x86/mm: Adapt MODULES_END based on fixmap section size

x86/mm: Adapt MODULES_END based on fixmap section size

This patch aligns MODULES_END to the beginning of the fixmap section.
It optimizes the space available for both sections. The address is
pre-computed based on the number of pages required by the fixmap
section.

It will allow GDT remapping in the fixmap section. The current
MODULES_END static address does not provide enough space for the kernel
to support a large number of processors.

Signed-off-by: Thomas Garnier <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Ard Biesheuvel <[email protected]>
Cc: Boris Ostrovsky <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Chris Wilson <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Jiri Kosina <[email protected]>
Cc: Joerg Roedel <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Juergen Gross <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Len Brown <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Lorenzo Stoakes <[email protected]>
Cc: Luis R . Rodriguez <[email protected]>
Cc: Matt Fleming <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Paolo Bonzini <[email protected]>
Cc: Paul Gortmaker <[email protected]>
Cc: Pavel Machek <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Radim Krčmář <[email protected]>
Cc: Rafael J . Wysocki <[email protected]>
Cc: Rusty Russell <[email protected]>
Cc: Stanislaw Gruszka <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Tim Chen <[email protected]>
Cc: Vitaly Kuznetsov <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: zijun_hu <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
[ Small build fix. ]
Signed-off-by: Ingo Molnar <[email protected]>