arm64: mm: Define arch_get_mmap_end, arch_get_mmap_base

Now that we have DEFAULT_MAP_WINDOW defined, we can arch_get_mmap_end
and arch_get_mmap_base helpers to allow for high addresses in mmap.
Signed-off-by: NSteve Capper <steve.capper@arm.com>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

arch/arm64/include/asm/processor.h

@@ -80,6 +80,13 @@
 #define STACK_TOP		STACK_TOP_MAX
 #endif /* CONFIG_COMPAT */
 
+#define arch_get_mmap_end(addr) ((addr > DEFAULT_MAP_WINDOW) ? TASK_SIZE :\
+				DEFAULT_MAP_WINDOW)
+
+#define arch_get_mmap_base(addr, base) ((addr > DEFAULT_MAP_WINDOW) ? \
+					base + TASK_SIZE - DEFAULT_MAP_WINDOW :\
+					base)
+
 extern phys_addr_t arm64_dma_phys_limit;
 #define ARCH_LOW_ADDRESS_LIMIT	(arm64_dma_phys_limit - 1)