Use the rsvd1 field in execbuf2 to specify the context ID associated
with the workload. This will allow the driver to do the proper context
switch when/if needed.
v2: Add checks for context switches on rings not supporting contexts.
Before the code would silently ignore such requests.
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
6e0a69dbc8