man pages section 9: DDI and DKI Kernel Functions

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Updated: July 2014
 
 

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 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_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 for Oracle Solaris 11.2

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.