• Mark Nelson's avatar
    powerpc: Update 64bit __copy_tofrom_user() using CPU_FTR_UNALIGNED_LD_STD · a4e22f02
    Mark Nelson authored
    In exactly the same way that we updated memcpy() with new feature
    sections in commit 25d6e2d7 ("powerpc:
    Update 64bit memcpy() using CPU_FTR_UNALIGNED_LD_STD"), we do the same
    thing here for __copy_tofrom_user().  Once again this is purely a
    performance tweak for Cell and Power6 - this has no effect on all the
    other 64bit powerpc chips.
    
    We can make these same changes to __copy_tofrom_user() because the
    basic copy algorithm is the same as in memcpy() - this version just
    has all the exception handling logic needed when copying to or from
    userspace as well as a special case for copying whole 4K pages that
    are page aligned.
    
    CPU_FTR_UNALIGNED_LD_STD CPU was added in commit
    4ec577a2 ("powerpc: Add new CPU
    feature: CPU_FTR_UNALIGNED_LD_STD").
    
    We also make the same simple one line change from cmpldi r1,... to
    cmpldi cr1,... for consistency.
    Signed-off-by: default avatarMark Nelson <markn@au1.ibm.com>
    Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
    a4e22f02
copyuser_64.S 9.41 KB