qemu/include/exec/translator.h
Richard Henderson 0ca41ccf1c accel/tcg: Track current value of can_do_io in the TB
Simplify translator_io_start by recording the current
known value of can_do_io within DisasContextBase.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-09-28 10:07:32 -07:00

242 lines
7.5 KiB
C

/*
* Generic intermediate code generation.
*
* Copyright (C) 2016-2017 Lluís Vilanova <vilanova@ac.upc.edu>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#ifndef EXEC__TRANSLATOR_H
#define EXEC__TRANSLATOR_H
/*
* Include this header from a target-specific file, and add a
*
* DisasContextBase base;
*
* member in your target-specific DisasContext.
*/
#include "qemu/bswap.h"
#include "exec/cpu_ldst.h" /* for abi_ptr */
/**
* gen_intermediate_code
* @cpu: cpu context
* @tb: translation block
* @max_insns: max number of instructions to translate
* @pc: guest virtual program counter address
* @host_pc: host physical program counter address
*
* This function must be provided by the target, which should create
* the target-specific DisasContext, and then invoke translator_loop.
*/
void gen_intermediate_code(CPUState *cpu, TranslationBlock *tb, int *max_insns,
target_ulong pc, void *host_pc);
/**
* DisasJumpType:
* @DISAS_NEXT: Next instruction in program order.
* @DISAS_TOO_MANY: Too many instructions translated.
* @DISAS_NORETURN: Following code is dead.
* @DISAS_TARGET_*: Start of target-specific conditions.
*
* What instruction to disassemble next.
*/
typedef enum DisasJumpType {
DISAS_NEXT,
DISAS_TOO_MANY,
DISAS_NORETURN,
DISAS_TARGET_0,
DISAS_TARGET_1,
DISAS_TARGET_2,
DISAS_TARGET_3,
DISAS_TARGET_4,
DISAS_TARGET_5,
DISAS_TARGET_6,
DISAS_TARGET_7,
DISAS_TARGET_8,
DISAS_TARGET_9,
DISAS_TARGET_10,
DISAS_TARGET_11,
} DisasJumpType;
/**
* DisasContextBase:
* @tb: Translation block for this disassembly.
* @pc_first: Address of first guest instruction in this TB.
* @pc_next: Address of next guest instruction in this TB (current during
* disassembly).
* @is_jmp: What instruction to disassemble next.
* @num_insns: Number of translated instructions (including current).
* @max_insns: Maximum number of instructions to be translated in this TB.
* @singlestep_enabled: "Hardware" single stepping enabled.
* @saved_can_do_io: Known value of cpu->neg.can_do_io, or -1 for unknown.
*
* Architecture-agnostic disassembly context.
*/
typedef struct DisasContextBase {
TranslationBlock *tb;
target_ulong pc_first;
target_ulong pc_next;
DisasJumpType is_jmp;
int num_insns;
int max_insns;
bool singlestep_enabled;
int8_t saved_can_do_io;
void *host_addr[2];
} DisasContextBase;
/**
* TranslatorOps:
* @init_disas_context:
* Initialize the target-specific portions of DisasContext struct.
* The generic DisasContextBase has already been initialized.
*
* @tb_start:
* Emit any code required before the start of the main loop,
* after the generic gen_tb_start().
*
* @insn_start:
* Emit the tcg_gen_insn_start opcode.
*
* @translate_insn:
* Disassemble one instruction and set db->pc_next for the start
* of the following instruction. Set db->is_jmp as necessary to
* terminate the main loop.
*
* @tb_stop:
* Emit any opcodes required to exit the TB, based on db->is_jmp.
*
* @disas_log:
* Print instruction disassembly to log.
*/
typedef struct TranslatorOps {
void (*init_disas_context)(DisasContextBase *db, CPUState *cpu);
void (*tb_start)(DisasContextBase *db, CPUState *cpu);
void (*insn_start)(DisasContextBase *db, CPUState *cpu);
void (*translate_insn)(DisasContextBase *db, CPUState *cpu);
void (*tb_stop)(DisasContextBase *db, CPUState *cpu);
void (*disas_log)(const DisasContextBase *db, CPUState *cpu, FILE *f);
} TranslatorOps;
/**
* translator_loop:
* @cpu: Target vCPU.
* @tb: Translation block.
* @max_insns: Maximum number of insns to translate.
* @pc: guest virtual program counter address
* @host_pc: host physical program counter address
* @ops: Target-specific operations.
* @db: Disassembly context.
*
* Generic translator loop.
*
* Translation will stop in the following cases (in order):
* - When is_jmp set by #TranslatorOps::breakpoint_check.
* - set to DISAS_TOO_MANY exits after translating one more insn
* - set to any other value than DISAS_NEXT exits immediately.
* - When is_jmp set by #TranslatorOps::translate_insn.
* - set to any value other than DISAS_NEXT exits immediately.
* - When the TCG operation buffer is full.
* - When single-stepping is enabled (system-wide or on the current vCPU).
* - When too many instructions have been translated.
*/
void translator_loop(CPUState *cpu, TranslationBlock *tb, int *max_insns,
vaddr pc, void *host_pc, const TranslatorOps *ops,
DisasContextBase *db);
/**
* translator_use_goto_tb
* @db: Disassembly context
* @dest: target pc of the goto
*
* Return true if goto_tb is allowed between the current TB
* and the destination PC.
*/
bool translator_use_goto_tb(DisasContextBase *db, vaddr dest);
/**
* translator_io_start
* @db: Disassembly context
*
* If icount is enabled, set cpu->can_do_io, adjust db->is_jmp to
* DISAS_TOO_MANY if it is still DISAS_NEXT, and return true.
* Otherwise return false.
*/
bool translator_io_start(DisasContextBase *db);
/*
* Translator Load Functions
*
* These are intended to replace the direct usage of the cpu_ld*_code
* functions and are mandatory for front-ends that have been migrated
* to the common translator_loop. These functions are only intended
* to be called from the translation stage and should not be called
* from helper functions. Those functions should be converted to encode
* the relevant information at translation time.
*/
uint8_t translator_ldub(CPUArchState *env, DisasContextBase *db, abi_ptr pc);
uint16_t translator_lduw(CPUArchState *env, DisasContextBase *db, abi_ptr pc);
uint32_t translator_ldl(CPUArchState *env, DisasContextBase *db, abi_ptr pc);
uint64_t translator_ldq(CPUArchState *env, DisasContextBase *db, abi_ptr pc);
static inline uint16_t
translator_lduw_swap(CPUArchState *env, DisasContextBase *db,
abi_ptr pc, bool do_swap)
{
uint16_t ret = translator_lduw(env, db, pc);
if (do_swap) {
ret = bswap16(ret);
}
return ret;
}
static inline uint32_t
translator_ldl_swap(CPUArchState *env, DisasContextBase *db,
abi_ptr pc, bool do_swap)
{
uint32_t ret = translator_ldl(env, db, pc);
if (do_swap) {
ret = bswap32(ret);
}
return ret;
}
static inline uint64_t
translator_ldq_swap(CPUArchState *env, DisasContextBase *db,
abi_ptr pc, bool do_swap)
{
uint64_t ret = translator_ldq(env, db, pc);
if (do_swap) {
ret = bswap64(ret);
}
return ret;
}
/**
* translator_fake_ldb - fake instruction load
* @insn8: byte of instruction
* @pc: program counter of instruction
*
* This is a special case helper used where the instruction we are
* about to translate comes from somewhere else (e.g. being
* re-synthesised for s390x "ex"). It ensures we update other areas of
* the translator with details of the executed instruction.
*/
void translator_fake_ldb(uint8_t insn8, abi_ptr pc);
/*
* Return whether addr is on the same page as where disassembly started.
* Translators can use this to enforce the rule that only single-insn
* translation blocks are allowed to cross page boundaries.
*/
static inline bool is_same_page(const DisasContextBase *db, target_ulong addr)
{
return ((addr ^ db->pc_first) & TARGET_PAGE_MASK) == 0;
}
#endif /* EXEC__TRANSLATOR_H */