Commit 7c2e1771 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

ACPICA: Introduce acpi_get_data_full() and rework acpi_get_data() 



Introduce a new function, acpi_get_data_full(), working in analogy
with acpi_get_data() except that it can execute a callback provided
as its 4th argument right after acpi_ns_get_attached_data() has
returned a success.

That will allow Linux to reference count the object pointed to by
*data before the namespace mutex is released so as to ensure that it
will not be freed going forward until the reference to it acquired
by acpi_get_data_full() is dropped.

Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
parent d3a1ebb0

drivers/acpi/acpica/nsxfeval.c

+30 −3
Original line number Diff line number Diff line
@@ -923,19 +923,22 @@ ACPI_EXPORT_SYMBOL(acpi_detach_data) 


/*******************************************************************************

 *

 * FUNCTION:    acpi_get_data

 * FUNCTION:    acpi_get_data_full

 *

 * PARAMETERS:  obj_handle          - Namespace node

 *              handler             - Handler used in call to attach_data

 *              data                - Where the data is returned

 *              callback            - function to execute before returning

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Retrieve data that was previously attached to a namespace node.

 * DESCRIPTION: Retrieve data that was previously attached to a namespace node

 *              and execute a callback before returning.

 *

 ******************************************************************************/

acpi_status

acpi_get_data(acpi_handle obj_handle, acpi_object_handler handler, void **data)

acpi_get_data_full(acpi_handle obj_handle, acpi_object_handler handler,

		   void **data, void (*callback)(void *))

{

	struct acpi_namespace_node *node;

	acpi_status status;
@@ -960,10 +963,34 @@ acpi_get_data(acpi_handle obj_handle, acpi_object_handler handler, void **data) 
	}



	status = acpi_ns_get_attached_data(node, handler, data);

	if (ACPI_SUCCESS(status) && callback) {

		callback(*data);

	}



unlock_and_exit:

	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);

	return (status);

}



ACPI_EXPORT_SYMBOL(acpi_get_data_full)



/*******************************************************************************

 *

 * FUNCTION:    acpi_get_data

 *

 * PARAMETERS:  obj_handle          - Namespace node

 *              handler             - Handler used in call to attach_data

 *              data                - Where the data is returned

 *

 * RETURN:      Status

 *

 * DESCRIPTION: Retrieve data that was previously attached to a namespace node.

 *

 ******************************************************************************/

acpi_status

acpi_get_data(acpi_handle obj_handle, acpi_object_handler handler, void **data)

{

	return acpi_get_data_full(obj_handle, handler, data, NULL);

}



ACPI_EXPORT_SYMBOL(acpi_get_data)

include/acpi/acpixf.h

+4 −0
Original line number Diff line number Diff line
@@ -229,6 +229,10 @@ acpi_attach_data(acpi_handle object, acpi_object_handler handler, void *data); 


acpi_status acpi_detach_data(acpi_handle object, acpi_object_handler handler);



acpi_status

acpi_get_data_full(acpi_handle object, acpi_object_handler handler, void **data,

		   void (*callback)(void *));



acpi_status

acpi_get_data(acpi_handle object, acpi_object_handler handler, void **data);

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