ddi_intr_get_nintrs(9F) 												   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).

       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

       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.

       If the device participates in resource management, a call to ddi_intr_get_navail() tells the device driver the number of interrupts of  the
       given  type that should be used. The host software can then use a policy-based decision to determine the number of interrupts to be allowed
       to the device. If the number is more than the number of interrupts currently being used, the device driver can ask for more  resources.	If
       the  number  is	less  than  the  number of interrupts currently being used, the device driver should prepare to disable and free the extra
       interrupts. The number of interrupts currently available is always a snapshot in time and can change if the interface is called again.

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

       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.

       See attributes(5) for descriptions of the following attributes:

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

       attributes(5), ddi_intr_alloc(9F), ddi_intr_enable(9F), ddi_intr_get_supported_types(9F)

       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.

       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.

								    07 Apr 2005 					   ddi_intr_get_nintrs(9F)