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Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Thunderbolt Cactus Ridge driver - PCIe tunnel
4 *
5 * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
6 */
7
8#include <linux/slab.h>
9#include <linux/list.h>
10
11#include "tunnel_pci.h"
12#include "tb.h"
13
14#define __TB_TUNNEL_PRINT(level, tunnel, fmt, arg...) \
15 do { \
16 struct tb_pci_tunnel *__tunnel = (tunnel); \
17 level(__tunnel->tb, "%llx:%x <-> %llx:%x (PCI): " fmt, \
18 tb_route(__tunnel->down_port->sw), \
19 __tunnel->down_port->port, \
20 tb_route(__tunnel->up_port->sw), \
21 __tunnel->up_port->port, \
22 ## arg); \
23 } while (0)
24
25#define tb_tunnel_WARN(tunnel, fmt, arg...) \
26 __TB_TUNNEL_PRINT(tb_WARN, tunnel, fmt, ##arg)
27#define tb_tunnel_warn(tunnel, fmt, arg...) \
28 __TB_TUNNEL_PRINT(tb_warn, tunnel, fmt, ##arg)
29#define tb_tunnel_info(tunnel, fmt, arg...) \
30 __TB_TUNNEL_PRINT(tb_info, tunnel, fmt, ##arg)
31
32static void tb_pci_init_path(struct tb_path *path)
33{
34 path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
35 path->egress_shared_buffer = TB_PATH_NONE;
36 path->ingress_fc_enable = TB_PATH_ALL;
37 path->ingress_shared_buffer = TB_PATH_NONE;
38 path->priority = 3;
39 path->weight = 1;
40 path->drop_packages = 0;
41 path->nfc_credits = 0;
42}
43
44/**
45 * tb_pci_alloc() - allocate a pci tunnel
46 *
47 * Allocate a PCI tunnel. The ports must be of type TB_TYPE_PCIE_UP and
48 * TB_TYPE_PCIE_DOWN.
49 *
50 * Currently only paths consisting of two hops are supported (that is the
51 * ports must be on "adjacent" switches).
52 *
53 * The paths are hard-coded to use hop 8 (the only working hop id available on
54 * my thunderbolt devices). Therefore at most ONE path per device may be
55 * activated.
56 *
57 * Return: Returns a tb_pci_tunnel on success or NULL on failure.
58 */
59struct tb_pci_tunnel *tb_pci_alloc(struct tb *tb, struct tb_port *up,
60 struct tb_port *down)
61{
62 struct tb_pci_tunnel *tunnel = kzalloc(sizeof(*tunnel), GFP_KERNEL);
63 if (!tunnel)
64 goto err;
65 tunnel->tb = tb;
66 tunnel->down_port = down;
67 tunnel->up_port = up;
68 INIT_LIST_HEAD(&tunnel->list);
69 tunnel->path_to_up = tb_path_alloc(up->sw->tb, 2);
70 if (!tunnel->path_to_up)
71 goto err;
72 tunnel->path_to_down = tb_path_alloc(up->sw->tb, 2);
73 if (!tunnel->path_to_down)
74 goto err;
75 tb_pci_init_path(tunnel->path_to_up);
76 tb_pci_init_path(tunnel->path_to_down);
77
78 tunnel->path_to_up->hops[0].in_port = down;
79 tunnel->path_to_up->hops[0].in_hop_index = 8;
80 tunnel->path_to_up->hops[0].in_counter_index = -1;
81 tunnel->path_to_up->hops[0].out_port = tb_upstream_port(up->sw)->remote;
82 tunnel->path_to_up->hops[0].next_hop_index = 8;
83
84 tunnel->path_to_up->hops[1].in_port = tb_upstream_port(up->sw);
85 tunnel->path_to_up->hops[1].in_hop_index = 8;
86 tunnel->path_to_up->hops[1].in_counter_index = -1;
87 tunnel->path_to_up->hops[1].out_port = up;
88 tunnel->path_to_up->hops[1].next_hop_index = 8;
89
90 tunnel->path_to_down->hops[0].in_port = up;
91 tunnel->path_to_down->hops[0].in_hop_index = 8;
92 tunnel->path_to_down->hops[0].in_counter_index = -1;
93 tunnel->path_to_down->hops[0].out_port = tb_upstream_port(up->sw);
94 tunnel->path_to_down->hops[0].next_hop_index = 8;
95
96 tunnel->path_to_down->hops[1].in_port =
97 tb_upstream_port(up->sw)->remote;
98 tunnel->path_to_down->hops[1].in_hop_index = 8;
99 tunnel->path_to_down->hops[1].in_counter_index = -1;
100 tunnel->path_to_down->hops[1].out_port = down;
101 tunnel->path_to_down->hops[1].next_hop_index = 8;
102 return tunnel;
103
104err:
105 if (tunnel) {
106 if (tunnel->path_to_down)
107 tb_path_free(tunnel->path_to_down);
108 if (tunnel->path_to_up)
109 tb_path_free(tunnel->path_to_up);
110 kfree(tunnel);
111 }
112 return NULL;
113}
114
115/**
116 * tb_pci_free() - free a tunnel
117 *
118 * The tunnel must have been deactivated.
119 */
120void tb_pci_free(struct tb_pci_tunnel *tunnel)
121{
122 if (tunnel->path_to_up->activated || tunnel->path_to_down->activated) {
123 tb_tunnel_WARN(tunnel, "trying to free an activated tunnel\n");
124 return;
125 }
126 tb_path_free(tunnel->path_to_up);
127 tb_path_free(tunnel->path_to_down);
128 kfree(tunnel);
129}
130
131/**
132 * tb_pci_is_invalid - check whether an activated path is still valid
133 */
134bool tb_pci_is_invalid(struct tb_pci_tunnel *tunnel)
135{
136 WARN_ON(!tunnel->path_to_up->activated);
137 WARN_ON(!tunnel->path_to_down->activated);
138
139 return tb_path_is_invalid(tunnel->path_to_up)
140 || tb_path_is_invalid(tunnel->path_to_down);
141}
142
143/**
144 * tb_pci_port_active() - activate/deactivate PCI capability
145 *
146 * Return: Returns 0 on success or an error code on failure.
147 */
148static int tb_pci_port_active(struct tb_port *port, bool active)
149{
150 u32 word = active ? 0x80000000 : 0x0;
151 int cap = tb_port_find_cap(port, TB_PORT_CAP_ADAP);
152 if (cap < 0) {
153 tb_port_warn(port, "TB_PORT_CAP_ADAP not found: %d\n", cap);
154 return cap;
155 }
156 return tb_port_write(port, &word, TB_CFG_PORT, cap, 1);
157}
158
159/**
160 * tb_pci_restart() - activate a tunnel after a hardware reset
161 */
162int tb_pci_restart(struct tb_pci_tunnel *tunnel)
163{
164 int res;
165 tunnel->path_to_up->activated = false;
166 tunnel->path_to_down->activated = false;
167
168 tb_tunnel_info(tunnel, "activating\n");
169
170 res = tb_path_activate(tunnel->path_to_up);
171 if (res)
172 goto err;
173 res = tb_path_activate(tunnel->path_to_down);
174 if (res)
175 goto err;
176
177 res = tb_pci_port_active(tunnel->down_port, true);
178 if (res)
179 goto err;
180
181 res = tb_pci_port_active(tunnel->up_port, true);
182 if (res)
183 goto err;
184 return 0;
185err:
186 tb_tunnel_warn(tunnel, "activation failed\n");
187 tb_pci_deactivate(tunnel);
188 return res;
189}
190
191/**
192 * tb_pci_activate() - activate a tunnel
193 *
194 * Return: Returns 0 on success or an error code on failure.
195 */
196int tb_pci_activate(struct tb_pci_tunnel *tunnel)
197{
198 if (tunnel->path_to_up->activated || tunnel->path_to_down->activated) {
199 tb_tunnel_WARN(tunnel,
200 "trying to activate an already activated tunnel\n");
201 return -EINVAL;
202 }
203
204 return tb_pci_restart(tunnel);
205}
206
207
208
209/**
210 * tb_pci_deactivate() - deactivate a tunnel
211 */
212void tb_pci_deactivate(struct tb_pci_tunnel *tunnel)
213{
214 tb_tunnel_info(tunnel, "deactivating\n");
215 /*
216 * TODO: enable reset by writing 0x04000000 to TB_CAP_PCIE + 1 on up
217 * port. Seems to have no effect?
218 */
219 tb_pci_port_active(tunnel->up_port, false);
220 tb_pci_port_active(tunnel->down_port, false);
221 if (tunnel->path_to_down->activated)
222 tb_path_deactivate(tunnel->path_to_down);
223 if (tunnel->path_to_up->activated)
224 tb_path_deactivate(tunnel->path_to_up);
225}
226