summaryrefslogtreecommitdiffstats
path: root/drivers/thunderbolt/tb.c
blob: 30e02c716f6c908f2dd3f11e0fd5bb5753776f6e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
// SPDX-License-Identifier: GPL-2.0
/*
 * Thunderbolt Cactus Ridge driver - bus logic (NHI independent)
 *
 * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
 */

#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/platform_data/x86/apple.h>

#include "tb.h"
#include "tb_regs.h"
#include "tunnel_pci.h"

/**
 * struct tb_cm - Simple Thunderbolt connection manager
 * @tunnel_list: List of active tunnels
 * @hotplug_active: tb_handle_hotplug will stop progressing plug
 *		    events and exit if this is not set (it needs to
 *		    acquire the lock one more time). Used to drain wq
 *		    after cfg has been paused.
 */
struct tb_cm {
	struct list_head tunnel_list;
	bool hotplug_active;
};

/* enumeration & hot plug handling */


static void tb_scan_port(struct tb_port *port);

/**
 * tb_scan_switch() - scan for and initialize downstream switches
 */
static void tb_scan_switch(struct tb_switch *sw)
{
	int i;
	for (i = 1; i <= sw->config.max_port_number; i++)
		tb_scan_port(&sw->ports[i]);
}

/**
 * tb_scan_port() - check for and initialize switches below port
 */
static void tb_scan_port(struct tb_port *port)
{
	struct tb_switch *sw;
	if (tb_is_upstream_port(port))
		return;
	if (port->config.type != TB_TYPE_PORT)
		return;
	if (port->dual_link_port && port->link_nr)
		return; /*
			 * Downstream switch is reachable through two ports.
			 * Only scan on the primary port (link_nr == 0).
			 */
	if (tb_wait_for_port(port, false) <= 0)
		return;
	if (port->remote) {
		tb_port_WARN(port, "port already has a remote!\n");
		return;
	}
	sw = tb_switch_alloc(port->sw->tb, &port->sw->dev,
			     tb_downstream_route(port));
	if (!sw)
		return;

	if (tb_switch_configure(sw)) {
		tb_switch_put(sw);
		return;
	}

	sw->authorized = true;

	if (tb_switch_add(sw)) {
		tb_switch_put(sw);
		return;
	}

	port->remote = tb_upstream_port(sw);
	tb_upstream_port(sw)->remote = port;
	tb_scan_switch(sw);
}

/**
 * tb_free_invalid_tunnels() - destroy tunnels of devices that have gone away
 */
static void tb_free_invalid_tunnels(struct tb *tb)
{
	struct tb_cm *tcm = tb_priv(tb);
	struct tb_pci_tunnel *tunnel;
	struct tb_pci_tunnel *n;

	list_for_each_entry_safe(tunnel, n, &tcm->tunnel_list, list) {
		if (tb_pci_is_invalid(tunnel)) {
			tb_pci_deactivate(tunnel);
			list_del(&tunnel->list);
			tb_pci_free(tunnel);
		}
	}
}

/**
 * tb_free_unplugged_children() - traverse hierarchy and free unplugged switches
 */
static void tb_free_unplugged_children(struct tb_switch *sw)
{
	int i;
	for (i = 1; i <= sw->config.max_port_number; i++) {
		struct tb_port *port = &sw->ports[i];
		if (tb_is_upstream_port(port))
			continue;
		if (!port->remote)
			continue;
		if (port->remote->sw->is_unplugged) {
			tb_switch_remove(port->remote->sw);
			port->remote = NULL;
		} else {
			tb_free_unplugged_children(port->remote->sw);
		}
	}
}


/**
 * find_pci_up_port() - return the first PCIe up port on @sw or NULL
 */
static struct tb_port *tb_find_pci_up_port(struct tb_switch *sw)
{
	int i;
	for (i = 1; i <= sw->config.max_port_number; i++)
		if (sw->ports[i].config.type == TB_TYPE_PCIE_UP)
			return &sw->ports[i];
	return NULL;
}

/**
 * find_unused_down_port() - return the first inactive PCIe down port on @sw
 */
static struct tb_port *tb_find_unused_down_port(struct tb_switch *sw)
{
	int i;
	int cap;
	int res;
	int data;
	for (i = 1; i <= sw->config.max_port_number; i++) {
		if (tb_is_upstream_port(&sw->ports[i]))
			continue;
		if (sw->ports[i].config.type != TB_TYPE_PCIE_DOWN)
			continue;
		cap = tb_port_find_cap(&sw->ports[i], TB_PORT_CAP_ADAP);
		if (cap < 0)
			continue;
		res = tb_port_read(&sw->ports[i], &data, TB_CFG_PORT, cap, 1);
		if (res < 0)
			continue;
		if (data & 0x80000000)
			continue;
		return &sw->ports[i];
	}
	return NULL;
}

/**
 * tb_activate_pcie_devices() - scan for and activate PCIe devices
 *
 * This method is somewhat ad hoc. For now it only supports one device
 * per port and only devices at depth 1.
 */
static void tb_activate_pcie_devices(struct tb *tb)
{
	int i;
	int cap;
	u32 data;
	struct tb_switch *sw;
	struct tb_port *up_port;
	struct tb_port *down_port;
	struct tb_pci_tunnel *tunnel;
	struct tb_cm *tcm = tb_priv(tb);

	/* scan for pcie devices at depth 1*/
	for (i = 1; i <= tb->root_switch->config.max_port_number; i++) {
		if (tb_is_upstream_port(&tb->root_switch->ports[i]))
			continue;
		if (tb->root_switch->ports[i].config.type != TB_TYPE_PORT)
			continue;
		if (!tb->root_switch->ports[i].remote)
			continue;
		sw = tb->root_switch->ports[i].remote->sw;
		up_port = tb_find_pci_up_port(sw);
		if (!up_port) {
			tb_sw_info(sw, "no PCIe devices found, aborting\n");
			continue;
		}

		/* check whether port is already activated */
		cap = tb_port_find_cap(up_port, TB_PORT_CAP_ADAP);
		if (cap < 0)
			continue;
		if (tb_port_read(up_port, &data, TB_CFG_PORT, cap, 1))
			continue;
		if (data & 0x80000000) {
			tb_port_info(up_port,
				     "PCIe port already activated, aborting\n");
			continue;
		}

		down_port = tb_find_unused_down_port(tb->root_switch);
		if (!down_port) {
			tb_port_info(up_port,
				     "All PCIe down ports are occupied, aborting\n");
			continue;
		}
		tunnel = tb_pci_alloc(tb, up_port, down_port);
		if (!tunnel) {
			tb_port_info(up_port,
				     "PCIe tunnel allocation failed, aborting\n");
			continue;
		}

		if (tb_pci_activate(tunnel)) {
			tb_port_info(up_port,
				     "PCIe tunnel activation failed, aborting\n");
			tb_pci_free(tunnel);
			continue;
		}

		list_add(&tunnel->list, &tcm->tunnel_list);
	}
}

/* hotplug handling */

struct tb_hotplug_event {
	struct work_struct work;
	struct tb *tb;
	u64 route;
	u8 port;
	bool unplug;
};

/**
 * tb_handle_hotplug() - handle hotplug event
 *
 * Executes on tb->wq.
 */
static void tb_handle_hotplug(struct work_struct *work)
{
	struct tb_hotplug_event *ev = container_of(work, typeof(*ev), work);
	struct tb *tb = ev->tb;
	struct tb_cm *tcm = tb_priv(tb);
	struct tb_switch *sw;
	struct tb_port *port;
	mutex_lock(&tb->lock);
	if (!tcm->hotplug_active)
		goto out; /* during init, suspend or shutdown */

	sw = get_switch_at_route(tb->root_switch, ev->route);
	if (!sw) {
		tb_warn(tb,
			"hotplug event from non existent switch %llx:%x (unplug: %d)\n",
			ev->route, ev->port, ev->unplug);
		goto out;
	}
	if (ev->port > sw->config.max_port_number) {
		tb_warn(tb,
			"hotplug event from non existent port %llx:%x (unplug: %d)\n",
			ev->route, ev->port, ev->unplug);
		goto out;
	}
	port = &sw->ports[ev->port];
	if (tb_is_upstream_port(port)) {
		tb_warn(tb,
			"hotplug event for upstream port %llx:%x (unplug: %d)\n",
			ev->route, ev->port, ev->unplug);
		goto out;
	}
	if (ev->unplug) {
		if (port->remote) {
			tb_port_info(port, "unplugged\n");
			tb_sw_set_unplugged(port->remote->sw);
			tb_free_invalid_tunnels(tb);
			tb_switch_remove(port->remote->sw);
			port->remote = NULL;
		} else {
			tb_port_info(port,
				     "got unplug event for disconnected port, ignoring\n");
		}
	} else if (port->remote) {
		tb_port_info(port,
			     "got plug event for connected port, ignoring\n");
	} else {
		tb_port_info(port, "hotplug: scanning\n");
		tb_scan_port(port);
		if (!port->remote) {
			tb_port_info(port, "hotplug: no switch found\n");
		} else if (port->remote->sw->config.depth > 1) {
			tb_sw_warn(port->remote->sw,
				   "hotplug: chaining not supported\n");
		} else {
			tb_sw_info(port->remote->sw,
				   "hotplug: activating pcie devices\n");
			tb_activate_pcie_devices(tb);
		}
	}
out:
	mutex_unlock(&tb->lock);
	kfree(ev);
}

/**
 * tb_schedule_hotplug_handler() - callback function for the control channel
 *
 * Delegates to tb_handle_hotplug.
 */
static void tb_handle_event(struct tb *tb, enum tb_cfg_pkg_type type,
			    const void *buf, size_t size)
{
	const struct cfg_event_pkg *pkg = buf;
	struct tb_hotplug_event *ev;
	u64 route;

	if (type != TB_CFG_PKG_EVENT) {
		tb_warn(tb, "unexpected event %#x, ignoring\n", type);
		return;
	}

	route = tb_cfg_get_route(&pkg->header);

	if (tb_cfg_error(tb->ctl, route, pkg->port,
			 TB_CFG_ERROR_ACK_PLUG_EVENT)) {
		tb_warn(tb, "could not ack plug event on %llx:%x\n", route,
			pkg->port);
	}

	ev = kmalloc(sizeof(*ev), GFP_KERNEL);
	if (!ev)
		return;
	INIT_WORK(&ev->work, tb_handle_hotplug);
	ev->tb = tb;
	ev->route = route;
	ev->port = pkg->port;
	ev->unplug = pkg->unplug;
	queue_work(tb->wq, &ev->work);
}

static void tb_stop(struct tb *tb)
{
	struct tb_cm *tcm = tb_priv(tb);
	struct tb_pci_tunnel *tunnel;
	struct tb_pci_tunnel *n;

	/* tunnels are only present after everything has been initialized */
	list_for_each_entry_safe(tunnel, n, &tcm->tunnel_list, list) {
		tb_pci_deactivate(tunnel);
		tb_pci_free(tunnel);
	}
	tb_switch_remove(tb->root_switch);
	tcm->hotplug_active = false; /* signal tb_handle_hotplug to quit */
}

static int tb_start(struct tb *tb)
{
	struct tb_cm *tcm = tb_priv(tb);
	int ret;

	tb->root_switch = tb_switch_alloc(tb, &tb->dev, 0);
	if (!tb->root_switch)
		return -ENOMEM;

	/*
	 * ICM firmware upgrade needs running firmware and in native
	 * mode that is not available so disable firmware upgrade of the
	 * root switch.
	 */
	tb->root_switch->no_nvm_upgrade = true;

	ret = tb_switch_configure(tb->root_switch);
	if (ret) {
		tb_switch_put(tb->root_switch);
		return ret;
	}

	/* Announce the switch to the world */
	ret = tb_switch_add(tb->root_switch);
	if (ret) {
		tb_switch_put(tb->root_switch);
		return ret;
	}

	/* Full scan to discover devices added before the driver was loaded. */
	tb_scan_switch(tb->root_switch);
	tb_activate_pcie_devices(tb);

	/* Allow tb_handle_hotplug to progress events */
	tcm->hotplug_active = true;
	return 0;
}

static int tb_suspend_noirq(struct tb *tb)
{
	struct tb_cm *tcm = tb_priv(tb);

	tb_dbg(tb, "suspending...\n");
	tb_switch_suspend(tb->root_switch);
	tcm->hotplug_active = false; /* signal tb_handle_hotplug to quit */
	tb_dbg(tb, "suspend finished\n");

	return 0;
}

static int tb_resume_noirq(struct tb *tb)
{
	struct tb_cm *tcm = tb_priv(tb);
	struct tb_pci_tunnel *tunnel, *n;

	tb_dbg(tb, "resuming...\n");

	/* remove any pci devices the firmware might have setup */
	tb_switch_reset(tb, 0);

	tb_switch_resume(tb->root_switch);
	tb_free_invalid_tunnels(tb);
	tb_free_unplugged_children(tb->root_switch);
	list_for_each_entry_safe(tunnel, n, &tcm->tunnel_list, list)
		tb_pci_restart(tunnel);
	if (!list_empty(&tcm->tunnel_list)) {
		/*
		 * the pcie links need some time to get going.
		 * 100ms works for me...
		 */
		tb_dbg(tb, "tunnels restarted, sleeping for 100ms\n");
		msleep(100);
	}
	 /* Allow tb_handle_hotplug to progress events */
	tcm->hotplug_active = true;
	tb_dbg(tb, "resume finished\n");

	return 0;
}

static const struct tb_cm_ops tb_cm_ops = {
	.start = tb_start,
	.stop = tb_stop,
	.suspend_noirq = tb_suspend_noirq,
	.resume_noirq = tb_resume_noirq,
	.handle_event = tb_handle_event,
};

struct tb *tb_probe(struct tb_nhi *nhi)
{
	struct tb_cm *tcm;
	struct tb *tb;

	if (!x86_apple_machine)
		return NULL;

	tb = tb_domain_alloc(nhi, sizeof(*tcm));
	if (!tb)
		return NULL;

	tb->security_level = TB_SECURITY_NONE;
	tb->cm_ops = &tb_cm_ops;

	tcm = tb_priv(tb);
	INIT_LIST_HEAD(&tcm->tunnel_list);

	return tb;
}
OpenPOWER on IntegriCloud