diff --git a/arch/loongarch/include/asm/bootinfo.h b/arch/loongarch/include/asm/bootinfo.h
index 0051b526ac6d..c60796869b2b 100644
--- a/arch/loongarch/include/asm/bootinfo.h
+++ b/arch/loongarch/include/asm/bootinfo.h
@@ -13,7 +13,6 @@ const char *get_system_type(void);
 extern void init_environ(void);
 extern void memblock_init(void);
 extern void platform_init(void);
-extern void plat_swiotlb_setup(void);
 extern int __init init_numa_memory(void);
 
 struct loongson_board_info {
diff --git a/arch/loongarch/kernel/setup.c b/arch/loongarch/kernel/setup.c
index 27f71f9531e1..4444b13418f0 100644
--- a/arch/loongarch/kernel/setup.c
+++ b/arch/loongarch/kernel/setup.c
@@ -389,8 +389,8 @@ static void __init arch_mem_init(char **cmdline_p)
 	/*
 	 * In order to reduce the possibility of kernel panic when failed to
 	 * get IO TLB memory under CONFIG_SWIOTLB, it is better to allocate
-	 * low memory as small as possible before plat_swiotlb_setup(), so
-	 * make sparse_init() using top-down allocation.
+	 * low memory as small as possible before swiotlb_init(), so make
+	 * sparse_init() using top-down allocation.
 	 */
 	memblock_set_bottom_up(false);
 	sparse_init();