shadow.c

  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
 30struct shadow {
 31	u32 skip;
 32	const struct nvbios_source *func;
 33	void *data;
 34	u32 size;
 35	int score;
 36};
 37
 38static bool
 39shadow_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 >= upto;
 49}
 50
 51static int
 52shadow_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 (mthd->func->no_pcir) {
 59		image.base = 0;
 60		image.type = 0;
 61		image.size = mthd->func->size(mthd->data);
 62		image.last = 1;
 63	} else {
 64		if (!shadow_fetch(bios, mthd, offset + 0x1000)) {
 65			nvkm_debug(subdev, "%08x: header fetch failed\n",
 66				   offset);
 67			return 0;
 68		}
 69
 70		if (!nvbios_image(bios, idx, &image)) {
 71			nvkm_debug(subdev, "image %d invalid\n", idx);
 72			return 0;
 73		}
 74	}
 75	nvkm_debug(subdev, "%08x: type %02x, %d bytes\n",
 76		   image.base, image.type, image.size);
 77
 78	if (!shadow_fetch(bios, mthd, image.base + image.size)) {
 79		nvkm_debug(subdev, "%08x: fetch failed\n", image.base);
 80		return 0;
 81	}
 82
 83	switch (image.type) {
 84	case 0x00:
 85		if (!mthd->func->ignore_checksum &&
 86		    nvbios_checksum(&bios->data[image.base], image.size)) {
 87			nvkm_debug(subdev, "%08x: checksum failed\n",
 88				   image.base);
 89			if (!mthd->func->require_checksum) {
 90				if (mthd->func->rw)
 91					score += 1;
 92				score += 1;
 93			} else
 94				return 0;
 95		} else {
 96			score += 3;
 97		}
 98		break;
 99	default:
100		score += 3;
101		break;
102	}
103
104	if (!image.last)
105		score += shadow_image(bios, idx + 1, offset + image.size, mthd);
106	return score;
107}
108
109static int
110shadow_method(struct nvkm_bios *bios, struct shadow *mthd, const char *name)
111{
112	const struct nvbios_source *func = mthd->func;
113	struct nvkm_subdev *subdev = &bios->subdev;
114	if (func->name) {
115		nvkm_debug(subdev, "trying %s...\n", name ? name : func->name);
116		if (func->init) {
117			mthd->data = func->init(bios, name);
118			if (IS_ERR(mthd->data)) {
119				mthd->data = NULL;
120				return 0;
121			}
122		}
123		mthd->score = shadow_image(bios, 0, 0, mthd);
124		if (func->fini)
125			func->fini(mthd->data);
126		nvkm_debug(subdev, "scored %d\n", mthd->score);
127		mthd->data = bios->data;
128		mthd->size = bios->size;
129		bios->data  = NULL;
130		bios->size  = 0;
131	}
132	return mthd->score;
133}
134
135static u32
136shadow_fw_read(void *data, u32 offset, u32 length, struct nvkm_bios *bios)
137{
138	const struct firmware *fw = data;
139	if (offset + length <= fw->size) {
140		memcpy(bios->data + offset, fw->data + offset, length);
141		return length;
142	}
143	return 0;
144}
145
146static void *
147shadow_fw_init(struct nvkm_bios *bios, const char *name)
148{
149	struct device *dev = bios->subdev.device->dev;
150	const struct firmware *fw;
151	int ret = request_firmware(&fw, name, dev);
152	if (ret)
153		return ERR_PTR(-ENOENT);
154	return (void *)fw;
155}
156
157static void
158shadow_fw_release(void *fw)
159{
160	release_firmware(fw);
161}
162
163static const struct nvbios_source
164shadow_fw = {
165	.name = "firmware",
166	.init = shadow_fw_init,
167	.fini = shadow_fw_release,
168	.read = shadow_fw_read,
169	.rw = false,
170};
171
172int
173nvbios_shadow(struct nvkm_bios *bios)
174{
175	struct nvkm_subdev *subdev = &bios->subdev;
176	struct nvkm_device *device = subdev->device;
177	struct shadow mthds[] = {
178		{ 0, &nvbios_of },
179		{ 0, &nvbios_ramin },
180		{ 0, &nvbios_prom },
181		{ 0, &nvbios_acpi_fast },
182		{ 4, &nvbios_acpi_slow },
183		{ 1, &nvbios_pcirom },
184		{ 1, &nvbios_platform },
185		{}
186	}, *mthd, *best = NULL;
187	const char *optarg;
188	char *source;
189	int optlen;
190
191	/* handle user-specified bios source */
192	optarg = nvkm_stropt(device->cfgopt, "NvBios", &optlen);
193	source = optarg ? kstrndup(optarg, optlen, GFP_KERNEL) : NULL;
194	if (source) {
195		/* try to match one of the built-in methods */
196		for (mthd = mthds; mthd->func; mthd++) {
197			if (mthd->func->name &&
198			    !strcasecmp(source, mthd->func->name)) {
199				best = mthd;
200				if (shadow_method(bios, mthd, NULL))
201					break;
202			}
203		}
204
205		/* otherwise, attempt to load as firmware */
206		if (!best && (best = mthd)) {
207			mthd->func = &shadow_fw;
208			shadow_method(bios, mthd, source);
209			mthd->func = NULL;
210		}
211
212		if (!best->score) {
213			nvkm_error(subdev, "%s invalid\n", source);
214			kfree(source);
215			source = NULL;
216		}
217	}
218
219	/* scan all potential bios sources, looking for best image */
220	if (!best || !best->score) {
221		for (mthd = mthds, best = mthd; mthd->func; mthd++) {
222			if (!mthd->skip || best->score < mthd->skip) {
223				if (shadow_method(bios, mthd, NULL)) {
224					if (mthd->score > best->score)
225						best = mthd;
226				}
227			}
228		}
229	}
230
231	/* cleanup the ones we didn't use */
232	for (mthd = mthds; mthd->func; mthd++) {
233		if (mthd != best)
234			kfree(mthd->data);
235	}
236
237	if (!best->score) {
238		nvkm_error(subdev, "unable to locate usable image\n");
239		return -EINVAL;
240	}
241
242	nvkm_debug(subdev, "using image from %s\n", best->func ?
243		   best->func->name : source);
244	bios->data = best->data;
245	bios->size = best->size;
246	kfree(source);
247	return 0;
248}