[Intel-gfx] [PATCH 16/23] drm/i915: Convert i915_perf to ww locking as well

[Maarten Lankhorst]

We have the ordering of timeline->mutex vs resv_lock wrong,
convert the i915_pin_vma and intel_context_pin as well to
future-proof this.

We may need to do future changes to do this more transaction-like,
and only get down to a single i915_gem_ww_ctx, but for now this
should work.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
---
 drivers/gpu/drm/i915/i915_perf.c | 57 +++++++++++++++++++++++---------
 1 file changed, 42 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c
index c533f569dd42..c675e6cd5967 100644
--- a/drivers/gpu/drm/i915/i915_perf.c
+++ b/drivers/gpu/drm/i915/i915_perf.c
@@ -1195,24 +1195,39 @@ static struct intel_context *oa_pin_context(struct i915_perf_stream *stream)
 	struct i915_gem_engines_iter it;
 	struct i915_gem_context *ctx = stream->ctx;
 	struct intel_context *ce;
-	int err;
+	struct i915_gem_ww_ctx ww;
+	int err = -ENODEV;
 
 	for_each_gem_engine(ce, i915_gem_context_lock_engines(ctx), it) {
 		if (ce->engine != stream->engine) /* first match! */
 			continue;
 
-		/*
-		 * As the ID is the gtt offset of the context's vma we
-		 * pin the vma to ensure the ID remains fixed.
-		 */
-		err = intel_context_pin(ce);
-		if (err == 0) {
-			stream->pinned_ctx = ce;
-			break;
-		}
+		err = 0;
+		break;
 	}
 	i915_gem_context_unlock_engines(ctx);
 
+	if (err)
+		return ERR_PTR(err);
+
+	i915_gem_ww_ctx_init(&ww, true);
+retry:
+	/*
+	 * As the ID is the gtt offset of the context's vma we
+	 * pin the vma to ensure the ID remains fixed.
+	 */
+	err = intel_context_pin_ww(ce, &ww);
+	if (err == -EDEADLK) {
+		err = i915_gem_ww_ctx_backoff(&ww);
+		if (!err)
+			goto retry;
+	}
+	i915_gem_ww_ctx_fini(&ww);
+
+	if (err)
+		return ERR_PTR(err);
+
+	stream->pinned_ctx = ce;
 	return stream->pinned_ctx;
 }
 
@@ -1925,15 +1940,22 @@ emit_oa_config(struct i915_perf_stream *stream,
 {
 	struct i915_request *rq;
 	struct i915_vma *vma;
+	struct i915_gem_ww_ctx ww;
 	int err;
 
 	vma = get_oa_vma(stream, oa_config);
 	if (IS_ERR(vma))
 		return PTR_ERR(vma);
 
-	err = i915_vma_pin(vma, 0, 0, PIN_GLOBAL | PIN_HIGH);
+	i915_gem_ww_ctx_init(&ww, true);
+retry:
+	err = i915_gem_object_lock(vma->obj, &ww);
+	if (err)
+		goto err;
+
+	err = i915_vma_pin_ww(vma, &ww, 0, 0, PIN_GLOBAL | PIN_HIGH);
 	if (err)
-		goto err_vma_put;
+		goto err;
 
 	intel_engine_pm_get(ce->engine);
 	rq = i915_request_create(ce);
@@ -1955,11 +1977,9 @@ emit_oa_config(struct i915_perf_stream *stream,
 			goto err_add_request;
 	}
 
-	i915_vma_lock(vma);
 	err = i915_request_await_object(rq, vma->obj, 0);
 	if (!err)
 		err = i915_vma_move_to_active(vma, rq, 0);
-	i915_vma_unlock(vma);
 	if (err)
 		goto err_add_request;
 
@@ -1973,7 +1993,14 @@ emit_oa_config(struct i915_perf_stream *stream,
 	i915_request_add(rq);
 err_vma_unpin:
 	i915_vma_unpin(vma);
-err_vma_put:
+err:
+	if (err == -EDEADLK) {
+		err = i915_gem_ww_ctx_backoff(&ww);
+		if (!err)
+			goto retry;
+	}
+
+	i915_gem_ww_ctx_fini(&ww);
 	i915_vma_put(vma);
 	return err;
 }
-- 
2.26.2