1 /* $NetBSD: nouveau_nvkm_subdev_pci_pcie.c,v 1.5 2023/09/30 10:46:45 mrg Exp $ */
2
3 /*
4 * Copyright 2015 Karol Herbst <nouveau@karolherbst.de>
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the "Software"),
8 * to deal in the Software without restriction, including without limitation
9 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10 * and/or sell copies of the Software, and to permit persons to whom the
11 * Software is furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
20 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
21 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
22 * OTHER DEALINGS IN THE SOFTWARE.
23 *
24 * Authors: Karol Herbst <git@karolherbst.de>
25 */
26 #include <sys/cdefs.h>
27 __KERNEL_RCSID(0, "$NetBSD: nouveau_nvkm_subdev_pci_pcie.c,v 1.5 2023/09/30 10:46:45 mrg Exp $");
28
29 #include "priv.h"
30
31 static const char *nvkm_pcie_speeds[] = {
32 "2.5GT/s",
33 "5.0GT/s",
34 "8.0GT/s",
35 };
36
37 static enum nvkm_pcie_speed
nvkm_pcie_speed(enum pci_bus_speed speed)38 nvkm_pcie_speed(enum pci_bus_speed speed)
39 {
40 switch (speed) {
41 case PCIE_SPEED_2_5GT:
42 return NVKM_PCIE_SPEED_2_5;
43 case PCIE_SPEED_5_0GT:
44 return NVKM_PCIE_SPEED_5_0;
45 case PCIE_SPEED_8_0GT:
46 return NVKM_PCIE_SPEED_8_0;
47 default:
48 /* XXX 0x16 is 8_0, assume 0x17 will be 16_0 for now */
49 if (speed == 0x17)
50 return NVKM_PCIE_SPEED_8_0;
51 return NVKM_PCIE_SPEED_2_5;
52 }
53 }
54
55 static int
nvkm_pcie_get_version(struct nvkm_pci * pci)56 nvkm_pcie_get_version(struct nvkm_pci *pci)
57 {
58 if (!pci->func->pcie.version)
59 return -ENOSYS;
60
61 return pci->func->pcie.version(pci);
62 }
63
64 static int
nvkm_pcie_get_max_version(struct nvkm_pci * pci)65 nvkm_pcie_get_max_version(struct nvkm_pci *pci)
66 {
67 if (!pci->func->pcie.version_supported)
68 return -ENOSYS;
69
70 return pci->func->pcie.version_supported(pci);
71 }
72
73 static int
nvkm_pcie_set_version(struct nvkm_pci * pci,int version)74 nvkm_pcie_set_version(struct nvkm_pci *pci, int version)
75 {
76 if (!pci->func->pcie.set_version)
77 return -ENOSYS;
78
79 nvkm_trace(&pci->subdev, "set to version %i\n", version);
80 pci->func->pcie.set_version(pci, version);
81 return nvkm_pcie_get_version(pci);
82 }
83
84 int
nvkm_pcie_oneinit(struct nvkm_pci * pci)85 nvkm_pcie_oneinit(struct nvkm_pci *pci)
86 {
87 if (pci->func->pcie.max_speed)
88 nvkm_debug(&pci->subdev, "pcie max speed: %s\n",
89 nvkm_pcie_speeds[pci->func->pcie.max_speed(pci)]);
90 return 0;
91 }
92
93 int
nvkm_pcie_init(struct nvkm_pci * pci)94 nvkm_pcie_init(struct nvkm_pci *pci)
95 {
96 struct nvkm_subdev *subdev = &pci->subdev;
97 int ret;
98
99 /* raise pcie version first */
100 ret = nvkm_pcie_get_version(pci);
101 if (ret > 0) {
102 int max_version = nvkm_pcie_get_max_version(pci);
103 if (max_version > 0 && max_version > ret)
104 ret = nvkm_pcie_set_version(pci, max_version);
105
106 if (ret < max_version)
107 nvkm_error(subdev, "couldn't raise version: %i\n", ret);
108 }
109
110 if (pci->func->pcie.init)
111 pci->func->pcie.init(pci);
112
113 if (pci->pcie.speed != -1)
114 nvkm_pcie_set_link(pci, pci->pcie.speed, pci->pcie.width);
115
116 return 0;
117 }
118
119 int
nvkm_pcie_set_link(struct nvkm_pci * pci,enum nvkm_pcie_speed speed,u8 width)120 nvkm_pcie_set_link(struct nvkm_pci *pci, enum nvkm_pcie_speed speed, u8 width)
121 {
122 struct nvkm_subdev *subdev = &pci->subdev;
123 enum nvkm_pcie_speed cur_speed, max_speed;
124 struct pci_bus *pbus;
125 int ret;
126
127 if (!pci || !pci_is_pcie(pci->pdev))
128 return 0;
129 pbus = pci->pdev->bus;
130
131 if (!pci->func->pcie.set_link)
132 return -ENOSYS;
133
134 nvkm_trace(subdev, "requested %s\n", nvkm_pcie_speeds[speed]);
135
136 if (pci->func->pcie.version(pci) < 2) {
137 nvkm_error(subdev, "setting link failed due to low version\n");
138 return -ENODEV;
139 }
140
141 cur_speed = pci->func->pcie.cur_speed(pci);
142 max_speed = min(nvkm_pcie_speed(pbus->max_bus_speed),
143 pci->func->pcie.max_speed(pci));
144
145 nvkm_trace(subdev, "current speed: %s\n", nvkm_pcie_speeds[cur_speed]);
146
147 if (speed > max_speed) {
148 nvkm_debug(subdev, "%s not supported by bus or card, dropping"
149 "requested speed to %s", nvkm_pcie_speeds[speed],
150 nvkm_pcie_speeds[max_speed]);
151 speed = max_speed;
152 }
153
154 pci->pcie.speed = speed;
155 pci->pcie.width = width;
156
157 if (speed == cur_speed) {
158 nvkm_debug(subdev, "requested matches current speed\n");
159 return speed;
160 }
161
162 nvkm_debug(subdev, "set link to %s x%i\n",
163 nvkm_pcie_speeds[speed], width);
164
165 ret = pci->func->pcie.set_link(pci, speed, width);
166 if (ret < 0)
167 nvkm_error(subdev, "setting link failed: %i\n", ret);
168
169 return ret;
170 }
171