1 /*
2  * Copyright 2012 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  */
23 #include "priv.h"
24 
25 #if defined(CONFIG_ACPI) && defined(CONFIG_X86)
26 int nouveau_acpi_get_bios_chunk(uint8_t *bios, int offset, int len);
27 bool nouveau_acpi_rom_supported(struct device *);
28 #else
29 static inline bool
30 nouveau_acpi_rom_supported(struct device *dev)
31 {
32 	return false;
33 }
34 
35 static inline int
36 nouveau_acpi_get_bios_chunk(uint8_t *bios, int offset, int len)
37 {
38 	return -EINVAL;
39 }
40 #endif
41 
42 /* This version of the shadow function disobeys the ACPI spec and tries
43  * to fetch in units of more than 4KiB at a time.  This is a LOT faster
44  * on some systems, such as Lenovo W530.
45  */
46 static u32
47 acpi_read_fast(void *data, u32 offset, u32 length, struct nvkm_bios *bios)
48 {
49 	u32 limit = (offset + length + 0xfff) & ~0xfff;
50 	u32 start = offset & ~0x00000fff;
51 	u32 fetch = limit - start;
52 
53 	if (nvbios_extend(bios, limit) >= 0) {
54 		int ret = nouveau_acpi_get_bios_chunk(bios->data, start, fetch);
55 		if (ret == fetch)
56 			return fetch;
57 	}
58 
59 	return 0;
60 }
61 
62 /* Other systems, such as the one in fdo#55948, will report a success
63  * but only return 4KiB of data.  The common bios fetching logic will
64  * detect an invalid image, and fall back to this version of the read
65  * function.
66  */
67 static u32
68 acpi_read_slow(void *data, u32 offset, u32 length, struct nvkm_bios *bios)
69 {
70 	u32 limit = (offset + length + 0xfff) & ~0xfff;
71 	u32 start = offset & ~0xfff;
72 	u32 fetch = 0;
73 
74 	if (nvbios_extend(bios, limit) >= 0) {
75 		while (start + fetch < limit) {
76 			int ret = nouveau_acpi_get_bios_chunk(bios->data,
77 							      start + fetch,
78 							      0x1000);
79 			if (ret != 0x1000)
80 				break;
81 			fetch += 0x1000;
82 		}
83 	}
84 
85 	return fetch;
86 }
87 
88 static void *
89 acpi_init(struct nvkm_bios *bios, const char *name)
90 {
91 	if (!nouveau_acpi_rom_supported(bios->subdev.device->dev))
92 		return ERR_PTR(-ENODEV);
93 	return NULL;
94 }
95 
96 const struct nvbios_source
97 nvbios_acpi_fast = {
98 	.name = "ACPI",
99 	.init = acpi_init,
100 	.read = acpi_read_fast,
101 	.rw = false,
102 };
103 
104 const struct nvbios_source
105 nvbios_acpi_slow = {
106 	.name = "ACPI",
107 	.init = acpi_init,
108 	.read = acpi_read_slow,
109 	.rw = false,
110 };
111