NAME

     BUS_BIND_INTR, bus_bind_intr — bind an interrupt resource to a specific CPU

SYNOPSIS

     #include <sys/param.h>
     #include <sys/bus.h>

     int
     BUS_BIND_INTR(device_t dev, device_t child, struct resource *irq, int cpu);

     int
     bus_bind_intr(device_t dev, struct resource *irq, int cpu);

DESCRIPTION

     The BUS_BIND_INTR() method allows an interrupt resource to be pinned to a specific CPU.  The
     interrupt resource must have an interrupt handler attached via BUS_SETUP_INTR(9).  The cpu
     parameter corresponds to the ID of a valid CPU in the system.  Binding an interrupt
     restricts the cpuset(2) of any associated interrupt threads to only include the specified
     CPU.  It may also direct the low-level interrupt handling of the interrupt to the specified
     CPU as well, but this behavior is platform-dependent.  If the value NOCPU is used for cpu,
     then the interrupt will be “unbound” which restores any associated interrupt threads back to
     the default cpuset.

     Non-sleepable locks such as mutexes should not be held across calls to these functions.

     The bus_bind_intr() function is a simple wrapper around BUS_BIND_INTR().

     Note that currently there is no attempt made to arbitrate between multiple bind requests for
     the same interrupt from either the same device or multiple devices.  There is also no
     arbitration between interrupt binding requests submitted by userland via cpuset(2) and
     BUS_BIND_INTR().  The most recent binding request is the one that will be in effect.

RETURN VALUES

     Zero is returned on success, otherwise an appropriate error is returned.

SEE ALSO

     BUS_SETUP_INTR(9), cpuset(2), device(9)

HISTORY

     The BUS_BIND_INTR() method and bus_bind_intr() functions first appeared in FreeBSD 7.2.