x86/mm/cpa: Optimize cpa_flush_array() TLB invalidation

x86/mm/cpa: Optimize cpa_flush_array() TLB invalidation

Instead of punting and doing tlb_flush_all(), do the same as
flush_tlb_kernel_range() does and use single page invalidations.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom.StDenis@amd.com
Cc: dave.hansen@intel.com
Link: http://lkml.kernel.org/r/20181203171043.430001980@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>