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 
13 #include "tunnel.h"
14 #include "tb.h"
15 
16 /* PCIe adapters use always HopID of 8 for both directions */
17 #define TB_PCI_HOPID			8
18 
19 #define TB_PCI_PATH_DOWN		0
20 #define TB_PCI_PATH_UP			1
21 
22 /* USB3 adapters use always HopID of 8 for both directions */
23 #define TB_USB3_HOPID			8
24 
25 #define TB_USB3_PATH_DOWN		0
26 #define TB_USB3_PATH_UP			1
27 
28 /* DP adapters use HopID 8 for AUX and 9 for Video */
29 #define TB_DP_AUX_TX_HOPID		8
30 #define TB_DP_AUX_RX_HOPID		8
31 #define TB_DP_VIDEO_HOPID		9
32 
33 #define TB_DP_VIDEO_PATH_OUT		0
34 #define TB_DP_AUX_PATH_OUT		1
35 #define TB_DP_AUX_PATH_IN		2
36 
37 /* Minimum number of credits needed for PCIe path */
38 #define TB_MIN_PCIE_CREDITS		6U
39 /*
40  * Number of credits we try to allocate for each DMA path if not limited
41  * by the host router baMaxHI.
42  */
43 #define TB_DMA_CREDITS			14U
44 /* Minimum number of credits for DMA path */
45 #define TB_MIN_DMA_CREDITS		1U
46 
47 static const char * const tb_tunnel_names[] = { "PCI", "DP", "DMA", "USB3" };
48 
49 #define __TB_TUNNEL_PRINT(level, tunnel, fmt, arg...)                   \
50 	do {                                                            \
51 		struct tb_tunnel *__tunnel = (tunnel);                  \
52 		level(__tunnel->tb, "%llx:%x <-> %llx:%x (%s): " fmt,   \
53 		      tb_route(__tunnel->src_port->sw),                 \
54 		      __tunnel->src_port->port,                         \
55 		      tb_route(__tunnel->dst_port->sw),                 \
56 		      __tunnel->dst_port->port,                         \
57 		      tb_tunnel_names[__tunnel->type],			\
58 		      ## arg);                                          \
59 	} while (0)
60 
61 #define tb_tunnel_WARN(tunnel, fmt, arg...) \
62 	__TB_TUNNEL_PRINT(tb_WARN, tunnel, fmt, ##arg)
63 #define tb_tunnel_warn(tunnel, fmt, arg...) \
64 	__TB_TUNNEL_PRINT(tb_warn, tunnel, fmt, ##arg)
65 #define tb_tunnel_info(tunnel, fmt, arg...) \
66 	__TB_TUNNEL_PRINT(tb_info, tunnel, fmt, ##arg)
67 #define tb_tunnel_dbg(tunnel, fmt, arg...) \
68 	__TB_TUNNEL_PRINT(tb_dbg, tunnel, fmt, ##arg)
69 
tb_usable_credits(const struct tb_port * port)70 static inline unsigned int tb_usable_credits(const struct tb_port *port)
71 {
72 	return port->total_credits - port->ctl_credits;
73 }
74 
75 /**
76  * tb_available_credits() - Available credits for PCIe and DMA
77  * @port: Lane adapter to check
78  * @max_dp_streams: If non-%NULL stores maximum number of simultaneous DP
79  *		    streams possible through this lane adapter
80  */
tb_available_credits(const struct tb_port * port,size_t * max_dp_streams)81 static unsigned int tb_available_credits(const struct tb_port *port,
82 					 size_t *max_dp_streams)
83 {
84 	const struct tb_switch *sw = port->sw;
85 	int credits, usb3, pcie, spare;
86 	size_t ndp;
87 
88 	usb3 = tb_acpi_may_tunnel_usb3() ? sw->max_usb3_credits : 0;
89 	pcie = tb_acpi_may_tunnel_pcie() ? sw->max_pcie_credits : 0;
90 
91 	if (tb_acpi_is_xdomain_allowed()) {
92 		spare = min_not_zero(sw->max_dma_credits, TB_DMA_CREDITS);
93 		/* Add some credits for potential second DMA tunnel */
94 		spare += TB_MIN_DMA_CREDITS;
95 	} else {
96 		spare = 0;
97 	}
98 
99 	credits = tb_usable_credits(port);
100 	if (tb_acpi_may_tunnel_dp()) {
101 		/*
102 		 * Maximum number of DP streams possible through the
103 		 * lane adapter.
104 		 */
105 		if (sw->min_dp_aux_credits + sw->min_dp_main_credits)
106 			ndp = (credits - (usb3 + pcie + spare)) /
107 			      (sw->min_dp_aux_credits + sw->min_dp_main_credits);
108 		else
109 			ndp = 0;
110 	} else {
111 		ndp = 0;
112 	}
113 	credits -= ndp * (sw->min_dp_aux_credits + sw->min_dp_main_credits);
114 	credits -= usb3;
115 
116 	if (max_dp_streams)
117 		*max_dp_streams = ndp;
118 
119 	return credits > 0 ? credits : 0;
120 }
121 
tb_tunnel_alloc(struct tb * tb,size_t npaths,enum tb_tunnel_type type)122 static struct tb_tunnel *tb_tunnel_alloc(struct tb *tb, size_t npaths,
123 					 enum tb_tunnel_type type)
124 {
125 	struct tb_tunnel *tunnel;
126 
127 	tunnel = kzalloc(sizeof(*tunnel), GFP_KERNEL);
128 	if (!tunnel)
129 		return NULL;
130 
131 	tunnel->paths = kcalloc(npaths, sizeof(tunnel->paths[0]), GFP_KERNEL);
132 	if (!tunnel->paths) {
133 		tb_tunnel_free(tunnel);
134 		return NULL;
135 	}
136 
137 	INIT_LIST_HEAD(&tunnel->list);
138 	tunnel->tb = tb;
139 	tunnel->npaths = npaths;
140 	tunnel->type = type;
141 
142 	return tunnel;
143 }
144 
tb_pci_activate(struct tb_tunnel * tunnel,bool activate)145 static int tb_pci_activate(struct tb_tunnel *tunnel, bool activate)
146 {
147 	int res;
148 
149 	res = tb_pci_port_enable(tunnel->src_port, activate);
150 	if (res)
151 		return res;
152 
153 	if (tb_port_is_pcie_up(tunnel->dst_port))
154 		return tb_pci_port_enable(tunnel->dst_port, activate);
155 
156 	return 0;
157 }
158 
tb_pci_init_credits(struct tb_path_hop * hop)159 static int tb_pci_init_credits(struct tb_path_hop *hop)
160 {
161 	struct tb_port *port = hop->in_port;
162 	struct tb_switch *sw = port->sw;
163 	unsigned int credits;
164 
165 	if (tb_port_use_credit_allocation(port)) {
166 		unsigned int available;
167 
168 		available = tb_available_credits(port, NULL);
169 		credits = min(sw->max_pcie_credits, available);
170 
171 		if (credits < TB_MIN_PCIE_CREDITS)
172 			return -ENOSPC;
173 
174 		credits = max(TB_MIN_PCIE_CREDITS, credits);
175 	} else {
176 		if (tb_port_is_null(port))
177 			credits = port->bonded ? 32 : 16;
178 		else
179 			credits = 7;
180 	}
181 
182 	hop->initial_credits = credits;
183 	return 0;
184 }
185 
tb_pci_init_path(struct tb_path * path)186 static int tb_pci_init_path(struct tb_path *path)
187 {
188 	struct tb_path_hop *hop;
189 
190 	path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
191 	path->egress_shared_buffer = TB_PATH_NONE;
192 	path->ingress_fc_enable = TB_PATH_ALL;
193 	path->ingress_shared_buffer = TB_PATH_NONE;
194 	path->priority = 3;
195 	path->weight = 1;
196 	path->drop_packages = 0;
197 
198 	tb_path_for_each_hop(path, hop) {
199 		int ret;
200 
201 		ret = tb_pci_init_credits(hop);
202 		if (ret)
203 			return ret;
204 	}
205 
206 	return 0;
207 }
208 
209 /**
210  * tb_tunnel_discover_pci() - Discover existing PCIe tunnels
211  * @tb: Pointer to the domain structure
212  * @down: PCIe downstream adapter
213  * @alloc_hopid: Allocate HopIDs from visited ports
214  *
215  * If @down adapter is active, follows the tunnel to the PCIe upstream
216  * adapter and back. Returns the discovered tunnel or %NULL if there was
217  * no tunnel.
218  */
tb_tunnel_discover_pci(struct tb * tb,struct tb_port * down,bool alloc_hopid)219 struct tb_tunnel *tb_tunnel_discover_pci(struct tb *tb, struct tb_port *down,
220 					 bool alloc_hopid)
221 {
222 	struct tb_tunnel *tunnel;
223 	struct tb_path *path;
224 
225 	if (!tb_pci_port_is_enabled(down))
226 		return NULL;
227 
228 	tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_PCI);
229 	if (!tunnel)
230 		return NULL;
231 
232 	tunnel->activate = tb_pci_activate;
233 	tunnel->src_port = down;
234 
235 	/*
236 	 * Discover both paths even if they are not complete. We will
237 	 * clean them up by calling tb_tunnel_deactivate() below in that
238 	 * case.
239 	 */
240 	path = tb_path_discover(down, TB_PCI_HOPID, NULL, -1,
241 				&tunnel->dst_port, "PCIe Up", alloc_hopid);
242 	if (!path) {
243 		/* Just disable the downstream port */
244 		tb_pci_port_enable(down, false);
245 		goto err_free;
246 	}
247 	tunnel->paths[TB_PCI_PATH_UP] = path;
248 	if (tb_pci_init_path(tunnel->paths[TB_PCI_PATH_UP]))
249 		goto err_free;
250 
251 	path = tb_path_discover(tunnel->dst_port, -1, down, TB_PCI_HOPID, NULL,
252 				"PCIe Down", alloc_hopid);
253 	if (!path)
254 		goto err_deactivate;
255 	tunnel->paths[TB_PCI_PATH_DOWN] = path;
256 	if (tb_pci_init_path(tunnel->paths[TB_PCI_PATH_DOWN]))
257 		goto err_deactivate;
258 
259 	/* Validate that the tunnel is complete */
260 	if (!tb_port_is_pcie_up(tunnel->dst_port)) {
261 		tb_port_warn(tunnel->dst_port,
262 			     "path does not end on a PCIe adapter, cleaning up\n");
263 		goto err_deactivate;
264 	}
265 
266 	if (down != tunnel->src_port) {
267 		tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");
268 		goto err_deactivate;
269 	}
270 
271 	if (!tb_pci_port_is_enabled(tunnel->dst_port)) {
272 		tb_tunnel_warn(tunnel,
273 			       "tunnel is not fully activated, cleaning up\n");
274 		goto err_deactivate;
275 	}
276 
277 	tb_tunnel_dbg(tunnel, "discovered\n");
278 	return tunnel;
279 
280 err_deactivate:
281 	tb_tunnel_deactivate(tunnel);
282 err_free:
283 	tb_tunnel_free(tunnel);
284 
285 	return NULL;
286 }
287 
288 /**
289  * tb_tunnel_alloc_pci() - allocate a pci tunnel
290  * @tb: Pointer to the domain structure
291  * @up: PCIe upstream adapter port
292  * @down: PCIe downstream adapter port
293  *
294  * Allocate a PCI tunnel. The ports must be of type TB_TYPE_PCIE_UP and
295  * TB_TYPE_PCIE_DOWN.
296  *
297  * Return: Returns a tb_tunnel on success or NULL on failure.
298  */
tb_tunnel_alloc_pci(struct tb * tb,struct tb_port * up,struct tb_port * down)299 struct tb_tunnel *tb_tunnel_alloc_pci(struct tb *tb, struct tb_port *up,
300 				      struct tb_port *down)
301 {
302 	struct tb_tunnel *tunnel;
303 	struct tb_path *path;
304 
305 	tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_PCI);
306 	if (!tunnel)
307 		return NULL;
308 
309 	tunnel->activate = tb_pci_activate;
310 	tunnel->src_port = down;
311 	tunnel->dst_port = up;
312 
313 	path = tb_path_alloc(tb, down, TB_PCI_HOPID, up, TB_PCI_HOPID, 0,
314 			     "PCIe Down");
315 	if (!path)
316 		goto err_free;
317 	tunnel->paths[TB_PCI_PATH_DOWN] = path;
318 	if (tb_pci_init_path(path))
319 		goto err_free;
320 
321 	path = tb_path_alloc(tb, up, TB_PCI_HOPID, down, TB_PCI_HOPID, 0,
322 			     "PCIe Up");
323 	if (!path)
324 		goto err_free;
325 	tunnel->paths[TB_PCI_PATH_UP] = path;
326 	if (tb_pci_init_path(path))
327 		goto err_free;
328 
329 	return tunnel;
330 
331 err_free:
332 	tb_tunnel_free(tunnel);
333 	return NULL;
334 }
335 
tb_dp_is_usb4(const struct tb_switch * sw)336 static bool tb_dp_is_usb4(const struct tb_switch *sw)
337 {
338 	/* Titan Ridge DP adapters need the same treatment as USB4 */
339 	return tb_switch_is_usb4(sw) || tb_switch_is_titan_ridge(sw);
340 }
341 
tb_dp_cm_handshake(struct tb_port * in,struct tb_port * out)342 static int tb_dp_cm_handshake(struct tb_port *in, struct tb_port *out)
343 {
344 	int timeout = 10;
345 	u32 val;
346 	int ret;
347 
348 	/* Both ends need to support this */
349 	if (!tb_dp_is_usb4(in->sw) || !tb_dp_is_usb4(out->sw))
350 		return 0;
351 
352 	ret = tb_port_read(out, &val, TB_CFG_PORT,
353 			   out->cap_adap + DP_STATUS_CTRL, 1);
354 	if (ret)
355 		return ret;
356 
357 	val |= DP_STATUS_CTRL_UF | DP_STATUS_CTRL_CMHS;
358 
359 	ret = tb_port_write(out, &val, TB_CFG_PORT,
360 			    out->cap_adap + DP_STATUS_CTRL, 1);
361 	if (ret)
362 		return ret;
363 
364 	do {
365 		ret = tb_port_read(out, &val, TB_CFG_PORT,
366 				   out->cap_adap + DP_STATUS_CTRL, 1);
367 		if (ret)
368 			return ret;
369 		if (!(val & DP_STATUS_CTRL_CMHS))
370 			return 0;
371 		usleep_range(10, 100);
372 	} while (timeout--);
373 
374 	return -ETIMEDOUT;
375 }
376 
tb_dp_cap_get_rate(u32 val)377 static inline u32 tb_dp_cap_get_rate(u32 val)
378 {
379 	u32 rate = (val & DP_COMMON_CAP_RATE_MASK) >> DP_COMMON_CAP_RATE_SHIFT;
380 
381 	switch (rate) {
382 	case DP_COMMON_CAP_RATE_RBR:
383 		return 1620;
384 	case DP_COMMON_CAP_RATE_HBR:
385 		return 2700;
386 	case DP_COMMON_CAP_RATE_HBR2:
387 		return 5400;
388 	case DP_COMMON_CAP_RATE_HBR3:
389 		return 8100;
390 	default:
391 		return 0;
392 	}
393 }
394 
tb_dp_cap_set_rate(u32 val,u32 rate)395 static inline u32 tb_dp_cap_set_rate(u32 val, u32 rate)
396 {
397 	val &= ~DP_COMMON_CAP_RATE_MASK;
398 	switch (rate) {
399 	default:
400 		WARN(1, "invalid rate %u passed, defaulting to 1620 MB/s\n", rate);
401 		fallthrough;
402 	case 1620:
403 		val |= DP_COMMON_CAP_RATE_RBR << DP_COMMON_CAP_RATE_SHIFT;
404 		break;
405 	case 2700:
406 		val |= DP_COMMON_CAP_RATE_HBR << DP_COMMON_CAP_RATE_SHIFT;
407 		break;
408 	case 5400:
409 		val |= DP_COMMON_CAP_RATE_HBR2 << DP_COMMON_CAP_RATE_SHIFT;
410 		break;
411 	case 8100:
412 		val |= DP_COMMON_CAP_RATE_HBR3 << DP_COMMON_CAP_RATE_SHIFT;
413 		break;
414 	}
415 	return val;
416 }
417 
tb_dp_cap_get_lanes(u32 val)418 static inline u32 tb_dp_cap_get_lanes(u32 val)
419 {
420 	u32 lanes = (val & DP_COMMON_CAP_LANES_MASK) >> DP_COMMON_CAP_LANES_SHIFT;
421 
422 	switch (lanes) {
423 	case DP_COMMON_CAP_1_LANE:
424 		return 1;
425 	case DP_COMMON_CAP_2_LANES:
426 		return 2;
427 	case DP_COMMON_CAP_4_LANES:
428 		return 4;
429 	default:
430 		return 0;
431 	}
432 }
433 
tb_dp_cap_set_lanes(u32 val,u32 lanes)434 static inline u32 tb_dp_cap_set_lanes(u32 val, u32 lanes)
435 {
436 	val &= ~DP_COMMON_CAP_LANES_MASK;
437 	switch (lanes) {
438 	default:
439 		WARN(1, "invalid number of lanes %u passed, defaulting to 1\n",
440 		     lanes);
441 		fallthrough;
442 	case 1:
443 		val |= DP_COMMON_CAP_1_LANE << DP_COMMON_CAP_LANES_SHIFT;
444 		break;
445 	case 2:
446 		val |= DP_COMMON_CAP_2_LANES << DP_COMMON_CAP_LANES_SHIFT;
447 		break;
448 	case 4:
449 		val |= DP_COMMON_CAP_4_LANES << DP_COMMON_CAP_LANES_SHIFT;
450 		break;
451 	}
452 	return val;
453 }
454 
tb_dp_bandwidth(unsigned int rate,unsigned int lanes)455 static unsigned int tb_dp_bandwidth(unsigned int rate, unsigned int lanes)
456 {
457 	/* Tunneling removes the DP 8b/10b encoding */
458 	return rate * lanes * 8 / 10;
459 }
460 
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)461 static int tb_dp_reduce_bandwidth(int max_bw, u32 in_rate, u32 in_lanes,
462 				  u32 out_rate, u32 out_lanes, u32 *new_rate,
463 				  u32 *new_lanes)
464 {
465 	static const u32 dp_bw[][2] = {
466 		/* Mb/s, lanes */
467 		{ 8100, 4 }, /* 25920 Mb/s */
468 		{ 5400, 4 }, /* 17280 Mb/s */
469 		{ 8100, 2 }, /* 12960 Mb/s */
470 		{ 2700, 4 }, /* 8640 Mb/s */
471 		{ 5400, 2 }, /* 8640 Mb/s */
472 		{ 8100, 1 }, /* 6480 Mb/s */
473 		{ 1620, 4 }, /* 5184 Mb/s */
474 		{ 5400, 1 }, /* 4320 Mb/s */
475 		{ 2700, 2 }, /* 4320 Mb/s */
476 		{ 1620, 2 }, /* 2592 Mb/s */
477 		{ 2700, 1 }, /* 2160 Mb/s */
478 		{ 1620, 1 }, /* 1296 Mb/s */
479 	};
480 	unsigned int i;
481 
482 	/*
483 	 * Find a combination that can fit into max_bw and does not
484 	 * exceed the maximum rate and lanes supported by the DP OUT and
485 	 * DP IN adapters.
486 	 */
487 	for (i = 0; i < ARRAY_SIZE(dp_bw); i++) {
488 		if (dp_bw[i][0] > out_rate || dp_bw[i][1] > out_lanes)
489 			continue;
490 
491 		if (dp_bw[i][0] > in_rate || dp_bw[i][1] > in_lanes)
492 			continue;
493 
494 		if (tb_dp_bandwidth(dp_bw[i][0], dp_bw[i][1]) <= max_bw) {
495 			*new_rate = dp_bw[i][0];
496 			*new_lanes = dp_bw[i][1];
497 			return 0;
498 		}
499 	}
500 
501 	return -ENOSR;
502 }
503 
tb_dp_xchg_caps(struct tb_tunnel * tunnel)504 static int tb_dp_xchg_caps(struct tb_tunnel *tunnel)
505 {
506 	u32 out_dp_cap, out_rate, out_lanes, in_dp_cap, in_rate, in_lanes, bw;
507 	struct tb_port *out = tunnel->dst_port;
508 	struct tb_port *in = tunnel->src_port;
509 	int ret, max_bw;
510 
511 	/*
512 	 * Copy DP_LOCAL_CAP register to DP_REMOTE_CAP register for
513 	 * newer generation hardware.
514 	 */
515 	if (in->sw->generation < 2 || out->sw->generation < 2)
516 		return 0;
517 
518 	/*
519 	 * Perform connection manager handshake between IN and OUT ports
520 	 * before capabilities exchange can take place.
521 	 */
522 	ret = tb_dp_cm_handshake(in, out);
523 	if (ret)
524 		return ret;
525 
526 	/* Read both DP_LOCAL_CAP registers */
527 	ret = tb_port_read(in, &in_dp_cap, TB_CFG_PORT,
528 			   in->cap_adap + DP_LOCAL_CAP, 1);
529 	if (ret)
530 		return ret;
531 
532 	ret = tb_port_read(out, &out_dp_cap, TB_CFG_PORT,
533 			   out->cap_adap + DP_LOCAL_CAP, 1);
534 	if (ret)
535 		return ret;
536 
537 	/* Write IN local caps to OUT remote caps */
538 	ret = tb_port_write(out, &in_dp_cap, TB_CFG_PORT,
539 			    out->cap_adap + DP_REMOTE_CAP, 1);
540 	if (ret)
541 		return ret;
542 
543 	in_rate = tb_dp_cap_get_rate(in_dp_cap);
544 	in_lanes = tb_dp_cap_get_lanes(in_dp_cap);
545 	tb_port_dbg(in, "maximum supported bandwidth %u Mb/s x%u = %u Mb/s\n",
546 		    in_rate, in_lanes, tb_dp_bandwidth(in_rate, in_lanes));
547 
548 	/*
549 	 * If the tunnel bandwidth is limited (max_bw is set) then see
550 	 * if we need to reduce bandwidth to fit there.
551 	 */
552 	out_rate = tb_dp_cap_get_rate(out_dp_cap);
553 	out_lanes = tb_dp_cap_get_lanes(out_dp_cap);
554 	bw = tb_dp_bandwidth(out_rate, out_lanes);
555 	tb_port_dbg(out, "maximum supported bandwidth %u Mb/s x%u = %u Mb/s\n",
556 		    out_rate, out_lanes, bw);
557 
558 	if (in->sw->config.depth < out->sw->config.depth)
559 		max_bw = tunnel->max_down;
560 	else
561 		max_bw = tunnel->max_up;
562 
563 	if (max_bw && bw > max_bw) {
564 		u32 new_rate, new_lanes, new_bw;
565 
566 		ret = tb_dp_reduce_bandwidth(max_bw, in_rate, in_lanes,
567 					     out_rate, out_lanes, &new_rate,
568 					     &new_lanes);
569 		if (ret) {
570 			tb_port_info(out, "not enough bandwidth for DP tunnel\n");
571 			return ret;
572 		}
573 
574 		new_bw = tb_dp_bandwidth(new_rate, new_lanes);
575 		tb_port_dbg(out, "bandwidth reduced to %u Mb/s x%u = %u Mb/s\n",
576 			    new_rate, new_lanes, new_bw);
577 
578 		/*
579 		 * Set new rate and number of lanes before writing it to
580 		 * the IN port remote caps.
581 		 */
582 		out_dp_cap = tb_dp_cap_set_rate(out_dp_cap, new_rate);
583 		out_dp_cap = tb_dp_cap_set_lanes(out_dp_cap, new_lanes);
584 	}
585 
586 	/*
587 	 * Titan Ridge does not disable AUX timers when it gets
588 	 * SET_CONFIG with SET_LTTPR_MODE set. This causes problems with
589 	 * DP tunneling.
590 	 */
591 	if (tb_route(out->sw) && tb_switch_is_titan_ridge(out->sw)) {
592 		out_dp_cap |= DP_COMMON_CAP_LTTPR_NS;
593 		tb_port_dbg(out, "disabling LTTPR\n");
594 	}
595 
596 	return tb_port_write(in, &out_dp_cap, TB_CFG_PORT,
597 			     in->cap_adap + DP_REMOTE_CAP, 1);
598 }
599 
tb_dp_activate(struct tb_tunnel * tunnel,bool active)600 static int tb_dp_activate(struct tb_tunnel *tunnel, bool active)
601 {
602 	int ret;
603 
604 	if (active) {
605 		struct tb_path **paths;
606 		int last;
607 
608 		paths = tunnel->paths;
609 		last = paths[TB_DP_VIDEO_PATH_OUT]->path_length - 1;
610 
611 		tb_dp_port_set_hops(tunnel->src_port,
612 			paths[TB_DP_VIDEO_PATH_OUT]->hops[0].in_hop_index,
613 			paths[TB_DP_AUX_PATH_OUT]->hops[0].in_hop_index,
614 			paths[TB_DP_AUX_PATH_IN]->hops[last].next_hop_index);
615 
616 		tb_dp_port_set_hops(tunnel->dst_port,
617 			paths[TB_DP_VIDEO_PATH_OUT]->hops[last].next_hop_index,
618 			paths[TB_DP_AUX_PATH_IN]->hops[0].in_hop_index,
619 			paths[TB_DP_AUX_PATH_OUT]->hops[last].next_hop_index);
620 	} else {
621 		tb_dp_port_hpd_clear(tunnel->src_port);
622 		tb_dp_port_set_hops(tunnel->src_port, 0, 0, 0);
623 		if (tb_port_is_dpout(tunnel->dst_port))
624 			tb_dp_port_set_hops(tunnel->dst_port, 0, 0, 0);
625 	}
626 
627 	ret = tb_dp_port_enable(tunnel->src_port, active);
628 	if (ret)
629 		return ret;
630 
631 	if (tb_port_is_dpout(tunnel->dst_port))
632 		return tb_dp_port_enable(tunnel->dst_port, active);
633 
634 	return 0;
635 }
636 
tb_dp_consumed_bandwidth(struct tb_tunnel * tunnel,int * consumed_up,int * consumed_down)637 static int tb_dp_consumed_bandwidth(struct tb_tunnel *tunnel, int *consumed_up,
638 				    int *consumed_down)
639 {
640 	struct tb_port *in = tunnel->src_port;
641 	const struct tb_switch *sw = in->sw;
642 	u32 val, rate = 0, lanes = 0;
643 	int ret;
644 
645 	if (tb_dp_is_usb4(sw)) {
646 		int timeout = 20;
647 
648 		/*
649 		 * Wait for DPRX done. Normally it should be already set
650 		 * for active tunnel.
651 		 */
652 		do {
653 			ret = tb_port_read(in, &val, TB_CFG_PORT,
654 					   in->cap_adap + DP_COMMON_CAP, 1);
655 			if (ret)
656 				return ret;
657 
658 			if (val & DP_COMMON_CAP_DPRX_DONE) {
659 				rate = tb_dp_cap_get_rate(val);
660 				lanes = tb_dp_cap_get_lanes(val);
661 				break;
662 			}
663 			msleep(250);
664 		} while (timeout--);
665 
666 		if (!timeout)
667 			return -ETIMEDOUT;
668 	} else if (sw->generation >= 2) {
669 		/*
670 		 * Read from the copied remote cap so that we take into
671 		 * account if capabilities were reduced during exchange.
672 		 */
673 		ret = tb_port_read(in, &val, TB_CFG_PORT,
674 				   in->cap_adap + DP_REMOTE_CAP, 1);
675 		if (ret)
676 			return ret;
677 
678 		rate = tb_dp_cap_get_rate(val);
679 		lanes = tb_dp_cap_get_lanes(val);
680 	} else {
681 		/* No bandwidth management for legacy devices  */
682 		*consumed_up = 0;
683 		*consumed_down = 0;
684 		return 0;
685 	}
686 
687 	if (in->sw->config.depth < tunnel->dst_port->sw->config.depth) {
688 		*consumed_up = 0;
689 		*consumed_down = tb_dp_bandwidth(rate, lanes);
690 	} else {
691 		*consumed_up = tb_dp_bandwidth(rate, lanes);
692 		*consumed_down = 0;
693 	}
694 
695 	return 0;
696 }
697 
tb_dp_init_aux_credits(struct tb_path_hop * hop)698 static void tb_dp_init_aux_credits(struct tb_path_hop *hop)
699 {
700 	struct tb_port *port = hop->in_port;
701 	struct tb_switch *sw = port->sw;
702 
703 	if (tb_port_use_credit_allocation(port))
704 		hop->initial_credits = sw->min_dp_aux_credits;
705 	else
706 		hop->initial_credits = 1;
707 }
708 
tb_dp_init_aux_path(struct tb_path * path)709 static void tb_dp_init_aux_path(struct tb_path *path)
710 {
711 	struct tb_path_hop *hop;
712 
713 	path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
714 	path->egress_shared_buffer = TB_PATH_NONE;
715 	path->ingress_fc_enable = TB_PATH_ALL;
716 	path->ingress_shared_buffer = TB_PATH_NONE;
717 	path->priority = 2;
718 	path->weight = 1;
719 
720 	tb_path_for_each_hop(path, hop)
721 		tb_dp_init_aux_credits(hop);
722 }
723 
tb_dp_init_video_credits(struct tb_path_hop * hop)724 static int tb_dp_init_video_credits(struct tb_path_hop *hop)
725 {
726 	struct tb_port *port = hop->in_port;
727 	struct tb_switch *sw = port->sw;
728 
729 	if (tb_port_use_credit_allocation(port)) {
730 		unsigned int nfc_credits;
731 		size_t max_dp_streams;
732 
733 		tb_available_credits(port, &max_dp_streams);
734 		/*
735 		 * Read the number of currently allocated NFC credits
736 		 * from the lane adapter. Since we only use them for DP
737 		 * tunneling we can use that to figure out how many DP
738 		 * tunnels already go through the lane adapter.
739 		 */
740 		nfc_credits = port->config.nfc_credits &
741 				ADP_CS_4_NFC_BUFFERS_MASK;
742 		if (nfc_credits / sw->min_dp_main_credits > max_dp_streams)
743 			return -ENOSPC;
744 
745 		hop->nfc_credits = sw->min_dp_main_credits;
746 	} else {
747 		hop->nfc_credits = min(port->total_credits - 2, 12U);
748 	}
749 
750 	return 0;
751 }
752 
tb_dp_init_video_path(struct tb_path * path)753 static int tb_dp_init_video_path(struct tb_path *path)
754 {
755 	struct tb_path_hop *hop;
756 
757 	path->egress_fc_enable = TB_PATH_NONE;
758 	path->egress_shared_buffer = TB_PATH_NONE;
759 	path->ingress_fc_enable = TB_PATH_NONE;
760 	path->ingress_shared_buffer = TB_PATH_NONE;
761 	path->priority = 1;
762 	path->weight = 1;
763 
764 	tb_path_for_each_hop(path, hop) {
765 		int ret;
766 
767 		ret = tb_dp_init_video_credits(hop);
768 		if (ret)
769 			return ret;
770 	}
771 
772 	return 0;
773 }
774 
775 /**
776  * tb_tunnel_discover_dp() - Discover existing Display Port tunnels
777  * @tb: Pointer to the domain structure
778  * @in: DP in adapter
779  * @alloc_hopid: Allocate HopIDs from visited ports
780  *
781  * If @in adapter is active, follows the tunnel to the DP out adapter
782  * and back. Returns the discovered tunnel or %NULL if there was no
783  * tunnel.
784  *
785  * Return: DP tunnel or %NULL if no tunnel found.
786  */
tb_tunnel_discover_dp(struct tb * tb,struct tb_port * in,bool alloc_hopid)787 struct tb_tunnel *tb_tunnel_discover_dp(struct tb *tb, struct tb_port *in,
788 					bool alloc_hopid)
789 {
790 	struct tb_tunnel *tunnel;
791 	struct tb_port *port;
792 	struct tb_path *path;
793 
794 	if (!tb_dp_port_is_enabled(in))
795 		return NULL;
796 
797 	tunnel = tb_tunnel_alloc(tb, 3, TB_TUNNEL_DP);
798 	if (!tunnel)
799 		return NULL;
800 
801 	tunnel->init = tb_dp_xchg_caps;
802 	tunnel->activate = tb_dp_activate;
803 	tunnel->consumed_bandwidth = tb_dp_consumed_bandwidth;
804 	tunnel->src_port = in;
805 
806 	path = tb_path_discover(in, TB_DP_VIDEO_HOPID, NULL, -1,
807 				&tunnel->dst_port, "Video", alloc_hopid);
808 	if (!path) {
809 		/* Just disable the DP IN port */
810 		tb_dp_port_enable(in, false);
811 		goto err_free;
812 	}
813 	tunnel->paths[TB_DP_VIDEO_PATH_OUT] = path;
814 	if (tb_dp_init_video_path(tunnel->paths[TB_DP_VIDEO_PATH_OUT]))
815 		goto err_free;
816 
817 	path = tb_path_discover(in, TB_DP_AUX_TX_HOPID, NULL, -1, NULL, "AUX TX",
818 				alloc_hopid);
819 	if (!path)
820 		goto err_deactivate;
821 	tunnel->paths[TB_DP_AUX_PATH_OUT] = path;
822 	tb_dp_init_aux_path(tunnel->paths[TB_DP_AUX_PATH_OUT]);
823 
824 	path = tb_path_discover(tunnel->dst_port, -1, in, TB_DP_AUX_RX_HOPID,
825 				&port, "AUX RX", alloc_hopid);
826 	if (!path)
827 		goto err_deactivate;
828 	tunnel->paths[TB_DP_AUX_PATH_IN] = path;
829 	tb_dp_init_aux_path(tunnel->paths[TB_DP_AUX_PATH_IN]);
830 
831 	/* Validate that the tunnel is complete */
832 	if (!tb_port_is_dpout(tunnel->dst_port)) {
833 		tb_port_warn(in, "path does not end on a DP adapter, cleaning up\n");
834 		goto err_deactivate;
835 	}
836 
837 	if (!tb_dp_port_is_enabled(tunnel->dst_port))
838 		goto err_deactivate;
839 
840 	if (!tb_dp_port_hpd_is_active(tunnel->dst_port))
841 		goto err_deactivate;
842 
843 	if (port != tunnel->src_port) {
844 		tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");
845 		goto err_deactivate;
846 	}
847 
848 	tb_tunnel_dbg(tunnel, "discovered\n");
849 	return tunnel;
850 
851 err_deactivate:
852 	tb_tunnel_deactivate(tunnel);
853 err_free:
854 	tb_tunnel_free(tunnel);
855 
856 	return NULL;
857 }
858 
859 /**
860  * tb_tunnel_alloc_dp() - allocate a Display Port tunnel
861  * @tb: Pointer to the domain structure
862  * @in: DP in adapter port
863  * @out: DP out adapter port
864  * @link_nr: Preferred lane adapter when the link is not bonded
865  * @max_up: Maximum available upstream bandwidth for the DP tunnel (%0
866  *	    if not limited)
867  * @max_down: Maximum available downstream bandwidth for the DP tunnel
868  *	      (%0 if not limited)
869  *
870  * Allocates a tunnel between @in and @out that is capable of tunneling
871  * Display Port traffic.
872  *
873  * Return: Returns a tb_tunnel on success or NULL on failure.
874  */
tb_tunnel_alloc_dp(struct tb * tb,struct tb_port * in,struct tb_port * out,int link_nr,int max_up,int max_down)875 struct tb_tunnel *tb_tunnel_alloc_dp(struct tb *tb, struct tb_port *in,
876 				     struct tb_port *out, int link_nr,
877 				     int max_up, int max_down)
878 {
879 	struct tb_tunnel *tunnel;
880 	struct tb_path **paths;
881 	struct tb_path *path;
882 
883 	if (WARN_ON(!in->cap_adap || !out->cap_adap))
884 		return NULL;
885 
886 	tunnel = tb_tunnel_alloc(tb, 3, TB_TUNNEL_DP);
887 	if (!tunnel)
888 		return NULL;
889 
890 	tunnel->init = tb_dp_xchg_caps;
891 	tunnel->activate = tb_dp_activate;
892 	tunnel->consumed_bandwidth = tb_dp_consumed_bandwidth;
893 	tunnel->src_port = in;
894 	tunnel->dst_port = out;
895 	tunnel->max_up = max_up;
896 	tunnel->max_down = max_down;
897 
898 	paths = tunnel->paths;
899 
900 	path = tb_path_alloc(tb, in, TB_DP_VIDEO_HOPID, out, TB_DP_VIDEO_HOPID,
901 			     link_nr, "Video");
902 	if (!path)
903 		goto err_free;
904 	tb_dp_init_video_path(path);
905 	paths[TB_DP_VIDEO_PATH_OUT] = path;
906 
907 	path = tb_path_alloc(tb, in, TB_DP_AUX_TX_HOPID, out,
908 			     TB_DP_AUX_TX_HOPID, link_nr, "AUX TX");
909 	if (!path)
910 		goto err_free;
911 	tb_dp_init_aux_path(path);
912 	paths[TB_DP_AUX_PATH_OUT] = path;
913 
914 	path = tb_path_alloc(tb, out, TB_DP_AUX_RX_HOPID, in,
915 			     TB_DP_AUX_RX_HOPID, link_nr, "AUX RX");
916 	if (!path)
917 		goto err_free;
918 	tb_dp_init_aux_path(path);
919 	paths[TB_DP_AUX_PATH_IN] = path;
920 
921 	return tunnel;
922 
923 err_free:
924 	tb_tunnel_free(tunnel);
925 	return NULL;
926 }
927 
tb_dma_available_credits(const struct tb_port * port)928 static unsigned int tb_dma_available_credits(const struct tb_port *port)
929 {
930 	const struct tb_switch *sw = port->sw;
931 	int credits;
932 
933 	credits = tb_available_credits(port, NULL);
934 	if (tb_acpi_may_tunnel_pcie())
935 		credits -= sw->max_pcie_credits;
936 	credits -= port->dma_credits;
937 
938 	return credits > 0 ? credits : 0;
939 }
940 
tb_dma_reserve_credits(struct tb_path_hop * hop,unsigned int credits)941 static int tb_dma_reserve_credits(struct tb_path_hop *hop, unsigned int credits)
942 {
943 	struct tb_port *port = hop->in_port;
944 
945 	if (tb_port_use_credit_allocation(port)) {
946 		unsigned int available = tb_dma_available_credits(port);
947 
948 		/*
949 		 * Need to have at least TB_MIN_DMA_CREDITS, otherwise
950 		 * DMA path cannot be established.
951 		 */
952 		if (available < TB_MIN_DMA_CREDITS)
953 			return -ENOSPC;
954 
955 		while (credits > available)
956 			credits--;
957 
958 		tb_port_dbg(port, "reserving %u credits for DMA path\n",
959 			    credits);
960 
961 		port->dma_credits += credits;
962 	} else {
963 		if (tb_port_is_null(port))
964 			credits = port->bonded ? 14 : 6;
965 		else
966 			credits = min(port->total_credits, credits);
967 	}
968 
969 	hop->initial_credits = credits;
970 	return 0;
971 }
972 
973 /* Path from lane adapter to NHI */
tb_dma_init_rx_path(struct tb_path * path,unsigned int credits)974 static int tb_dma_init_rx_path(struct tb_path *path, unsigned int credits)
975 {
976 	struct tb_path_hop *hop;
977 	unsigned int i, tmp;
978 
979 	path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
980 	path->ingress_fc_enable = TB_PATH_ALL;
981 	path->egress_shared_buffer = TB_PATH_NONE;
982 	path->ingress_shared_buffer = TB_PATH_NONE;
983 	path->priority = 5;
984 	path->weight = 1;
985 	path->clear_fc = true;
986 
987 	/*
988 	 * First lane adapter is the one connected to the remote host.
989 	 * We don't tunnel other traffic over this link so can use all
990 	 * the credits (except the ones reserved for control traffic).
991 	 */
992 	hop = &path->hops[0];
993 	tmp = min(tb_usable_credits(hop->in_port), credits);
994 	hop->initial_credits = tmp;
995 	hop->in_port->dma_credits += tmp;
996 
997 	for (i = 1; i < path->path_length; i++) {
998 		int ret;
999 
1000 		ret = tb_dma_reserve_credits(&path->hops[i], credits);
1001 		if (ret)
1002 			return ret;
1003 	}
1004 
1005 	return 0;
1006 }
1007 
1008 /* Path from NHI to lane adapter */
tb_dma_init_tx_path(struct tb_path * path,unsigned int credits)1009 static int tb_dma_init_tx_path(struct tb_path *path, unsigned int credits)
1010 {
1011 	struct tb_path_hop *hop;
1012 
1013 	path->egress_fc_enable = TB_PATH_ALL;
1014 	path->ingress_fc_enable = TB_PATH_ALL;
1015 	path->egress_shared_buffer = TB_PATH_NONE;
1016 	path->ingress_shared_buffer = TB_PATH_NONE;
1017 	path->priority = 5;
1018 	path->weight = 1;
1019 	path->clear_fc = true;
1020 
1021 	tb_path_for_each_hop(path, hop) {
1022 		int ret;
1023 
1024 		ret = tb_dma_reserve_credits(hop, credits);
1025 		if (ret)
1026 			return ret;
1027 	}
1028 
1029 	return 0;
1030 }
1031 
tb_dma_release_credits(struct tb_path_hop * hop)1032 static void tb_dma_release_credits(struct tb_path_hop *hop)
1033 {
1034 	struct tb_port *port = hop->in_port;
1035 
1036 	if (tb_port_use_credit_allocation(port)) {
1037 		port->dma_credits -= hop->initial_credits;
1038 
1039 		tb_port_dbg(port, "released %u DMA path credits\n",
1040 			    hop->initial_credits);
1041 	}
1042 }
1043 
tb_dma_deinit_path(struct tb_path * path)1044 static void tb_dma_deinit_path(struct tb_path *path)
1045 {
1046 	struct tb_path_hop *hop;
1047 
1048 	tb_path_for_each_hop(path, hop)
1049 		tb_dma_release_credits(hop);
1050 }
1051 
tb_dma_deinit(struct tb_tunnel * tunnel)1052 static void tb_dma_deinit(struct tb_tunnel *tunnel)
1053 {
1054 	int i;
1055 
1056 	for (i = 0; i < tunnel->npaths; i++) {
1057 		if (!tunnel->paths[i])
1058 			continue;
1059 		tb_dma_deinit_path(tunnel->paths[i]);
1060 	}
1061 }
1062 
1063 /**
1064  * tb_tunnel_alloc_dma() - allocate a DMA tunnel
1065  * @tb: Pointer to the domain structure
1066  * @nhi: Host controller port
1067  * @dst: Destination null port which the other domain is connected to
1068  * @transmit_path: HopID used for transmitting packets
1069  * @transmit_ring: NHI ring number used to send packets towards the
1070  *		   other domain. Set to %-1 if TX path is not needed.
1071  * @receive_path: HopID used for receiving packets
1072  * @receive_ring: NHI ring number used to receive packets from the
1073  *		  other domain. Set to %-1 if RX path is not needed.
1074  *
1075  * Return: Returns a tb_tunnel on success or NULL on failure.
1076  */
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)1077 struct tb_tunnel *tb_tunnel_alloc_dma(struct tb *tb, struct tb_port *nhi,
1078 				      struct tb_port *dst, int transmit_path,
1079 				      int transmit_ring, int receive_path,
1080 				      int receive_ring)
1081 {
1082 	struct tb_tunnel *tunnel;
1083 	size_t npaths = 0, i = 0;
1084 	struct tb_path *path;
1085 	int credits;
1086 
1087 	if (receive_ring > 0)
1088 		npaths++;
1089 	if (transmit_ring > 0)
1090 		npaths++;
1091 
1092 	if (WARN_ON(!npaths))
1093 		return NULL;
1094 
1095 	tunnel = tb_tunnel_alloc(tb, npaths, TB_TUNNEL_DMA);
1096 	if (!tunnel)
1097 		return NULL;
1098 
1099 	tunnel->src_port = nhi;
1100 	tunnel->dst_port = dst;
1101 	tunnel->deinit = tb_dma_deinit;
1102 
1103 	credits = min_not_zero(TB_DMA_CREDITS, nhi->sw->max_dma_credits);
1104 
1105 	if (receive_ring > 0) {
1106 		path = tb_path_alloc(tb, dst, receive_path, nhi, receive_ring, 0,
1107 				     "DMA RX");
1108 		if (!path)
1109 			goto err_free;
1110 		tunnel->paths[i++] = path;
1111 		if (tb_dma_init_rx_path(path, credits)) {
1112 			tb_tunnel_dbg(tunnel, "not enough buffers for RX path\n");
1113 			goto err_free;
1114 		}
1115 	}
1116 
1117 	if (transmit_ring > 0) {
1118 		path = tb_path_alloc(tb, nhi, transmit_ring, dst, transmit_path, 0,
1119 				     "DMA TX");
1120 		if (!path)
1121 			goto err_free;
1122 		tunnel->paths[i++] = path;
1123 		if (tb_dma_init_tx_path(path, credits)) {
1124 			tb_tunnel_dbg(tunnel, "not enough buffers for TX path\n");
1125 			goto err_free;
1126 		}
1127 	}
1128 
1129 	return tunnel;
1130 
1131 err_free:
1132 	tb_tunnel_free(tunnel);
1133 	return NULL;
1134 }
1135 
1136 /**
1137  * tb_tunnel_match_dma() - Match DMA tunnel
1138  * @tunnel: Tunnel to match
1139  * @transmit_path: HopID used for transmitting packets. Pass %-1 to ignore.
1140  * @transmit_ring: NHI ring number used to send packets towards the
1141  *		   other domain. Pass %-1 to ignore.
1142  * @receive_path: HopID used for receiving packets. Pass %-1 to ignore.
1143  * @receive_ring: NHI ring number used to receive packets from the
1144  *		  other domain. Pass %-1 to ignore.
1145  *
1146  * This function can be used to match specific DMA tunnel, if there are
1147  * multiple DMA tunnels going through the same XDomain connection.
1148  * Returns true if there is match and false otherwise.
1149  */
tb_tunnel_match_dma(const struct tb_tunnel * tunnel,int transmit_path,int transmit_ring,int receive_path,int receive_ring)1150 bool tb_tunnel_match_dma(const struct tb_tunnel *tunnel, int transmit_path,
1151 			 int transmit_ring, int receive_path, int receive_ring)
1152 {
1153 	const struct tb_path *tx_path = NULL, *rx_path = NULL;
1154 	int i;
1155 
1156 	if (!receive_ring || !transmit_ring)
1157 		return false;
1158 
1159 	for (i = 0; i < tunnel->npaths; i++) {
1160 		const struct tb_path *path = tunnel->paths[i];
1161 
1162 		if (!path)
1163 			continue;
1164 
1165 		if (tb_port_is_nhi(path->hops[0].in_port))
1166 			tx_path = path;
1167 		else if (tb_port_is_nhi(path->hops[path->path_length - 1].out_port))
1168 			rx_path = path;
1169 	}
1170 
1171 	if (transmit_ring > 0 || transmit_path > 0) {
1172 		if (!tx_path)
1173 			return false;
1174 		if (transmit_ring > 0 &&
1175 		    (tx_path->hops[0].in_hop_index != transmit_ring))
1176 			return false;
1177 		if (transmit_path > 0 &&
1178 		    (tx_path->hops[tx_path->path_length - 1].next_hop_index != transmit_path))
1179 			return false;
1180 	}
1181 
1182 	if (receive_ring > 0 || receive_path > 0) {
1183 		if (!rx_path)
1184 			return false;
1185 		if (receive_path > 0 &&
1186 		    (rx_path->hops[0].in_hop_index != receive_path))
1187 			return false;
1188 		if (receive_ring > 0 &&
1189 		    (rx_path->hops[rx_path->path_length - 1].next_hop_index != receive_ring))
1190 			return false;
1191 	}
1192 
1193 	return true;
1194 }
1195 
tb_usb3_max_link_rate(struct tb_port * up,struct tb_port * down)1196 static int tb_usb3_max_link_rate(struct tb_port *up, struct tb_port *down)
1197 {
1198 	int ret, up_max_rate, down_max_rate;
1199 
1200 	ret = usb4_usb3_port_max_link_rate(up);
1201 	if (ret < 0)
1202 		return ret;
1203 	up_max_rate = ret;
1204 
1205 	ret = usb4_usb3_port_max_link_rate(down);
1206 	if (ret < 0)
1207 		return ret;
1208 	down_max_rate = ret;
1209 
1210 	return min(up_max_rate, down_max_rate);
1211 }
1212 
tb_usb3_init(struct tb_tunnel * tunnel)1213 static int tb_usb3_init(struct tb_tunnel *tunnel)
1214 {
1215 	tb_tunnel_dbg(tunnel, "allocating initial bandwidth %d/%d Mb/s\n",
1216 		      tunnel->allocated_up, tunnel->allocated_down);
1217 
1218 	return usb4_usb3_port_allocate_bandwidth(tunnel->src_port,
1219 						 &tunnel->allocated_up,
1220 						 &tunnel->allocated_down);
1221 }
1222 
tb_usb3_activate(struct tb_tunnel * tunnel,bool activate)1223 static int tb_usb3_activate(struct tb_tunnel *tunnel, bool activate)
1224 {
1225 	int res;
1226 
1227 	res = tb_usb3_port_enable(tunnel->src_port, activate);
1228 	if (res)
1229 		return res;
1230 
1231 	if (tb_port_is_usb3_up(tunnel->dst_port))
1232 		return tb_usb3_port_enable(tunnel->dst_port, activate);
1233 
1234 	return 0;
1235 }
1236 
tb_usb3_consumed_bandwidth(struct tb_tunnel * tunnel,int * consumed_up,int * consumed_down)1237 static int tb_usb3_consumed_bandwidth(struct tb_tunnel *tunnel,
1238 		int *consumed_up, int *consumed_down)
1239 {
1240 	int pcie_enabled = tb_acpi_may_tunnel_pcie();
1241 
1242 	/*
1243 	 * PCIe tunneling, if enabled, affects the USB3 bandwidth so
1244 	 * take that it into account here.
1245 	 */
1246 	*consumed_up = tunnel->allocated_up * (3 + pcie_enabled) / 3;
1247 	*consumed_down = tunnel->allocated_down * (3 + pcie_enabled) / 3;
1248 	return 0;
1249 }
1250 
tb_usb3_release_unused_bandwidth(struct tb_tunnel * tunnel)1251 static int tb_usb3_release_unused_bandwidth(struct tb_tunnel *tunnel)
1252 {
1253 	int ret;
1254 
1255 	ret = usb4_usb3_port_release_bandwidth(tunnel->src_port,
1256 					       &tunnel->allocated_up,
1257 					       &tunnel->allocated_down);
1258 	if (ret)
1259 		return ret;
1260 
1261 	tb_tunnel_dbg(tunnel, "decreased bandwidth allocation to %d/%d Mb/s\n",
1262 		      tunnel->allocated_up, tunnel->allocated_down);
1263 	return 0;
1264 }
1265 
tb_usb3_reclaim_available_bandwidth(struct tb_tunnel * tunnel,int * available_up,int * available_down)1266 static void tb_usb3_reclaim_available_bandwidth(struct tb_tunnel *tunnel,
1267 						int *available_up,
1268 						int *available_down)
1269 {
1270 	int ret, max_rate, allocate_up, allocate_down;
1271 
1272 	ret = usb4_usb3_port_actual_link_rate(tunnel->src_port);
1273 	if (ret < 0) {
1274 		tb_tunnel_warn(tunnel, "failed to read actual link rate\n");
1275 		return;
1276 	} else if (!ret) {
1277 		/* Use maximum link rate if the link valid is not set */
1278 		ret = tb_usb3_max_link_rate(tunnel->dst_port, tunnel->src_port);
1279 		if (ret < 0) {
1280 			tb_tunnel_warn(tunnel, "failed to read maximum link rate\n");
1281 			return;
1282 		}
1283 	}
1284 
1285 	/*
1286 	 * 90% of the max rate can be allocated for isochronous
1287 	 * transfers.
1288 	 */
1289 	max_rate = ret * 90 / 100;
1290 
1291 	/* No need to reclaim if already at maximum */
1292 	if (tunnel->allocated_up >= max_rate &&
1293 	    tunnel->allocated_down >= max_rate)
1294 		return;
1295 
1296 	/* Don't go lower than what is already allocated */
1297 	allocate_up = min(max_rate, *available_up);
1298 	if (allocate_up < tunnel->allocated_up)
1299 		allocate_up = tunnel->allocated_up;
1300 
1301 	allocate_down = min(max_rate, *available_down);
1302 	if (allocate_down < tunnel->allocated_down)
1303 		allocate_down = tunnel->allocated_down;
1304 
1305 	/* If no changes no need to do more */
1306 	if (allocate_up == tunnel->allocated_up &&
1307 	    allocate_down == tunnel->allocated_down)
1308 		return;
1309 
1310 	ret = usb4_usb3_port_allocate_bandwidth(tunnel->src_port, &allocate_up,
1311 						&allocate_down);
1312 	if (ret) {
1313 		tb_tunnel_info(tunnel, "failed to allocate bandwidth\n");
1314 		return;
1315 	}
1316 
1317 	tunnel->allocated_up = allocate_up;
1318 	*available_up -= tunnel->allocated_up;
1319 
1320 	tunnel->allocated_down = allocate_down;
1321 	*available_down -= tunnel->allocated_down;
1322 
1323 	tb_tunnel_dbg(tunnel, "increased bandwidth allocation to %d/%d Mb/s\n",
1324 		      tunnel->allocated_up, tunnel->allocated_down);
1325 }
1326 
tb_usb3_init_credits(struct tb_path_hop * hop)1327 static void tb_usb3_init_credits(struct tb_path_hop *hop)
1328 {
1329 	struct tb_port *port = hop->in_port;
1330 	struct tb_switch *sw = port->sw;
1331 	unsigned int credits;
1332 
1333 	if (tb_port_use_credit_allocation(port)) {
1334 		credits = sw->max_usb3_credits;
1335 	} else {
1336 		if (tb_port_is_null(port))
1337 			credits = port->bonded ? 32 : 16;
1338 		else
1339 			credits = 7;
1340 	}
1341 
1342 	hop->initial_credits = credits;
1343 }
1344 
tb_usb3_init_path(struct tb_path * path)1345 static void tb_usb3_init_path(struct tb_path *path)
1346 {
1347 	struct tb_path_hop *hop;
1348 
1349 	path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
1350 	path->egress_shared_buffer = TB_PATH_NONE;
1351 	path->ingress_fc_enable = TB_PATH_ALL;
1352 	path->ingress_shared_buffer = TB_PATH_NONE;
1353 	path->priority = 3;
1354 	path->weight = 3;
1355 	path->drop_packages = 0;
1356 
1357 	tb_path_for_each_hop(path, hop)
1358 		tb_usb3_init_credits(hop);
1359 }
1360 
1361 /**
1362  * tb_tunnel_discover_usb3() - Discover existing USB3 tunnels
1363  * @tb: Pointer to the domain structure
1364  * @down: USB3 downstream adapter
1365  * @alloc_hopid: Allocate HopIDs from visited ports
1366  *
1367  * If @down adapter is active, follows the tunnel to the USB3 upstream
1368  * adapter and back. Returns the discovered tunnel or %NULL if there was
1369  * no tunnel.
1370  */
tb_tunnel_discover_usb3(struct tb * tb,struct tb_port * down,bool alloc_hopid)1371 struct tb_tunnel *tb_tunnel_discover_usb3(struct tb *tb, struct tb_port *down,
1372 					  bool alloc_hopid)
1373 {
1374 	struct tb_tunnel *tunnel;
1375 	struct tb_path *path;
1376 
1377 	if (!tb_usb3_port_is_enabled(down))
1378 		return NULL;
1379 
1380 	tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_USB3);
1381 	if (!tunnel)
1382 		return NULL;
1383 
1384 	tunnel->activate = tb_usb3_activate;
1385 	tunnel->src_port = down;
1386 
1387 	/*
1388 	 * Discover both paths even if they are not complete. We will
1389 	 * clean them up by calling tb_tunnel_deactivate() below in that
1390 	 * case.
1391 	 */
1392 	path = tb_path_discover(down, TB_USB3_HOPID, NULL, -1,
1393 				&tunnel->dst_port, "USB3 Down", alloc_hopid);
1394 	if (!path) {
1395 		/* Just disable the downstream port */
1396 		tb_usb3_port_enable(down, false);
1397 		goto err_free;
1398 	}
1399 	tunnel->paths[TB_USB3_PATH_DOWN] = path;
1400 	tb_usb3_init_path(tunnel->paths[TB_USB3_PATH_DOWN]);
1401 
1402 	path = tb_path_discover(tunnel->dst_port, -1, down, TB_USB3_HOPID, NULL,
1403 				"USB3 Up", alloc_hopid);
1404 	if (!path)
1405 		goto err_deactivate;
1406 	tunnel->paths[TB_USB3_PATH_UP] = path;
1407 	tb_usb3_init_path(tunnel->paths[TB_USB3_PATH_UP]);
1408 
1409 	/* Validate that the tunnel is complete */
1410 	if (!tb_port_is_usb3_up(tunnel->dst_port)) {
1411 		tb_port_warn(tunnel->dst_port,
1412 			     "path does not end on an USB3 adapter, cleaning up\n");
1413 		goto err_deactivate;
1414 	}
1415 
1416 	if (down != tunnel->src_port) {
1417 		tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");
1418 		goto err_deactivate;
1419 	}
1420 
1421 	if (!tb_usb3_port_is_enabled(tunnel->dst_port)) {
1422 		tb_tunnel_warn(tunnel,
1423 			       "tunnel is not fully activated, cleaning up\n");
1424 		goto err_deactivate;
1425 	}
1426 
1427 	if (!tb_route(down->sw)) {
1428 		int ret;
1429 
1430 		/*
1431 		 * Read the initial bandwidth allocation for the first
1432 		 * hop tunnel.
1433 		 */
1434 		ret = usb4_usb3_port_allocated_bandwidth(down,
1435 			&tunnel->allocated_up, &tunnel->allocated_down);
1436 		if (ret)
1437 			goto err_deactivate;
1438 
1439 		tb_tunnel_dbg(tunnel, "currently allocated bandwidth %d/%d Mb/s\n",
1440 			      tunnel->allocated_up, tunnel->allocated_down);
1441 
1442 		tunnel->init = tb_usb3_init;
1443 		tunnel->consumed_bandwidth = tb_usb3_consumed_bandwidth;
1444 		tunnel->release_unused_bandwidth =
1445 			tb_usb3_release_unused_bandwidth;
1446 		tunnel->reclaim_available_bandwidth =
1447 			tb_usb3_reclaim_available_bandwidth;
1448 	}
1449 
1450 	tb_tunnel_dbg(tunnel, "discovered\n");
1451 	return tunnel;
1452 
1453 err_deactivate:
1454 	tb_tunnel_deactivate(tunnel);
1455 err_free:
1456 	tb_tunnel_free(tunnel);
1457 
1458 	return NULL;
1459 }
1460 
1461 /**
1462  * tb_tunnel_alloc_usb3() - allocate a USB3 tunnel
1463  * @tb: Pointer to the domain structure
1464  * @up: USB3 upstream adapter port
1465  * @down: USB3 downstream adapter port
1466  * @max_up: Maximum available upstream bandwidth for the USB3 tunnel (%0
1467  *	    if not limited).
1468  * @max_down: Maximum available downstream bandwidth for the USB3 tunnel
1469  *	      (%0 if not limited).
1470  *
1471  * Allocate an USB3 tunnel. The ports must be of type @TB_TYPE_USB3_UP and
1472  * @TB_TYPE_USB3_DOWN.
1473  *
1474  * Return: Returns a tb_tunnel on success or %NULL on failure.
1475  */
tb_tunnel_alloc_usb3(struct tb * tb,struct tb_port * up,struct tb_port * down,int max_up,int max_down)1476 struct tb_tunnel *tb_tunnel_alloc_usb3(struct tb *tb, struct tb_port *up,
1477 				       struct tb_port *down, int max_up,
1478 				       int max_down)
1479 {
1480 	struct tb_tunnel *tunnel;
1481 	struct tb_path *path;
1482 	int max_rate = 0;
1483 
1484 	/*
1485 	 * Check that we have enough bandwidth available for the new
1486 	 * USB3 tunnel.
1487 	 */
1488 	if (max_up > 0 || max_down > 0) {
1489 		max_rate = tb_usb3_max_link_rate(down, up);
1490 		if (max_rate < 0)
1491 			return NULL;
1492 
1493 		/* Only 90% can be allocated for USB3 isochronous transfers */
1494 		max_rate = max_rate * 90 / 100;
1495 		tb_port_dbg(up, "required bandwidth for USB3 tunnel %d Mb/s\n",
1496 			    max_rate);
1497 
1498 		if (max_rate > max_up || max_rate > max_down) {
1499 			tb_port_warn(up, "not enough bandwidth for USB3 tunnel\n");
1500 			return NULL;
1501 		}
1502 	}
1503 
1504 	tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_USB3);
1505 	if (!tunnel)
1506 		return NULL;
1507 
1508 	tunnel->activate = tb_usb3_activate;
1509 	tunnel->src_port = down;
1510 	tunnel->dst_port = up;
1511 	tunnel->max_up = max_up;
1512 	tunnel->max_down = max_down;
1513 
1514 	path = tb_path_alloc(tb, down, TB_USB3_HOPID, up, TB_USB3_HOPID, 0,
1515 			     "USB3 Down");
1516 	if (!path) {
1517 		tb_tunnel_free(tunnel);
1518 		return NULL;
1519 	}
1520 	tb_usb3_init_path(path);
1521 	tunnel->paths[TB_USB3_PATH_DOWN] = path;
1522 
1523 	path = tb_path_alloc(tb, up, TB_USB3_HOPID, down, TB_USB3_HOPID, 0,
1524 			     "USB3 Up");
1525 	if (!path) {
1526 		tb_tunnel_free(tunnel);
1527 		return NULL;
1528 	}
1529 	tb_usb3_init_path(path);
1530 	tunnel->paths[TB_USB3_PATH_UP] = path;
1531 
1532 	if (!tb_route(down->sw)) {
1533 		tunnel->allocated_up = max_rate;
1534 		tunnel->allocated_down = max_rate;
1535 
1536 		tunnel->init = tb_usb3_init;
1537 		tunnel->consumed_bandwidth = tb_usb3_consumed_bandwidth;
1538 		tunnel->release_unused_bandwidth =
1539 			tb_usb3_release_unused_bandwidth;
1540 		tunnel->reclaim_available_bandwidth =
1541 			tb_usb3_reclaim_available_bandwidth;
1542 	}
1543 
1544 	return tunnel;
1545 }
1546 
1547 /**
1548  * tb_tunnel_free() - free a tunnel
1549  * @tunnel: Tunnel to be freed
1550  *
1551  * Frees a tunnel. The tunnel does not need to be deactivated.
1552  */
tb_tunnel_free(struct tb_tunnel * tunnel)1553 void tb_tunnel_free(struct tb_tunnel *tunnel)
1554 {
1555 	int i;
1556 
1557 	if (!tunnel)
1558 		return;
1559 
1560 	if (tunnel->deinit)
1561 		tunnel->deinit(tunnel);
1562 
1563 	for (i = 0; i < tunnel->npaths; i++) {
1564 		if (tunnel->paths[i])
1565 			tb_path_free(tunnel->paths[i]);
1566 	}
1567 
1568 	kfree(tunnel->paths);
1569 	kfree(tunnel);
1570 }
1571 
1572 /**
1573  * tb_tunnel_is_invalid - check whether an activated path is still valid
1574  * @tunnel: Tunnel to check
1575  */
tb_tunnel_is_invalid(struct tb_tunnel * tunnel)1576 bool tb_tunnel_is_invalid(struct tb_tunnel *tunnel)
1577 {
1578 	int i;
1579 
1580 	for (i = 0; i < tunnel->npaths; i++) {
1581 		WARN_ON(!tunnel->paths[i]->activated);
1582 		if (tb_path_is_invalid(tunnel->paths[i]))
1583 			return true;
1584 	}
1585 
1586 	return false;
1587 }
1588 
1589 /**
1590  * tb_tunnel_restart() - activate a tunnel after a hardware reset
1591  * @tunnel: Tunnel to restart
1592  *
1593  * Return: 0 on success and negative errno in case if failure
1594  */
tb_tunnel_restart(struct tb_tunnel * tunnel)1595 int tb_tunnel_restart(struct tb_tunnel *tunnel)
1596 {
1597 	int res, i;
1598 
1599 	tb_tunnel_dbg(tunnel, "activating\n");
1600 
1601 	/*
1602 	 * Make sure all paths are properly disabled before enabling
1603 	 * them again.
1604 	 */
1605 	for (i = 0; i < tunnel->npaths; i++) {
1606 		if (tunnel->paths[i]->activated) {
1607 			tb_path_deactivate(tunnel->paths[i]);
1608 			tunnel->paths[i]->activated = false;
1609 		}
1610 	}
1611 
1612 	if (tunnel->init) {
1613 		res = tunnel->init(tunnel);
1614 		if (res)
1615 			return res;
1616 	}
1617 
1618 	for (i = 0; i < tunnel->npaths; i++) {
1619 		res = tb_path_activate(tunnel->paths[i]);
1620 		if (res)
1621 			goto err;
1622 	}
1623 
1624 	if (tunnel->activate) {
1625 		res = tunnel->activate(tunnel, true);
1626 		if (res)
1627 			goto err;
1628 	}
1629 
1630 	return 0;
1631 
1632 err:
1633 	tb_tunnel_warn(tunnel, "activation failed\n");
1634 	tb_tunnel_deactivate(tunnel);
1635 	return res;
1636 }
1637 
1638 /**
1639  * tb_tunnel_activate() - activate a tunnel
1640  * @tunnel: Tunnel to activate
1641  *
1642  * Return: Returns 0 on success or an error code on failure.
1643  */
tb_tunnel_activate(struct tb_tunnel * tunnel)1644 int tb_tunnel_activate(struct tb_tunnel *tunnel)
1645 {
1646 	int i;
1647 
1648 	for (i = 0; i < tunnel->npaths; i++) {
1649 		if (tunnel->paths[i]->activated) {
1650 			tb_tunnel_WARN(tunnel,
1651 				       "trying to activate an already activated tunnel\n");
1652 			return -EINVAL;
1653 		}
1654 	}
1655 
1656 	return tb_tunnel_restart(tunnel);
1657 }
1658 
1659 /**
1660  * tb_tunnel_deactivate() - deactivate a tunnel
1661  * @tunnel: Tunnel to deactivate
1662  */
tb_tunnel_deactivate(struct tb_tunnel * tunnel)1663 void tb_tunnel_deactivate(struct tb_tunnel *tunnel)
1664 {
1665 	int i;
1666 
1667 	tb_tunnel_dbg(tunnel, "deactivating\n");
1668 
1669 	if (tunnel->activate)
1670 		tunnel->activate(tunnel, false);
1671 
1672 	for (i = 0; i < tunnel->npaths; i++) {
1673 		if (tunnel->paths[i] && tunnel->paths[i]->activated)
1674 			tb_path_deactivate(tunnel->paths[i]);
1675 	}
1676 }
1677 
1678 /**
1679  * tb_tunnel_port_on_path() - Does the tunnel go through port
1680  * @tunnel: Tunnel to check
1681  * @port: Port to check
1682  *
1683  * Returns true if @tunnel goes through @port (direction does not matter),
1684  * false otherwise.
1685  */
tb_tunnel_port_on_path(const struct tb_tunnel * tunnel,const struct tb_port * port)1686 bool tb_tunnel_port_on_path(const struct tb_tunnel *tunnel,
1687 			    const struct tb_port *port)
1688 {
1689 	int i;
1690 
1691 	for (i = 0; i < tunnel->npaths; i++) {
1692 		if (!tunnel->paths[i])
1693 			continue;
1694 
1695 		if (tb_path_port_on_path(tunnel->paths[i], port))
1696 			return true;
1697 	}
1698 
1699 	return false;
1700 }
1701 
tb_tunnel_is_active(const struct tb_tunnel * tunnel)1702 static bool tb_tunnel_is_active(const struct tb_tunnel *tunnel)
1703 {
1704 	int i;
1705 
1706 	for (i = 0; i < tunnel->npaths; i++) {
1707 		if (!tunnel->paths[i])
1708 			return false;
1709 		if (!tunnel->paths[i]->activated)
1710 			return false;
1711 	}
1712 
1713 	return true;
1714 }
1715 
1716 /**
1717  * tb_tunnel_consumed_bandwidth() - Return bandwidth consumed by the tunnel
1718  * @tunnel: Tunnel to check
1719  * @consumed_up: Consumed bandwidth in Mb/s from @dst_port to @src_port.
1720  *		 Can be %NULL.
1721  * @consumed_down: Consumed bandwidth in Mb/s from @src_port to @dst_port.
1722  *		   Can be %NULL.
1723  *
1724  * Stores the amount of isochronous bandwidth @tunnel consumes in
1725  * @consumed_up and @consumed_down. In case of success returns %0,
1726  * negative errno otherwise.
1727  */
tb_tunnel_consumed_bandwidth(struct tb_tunnel * tunnel,int * consumed_up,int * consumed_down)1728 int tb_tunnel_consumed_bandwidth(struct tb_tunnel *tunnel, int *consumed_up,
1729 				 int *consumed_down)
1730 {
1731 	int up_bw = 0, down_bw = 0;
1732 
1733 	if (!tb_tunnel_is_active(tunnel))
1734 		goto out;
1735 
1736 	if (tunnel->consumed_bandwidth) {
1737 		int ret;
1738 
1739 		ret = tunnel->consumed_bandwidth(tunnel, &up_bw, &down_bw);
1740 		if (ret)
1741 			return ret;
1742 
1743 		tb_tunnel_dbg(tunnel, "consumed bandwidth %d/%d Mb/s\n", up_bw,
1744 			      down_bw);
1745 	}
1746 
1747 out:
1748 	if (consumed_up)
1749 		*consumed_up = up_bw;
1750 	if (consumed_down)
1751 		*consumed_down = down_bw;
1752 
1753 	return 0;
1754 }
1755 
1756 /**
1757  * tb_tunnel_release_unused_bandwidth() - Release unused bandwidth
1758  * @tunnel: Tunnel whose unused bandwidth to release
1759  *
1760  * If tunnel supports dynamic bandwidth management (USB3 tunnels at the
1761  * moment) this function makes it to release all the unused bandwidth.
1762  *
1763  * Returns %0 in case of success and negative errno otherwise.
1764  */
tb_tunnel_release_unused_bandwidth(struct tb_tunnel * tunnel)1765 int tb_tunnel_release_unused_bandwidth(struct tb_tunnel *tunnel)
1766 {
1767 	if (!tb_tunnel_is_active(tunnel))
1768 		return 0;
1769 
1770 	if (tunnel->release_unused_bandwidth) {
1771 		int ret;
1772 
1773 		ret = tunnel->release_unused_bandwidth(tunnel);
1774 		if (ret)
1775 			return ret;
1776 	}
1777 
1778 	return 0;
1779 }
1780 
1781 /**
1782  * tb_tunnel_reclaim_available_bandwidth() - Reclaim available bandwidth
1783  * @tunnel: Tunnel reclaiming available bandwidth
1784  * @available_up: Available upstream bandwidth (in Mb/s)
1785  * @available_down: Available downstream bandwidth (in Mb/s)
1786  *
1787  * Reclaims bandwidth from @available_up and @available_down and updates
1788  * the variables accordingly (e.g decreases both according to what was
1789  * reclaimed by the tunnel). If nothing was reclaimed the values are
1790  * kept as is.
1791  */
tb_tunnel_reclaim_available_bandwidth(struct tb_tunnel * tunnel,int * available_up,int * available_down)1792 void tb_tunnel_reclaim_available_bandwidth(struct tb_tunnel *tunnel,
1793 					   int *available_up,
1794 					   int *available_down)
1795 {
1796 	if (!tb_tunnel_is_active(tunnel))
1797 		return;
1798 
1799 	if (tunnel->reclaim_available_bandwidth)
1800 		tunnel->reclaim_available_bandwidth(tunnel, available_up,
1801 						    available_down);
1802 }
1803