Content-type: text/html Man page of ddi_intr_get_nintrs

ddi_intr_get_nintrs

Section: Kernel Functions for Drivers (9F)
Updated: 07 Apr 2005
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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.

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().  

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 TYPEATTRIBUTE VALUE
Interface StabilityEvolving

 

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.

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.


 

Index

NAME
SYNOPSIS
INTERFACE LEVEL
PARAMETERS
DESCRIPTION
RETURN VALUES
CONTEXT
ATTRIBUTES
SEE ALSO
NOTES

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Time: 02:39:40 GMT, October 02, 2010