xref: /openbmc/qemu/include/exec/cpu-defs.h (revision e4b4b642)
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 #ifdef CONFIG_TCG
29 #include "tcg-target.h"
30 #endif
31 #ifndef CONFIG_USER_ONLY
32 #include "exec/hwaddr.h"
33 #endif
34 #include "exec/memattrs.h"
35 
36 #ifndef TARGET_LONG_BITS
37 #error TARGET_LONG_BITS must be defined before including this header
38 #endif
39 
40 #define TARGET_LONG_SIZE (TARGET_LONG_BITS / 8)
41 
42 /* target_ulong is the type of a virtual address */
43 #if TARGET_LONG_SIZE == 4
44 typedef int32_t target_long;
45 typedef uint32_t target_ulong;
46 #define TARGET_FMT_lx "%08x"
47 #define TARGET_FMT_ld "%d"
48 #define TARGET_FMT_lu "%u"
49 #elif TARGET_LONG_SIZE == 8
50 typedef int64_t target_long;
51 typedef uint64_t target_ulong;
52 #define TARGET_FMT_lx "%016" PRIx64
53 #define TARGET_FMT_ld "%" PRId64
54 #define TARGET_FMT_lu "%" PRIu64
55 #else
56 #error TARGET_LONG_SIZE undefined
57 #endif
58 
59 #if !defined(CONFIG_USER_ONLY) && defined(CONFIG_TCG)
60 /* use a fully associative victim tlb of 8 entries */
61 #define CPU_VTLB_SIZE 8
62 
63 #if HOST_LONG_BITS == 32 && TARGET_LONG_BITS == 32
64 #define CPU_TLB_ENTRY_BITS 4
65 #else
66 #define CPU_TLB_ENTRY_BITS 5
67 #endif
68 
69 /* TCG_TARGET_TLB_DISPLACEMENT_BITS is used in CPU_TLB_BITS to ensure that
70  * the TLB is not unnecessarily small, but still small enough for the
71  * TLB lookup instruction sequence used by the TCG target.
72  *
73  * TCG will have to generate an operand as large as the distance between
74  * env and the tlb_table[NB_MMU_MODES - 1][0].addend.  For simplicity,
75  * the TCG targets just round everything up to the next power of two, and
76  * count bits.  This works because: 1) the size of each TLB is a largish
77  * power of two, 2) and because the limit of the displacement is really close
78  * to a power of two, 3) the offset of tlb_table[0][0] inside env is smaller
79  * than the size of a TLB.
80  *
81  * For example, the maximum displacement 0xFFF0 on PPC and MIPS, but TCG
82  * just says "the displacement is 16 bits".  TCG_TARGET_TLB_DISPLACEMENT_BITS
83  * then ensures that tlb_table at least 0x8000 bytes large ("not unnecessarily
84  * small": 2^15).  The operand then will come up smaller than 0xFFF0 without
85  * any particular care, because the TLB for a single MMU mode is larger than
86  * 0x10000-0xFFF0=16 bytes.  In the end, the maximum value of the operand
87  * could be something like 0xC000 (the offset of the last TLB table) plus
88  * 0x18 (the offset of the addend field in each TLB entry) plus the offset
89  * of tlb_table inside env (which is non-trivial but not huge).
90  */
91 #define CPU_TLB_BITS                                             \
92     MIN(8,                                                       \
93         TCG_TARGET_TLB_DISPLACEMENT_BITS - CPU_TLB_ENTRY_BITS -  \
94         (NB_MMU_MODES <= 1 ? 0 :                                 \
95          NB_MMU_MODES <= 2 ? 1 :                                 \
96          NB_MMU_MODES <= 4 ? 2 :                                 \
97          NB_MMU_MODES <= 8 ? 3 : 4))
98 
99 #define CPU_TLB_SIZE (1 << CPU_TLB_BITS)
100 
101 typedef struct CPUTLBEntry {
102     /* bit TARGET_LONG_BITS to TARGET_PAGE_BITS : virtual address
103        bit TARGET_PAGE_BITS-1..4  : Nonzero for accesses that should not
104                                     go directly to ram.
105        bit 3                      : indicates that the entry is invalid
106        bit 2..0                   : zero
107     */
108     union {
109         struct {
110             target_ulong addr_read;
111             target_ulong addr_write;
112             target_ulong addr_code;
113             /* Addend to virtual address to get host address.  IO accesses
114                use the corresponding iotlb value.  */
115             uintptr_t addend;
116         };
117         /* padding to get a power of two size */
118         uint8_t dummy[1 << CPU_TLB_ENTRY_BITS];
119     };
120 } CPUTLBEntry;
121 
122 QEMU_BUILD_BUG_ON(sizeof(CPUTLBEntry) != (1 << CPU_TLB_ENTRY_BITS));
123 
124 /* The IOTLB is not accessed directly inline by generated TCG code,
125  * so the CPUIOTLBEntry layout is not as critical as that of the
126  * CPUTLBEntry. (This is also why we don't want to combine the two
127  * structs into one.)
128  */
129 typedef struct CPUIOTLBEntry {
130     hwaddr addr;
131     MemTxAttrs attrs;
132 } CPUIOTLBEntry;
133 
134 #define CPU_COMMON_TLB \
135     /* The meaning of the MMU modes is defined in the target code. */   \
136     CPUTLBEntry tlb_table[NB_MMU_MODES][CPU_TLB_SIZE];                  \
137     CPUTLBEntry tlb_v_table[NB_MMU_MODES][CPU_VTLB_SIZE];               \
138     CPUIOTLBEntry iotlb[NB_MMU_MODES][CPU_TLB_SIZE];                    \
139     CPUIOTLBEntry iotlb_v[NB_MMU_MODES][CPU_VTLB_SIZE];                 \
140     target_ulong tlb_flush_addr;                                        \
141     target_ulong tlb_flush_mask;                                        \
142     target_ulong vtlb_index;                                            \
143 
144 #else
145 
146 #define CPU_COMMON_TLB
147 
148 #endif
149 
150 
151 #define CPU_COMMON                                                      \
152     /* soft mmu support */                                              \
153     CPU_COMMON_TLB                                                      \
154 
155 #endif
156