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 - 2012, 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 #define __DSCONTROL_C__ 118 119 #include "acpi.h" 120 #include "accommon.h" 121 #include "amlcode.h" 122 #include "acdispat.h" 123 #include "acinterp.h" 124 125 #define _COMPONENT ACPI_DISPATCHER 126 ACPI_MODULE_NAME ("dscontrol") 127 128 129 /******************************************************************************* 130 * 131 * FUNCTION: AcpiDsExecBeginControlOp 132 * 133 * PARAMETERS: WalkList - The list that owns the walk stack 134 * Op - The control Op 135 * 136 * RETURN: Status 137 * 138 * DESCRIPTION: Handles all control ops encountered during control method 139 * execution. 140 * 141 ******************************************************************************/ 142 143 ACPI_STATUS 144 AcpiDsExecBeginControlOp ( 145 ACPI_WALK_STATE *WalkState, 146 ACPI_PARSE_OBJECT *Op) 147 { 148 ACPI_STATUS Status = AE_OK; 149 ACPI_GENERIC_STATE *ControlState; 150 151 152 ACPI_FUNCTION_NAME (DsExecBeginControlOp); 153 154 155 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "Op=%p Opcode=%2.2X State=%p\n", 156 Op, Op->Common.AmlOpcode, WalkState)); 157 158 switch (Op->Common.AmlOpcode) 159 { 160 case AML_WHILE_OP: 161 162 /* 163 * If this is an additional iteration of a while loop, continue. 164 * There is no need to allocate a new control state. 165 */ 166 if (WalkState->ControlState) 167 { 168 if (WalkState->ControlState->Control.AmlPredicateStart == 169 (WalkState->ParserState.Aml - 1)) 170 { 171 /* Reset the state to start-of-loop */ 172 173 WalkState->ControlState->Common.State = 174 ACPI_CONTROL_CONDITIONAL_EXECUTING; 175 break; 176 } 177 } 178 179 /*lint -fallthrough */ 180 181 case AML_IF_OP: 182 183 /* 184 * IF/WHILE: Create a new control state to manage these 185 * constructs. We need to manage these as a stack, in order 186 * to handle nesting. 187 */ 188 ControlState = AcpiUtCreateControlState (); 189 if (!ControlState) 190 { 191 Status = AE_NO_MEMORY; 192 break; 193 } 194 /* 195 * Save a pointer to the predicate for multiple executions 196 * of a loop 197 */ 198 ControlState->Control.AmlPredicateStart = WalkState->ParserState.Aml - 1; 199 ControlState->Control.PackageEnd = WalkState->ParserState.PkgEnd; 200 ControlState->Control.Opcode = Op->Common.AmlOpcode; 201 202 203 /* Push the control state on this walk's control stack */ 204 205 AcpiUtPushGenericState (&WalkState->ControlState, ControlState); 206 break; 207 208 case AML_ELSE_OP: 209 210 /* Predicate is in the state object */ 211 /* If predicate is true, the IF was executed, ignore ELSE part */ 212 213 if (WalkState->LastPredicate) 214 { 215 Status = AE_CTRL_TRUE; 216 } 217 218 break; 219 220 case AML_RETURN_OP: 221 222 break; 223 224 default: 225 break; 226 } 227 228 return (Status); 229 } 230 231 232 /******************************************************************************* 233 * 234 * FUNCTION: AcpiDsExecEndControlOp 235 * 236 * PARAMETERS: WalkList - The list that owns the walk stack 237 * Op - The control Op 238 * 239 * RETURN: Status 240 * 241 * DESCRIPTION: Handles all control ops encountered during control method 242 * execution. 243 * 244 ******************************************************************************/ 245 246 ACPI_STATUS 247 AcpiDsExecEndControlOp ( 248 ACPI_WALK_STATE *WalkState, 249 ACPI_PARSE_OBJECT *Op) 250 { 251 ACPI_STATUS Status = AE_OK; 252 ACPI_GENERIC_STATE *ControlState; 253 254 255 ACPI_FUNCTION_NAME (DsExecEndControlOp); 256 257 258 switch (Op->Common.AmlOpcode) 259 { 260 case AML_IF_OP: 261 262 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "[IF_OP] Op=%p\n", Op)); 263 264 /* 265 * Save the result of the predicate in case there is an 266 * ELSE to come 267 */ 268 WalkState->LastPredicate = 269 (BOOLEAN) WalkState->ControlState->Common.Value; 270 271 /* 272 * Pop the control state that was created at the start 273 * of the IF and free it 274 */ 275 ControlState = AcpiUtPopGenericState (&WalkState->ControlState); 276 AcpiUtDeleteGenericState (ControlState); 277 break; 278 279 280 case AML_ELSE_OP: 281 282 break; 283 284 285 case AML_WHILE_OP: 286 287 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "[WHILE_OP] Op=%p\n", Op)); 288 289 ControlState = WalkState->ControlState; 290 if (ControlState->Common.Value) 291 { 292 /* Predicate was true, the body of the loop was just executed */ 293 294 /* 295 * This loop counter mechanism allows the interpreter to escape 296 * possibly infinite loops. This can occur in poorly written AML 297 * when the hardware does not respond within a while loop and the 298 * loop does not implement a timeout. 299 */ 300 ControlState->Control.LoopCount++; 301 if (ControlState->Control.LoopCount > ACPI_MAX_LOOP_ITERATIONS) 302 { 303 Status = AE_AML_INFINITE_LOOP; 304 break; 305 } 306 307 /* 308 * Go back and evaluate the predicate and maybe execute the loop 309 * another time 310 */ 311 Status = AE_CTRL_PENDING; 312 WalkState->AmlLastWhile = ControlState->Control.AmlPredicateStart; 313 break; 314 } 315 316 /* Predicate was false, terminate this while loop */ 317 318 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, 319 "[WHILE_OP] termination! Op=%p\n",Op)); 320 321 /* Pop this control state and free it */ 322 323 ControlState = AcpiUtPopGenericState (&WalkState->ControlState); 324 AcpiUtDeleteGenericState (ControlState); 325 break; 326 327 328 case AML_RETURN_OP: 329 330 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, 331 "[RETURN_OP] Op=%p Arg=%p\n",Op, Op->Common.Value.Arg)); 332 333 /* 334 * One optional operand -- the return value 335 * It can be either an immediate operand or a result that 336 * has been bubbled up the tree 337 */ 338 if (Op->Common.Value.Arg) 339 { 340 /* Since we have a real Return(), delete any implicit return */ 341 342 AcpiDsClearImplicitReturn (WalkState); 343 344 /* Return statement has an immediate operand */ 345 346 Status = AcpiDsCreateOperands (WalkState, Op->Common.Value.Arg); 347 if (ACPI_FAILURE (Status)) 348 { 349 return (Status); 350 } 351 352 /* 353 * If value being returned is a Reference (such as 354 * an arg or local), resolve it now because it may 355 * cease to exist at the end of the method. 356 */ 357 Status = AcpiExResolveToValue (&WalkState->Operands [0], WalkState); 358 if (ACPI_FAILURE (Status)) 359 { 360 return (Status); 361 } 362 363 /* 364 * Get the return value and save as the last result 365 * value. This is the only place where WalkState->ReturnDesc 366 * is set to anything other than zero! 367 */ 368 WalkState->ReturnDesc = WalkState->Operands[0]; 369 } 370 else if (WalkState->ResultCount) 371 { 372 /* Since we have a real Return(), delete any implicit return */ 373 374 AcpiDsClearImplicitReturn (WalkState); 375 376 /* 377 * The return value has come from a previous calculation. 378 * 379 * If value being returned is a Reference (such as 380 * an arg or local), resolve it now because it may 381 * cease to exist at the end of the method. 382 * 383 * Allow references created by the Index operator to return 384 * unchanged. 385 */ 386 if ((ACPI_GET_DESCRIPTOR_TYPE (WalkState->Results->Results.ObjDesc[0]) == ACPI_DESC_TYPE_OPERAND) && 387 ((WalkState->Results->Results.ObjDesc [0])->Common.Type == ACPI_TYPE_LOCAL_REFERENCE) && 388 ((WalkState->Results->Results.ObjDesc [0])->Reference.Class != ACPI_REFCLASS_INDEX)) 389 { 390 Status = AcpiExResolveToValue (&WalkState->Results->Results.ObjDesc [0], WalkState); 391 if (ACPI_FAILURE (Status)) 392 { 393 return (Status); 394 } 395 } 396 397 WalkState->ReturnDesc = WalkState->Results->Results.ObjDesc [0]; 398 } 399 else 400 { 401 /* No return operand */ 402 403 if (WalkState->NumOperands) 404 { 405 AcpiUtRemoveReference (WalkState->Operands [0]); 406 } 407 408 WalkState->Operands [0] = NULL; 409 WalkState->NumOperands = 0; 410 WalkState->ReturnDesc = NULL; 411 } 412 413 414 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, 415 "Completed RETURN_OP State=%p, RetVal=%p\n", 416 WalkState, WalkState->ReturnDesc)); 417 418 /* End the control method execution right now */ 419 420 Status = AE_CTRL_TERMINATE; 421 break; 422 423 424 case AML_NOOP_OP: 425 426 /* Just do nothing! */ 427 break; 428 429 430 case AML_BREAK_POINT_OP: 431 432 /* 433 * Set the single-step flag. This will cause the debugger (if present) 434 * to break to the console within the AML debugger at the start of the 435 * next AML instruction. 436 */ 437 ACPI_DEBUGGER_EXEC ( 438 AcpiGbl_CmSingleStep = TRUE); 439 ACPI_DEBUGGER_EXEC ( 440 AcpiOsPrintf ("**break** Executed AML BreakPoint opcode\n")); 441 442 /* Call to the OSL in case OS wants a piece of the action */ 443 444 Status = AcpiOsSignal (ACPI_SIGNAL_BREAKPOINT, 445 "Executed AML Breakpoint opcode"); 446 break; 447 448 449 case AML_BREAK_OP: 450 case AML_CONTINUE_OP: /* ACPI 2.0 */ 451 452 453 /* Pop and delete control states until we find a while */ 454 455 while (WalkState->ControlState && 456 (WalkState->ControlState->Control.Opcode != AML_WHILE_OP)) 457 { 458 ControlState = AcpiUtPopGenericState (&WalkState->ControlState); 459 AcpiUtDeleteGenericState (ControlState); 460 } 461 462 /* No while found? */ 463 464 if (!WalkState->ControlState) 465 { 466 return (AE_AML_NO_WHILE); 467 } 468 469 /* Was: WalkState->AmlLastWhile = WalkState->ControlState->Control.AmlPredicateStart; */ 470 471 WalkState->AmlLastWhile = WalkState->ControlState->Control.PackageEnd; 472 473 /* Return status depending on opcode */ 474 475 if (Op->Common.AmlOpcode == AML_BREAK_OP) 476 { 477 Status = AE_CTRL_BREAK; 478 } 479 else 480 { 481 Status = AE_CTRL_CONTINUE; 482 } 483 break; 484 485 486 default: 487 488 ACPI_ERROR ((AE_INFO, "Unknown control opcode=0x%X Op=%p", 489 Op->Common.AmlOpcode, Op)); 490 491 Status = AE_AML_BAD_OPCODE; 492 break; 493 } 494 495 return (Status); 496 } 497