x86: page.h: move and unify types for pagetable entry

# HG changeset patch
# User Jeremy Fitzhardinge <jeremy@xensource.com>
# Date 1199319654 28800
# Node ID 3bd7db6e85e66e7f3362874802df26a82fcb2d92
# Parent  f7e7db3facd9406545103164f9be8f9ba1a2b549
x86: page.h: move and unify types for pagetable entry definitions

This patch:

1. Defines arch-specific types for the contents of a pagetable entry.
That is, 32-bit entries for 32-bit non-PAE, and 64-bit entries for
32-bit PAE and 64-bit.  However, even though the latter two are the
same size, they're defined with different types in order to retain
compatibility with printk format strings, etc.

2. Defines arch-specific pte_t.  This is different because 32-bit PAE
defines it in two halves, whereas 32-bit PAE and 64-bit define it as a
single entry.  All the other pagetable levels can be defined in a
common way.  This also defines arch-specific pte_val/make_pte functions.

3. Define PAGETABLE_LEVELS for each architecture variation, for later use.

4. Define common pagetable entry accessors in a paravirt-compatible
way. (64-bit does not yet use paravirt-ops in any way).

5. Convert a few instances of using a *_val() as an lvalue where it is
no longer a macro.  There are still places in the 64-bit code which
use pte_val() as an lvalue.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>