.\" Copyright (c) 2000 Jeroen Ruigrok van der Werven
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.Dd March 28, 2003
.Dt BUS_SETUP_INTR 9
.Os
.Sh NAME
.Nm BUS_SETUP_INTR ,
.Nm bus_setup_intr ,
.Nm BUS_TEARDOWN_INTR ,
.Nm bus_teardown_intr
.Nd create, attach and teardown an interrupt handler
.Sh SYNOPSIS
.In sys/param.h
.In sys/bus.h
.Ft int
.Fn BUS_SETUP_INTR "device_t dev" "device_t child" "struct resource *irq" "int flags" "driver_intr_t *intr" "void *arg" "void **cookiep"
.Ft int
.Fn bus_setup_intr "device_t dev" "struct resource *r" "int flags" "driver_intr_t handler" "void *arg" "void **cookiep"
.Ft int
.Fn BUS_TEARDOWN_INTR "device_t dev" "device_t child" "struct resource *irq" "void *cookiep"
.Ft int
.Fn bus_teardown_intr "device_t dev" "struct resource *r" "void *cookiep"
.Sh DESCRIPTION
The method
.Nm
will create and attach an interrupt handler to an interrupt
previously allocated by the resource manager's
.Xr BUS_ALLOC_RESOURCE 9
method.
The
.Fa flags
are found in
.Aq Pa sys/bus.h ,
and give the broad category of interrupt.
The
.Fa flags
also tell the interrupt handlers the about certain
device driver characteristics.
.Dv INTR_FAST
means the handler is for a timing-critical function.
Extra care is take to speed up these handlers.
Use of this implies
.Dv INTR_EXCL .
.Dv INTR_EXCL
marks the handler as being
an exclusive handler for this interrupt.
.Dv INTR_MPSAFE
tells the scheduler that the interrupt handler
is well behaved in a preemptive environment
(``SMP safe''),
and does not need
to be protected by the ``Giant Lock'' mutex.
.Dv INTR_ENTROPY
marks the interrupt as being a good source of entropy -
this may be used by the entropy device
.Pa /dev/random .
The handler
.Fa intr
will be called with the value
.Fa arg
as its only argument.
.Pp
The
.Fa cookiep 
argument is a pointer to a void * that
.Nm
will write a cookie for the parent bus' use to if it is successful in
establishing an interrupt.
Driver writers may assume that this cookie will be non-zero.
The nexus driver will write 0 on failure to
.Fa cookiep.
.Pp
The interrupt handler will be detached by
.Fn BUS_TEARDOWN_INTR .
The cookie needs to be passed to
.Fn BUS_TEARDOWN_INTR
in order to tear down the correct interrupt handler.
.Sh RETURN VALUES
Zero is returned on success,
otherwise an appropriate error is returned.
.Sh SEE ALSO
.Xr random 4 ,
.Xr device 9 ,
.Xr driver 9
.Sh AUTHORS
.An -nosplit
This man page was written by
.An Jeroen Ruigrok van der Werven
.Aq asmodai@FreeBSD.org
based on the man pages for BUS_CREATE_INTR and BUS_CONNECT_INTR written by
.An Doug Rabson
.Aq dfr@FreeBSD.org .