Revert "ARM: tegra: tegratab: dummy change"
[linux-2.6.git] / drivers / acpi / acpica / 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 - 2012, 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/acpi.h>
46 #include "accommon.h"
47 #include "amlcode.h"
48 #include "acdispat.h"
49 #include "acinterp.h"
50
51 #define _COMPONENT          ACPI_DISPATCHER
52 ACPI_MODULE_NAME("dscontrol")
53
54 /*******************************************************************************
55  *
56  * FUNCTION:    acpi_ds_exec_begin_control_op
57  *
58  * PARAMETERS:  walk_list       - The list that owns the walk stack
59  *              Op              - The control Op
60  *
61  * RETURN:      Status
62  *
63  * DESCRIPTION: Handles all control ops encountered during control method
64  *              execution.
65  *
66  ******************************************************************************/
67 acpi_status
68 acpi_ds_exec_begin_control_op(struct acpi_walk_state *walk_state,
69                               union acpi_parse_object *op)
70 {
71         acpi_status status = AE_OK;
72         union acpi_generic_state *control_state;
73
74         ACPI_FUNCTION_NAME(ds_exec_begin_control_op);
75
76         ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "Op=%p Opcode=%2.2X State=%p\n",
77                           op, op->common.aml_opcode, walk_state));
78
79         switch (op->common.aml_opcode) {
80         case AML_WHILE_OP:
81
82                 /*
83                  * If this is an additional iteration of a while loop, continue.
84                  * There is no need to allocate a new control state.
85                  */
86                 if (walk_state->control_state) {
87                         if (walk_state->control_state->control.
88                             aml_predicate_start ==
89                             (walk_state->parser_state.aml - 1)) {
90
91                                 /* Reset the state to start-of-loop */
92
93                                 walk_state->control_state->common.state =
94                                     ACPI_CONTROL_CONDITIONAL_EXECUTING;
95                                 break;
96                         }
97                 }
98
99                 /*lint -fallthrough */
100
101         case AML_IF_OP:
102
103                 /*
104                  * IF/WHILE: Create a new control state to manage these
105                  * constructs. We need to manage these as a stack, in order
106                  * to handle nesting.
107                  */
108                 control_state = acpi_ut_create_control_state();
109                 if (!control_state) {
110                         status = AE_NO_MEMORY;
111                         break;
112                 }
113                 /*
114                  * Save a pointer to the predicate for multiple executions
115                  * of a loop
116                  */
117                 control_state->control.aml_predicate_start =
118                     walk_state->parser_state.aml - 1;
119                 control_state->control.package_end =
120                     walk_state->parser_state.pkg_end;
121                 control_state->control.opcode = op->common.aml_opcode;
122
123                 /* Push the control state on this walk's control stack */
124
125                 acpi_ut_push_generic_state(&walk_state->control_state,
126                                            control_state);
127                 break;
128
129         case AML_ELSE_OP:
130
131                 /* Predicate is in the state object */
132                 /* If predicate is true, the IF was executed, ignore ELSE part */
133
134                 if (walk_state->last_predicate) {
135                         status = AE_CTRL_TRUE;
136                 }
137
138                 break;
139
140         case AML_RETURN_OP:
141
142                 break;
143
144         default:
145                 break;
146         }
147
148         return (status);
149 }
150
151 /*******************************************************************************
152  *
153  * FUNCTION:    acpi_ds_exec_end_control_op
154  *
155  * PARAMETERS:  walk_list       - The list that owns the walk stack
156  *              Op              - The control Op
157  *
158  * RETURN:      Status
159  *
160  * DESCRIPTION: Handles all control ops encountered during control method
161  *              execution.
162  *
163  ******************************************************************************/
164
165 acpi_status
166 acpi_ds_exec_end_control_op(struct acpi_walk_state * walk_state,
167                             union acpi_parse_object * op)
168 {
169         acpi_status status = AE_OK;
170         union acpi_generic_state *control_state;
171
172         ACPI_FUNCTION_NAME(ds_exec_end_control_op);
173
174         switch (op->common.aml_opcode) {
175         case AML_IF_OP:
176
177                 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "[IF_OP] Op=%p\n", op));
178
179                 /*
180                  * Save the result of the predicate in case there is an
181                  * ELSE to come
182                  */
183                 walk_state->last_predicate =
184                     (u8)walk_state->control_state->common.value;
185
186                 /*
187                  * Pop the control state that was created at the start
188                  * of the IF and free it
189                  */
190                 control_state =
191                     acpi_ut_pop_generic_state(&walk_state->control_state);
192                 acpi_ut_delete_generic_state(control_state);
193                 break;
194
195         case AML_ELSE_OP:
196
197                 break;
198
199         case AML_WHILE_OP:
200
201                 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "[WHILE_OP] Op=%p\n", op));
202
203                 control_state = walk_state->control_state;
204                 if (control_state->common.value) {
205
206                         /* Predicate was true, the body of the loop was just executed */
207
208                         /*
209                          * This loop counter mechanism allows the interpreter to escape
210                          * possibly infinite loops. This can occur in poorly written AML
211                          * when the hardware does not respond within a while loop and the
212                          * loop does not implement a timeout.
213                          */
214                         control_state->control.loop_count++;
215                         if (control_state->control.loop_count >
216                             ACPI_MAX_LOOP_ITERATIONS) {
217                                 status = AE_AML_INFINITE_LOOP;
218                                 break;
219                         }
220
221                         /*
222                          * Go back and evaluate the predicate and maybe execute the loop
223                          * another time
224                          */
225                         status = AE_CTRL_PENDING;
226                         walk_state->aml_last_while =
227                             control_state->control.aml_predicate_start;
228                         break;
229                 }
230
231                 /* Predicate was false, terminate this while loop */
232
233                 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
234                                   "[WHILE_OP] termination! Op=%p\n", op));
235
236                 /* Pop this control state and free it */
237
238                 control_state =
239                     acpi_ut_pop_generic_state(&walk_state->control_state);
240                 acpi_ut_delete_generic_state(control_state);
241                 break;
242
243         case AML_RETURN_OP:
244
245                 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
246                                   "[RETURN_OP] Op=%p Arg=%p\n", op,
247                                   op->common.value.arg));
248
249                 /*
250                  * One optional operand -- the return value
251                  * It can be either an immediate operand or a result that
252                  * has been bubbled up the tree
253                  */
254                 if (op->common.value.arg) {
255
256                         /* Since we have a real Return(), delete any implicit return */
257
258                         acpi_ds_clear_implicit_return(walk_state);
259
260                         /* Return statement has an immediate operand */
261
262                         status =
263                             acpi_ds_create_operands(walk_state,
264                                                     op->common.value.arg);
265                         if (ACPI_FAILURE(status)) {
266                                 return (status);
267                         }
268
269                         /*
270                          * If value being returned is a Reference (such as
271                          * an arg or local), resolve it now because it may
272                          * cease to exist at the end of the method.
273                          */
274                         status =
275                             acpi_ex_resolve_to_value(&walk_state->operands[0],
276                                                      walk_state);
277                         if (ACPI_FAILURE(status)) {
278                                 return (status);
279                         }
280
281                         /*
282                          * Get the return value and save as the last result
283                          * value.  This is the only place where walk_state->return_desc
284                          * is set to anything other than zero!
285                          */
286                         walk_state->return_desc = walk_state->operands[0];
287                 } else if (walk_state->result_count) {
288
289                         /* Since we have a real Return(), delete any implicit return */
290
291                         acpi_ds_clear_implicit_return(walk_state);
292
293                         /*
294                          * The return value has come from a previous calculation.
295                          *
296                          * If value being returned is a Reference (such as
297                          * an arg or local), resolve it now because it may
298                          * cease to exist at the end of the method.
299                          *
300                          * Allow references created by the Index operator to return
301                          * unchanged.
302                          */
303                         if ((ACPI_GET_DESCRIPTOR_TYPE
304                              (walk_state->results->results.obj_desc[0]) ==
305                              ACPI_DESC_TYPE_OPERAND)
306                             && ((walk_state->results->results.obj_desc[0])->
307                                 common.type == ACPI_TYPE_LOCAL_REFERENCE)
308                             && ((walk_state->results->results.obj_desc[0])->
309                                 reference.class != ACPI_REFCLASS_INDEX)) {
310                                 status =
311                                     acpi_ex_resolve_to_value(&walk_state->
312                                                              results->results.
313                                                              obj_desc[0],
314                                                              walk_state);
315                                 if (ACPI_FAILURE(status)) {
316                                         return (status);
317                                 }
318                         }
319
320                         walk_state->return_desc =
321                             walk_state->results->results.obj_desc[0];
322                 } else {
323                         /* No return operand */
324
325                         if (walk_state->num_operands) {
326                                 acpi_ut_remove_reference(walk_state->
327                                                          operands[0]);
328                         }
329
330                         walk_state->operands[0] = NULL;
331                         walk_state->num_operands = 0;
332                         walk_state->return_desc = NULL;
333                 }
334
335                 ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
336                                   "Completed RETURN_OP State=%p, RetVal=%p\n",
337                                   walk_state, walk_state->return_desc));
338
339                 /* End the control method execution right now */
340
341                 status = AE_CTRL_TERMINATE;
342                 break;
343
344         case AML_NOOP_OP:
345
346                 /* Just do nothing! */
347                 break;
348
349         case AML_BREAK_POINT_OP:
350
351                 /*
352                  * Set the single-step flag. This will cause the debugger (if present)
353                  * to break to the console within the AML debugger at the start of the
354                  * next AML instruction.
355                  */
356                 ACPI_DEBUGGER_EXEC(acpi_gbl_cm_single_step = TRUE);
357                 ACPI_DEBUGGER_EXEC(acpi_os_printf
358                                    ("**break** Executed AML BreakPoint opcode\n"));
359
360                 /* Call to the OSL in case OS wants a piece of the action */
361
362                 status = acpi_os_signal(ACPI_SIGNAL_BREAKPOINT,
363                                         "Executed AML Breakpoint opcode");
364                 break;
365
366         case AML_BREAK_OP:
367         case AML_CONTINUE_OP:   /* ACPI 2.0 */
368
369                 /* Pop and delete control states until we find a while */
370
371                 while (walk_state->control_state &&
372                        (walk_state->control_state->control.opcode !=
373                         AML_WHILE_OP)) {
374                         control_state =
375                             acpi_ut_pop_generic_state(&walk_state->
376                                                       control_state);
377                         acpi_ut_delete_generic_state(control_state);
378                 }
379
380                 /* No while found? */
381
382                 if (!walk_state->control_state) {
383                         return (AE_AML_NO_WHILE);
384                 }
385
386                 /* Was: walk_state->aml_last_while = walk_state->control_state->Control.aml_predicate_start; */
387
388                 walk_state->aml_last_while =
389                     walk_state->control_state->control.package_end;
390
391                 /* Return status depending on opcode */
392
393                 if (op->common.aml_opcode == AML_BREAK_OP) {
394                         status = AE_CTRL_BREAK;
395                 } else {
396                         status = AE_CTRL_CONTINUE;
397                 }
398                 break;
399
400         default:
401
402                 ACPI_ERROR((AE_INFO, "Unknown control opcode=0x%X Op=%p",
403                             op->common.aml_opcode, op));
404
405                 status = AE_AML_BAD_OPCODE;
406                 break;
407         }
408
409         return (status);
410 }