[S390] ipl: Reboot from alternate device does not work when booting from file

During startup we check if diag308 works using diag 308 subcode 6,
which stores the actual ipl information. This fails with rc = 0x102, if
the system has been ipled from the HMC using load from CD or load from file.
In the case of rc = 0x102 we have to assume that diag 308 is working,
since it still can be used to ipl from an alternative device.

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/kernel/ipl.c

@@ -1705,7 +1705,10 @@ void __init setup_ipl(void)
 
 void __init ipl_update_parameters(void)
 {
-	if (diag308(DIAG308_STORE, &ipl_block) == DIAG308_RC_OK)
+	int rc;
+
+	rc = diag308(DIAG308_STORE, &ipl_block);
+	if ((rc == DIAG308_RC_OK) || (rc == DIAG308_RC_NOCONFIG))
 		diag308_set_works = 1;
 }
 

include/asm-s390/ipl.h

@@ -159,7 +159,8 @@ enum diag308_vm_flags {
 };
 
 enum diag308_rc {
-	DIAG308_RC_OK	= 1,
+	DIAG308_RC_OK		= 0x0001,
+	DIAG308_RC_NOCONFIG	= 0x0102,
 };
 
 extern int diag308(unsigned long subcode, void *addr);