xref: /openbmc/linux/drivers/thunderbolt/switch.c (revision 8730046c)
1 /*
2  * Thunderbolt Cactus Ridge driver - switch/port utility functions
3  *
4  * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
5  */
6 
7 #include <linux/delay.h>
8 #include <linux/slab.h>
9 
10 #include "tb.h"
11 
12 /* port utility functions */
13 
14 static const char *tb_port_type(struct tb_regs_port_header *port)
15 {
16 	switch (port->type >> 16) {
17 	case 0:
18 		switch ((u8) port->type) {
19 		case 0:
20 			return "Inactive";
21 		case 1:
22 			return "Port";
23 		case 2:
24 			return "NHI";
25 		default:
26 			return "unknown";
27 		}
28 	case 0x2:
29 		return "Ethernet";
30 	case 0x8:
31 		return "SATA";
32 	case 0xe:
33 		return "DP/HDMI";
34 	case 0x10:
35 		return "PCIe";
36 	case 0x20:
37 		return "USB";
38 	default:
39 		return "unknown";
40 	}
41 }
42 
43 static void tb_dump_port(struct tb *tb, struct tb_regs_port_header *port)
44 {
45 	tb_info(tb,
46 		" Port %d: %x:%x (Revision: %d, TB Version: %d, Type: %s (%#x))\n",
47 		port->port_number, port->vendor_id, port->device_id,
48 		port->revision, port->thunderbolt_version, tb_port_type(port),
49 		port->type);
50 	tb_info(tb, "  Max hop id (in/out): %d/%d\n",
51 		port->max_in_hop_id, port->max_out_hop_id);
52 	tb_info(tb, "  Max counters: %d\n", port->max_counters);
53 	tb_info(tb, "  NFC Credits: %#x\n", port->nfc_credits);
54 }
55 
56 /**
57  * tb_port_state() - get connectedness state of a port
58  *
59  * The port must have a TB_CAP_PHY (i.e. it should be a real port).
60  *
61  * Return: Returns an enum tb_port_state on success or an error code on failure.
62  */
63 static int tb_port_state(struct tb_port *port)
64 {
65 	struct tb_cap_phy phy;
66 	int res;
67 	if (port->cap_phy == 0) {
68 		tb_port_WARN(port, "does not have a PHY\n");
69 		return -EINVAL;
70 	}
71 	res = tb_port_read(port, &phy, TB_CFG_PORT, port->cap_phy, 2);
72 	if (res)
73 		return res;
74 	return phy.state;
75 }
76 
77 /**
78  * tb_wait_for_port() - wait for a port to become ready
79  *
80  * Wait up to 1 second for a port to reach state TB_PORT_UP. If
81  * wait_if_unplugged is set then we also wait if the port is in state
82  * TB_PORT_UNPLUGGED (it takes a while for the device to be registered after
83  * switch resume). Otherwise we only wait if a device is registered but the link
84  * has not yet been established.
85  *
86  * Return: Returns an error code on failure. Returns 0 if the port is not
87  * connected or failed to reach state TB_PORT_UP within one second. Returns 1
88  * if the port is connected and in state TB_PORT_UP.
89  */
90 int tb_wait_for_port(struct tb_port *port, bool wait_if_unplugged)
91 {
92 	int retries = 10;
93 	int state;
94 	if (!port->cap_phy) {
95 		tb_port_WARN(port, "does not have PHY\n");
96 		return -EINVAL;
97 	}
98 	if (tb_is_upstream_port(port)) {
99 		tb_port_WARN(port, "is the upstream port\n");
100 		return -EINVAL;
101 	}
102 
103 	while (retries--) {
104 		state = tb_port_state(port);
105 		if (state < 0)
106 			return state;
107 		if (state == TB_PORT_DISABLED) {
108 			tb_port_info(port, "is disabled (state: 0)\n");
109 			return 0;
110 		}
111 		if (state == TB_PORT_UNPLUGGED) {
112 			if (wait_if_unplugged) {
113 				/* used during resume */
114 				tb_port_info(port,
115 					     "is unplugged (state: 7), retrying...\n");
116 				msleep(100);
117 				continue;
118 			}
119 			tb_port_info(port, "is unplugged (state: 7)\n");
120 			return 0;
121 		}
122 		if (state == TB_PORT_UP) {
123 			tb_port_info(port,
124 				     "is connected, link is up (state: 2)\n");
125 			return 1;
126 		}
127 
128 		/*
129 		 * After plug-in the state is TB_PORT_CONNECTING. Give it some
130 		 * time.
131 		 */
132 		tb_port_info(port,
133 			     "is connected, link is not up (state: %d), retrying...\n",
134 			     state);
135 		msleep(100);
136 	}
137 	tb_port_warn(port,
138 		     "failed to reach state TB_PORT_UP. Ignoring port...\n");
139 	return 0;
140 }
141 
142 /**
143  * tb_port_add_nfc_credits() - add/remove non flow controlled credits to port
144  *
145  * Change the number of NFC credits allocated to @port by @credits. To remove
146  * NFC credits pass a negative amount of credits.
147  *
148  * Return: Returns 0 on success or an error code on failure.
149  */
150 int tb_port_add_nfc_credits(struct tb_port *port, int credits)
151 {
152 	if (credits == 0)
153 		return 0;
154 	tb_port_info(port,
155 		     "adding %#x NFC credits (%#x -> %#x)",
156 		     credits,
157 		     port->config.nfc_credits,
158 		     port->config.nfc_credits + credits);
159 	port->config.nfc_credits += credits;
160 	return tb_port_write(port, &port->config.nfc_credits,
161 			     TB_CFG_PORT, 4, 1);
162 }
163 
164 /**
165  * tb_port_clear_counter() - clear a counter in TB_CFG_COUNTER
166  *
167  * Return: Returns 0 on success or an error code on failure.
168  */
169 int tb_port_clear_counter(struct tb_port *port, int counter)
170 {
171 	u32 zero[3] = { 0, 0, 0 };
172 	tb_port_info(port, "clearing counter %d\n", counter);
173 	return tb_port_write(port, zero, TB_CFG_COUNTERS, 3 * counter, 3);
174 }
175 
176 /**
177  * tb_init_port() - initialize a port
178  *
179  * This is a helper method for tb_switch_alloc. Does not check or initialize
180  * any downstream switches.
181  *
182  * Return: Returns 0 on success or an error code on failure.
183  */
184 static int tb_init_port(struct tb_port *port)
185 {
186 	int res;
187 	int cap;
188 
189 	res = tb_port_read(port, &port->config, TB_CFG_PORT, 0, 8);
190 	if (res)
191 		return res;
192 
193 	/* Port 0 is the switch itself and has no PHY. */
194 	if (port->config.type == TB_TYPE_PORT && port->port != 0) {
195 		cap = tb_find_cap(port, TB_CFG_PORT, TB_CAP_PHY);
196 
197 		if (cap > 0)
198 			port->cap_phy = cap;
199 		else
200 			tb_port_WARN(port, "non switch port without a PHY\n");
201 	}
202 
203 	tb_dump_port(port->sw->tb, &port->config);
204 
205 	/* TODO: Read dual link port, DP port and more from EEPROM. */
206 	return 0;
207 
208 }
209 
210 /* switch utility functions */
211 
212 static void tb_dump_switch(struct tb *tb, struct tb_regs_switch_header *sw)
213 {
214 	tb_info(tb,
215 		" Switch: %x:%x (Revision: %d, TB Version: %d)\n",
216 		sw->vendor_id, sw->device_id, sw->revision,
217 		sw->thunderbolt_version);
218 	tb_info(tb, "  Max Port Number: %d\n", sw->max_port_number);
219 	tb_info(tb, "  Config:\n");
220 	tb_info(tb,
221 		"   Upstream Port Number: %d Depth: %d Route String: %#llx Enabled: %d, PlugEventsDelay: %dms\n",
222 		sw->upstream_port_number, sw->depth,
223 		(((u64) sw->route_hi) << 32) | sw->route_lo,
224 		sw->enabled, sw->plug_events_delay);
225 	tb_info(tb,
226 		"   unknown1: %#x unknown4: %#x\n",
227 		sw->__unknown1, sw->__unknown4);
228 }
229 
230 /**
231  * reset_switch() - reconfigure route, enable and send TB_CFG_PKG_RESET
232  *
233  * Return: Returns 0 on success or an error code on failure.
234  */
235 int tb_switch_reset(struct tb *tb, u64 route)
236 {
237 	struct tb_cfg_result res;
238 	struct tb_regs_switch_header header = {
239 		header.route_hi = route >> 32,
240 		header.route_lo = route,
241 		header.enabled = true,
242 	};
243 	tb_info(tb, "resetting switch at %llx\n", route);
244 	res.err = tb_cfg_write(tb->ctl, ((u32 *) &header) + 2, route,
245 			0, 2, 2, 2);
246 	if (res.err)
247 		return res.err;
248 	res = tb_cfg_reset(tb->ctl, route, TB_CFG_DEFAULT_TIMEOUT);
249 	if (res.err > 0)
250 		return -EIO;
251 	return res.err;
252 }
253 
254 struct tb_switch *get_switch_at_route(struct tb_switch *sw, u64 route)
255 {
256 	u8 next_port = route; /*
257 			       * Routes use a stride of 8 bits,
258 			       * eventhough a port index has 6 bits at most.
259 			       * */
260 	if (route == 0)
261 		return sw;
262 	if (next_port > sw->config.max_port_number)
263 		return NULL;
264 	if (tb_is_upstream_port(&sw->ports[next_port]))
265 		return NULL;
266 	if (!sw->ports[next_port].remote)
267 		return NULL;
268 	return get_switch_at_route(sw->ports[next_port].remote->sw,
269 				   route >> TB_ROUTE_SHIFT);
270 }
271 
272 /**
273  * tb_plug_events_active() - enable/disable plug events on a switch
274  *
275  * Also configures a sane plug_events_delay of 255ms.
276  *
277  * Return: Returns 0 on success or an error code on failure.
278  */
279 static int tb_plug_events_active(struct tb_switch *sw, bool active)
280 {
281 	u32 data;
282 	int res;
283 
284 	sw->config.plug_events_delay = 0xff;
285 	res = tb_sw_write(sw, ((u32 *) &sw->config) + 4, TB_CFG_SWITCH, 4, 1);
286 	if (res)
287 		return res;
288 
289 	res = tb_sw_read(sw, &data, TB_CFG_SWITCH, sw->cap_plug_events + 1, 1);
290 	if (res)
291 		return res;
292 
293 	if (active) {
294 		data = data & 0xFFFFFF83;
295 		switch (sw->config.device_id) {
296 		case PCI_DEVICE_ID_INTEL_LIGHT_RIDGE:
297 		case PCI_DEVICE_ID_INTEL_EAGLE_RIDGE:
298 		case PCI_DEVICE_ID_INTEL_PORT_RIDGE:
299 			break;
300 		default:
301 			data |= 4;
302 		}
303 	} else {
304 		data = data | 0x7c;
305 	}
306 	return tb_sw_write(sw, &data, TB_CFG_SWITCH,
307 			   sw->cap_plug_events + 1, 1);
308 }
309 
310 
311 /**
312  * tb_switch_free() - free a tb_switch and all downstream switches
313  */
314 void tb_switch_free(struct tb_switch *sw)
315 {
316 	int i;
317 	/* port 0 is the switch itself and never has a remote */
318 	for (i = 1; i <= sw->config.max_port_number; i++) {
319 		if (tb_is_upstream_port(&sw->ports[i]))
320 			continue;
321 		if (sw->ports[i].remote)
322 			tb_switch_free(sw->ports[i].remote->sw);
323 		sw->ports[i].remote = NULL;
324 	}
325 
326 	if (!sw->is_unplugged)
327 		tb_plug_events_active(sw, false);
328 
329 	kfree(sw->ports);
330 	kfree(sw->drom);
331 	kfree(sw);
332 }
333 
334 /**
335  * tb_switch_alloc() - allocate and initialize a switch
336  *
337  * Return: Returns a NULL on failure.
338  */
339 struct tb_switch *tb_switch_alloc(struct tb *tb, u64 route)
340 {
341 	int i;
342 	int cap;
343 	struct tb_switch *sw;
344 	int upstream_port = tb_cfg_get_upstream_port(tb->ctl, route);
345 	if (upstream_port < 0)
346 		return NULL;
347 
348 	sw = kzalloc(sizeof(*sw), GFP_KERNEL);
349 	if (!sw)
350 		return NULL;
351 
352 	sw->tb = tb;
353 	if (tb_cfg_read(tb->ctl, &sw->config, route, 0, TB_CFG_SWITCH, 0, 5))
354 		goto err;
355 	tb_info(tb,
356 		"initializing Switch at %#llx (depth: %d, up port: %d)\n",
357 		route, tb_route_length(route), upstream_port);
358 	tb_info(tb, "old switch config:\n");
359 	tb_dump_switch(tb, &sw->config);
360 
361 	/* configure switch */
362 	sw->config.upstream_port_number = upstream_port;
363 	sw->config.depth = tb_route_length(route);
364 	sw->config.route_lo = route;
365 	sw->config.route_hi = route >> 32;
366 	sw->config.enabled = 1;
367 	/* from here on we may use the tb_sw_* functions & macros */
368 
369 	if (sw->config.vendor_id != 0x8086)
370 		tb_sw_warn(sw, "unknown switch vendor id %#x\n",
371 			   sw->config.vendor_id);
372 
373 	if (sw->config.device_id != PCI_DEVICE_ID_INTEL_LIGHT_RIDGE &&
374 	    sw->config.device_id != PCI_DEVICE_ID_INTEL_CACTUS_RIDGE_4C &&
375 	    sw->config.device_id != PCI_DEVICE_ID_INTEL_PORT_RIDGE &&
376 	    sw->config.device_id != PCI_DEVICE_ID_INTEL_FALCON_RIDGE_2C_BRIDGE &&
377 	    sw->config.device_id != PCI_DEVICE_ID_INTEL_FALCON_RIDGE_4C_BRIDGE)
378 		tb_sw_warn(sw, "unsupported switch device id %#x\n",
379 			   sw->config.device_id);
380 
381 	/* upload configuration */
382 	if (tb_sw_write(sw, 1 + (u32 *) &sw->config, TB_CFG_SWITCH, 1, 3))
383 		goto err;
384 
385 	/* initialize ports */
386 	sw->ports = kcalloc(sw->config.max_port_number + 1, sizeof(*sw->ports),
387 				GFP_KERNEL);
388 	if (!sw->ports)
389 		goto err;
390 
391 	for (i = 0; i <= sw->config.max_port_number; i++) {
392 		/* minimum setup for tb_find_cap and tb_drom_read to work */
393 		sw->ports[i].sw = sw;
394 		sw->ports[i].port = i;
395 	}
396 
397 	cap = tb_find_cap(&sw->ports[0], TB_CFG_SWITCH, TB_CAP_PLUG_EVENTS);
398 	if (cap < 0) {
399 		tb_sw_warn(sw, "cannot find TB_CAP_PLUG_EVENTS aborting\n");
400 		goto err;
401 	}
402 	sw->cap_plug_events = cap;
403 
404 	/* read drom */
405 	if (tb_drom_read(sw))
406 		tb_sw_warn(sw, "tb_eeprom_read_rom failed, continuing\n");
407 	tb_sw_info(sw, "uid: %#llx\n", sw->uid);
408 
409 	for (i = 0; i <= sw->config.max_port_number; i++) {
410 		if (sw->ports[i].disabled) {
411 			tb_port_info(&sw->ports[i], "disabled by eeprom\n");
412 			continue;
413 		}
414 		if (tb_init_port(&sw->ports[i]))
415 			goto err;
416 	}
417 
418 	/* TODO: I2C, IECS, link controller */
419 
420 	if (tb_plug_events_active(sw, true))
421 		goto err;
422 
423 	return sw;
424 err:
425 	kfree(sw->ports);
426 	kfree(sw->drom);
427 	kfree(sw);
428 	return NULL;
429 }
430 
431 /**
432  * tb_sw_set_unplugged() - set is_unplugged on switch and downstream switches
433  */
434 void tb_sw_set_unplugged(struct tb_switch *sw)
435 {
436 	int i;
437 	if (sw == sw->tb->root_switch) {
438 		tb_sw_WARN(sw, "cannot unplug root switch\n");
439 		return;
440 	}
441 	if (sw->is_unplugged) {
442 		tb_sw_WARN(sw, "is_unplugged already set\n");
443 		return;
444 	}
445 	sw->is_unplugged = true;
446 	for (i = 0; i <= sw->config.max_port_number; i++) {
447 		if (!tb_is_upstream_port(&sw->ports[i]) && sw->ports[i].remote)
448 			tb_sw_set_unplugged(sw->ports[i].remote->sw);
449 	}
450 }
451 
452 int tb_switch_resume(struct tb_switch *sw)
453 {
454 	int i, err;
455 	u64 uid;
456 	tb_sw_info(sw, "resuming switch\n");
457 
458 	err = tb_drom_read_uid_only(sw, &uid);
459 	if (err) {
460 		tb_sw_warn(sw, "uid read failed\n");
461 		return err;
462 	}
463 	if (sw != sw->tb->root_switch && sw->uid != uid) {
464 		tb_sw_info(sw,
465 			"changed while suspended (uid %#llx -> %#llx)\n",
466 			sw->uid, uid);
467 		return -ENODEV;
468 	}
469 
470 	/* upload configuration */
471 	err = tb_sw_write(sw, 1 + (u32 *) &sw->config, TB_CFG_SWITCH, 1, 3);
472 	if (err)
473 		return err;
474 
475 	err = tb_plug_events_active(sw, true);
476 	if (err)
477 		return err;
478 
479 	/* check for surviving downstream switches */
480 	for (i = 1; i <= sw->config.max_port_number; i++) {
481 		struct tb_port *port = &sw->ports[i];
482 		if (tb_is_upstream_port(port))
483 			continue;
484 		if (!port->remote)
485 			continue;
486 		if (tb_wait_for_port(port, true) <= 0
487 			|| tb_switch_resume(port->remote->sw)) {
488 			tb_port_warn(port,
489 				     "lost during suspend, disconnecting\n");
490 			tb_sw_set_unplugged(port->remote->sw);
491 		}
492 	}
493 	return 0;
494 }
495 
496 void tb_switch_suspend(struct tb_switch *sw)
497 {
498 	int i, err;
499 	err = tb_plug_events_active(sw, false);
500 	if (err)
501 		return;
502 
503 	for (i = 1; i <= sw->config.max_port_number; i++) {
504 		if (!tb_is_upstream_port(&sw->ports[i]) && sw->ports[i].remote)
505 			tb_switch_suspend(sw->ports[i].remote->sw);
506 	}
507 	/*
508 	 * TODO: invoke tb_cfg_prepare_to_sleep here? does not seem to have any
509 	 * effect?
510 	 */
511 }
512