pcie.c

  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
 26static char *nvkm_pcie_speeds[] = {
 27	"2.5GT/s",
 28	"5.0GT/s",
 29	"8.0GT/s",
 30};
 31
 32static enum nvkm_pcie_speed
 33nvkm_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
 50static int
 51nvkm_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
 59static int
 60nvkm_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
 68static int
 69nvkm_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
 79int
 80nvkm_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
 88int
 89nvkm_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
114int
115nvkm_pcie_set_link(struct nvkm_pci *pci, enum nvkm_pcie_speed speed, u8 width)
116{
117	struct nvkm_subdev *subdev;
118	enum nvkm_pcie_speed cur_speed, max_speed;
119	int ret;
120
121	if (!pci || !pci_is_pcie(pci->pdev))
122		return 0;
123
124	if (!pci->func->pcie.set_link)
125		return -ENOSYS;
126
127	subdev = &pci->subdev;
128	nvkm_trace(subdev, "requested %s\n", nvkm_pcie_speeds[speed]);
129
130	if (pci->func->pcie.version(pci) < 2) {
131		nvkm_error(subdev, "setting link failed due to low version\n");
132		return -ENODEV;
133	}
134
135	cur_speed = pci->func->pcie.cur_speed(pci);
136	max_speed = min(nvkm_pcie_speed(pci->pdev->bus->max_bus_speed),
137			pci->func->pcie.max_speed(pci));
138
139	nvkm_trace(subdev, "current speed: %s\n", nvkm_pcie_speeds[cur_speed]);
140
141	if (speed > max_speed) {
142		nvkm_debug(subdev, "%s not supported by bus or card, dropping"
143			   "requested speed to %s", nvkm_pcie_speeds[speed],
144			   nvkm_pcie_speeds[max_speed]);
145		speed = max_speed;
146	}
147
148	pci->pcie.speed = speed;
149	pci->pcie.width = width;
150
151	if (speed == cur_speed) {
152		nvkm_debug(subdev, "requested matches current speed\n");
153		return speed;
154	}
155
156	nvkm_debug(subdev, "set link to %s x%i\n",
157		   nvkm_pcie_speeds[speed], width);
158
159	ret = pci->func->pcie.set_link(pci, speed, width);
160	if (ret < 0)
161		nvkm_error(subdev, "setting link failed: %i\n", ret);
162
163	return ret;
164}