• David Woods's avatar
    arm64: hugetlb: add support for PTE contiguous bit · 66b3923a
    David Woods authored
    The arm64 MMU supports a Contiguous bit which is a hint that the TTE
    is one of a set of contiguous entries which can be cached in a single
    TLB entry.  Supporting this bit adds new intermediate huge page sizes.
    The set of huge page sizes available depends on the base page size.
    Without using contiguous pages the huge page sizes are as follows.
     4KB:   2MB  1GB
    64KB: 512MB
    With a 4KB granule, the contiguous bit groups together sets of 16 pages
    and with a 64KB granule it groups sets of 32 pages.  This enables two new
    huge page sizes in each case, so that the full set of available sizes
    is as follows.
     4KB:  64KB   2MB  32MB  1GB
    64KB:   2MB 512MB  16GB
    If a 16KB granule is used then the contiguous bit groups 128 pages
    at the PTE level and 32 pages at the PMD level.
    If the base page size is set to 64KB then 2MB pages are enabled by
    default.  It is possible in the future to make 2MB the default huge
    page size for both 4KB and 64KB granules.
    Reviewed-by: default avatarChris Metcalf <cmetcalf@ezchip.com>
    Reviewed-by: default avatarSteve Capper <steve.capper@linaro.org>
    Signed-off-by: default avatarDavid Woods <dwoods@ezchip.com>
    Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
hugetlb.h 14.9 KB