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path: root/drivers/s390/cio/chsc_sch.c
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2008-12-25[S390] cio: introduce cio_update_schibSebastian Ott
There is the chance that we get condition code 0 for a stsch but the resulting schib is not vaild. In the current code there are 2 cases: * we do a check for validity of the schib after stsch, but at this time we have already stored the invaild schib in the subchannel structure. This may lead to problems. * we don't do a check for validity, which is not that good either. The patch addresses both issues by introducing the stsch wrapper cio_update_schib which performs stsch on a local schib. This schib is only written back to the subchannel if it's valid. side note: For some functions (chp_events) the return codes are different now (-ENXIO vs -ENODEV) but this shouldn't do harm since the caller doesn't check for _specific_ errors. Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-10-10[S390] cio: Correct use of ! and &Julia Lawall
In commit e6bafba5b4765a5a252f1b8d31cbf6d2459da337, a bug was fixed that involved converting !x & y to !(x & y). The code below shows the same pattern, and thus should perhaps be fixed in the same way. In particular, the result of !scsw_stctl(&request->irb.scsw) & SCSW_STCTL_STATUS_PEND is always just !scsw_stctl(&request->irb.scsw). The semantic patch that makes this change is as follows: (http://www.emn.fr/x-info/coccinelle/) // <smpl> @@ expression E; constant C; @@ ( !E & !C | - !E & C + !(E & C) ) // </smpl> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2008-07-14[S390] cio: Add chsc subchannel driver.Cornelia Huck
This patch adds a driver for subchannels of type chsc. A device /dev/chsc is created which may be used to issue ioctls to: - obtain information about the machine's I/O configuration - dynamically change the machine's I/O configuration via asynchronous chsc commands Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>