[S390] Limit cpu detection to 256 physical cpus.

Saves us more than 65k pointless IPIs.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/kernel/head64.S b/arch/s390/kernel/head64.S
index bdcb3f0..6a25080 100644
--- a/arch/s390/kernel/head64.S
+++ b/arch/s390/kernel/head64.S
@@ -62,9 +62,9 @@
 	clr	%r11,%r12
 	je	5f			# no more space in prefix array
 4:
-	ahi	%r8,1				# next cpu (r8 += 1)
-	cl	%r8,.Llast_cpu-.LPG1(%r13)	# is last possible cpu ?
-	jl	1b				# jump if not last cpu
+	ahi	%r8,1			# next cpu (r8 += 1)
+	chi	%r8,MAX_CPU_ADDRESS	# is last possible cpu ?
+	jle	1b			# jump if not last cpu
 5:
 	lhi	%r1,2			# mode 2 = esame (dump)
 	j	6f
@@ -130,8 +130,6 @@
 #ifdef CONFIG_ZFCPDUMP
 .Lcurrent_cpu:
 	.long 0x0
-.Llast_cpu:
-	.long 0x0000ffff
 .Lpref_arr_ptr:
 	.long zfcpdump_prefix_array
 #endif /* CONFIG_ZFCPDUMP */