drivers/acpi/acpica/exfield.c

   1 /******************************************************************************
   2  *
   3  * Module Name: exfield - ACPI AML (p-code) execution - field manipulation
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2008, Intel Corp.
   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 "accommon.h"
  46 #include "acdispat.h"
  47 #include "acinterp.h"
  48
  49 #define _COMPONENT          ACPI_EXECUTER
  50 ACPI_MODULE_NAME("exfield")
  51
  52 /*******************************************************************************
  53  *
  54  * FUNCTION:    acpi_ex_read_data_from_field
  55  *
  56  * PARAMETERS:  walk_state          - Current execution state
  57  *              obj_desc            - The named field
  58  *              ret_buffer_desc     - Where the return data object is stored
  59  *
  60  * RETURN:      Status
  61  *
  62  * DESCRIPTION: Read from a named field.  Returns either an Integer or a
  63  *              Buffer, depending on the size of the field.
  64  *
  65  ******************************************************************************/
  66 acpi_status
  67 acpi_ex_read_data_from_field(struct acpi_walk_state *walk_state,
  68                              union acpi_operand_object *obj_desc,
  69                              union acpi_operand_object **ret_buffer_desc)
  70 {
  71         acpi_status status;
  72         union acpi_operand_object *buffer_desc;
  73         acpi_size length;
  74         void *buffer;
  75         u32 function;
  76
  77         ACPI_FUNCTION_TRACE_PTR(ex_read_data_from_field, obj_desc);
  78
  79         /* Parameter validation */
  80
  81         if (!obj_desc) {
  82                 return_ACPI_STATUS(AE_AML_NO_OPERAND);
  83         }
  84         if (!ret_buffer_desc) {
  85                 return_ACPI_STATUS(AE_BAD_PARAMETER);
  86         }
  87
  88         if (obj_desc->common.type == ACPI_TYPE_BUFFER_FIELD) {
  89                 /*
  90                  * If the buffer_field arguments have not been previously evaluated,
  91                  * evaluate them now and save the results.
  92                  */
  93                 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
  94                         status = acpi_ds_get_buffer_field_arguments(obj_desc);
  95                         if (ACPI_FAILURE(status)) {
  96                                 return_ACPI_STATUS(status);
  97                         }
  98                 }
  99         } else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
 100                    (obj_desc->field.region_obj->region.space_id ==
 101                     ACPI_ADR_SPACE_SMBUS
 102                     || obj_desc->field.region_obj->region.space_id ==
 103                     ACPI_ADR_SPACE_IPMI)) {
 104                 /*
 105                  * This is an SMBus or IPMI read. We must create a buffer to hold
 106                  * the data and then directly access the region handler.
 107                  *
 108                  * Note: Smbus protocol value is passed in upper 16-bits of Function
 109                  */
 110                 if (obj_desc->field.region_obj->region.space_id ==
 111                     ACPI_ADR_SPACE_SMBUS) {
 112                         length = ACPI_SMBUS_BUFFER_SIZE;
 113                         function =
 114                             ACPI_READ | (obj_desc->field.attribute << 16);
 115                 } else {        /* IPMI */
 116
 117                         length = ACPI_IPMI_BUFFER_SIZE;
 118                         function = ACPI_READ;
 119                 }
 120
 121                 buffer_desc = acpi_ut_create_buffer_object(length);
 122                 if (!buffer_desc) {
 123                         return_ACPI_STATUS(AE_NO_MEMORY);
 124                 }
 125
 126                 /* Lock entire transaction if requested */
 127
 128                 acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
 129
 130                 /* Call the region handler for the read */
 131
 132                 status = acpi_ex_access_region(obj_desc, 0,
 133                                                ACPI_CAST_PTR(acpi_integer,
 134                                                              buffer_desc->
 135                                                              buffer.pointer),
 136                                                function);
 137                 acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
 138                 goto exit;
 139         }
 140
 141         /*
 142          * Allocate a buffer for the contents of the field.
 143          *
 144          * If the field is larger than the size of an acpi_integer, create
 145          * a BUFFER to hold it.  Otherwise, use an INTEGER.  This allows
 146          * the use of arithmetic operators on the returned value if the
 147          * field size is equal or smaller than an Integer.
 148          *
 149          * Note: Field.length is in bits.
 150          */
 151         length =
 152             (acpi_size) ACPI_ROUND_BITS_UP_TO_BYTES(obj_desc->field.bit_length);
 153         if (length > acpi_gbl_integer_byte_width) {
 154
 155                 /* Field is too large for an Integer, create a Buffer instead */
 156
 157                 buffer_desc = acpi_ut_create_buffer_object(length);
 158                 if (!buffer_desc) {
 159                         return_ACPI_STATUS(AE_NO_MEMORY);
 160                 }
 161                 buffer = buffer_desc->buffer.pointer;
 162         } else {
 163                 /* Field will fit within an Integer (normal case) */
 164
 165                 buffer_desc = acpi_ut_create_internal_object(ACPI_TYPE_INTEGER);
 166                 if (!buffer_desc) {
 167                         return_ACPI_STATUS(AE_NO_MEMORY);
 168                 }
 169
 170                 length = acpi_gbl_integer_byte_width;
 171                 buffer_desc->integer.value = 0;
 172                 buffer = &buffer_desc->integer.value;
 173         }
 174
 175         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 176                           "FieldRead [TO]:   Obj %p, Type %X, Buf %p, ByteLen %X\n",
 177                           obj_desc, obj_desc->common.type, buffer,
 178                           (u32) length));
 179         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 180                           "FieldRead [FROM]: BitLen %X, BitOff %X, ByteOff %X\n",
 181                           obj_desc->common_field.bit_length,
 182                           obj_desc->common_field.start_field_bit_offset,
 183                           obj_desc->common_field.base_byte_offset));
 184
 185         /* Lock entire transaction if requested */
 186
 187         acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
 188
 189         /* Read from the field */
 190
 191         status = acpi_ex_extract_from_field(obj_desc, buffer, (u32) length);
 192         acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
 193
 194       exit:
 195         if (ACPI_FAILURE(status)) {
 196                 acpi_ut_remove_reference(buffer_desc);
 197         } else {
 198                 *ret_buffer_desc = buffer_desc;
 199         }
 200
 201         return_ACPI_STATUS(status);
 202 }
 203
 204 /*******************************************************************************
 205  *
 206  * FUNCTION:    acpi_ex_write_data_to_field
 207  *
 208  * PARAMETERS:  source_desc         - Contains data to write
 209  *              obj_desc            - The named field
 210  *              result_desc         - Where the return value is returned, if any
 211  *
 212  * RETURN:      Status
 213  *
 214  * DESCRIPTION: Write to a named field
 215  *
 216  ******************************************************************************/
 217
 218 acpi_status
 219 acpi_ex_write_data_to_field(union acpi_operand_object *source_desc,
 220                             union acpi_operand_object *obj_desc,
 221                             union acpi_operand_object **result_desc)
 222 {
 223         acpi_status status;
 224         u32 length;
 225         void *buffer;
 226         union acpi_operand_object *buffer_desc;
 227         u32 function;
 228
 229         ACPI_FUNCTION_TRACE_PTR(ex_write_data_to_field, obj_desc);
 230
 231         /* Parameter validation */
 232
 233         if (!source_desc || !obj_desc) {
 234                 return_ACPI_STATUS(AE_AML_NO_OPERAND);
 235         }
 236
 237         if (obj_desc->common.type == ACPI_TYPE_BUFFER_FIELD) {
 238                 /*
 239                  * If the buffer_field arguments have not been previously evaluated,
 240                  * evaluate them now and save the results.
 241                  */
 242                 if (!(obj_desc->common.flags & AOPOBJ_DATA_VALID)) {
 243                         status = acpi_ds_get_buffer_field_arguments(obj_desc);
 244                         if (ACPI_FAILURE(status)) {
 245                                 return_ACPI_STATUS(status);
 246                         }
 247                 }
 248         } else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
 249                    (obj_desc->field.region_obj->region.space_id ==
 250                     ACPI_ADR_SPACE_SMBUS
 251                     || obj_desc->field.region_obj->region.space_id ==
 252                     ACPI_ADR_SPACE_IPMI)) {
 253                 /*
 254                  * This is an SMBus or IPMI write. We will bypass the entire field
 255                  * mechanism and handoff the buffer directly to the handler. For
 256                  * these address spaces, the buffer is bi-directional; on a write,
 257                  * return data is returned in the same buffer.
 258                  *
 259                  * Source must be a buffer of sufficient size:
 260                  * ACPI_SMBUS_BUFFER_SIZE or ACPI_IPMI_BUFFER_SIZE.
 261                  *
 262                  * Note: SMBus protocol type is passed in upper 16-bits of Function
 263                  */
 264                 if (source_desc->common.type != ACPI_TYPE_BUFFER) {
 265                         ACPI_ERROR((AE_INFO,
 266                                     "SMBus or IPMI write requires Buffer, found type %s",
 267                                     acpi_ut_get_object_type_name(source_desc)));
 268
 269                         return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
 270                 }
 271
 272                 if (obj_desc->field.region_obj->region.space_id ==
 273                     ACPI_ADR_SPACE_SMBUS) {
 274                         length = ACPI_SMBUS_BUFFER_SIZE;
 275                         function =
 276                             ACPI_WRITE | (obj_desc->field.attribute << 16);
 277                 } else {        /* IPMI */
 278
 279                         length = ACPI_IPMI_BUFFER_SIZE;
 280                         function = ACPI_WRITE;
 281                 }
 282
 283                 if (source_desc->buffer.length < length) {
 284                         ACPI_ERROR((AE_INFO,
 285                                     "SMBus or IPMI write requires Buffer of length %X, found length %X",
 286                                     length, source_desc->buffer.length));
 287
 288                         return_ACPI_STATUS(AE_AML_BUFFER_LIMIT);
 289                 }
 290
 291                 /* Create the bi-directional buffer */
 292
 293                 buffer_desc = acpi_ut_create_buffer_object(length);
 294                 if (!buffer_desc) {
 295                         return_ACPI_STATUS(AE_NO_MEMORY);
 296                 }
 297
 298                 buffer = buffer_desc->buffer.pointer;
 299                 ACPI_MEMCPY(buffer, source_desc->buffer.pointer, length);
 300
 301                 /* Lock entire transaction if requested */
 302
 303                 acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
 304
 305                 /*
 306                  * Perform the write (returns status and perhaps data in the
 307                  * same buffer)
 308                  */
 309                 status = acpi_ex_access_region(obj_desc, 0,
 310                                                (acpi_integer *) buffer,
 311                                                function);
 312                 acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
 313
 314                 *result_desc = buffer_desc;
 315                 return_ACPI_STATUS(status);
 316         }
 317
 318         /* Get a pointer to the data to be written */
 319
 320         switch (source_desc->common.type) {
 321         case ACPI_TYPE_INTEGER:
 322                 buffer = &source_desc->integer.value;
 323                 length = sizeof(source_desc->integer.value);
 324                 break;
 325
 326         case ACPI_TYPE_BUFFER:
 327                 buffer = source_desc->buffer.pointer;
 328                 length = source_desc->buffer.length;
 329                 break;
 330
 331         case ACPI_TYPE_STRING:
 332                 buffer = source_desc->string.pointer;
 333                 length = source_desc->string.length;
 334                 break;
 335
 336         default:
 337                 return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
 338         }
 339
 340         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 341                           "FieldWrite [FROM]: Obj %p (%s:%X), Buf %p, ByteLen %X\n",
 342                           source_desc,
 343                           acpi_ut_get_type_name(source_desc->common.type),
 344                           source_desc->common.type, buffer, length));
 345
 346         ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
 347                           "FieldWrite [TO]:   Obj %p (%s:%X), BitLen %X, BitOff %X, ByteOff %X\n",
 348                           obj_desc,
 349                           acpi_ut_get_type_name(obj_desc->common.type),
 350                           obj_desc->common.type,
 351                           obj_desc->common_field.bit_length,
 352                           obj_desc->common_field.start_field_bit_offset,
 353                           obj_desc->common_field.base_byte_offset));
 354
 355         /* Lock entire transaction if requested */
 356
 357         acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
 358
 359         /* Write to the field */
 360
 361         status = acpi_ex_insert_into_field(obj_desc, buffer, length);
 362         acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
 363
 364         return_ACPI_STATUS(status);
 365 }