drm/i915: Add initial selftests for hang detection and resets

Check that we can reset the GPU and continue executing from the next
request.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170213171558.20942-47-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/i915_drv.h

@@ -3377,7 +3377,7 @@ int __must_check i915_gem_init(struct drm_i915_private *dev_priv);
 int __must_check i915_gem_init_hw(struct drm_i915_private *dev_priv);
 void i915_gem_init_swizzling(struct drm_i915_private *dev_priv);
 void i915_gem_cleanup_engines(struct drm_i915_private *dev_priv);
-int __must_check i915_gem_wait_for_idle(struct drm_i915_private *dev_priv,
+int i915_gem_wait_for_idle(struct drm_i915_private *dev_priv,
 			   unsigned int flags);
 int __must_check i915_gem_suspend(struct drm_i915_private *dev_priv);
 void i915_gem_resume(struct drm_i915_private *dev_priv);

drivers/gpu/drm/i915/intel_hangcheck.c

@@ -480,3 +480,7 @@ void intel_hangcheck_init(struct drm_i915_private *i915)
 	INIT_DELAYED_WORK(&i915->gpu_error.hangcheck_work,
 			  i915_hangcheck_elapsed);
 }
+
+#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
+#include "selftests/intel_hangcheck.c"
+#endif

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

@@ -16,3 +16,4 @@ 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)
+selftest(hangcheck, intel_hangcheck_live_selftests)