x86/PCI: X86_PAT & mprotect
authorVenki Pallipadi <venkatesh.pallipadi@intel.com>
Fri, 9 May 2008 20:05:19 +0000 (13:05 -0700)
committerJesse Barnes <jbarnes@virtuousgeek.org>
Tue, 13 May 2008 16:51:54 +0000 (09:51 -0700)
commit77db9885646f8a88214ea482988d41f8f73630f4
tree8adc0ff3a373c107a5226ed1afca23c23530f1c4
parent439a7733e8fcbaee39979c10246101565834d6b2
x86/PCI: X86_PAT & mprotect

Some versions of X used the mprotect workaround to change caching type from UC
to WB, so that it can then use mtrr to program WC for that region [1].  Change
the mmap of pci space through /sys or /proc interfaces from UC to UC_MINUS.
With this change, X will not need to use mprotect workaround to get WC type
since the MTRR mapping type will be honored.

The bug in mprotect that clobbers PAT bits is fixed in a follow on patch. So,
this X workaround will stop working as well.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
arch/x86/pci/i386.c