xref: /openbmc/qemu/include/exec/cpu-defs.h (revision 4a09d0bb)
1 /*
2  * common defines for all CPUs
3  *
4  * Copyright (c) 2003 Fabrice Bellard
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2 of the License, or (at your option) any later version.
10  *
11  * This library is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
18  */
19 #ifndef CPU_DEFS_H
20 #define CPU_DEFS_H
21 
22 #ifndef NEED_CPU_H
23 #error cpu.h included from common code
24 #endif
25 
26 #include "qemu/host-utils.h"
27 #include "qemu/queue.h"
28 #include "tcg-target.h"
29 #ifndef CONFIG_USER_ONLY
30 #include "exec/hwaddr.h"
31 #endif
32 #include "exec/memattrs.h"
33 
34 #ifndef TARGET_LONG_BITS
35 #error TARGET_LONG_BITS must be defined before including this header
36 #endif
37 
38 #define TARGET_LONG_SIZE (TARGET_LONG_BITS / 8)
39 
40 /* target_ulong is the type of a virtual address */
41 #if TARGET_LONG_SIZE == 4
42 typedef int32_t target_long;
43 typedef uint32_t target_ulong;
44 #define TARGET_FMT_lx "%08x"
45 #define TARGET_FMT_ld "%d"
46 #define TARGET_FMT_lu "%u"
47 #elif TARGET_LONG_SIZE == 8
48 typedef int64_t target_long;
49 typedef uint64_t target_ulong;
50 #define TARGET_FMT_lx "%016" PRIx64
51 #define TARGET_FMT_ld "%" PRId64
52 #define TARGET_FMT_lu "%" PRIu64
53 #else
54 #error TARGET_LONG_SIZE undefined
55 #endif
56 
57 #if !defined(CONFIG_USER_ONLY)
58 /* use a fully associative victim tlb of 8 entries */
59 #define CPU_VTLB_SIZE 8
60 
61 #if HOST_LONG_BITS == 32 && TARGET_LONG_BITS == 32
62 #define CPU_TLB_ENTRY_BITS 4
63 #else
64 #define CPU_TLB_ENTRY_BITS 5
65 #endif
66 
67 /* TCG_TARGET_TLB_DISPLACEMENT_BITS is used in CPU_TLB_BITS to ensure that
68  * the TLB is not unnecessarily small, but still small enough for the
69  * TLB lookup instruction sequence used by the TCG target.
70  *
71  * TCG will have to generate an operand as large as the distance between
72  * env and the tlb_table[NB_MMU_MODES - 1][0].addend.  For simplicity,
73  * the TCG targets just round everything up to the next power of two, and
74  * count bits.  This works because: 1) the size of each TLB is a largish
75  * power of two, 2) and because the limit of the displacement is really close
76  * to a power of two, 3) the offset of tlb_table[0][0] inside env is smaller
77  * than the size of a TLB.
78  *
79  * For example, the maximum displacement 0xFFF0 on PPC and MIPS, but TCG
80  * just says "the displacement is 16 bits".  TCG_TARGET_TLB_DISPLACEMENT_BITS
81  * then ensures that tlb_table at least 0x8000 bytes large ("not unnecessarily
82  * small": 2^15).  The operand then will come up smaller than 0xFFF0 without
83  * any particular care, because the TLB for a single MMU mode is larger than
84  * 0x10000-0xFFF0=16 bytes.  In the end, the maximum value of the operand
85  * could be something like 0xC000 (the offset of the last TLB table) plus
86  * 0x18 (the offset of the addend field in each TLB entry) plus the offset
87  * of tlb_table inside env (which is non-trivial but not huge).
88  */
89 #define CPU_TLB_BITS                                             \
90     MIN(8,                                                       \
91         TCG_TARGET_TLB_DISPLACEMENT_BITS - CPU_TLB_ENTRY_BITS -  \
92         (NB_MMU_MODES <= 1 ? 0 :                                 \
93          NB_MMU_MODES <= 2 ? 1 :                                 \
94          NB_MMU_MODES <= 4 ? 2 :                                 \
95          NB_MMU_MODES <= 8 ? 3 : 4))
96 
97 #define CPU_TLB_SIZE (1 << CPU_TLB_BITS)
98 
99 typedef struct CPUTLBEntry {
100     /* bit TARGET_LONG_BITS to TARGET_PAGE_BITS : virtual address
101        bit TARGET_PAGE_BITS-1..4  : Nonzero for accesses that should not
102                                     go directly to ram.
103        bit 3                      : indicates that the entry is invalid
104        bit 2..0                   : zero
105     */
106     union {
107         struct {
108             target_ulong addr_read;
109             target_ulong addr_write;
110             target_ulong addr_code;
111             /* Addend to virtual address to get host address.  IO accesses
112                use the corresponding iotlb value.  */
113             uintptr_t addend;
114         };
115         /* padding to get a power of two size */
116         uint8_t dummy[1 << CPU_TLB_ENTRY_BITS];
117     };
118 } CPUTLBEntry;
119 
120 QEMU_BUILD_BUG_ON(sizeof(CPUTLBEntry) != (1 << CPU_TLB_ENTRY_BITS));
121 
122 /* The IOTLB is not accessed directly inline by generated TCG code,
123  * so the CPUIOTLBEntry layout is not as critical as that of the
124  * CPUTLBEntry. (This is also why we don't want to combine the two
125  * structs into one.)
126  */
127 typedef struct CPUIOTLBEntry {
128     hwaddr addr;
129     MemTxAttrs attrs;
130 } CPUIOTLBEntry;
131 
132 #define CPU_COMMON_TLB \
133     /* The meaning of the MMU modes is defined in the target code. */   \
134     CPUTLBEntry tlb_table[NB_MMU_MODES][CPU_TLB_SIZE];                  \
135     CPUTLBEntry tlb_v_table[NB_MMU_MODES][CPU_VTLB_SIZE];               \
136     CPUIOTLBEntry iotlb[NB_MMU_MODES][CPU_TLB_SIZE];                    \
137     CPUIOTLBEntry iotlb_v[NB_MMU_MODES][CPU_VTLB_SIZE];                 \
138     target_ulong tlb_flush_addr;                                        \
139     target_ulong tlb_flush_mask;                                        \
140     target_ulong vtlb_index;                                            \
141 
142 #else
143 
144 #define CPU_COMMON_TLB
145 
146 #endif
147 
148 
149 #define CPU_COMMON                                                      \
150     /* soft mmu support */                                              \
151     CPU_COMMON_TLB                                                      \
152 
153 #endif
154