[RFC:PATCH 00/06] Strong Access Ordering page attributes for POWER7

[Dave Kleikamp]

Allow an application to enable Strong Access Ordering on specific pages of
memory on Power 7 hardware. Currently, power has a weaker memory model than
x86. Implementing a stronger memory model allows an emulator to more
efficiently translate x86 code into power code, resulting in faster code
execution.

On Power 7 hardware, storing 0b1110 in the WIMG bits of the hpte enables
strong access ordering mode for the memory page.  This patchset allows a
user to specify which pages are thus enabled by passing a new protection
bit through mmap() and mprotect().  I have tentatively defined this bit,
PROT_SAO, as 0x10.

In order to accomplish this, I had to modify the architecture-independent
code to allow the architecture to deal with additional protection bits.

Patches built against 2.6.26-rc5.

Any and all suggestions, complaints, flames, insults, etc. are appreciated.

Thanks,
Shaggy