[review] core: non-LPAE reuse xlat table when possible at static map …

…init

Add a comment to clarify why asserting level2 table address is sufficient.

Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>

core/arch/arm/mm/core_mmu_v7.c

@@ -679,8 +679,12 @@ static paddr_t map_page_memarea(const struct tee_mmap_region *mm, uint32_t xlat)
 	else
 		l2 = phys_to_virt(xlat & SECTION_PT_ATTR_MASK,
 				  MEM_AREA_TEE_RAM_RW_DATA);
-
+	/*
+	 * If allocation above failed, it panicked.
+	 * If xlat was non null, it is expected already a valid entry.
+	 */
 	assert(l2);
+
 	attr = mattr_to_desc(2, mm->attr);
 
 	pg_idx = (mm->va & SECTION_MASK) >> SMALL_PAGE_SHIFT;