drivers/acpi/executer/exsystem.c

   1
   2 /******************************************************************************
   3  *
   4  * Module Name: exsystem - Interface to OS services
   5  *
   6  *****************************************************************************/
   7
   8 /*
   9  * Copyright (C) 2000 - 2005, R. Byron Moore
  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 <acpi/acinterp.h>
  47 #include <acpi/acevents.h>
  48
  49 #define _COMPONENT          ACPI_EXECUTER
  50 ACPI_MODULE_NAME("exsystem")
  51
  52 /*******************************************************************************
  53  *
  54  * FUNCTION:    acpi_ex_system_wait_semaphore
  55  *
  56  * PARAMETERS:  Semaphore       - Semaphore to wait on
  57  *              Timeout         - Max time to wait
  58  *
  59  * RETURN:      Status
  60  *
  61  * DESCRIPTION: Implements a semaphore wait with a check to see if the
  62  *              semaphore is available immediately.  If it is not, the
  63  *              interpreter is released.
  64  *
  65  ******************************************************************************/
  66 acpi_status acpi_ex_system_wait_semaphore(acpi_handle semaphore, u16 timeout)
  67 {
  68         acpi_status status;
  69         acpi_status status2;
  70
  71         ACPI_FUNCTION_TRACE("ex_system_wait_semaphore");
  72
  73         status = acpi_os_wait_semaphore(semaphore, 1, 0);
  74         if (ACPI_SUCCESS(status)) {
  75                 return_ACPI_STATUS(status);
  76         }
  77
  78         if (status == AE_TIME) {
  79                 /* We must wait, so unlock the interpreter */
  80
  81                 acpi_ex_exit_interpreter();
  82
  83                 status = acpi_os_wait_semaphore(semaphore, 1, timeout);
  84
  85                 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
  86                                   "*** Thread awake after blocking, %s\n",
  87                                   acpi_format_exception(status)));
  88
  89                 /* Reacquire the interpreter */
  90
  91                 status2 = acpi_ex_enter_interpreter();
  92                 if (ACPI_FAILURE(status2)) {
  93                         /* Report fatal error, could not acquire interpreter */
  94
  95                         return_ACPI_STATUS(status2);
  96                 }
  97         }
  98
  99         return_ACPI_STATUS(status);
 100 }
 101
 102 /*******************************************************************************
 103  *
 104  * FUNCTION:    acpi_ex_system_do_stall
 105  *
 106  * PARAMETERS:  how_long        - The amount of time to stall,
 107  *                                in microseconds
 108  *
 109  * RETURN:      Status
 110  *
 111  * DESCRIPTION: Suspend running thread for specified amount of time.
 112  *              Note: ACPI specification requires that Stall() does not
 113  *              relinquish the processor, and delays longer than 100 usec
 114  *              should use Sleep() instead.  We allow stalls up to 255 usec
 115  *              for compatibility with other interpreters and existing BIOSs.
 116  *
 117  ******************************************************************************/
 118
 119 acpi_status acpi_ex_system_do_stall(u32 how_long)
 120 {
 121         acpi_status status = AE_OK;
 122
 123         ACPI_FUNCTION_ENTRY();
 124
 125         if (how_long > 255) {   /* 255 microseconds */
 126                 /*
 127                  * Longer than 255 usec, this is an error
 128                  *
 129                  * (ACPI specifies 100 usec as max, but this gives some slack in
 130                  * order to support existing BIOSs)
 131                  */
 132                 ACPI_REPORT_ERROR(("Stall: Time parameter is too large (%d)\n",
 133                                    how_long));
 134                 status = AE_AML_OPERAND_VALUE;
 135         } else {
 136                 acpi_os_stall(how_long);
 137         }
 138
 139         return (status);
 140 }
 141
 142 /*******************************************************************************
 143  *
 144  * FUNCTION:    acpi_ex_system_do_suspend
 145  *
 146  * PARAMETERS:  how_long        - The amount of time to suspend,
 147  *                                in milliseconds
 148  *
 149  * RETURN:      None
 150  *
 151  * DESCRIPTION: Suspend running thread for specified amount of time.
 152  *
 153  ******************************************************************************/
 154
 155 acpi_status acpi_ex_system_do_suspend(acpi_integer how_long)
 156 {
 157         acpi_status status;
 158
 159         ACPI_FUNCTION_ENTRY();
 160
 161         /* Since this thread will sleep, we must release the interpreter */
 162
 163         acpi_ex_exit_interpreter();
 164
 165         acpi_os_sleep(how_long);
 166
 167         /* And now we must get the interpreter again */
 168
 169         status = acpi_ex_enter_interpreter();
 170         return (status);
 171 }
 172
 173 /*******************************************************************************
 174  *
 175  * FUNCTION:    acpi_ex_system_acquire_mutex
 176  *
 177  * PARAMETERS:  time_desc       - The 'time to delay' object descriptor
 178  *              obj_desc        - The object descriptor for this op
 179  *
 180  * RETURN:      Status
 181  *
 182  * DESCRIPTION: Provides an access point to perform synchronization operations
 183  *              within the AML.  This function will cause a lock to be generated
 184  *              for the Mutex pointed to by obj_desc.
 185  *
 186  ******************************************************************************/
 187
 188 acpi_status
 189 acpi_ex_system_acquire_mutex(union acpi_operand_object * time_desc,
 190                              union acpi_operand_object * obj_desc)
 191 {
 192         acpi_status status = AE_OK;
 193
 194         ACPI_FUNCTION_TRACE_PTR("ex_system_acquire_mutex", obj_desc);
 195
 196         if (!obj_desc) {
 197                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 198         }
 199
 200         /* Support for the _GL_ Mutex object -- go get the global lock */
 201
 202         if (obj_desc->mutex.semaphore == acpi_gbl_global_lock_semaphore) {
 203                 status =
 204                     acpi_ev_acquire_global_lock((u16) time_desc->integer.value);
 205                 return_ACPI_STATUS(status);
 206         }
 207
 208         status = acpi_ex_system_wait_semaphore(obj_desc->mutex.semaphore,
 209                                                (u16) time_desc->integer.value);
 210         return_ACPI_STATUS(status);
 211 }
 212
 213 /*******************************************************************************
 214  *
 215  * FUNCTION:    acpi_ex_system_release_mutex
 216  *
 217  * PARAMETERS:  obj_desc        - The object descriptor for this op
 218  *
 219  * RETURN:      Status
 220  *
 221  * DESCRIPTION: Provides an access point to perform synchronization operations
 222  *              within the AML.  This operation is a request to release a
 223  *              previously acquired Mutex.  If the Mutex variable is set then
 224  *              it will be decremented.
 225  *
 226  ******************************************************************************/
 227
 228 acpi_status acpi_ex_system_release_mutex(union acpi_operand_object *obj_desc)
 229 {
 230         acpi_status status = AE_OK;
 231
 232         ACPI_FUNCTION_TRACE("ex_system_release_mutex");
 233
 234         if (!obj_desc) {
 235                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 236         }
 237
 238         /* Support for the _GL_ Mutex object -- release the global lock */
 239
 240         if (obj_desc->mutex.semaphore == acpi_gbl_global_lock_semaphore) {
 241                 status = acpi_ev_release_global_lock();
 242                 return_ACPI_STATUS(status);
 243         }
 244
 245         status = acpi_os_signal_semaphore(obj_desc->mutex.semaphore, 1);
 246         return_ACPI_STATUS(status);
 247 }
 248
 249 /*******************************************************************************
 250  *
 251  * FUNCTION:    acpi_ex_system_signal_event
 252  *
 253  * PARAMETERS:  obj_desc        - The object descriptor for this op
 254  *
 255  * RETURN:      Status
 256  *
 257  * DESCRIPTION: Provides an access point to perform synchronization operations
 258  *              within the AML.
 259  *
 260  ******************************************************************************/
 261
 262 acpi_status acpi_ex_system_signal_event(union acpi_operand_object *obj_desc)
 263 {
 264         acpi_status status = AE_OK;
 265
 266         ACPI_FUNCTION_TRACE("ex_system_signal_event");
 267
 268         if (obj_desc) {
 269                 status = acpi_os_signal_semaphore(obj_desc->event.semaphore, 1);
 270         }
 271
 272         return_ACPI_STATUS(status);
 273 }
 274
 275 /*******************************************************************************
 276  *
 277  * FUNCTION:    acpi_ex_system_wait_event
 278  *
 279  * PARAMETERS:  time_desc       - The 'time to delay' object descriptor
 280  *              obj_desc        - The object descriptor for this op
 281  *
 282  * RETURN:      Status
 283  *
 284  * DESCRIPTION: Provides an access point to perform synchronization operations
 285  *              within the AML.  This operation is a request to wait for an
 286  *              event.
 287  *
 288  ******************************************************************************/
 289
 290 acpi_status
 291 acpi_ex_system_wait_event(union acpi_operand_object *time_desc,
 292                           union acpi_operand_object *obj_desc)
 293 {
 294         acpi_status status = AE_OK;
 295
 296         ACPI_FUNCTION_TRACE("ex_system_wait_event");
 297
 298         if (obj_desc) {
 299                 status =
 300                     acpi_ex_system_wait_semaphore(obj_desc->event.semaphore,
 301                                                   (u16) time_desc->integer.
 302                                                   value);
 303         }
 304
 305         return_ACPI_STATUS(status);
 306 }
 307
 308 /*******************************************************************************
 309  *
 310  * FUNCTION:    acpi_ex_system_reset_event
 311  *
 312  * PARAMETERS:  obj_desc        - The object descriptor for this op
 313  *
 314  * RETURN:      Status
 315  *
 316  * DESCRIPTION: Reset an event to a known state.
 317  *
 318  ******************************************************************************/
 319
 320 acpi_status acpi_ex_system_reset_event(union acpi_operand_object *obj_desc)
 321 {
 322         acpi_status status = AE_OK;
 323         void *temp_semaphore;
 324
 325         ACPI_FUNCTION_ENTRY();
 326
 327         /*
 328          * We are going to simply delete the existing semaphore and
 329          * create a new one!
 330          */
 331         status =
 332             acpi_os_create_semaphore(ACPI_NO_UNIT_LIMIT, 0, &temp_semaphore);
 333         if (ACPI_SUCCESS(status)) {
 334                 (void)acpi_os_delete_semaphore(obj_desc->event.semaphore);
 335                 obj_desc->event.semaphore = temp_semaphore;
 336         }
 337
 338         return (status);
 339 }