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 - 2017, 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 ******************************************************************************/ 177 178 ACPI_STATUS 179 AcpiDsExecBeginControlOp ( 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 /*lint -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; 237 238 239 /* Push the control state on this walk's control stack */ 240 241 AcpiUtPushGenericState (&WalkState->ControlState, ControlState); 242 break; 243 244 case AML_ELSE_OP: 245 246 /* Predicate is in the state object */ 247 /* If predicate is true, the IF was executed, ignore ELSE part */ 248 249 if (WalkState->LastPredicate) 250 { 251 Status = AE_CTRL_TRUE; 252 } 253 254 break; 255 256 case AML_RETURN_OP: 257 258 break; 259 260 default: 261 262 break; 263 } 264 265 return (Status); 266 } 267 268 269 /******************************************************************************* 270 * 271 * FUNCTION: AcpiDsExecEndControlOp 272 * 273 * PARAMETERS: WalkList - The list that owns the walk stack 274 * Op - The control Op 275 * 276 * RETURN: Status 277 * 278 * DESCRIPTION: Handles all control ops encountered during control method 279 * execution. 280 * 281 ******************************************************************************/ 282 283 ACPI_STATUS 284 AcpiDsExecEndControlOp ( 285 ACPI_WALK_STATE *WalkState, 286 ACPI_PARSE_OBJECT *Op) 287 { 288 ACPI_STATUS Status = AE_OK; 289 ACPI_GENERIC_STATE *ControlState; 290 291 292 ACPI_FUNCTION_NAME (DsExecEndControlOp); 293 294 295 switch (Op->Common.AmlOpcode) 296 { 297 case AML_IF_OP: 298 299 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "[IF_OP] Op=%p\n", Op)); 300 301 /* 302 * Save the result of the predicate in case there is an 303 * ELSE to come 304 */ 305 WalkState->LastPredicate = 306 (BOOLEAN) WalkState->ControlState->Common.Value; 307 308 /* 309 * Pop the control state that was created at the start 310 * of the IF and free it 311 */ 312 ControlState = AcpiUtPopGenericState (&WalkState->ControlState); 313 AcpiUtDeleteGenericState (ControlState); 314 break; 315 316 case AML_ELSE_OP: 317 318 break; 319 320 case AML_WHILE_OP: 321 322 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "[WHILE_OP] Op=%p\n", Op)); 323 324 ControlState = WalkState->ControlState; 325 if (ControlState->Common.Value) 326 { 327 /* Predicate was true, the body of the loop was just executed */ 328 329 /* 330 * This loop counter mechanism allows the interpreter to escape 331 * possibly infinite loops. This can occur in poorly written AML 332 * when the hardware does not respond within a while loop and the 333 * loop does not implement a timeout. 334 */ 335 ControlState->Control.LoopCount++; 336 if (ControlState->Control.LoopCount > AcpiGbl_MaxLoopIterations) 337 { 338 Status = AE_AML_INFINITE_LOOP; 339 break; 340 } 341 342 /* 343 * Go back and evaluate the predicate and maybe execute the loop 344 * another time 345 */ 346 Status = AE_CTRL_PENDING; 347 WalkState->AmlLastWhile = 348 ControlState->Control.AmlPredicateStart; 349 break; 350 } 351 352 /* Predicate was false, terminate this while loop */ 353 354 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, 355 "[WHILE_OP] termination! Op=%p\n",Op)); 356 357 /* Pop this control state and free it */ 358 359 ControlState = AcpiUtPopGenericState (&WalkState->ControlState); 360 AcpiUtDeleteGenericState (ControlState); 361 break; 362 363 case AML_RETURN_OP: 364 365 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, 366 "[RETURN_OP] Op=%p Arg=%p\n",Op, Op->Common.Value.Arg)); 367 368 /* 369 * One optional operand -- the return value 370 * It can be either an immediate operand or a result that 371 * has been bubbled up the tree 372 */ 373 if (Op->Common.Value.Arg) 374 { 375 /* Since we have a real Return(), delete any implicit return */ 376 377 AcpiDsClearImplicitReturn (WalkState); 378 379 /* Return statement has an immediate operand */ 380 381 Status = AcpiDsCreateOperands (WalkState, Op->Common.Value.Arg); 382 if (ACPI_FAILURE (Status)) 383 { 384 return (Status); 385 } 386 387 /* 388 * If value being returned is a Reference (such as 389 * an arg or local), resolve it now because it may 390 * cease to exist at the end of the method. 391 */ 392 Status = AcpiExResolveToValue ( 393 &WalkState->Operands [0], WalkState); 394 if (ACPI_FAILURE (Status)) 395 { 396 return (Status); 397 } 398 399 /* 400 * Get the return value and save as the last result 401 * value. This is the only place where WalkState->ReturnDesc 402 * is set to anything other than zero! 403 */ 404 WalkState->ReturnDesc = WalkState->Operands[0]; 405 } 406 else if (WalkState->ResultCount) 407 { 408 /* Since we have a real Return(), delete any implicit return */ 409 410 AcpiDsClearImplicitReturn (WalkState); 411 412 /* 413 * The return value has come from a previous calculation. 414 * 415 * If value being returned is a Reference (such as 416 * an arg or local), resolve it now because it may 417 * cease to exist at the end of the method. 418 * 419 * Allow references created by the Index operator to return 420 * unchanged. 421 */ 422 if ((ACPI_GET_DESCRIPTOR_TYPE (WalkState->Results->Results.ObjDesc[0]) == 423 ACPI_DESC_TYPE_OPERAND) && 424 ((WalkState->Results->Results.ObjDesc [0])->Common.Type == 425 ACPI_TYPE_LOCAL_REFERENCE) && 426 ((WalkState->Results->Results.ObjDesc [0])->Reference.Class != 427 ACPI_REFCLASS_INDEX)) 428 { 429 Status = AcpiExResolveToValue ( 430 &WalkState->Results->Results.ObjDesc [0], WalkState); 431 if (ACPI_FAILURE (Status)) 432 { 433 return (Status); 434 } 435 } 436 437 WalkState->ReturnDesc = WalkState->Results->Results.ObjDesc [0]; 438 } 439 else 440 { 441 /* No return operand */ 442 443 if (WalkState->NumOperands) 444 { 445 AcpiUtRemoveReference (WalkState->Operands [0]); 446 } 447 448 WalkState->Operands[0] = NULL; 449 WalkState->NumOperands = 0; 450 WalkState->ReturnDesc = NULL; 451 } 452 453 454 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, 455 "Completed RETURN_OP State=%p, RetVal=%p\n", 456 WalkState, WalkState->ReturnDesc)); 457 458 /* End the control method execution right now */ 459 460 Status = AE_CTRL_TERMINATE; 461 break; 462 463 case AML_NOOP_OP: 464 465 /* Just do nothing! */ 466 467 break; 468 469 case AML_BREAKPOINT_OP: 470 471 AcpiDbSignalBreakPoint (WalkState); 472 473 /* Call to the OSL in case OS wants a piece of the action */ 474 475 Status = AcpiOsSignal (ACPI_SIGNAL_BREAKPOINT, 476 "Executed AML Breakpoint opcode"); 477 break; 478 479 case AML_BREAK_OP: 480 case AML_CONTINUE_OP: /* ACPI 2.0 */ 481 482 /* Pop and delete control states until we find a while */ 483 484 while (WalkState->ControlState && 485 (WalkState->ControlState->Control.Opcode != AML_WHILE_OP)) 486 { 487 ControlState = AcpiUtPopGenericState (&WalkState->ControlState); 488 AcpiUtDeleteGenericState (ControlState); 489 } 490 491 /* No while found? */ 492 493 if (!WalkState->ControlState) 494 { 495 return (AE_AML_NO_WHILE); 496 } 497 498 /* Was: WalkState->AmlLastWhile = WalkState->ControlState->Control.AmlPredicateStart; */ 499 500 WalkState->AmlLastWhile = 501 WalkState->ControlState->Control.PackageEnd; 502 503 /* Return status depending on opcode */ 504 505 if (Op->Common.AmlOpcode == AML_BREAK_OP) 506 { 507 Status = AE_CTRL_BREAK; 508 } 509 else 510 { 511 Status = AE_CTRL_CONTINUE; 512 } 513 break; 514 515 default: 516 517 ACPI_ERROR ((AE_INFO, "Unknown control opcode=0x%X Op=%p", 518 Op->Common.AmlOpcode, Op)); 519 520 Status = AE_AML_BAD_OPCODE; 521 break; 522 } 523 524 return (Status); 525 } 526