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 <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
  76 static 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
  82 static 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
  88 static 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  */
  99 static 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
 118 int __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
 129 static 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
 144 static 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  */
 154 int 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 }