DDI_INTR_GET_NINTRS(9F) Kernel Functions for Drivers DDI_INTR_GET_NINTRS(9F)

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)