text: 
  /******************************************************************************
   *
   * Module Name: exutils - interpreter/scanner utilities
   *
   *****************************************************************************/
  
  /*
   * Copyright (C) 2000 - 2012, 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.
   */
  
  /*
   * DEFINE_AML_GLOBALS is tested in amlcode.h
   * to determine whether certain global names should be "defined" or only
   * "declared" in the current compilation.  This enhances maintainability
   * by enabling a single header file to embody all knowledge of the names
   * in question.
   *
   * Exactly one module of any executable should #define DEFINE_GLOBALS
   * before #including the header files which use this convention.  The
   * names in question will be defined and initialized in that module,
   * and declared as extern in all other modules which #include those
   * header files.
   */
  
  #define DEFINE_AML_GLOBALS
  
  #include <acpi/acpi.h>
  #include "accommon.h"
  #include "acinterp.h"
  #include "amlcode.h"
  
  #define _COMPONENT          ACPI_EXECUTER
  ACPI_MODULE_NAME("exutils")
  
  /* Local prototypes */
  static u32 acpi_ex_digits_needed(u64 value, u32 base);
  
  #ifndef ACPI_NO_METHOD_EXECUTION
  /*******************************************************************************
   *
   * FUNCTION:    acpi_ex_enter_interpreter
   *
   * PARAMETERS:  None
   *
   * RETURN:      None
   *
   * DESCRIPTION: Enter the interpreter execution region. Failure to enter
   *              the interpreter region is a fatal system error. Used in
   *              conjunction with exit_interpreter.
   *
   ******************************************************************************/
  
  void acpi_ex_enter_interpreter(void)
  {
  	acpi_status status;
  
  	ACPI_FUNCTION_TRACE(ex_enter_interpreter);
  
  	status = acpi_ut_acquire_mutex(ACPI_MTX_INTERPRETER);
  	if (ACPI_FAILURE(status)) {
  		ACPI_ERROR((AE_INFO,
  			    "Could not acquire AML Interpreter mutex"));
  	}
  
  	return_VOID;
  }
  
  /*******************************************************************************
   *
   * FUNCTION:    acpi_ex_reacquire_interpreter
   *
   * PARAMETERS:  None
   *
   * RETURN:      None
   *
   * DESCRIPTION: Reacquire the interpreter execution region from within the
   *              interpreter code. Failure to enter the interpreter region is a
   *              fatal system error. Used in conjunction with
   *              relinquish_interpreter
   *
   ******************************************************************************/
  
  void acpi_ex_reacquire_interpreter(void)
  {
  	ACPI_FUNCTION_TRACE(ex_reacquire_interpreter);
  
  	/*
  	 * If the global serialized flag is set, do not release the interpreter,
  	 * since it was not actually released by acpi_ex_relinquish_interpreter.
  	 * This forces the interpreter to be single threaded.
  	 */
  	if (!acpi_gbl_all_methods_serialized) {
  		acpi_ex_enter_interpreter();
  	}
  
  	return_VOID;
  }
  
  /*******************************************************************************
   *
   * FUNCTION:    acpi_ex_exit_interpreter
   *
   * PARAMETERS:  None
   *
   * RETURN:      None
   *
   * DESCRIPTION: Exit the interpreter execution region. This is the top level
   *              routine used to exit the interpreter when all processing has
   *              been completed.
   *
   ******************************************************************************/
  
  void acpi_ex_exit_interpreter(void)
  {
  	acpi_status status;
  
  	ACPI_FUNCTION_TRACE(ex_exit_interpreter);
  
  	status = acpi_ut_release_mutex(ACPI_MTX_INTERPRETER);
  	if (ACPI_FAILURE(status)) {
  		ACPI_ERROR((AE_INFO,
  			    "Could not release AML Interpreter mutex"));
  	}
  
  	return_VOID;
  }
  
  /*******************************************************************************
   *
   * FUNCTION:    acpi_ex_relinquish_interpreter
   *
   * PARAMETERS:  None
   *
   * RETURN:      None
   *
   * DESCRIPTION: Exit the interpreter execution region, from within the
   *              interpreter - before attempting an operation that will possibly
   *              block the running thread.
   *
   * Cases where the interpreter is unlocked internally
   *      1) Method to be blocked on a Sleep() AML opcode
   *      2) Method to be blocked on an Acquire() AML opcode
   *      3) Method to be blocked on a Wait() AML opcode
   *      4) Method to be blocked to acquire the global lock
   *      5) Method to be blocked waiting to execute a serialized control method
   *          that is currently executing
   *      6) About to invoke a user-installed opregion handler
   *
   ******************************************************************************/
  
  void acpi_ex_relinquish_interpreter(void)
  {
  	ACPI_FUNCTION_TRACE(ex_relinquish_interpreter);
  
  	/*
  	 * If the global serialized flag is set, do not release the interpreter.
  	 * This forces the interpreter to be single threaded.
  	 */
  	if (!acpi_gbl_all_methods_serialized) {
  		acpi_ex_exit_interpreter();
  	}
  
  	return_VOID;
  }
  
  /*******************************************************************************
   *
   * FUNCTION:    acpi_ex_truncate_for32bit_table
   *
   * PARAMETERS:  obj_desc        - Object to be truncated
   *
   * RETURN:      none
   *
   * DESCRIPTION: Truncate an ACPI Integer to 32 bits if the execution mode is
   *              32-bit, as determined by the revision of the DSDT.
   *
   ******************************************************************************/
  
  void acpi_ex_truncate_for32bit_table(union acpi_operand_object *obj_desc)
  {
  
  	ACPI_FUNCTION_ENTRY();
  
  	/*
  	 * Object must be a valid number and we must be executing
  	 * a control method. NS node could be there for AML_INT_NAMEPATH_OP.
  	 */
  	if ((!obj_desc) ||
  	    (ACPI_GET_DESCRIPTOR_TYPE(obj_desc) != ACPI_DESC_TYPE_OPERAND) ||
  	    (obj_desc->common.type != ACPI_TYPE_INTEGER)) {
  		return;
  	}
  
  	if (acpi_gbl_integer_byte_width == 4) {
  		/*
  		 * We are running a method that exists in a 32-bit ACPI table.
  		 * Truncate the value to 32 bits by zeroing out the upper 32-bit field
  		 */
  		obj_desc->integer.value &= (u64) ACPI_UINT32_MAX;
  	}
  }
  
  /*******************************************************************************
   *
   * FUNCTION:    acpi_ex_acquire_global_lock
   *
   * PARAMETERS:  field_flags           - Flags with Lock rule:
   *                                      always_lock or never_lock
   *
   * RETURN:      None
   *
   * DESCRIPTION: Obtain the ACPI hardware Global Lock, only if the field
   *              flags specifiy that it is to be obtained before field access.
   *
   ******************************************************************************/
  
  void acpi_ex_acquire_global_lock(u32 field_flags)
  {
  	acpi_status status;
  
  	ACPI_FUNCTION_TRACE(ex_acquire_global_lock);
  
  	/* Only use the lock if the always_lock bit is set */
  
  	if (!(field_flags & AML_FIELD_LOCK_RULE_MASK)) {
  		return_VOID;
  	}
  
  	/* Attempt to get the global lock, wait forever */
  
  	status = acpi_ex_acquire_mutex_object(ACPI_WAIT_FOREVER,
  					      acpi_gbl_global_lock_mutex,
  					      acpi_os_get_thread_id());
  
  	if (ACPI_FAILURE(status)) {
  		ACPI_EXCEPTION((AE_INFO, status,
  				"Could not acquire Global Lock"));
  	}
  
  	return_VOID;
  }
  
  /*******************************************************************************
   *
   * FUNCTION:    acpi_ex_release_global_lock
   *
   * PARAMETERS:  field_flags           - Flags with Lock rule:
   *                                      always_lock or never_lock
   *
   * RETURN:      None
   *
   * DESCRIPTION: Release the ACPI hardware Global Lock
   *
   ******************************************************************************/
  
  void acpi_ex_release_global_lock(u32 field_flags)
  {
  	acpi_status status;
  
  	ACPI_FUNCTION_TRACE(ex_release_global_lock);
  
  	/* Only use the lock if the always_lock bit is set */
  
  	if (!(field_flags & AML_FIELD_LOCK_RULE_MASK)) {
  		return_VOID;
  	}
  
  	/* Release the global lock */
  
  	status = acpi_ex_release_mutex_object(acpi_gbl_global_lock_mutex);
  	if (ACPI_FAILURE(status)) {
  
  		/* Report the error, but there isn't much else we can do */
  
  		ACPI_EXCEPTION((AE_INFO, status,
  				"Could not release Global Lock"));
  	}
  
  	return_VOID;
  }
  
  /*******************************************************************************
   *
   * FUNCTION:    acpi_ex_digits_needed
   *
   * PARAMETERS:  value           - Value to be represented
   *              base            - Base of representation
   *
   * RETURN:      The number of digits.
   *
   * DESCRIPTION: Calculate the number of digits needed to represent the Value
   *              in the given Base (Radix)
   *
   ******************************************************************************/
  
  static u32 acpi_ex_digits_needed(u64 value, u32 base)
  {
  	u32 num_digits;
  	u64 current_value;
  
  	ACPI_FUNCTION_TRACE(ex_digits_needed);
  
  	/* u64 is unsigned, so we don't worry about a '-' prefix */
  
  	if (value == 0) {
  		return_UINT32(1);
  	}
  
  	current_value = value;
  	num_digits = 0;
  
  	/* Count the digits in the requested base */
  
  	while (current_value) {
  		(void)acpi_ut_short_divide(current_value, base, &current_value,
  					   NULL);
  		num_digits++;
  	}
  
  	return_UINT32(num_digits);
  }
  
  /*******************************************************************************
   *
   * FUNCTION:    acpi_ex_eisa_id_to_string
   *
   * PARAMETERS:  compressed_id   - EISAID to be converted
   *              out_string      - Where to put the converted string (8 bytes)
   *
   * RETURN:      None
   *
   * DESCRIPTION: Convert a numeric EISAID to string representation. Return
   *              buffer must be large enough to hold the string. The string
   *              returned is always exactly of length ACPI_EISAID_STRING_SIZE
   *              (includes null terminator). The EISAID is always 32 bits.
   *
   ******************************************************************************/
  
  void acpi_ex_eisa_id_to_string(char *out_string, u64 compressed_id)
  {
  	u32 swapped_id;
  
  	ACPI_FUNCTION_ENTRY();
  
  	/* The EISAID should be a 32-bit integer */
  
  	if (compressed_id > ACPI_UINT32_MAX) {
  		ACPI_WARNING((AE_INFO,
  			      "Expected EISAID is larger than 32 bits: 0x%8.8X%8.8X, truncating",
  			      ACPI_FORMAT_UINT64(compressed_id)));
  	}
  
  	/* Swap ID to big-endian to get contiguous bits */
  
  	swapped_id = acpi_ut_dword_byte_swap((u32)compressed_id);
  
  	/* First 3 bytes are uppercase letters. Next 4 bytes are hexadecimal */
  
  	out_string[0] =
  	    (char)(0x40 + (((unsigned long)swapped_id >> 26) & 0x1F));
  	out_string[1] = (char)(0x40 + ((swapped_id >> 21) & 0x1F));
  	out_string[2] = (char)(0x40 + ((swapped_id >> 16) & 0x1F));
  	out_string[3] = acpi_ut_hex_to_ascii_char((u64) swapped_id, 12);
  	out_string[4] = acpi_ut_hex_to_ascii_char((u64) swapped_id, 8);
  	out_string[5] = acpi_ut_hex_to_ascii_char((u64) swapped_id, 4);
  	out_string[6] = acpi_ut_hex_to_ascii_char((u64) swapped_id, 0);
  	out_string[7] = 0;
  }
  
  /*******************************************************************************
   *
   * FUNCTION:    acpi_ex_integer_to_string
   *
   * PARAMETERS:  out_string      - Where to put the converted string. At least
   *                                21 bytes are needed to hold the largest
   *                                possible 64-bit integer.
   *              value           - Value to be converted
   *
   * RETURN:      None, string
   *
   * DESCRIPTION: Convert a 64-bit integer to decimal string representation.
   *              Assumes string buffer is large enough to hold the string. The
   *              largest string is (ACPI_MAX64_DECIMAL_DIGITS + 1).
   *
   ******************************************************************************/
  
  void acpi_ex_integer_to_string(char *out_string, u64 value)
  {
  	u32 count;
  	u32 digits_needed;
  	u32 remainder;
  
  	ACPI_FUNCTION_ENTRY();
  
  	digits_needed = acpi_ex_digits_needed(value, 10);
  	out_string[digits_needed] = 0;
  
  	for (count = digits_needed; count > 0; count--) {
  		(void)acpi_ut_short_divide(value, 10, &value, &remainder);
  		out_string[count - 1] = (char)('0' + remainder);
  	}
  }
  
  /*******************************************************************************
   *
   * FUNCTION:    acpi_is_valid_space_id
   *
   * PARAMETERS:  space_id            - ID to be validated
   *
   * RETURN:      TRUE if valid/supported ID.
   *
   * DESCRIPTION: Validate an operation region space_ID.
   *
   ******************************************************************************/
  
  u8 acpi_is_valid_space_id(u8 space_id)
  {
  
  	if ((space_id >= ACPI_NUM_PREDEFINED_REGIONS) &&
  	    (space_id < ACPI_USER_REGION_BEGIN) &&
  	    (space_id != ACPI_ADR_SPACE_DATA_TABLE) &&
  	    (space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)) {
  		return (FALSE);
  	}
  
  	return (TRUE);
  }
  
  #endif
  