evmisc.c

h内核

	/* Signal threads that are waiting for the lock */

	if (acpi_gbl_global_lock_thread_count) {
		/* Send sufficient units to the semaphore */

		status = acpi_os_signal_semaphore (acpi_gbl_global_lock_semaphore,
				 acpi_gbl_global_lock_thread_count);
		if (ACPI_FAILURE (status)) {
			ACPI_REPORT_ERROR (("Could not signal Global Lock semaphore\n"));
		}
	}
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_global_lock_handler
 *
 * PARAMETERS:  Context         - From thread interface, not used
 *
 * RETURN:      ACPI_INTERRUPT_HANDLED or ACPI_INTERRUPT_NOT_HANDLED
 *
 * DESCRIPTION: Invoked directly from the SCI handler when a global lock
 *              release interrupt occurs.  Grab the global lock and queue
 *              the global lock thread for execution
 *
 ******************************************************************************/

static u32
acpi_ev_global_lock_handler (
	void                            *context)
{
	u8                              acquired = FALSE;
	acpi_status                     status;


	/*
	 * Attempt to get the lock
	 * If we don't get it now, it will be marked pending and we will
	 * take another interrupt when it becomes free.
	 */
	ACPI_ACQUIRE_GLOBAL_LOCK (acpi_gbl_common_fACS.global_lock, acquired);
	if (acquired) {
		/* Got the lock, now wake all threads waiting for it */

		acpi_gbl_global_lock_acquired = TRUE;

		/* Run the Global Lock thread which will signal all waiting threads */

		status = acpi_os_queue_for_execution (OSD_PRIORITY_HIGH,
				  acpi_ev_global_lock_thread, context);
		if (ACPI_FAILURE (status)) {
			ACPI_REPORT_ERROR (("Could not queue Global Lock thread, %s\n",
				acpi_format_exception (status)));

			return (ACPI_INTERRUPT_NOT_HANDLED);
		}
	}

	return (ACPI_INTERRUPT_HANDLED);
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_init_global_lock_handler
 *
 * PARAMETERS:  None
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Install a handler for the global lock release event
 *
 ******************************************************************************/

acpi_status
acpi_ev_init_global_lock_handler (void)
{
	acpi_status                     status;


	ACPI_FUNCTION_TRACE ("ev_init_global_lock_handler");


	acpi_gbl_global_lock_present = TRUE;
	status = acpi_install_fixed_event_handler (ACPI_EVENT_GLOBAL,
			  acpi_ev_global_lock_handler, NULL);

	/*
	 * If the global lock does not exist on this platform, the attempt
	 * to enable GBL_STATUS will fail (the GBL_ENABLE bit will not stick)
	 * Map to AE_OK, but mark global lock as not present.
	 * Any attempt to actually use the global lock will be flagged
	 * with an error.
	 */
	if (status == AE_NO_HARDWARE_RESPONSE) {
		acpi_gbl_global_lock_present = FALSE;
		status = AE_OK;
	}

	return_ACPI_STATUS (status);
}


/******************************************************************************
 *
 * FUNCTION:    acpi_ev_acquire_global_lock
 *
 * PARAMETERS:  Timeout         - Max time to wait for the lock, in millisec.
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Attempt to gain ownership of the Global Lock.
 *
 *****************************************************************************/

acpi_status
acpi_ev_acquire_global_lock (
	u16                             timeout)
{
	acpi_status                     status = AE_OK;
	u8                              acquired = FALSE;


	ACPI_FUNCTION_TRACE ("ev_acquire_global_lock");


#ifndef ACPI_APPLICATION
	/* Make sure that we actually have a global lock */

	if (!acpi_gbl_global_lock_present) {
		return_ACPI_STATUS (AE_NO_GLOBAL_LOCK);
	}
#endif

	/* One more thread wants the global lock */

	acpi_gbl_global_lock_thread_count++;

	/* If we (OS side vs. BIOS side) have the hardware lock already, we are done */

	if (acpi_gbl_global_lock_acquired) {
		return_ACPI_STATUS (AE_OK);
	}

	/* We must acquire the actual hardware lock */

	ACPI_ACQUIRE_GLOBAL_LOCK (acpi_gbl_common_fACS.global_lock, acquired);
	if (acquired) {
	   /* We got the lock */

		ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, "Acquired the HW Global Lock\n"));

		acpi_gbl_global_lock_acquired = TRUE;
		return_ACPI_STATUS (AE_OK);
	}

	/*
	 * Did not get the lock.  The pending bit was set above, and we must now
	 * wait until we get the global lock released interrupt.
	 */
	ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, "Waiting for the HW Global Lock\n"));

	/*
	 * Acquire the global lock semaphore first.
	 * Since this wait will block, we must release the interpreter
	 */
	status = acpi_ex_system_wait_semaphore (acpi_gbl_global_lock_semaphore,
			  timeout);
	return_ACPI_STATUS (status);
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_release_global_lock
 *
 * PARAMETERS:  None
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Releases ownership of the Global Lock.
 *
 ******************************************************************************/

acpi_status
acpi_ev_release_global_lock (void)
{
	u8                              pending = FALSE;
	acpi_status                     status = AE_OK;


	ACPI_FUNCTION_TRACE ("ev_release_global_lock");


	if (!acpi_gbl_global_lock_thread_count) {
		ACPI_REPORT_WARNING(("Cannot release HW Global Lock, it has not been acquired\n"));
		return_ACPI_STATUS (AE_NOT_ACQUIRED);
	}

	/* One fewer thread has the global lock */

	acpi_gbl_global_lock_thread_count--;
	if (acpi_gbl_global_lock_thread_count) {
		/* There are still some threads holding the lock, cannot release */

		return_ACPI_STATUS (AE_OK);
	}

	/*
	 * No more threads holding lock, we can do the actual hardware
	 * release
	 */
	ACPI_RELEASE_GLOBAL_LOCK (acpi_gbl_common_fACS.global_lock, pending);
	acpi_gbl_global_lock_acquired = FALSE;

	/*
	 * If the pending bit was set, we must write GBL_RLS to the control
	 * register
	 */
	if (pending) {
		status = acpi_set_register (ACPI_BITREG_GLOBAL_LOCK_RELEASE, 1, ACPI_MTX_LOCK);
	}

	return_ACPI_STATUS (status);
}


/******************************************************************************
 *
 * FUNCTION:    acpi_ev_terminate
 *
 * PARAMETERS:  none
 *
 * RETURN:      none
 *
 * DESCRIPTION: Disable events and free memory allocated for table storage.
 *
 ******************************************************************************/

void
acpi_ev_terminate (void)
{
	acpi_native_uint                i;
	acpi_status                     status;


	ACPI_FUNCTION_TRACE ("ev_terminate");


	if (acpi_gbl_events_initialized) {
		/*
		 * Disable all event-related functionality.
		 * In all cases, on error, print a message but obviously we don't abort.
		 */

		/* Disable all fixed events */

		for (i = 0; i < ACPI_NUM_FIXED_EVENTS; i++) {
			status = acpi_disable_event ((u32) i, 0);
			if (ACPI_FAILURE (status)) {
				ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Could not disable fixed event %d\n", (u32) i));
			}
		}

		/* Disable all GPEs in all GPE blocks */

		status = acpi_ev_walk_gpe_list (acpi_hw_disable_gpe_block, ACPI_NOT_ISR);

		/* Remove SCI handler */

		status = acpi_ev_remove_sci_handler ();
		if (ACPI_FAILURE(status)) {
			ACPI_DEBUG_PRINT ((ACPI_DB_ERROR, "Could not remove SCI handler\n"));
		}
	}

	/* Deallocate all handler objects installed within GPE info structs */

	status = acpi_ev_walk_gpe_list (acpi_ev_delete_gpe_handlers, ACPI_NOT_ISR);

	/* Return to original mode if necessary */

	if (acpi_gbl_original_mode == ACPI_SYS_MODE_LEGACY) {
		status = acpi_disable ();
		if (ACPI_FAILURE (status)) {
			ACPI_DEBUG_PRINT ((ACPI_DB_WARN, "acpi_disable failed\n"));
		}
	}
	return_VOID;
}