armv8: mmu: add a way to map additional regions

In some cases we might want to map some memory region after enabling
caches. Introduce a new helper for this.

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Caleb Connolly <caleb.connolly@linaro.org>

arch/arm/include/asm/system.h

@@ -277,6 +277,16 @@ void protect_secure_region(void);
 void smp_kick_all_cpus(void);
 
 void flush_l3_cache(void);
+
+/**
+ * mmu_map_region() - map a region of previously unmapped memory.
+ * Will be mapped MT_NORMAL & PTE_BLOCK_INNER_SHARE.
+ *
+ * @start: Start address of the region
+ * @size: Size of the region
+ * @emerg: Also map the region in the emergency table
+ */
+void mmu_map_region(phys_addr_t start, u64 size, bool emerg);
 void mmu_change_region_attr(phys_addr_t start, size_t size, u64 attrs);
 
 /*