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