DDI_GET_INSTANCE(9F) Kernel Functions for Drivers DDI_GET_INSTANCE(9F)
ddi_get_instance - get device instance number
#include <sys/ddi.h>
#include <sys/sunddi.h>
int ddi_get_instance(dev_info_t *dip);
illumos DDI specific (illumos DDI).
dip
Pointer to dev_info structure.
The ddi_get_instance() function returns the instance number of the
device corresponding to dip.
The system assigns an instance number to every device. Instance
numbers for devices attached to the same driver are unique. This
provides a way for the system and the driver to uniquely identify one
or more devices of the same type. The instance number is derived by
the system from different properties for different device types in an
implementation specific manner.
Once an instance number has been assigned to a device, it will remain
the same even across reconfigurations and reboots. Therefore,
instance numbers seen by a driver may not appear to be in consecutive
order. For example, if device foo0 has been assigned an instance
number of 0 and device foo1 has been assigned an instance number of
1, if foo0 is removed, foo1 will continue to be associated with
instance number 1 (even though foo1 is now the only device of its
type on the system).
The ddi_get_instance() function returns the instance number of the
device corresponding to dip.
The ddi_get_instance() function can be called from user, interrupt,
or kernel context.
path_to_inst(5)
Writing Device Drivers
January 16, 2006 DDI_GET_INSTANCE(9F)
NAME
ddi_get_instance - get device instance number
SYNOPSIS
#include <sys/ddi.h>
#include <sys/sunddi.h>
int ddi_get_instance(dev_info_t *dip);
INTERFACE LEVEL
illumos DDI specific (illumos DDI).
PARAMETERS
dip
Pointer to dev_info structure.
DESCRIPTION
The ddi_get_instance() function returns the instance number of the
device corresponding to dip.
The system assigns an instance number to every device. Instance
numbers for devices attached to the same driver are unique. This
provides a way for the system and the driver to uniquely identify one
or more devices of the same type. The instance number is derived by
the system from different properties for different device types in an
implementation specific manner.
Once an instance number has been assigned to a device, it will remain
the same even across reconfigurations and reboots. Therefore,
instance numbers seen by a driver may not appear to be in consecutive
order. For example, if device foo0 has been assigned an instance
number of 0 and device foo1 has been assigned an instance number of
1, if foo0 is removed, foo1 will continue to be associated with
instance number 1 (even though foo1 is now the only device of its
type on the system).
RETURN VALUES
The ddi_get_instance() function returns the instance number of the
device corresponding to dip.
CONTEXT
The ddi_get_instance() function can be called from user, interrupt,
or kernel context.
SEE ALSO
path_to_inst(5)
Writing Device Drivers
January 16, 2006 DDI_GET_INSTANCE(9F)