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author | Cornelia Huck <cohuck@redhat.com> | 2019-01-29 16:13:57 +0100 |
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committer | Cornelia Huck <cohuck@redhat.com> | 2019-04-24 14:18:51 +0200 |
commit | 690f6a1581c7c08e85451f62bcbfe40f29072842 (patch) | |
tree | 27971d432e7baa0f7d74a182575fda241c704a75 /drivers/connector/connector.c | |
parent | vfio-ccw: make it safe to access channel programs (diff) | |
download | linux-dev-690f6a1581c7c08e85451f62bcbfe40f29072842.tar.xz linux-dev-690f6a1581c7c08e85451f62bcbfe40f29072842.zip |
vfio-ccw: rework ssch state handling
The flow for processing ssch requests can be improved by splitting
the BUSY state:
- CP_PROCESSING: We reject any user space requests while we are in
the process of translating a channel program and submitting it to
the hardware. Use -EAGAIN to signal user space that it should
retry the request.
- CP_PENDING: We have successfully submitted a request with ssch and
are now expecting an interrupt. As we can't handle more than one
channel program being processed, reject any further requests with
-EBUSY. A final interrupt will move us out of this state.
By making this a separate state, we make it possible to issue a
halt or a clear while we're still waiting for the final interrupt
for the ssch (in a follow-on patch).
It also makes a lot of sense not to preemptively filter out writes to
the io_region if we're in an incorrect state: the state machine will
handle this correctly.
Reviewed-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Diffstat (limited to 'drivers/connector/connector.c')
0 files changed, 0 insertions, 0 deletions