linux-headers (unknown)
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 _LINUX_ASPEED_P2A_CTRL_H
15 #define _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 /* _LINUX_ASPEED_P2A_CTRL_H */
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