Revert "s390/kdump: Clear subchannel ID to signal non-CCW/SCSI IPL"

commit 5419447e2142d6ed68c9f5c1a28630b3a290a845 upstream.

This reverts commit 852ffd0f4e23248b47531058e531066a988434b5.

There are use cases where an intermediate boot kernel (1) uses kexec
to boot the final production kernel (2). For this scenario we should
provide the original boot information to the production kernel (2).
Therefore clearing the boot information during kexec() should not
be done.

Reported-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/s390/kernel/ipl.c b/arch/s390/kernel/ipl.c
index b1f0a90f933bbc95cc04c9e028d87865555909a9..42570d8fb265f5580ef9fb56b9a351a3c6fa596f 100644 (file)
--- a/arch/s390/kernel/ipl.c
+++ b/arch/s390/kernel/ipl.c
@@ -2070,13 +2070,6 @@ void s390_reset_system(void (*fn_pre)(void),
        S390_lowcore.program_new_psw.addr =
                PSW_ADDR_AMODE | (unsigned long) s390_base_pgm_handler;
 
-       /*
-        * Clear subchannel ID and number to signal new kernel that no CCW or
-        * SCSI IPL has been done (for kexec and kdump)
-        */
-       S390_lowcore.subchannel_id = 0;
-       S390_lowcore.subchannel_nr = 0;
-
        /* Store status at absolute zero */
        store_status();