s390/early: get rid of memmove_early

memmove_early was introduced with commit d543a10 ("s390: fix
initrd corruptions with gcov/kcov instrumented kernels"). The reason
for writing this extra memmove implementation was to be able to move
memory from an unknown location (aka SCSI IPL parameter block) to a
known location.

This had to done early before it was known if the SCSI IPL parameter
block pointer was valid or not, and therefore the memmove
implementation was supposed to be able to handle program checks.

The code has been changed and especially with commit d08091a
("s390/ipl: rely on diag308 store to get ipl info") and
commit b4623d4 ("s390: provide memmove implementation") there
is no need to have a memmove version that can handle program checks,
and in addition it cannot be gcov/kcov instrumented anymore.

Reviewed-by: Christian Borntraeger <[email protected]>
Reviewed-by: Vasily Gorbik <[email protected]>
Signed-off-by: Heiko Carstens <[email protected]>
Signed-off-by: Martin Schwidefsky <[email protected]>

arch/s390/kernel/early.c

@@ -310,38 +310,6 @@ static int __init cad_setup(char *str)
 }
 early_param("cad", cad_setup);
 
-static __init void memmove_early(void *dst, const void *src, size_t n)
-{
-	unsigned long addr;
-	long incr;
-	psw_t old;
-
-	if (!n)
-		return;
-	incr = 1;
-	if (dst > src) {
-		incr = -incr;
-		dst += n - 1;
-		src += n - 1;
-	}
-	old = S390_lowcore.program_new_psw;
-	S390_lowcore.program_new_psw.mask = __extract_psw();
-	asm volatile(
-		"	larl	%[addr],1f\n"
-		"	stg	%[addr],%[psw_pgm_addr]\n"
-		"0:     mvc	0(1,%[dst]),0(%[src])\n"
-		"	agr	%[dst],%[incr]\n"
-		"	agr	%[src],%[incr]\n"
-		"	brctg	%[n],0b\n"
-		"1:\n"
-		: [addr] "=&d" (addr),
-		  [psw_pgm_addr] "=Q" (S390_lowcore.program_new_psw.addr),
-		  [dst] "+&a" (dst), [src] "+&a" (src),  [n] "+d" (n)
-		: [incr] "d" (incr)
-		: "cc", "memory");
-	S390_lowcore.program_new_psw = old;
-}
-
 static __init noinline void rescue_initrd(void)
 {
 #ifdef CONFIG_BLK_DEV_INITRD
@@ -356,7 +324,7 @@ static __init noinline void rescue_initrd(void)
 		return;
 	if (INITRD_START >= min_initrd_addr)
 		return;
-	memmove_early((void *) min_initrd_addr, (void *) INITRD_START, INITRD_SIZE);
+	memmove((void *) min_initrd_addr, (void *) INITRD_START, INITRD_SIZE);
 	INITRD_START = min_initrd_addr;
 #endif
 }