Skip to content
  • Thierry Reding's avatar
    ARM: Implement non-cached memory support · 1dfdd9ba
    Thierry Reding authored
    
    
    Implement an API that can be used by drivers to allocate memory from a
    pool that is mapped uncached. This is useful if drivers would otherwise
    need to do extensive cache maintenance (or explicitly maintaining the
    cache isn't safe).
    
    The API is protected using the new CONFIG_SYS_NONCACHED_MEMORY setting.
    Boards can set this to the size to be used for the non-cached area. The
    area will typically be right below the malloc() area, but architectures
    should take care of aligning the beginning and end of the area to honor
    any mapping restrictions. Architectures must also ensure that mappings
    established for this area do not overlap with the malloc() area (which
    should remain cached for improved performance).
    
    While the API is currently only implemented for ARM v7, it should be
    generic enough to allow other architectures to implement it as well.
    
    Signed-off-by: default avatarThierry Reding <treding@nvidia.com>
    Signed-off-by: default avatarSimon Glass <sjg@chromium.org>
    Signed-off-by: default avatarTom Warren <twarren@nvidia.com>
    1dfdd9ba