From bd2710d5da06ad7706d4864f65b3f0c9f7cb4d7f Mon Sep 17 00:00:00 2001 From: Sergey Fedorov Date: Fri, 15 Jul 2016 20:58:51 +0300 Subject: tcg: Merge tb_find_slow() and tb_find_fast() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit These functions are not too big and can be merged together. This makes locking scheme more clear and easier to follow. Signed-off-by: Sergey Fedorov Signed-off-by: Sergey Fedorov Reviewed-by: Alex Bennée Message-Id: <20160715175852.30749-12-sergey.fedorov@linaro.org> Signed-off-by: Paolo Bonzini --- cpu-exec.c | 72 ++++++++++++++++++++++++++------------------------------------ 1 file changed, 30 insertions(+), 42 deletions(-) diff --git a/cpu-exec.c b/cpu-exec.c index bd9fa5a538..f7f60b16b1 100644 --- a/cpu-exec.c +++ b/cpu-exec.c @@ -279,45 +279,9 @@ static TranslationBlock *tb_find_physical(CPUState *cpu, return qht_lookup(&tcg_ctx.tb_ctx.htable, tb_cmp, &desc, h); } -static TranslationBlock *tb_find_slow(CPUState *cpu, - target_ulong pc, - target_ulong cs_base, - uint32_t flags, - bool *have_tb_lock) -{ - TranslationBlock *tb; - - tb = tb_find_physical(cpu, pc, cs_base, flags); - if (!tb) { - - /* mmap_lock is needed by tb_gen_code, and mmap_lock must be - * taken outside tb_lock. As system emulation is currently - * single threaded the locks are NOPs. - */ - mmap_lock(); - tb_lock(); - *have_tb_lock = true; - - /* There's a chance that our desired tb has been translated while - * taking the locks so we check again inside the lock. - */ - tb = tb_find_physical(cpu, pc, cs_base, flags); - if (!tb) { - /* if no translated code available, then translate it now */ - tb = tb_gen_code(cpu, pc, cs_base, flags, 0); - } - - mmap_unlock(); - } - - /* We add the TB in the virtual pc hash table for the fast lookup */ - atomic_set(&cpu->tb_jmp_cache[tb_jmp_cache_hash_func(pc)], tb); - return tb; -} - -static inline TranslationBlock *tb_find_fast(CPUState *cpu, - TranslationBlock *last_tb, - int tb_exit) +static inline TranslationBlock *tb_find(CPUState *cpu, + TranslationBlock *last_tb, + int tb_exit) { CPUArchState *env = (CPUArchState *)cpu->env_ptr; TranslationBlock *tb; @@ -332,7 +296,31 @@ static inline TranslationBlock *tb_find_fast(CPUState *cpu, tb = atomic_rcu_read(&cpu->tb_jmp_cache[tb_jmp_cache_hash_func(pc)]); if (unlikely(!tb || tb->pc != pc || tb->cs_base != cs_base || tb->flags != flags)) { - tb = tb_find_slow(cpu, pc, cs_base, flags, &have_tb_lock); + tb = tb_find_physical(cpu, pc, cs_base, flags); + if (!tb) { + + /* mmap_lock is needed by tb_gen_code, and mmap_lock must be + * taken outside tb_lock. As system emulation is currently + * single threaded the locks are NOPs. + */ + mmap_lock(); + tb_lock(); + have_tb_lock = true; + + /* There's a chance that our desired tb has been translated while + * taking the locks so we check again inside the lock. + */ + tb = tb_find_physical(cpu, pc, cs_base, flags); + if (!tb) { + /* if no translated code available, then translate it now */ + tb = tb_gen_code(cpu, pc, cs_base, flags, 0); + } + + mmap_unlock(); + } + + /* We add the TB in the virtual pc hash table for the fast lookup */ + atomic_set(&cpu->tb_jmp_cache[tb_jmp_cache_hash_func(pc)], tb); } #ifndef CONFIG_USER_ONLY /* We don't take care of direct jumps when address mapping changes in @@ -437,7 +425,7 @@ static inline bool cpu_handle_exception(CPUState *cpu, int *ret) } else if (replay_has_exception() && cpu->icount_decr.u16.low + cpu->icount_extra == 0) { /* try to cause an exception pending in the log */ - cpu_exec_nocache(cpu, 1, tb_find_fast(cpu, NULL, 0), true); + cpu_exec_nocache(cpu, 1, tb_find(cpu, NULL, 0), true); *ret = -1; return true; #endif @@ -620,7 +608,7 @@ int cpu_exec(CPUState *cpu) atomic_mb_set(&cpu->tb_flushed, false); /* reset before first TB lookup */ for(;;) { cpu_handle_interrupt(cpu, &last_tb); - tb = tb_find_fast(cpu, last_tb, tb_exit); + tb = tb_find(cpu, last_tb, tb_exit); cpu_loop_exec_tb(cpu, tb, &last_tb, &tb_exit, &sc); /* Try to align the host and virtual clocks if the guest is in advance */ -- cgit v1.2.3