[Intel-gfx] [PATCH v6 03/11] drm/i915/perf: allow for CS OA configs to be created lazily

[Chris Wilson]

Quoting Lionel Landwerlin (2019-07-01 12:34:29)
> Here we introduce a mechanism by which the execbuf part of the i915
> driver will be able to request that a batch buffer containing the
> programming for a particular OA config be created.
> 
> We'll execute these OA configuration buffers right before executing a
> set of userspace commands so that a particular user batchbuffer be
> executed with a given OA configuration.
> 
> This mechanism essentially allows the userspace driver to go through
> several OA configuration without having to open/close the i915/perf
> stream.
> 
> v2: No need for locking on object OA config object creation (Chris)
>     Flush cpu mapping of OA config (Chris)
> 
> v3: Properly deal with the perf_metric lock (Chris/Lionel)
> 
> Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin at intel.com>
Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
-Chris