ACPICA: Release global lock from interrupt handler
[safe/jmp/linux-2.6] / drivers / acpi / events / evmisc.c
1 /******************************************************************************
2  *
3  * Module Name: evmisc - Miscellaneous event manager support functions
4  *
5  *****************************************************************************/
6
7 /*
8  * Copyright (C) 2000 - 2006, 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/acevents.h>
46 #include <acpi/acnamesp.h>
47 #include <acpi/acinterp.h>
48
49 #define _COMPONENT          ACPI_EVENTS
50 ACPI_MODULE_NAME("evmisc")
51
52 /* Names for Notify() values, used for debug output */
53 #ifdef ACPI_DEBUG_OUTPUT
54 static const char *acpi_notify_value_names[] = {
55         "Bus Check",
56         "Device Check",
57         "Device Wake",
58         "Eject Request",
59         "Device Check Light",
60         "Frequency Mismatch",
61         "Bus Mode Mismatch",
62         "Power Fault"
63 };
64 #endif
65
66 /* Local prototypes */
67
68 static void ACPI_SYSTEM_XFACE acpi_ev_notify_dispatch(void *context);
69
70 static u32 acpi_ev_global_lock_handler(void *context);
71
72 /*******************************************************************************
73  *
74  * FUNCTION:    acpi_ev_is_notify_object
75  *
76  * PARAMETERS:  Node            - Node to check
77  *
78  * RETURN:      TRUE if notifies allowed on this object
79  *
80  * DESCRIPTION: Check type of node for a object that supports notifies.
81  *
82  *              TBD: This could be replaced by a flag bit in the node.
83  *
84  ******************************************************************************/
85
86 u8 acpi_ev_is_notify_object(struct acpi_namespace_node *node)
87 {
88         switch (node->type) {
89         case ACPI_TYPE_DEVICE:
90         case ACPI_TYPE_PROCESSOR:
91         case ACPI_TYPE_POWER:
92         case ACPI_TYPE_THERMAL:
93                 /*
94                  * These are the ONLY objects that can receive ACPI notifications
95                  */
96                 return (TRUE);
97
98         default:
99                 return (FALSE);
100         }
101 }
102
103 /*******************************************************************************
104  *
105  * FUNCTION:    acpi_ev_queue_notify_request
106  *
107  * PARAMETERS:  Node            - NS node for the notified object
108  *              notify_value    - Value from the Notify() request
109  *
110  * RETURN:      Status
111  *
112  * DESCRIPTION: Dispatch a device notification event to a previously
113  *              installed handler.
114  *
115  ******************************************************************************/
116
117 acpi_status
118 acpi_ev_queue_notify_request(struct acpi_namespace_node * node,
119                              u32 notify_value)
120 {
121         union acpi_operand_object *obj_desc;
122         union acpi_operand_object *handler_obj = NULL;
123         union acpi_generic_state *notify_info;
124         acpi_status status = AE_OK;
125
126         ACPI_FUNCTION_NAME(ev_queue_notify_request);
127
128         /*
129          * For value 3 (Ejection Request), some device method may need to be run.
130          * For value 2 (Device Wake) if _PRW exists, the _PS0 method may need
131          *   to be run.
132          * For value 0x80 (Status Change) on the power button or sleep button,
133          *   initiate soft-off or sleep operation?
134          */
135         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
136                           "Dispatching Notify(%X) on node %p\n", notify_value,
137                           node));
138
139         if (notify_value <= 7) {
140                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Notify value: %s\n",
141                                   acpi_notify_value_names[notify_value]));
142         } else {
143                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
144                                   "Notify value: 0x%2.2X **Device Specific**\n",
145                                   notify_value));
146         }
147
148         /* Get the notify object attached to the NS Node */
149
150         obj_desc = acpi_ns_get_attached_object(node);
151         if (obj_desc) {
152
153                 /* We have the notify object, Get the right handler */
154
155                 switch (node->type) {
156                 case ACPI_TYPE_DEVICE:
157                 case ACPI_TYPE_THERMAL:
158                 case ACPI_TYPE_PROCESSOR:
159                 case ACPI_TYPE_POWER:
160
161                         if (notify_value <= ACPI_MAX_SYS_NOTIFY) {
162                                 handler_obj =
163                                     obj_desc->common_notify.system_notify;
164                         } else {
165                                 handler_obj =
166                                     obj_desc->common_notify.device_notify;
167                         }
168                         break;
169
170                 default:
171                         /* All other types are not supported */
172                         return (AE_TYPE);
173                 }
174         }
175
176         /* If there is any handler to run, schedule the dispatcher */
177
178         if ((acpi_gbl_system_notify.handler
179              && (notify_value <= ACPI_MAX_SYS_NOTIFY))
180             || (acpi_gbl_device_notify.handler
181                 && (notify_value > ACPI_MAX_SYS_NOTIFY)) || handler_obj) {
182                 notify_info = acpi_ut_create_generic_state();
183                 if (!notify_info) {
184                         return (AE_NO_MEMORY);
185                 }
186
187                 notify_info->common.descriptor_type =
188                     ACPI_DESC_TYPE_STATE_NOTIFY;
189                 notify_info->notify.node = node;
190                 notify_info->notify.value = (u16) notify_value;
191                 notify_info->notify.handler_obj = handler_obj;
192
193                 status =
194                     acpi_os_execute(OSL_NOTIFY_HANDLER, acpi_ev_notify_dispatch,
195                                     notify_info);
196                 if (ACPI_FAILURE(status)) {
197                         acpi_ut_delete_generic_state(notify_info);
198                 }
199         }
200
201         if (!handler_obj) {
202                 /*
203                  * There is no per-device notify handler for this device.
204                  * This may or may not be a problem.
205                  */
206                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
207                                   "No notify handler for Notify(%4.4s, %X) node %p\n",
208                                   acpi_ut_get_node_name(node), notify_value,
209                                   node));
210         }
211
212         return (status);
213 }
214
215 /*******************************************************************************
216  *
217  * FUNCTION:    acpi_ev_notify_dispatch
218  *
219  * PARAMETERS:  Context         - To be passed to the notify handler
220  *
221  * RETURN:      None.
222  *
223  * DESCRIPTION: Dispatch a device notification event to a previously
224  *              installed handler.
225  *
226  ******************************************************************************/
227
228 static void ACPI_SYSTEM_XFACE acpi_ev_notify_dispatch(void *context)
229 {
230         union acpi_generic_state *notify_info =
231             (union acpi_generic_state *)context;
232         acpi_notify_handler global_handler = NULL;
233         void *global_context = NULL;
234         union acpi_operand_object *handler_obj;
235
236         ACPI_FUNCTION_ENTRY();
237
238         /*
239          * We will invoke a global notify handler if installed.
240          * This is done _before_ we invoke the per-device handler attached
241          * to the device.
242          */
243         if (notify_info->notify.value <= ACPI_MAX_SYS_NOTIFY) {
244
245                 /* Global system notification handler */
246
247                 if (acpi_gbl_system_notify.handler) {
248                         global_handler = acpi_gbl_system_notify.handler;
249                         global_context = acpi_gbl_system_notify.context;
250                 }
251         } else {
252                 /* Global driver notification handler */
253
254                 if (acpi_gbl_device_notify.handler) {
255                         global_handler = acpi_gbl_device_notify.handler;
256                         global_context = acpi_gbl_device_notify.context;
257                 }
258         }
259
260         /* Invoke the system handler first, if present */
261
262         if (global_handler) {
263                 global_handler(notify_info->notify.node,
264                                notify_info->notify.value, global_context);
265         }
266
267         /* Now invoke the per-device handler, if present */
268
269         handler_obj = notify_info->notify.handler_obj;
270         if (handler_obj) {
271                 handler_obj->notify.handler(notify_info->notify.node,
272                                             notify_info->notify.value,
273                                             handler_obj->notify.context);
274         }
275
276         /* All done with the info object */
277
278         acpi_ut_delete_generic_state(notify_info);
279 }
280
281 /*******************************************************************************
282  *
283  * FUNCTION:    acpi_ev_global_lock_handler
284  *
285  * PARAMETERS:  Context         - From thread interface, not used
286  *
287  * RETURN:      ACPI_INTERRUPT_HANDLED
288  *
289  * DESCRIPTION: Invoked directly from the SCI handler when a global lock
290  *              release interrupt occurs. Attempt to acquire the global lock,
291  *              if successful, signal the thread waiting for the lock.
292  *
293  * NOTE: Assumes that the semaphore can be signaled from interrupt level. If
294  * this is not possible for some reason, a separate thread will have to be
295  * scheduled to do this.
296  *
297  ******************************************************************************/
298
299 static u32 acpi_ev_global_lock_handler(void *context)
300 {
301         u8 acquired = FALSE;
302
303         /*
304          * Attempt to get the lock.
305          *
306          * If we don't get it now, it will be marked pending and we will
307          * take another interrupt when it becomes free.
308          */
309         ACPI_ACQUIRE_GLOBAL_LOCK(acpi_gbl_common_fACS.global_lock, acquired);
310         if (acquired) {
311
312                 /* Got the lock, now wake all threads waiting for it */
313
314                 acpi_gbl_global_lock_acquired = TRUE;
315                 /* Send a unit to the semaphore */
316
317                 if (ACPI_FAILURE(acpi_os_signal_semaphore(
318                         acpi_gbl_global_lock_semaphore, 1))) {
319                         ACPI_ERROR((AE_INFO,
320                                     "Could not signal Global Lock semaphore"));
321                 }
322         }
323
324         return (ACPI_INTERRUPT_HANDLED);
325 }
326
327 /*******************************************************************************
328  *
329  * FUNCTION:    acpi_ev_init_global_lock_handler
330  *
331  * PARAMETERS:  None
332  *
333  * RETURN:      Status
334  *
335  * DESCRIPTION: Install a handler for the global lock release event
336  *
337  ******************************************************************************/
338
339 acpi_status acpi_ev_init_global_lock_handler(void)
340 {
341         acpi_status status;
342
343         ACPI_FUNCTION_TRACE(ev_init_global_lock_handler);
344
345         acpi_gbl_global_lock_present = TRUE;
346         status = acpi_install_fixed_event_handler(ACPI_EVENT_GLOBAL,
347                                                   acpi_ev_global_lock_handler,
348                                                   NULL);
349
350         /*
351          * If the global lock does not exist on this platform, the attempt
352          * to enable GBL_STATUS will fail (the GBL_ENABLE bit will not stick)
353          * Map to AE_OK, but mark global lock as not present.
354          * Any attempt to actually use the global lock will be flagged
355          * with an error.
356          */
357         if (status == AE_NO_HARDWARE_RESPONSE) {
358                 ACPI_ERROR((AE_INFO,
359                             "No response from Global Lock hardware, disabling lock"));
360
361                 acpi_gbl_global_lock_present = FALSE;
362                 status = AE_OK;
363         }
364
365         return_ACPI_STATUS(status);
366 }
367
368 /******************************************************************************
369  *
370  * FUNCTION:    acpi_ev_acquire_global_lock
371  *
372  * PARAMETERS:  Timeout         - Max time to wait for the lock, in millisec.
373  *
374  * RETURN:      Status
375  *
376  * DESCRIPTION: Attempt to gain ownership of the Global Lock.
377  *
378  * MUTEX:       Interpreter must be locked
379  *
380  * Note: The original implementation allowed multiple threads to "acquire" the
381  * Global Lock, and the OS would hold the lock until the last thread had
382  * released it. However, this could potentially starve the BIOS out of the
383  * lock, especially in the case where there is a tight handshake between the
384  * Embedded Controller driver and the BIOS. Therefore, this implementation
385  * allows only one thread to acquire the HW Global Lock at a time, and makes
386  * the global lock appear as a standard mutex on the OS side.
387  *
388  *****************************************************************************/
389
390 acpi_status acpi_ev_acquire_global_lock(u16 timeout)
391 {
392         acpi_status status = AE_OK;
393         u8 acquired = FALSE;
394
395         ACPI_FUNCTION_TRACE(ev_acquire_global_lock);
396
397         /*
398          * Only one thread can acquire the GL at a time, the global_lock_mutex
399          * enforces this. This interface releases the interpreter if we must wait.
400          */
401         status = acpi_ex_system_wait_mutex(acpi_gbl_global_lock_mutex, timeout);
402         if (ACPI_FAILURE(status)) {
403                 return_ACPI_STATUS(status);
404         }
405
406         /*
407          * Make sure that a global lock actually exists. If not, just treat
408          * the lock as a standard mutex.
409          */
410         if (!acpi_gbl_global_lock_present) {
411                 acpi_gbl_global_lock_acquired = TRUE;
412                 return_ACPI_STATUS(AE_OK);
413         }
414
415         /* Attempt to acquire the actual hardware lock */
416
417         ACPI_ACQUIRE_GLOBAL_LOCK(acpi_gbl_common_fACS.global_lock, acquired);
418         if (acquired) {
419
420                 /* We got the lock */
421
422                 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
423                                   "Acquired hardware Global Lock\n"));
424
425                 acpi_gbl_global_lock_acquired = TRUE;
426                 return_ACPI_STATUS(AE_OK);
427         }
428
429         /*
430          * Did not get the lock. The pending bit was set above, and we must now
431          * wait until we get the global lock released interrupt.
432          */
433         ACPI_DEBUG_PRINT((ACPI_DB_EXEC, "Waiting for hardware Global Lock\n"));
434
435         /*
436          * Wait for handshake with the global lock interrupt handler.
437          * This interface releases the interpreter if we must wait.
438          */
439         status = acpi_ex_system_wait_semaphore(acpi_gbl_global_lock_semaphore,
440                                                ACPI_WAIT_FOREVER);
441         return_ACPI_STATUS(status);
442 }
443
444 /*******************************************************************************
445  *
446  * FUNCTION:    acpi_ev_release_global_lock
447  *
448  * PARAMETERS:  None
449  *
450  * RETURN:      Status
451  *
452  * DESCRIPTION: Releases ownership of the Global Lock.
453  *
454  ******************************************************************************/
455
456 acpi_status acpi_ev_release_global_lock(void)
457 {
458         u8 pending = FALSE;
459         acpi_status status = AE_OK;
460
461         ACPI_FUNCTION_TRACE(ev_release_global_lock);
462
463         /* Lock must be already acquired */
464
465         if (!acpi_gbl_global_lock_acquired) {
466                 ACPI_WARNING((AE_INFO,
467                               "Cannot release the ACPI Global Lock, it has not been acquired"));
468                 return_ACPI_STATUS(AE_NOT_ACQUIRED);
469         }
470
471         if (acpi_gbl_global_lock_present) {
472
473                 /* Allow any thread to release the lock */
474
475                 ACPI_RELEASE_GLOBAL_LOCK(acpi_gbl_common_fACS.global_lock,
476                                          pending);
477
478                 /*
479                  * If the pending bit was set, we must write GBL_RLS to the control
480                  * register
481                  */
482                 if (pending) {
483                         status =
484                             acpi_set_register(ACPI_BITREG_GLOBAL_LOCK_RELEASE,
485                                               1, ACPI_MTX_LOCK);
486                 }
487
488                 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
489                                   "Released hardware Global Lock\n"));
490         }
491
492         acpi_gbl_global_lock_acquired = FALSE;
493
494         /* Release the local GL mutex */
495
496         acpi_os_release_mutex(acpi_gbl_global_lock_mutex);
497         return_ACPI_STATUS(status);
498 }
499
500 /******************************************************************************
501  *
502  * FUNCTION:    acpi_ev_terminate
503  *
504  * PARAMETERS:  none
505  *
506  * RETURN:      none
507  *
508  * DESCRIPTION: Disable events and free memory allocated for table storage.
509  *
510  ******************************************************************************/
511
512 void acpi_ev_terminate(void)
513 {
514         acpi_native_uint i;
515         acpi_status status;
516
517         ACPI_FUNCTION_TRACE(ev_terminate);
518
519         if (acpi_gbl_events_initialized) {
520                 /*
521                  * Disable all event-related functionality.
522                  * In all cases, on error, print a message but obviously we don't abort.
523                  */
524
525                 /* Disable all fixed events */
526
527                 for (i = 0; i < ACPI_NUM_FIXED_EVENTS; i++) {
528                         status = acpi_disable_event((u32) i, 0);
529                         if (ACPI_FAILURE(status)) {
530                                 ACPI_ERROR((AE_INFO,
531                                             "Could not disable fixed event %d",
532                                             (u32) i));
533                         }
534                 }
535
536                 /* Disable all GPEs in all GPE blocks */
537
538                 status = acpi_ev_walk_gpe_list(acpi_hw_disable_gpe_block);
539
540                 /* Remove SCI handler */
541
542                 status = acpi_ev_remove_sci_handler();
543                 if (ACPI_FAILURE(status)) {
544                         ACPI_ERROR((AE_INFO, "Could not remove SCI handler"));
545                 }
546         }
547
548         /* Deallocate all handler objects installed within GPE info structs */
549
550         status = acpi_ev_walk_gpe_list(acpi_ev_delete_gpe_handlers);
551
552         /* Return to original mode if necessary */
553
554         if (acpi_gbl_original_mode == ACPI_SYS_MODE_LEGACY) {
555                 status = acpi_disable();
556                 if (ACPI_FAILURE(status)) {
557                         ACPI_WARNING((AE_INFO, "AcpiDisable failed"));
558                 }
559         }
560         return_VOID;
561 }