gpu: host1x: Add context device management code

Add code to register context devices from device tree, allocate them
out and manage their refcounts.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

1 files changed, 38 insertions, 0 deletions

diff --git a/drivers/gpu/host1x/context.h b/drivers/gpu/host1x/context.h
new file mode 100644
index 000000000000..3e03bc1d3bac
--- /dev/null
+++ b/drivers/gpu/host1x/context.h
@@ -0,0 +1,38 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Host1x context devices
+ *
+ * Copyright (c) 2020, NVIDIA Corporation.
+ */
+
+#ifndef __HOST1X_CONTEXT_H
+#define __HOST1X_CONTEXT_H
+
+#include <linux/mutex.h>
+#include <linux/refcount.h>
+
+struct host1x;
+
+extern struct bus_type host1x_context_device_bus_type;
+
+struct host1x_memory_context_list {
+	struct mutex lock;
+	struct host1x_memory_context *devs;
+	unsigned int len;
+};
+
+#ifdef CONFIG_IOMMU_API
+int host1x_memory_context_list_init(struct host1x *host1x);
+void host1x_memory_context_list_free(struct host1x_memory_context_list *cdl);
+#else
+static inline int host1x_memory_context_list_init(struct host1x *host1x)
+{
+	return 0;
+}
+
+static inline void host1x_memory_context_list_free(struct host1x_memory_context_list *cdl)
+{
+}
+#endif
+
+#endif