1 /* sfi_acpi.c Simple Firmware Interface - ACPI extensions */
2
3 /*
4
5 This file is provided under a dual BSD/GPLv2 license. When using or
6 redistributing this file, you may do so under either license.
7
8 GPL LICENSE SUMMARY
9
10 Copyright(c) 2009 Intel Corporation. All rights reserved.
11
12 This program is free software; you can redistribute it and/or modify
13 it under the terms of version 2 of the GNU General Public License as
14 published by the Free Software Foundation.
15
16 This program is distributed in the hope that it will be useful, but
17 WITHOUT ANY WARRANTY; without even the implied warranty of
18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19 General Public License for more details.
20
21 You should have received a copy of the GNU General Public License
22 along with this program; if not, write to the Free Software
23 Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
24 The full GNU General Public License is included in this distribution
25 in the file called LICENSE.GPL.
26
27 BSD LICENSE
28
29 Copyright(c) 2009 Intel Corporation. All rights reserved.
30
31 Redistribution and use in source and binary forms, with or without
32 modification, are permitted provided that the following conditions
33 are met:
34
35 * Redistributions of source code must retain the above copyright
36 notice, this list of conditions and the following disclaimer.
37 * Redistributions in binary form must reproduce the above copyright
38 notice, this list of conditions and the following disclaimer in
39 the documentation and/or other materials provided with the
40 distribution.
41 * Neither the name of Intel Corporation nor the names of its
42 contributors may be used to endorse or promote products derived
43 from this software without specific prior written permission.
44
45 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
46 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
47 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
48 A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
49 OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
50 SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
51 LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
52 DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
53 THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
54 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
55 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
56
57 */
58
59 #define KMSG_COMPONENT "SFI"
60 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
61
62 #include <linux/kernel.h>
63 #include <linux/sfi_acpi.h>
64 #include "sfi_core.h"
65
66 /*
67 * SFI can access ACPI-defined tables via an optional ACPI XSDT.
68 *
69 * This allows re-use, and avoids re-definition, of standard tables.
70 * For example, the "MCFG" table is defined by PCI, reserved by ACPI,
71 * and is expected to be present many SFI-only systems.
72 */
73
74 static struct acpi_table_xsdt *xsdt_va __read_mostly;
75
76 #define XSDT_GET_NUM_ENTRIES(ptable, entry_type) \
77 ((ptable->header.length - sizeof(struct acpi_table_header)) / \
78 (sizeof(entry_type)))
79
80 static inline struct sfi_table_header *acpi_to_sfi_th(
81 struct acpi_table_header *th)
82 {
83 return (struct sfi_table_header *)th;
84 }
85
86 static inline struct acpi_table_header *sfi_to_acpi_th(
87 struct sfi_table_header *th)
88 {
89 return (struct acpi_table_header *)th;
90 }
91
92 /*
93 * sfi_acpi_parse_xsdt()
94 *
95 * Parse the ACPI XSDT for later access by sfi_acpi_table_parse().
96 */
97 static int __init sfi_acpi_parse_xsdt(struct sfi_table_header *th)
98 {
99 struct sfi_table_key key = SFI_ANY_KEY;
100 int tbl_cnt, i;
101 void *ret;
102
103 xsdt_va = (struct acpi_table_xsdt *)th;
104 tbl_cnt = XSDT_GET_NUM_ENTRIES(xsdt_va, u64);
105 for (i = 0; i < tbl_cnt; i++) {
106 ret = sfi_check_table(xsdt_va->table_offset_entry[i], &key);
107 if (IS_ERR(ret)) {
108 disable_sfi();
109 return -1;
110 }
111 }
112
113 return 0;
114 }
115
116 int __init sfi_acpi_init(void)
117 {
118 struct sfi_table_key xsdt_key = { .sig = SFI_SIG_XSDT };
119
120 sfi_table_parse(SFI_SIG_XSDT, NULL, NULL, sfi_acpi_parse_xsdt);
121
122 /* Only call the get_table to keep the table mapped */
123 xsdt_va = (struct acpi_table_xsdt *)sfi_get_table(&xsdt_key);
124 return 0;
125 }
126
127 static struct acpi_table_header *sfi_acpi_get_table(struct sfi_table_key *key)
128 {
129 u32 tbl_cnt, i;
130 void *ret;
131
132 tbl_cnt = XSDT_GET_NUM_ENTRIES(xsdt_va, u64);
133 for (i = 0; i < tbl_cnt; i++) {
134 ret = sfi_check_table(xsdt_va->table_offset_entry[i], key);
135 if (!IS_ERR(ret) && ret)
136 return sfi_to_acpi_th(ret);
137 }
138
139 return NULL;
140 }
141
142 static void sfi_acpi_put_table(struct acpi_table_header *table)
143 {
144 sfi_put_table(acpi_to_sfi_th(table));
145 }
146
147 /*
148 * sfi_acpi_table_parse()
149 *
150 * Find specified table in XSDT, run handler on it and return its return value
151 */
152 int sfi_acpi_table_parse(char *signature, char *oem_id, char *oem_table_id,
153 int(*handler)(struct acpi_table_header *))
154 {
155 struct acpi_table_header *table = NULL;
156 struct sfi_table_key key;
157 int ret = 0;
158
159 if (sfi_disabled)
160 return -1;
161
162 key.sig = signature;
163 key.oem_id = oem_id;
164 key.oem_table_id = oem_table_id;
165
166 table = sfi_acpi_get_table(&key);
167 if (!table)
168 return -EINVAL;
169
170 ret = handler(table);
171 sfi_acpi_put_table(table);
172 return ret;
173 }
174
175 static ssize_t sfi_acpi_table_show(struct file *filp, struct kobject *kobj,
176 struct bin_attribute *bin_attr, char *buf,
177 loff_t offset, size_t count)
178 {
179 struct sfi_table_attr *tbl_attr =
180 container_of(bin_attr, struct sfi_table_attr, attr);
181 struct acpi_table_header *th = NULL;
182 struct sfi_table_key key;
183 ssize_t cnt;
184
185 key.sig = tbl_attr->name;
186 key.oem_id = NULL;
187 key.oem_table_id = NULL;
188
189 th = sfi_acpi_get_table(&key);
190 if (!th)
191 return 0;
192
193 cnt = memory_read_from_buffer(buf, count, &offset,
194 th, th->length);
195 sfi_acpi_put_table(th);
196
197 return cnt;
198 }
199
200
201 void __init sfi_acpi_sysfs_init(void)
202 {
203 u32 tbl_cnt, i;
204 struct sfi_table_attr *tbl_attr;
205
206 tbl_cnt = XSDT_GET_NUM_ENTRIES(xsdt_va, u64);
207 for (i = 0; i < tbl_cnt; i++) {
208 tbl_attr =
209 sfi_sysfs_install_table(xsdt_va->table_offset_entry[i]);
210 tbl_attr->attr.read = sfi_acpi_table_show;
211 }
212
213 return;
214 }