8f00f63dab
assigned conflicting ranges to BARs then leaving the BARs alone could result in one device stealing mmio accesses intended to go to a second device. Prior to 233677 the PCI bus driver attempted to handle this case by clearing the BAR to 0 depending on BARs based at 0 not decoding (which is not guaranteed to be true). Now when a conflicting BAR is detected the following steps are taken: 1) If hw.pci.realloc_bars (a new tunable) is enabled (default is enabled), then ignore the current BAR setting from the firmware and attempt to allocate a fresh resource range for the BAR. 2) If 1) failed (or was disabled), disable decoding for the relevant BAR type (e.g. disable mem decoding for a memory BAR) and emit a warning if booting verbose. Tested by: Alex Keda <admin@lissyara.su> MFC after: 1 week