/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
 46#include <acpi/acpi.h>
 47#include <acpi/acinterp.h>
 48#include <acpi/acevents.h>
 49
 50#define _COMPONENT          ACPI_EXECUTER
 51	 ACPI_MODULE_NAME    ("exsystem")
 52
 53
 54/*******************************************************************************
 55 *
 56 * FUNCTION:    acpi_ex_system_wait_semaphore
 57 *
 58 * PARAMETERS:  Semaphore           - OSD semaphore to wait on
 59 *              Timeout             - Max time to wait
 60 *
 61 * RETURN:      Status
 62 *
 63 * DESCRIPTION: Implements a semaphore wait with a check to see if the
 64 *              semaphore is available immediately.  If it is not, the
 65 *              interpreter is released.
 66 *
 67 ******************************************************************************/
 68
 69acpi_status
 70acpi_ex_system_wait_semaphore (
 71	acpi_handle                     semaphore,
 72	u16                             timeout)
 73{
 74	acpi_status                     status;
 75	acpi_status                     status2;
 76
 77
 78	ACPI_FUNCTION_TRACE ("ex_system_wait_semaphore");
 79
 80
 81	status = acpi_os_wait_semaphore (semaphore, 1, 0);
 82	if (ACPI_SUCCESS (status)) {
 83		return_ACPI_STATUS (status);
 84	}
 85
 86	if (status == AE_TIME) {
 87		/* We must wait, so unlock the interpreter */
 88
 89		acpi_ex_exit_interpreter ();
 90
 91		status = acpi_os_wait_semaphore (semaphore, 1, timeout);
 92
 93		ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, "*** Thread awake after blocking, %s\n",
 94			acpi_format_exception (status)));
 95
 96		/* Reacquire the interpreter */
 97
 98		status2 = acpi_ex_enter_interpreter ();
 99		if (ACPI_FAILURE (status2)) {
100			/* Report fatal error, could not acquire interpreter */
101
102			return_ACPI_STATUS (status2);
103		}
104	}
105
106	return_ACPI_STATUS (status);
107}
108
109
110/*******************************************************************************
111 *
112 * FUNCTION:    acpi_ex_system_do_stall
113 *
114 * PARAMETERS:  how_long            - The amount of time to stall,
115 *                                    in microseconds
116 *
117 * RETURN:      Status
118 *
119 * DESCRIPTION: Suspend running thread for specified amount of time.
120 *              Note: ACPI specification requires that Stall() does not
121 *              relinquish the processor, and delays longer than 100 usec
122 *              should use Sleep() instead.  We allow stalls up to 255 usec
123 *              for compatibility with other interpreters and existing BIOSs.
124 *
125 ******************************************************************************/
126
127acpi_status
128acpi_ex_system_do_stall (
129	u32                             how_long)
130{
131	acpi_status                     status = AE_OK;
132
133
134	ACPI_FUNCTION_ENTRY ();
135
136
137	if (how_long > 255) /* 255 microseconds */ {
138		/*
139		 * Longer than 255 usec, this is an error
140		 *
141		 * (ACPI specifies 100 usec as max, but this gives some slack in
142		 * order to support existing BIOSs)
143		 */
144		ACPI_REPORT_ERROR (("Stall: Time parameter is too large (%d)\n", how_long));
145		status = AE_AML_OPERAND_VALUE;
146	}
147	else {
148		acpi_os_stall (how_long);
149	}
150
151	return (status);
152}
153
154
155/*******************************************************************************
156 *
157 * FUNCTION:    acpi_ex_system_do_suspend
158 *
159 * PARAMETERS:  how_long            - The amount of time to suspend,
160 *                                    in milliseconds
161 *
162 * RETURN:      None
163 *
164 * DESCRIPTION: Suspend running thread for specified amount of time.
165 *
166 ******************************************************************************/
167
168acpi_status
169acpi_ex_system_do_suspend (
170	acpi_integer                    how_long)
171{
172	acpi_status                     status;
173
174
175	ACPI_FUNCTION_ENTRY ();
176
177
178	/* Since this thread will sleep, we must release the interpreter */
179
180	acpi_ex_exit_interpreter ();
181
182	acpi_os_sleep (how_long);
183
184	/* And now we must get the interpreter again */
185
186	status = acpi_ex_enter_interpreter ();
187	return (status);
188}
189
190
191/*******************************************************************************
192 *
193 * FUNCTION:    acpi_ex_system_acquire_mutex
194 *
195 * PARAMETERS:  *time_desc          - The 'time to delay' object descriptor
196 *              *obj_desc           - The object descriptor for this op
197 *
198 * RETURN:      Status
199 *
200 * DESCRIPTION: Provides an access point to perform synchronization operations
201 *              within the AML.  This function will cause a lock to be generated
202 *              for the Mutex pointed to by obj_desc.
203 *
204 ******************************************************************************/
205
206acpi_status
207acpi_ex_system_acquire_mutex (
208	union acpi_operand_object       *time_desc,
209	union acpi_operand_object       *obj_desc)
210{
211	acpi_status                     status = AE_OK;
212
213
214	ACPI_FUNCTION_TRACE_PTR ("ex_system_acquire_mutex", obj_desc);
215
216
217	if (!obj_desc) {
218		return_ACPI_STATUS (AE_BAD_PARAMETER);
219	}
220
221	/*
222	 * Support for the _GL_ Mutex object -- go get the global lock
223	 */
224	if (obj_desc->mutex.semaphore == acpi_gbl_global_lock_semaphore) {
225		status = acpi_ev_acquire_global_lock ((u16) time_desc->integer.value);
226		return_ACPI_STATUS (status);
227	}
228
229	status = acpi_ex_system_wait_semaphore (obj_desc->mutex.semaphore,
230			  (u16) time_desc->integer.value);
231	return_ACPI_STATUS (status);
232}
233
234
235/*******************************************************************************
236 *
237 * FUNCTION:    acpi_ex_system_release_mutex
238 *
239 * PARAMETERS:  *obj_desc           - The object descriptor for this op
240 *
241 * RETURN:      Status
242 *
243 * DESCRIPTION: Provides an access point to perform synchronization operations
244 *              within the AML.  This operation is a request to release a
245 *              previously acquired Mutex.  If the Mutex variable is set then
246 *              it will be decremented.
247 *
248 ******************************************************************************/
249
250acpi_status
251acpi_ex_system_release_mutex (
252	union acpi_operand_object       *obj_desc)
253{
254	acpi_status                     status = AE_OK;
255
256
257	ACPI_FUNCTION_TRACE ("ex_system_release_mutex");
258
259
260	if (!obj_desc) {
261		return_ACPI_STATUS (AE_BAD_PARAMETER);
262	}
263
264	/*
265	 * Support for the _GL_ Mutex object -- release the global lock
266	 */
267	if (obj_desc->mutex.semaphore == acpi_gbl_global_lock_semaphore) {
268		status = acpi_ev_release_global_lock ();
269		return_ACPI_STATUS (status);
270	}
271
272	status = acpi_os_signal_semaphore (obj_desc->mutex.semaphore, 1);
273	return_ACPI_STATUS (status);
274}
275
276
277/*******************************************************************************
278 *
279 * FUNCTION:    acpi_ex_system_signal_event
280 *
281 * PARAMETERS:  *obj_desc           - The object descriptor for this op
282 *
283 * RETURN:      AE_OK
284 *
285 * DESCRIPTION: Provides an access point to perform synchronization operations
286 *              within the AML.
287 *
288 ******************************************************************************/
289
290acpi_status
291acpi_ex_system_signal_event (
292	union acpi_operand_object       *obj_desc)
293{
294	acpi_status                     status = AE_OK;
295
296
297	ACPI_FUNCTION_TRACE ("ex_system_signal_event");
298
299
300	if (obj_desc) {
301		status = acpi_os_signal_semaphore (obj_desc->event.semaphore, 1);
302	}
303
304	return_ACPI_STATUS (status);
305}
306
307
308/*******************************************************************************
309 *
310 * FUNCTION:    acpi_ex_system_wait_event
311 *
312 * PARAMETERS:  *time_desc          - The 'time to delay' object descriptor
313 *              *obj_desc           - The object descriptor for this op
314 *
315 * RETURN:      Status
316 *
317 * DESCRIPTION: Provides an access point to perform synchronization operations
318 *              within the AML.  This operation is a request to wait for an
319 *              event.
320 *
321 ******************************************************************************/
322
323acpi_status
324acpi_ex_system_wait_event (
325	union acpi_operand_object       *time_desc,
326	union acpi_operand_object       *obj_desc)
327{
328	acpi_status                     status = AE_OK;
329
330
331	ACPI_FUNCTION_TRACE ("ex_system_wait_event");
332
333
334	if (obj_desc) {
335		status = acpi_ex_system_wait_semaphore (obj_desc->event.semaphore,
336				  (u16) time_desc->integer.value);
337	}
338
339	return_ACPI_STATUS (status);
340}
341
342
343/*******************************************************************************
344 *
345 * FUNCTION:    acpi_ex_system_reset_event
346 *
347 * PARAMETERS:  *obj_desc           - The object descriptor for this op
348 *
349 * RETURN:      Status
350 *
351 * DESCRIPTION: Reset an event to a known state.
352 *
353 ******************************************************************************/
354
355acpi_status
356acpi_ex_system_reset_event (
357	union acpi_operand_object       *obj_desc)
358{
359	acpi_status                     status = AE_OK;
360	void                            *temp_semaphore;
361
362
363	ACPI_FUNCTION_ENTRY ();
364
365
366	/*
367	 * We are going to simply delete the existing semaphore and
368	 * create a new one!
369	 */
370	status = acpi_os_create_semaphore (ACPI_NO_UNIT_LIMIT, 0, &temp_semaphore);
371	if (ACPI_SUCCESS (status)) {
372		(void) acpi_os_delete_semaphore (obj_desc->event.semaphore);
373		obj_desc->event.semaphore = temp_semaphore;
374	}
375
376	return (status);
377}
378