ARM: pgtable: consolidate set_pte_ext(TOP_PTE,...) + tlb flush

A number of places establish a PTE in our top page table and
immediately flush the TLB.  Rather than having this at every callsite,
provide an inline function for this purpose.

This changes some global tlb flushes to be local; each time we setup
one of these mappings, we always do it with preemption disabled which
would prevent us migrating to another CPU.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mm/mm.h b/arch/arm/mm/mm.h
index 6ee1ff2..a4e7feb 100644
--- a/arch/arm/mm/mm.h
+++ b/arch/arm/mm/mm.h
@@ -18,6 +18,12 @@
 /* PFN alias flushing, for VIPT caches */
 #define FLUSH_ALIAS_START	0xffff4000
 
+static inline void set_top_pte(unsigned long va, pte_t pte)
+{
+	set_pte_ext(TOP_PTE(va), pte, 0);
+	local_flush_tlb_kernel_page(va);
+}
+
 static inline pmd_t *pmd_off_k(unsigned long virt)
 {
 	return pmd_offset(pud_offset(pgd_offset_k(virt), virt), virt);