df22ddfb4437216317dc3a4d0504bdcee63db85f
[reactos.git] / drivers / bus / acpi / acpica / dispatcher / dscontrol.c
1 /******************************************************************************
2 *
3 * Module Name: dscontrol - Support for execution control opcodes -
4 * if/else/while/return
5 *
6 *****************************************************************************/
7
8 /*
9 * Copyright (C) 2000 - 2017, Intel Corp.
10 * All rights reserved.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions, and the following disclaimer,
17 * without modification.
18 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
19 * substantially similar to the "NO WARRANTY" disclaimer below
20 * ("Disclaimer") and any redistribution must be conditioned upon
21 * including a substantially similar Disclaimer requirement for further
22 * binary redistribution.
23 * 3. Neither the names of the above-listed copyright holders nor the names
24 * of any contributors may be used to endorse or promote products derived
25 * from this software without specific prior written permission.
26 *
27 * Alternatively, this software may be distributed under the terms of the
28 * GNU General Public License ("GPL") version 2 as published by the Free
29 * Software Foundation.
30 *
31 * NO WARRANTY
32 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
33 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
34 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
35 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
36 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
37 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
38 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
39 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
40 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
41 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
42 * POSSIBILITY OF SUCH DAMAGES.
43 */
44
45 #include "acpi.h"
46 #include "accommon.h"
47 #include "amlcode.h"
48 #include "acdispat.h"
49 #include "acinterp.h"
50 #include "acdebug.h"
51
52 #define _COMPONENT ACPI_DISPATCHER
53 ACPI_MODULE_NAME ("dscontrol")
54
55
56 /*******************************************************************************
57 *
58 * FUNCTION: AcpiDsExecBeginControlOp
59 *
60 * PARAMETERS: WalkList - The list that owns the walk stack
61 * Op - The control Op
62 *
63 * RETURN: Status
64 *
65 * DESCRIPTION: Handles all control ops encountered during control method
66 * execution.
67 *
68 ******************************************************************************/
69
70 ACPI_STATUS
71 AcpiDsExecBeginControlOp (
72 ACPI_WALK_STATE *WalkState,
73 ACPI_PARSE_OBJECT *Op)
74 {
75 ACPI_STATUS Status = AE_OK;
76 ACPI_GENERIC_STATE *ControlState;
77
78
79 ACPI_FUNCTION_NAME (DsExecBeginControlOp);
80
81
82 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "Op=%p Opcode=%2.2X State=%p\n",
83 Op, Op->Common.AmlOpcode, WalkState));
84
85 switch (Op->Common.AmlOpcode)
86 {
87 case AML_WHILE_OP:
88 /*
89 * If this is an additional iteration of a while loop, continue.
90 * There is no need to allocate a new control state.
91 */
92 if (WalkState->ControlState)
93 {
94 if (WalkState->ControlState->Control.AmlPredicateStart ==
95 (WalkState->ParserState.Aml - 1))
96 {
97 /* Reset the state to start-of-loop */
98
99 WalkState->ControlState->Common.State =
100 ACPI_CONTROL_CONDITIONAL_EXECUTING;
101 break;
102 }
103 }
104
105 /*lint -fallthrough */
106
107 case AML_IF_OP:
108 /*
109 * IF/WHILE: Create a new control state to manage these
110 * constructs. We need to manage these as a stack, in order
111 * to handle nesting.
112 */
113 ControlState = AcpiUtCreateControlState ();
114 if (!ControlState)
115 {
116 Status = AE_NO_MEMORY;
117 break;
118 }
119 /*
120 * Save a pointer to the predicate for multiple executions
121 * of a loop
122 */
123 ControlState->Control.AmlPredicateStart =
124 WalkState->ParserState.Aml - 1;
125 ControlState->Control.PackageEnd =
126 WalkState->ParserState.PkgEnd;
127 ControlState->Control.Opcode =
128 Op->Common.AmlOpcode;
129
130
131 /* Push the control state on this walk's control stack */
132
133 AcpiUtPushGenericState (&WalkState->ControlState, ControlState);
134 break;
135
136 case AML_ELSE_OP:
137
138 /* Predicate is in the state object */
139 /* If predicate is true, the IF was executed, ignore ELSE part */
140
141 if (WalkState->LastPredicate)
142 {
143 Status = AE_CTRL_TRUE;
144 }
145
146 break;
147
148 case AML_RETURN_OP:
149
150 break;
151
152 default:
153
154 break;
155 }
156
157 return (Status);
158 }
159
160
161 /*******************************************************************************
162 *
163 * FUNCTION: AcpiDsExecEndControlOp
164 *
165 * PARAMETERS: WalkList - The list that owns the walk stack
166 * Op - The control Op
167 *
168 * RETURN: Status
169 *
170 * DESCRIPTION: Handles all control ops encountered during control method
171 * execution.
172 *
173 ******************************************************************************/
174
175 ACPI_STATUS
176 AcpiDsExecEndControlOp (
177 ACPI_WALK_STATE *WalkState,
178 ACPI_PARSE_OBJECT *Op)
179 {
180 ACPI_STATUS Status = AE_OK;
181 ACPI_GENERIC_STATE *ControlState;
182
183
184 ACPI_FUNCTION_NAME (DsExecEndControlOp);
185
186
187 switch (Op->Common.AmlOpcode)
188 {
189 case AML_IF_OP:
190
191 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "[IF_OP] Op=%p\n", Op));
192
193 /*
194 * Save the result of the predicate in case there is an
195 * ELSE to come
196 */
197 WalkState->LastPredicate =
198 (BOOLEAN) WalkState->ControlState->Common.Value;
199
200 /*
201 * Pop the control state that was created at the start
202 * of the IF and free it
203 */
204 ControlState = AcpiUtPopGenericState (&WalkState->ControlState);
205 AcpiUtDeleteGenericState (ControlState);
206 break;
207
208 case AML_ELSE_OP:
209
210 break;
211
212 case AML_WHILE_OP:
213
214 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH, "[WHILE_OP] Op=%p\n", Op));
215
216 ControlState = WalkState->ControlState;
217 if (ControlState->Common.Value)
218 {
219 /* Predicate was true, the body of the loop was just executed */
220
221 /*
222 * This loop counter mechanism allows the interpreter to escape
223 * possibly infinite loops. This can occur in poorly written AML
224 * when the hardware does not respond within a while loop and the
225 * loop does not implement a timeout.
226 */
227 ControlState->Control.LoopCount++;
228 if (ControlState->Control.LoopCount > AcpiGbl_MaxLoopIterations)
229 {
230 Status = AE_AML_INFINITE_LOOP;
231 break;
232 }
233
234 /*
235 * Go back and evaluate the predicate and maybe execute the loop
236 * another time
237 */
238 Status = AE_CTRL_PENDING;
239 WalkState->AmlLastWhile =
240 ControlState->Control.AmlPredicateStart;
241 break;
242 }
243
244 /* Predicate was false, terminate this while loop */
245
246 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
247 "[WHILE_OP] termination! Op=%p\n",Op));
248
249 /* Pop this control state and free it */
250
251 ControlState = AcpiUtPopGenericState (&WalkState->ControlState);
252 AcpiUtDeleteGenericState (ControlState);
253 break;
254
255 case AML_RETURN_OP:
256
257 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
258 "[RETURN_OP] Op=%p Arg=%p\n",Op, Op->Common.Value.Arg));
259
260 /*
261 * One optional operand -- the return value
262 * It can be either an immediate operand or a result that
263 * has been bubbled up the tree
264 */
265 if (Op->Common.Value.Arg)
266 {
267 /* Since we have a real Return(), delete any implicit return */
268
269 AcpiDsClearImplicitReturn (WalkState);
270
271 /* Return statement has an immediate operand */
272
273 Status = AcpiDsCreateOperands (WalkState, Op->Common.Value.Arg);
274 if (ACPI_FAILURE (Status))
275 {
276 return (Status);
277 }
278
279 /*
280 * If value being returned is a Reference (such as
281 * an arg or local), resolve it now because it may
282 * cease to exist at the end of the method.
283 */
284 Status = AcpiExResolveToValue (
285 &WalkState->Operands [0], WalkState);
286 if (ACPI_FAILURE (Status))
287 {
288 return (Status);
289 }
290
291 /*
292 * Get the return value and save as the last result
293 * value. This is the only place where WalkState->ReturnDesc
294 * is set to anything other than zero!
295 */
296 WalkState->ReturnDesc = WalkState->Operands[0];
297 }
298 else if (WalkState->ResultCount)
299 {
300 /* Since we have a real Return(), delete any implicit return */
301
302 AcpiDsClearImplicitReturn (WalkState);
303
304 /*
305 * The return value has come from a previous calculation.
306 *
307 * If value being returned is a Reference (such as
308 * an arg or local), resolve it now because it may
309 * cease to exist at the end of the method.
310 *
311 * Allow references created by the Index operator to return
312 * unchanged.
313 */
314 if ((ACPI_GET_DESCRIPTOR_TYPE (WalkState->Results->Results.ObjDesc[0]) ==
315 ACPI_DESC_TYPE_OPERAND) &&
316 ((WalkState->Results->Results.ObjDesc [0])->Common.Type ==
317 ACPI_TYPE_LOCAL_REFERENCE) &&
318 ((WalkState->Results->Results.ObjDesc [0])->Reference.Class !=
319 ACPI_REFCLASS_INDEX))
320 {
321 Status = AcpiExResolveToValue (
322 &WalkState->Results->Results.ObjDesc [0], WalkState);
323 if (ACPI_FAILURE (Status))
324 {
325 return (Status);
326 }
327 }
328
329 WalkState->ReturnDesc = WalkState->Results->Results.ObjDesc [0];
330 }
331 else
332 {
333 /* No return operand */
334
335 if (WalkState->NumOperands)
336 {
337 AcpiUtRemoveReference (WalkState->Operands [0]);
338 }
339
340 WalkState->Operands[0] = NULL;
341 WalkState->NumOperands = 0;
342 WalkState->ReturnDesc = NULL;
343 }
344
345
346 ACPI_DEBUG_PRINT ((ACPI_DB_DISPATCH,
347 "Completed RETURN_OP State=%p, RetVal=%p\n",
348 WalkState, WalkState->ReturnDesc));
349
350 /* End the control method execution right now */
351
352 Status = AE_CTRL_TERMINATE;
353 break;
354
355 case AML_NOOP_OP:
356
357 /* Just do nothing! */
358
359 break;
360
361 case AML_BREAKPOINT_OP:
362
363 AcpiDbSignalBreakPoint (WalkState);
364
365 /* Call to the OSL in case OS wants a piece of the action */
366
367 Status = AcpiOsSignal (ACPI_SIGNAL_BREAKPOINT,
368 "Executed AML Breakpoint opcode");
369 break;
370
371 case AML_BREAK_OP:
372 case AML_CONTINUE_OP: /* ACPI 2.0 */
373
374 /* Pop and delete control states until we find a while */
375
376 while (WalkState->ControlState &&
377 (WalkState->ControlState->Control.Opcode != AML_WHILE_OP))
378 {
379 ControlState = AcpiUtPopGenericState (&WalkState->ControlState);
380 AcpiUtDeleteGenericState (ControlState);
381 }
382
383 /* No while found? */
384
385 if (!WalkState->ControlState)
386 {
387 return (AE_AML_NO_WHILE);
388 }
389
390 /* Was: WalkState->AmlLastWhile = WalkState->ControlState->Control.AmlPredicateStart; */
391
392 WalkState->AmlLastWhile =
393 WalkState->ControlState->Control.PackageEnd;
394
395 /* Return status depending on opcode */
396
397 if (Op->Common.AmlOpcode == AML_BREAK_OP)
398 {
399 Status = AE_CTRL_BREAK;
400 }
401 else
402 {
403 Status = AE_CTRL_CONTINUE;
404 }
405 break;
406
407 default:
408
409 ACPI_ERROR ((AE_INFO, "Unknown control opcode=0x%X Op=%p",
410 Op->Common.AmlOpcode, Op));
411
412 Status = AE_AML_BAD_OPCODE;
413 break;
414 }
415
416 return (Status);
417 }