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    cxl: Disable AFU debug flag · d6a6af2c
    Ian Munsie 提交于
    Upon inspection of the implementation specific registers, it was
    discovered that the high bit of the implementation specific RXCTL
    register was enabled, which enables the DEADB00F debug feature.
    
    The debug feature causes MMIO reads to a disabled AFU to respond with
    0xDEADB00F instead of all Fs. In general this should not be visible as
    the kernel will only allow MMIO access to enabled AFUs, but there may be
    some circumstances where an AFU may become disabled while it is use.
    One such case would be an AFU designed to only be used in the dedicated
    process mode and to disable itself after it has completed it's work
    (however even in that case the effects of this debug flag would be
    limited as the userspace application must have completed any required
    MMIO accesses before the AFU disables itself with or without the flag).
    
    This patch removes the debug flag and replaces the magic value
    programmed into this register with a preprocessor define so it is
    clearer what the rest of this initialisation does.
    Signed-off-by: NIan Munsie <imunsie@au1.ibm.com>
    Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
    d6a6af2c
cxl.h 23.0 KB