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 static int
acpi_read_bios(acpi_handle rom_handle,u8 * bios,u32 offset,u32 length)26 acpi_read_bios(acpi_handle rom_handle, u8 *bios, u32 offset, u32 length)
27 {
28 #if defined(CONFIG_ACPI) && defined(CONFIG_X86)
29 acpi_status status;
30 union acpi_object rom_arg_elements[2], *obj;
31 struct acpi_object_list rom_arg;
32 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL};
33
34 rom_arg.count = 2;
35 rom_arg.pointer = &rom_arg_elements[0];
36
37 rom_arg_elements[0].type = ACPI_TYPE_INTEGER;
38 rom_arg_elements[0].integer.value = offset;
39
40 rom_arg_elements[1].type = ACPI_TYPE_INTEGER;
41 rom_arg_elements[1].integer.value = length;
42
43 status = acpi_evaluate_object(rom_handle, NULL, &rom_arg, &buffer);
44 if (ACPI_FAILURE(status)) {
45 pr_info("failed to evaluate ROM got %s\n",
46 acpi_format_exception(status));
47 return -ENODEV;
48 }
49 obj = (union acpi_object *)buffer.pointer;
50 length = min(length, obj->buffer.length);
51 memcpy(bios+offset, obj->buffer.pointer, length);
52 kfree(buffer.pointer);
53 return length;
54 #else
55 return -EINVAL;
56 #endif
57 }
58
59 /* This version of the shadow function disobeys the ACPI spec and tries
60 * to fetch in units of more than 4KiB at a time. This is a LOT faster
61 * on some systems, such as Lenovo W530.
62 */
63 static u32
acpi_read_fast(void * data,u32 offset,u32 length,struct nvkm_bios * bios)64 acpi_read_fast(void *data, u32 offset, u32 length, struct nvkm_bios *bios)
65 {
66 u32 limit = (offset + length + 0xfff) & ~0xfff;
67 u32 start = offset & ~0x00000fff;
68 u32 fetch = limit - start;
69
70 if (nvbios_extend(bios, limit) >= 0) {
71 int ret = acpi_read_bios(data, bios->data, start, fetch);
72 if (ret == fetch)
73 return fetch;
74 }
75
76 return 0;
77 }
78
79 /* Other systems, such as the one in fdo#55948, will report a success
80 * but only return 4KiB of data. The common bios fetching logic will
81 * detect an invalid image, and fall back to this version of the read
82 * function.
83 */
84 static u32
acpi_read_slow(void * data,u32 offset,u32 length,struct nvkm_bios * bios)85 acpi_read_slow(void *data, u32 offset, u32 length, struct nvkm_bios *bios)
86 {
87 u32 limit = (offset + length + 0xfff) & ~0xfff;
88 u32 start = offset & ~0xfff;
89 u32 fetch = 0;
90
91 if (nvbios_extend(bios, limit) >= 0) {
92 while (start + fetch < limit) {
93 int ret = acpi_read_bios(data, bios->data,
94 start + fetch, 0x1000);
95 if (ret != 0x1000)
96 break;
97 fetch += 0x1000;
98 }
99 }
100
101 return fetch;
102 }
103
104 static void *
acpi_init(struct nvkm_bios * bios,const char * name)105 acpi_init(struct nvkm_bios *bios, const char *name)
106 {
107 #if defined(CONFIG_ACPI) && defined(CONFIG_X86)
108 acpi_status status;
109 acpi_handle dhandle, rom_handle;
110
111 dhandle = ACPI_HANDLE(bios->subdev.device->dev);
112 if (!dhandle)
113 return ERR_PTR(-ENODEV);
114
115 status = acpi_get_handle(dhandle, "_ROM", &rom_handle);
116 if (ACPI_FAILURE(status))
117 return ERR_PTR(-ENODEV);
118
119 return rom_handle;
120 #else
121 return ERR_PTR(-ENODEV);
122 #endif
123 }
124
125 const struct nvbios_source
126 nvbios_acpi_fast = {
127 .name = "ACPI",
128 .init = acpi_init,
129 .read = acpi_read_fast,
130 .rw = false,
131 .require_checksum = true,
132 };
133
134 const struct nvbios_source
135 nvbios_acpi_slow = {
136 .name = "ACPI",
137 .init = acpi_init,
138 .read = acpi_read_slow,
139 .rw = false,
140 };
141