Multiple PCI controllers

M. Warner Losh imp at bsdimp.com
Thu Apr 15 14:58:26 UTC 2010


In message: <p2t292693081004150738je2d9de95ya52cbc5ad9ce82b3 at mail.gmail.com>
            Daniel Rodrick <daniel.rodrick at gmail.com> writes:
: Can some one please help me understand how did the old FreeBSD kernel
: that DID not have the PCI domains concept (say 6.x) used to deal with
: systems that had multiple PCI / PCIe controllers on them, from a bus
: numbering point of view? Was there a unified PCI tree - thus each PCI
: bus number being unique in the system?

FreeBSD has handled multiple PCI domains for a very long time.  The
support was added so that the Alpha machines could run FreeBSD.

The bus numbers were whatever the BIOS programmed them to be.  FreeBSD
doesn't program bus numbers at all, except in some very limited cases.

: Also, how is this dealt with now?

The same.  Each host controller will have a pci device tree under it.

Warner


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