bus_setup_intr(9)

NAME

BUS_SETUP_INTR, bus_setup_intr, BUS_TEARDOWN_INTR,

bus_teardown_intr create, attach and teardown an interrupt handler

SYNOPSIS

#include <sys/param.h>
#include <sys/bus.h>
int
BUS_SETUP_INTR(device_t dev, device_t child, struct resource
*irq,
        int flags,  driver_intr_t  *intr,  void  *arg,  void
**cookiep);
int
bus_setup_intr(device_t dev, struct resource *r, int flags,
        driver_intr_t handler, void *arg, void **cookiep);
int
BUS_TEARDOWN_INTR(device_t   dev,   device_t  child,  struct
resource *irq,
        void *cookiep);
int
bus_teardown_intr(device_t dev,  struct  resource  *r,  void
*cookiep);

DESCRIPTION

The BUS_SETUP_INTR() method will create and attach an inter

rupt handler
to an interrupt previously allocated by the resource manag

er's
BUS_ALLOC_RESOURCE(9) method. The flags are found in and

give the broad
category of interrupt. The flags also tell the interrupt

handlers about
certain device driver characteristics. INTR_FAST means the

handler is
for a timing-critical function. Extra care is take to speed

up these
handlers. Use of this implies INTR_EXCL. INTR_EXCL marks

the handler as
being an exclusive handler for this interrupt. INTR_MPSAFE

tells the
scheduler that the interrupt handler is well behaved in a

preemptive
environment (``SMP safe''), and does not need to be protect

ed by the
``Giant Lock'' mutex. INTR_ENTROPY marks the interrupt as

being a good
source of entropy - this may be used by the entropy device

/dev/random.
The handler intr will be called with the value arg as its

only argument.

The cookiep argument is a pointer to a void * that

BUS_SETUP_INTR

write a cookie for the parent bus' use to if it is success

ful in establishing an interrupt. Driver writers may assume that this

cookie will be
non-zero. The nexus driver will write 0 on failure to

cookiep.

The interrupt handler will be detached by

BUS_TEARDOWN_INTR

cookie needs to be passed to BUS_TEARDOWN_INTR() in order to

tear down
the correct interrupt handler. Once BUS_TEARDOWN_INTR() re

turns, it is
guaranteed that the interrupt function is not active and

will no longer
be called.

Mutexes are not allowed to be held across calls to these

functions.

RETURN VALUES

Zero is returned on success, otherwise an appropriate error

is returned.

SEE ALSO

random(4), device(9), driver(9)

AUTHORS

This manual page was written by Jeroen Ruigrok van der Wer

ven
<asmodai@FreeBSD.org> based on the manual pages for

BUS_CREATE_INTR

BUS_CONNECT_INTR() written by Doug Rabson <dfr@FreeBSD.org>.

BSD January 6, 2005

BSD