Revert "x86/mm: Fix the size calculation of mapping tables"

Revert "x86/mm: Fix the size calculation of mapping tables"

Commit:

   722bc6b16771 x86/mm: Fix the size calculation of mapping tables

Tried to address the issue that the first 2/4M should use 4k pages
if PSE enabled, but extra counts should only be valid for x86_32.

This commit caused a kdump regression: the kdump kernel hangs.

Work is in progress to fundamentally fix the various page table
initialization issues that we have, via the design suggested
by H. Peter Anvin, but it's not ready yet to be merged.

So, to get a working kdump revert to the last known working version,
which is the revert of this commit and of a followup fix (which was
incomplete):

   bd2753b2dda7 x86/mm: Only add extra pages count for the first memory range during pre-allocation

Tested kdump on physical and virtual machines.

Signed-off-by: Dave Young <[email protected]>
Acked-by: Yinghai Lu <[email protected]>
Acked-by: Cong Wang <[email protected]>
Acked-by: Flavio Leitner <[email protected]>
Tested-by: Flavio Leitner <[email protected]>
Cc: Dan Carpenter <[email protected]>
Cc: Cong Wang <[email protected]>
Cc: Flavio Leitner <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: [email protected]
Cc: Vivek Goyal <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>