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

       Solaris DDI specific (Solaris 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 suc-
       cessful 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_int_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(5) for descriptions of the following attributes:

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

SEE ALSO

       attributes(5), 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.

SunOS 5.11							 13 November 2006					   ddi_intr_get_nintrs(9F)