[process] Include process name in debug messages
[ipxe.git] / src / core / acpi_settings.c
1 /*
2 * Copyright (C) 2017 Michael Brown <mbrown@fensystems.co.uk>.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation; either version 2 of the
7 * License, or any later version.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
17 * 02110-1301, USA.
18 *
19 * You can also choose to distribute this program under the terms of
20 * the Unmodified Binary Distribution Licence (as given in the file
21 * COPYING.UBDL), provided that you have satisfied its requirements.
22 */
23
24 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
25
26 /**
27 * @file
28 *
29 * ACPI settings
30 *
31 */
32
33 #include <string.h>
34 #include <errno.h>
35 #include <ipxe/init.h>
36 #include <ipxe/settings.h>
37 #include <ipxe/acpi.h>
38
39 /** ACPI settings scope */
40 static const struct settings_scope acpi_settings_scope;
41
42 /**
43 * Check applicability of ACPI setting
44 *
45 * @v settings Settings block
46 * @v setting Setting
47 * @ret applies Setting applies within this settings block
48 */
49 static int acpi_settings_applies ( struct settings *settings __unused,
50 const struct setting *setting ) {
51
52 return ( setting->scope == &acpi_settings_scope );
53 }
54
55 /**
56 * Fetch value of ACPI setting
57 *
58 * @v settings Settings block
59 * @v setting Setting to fetch
60 * @v data Buffer to fill with setting data
61 * @v len Length of buffer
62 * @ret len Length of setting data, or negative error
63 */
64 static int acpi_settings_fetch ( struct settings *settings,
65 struct setting *setting,
66 void *data, size_t len ) {
67 struct acpi_header acpi;
68 uint32_t tag_high;
69 uint32_t tag_low;
70 uint32_t tag_signature;
71 unsigned int tag_index;
72 size_t tag_offset;
73 size_t tag_len;
74 userptr_t table;
75 size_t offset;
76 size_t max_len;
77 int delta;
78 unsigned int i;
79
80 /* Parse settings tag */
81 tag_high = ( setting->tag >> 32 );
82 tag_low = setting->tag;
83 tag_signature = bswap_32 ( tag_high );
84 tag_index = ( ( tag_low >> 24 ) & 0xff );
85 tag_offset = ( ( tag_low >> 8 ) & 0xffff );
86 tag_len = ( ( tag_low >> 0 ) & 0xff );
87 DBGC ( settings, "ACPI %s.%d offset %#zx length %#zx\n",
88 acpi_name ( tag_signature ), tag_index, tag_offset, tag_len );
89
90 /* Locate ACPI table */
91 table = acpi_find ( tag_signature, tag_index );
92 if ( ! table )
93 return -ENOENT;
94
95 /* Read table header */
96 copy_from_user ( &acpi, table, 0, sizeof ( acpi ) );
97
98 /* Calculate starting offset and maximum available length */
99 max_len = le32_to_cpu ( acpi.length );
100 if ( tag_offset > max_len )
101 return -ENOENT;
102 offset = tag_offset;
103 max_len -= offset;
104
105 /* Restrict to requested length, if specified */
106 if ( tag_len && ( tag_len < max_len ) )
107 max_len = tag_len;
108
109 /* Invert endianness for numeric settings */
110 if ( setting->type && setting->type->numerate ) {
111 offset += ( max_len - 1 );
112 delta = -1;
113 } else {
114 delta = +1;
115 }
116
117 /* Read data */
118 for ( i = 0 ; ( ( i < max_len ) && ( i < len ) ) ; i++ ) {
119 copy_from_user ( data, table, offset, 1 );
120 data++;
121 offset += delta;
122 }
123
124 /* Set type if not already specified */
125 if ( ! setting->type )
126 setting->type = &setting_type_hexraw;
127
128 return max_len;
129 }
130
131 /** ACPI settings operations */
132 static struct settings_operations acpi_settings_operations = {
133 .applies = acpi_settings_applies,
134 .fetch = acpi_settings_fetch,
135 };
136
137 /** ACPI settings */
138 static struct settings acpi_settings = {
139 .refcnt = NULL,
140 .siblings = LIST_HEAD_INIT ( acpi_settings.siblings ),
141 .children = LIST_HEAD_INIT ( acpi_settings.children ),
142 .op = &acpi_settings_operations,
143 .default_scope = &acpi_settings_scope,
144 };
145
146 /** Initialise ACPI settings */
147 static void acpi_settings_init ( void ) {
148 int rc;
149
150 if ( ( rc = register_settings ( &acpi_settings, NULL,
151 "acpi" ) ) != 0 ) {
152 DBG ( "ACPI could not register settings: %s\n",
153 strerror ( rc ) );
154 return;
155 }
156 }
157
158 /** ACPI settings initialiser */
159 struct init_fn acpi_settings_init_fn __init_fn ( INIT_NORMAL ) = {
160 .initialise = acpi_settings_init,
161 };