x86, memblock: Add memblock_x86_reserve_range/memblock_x86_free_range

They are wrappers for core versions, which take start/end/name instead
of base/size.  This will make x86 conversion eaasier.

could add more debug print out

-v2: change get_max_mapped() to memblock.default_alloc_limit according to Michael
      Ellerman and Ben
     change to memblock_x86_reserve_range and memblock_x86_free_range according to Michael Ellerman
-v3: call check_and_double after reserve/free, so could avoid to use
      find_memblock_area. Suggested by Michael Ellerman

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

arch/x86/include/asm/memblock.h

@@ -6,4 +6,7 @@
 u64 memblock_x86_find_in_range_size(u64 start, u64 *sizep, u64 align);
 void memblock_x86_to_bootmem(u64 start, u64 end);
 
+void memblock_x86_reserve_range(u64 start, u64 end, char *name);
+void memblock_x86_free_range(u64 start, u64 end);
+
 #endif

arch/x86/mm/memblock.c

@@ -114,3 +114,25 @@ void __init memblock_x86_to_bootmem(u64 start, u64 end)
 	memblock_reserve_reserved_regions();
 }
 #endif
+
+void __init memblock_x86_reserve_range(u64 start, u64 end, char *name)
+{
+	if (start == end)
+		return;
+
+	if (WARN_ONCE(start > end, "memblock_x86_reserve_range: wrong range [%#llx, %#llx]\n", start, end))
+		return;
+
+	memblock_reserve(start, end - start);
+}
+
+void __init memblock_x86_free_range(u64 start, u64 end)
+{
+	if (start == end)
+		return;
+
+	if (WARN_ONCE(start > end, "memblock_x86_free_range: wrong range [%#llx, %#llx]\n", start, end))
+		return;
+
+	memblock_free(start, end - start);
+}