On Wed, Nov 18, 2020 at 07:36:08PM -0300, Guilherme Piccoli wrote: > Thanks a lot Bjorn! I confess except for PPC64 Server machines, I > never saw other "domains" or segments. Is it common in x86 to have > that? The early_quirks() are restricted to the first segment, no > matter how many host bridges we have in segment 0000? I don't know whether it's *common* to have multiple domains on x86, but they're definitely used on large systems. This includes some lspci info from an HPE Superdome Flex system: https://lore.kernel.org/lkml/5350E02A-6457-41A8-8F33-AF67BFDAEE3E@xxxxxx/ The early quirks in arch/x86/kernel/early-quirks.c (not the DECLARE_PCI_FIXUP_EARLY quirks in drivers/pci/quirks.c) are restricted to segment 0, no matter how many host bridges there are. This is because they use read_pci_config_16(), which uses a config access mechanism that has no provision for a segment number. Bjorn
