PCI: treat mem BAR type "11" (reserved) as 32-bit, not 64-bit, BAR

This fixes a minor regression where broken PCI devices that use the
reserved "11" memory BAR type worked before e354597cce but not after.

The low four bits of a memory BAR are "PTT0" where P=1 for prefetchable
BARs, and TT is as follows:

  00  32-bit BAR, anywhere in lower 4GB
  01  anywhere below 1MB (reserved as of PCI 2.2)
  10  64-bit BAR
  11  reserved

Prior to e354597cce, we treated "0100" as a 64-bit BAR and all others,
including prefetchable 64-bit BARs ("1100") as 32-bit BARs.  The e354597cce
fix, which appeared in 2.6.28, treats "x1x0" as 64-bit BARs, so the
reserved "x110" types are treated as 64-bit instead of 32-bit.

This patch returns to treating the reserved "11" type as a 32-bit BAR and
adds a warning if we see it.

It also logs a note if we see a 1M BAR.  This is not a warning, because
such hardware conforms to pre-PCI 2.2 spec, but I think it's worth noting
because Linux ignores the 1M restriction if it ever has to assign the BAR.

CC: Peter Chubb <peterc@gelato.unsw.edu.au>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=35952
Reported-by: Jan Zwiegers <jan@radicalsystems.co.za>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

0 files changed, 0 insertions, 0 deletions