xref: /openbmc/qemu/include/exec/memop.h (revision 0b84b662)
1 /*
2  * Constants for memory operations
3  *
4  * Authors:
5  *  Richard Henderson <rth@twiddle.net>
6  *
7  * This work is licensed under the terms of the GNU GPL, version 2 or later.
8  * See the COPYING file in the top-level directory.
9  *
10  */
11 
12 #ifndef MEMOP_H
13 #define MEMOP_H
14 
15 #include "qemu/host-utils.h"
16 
17 typedef enum MemOp {
18     MO_8     = 0,
19     MO_16    = 1,
20     MO_32    = 2,
21     MO_64    = 3,
22     MO_SIZE  = 3,   /* Mask for the above.  */
23 
24     MO_SIGN  = 4,   /* Sign-extended, otherwise zero-extended.  */
25 
26     MO_BSWAP = 8,   /* Host reverse endian.  */
27 #ifdef HOST_WORDS_BIGENDIAN
28     MO_LE    = MO_BSWAP,
29     MO_BE    = 0,
30 #else
31     MO_LE    = 0,
32     MO_BE    = MO_BSWAP,
33 #endif
34 #ifdef NEED_CPU_H
35 #ifdef TARGET_WORDS_BIGENDIAN
36     MO_TE    = MO_BE,
37 #else
38     MO_TE    = MO_LE,
39 #endif
40 #endif
41 
42     /*
43      * MO_UNALN accesses are never checked for alignment.
44      * MO_ALIGN accesses will result in a call to the CPU's
45      * do_unaligned_access hook if the guest address is not aligned.
46      * The default depends on whether the target CPU defines
47      * TARGET_ALIGNED_ONLY.
48      *
49      * Some architectures (e.g. ARMv8) need the address which is aligned
50      * to a size more than the size of the memory access.
51      * Some architectures (e.g. SPARCv9) need an address which is aligned,
52      * but less strictly than the natural alignment.
53      *
54      * MO_ALIGN supposes the alignment size is the size of a memory access.
55      *
56      * There are three options:
57      * - unaligned access permitted (MO_UNALN).
58      * - an alignment to the size of an access (MO_ALIGN);
59      * - an alignment to a specified size, which may be more or less than
60      *   the access size (MO_ALIGN_x where 'x' is a size in bytes);
61      */
62     MO_ASHIFT = 4,
63     MO_AMASK = 7 << MO_ASHIFT,
64 #ifdef NEED_CPU_H
65 #ifdef TARGET_ALIGNED_ONLY
66     MO_ALIGN = 0,
67     MO_UNALN = MO_AMASK,
68 #else
69     MO_ALIGN = MO_AMASK,
70     MO_UNALN = 0,
71 #endif
72 #endif
73     MO_ALIGN_2  = 1 << MO_ASHIFT,
74     MO_ALIGN_4  = 2 << MO_ASHIFT,
75     MO_ALIGN_8  = 3 << MO_ASHIFT,
76     MO_ALIGN_16 = 4 << MO_ASHIFT,
77     MO_ALIGN_32 = 5 << MO_ASHIFT,
78     MO_ALIGN_64 = 6 << MO_ASHIFT,
79 
80     /* Combinations of the above, for ease of use.  */
81     MO_UB    = MO_8,
82     MO_UW    = MO_16,
83     MO_UL    = MO_32,
84     MO_SB    = MO_SIGN | MO_8,
85     MO_SW    = MO_SIGN | MO_16,
86     MO_SL    = MO_SIGN | MO_32,
87     MO_Q     = MO_64,
88 
89     MO_LEUW  = MO_LE | MO_UW,
90     MO_LEUL  = MO_LE | MO_UL,
91     MO_LESW  = MO_LE | MO_SW,
92     MO_LESL  = MO_LE | MO_SL,
93     MO_LEQ   = MO_LE | MO_Q,
94 
95     MO_BEUW  = MO_BE | MO_UW,
96     MO_BEUL  = MO_BE | MO_UL,
97     MO_BESW  = MO_BE | MO_SW,
98     MO_BESL  = MO_BE | MO_SL,
99     MO_BEQ   = MO_BE | MO_Q,
100 
101 #ifdef NEED_CPU_H
102     MO_TEUW  = MO_TE | MO_UW,
103     MO_TEUL  = MO_TE | MO_UL,
104     MO_TESW  = MO_TE | MO_SW,
105     MO_TESL  = MO_TE | MO_SL,
106     MO_TEQ   = MO_TE | MO_Q,
107 #endif
108 
109     MO_SSIZE = MO_SIZE | MO_SIGN,
110 } MemOp;
111 
112 /* MemOp to size in bytes.  */
113 static inline unsigned memop_size(MemOp op)
114 {
115     return 1 << (op & MO_SIZE);
116 }
117 
118 /* Size in bytes to MemOp.  */
119 static inline MemOp size_memop(unsigned size)
120 {
121 #ifdef CONFIG_DEBUG_TCG
122     /* Power of 2 up to 8.  */
123     assert((size & (size - 1)) == 0 && size >= 1 && size <= 8);
124 #endif
125     return ctz32(size);
126 }
127 
128 /* Big endianness from MemOp.  */
129 static inline bool memop_big_endian(MemOp op)
130 {
131     return (op & MO_BSWAP) == MO_BE;
132 }
133 
134 #endif
135