From: Bjorn Helgaas <bhelgaas@google.com>
Date: Tue, 19 Jun 2012 13:45:44 +0000 (-0600)
Subject: PCI: fix P2P bridge I/O port window sign extension
X-Git-Tag: v3.6-rc1~112^2~13^2~3
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8f38eaca55d0fab7499b33adb1dec33e16de5abb;p=pandora-kernel.git

PCI: fix P2P bridge I/O port window sign extension

On P2P bridges with 32-bit I/O decoding, we incorrectly sign-extended
windows starting at 0x80000000 or above.  In "base |= (io_base_hi << 16)",
"io_base_hi" is promoted to a signed int before being extended to an
unsigned long.

This would cause a window starting at I/O address 0x80000000 to be
treated as though it started at 0xffffffff80008000 instead, which
should cause "no compatible bridge window" errors when we enumerate
devices using that I/O space.

The mmio and mmio_pref casts are not strictly necessary, but without
them, correctness depends on the types of the PCI_MEMORY_RANGE_MASK and
PCI_PREF_RANGE_MASK constants, which are not obvious from reading the
local code.

Found by Coverity (CID 138747 and CID 138748).

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
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