/*
* Copyright (C) 2017 Michael Brown <mbrown@fensystems.co.uk>.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*
* You can also choose to distribute this program under the terms of
* the Unmodified Binary Distribution Licence (as given in the file
* COPYING.UBDL), provided that you have satisfied its requirements.
*/
FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
/**
* @file
*
* ACPI settings
*
*/
#include <string.h>
#include <errno.h>
#include <ipxe/init.h>
#include <ipxe/settings.h>
#include <ipxe/acpi.h>
/** ACPI settings scope */
static const struct settings_scope acpi_settings_scope;
/**
* Check applicability of ACPI setting
*
* @v settings Settings block
* @v setting Setting
* @ret applies Setting applies within this settings block
*/
static int acpi_settings_applies ( struct settings *settings __unused,
const struct setting *setting ) {
return ( setting->scope == &acpi_settings_scope );
}
/**
* Fetch value of ACPI setting
*
* @v settings Settings block
* @v setting Setting to fetch
* @v data Buffer to fill with setting data
* @v len Length of buffer
* @ret len Length of setting data, or negative error
*/
static int acpi_settings_fetch ( struct settings *settings,
struct setting *setting,
void *data, size_t len ) {
struct acpi_header acpi;
uint32_t tag_high;
uint32_t tag_low;
uint32_t tag_signature;
unsigned int tag_index;
size_t tag_offset;
size_t tag_len;
userptr_t table;
size_t offset;
size_t max_len;
int delta;
unsigned int i;
/* Parse settings tag */
tag_high = ( setting->tag >> 32 );
tag_low = setting->tag;
tag_signature = bswap_32 ( tag_high );
tag_index = ( ( tag_low >> 24 ) & 0xff );
tag_offset = ( ( tag_low >> 8 ) & 0xffff );
tag_len = ( ( tag_low >> 0 ) & 0xff );
DBGC ( settings, "ACPI %s.%d offset %#zx length %#zx\n",
acpi_name ( tag_signature ), tag_index, tag_offset, tag_len );
/* Locate ACPI table */
table = acpi_find ( tag_signature, tag_index );
if ( ! table )
return -ENOENT;
/* Read table header */
copy_from_user ( &acpi, table, 0, sizeof ( acpi ) );
/* Calculate starting offset and maximum available length */
max_len = le32_to_cpu ( acpi.length );
if ( tag_offset > max_len )
return -ENOENT;
offset = tag_offset;
max_len -= offset;
/* Restrict to requested length, if specified */
if ( tag_len && ( tag_len < max_len ) )
max_len = tag_len;
/* Invert endianness for numeric settings */
if ( setting->type && setting->type->numerate ) {
offset += ( max_len - 1 );
delta = -1;
} else {
delta = +1;
}
/* Read data */
for ( i = 0 ; ( ( i < max_len ) && ( i < len ) ) ; i++ ) {
copy_from_user ( data, table, offset, 1 );
data++;
offset += delta;
}
/* Set type if not already specified */
if ( ! setting->type )
setting->type = &setting_type_hexraw;
return max_len;
}
/** ACPI settings operations */
static struct settings_operations acpi_settings_operations = {
.applies = acpi_settings_applies,
.fetch = acpi_settings_fetch,
};
/** ACPI settings */
static struct settings acpi_settings = {
.refcnt = NULL,
.siblings = LIST_HEAD_INIT ( acpi_settings.siblings ),
.children = LIST_HEAD_INIT ( acpi_settings.children ),
.op = &acpi_settings_operations,
.default_scope = &acpi_settings_scope,
};
/** Initialise ACPI settings */
static void acpi_settings_init ( void ) {
int rc;
if ( ( rc = register_settings ( &acpi_settings, NULL,
"acpi" ) ) != 0 ) {
DBG ( "ACPI could not register settings: %s\n",
strerror ( rc ) );
return;
}
}
/** ACPI settings initialiser */
struct init_fn acpi_settings_init_fn __init_fn ( INIT_NORMAL ) = {
.initialise = acpi_settings_init,
};
