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 - 2018, 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        /*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        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