s390/dasd: Make module parameter visible in sysfs

Change the visibility of the dasd parameter of kernel module dasd_mod
to be consistent with the eer_pages parameter.

Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Acked-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
s390/ipl: Add missing SCSI loadparm attributes to /sys/firmware

Currently the loadparm is only supported for CCW IPL. But also for SCSI
IPL it can be specified either on the HMC load panel respectively
z/VM console or via diagnose 308.

So fix this for SCSI and add the required sysfs attributes for reading the
IPL loadparm and for setting the loadparm for re-IPL.

With this patch the following two sysfs attributes are introduced:

 - /sys/firmware/ipl/loadparm (for system that have been IPLed from SCSI)
 - /sys/firmware/reipl/fcp/loadparm

Because the loadparm is now available for SCSI and CCW it is moved
now from "struct ipl_block_ccw" to the generic "struct ipl_list_hdr".

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
s390/vdso: remove NULL pointer check from clock_gettime

The explicit NULL pointer check on the timespec argument is only
required for clock_getres but not for clock_gettime.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 fixes from Martin Schwidefsky:
 "A bug fix for the vdso code, the loadparm for booting from SCSI is
  added and the access permissions for the dasd module parameters are
  corrected"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/vdso: remove NULL pointer check from clock_gettime
  s390/ipl: Add missing SCSI loadparm attributes to /sys/firmware
  s390/dasd: Make module parameter visible in sysfs