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-rw-r--r--target/arm/translate.c67
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;
}