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 - 2014, 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 * If this is an additional iteration of a while loop, continue. 163 * There is no need to allocate a new control state. 164 */ 165 if (WalkState->ControlState) 166 { 167 if (WalkState->ControlState->Control.AmlPredicateStart == 168 (WalkState->ParserState.Aml - 1)) 169 { 170 /* Reset the state to start-of-loop */ 171 172 WalkState->ControlState->Common.State = 173 ACPI_CONTROL_CONDITIONAL_EXECUTING; 174 break; 175 } 176 } 177 178 /*lint -fallthrough */ 179 180 case AML_IF_OP: 181 /* 182 * IF/WHILE: Create a new control state to manage these 183 * constructs. We need to manage these as a stack, in order 184 * to handle nesting. 185 */ 186 ControlState = AcpiUtCreateControlState (); 187 if (!ControlState) 188 { 189 Status = AE_NO_MEMORY; 190 break; 191 } 192 /* 193 * Save a pointer to the predicate for multiple executions 194 * of a loop 195 */ 196 ControlState->Control.AmlPredicateStart = WalkState->ParserState.Aml - 1; 197 ControlState->Control.PackageEnd = WalkState->ParserState.PkgEnd; 198 ControlState->Control.Opcode = Op->Common.AmlOpcode; 199 200 201 /* Push the control state on this walk's control stack */ 202 203 AcpiUtPushGenericState (&WalkState->ControlState, ControlState); 204 break; 205 206 case AML_ELSE_OP: 207 208 /* Predicate is in the state object */ 209 /* If predicate is true, the IF was executed, ignore ELSE part */ 210 211 if (WalkState->LastPredicate) 212 { 213 Status = AE_CTRL_TRUE; 214 } 215 216 break; 217 218 case AML_RETURN_OP: 219 220 break; 221 222 default: 223 224 break; 225 } 226 227 return (Status); 228 } 229 230 231 /******************************************************************************* 232 * 233 * FUNCTION: AcpiDsExecEndControlOp 234 * 235 * PARAMETERS: WalkList - The list that owns the walk stack 236 * Op - The control Op 237 * 238 * RETURN: Status 239 * 240 * DESCRIPTION: Handles all control ops encountered during control method 241 * execution. 242 * 243 ******************************************************************************/ 244 245 ACPI_STATUS 246 AcpiDsExecEndControlOp ( 247 ACPI_WALK_STATE *WalkState, 248 ACPI_PARSE_OBJECT *Op) 249 { 250 ACPI_STATUS Status = AE_OK; 251 ACPI_GENERIC_STATE *ControlState; 252 253 254 ACPI_FUNCTION_NAME (DsExecEndControlOp); 255 256 257 switch (Op->Common.AmlOpcode) 258 { 259 case AML_IF_OP: 260 261 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "[IF_OP] Op=%p\n", Op)); 262 263 /* 264 * Save the result of the predicate in case there is an 265 * ELSE to come 266 */ 267 WalkState->LastPredicate = 268 (BOOLEAN) WalkState->ControlState->Common.Value; 269 270 /* 271 * Pop the control state that was created at the start 272 * of the IF and free it 273 */ 274 ControlState = AcpiUtPopGenericState (&WalkState->ControlState); 275 AcpiUtDeleteGenericState (ControlState); 276 break; 277 278 case AML_ELSE_OP: 279 280 break; 281 282 case AML_WHILE_OP: 283 284 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "[WHILE_OP] Op=%p\n", Op)); 285 286 ControlState = WalkState->ControlState; 287 if (ControlState->Common.Value) 288 { 289 /* Predicate was true, the body of the loop was just executed */ 290 291 /* 292 * This loop counter mechanism allows the interpreter to escape 293 * possibly infinite loops. This can occur in poorly written AML 294 * when the hardware does not respond within a while loop and the 295 * loop does not implement a timeout. 296 */ 297 ControlState->Control.LoopCount++; 298 if (ControlState->Control.LoopCount > ACPI_MAX_LOOP_ITERATIONS) 299 { 300 Status = AE_AML_INFINITE_LOOP; 301 break; 302 } 303 304 /* 305 * Go back and evaluate the predicate and maybe execute the loop 306 * another time 307 */ 308 Status = AE_CTRL_PENDING; 309 WalkState->AmlLastWhile = ControlState->Control.AmlPredicateStart; 310 break; 311 } 312 313 /* Predicate was false, terminate this while loop */ 314 315 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, 316 "[WHILE_OP] termination! Op=%p\n",Op)); 317 318 /* Pop this control state and free it */ 319 320 ControlState = AcpiUtPopGenericState (&WalkState->ControlState); 321 AcpiUtDeleteGenericState (ControlState); 322 break; 323 324 case AML_RETURN_OP: 325 326 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, 327 "[RETURN_OP] Op=%p Arg=%p\n",Op, Op->Common.Value.Arg)); 328 329 /* 330 * One optional operand -- the return value 331 * It can be either an immediate operand or a result that 332 * has been bubbled up the tree 333 */ 334 if (Op->Common.Value.Arg) 335 { 336 /* Since we have a real Return(), delete any implicit return */ 337 338 AcpiDsClearImplicitReturn (WalkState); 339 340 /* Return statement has an immediate operand */ 341 342 Status = AcpiDsCreateOperands (WalkState, Op->Common.Value.Arg); 343 if (ACPI_FAILURE (Status)) 344 { 345 return (Status); 346 } 347 348 /* 349 * If value being returned is a Reference (such as 350 * an arg or local), resolve it now because it may 351 * cease to exist at the end of the method. 352 */ 353 Status = AcpiExResolveToValue (&WalkState->Operands [0], WalkState); 354 if (ACPI_FAILURE (Status)) 355 { 356 return (Status); 357 } 358 359 /* 360 * Get the return value and save as the last result 361 * value. This is the only place where WalkState->ReturnDesc 362 * is set to anything other than zero! 363 */ 364 WalkState->ReturnDesc = WalkState->Operands[0]; 365 } 366 else if (WalkState->ResultCount) 367 { 368 /* Since we have a real Return(), delete any implicit return */ 369 370 AcpiDsClearImplicitReturn (WalkState); 371 372 /* 373 * The return value has come from a previous calculation. 374 * 375 * If value being returned is a Reference (such as 376 * an arg or local), resolve it now because it may 377 * cease to exist at the end of the method. 378 * 379 * Allow references created by the Index operator to return 380 * unchanged. 381 */ 382 if ((ACPI_GET_DESCRIPTOR_TYPE (WalkState->Results->Results.ObjDesc[0]) == ACPI_DESC_TYPE_OPERAND) && 383 ((WalkState->Results->Results.ObjDesc [0])->Common.Type == ACPI_TYPE_LOCAL_REFERENCE) && 384 ((WalkState->Results->Results.ObjDesc [0])->Reference.Class != ACPI_REFCLASS_INDEX)) 385 { 386 Status = AcpiExResolveToValue (&WalkState->Results->Results.ObjDesc [0], WalkState); 387 if (ACPI_FAILURE (Status)) 388 { 389 return (Status); 390 } 391 } 392 393 WalkState->ReturnDesc = WalkState->Results->Results.ObjDesc [0]; 394 } 395 else 396 { 397 /* No return operand */ 398 399 if (WalkState->NumOperands) 400 { 401 AcpiUtRemoveReference (WalkState->Operands [0]); 402 } 403 404 WalkState->Operands [0] = NULL; 405 WalkState->NumOperands = 0; 406 WalkState->ReturnDesc = NULL; 407 } 408 409 410 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, 411 "Completed RETURN_OP State=%p, RetVal=%p\n", 412 WalkState, WalkState->ReturnDesc)); 413 414 /* End the control method execution right now */ 415 416 Status = AE_CTRL_TERMINATE; 417 break; 418 419 case AML_NOOP_OP: 420 421 /* Just do nothing! */ 422 423 break; 424 425 case AML_BREAK_POINT_OP: 426 427 /* 428 * Set the single-step flag. This will cause the debugger (if present) 429 * to break to the console within the AML debugger at the start of the 430 * next AML instruction. 431 */ 432 ACPI_DEBUGGER_EXEC ( 433 AcpiGbl_CmSingleStep = TRUE); 434 ACPI_DEBUGGER_EXEC ( 435 AcpiOsPrintf ("**break** Executed AML BreakPoint opcode\n")); 436 437 /* Call to the OSL in case OS wants a piece of the action */ 438 439 Status = AcpiOsSignal (ACPI_SIGNAL_BREAKPOINT, 440 "Executed AML Breakpoint opcode"); 441 break; 442 443 case AML_BREAK_OP: 444 case AML_CONTINUE_OP: /* ACPI 2.0 */ 445 446 /* Pop and delete control states until we find a while */ 447 448 while (WalkState->ControlState && 449 (WalkState->ControlState->Control.Opcode != AML_WHILE_OP)) 450 { 451 ControlState = AcpiUtPopGenericState (&WalkState->ControlState); 452 AcpiUtDeleteGenericState (ControlState); 453 } 454 455 /* No while found? */ 456 457 if (!WalkState->ControlState) 458 { 459 return (AE_AML_NO_WHILE); 460 } 461 462 /* Was: WalkState->AmlLastWhile = WalkState->ControlState->Control.AmlPredicateStart; */ 463 464 WalkState->AmlLastWhile = WalkState->ControlState->Control.PackageEnd; 465 466 /* Return status depending on opcode */ 467 468 if (Op->Common.AmlOpcode == AML_BREAK_OP) 469 { 470 Status = AE_CTRL_BREAK; 471 } 472 else 473 { 474 Status = AE_CTRL_CONTINUE; 475 } 476 break; 477 478 default: 479 480 ACPI_ERROR ((AE_INFO, "Unknown control opcode=0x%X Op=%p", 481 Op->Common.AmlOpcode, Op)); 482 483 Status = AE_AML_BAD_OPCODE; 484 break; 485 } 486 487 return (Status); 488 } 489