[PATCH 55/59] drm/i915/selftests: Prepare timeline tests for obj->mm.lock removal

[Maarten Lankhorst]

We can no longer call intel_timeline_pin with a null argument,
so add a ww loop that locks the backing object.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
---
 drivers/gpu/drm/i915/gt/selftest_timeline.c | 26 ++++++++++++++++++---
 1 file changed, 23 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/selftest_timeline.c b/drivers/gpu/drm/i915/gt/selftest_timeline.c
index 6d6092a28e6b..0f1f5bd17b36 100644
--- a/drivers/gpu/drm/i915/gt/selftest_timeline.c
+++ b/drivers/gpu/drm/i915/gt/selftest_timeline.c
@@ -36,6 +36,26 @@ static unsigned long hwsp_cacheline(struct intel_timeline *tl)
 	return (address + offset_in_page(tl->hwsp_offset)) / CACHELINE_BYTES;
 }
 
+static int selftest_tl_pin(struct intel_timeline *tl)
+{
+	struct i915_gem_ww_ctx ww;
+	int err;
+
+	i915_gem_ww_ctx_init(&ww, false);
+retry:
+	err = i915_gem_object_lock(tl->hwsp_ggtt->obj, &ww);
+	if (!err)
+		err = intel_timeline_pin(tl, &ww);
+
+	if (err == -EDEADLK) {
+		err = i915_gem_ww_ctx_backoff(&ww);
+		if (err)
+			goto retry;
+	}
+	i915_gem_ww_ctx_fini(&ww);
+	return err;
+}
+
 #define CACHELINES_PER_PAGE (PAGE_SIZE / CACHELINE_BYTES)
 
 struct mock_hwsp_freelist {
@@ -77,7 +97,7 @@ static int __mock_hwsp_timeline(struct mock_hwsp_freelist *state,
 		if (IS_ERR(tl))
 			return PTR_ERR(tl);
 
-		err = intel_timeline_pin(tl, NULL);
+		err = selftest_tl_pin(tl);
 		if (err) {
 			intel_timeline_put(tl);
 			return err;
@@ -463,7 +483,7 @@ checked_tl_write(struct intel_timeline *tl, struct intel_engine_cs *engine, u32
 	struct i915_request *rq;
 	int err;
 
-	err = intel_timeline_pin(tl, NULL);
+	err = selftest_tl_pin(tl);
 	if (err) {
 		rq = ERR_PTR(err);
 		goto out;
@@ -663,7 +683,7 @@ static int live_hwsp_wrap(void *arg)
 	if (!tl->has_initial_breadcrumb)
 		goto out_free;
 
-	err = intel_timeline_pin(tl, NULL);
+	err = selftest_tl_pin(tl);
 	if (err)
 		goto out_free;
 
-- 
2.28.0