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/device.h>
27#include <core/option.h>
28#include <subdev/bios.h>
29#include <subdev/bios/image.h>
30
31struct shadow {
32	struct nvkm_oclass base;
33	u32 skip;
34	const struct nvbios_source *func;
35	void *data;
36	u32 size;
37	int score;
38};
39
40static bool
41shadow_fetch(struct nvkm_bios *bios, u32 upto)
42{
43	struct shadow *mthd = (void *)nv_object(bios)->oclass;
44	const u32 limit = (upto + 3) & ~3;
45	const u32 start = bios->size;
46	void *data = mthd->data;
47	if (nvbios_extend(bios, limit) > 0) {
48		u32 read = mthd->func->read(data, start, limit - start, bios);
49		bios->size = start + read;
50	}
51	return bios->size >= limit;
52}
53
54static u8
55shadow_rd08(struct nvkm_object *object, u64 addr)
56{
57	struct nvkm_bios *bios = (void *)object;
58	if (shadow_fetch(bios, addr + 1))
59		return bios->data[addr];
60	return 0x00;
61}
62
63static u16
64shadow_rd16(struct nvkm_object *object, u64 addr)
65{
66	struct nvkm_bios *bios = (void *)object;
67	if (shadow_fetch(bios, addr + 2))
68		return get_unaligned_le16(&bios->data[addr]);
69	return 0x0000;
70}
71
72static u32
73shadow_rd32(struct nvkm_object *object, u64 addr)
74{
75	struct nvkm_bios *bios = (void *)object;
76	if (shadow_fetch(bios, addr + 4))
77		return get_unaligned_le32(&bios->data[addr]);
78	return 0x00000000;
79}
80
81static struct nvkm_oclass
82shadow_class = {
83	.handle = NV_SUBDEV(VBIOS, 0x00),
84	.ofuncs = &(struct nvkm_ofuncs) {
85		.rd08 = shadow_rd08,
86		.rd16 = shadow_rd16,
87		.rd32 = shadow_rd32,
88	},
89};
90
91static int
92shadow_image(struct nvkm_bios *bios, int idx, struct shadow *mthd)
93{
94	struct nvbios_image image;
95	int score = 1;
96
97	if (!nvbios_image(bios, idx, &image)) {
98		nv_debug(bios, "image %d invalid\n", idx);
99		return 0;
100	}
101	nv_debug(bios, "%08x: type %02x, %d bytes\n",
102		 image.base, image.type, image.size);
103
104	if (!shadow_fetch(bios, image.size)) {
105		nv_debug(bios, "%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			nv_debug(bios, "%08x: checksum failed\n", image.base);
113			if (mthd->func->rw)
114				score += 1;
115			score += 1;
116		} else {
117			score += 3;
118		}
119		break;
120	default:
121		score += 3;
122		break;
123	}
124
125	if (!image.last)
126		score += shadow_image(bios, idx + 1, mthd);
127	return score;
128}
129
130static int
131shadow_score(struct nvkm_bios *bios, struct shadow *mthd)
132{
133	struct nvkm_oclass *oclass = nv_object(bios)->oclass;
134	int score;
135	nv_object(bios)->oclass = &mthd->base;
136	score = shadow_image(bios, 0, mthd);
137	nv_object(bios)->oclass = oclass;
138	return score;
139
140}
141
142static int
143shadow_method(struct nvkm_bios *bios, struct shadow *mthd, const char *name)
144{
145	const struct nvbios_source *func = mthd->func;
146	if (func->name) {
147		nv_debug(bios, "trying %s...\n", name ? name : func->name);
148		if (func->init) {
149			mthd->data = func->init(bios, name);
150			if (IS_ERR(mthd->data)) {
151				mthd->data = NULL;
152				return 0;
153			}
154		}
155		mthd->score = shadow_score(bios, mthd);
156		if (func->fini)
157			func->fini(mthd->data);
158		nv_debug(bios, "scored %d\n", mthd->score);
159		mthd->data = bios->data;
160		mthd->size = bios->size;
161		bios->data  = NULL;
162		bios->size  = 0;
163	}
164	return mthd->score;
165}
166
167static u32
168shadow_fw_read(void *data, u32 offset, u32 length, struct nvkm_bios *bios)
169{
170	const struct firmware *fw = data;
171	if (offset + length <= fw->size) {
172		memcpy(bios->data + offset, fw->data + offset, length);
173		return length;
174	}
175	return 0;
176}
177
178static void *
179shadow_fw_init(struct nvkm_bios *bios, const char *name)
180{
181	struct device *dev = &nv_device(bios)->pdev->dev;
182	const struct firmware *fw;
183	int ret = request_firmware(&fw, name, dev);
184	if (ret)
185		return ERR_PTR(-ENOENT);
186	return (void *)fw;
187}
188
189static const struct nvbios_source
190shadow_fw = {
191	.name = "firmware",
192	.init = shadow_fw_init,
193	.fini = (void(*)(void *))release_firmware,
194	.read = shadow_fw_read,
195	.rw = false,
196};
197
198int
199nvbios_shadow(struct nvkm_bios *bios)
200{
201	struct shadow mthds[] = {
202		{ shadow_class, 0, &nvbios_of },
203		{ shadow_class, 0, &nvbios_ramin },
204		{ shadow_class, 0, &nvbios_rom },
205		{ shadow_class, 0, &nvbios_acpi_fast },
206		{ shadow_class, 4, &nvbios_acpi_slow },
207		{ shadow_class, 1, &nvbios_pcirom },
208		{ shadow_class, 1, &nvbios_platform },
209		{ shadow_class }
210	}, *mthd = mthds, *best = NULL;
211	const char *optarg;
212	char *source;
213	int optlen;
214
215	/* handle user-specified bios source */
216	optarg = nvkm_stropt(nv_device(bios)->cfgopt, "NvBios", &optlen);
217	source = optarg ? kstrndup(optarg, optlen, GFP_KERNEL) : NULL;
218	if (source) {
219		/* try to match one of the built-in methods */
220		for (mthd = mthds; mthd->func; mthd++) {
221			if (mthd->func->name &&
222			    !strcasecmp(source, mthd->func->name)) {
223				best = mthd;
224				if (shadow_method(bios, mthd, NULL))
225					break;
226			}
227		}
228
229		/* otherwise, attempt to load as firmware */
230		if (!best && (best = mthd)) {
231			mthd->func = &shadow_fw;
232			shadow_method(bios, mthd, source);
233			mthd->func = NULL;
234		}
235
236		if (!best->score) {
237			nv_error(bios, "%s invalid\n", source);
238			kfree(source);
239			source = NULL;
240		}
241	}
242
243	/* scan all potential bios sources, looking for best image */
244	if (!best || !best->score) {
245		for (mthd = mthds, best = mthd; mthd->func; mthd++) {
246			if (!mthd->skip || best->score < mthd->skip) {
247				if (shadow_method(bios, mthd, NULL)) {
248					if (mthd->score > best->score)
249						best = mthd;
250				}
251			}
252		}
253	}
254
255	/* cleanup the ones we didn't use */
256	for (mthd = mthds; mthd->func; mthd++) {
257		if (mthd != best)
258			kfree(mthd->data);
259	}
260
261	if (!best->score) {
262		nv_fatal(bios, "unable to locate usable image\n");
263		return -EINVAL;
264	}
265
266	nv_info(bios, "using image from %s\n", best->func ?
267		best->func->name : source);
268	bios->data = best->data;
269	bios->size = best->size;
270	kfree(source);
271	return 0;
272}
273