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- /*
- * 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,
- };
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