• Jan Beulich's avatar
    x86/PCI: config space accessor functions should not ignore the segment argument · db34a363
    Jan Beulich authored
    Without this change, the majority of the raw PCI config space access
    functions silently ignore a non-zero segment argument, which is
    certainly wrong.
    
    Apart from pci_direct_conf1, all other non-MMCFG access methods get
    used only for non-extended accesses (i.e. assigned to raw_pci_ops
    only). Consequently, with the way raw_pci_{read,write}() work, it would
    be a coding error to call these functions with a non-zero segment (with
    the current call flow this cannot happen afaict).
    
    The access method 1 accessor, as it can be used for extended accesses
    (on AMD systems) instead gets checks added for the passed in segment to
    be zero. This would be the case when on such a system having multiple
    PCI segments (don't know whether any exist in practice) MMCFG for some
    reason is not usable, and method 1 gets selected for doing extended
    accesses. Rather than accessing the wrong device's config space, the
    function will now error out.
    
    v2: Convert BUG_ON() to WARN_ON(), and extend description as per Ingo's
    request.
    Signed-off-by: default avatarJan Beulich <jbeulich@novell.com>
    Reviewed-by: default avatarIngo Molnar <mingo@elte.hu>
    Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
    db34a363
pcbios.c 10.9 KB