xref: /openbmc/qemu/include/exec/memattrs.h (revision 786a4ea8)
1 /*
2  * Memory transaction attributes
3  *
4  * Copyright (c) 2015 Linaro Limited.
5  *
6  * Authors:
7  *  Peter Maydell <peter.maydell@linaro.org>
8  *
9  * This work is licensed under the terms of the GNU GPL, version 2 or later.
10  * See the COPYING file in the top-level directory.
11  *
12  */
13 
14 #ifndef MEMATTRS_H
15 #define MEMATTRS_H
16 
17 /* Every memory transaction has associated with it a set of
18  * attributes. Some of these are generic (such as the ID of
19  * the bus master); some are specific to a particular kind of
20  * bus (such as the ARM Secure/NonSecure bit). We define them
21  * all as non-overlapping bitfields in a single struct to avoid
22  * confusion if different parts of QEMU used the same bit for
23  * different semantics.
24  */
25 typedef struct MemTxAttrs {
26     /* Bus masters which don't specify any attributes will get this
27      * (via the MEMTXATTRS_UNSPECIFIED constant), so that we can
28      * distinguish "all attributes deliberately clear" from
29      * "didn't specify" if necessary.
30      */
31     unsigned int unspecified:1;
32     /* ARM/AMBA TrustZone Secure access */
33     unsigned int secure:1;
34     /* Memory access is usermode (unprivileged) */
35     unsigned int user:1;
36 } MemTxAttrs;
37 
38 /* Bus masters which don't specify any attributes will get this,
39  * which has all attribute bits clear except the topmost one
40  * (so that we can distinguish "all attributes deliberately clear"
41  * from "didn't specify" if necessary).
42  */
43 #define MEMTXATTRS_UNSPECIFIED ((MemTxAttrs) { .unspecified = 1 })
44 
45 #endif
46