Comment 12 for bug 1439562

Also, the 'powerpc/powernv: Support OPAL requested heartbeat' change requires a couple of prereqs if you're looking to use the pristine upstream version too:

commit 08135139430fabdeaa990da8a9e0d436aad0672b
Author: Michael Ellerman <email address hidden>
Date: Wed Jan 28 15:10:33 2015 +1100

    powerpc/powernv: Remove "opal" prefix from pr_xxx()s

    In commit c8742f85125d "powerpc/powernv: Expose OPAL firmware symbol
    map" I added pr_fmt() to opal.c. This left some existing pr_xxx()s with
    duplicate "opal" prefixes, eg:

        opal: opal: Found 0 interrupts reserved for OPAL

    Fix them all up. Also make the "Not not found" message a bit more
    verbose.

    Signed-off-by: Michael Ellerman <email address hidden>

commit c1c3a526bb4ddbec7639a9fb3b84fede25b201d9
Author: Gavin Shan <email address hidden>
Date: Fri Jan 23 14:25:05 2015 +1100

    powerpc/powernv: Separate function for OPAL IRQ setup

    The patch put the OPAL interrupt setup logic in opal_init() into
    seperate function opal_irq_init() for easier code maintaining. The
    patch doesn't introduce logic changes except:

       * Rename variable names.
       * Release virtual IRQ upon error from request_irq().
       * Don't cache the virtual IRQ to opal_irqs[] upon error from
         request_irq().

    Suggested-by: Michael Ellerman <email address hidden>
    Signed-off-by: Gavin Shan <email address hidden>
    Signed-off-by: Michael Ellerman <email address hidden>