• Neil Turton's avatar
    sfc: Use rmb() to ensure reads occur in order · fcfa0604
    Neil Turton authored
    Enabling write-combining may also enable read reordering.  The BIU is
    only guaranteed to read from a 128-bit CSR or 64-bit SRAM word when
    the host reads from its lowest address; otherwise the BIU may use the
    latched value.  Therefore we need to reinstate the read memory
    barriers after the first read operation for each CSR or SRAM word.
    
    Signed-off-by; Ben Hutchings <bhutchings@solarflare.com>
    fcfa0604
io.h 9.79 KB