drivers/acpi/resources/rslist.c

   1 /*******************************************************************************
   2  *
   3  * Module Name: rslist - Linked list utilities
   4  *
   5  ******************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2005, 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/acresrc.h>
  46
  47 #define _COMPONENT          ACPI_RESOURCES
  48 ACPI_MODULE_NAME("rslist")
  49
  50 /* Local prototypes */
  51 static ACPI_GET_RESOURCE_HANDLER acpi_rs_get_resource_handler(u8 resource_type);
  52
  53 static acpi_status acpi_rs_validate_resource_length(union aml_resource *aml);
  54
  55 /*******************************************************************************
  56  *
  57  * FUNCTION:    acpi_rs_validate_resource_length
  58  *
  59  * PARAMETERS:  Aml                 - Pointer to the AML resource descriptor
  60  *
  61  * RETURN:      Status - AE_OK if the resource length appears valid
  62  *
  63  * DESCRIPTION: Validate the resource_length. Fixed-length descriptors must
  64  *              have the exact length; variable-length descriptors must be
  65  *              at least as long as the minimum. Certain Small descriptors
  66  *              can vary in size by at most one byte.
  67  *
  68  ******************************************************************************/
  69
  70 static acpi_status acpi_rs_validate_resource_length(union aml_resource *aml)
  71 {
  72         struct acpi_resource_info *resource_info;
  73         u16 minimum_aml_resource_length;
  74         u16 resource_length;
  75
  76         ACPI_FUNCTION_ENTRY();
  77
  78         /* Get the size and type info about this resource descriptor */
  79
  80         resource_info =
  81             acpi_rs_get_resource_info(aml->small_header.descriptor_type);
  82         if (!resource_info) {
  83                 return (AE_AML_INVALID_RESOURCE_TYPE);
  84         }
  85
  86         resource_length = acpi_rs_get_resource_length(aml);
  87         minimum_aml_resource_length =
  88             resource_info->minimum_aml_resource_length;
  89
  90         /* Validate based upon the type of resource, fixed length or variable */
  91
  92         if (resource_info->length_type == ACPI_FIXED_LENGTH) {
  93                 /* Fixed length resource, length must match exactly */
  94
  95                 if (resource_length != minimum_aml_resource_length) {
  96                         return (AE_AML_BAD_RESOURCE_LENGTH);
  97                 }
  98         } else if (resource_info->length_type == ACPI_VARIABLE_LENGTH) {
  99                 /* Variable length resource, must be at least the minimum */
 100
 101                 if (resource_length < minimum_aml_resource_length) {
 102                         return (AE_AML_BAD_RESOURCE_LENGTH);
 103                 }
 104         } else {
 105                 /* Small variable length resource, allowed to be (Min) or (Min-1) */
 106
 107                 if ((resource_length > minimum_aml_resource_length) ||
 108                     (resource_length < (minimum_aml_resource_length - 1))) {
 109                         return (AE_AML_BAD_RESOURCE_LENGTH);
 110                 }
 111         }
 112
 113         return (AE_OK);
 114 }
 115
 116 /*******************************************************************************
 117  *
 118  * FUNCTION:    acpi_rs_get_resource_handler
 119  *
 120  * PARAMETERS:  resource_type       - Byte 0 of a resource descriptor
 121  *
 122  * RETURN:      Pointer to the resource conversion handler
 123  *
 124  * DESCRIPTION: Extract the Resource Type/Name from the first byte of
 125  *              a resource descriptor.
 126  *
 127  ******************************************************************************/
 128
 129 static ACPI_GET_RESOURCE_HANDLER acpi_rs_get_resource_handler(u8 resource_type)
 130 {
 131         ACPI_FUNCTION_ENTRY();
 132
 133         /* Determine if this is a small or large resource */
 134
 135         if (resource_type & ACPI_RESOURCE_NAME_LARGE) {
 136                 /* Large Resource Type -- bits 6:0 contain the name */
 137
 138                 if (resource_type > ACPI_RESOURCE_NAME_LARGE_MAX) {
 139                         return (NULL);
 140                 }
 141
 142                 return (acpi_gbl_lg_get_resource_dispatch[(resource_type &
 143                                                            ACPI_RESOURCE_NAME_LARGE_MASK)]);
 144         } else {
 145                 /* Small Resource Type -- bits 6:3 contain the name */
 146
 147                 return (acpi_gbl_sm_get_resource_dispatch[((resource_type &
 148                                                             ACPI_RESOURCE_NAME_SMALL_MASK)
 149                                                            >> 3)]);
 150         }
 151 }
 152
 153 /*******************************************************************************
 154  *
 155  * FUNCTION:    acpi_rs_convert_aml_to_resources
 156  *
 157  * PARAMETERS:  aml_buffer          - Pointer to the resource byte stream
 158  *              aml_buffer_length   - Length of aml_buffer
 159  *              output_buffer       - Pointer to the buffer that will
 160  *                                    contain the output structures
 161  *
 162  * RETURN:      Status
 163  *
 164  * DESCRIPTION: Takes the resource byte stream and parses it, creating a
 165  *              linked list of resources in the caller's output buffer
 166  *
 167  ******************************************************************************/
 168
 169 acpi_status
 170 acpi_rs_convert_aml_to_resources(u8 * aml_buffer,
 171                                  u32 aml_buffer_length, u8 * output_buffer)
 172 {
 173         u8 *buffer = output_buffer;
 174         acpi_status status;
 175         acpi_size bytes_parsed = 0;
 176         struct acpi_resource *resource;
 177         u16 resource_length;
 178         u32 descriptor_length;
 179         ACPI_GET_RESOURCE_HANDLER handler;
 180
 181         ACPI_FUNCTION_TRACE("rs_convert_aml_to_resources");
 182
 183         /* Loop until end-of-buffer or an end_tag is found */
 184
 185         while (bytes_parsed < aml_buffer_length) {
 186                 /* Get the handler associated with this Descriptor Type */
 187
 188                 handler = acpi_rs_get_resource_handler(*aml_buffer);
 189                 if (!handler) {
 190                         /* No handler indicates invalid resource type */
 191
 192                         return_ACPI_STATUS(AE_AML_INVALID_RESOURCE_TYPE);
 193                 }
 194
 195                 resource_length =
 196                     acpi_rs_get_resource_length(ACPI_CAST_PTR
 197                                                 (union aml_resource,
 198                                                  aml_buffer));
 199
 200                 descriptor_length =
 201                     acpi_rs_get_descriptor_length(ACPI_CAST_PTR
 202                                                   (union aml_resource,
 203                                                    aml_buffer));
 204
 205                 /*
 206                  * Perform limited validation of the resource length, based upon
 207                  * what we know about the resource type
 208                  */
 209                 status =
 210                     acpi_rs_validate_resource_length(ACPI_CAST_PTR
 211                                                      (union aml_resource,
 212                                                       aml_buffer));
 213                 if (ACPI_FAILURE(status)) {
 214                         return_ACPI_STATUS(status);
 215                 }
 216
 217                 /* Convert a byte stream resource to local resource struct */
 218
 219                 status = handler(ACPI_CAST_PTR(union aml_resource, aml_buffer),
 220                                  resource_length,
 221                                  ACPI_CAST_PTR(struct acpi_resource, buffer));
 222                 if (ACPI_FAILURE(status)) {
 223                         ACPI_REPORT_ERROR(("Could not convert AML resource (type %X) to resource, %s\n", *aml_buffer, acpi_format_exception(status)));
 224                         return_ACPI_STATUS(status);
 225                 }
 226
 227                 /* Set the aligned length of the new resource descriptor */
 228
 229                 resource = ACPI_CAST_PTR(struct acpi_resource, buffer);
 230                 resource->length =
 231                     (u32) ACPI_ALIGN_RESOURCE_SIZE(resource->length);
 232
 233                 /* Normal exit on completion of an end_tag resource descriptor */
 234
 235                 if (acpi_rs_get_resource_type(*aml_buffer) ==
 236                     ACPI_RESOURCE_NAME_END_TAG) {
 237                         return_ACPI_STATUS(AE_OK);
 238                 }
 239
 240                 /* Update counter and point to the next input resource */
 241
 242                 bytes_parsed += descriptor_length;
 243                 aml_buffer += descriptor_length;
 244
 245                 /* Point to the next structure in the output buffer */
 246
 247                 buffer += resource->length;
 248         }
 249
 250         /* Completed buffer, but did not find an end_tag resource descriptor */
 251
 252         return_ACPI_STATUS(AE_AML_NO_RESOURCE_END_TAG);
 253 }
 254
 255 /*******************************************************************************
 256  *
 257  * FUNCTION:    acpi_rs_convert_resources_to_aml
 258  *
 259  * PARAMETERS:  Resource            - Pointer to the resource linked list
 260  *              aml_size_needed     - Calculated size of the byte stream
 261  *                                    needed from calling acpi_rs_get_aml_length()
 262  *                                    The size of the output_buffer is
 263  *                                    guaranteed to be >= aml_size_needed
 264  *              output_buffer       - Pointer to the buffer that will
 265  *                                    contain the byte stream
 266  *
 267  * RETURN:      Status
 268  *
 269  * DESCRIPTION: Takes the resource linked list and parses it, creating a
 270  *              byte stream of resources in the caller's output buffer
 271  *
 272  ******************************************************************************/
 273
 274 acpi_status
 275 acpi_rs_convert_resources_to_aml(struct acpi_resource *resource,
 276                                  acpi_size aml_size_needed, u8 * output_buffer)
 277 {
 278         u8 *aml_buffer = output_buffer;
 279         acpi_status status;
 280
 281         ACPI_FUNCTION_TRACE("rs_convert_resources_to_aml");
 282
 283         /* Convert each resource descriptor in the list */
 284
 285         while (1) {
 286                 /* Validate Resource Descriptor Type before dispatch */
 287
 288                 if (resource->type > ACPI_RESOURCE_TYPE_MAX) {
 289                         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 290                                           "Invalid descriptor type (%X) in resource list\n",
 291                                           resource->type));
 292                         return_ACPI_STATUS(AE_BAD_DATA);
 293                 }
 294
 295                 /* Perform the conversion per resource type */
 296
 297                 status =
 298                     acpi_gbl_set_resource_dispatch[resource->type] (resource,
 299                                                                     ACPI_CAST_PTR
 300                                                                     (union
 301                                                                      aml_resource,
 302                                                                      aml_buffer));
 303                 if (ACPI_FAILURE(status)) {
 304                         ACPI_REPORT_ERROR(("Could not convert resource (type %X) to AML, %s\n", resource->type, acpi_format_exception(status)));
 305                         return_ACPI_STATUS(status);
 306                 }
 307
 308                 /* Perform final sanity check on the new AML resource descriptor */
 309
 310                 status =
 311                     acpi_rs_validate_resource_length(ACPI_CAST_PTR
 312                                                      (union aml_resource,
 313                                                       aml_buffer));
 314                 if (ACPI_FAILURE(status)) {
 315                         return_ACPI_STATUS(status);
 316                 }
 317
 318                 /* Check for end-of-list, normal exit */
 319
 320                 if (resource->type == ACPI_RESOURCE_TYPE_END_TAG) {
 321                         /* An End Tag indicates the end of the input Resource Template */
 322
 323                         return_ACPI_STATUS(AE_OK);
 324                 }
 325
 326                 /* Extract the total length of the new descriptor */
 327                 /* Set the aml_buffer to point to the next (output) resource descriptor */
 328
 329                 aml_buffer +=
 330                     acpi_rs_get_descriptor_length(ACPI_CAST_PTR
 331                                                   (union aml_resource,
 332                                                    aml_buffer));
 333
 334                 /* Point to the next input resource descriptor */
 335
 336                 resource =
 337                     ACPI_PTR_ADD(struct acpi_resource, resource,
 338                                  resource->length);
 339         }
 340 }