Commit ac03ee53 authored by Emilio G. Cota's avatar Emilio G. Cota Committed by Richard Henderson
Browse files

cpu-exec: lookup/generate TB outside exclusive region during step_atomic 



Now that all code generation has been converted to check CF_PARALLEL, we can
generate !CF_PARALLEL code without having yet set !parallel_cpus --
and therefore without having to be in the exclusive region during
cpu_exec_step_atomic.

While at it, merge cpu_exec_step into cpu_exec_step_atomic.

Reviewed-by: default avatarRichard Henderson <rth@twiddle.net>
Signed-off-by: default avatarEmilio G. Cota <cota@braap.org>
Signed-off-by: default avatarRichard Henderson <richard.henderson@linaro.org>
parent e82d5a24

accel/tcg/cpu-exec.c

+14 −16
Original line number Diff line number Diff line
@@ -223,30 +223,40 @@ static void cpu_exec_nocache(CPUState *cpu, int max_cycles, 
}

#endif



static void cpu_exec_step(CPUState *cpu)

void cpu_exec_step_atomic(CPUState *cpu)

{

    CPUClass *cc = CPU_GET_CLASS(cpu);

    TranslationBlock *tb;

    target_ulong cs_base, pc;

    uint32_t flags;

    uint32_t cflags = 1 | CF_IGNORE_ICOUNT;

    uint32_t cf_mask = cflags & CF_HASH_MASK;



    if (sigsetjmp(cpu->jmp_env, 0) == 0) {

        tb = tb_lookup__cpu_state(cpu, &pc, &cs_base, &flags,

                                  cflags & CF_HASH_MASK);

        tb = tb_lookup__cpu_state(cpu, &pc, &cs_base, &flags, cf_mask);

        if (tb == NULL) {

            mmap_lock();

            tb_lock();

            tb = tb_htable_lookup(cpu, pc, cs_base, flags, cf_mask);

            if (likely(tb == NULL)) {

                tb = tb_gen_code(cpu, pc, cs_base, flags, cflags);

            }

            tb_unlock();

            mmap_unlock();

        }



        start_exclusive();



        /* Since we got here, we know that parallel_cpus must be true.  */

        parallel_cpus = false;

        cc->cpu_exec_enter(cpu);

        /* execute the generated code */

        trace_exec_tb(tb, pc);

        cpu_tb_exec(cpu, tb);

        cc->cpu_exec_exit(cpu);

        parallel_cpus = true;



        end_exclusive();

    } else {

        /* We may have exited due to another problem here, so we need

         * to reset any tb_locks we may have taken but didn't release.
@@ -260,18 +270,6 @@ static void cpu_exec_step(CPUState *cpu) 
    }

}



void cpu_exec_step_atomic(CPUState *cpu)

{

    start_exclusive();



    /* Since we got here, we know that parallel_cpus must be true.  */

    parallel_cpus = false;

    cpu_exec_step(cpu);

    parallel_cpus = true;



    end_exclusive();

}



struct tb_desc {

    target_ulong pc;

    target_ulong cs_base;