aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/thunderbolt/tunnel_pci.c
blob: baf1cd370446d6e12e9b69efba7b214b17092c8b (plain) (blame)
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
/*
 * Thunderbolt Cactus Ridge driver - PCIe tunnel
 *
 * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
 */

#include <linux/slab.h>
#include <linux/list.h>

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

#define __TB_TUNNEL_PRINT(level, tunnel, fmt, arg...)                   \
	do {                                                            \
		struct tb_pci_tunnel *__tunnel = (tunnel);              \
		level(__tunnel->tb, "%llx:%x <-> %llx:%x (PCI): " fmt,  \
		      tb_route(__tunnel->down_port->sw),                \
		      __tunnel->down_port->port,                        \
		      tb_route(__tunnel->up_port->sw),                  \
		      __tunnel->up_port->port,                          \
		      ## arg);                                          \
	} while (0)

#define tb_tunnel_WARN(tunnel, fmt, arg...) \
	__TB_TUNNEL_PRINT(tb_WARN, tunnel, fmt, ##arg)
#define tb_tunnel_warn(tunnel, fmt, arg...) \
	__TB_TUNNEL_PRINT(tb_warn, tunnel, fmt, ##arg)
#define tb_tunnel_info(tunnel, fmt, arg...) \
	__TB_TUNNEL_PRINT(tb_info, tunnel, fmt, ##arg)

static void tb_pci_init_path(struct tb_path *path)
{
	path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
	path->egress_shared_buffer = TB_PATH_NONE;
	path->ingress_fc_enable = TB_PATH_ALL;
	path->ingress_shared_buffer = TB_PATH_NONE;
	path->priority = 3;
	path->weight = 1;
	path->drop_packages = 0;
	path->nfc_credits = 0;
}

/**
 * tb_pci_alloc() - allocate a pci tunnel
 *
 * Allocate a PCI tunnel. The ports must be of type TB_TYPE_PCIE_UP and
 * TB_TYPE_PCIE_DOWN.
 *
 * Currently only paths consisting of two hops are supported (that is the
 * ports must be on "adjacent" switches).
 *
 * The paths are hard-coded to use hop 8 (the only working hop id available on
 * my thunderbolt devices). Therefore at most ONE path per device may be
 * activated.
 *
 * Return: Returns a tb_pci_tunnel on success or NULL on failure.
 */
struct tb_pci_tunnel *tb_pci_alloc(struct tb *tb, struct tb_port *up,
				   struct tb_port *down)
{
	struct tb_pci_tunnel *tunnel = kzalloc(sizeof(*tunnel), GFP_KERNEL);
	if (!tunnel)
		goto err;
	tunnel->tb = tb;
	tunnel->down_port = down;
	tunnel->up_port = up;
	INIT_LIST_HEAD(&tunnel->list);
	tunnel->path_to_up = tb_path_alloc(up->sw->tb, 2);
	if (!tunnel->path_to_up)
		goto err;
	tunnel->path_to_down = tb_path_alloc(up->sw->tb, 2);
	if (!tunnel->path_to_down)
		goto err;
	tb_pci_init_path(tunnel->path_to_up);
	tb_pci_init_path(tunnel->path_to_down);

	tunnel->path_to_up->hops[0].in_port = down;
	tunnel->path_to_up->hops[0].in_hop_index = 8;
	tunnel->path_to_up->hops[0].in_counter_index = -1;
	tunnel->path_to_up->hops[0].out_port = tb_upstream_port(up->sw)->remote;
	tunnel->path_to_up->hops[0].next_hop_index = 8;

	tunnel->path_to_up->hops[1].in_port = tb_upstream_port(up->sw);
	tunnel->path_to_up->hops[1].in_hop_index = 8;
	tunnel->path_to_up->hops[1].in_counter_index = -1;
	tunnel->path_to_up->hops[1].out_port = up;
	tunnel->path_to_up->hops[1].next_hop_index = 8;

	tunnel->path_to_down->hops[0].in_port = up;
	tunnel->path_to_down->hops[0].in_hop_index = 8;
	tunnel->path_to_down->hops[0].in_counter_index = -1;
	tunnel->path_to_down->hops[0].out_port = tb_upstream_port(up->sw);
	tunnel->path_to_down->hops[0].next_hop_index = 8;

	tunnel->path_to_down->hops[1].in_port =
		tb_upstream_port(up->sw)->remote;
	tunnel->path_to_down->hops[1].in_hop_index = 8;
	tunnel->path_to_down->hops[1].in_counter_index = -1;
	tunnel->path_to_down->hops[1].out_port = down;
	tunnel->path_to_down->hops[1].next_hop_index = 8;
	return tunnel;

err:
	if (tunnel) {
		if (tunnel->path_to_down)
			tb_path_free(tunnel->path_to_down);
		if (tunnel->path_to_up)
			tb_path_free(tunnel->path_to_up);
		kfree(tunnel);
	}
	return NULL;
}

/**
 * tb_pci_free() - free a tunnel
 *
 * The tunnel must have been deactivated.
 */
void tb_pci_free(struct tb_pci_tunnel *tunnel)
{
	if (tunnel->path_to_up->activated || tunnel->path_to_down->activated) {
		tb_tunnel_WARN(tunnel, "trying to free an activated tunnel\n");
		return;
	}
	tb_path_free(tunnel->path_to_up);
	tb_path_free(tunnel->path_to_down);
	kfree(tunnel);
}

/**
 * tb_pci_is_invalid - check whether an activated path is still valid
 */
bool tb_pci_is_invalid(struct tb_pci_tunnel *tunnel)
{
	WARN_ON(!tunnel->path_to_up->activated);
	WARN_ON(!tunnel->path_to_down->activated);

	return tb_path_is_invalid(tunnel->path_to_up)
	       || tb_path_is_invalid(tunnel->path_to_down);
}

/**
 * tb_pci_port_active() - activate/deactivate PCI capability
 *
 * Return: Returns 0 on success or an error code on failure.
 */
static int tb_pci_port_active(struct tb_port *port, bool active)
{
	u32 word = active ? 0x80000000 : 0x0;
	int cap = tb_find_cap(port, TB_CFG_PORT, TB_CAP_PCIE);
	if (cap <= 0) {
		tb_port_warn(port, "TB_CAP_PCIE not found: %d\n", cap);
		return cap ? cap : -ENXIO;
	}
	return tb_port_write(port, &word, TB_CFG_PORT, cap, 1);
}

/**
 * tb_pci_restart() - activate a tunnel after a hardware reset
 */
int tb_pci_restart(struct tb_pci_tunnel *tunnel)
{
	int res;
	tunnel->path_to_up->activated = false;
	tunnel->path_to_down->activated = false;

	tb_tunnel_info(tunnel, "activating\n");

	res = tb_path_activate(tunnel->path_to_up);
	if (res)
		goto err;
	res = tb_path_activate(tunnel->path_to_down);
	if (res)
		goto err;

	res = tb_pci_port_active(tunnel->down_port, true);
	if (res)
		goto err;

	res = tb_pci_port_active(tunnel->up_port, true);
	if (res)
		goto err;
	return 0;
err:
	tb_tunnel_warn(tunnel, "activation failed\n");
	tb_pci_deactivate(tunnel);
	return res;
}

/**
 * tb_pci_activate() - activate a tunnel
 *
 * Return: Returns 0 on success or an error code on failure.
 */
int tb_pci_activate(struct tb_pci_tunnel *tunnel)
{
	int res;
	if (tunnel->path_to_up->activated || tunnel->path_to_down->activated) {
		tb_tunnel_WARN(tunnel,
			       "trying to activate an already activated tunnel\n");
		return -EINVAL;
	}

	res = tb_pci_restart(tunnel);
	if (res)
		return res;

	list_add(&tunnel->list, &tunnel->tb->tunnel_list);
	return 0;
}



/**
 * tb_pci_deactivate() - deactivate a tunnel
 */
void tb_pci_deactivate(struct tb_pci_tunnel *tunnel)
{
	tb_tunnel_info(tunnel, "deactivating\n");
	/*
	 * TODO: enable reset by writing 0x04000000 to TB_CAP_PCIE + 1 on up
	 * port. Seems to have no effect?
	 */
	tb_pci_port_active(tunnel->up_port, false);
	tb_pci_port_active(tunnel->down_port, false);
	if (tunnel->path_to_down->activated)
		tb_path_deactivate(tunnel->path_to_down);
	if (tunnel->path_to_up->activated)
		tb_path_deactivate(tunnel->path_to_up);
	list_del_init(&tunnel->list);
}