• Dave Gerlach's avatar
    misc: sram: Integrate protect-exec reserved sram area type · 37afff0d
    Dave Gerlach authored
    Introduce a new "protect-exec" reserved sram area type which is
    makes use of the the existing functionality provided for the "pool"
    sram region type for use with the genalloc framework and with the
    added requirement that it be maintained as read-only and executable
    while allowing for an arbitrary number of drivers to share the space.
    
    This introduces a common way to maintain a region of sram as read-only
    and executable and also introduces a helper function, sram_exec_copy,
    which allows for copying data to this protected region while maintaining
    locking to avoid conflicts between multiple users of the same space. A
    region of memory that is marked with the "protect-exec" flag in the
    device tree also has the requirement of providing a page aligned block
    of memory so that the page attribute manipulation does not affect
    surrounding regions.
    
    Also, selectively enable this only for builds that support set_memory_*
    calls, for now just ARM, through the use of Kconfig.
    Signed-off-by: 's avatarDave Gerlach <d-gerlach@ti.com>
    Acked-by: 's avatarTony Lindgren <tony@atomide.com>
    Signed-off-by: 's avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    37afff0d