1 files changed, 62 insertions, 0 deletions
diff --git a/include/uapi/linux/aspeed-p2a-ctrl.h b/include/uapi/linux/aspeed-p2a-ctrl.h
new file mode 100644
index 000000000000..033355552a6e
--- /dev/null
+++ b/include/uapi/linux/aspeed-p2a-ctrl.h
@@ -0,0 +1,62 @@
+/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
+/*
+ * Copyright 2019 Google Inc
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * Provides a simple driver to control the ASPEED P2A interface which allows
+ * the host to read and write to various regions of the BMC's memory.
+ */
+
+#ifndef _UAPI_LINUX_ASPEED_P2A_CTRL_H
+#define _UAPI_LINUX_ASPEED_P2A_CTRL_H
+
+#include <linux/ioctl.h>
+#include <linux/types.h>
+
+#define ASPEED_P2A_CTRL_READ_ONLY 0
+#define ASPEED_P2A_CTRL_READWRITE 1
+
+/*
+ * This driver provides a mechanism for enabling or disabling the read-write
+ * property of specific windows into the ASPEED BMC's memory.
+ *
+ * A user can map a region of the BMC's memory as read-only or read-write, with
+ * the caveat that once any region is mapped, all regions are unlocked for
+ * reading.
+ */
+
+/*
+ * Unlock a region of BMC physical memory for access from the host.
+ *
+ * Also used to read back the optional memory-region configuration for the
+ * driver.
+ */
+struct aspeed_p2a_ctrl_mapping {
+	__u64 addr;
+	__u32 length;
+	__u32 flags;
+};
+
+#define __ASPEED_P2A_CTRL_IOCTL_MAGIC 0xb3
+
+/*
+ * This IOCTL is meant to configure a region or regions of memory given a
+ * starting address and length to be readable by the host, or
+ * readable-writeable.
+ */
+#define ASPEED_P2A_CTRL_IOCTL_SET_WINDOW _IOW(__ASPEED_P2A_CTRL_IOCTL_MAGIC, \
+		0x00, struct aspeed_p2a_ctrl_mapping)
+
+/*
+ * This IOCTL is meant to read back to the user the base address and length of
+ * the memory-region specified to the driver for use with mmap.
+ */
+#define ASPEED_P2A_CTRL_IOCTL_GET_MEMORY_CONFIG \
+	_IOWR(__ASPEED_P2A_CTRL_IOCTL_MAGIC, \
+		0x01, struct aspeed_p2a_ctrl_mapping)
+
+#endif /* _UAPI_LINUX_ASPEED_P2A_CTRL_H */