drivers/acpi/parser/psutils.c

   1 /******************************************************************************
   2  *
   3  * Module Name: psutils - Parser miscellaneous utilities (Parser only)
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2007, R. Byron Moore
   9  * All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice, this list of conditions, and the following disclaimer,
  16  *    without modification.
  17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  18  *    substantially similar to the "NO WARRANTY" disclaimer below
  19  *    ("Disclaimer") and any redistribution must be conditioned upon
  20  *    including a substantially similar Disclaimer requirement for further
  21  *    binary redistribution.
  22  * 3. Neither the names of the above-listed copyright holders nor the names
  23  *    of any contributors may be used to endorse or promote products derived
  24  *    from this software without specific prior written permission.
  25  *
  26  * Alternatively, this software may be distributed under the terms of the
  27  * GNU General Public License ("GPL") version 2 as published by the Free
  28  * Software Foundation.
  29  *
  30  * NO WARRANTY
  31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  41  * POSSIBILITY OF SUCH DAMAGES.
  42  */
  43
  44 #include <acpi/acpi.h>
  45 #include <acpi/acparser.h>
  46 #include <acpi/amlcode.h>
  47
  48 #define _COMPONENT          ACPI_PARSER
  49 ACPI_MODULE_NAME("psutils")
  50
  51 /*******************************************************************************
  52  *
  53  * FUNCTION:    acpi_ps_create_scope_op
  54  *
  55  * PARAMETERS:  None
  56  *
  57  * RETURN:      A new Scope object, null on failure
  58  *
  59  * DESCRIPTION: Create a Scope and associated namepath op with the root name
  60  *
  61  ******************************************************************************/
  62 union acpi_parse_object *acpi_ps_create_scope_op(void)
  63 {
  64         union acpi_parse_object *scope_op;
  65
  66         scope_op = acpi_ps_alloc_op(AML_SCOPE_OP);
  67         if (!scope_op) {
  68                 return (NULL);
  69         }
  70
  71         scope_op->named.name = ACPI_ROOT_NAME;
  72         return (scope_op);
  73 }
  74
  75 /*******************************************************************************
  76  *
  77  * FUNCTION:    acpi_ps_init_op
  78  *
  79  * PARAMETERS:  Op              - A newly allocated Op object
  80  *              Opcode          - Opcode to store in the Op
  81  *
  82  * RETURN:      None
  83  *
  84  * DESCRIPTION: Initialize a parse (Op) object
  85  *
  86  ******************************************************************************/
  87
  88 void acpi_ps_init_op(union acpi_parse_object *op, u16 opcode)
  89 {
  90         ACPI_FUNCTION_ENTRY();
  91
  92         op->common.descriptor_type = ACPI_DESC_TYPE_PARSER;
  93         op->common.aml_opcode = opcode;
  94
  95         ACPI_DISASM_ONLY_MEMBERS(ACPI_STRNCPY(op->common.aml_op_name,
  96                                               (acpi_ps_get_opcode_info
  97                                                (opcode))->name,
  98                                               sizeof(op->common.aml_op_name)));
  99 }
 100
 101 /*******************************************************************************
 102  *
 103  * FUNCTION:    acpi_ps_alloc_op
 104  *
 105  * PARAMETERS:  Opcode          - Opcode that will be stored in the new Op
 106  *
 107  * RETURN:      Pointer to the new Op, null on failure
 108  *
 109  * DESCRIPTION: Allocate an acpi_op, choose op type (and thus size) based on
 110  *              opcode.  A cache of opcodes is available for the pure
 111  *              GENERIC_OP, since this is by far the most commonly used.
 112  *
 113  ******************************************************************************/
 114
 115 union acpi_parse_object *acpi_ps_alloc_op(u16 opcode)
 116 {
 117         union acpi_parse_object *op;
 118         const struct acpi_opcode_info *op_info;
 119         u8 flags = ACPI_PARSEOP_GENERIC;
 120
 121         ACPI_FUNCTION_ENTRY();
 122
 123         op_info = acpi_ps_get_opcode_info(opcode);
 124
 125         /* Determine type of parse_op required */
 126
 127         if (op_info->flags & AML_DEFER) {
 128                 flags = ACPI_PARSEOP_DEFERRED;
 129         } else if (op_info->flags & AML_NAMED) {
 130                 flags = ACPI_PARSEOP_NAMED;
 131         } else if (opcode == AML_INT_BYTELIST_OP) {
 132                 flags = ACPI_PARSEOP_BYTELIST;
 133         }
 134
 135         /* Allocate the minimum required size object */
 136
 137         if (flags == ACPI_PARSEOP_GENERIC) {
 138
 139                 /* The generic op (default) is by far the most common (16 to 1) */
 140
 141                 op = acpi_os_acquire_object(acpi_gbl_ps_node_cache);
 142         } else {
 143                 /* Extended parseop */
 144
 145                 op = acpi_os_acquire_object(acpi_gbl_ps_node_ext_cache);
 146         }
 147
 148         /* Initialize the Op */
 149
 150         if (op) {
 151                 acpi_ps_init_op(op, opcode);
 152                 op->common.flags = flags;
 153         }
 154
 155         return (op);
 156 }
 157
 158 /*******************************************************************************
 159  *
 160  * FUNCTION:    acpi_ps_free_op
 161  *
 162  * PARAMETERS:  Op              - Op to be freed
 163  *
 164  * RETURN:      None.
 165  *
 166  * DESCRIPTION: Free an Op object.  Either put it on the GENERIC_OP cache list
 167  *              or actually free it.
 168  *
 169  ******************************************************************************/
 170
 171 void acpi_ps_free_op(union acpi_parse_object *op)
 172 {
 173         ACPI_FUNCTION_NAME(ps_free_op);
 174
 175         if (op->common.aml_opcode == AML_INT_RETURN_VALUE_OP) {
 176                 ACPI_DEBUG_PRINT((ACPI_DB_ALLOCATIONS, "Free retval op: %p\n",
 177                                   op));
 178         }
 179
 180         if (op->common.flags & ACPI_PARSEOP_GENERIC) {
 181                 (void)acpi_os_release_object(acpi_gbl_ps_node_cache, op);
 182         } else {
 183                 (void)acpi_os_release_object(acpi_gbl_ps_node_ext_cache, op);
 184         }
 185 }
 186
 187 /*******************************************************************************
 188  *
 189  * FUNCTION:    Utility functions
 190  *
 191  * DESCRIPTION: Low level character and object functions
 192  *
 193  ******************************************************************************/
 194
 195 /*
 196  * Is "c" a namestring lead character?
 197  */
 198 u8 acpi_ps_is_leading_char(u32 c)
 199 {
 200         return ((u8) (c == '_' || (c >= 'A' && c <= 'Z')));
 201 }
 202
 203 /*
 204  * Is "c" a namestring prefix character?
 205  */
 206 u8 acpi_ps_is_prefix_char(u32 c)
 207 {
 208         return ((u8) (c == '\\' || c == '^'));
 209 }
 210
 211 /*
 212  * Get op's name (4-byte name segment) or 0 if unnamed
 213  */
 214 #ifdef ACPI_FUTURE_USAGE
 215 u32 acpi_ps_get_name(union acpi_parse_object * op)
 216 {
 217
 218         /* The "generic" object has no name associated with it */
 219
 220         if (op->common.flags & ACPI_PARSEOP_GENERIC) {
 221                 return (0);
 222         }
 223
 224         /* Only the "Extended" parse objects have a name */
 225
 226         return (op->named.name);
 227 }
 228 #endif                          /*  ACPI_FUTURE_USAGE  */
 229
 230 /*
 231  * Set op's name
 232  */
 233 void acpi_ps_set_name(union acpi_parse_object *op, u32 name)
 234 {
 235
 236         /* The "generic" object has no name associated with it */
 237
 238         if (op->common.flags & ACPI_PARSEOP_GENERIC) {
 239                 return;
 240         }
 241
 242         op->named.name = name;
 243 }