xref: /openbmc/qemu/include/exec/translator.h (revision 1da79ecc)
1 /*
2  * Generic intermediate code generation.
3  *
4  * Copyright (C) 2016-2017 Lluís Vilanova <vilanova@ac.upc.edu>
5  *
6  * This work is licensed under the terms of the GNU GPL, version 2 or later.
7  * See the COPYING file in the top-level directory.
8  */
9 
10 #ifndef EXEC__TRANSLATOR_H
11 #define EXEC__TRANSLATOR_H
12 
13 /*
14  * Include this header from a target-specific file, and add a
15  *
16  *     DisasContextBase base;
17  *
18  * member in your target-specific DisasContext.
19  */
20 
21 
22 #include "qemu/bswap.h"
23 #include "exec/exec-all.h"
24 #include "exec/cpu_ldst.h"
25 #include "exec/plugin-gen.h"
26 #include "tcg/tcg.h"
27 
28 
29 /**
30  * DisasJumpType:
31  * @DISAS_NEXT: Next instruction in program order.
32  * @DISAS_TOO_MANY: Too many instructions translated.
33  * @DISAS_NORETURN: Following code is dead.
34  * @DISAS_TARGET_*: Start of target-specific conditions.
35  *
36  * What instruction to disassemble next.
37  */
38 typedef enum DisasJumpType {
39     DISAS_NEXT,
40     DISAS_TOO_MANY,
41     DISAS_NORETURN,
42     DISAS_TARGET_0,
43     DISAS_TARGET_1,
44     DISAS_TARGET_2,
45     DISAS_TARGET_3,
46     DISAS_TARGET_4,
47     DISAS_TARGET_5,
48     DISAS_TARGET_6,
49     DISAS_TARGET_7,
50     DISAS_TARGET_8,
51     DISAS_TARGET_9,
52     DISAS_TARGET_10,
53     DISAS_TARGET_11,
54 } DisasJumpType;
55 
56 /**
57  * DisasContextBase:
58  * @tb: Translation block for this disassembly.
59  * @pc_first: Address of first guest instruction in this TB.
60  * @pc_next: Address of next guest instruction in this TB (current during
61  *           disassembly).
62  * @is_jmp: What instruction to disassemble next.
63  * @num_insns: Number of translated instructions (including current).
64  * @max_insns: Maximum number of instructions to be translated in this TB.
65  * @singlestep_enabled: "Hardware" single stepping enabled.
66  *
67  * Architecture-agnostic disassembly context.
68  */
69 typedef struct DisasContextBase {
70     const TranslationBlock *tb;
71     target_ulong pc_first;
72     target_ulong pc_next;
73     DisasJumpType is_jmp;
74     int num_insns;
75     int max_insns;
76     bool singlestep_enabled;
77 } DisasContextBase;
78 
79 /**
80  * TranslatorOps:
81  * @init_disas_context:
82  *      Initialize the target-specific portions of DisasContext struct.
83  *      The generic DisasContextBase has already been initialized.
84  *
85  * @tb_start:
86  *      Emit any code required before the start of the main loop,
87  *      after the generic gen_tb_start().
88  *
89  * @insn_start:
90  *      Emit the tcg_gen_insn_start opcode.
91  *
92  * @breakpoint_check:
93  *      When called, the breakpoint has already been checked to match the PC,
94  *      but the target may decide the breakpoint missed the address
95  *      (e.g., due to conditions encoded in their flags).  Return true to
96  *      indicate that the breakpoint did hit, in which case no more breakpoints
97  *      are checked.  If the breakpoint did hit, emit any code required to
98  *      signal the exception, and set db->is_jmp as necessary to terminate
99  *      the main loop.
100  *
101  * @translate_insn:
102  *      Disassemble one instruction and set db->pc_next for the start
103  *      of the following instruction.  Set db->is_jmp as necessary to
104  *      terminate the main loop.
105  *
106  * @tb_stop:
107  *      Emit any opcodes required to exit the TB, based on db->is_jmp.
108  *
109  * @disas_log:
110  *      Print instruction disassembly to log.
111  */
112 typedef struct TranslatorOps {
113     void (*init_disas_context)(DisasContextBase *db, CPUState *cpu);
114     void (*tb_start)(DisasContextBase *db, CPUState *cpu);
115     void (*insn_start)(DisasContextBase *db, CPUState *cpu);
116     bool (*breakpoint_check)(DisasContextBase *db, CPUState *cpu,
117                              const CPUBreakpoint *bp);
118     void (*translate_insn)(DisasContextBase *db, CPUState *cpu);
119     void (*tb_stop)(DisasContextBase *db, CPUState *cpu);
120     void (*disas_log)(const DisasContextBase *db, CPUState *cpu);
121 } TranslatorOps;
122 
123 /**
124  * translator_loop:
125  * @ops: Target-specific operations.
126  * @db: Disassembly context.
127  * @cpu: Target vCPU.
128  * @tb: Translation block.
129  * @max_insns: Maximum number of insns to translate.
130  *
131  * Generic translator loop.
132  *
133  * Translation will stop in the following cases (in order):
134  * - When is_jmp set by #TranslatorOps::breakpoint_check.
135  *   - set to DISAS_TOO_MANY exits after translating one more insn
136  *   - set to any other value than DISAS_NEXT exits immediately.
137  * - When is_jmp set by #TranslatorOps::translate_insn.
138  *   - set to any value other than DISAS_NEXT exits immediately.
139  * - When the TCG operation buffer is full.
140  * - When single-stepping is enabled (system-wide or on the current vCPU).
141  * - When too many instructions have been translated.
142  */
143 void translator_loop(const TranslatorOps *ops, DisasContextBase *db,
144                      CPUState *cpu, TranslationBlock *tb, int max_insns);
145 
146 void translator_loop_temp_check(DisasContextBase *db);
147 
148 /*
149  * Translator Load Functions
150  *
151  * These are intended to replace the direct usage of the cpu_ld*_code
152  * functions and are mandatory for front-ends that have been migrated
153  * to the common translator_loop. These functions are only intended
154  * to be called from the translation stage and should not be called
155  * from helper functions. Those functions should be converted to encode
156  * the relevant information at translation time.
157  */
158 
159 #define GEN_TRANSLATOR_LD(fullname, type, load_fn, swap_fn)             \
160     static inline type                                                  \
161     fullname ## _swap(CPUArchState *env, abi_ptr pc, bool do_swap)      \
162     {                                                                   \
163         type ret = load_fn(env, pc);                                    \
164         if (do_swap) {                                                  \
165             ret = swap_fn(ret);                                         \
166         }                                                               \
167         plugin_insn_append(&ret, sizeof(ret));                          \
168         return ret;                                                     \
169     }                                                                   \
170                                                                         \
171     static inline type fullname(CPUArchState *env, abi_ptr pc)          \
172     {                                                                   \
173         return fullname ## _swap(env, pc, false);                       \
174     }
175 
176 GEN_TRANSLATOR_LD(translator_ldub, uint8_t, cpu_ldub_code, /* no swap */)
177 GEN_TRANSLATOR_LD(translator_ldsw, int16_t, cpu_ldsw_code, bswap16)
178 GEN_TRANSLATOR_LD(translator_lduw, uint16_t, cpu_lduw_code, bswap16)
179 GEN_TRANSLATOR_LD(translator_ldl, uint32_t, cpu_ldl_code, bswap32)
180 GEN_TRANSLATOR_LD(translator_ldq, uint64_t, cpu_ldq_code, bswap64)
181 #undef GEN_TRANSLATOR_LD
182 
183 #endif  /* EXEC__TRANSLATOR_H */
184