BUS_SETUP_INTR(9) MidnightBSD Kernel Developer’s Manual 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_filter_t *filter, driver_intr_t *ithread, void *arg, void **cookiep);

int

bus_setup_intr(device_t dev, struct resource *r, int flags, driver_filter_t filter, driver_intr_t ithread, 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 interrupt handler to an interrupt previously allocated by the resource manager’s BUS_ALLOC_RESOURCE(9) method. The flags are found in <sys/bus.h>, and give the broad category of interrupt. The flags also tell the interrupt handlers about certain device driver characteristics. 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 protected 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.

To define a time-critical handler (previously known as INTR_FAST) that will not execute any potentially blocking operation, use the filter argument. Otherwise, use the ithread argument. The defined handler will be called with the value arg as its only argument.

The cookiep argument is a pointer to a void * that BUS_SETUP_INTR() 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 cookiep.

The interrupt handler will be detached by BUS_TEARDOWN_INTR(). The cookie needs to be passed to BUS_TEARDOWN_INTR() in order to tear down the correct interrupt handler. Once BUS_TEARDOWN_INTR() returns, 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 Werven 〈asmodai@FreeBSD.org〉 based on the manual pages for BUS_CREATE_INTR() and BUS_CONNECT_INTR() written by Doug Rabson 〈dfr@FreeBSD.org〉.

MidnightBSD 0.3 March 1, 2007 MidnightBSD 0.3