focal (9) BUS_BIND_INTR.9freebsd.gz

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

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

HISTORY

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