• Vineet Gupta's avatar
    ARC: mm: Introduce explicit super page size support · 37eda9df
    Vineet Gupta authored
    MMUv4 supports 2 concurrent page sizes: Normal and Super [4K to 16M]
    
    So far Linux supported a single super page size for a given Normal page,
    depending on the software page walking address split.
    e.g. we had 11:8:13 address split for 8K page, which meant super page
    was 2 ^(8+13) = 2M (given that THP size has to be PMD_SHIFT)
    
    Now we turn this around, by allowing multiple Super Pages in Kconfig
    (currently 2M and 16M only) and forcing page walker address split to
    PGDIR_SHIFT and PAGE_SHIFT
    
    For configs without Super page, things are same as before and
    PGDIR_SHIFT can be hacked to get non default address split
    
    The motivation for this change is a customer who needs 16M super page
    and a 8K Normal page combo.
    Signed-off-by: default avatarVineet Gupta <vgupta@synopsys.com>
    37eda9df
Kconfig 14 KB