memblock: Add memblock_find_in_range()

This is a wrapper for memblock_find_base() using slightly different
arguments (start,end instead of start,size for example) in order to
make it easier to convert existing arch/x86 code.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

include/linux/memblock.h

@@ -47,6 +47,8 @@ extern int memblock_can_resize;
 #define memblock_dbg(fmt, ...) \
 	if (memblock_debug) printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
 
+u64 memblock_find_in_range(u64 start, u64 end, u64 size, u64 align);
+
 extern void __init memblock_init(void);
 extern void __init memblock_analyze(void);
 extern long memblock_add(phys_addr_t base, phys_addr_t size);

mm/memblock.c

@@ -162,6 +162,14 @@ static phys_addr_t __init memblock_find_base(phys_addr_t size, phys_addr_t align
 	return MEMBLOCK_ERROR;
 }
 
+/*
+ * Find a free area with specified alignment in a specific range.
+ */
+u64 __init_memblock memblock_find_in_range(u64 start, u64 end, u64 size, u64 align)
+{
+	return memblock_find_base(size, align, start, end);
+}
+
 static void __init_memblock memblock_remove_region(struct memblock_type *type, unsigned long r)
 {
 	unsigned long i;