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linux-next/drivers/acpi/acpica/actables.h
Lv Zheng 174cc7187e ACPICA: Tables: Back port acpi_get_table_with_size() and early_acpi_os_unmap_memory() from Linux kernel
ACPICA commit cac6790954d4d752a083e6122220b8a22febcd07

This patch back ports Linux acpi_get_table_with_size() and
early_acpi_os_unmap_memory() into ACPICA upstream to reduce divergences.

The 2 APIs are used by Linux as table management APIs for long time, it
contains a hidden logic that during the early stage, the mapped tables
should be unmapped before the early stage ends.

During the early stage, tables are handled by the following sequence:
 acpi_get_table_with_size();
 parse the table
 early_acpi_os_unmap_memory();
During the late stage, tables are handled by the following sequence:
 acpi_get_table();
 parse the table
Linux uses acpi_gbl_permanent_mmap to distinguish the early stage and the
late stage.

The reasoning of introducing acpi_get_table_with_size() is: ACPICA will
remember the early mapped pointer in acpi_get_table() and Linux isn't able to
prevent ACPICA from using the wrong early mapped pointer during the late
stage as there is no API provided from ACPICA to be an inverse of
acpi_get_table() to forget the early mapped pointer.

But how ACPICA can work with the early/late stage requirement? Inside of
ACPICA, tables are ensured to be remained in "INSTALLED" state during the
early stage, and they are carefully not transitioned to "VALIDATED" state
until the late stage. So the same logic is in fact implemented inside of
ACPICA in a different way. The gap is only that the feature is not provided
to the OSPMs in an accessible external API style.

It then is possible to fix the gap by providing an inverse of
acpi_get_table() from ACPICA, so that the two Linux sequences can be
combined:
 acpi_get_table();
 parse the table
 acpi_put_table();
In order to work easier with the current Linux code, acpi_get_table() and
acpi_put_table() is implemented in a usage counting based style:
 1. When the usage count of the table is increased from 0 to 1, table is
    mapped and .Pointer is set with the mapping address (VALIDATED);
 2. When the usage count of the table is decreased from 1 to 0, .Pointer
    is unset and the mapping address is unmapped (INVALIDATED).
So that we can deploy the new APIs to Linux with minimal effort by just
invoking acpi_get_table() in acpi_get_table_with_size() and invoking
acpi_put_table() in early_acpi_os_unmap_memory(). Lv Zheng.

Link: https://github.com/acpica/acpica/commit/cac67909
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-12-21 02:36:38 +01:00

181 lines
5.6 KiB
C

/******************************************************************************
*
* Name: actables.h - ACPI table management
*
*****************************************************************************/
/*
* Copyright (C) 2000 - 2016, Intel Corp.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions, and the following disclaimer,
* without modification.
* 2. Redistributions in binary form must reproduce at minimum a disclaimer
* substantially similar to the "NO WARRANTY" disclaimer below
* ("Disclaimer") and any redistribution must be conditioned upon
* including a substantially similar Disclaimer requirement for further
* binary redistribution.
* 3. Neither the names of the above-listed copyright holders nor the names
* of any contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* NO WARRANTY
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGES.
*/
#ifndef __ACTABLES_H__
#define __ACTABLES_H__
acpi_status acpi_allocate_root_table(u32 initial_table_count);
/*
* tbxfroot - Root pointer utilities
*/
u32 acpi_tb_get_rsdp_length(struct acpi_table_rsdp *rsdp);
acpi_status acpi_tb_validate_rsdp(struct acpi_table_rsdp *rsdp);
u8 *acpi_tb_scan_memory_for_rsdp(u8 *start_address, u32 length);
/*
* tbdata - table data structure management
*/
acpi_status
acpi_tb_get_next_table_descriptor(u32 *table_index,
struct acpi_table_desc **table_desc);
void
acpi_tb_init_table_descriptor(struct acpi_table_desc *table_desc,
acpi_physical_address address,
u8 flags, struct acpi_table_header *table);
acpi_status
acpi_tb_acquire_temp_table(struct acpi_table_desc *table_desc,
acpi_physical_address address, u8 flags);
void acpi_tb_release_temp_table(struct acpi_table_desc *table_desc);
acpi_status acpi_tb_validate_temp_table(struct acpi_table_desc *table_desc);
acpi_status
acpi_tb_verify_temp_table(struct acpi_table_desc *table_desc, char *signature);
u8 acpi_tb_is_table_loaded(u32 table_index);
void acpi_tb_set_table_loaded_flag(u32 table_index, u8 is_loaded);
/*
* tbfadt - FADT parse/convert/validate
*/
void acpi_tb_parse_fadt(void);
void acpi_tb_create_local_fadt(struct acpi_table_header *table, u32 length);
/*
* tbfind - find ACPI table
*/
acpi_status
acpi_tb_find_table(char *signature,
char *oem_id, char *oem_table_id, u32 *table_index);
/*
* tbinstal - Table removal and deletion
*/
acpi_status acpi_tb_resize_root_table_list(void);
acpi_status acpi_tb_validate_table(struct acpi_table_desc *table_desc);
void acpi_tb_invalidate_table(struct acpi_table_desc *table_desc);
void acpi_tb_override_table(struct acpi_table_desc *old_table_desc);
acpi_status
acpi_tb_acquire_table(struct acpi_table_desc *table_desc,
struct acpi_table_header **table_ptr,
u32 *table_length, u8 *table_flags);
void
acpi_tb_release_table(struct acpi_table_header *table,
u32 table_length, u8 table_flags);
acpi_status
acpi_tb_install_standard_table(acpi_physical_address address,
u8 flags,
u8 reload, u8 override, u32 *table_index);
void acpi_tb_uninstall_table(struct acpi_table_desc *table_desc);
acpi_status
acpi_tb_load_table(u32 table_index, struct acpi_namespace_node *parent_node);
acpi_status
acpi_tb_install_and_load_table(acpi_physical_address address,
u8 flags, u8 override, u32 *table_index);
acpi_status acpi_tb_unload_table(u32 table_index);
void acpi_tb_terminate(void);
acpi_status acpi_tb_delete_namespace_by_owner(u32 table_index);
acpi_status acpi_tb_allocate_owner_id(u32 table_index);
acpi_status acpi_tb_release_owner_id(u32 table_index);
acpi_status acpi_tb_get_owner_id(u32 table_index, acpi_owner_id *owner_id);
/*
* tbutils - table manager utilities
*/
acpi_status acpi_tb_initialize_facs(void);
void
acpi_tb_print_table_header(acpi_physical_address address,
struct acpi_table_header *header);
u8 acpi_tb_checksum(u8 *buffer, u32 length);
acpi_status
acpi_tb_verify_checksum(struct acpi_table_header *table, u32 length);
void acpi_tb_check_dsdt_header(void);
struct acpi_table_header *acpi_tb_copy_dsdt(u32 table_index);
void
acpi_tb_install_table_with_override(struct acpi_table_desc *new_table_desc,
u8 override, u32 *table_index);
acpi_status acpi_tb_parse_root_table(acpi_physical_address rsdp_address);
acpi_status
acpi_tb_get_table(struct acpi_table_desc *table_desc,
struct acpi_table_header **out_table);
void acpi_tb_put_table(struct acpi_table_desc *table_desc);
/*
* tbxfload
*/
acpi_status acpi_tb_load_namespace(void);
#endif /* __ACTABLES_H__ */