drm/i915: Live testing for context execution

Check we can create and execution within a context.

v2: Write one set of dwords through each context/engine to exercise more
contexts within the same time period.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170213171558.20942-38-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/i915_gem_context.c

@@ -1202,4 +1202,5 @@ int i915_gem_context_reset_stats_ioctl(struct drm_device *dev,
 
 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
 #include "selftests/mock_context.c"
+#include "selftests/i915_gem_context.c"
 #endif

drivers/gpu/drm/i915/selftests/i915_live_selftests.h

@@ -15,3 +15,4 @@ selftest(objects, i915_gem_object_live_selftests)
 selftest(dmabuf, i915_gem_dmabuf_live_selftests)
 selftest(coherency, i915_gem_coherency_live_selftests)
 selftest(gtt, i915_gem_gtt_live_selftests)
+selftest(contexts, i915_gem_context_live_selftests)