• Tejun Heo's avatar
    alpha: fix percpu build breakage · b01e8dc3
    Tejun Heo authored
    alpha percpu access requires custom SHIFT_PERCPU_PTR() definition for
    modules to work around addressing range limitation.  This is done via
    generating inline assembly using C preprocessing which forces the
    assembler to generate external reference.  This happens behind the
    compiler's back and makes the compiler think that static percpu variables
    in modules are unused.
    This used to be worked around by using __unused attribute for percpu
    variables which prevent the compiler from omitting the variable; however,
    recent declare/definition attribute unification change broke this as
    __used can't be used for declaration.  Also, in the process,
    PER_CPU_ATTRIBUTES definition in alpha percpu.h got broken.
    This patch adds PER_CPU_DEF_ATTRIBUTES which is only used for definitions
    and make alpha use it to add __used for percpu variables in modules.  This
    also fixes the PER_CPU_ATTRIBUTES double definition bug.
    Signed-off-by: default avatarTejun Heo <tj@kernel.org>
    Tested-by: default avatarmaximilian attems <max@stro.at>
    Acked-by: default avatarIvan Kokshaysky <ink@jurassic.park.msu.ru>
    Cc: Richard Henderson <rth@twiddle.net>
    Cc: <stable@kernel.org>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
percpu.h 2.51 KB