drivers/acpi/executer/exsystem.c

   1
   2 /******************************************************************************
   3  *
   4  * Module Name: exsystem - Interface to OS services
   5  *
   6  *****************************************************************************/
   7
   8 /*
   9  * Copyright (C) 2000 - 2006, 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
  80                 /* We must wait, so unlock the interpreter */
  81
  82                 acpi_ex_exit_interpreter();
  83
  84                 status = acpi_os_wait_semaphore(semaphore, 1, timeout);
  85
  86                 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
  87                                   "*** Thread awake after blocking, %s\n",
  88                                   acpi_format_exception(status)));
  89
  90                 /* Reacquire the interpreter */
  91
  92                 status2 = acpi_ex_enter_interpreter();
  93                 if (ACPI_FAILURE(status2)) {
  94
  95                         /* Report fatal error, could not acquire interpreter */
  96
  97                         return_ACPI_STATUS(status2);
  98                 }
  99         }
 100
 101         return_ACPI_STATUS(status);
 102 }
 103
 104 /*******************************************************************************
 105  *
 106  * FUNCTION:    acpi_ex_system_do_stall
 107  *
 108  * PARAMETERS:  how_long        - The amount of time to stall,
 109  *                                in microseconds
 110  *
 111  * RETURN:      Status
 112  *
 113  * DESCRIPTION: Suspend running thread for specified amount of time.
 114  *              Note: ACPI specification requires that Stall() does not
 115  *              relinquish the processor, and delays longer than 100 usec
 116  *              should use Sleep() instead.  We allow stalls up to 255 usec
 117  *              for compatibility with other interpreters and existing BIOSs.
 118  *
 119  ******************************************************************************/
 120
 121 acpi_status acpi_ex_system_do_stall(u32 how_long)
 122 {
 123         acpi_status status = AE_OK;
 124
 125         ACPI_FUNCTION_ENTRY();
 126
 127         if (how_long > 255) {   /* 255 microseconds */
 128                 /*
 129                  * Longer than 255 usec, this is an error
 130                  *
 131                  * (ACPI specifies 100 usec as max, but this gives some slack in
 132                  * order to support existing BIOSs)
 133                  */
 134                 ACPI_ERROR((AE_INFO, "Time parameter is too large (%d)",
 135                             how_long));
 136                 status = AE_AML_OPERAND_VALUE;
 137         } else {
 138                 acpi_os_stall(how_long);
 139         }
 140
 141         return (status);
 142 }
 143
 144 /*******************************************************************************
 145  *
 146  * FUNCTION:    acpi_ex_system_do_suspend
 147  *
 148  * PARAMETERS:  how_long        - The amount of time to suspend,
 149  *                                in milliseconds
 150  *
 151  * RETURN:      None
 152  *
 153  * DESCRIPTION: Suspend running thread for specified amount of time.
 154  *
 155  ******************************************************************************/
 156
 157 acpi_status acpi_ex_system_do_suspend(acpi_integer how_long)
 158 {
 159         acpi_status status;
 160
 161         ACPI_FUNCTION_ENTRY();
 162
 163         /* Since this thread will sleep, we must release the interpreter */
 164
 165         acpi_ex_exit_interpreter();
 166
 167         acpi_os_sleep(how_long);
 168
 169         /* And now we must get the interpreter again */
 170
 171         status = acpi_ex_enter_interpreter();
 172         return (status);
 173 }
 174
 175 /*******************************************************************************
 176  *
 177  * FUNCTION:    acpi_ex_system_acquire_mutex
 178  *
 179  * PARAMETERS:  time_desc       - The 'time to delay' object descriptor
 180  *              obj_desc        - The object descriptor for this op
 181  *
 182  * RETURN:      Status
 183  *
 184  * DESCRIPTION: Provides an access point to perform synchronization operations
 185  *              within the AML.  This function will cause a lock to be generated
 186  *              for the Mutex pointed to by obj_desc.
 187  *
 188  ******************************************************************************/
 189
 190 acpi_status
 191 acpi_ex_system_acquire_mutex(union acpi_operand_object * time_desc,
 192                              union acpi_operand_object * obj_desc)
 193 {
 194         acpi_status status = AE_OK;
 195
 196         ACPI_FUNCTION_TRACE_PTR("ex_system_acquire_mutex", obj_desc);
 197
 198         if (!obj_desc) {
 199                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 200         }
 201
 202         /* Support for the _GL_ Mutex object -- go get the global lock */
 203
 204         if (obj_desc->mutex.semaphore == acpi_gbl_global_lock_semaphore) {
 205                 status =
 206                     acpi_ev_acquire_global_lock((u16) time_desc->integer.value);
 207                 return_ACPI_STATUS(status);
 208         }
 209
 210         status = acpi_ex_system_wait_semaphore(obj_desc->mutex.semaphore,
 211                                                (u16) time_desc->integer.value);
 212         return_ACPI_STATUS(status);
 213 }
 214
 215 /*******************************************************************************
 216  *
 217  * FUNCTION:    acpi_ex_system_release_mutex
 218  *
 219  * PARAMETERS:  obj_desc        - The object descriptor for this op
 220  *
 221  * RETURN:      Status
 222  *
 223  * DESCRIPTION: Provides an access point to perform synchronization operations
 224  *              within the AML.  This operation is a request to release a
 225  *              previously acquired Mutex.  If the Mutex variable is set then
 226  *              it will be decremented.
 227  *
 228  ******************************************************************************/
 229
 230 acpi_status acpi_ex_system_release_mutex(union acpi_operand_object *obj_desc)
 231 {
 232         acpi_status status = AE_OK;
 233
 234         ACPI_FUNCTION_TRACE("ex_system_release_mutex");
 235
 236         if (!obj_desc) {
 237                 return_ACPI_STATUS(AE_BAD_PARAMETER);
 238         }
 239
 240         /* Support for the _GL_ Mutex object -- release the global lock */
 241
 242         if (obj_desc->mutex.semaphore == acpi_gbl_global_lock_semaphore) {
 243                 status = acpi_ev_release_global_lock();
 244                 return_ACPI_STATUS(status);
 245         }
 246
 247         status = acpi_os_signal_semaphore(obj_desc->mutex.semaphore, 1);
 248         return_ACPI_STATUS(status);
 249 }
 250
 251 /*******************************************************************************
 252  *
 253  * FUNCTION:    acpi_ex_system_signal_event
 254  *
 255  * PARAMETERS:  obj_desc        - The object descriptor for this op
 256  *
 257  * RETURN:      Status
 258  *
 259  * DESCRIPTION: Provides an access point to perform synchronization operations
 260  *              within the AML.
 261  *
 262  ******************************************************************************/
 263
 264 acpi_status acpi_ex_system_signal_event(union acpi_operand_object *obj_desc)
 265 {
 266         acpi_status status = AE_OK;
 267
 268         ACPI_FUNCTION_TRACE("ex_system_signal_event");
 269
 270         if (obj_desc) {
 271                 status = acpi_os_signal_semaphore(obj_desc->event.semaphore, 1);
 272         }
 273
 274         return_ACPI_STATUS(status);
 275 }
 276
 277 /*******************************************************************************
 278  *
 279  * FUNCTION:    acpi_ex_system_wait_event
 280  *
 281  * PARAMETERS:  time_desc       - The 'time to delay' object descriptor
 282  *              obj_desc        - The object descriptor for this op
 283  *
 284  * RETURN:      Status
 285  *
 286  * DESCRIPTION: Provides an access point to perform synchronization operations
 287  *              within the AML.  This operation is a request to wait for an
 288  *              event.
 289  *
 290  ******************************************************************************/
 291
 292 acpi_status
 293 acpi_ex_system_wait_event(union acpi_operand_object *time_desc,
 294                           union acpi_operand_object *obj_desc)
 295 {
 296         acpi_status status = AE_OK;
 297
 298         ACPI_FUNCTION_TRACE("ex_system_wait_event");
 299
 300         if (obj_desc) {
 301                 status =
 302                     acpi_ex_system_wait_semaphore(obj_desc->event.semaphore,
 303                                                   (u16) time_desc->integer.
 304                                                   value);
 305         }
 306
 307         return_ACPI_STATUS(status);
 308 }
 309
 310 /*******************************************************************************
 311  *
 312  * FUNCTION:    acpi_ex_system_reset_event
 313  *
 314  * PARAMETERS:  obj_desc        - The object descriptor for this op
 315  *
 316  * RETURN:      Status
 317  *
 318  * DESCRIPTION: Reset an event to a known state.
 319  *
 320  ******************************************************************************/
 321
 322 acpi_status acpi_ex_system_reset_event(union acpi_operand_object *obj_desc)
 323 {
 324         acpi_status status = AE_OK;
 325         void *temp_semaphore;
 326
 327         ACPI_FUNCTION_ENTRY();
 328
 329         /*
 330          * We are going to simply delete the existing semaphore and
 331          * create a new one!
 332          */
 333         status =
 334             acpi_os_create_semaphore(ACPI_NO_UNIT_LIMIT, 0, &temp_semaphore);
 335         if (ACPI_SUCCESS(status)) {
 336                 (void)acpi_os_delete_semaphore(obj_desc->event.semaphore);
 337                 obj_desc->event.semaphore = temp_semaphore;
 338         }
 339
 340         return (status);
 341 }