1 /*
2  * Copyright 2014 Red Hat Inc.
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: Ben Skeggs <bskeggs@redhat.com>
23  */
24 #include "priv.h"
25 
26 #include <core/option.h>
27 #include <subdev/bios.h>
28 #include <subdev/bios/image.h>
29 
30 struct shadow {
31 	u32 skip;
32 	const struct nvbios_source *func;
33 	void *data;
34 	u32 size;
35 	int score;
36 };
37 
38 static bool
39 shadow_fetch(struct nvkm_bios *bios, struct shadow *mthd, u32 upto)
40 {
41 	const u32 limit = (upto + 3) & ~3;
42 	const u32 start = bios->size;
43 	void *data = mthd->data;
44 	if (nvbios_extend(bios, limit) > 0) {
45 		u32 read = mthd->func->read(data, start, limit - start, bios);
46 		bios->size = start + read;
47 	}
48 	return bios->size >= limit;
49 }
50 
51 static int
52 shadow_image(struct nvkm_bios *bios, int idx, u32 offset, struct shadow *mthd)
53 {
54 	struct nvkm_subdev *subdev = &bios->subdev;
55 	struct nvbios_image image;
56 	int score = 1;
57 
58 	if (!shadow_fetch(bios, mthd, offset + 0x1000)) {
59 		nvkm_debug(subdev, "%08x: header fetch failed\n", offset);
60 		return 0;
61 	}
62 
63 	if (!nvbios_image(bios, idx, &image)) {
64 		nvkm_debug(subdev, "image %d invalid\n", idx);
65 		return 0;
66 	}
67 	nvkm_debug(subdev, "%08x: type %02x, %d bytes\n",
68 		   image.base, image.type, image.size);
69 
70 	if (!shadow_fetch(bios, mthd, image.size)) {
71 		nvkm_debug(subdev, "%08x: fetch failed\n", image.base);
72 		return 0;
73 	}
74 
75 	switch (image.type) {
76 	case 0x00:
77 		if (nvbios_checksum(&bios->data[image.base], image.size)) {
78 			nvkm_debug(subdev, "%08x: checksum failed\n",
79 				   image.base);
80 			if (mthd->func->rw)
81 				score += 1;
82 			score += 1;
83 		} else {
84 			score += 3;
85 		}
86 		break;
87 	default:
88 		score += 3;
89 		break;
90 	}
91 
92 	if (!image.last)
93 		score += shadow_image(bios, idx + 1, offset + image.size, mthd);
94 	return score;
95 }
96 
97 static int
98 shadow_method(struct nvkm_bios *bios, struct shadow *mthd, const char *name)
99 {
100 	const struct nvbios_source *func = mthd->func;
101 	struct nvkm_subdev *subdev = &bios->subdev;
102 	if (func->name) {
103 		nvkm_debug(subdev, "trying %s...\n", name ? name : func->name);
104 		if (func->init) {
105 			mthd->data = func->init(bios, name);
106 			if (IS_ERR(mthd->data)) {
107 				mthd->data = NULL;
108 				return 0;
109 			}
110 		}
111 		mthd->score = shadow_image(bios, 0, 0, mthd);
112 		if (func->fini)
113 			func->fini(mthd->data);
114 		nvkm_debug(subdev, "scored %d\n", mthd->score);
115 		mthd->data = bios->data;
116 		mthd->size = bios->size;
117 		bios->data  = NULL;
118 		bios->size  = 0;
119 	}
120 	return mthd->score;
121 }
122 
123 static u32
124 shadow_fw_read(void *data, u32 offset, u32 length, struct nvkm_bios *bios)
125 {
126 	const struct firmware *fw = data;
127 	if (offset + length <= fw->size) {
128 		memcpy(bios->data + offset, fw->data + offset, length);
129 		return length;
130 	}
131 	return 0;
132 }
133 
134 static void *
135 shadow_fw_init(struct nvkm_bios *bios, const char *name)
136 {
137 	struct device *dev = bios->subdev.device->dev;
138 	const struct firmware *fw;
139 	int ret = request_firmware(&fw, name, dev);
140 	if (ret)
141 		return ERR_PTR(-ENOENT);
142 	return (void *)fw;
143 }
144 
145 static const struct nvbios_source
146 shadow_fw = {
147 	.name = "firmware",
148 	.init = shadow_fw_init,
149 	.fini = (void(*)(void *))release_firmware,
150 	.read = shadow_fw_read,
151 	.rw = false,
152 };
153 
154 int
155 nvbios_shadow(struct nvkm_bios *bios)
156 {
157 	struct nvkm_subdev *subdev = &bios->subdev;
158 	struct nvkm_device *device = subdev->device;
159 	struct shadow mthds[] = {
160 		{ 0, &nvbios_of },
161 		{ 0, &nvbios_ramin },
162 		{ 0, &nvbios_rom },
163 		{ 0, &nvbios_acpi_fast },
164 		{ 4, &nvbios_acpi_slow },
165 		{ 1, &nvbios_pcirom },
166 		{ 1, &nvbios_platform },
167 		{}
168 	}, *mthd, *best = NULL;
169 	const char *optarg;
170 	char *source;
171 	int optlen;
172 
173 	/* handle user-specified bios source */
174 	optarg = nvkm_stropt(device->cfgopt, "NvBios", &optlen);
175 	source = optarg ? kstrndup(optarg, optlen, GFP_KERNEL) : NULL;
176 	if (source) {
177 		/* try to match one of the built-in methods */
178 		for (mthd = mthds; mthd->func; mthd++) {
179 			if (mthd->func->name &&
180 			    !strcasecmp(source, mthd->func->name)) {
181 				best = mthd;
182 				if (shadow_method(bios, mthd, NULL))
183 					break;
184 			}
185 		}
186 
187 		/* otherwise, attempt to load as firmware */
188 		if (!best && (best = mthd)) {
189 			mthd->func = &shadow_fw;
190 			shadow_method(bios, mthd, source);
191 			mthd->func = NULL;
192 		}
193 
194 		if (!best->score) {
195 			nvkm_error(subdev, "%s invalid\n", source);
196 			kfree(source);
197 			source = NULL;
198 		}
199 	}
200 
201 	/* scan all potential bios sources, looking for best image */
202 	if (!best || !best->score) {
203 		for (mthd = mthds, best = mthd; mthd->func; mthd++) {
204 			if (!mthd->skip || best->score < mthd->skip) {
205 				if (shadow_method(bios, mthd, NULL)) {
206 					if (mthd->score > best->score)
207 						best = mthd;
208 				}
209 			}
210 		}
211 	}
212 
213 	/* cleanup the ones we didn't use */
214 	for (mthd = mthds; mthd->func; mthd++) {
215 		if (mthd != best)
216 			kfree(mthd->data);
217 	}
218 
219 	if (!best->score) {
220 		nvkm_error(subdev, "unable to locate usable image\n");
221 		return -EINVAL;
222 	}
223 
224 	nvkm_debug(subdev, "using image from %s\n", best->func ?
225 		   best->func->name : source);
226 	bios->data = best->data;
227 	bios->size = best->size;
228 	kfree(source);
229 	return 0;
230 }
231