1453 	credits -= port->dma_credits;
1454 
1455 	return credits > 0 ? credits : 0;
1456 }
1457 
tb_dma_reserve_credits(struct tb_path_hop * hop,unsigned int credits)1458 static int tb_dma_reserve_credits(struct tb_path_hop *hop, unsigned int credits)
1459 {
1460 	struct tb_port *port = hop->in_port;
1461 
1462 	if (tb_port_use_credit_allocation(port)) {
1463 		unsigned int available = tb_dma_available_credits(port);
1464 
1465 		/*
1466 		 * Need to have at least TB_MIN_DMA_CREDITS, otherwise
1467 		 * DMA path cannot be established.
1468 		 */
1469 		if (available < TB_MIN_DMA_CREDITS)
1470 			return -ENOSPC;
1471 
1472 		while (credits > available)
1473 			credits--;
1474 
1475 		tb_port_dbg(port, "reserving %u credits for DMA path\n",
1476 			    credits);
1477 
1478 		port->dma_credits += credits;
1479 	} else {
1480 		if (tb_port_is_null(port))
1481 			credits = port->bonded ? 14 : 6;
1482 		else
1483 			credits = min(port->total_credits, credits);
1484 	}
1485 
1486 	hop->initial_credits = credits;
1487 	return 0;
1488 }
1489 
1490 /* Path from lane adapter to NHI */
tb_dma_init_rx_path(struct tb_path * path,unsigned int credits)1491 static int tb_dma_init_rx_path(struct tb_path *path, unsigned int credits)
1492 {
1493 	struct tb_path_hop *hop;
1494 	unsigned int i, tmp;
1495 
1496 	path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
1497 	path->ingress_fc_enable = TB_PATH_ALL;
1498 	path->egress_shared_buffer = TB_PATH_NONE;
1499 	path->ingress_shared_buffer = TB_PATH_NONE;
1500 	path->priority = 5;
1501 	path->weight = 1;
1502 	path->clear_fc = true;
1503 
1504 	/*
1505 	 * First lane adapter is the one connected to the remote host.
1506 	 * We don't tunnel other traffic over this link so can use all
1507 	 * the credits (except the ones reserved for control traffic).
1508 	 */
1509 	hop = &path->hops[0];
1510 	tmp = min(tb_usable_credits(hop->in_port), credits);
1511 	hop->initial_credits = tmp;
1512 	hop->in_port->dma_credits += tmp;
1513 
1514 	for (i = 1; i < path->path_length; i++) {
1515 		int ret;
1516 
1517 		ret = tb_dma_reserve_credits(&path->hops[i], credits);
1518 		if (ret)
1519 			return ret;
1520 	}
1521 
1522 	return 0;
1523 }
1524 
1525 /* Path from NHI to lane adapter */
tb_dma_init_tx_path(struct tb_path * path,unsigned int credits)1526 static int tb_dma_init_tx_path(struct tb_path *path, unsigned int credits)
1527 {
1528 	struct tb_path_hop *hop;
1529 
1530 	path->egress_fc_enable = TB_PATH_ALL;
1531 	path->ingress_fc_enable = TB_PATH_ALL;
1532 	path->egress_shared_buffer = TB_PATH_NONE;
1533 	path->ingress_shared_buffer = TB_PATH_NONE;
1534 	path->priority = 5;
1535 	path->weight = 1;
1536 	path->clear_fc = true;
1537 
1538 	tb_path_for_each_hop(path, hop) {
1539 		int ret;
1540 
1541 		ret = tb_dma_reserve_credits(hop, credits);
1542 		if (ret)
1543 			return ret;
1544 	}
1545 
1546 	return 0;
1547 }
1548 
tb_dma_release_credits(struct tb_path_hop * hop)1549 static void tb_dma_release_credits(struct tb_path_hop *hop)
1550 {
1551 	struct tb_port *port = hop->in_port;
1552 
1553 	if (tb_port_use_credit_allocation(port)) {
1554 		port->dma_credits -= hop->initial_credits;
1555 
1556 		tb_port_dbg(port, "released %u DMA path credits\n",
1557 			    hop->initial_credits);
1558 	}
1559 }
1560 
tb_dma_deinit_path(struct tb_path * path)1561 static void tb_dma_deinit_path(struct tb_path *path)
1562 {
1563 	struct tb_path_hop *hop;
1564 
1565 	tb_path_for_each_hop(path, hop)
1566 		tb_dma_release_credits(hop);
1567 }
1568 
tb_dma_deinit(struct tb_tunnel * tunnel)1569 static void tb_dma_deinit(struct tb_tunnel *tunnel)
1570 {
1571 	int i;
1572 
1573 	for (i = 0; i < tunnel->npaths; i++) {
1574 		if (!tunnel->paths[i])
1575 			continue;
1576 		tb_dma_deinit_path(tunnel->paths[i]);
1577 	}
1578 }
1579 
1580 /**
1581  * tb_tunnel_alloc_dma() - allocate a DMA tunnel
1582  * @tb: Pointer to the domain structure
1583  * @nhi: Host controller port
1584  * @dst: Destination null port which the other domain is connected to
1585  * @transmit_path: HopID used for transmitting packets
1586  * @transmit_ring: NHI ring number used to send packets towards the
1587  *		   other domain. Set to %-1 if TX path is not needed.
1588  * @receive_path: HopID used for receiving packets
1589  * @receive_ring: NHI ring number used to receive packets from the
1590  *		  other domain. Set to %-1 if RX path is not needed.
1591  *
1592  * Return: Returns a tb_tunnel on success or NULL on failure.
1593  */
tb_tunnel_alloc_dma(struct tb * tb,struct tb_port * nhi,struct tb_port * dst,int transmit_path,int transmit_ring,int receive_path,int receive_ring)1594 struct tb_tunnel *tb_tunnel_alloc_dma(struct tb *tb, struct tb_port *nhi,
1595 				      struct tb_port *dst, int transmit_path,
1596 				      int transmit_ring, int receive_path,
1597 				      int receive_ring)
1598 {
1599 	struct tb_tunnel *tunnel;
1600 	size_t npaths = 0, i = 0;
1601 	struct tb_path *path;
1602 	int credits;
1603 
1604 	/* Ring 0 is reserved for control channel */
1605 	if (WARN_ON(!receive_ring || !transmit_ring))
1606 		return NULL;
1607 
1608 	if (receive_ring > 0)
1609 		npaths++;
1610 	if (transmit_ring > 0)
1611 		npaths++;
1612 
1613 	if (WARN_ON(!npaths))
1614 		return NULL;
1615 
1616 	tunnel = tb_tunnel_alloc(tb, npaths, TB_TUNNEL_DMA);
1617 	if (!tunnel)
1618 		return NULL;
1619 
1620 	tunnel->src_port = nhi;
1621 	tunnel->dst_port = dst;
1622 	tunnel->deinit = tb_dma_deinit;
1623 
1624 	credits = min_not_zero(dma_credits, nhi->sw->max_dma_credits);
1625 
1626 	if (receive_ring > 0) {
1627 		path = tb_path_alloc(tb, dst, receive_path, nhi, receive_ring, 0,
1628 				     "DMA RX");
1629 		if (!path)
1630 			goto err_free;
1631 		tunnel->paths[i++] = path;
1632 		if (tb_dma_init_rx_path(path, credits)) {
1633 			tb_tunnel_dbg(tunnel, "not enough buffers for RX path\n");
1634 			goto err_free;
1635 		}
1636 	}
1637 
1638 	if (transmit_ring > 0) {
1639 		path = tb_path_alloc(tb, nhi, transmit_ring, dst, transmit_path, 0,
1640 				     "DMA TX");
1641 		if (!path)
1642 			goto err_free;
1643 		tunnel->paths[i++] = path;
1644 		if (tb_dma_init_tx_path(path, credits)) {
1645 			tb_tunnel_dbg(tunnel, "not enough buffers for TX path\n");
1646 			goto err_free;
1647 		}
1648 	}
1649 
1650 	return tunnel;
1651 
1652 err_free:
1653 	tb_tunnel_free(tunnel);
1654 	return NULL;
1655 }
1656 
1657 /**
1658  * tb_tunnel_match_dma() - Match DMA tunnel
1659  * @tunnel: Tunnel to match
1660  * @transmit_path: HopID used for transmitting packets. Pass %-1 to ignore.
1661  * @transmit_ring: NHI ring number used to send packets towards the
1662  *		   other domain. Pass %-1 to ignore.
1663  * @receive_path: HopID used for receiving packets. Pass %-1 to ignore.
1664  * @receive_ring: NHI ring number used to receive packets from the
1665  *		  other domain. Pass %-1 to ignore.
1666  *
1667  * This function can be used to match specific DMA tunnel, if there are
1668  * multiple DMA tunnels going through the same XDomain connection.
1669  * Returns true if there is match and false otherwise.
1670  */
tb_tunnel_match_dma(const struct tb_tunnel * tunnel,int transmit_path,int transmit_ring,int receive_path,int receive_ring)1671 bool tb_tunnel_match_dma(const struct tb_tunnel *tunnel, int transmit_path,
1672 			 int transmit_ring, int receive_path, int receive_ring)
1673 {
1674 	const struct tb_path *tx_path = NULL, *rx_path = NULL;
1675 	int i;
1676 
1677 	if (!receive_ring || !transmit_ring)
1678 		return false;
1679 
1680 	for (i = 0; i < tunnel->npaths; i++) {
1681 		const struct tb_path *path = tunnel->paths[i];
1682 
1683 		if (!path)
1684 			continue;
1685 
1686 		if (tb_port_is_nhi(path->hops[0].in_port))
1687 			tx_path = path;
1688 		else if (tb_port_is_nhi(path->hops[path->path_length - 1].out_port))
1689 			rx_path = path;
1690 	}
1691 
1692 	if (transmit_ring > 0 || transmit_path > 0) {
1693 		if (!tx_path)
1694 			return false;
1695 		if (transmit_ring > 0 &&
1696 		    (tx_path->hops[0].in_hop_index != transmit_ring))
1697 			return false;
1698 		if (transmit_path > 0 &&
1699 		    (tx_path->hops[tx_path->path_length - 1].next_hop_index != transmit_path))
1700 			return false;
1701 	}
1702 
1703 	if (receive_ring > 0 || receive_path > 0) {
1704 		if (!rx_path)
1705 			return false;
1706 		if (receive_path > 0 &&
1707 		    (rx_path->hops[0].in_hop_index != receive_path))
1708 			return false;
1709 		if (receive_ring > 0 &&
1710 		    (rx_path->hops[rx_path->path_length - 1].next_hop_index != receive_ring))
1711 			return false;
1712 	}
1713 
1714 	return true;
1715 }
1716 
tb_usb3_max_link_rate(struct tb_port * up,struct tb_port * down)1717 static int tb_usb3_max_link_rate(struct tb_port *up, struct tb_port *down)
1718 {
1719 	int ret, up_max_rate, down_max_rate;
1720 
1721 	ret = usb4_usb3_port_max_link_rate(up);
1722 	if (ret < 0)
1723 		return ret;
1724 	up_max_rate = ret;
1725 
1726 	ret = usb4_usb3_port_max_link_rate(down);
1727 	if (ret < 0)
1728 		return ret;
1729 	down_max_rate = ret;
1730 
1731 	return min(up_max_rate, down_max_rate);
1732 }
1733 
tb_usb3_init(struct tb_tunnel * tunnel)1734 static int tb_usb3_init(struct tb_tunnel *tunnel)
1735 {
1736 	tb_tunnel_dbg(tunnel, "allocating initial bandwidth %d/%d Mb/s\n",
1737 		      tunnel->allocated_up, tunnel->allocated_down);
1738 
1739 	return usb4_usb3_port_allocate_bandwidth(tunnel->src_port,
1740 						 &tunnel->allocated_up,
1741 						 &tunnel->allocated_down);
1742 }
1743 
tb_usb3_activate(struct tb_tunnel * tunnel,bool activate)1744 static int tb_usb3_activate(struct tb_tunnel *tunnel, bool activate)
1745 {
1746 	int res;
1747 
1748 	res = tb_usb3_port_enable(tunnel->src_port, activate);
1749 	if (res)
1750 		return res;
1751 
1752 	if (tb_port_is_usb3_up(tunnel->dst_port))
1753 		return tb_usb3_port_enable(tunnel->dst_port, activate);
1754 
1755 	return 0;
1756 }
1757 
tb_usb3_consumed_bandwidth(struct tb_tunnel * tunnel,int * consumed_up,int * consumed_down)1758 static int tb_usb3_consumed_bandwidth(struct tb_tunnel *tunnel,
1759 		int *consumed_up, int *consumed_down)
1760 {
1761 	int pcie_enabled = tb_acpi_may_tunnel_pcie();
1762 
1763 	/*
1764 	 * PCIe tunneling, if enabled, affects the USB3 bandwidth so
1765 	 * take that it into account here.
1766 	 */
1767 	*consumed_up = tunnel->allocated_up * (3 + pcie_enabled) / 3;
1768 	*consumed_down = tunnel->allocated_down * (3 + pcie_enabled) / 3;
1769 	return 0;
1770 }
1771 
tb_usb3_release_unused_bandwidth(struct tb_tunnel * tunnel)1772 static int tb_usb3_release_unused_bandwidth(struct tb_tunnel *tunnel)
1773 {
1774 	int ret;
1775 
1776 	ret = usb4_usb3_port_release_bandwidth(tunnel->src_port,
1777 					       &tunnel->allocated_up,
1778 					       &tunnel->allocated_down);
1779 	if (ret)
1780 		return ret;
1781 
1782 	tb_tunnel_dbg(tunnel, "decreased bandwidth allocation to %d/%d Mb/s\n",
1783 		      tunnel->allocated_up, tunnel->allocated_down);
1784 	return 0;
1785 }
1786 
tb_usb3_reclaim_available_bandwidth(struct tb_tunnel * tunnel,int * available_up,int * available_down)1787 static void tb_usb3_reclaim_available_bandwidth(struct tb_tunnel *tunnel,
1788 						int *available_up,
1789 						int *available_down)
1790 {
1791 	int ret, max_rate, allocate_up, allocate_down;
1792 
1793 	ret = usb4_usb3_port_actual_link_rate(tunnel->src_port);
1794 	if (ret < 0) {
1795 		tb_tunnel_warn(tunnel, "failed to read actual link rate\n");
1796 		return;
1797 	} else if (!ret) {
1798 		/* Use maximum link rate if the link valid is not set */
1799 		ret = tb_usb3_max_link_rate(tunnel->dst_port, tunnel->src_port);
1800 		if (ret < 0) {
1801 			tb_tunnel_warn(tunnel, "failed to read maximum link rate\n");
1802 			return;
1803 		}
1804 	}
1805 
1806 	/*
1807 	 * 90% of the max rate can be allocated for isochronous
1808 	 * transfers.
1809 	 */
1810 	max_rate = ret * 90 / 100;
1811 
1812 	/* No need to reclaim if already at maximum */
1813 	if (tunnel->allocated_up >= max_rate &&
1814 	    tunnel->allocated_down >= max_rate)
1815 		return;
1816 
1817 	/* Don't go lower than what is already allocated */
1818 	allocate_up = min(max_rate, *available_up);
1819 	if (allocate_up < tunnel->allocated_up)
1820 		allocate_up = tunnel->allocated_up;
1821 
1822 	allocate_down = min(max_rate, *available_down);
1823 	if (allocate_down < tunnel->allocated_down)
1824 		allocate_down = tunnel->allocated_down;
1825 
1826 	/* If no changes no need to do more */
1827 	if (allocate_up == tunnel->allocated_up &&
1828 	    allocate_down == tunnel->allocated_down)
1829 		return;
1830 
1831 	ret = usb4_usb3_port_allocate_bandwidth(tunnel->src_port, &allocate_up,
1832 						&allocate_down);
1833 	if (ret) {
1834 		tb_tunnel_info(tunnel, "failed to allocate bandwidth\n");
1835 		return;
1836 	}
1837 
1838 	tunnel->allocated_up = allocate_up;
1839 	*available_up -= tunnel->allocated_up;
1840 
1841 	tunnel->allocated_down = allocate_down;
1842 	*available_down -= tunnel->allocated_down;
1843 
1844 	tb_tunnel_dbg(tunnel, "increased bandwidth allocation to %d/%d Mb/s\n",
1845 		      tunnel->allocated_up, tunnel->allocated_down);
1846 }
1847 
tb_usb3_init_credits(struct tb_path_hop * hop)1848 static void tb_usb3_init_credits(struct tb_path_hop *hop)
1849 {
1850 	struct tb_port *port = hop->in_port;
1851 	struct tb_switch *sw = port->sw;
1852 	unsigned int credits;
1853 
1854 	if (tb_port_use_credit_allocation(port)) {
1855 		credits = sw->max_usb3_credits;
1856 	} else {
1857 		if (tb_port_is_null(port))
1858 			credits = port->bonded ? 32 : 16;
1859 		else
1860 			credits = 7;
1861 	}
1862 
1863 	hop->initial_credits = credits;
1864 }
1865 
tb_usb3_init_path(struct tb_path * path)1866 static void tb_usb3_init_path(struct tb_path *path)
1867 {
1868 	struct tb_path_hop *hop;
1869 
1870 	path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
1871 	path->egress_shared_buffer = TB_PATH_NONE;
1872 	path->ingress_fc_enable = TB_PATH_ALL;
1873 	path->ingress_shared_buffer = TB_PATH_NONE;
1874 	path->priority = 3;
1875 	path->weight = 3;
1876 	path->drop_packages = 0;
1877 
1878 	tb_path_for_each_hop(path, hop)
1879 		tb_usb3_init_credits(hop);
1880 }
1881 
1882 /**
1883  * tb_tunnel_discover_usb3() - Discover existing USB3 tunnels
1884  * @tb: Pointer to the domain structure
1885  * @down: USB3 downstream adapter
1886  * @alloc_hopid: Allocate HopIDs from visited ports
1887  *
1888  * If @down adapter is active, follows the tunnel to the USB3 upstream
1889  * adapter and back. Returns the discovered tunnel or %NULL if there was
1890  * no tunnel.
1891  */
tb_tunnel_discover_usb3(struct tb * tb,struct tb_port * down,bool alloc_hopid)1892 struct tb_tunnel *tb_tunnel_discover_usb3(struct tb *tb, struct tb_port *down,
1893 					  bool alloc_hopid)
1894 {
1895 	struct tb_tunnel *tunnel;
1896 	struct tb_path *path;
1897 
1898 	if (!tb_usb3_port_is_enabled(down))
1899 		return NULL;
1900 
1901 	tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_USB3);
1902 	if (!tunnel)
1903 		return NULL;
1904 
1905 	tunnel->activate = tb_usb3_activate;
1906 	tunnel->src_port = down;
1907 
1908 	/*
1909 	 * Discover both paths even if they are not complete. We will
1910 	 * clean them up by calling tb_tunnel_deactivate() below in that
1911 	 * case.
1912 	 */
1913 	path = tb_path_discover(down, TB_USB3_HOPID, NULL, -1,
1914 				&tunnel->dst_port, "USB3 Down", alloc_hopid);
1915 	if (!path) {
1916 		/* Just disable the downstream port */
1917 		tb_usb3_port_enable(down, false);
1918 		goto err_free;
1919 	}
1920 	tunnel->paths[TB_USB3_PATH_DOWN] = path;
1921 	tb_usb3_init_path(tunnel->paths[TB_USB3_PATH_DOWN]);
1922 
1923 	path = tb_path_discover(tunnel->dst_port, -1, down, TB_USB3_HOPID, NULL,
1924 				"USB3 Up", alloc_hopid);
1925 	if (!path)
1926 		goto err_deactivate;
1927 	tunnel->paths[TB_USB3_PATH_UP] = path;
1928 	tb_usb3_init_path(tunnel->paths[TB_USB3_PATH_UP]);
1929 
1930 	/* Validate that the tunnel is complete */
1931 	if (!tb_port_is_usb3_up(tunnel->dst_port)) {
1932 		tb_port_warn(tunnel->dst_port,
1933 			     "path does not end on an USB3 adapter, cleaning up\n");
1934 		goto err_deactivate;
1935 	}
1936 
1937 	if (down != tunnel->src_port) {
1938 		tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");
1939 		goto err_deactivate;
1940 	}
1941 
1942 	if (!tb_usb3_port_is_enabled(tunnel->dst_port)) {
1943 		tb_tunnel_warn(tunnel,
1944 			       "tunnel is not fully activated, cleaning up\n");
1945 		goto err_deactivate;
1946 	}
1947 
1948 	if (!tb_route(down->sw)) {
1949 		int ret;
1950 
1951 		/*
1952 		 * Read the initial bandwidth allocation for the first
1953 		 * hop tunnel.
1954 		 */
1955 		ret = usb4_usb3_port_allocated_bandwidth(down,
1956 			&tunnel->allocated_up, &tunnel->allocated_down);
1957 		if (ret)
1958 			goto err_deactivate;
1959 
1960 		tb_tunnel_dbg(tunnel, "currently allocated bandwidth %d/%d Mb/s\n",
1961 			      tunnel->allocated_up, tunnel->allocated_down);
1962 
1963 		tunnel->init = tb_usb3_init;
1964 		tunnel->consumed_bandwidth = tb_usb3_consumed_bandwidth;
1965 		tunnel->release_unused_bandwidth =
1966 			tb_usb3_release_unused_bandwidth;
1967 		tunnel->reclaim_available_bandwidth =
1968 			tb_usb3_reclaim_available_bandwidth;
1969 	}
1970 
1971 	tb_tunnel_dbg(tunnel, "discovered\n");
1972 	return tunnel;
1973 
1974 err_deactivate:
1975 	tb_tunnel_deactivate(tunnel);
1976 err_free:
1977 	tb_tunnel_free(tunnel);
1978 
1979 	return NULL;
1980 }
1981 
1982 /**
1983  * tb_tunnel_alloc_usb3() - allocate a USB3 tunnel
1984  * @tb: Pointer to the domain structure
1985  * @up: USB3 upstream adapter port
1986  * @down: USB3 downstream adapter port
1987  * @max_up: Maximum available upstream bandwidth for the USB3 tunnel (%0
1988  *	    if not limited).
1989  * @max_down: Maximum available downstream bandwidth for the USB3 tunnel
1990  *	      (%0 if not limited).
1991  *
1992  * Allocate an USB3 tunnel. The ports must be of type @TB_TYPE_USB3_UP and
1993  * @TB_TYPE_USB3_DOWN.
1994  *
1995  * Return: Returns a tb_tunnel on success or %NULL on failure.
1996  */
tb_tunnel_alloc_usb3(struct tb * tb,struct tb_port * up,struct tb_port * down,int max_up,int max_down)1997 struct tb_tunnel *tb_tunnel_alloc_usb3(struct tb *tb, struct tb_port *up,
1998 				       struct tb_port *down, int max_up,
1999 				       int max_down)
2000 {
2001 	struct tb_tunnel *tunnel;
2002 	struct tb_path *path;
2003 	int max_rate = 0;
2004 
2005 	/*
2006 	 * Check that we have enough bandwidth available for the new
2007 	 * USB3 tunnel.
2008 	 */
2009 	if (max_up > 0 || max_down > 0) {
2010 		max_rate = tb_usb3_max_link_rate(down, up);
2011 		if (max_rate < 0)
2012 			return NULL;
2013 
2014 		/* Only 90% can be allocated for USB3 isochronous transfers */
2015 		max_rate = max_rate * 90 / 100;
2016 		tb_port_dbg(up, "required bandwidth for USB3 tunnel %d Mb/s\n",
2017 			    max_rate);
2018 
2019 		if (max_rate > max_up || max_rate > max_down) {
2020 			tb_port_warn(up, "not enough bandwidth for USB3 tunnel\n");
2021 			return NULL;
2022 		}
2023 	}
2024 
2025 	tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_USB3);
2026 	if (!tunnel)
2027 		return NULL;
2028 
2029 	tunnel->activate = tb_usb3_activate;
2030 	tunnel->src_port = down;
2031 	tunnel->dst_port = up;
2032 	tunnel->max_up = max_up;
2033 	tunnel->max_down = max_down;
2034 
2035 	path = tb_path_alloc(tb, down, TB_USB3_HOPID, up, TB_USB3_HOPID, 0,
2036 			     "USB3 Down");
2037 	if (!path) {
2038 		tb_tunnel_free(tunnel);
2039 		return NULL;
2040 	}
2041 	tb_usb3_init_path(path);
2042 	tunnel->paths[TB_USB3_PATH_DOWN] = path;
2043 
2044 	path = tb_path_alloc(tb, up, TB_USB3_HOPID, down, TB_USB3_HOPID, 0,
2045 			     "USB3 Up");
2046 	if (!path) {
2047 		tb_tunnel_free(tunnel);
2048 		return NULL;
2049 	}
2050 	tb_usb3_init_path(path);
2051 	tunnel->paths[TB_USB3_PATH_UP] = path;
2052 
2053 	if (!tb_route(down->sw)) {
2054 		tunnel->allocated_up = max_rate;
2055 		tunnel->allocated_down = max_rate;
2056 
2057 		tunnel->init = tb_usb3_init;
2058 		tunnel->consumed_bandwidth = tb_usb3_consumed_bandwidth;
2059 		tunnel->release_unused_bandwidth =
2060 			tb_usb3_release_unused_bandwidth;
2061 		tunnel->reclaim_available_bandwidth =
2062 			tb_usb3_reclaim_available_bandwidth;
2063 	}
2064 
2065 	return tunnel;
2066 }
2067 
2068 /**
2069  * tb_tunnel_free() - free a tunnel
2070  * @tunnel: Tunnel to be freed
2071  *
2072  * Frees a tunnel. The tunnel does not need to be deactivated.
2073  */
tb_tunnel_free(struct tb_tunnel * tunnel)2074 void tb_tunnel_free(struct tb_tunnel *tunnel)
2075 {
2076 	int i;
2077 
2078 	if (!tunnel)
2079 		return;
2080 
2081 	if (tunnel->deinit)
2082 		tunnel->deinit(tunnel);
2083 
2084 	for (i = 0; i < tunnel->npaths; i++) {
2085 		if (tunnel->paths[i])
2086 			tb_path_free(tunnel->paths[i]);
2087 	}
2088 
2089 	kfree(tunnel->paths);
2090 	kfree(tunnel);
2091 }
2092 
2093 /**
2094  * tb_tunnel_is_invalid - check whether an activated path is still valid
2095  * @tunnel: Tunnel to check
2096  */
tb_tunnel_is_invalid(struct tb_tunnel * tunnel)2097 bool tb_tunnel_is_invalid(struct tb_tunnel *tunnel)
2098 {
2099 	int i;
2100 
2101 	for (i = 0; i < tunnel->npaths; i++) {
2102 		WARN_ON(!tunnel->paths[i]->activated);
2103 		if (tb_path_is_invalid(tunnel->paths[i]))
2104 			return true;
2105 	}
2106 
2107 	return false;
2108 }
2109 
2110 /**
2111  * tb_tunnel_restart() - activate a tunnel after a hardware reset
2112  * @tunnel: Tunnel to restart
2113  *
2114  * Return: 0 on success and negative errno in case if failure
2115  */
tb_tunnel_restart(struct tb_tunnel * tunnel)2116 int tb_tunnel_restart(struct tb_tunnel *tunnel)
2117 {
2118 	int res, i;
2119 
2120 	tb_tunnel_dbg(tunnel, "activating\n");
2121 
2122 	/*
2123 	 * Make sure all paths are properly disabled before enabling
2124 	 * them again.
2125 	 */
2126 	for (i = 0; i < tunnel->npaths; i++) {
2127 		if (tunnel->paths[i]->activated) {
2128 			tb_path_deactivate(tunnel->paths[i]);
2129 			tunnel->paths[i]->activated = false;
2130 		}
2131 	}
2132 
2133 	if (tunnel->init) {
2134 		res = tunnel->init(tunnel);
2135 		if (res)
2136 			return res;
2137 	}
2138 
2139 	for (i = 0; i < tunnel->npaths; i++) {
2140 		res = tb_path_activate(tunnel->paths[i]);
2141 		if (res)
2142 			goto err;
2143 	}
2144 
2145 	if (tunnel->activate) {
2146 		res = tunnel->activate(tunnel, true);
2147 		if (res)
2148 			goto err;
2149 	}
2150 
2151 	return 0;
2152 
2153 err:
2154 	tb_tunnel_warn(tunnel, "activation failed\n");
2155 	tb_tunnel_deactivate(tunnel);
2156 	return res;
2157 }
2158 
2159 /**
2160  * tb_tunnel_activate() - activate a tunnel
2161  * @tunnel: Tunnel to activate
2162  *
2163  * Return: Returns 0 on success or an error code on failure.
2164  */
tb_tunnel_activate(struct tb_tunnel * tunnel)2165 int tb_tunnel_activate(struct tb_tunnel *tunnel)
2166 {
2167 	int i;
2168 
2169 	for (i = 0; i < tunnel->npaths; i++) {
2170 		if (tunnel->paths[i]->activated) {
2171 			tb_tunnel_WARN(tunnel,
2172 				       "trying to activate an already activated tunnel\n");
2173 			return -EINVAL;
2174 		}
2175 	}
2176 
2177 	return tb_tunnel_restart(tunnel);
2178 }
2179 
2180 /**
2181  * tb_tunnel_deactivate() - deactivate a tunnel
2182  * @tunnel: Tunnel to deactivate
2183  */
tb_tunnel_deactivate(struct tb_tunnel * tunnel)2184 void tb_tunnel_deactivate(struct tb_tunnel *tunnel)
2185 {
2186 	int i;
2187 
2188 	tb_tunnel_dbg(tunnel, "deactivating\n");
2189 
2190 	if (tunnel->activate)
2191 		tunnel->activate(tunnel, false);
2192 
2193 	for (i = 0; i < tunnel->npaths; i++) {
2194 		if (tunnel->paths[i] && tunnel->paths[i]->activated)
2195 			tb_path_deactivate(tunnel->paths[i]);
2196 	}
2197 }
2198 
2199 /**
2200  * tb_tunnel_port_on_path() - Does the tunnel go through port
2201  * @tunnel: Tunnel to check
2202  * @port: Port to check
2203  *
2204  * Returns true if @tunnel goes through @port (direction does not matter),
2205  * false otherwise.
2206  */
tb_tunnel_port_on_path(const struct tb_tunnel * tunnel,const struct tb_port * port)2207 bool tb_tunnel_port_on_path(const struct tb_tunnel *tunnel,
2208 			    const struct tb_port *port)
2209 {
2210 	int i;
2211 
2212 	for (i = 0; i < tunnel->npaths; i++) {
2213 		if (!tunnel->paths[i])
2214 			continue;
2215 
2216 		if (tb_path_port_on_path(tunnel->paths[i], port))
2217 			return true;
2218 	}
2219 
2220 	return false;
2221 }
2222 
tb_tunnel_is_active(const struct tb_tunnel * tunnel)2223 static bool tb_tunnel_is_active(const struct tb_tunnel *tunnel)
2224 {
2225 	int i;
2226 
2227 	for (i = 0; i < tunnel->npaths; i++) {
2228 		if (!tunnel->paths[i])
2229 			return false;
2230 		if (!tunnel->paths[i]->activated)
2231 			return false;
2232 	}
2233 
2234 	return true;
2235 }
2236 
2237 /**
2238  * tb_tunnel_maximum_bandwidth() - Return maximum possible bandwidth
2239  * @tunnel: Tunnel to check
2240  * @max_up: Maximum upstream bandwidth in Mb/s
2241  * @max_down: Maximum downstream bandwidth in Mb/s
2242  *
2243  * Returns maximum possible bandwidth this tunnel can go if not limited
2244  * by other bandwidth clients. If the tunnel does not support this
2245  * returns %-EOPNOTSUPP.
2246  */
tb_tunnel_maximum_bandwidth(struct tb_tunnel * tunnel,int * max_up,int * max_down)2247 int tb_tunnel_maximum_bandwidth(struct tb_tunnel *tunnel, int *max_up,
2248 				int *max_down)
2249 {
2250 	if (!tb_tunnel_is_active(tunnel))
2251 		return -EINVAL;
2252 
2253 	if (tunnel->maximum_bandwidth)
2254 		return tunnel->maximum_bandwidth(tunnel, max_up, max_down);
2255 	return -EOPNOTSUPP;
2256 }
2257 
2258 /**
2259  * tb_tunnel_allocated_bandwidth() - Return bandwidth allocated for the tunnel
2260  * @tunnel: Tunnel to check
2261  * @allocated_up: Currently allocated upstream bandwidth in Mb/s is stored here
2262  * @allocated_down: Currently allocated downstream bandwidth in Mb/s is
2263  *		    stored here
2264  *
2265  * Returns the bandwidth allocated for the tunnel. This may be higher
2266  * than what the tunnel actually consumes.
2267  */
tb_tunnel_allocated_bandwidth(struct tb_tunnel * tunnel,int * allocated_up,int * allocated_down)2268 int tb_tunnel_allocated_bandwidth(struct tb_tunnel *tunnel, int *allocated_up,
2269 				  int *allocated_down)
2270 {
2271 	if (!tb_tunnel_is_active(tunnel))
2272 		return -EINVAL;
2273 
2274 	if (tunnel->allocated_bandwidth)
2275 		return tunnel->allocated_bandwidth(tunnel, allocated_up,
2276 						   allocated_down);
2277 	return -EOPNOTSUPP;
2278 }
2279 
2280 /**
2281  * tb_tunnel_alloc_bandwidth() - Change tunnel bandwidth allocation
2282  * @tunnel: Tunnel whose bandwidth allocation to change
2283  * @alloc_up: New upstream bandwidth in Mb/s
2284  * @alloc_down: New downstream bandwidth in Mb/s
2285  *
2286  * Tries to change tunnel bandwidth allocation. If succeeds returns %0
2287  * and updates @alloc_up and @alloc_down to that was actually allocated
2288  * (it may not be the same as passed originally). Returns negative errno
2289  * in case of failure.
2290  */
tb_tunnel_alloc_bandwidth(struct tb_tunnel * tunnel,int * alloc_up,int * alloc_down)2291 int tb_tunnel_alloc_bandwidth(struct tb_tunnel *tunnel, int *alloc_up,
2292 			      int *alloc_down)
2293 {
2294 	if (!tb_tunnel_is_active(tunnel))
2295 		return -EINVAL;
2296 
2297 	if (tunnel->alloc_bandwidth)
2298 		return tunnel->alloc_bandwidth(tunnel, alloc_up, alloc_down);
2299 
2300 	return -EOPNOTSUPP;
2301 }
2302 
2303 /**
2304  * tb_tunnel_consumed_bandwidth() - Return bandwidth consumed by the tunnel
2305  * @tunnel: Tunnel to check
2306  * @consumed_up: Consumed bandwidth in Mb/s from @dst_port to @src_port.
2307  *		 Can be %NULL.
2308  * @consumed_down: Consumed bandwidth in Mb/s from @src_port to @dst_port.
2309  *		   Can be %NULL.
2310  *
2311  * Stores the amount of isochronous bandwidth @tunnel consumes in
2312  * @consumed_up and @consumed_down. In case of success returns %0,
2313  * negative errno otherwise.
2314  */
tb_tunnel_consumed_bandwidth(struct tb_tunnel * tunnel,int * consumed_up,int * consumed_down)2315 int tb_tunnel_consumed_bandwidth(struct tb_tunnel *tunnel, int *consumed_up,
2316 				 int *consumed_down)
2317 {
2318 	int up_bw = 0, down_bw = 0;
2319 
2320 	if (!tb_tunnel_is_active(tunnel))
2321 		goto out;
2322 
2323 	if (tunnel->consumed_bandwidth) {
2324 		int ret;
2325 
2326 		ret = tunnel->consumed_bandwidth(tunnel, &up_bw, &down_bw);
2327 		if (ret)
2328 			return ret;
2329 
2330 		tb_tunnel_dbg(tunnel, "consumed bandwidth %d/%d Mb/s\n", up_bw,
2331 			      down_bw);
2332 	}
2333 
2334 out:
2335 	if (consumed_up)
2336 		*consumed_up = up_bw;
2337 	if (consumed_down)
2338 		*consumed_down = down_bw;
2339 
2340 	return 0;
2341 }
2342 
2343 /**
2344  * tb_tunnel_release_unused_bandwidth() - Release unused bandwidth
2345  * @tunnel: Tunnel whose unused bandwidth to release
2346  *
2347  * If tunnel supports dynamic bandwidth management (USB3 tunnels at the
2348  * moment) this function makes it to release all the unused bandwidth.
2349  *
2350  * Returns %0 in case of success and negative errno otherwise.
2351  */
tb_tunnel_release_unused_bandwidth(struct tb_tunnel * tunnel)2352 int tb_tunnel_release_unused_bandwidth(struct tb_tunnel *tunnel)
2353 {
2354 	if (!tb_tunnel_is_active(tunnel))
2355 		return 0;
2356 
2357 	if (tunnel->release_unused_bandwidth) {
2358 		int ret;
2359 
2360 		ret = tunnel->release_unused_bandwidth(tunnel);
2361 		if (ret)
2362 			return ret;
2363 	}
2364 
2365 	return 0;
2366 }
2367 
2368 /**
2369  * tb_tunnel_reclaim_available_bandwidth() - Reclaim available bandwidth
2370  * @tunnel: Tunnel reclaiming available bandwidth
2371  * @available_up: Available upstream bandwidth (in Mb/s)
2372  * @available_down: Available downstream bandwidth (in Mb/s)
2373  *
2374  * Reclaims bandwidth from @available_up and @available_down and updates
2375  * the variables accordingly (e.g decreases both according to what was
2376  * reclaimed by the tunnel). If nothing was reclaimed the values are
2377  * kept as is.
2378  */
tb_tunnel_reclaim_available_bandwidth(struct tb_tunnel * tunnel,int * available_up,int * available_down)2379 void tb_tunnel_reclaim_available_bandwidth(struct tb_tunnel *tunnel,
2380 					   int *available_up,
2381 					   int *available_down)
2382 {
2383 	if (!tb_tunnel_is_active(tunnel))
2384 		return;
2385 
2386 	if (tunnel->reclaim_available_bandwidth)
2387 		tunnel->reclaim_available_bandwidth(tunnel, available_up,
2388 						    available_down);
2389 }
2390