1 /* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
2 /*
3  * Copyright 2019 Google Inc
4  *
5  * This program is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU General Public License
7  * as published by the Free Software Foundation; either version
8  * 2 of the License, or (at your option) any later version.
9  *
10  * Provides a simple driver to control the ASPEED P2A interface which allows
11  * the host to read and write to various regions of the BMC's memory.
12  */
13 
14 #ifndef _UAPI_LINUX_ASPEED_P2A_CTRL_H
15 #define _UAPI_LINUX_ASPEED_P2A_CTRL_H
16 
17 #include <linux/ioctl.h>
18 #include <linux/types.h>
19 
20 #define ASPEED_P2A_CTRL_READ_ONLY 0
21 #define ASPEED_P2A_CTRL_READWRITE 1
22 
23 /*
24  * This driver provides a mechanism for enabling or disabling the read-write
25  * property of specific windows into the ASPEED BMC's memory.
26  *
27  * A user can map a region of the BMC's memory as read-only or read-write, with
28  * the caveat that once any region is mapped, all regions are unlocked for
29  * reading.
30  */
31 
32 /*
33  * Unlock a region of BMC physical memory for access from the host.
34  *
35  * Also used to read back the optional memory-region configuration for the
36  * driver.
37  */
38 struct aspeed_p2a_ctrl_mapping {
39 	__u64 addr;
40 	__u32 length;
41 	__u32 flags;
42 };
43 
44 #define __ASPEED_P2A_CTRL_IOCTL_MAGIC 0xb3
45 
46 /*
47  * This IOCTL is meant to configure a region or regions of memory given a
48  * starting address and length to be readable by the host, or
49  * readable-writeable.
50  */
51 #define ASPEED_P2A_CTRL_IOCTL_SET_WINDOW _IOW(__ASPEED_P2A_CTRL_IOCTL_MAGIC, \
52 		0x00, struct aspeed_p2a_ctrl_mapping)
53 
54 /*
55  * This IOCTL is meant to read back to the user the base address and length of
56  * the memory-region specified to the driver for use with mmap.
57  */
58 #define ASPEED_P2A_CTRL_IOCTL_GET_MEMORY_CONFIG \
59 	_IOWR(__ASPEED_P2A_CTRL_IOCTL_MAGIC, \
60 		0x01, struct aspeed_p2a_ctrl_mapping)
61 
62 #endif /* _UAPI_LINUX_ASPEED_P2A_CTRL_H */
63