• Bjorn Helgaas's avatar
    PCI: Disable IO/MEM decoding for devices with non-compliant BARs · aa57ba13
    Bjorn Helgaas authored
    [ Upstream commit b84106b4 ]
    
    The PCI config header (first 64 bytes of each device's config space) is
    defined by the PCI spec so generic software can identify the device and
    manage its usage of I/O, memory, and IRQ resources.
    
    Some non-spec-compliant devices put registers other than BARs where the
    BARs should be.  When the PCI core sizes these "BARs", the reads and writes
    it does may have unwanted side effects, and the "BAR" may appear to
    describe non-sensical address space.
    
    Add a flag bit to mark non-compliant devices so we don't touch their BARs.
    Turn off IO/MEM decoding to prevent the devices from consuming address
    space, since we can't read the BARs to find out what that address space
    would be.
    Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
    Tested-by: default avatarAndi Kleen <ak@linux.intel.com>
    CC: stable@vger.kernel.org
    Signed-off-by: default avatarSasha Levin <sasha.levin@oracle.com>
    aa57ba13
probe.c 58.1 KB