Commit 852ffd0f authored Aug 08, 2014 by Michael Holzheu Committed by Martin Schwidefsky Aug 12, 2014

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



For CCW and SCSI IPL the hardware sets the subchannel ID and number
correctly at 0xb8. For kdump at 0xb8 normally there is the data of
the previously IPLed system.

In order to be clean now for kdump and kexec always set the subchannel
ID and number to zero. This tells the next OS that no CCW/SCSI IPL
has been done.

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

parent b8a7a990

arch/s390/kernel/ipl.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -2060,6 +2060,13 @@ void s390_reset_system(void (func)(void ), void *data)
		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();

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