drm/i915: Move i915_vma_lock in the selftests to avoid lock inversion, v3.

Make sure vma_lock is not used as inner lock when kernel context is used,
and add ww handling where appropriate.

Ensure that execbuf selftests keep passing by using ww handling.

Changes since v2:
- Fix i915_gem_context finally.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Thomas Hellström <thomas.hellstrom@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200819140904.1708856-22-maarten.lankhorst@linux.intel.com
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

1 files changed, 12 insertions, 6 deletions

diff --git a/drivers/gpu/drm/i915/selftests/i915_request.c b/drivers/gpu/drm/i915/selftests/i915_request.c
index c1dcd4b91bda..3092ca763789 100644
--- a/drivers/gpu/drm/i915/selftests/i915_request.c
+++ b/drivers/gpu/drm/i915/selftests/i915_request.c
@@ -862,6 +862,8 @@ static int live_all_engines(void *arg)
 		goto out_free;
 	}
 
+	i915_vma_lock(batch);
+
 	idx = 0;
 	for_each_uabi_engine(engine, i915) {
 		request[idx] = intel_engine_create_kernel_request(engine);
@@ -872,11 +874,9 @@ static int live_all_engines(void *arg)
 			goto out_request;
 		}
 
-		i915_vma_lock(batch);
 		err = i915_request_await_object(request[idx], batch->obj, 0);
 		if (err == 0)
 			err = i915_vma_move_to_active(batch, request[idx], 0);
-		i915_vma_unlock(batch);
 		GEM_BUG_ON(err);
 
 		err = engine->emit_bb_start(request[idx],
@@ -891,6 +891,8 @@ static int live_all_engines(void *arg)
 		idx++;
 	}
 
+	i915_vma_unlock(batch);
+
 	idx = 0;
 	for_each_uabi_engine(engine, i915) {
 		if (i915_request_completed(request[idx])) {
@@ -981,12 +983,13 @@ static int live_sequential_engines(void *arg)
 			goto out_free;
 		}
 
+		i915_vma_lock(batch);
 		request[idx] = intel_engine_create_kernel_request(engine);
 		if (IS_ERR(request[idx])) {
 			err = PTR_ERR(request[idx]);
 			pr_err("%s: Request allocation failed for %s with err=%d\n",
 			       __func__, engine->name, err);
-			goto out_request;
+			goto out_unlock;
 		}
 
 		if (prev) {
@@ -996,16 +999,14 @@ static int live_sequential_engines(void *arg)
 				i915_request_add(request[idx]);
 				pr_err("%s: Request await failed for %s with err=%d\n",
 				       __func__, engine->name, err);
-				goto out_request;
+				goto out_unlock;
 			}
 		}
 
-		i915_vma_lock(batch);
 		err = i915_request_await_object(request[idx],
 						batch->obj, false);
 		if (err == 0)
 			err = i915_vma_move_to_active(batch, request[idx], 0);
-		i915_vma_unlock(batch);
 		GEM_BUG_ON(err);
 
 		err = engine->emit_bb_start(request[idx],
@@ -1020,6 +1021,11 @@ static int live_sequential_engines(void *arg)
 
 		prev = request[idx];
 		idx++;
+
+out_unlock:
+		i915_vma_unlock(batch);
+		if (err)
+			goto out_request;
 	}
 
 	idx = 0;