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 <acpi/acpi.h>
64
65#include <linux/sfi.h>
66#include "sfi_core.h"
67
68/*
69 * SFI can access ACPI-defined tables via an optional ACPI XSDT.
70 *
71 * This allows re-use, and avoids re-definition, of standard tables.
72 * For example, the "MCFG" table is defined by PCI, reserved by ACPI,
73 * and is expected to be present many SFI-only systems.
74 */
75
76static struct acpi_table_xsdt *xsdt_va __read_mostly;
77
78#define XSDT_GET_NUM_ENTRIES(ptable, entry_type) \
79	((ptable->header.length - sizeof(struct acpi_table_header)) / \
80	(sizeof(entry_type)))
81
82static inline struct sfi_table_header *acpi_to_sfi_th(
83				struct acpi_table_header *th)
84{
85	return (struct sfi_table_header *)th;
86}
87
88static inline struct acpi_table_header *sfi_to_acpi_th(
89				struct sfi_table_header *th)
90{
91	return (struct acpi_table_header *)th;
92}
93
94/*
95 * sfi_acpi_parse_xsdt()
96 *
97 * Parse the ACPI XSDT for later access by sfi_acpi_table_parse().
98 */
99static int __init sfi_acpi_parse_xsdt(struct sfi_table_header *th)
100{
101	struct sfi_table_key key = SFI_ANY_KEY;
102	int tbl_cnt, i;
103	void *ret;
104
105	xsdt_va = (struct acpi_table_xsdt *)th;
106	tbl_cnt = XSDT_GET_NUM_ENTRIES(xsdt_va, u64);
107	for (i = 0; i < tbl_cnt; i++) {
108		ret = sfi_check_table(xsdt_va->table_offset_entry[i], &key);
109		if (IS_ERR(ret)) {
110			disable_sfi();
111			return -1;
112		}
113	}
114
115	return 0;
116}
117
118int __init sfi_acpi_init(void)
119{
120	struct sfi_table_key xsdt_key = { .sig = SFI_SIG_XSDT };
121
122	sfi_table_parse(SFI_SIG_XSDT, NULL, NULL, sfi_acpi_parse_xsdt);
123
124	/* Only call the get_table to keep the table mapped */
125	xsdt_va = (struct acpi_table_xsdt *)sfi_get_table(&xsdt_key);
126	return 0;
127}
128
129static struct acpi_table_header *sfi_acpi_get_table(struct sfi_table_key *key)
130{
131	u32 tbl_cnt, i;
132	void *ret;
133
134	tbl_cnt = XSDT_GET_NUM_ENTRIES(xsdt_va, u64);
135	for (i = 0; i < tbl_cnt; i++) {
136		ret = sfi_check_table(xsdt_va->table_offset_entry[i], key);
137		if (!IS_ERR(ret) && ret)
138			return sfi_to_acpi_th(ret);
139	}
140
141	return NULL;
142}
143
144static void sfi_acpi_put_table(struct acpi_table_header *table)
145{
146	sfi_put_table(acpi_to_sfi_th(table));
147}
148
149/*
150 * sfi_acpi_table_parse()
151 *
152 * Find specified table in XSDT, run handler on it and return its return value
153 */
154int sfi_acpi_table_parse(char *signature, char *oem_id, char *oem_table_id,
155			int(*handler)(struct acpi_table_header *))
156{
157	struct acpi_table_header *table = NULL;
158	struct sfi_table_key key;
159	int ret = 0;
160
161	if (sfi_disabled)
162		return -1;
163
164	key.sig = signature;
165	key.oem_id = oem_id;
166	key.oem_table_id = oem_table_id;
167
168	table = sfi_acpi_get_table(&key);
169	if (!table)
170		return -EINVAL;
171
172	ret = handler(table);
173	sfi_acpi_put_table(table);
174	return ret;
175}
176
177static ssize_t sfi_acpi_table_show(struct file *filp, struct kobject *kobj,
178			       struct bin_attribute *bin_attr, char *buf,
179			       loff_t offset, size_t count)
180{
181	struct sfi_table_attr *tbl_attr =
182	    container_of(bin_attr, struct sfi_table_attr, attr);
183	struct acpi_table_header *th = NULL;
184	struct sfi_table_key key;
185	ssize_t cnt;
186
187	key.sig = tbl_attr->name;
188	key.oem_id = NULL;
189	key.oem_table_id = NULL;
190
191	th = sfi_acpi_get_table(&key);
192	if (!th)
193		return 0;
194
195	cnt =  memory_read_from_buffer(buf, count, &offset,
196					th, th->length);
197	sfi_acpi_put_table(th);
198
199	return cnt;
200}
201
202
203void __init sfi_acpi_sysfs_init(void)
204{
205	u32 tbl_cnt, i;
206	struct sfi_table_attr *tbl_attr;
207
208	tbl_cnt = XSDT_GET_NUM_ENTRIES(xsdt_va, u64);
209	for (i = 0; i < tbl_cnt; i++) {
210		tbl_attr =
211			sfi_sysfs_install_table(xsdt_va->table_offset_entry[i]);
212		tbl_attr->attr.read = sfi_acpi_table_show;
213	}
214
215	return;
216}
217