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1// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.02/******************************************************************************3 *4 * Module Name: exoparg1 - AML execution - opcodes with 1 argument5 *6 * Copyright (C) 2000 - 2023, Intel Corp.7 *8 *****************************************************************************/9 10#include <acpi/acpi.h>11#include "accommon.h"12#include "acparser.h"13#include "acdispat.h"14#include "acinterp.h"15#include "amlcode.h"16#include "acnamesp.h"17 18#define _COMPONENT          ACPI_EXECUTER19ACPI_MODULE_NAME("exoparg1")20 21/*!22 * Naming convention for AML interpreter execution routines.23 *24 * The routines that begin execution of AML opcodes are named with a common25 * convention based upon the number of arguments, the number of target operands,26 * and whether or not a value is returned:27 *28 *      AcpiExOpcode_xA_yT_zR29 *30 * Where:31 *32 * xA - ARGUMENTS:    The number of arguments (input operands) that are33 *                    required for this opcode type (0 through 6 args).34 * yT - TARGETS:      The number of targets (output operands) that are required35 *                    for this opcode type (0, 1, or 2 targets).36 * zR - RETURN VALUE: Indicates whether this opcode type returns a value37 *                    as the function return (0 or 1).38 *39 * The AcpiExOpcode* functions are called via the Dispatcher component with40 * fully resolved operands.41!*/42/*******************************************************************************43 *44 * FUNCTION:    acpi_ex_opcode_0A_0T_1R45 *46 * PARAMETERS:  walk_state          - Current state (contains AML opcode)47 *48 * RETURN:      Status49 *50 * DESCRIPTION: Execute operator with no operands, one return value51 *52 ******************************************************************************/53acpi_status acpi_ex_opcode_0A_0T_1R(struct acpi_walk_state *walk_state)54{55	acpi_status status = AE_OK;56	union acpi_operand_object *return_desc = NULL;57 58	ACPI_FUNCTION_TRACE_STR(ex_opcode_0A_0T_1R,59				acpi_ps_get_opcode_name(walk_state->opcode));60 61	/* Examine the AML opcode */62 63	switch (walk_state->opcode) {64	case AML_TIMER_OP:	/*  Timer () */65 66		/* Create a return object of type Integer */67 68		return_desc =69		    acpi_ut_create_integer_object(acpi_os_get_timer());70		if (!return_desc) {71			status = AE_NO_MEMORY;72			goto cleanup;73		}74		break;75 76	default:		/*  Unknown opcode  */77 78		ACPI_ERROR((AE_INFO, "Unknown AML opcode 0x%X",79			    walk_state->opcode));80		status = AE_AML_BAD_OPCODE;81		break;82	}83 84cleanup:85 86	/* Delete return object on error */87 88	if ((ACPI_FAILURE(status)) || walk_state->result_obj) {89		acpi_ut_remove_reference(return_desc);90		walk_state->result_obj = NULL;91	} else {92		/* Save the return value */93 94		walk_state->result_obj = return_desc;95	}96 97	return_ACPI_STATUS(status);98}99 100/*******************************************************************************101 *102 * FUNCTION:    acpi_ex_opcode_1A_0T_0R103 *104 * PARAMETERS:  walk_state          - Current state (contains AML opcode)105 *106 * RETURN:      Status107 *108 * DESCRIPTION: Execute Type 1 monadic operator with numeric operand on109 *              object stack110 *111 ******************************************************************************/112 113acpi_status acpi_ex_opcode_1A_0T_0R(struct acpi_walk_state *walk_state)114{115	union acpi_operand_object **operand = &walk_state->operands[0];116	acpi_status status = AE_OK;117 118	ACPI_FUNCTION_TRACE_STR(ex_opcode_1A_0T_0R,119				acpi_ps_get_opcode_name(walk_state->opcode));120 121	/* Examine the AML opcode */122 123	switch (walk_state->opcode) {124	case AML_RELEASE_OP:	/*  Release (mutex_object) */125 126		status = acpi_ex_release_mutex(operand[0], walk_state);127		break;128 129	case AML_RESET_OP:	/*  Reset (event_object) */130 131		status = acpi_ex_system_reset_event(operand[0]);132		break;133 134	case AML_SIGNAL_OP:	/*  Signal (event_object) */135 136		status = acpi_ex_system_signal_event(operand[0]);137		break;138 139	case AML_SLEEP_OP:	/*  Sleep (msec_time) */140 141		status = acpi_ex_system_do_sleep(operand[0]->integer.value);142		break;143 144	case AML_STALL_OP:	/*  Stall (usec_time) */145 146		status =147		    acpi_ex_system_do_stall((u32) operand[0]->integer.value);148		break;149 150	case AML_UNLOAD_OP:	/*  Unload (Handle) */151 152		status = acpi_ex_unload_table(operand[0]);153		break;154 155	default:		/*  Unknown opcode  */156 157		ACPI_ERROR((AE_INFO, "Unknown AML opcode 0x%X",158			    walk_state->opcode));159		status = AE_AML_BAD_OPCODE;160		break;161	}162 163	return_ACPI_STATUS(status);164}165 166#ifdef _OBSOLETE_CODE		/* Was originally used for Load() operator */167/*******************************************************************************168 *169 * FUNCTION:    acpi_ex_opcode_1A_1T_0R170 *171 * PARAMETERS:  walk_state          - Current state (contains AML opcode)172 *173 * RETURN:      Status174 *175 * DESCRIPTION: Execute opcode with one argument, one target, and no176 *              return value.177 *178 ******************************************************************************/179 180acpi_status acpi_ex_opcode_1A_1T_0R(struct acpi_walk_state *walk_state)181{182	acpi_status status = AE_OK;183	union acpi_operand_object **operand = &walk_state->operands[0];184 185	ACPI_FUNCTION_TRACE_STR(ex_opcode_1A_1T_0R,186				acpi_ps_get_opcode_name(walk_state->opcode));187 188	/* Examine the AML opcode */189 190	switch (walk_state->opcode) {191#ifdef _OBSOLETE_CODE192	case AML_LOAD_OP:193 194		status = acpi_ex_load_op(operand[0], operand[1], walk_state);195		break;196#endif197 198	default:		/* Unknown opcode */199 200		ACPI_ERROR((AE_INFO, "Unknown AML opcode 0x%X",201			    walk_state->opcode));202		status = AE_AML_BAD_OPCODE;203		goto cleanup;204	}205 206cleanup:207 208	return_ACPI_STATUS(status);209}210#endif211 212/*******************************************************************************213 *214 * FUNCTION:    acpi_ex_opcode_1A_1T_1R215 *216 * PARAMETERS:  walk_state          - Current state (contains AML opcode)217 *218 * RETURN:      Status219 *220 * DESCRIPTION: Execute opcode with one argument, one target, and a221 *              return value.222 *              January 2022: Added Load operator, with new ACPI 6.4223 *              semantics.224 *225 ******************************************************************************/226 227acpi_status acpi_ex_opcode_1A_1T_1R(struct acpi_walk_state *walk_state)228{229	acpi_status status = AE_OK;230	union acpi_operand_object **operand = &walk_state->operands[0];231	union acpi_operand_object *return_desc = NULL;232	union acpi_operand_object *return_desc2 = NULL;233	u32 temp32;234	u32 i;235	u64 power_of_ten;236	u64 digit;237 238	ACPI_FUNCTION_TRACE_STR(ex_opcode_1A_1T_1R,239				acpi_ps_get_opcode_name(walk_state->opcode));240 241	/* Examine the AML opcode */242 243	switch (walk_state->opcode) {244	case AML_BIT_NOT_OP:245	case AML_FIND_SET_LEFT_BIT_OP:246	case AML_FIND_SET_RIGHT_BIT_OP:247	case AML_FROM_BCD_OP:248	case AML_LOAD_OP:249	case AML_TO_BCD_OP:250	case AML_CONDITIONAL_REF_OF_OP:251 252		/* Create a return object of type Integer for these opcodes */253 254		return_desc = acpi_ut_create_internal_object(ACPI_TYPE_INTEGER);255		if (!return_desc) {256			status = AE_NO_MEMORY;257			goto cleanup;258		}259 260		switch (walk_state->opcode) {261		case AML_BIT_NOT_OP:	/* Not (Operand, Result)  */262 263			return_desc->integer.value = ~operand[0]->integer.value;264			break;265 266		case AML_FIND_SET_LEFT_BIT_OP:	/* find_set_left_bit (Operand, Result) */267 268			return_desc->integer.value = operand[0]->integer.value;269 270			/*271			 * Acpi specification describes Integer type as a little272			 * endian unsigned value, so this boundary condition is valid.273			 */274			for (temp32 = 0; return_desc->integer.value &&275			     temp32 < ACPI_INTEGER_BIT_SIZE; ++temp32) {276				return_desc->integer.value >>= 1;277			}278 279			return_desc->integer.value = temp32;280			break;281 282		case AML_FIND_SET_RIGHT_BIT_OP:	/* find_set_right_bit (Operand, Result) */283 284			return_desc->integer.value = operand[0]->integer.value;285 286			/*287			 * The Acpi specification describes Integer type as a little288			 * endian unsigned value, so this boundary condition is valid.289			 */290			for (temp32 = 0; return_desc->integer.value &&291			     temp32 < ACPI_INTEGER_BIT_SIZE; ++temp32) {292				return_desc->integer.value <<= 1;293			}294 295			/* Since the bit position is one-based, subtract from 33 (65) */296 297			return_desc->integer.value =298			    temp32 ==299			    0 ? 0 : (ACPI_INTEGER_BIT_SIZE + 1) - temp32;300			break;301 302		case AML_FROM_BCD_OP:	/* from_bcd (BCDValue, Result) */303			/*304			 * The 64-bit ACPI integer can hold 16 4-bit BCD characters305			 * (if table is 32-bit, integer can hold 8 BCD characters)306			 * Convert each 4-bit BCD value307			 */308			power_of_ten = 1;309			return_desc->integer.value = 0;310			digit = operand[0]->integer.value;311 312			/* Convert each BCD digit (each is one nybble wide) */313 314			for (i = 0;315			     (i < acpi_gbl_integer_nybble_width) && (digit > 0);316			     i++) {317 318				/* Get the least significant 4-bit BCD digit */319 320				temp32 = ((u32) digit) & 0xF;321 322				/* Check the range of the digit */323 324				if (temp32 > 9) {325					ACPI_ERROR((AE_INFO,326						    "BCD digit too large (not decimal): 0x%X",327						    temp32));328 329					status = AE_AML_NUMERIC_OVERFLOW;330					goto cleanup;331				}332 333				/* Sum the digit into the result with the current power of 10 */334 335				return_desc->integer.value +=336				    (((u64) temp32) * power_of_ten);337 338				/* Shift to next BCD digit */339 340				digit >>= 4;341 342				/* Next power of 10 */343 344				power_of_ten *= 10;345			}346			break;347 348		case AML_LOAD_OP:	/* Result1 = Load (Operand[0], Result1) */349 350			return_desc->integer.value = 0;351			status =352			    acpi_ex_load_op(operand[0], return_desc,353					    walk_state);354			if (ACPI_SUCCESS(status)) {355 356				/* Return -1 (non-zero) indicates success */357 358				return_desc->integer.value = 0xFFFFFFFFFFFFFFFF;359			}360			break;361 362		case AML_TO_BCD_OP:	/* to_bcd (Operand, Result) */363 364			return_desc->integer.value = 0;365			digit = operand[0]->integer.value;366 367			/* Each BCD digit is one nybble wide */368 369			for (i = 0;370			     (i < acpi_gbl_integer_nybble_width) && (digit > 0);371			     i++) {372				(void)acpi_ut_short_divide(digit, 10, &digit,373							   &temp32);374 375				/*376				 * Insert the BCD digit that resides in the377				 * remainder from above378				 */379				return_desc->integer.value |=380				    (((u64) temp32) << ACPI_MUL_4(i));381			}382 383			/* Overflow if there is any data left in Digit */384 385			if (digit > 0) {386				ACPI_ERROR((AE_INFO,387					    "Integer too large to convert to BCD: 0x%8.8X%8.8X",388					    ACPI_FORMAT_UINT64(operand[0]->389							       integer.value)));390				status = AE_AML_NUMERIC_OVERFLOW;391				goto cleanup;392			}393			break;394 395		case AML_CONDITIONAL_REF_OF_OP:	/* cond_ref_of (source_object, Result) */396			/*397			 * This op is a little strange because the internal return value is398			 * different than the return value stored in the result descriptor399			 * (There are really two return values)400			 */401			if ((struct acpi_namespace_node *)operand[0] ==402			    acpi_gbl_root_node) {403				/*404				 * This means that the object does not exist in the namespace,405				 * return FALSE406				 */407				return_desc->integer.value = 0;408				goto cleanup;409			}410 411			/* Get the object reference, store it, and remove our reference */412 413			status = acpi_ex_get_object_reference(operand[0],414							      &return_desc2,415							      walk_state);416			if (ACPI_FAILURE(status)) {417				goto cleanup;418			}419 420			status =421			    acpi_ex_store(return_desc2, operand[1], walk_state);422			acpi_ut_remove_reference(return_desc2);423 424			/* The object exists in the namespace, return TRUE */425 426			return_desc->integer.value = ACPI_UINT64_MAX;427			goto cleanup;428 429		default:430 431			/* No other opcodes get here */432 433			break;434		}435		break;436 437	case AML_STORE_OP:	/* Store (Source, Target) */438		/*439		 * A store operand is typically a number, string, buffer or lvalue440		 * Be careful about deleting the source object,441		 * since the object itself may have been stored.442		 */443		status = acpi_ex_store(operand[0], operand[1], walk_state);444		if (ACPI_FAILURE(status)) {445			return_ACPI_STATUS(status);446		}447 448		/* It is possible that the Store already produced a return object */449 450		if (!walk_state->result_obj) {451			/*452			 * Normally, we would remove a reference on the Operand[0]453			 * parameter; But since it is being used as the internal return454			 * object (meaning we would normally increment it), the two455			 * cancel out, and we simply don't do anything.456			 */457			walk_state->result_obj = operand[0];458			walk_state->operands[0] = NULL;	/* Prevent deletion */459		}460		return_ACPI_STATUS(status);461 462		/*463		 * ACPI 2.0 Opcodes464		 */465	case AML_COPY_OBJECT_OP:	/* copy_object (Source, Target) */466 467		status =468		    acpi_ut_copy_iobject_to_iobject(operand[0], &return_desc,469						    walk_state);470		break;471 472	case AML_TO_DECIMAL_STRING_OP:	/* to_decimal_string (Data, Result) */473 474		status =475		    acpi_ex_convert_to_string(operand[0], &return_desc,476					      ACPI_EXPLICIT_CONVERT_DECIMAL);477		if (return_desc == operand[0]) {478 479			/* No conversion performed, add ref to handle return value */480 481			acpi_ut_add_reference(return_desc);482		}483		break;484 485	case AML_TO_HEX_STRING_OP:	/* to_hex_string (Data, Result) */486 487		status =488		    acpi_ex_convert_to_string(operand[0], &return_desc,489					      ACPI_EXPLICIT_CONVERT_HEX);490		if (return_desc == operand[0]) {491 492			/* No conversion performed, add ref to handle return value */493 494			acpi_ut_add_reference(return_desc);495		}496		break;497 498	case AML_TO_BUFFER_OP:	/* to_buffer (Data, Result) */499 500		status = acpi_ex_convert_to_buffer(operand[0], &return_desc);501		if (return_desc == operand[0]) {502 503			/* No conversion performed, add ref to handle return value */504 505			acpi_ut_add_reference(return_desc);506		}507		break;508 509	case AML_TO_INTEGER_OP:	/* to_integer (Data, Result) */510 511		/* Perform "explicit" conversion */512 513		status =514		    acpi_ex_convert_to_integer(operand[0], &return_desc, 0);515		if (return_desc == operand[0]) {516 517			/* No conversion performed, add ref to handle return value */518 519			acpi_ut_add_reference(return_desc);520		}521		break;522 523	case AML_SHIFT_LEFT_BIT_OP:	/* shift_left_bit (Source, bit_num) */524	case AML_SHIFT_RIGHT_BIT_OP:	/* shift_right_bit (Source, bit_num) */525 526		/* These are two obsolete opcodes */527 528		ACPI_ERROR((AE_INFO,529			    "%s is obsolete and not implemented",530			    acpi_ps_get_opcode_name(walk_state->opcode)));531		status = AE_SUPPORT;532		goto cleanup;533 534	default:		/* Unknown opcode */535 536		ACPI_ERROR((AE_INFO, "Unknown AML opcode 0x%X",537			    walk_state->opcode));538		status = AE_AML_BAD_OPCODE;539		goto cleanup;540	}541 542	if (ACPI_SUCCESS(status)) {543 544		/* Store the return value computed above into the target object */545 546		status = acpi_ex_store(return_desc, operand[1], walk_state);547	}548 549cleanup:550 551	/* Delete return object on error */552 553	if (ACPI_FAILURE(status)) {554		acpi_ut_remove_reference(return_desc);555	}556 557	/* Save return object on success */558 559	else if (!walk_state->result_obj) {560		walk_state->result_obj = return_desc;561	}562 563	return_ACPI_STATUS(status);564}565 566/*******************************************************************************567 *568 * FUNCTION:    acpi_ex_opcode_1A_0T_1R569 *570 * PARAMETERS:  walk_state          - Current state (contains AML opcode)571 *572 * RETURN:      Status573 *574 * DESCRIPTION: Execute opcode with one argument, no target, and a return value575 *576 ******************************************************************************/577 578acpi_status acpi_ex_opcode_1A_0T_1R(struct acpi_walk_state *walk_state)579{580	union acpi_operand_object **operand = &walk_state->operands[0];581	union acpi_operand_object *temp_desc;582	union acpi_operand_object *return_desc = NULL;583	acpi_status status = AE_OK;584	u32 type;585	u64 value;586 587	ACPI_FUNCTION_TRACE_STR(ex_opcode_1A_0T_1R,588				acpi_ps_get_opcode_name(walk_state->opcode));589 590	/* Examine the AML opcode */591 592	switch (walk_state->opcode) {593	case AML_LOGICAL_NOT_OP:	/* LNot (Operand) */594 595		return_desc = acpi_ut_create_integer_object((u64) 0);596		if (!return_desc) {597			status = AE_NO_MEMORY;598			goto cleanup;599		}600 601		/*602		 * Set result to ONES (TRUE) if Value == 0. Note:603		 * return_desc->Integer.Value is initially == 0 (FALSE) from above.604		 */605		if (!operand[0]->integer.value) {606			return_desc->integer.value = ACPI_UINT64_MAX;607		}608		break;609 610	case AML_DECREMENT_OP:	/* Decrement (Operand)  */611	case AML_INCREMENT_OP:	/* Increment (Operand)  */612		/*613		 * Create a new integer. Can't just get the base integer and614		 * increment it because it may be an Arg or Field.615		 */616		return_desc = acpi_ut_create_internal_object(ACPI_TYPE_INTEGER);617		if (!return_desc) {618			status = AE_NO_MEMORY;619			goto cleanup;620		}621 622		/*623		 * Since we are expecting a Reference operand, it can be either a624		 * NS Node or an internal object.625		 */626		temp_desc = operand[0];627		if (ACPI_GET_DESCRIPTOR_TYPE(temp_desc) ==628		    ACPI_DESC_TYPE_OPERAND) {629 630			/* Internal reference object - prevent deletion */631 632			acpi_ut_add_reference(temp_desc);633		}634 635		/*636		 * Convert the Reference operand to an Integer (This removes a637		 * reference on the Operand[0] object)638		 *639		 * NOTE:  We use LNOT_OP here in order to force resolution of the640		 * reference operand to an actual integer.641		 */642		status = acpi_ex_resolve_operands(AML_LOGICAL_NOT_OP,643						  &temp_desc, walk_state);644		if (ACPI_FAILURE(status)) {645			ACPI_EXCEPTION((AE_INFO, status,646					"While resolving operands for [%s]",647					acpi_ps_get_opcode_name(walk_state->648								opcode)));649 650			goto cleanup;651		}652 653		/*654		 * temp_desc is now guaranteed to be an Integer object --655		 * Perform the actual increment or decrement656		 */657		if (walk_state->opcode == AML_INCREMENT_OP) {658			return_desc->integer.value =659			    temp_desc->integer.value + 1;660		} else {661			return_desc->integer.value =662			    temp_desc->integer.value - 1;663		}664 665		/* Finished with this Integer object */666 667		acpi_ut_remove_reference(temp_desc);668 669		/*670		 * Store the result back (indirectly) through the original671		 * Reference object672		 */673		status = acpi_ex_store(return_desc, operand[0], walk_state);674		break;675 676	case AML_OBJECT_TYPE_OP:	/* object_type (source_object) */677		/*678		 * Note: The operand is not resolved at this point because we want to679		 * get the associated object, not its value. For example, we don't680		 * want to resolve a field_unit to its value, we want the actual681		 * field_unit object.682		 */683 684		/* Get the type of the base object */685 686		status =687		    acpi_ex_resolve_multiple(walk_state, operand[0], &type,688					     NULL);689		if (ACPI_FAILURE(status)) {690			goto cleanup;691		}692 693		/* Allocate a descriptor to hold the type. */694 695		return_desc = acpi_ut_create_integer_object((u64) type);696		if (!return_desc) {697			status = AE_NO_MEMORY;698			goto cleanup;699		}700		break;701 702	case AML_SIZE_OF_OP:	/* size_of (source_object) */703		/*704		 * Note: The operand is not resolved at this point because we want to705		 * get the associated object, not its value.706		 */707 708		/* Get the base object */709 710		status =711		    acpi_ex_resolve_multiple(walk_state, operand[0], &type,712					     &temp_desc);713		if (ACPI_FAILURE(status)) {714			goto cleanup;715		}716 717		/*718		 * The type of the base object must be integer, buffer, string, or719		 * package. All others are not supported.720		 *721		 * NOTE: Integer is not specifically supported by the ACPI spec,722		 * but is supported implicitly via implicit operand conversion.723		 * rather than bother with conversion, we just use the byte width724		 * global (4 or 8 bytes).725		 */726		switch (type) {727		case ACPI_TYPE_INTEGER:728 729			value = acpi_gbl_integer_byte_width;730			break;731 732		case ACPI_TYPE_STRING:733 734			value = temp_desc->string.length;735			break;736 737		case ACPI_TYPE_BUFFER:738 739			/* Buffer arguments may not be evaluated at this point */740 741			status = acpi_ds_get_buffer_arguments(temp_desc);742			value = temp_desc->buffer.length;743			break;744 745		case ACPI_TYPE_PACKAGE:746 747			/* Package arguments may not be evaluated at this point */748 749			status = acpi_ds_get_package_arguments(temp_desc);750			value = temp_desc->package.count;751			break;752 753		default:754 755			ACPI_ERROR((AE_INFO,756				    "Operand must be Buffer/Integer/String/Package"757				    " - found type %s",758				    acpi_ut_get_type_name(type)));759 760			status = AE_AML_OPERAND_TYPE;761			goto cleanup;762		}763 764		if (ACPI_FAILURE(status)) {765			goto cleanup;766		}767 768		/*769		 * Now that we have the size of the object, create a result770		 * object to hold the value771		 */772		return_desc = acpi_ut_create_integer_object(value);773		if (!return_desc) {774			status = AE_NO_MEMORY;775			goto cleanup;776		}777		break;778 779	case AML_REF_OF_OP:	/* ref_of (source_object) */780 781		status =782		    acpi_ex_get_object_reference(operand[0], &return_desc,783						 walk_state);784		if (ACPI_FAILURE(status)) {785			goto cleanup;786		}787		break;788 789	case AML_DEREF_OF_OP:	/* deref_of (obj_reference | String) */790 791		/* Check for a method local or argument, or standalone String */792 793		if (ACPI_GET_DESCRIPTOR_TYPE(operand[0]) ==794		    ACPI_DESC_TYPE_NAMED) {795			temp_desc =796			    acpi_ns_get_attached_object((struct797							 acpi_namespace_node *)798							operand[0]);799			if (temp_desc800			    && ((temp_desc->common.type == ACPI_TYPE_STRING)801				|| (temp_desc->common.type ==802				    ACPI_TYPE_LOCAL_REFERENCE))) {803				operand[0] = temp_desc;804				acpi_ut_add_reference(temp_desc);805			} else {806				status = AE_AML_OPERAND_TYPE;807				goto cleanup;808			}809		} else {810			switch ((operand[0])->common.type) {811			case ACPI_TYPE_LOCAL_REFERENCE:812				/*813				 * This is a deref_of (local_x | arg_x)814				 *815				 * Must resolve/dereference the local/arg reference first816				 */817				switch (operand[0]->reference.class) {818				case ACPI_REFCLASS_LOCAL:819				case ACPI_REFCLASS_ARG:820 821					/* Set Operand[0] to the value of the local/arg */822 823					status =824					    acpi_ds_method_data_get_value825					    (operand[0]->reference.class,826					     operand[0]->reference.value,827					     walk_state, &temp_desc);828					if (ACPI_FAILURE(status)) {829						goto cleanup;830					}831 832					/*833					 * Delete our reference to the input object and834					 * point to the object just retrieved835					 */836					acpi_ut_remove_reference(operand[0]);837					operand[0] = temp_desc;838					break;839 840				case ACPI_REFCLASS_REFOF:841 842					/* Get the object to which the reference refers */843 844					temp_desc =845					    operand[0]->reference.object;846					acpi_ut_remove_reference(operand[0]);847					operand[0] = temp_desc;848					break;849 850				default:851 852					/* Must be an Index op - handled below */853					break;854				}855				break;856 857			case ACPI_TYPE_STRING:858 859				break;860 861			default:862 863				status = AE_AML_OPERAND_TYPE;864				goto cleanup;865			}866		}867 868		if (ACPI_GET_DESCRIPTOR_TYPE(operand[0]) !=869		    ACPI_DESC_TYPE_NAMED) {870			if ((operand[0])->common.type == ACPI_TYPE_STRING) {871				/*872				 * This is a deref_of (String). The string is a reference873				 * to a named ACPI object.874				 *875				 * 1) Find the owning Node876				 * 2) Dereference the node to an actual object. Could be a877				 *    Field, so we need to resolve the node to a value.878				 */879				status =880				    acpi_ns_get_node_unlocked(walk_state->881							      scope_info->scope.882							      node,883							      operand[0]->884							      string.pointer,885							      ACPI_NS_SEARCH_PARENT,886							      ACPI_CAST_INDIRECT_PTR887							      (struct888							       acpi_namespace_node,889							       &return_desc));890				if (ACPI_FAILURE(status)) {891					goto cleanup;892				}893 894				status =895				    acpi_ex_resolve_node_to_value896				    (ACPI_CAST_INDIRECT_PTR897				     (struct acpi_namespace_node, &return_desc),898				     walk_state);899				goto cleanup;900			}901		}902 903		/* Operand[0] may have changed from the code above */904 905		if (ACPI_GET_DESCRIPTOR_TYPE(operand[0]) ==906		    ACPI_DESC_TYPE_NAMED) {907			/*908			 * This is a deref_of (object_reference)909			 * Get the actual object from the Node (This is the dereference).910			 * This case may only happen when a local_x or arg_x is911			 * dereferenced above, or for references to device and912			 * thermal objects.913			 */914			switch (((struct acpi_namespace_node *)operand[0])->915				type) {916			case ACPI_TYPE_DEVICE:917			case ACPI_TYPE_THERMAL:918 919				/* These types have no node subobject, return the NS node */920 921				return_desc = operand[0];922				break;923 924			default:925				/* For most types, get the object attached to the node */926 927				return_desc = acpi_ns_get_attached_object((struct acpi_namespace_node *)operand[0]);928				acpi_ut_add_reference(return_desc);929				break;930			}931		} else {932			/*933			 * This must be a reference object produced by either the934			 * Index() or ref_of() operator935			 */936			switch (operand[0]->reference.class) {937			case ACPI_REFCLASS_INDEX:938				/*939				 * The target type for the Index operator must be940				 * either a Buffer or a Package941				 */942				switch (operand[0]->reference.target_type) {943				case ACPI_TYPE_BUFFER_FIELD:944 945					temp_desc =946					    operand[0]->reference.object;947 948					/*949					 * Create a new object that contains one element of the950					 * buffer -- the element pointed to by the index.951					 *952					 * NOTE: index into a buffer is NOT a pointer to a953					 * sub-buffer of the main buffer, it is only a pointer to a954					 * single element (byte) of the buffer!955					 *956					 * Since we are returning the value of the buffer at the957					 * indexed location, we don't need to add an additional958					 * reference to the buffer itself.959					 */960					return_desc =961					    acpi_ut_create_integer_object((u64)962									  temp_desc->buffer.pointer[operand[0]->reference.value]);963					if (!return_desc) {964						status = AE_NO_MEMORY;965						goto cleanup;966					}967					break;968 969				case ACPI_TYPE_PACKAGE:970					/*971					 * Return the referenced element of the package. We must972					 * add another reference to the referenced object, however.973					 */974					return_desc =975					    *(operand[0]->reference.where);976					if (!return_desc) {977						/*978						 * Element is NULL, do not allow the dereference.979						 * This provides compatibility with other ACPI980						 * implementations.981						 */982						return_ACPI_STATUS983						    (AE_AML_UNINITIALIZED_ELEMENT);984					}985 986					acpi_ut_add_reference(return_desc);987					break;988 989				default:990 991					ACPI_ERROR((AE_INFO,992						    "Unknown Index TargetType 0x%X in reference object %p",993						    operand[0]->reference.994						    target_type, operand[0]));995 996					status = AE_AML_OPERAND_TYPE;997					goto cleanup;998				}999				break;1000 1001			case ACPI_REFCLASS_REFOF:1002 1003				return_desc = operand[0]->reference.object;1004 1005				if (ACPI_GET_DESCRIPTOR_TYPE(return_desc) ==1006				    ACPI_DESC_TYPE_NAMED) {1007					return_desc =1008					    acpi_ns_get_attached_object((struct1009									 acpi_namespace_node1010									 *)1011									return_desc);1012					if (!return_desc) {1013						break;1014					}1015 1016					/*1017					 * June 2013:1018					 * buffer_fields/field_units require additional resolution1019					 */1020					switch (return_desc->common.type) {1021					case ACPI_TYPE_BUFFER_FIELD:1022					case ACPI_TYPE_LOCAL_REGION_FIELD:1023					case ACPI_TYPE_LOCAL_BANK_FIELD:1024					case ACPI_TYPE_LOCAL_INDEX_FIELD:1025 1026						status =1027						    acpi_ex_read_data_from_field1028						    (walk_state, return_desc,1029						     &temp_desc);1030						if (ACPI_FAILURE(status)) {1031							return_ACPI_STATUS1032							    (status);1033						}1034 1035						return_desc = temp_desc;1036						break;1037 1038					default:1039 1040						/* Add another reference to the object */1041 1042						acpi_ut_add_reference1043						    (return_desc);1044						break;1045					}1046				}1047				break;1048 1049			default:1050 1051				ACPI_ERROR((AE_INFO,1052					    "Unknown class in reference(%p) - 0x%2.2X",1053					    operand[0],1054					    operand[0]->reference.class));1055 1056				status = AE_TYPE;1057				goto cleanup;1058			}1059		}1060		break;1061 1062	default:1063 1064		ACPI_ERROR((AE_INFO, "Unknown AML opcode 0x%X",1065			    walk_state->opcode));1066 1067		status = AE_AML_BAD_OPCODE;1068		goto cleanup;1069	}1070 1071cleanup:1072 1073	/* Delete return object on error */1074 1075	if (ACPI_FAILURE(status)) {1076		acpi_ut_remove_reference(return_desc);1077	}1078 1079	/* Save return object on success */1080 1081	else {1082		walk_state->result_obj = return_desc;1083	}1084 1085	return_ACPI_STATUS(status);1086}1087