1 files changed, 50 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_gem_ww.h b/drivers/gpu/drm/i915/i915_gem_ww.h
new file mode 100644
index 000000000000..f6b1a796667b
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_gem_ww.h
@@ -0,0 +1,50 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2020 Intel Corporation
+ */
+#ifndef __I915_GEM_WW_H__
+#define __I915_GEM_WW_H__
+
+#include <drm/drm_drv.h>
+
+struct i915_gem_ww_ctx {
+	struct ww_acquire_ctx ctx;
+	struct list_head obj_list;
+	struct drm_i915_gem_object *contended;
+	unsigned short intr;
+	unsigned short loop;
+};
+
+void i915_gem_ww_ctx_init(struct i915_gem_ww_ctx *ctx, bool intr);
+void i915_gem_ww_ctx_fini(struct i915_gem_ww_ctx *ctx);
+int __must_check i915_gem_ww_ctx_backoff(struct i915_gem_ww_ctx *ctx);
+void i915_gem_ww_unlock_single(struct drm_i915_gem_object *obj);
+
+/* Internal functions used by the inlines! Don't use. */
+static inline int __i915_gem_ww_fini(struct i915_gem_ww_ctx *ww, int err)
+{
+	ww->loop = 0;
+	if (err == -EDEADLK) {
+		err = i915_gem_ww_ctx_backoff(ww);
+		if (!err)
+			ww->loop = 1;
+	}
+
+	if (!ww->loop)
+		i915_gem_ww_ctx_fini(ww);
+
+	return err;
+}
+
+static inline void
+__i915_gem_ww_init(struct i915_gem_ww_ctx *ww, bool intr)
+{
+	i915_gem_ww_ctx_init(ww, intr);
+	ww->loop = 1;
+}
+
+#define for_i915_gem_ww(_ww, _err, _intr)			\
+	for (__i915_gem_ww_init(_ww, _intr); (_ww)->loop;	\
+	     _err = __i915_gem_ww_fini(_ww, _err))
+
+#endif