linux/drivers/acpi/acpica/dsinit.c
Bob Moore 8a335a2331 ACPICA: Fix AcpiWalkNamespace race condition with table unload
Added a reader/writer locking mechanism to allow multiple
concurrent namespace walks (readers), but a dynamic table unload
will have exclusive access to the namespace. This fixes a problem
where a table unload could delete the portion of the namespace that
is currently being examined by a walk.  Adds a new file, utlock.c
that implements the reader/writer lock mechanism. ACPICA BZ 749.

http://www.acpica.org/bugzilla/show_bug.cgi?id=749

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
2009-03-27 12:11:02 -04:00

218 lines
6.6 KiB
C

/******************************************************************************
*
* Module Name: dsinit - Object initialization namespace walk
*
*****************************************************************************/
/*
* Copyright (C) 2000 - 2008, 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.
*/
#include <acpi/acpi.h>
#include "accommon.h"
#include "acdispat.h"
#include "acnamesp.h"
#include "actables.h"
#define _COMPONENT ACPI_DISPATCHER
ACPI_MODULE_NAME("dsinit")
/* Local prototypes */
static acpi_status
acpi_ds_init_one_object(acpi_handle obj_handle,
u32 level, void *context, void **return_value);
/*******************************************************************************
*
* FUNCTION: acpi_ds_init_one_object
*
* PARAMETERS: obj_handle - Node for the object
* Level - Current nesting level
* Context - Points to a init info struct
* return_value - Not used
*
* RETURN: Status
*
* DESCRIPTION: Callback from acpi_walk_namespace. Invoked for every object
* within the namespace.
*
* Currently, the only objects that require initialization are:
* 1) Methods
* 2) Operation Regions
*
******************************************************************************/
static acpi_status
acpi_ds_init_one_object(acpi_handle obj_handle,
u32 level, void *context, void **return_value)
{
struct acpi_init_walk_info *info =
(struct acpi_init_walk_info *)context;
struct acpi_namespace_node *node =
(struct acpi_namespace_node *)obj_handle;
acpi_object_type type;
acpi_status status;
ACPI_FUNCTION_ENTRY();
/*
* We are only interested in NS nodes owned by the table that
* was just loaded
*/
if (node->owner_id != info->owner_id) {
return (AE_OK);
}
info->object_count++;
/* And even then, we are only interested in a few object types */
type = acpi_ns_get_type(obj_handle);
switch (type) {
case ACPI_TYPE_REGION:
status = acpi_ds_initialize_region(obj_handle);
if (ACPI_FAILURE(status)) {
ACPI_EXCEPTION((AE_INFO, status,
"During Region initialization %p [%4.4s]",
obj_handle,
acpi_ut_get_node_name(obj_handle)));
}
info->op_region_count++;
break;
case ACPI_TYPE_METHOD:
info->method_count++;
break;
case ACPI_TYPE_DEVICE:
info->device_count++;
break;
default:
break;
}
/*
* We ignore errors from above, and always return OK, since
* we don't want to abort the walk on a single error.
*/
return (AE_OK);
}
/*******************************************************************************
*
* FUNCTION: acpi_ds_initialize_objects
*
* PARAMETERS: table_desc - Descriptor for parent ACPI table
* start_node - Root of subtree to be initialized.
*
* RETURN: Status
*
* DESCRIPTION: Walk the namespace starting at "StartNode" and perform any
* necessary initialization on the objects found therein
*
******************************************************************************/
acpi_status
acpi_ds_initialize_objects(u32 table_index,
struct acpi_namespace_node * start_node)
{
acpi_status status;
struct acpi_init_walk_info info;
struct acpi_table_header *table;
acpi_owner_id owner_id;
ACPI_FUNCTION_TRACE(ds_initialize_objects);
status = acpi_tb_get_owner_id(table_index, &owner_id);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
"**** Starting initialization of namespace objects ****\n"));
ACPI_DEBUG_PRINT_RAW((ACPI_DB_INIT, "Parsing all Control Methods:"));
info.method_count = 0;
info.op_region_count = 0;
info.object_count = 0;
info.device_count = 0;
info.table_index = table_index;
info.owner_id = owner_id;
/* Walk entire namespace from the supplied root */
status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
/*
* We don't use acpi_walk_namespace since we do not want to acquire
* the namespace reader lock.
*/
status =
acpi_ns_walk_namespace(ACPI_TYPE_ANY, start_node, ACPI_UINT32_MAX,
ACPI_NS_WALK_UNLOCK, acpi_ds_init_one_object,
&info, NULL);
if (ACPI_FAILURE(status)) {
ACPI_EXCEPTION((AE_INFO, status, "During WalkNamespace"));
}
(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
status = acpi_get_table_by_index(table_index, &table);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
ACPI_DEBUG_PRINT_RAW((ACPI_DB_INIT,
"\nTable [%4.4s](id %4.4X) - %hd Objects with %hd Devices %hd Methods %hd Regions\n",
table->signature, owner_id, info.object_count,
info.device_count, info.method_count,
info.op_region_count));
ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
"%hd Methods, %hd Regions\n", info.method_count,
info.op_region_count));
return_ACPI_STATUS(AE_OK);
}