• Paul Mackerras's avatar
    [POWERPC] Use 1TB segments · 1189be65
    Paul Mackerras authored
    This makes the kernel use 1TB segments for all kernel mappings and for
    user addresses of 1TB and above, on machines which support them
    (currently POWER5+, POWER6 and PA6T).
    
    We detect that the machine supports 1TB segments by looking at the
    ibm,processor-segment-sizes property in the device tree.
    
    We don't currently use 1TB segments for user addresses < 1T, since
    that would effectively prevent 32-bit processes from using huge pages
    unless we also had a way to revert to using 256MB segments.  That
    would be possible but would involve extra complications (such as
    keeping track of which segment size was used when HPTEs were inserted)
    and is not addressed here.
    
    Parts of this patch were originally written by Ben Herrenschmidt.
    Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
    1189be65
head_64.S 39.2 KB