• Russell King's avatar
    ARM: btc: avoid invalidating the branch target cache on kernel TLB maintanence · 4348810a
    Russell King authored
    Kernel space needs very little in the way of BTC maintanence as most
    mappings which are created and destroyed are non-executable, and so
    could never enter the instruction stream.
    
    The case which does warrant BTC maintanence is when a module is loaded.
    This creates a new executable mapping, but at that point the pages have
    not been initialized with code and data, so at that point they contain
    unpredictable information.  Invalidating the BTC at this stage serves
    little useful purpose.
    
    Before we execute module code, we call flush_icache_range(), which deals
    with the BTC maintanence requirements.  This ensures that we have a BTC
    maintanence operation before we execute code via the newly created
    mapping.
    Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
    4348810a
tlb-v7.S 2.33 KB