linux/drivers/sfi/sfi_acpi.c
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   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
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