DDI_ADD_EVENT_HANDLER(9F) Kernel Functions for Drivers

NAME

ddi_add_event_handler - add an NDI event service callback handler

SYNOPSIS

#include <sys/dditypes.h>
#include <sys/sunddi.h>

int
ddi_add_event_handler(dev_info_t *dip, ddi_eventcookie_t cookie,
void
(*handler)(dev_info_t *dip, ddi_eventcookie_t cookie, void
*arg, void *bus), void *arg, ddi_callback_id_t *id);

INTERFACE LEVEL

illumos DDI specific (illumos DDI).

PARAMETERS

dip Device node registering the callback.

cookie Cookie returned from call to ddi_get_eventcookie(9F).

handler Callback handler responsible for handling an NDI event
service notification. Its first void * argument
corresponds to arg. The second is bus-specific data.

arg Pointer to opaque data supplied by the caller.
Typically, this would be a pointer to the driver's
softstate structure.

id Pointer to a callback ID. The callback ID will be filled
in when this function is called and serves as a unique
identifier for this particular event handler. This ID
must be saved so it can be used in a later call to
ddi_remove_event_handler(9F) to remove the callback.

DESCRIPTION

The ddi_add_event_handler() function adds a callback handler to be
invoked in the face of the event specified by cookie. The process of
adding a callback handler is also known as subscribing to an event.
Upon successful subscription, the handler will be invoked by the system
when the event occurs. The handler can be unregistered by using
ddi_remove_event_handler(9F).

An instance of a driver can register multiple handlers for an event or
a single handler for multiple events. Callback order is not defined
and should assumed to be random.

The callback. handler will be invoked with the following arguments:

dev_info_t *dip
Device node requesting the notification.

ddi_eventcookie_t cookie
Structure describing event that occurred.

void *arg Opaque data pointer provided, by the driver, during
callback registration.

void *bus Pointer to event specific data defined by the framework
which invokes the callback function.

CONTEXT

The ddi_add_event_handler() and handler() function can be called from
user and kernel contexts only.

RETURN VALUES

Upon successful completion, the ddi_add_event_handler() function
returns DDI_SUCCESS and the callback handler is successfully
registered. Otherwise, DDI_FAILURE is returned and the callback
handler failed to register. Possible reasons include lack of resources
or a bad cookie.

INTERFACE STABILITY

Committed

SEE ALSO

attributes(7), ddi_get_eventcookie(9F), ddi_remove_event_handler(9F)

Writing Device Drivers.

NOTES

Drivers must remove all registered callback handlers for a device
instance by calling ddi_remove_event_handler(9F) before detach(9E)
completes.

illumos September 15, 2024 illumos