diff options
Diffstat (limited to 'target')
-rw-r--r-- | target/arm/translate.c | 67 |
1 files changed, 24 insertions, 43 deletions
diff --git a/target/arm/translate.c b/target/arm/translate.c index 69092c12c3..d076c962ea 100644 --- a/target/arm/translate.c +++ b/target/arm/translate.c @@ -3061,46 +3061,6 @@ static void gen_exception_return(DisasContext *s, TCGv_i32 pc) gen_rfe(s, pc, load_cpu_field(spsr)); } -/* - * For WFI we will halt the vCPU until an IRQ. For WFE and YIELD we - * only call the helper when running single threaded TCG code to ensure - * the next round-robin scheduled vCPU gets a crack. In MTTCG mode we - * just skip this instruction. Currently the SEV/SEVL instructions - * which are *one* of many ways to wake the CPU from WFE are not - * implemented so we can't sleep like WFI does. - */ -static void gen_nop_hint(DisasContext *s, int val) -{ - switch (val) { - /* When running in MTTCG we don't generate jumps to the yield and - * WFE helpers as it won't affect the scheduling of other vCPUs. - * If we wanted to more completely model WFE/SEV so we don't busy - * spin unnecessarily we would need to do something more involved. - */ - case 1: /* yield */ - if (!(tb_cflags(s->base.tb) & CF_PARALLEL)) { - gen_set_pc_im(s, s->base.pc_next); - s->base.is_jmp = DISAS_YIELD; - } - break; - case 3: /* wfi */ - gen_set_pc_im(s, s->base.pc_next); - s->base.is_jmp = DISAS_WFI; - break; - case 2: /* wfe */ - if (!(tb_cflags(s->base.tb) & CF_PARALLEL)) { - gen_set_pc_im(s, s->base.pc_next); - s->base.is_jmp = DISAS_WFE; - } - break; - case 4: /* sev */ - case 5: /* sevl */ - /* TODO: Implement SEV, SEVL and WFE. May help SMP performance. */ - default: /* nop */ - break; - } -} - #define CPU_V001 cpu_V0, cpu_V0, cpu_V1 static inline void gen_neon_add(int size, TCGv_i32 t0, TCGv_i32 t1) @@ -8194,19 +8154,40 @@ DO_SMLAWX(SMLAWT, 1, 1) static bool trans_YIELD(DisasContext *s, arg_YIELD *a) { - gen_nop_hint(s, 1); + /* + * When running single-threaded TCG code, use the helper to ensure that + * the next round-robin scheduled vCPU gets a crack. When running in + * MTTCG we don't generate jumps to the helper as it won't affect the + * scheduling of other vCPUs. + */ + if (!(tb_cflags(s->base.tb) & CF_PARALLEL)) { + gen_set_pc_im(s, s->base.pc_next); + s->base.is_jmp = DISAS_YIELD; + } return true; } static bool trans_WFE(DisasContext *s, arg_WFE *a) { - gen_nop_hint(s, 2); + /* + * When running single-threaded TCG code, use the helper to ensure that + * the next round-robin scheduled vCPU gets a crack. In MTTCG mode we + * just skip this instruction. Currently the SEV/SEVL instructions, + * which are *one* of many ways to wake the CPU from WFE, are not + * implemented so we can't sleep like WFI does. + */ + if (!(tb_cflags(s->base.tb) & CF_PARALLEL)) { + gen_set_pc_im(s, s->base.pc_next); + s->base.is_jmp = DISAS_WFE; + } return true; } static bool trans_WFI(DisasContext *s, arg_WFI *a) { - gen_nop_hint(s, 3); + /* For WFI, halt the vCPU until an IRQ. */ + gen_set_pc_im(s, s->base.pc_next); + s->base.is_jmp = DISAS_WFI; return true; } |