drm/i915: Import the kfence selftests for i915_sw_fence

A long time ago, I wrote some selftests for the struct kfence idea. Now
that we have infrastructure in i915/igt for running kselftests, include
some for i915_sw_fence.

v2: INIT_WORK_ONSTACK/destroy_work_on_stack (Mika)
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/20170517121007.27224-2-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/Kconfig.debug

@@ -61,6 +61,18 @@ config DRM_I915_SW_FENCE_DEBUG_OBJECTS
 
           If in doubt, say "N".
 
+config DRM_I915_SW_FENCE_CHECK_DAG
+        bool "Enable additional driver debugging for detecting dependency cycles"
+        depends on DRM_I915
+        default n
+        help
+          Choose this option to turn on extra driver debugging that may affect
+          performance but will catch some internal issues.
+
+          Recommended for driver developers only.
+
+          If in doubt, say "N".
+
 config DRM_I915_SELFTEST
 	bool "Enable selftests upon driver load"
 	depends on DRM_I915

drivers/gpu/drm/i915/i915_sw_fence.c

@@ -12,6 +12,7 @@
 #include <linux/reservation.h>
 
 #include "i915_sw_fence.h"
+#include "i915_selftest.h"
 
 #define I915_SW_FENCE_FLAG_ALLOC BIT(3) /* after WQ_FLAG_* for safety */
 
@@ -274,7 +275,7 @@ static bool i915_sw_fence_check_if_after(struct i915_sw_fence *fence,
 	unsigned long flags;
 	bool err;
 
-	if (!IS_ENABLED(CONFIG_I915_SW_FENCE_CHECK_DAG))
+	if (!IS_ENABLED(CONFIG_DRM_I915_SW_FENCE_CHECK_DAG))
 		return false;
 
 	spin_lock_irqsave(&i915_sw_fence_lock, flags);
@@ -490,3 +491,7 @@ int i915_sw_fence_await_reservation(struct i915_sw_fence *fence,
 
 	return ret;
 }
+
+#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
+#include "selftests/i915_sw_fence.c"
+#endif

drivers/gpu/drm/i915/selftests/i915_mock_selftests.h

@@ -9,6 +9,7 @@
  * Tests are executed in order by igt/drv_selftest
  */
 selftest(sanitycheck, i915_mock_sanitycheck) /* keep first (igt selfcheck) */
+selftest(fence, i915_sw_fence_mock_selftests)
 selftest(scatterlist, scatterlist_mock_selftests)
 selftest(syncmap, i915_syncmap_mock_selftests)
 selftest(uncore, intel_uncore_mock_selftests)