evgpe.c

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 *
 * FUNCTION:    acpi_ev_gpe_detect
 *
 * PARAMETERS:  gpe_xrupt_list      - Interrupt block for this interrupt.
 *                                    Can have multiple GPE blocks attached.
 *
 * RETURN:      INTERRUPT_HANDLED or INTERRUPT_NOT_HANDLED
 *
 * DESCRIPTION: Detect if any GP events have occurred.  This function is
 *              executed at interrupt level.
 *
 ******************************************************************************/

u32 acpi_ev_gpe_detect(struct acpi_gpe_xrupt_info * gpe_xrupt_list)
{
	acpi_status status;
	struct acpi_gpe_block_info *gpe_block;
	struct acpi_gpe_register_info *gpe_register_info;
	u32 int_status = ACPI_INTERRUPT_NOT_HANDLED;
	u8 enabled_status_byte;
	u32 status_reg;
	u32 enable_reg;
	acpi_cpu_flags flags;
	acpi_native_uint i;
	acpi_native_uint j;

	ACPI_FUNCTION_NAME(ev_gpe_detect);

	/* Check for the case where there are no GPEs */

	if (!gpe_xrupt_list) {
		return (int_status);
	}

	/*
	 * We need to obtain the GPE lock for both the data structs and registers
	 * Note: Not necessary to obtain the hardware lock, since the GPE registers
	 * are owned by the gpe_lock.
	 */
	flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);

	/* Examine all GPE blocks attached to this interrupt level */

	gpe_block = gpe_xrupt_list->gpe_block_list_head;
	while (gpe_block) {
		/*
		 * Read all of the 8-bit GPE status and enable registers
		 * in this GPE block, saving all of them.
		 * Find all currently active GP events.
		 */
		for (i = 0; i < gpe_block->register_count; i++) {

			/* Get the next status/enable pair */

			gpe_register_info = &gpe_block->register_info[i];

			/* Read the Status Register */

			status =
			    acpi_hw_low_level_read(ACPI_GPE_REGISTER_WIDTH,
						   &status_reg,
						   &gpe_register_info->
						   status_address);
			if (ACPI_FAILURE(status)) {
				goto unlock_and_exit;
			}

			/* Read the Enable Register */

			status =
			    acpi_hw_low_level_read(ACPI_GPE_REGISTER_WIDTH,
						   &enable_reg,
						   &gpe_register_info->
						   enable_address);
			if (ACPI_FAILURE(status)) {
				goto unlock_and_exit;
			}

			ACPI_DEBUG_PRINT((ACPI_DB_INTERRUPTS,
					  "Read GPE Register at GPE%X: Status=%02X, Enable=%02X\n",
					  gpe_register_info->base_gpe_number,
					  status_reg, enable_reg));

			/* Check if there is anything active at all in this register */

			enabled_status_byte = (u8) (status_reg & enable_reg);
			if (!enabled_status_byte) {

				/* No active GPEs in this register, move on */

				continue;
			}

			/* Now look at the individual GPEs in this byte register */

			for (j = 0; j < ACPI_GPE_REGISTER_WIDTH; j++) {

				/* Examine one GPE bit */

				if (enabled_status_byte & (1 << j)) {
					/*
					 * Found an active GPE. Dispatch the event to a handler
					 * or method.
					 */
					int_status |=
					    acpi_ev_gpe_dispatch(&gpe_block->
								 event_info[(i *
									     ACPI_GPE_REGISTER_WIDTH)
									    +
									    j],
								 (u32) j +
								 gpe_register_info->
								 base_gpe_number);
				}
			}
		}

		gpe_block = gpe_block->next;
	}

      unlock_and_exit:

	acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
	return (int_status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_asynch_execute_gpe_method
 *
 * PARAMETERS:  Context (gpe_event_info) - Info for this GPE
 *
 * RETURN:      None
 *
 * DESCRIPTION: Perform the actual execution of a GPE control method. This
 *              function is called from an invocation of acpi_os_execute and
 *              therefore does NOT execute at interrupt level - so that
 *              the control method itself is not executed in the context of
 *              an interrupt handler.
 *
 ******************************************************************************/

static void ACPI_SYSTEM_XFACE acpi_ev_asynch_execute_gpe_method(void *context)
{
	struct acpi_gpe_event_info *gpe_event_info = (void *)context;
	acpi_status status;
	struct acpi_gpe_event_info local_gpe_event_info;
	struct acpi_evaluate_info *info;

	ACPI_FUNCTION_TRACE(ev_asynch_execute_gpe_method);

	status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
	if (ACPI_FAILURE(status)) {
		return_VOID;
	}

	/* Must revalidate the gpe_number/gpe_block */

	if (!acpi_ev_valid_gpe_event(gpe_event_info)) {
		status = acpi_ut_release_mutex(ACPI_MTX_EVENTS);
		return_VOID;
	}

	/* Set the GPE flags for return to enabled state */

	(void)acpi_ev_enable_gpe(gpe_event_info, FALSE);

	/*
	 * Take a snapshot of the GPE info for this level - we copy the
	 * info to prevent a race condition with remove_handler/remove_block.
	 */
	ACPI_MEMCPY(&local_gpe_event_info, gpe_event_info,
		    sizeof(struct acpi_gpe_event_info));

	status = acpi_ut_release_mutex(ACPI_MTX_EVENTS);
	if (ACPI_FAILURE(status)) {
		return_VOID;
	}

	/*
	 * Must check for control method type dispatch one more
	 * time to avoid race with ev_gpe_install_handler
	 */
	if ((local_gpe_event_info.flags & ACPI_GPE_DISPATCH_MASK) ==
	    ACPI_GPE_DISPATCH_METHOD) {

		/* Allocate the evaluation information block */

		info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
		if (!info) {
			status = AE_NO_MEMORY;
		} else {
			/*
			 * Invoke the GPE Method (_Lxx, _Exx) i.e., evaluate the _Lxx/_Exx
			 * control method that corresponds to this GPE
			 */
			info->prefix_node =
			    local_gpe_event_info.dispatch.method_node;
			info->parameters =
			    ACPI_CAST_PTR(union acpi_operand_object *,
					  gpe_event_info);
			info->parameter_type = ACPI_PARAM_GPE;
			info->flags = ACPI_IGNORE_RETURN_VALUE;

			status = acpi_ns_evaluate(info);
			ACPI_FREE(info);
		}

		if (ACPI_FAILURE(status)) {
			ACPI_EXCEPTION((AE_INFO, status,
					"while evaluating GPE method [%4.4s]",
					acpi_ut_get_node_name
					(local_gpe_event_info.dispatch.
					 method_node)));
		}
	}

	if ((local_gpe_event_info.flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
	    ACPI_GPE_LEVEL_TRIGGERED) {
		/*
		 * GPE is level-triggered, we clear the GPE status bit after
		 * handling the event.
		 */
		status = acpi_hw_clear_gpe(&local_gpe_event_info);
		if (ACPI_FAILURE(status)) {
			return_VOID;
		}
	}

	/* Enable this GPE */

	(void)acpi_hw_write_gpe_enable_reg(&local_gpe_event_info);
	return_VOID;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ev_gpe_dispatch
 *
 * PARAMETERS:  gpe_event_info  - Info for this GPE
 *              gpe_number      - Number relative to the parent GPE block
 *
 * RETURN:      INTERRUPT_HANDLED or INTERRUPT_NOT_HANDLED
 *
 * DESCRIPTION: Dispatch a General Purpose Event to either a function (e.g. EC)
 *              or method (e.g. _Lxx/_Exx) handler.
 *
 *              This function executes at interrupt level.
 *
 ******************************************************************************/

u32
acpi_ev_gpe_dispatch(struct acpi_gpe_event_info *gpe_event_info, u32 gpe_number)
{
	acpi_status status;

	ACPI_FUNCTION_TRACE(ev_gpe_dispatch);

	acpi_gpe_count++;

	/*
	 * If edge-triggered, clear the GPE status bit now.  Note that
	 * level-triggered events are cleared after the GPE is serviced.
	 */
	if ((gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
	    ACPI_GPE_EDGE_TRIGGERED) {
		status = acpi_hw_clear_gpe(gpe_event_info);
		if (ACPI_FAILURE(status)) {
			ACPI_EXCEPTION((AE_INFO, status,
					"Unable to clear GPE[%2X]",
					gpe_number));
			return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
		}
	}

	/*
	 * Dispatch the GPE to either an installed handler, or the control method
	 * associated with this GPE (_Lxx or _Exx). If a handler exists, we invoke
	 * it and do not attempt to run the method. If there is neither a handler
	 * nor a method, we disable this GPE to prevent further such pointless
	 * events from firing.
	 */
	switch (gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) {
	case ACPI_GPE_DISPATCH_HANDLER:

		/*
		 * Invoke the installed handler (at interrupt level)
		 * Ignore return status for now.  TBD: leave GPE disabled on error?
		 */
		(void)gpe_event_info->dispatch.handler->address(gpe_event_info->
								dispatch.
								handler->
								context);

		/* It is now safe to clear level-triggered events. */

		if ((gpe_event_info->flags & ACPI_GPE_XRUPT_TYPE_MASK) ==
		    ACPI_GPE_LEVEL_TRIGGERED) {
			status = acpi_hw_clear_gpe(gpe_event_info);
			if (ACPI_FAILURE(status)) {
				ACPI_EXCEPTION((AE_INFO, status,
						"Unable to clear GPE[%2X]",
						gpe_number));
				return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
			}
		}
		break;

	case ACPI_GPE_DISPATCH_METHOD:

		/*
		 * Disable the GPE, so it doesn't keep firing before the method has a
		 * chance to run (it runs asynchronously with interrupts enabled).
		 */
		status = acpi_ev_disable_gpe(gpe_event_info);
		if (ACPI_FAILURE(status)) {
			ACPI_EXCEPTION((AE_INFO, status,
					"Unable to disable GPE[%2X]",
					gpe_number));
			return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
		}

		/*
		 * Execute the method associated with the GPE
		 * NOTE: Level-triggered GPEs are cleared after the method completes.
		 */
		status = acpi_os_execute(OSL_GPE_HANDLER,
					 acpi_ev_asynch_execute_gpe_method,
					 gpe_event_info);
		if (ACPI_FAILURE(status)) {
			ACPI_EXCEPTION((AE_INFO, status,
					"Unable to queue handler for GPE[%2X] - event disabled",
					gpe_number));
		}
		break;

	default:

		/* No handler or method to run! */

		ACPI_ERROR((AE_INFO,
			    "No handler or method for GPE[%2X], disabling event",
			    gpe_number));

		/*
		 * Disable the GPE. The GPE will remain disabled until the ACPI
		 * Core Subsystem is restarted, or a handler is installed.
		 */
		status = acpi_ev_disable_gpe(gpe_event_info);
		if (ACPI_FAILURE(status)) {
			ACPI_EXCEPTION((AE_INFO, status,
					"Unable to disable GPE[%2X]",
					gpe_number));
			return_UINT32(ACPI_INTERRUPT_NOT_HANDLED);
		}
		break;
	}

	return_UINT32(ACPI_INTERRUPT_HANDLED);
}