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 	struct nvkm_oclass base;
32 	u32 skip;
33 	const struct nvbios_source *func;
34 	void *data;
35 	u32 size;
36 	int score;
37 };
38 
39 static bool
40 shadow_fetch(struct nvkm_bios *bios, u32 upto)
41 {
42 	struct shadow *mthd = (void *)nv_object(bios)->oclass;
43 	const u32 limit = (upto + 3) & ~3;
44 	const u32 start = bios->size;
45 	void *data = mthd->data;
46 	if (nvbios_extend(bios, limit) > 0) {
47 		u32 read = mthd->func->read(data, start, limit - start, bios);
48 		bios->size = start + read;
49 	}
50 	return bios->size >= limit;
51 }
52 
53 static u8
54 shadow_rd08(struct nvkm_object *object, u64 addr)
55 {
56 	struct nvkm_bios *bios = (void *)object;
57 	if (shadow_fetch(bios, addr + 1))
58 		return bios->data[addr];
59 	return 0x00;
60 }
61 
62 static u16
63 shadow_rd16(struct nvkm_object *object, u64 addr)
64 {
65 	struct nvkm_bios *bios = (void *)object;
66 	if (shadow_fetch(bios, addr + 2))
67 		return get_unaligned_le16(&bios->data[addr]);
68 	return 0x0000;
69 }
70 
71 static u32
72 shadow_rd32(struct nvkm_object *object, u64 addr)
73 {
74 	struct nvkm_bios *bios = (void *)object;
75 	if (shadow_fetch(bios, addr + 4))
76 		return get_unaligned_le32(&bios->data[addr]);
77 	return 0x00000000;
78 }
79 
80 static struct nvkm_oclass
81 shadow_class = {
82 	.handle = NV_SUBDEV(VBIOS, 0x00),
83 	.ofuncs = &(struct nvkm_ofuncs) {
84 		.rd08 = shadow_rd08,
85 		.rd16 = shadow_rd16,
86 		.rd32 = shadow_rd32,
87 	},
88 };
89 
90 static int
91 shadow_image(struct nvkm_bios *bios, int idx, struct shadow *mthd)
92 {
93 	struct nvkm_subdev *subdev = &bios->subdev;
94 	struct nvbios_image image;
95 	int score = 1;
96 
97 	if (!nvbios_image(bios, idx, &image)) {
98 		nvkm_debug(subdev, "image %d invalid\n", idx);
99 		return 0;
100 	}
101 	nvkm_debug(subdev, "%08x: type %02x, %d bytes\n",
102 		   image.base, image.type, image.size);
103 
104 	if (!shadow_fetch(bios, image.size)) {
105 		nvkm_debug(subdev, "%08x: fetch failed\n", image.base);
106 		return 0;
107 	}
108 
109 	switch (image.type) {
110 	case 0x00:
111 		if (nvbios_checksum(&bios->data[image.base], image.size)) {
112 			nvkm_debug(subdev, "%08x: checksum failed\n",
113 				   image.base);
114 			if (mthd->func->rw)
115 				score += 1;
116 			score += 1;
117 		} else {
118 			score += 3;
119 		}
120 		break;
121 	default:
122 		score += 3;
123 		break;
124 	}
125 
126 	if (!image.last)
127 		score += shadow_image(bios, idx + 1, mthd);
128 	return score;
129 }
130 
131 static int
132 shadow_score(struct nvkm_bios *bios, struct shadow *mthd)
133 {
134 	struct nvkm_oclass *oclass = nv_object(bios)->oclass;
135 	int score;
136 	nv_object(bios)->oclass = &mthd->base;
137 	score = shadow_image(bios, 0, mthd);
138 	nv_object(bios)->oclass = oclass;
139 	return score;
140 
141 }
142 
143 static int
144 shadow_method(struct nvkm_bios *bios, struct shadow *mthd, const char *name)
145 {
146 	const struct nvbios_source *func = mthd->func;
147 	struct nvkm_subdev *subdev = &bios->subdev;
148 	if (func->name) {
149 		nvkm_debug(subdev, "trying %s...\n", name ? name : func->name);
150 		if (func->init) {
151 			mthd->data = func->init(bios, name);
152 			if (IS_ERR(mthd->data)) {
153 				mthd->data = NULL;
154 				return 0;
155 			}
156 		}
157 		mthd->score = shadow_score(bios, mthd);
158 		if (func->fini)
159 			func->fini(mthd->data);
160 		nvkm_debug(subdev, "scored %d\n", mthd->score);
161 		mthd->data = bios->data;
162 		mthd->size = bios->size;
163 		bios->data  = NULL;
164 		bios->size  = 0;
165 	}
166 	return mthd->score;
167 }
168 
169 static u32
170 shadow_fw_read(void *data, u32 offset, u32 length, struct nvkm_bios *bios)
171 {
172 	const struct firmware *fw = data;
173 	if (offset + length <= fw->size) {
174 		memcpy(bios->data + offset, fw->data + offset, length);
175 		return length;
176 	}
177 	return 0;
178 }
179 
180 static void *
181 shadow_fw_init(struct nvkm_bios *bios, const char *name)
182 {
183 	struct device *dev = &nv_device(bios)->pdev->dev;
184 	const struct firmware *fw;
185 	int ret = request_firmware(&fw, name, dev);
186 	if (ret)
187 		return ERR_PTR(-ENOENT);
188 	return (void *)fw;
189 }
190 
191 static const struct nvbios_source
192 shadow_fw = {
193 	.name = "firmware",
194 	.init = shadow_fw_init,
195 	.fini = (void(*)(void *))release_firmware,
196 	.read = shadow_fw_read,
197 	.rw = false,
198 };
199 
200 int
201 nvbios_shadow(struct nvkm_bios *bios)
202 {
203 	struct nvkm_subdev *subdev = &bios->subdev;
204 	struct nvkm_device *device = subdev->device;
205 	struct shadow mthds[] = {
206 		{ shadow_class, 0, &nvbios_of },
207 		{ shadow_class, 0, &nvbios_ramin },
208 		{ shadow_class, 0, &nvbios_rom },
209 		{ shadow_class, 0, &nvbios_acpi_fast },
210 		{ shadow_class, 4, &nvbios_acpi_slow },
211 		{ shadow_class, 1, &nvbios_pcirom },
212 		{ shadow_class, 1, &nvbios_platform },
213 		{ shadow_class }
214 	}, *mthd, *best = NULL;
215 	const char *optarg;
216 	char *source;
217 	int optlen;
218 
219 	/* handle user-specified bios source */
220 	optarg = nvkm_stropt(device->cfgopt, "NvBios", &optlen);
221 	source = optarg ? kstrndup(optarg, optlen, GFP_KERNEL) : NULL;
222 	if (source) {
223 		/* try to match one of the built-in methods */
224 		for (mthd = mthds; mthd->func; mthd++) {
225 			if (mthd->func->name &&
226 			    !strcasecmp(source, mthd->func->name)) {
227 				best = mthd;
228 				if (shadow_method(bios, mthd, NULL))
229 					break;
230 			}
231 		}
232 
233 		/* otherwise, attempt to load as firmware */
234 		if (!best && (best = mthd)) {
235 			mthd->func = &shadow_fw;
236 			shadow_method(bios, mthd, source);
237 			mthd->func = NULL;
238 		}
239 
240 		if (!best->score) {
241 			nvkm_error(subdev, "%s invalid\n", source);
242 			kfree(source);
243 			source = NULL;
244 		}
245 	}
246 
247 	/* scan all potential bios sources, looking for best image */
248 	if (!best || !best->score) {
249 		for (mthd = mthds, best = mthd; mthd->func; mthd++) {
250 			if (!mthd->skip || best->score < mthd->skip) {
251 				if (shadow_method(bios, mthd, NULL)) {
252 					if (mthd->score > best->score)
253 						best = mthd;
254 				}
255 			}
256 		}
257 	}
258 
259 	/* cleanup the ones we didn't use */
260 	for (mthd = mthds; mthd->func; mthd++) {
261 		if (mthd != best)
262 			kfree(mthd->data);
263 	}
264 
265 	if (!best->score) {
266 		nvkm_error(subdev, "unable to locate usable image\n");
267 		return -EINVAL;
268 	}
269 
270 	nvkm_debug(subdev, "using image from %s\n", best->func ?
271 		   best->func->name : source);
272 	bios->data = best->data;
273 	bios->size = best->size;
274 	kfree(source);
275 	return 0;
276 }
277