exregion.c

h内核

/******************************************************************************
 *
 * Module Name: exregion - ACPI default op_region (address space) handlers
 *
 *****************************************************************************/

/*
 * Copyright (C) 2000 - 2005, 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>
#include <acpi/acinterp.h>


#define _COMPONENT          ACPI_EXECUTER
	 ACPI_MODULE_NAME    ("exregion")


/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_system_memory_space_handler
 *
 * PARAMETERS:  Function            - Read or Write operation
 *              Address             - Where in the space to read or write
 *              bit_width           - Field width in bits (8, 16, or 32)
 *              Value               - Pointer to in or out value
 *              handler_context     - Pointer to Handler's context
 *              region_context      - Pointer to context specific to the
 *                                    accessed region
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Handler for the System Memory address space (Op Region)
 *
 ******************************************************************************/

acpi_status
acpi_ex_system_memory_space_handler (
	u32                             function,
	acpi_physical_address           address,
	u32                             bit_width,
	acpi_integer                    *value,
	void                            *handler_context,
	void                            *region_context)
{
	acpi_status                     status = AE_OK;
	void                            *logical_addr_ptr = NULL;
	struct acpi_mem_space_context   *mem_info = region_context;
	u32                             length;
	acpi_size                       window_size;
#ifndef ACPI_MISALIGNED_TRANSFERS
	u32                             remainder;
#endif

	ACPI_FUNCTION_TRACE ("ex_system_memory_space_handler");


	/* Validate and translate the bit width */

	switch (bit_width) {
	case 8:
		length = 1;
		break;

	case 16:
		length = 2;
		break;

	case 32:
		length = 4;
		break;

	case 64:
		length = 8;
		break;

	default:
		ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Invalid system_memory width %d\n",
			bit_width));
		return_ACPI_STATUS (AE_AML_OPERAND_VALUE);
	}


#ifndef ACPI_MISALIGNED_TRANSFERS
	/*
	 * Hardware does not support non-aligned data transfers, we must verify
	 * the request.
	 */
	(void) acpi_ut_short_divide ((acpi_integer) address, length, NULL, &remainder);
	if (remainder != 0) {
		return_ACPI_STATUS (AE_AML_ALIGNMENT);
	}
#endif

	/*
	 * Does the request fit into the cached memory mapping?
	 * Is 1) Address below the current mapping? OR
	 *    2) Address beyond the current mapping?
	 */
	if ((address < mem_info->mapped_physical_address) ||
		(((acpi_integer) address + length) >
			((acpi_integer) mem_info->mapped_physical_address + mem_info->mapped_length))) {
		/*
		 * The request cannot be resolved by the current memory mapping;
		 * Delete the existing mapping and create a new one.
		 */
		if (mem_info->mapped_length) {
			/* Valid mapping, delete it */

			acpi_os_unmap_memory (mem_info->mapped_logical_address,
					   mem_info->mapped_length);
		}

		/*
		 * Don't attempt to map memory beyond the end of the region, and
		 * constrain the maximum mapping size to something reasonable.
		 */
		window_size = (acpi_size) ((mem_info->address + mem_info->length) - address);
		if (window_size > ACPI_SYSMEM_REGION_WINDOW_SIZE) {
			window_size = ACPI_SYSMEM_REGION_WINDOW_SIZE;
		}

		/* Create a new mapping starting at the address given */

		status = acpi_os_map_memory (address, window_size,
				  (void **) &mem_info->mapped_logical_address);
		if (ACPI_FAILURE (status)) {
			ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Could not map memory at %8.8X%8.8X, size %X\n",
					ACPI_FORMAT_UINT64 (address), (u32) window_size));
			mem_info->mapped_length = 0;
			return_ACPI_STATUS (status);
		}

		/* Save the physical address and mapping size */

		mem_info->mapped_physical_address = address;
		mem_info->mapped_length = window_size;
	}

	/*
	 * Generate a logical pointer corresponding to the address we want to
	 * access
	 */
	logical_addr_ptr = mem_info->mapped_logical_address +
			  ((acpi_integer) address - (acpi_integer) mem_info->mapped_physical_address);

	ACPI_DEBUG_PRINT ((ACPI_DB_INFO,
			"system_memory %d (%d width) Address=%8.8X%8.8X\n", function, bit_width,
			ACPI_FORMAT_UINT64 (address)));

   /*
	* Perform the memory read or write
	*
	* Note: For machines that do not support non-aligned transfers, the target
	* address was checked for alignment above.  We do not attempt to break the
	* transfer up into smaller (byte-size) chunks because the AML specifically
	* asked for a transfer width that the hardware may require.
	*/
	switch (function) {
	case ACPI_READ:

		*value = 0;
		switch (bit_width) {
		case 8:
			*value = (acpi_integer) *((u8 *) logical_addr_ptr);
			break;

		case 16:
			*value = (acpi_integer) *((u16 *) logical_addr_ptr);
			break;

		case 32:
			*value = (acpi_integer) *((u32 *) logical_addr_ptr);
			break;

#if ACPI_MACHINE_WIDTH != 16
		case 64:
			*value = (acpi_integer) *((u64 *) logical_addr_ptr);
			break;
#endif
		default:
			/* bit_width was already validated */
			break;
		}
		break;

	case ACPI_WRITE:

		switch (bit_width) {
		case 8:
			*(u8 *) logical_addr_ptr = (u8) *value;
			break;

		case 16:
			*(u16 *) logical_addr_ptr = (u16) *value;
			break;

		case 32:
			*(u32 *) logical_addr_ptr = (u32) *value;
			break;

#if ACPI_MACHINE_WIDTH != 16
		case 64:
			*(u64 *) logical_addr_ptr = (u64) *value;
			break;
#endif

		default:
			/* bit_width was already validated */
			break;
		}
		break;

	default:
		status = AE_BAD_PARAMETER;
		break;
	}

	return_ACPI_STATUS (status);
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_system_io_space_handler
 *
 * PARAMETERS:  Function            - Read or Write operation
 *              Address             - Where in the space to read or write
 *              bit_width           - Field width in bits (8, 16, or 32)
 *              Value               - Pointer to in or out value