• Gary Hade's avatar
    PCI: avoid P2P prefetch window for expansion ROMs · fd64cb46
    Gary Hade authored
    Avoid creating P2P prefetch window for expansion ROMs
    
    Because of the future possibility that P2P prefetch windows will contain
    address ranges above 4GB some BIOSes are providing space in the P2P
    non-prefetch windows for expansion ROMs.  This is due to expansion ROM
    BAR 32-bit limitation.  When expansion ROM BARs without BIOS assigned
    address(es) are currently found behind a P2P bridge, the kernel attempts
    to create a P2P prefetch window for them even though space for them has
    already been provided in the non-prefetch window.  _CRS on some systems
    with certain resource conservation conscious BIOSes may not provide the
    extra 1MB or more memory resource needed for the expansion ROM motivated
    prefetch window causing resource allocation errors.
    
    This change corrects the problem by removing IORESOURCE_PREFETCH from
    the expansion ROM flags initialization.  It also removes
    IORESOURCE_CACHEABLE which seems inappropriate if only non-cacheable
    memory is available.
    Signed-off-by: default avatarGary Hade <gary.hade@us.ibm.com>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
    fd64cb46
probe.c 34 KB