DDI_INTR_GET_NINTRS(9F) Kernel Functions for Drivers

NAME

ddi_intr_get_nintrs, ddi_intr_get_navail - return number of
interrupts supported or available for a given interrupt type

SYNOPSIS

#include <sys/types.h>
#include <sys/conf.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>

int ddi_intr_get_nintrs(dev_info_t *dip, int type, int *nintrsp);


int ddi_intr_get_navail(dev_info_t *dip, int type, int *navailp);

INTERFACE LEVEL

illumos DDI specific (illumos DDI).

PARAMETERS

ddi_intr_get_nintrs()

dip
Pointer to dev_info structure


type
Interrupt type


nintrsp
Pointer to number of interrupts of the given type that are
supported by the system


ddi_intr_get_navail()

dip
Pointer to dev_info structure


type
Interrupt type


navailp
Pointer to number of interrupts of the given type that are
currently available from the system

DESCRIPTION

The ddi_intr_get_nintrs() function returns the number of interrupts
of the given type supported by a particular hardware device. On a
successful return, the number of supported interrupts is returned as
an integer pointed to by the nintrsp argument.


If the hardware device is not found to support any interrupts of the
given type, the DDI_INTR_NOTFOUND failure is returned rather than a
zero in nintrsp.


The ddi_intr_get_navail() function returns the number of interrupts
of a given type that is available to a particular hardware device. On
a successful return, the number of available interrupts is returned
as an integer pointed to by navailp.


The hardware device may support more than one interrupt and can
request that all interrupts be allocated. The host software can then
use policy-based decisions to determine how many interrupts are made
available to the device. Based on the determination, a value is
returned that should be used to allocate interrupts with the
ddi_intr_alloc() function.


The ddi_intr_get_supported_types(9F) function returns a list of valid
supported types for the given hardware device. It must be called
prior to calling either the ddi_intr_get_nintrs() or
ddi_intr_get_navail().

RETURN VALUES

The ddi_intr_get_nintrs() and ddi_intr_get_navail() functions return:

DDI_SUCCESS
On success.


DDI_EINVAL
On encountering invalid input parameters.


DDI_INTR_NOTFOUND
On not finding any interrupts for the given
interrupt type.


DDI_FAILURE
On any implementation specific failure.

CONTEXT

The ddi_intr_get_nintrs() and ddi_intr_get_navail() functions can be
called from either user or kernel non-interrupt context.

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:


+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|Interface Stability | Committed |
+--------------------+-----------------+

SEE ALSO

attributes(7), ddi_intr_alloc(9F), ddi_intr_enable(9F),
ddi_intr_get_supported_types(9F)


Writing Device Drivers

NOTES

The ddi_intr_get_nintrs() and ddi_intr_get_navail() functions can be
called at any time, even if the driver has added an interrupt handler
for a given interrupt specification.


On x86 platforms, the number of interrupts returned by the
ddi_intr_get_navail() function might need to be further reduced by
the number of interrupts available for each interrupt priority on the
system. In that case, drivers should use different priorities for
some of the interrupts.


Consumers of these interfaces should verify that the return value is
not equal to DDI_SUCCESS. Incomplete checking for failure codes could
result in inconsistent behavior among platforms.

December 13, 2013 DDI_INTR_GET_NINTRS(9F)