v4.19.13 snapshot.
diff --git a/arch/s390/lib/xor.c b/arch/s390/lib/xor.c
new file mode 100644
index 0000000..9658059
--- /dev/null
+++ b/arch/s390/lib/xor.c
@@ -0,0 +1,135 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Optimized xor_block operation for RAID4/5
+ *
+ * Copyright IBM Corp. 2016
+ * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
+ */
+
+#include <linux/types.h>
+#include <linux/export.h>
+#include <linux/raid/xor.h>
+
+static void xor_xc_2(unsigned long bytes, unsigned long *p1, unsigned long *p2)
+{
+ asm volatile(
+ " larl 1,2f\n"
+ " aghi %0,-1\n"
+ " jm 3f\n"
+ " srlg 0,%0,8\n"
+ " ltgr 0,0\n"
+ " jz 1f\n"
+ "0: xc 0(256,%1),0(%2)\n"
+ " la %1,256(%1)\n"
+ " la %2,256(%2)\n"
+ " brctg 0,0b\n"
+ "1: ex %0,0(1)\n"
+ " j 3f\n"
+ "2: xc 0(1,%1),0(%2)\n"
+ "3:\n"
+ : : "d" (bytes), "a" (p1), "a" (p2)
+ : "0", "1", "cc", "memory");
+}
+
+static void xor_xc_3(unsigned long bytes, unsigned long *p1, unsigned long *p2,
+ unsigned long *p3)
+{
+ asm volatile(
+ " larl 1,2f\n"
+ " aghi %0,-1\n"
+ " jm 3f\n"
+ " srlg 0,%0,8\n"
+ " ltgr 0,0\n"
+ " jz 1f\n"
+ "0: xc 0(256,%1),0(%2)\n"
+ " xc 0(256,%1),0(%3)\n"
+ " la %1,256(%1)\n"
+ " la %2,256(%2)\n"
+ " la %3,256(%3)\n"
+ " brctg 0,0b\n"
+ "1: ex %0,0(1)\n"
+ " ex %0,6(1)\n"
+ " j 3f\n"
+ "2: xc 0(1,%1),0(%2)\n"
+ " xc 0(1,%1),0(%3)\n"
+ "3:\n"
+ : "+d" (bytes), "+a" (p1), "+a" (p2), "+a" (p3)
+ : : "0", "1", "cc", "memory");
+}
+
+static void xor_xc_4(unsigned long bytes, unsigned long *p1, unsigned long *p2,
+ unsigned long *p3, unsigned long *p4)
+{
+ asm volatile(
+ " larl 1,2f\n"
+ " aghi %0,-1\n"
+ " jm 3f\n"
+ " srlg 0,%0,8\n"
+ " ltgr 0,0\n"
+ " jz 1f\n"
+ "0: xc 0(256,%1),0(%2)\n"
+ " xc 0(256,%1),0(%3)\n"
+ " xc 0(256,%1),0(%4)\n"
+ " la %1,256(%1)\n"
+ " la %2,256(%2)\n"
+ " la %3,256(%3)\n"
+ " la %4,256(%4)\n"
+ " brctg 0,0b\n"
+ "1: ex %0,0(1)\n"
+ " ex %0,6(1)\n"
+ " ex %0,12(1)\n"
+ " j 3f\n"
+ "2: xc 0(1,%1),0(%2)\n"
+ " xc 0(1,%1),0(%3)\n"
+ " xc 0(1,%1),0(%4)\n"
+ "3:\n"
+ : "+d" (bytes), "+a" (p1), "+a" (p2), "+a" (p3), "+a" (p4)
+ : : "0", "1", "cc", "memory");
+}
+
+static void xor_xc_5(unsigned long bytes, unsigned long *p1, unsigned long *p2,
+ unsigned long *p3, unsigned long *p4, unsigned long *p5)
+{
+ /* Get around a gcc oddity */
+ register unsigned long *reg7 asm ("7") = p5;
+
+ asm volatile(
+ " larl 1,2f\n"
+ " aghi %0,-1\n"
+ " jm 3f\n"
+ " srlg 0,%0,8\n"
+ " ltgr 0,0\n"
+ " jz 1f\n"
+ "0: xc 0(256,%1),0(%2)\n"
+ " xc 0(256,%1),0(%3)\n"
+ " xc 0(256,%1),0(%4)\n"
+ " xc 0(256,%1),0(%5)\n"
+ " la %1,256(%1)\n"
+ " la %2,256(%2)\n"
+ " la %3,256(%3)\n"
+ " la %4,256(%4)\n"
+ " la %5,256(%5)\n"
+ " brctg 0,0b\n"
+ "1: ex %0,0(1)\n"
+ " ex %0,6(1)\n"
+ " ex %0,12(1)\n"
+ " ex %0,18(1)\n"
+ " j 3f\n"
+ "2: xc 0(1,%1),0(%2)\n"
+ " xc 0(1,%1),0(%3)\n"
+ " xc 0(1,%1),0(%4)\n"
+ " xc 0(1,%1),0(%5)\n"
+ "3:\n"
+ : "+d" (bytes), "+a" (p1), "+a" (p2), "+a" (p3), "+a" (p4),
+ "+a" (reg7)
+ : : "0", "1", "cc", "memory");
+}
+
+struct xor_block_template xor_block_xc = {
+ .name = "xc",
+ .do_2 = xor_xc_2,
+ .do_3 = xor_xc_3,
+ .do_4 = xor_xc_4,
+ .do_5 = xor_xc_5,
+};
+EXPORT_SYMBOL(xor_block_xc);