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IB/hfi1: Fix an assign/ordering issue with shared context IDs
The current algorithm for generating sub-context IDs is FILO. If the
contexts are not closed in that order, the uniqueness of the ID will be
compromised. I.e. logging the creation/deletion of context IDs with an
application that assigns and closes in a FIFO order reveals:
cache_id: assign: uctxt: 3 sub_ctxt: 0
cache_id: assign: uctxt: 3 sub_ctxt: 1
cache_id: assign: uctxt: 3 sub_ctxt: 2
cache_id: close: uctxt: 3 sub_ctxt: 0
cache_id: assign: uctxt: 3 sub_ctxt: 2 <<<
The sub_ctxt ID 2 is reused incorrectly.
Update the sub-context ID assign algorithm to use a bitmask of in_use
contexts. The new algorithm will allow the contexts to be closed in any
order, and will only re-use unused contexts.
Size subctxt and subctxt_cnt to match the user API size.
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>