s390/kasan: remove obvious parameter with the only possible value

Kasan early code is only working on init_mm, remove unneeded pgd
parameter from kasan_copy_shadow and rename it to
kasan_copy_shadow_mapping.
Reviewed-by: NAlexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>
Signed-off-by: NHeiko Carstens <hca@linux.ibm.com>

arch/s390/include/asm/kasan.h

@@ -12,12 +12,12 @@
 #define KASAN_SHADOW_END	(KASAN_SHADOW_START + KASAN_SHADOW_SIZE)
 
 extern void kasan_early_init(void);
-extern void kasan_copy_shadow(pgd_t *dst);
+extern void kasan_copy_shadow_mapping(void);
 extern void kasan_free_early_identity(void);
 extern unsigned long kasan_vmax;
 #else
 static inline void kasan_early_init(void) { }
-static inline void kasan_copy_shadow(pgd_t *dst) { }
+static inline void kasan_copy_shadow_mapping(void) { }
 static inline void kasan_free_early_identity(void) { }
 #endif
 

arch/s390/mm/init.c

@@ -105,7 +105,7 @@ void __init paging_init(void)
 	S390_lowcore.user_asce = S390_lowcore.kernel_asce;
 	crst_table_init((unsigned long *) init_mm.pgd, pgd_type);
 	vmem_map_init();
-	kasan_copy_shadow(init_mm.pgd);
+	kasan_copy_shadow_mapping();
 
 	/* enable virtual mapping in kernel mode */
 	__ctl_load(S390_lowcore.kernel_asce, 1, 1);

arch/s390/mm/kasan_init.c

@@ -393,7 +393,7 @@ void __init kasan_early_init(void)
 	sclp_early_printk("KernelAddressSanitizer initialized\n");
 }
 
-void __init kasan_copy_shadow(pgd_t *pg_dir)
+void __init kasan_copy_shadow_mapping(void)
 {
 	/*
 	 * At this point we are still running on early pages setup early_pg_dir,
@@ -407,7 +407,7 @@ void __init kasan_copy_shadow(pgd_t *pg_dir)
 	p4d_t *p4_dir_dst;
 
 	pg_dir_src = pgd_offset_raw(early_pg_dir, KASAN_SHADOW_START);
-	pg_dir_dst = pgd_offset_raw(pg_dir, KASAN_SHADOW_START);
+	pg_dir_dst = pgd_offset_raw(init_mm.pgd, KASAN_SHADOW_START);
 	p4_dir_src = p4d_offset(pg_dir_src, KASAN_SHADOW_START);
 	p4_dir_dst = p4d_offset(pg_dir_dst, KASAN_SHADOW_START);
 	memcpy(p4_dir_dst, p4_dir_src,