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author | Eric Farman <farman@linux.ibm.com> | 2019-05-16 18:14:03 +0200 |
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committer | Cornelia Huck <cohuck@redhat.com> | 2019-06-03 12:02:55 +0200 |
commit | 9b6e57e5a51696171de990b3c41bd53d4b8ab8ac (patch) | |
tree | 1c8eb0b1fe09b72cf400a17ec5b8419258ef45a8 /arch/s390/Kconfig | |
parent | s390/cio: Allow zero-length CCWs in vfio-ccw (diff) | |
download | linux-dev-9b6e57e5a51696171de990b3c41bd53d4b8ab8ac.tar.xz linux-dev-9b6e57e5a51696171de990b3c41bd53d4b8ab8ac.zip |
s390/cio: Remove vfio-ccw checks of command codes
If the CCW being processed is a No-Operation, then by definition no
data is being transferred. Let's fold those checks into the normal
CCW processors, rather than skipping out early.
Likewise, if the CCW being processed is a "test" (a category defined
here as an opcode that contains zero in the lowest four bits) then no
special processing is necessary as far as vfio-ccw is concerned.
These command codes have not been valid since the S/370 days, meaning
they are invalid in the same way as one that ends in an eight [1] or
an otherwise valid command code that is undefined for the device type
in question. Considering that, let's just process "test" CCWs like
any other CCW, and send everything to the hardware.
[1] POPS states that a x08 is a TIC CCW, and that having any high-order
bits enabled is invalid for format-1 CCWs. For format-0 CCWs, the
high-order bits are ignored.
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Message-Id: <20190516161403.79053-4-farman@linux.ibm.com>
Acked-by: Farhan Ali <alifm@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Diffstat (limited to 'arch/s390/Kconfig')
0 files changed, 0 insertions, 0 deletions