utalloc.c

linux-2.4.29操作系统的源码

/******************************************************************************
 *
 * Module Name: utalloc - local cache and memory allocation routines
 *
 *****************************************************************************/

/*
 * Copyright (C) 2000 - 2004, R. Byron Moore
 * 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>

#define _COMPONENT          ACPI_UTILITIES
	 ACPI_MODULE_NAME    ("utalloc")


/******************************************************************************
 *
 * FUNCTION:    acpi_ut_release_to_cache
 *
 * PARAMETERS:  list_id             - Memory list/cache ID
 *              Object              - The object to be released
 *
 * RETURN:      None
 *
 * DESCRIPTION: Release an object to the specified cache.  If cache is full,
 *              the object is deleted.
 *
 ******************************************************************************/

void
acpi_ut_release_to_cache (
	u32                             list_id,
	void                            *object)
{
	struct acpi_memory_list         *cache_info;


	ACPI_FUNCTION_ENTRY ();


	/* If walk cache is full, just free this wallkstate object */

	cache_info = &acpi_gbl_memory_lists[list_id];
	if (cache_info->cache_depth >= cache_info->max_cache_depth) {
		ACPI_MEM_FREE (object);
		ACPI_MEM_TRACKING (cache_info->total_freed++);
	}

	/* Otherwise put this object back into the cache */

	else {
		if (ACPI_FAILURE (acpi_ut_acquire_mutex (ACPI_MTX_CACHES))) {
			return;
		}

		/* Mark the object as cached */

		ACPI_MEMSET (object, 0xCA, cache_info->object_size);
		ACPI_SET_DESCRIPTOR_TYPE (object, ACPI_DESC_TYPE_CACHED);

		/* Put the object at the head of the cache list */

		* (ACPI_CAST_INDIRECT_PTR (char, &(((char *) object)[cache_info->link_offset]))) = cache_info->list_head;
		cache_info->list_head = object;
		cache_info->cache_depth++;

		(void) acpi_ut_release_mutex (ACPI_MTX_CACHES);
	}
}


/******************************************************************************
 *
 * FUNCTION:    acpi_ut_acquire_from_cache
 *
 * PARAMETERS:  list_id             - Memory list ID
 *
 * RETURN:      A requested object.  NULL if the object could not be
 *              allocated.
 *
 * DESCRIPTION: Get an object from the specified cache.  If cache is empty,
 *              the object is allocated.
 *
 ******************************************************************************/

void *
acpi_ut_acquire_from_cache (
	u32                             list_id)
{
	struct acpi_memory_list         *cache_info;
	void                            *object;


	ACPI_FUNCTION_NAME ("ut_acquire_from_cache");


	cache_info = &acpi_gbl_memory_lists[list_id];
	if (ACPI_FAILURE (acpi_ut_acquire_mutex (ACPI_MTX_CACHES))) {
		return (NULL);
	}

	ACPI_MEM_TRACKING (cache_info->cache_requests++);

	/* Check the cache first */

	if (cache_info->list_head) {
		/* There is an object available, use it */

		object = cache_info->list_head;
		cache_info->list_head = *(ACPI_CAST_INDIRECT_PTR (char, &(((char *) object)[cache_info->link_offset])));

		ACPI_MEM_TRACKING (cache_info->cache_hits++);
		cache_info->cache_depth--;

#ifdef ACPI_DBG_TRACK_ALLOCATIONS
		ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, "Object %p from %s\n",
			object, acpi_gbl_memory_lists[list_id].list_name));
#endif

		if (ACPI_FAILURE (acpi_ut_release_mutex (ACPI_MTX_CACHES))) {
			return (NULL);
		}

		/* Clear (zero) the previously used Object */

		ACPI_MEMSET (object, 0, cache_info->object_size);
	}

	else {
		/* The cache is empty, create a new object */

		/* Avoid deadlock with ACPI_MEM_CALLOCATE */

		if (ACPI_FAILURE (acpi_ut_release_mutex (ACPI_MTX_CACHES))) {
			return (NULL);
		}

		object = ACPI_MEM_CALLOCATE (cache_info->object_size);
		ACPI_MEM_TRACKING (cache_info->total_allocated++);
	}

	return (object);
}


/******************************************************************************
 *
 * FUNCTION:    acpi_ut_delete_generic_cache
 *
 * PARAMETERS:  list_id         - Memory list ID
 *
 * RETURN:      None
 *
 * DESCRIPTION: Free all objects within the requested cache.
 *
 ******************************************************************************/

void
acpi_ut_delete_generic_cache (
	u32                             list_id)
{
	struct acpi_memory_list         *cache_info;
	char                            *next;


	ACPI_FUNCTION_ENTRY ();


	cache_info = &acpi_gbl_memory_lists[list_id];
	while (cache_info->list_head) {
		/* Delete one cached state object */

		next = *(ACPI_CAST_INDIRECT_PTR (char, &(((char *) cache_info->list_head)[cache_info->link_offset])));
		ACPI_MEM_FREE (cache_info->list_head);

		cache_info->list_head = next;
		cache_info->cache_depth--;
	}
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_validate_buffer
 *
 * PARAMETERS:  Buffer              - Buffer descriptor to be validated
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Perform parameter validation checks on an struct acpi_buffer
 *
 ******************************************************************************/

acpi_status
acpi_ut_validate_buffer (
	struct acpi_buffer              *buffer)
{

	/* Obviously, the structure pointer must be valid */

	if (!buffer) {
		return (AE_BAD_PARAMETER);
	}

	/* Special semantics for the length */

	if ((buffer->length == ACPI_NO_BUFFER)              ||
		(buffer->length == ACPI_ALLOCATE_BUFFER)        ||
		(buffer->length == ACPI_ALLOCATE_LOCAL_BUFFER)) {
		return (AE_OK);
	}

	/* Length is valid, the buffer pointer must be also */

	if (!buffer->pointer) {
		return (AE_BAD_PARAMETER);
	}

	return (AE_OK);
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_initialize_buffer
 *
 * PARAMETERS:  required_length     - Length needed
 *              Buffer              - Buffer to be validated
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Validate that the buffer is of the required length or
 *              allocate a new buffer.
 *
 ******************************************************************************/

acpi_status
acpi_ut_initialize_buffer (
	struct acpi_buffer              *buffer,
	acpi_size                       required_length)
{
	acpi_status                     status = AE_OK;


	switch (buffer->length) {
	case ACPI_NO_BUFFER:

		/* Set the exception and returned the required length */

		status = AE_BUFFER_OVERFLOW;
		break;


	case ACPI_ALLOCATE_BUFFER:

		/* Allocate a new buffer */

		buffer->pointer = acpi_os_allocate (required_length);
		if (!buffer->pointer) {
			return (AE_NO_MEMORY);
		}

		/* Clear the buffer */

		ACPI_MEMSET (buffer->pointer, 0, required_length);
		break;


	case ACPI_ALLOCATE_LOCAL_BUFFER:

		/* Allocate a new buffer with local interface to allow tracking */

		buffer->pointer = ACPI_MEM_ALLOCATE (required_length);
		if (!buffer->pointer) {
			return (AE_NO_MEMORY);
		}

		/* Clear the buffer */

		ACPI_MEMSET (buffer->pointer, 0, required_length);
		break;


	default:

		/* Validate the size of the buffer */

		if (buffer->length < required_length) {
			status = AE_BUFFER_OVERFLOW;
		}
		break;
	}

	buffer->length = required_length;
	return (status);
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_allocate
 *
 * PARAMETERS:  Size                - Size of the allocation
 *              Component           - Component type of caller
 *              Module              - Source file name of caller
 *              Line                - Line number of caller
 *
 * RETURN:      Address of the allocated memory on success, NULL on failure.
 *
 * DESCRIPTION: The subsystem's equivalent of malloc.
 *
 ******************************************************************************/

void *
acpi_ut_allocate (
	acpi_size                       size,
	u32                             component,
	char                            *module,
	u32                             line)
{
	void                            *allocation;


	ACPI_FUNCTION_TRACE_U32 ("ut_allocate", size);


	/* Check for an inadvertent size of zero bytes */

	if (!size) {
		_ACPI_REPORT_ERROR (module, line, component,
				("ut_allocate: Attempt to allocate zero bytes\n"));
		size = 1;
	}

	allocation = acpi_os_allocate (size);
	if (!allocation) {
		/* Report allocation error */

		_ACPI_REPORT_ERROR (module, line, component,
				("ut_allocate: Could not allocate size %X\n", (u32) size));

		return_PTR (NULL);
	}

	return_PTR (allocation);
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_callocate
 *
 * PARAMETERS:  Size                - Size of the allocation
 *              Component           - Component type of caller
 *              Module              - Source file name of caller
 *              Line                - Line number of caller
 *
 * RETURN:      Address of the allocated memory on success, NULL on failure.
 *
 * DESCRIPTION: Subsystem equivalent of calloc.
 *
 ******************************************************************************/

void *
acpi_ut_callocate (
	acpi_size                       size,
	u32                             component,
	char                            *module,
	u32                             line)
{
	void                            *allocation;


	ACPI_FUNCTION_TRACE_U32 ("ut_callocate", size);


	/* Check for an inadvertent size of zero bytes */

	if (!size) {
		_ACPI_REPORT_ERROR (module, line, component,
				("ut_callocate: Attempt to allocate zero bytes\n"));
		return_PTR (NULL);
	}

	allocation = acpi_os_allocate (size);
	if (!allocation) {
		/* Report allocation error */

		_ACPI_REPORT_ERROR (module, line, component,
				("ut_callocate: Could not allocate size %X\n", (u32) size));
		return_PTR (NULL);
	}

	/* Clear the memory block */

	ACPI_MEMSET (allocation, 0, size);
	return_PTR (allocation);
}


#ifdef ACPI_DBG_TRACK_ALLOCATIONS
/*
 * These procedures are used for tracking memory leaks in the subsystem, and
 * they get compiled out when the ACPI_DBG_TRACK_ALLOCATIONS is not set.
 *
 * Each memory allocation is tracked via a doubly linked list.  Each
 * element contains the caller's component, module name, function name, and
 * line number.  acpi_ut_allocate and acpi_ut_callocate call
 * acpi_ut_track_allocation to add an element to the list; deletion
 * occurs in the body of acpi_ut_free.
 */


/*******************************************************************************
 *
 * FUNCTION:    acpi_ut_allocate_and_track
 *
 * PARAMETERS:  Size                - Size of the allocation
 *              Component           - Component type of caller
 *              Module              - Source file name of caller
 *              Line                - Line number of caller
 *
 * RETURN:      Address of the allocated memory on success, NULL on failure.
 *
 * DESCRIPTION: The subsystem's equivalent of malloc.
 *
 ******************************************************************************/

void *
acpi_ut_allocate_and_track (
	acpi_size                       size,
	u32                             component,
	char                            *module,
	u32                             line)
{
	struct acpi_debug_mem_block     *allocation;
	acpi_status                     status;


	allocation = acpi_ut_allocate (size + sizeof (struct acpi_debug_mem_block), component,
			  module, line);
	if (!allocation) {
		return (NULL);
	}