rscreate.c

Linux内核源代码 为压缩文件 是<<Linux内核>>一书中的源代码

/*******************************************************************************
 *
 * Module Name: rscreate - Acpi_rs_create_resource_list
 *                         Acpi_rs_create_pci_routing_table
 *                         Acpi_rs_create_byte_stream
 *              $Revision: 22 $
 *
 ******************************************************************************/

/*
 *  Copyright (C) 2000 R. Byron Moore
 *
 *  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
 *  (at your option) 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */


#include "acpi.h"
#include "acresrc.h"

#define _COMPONENT          RESOURCE_MANAGER
	 MODULE_NAME         ("rscreate")


/*******************************************************************************
 *
 * FUNCTION:    Acpi_rs_create_resource_list
 *
 * PARAMETERS:
 *              Byte_stream_buffer      - Pointer to the resource byte stream
 *              Output_buffer           - Pointer to the user's buffer
 *              Output_buffer_length    - Pointer to the size of Output_buffer
 *
 * RETURN:      Status  - AE_OK if okay, else a valid ACPI_STATUS code
 *              If Output_buffer is not large enough, Output_buffer_length
 *              indicates how large Output_buffer should be, else it
 *              indicates how may u8 elements of Output_buffer are valid.
 *
 * DESCRIPTION: Takes the byte stream returned from a _CRS, _PRS control method
 *              execution and parses the stream to create a linked list
 *              of device resources.
 *
 ******************************************************************************/

ACPI_STATUS
acpi_rs_create_resource_list (
	ACPI_OPERAND_OBJECT     *byte_stream_buffer,
	u8                      *output_buffer,
	u32                     *output_buffer_length)
{

	ACPI_STATUS             status;
	u8                      *byte_stream_start = NULL;
	u32                     list_size_needed = 0;
	u32                     byte_stream_buffer_length = 0;


	/*
	 * Params already validated, so we don't re-validate here
	 */

	byte_stream_buffer_length = byte_stream_buffer->buffer.length;
	byte_stream_start = byte_stream_buffer->buffer.pointer;

	/*
	 * Pass the Byte_stream_buffer into a module that can calculate
	 * the buffer size needed for the linked list
	 */
	status = acpi_rs_calculate_list_length (byte_stream_start,
			 byte_stream_buffer_length,
			 &list_size_needed);

	/*
	 * Exit with the error passed back
	 */
	if (ACPI_FAILURE (status)) {
		return (status);
	}

	/*
	 * If the linked list will fit into the available buffer
	 * call to fill in the list
	 */

	if (list_size_needed <= *output_buffer_length) {
		/*
		 * Zero out the return buffer before proceeding
		 */
		MEMSET (output_buffer, 0x00, *output_buffer_length);

		status = acpi_rs_byte_stream_to_list (byte_stream_start,
				 byte_stream_buffer_length,
				 &output_buffer);

		/*
		 * Exit with the error passed back
		 */
		if (ACPI_FAILURE (status)) {
			return (status);
		}

	}

	else {
		*output_buffer_length = list_size_needed;
		return (AE_BUFFER_OVERFLOW);
	}

	*output_buffer_length = list_size_needed;
	return (AE_OK);

}


/*******************************************************************************
 *
 * FUNCTION:    Acpi_rs_create_pci_routing_table
 *
 * PARAMETERS:
 *              Package_object          - Pointer to an ACPI_OPERAND_OBJECT
 *                                          package
 *              Output_buffer           - Pointer to the user's buffer
 *              Output_buffer_length    - Size of Output_buffer
 *
 * RETURN:      Status  AE_OK if okay, else a valid ACPI_STATUS code.
 *              If the Output_buffer is too small, the error will be
 *              AE_BUFFER_OVERFLOW and Output_buffer_length will point
 *              to the size buffer needed.
 *
 * DESCRIPTION: Takes the ACPI_OPERAND_OBJECT  package and creates a
 *              linked list of PCI interrupt descriptions
 *
 ******************************************************************************/

ACPI_STATUS
acpi_rs_create_pci_routing_table (
	ACPI_OPERAND_OBJECT     *package_object,
	u8                      *output_buffer,
	u32                     *output_buffer_length)
{
	u8                      *buffer = output_buffer;
	ACPI_OPERAND_OBJECT     **top_object_list = NULL;
	ACPI_OPERAND_OBJECT     **sub_object_list = NULL;
	ACPI_OPERAND_OBJECT     *package_element = NULL;
	u32                     buffer_size_needed = 0;
	u32                     number_of_elements = 0;
	u32                     index = 0;
	PCI_ROUTING_TABLE       *user_prt = NULL;
	ACPI_STATUS             status;


	/*
	 * Params already validated, so we don't re-validate here
	 */

	status = acpi_rs_calculate_pci_routing_table_length(package_object,
			  &buffer_size_needed);

	/*
	 * If the data will fit into the available buffer
	 * call to fill in the list
	 */
	if (buffer_size_needed <= *output_buffer_length) {
		/*
		 * Zero out the return buffer before proceeding
		 */
		MEMSET (output_buffer, 0x00, *output_buffer_length);

		/*
		 * Loop through the ACPI_INTERNAL_OBJECTS - Each object should
		 * contain a u32 Address, a u8 Pin, a Name and a u8
		 * Source_index.
		 */
		top_object_list     = package_object->package.elements;
		number_of_elements  = package_object->package.count;
		user_prt            = (PCI_ROUTING_TABLE *) buffer;


		buffer = ROUND_PTR_UP_TO_8 (buffer, u8);

		for (index = 0; index < number_of_elements; index++) {
			/*
			 * Point User_prt past this current structure
			 *
			 * NOTE: On the first iteration, User_prt->Length will
			 * be zero because we cleared the return buffer earlier
			 */
			buffer += user_prt->length;
			user_prt = (PCI_ROUTING_TABLE *) buffer;


			/*
			 * Fill in the Length field with the information we
			 * have at this point.
			 * The minus one is to subtract the size of the
			 * u8 Source[1] member because it is added below.
			 */
			user_prt->length = (sizeof (PCI_ROUTING_TABLE) - 1);

			/*
			 * Dereference the sub-package
			 */
			package_element = *top_object_list;

			/*
			 * The Sub_object_list will now point to an array of
			 * the four IRQ elements: Address, Pin, Source and
			 * Source_index
			 */
			sub_object_list = package_element->package.elements;

			/*
			 * Dereference the Address
			 */
			if (ACPI_TYPE_NUMBER == (*sub_object_list)->common.type) {
				user_prt->data.address =
						(*sub_object_list)->number.value;
			}

			else {
				return (AE_BAD_DATA);
			}

			/*
			 * Dereference the Pin
			 */
			sub_object_list++;

			if (ACPI_TYPE_NUMBER == (*sub_object_list)->common.type) {
				user_prt->data.pin =
						(u32) (*sub_object_list)->number.value;
			}

			else {
				return (AE_BAD_DATA);
			}

			/*
			 * Dereference the Source Name
			 */
			sub_object_list++;

			if (ACPI_TYPE_STRING == (*sub_object_list)->common.type) {
				STRCPY (user_prt->data.source,
					  (*sub_object_list)->string.pointer);

				/*
				 * Add to the Length field the length of the string
				 */
				user_prt->length += (*sub_object_list)->string.length;
			}

			else {
				/*
				 * If this is a number, then the Source Name
				 * is NULL, since the entire buffer was zeroed
				 * out, we can leave this alone.
				 */
				if (ACPI_TYPE_NUMBER == (*sub_object_list)->common.type) {
					/*
					 * Add to the Length field the length of
					 * the u32 NULL
					 */
					user_prt->length += sizeof (u32);
				}

				else {
					return (AE_BAD_DATA);
				}
			}

			/* Now align the current length */

			user_prt->length = ROUND_UP_TO_64_bITS (user_prt->length);

			/*
			 * Dereference the Source Index
			 */
			sub_object_list++;

			if (ACPI_TYPE_NUMBER == (*sub_object_list)->common.type) {
				user_prt->data.source_index =
						(u32) (*sub_object_list)->number.value;
			}

			else {
				return (AE_BAD_DATA);
			}

			/*
			 * Point to the next ACPI_OPERAND_OBJECT
			 */
			top_object_list++;
		}

	}

	else {
		*output_buffer_length = buffer_size_needed;

		return (AE_BUFFER_OVERFLOW);
	}

	/*
	 * Report the amount of buffer used
	 */
	*output_buffer_length = buffer_size_needed;

	return (AE_OK);
}


/*******************************************************************************
 *
 * FUNCTION:    Acpi_rs_create_byte_stream
 *
 * PARAMETERS:
 *              Linked_list_buffer      - Pointer to the resource linked list
 *              Output_buffer           - Pointer to the user's buffer
 *              Output_buffer_length    - Size of Output_buffer
 *
 * RETURN:      Status  AE_OK if okay, else a valid ACPI_STATUS code.
 *              If the Output_buffer is too small, the error will be
 *              AE_BUFFER_OVERFLOW and Output_buffer_length will point
 *              to the size buffer needed.
 *
 * DESCRIPTION: Takes the linked list of device resources and
 *              creates a bytestream to be used as input for the
 *              _SRS control method.
 *
 ******************************************************************************/

ACPI_STATUS
acpi_rs_create_byte_stream (
	RESOURCE                *linked_list_buffer,
	u8                      *output_buffer,
	u32                     *output_buffer_length)
{
	ACPI_STATUS             status;
	u32                     byte_stream_size_needed = 0;


	/*
	 * Params already validated, so we don't re-validate here
	 *
	 * Pass the Linked_list_buffer into a module that can calculate
	 * the buffer size needed for the byte stream.
	 */
	status = acpi_rs_calculate_byte_stream_length (linked_list_buffer,
			 &byte_stream_size_needed);

	/*
	 * Exit with the error passed back
	 */
	if (ACPI_FAILURE (status)) {
		return (status);
	}

	/*
	 * If the linked list will fit into the available buffer
	 * call to fill in the list
	 */

	if (byte_stream_size_needed <= *output_buffer_length) {
		/*
		 * Zero out the return buffer before proceeding
		 */
		MEMSET (output_buffer, 0x00, *output_buffer_length);

		status = acpi_rs_list_to_byte_stream (linked_list_buffer,
				 byte_stream_size_needed,
				 &output_buffer);

		/*
		 * Exit with the error passed back
		 */
		if (ACPI_FAILURE (status)) {
			return (status);
		}

	}
	else {
		*output_buffer_length = byte_stream_size_needed;
		return (AE_BUFFER_OVERFLOW);
	}

	return (AE_OK);
}