arm64/mm: Delete __init region from memblock.reserved

If CONFIG_ARCH_KEEP_MEMBLOCK is enabled, the memory information in
memblock will be retained.  We release the __init memory here, and
we should also delete the corresponding region in memblock.reserved,
which allows debugfs/memblock/reserved to display correct memory
information.
Signed-off-by: Rong Qianfeng <rongqianfeng@vivo.com>
Link: https://lore.kernel.org/r/20240902023940.43227-1-rongqianfeng@vivo.comSigned-off-by: Will Deacon <will@kernel.org>

arch/arm64/mm/init.c

@@ -414,6 +414,12 @@ void __init mem_init(void)
 
 void free_initmem(void)
 {
+	unsigned long aligned_begin = ALIGN_DOWN((u64)__init_begin, PAGE_SIZE);
+	unsigned long aligned_end = ALIGN((u64)__init_end, PAGE_SIZE);
+
+	/* Delete __init region from memblock.reserved. */
+	memblock_free((void *)aligned_begin, aligned_end - aligned_begin);
+
 	free_reserved_area(lm_alias(__init_begin),
 			   lm_alias(__init_end),
 			   POISON_FREE_INITMEM, "unused kernel");