1/****************************************************************************** 2 * 3 * Module Name: dscontrol - Support for execution control opcodes - 4 * if/else/while/return 5 * 6 *****************************************************************************/ 7 8/****************************************************************************** 9 * 10 * 1. Copyright Notice 11 * 12 * Some or all of this work - Copyright (c) 1999 - 2023, Intel Corp. 13 * All rights reserved. 14 * 15 * 2. License 16 * 17 * 2.1. This is your license from Intel Corp. under its intellectual property 18 * rights. You may have additional license terms from the party that provided 19 * you this software, covering your right to use that party's intellectual 20 * property rights. 21 * 22 * 2.2. Intel grants, free of charge, to any person ("Licensee") obtaining a 23 * copy of the source code appearing in this file ("Covered Code") an 24 * irrevocable, perpetual, worldwide license under Intel's copyrights in the 25 * base code distributed originally by Intel ("Original Intel Code") to copy, 26 * make derivatives, distribute, use and display any portion of the Covered 27 * Code in any form, with the right to sublicense such rights; and 28 * 29 * 2.3. Intel grants Licensee a non-exclusive and non-transferable patent 30 * license (with the right to sublicense), under only those claims of Intel 31 * patents that are infringed by the Original Intel Code, to make, use, sell, 32 * offer to sell, and import the Covered Code and derivative works thereof 33 * solely to the minimum extent necessary to exercise the above copyright 34 * license, and in no event shall the patent license extend to any additions 35 * to or modifications of the Original Intel Code. No other license or right 36 * is granted directly or by implication, estoppel or otherwise; 37 * 38 * The above copyright and patent license is granted only if the following 39 * conditions are met: 40 * 41 * 3. Conditions 42 * 43 * 3.1. Redistribution of Source with Rights to Further Distribute Source. 44 * Redistribution of source code of any substantial portion of the Covered 45 * Code or modification with rights to further distribute source must include 46 * the above Copyright Notice, the above License, this list of Conditions, 47 * and the following Disclaimer and Export Compliance provision. In addition, 48 * Licensee must cause all Covered Code to which Licensee contributes to 49 * contain a file documenting the changes Licensee made to create that Covered 50 * Code and the date of any change. Licensee must include in that file the 51 * documentation of any changes made by any predecessor Licensee. Licensee 52 * must include a prominent statement that the modification is derived, 53 * directly or indirectly, from Original Intel Code. 54 * 55 * 3.2. Redistribution of Source with no Rights to Further Distribute Source. 56 * Redistribution of source code of any substantial portion of the Covered 57 * Code or modification without rights to further distribute source must 58 * include the following Disclaimer and Export Compliance provision in the 59 * documentation and/or other materials provided with distribution. In 60 * addition, Licensee may not authorize further sublicense of source of any 61 * portion of the Covered Code, and must include terms to the effect that the 62 * license from Licensee to its licensee is limited to the intellectual 63 * property embodied in the software Licensee provides to its licensee, and 64 * not to intellectual property embodied in modifications its licensee may 65 * make. 66 * 67 * 3.3. Redistribution of Executable. Redistribution in executable form of any 68 * substantial portion of the Covered Code or modification must reproduce the 69 * above Copyright Notice, and the following Disclaimer and Export Compliance 70 * provision in the documentation and/or other materials provided with the 71 * distribution. 72 * 73 * 3.4. Intel retains all right, title, and interest in and to the Original 74 * Intel Code. 75 * 76 * 3.5. Neither the name Intel nor any other trademark owned or controlled by 77 * Intel shall be used in advertising or otherwise to promote the sale, use or 78 * other dealings in products derived from or relating to the Covered Code 79 * without prior written authorization from Intel. 80 * 81 * 4. Disclaimer and Export Compliance 82 * 83 * 4.1. INTEL MAKES NO WARRANTY OF ANY KIND REGARDING ANY SOFTWARE PROVIDED 84 * HERE. ANY SOFTWARE ORIGINATING FROM INTEL OR DERIVED FROM INTEL SOFTWARE 85 * IS PROVIDED "AS IS," AND INTEL WILL NOT PROVIDE ANY SUPPORT, ASSISTANCE, 86 * INSTALLATION, TRAINING OR OTHER SERVICES. INTEL WILL NOT PROVIDE ANY 87 * UPDATES, ENHANCEMENTS OR EXTENSIONS. INTEL SPECIFICALLY DISCLAIMS ANY 88 * IMPLIED WARRANTIES OF MERCHANTABILITY, NONINFRINGEMENT AND FITNESS FOR A 89 * PARTICULAR PURPOSE. 90 * 91 * 4.2. IN NO EVENT SHALL INTEL HAVE ANY LIABILITY TO LICENSEE, ITS LICENSEES 92 * OR ANY OTHER THIRD PARTY, FOR ANY LOST PROFITS, LOST DATA, LOSS OF USE OR 93 * COSTS OF PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, OR FOR ANY INDIRECT, 94 * SPECIAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS AGREEMENT, UNDER ANY 95 * CAUSE OF ACTION OR THEORY OF LIABILITY, AND IRRESPECTIVE OF WHETHER INTEL 96 * HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES. THESE LIMITATIONS 97 * SHALL APPLY NOTWITHSTANDING THE FAILURE OF THE ESSENTIAL PURPOSE OF ANY 98 * LIMITED REMEDY. 99 * 100 * 4.3. Licensee shall not export, either directly or indirectly, any of this 101 * software or system incorporating such software without first obtaining any 102 * required license or other approval from the U. S. Department of Commerce or 103 * any other agency or department of the United States Government. In the 104 * event Licensee exports any such software from the United States or 105 * re-exports any such software from a foreign destination, Licensee shall 106 * ensure that the distribution and export/re-export of the software is in 107 * compliance with all laws, regulations, orders, or other restrictions of the 108 * U.S. Export Administration Regulations. Licensee agrees that neither it nor 109 * any of its subsidiaries will export/re-export any technical data, process, 110 * software, or service, directly or indirectly, to any country for which the 111 * United States government or any agency thereof requires an export license, 112 * other governmental approval, or letter of assurance, without first obtaining 113 * such license, approval or letter. 114 * 115 ***************************************************************************** 116 * 117 * Alternatively, you may choose to be licensed under the terms of the 118 * following license: 119 * 120 * Redistribution and use in source and binary forms, with or without 121 * modification, are permitted provided that the following conditions 122 * are met: 123 * 1. Redistributions of source code must retain the above copyright 124 * notice, this list of conditions, and the following disclaimer, 125 * without modification. 126 * 2. Redistributions in binary form must reproduce at minimum a disclaimer 127 * substantially similar to the "NO WARRANTY" disclaimer below 128 * ("Disclaimer") and any redistribution must be conditioned upon 129 * including a substantially similar Disclaimer requirement for further 130 * binary redistribution. 131 * 3. Neither the names of the above-listed copyright holders nor the names 132 * of any contributors may be used to endorse or promote products derived 133 * from this software without specific prior written permission. 134 * 135 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 136 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 137 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 138 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 139 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 140 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 141 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 142 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 143 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 144 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 145 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 146 * 147 * Alternatively, you may choose to be licensed under the terms of the 148 * GNU General Public License ("GPL") version 2 as published by the Free 149 * Software Foundation. 150 * 151 *****************************************************************************/ 152 153#include "acpi.h" 154#include "accommon.h" 155#include "amlcode.h" 156#include "acdispat.h" 157#include "acinterp.h" 158#include "acdebug.h" 159 160#define _COMPONENT ACPI_DISPATCHER 161 ACPI_MODULE_NAME ("dscontrol") 162 163 164/******************************************************************************* 165 * 166 * FUNCTION: AcpiDsExecBeginControlOp 167 * 168 * PARAMETERS: WalkList - The list that owns the walk stack 169 * Op - The control Op 170 * 171 * RETURN: Status 172 * 173 * DESCRIPTION: Handles all control ops encountered during control method 174 * execution. 175 * 176 ******************************************************************************/ 177 178ACPI_STATUS 179AcpiDsExecBeginControlOp ( 180 ACPI_WALK_STATE *WalkState, 181 ACPI_PARSE_OBJECT *Op) 182{ 183 ACPI_STATUS Status = AE_OK; 184 ACPI_GENERIC_STATE *ControlState; 185 186 187 ACPI_FUNCTION_NAME (DsExecBeginControlOp); 188 189 190 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "Op=%p Opcode=%2.2X State=%p\n", 191 Op, Op->Common.AmlOpcode, WalkState)); 192 193 switch (Op->Common.AmlOpcode) 194 { 195 case AML_WHILE_OP: 196 /* 197 * If this is an additional iteration of a while loop, continue. 198 * There is no need to allocate a new control state. 199 */ 200 if (WalkState->ControlState) 201 { 202 if (WalkState->ControlState->Control.AmlPredicateStart == 203 (WalkState->ParserState.Aml - 1)) 204 { 205 /* Reset the state to start-of-loop */ 206 207 WalkState->ControlState->Common.State = 208 ACPI_CONTROL_CONDITIONAL_EXECUTING; 209 break; 210 } 211 } 212 213 ACPI_FALLTHROUGH; 214 215 case AML_IF_OP: 216 /* 217 * IF/WHILE: Create a new control state to manage these 218 * constructs. We need to manage these as a stack, in order 219 * to handle nesting. 220 */ 221 ControlState = AcpiUtCreateControlState (); 222 if (!ControlState) 223 { 224 Status = AE_NO_MEMORY; 225 break; 226 } 227 /* 228 * Save a pointer to the predicate for multiple executions 229 * of a loop 230 */ 231 ControlState->Control.AmlPredicateStart = 232 WalkState->ParserState.Aml - 1; 233 ControlState->Control.PackageEnd = 234 WalkState->ParserState.PkgEnd; 235 ControlState->Control.Opcode = 236 Op->Common.AmlOpcode; 237 ControlState->Control.LoopTimeout = AcpiOsGetTimer () + 238 ((UINT64) AcpiGbl_MaxLoopIterations * ACPI_100NSEC_PER_SEC); 239 240 /* Push the control state on this walk's control stack */ 241 242 AcpiUtPushGenericState (&WalkState->ControlState, ControlState); 243 break; 244 245 case AML_ELSE_OP: 246 247 /* Predicate is in the state object */ 248 /* If predicate is true, the IF was executed, ignore ELSE part */ 249 250 if (WalkState->LastPredicate) 251 { 252 Status = AE_CTRL_TRUE; 253 } 254 255 break; 256 257 case AML_RETURN_OP: 258 259 break; 260 261 default: 262 263 break; 264 } 265 266 return (Status); 267} 268 269 270/******************************************************************************* 271 * 272 * FUNCTION: AcpiDsExecEndControlOp 273 * 274 * PARAMETERS: WalkList - The list that owns the walk stack 275 * Op - The control Op 276 * 277 * RETURN: Status 278 * 279 * DESCRIPTION: Handles all control ops encountered during control method 280 * execution. 281 * 282 ******************************************************************************/ 283 284ACPI_STATUS 285AcpiDsExecEndControlOp ( 286 ACPI_WALK_STATE *WalkState, 287 ACPI_PARSE_OBJECT *Op) 288{ 289 ACPI_STATUS Status = AE_OK; 290 ACPI_GENERIC_STATE *ControlState; 291 292 293 ACPI_FUNCTION_NAME (DsExecEndControlOp); 294 295 296 switch (Op->Common.AmlOpcode) 297 { 298 case AML_IF_OP: 299 300 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "[IF_OP] Op=%p\n", Op)); 301 302 /* 303 * Save the result of the predicate in case there is an 304 * ELSE to come 305 */ 306 WalkState->LastPredicate = 307 (BOOLEAN) WalkState->ControlState->Common.Value; 308 309 /* 310 * Pop the control state that was created at the start 311 * of the IF and free it 312 */ 313 ControlState = AcpiUtPopGenericState (&WalkState->ControlState); 314 AcpiUtDeleteGenericState (ControlState); 315 break; 316 317 case AML_ELSE_OP: 318 319 break; 320 321 case AML_WHILE_OP: 322 323 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "[WHILE_OP] Op=%p\n", Op)); 324 325 ControlState = WalkState->ControlState; 326 if (ControlState->Common.Value) 327 { 328 /* Predicate was true, the body of the loop was just executed */ 329 330 /* 331 * This infinite loop detection mechanism allows the interpreter 332 * to escape possibly infinite loops. This can occur in poorly 333 * written AML when the hardware does not respond within a while 334 * loop and the loop does not implement a timeout. 335 */ 336 if (ACPI_TIME_AFTER (AcpiOsGetTimer (), 337 ControlState->Control.LoopTimeout)) 338 { 339 Status = AE_AML_LOOP_TIMEOUT; 340 break; 341 } 342 343 /* 344 * Go back and evaluate the predicate and maybe execute the loop 345 * another time 346 */ 347 Status = AE_CTRL_PENDING; 348 WalkState->AmlLastWhile = 349 ControlState->Control.AmlPredicateStart; 350 break; 351 } 352 353 /* Predicate was false, terminate this while loop */ 354 355 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, 356 "[WHILE_OP] termination! Op=%p\n",Op)); 357 358 /* Pop this control state and free it */ 359 360 ControlState = AcpiUtPopGenericState (&WalkState->ControlState); 361 AcpiUtDeleteGenericState (ControlState); 362 break; 363 364 case AML_RETURN_OP: 365 366 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, 367 "[RETURN_OP] Op=%p Arg=%p\n",Op, Op->Common.Value.Arg)); 368 369 /* 370 * One optional operand -- the return value 371 * It can be either an immediate operand or a result that 372 * has been bubbled up the tree 373 */ 374 if (Op->Common.Value.Arg) 375 { 376 /* Since we have a real Return(), delete any implicit return */ 377 378 AcpiDsClearImplicitReturn (WalkState); 379 380 /* Return statement has an immediate operand */ 381 382 Status = AcpiDsCreateOperands (WalkState, Op->Common.Value.Arg); 383 if (ACPI_FAILURE (Status)) 384 { 385 return (Status); 386 } 387 388 /* 389 * If value being returned is a Reference (such as 390 * an arg or local), resolve it now because it may 391 * cease to exist at the end of the method. 392 */ 393 Status = AcpiExResolveToValue ( 394 &WalkState->Operands [0], WalkState); 395 if (ACPI_FAILURE (Status)) 396 { 397 return (Status); 398 } 399 400 /* 401 * Get the return value and save as the last result 402 * value. This is the only place where WalkState->ReturnDesc 403 * is set to anything other than zero! 404 */ 405 WalkState->ReturnDesc = WalkState->Operands[0]; 406 } 407 else if (WalkState->ResultCount) 408 { 409 /* Since we have a real Return(), delete any implicit return */ 410 411 AcpiDsClearImplicitReturn (WalkState); 412 413 /* 414 * The return value has come from a previous calculation. 415 * 416 * If value being returned is a Reference (such as 417 * an arg or local), resolve it now because it may 418 * cease to exist at the end of the method. 419 * 420 * Allow references created by the Index operator to return 421 * unchanged. 422 */ 423 if ((ACPI_GET_DESCRIPTOR_TYPE (WalkState->Results->Results.ObjDesc[0]) == 424 ACPI_DESC_TYPE_OPERAND) && 425 ((WalkState->Results->Results.ObjDesc [0])->Common.Type == 426 ACPI_TYPE_LOCAL_REFERENCE) && 427 ((WalkState->Results->Results.ObjDesc [0])->Reference.Class != 428 ACPI_REFCLASS_INDEX)) 429 { 430 Status = AcpiExResolveToValue ( 431 &WalkState->Results->Results.ObjDesc [0], WalkState); 432 if (ACPI_FAILURE (Status)) 433 { 434 return (Status); 435 } 436 } 437 438 WalkState->ReturnDesc = WalkState->Results->Results.ObjDesc [0]; 439 } 440 else 441 { 442 /* No return operand */ 443 444 if (WalkState->NumOperands) 445 { 446 AcpiUtRemoveReference (WalkState->Operands [0]); 447 } 448 449 WalkState->Operands[0] = NULL; 450 WalkState->NumOperands = 0; 451 WalkState->ReturnDesc = NULL; 452 } 453 454 455 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, 456 "Completed RETURN_OP State=%p, RetVal=%p\n", 457 WalkState, WalkState->ReturnDesc)); 458 459 /* End the control method execution right now */ 460 461 Status = AE_CTRL_TERMINATE; 462 break; 463 464 case AML_NOOP_OP: 465 466 /* Just do nothing! */ 467 468 break; 469 470 case AML_BREAKPOINT_OP: 471 472 AcpiDbSignalBreakPoint (WalkState); 473 474 /* Call to the OSL in case OS wants a piece of the action */ 475 476 Status = AcpiOsSignal (ACPI_SIGNAL_BREAKPOINT, 477 "Executed AML Breakpoint opcode"); 478 break; 479 480 case AML_BREAK_OP: 481 case AML_CONTINUE_OP: /* ACPI 2.0 */ 482 483 /* Pop and delete control states until we find a while */ 484 485 while (WalkState->ControlState && 486 (WalkState->ControlState->Control.Opcode != AML_WHILE_OP)) 487 { 488 ControlState = AcpiUtPopGenericState (&WalkState->ControlState); 489 AcpiUtDeleteGenericState (ControlState); 490 } 491 492 /* No while found? */ 493 494 if (!WalkState->ControlState) 495 { 496 return (AE_AML_NO_WHILE); 497 } 498 499 /* Was: WalkState->AmlLastWhile = WalkState->ControlState->Control.AmlPredicateStart; */ 500 501 WalkState->AmlLastWhile = 502 WalkState->ControlState->Control.PackageEnd; 503 504 /* Return status depending on opcode */ 505 506 if (Op->Common.AmlOpcode == AML_BREAK_OP) 507 { 508 Status = AE_CTRL_BREAK; 509 } 510 else 511 { 512 Status = AE_CTRL_CONTINUE; 513 } 514 break; 515 516 default: 517 518 ACPI_ERROR ((AE_INFO, "Unknown control opcode=0x%X Op=%p", 519 Op->Common.AmlOpcode, Op)); 520 521 Status = AE_AML_BAD_OPCODE; 522 break; 523 } 524 525 return (Status); 526} 527