drm/i915: Use ww pinning for intel_context_create_request()

We want to get rid of intel_context_pin(), convert
intel_context_create_request() first. :)

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/20200819140904.1708856-21-maarten.lankhorst@linux.intel.com
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

drivers/gpu/drm/i915/gt/intel_context.c

@@ -449,15 +449,25 @@ int intel_context_prepare_remote_request(struct intel_context *ce,
 
 struct i915_request *intel_context_create_request(struct intel_context *ce)
 {
+	struct i915_gem_ww_ctx ww;
 	struct i915_request *rq;
 	int err;
 
-	err = intel_context_pin(ce);
-	if (unlikely(err))
-		return ERR_PTR(err);
+	i915_gem_ww_ctx_init(&ww, true);
+retry:
+	err = intel_context_pin_ww(ce, &ww);
+	if (!err) {
+		rq = i915_request_create(ce);
+		intel_context_unpin(ce);
+	} else if (err == -EDEADLK) {
+		err = i915_gem_ww_ctx_backoff(&ww);
+		if (!err)
+			goto retry;
+	} else {
+		rq = ERR_PTR(err);
+	}
 
-	rq = i915_request_create(ce);
-	intel_context_unpin(ce);
+	i915_gem_ww_ctx_fini(&ww);
 
 	if (IS_ERR(rq))
 		return rq;