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).
PARAMETERSddi_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 success‐
ful return, the number of supported interrupts is returned as an inte‐
ger 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 pol‐
icy-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() func‐
tion.
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 inter‐
rupts currently being used, the device driver can ask for more
resources. If the number is less than the number of interrupts cur‐
rently 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().
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 │Evolving │
└─────────────────────────────┴─────────────────────────────┘
SEE ALSOattributes(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.
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 5.10 07 Apr 2005 ddi_intr_get_nintrs(9F)
