drivers/acpi/parser/psscope.c

   1 /******************************************************************************
   2  *
   3  * Module Name: psscope - Parser scope stack management routines
   4  *              $Revision: 22 $
   5  *
   6  *****************************************************************************/
   7
   8 /*
   9  *  Copyright (C) 2000 R. Byron Moore
  10  *
  11  *  This program is free software; you can redistribute it and/or modify
  12  *  it under the terms of the GNU General Public License as published by
  13  *  the Free Software Foundation; either version 2 of the License, or
  14  *  (at your option) any later version.
  15  *
  16  *  This program is distributed in the hope that it will be useful,
  17  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  *  GNU General Public License for more details.
  20  *
  21  *  You should have received a copy of the GNU General Public License
  22  *  along with this program; if not, write to the Free Software
  23  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  24  */
  25
  26
  27 #include "acpi.h"
  28 #include "acparser.h"
  29
  30 #define _COMPONENT          PARSER
  31          MODULE_NAME         ("psscope")
  32
  33
  34 /*******************************************************************************
  35  *
  36  * FUNCTION:    Acpi_ps_get_parent_scope
  37  *
  38  * PARAMETERS:  Parser_state        - Current parser state object
  39  *
  40  * RETURN:      Pointer to an Op object
  41  *
  42  * DESCRIPTION: Get parent of current op being parsed
  43  *
  44  ******************************************************************************/
  45
  46 ACPI_PARSE_OBJECT *
  47 acpi_ps_get_parent_scope (
  48         ACPI_PARSE_STATE        *parser_state)
  49 {
  50         return (parser_state->scope->parse_scope.op);
  51 }
  52
  53
  54 /*******************************************************************************
  55  *
  56  * FUNCTION:    Acpi_ps_has_completed_scope
  57  *
  58  * PARAMETERS:  Parser_state        - Current parser state object
  59  *
  60  * RETURN:      Boolean, TRUE = scope completed.
  61  *
  62  * DESCRIPTION: Is parsing of current argument complete?  Determined by
  63  *              1) AML pointer is at or beyond the end of the scope
  64  *              2) The scope argument count has reached zero.
  65  *
  66  ******************************************************************************/
  67
  68 u8
  69 acpi_ps_has_completed_scope (
  70         ACPI_PARSE_STATE        *parser_state)
  71 {
  72         return ((u8) ((parser_state->aml >= parser_state->scope->parse_scope.arg_end ||
  73                            !parser_state->scope->parse_scope.arg_count)));
  74 }
  75
  76
  77 /*******************************************************************************
  78  *
  79  * FUNCTION:    Acpi_ps_init_scope
  80  *
  81  * PARAMETERS:  Parser_state        - Current parser state object
  82  *              Root                - the Root Node of this new scope
  83  *
  84  * RETURN:      Status
  85  *
  86  * DESCRIPTION: Allocate and init a new scope object
  87  *
  88  ******************************************************************************/
  89
  90 ACPI_STATUS
  91 acpi_ps_init_scope (
  92         ACPI_PARSE_STATE        *parser_state,
  93         ACPI_PARSE_OBJECT       *root_op)
  94 {
  95         ACPI_GENERIC_STATE      *scope;
  96
  97
  98         scope = acpi_cm_create_generic_state ();
  99         if (!scope) {
 100                 return (AE_NO_MEMORY);
 101         }
 102
 103         scope->parse_scope.op       = root_op;
 104         scope->parse_scope.arg_count = ACPI_VAR_ARGS;
 105         scope->parse_scope.arg_end  = parser_state->aml_end;
 106         scope->parse_scope.pkg_end  = parser_state->aml_end;
 107
 108         parser_state->scope         = scope;
 109         parser_state->start_op      = root_op;
 110
 111         return (AE_OK);
 112 }
 113
 114
 115 /*******************************************************************************
 116  *
 117  * FUNCTION:    Acpi_ps_push_scope
 118  *
 119  * PARAMETERS:  Parser_state        - Current parser state object
 120  *              Op                  - Current op to be pushed
 121  *              Remaining_args      - List of args remaining
 122  *              Arg_count           - Fixed or variable number of args
 123  *
 124  * RETURN:      Status
 125  *
 126  * DESCRIPTION: Push current op to begin parsing its argument
 127  *
 128  ******************************************************************************/
 129
 130 ACPI_STATUS
 131 acpi_ps_push_scope (
 132         ACPI_PARSE_STATE        *parser_state,
 133         ACPI_PARSE_OBJECT       *op,
 134         u32                     remaining_args,
 135         u32                     arg_count)
 136 {
 137         ACPI_GENERIC_STATE      *scope;
 138
 139
 140         scope = acpi_cm_create_generic_state ();
 141         if (!scope) {
 142                 return (AE_NO_MEMORY);
 143         }
 144
 145
 146         scope->parse_scope.op          = op;
 147         scope->parse_scope.arg_list    = remaining_args;
 148         scope->parse_scope.arg_count   = arg_count;
 149         scope->parse_scope.pkg_end     = parser_state->pkg_end;
 150
 151         /* Push onto scope stack */
 152
 153         acpi_cm_push_generic_state (&parser_state->scope, scope);
 154
 155
 156         if (arg_count == ACPI_VAR_ARGS) {
 157                 /* multiple arguments */
 158
 159                 scope->parse_scope.arg_end = parser_state->pkg_end;
 160         }
 161
 162         else {
 163                 /* single argument */
 164
 165                 scope->parse_scope.arg_end = ACPI_MAX_AML;
 166         }
 167
 168         return (AE_OK);
 169 }
 170
 171
 172 /*******************************************************************************
 173  *
 174  * FUNCTION:    Acpi_ps_pop_scope
 175  *
 176  * PARAMETERS:  Parser_state        - Current parser state object
 177  *              Op                  - Where the popped op is returned
 178  *              Arg_list            - Where the popped "next argument" is
 179  *                                    returned
 180  *              Arg_count           - Count of objects in Arg_list
 181  *
 182  * RETURN:      Status
 183  *
 184  * DESCRIPTION: Return to parsing a previous op
 185  *
 186  ******************************************************************************/
 187
 188 void
 189 acpi_ps_pop_scope (
 190         ACPI_PARSE_STATE        *parser_state,
 191         ACPI_PARSE_OBJECT       **op,
 192         u32                     *arg_list,
 193         u32                     *arg_count)
 194 {
 195         ACPI_GENERIC_STATE      *scope = parser_state->scope;
 196
 197
 198         /*
 199          * Only pop the scope if there is in fact a next scope
 200          */
 201         if (scope->common.next) {
 202                 scope = acpi_cm_pop_generic_state (&parser_state->scope);
 203
 204
 205                 /* return to parsing previous op */
 206
 207                 *op                     = scope->parse_scope.op;
 208                 *arg_list               = scope->parse_scope.arg_list;
 209                 *arg_count              = scope->parse_scope.arg_count;
 210                 parser_state->pkg_end   = scope->parse_scope.pkg_end;
 211
 212                 /* All done with this scope state structure */
 213
 214                 acpi_cm_delete_generic_state (scope);
 215         }
 216
 217         else {
 218                 /* empty parse stack, prepare to fetch next opcode */
 219
 220                 *op                     = NULL;
 221                 *arg_list               = 0;
 222                 *arg_count              = 0;
 223         }
 224
 225
 226         return;
 227 }
 228
 229
 230 /*******************************************************************************
 231  *
 232  * FUNCTION:    Acpi_ps_cleanup_scope
 233  *
 234  * PARAMETERS:  Parser_state        - Current parser state object
 235  *
 236  * RETURN:      Status
 237  *
 238  * DESCRIPTION: Destroy available list, remaining stack levels, and return
 239  *              root scope
 240  *
 241  ******************************************************************************/
 242
 243 void
 244 acpi_ps_cleanup_scope (
 245         ACPI_PARSE_STATE        *parser_state)
 246 {
 247         ACPI_GENERIC_STATE      *scope;
 248
 249
 250         if (!parser_state) {
 251                 return;
 252         }
 253
 254
 255         /* Delete anything on the scope stack */
 256
 257         while (parser_state->scope) {
 258                 scope = acpi_cm_pop_generic_state (&parser_state->scope);
 259                 acpi_cm_delete_generic_state (scope);
 260         }
 261
 262         return;
 263 }
 264