arm64: mm: free the initrd reserved memblock in a aligned manner

We should free the initrd reserved memblock in an aligned manner,
because the initrd reserves the memblock in an aligned manner
in arm64_memblock_init().
Otherwise there are some fragments in memblock_reserved regions
after free_initrd_mem(). e.g.:
/sys/kernel/debug/memblock # cat reserved
   0: 0x0000000080080000..0x00000000817fafff
   1: 0x0000000083400000..0x0000000083ffffff
   2: 0x0000000090000000..0x000000009000407f
   3: 0x00000000b0000000..0x00000000b000003f
   4: 0x00000000b26184ea..0x00000000b2618fff
The fragments like the ranges from b0000000 to b000003f and
from b26184ea to b2618fff should be freed.

And we can do free_reserved_area() after memblock_free(),
as free_reserved_area() calls __free_pages(), once we've done
that it could be allocated somewhere else,
but memblock and iomem still say this is reserved memory.

Fixes: 05c58752 ("arm64: To remove initrd reserved area entry from memblock")
Signed-off-by: Junhua Huang <huang.junhua@zte.com.cn>
Signed-off-by: Will Deacon <will@kernel.org>

arch/arm64/mm/init.c

@@ -570,8 +570,12 @@ void free_initmem(void)
 #ifdef CONFIG_BLK_DEV_INITRD
 void __init free_initrd_mem(unsigned long start, unsigned long end)
 {
+	unsigned long aligned_start, aligned_end;
+
+	aligned_start = __virt_to_phys(start) & PAGE_MASK;
+	aligned_end = PAGE_ALIGN(__virt_to_phys(end));
+	memblock_free(aligned_start, aligned_end - aligned_start);
 	free_reserved_area((void *)start, (void *)end, 0, "initrd");
-	memblock_free(__virt_to_phys(start), end - start);
 }
 #endif