Merge tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux-2.6-microblaze.git] / drivers / thunderbolt / tunnel.c
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 static const char * const tb_tunnel_names[] = { "PCI", "DP", "DMA", "USB3" };
38
39 #define __TB_TUNNEL_PRINT(level, tunnel, fmt, arg...)                   \
40         do {                                                            \
41                 struct tb_tunnel *__tunnel = (tunnel);                  \
42                 level(__tunnel->tb, "%llx:%x <-> %llx:%x (%s): " fmt,   \
43                       tb_route(__tunnel->src_port->sw),                 \
44                       __tunnel->src_port->port,                         \
45                       tb_route(__tunnel->dst_port->sw),                 \
46                       __tunnel->dst_port->port,                         \
47                       tb_tunnel_names[__tunnel->type],                  \
48                       ## arg);                                          \
49         } while (0)
50
51 #define tb_tunnel_WARN(tunnel, fmt, arg...) \
52         __TB_TUNNEL_PRINT(tb_WARN, tunnel, fmt, ##arg)
53 #define tb_tunnel_warn(tunnel, fmt, arg...) \
54         __TB_TUNNEL_PRINT(tb_warn, tunnel, fmt, ##arg)
55 #define tb_tunnel_info(tunnel, fmt, arg...) \
56         __TB_TUNNEL_PRINT(tb_info, tunnel, fmt, ##arg)
57 #define tb_tunnel_dbg(tunnel, fmt, arg...) \
58         __TB_TUNNEL_PRINT(tb_dbg, tunnel, fmt, ##arg)
59
60 static struct tb_tunnel *tb_tunnel_alloc(struct tb *tb, size_t npaths,
61                                          enum tb_tunnel_type type)
62 {
63         struct tb_tunnel *tunnel;
64
65         tunnel = kzalloc(sizeof(*tunnel), GFP_KERNEL);
66         if (!tunnel)
67                 return NULL;
68
69         tunnel->paths = kcalloc(npaths, sizeof(tunnel->paths[0]), GFP_KERNEL);
70         if (!tunnel->paths) {
71                 tb_tunnel_free(tunnel);
72                 return NULL;
73         }
74
75         INIT_LIST_HEAD(&tunnel->list);
76         tunnel->tb = tb;
77         tunnel->npaths = npaths;
78         tunnel->type = type;
79
80         return tunnel;
81 }
82
83 static int tb_pci_activate(struct tb_tunnel *tunnel, bool activate)
84 {
85         int res;
86
87         res = tb_pci_port_enable(tunnel->src_port, activate);
88         if (res)
89                 return res;
90
91         if (tb_port_is_pcie_up(tunnel->dst_port))
92                 return tb_pci_port_enable(tunnel->dst_port, activate);
93
94         return 0;
95 }
96
97 static int tb_initial_credits(const struct tb_switch *sw)
98 {
99         /* If the path is complete sw is not NULL */
100         if (sw) {
101                 /* More credits for faster link */
102                 switch (sw->link_speed * sw->link_width) {
103                 case 40:
104                         return 32;
105                 case 20:
106                         return 24;
107                 }
108         }
109
110         return 16;
111 }
112
113 static void tb_pci_init_path(struct tb_path *path)
114 {
115         path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
116         path->egress_shared_buffer = TB_PATH_NONE;
117         path->ingress_fc_enable = TB_PATH_ALL;
118         path->ingress_shared_buffer = TB_PATH_NONE;
119         path->priority = 3;
120         path->weight = 1;
121         path->drop_packages = 0;
122         path->nfc_credits = 0;
123         path->hops[0].initial_credits = 7;
124         if (path->path_length > 1)
125                 path->hops[1].initial_credits =
126                         tb_initial_credits(path->hops[1].in_port->sw);
127 }
128
129 /**
130  * tb_tunnel_discover_pci() - Discover existing PCIe tunnels
131  * @tb: Pointer to the domain structure
132  * @down: PCIe downstream adapter
133  *
134  * If @down adapter is active, follows the tunnel to the PCIe upstream
135  * adapter and back. Returns the discovered tunnel or %NULL if there was
136  * no tunnel.
137  */
138 struct tb_tunnel *tb_tunnel_discover_pci(struct tb *tb, struct tb_port *down)
139 {
140         struct tb_tunnel *tunnel;
141         struct tb_path *path;
142
143         if (!tb_pci_port_is_enabled(down))
144                 return NULL;
145
146         tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_PCI);
147         if (!tunnel)
148                 return NULL;
149
150         tunnel->activate = tb_pci_activate;
151         tunnel->src_port = down;
152
153         /*
154          * Discover both paths even if they are not complete. We will
155          * clean them up by calling tb_tunnel_deactivate() below in that
156          * case.
157          */
158         path = tb_path_discover(down, TB_PCI_HOPID, NULL, -1,
159                                 &tunnel->dst_port, "PCIe Up");
160         if (!path) {
161                 /* Just disable the downstream port */
162                 tb_pci_port_enable(down, false);
163                 goto err_free;
164         }
165         tunnel->paths[TB_PCI_PATH_UP] = path;
166         tb_pci_init_path(tunnel->paths[TB_PCI_PATH_UP]);
167
168         path = tb_path_discover(tunnel->dst_port, -1, down, TB_PCI_HOPID, NULL,
169                                 "PCIe Down");
170         if (!path)
171                 goto err_deactivate;
172         tunnel->paths[TB_PCI_PATH_DOWN] = path;
173         tb_pci_init_path(tunnel->paths[TB_PCI_PATH_DOWN]);
174
175         /* Validate that the tunnel is complete */
176         if (!tb_port_is_pcie_up(tunnel->dst_port)) {
177                 tb_port_warn(tunnel->dst_port,
178                              "path does not end on a PCIe adapter, cleaning up\n");
179                 goto err_deactivate;
180         }
181
182         if (down != tunnel->src_port) {
183                 tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");
184                 goto err_deactivate;
185         }
186
187         if (!tb_pci_port_is_enabled(tunnel->dst_port)) {
188                 tb_tunnel_warn(tunnel,
189                                "tunnel is not fully activated, cleaning up\n");
190                 goto err_deactivate;
191         }
192
193         tb_tunnel_dbg(tunnel, "discovered\n");
194         return tunnel;
195
196 err_deactivate:
197         tb_tunnel_deactivate(tunnel);
198 err_free:
199         tb_tunnel_free(tunnel);
200
201         return NULL;
202 }
203
204 /**
205  * tb_tunnel_alloc_pci() - allocate a pci tunnel
206  * @tb: Pointer to the domain structure
207  * @up: PCIe upstream adapter port
208  * @down: PCIe downstream adapter port
209  *
210  * Allocate a PCI tunnel. The ports must be of type TB_TYPE_PCIE_UP and
211  * TB_TYPE_PCIE_DOWN.
212  *
213  * Return: Returns a tb_tunnel on success or NULL on failure.
214  */
215 struct tb_tunnel *tb_tunnel_alloc_pci(struct tb *tb, struct tb_port *up,
216                                       struct tb_port *down)
217 {
218         struct tb_tunnel *tunnel;
219         struct tb_path *path;
220
221         tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_PCI);
222         if (!tunnel)
223                 return NULL;
224
225         tunnel->activate = tb_pci_activate;
226         tunnel->src_port = down;
227         tunnel->dst_port = up;
228
229         path = tb_path_alloc(tb, down, TB_PCI_HOPID, up, TB_PCI_HOPID, 0,
230                              "PCIe Down");
231         if (!path) {
232                 tb_tunnel_free(tunnel);
233                 return NULL;
234         }
235         tb_pci_init_path(path);
236         tunnel->paths[TB_PCI_PATH_DOWN] = path;
237
238         path = tb_path_alloc(tb, up, TB_PCI_HOPID, down, TB_PCI_HOPID, 0,
239                              "PCIe Up");
240         if (!path) {
241                 tb_tunnel_free(tunnel);
242                 return NULL;
243         }
244         tb_pci_init_path(path);
245         tunnel->paths[TB_PCI_PATH_UP] = path;
246
247         return tunnel;
248 }
249
250 static bool tb_dp_is_usb4(const struct tb_switch *sw)
251 {
252         /* Titan Ridge DP adapters need the same treatment as USB4 */
253         return tb_switch_is_usb4(sw) || tb_switch_is_titan_ridge(sw);
254 }
255
256 static int tb_dp_cm_handshake(struct tb_port *in, struct tb_port *out)
257 {
258         int timeout = 10;
259         u32 val;
260         int ret;
261
262         /* Both ends need to support this */
263         if (!tb_dp_is_usb4(in->sw) || !tb_dp_is_usb4(out->sw))
264                 return 0;
265
266         ret = tb_port_read(out, &val, TB_CFG_PORT,
267                            out->cap_adap + DP_STATUS_CTRL, 1);
268         if (ret)
269                 return ret;
270
271         val |= DP_STATUS_CTRL_UF | DP_STATUS_CTRL_CMHS;
272
273         ret = tb_port_write(out, &val, TB_CFG_PORT,
274                             out->cap_adap + DP_STATUS_CTRL, 1);
275         if (ret)
276                 return ret;
277
278         do {
279                 ret = tb_port_read(out, &val, TB_CFG_PORT,
280                                    out->cap_adap + DP_STATUS_CTRL, 1);
281                 if (ret)
282                         return ret;
283                 if (!(val & DP_STATUS_CTRL_CMHS))
284                         return 0;
285                 usleep_range(10, 100);
286         } while (timeout--);
287
288         return -ETIMEDOUT;
289 }
290
291 static inline u32 tb_dp_cap_get_rate(u32 val)
292 {
293         u32 rate = (val & DP_COMMON_CAP_RATE_MASK) >> DP_COMMON_CAP_RATE_SHIFT;
294
295         switch (rate) {
296         case DP_COMMON_CAP_RATE_RBR:
297                 return 1620;
298         case DP_COMMON_CAP_RATE_HBR:
299                 return 2700;
300         case DP_COMMON_CAP_RATE_HBR2:
301                 return 5400;
302         case DP_COMMON_CAP_RATE_HBR3:
303                 return 8100;
304         default:
305                 return 0;
306         }
307 }
308
309 static inline u32 tb_dp_cap_set_rate(u32 val, u32 rate)
310 {
311         val &= ~DP_COMMON_CAP_RATE_MASK;
312         switch (rate) {
313         default:
314                 WARN(1, "invalid rate %u passed, defaulting to 1620 MB/s\n", rate);
315                 fallthrough;
316         case 1620:
317                 val |= DP_COMMON_CAP_RATE_RBR << DP_COMMON_CAP_RATE_SHIFT;
318                 break;
319         case 2700:
320                 val |= DP_COMMON_CAP_RATE_HBR << DP_COMMON_CAP_RATE_SHIFT;
321                 break;
322         case 5400:
323                 val |= DP_COMMON_CAP_RATE_HBR2 << DP_COMMON_CAP_RATE_SHIFT;
324                 break;
325         case 8100:
326                 val |= DP_COMMON_CAP_RATE_HBR3 << DP_COMMON_CAP_RATE_SHIFT;
327                 break;
328         }
329         return val;
330 }
331
332 static inline u32 tb_dp_cap_get_lanes(u32 val)
333 {
334         u32 lanes = (val & DP_COMMON_CAP_LANES_MASK) >> DP_COMMON_CAP_LANES_SHIFT;
335
336         switch (lanes) {
337         case DP_COMMON_CAP_1_LANE:
338                 return 1;
339         case DP_COMMON_CAP_2_LANES:
340                 return 2;
341         case DP_COMMON_CAP_4_LANES:
342                 return 4;
343         default:
344                 return 0;
345         }
346 }
347
348 static inline u32 tb_dp_cap_set_lanes(u32 val, u32 lanes)
349 {
350         val &= ~DP_COMMON_CAP_LANES_MASK;
351         switch (lanes) {
352         default:
353                 WARN(1, "invalid number of lanes %u passed, defaulting to 1\n",
354                      lanes);
355                 fallthrough;
356         case 1:
357                 val |= DP_COMMON_CAP_1_LANE << DP_COMMON_CAP_LANES_SHIFT;
358                 break;
359         case 2:
360                 val |= DP_COMMON_CAP_2_LANES << DP_COMMON_CAP_LANES_SHIFT;
361                 break;
362         case 4:
363                 val |= DP_COMMON_CAP_4_LANES << DP_COMMON_CAP_LANES_SHIFT;
364                 break;
365         }
366         return val;
367 }
368
369 static unsigned int tb_dp_bandwidth(unsigned int rate, unsigned int lanes)
370 {
371         /* Tunneling removes the DP 8b/10b encoding */
372         return rate * lanes * 8 / 10;
373 }
374
375 static int tb_dp_reduce_bandwidth(int max_bw, u32 in_rate, u32 in_lanes,
376                                   u32 out_rate, u32 out_lanes, u32 *new_rate,
377                                   u32 *new_lanes)
378 {
379         static const u32 dp_bw[][2] = {
380                 /* Mb/s, lanes */
381                 { 8100, 4 }, /* 25920 Mb/s */
382                 { 5400, 4 }, /* 17280 Mb/s */
383                 { 8100, 2 }, /* 12960 Mb/s */
384                 { 2700, 4 }, /* 8640 Mb/s */
385                 { 5400, 2 }, /* 8640 Mb/s */
386                 { 8100, 1 }, /* 6480 Mb/s */
387                 { 1620, 4 }, /* 5184 Mb/s */
388                 { 5400, 1 }, /* 4320 Mb/s */
389                 { 2700, 2 }, /* 4320 Mb/s */
390                 { 1620, 2 }, /* 2592 Mb/s */
391                 { 2700, 1 }, /* 2160 Mb/s */
392                 { 1620, 1 }, /* 1296 Mb/s */
393         };
394         unsigned int i;
395
396         /*
397          * Find a combination that can fit into max_bw and does not
398          * exceed the maximum rate and lanes supported by the DP OUT and
399          * DP IN adapters.
400          */
401         for (i = 0; i < ARRAY_SIZE(dp_bw); i++) {
402                 if (dp_bw[i][0] > out_rate || dp_bw[i][1] > out_lanes)
403                         continue;
404
405                 if (dp_bw[i][0] > in_rate || dp_bw[i][1] > in_lanes)
406                         continue;
407
408                 if (tb_dp_bandwidth(dp_bw[i][0], dp_bw[i][1]) <= max_bw) {
409                         *new_rate = dp_bw[i][0];
410                         *new_lanes = dp_bw[i][1];
411                         return 0;
412                 }
413         }
414
415         return -ENOSR;
416 }
417
418 static int tb_dp_xchg_caps(struct tb_tunnel *tunnel)
419 {
420         u32 out_dp_cap, out_rate, out_lanes, in_dp_cap, in_rate, in_lanes, bw;
421         struct tb_port *out = tunnel->dst_port;
422         struct tb_port *in = tunnel->src_port;
423         int ret, max_bw;
424
425         /*
426          * Copy DP_LOCAL_CAP register to DP_REMOTE_CAP register for
427          * newer generation hardware.
428          */
429         if (in->sw->generation < 2 || out->sw->generation < 2)
430                 return 0;
431
432         /*
433          * Perform connection manager handshake between IN and OUT ports
434          * before capabilities exchange can take place.
435          */
436         ret = tb_dp_cm_handshake(in, out);
437         if (ret)
438                 return ret;
439
440         /* Read both DP_LOCAL_CAP registers */
441         ret = tb_port_read(in, &in_dp_cap, TB_CFG_PORT,
442                            in->cap_adap + DP_LOCAL_CAP, 1);
443         if (ret)
444                 return ret;
445
446         ret = tb_port_read(out, &out_dp_cap, TB_CFG_PORT,
447                            out->cap_adap + DP_LOCAL_CAP, 1);
448         if (ret)
449                 return ret;
450
451         /* Write IN local caps to OUT remote caps */
452         ret = tb_port_write(out, &in_dp_cap, TB_CFG_PORT,
453                             out->cap_adap + DP_REMOTE_CAP, 1);
454         if (ret)
455                 return ret;
456
457         in_rate = tb_dp_cap_get_rate(in_dp_cap);
458         in_lanes = tb_dp_cap_get_lanes(in_dp_cap);
459         tb_port_dbg(in, "maximum supported bandwidth %u Mb/s x%u = %u Mb/s\n",
460                     in_rate, in_lanes, tb_dp_bandwidth(in_rate, in_lanes));
461
462         /*
463          * If the tunnel bandwidth is limited (max_bw is set) then see
464          * if we need to reduce bandwidth to fit there.
465          */
466         out_rate = tb_dp_cap_get_rate(out_dp_cap);
467         out_lanes = tb_dp_cap_get_lanes(out_dp_cap);
468         bw = tb_dp_bandwidth(out_rate, out_lanes);
469         tb_port_dbg(out, "maximum supported bandwidth %u Mb/s x%u = %u Mb/s\n",
470                     out_rate, out_lanes, bw);
471
472         if (in->sw->config.depth < out->sw->config.depth)
473                 max_bw = tunnel->max_down;
474         else
475                 max_bw = tunnel->max_up;
476
477         if (max_bw && bw > max_bw) {
478                 u32 new_rate, new_lanes, new_bw;
479
480                 ret = tb_dp_reduce_bandwidth(max_bw, in_rate, in_lanes,
481                                              out_rate, out_lanes, &new_rate,
482                                              &new_lanes);
483                 if (ret) {
484                         tb_port_info(out, "not enough bandwidth for DP tunnel\n");
485                         return ret;
486                 }
487
488                 new_bw = tb_dp_bandwidth(new_rate, new_lanes);
489                 tb_port_dbg(out, "bandwidth reduced to %u Mb/s x%u = %u Mb/s\n",
490                             new_rate, new_lanes, new_bw);
491
492                 /*
493                  * Set new rate and number of lanes before writing it to
494                  * the IN port remote caps.
495                  */
496                 out_dp_cap = tb_dp_cap_set_rate(out_dp_cap, new_rate);
497                 out_dp_cap = tb_dp_cap_set_lanes(out_dp_cap, new_lanes);
498         }
499
500         return tb_port_write(in, &out_dp_cap, TB_CFG_PORT,
501                              in->cap_adap + DP_REMOTE_CAP, 1);
502 }
503
504 static int tb_dp_activate(struct tb_tunnel *tunnel, bool active)
505 {
506         int ret;
507
508         if (active) {
509                 struct tb_path **paths;
510                 int last;
511
512                 paths = tunnel->paths;
513                 last = paths[TB_DP_VIDEO_PATH_OUT]->path_length - 1;
514
515                 tb_dp_port_set_hops(tunnel->src_port,
516                         paths[TB_DP_VIDEO_PATH_OUT]->hops[0].in_hop_index,
517                         paths[TB_DP_AUX_PATH_OUT]->hops[0].in_hop_index,
518                         paths[TB_DP_AUX_PATH_IN]->hops[last].next_hop_index);
519
520                 tb_dp_port_set_hops(tunnel->dst_port,
521                         paths[TB_DP_VIDEO_PATH_OUT]->hops[last].next_hop_index,
522                         paths[TB_DP_AUX_PATH_IN]->hops[0].in_hop_index,
523                         paths[TB_DP_AUX_PATH_OUT]->hops[last].next_hop_index);
524         } else {
525                 tb_dp_port_hpd_clear(tunnel->src_port);
526                 tb_dp_port_set_hops(tunnel->src_port, 0, 0, 0);
527                 if (tb_port_is_dpout(tunnel->dst_port))
528                         tb_dp_port_set_hops(tunnel->dst_port, 0, 0, 0);
529         }
530
531         ret = tb_dp_port_enable(tunnel->src_port, active);
532         if (ret)
533                 return ret;
534
535         if (tb_port_is_dpout(tunnel->dst_port))
536                 return tb_dp_port_enable(tunnel->dst_port, active);
537
538         return 0;
539 }
540
541 static int tb_dp_consumed_bandwidth(struct tb_tunnel *tunnel, int *consumed_up,
542                                     int *consumed_down)
543 {
544         struct tb_port *in = tunnel->src_port;
545         const struct tb_switch *sw = in->sw;
546         u32 val, rate = 0, lanes = 0;
547         int ret;
548
549         if (tb_dp_is_usb4(sw)) {
550                 int timeout = 20;
551
552                 /*
553                  * Wait for DPRX done. Normally it should be already set
554                  * for active tunnel.
555                  */
556                 do {
557                         ret = tb_port_read(in, &val, TB_CFG_PORT,
558                                            in->cap_adap + DP_COMMON_CAP, 1);
559                         if (ret)
560                                 return ret;
561
562                         if (val & DP_COMMON_CAP_DPRX_DONE) {
563                                 rate = tb_dp_cap_get_rate(val);
564                                 lanes = tb_dp_cap_get_lanes(val);
565                                 break;
566                         }
567                         msleep(250);
568                 } while (timeout--);
569
570                 if (!timeout)
571                         return -ETIMEDOUT;
572         } else if (sw->generation >= 2) {
573                 /*
574                  * Read from the copied remote cap so that we take into
575                  * account if capabilities were reduced during exchange.
576                  */
577                 ret = tb_port_read(in, &val, TB_CFG_PORT,
578                                    in->cap_adap + DP_REMOTE_CAP, 1);
579                 if (ret)
580                         return ret;
581
582                 rate = tb_dp_cap_get_rate(val);
583                 lanes = tb_dp_cap_get_lanes(val);
584         } else {
585                 /* No bandwidth management for legacy devices  */
586                 *consumed_up = 0;
587                 *consumed_down = 0;
588                 return 0;
589         }
590
591         if (in->sw->config.depth < tunnel->dst_port->sw->config.depth) {
592                 *consumed_up = 0;
593                 *consumed_down = tb_dp_bandwidth(rate, lanes);
594         } else {
595                 *consumed_up = tb_dp_bandwidth(rate, lanes);
596                 *consumed_down = 0;
597         }
598
599         return 0;
600 }
601
602 static void tb_dp_init_aux_path(struct tb_path *path)
603 {
604         int i;
605
606         path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
607         path->egress_shared_buffer = TB_PATH_NONE;
608         path->ingress_fc_enable = TB_PATH_ALL;
609         path->ingress_shared_buffer = TB_PATH_NONE;
610         path->priority = 2;
611         path->weight = 1;
612
613         for (i = 0; i < path->path_length; i++)
614                 path->hops[i].initial_credits = 1;
615 }
616
617 static void tb_dp_init_video_path(struct tb_path *path, bool discover)
618 {
619         u32 nfc_credits = path->hops[0].in_port->config.nfc_credits;
620
621         path->egress_fc_enable = TB_PATH_NONE;
622         path->egress_shared_buffer = TB_PATH_NONE;
623         path->ingress_fc_enable = TB_PATH_NONE;
624         path->ingress_shared_buffer = TB_PATH_NONE;
625         path->priority = 1;
626         path->weight = 1;
627
628         if (discover) {
629                 path->nfc_credits = nfc_credits & ADP_CS_4_NFC_BUFFERS_MASK;
630         } else {
631                 u32 max_credits;
632
633                 max_credits = (nfc_credits & ADP_CS_4_TOTAL_BUFFERS_MASK) >>
634                         ADP_CS_4_TOTAL_BUFFERS_SHIFT;
635                 /* Leave some credits for AUX path */
636                 path->nfc_credits = min(max_credits - 2, 12U);
637         }
638 }
639
640 /**
641  * tb_tunnel_discover_dp() - Discover existing Display Port tunnels
642  * @tb: Pointer to the domain structure
643  * @in: DP in adapter
644  *
645  * If @in adapter is active, follows the tunnel to the DP out adapter
646  * and back. Returns the discovered tunnel or %NULL if there was no
647  * tunnel.
648  *
649  * Return: DP tunnel or %NULL if no tunnel found.
650  */
651 struct tb_tunnel *tb_tunnel_discover_dp(struct tb *tb, struct tb_port *in)
652 {
653         struct tb_tunnel *tunnel;
654         struct tb_port *port;
655         struct tb_path *path;
656
657         if (!tb_dp_port_is_enabled(in))
658                 return NULL;
659
660         tunnel = tb_tunnel_alloc(tb, 3, TB_TUNNEL_DP);
661         if (!tunnel)
662                 return NULL;
663
664         tunnel->init = tb_dp_xchg_caps;
665         tunnel->activate = tb_dp_activate;
666         tunnel->consumed_bandwidth = tb_dp_consumed_bandwidth;
667         tunnel->src_port = in;
668
669         path = tb_path_discover(in, TB_DP_VIDEO_HOPID, NULL, -1,
670                                 &tunnel->dst_port, "Video");
671         if (!path) {
672                 /* Just disable the DP IN port */
673                 tb_dp_port_enable(in, false);
674                 goto err_free;
675         }
676         tunnel->paths[TB_DP_VIDEO_PATH_OUT] = path;
677         tb_dp_init_video_path(tunnel->paths[TB_DP_VIDEO_PATH_OUT], true);
678
679         path = tb_path_discover(in, TB_DP_AUX_TX_HOPID, NULL, -1, NULL, "AUX TX");
680         if (!path)
681                 goto err_deactivate;
682         tunnel->paths[TB_DP_AUX_PATH_OUT] = path;
683         tb_dp_init_aux_path(tunnel->paths[TB_DP_AUX_PATH_OUT]);
684
685         path = tb_path_discover(tunnel->dst_port, -1, in, TB_DP_AUX_RX_HOPID,
686                                 &port, "AUX RX");
687         if (!path)
688                 goto err_deactivate;
689         tunnel->paths[TB_DP_AUX_PATH_IN] = path;
690         tb_dp_init_aux_path(tunnel->paths[TB_DP_AUX_PATH_IN]);
691
692         /* Validate that the tunnel is complete */
693         if (!tb_port_is_dpout(tunnel->dst_port)) {
694                 tb_port_warn(in, "path does not end on a DP adapter, cleaning up\n");
695                 goto err_deactivate;
696         }
697
698         if (!tb_dp_port_is_enabled(tunnel->dst_port))
699                 goto err_deactivate;
700
701         if (!tb_dp_port_hpd_is_active(tunnel->dst_port))
702                 goto err_deactivate;
703
704         if (port != tunnel->src_port) {
705                 tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");
706                 goto err_deactivate;
707         }
708
709         tb_tunnel_dbg(tunnel, "discovered\n");
710         return tunnel;
711
712 err_deactivate:
713         tb_tunnel_deactivate(tunnel);
714 err_free:
715         tb_tunnel_free(tunnel);
716
717         return NULL;
718 }
719
720 /**
721  * tb_tunnel_alloc_dp() - allocate a Display Port tunnel
722  * @tb: Pointer to the domain structure
723  * @in: DP in adapter port
724  * @out: DP out adapter port
725  * @max_up: Maximum available upstream bandwidth for the DP tunnel (%0
726  *          if not limited)
727  * @max_down: Maximum available downstream bandwidth for the DP tunnel
728  *            (%0 if not limited)
729  *
730  * Allocates a tunnel between @in and @out that is capable of tunneling
731  * Display Port traffic.
732  *
733  * Return: Returns a tb_tunnel on success or NULL on failure.
734  */
735 struct tb_tunnel *tb_tunnel_alloc_dp(struct tb *tb, struct tb_port *in,
736                                      struct tb_port *out, int max_up,
737                                      int max_down)
738 {
739         struct tb_tunnel *tunnel;
740         struct tb_path **paths;
741         struct tb_path *path;
742
743         if (WARN_ON(!in->cap_adap || !out->cap_adap))
744                 return NULL;
745
746         tunnel = tb_tunnel_alloc(tb, 3, TB_TUNNEL_DP);
747         if (!tunnel)
748                 return NULL;
749
750         tunnel->init = tb_dp_xchg_caps;
751         tunnel->activate = tb_dp_activate;
752         tunnel->consumed_bandwidth = tb_dp_consumed_bandwidth;
753         tunnel->src_port = in;
754         tunnel->dst_port = out;
755         tunnel->max_up = max_up;
756         tunnel->max_down = max_down;
757
758         paths = tunnel->paths;
759
760         path = tb_path_alloc(tb, in, TB_DP_VIDEO_HOPID, out, TB_DP_VIDEO_HOPID,
761                              1, "Video");
762         if (!path)
763                 goto err_free;
764         tb_dp_init_video_path(path, false);
765         paths[TB_DP_VIDEO_PATH_OUT] = path;
766
767         path = tb_path_alloc(tb, in, TB_DP_AUX_TX_HOPID, out,
768                              TB_DP_AUX_TX_HOPID, 1, "AUX TX");
769         if (!path)
770                 goto err_free;
771         tb_dp_init_aux_path(path);
772         paths[TB_DP_AUX_PATH_OUT] = path;
773
774         path = tb_path_alloc(tb, out, TB_DP_AUX_RX_HOPID, in,
775                              TB_DP_AUX_RX_HOPID, 1, "AUX RX");
776         if (!path)
777                 goto err_free;
778         tb_dp_init_aux_path(path);
779         paths[TB_DP_AUX_PATH_IN] = path;
780
781         return tunnel;
782
783 err_free:
784         tb_tunnel_free(tunnel);
785         return NULL;
786 }
787
788 static u32 tb_dma_credits(struct tb_port *nhi)
789 {
790         u32 max_credits;
791
792         max_credits = (nhi->config.nfc_credits & ADP_CS_4_TOTAL_BUFFERS_MASK) >>
793                 ADP_CS_4_TOTAL_BUFFERS_SHIFT;
794         return min(max_credits, 13U);
795 }
796
797 static int tb_dma_activate(struct tb_tunnel *tunnel, bool active)
798 {
799         struct tb_port *nhi = tunnel->src_port;
800         u32 credits;
801
802         credits = active ? tb_dma_credits(nhi) : 0;
803         return tb_port_set_initial_credits(nhi, credits);
804 }
805
806 static void tb_dma_init_path(struct tb_path *path, unsigned int isb,
807                              unsigned int efc, u32 credits)
808 {
809         int i;
810
811         path->egress_fc_enable = efc;
812         path->ingress_fc_enable = TB_PATH_ALL;
813         path->egress_shared_buffer = TB_PATH_NONE;
814         path->ingress_shared_buffer = isb;
815         path->priority = 5;
816         path->weight = 1;
817         path->clear_fc = true;
818
819         for (i = 0; i < path->path_length; i++)
820                 path->hops[i].initial_credits = credits;
821 }
822
823 /**
824  * tb_tunnel_alloc_dma() - allocate a DMA tunnel
825  * @tb: Pointer to the domain structure
826  * @nhi: Host controller port
827  * @dst: Destination null port which the other domain is connected to
828  * @transmit_ring: NHI ring number used to send packets towards the
829  *                 other domain. Set to %0 if TX path is not needed.
830  * @transmit_path: HopID used for transmitting packets
831  * @receive_ring: NHI ring number used to receive packets from the
832  *                other domain. Set to %0 if RX path is not needed.
833  * @receive_path: HopID used for receiving packets
834  *
835  * Return: Returns a tb_tunnel on success or NULL on failure.
836  */
837 struct tb_tunnel *tb_tunnel_alloc_dma(struct tb *tb, struct tb_port *nhi,
838                                       struct tb_port *dst, int transmit_ring,
839                                       int transmit_path, int receive_ring,
840                                       int receive_path)
841 {
842         struct tb_tunnel *tunnel;
843         size_t npaths = 0, i = 0;
844         struct tb_path *path;
845         u32 credits;
846
847         if (receive_ring)
848                 npaths++;
849         if (transmit_ring)
850                 npaths++;
851
852         if (WARN_ON(!npaths))
853                 return NULL;
854
855         tunnel = tb_tunnel_alloc(tb, npaths, TB_TUNNEL_DMA);
856         if (!tunnel)
857                 return NULL;
858
859         tunnel->activate = tb_dma_activate;
860         tunnel->src_port = nhi;
861         tunnel->dst_port = dst;
862
863         credits = tb_dma_credits(nhi);
864
865         if (receive_ring) {
866                 path = tb_path_alloc(tb, dst, receive_path, nhi, receive_ring, 0,
867                                      "DMA RX");
868                 if (!path) {
869                         tb_tunnel_free(tunnel);
870                         return NULL;
871                 }
872                 tb_dma_init_path(path, TB_PATH_NONE, TB_PATH_SOURCE | TB_PATH_INTERNAL,
873                                  credits);
874                 tunnel->paths[i++] = path;
875         }
876
877         if (transmit_ring) {
878                 path = tb_path_alloc(tb, nhi, transmit_ring, dst, transmit_path, 0,
879                                      "DMA TX");
880                 if (!path) {
881                         tb_tunnel_free(tunnel);
882                         return NULL;
883                 }
884                 tb_dma_init_path(path, TB_PATH_SOURCE, TB_PATH_ALL, credits);
885                 tunnel->paths[i++] = path;
886         }
887
888         return tunnel;
889 }
890
891 static int tb_usb3_max_link_rate(struct tb_port *up, struct tb_port *down)
892 {
893         int ret, up_max_rate, down_max_rate;
894
895         ret = usb4_usb3_port_max_link_rate(up);
896         if (ret < 0)
897                 return ret;
898         up_max_rate = ret;
899
900         ret = usb4_usb3_port_max_link_rate(down);
901         if (ret < 0)
902                 return ret;
903         down_max_rate = ret;
904
905         return min(up_max_rate, down_max_rate);
906 }
907
908 static int tb_usb3_init(struct tb_tunnel *tunnel)
909 {
910         tb_tunnel_dbg(tunnel, "allocating initial bandwidth %d/%d Mb/s\n",
911                       tunnel->allocated_up, tunnel->allocated_down);
912
913         return usb4_usb3_port_allocate_bandwidth(tunnel->src_port,
914                                                  &tunnel->allocated_up,
915                                                  &tunnel->allocated_down);
916 }
917
918 static int tb_usb3_activate(struct tb_tunnel *tunnel, bool activate)
919 {
920         int res;
921
922         res = tb_usb3_port_enable(tunnel->src_port, activate);
923         if (res)
924                 return res;
925
926         if (tb_port_is_usb3_up(tunnel->dst_port))
927                 return tb_usb3_port_enable(tunnel->dst_port, activate);
928
929         return 0;
930 }
931
932 static int tb_usb3_consumed_bandwidth(struct tb_tunnel *tunnel,
933                 int *consumed_up, int *consumed_down)
934 {
935         int pcie_enabled = tb_acpi_may_tunnel_pcie();
936
937         /*
938          * PCIe tunneling, if enabled, affects the USB3 bandwidth so
939          * take that it into account here.
940          */
941         *consumed_up = tunnel->allocated_up * (3 + pcie_enabled) / 3;
942         *consumed_down = tunnel->allocated_down * (3 + pcie_enabled) / 3;
943         return 0;
944 }
945
946 static int tb_usb3_release_unused_bandwidth(struct tb_tunnel *tunnel)
947 {
948         int ret;
949
950         ret = usb4_usb3_port_release_bandwidth(tunnel->src_port,
951                                                &tunnel->allocated_up,
952                                                &tunnel->allocated_down);
953         if (ret)
954                 return ret;
955
956         tb_tunnel_dbg(tunnel, "decreased bandwidth allocation to %d/%d Mb/s\n",
957                       tunnel->allocated_up, tunnel->allocated_down);
958         return 0;
959 }
960
961 static void tb_usb3_reclaim_available_bandwidth(struct tb_tunnel *tunnel,
962                                                 int *available_up,
963                                                 int *available_down)
964 {
965         int ret, max_rate, allocate_up, allocate_down;
966
967         ret = usb4_usb3_port_actual_link_rate(tunnel->src_port);
968         if (ret < 0) {
969                 tb_tunnel_warn(tunnel, "failed to read actual link rate\n");
970                 return;
971         } else if (!ret) {
972                 /* Use maximum link rate if the link valid is not set */
973                 ret = usb4_usb3_port_max_link_rate(tunnel->src_port);
974                 if (ret < 0) {
975                         tb_tunnel_warn(tunnel, "failed to read maximum link rate\n");
976                         return;
977                 }
978         }
979
980         /*
981          * 90% of the max rate can be allocated for isochronous
982          * transfers.
983          */
984         max_rate = ret * 90 / 100;
985
986         /* No need to reclaim if already at maximum */
987         if (tunnel->allocated_up >= max_rate &&
988             tunnel->allocated_down >= max_rate)
989                 return;
990
991         /* Don't go lower than what is already allocated */
992         allocate_up = min(max_rate, *available_up);
993         if (allocate_up < tunnel->allocated_up)
994                 allocate_up = tunnel->allocated_up;
995
996         allocate_down = min(max_rate, *available_down);
997         if (allocate_down < tunnel->allocated_down)
998                 allocate_down = tunnel->allocated_down;
999
1000         /* If no changes no need to do more */
1001         if (allocate_up == tunnel->allocated_up &&
1002             allocate_down == tunnel->allocated_down)
1003                 return;
1004
1005         ret = usb4_usb3_port_allocate_bandwidth(tunnel->src_port, &allocate_up,
1006                                                 &allocate_down);
1007         if (ret) {
1008                 tb_tunnel_info(tunnel, "failed to allocate bandwidth\n");
1009                 return;
1010         }
1011
1012         tunnel->allocated_up = allocate_up;
1013         *available_up -= tunnel->allocated_up;
1014
1015         tunnel->allocated_down = allocate_down;
1016         *available_down -= tunnel->allocated_down;
1017
1018         tb_tunnel_dbg(tunnel, "increased bandwidth allocation to %d/%d Mb/s\n",
1019                       tunnel->allocated_up, tunnel->allocated_down);
1020 }
1021
1022 static void tb_usb3_init_path(struct tb_path *path)
1023 {
1024         path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
1025         path->egress_shared_buffer = TB_PATH_NONE;
1026         path->ingress_fc_enable = TB_PATH_ALL;
1027         path->ingress_shared_buffer = TB_PATH_NONE;
1028         path->priority = 3;
1029         path->weight = 3;
1030         path->drop_packages = 0;
1031         path->nfc_credits = 0;
1032         path->hops[0].initial_credits = 7;
1033         if (path->path_length > 1)
1034                 path->hops[1].initial_credits =
1035                         tb_initial_credits(path->hops[1].in_port->sw);
1036 }
1037
1038 /**
1039  * tb_tunnel_discover_usb3() - Discover existing USB3 tunnels
1040  * @tb: Pointer to the domain structure
1041  * @down: USB3 downstream adapter
1042  *
1043  * If @down adapter is active, follows the tunnel to the USB3 upstream
1044  * adapter and back. Returns the discovered tunnel or %NULL if there was
1045  * no tunnel.
1046  */
1047 struct tb_tunnel *tb_tunnel_discover_usb3(struct tb *tb, struct tb_port *down)
1048 {
1049         struct tb_tunnel *tunnel;
1050         struct tb_path *path;
1051
1052         if (!tb_usb3_port_is_enabled(down))
1053                 return NULL;
1054
1055         tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_USB3);
1056         if (!tunnel)
1057                 return NULL;
1058
1059         tunnel->activate = tb_usb3_activate;
1060         tunnel->src_port = down;
1061
1062         /*
1063          * Discover both paths even if they are not complete. We will
1064          * clean them up by calling tb_tunnel_deactivate() below in that
1065          * case.
1066          */
1067         path = tb_path_discover(down, TB_USB3_HOPID, NULL, -1,
1068                                 &tunnel->dst_port, "USB3 Down");
1069         if (!path) {
1070                 /* Just disable the downstream port */
1071                 tb_usb3_port_enable(down, false);
1072                 goto err_free;
1073         }
1074         tunnel->paths[TB_USB3_PATH_DOWN] = path;
1075         tb_usb3_init_path(tunnel->paths[TB_USB3_PATH_DOWN]);
1076
1077         path = tb_path_discover(tunnel->dst_port, -1, down, TB_USB3_HOPID, NULL,
1078                                 "USB3 Up");
1079         if (!path)
1080                 goto err_deactivate;
1081         tunnel->paths[TB_USB3_PATH_UP] = path;
1082         tb_usb3_init_path(tunnel->paths[TB_USB3_PATH_UP]);
1083
1084         /* Validate that the tunnel is complete */
1085         if (!tb_port_is_usb3_up(tunnel->dst_port)) {
1086                 tb_port_warn(tunnel->dst_port,
1087                              "path does not end on an USB3 adapter, cleaning up\n");
1088                 goto err_deactivate;
1089         }
1090
1091         if (down != tunnel->src_port) {
1092                 tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");
1093                 goto err_deactivate;
1094         }
1095
1096         if (!tb_usb3_port_is_enabled(tunnel->dst_port)) {
1097                 tb_tunnel_warn(tunnel,
1098                                "tunnel is not fully activated, cleaning up\n");
1099                 goto err_deactivate;
1100         }
1101
1102         if (!tb_route(down->sw)) {
1103                 int ret;
1104
1105                 /*
1106                  * Read the initial bandwidth allocation for the first
1107                  * hop tunnel.
1108                  */
1109                 ret = usb4_usb3_port_allocated_bandwidth(down,
1110                         &tunnel->allocated_up, &tunnel->allocated_down);
1111                 if (ret)
1112                         goto err_deactivate;
1113
1114                 tb_tunnel_dbg(tunnel, "currently allocated bandwidth %d/%d Mb/s\n",
1115                               tunnel->allocated_up, tunnel->allocated_down);
1116
1117                 tunnel->init = tb_usb3_init;
1118                 tunnel->consumed_bandwidth = tb_usb3_consumed_bandwidth;
1119                 tunnel->release_unused_bandwidth =
1120                         tb_usb3_release_unused_bandwidth;
1121                 tunnel->reclaim_available_bandwidth =
1122                         tb_usb3_reclaim_available_bandwidth;
1123         }
1124
1125         tb_tunnel_dbg(tunnel, "discovered\n");
1126         return tunnel;
1127
1128 err_deactivate:
1129         tb_tunnel_deactivate(tunnel);
1130 err_free:
1131         tb_tunnel_free(tunnel);
1132
1133         return NULL;
1134 }
1135
1136 /**
1137  * tb_tunnel_alloc_usb3() - allocate a USB3 tunnel
1138  * @tb: Pointer to the domain structure
1139  * @up: USB3 upstream adapter port
1140  * @down: USB3 downstream adapter port
1141  * @max_up: Maximum available upstream bandwidth for the USB3 tunnel (%0
1142  *          if not limited).
1143  * @max_down: Maximum available downstream bandwidth for the USB3 tunnel
1144  *            (%0 if not limited).
1145  *
1146  * Allocate an USB3 tunnel. The ports must be of type @TB_TYPE_USB3_UP and
1147  * @TB_TYPE_USB3_DOWN.
1148  *
1149  * Return: Returns a tb_tunnel on success or %NULL on failure.
1150  */
1151 struct tb_tunnel *tb_tunnel_alloc_usb3(struct tb *tb, struct tb_port *up,
1152                                        struct tb_port *down, int max_up,
1153                                        int max_down)
1154 {
1155         struct tb_tunnel *tunnel;
1156         struct tb_path *path;
1157         int max_rate = 0;
1158
1159         /*
1160          * Check that we have enough bandwidth available for the new
1161          * USB3 tunnel.
1162          */
1163         if (max_up > 0 || max_down > 0) {
1164                 max_rate = tb_usb3_max_link_rate(down, up);
1165                 if (max_rate < 0)
1166                         return NULL;
1167
1168                 /* Only 90% can be allocated for USB3 isochronous transfers */
1169                 max_rate = max_rate * 90 / 100;
1170                 tb_port_dbg(up, "required bandwidth for USB3 tunnel %d Mb/s\n",
1171                             max_rate);
1172
1173                 if (max_rate > max_up || max_rate > max_down) {
1174                         tb_port_warn(up, "not enough bandwidth for USB3 tunnel\n");
1175                         return NULL;
1176                 }
1177         }
1178
1179         tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_USB3);
1180         if (!tunnel)
1181                 return NULL;
1182
1183         tunnel->activate = tb_usb3_activate;
1184         tunnel->src_port = down;
1185         tunnel->dst_port = up;
1186         tunnel->max_up = max_up;
1187         tunnel->max_down = max_down;
1188
1189         path = tb_path_alloc(tb, down, TB_USB3_HOPID, up, TB_USB3_HOPID, 0,
1190                              "USB3 Down");
1191         if (!path) {
1192                 tb_tunnel_free(tunnel);
1193                 return NULL;
1194         }
1195         tb_usb3_init_path(path);
1196         tunnel->paths[TB_USB3_PATH_DOWN] = path;
1197
1198         path = tb_path_alloc(tb, up, TB_USB3_HOPID, down, TB_USB3_HOPID, 0,
1199                              "USB3 Up");
1200         if (!path) {
1201                 tb_tunnel_free(tunnel);
1202                 return NULL;
1203         }
1204         tb_usb3_init_path(path);
1205         tunnel->paths[TB_USB3_PATH_UP] = path;
1206
1207         if (!tb_route(down->sw)) {
1208                 tunnel->allocated_up = max_rate;
1209                 tunnel->allocated_down = max_rate;
1210
1211                 tunnel->init = tb_usb3_init;
1212                 tunnel->consumed_bandwidth = tb_usb3_consumed_bandwidth;
1213                 tunnel->release_unused_bandwidth =
1214                         tb_usb3_release_unused_bandwidth;
1215                 tunnel->reclaim_available_bandwidth =
1216                         tb_usb3_reclaim_available_bandwidth;
1217         }
1218
1219         return tunnel;
1220 }
1221
1222 /**
1223  * tb_tunnel_free() - free a tunnel
1224  * @tunnel: Tunnel to be freed
1225  *
1226  * Frees a tunnel. The tunnel does not need to be deactivated.
1227  */
1228 void tb_tunnel_free(struct tb_tunnel *tunnel)
1229 {
1230         int i;
1231
1232         if (!tunnel)
1233                 return;
1234
1235         for (i = 0; i < tunnel->npaths; i++) {
1236                 if (tunnel->paths[i])
1237                         tb_path_free(tunnel->paths[i]);
1238         }
1239
1240         kfree(tunnel->paths);
1241         kfree(tunnel);
1242 }
1243
1244 /**
1245  * tb_tunnel_is_invalid - check whether an activated path is still valid
1246  * @tunnel: Tunnel to check
1247  */
1248 bool tb_tunnel_is_invalid(struct tb_tunnel *tunnel)
1249 {
1250         int i;
1251
1252         for (i = 0; i < tunnel->npaths; i++) {
1253                 WARN_ON(!tunnel->paths[i]->activated);
1254                 if (tb_path_is_invalid(tunnel->paths[i]))
1255                         return true;
1256         }
1257
1258         return false;
1259 }
1260
1261 /**
1262  * tb_tunnel_restart() - activate a tunnel after a hardware reset
1263  * @tunnel: Tunnel to restart
1264  *
1265  * Return: 0 on success and negative errno in case if failure
1266  */
1267 int tb_tunnel_restart(struct tb_tunnel *tunnel)
1268 {
1269         int res, i;
1270
1271         tb_tunnel_dbg(tunnel, "activating\n");
1272
1273         /*
1274          * Make sure all paths are properly disabled before enabling
1275          * them again.
1276          */
1277         for (i = 0; i < tunnel->npaths; i++) {
1278                 if (tunnel->paths[i]->activated) {
1279                         tb_path_deactivate(tunnel->paths[i]);
1280                         tunnel->paths[i]->activated = false;
1281                 }
1282         }
1283
1284         if (tunnel->init) {
1285                 res = tunnel->init(tunnel);
1286                 if (res)
1287                         return res;
1288         }
1289
1290         for (i = 0; i < tunnel->npaths; i++) {
1291                 res = tb_path_activate(tunnel->paths[i]);
1292                 if (res)
1293                         goto err;
1294         }
1295
1296         if (tunnel->activate) {
1297                 res = tunnel->activate(tunnel, true);
1298                 if (res)
1299                         goto err;
1300         }
1301
1302         return 0;
1303
1304 err:
1305         tb_tunnel_warn(tunnel, "activation failed\n");
1306         tb_tunnel_deactivate(tunnel);
1307         return res;
1308 }
1309
1310 /**
1311  * tb_tunnel_activate() - activate a tunnel
1312  * @tunnel: Tunnel to activate
1313  *
1314  * Return: Returns 0 on success or an error code on failure.
1315  */
1316 int tb_tunnel_activate(struct tb_tunnel *tunnel)
1317 {
1318         int i;
1319
1320         for (i = 0; i < tunnel->npaths; i++) {
1321                 if (tunnel->paths[i]->activated) {
1322                         tb_tunnel_WARN(tunnel,
1323                                        "trying to activate an already activated tunnel\n");
1324                         return -EINVAL;
1325                 }
1326         }
1327
1328         return tb_tunnel_restart(tunnel);
1329 }
1330
1331 /**
1332  * tb_tunnel_deactivate() - deactivate a tunnel
1333  * @tunnel: Tunnel to deactivate
1334  */
1335 void tb_tunnel_deactivate(struct tb_tunnel *tunnel)
1336 {
1337         int i;
1338
1339         tb_tunnel_dbg(tunnel, "deactivating\n");
1340
1341         if (tunnel->activate)
1342                 tunnel->activate(tunnel, false);
1343
1344         for (i = 0; i < tunnel->npaths; i++) {
1345                 if (tunnel->paths[i] && tunnel->paths[i]->activated)
1346                         tb_path_deactivate(tunnel->paths[i]);
1347         }
1348 }
1349
1350 /**
1351  * tb_tunnel_port_on_path() - Does the tunnel go through port
1352  * @tunnel: Tunnel to check
1353  * @port: Port to check
1354  *
1355  * Returns true if @tunnel goes through @port (direction does not matter),
1356  * false otherwise.
1357  */
1358 bool tb_tunnel_port_on_path(const struct tb_tunnel *tunnel,
1359                             const struct tb_port *port)
1360 {
1361         int i;
1362
1363         for (i = 0; i < tunnel->npaths; i++) {
1364                 if (!tunnel->paths[i])
1365                         continue;
1366
1367                 if (tb_path_port_on_path(tunnel->paths[i], port))
1368                         return true;
1369         }
1370
1371         return false;
1372 }
1373
1374 static bool tb_tunnel_is_active(const struct tb_tunnel *tunnel)
1375 {
1376         int i;
1377
1378         for (i = 0; i < tunnel->npaths; i++) {
1379                 if (!tunnel->paths[i])
1380                         return false;
1381                 if (!tunnel->paths[i]->activated)
1382                         return false;
1383         }
1384
1385         return true;
1386 }
1387
1388 /**
1389  * tb_tunnel_consumed_bandwidth() - Return bandwidth consumed by the tunnel
1390  * @tunnel: Tunnel to check
1391  * @consumed_up: Consumed bandwidth in Mb/s from @dst_port to @src_port.
1392  *               Can be %NULL.
1393  * @consumed_down: Consumed bandwidth in Mb/s from @src_port to @dst_port.
1394  *                 Can be %NULL.
1395  *
1396  * Stores the amount of isochronous bandwidth @tunnel consumes in
1397  * @consumed_up and @consumed_down. In case of success returns %0,
1398  * negative errno otherwise.
1399  */
1400 int tb_tunnel_consumed_bandwidth(struct tb_tunnel *tunnel, int *consumed_up,
1401                                  int *consumed_down)
1402 {
1403         int up_bw = 0, down_bw = 0;
1404
1405         if (!tb_tunnel_is_active(tunnel))
1406                 goto out;
1407
1408         if (tunnel->consumed_bandwidth) {
1409                 int ret;
1410
1411                 ret = tunnel->consumed_bandwidth(tunnel, &up_bw, &down_bw);
1412                 if (ret)
1413                         return ret;
1414
1415                 tb_tunnel_dbg(tunnel, "consumed bandwidth %d/%d Mb/s\n", up_bw,
1416                               down_bw);
1417         }
1418
1419 out:
1420         if (consumed_up)
1421                 *consumed_up = up_bw;
1422         if (consumed_down)
1423                 *consumed_down = down_bw;
1424
1425         return 0;
1426 }
1427
1428 /**
1429  * tb_tunnel_release_unused_bandwidth() - Release unused bandwidth
1430  * @tunnel: Tunnel whose unused bandwidth to release
1431  *
1432  * If tunnel supports dynamic bandwidth management (USB3 tunnels at the
1433  * moment) this function makes it to release all the unused bandwidth.
1434  *
1435  * Returns %0 in case of success and negative errno otherwise.
1436  */
1437 int tb_tunnel_release_unused_bandwidth(struct tb_tunnel *tunnel)
1438 {
1439         if (!tb_tunnel_is_active(tunnel))
1440                 return 0;
1441
1442         if (tunnel->release_unused_bandwidth) {
1443                 int ret;
1444
1445                 ret = tunnel->release_unused_bandwidth(tunnel);
1446                 if (ret)
1447                         return ret;
1448         }
1449
1450         return 0;
1451 }
1452
1453 /**
1454  * tb_tunnel_reclaim_available_bandwidth() - Reclaim available bandwidth
1455  * @tunnel: Tunnel reclaiming available bandwidth
1456  * @available_up: Available upstream bandwidth (in Mb/s)
1457  * @available_down: Available downstream bandwidth (in Mb/s)
1458  *
1459  * Reclaims bandwidth from @available_up and @available_down and updates
1460  * the variables accordingly (e.g decreases both according to what was
1461  * reclaimed by the tunnel). If nothing was reclaimed the values are
1462  * kept as is.
1463  */
1464 void tb_tunnel_reclaim_available_bandwidth(struct tb_tunnel *tunnel,
1465                                            int *available_up,
1466                                            int *available_down)
1467 {
1468         if (!tb_tunnel_is_active(tunnel))
1469                 return;
1470
1471         if (tunnel->reclaim_available_bandwidth)
1472                 tunnel->reclaim_available_bandwidth(tunnel, available_up,
1473                                                     available_down);
1474 }