1 files changed, 67 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_sw_fence_work.h b/drivers/gpu/drm/i915/i915_sw_fence_work.h
new file mode 100644
index 000000000000..d56806918d13
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_sw_fence_work.h
@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: MIT */
+
+/*
+ * Copyright © 2019 Intel Corporation
+ */
+
+#ifndef I915_SW_FENCE_WORK_H
+#define I915_SW_FENCE_WORK_H
+
+#include <linux/dma-fence.h>
+#include <linux/spinlock.h>
+#include <linux/workqueue.h>
+
+#include "i915_sw_fence.h"
+
+struct dma_fence_work;
+
+struct dma_fence_work_ops {
+	const char *name;
+	void (*work)(struct dma_fence_work *f);
+	void (*release)(struct dma_fence_work *f);
+};
+
+struct dma_fence_work {
+	struct dma_fence dma;
+	spinlock_t lock;
+
+	struct i915_sw_fence chain;
+	struct i915_sw_dma_fence_cb cb;
+
+	struct work_struct work;
+	const struct dma_fence_work_ops *ops;
+};
+
+enum {
+	DMA_FENCE_WORK_IMM = DMA_FENCE_FLAG_USER_BITS,
+};
+
+void dma_fence_work_init(struct dma_fence_work *f,
+			 const struct dma_fence_work_ops *ops);
+int dma_fence_work_chain(struct dma_fence_work *f, struct dma_fence *signal);
+
+static inline void dma_fence_work_commit(struct dma_fence_work *f)
+{
+	i915_sw_fence_commit(&f->chain);
+}
+
+/**
+ * dma_fence_work_commit_imm: Commit the fence, and if possible execute locally.
+ * @f: the fenced worker
+ *
+ * Instead of always scheduling a worker to execute the callback (see
+ * dma_fence_work_commit()), we try to execute the callback immediately in
+ * the local context. It is required that the fence be committed before it
+ * is published, and that no other threads try to tamper with the number
+ * of asynchronous waits on the fence (or else the callback will be
+ * executed in the wrong context, i.e. not the callers).
+ */
+static inline void dma_fence_work_commit_imm(struct dma_fence_work *f)
+{
+	if (atomic_read(&f->chain.pending) <= 1)
+		__set_bit(DMA_FENCE_WORK_IMM, &f->dma.flags);
+
+	dma_fence_work_commit(f);
+}
+
+#endif /* I915_SW_FENCE_WORK_H */