s390/diag: add missing virt_to_phys() translation to diag14()

diag14() is currently only used by the vmur device driver.  The third
parameter, called subcommand, determines the type of the first
parameter. For some subcommands the value of the first parameter is an
address to a memory buffer and needs virtual to physical address
conversion. Other subcommands interpret the first parameter is an
integer.
This doesn't fix a bug since virtual and physical addresses
are currently the same.
Suggested-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

arch/s390/kernel/diag.c

@@ -157,10 +157,30 @@ void diag0c(struct hypfs_diag0c_entry *data)
 
 /*
  * Diagnose 14: Input spool file manipulation
+ *
+ * The subcode parameter determines the type of the first parameter rx.
+ * Currently used are the following 3 subcommands:
+ * 0x0:   Read the Next Spool File Buffer (Data Record)
+ * 0x28:  Position a Spool File to the Designated Record
+ * 0xfff: Retrieve Next File Descriptor
+ *
+ * For subcommands 0x0 and 0xfff, the value of the first parameter is
+ * a virtual address of a memory buffer and needs virtual to physical
+ * address translation. For other subcommands the rx parameter is not
+ * a virtual address.
  */
 int diag14(unsigned long rx, unsigned long ry1, unsigned long subcode)
 {
 	diag_stat_inc(DIAG_STAT_X014);
+	switch (subcode) {
+	case 0x0:
+	case 0xfff:
+		rx = virt_to_phys((void *)rx);
+		break;
+	default:
+		/* Do nothing */
+		break;
+	}
 	return diag_amode31_ops.diag14(rx, ry1, subcode);
 }
 EXPORT_SYMBOL(diag14);