clean_sort_range() should return a number of nonempty elements of range
array, but if the array is full clean_sort_range() returns 0.

The problem is that the number of nonempty elements is evaluated by
finding the first empty element of the array.  If there is no such element
it returns an initial value of local variable nr_range that is zero.

The fix is trivial: it changes initial value of nr_range to size of the
array.

The bug can lead to loss of information regarding all ranges, since
typically returned value of clean_sort_range() is considered as an actual
number of ranges in the array after a series of add/subtract operations.

Found by Analytical Verification project of Linux Verification Center
(linuxtesting.org), thanks to Alexander Kolosov.
Signed-off-by: NAlexey Khoroshilov <khoroshilov@ispras.ru>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove duplicate definition of ARRAY_SIZE(), which was never used anyway.
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

So make interface more consistent with early_res.
Later we can share some code with early_res.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
LKML-Reference: <1265793639-15071-10-git-send-email-yinghai@kernel.org>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

We have almost the same code for mtrr cleanup and amd_bus checkup, and
this code  will also be used in replacing bootmem with early_res,
so try to move them together and reuse it from different parts.

Also rename update_range to subtract_range as that is what the
function is actually doing.

-v2: update comments as Christoph requested
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
LKML-Reference: <1265793639-15071-4-git-send-email-yinghai@kernel.org>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>