qemu-e2k/accel/tcg/tb-jmp-cache.h
Richard Henderson 8ed558ec0c accel/tcg: Introduce TARGET_TB_PCREL
Prepare for targets to be able to produce TBs that can
run in more than one virtual context.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2022-10-04 12:13:16 -07:00

66 lines
1.6 KiB
C

/*
* The per-CPU TranslationBlock jump cache.
*
* Copyright (c) 2003 Fabrice Bellard
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#ifndef ACCEL_TCG_TB_JMP_CACHE_H
#define ACCEL_TCG_TB_JMP_CACHE_H
#define TB_JMP_CACHE_BITS 12
#define TB_JMP_CACHE_SIZE (1 << TB_JMP_CACHE_BITS)
/*
* Accessed in parallel; all accesses to 'tb' must be atomic.
* For TARGET_TB_PCREL, accesses to 'pc' must be protected by
* a load_acquire/store_release to 'tb'.
*/
struct CPUJumpCache {
struct {
TranslationBlock *tb;
#if TARGET_TB_PCREL
target_ulong pc;
#endif
} array[TB_JMP_CACHE_SIZE];
};
static inline TranslationBlock *
tb_jmp_cache_get_tb(CPUJumpCache *jc, uint32_t hash)
{
#if TARGET_TB_PCREL
/* Use acquire to ensure current load of pc from jc. */
return qatomic_load_acquire(&jc->array[hash].tb);
#else
/* Use rcu_read to ensure current load of pc from *tb. */
return qatomic_rcu_read(&jc->array[hash].tb);
#endif
}
static inline target_ulong
tb_jmp_cache_get_pc(CPUJumpCache *jc, uint32_t hash, TranslationBlock *tb)
{
#if TARGET_TB_PCREL
return jc->array[hash].pc;
#else
return tb_pc(tb);
#endif
}
static inline void
tb_jmp_cache_set(CPUJumpCache *jc, uint32_t hash,
TranslationBlock *tb, target_ulong pc)
{
#if TARGET_TB_PCREL
jc->array[hash].pc = pc;
/* Use store_release on tb to ensure pc is written first. */
qatomic_store_release(&jc->array[hash].tb, tb);
#else
/* Use the pc value already stored in tb->pc. */
qatomic_set(&jc->array[hash].tb, tb);
#endif
}
#endif /* ACCEL_TCG_TB_JMP_CACHE_H */