drivers/sfi/sfi_acpi.c

   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 }