x86/mm: Remove the UP asm/tlbflush.h code, always use the (formerly) SMP code

x86/mm: Remove the UP asm/tlbflush.h code, always use the (formerly) SMP code

commit ce4a4e565f5264909a18c733b864c3f74467f69e upstream.

The UP asm/tlbflush.h generates somewhat nicer code than the SMP version.
Aside from that, it's fallen quite a bit behind the SMP code:

 - flush_tlb_mm_range() didn't flush individual pages if the range
   was small.

 - The lazy TLB code was much weaker.  This usually wouldn't matter,
   but, if a kernel thread flushed its lazy "active_mm" more than
   once (due to reclaim or similar), it wouldn't be unlazied and
   would instead pointlessly flush repeatedly.

 - Tracepoints were missing.

Aside from that, simply having the UP code around was a maintanence
burden, since it means that any change to the TLB flush code had to
make sure not to break it.

Simplify everything by deleting the UP code.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Nadav Amit <namit@vmware.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit b2e24274d50e0ecdf560ebe06dbed0cc648ad3f9)
Orabug: 27333760
CVE: CVE-2017-5754
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Conflicts:
	arch/x86/Kconfig

Signed-off-by: Kirtikar Kashyap <kirtikar.kashyap@oracle.com>