[RFC PATCH v2 07/17] gpu: host1x: Introduce UAPI header

[Mikko Perttunen]

Add the userspace interface header, specifying interfaces
for allocating and accessing syncpoints from userspace,
and for creating sync_file based fences based on syncpoint
thresholds.

Signed-off-by: Mikko Perttunen <mperttunen at nvidia.com>
---
 include/uapi/linux/host1x.h | 134 ++++++++++++++++++++++++++++++++++++
 1 file changed, 134 insertions(+)
 create mode 100644 include/uapi/linux/host1x.h

diff --git a/include/uapi/linux/host1x.h b/include/uapi/linux/host1x.h
new file mode 100644
index 000000000000..9c8fb9425cb2
--- /dev/null
+++ b/include/uapi/linux/host1x.h
@@ -0,0 +1,134 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/* Copyright (c) 2020 NVIDIA Corporation */
+
+#ifndef _UAPI__LINUX_HOST1X_H
+#define _UAPI__LINUX_HOST1X_H
+
+#include <linux/ioctl.h>
+#include <linux/types.h>
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
+struct host1x_allocate_syncpoint {
+	/**
+	 * @fd: [out]
+	 *
+	 * New file descriptor representing the allocated syncpoint.
+	 */
+	__s32 fd;
+
+	__u32 reserved[3];
+};
+
+struct host1x_syncpoint_info {
+	/**
+	 * @id: [out]
+	 *
+	 * System-global ID of the syncpoint.
+	 */
+	__u32 id;
+
+	__u32 reserved[3];
+};
+
+struct host1x_syncpoint_increment {
+	/**
+	 * @count: [in]
+	 *
+	 * Number of times to increment the syncpoint. The syncpoint can
+	 * be observed at in-between values, but each increment is atomic.
+	 */
+	__u32 count;
+};
+
+struct host1x_read_syncpoint {
+	/**
+	 * @id: [in]
+	 *
+	 * ID of the syncpoint to read.
+	 */
+	__u32 id;
+
+	/**
+	 * @value: [out]
+	 *
+	 * Current value of the syncpoint.
+	 */
+	__u32 value;
+};
+
+struct host1x_create_fence {
+	/**
+	 * @id: [in]
+	 *
+	 * ID of the syncpoint to create a fence for.
+	 */
+	__u32 id;
+
+	/**
+	 * @threshold: [in]
+	 *
+	 * When the syncpoint reaches this value, the fence will be signaled.
+	 * The syncpoint is considered to have reached the threshold when the
+	 * following condition is true:
+	 *
+	 * 	((value - threshold) & 0x80000000U) == 0U
+	 *
+	 */
+	__u32 threshold;
+
+	/**
+	 * @fence_fd: [out]
+	 *
+	 * New sync_file file descriptor containing the created fence.
+	 */
+	__s32 fence_fd;
+
+	__u32 reserved[1];
+};
+
+struct host1x_fence_extract_fence {
+	__u32 id;
+	__u32 threshold;
+};
+
+struct host1x_fence_extract {
+	/**
+	 * @fence_fd: [in]
+	 *
+	 * sync_file file descriptor
+	 */
+	__s32 fence_fd;
+
+	/**
+	 * @num_fences: [in,out]
+	 *
+	 * In: size of the `fences_ptr` array counted in elements.
+	 * Out: required size of the `fences_ptr` array counted in elements.
+	 */
+	__u32 num_fences;
+
+	/**
+	 * @fences_ptr: [in]
+	 *
+	 * Pointer to array of `struct host1x_fence_extract_fence`.
+	 */
+	__u64 fences_ptr;
+
+	__u32 reserved[2];
+};
+
+#define HOST1X_IOCTL_ALLOCATE_SYNCPOINT  _IOWR('X', 0x00, struct host1x_allocate_syncpoint)
+#define HOST1X_IOCTL_READ_SYNCPOINT      _IOR ('X', 0x01, struct host1x_read_syncpoint)
+#define HOST1X_IOCTL_CREATE_FENCE        _IOWR('X', 0x02, struct host1x_create_fence)
+#define HOST1X_IOCTL_SYNCPOINT_INFO      _IOWR('X', 0x03, struct host1x_syncpoint_info)
+#define HOST1X_IOCTL_SYNCPOINT_INCREMENT _IOWR('X', 0x04, struct host1x_syncpoint_increment)
+#define HOST1X_IOCTL_FENCE_EXTRACT       _IOWR('X', 0x05, struct host1x_fence_extract)
+
+#if defined(__cplusplus)
+}
+#endif
+
+#endif
-- 
2.28.0