From 1212c9b73cb96995dd77d60ac24f1bb90993f62a Mon Sep 17 00:00:00 2001 From: Stefano Stabellini Date: Mon, 5 Mar 2018 11:21:40 -0500 Subject: [PATCH] fix WFI/WFE length in syndrome register WFI/E are often, but not always, 4 bytes long. When they are, we need to set ARM_EL_IL_SHIFT in the syndrome register. Pass the instruction length to HELPER(wfi), use it to decrement pc appropriately and to pass an is_16bit flag to syn_wfx, which sets ARM_EL_IL_SHIFT if needed. Set dc->insn in both arm_tr_translate_insn and thumb_tr_translate_insn. Backports commit 58803318e5a546b2eb0efd7a053ed36b6c29ae6f from qemu --- qemu/target/arm/helper.h | 2 +- qemu/target/arm/internals.h | 3 ++- qemu/target/arm/op_helper.c | 7 ++++--- qemu/target/arm/psci.c | 2 +- qemu/target/arm/translate-a64.c | 7 ++++++- qemu/target/arm/translate.c | 10 +++++++++- 6 files changed, 23 insertions(+), 8 deletions(-) diff --git a/qemu/target/arm/helper.h b/qemu/target/arm/helper.h index 5887cd70..26146d99 100644 --- a/qemu/target/arm/helper.h +++ b/qemu/target/arm/helper.h @@ -50,7 +50,7 @@ DEF_HELPER_FLAGS_3(sel_flags, TCG_CALL_NO_RWG_SE, DEF_HELPER_2(exception_internal, void, env, i32) DEF_HELPER_4(exception_with_syndrome, void, env, i32, i32, i32) DEF_HELPER_1(setend, void, env) -DEF_HELPER_1(wfi, void, env) +DEF_HELPER_2(wfi, void, env, i32) DEF_HELPER_1(wfe, void, env) DEF_HELPER_1(yield, void, env) DEF_HELPER_1(pre_hvc, void, env) diff --git a/qemu/target/arm/internals.h b/qemu/target/arm/internals.h index 527b9236..b112021e 100644 --- a/qemu/target/arm/internals.h +++ b/qemu/target/arm/internals.h @@ -430,9 +430,10 @@ static inline uint32_t syn_breakpoint(int same_el) | ARM_EL_IL | 0x22; } -static inline uint32_t syn_wfx(int cv, int cond, int ti) +static inline uint32_t syn_wfx(int cv, int cond, int ti, bool is_16bit) { return (EC_WFX_TRAP << ARM_EL_EC_SHIFT) | + (is_16bit ? 0 : (1 << ARM_EL_IL_SHIFT)) | (cv << 24) | (cond << 20) | ti; } diff --git a/qemu/target/arm/op_helper.c b/qemu/target/arm/op_helper.c index dfa66d20..1f7f3269 100644 --- a/qemu/target/arm/op_helper.c +++ b/qemu/target/arm/op_helper.c @@ -462,7 +462,7 @@ static inline int check_wfx_trap(CPUARMState *env, bool is_wfe) return 0; } -void HELPER(wfi)(CPUARMState *env) +void HELPER(wfi)(CPUARMState *env, uint32_t insn_len) { CPUState *cs = CPU(arm_env_get_cpu(env)); int target_el = check_wfx_trap(env, false); @@ -475,8 +475,9 @@ void HELPER(wfi)(CPUARMState *env) } if (target_el) { - env->pc -= 4; - raise_exception(env, EXCP_UDEF, syn_wfx(1, 0xe, 0), target_el); + env->pc -= insn_len; + raise_exception(env, EXCP_UDEF, syn_wfx(1, 0xe, 0, insn_len == 2), + target_el); } cs->exception_index = EXCP_HLT; diff --git a/qemu/target/arm/psci.c b/qemu/target/arm/psci.c index cff08d27..b6783888 100644 --- a/qemu/target/arm/psci.c +++ b/qemu/target/arm/psci.c @@ -189,7 +189,7 @@ void arm_handle_psci_call(ARMCPU *cpu) } else { env->regs[0] = 0; } - helper_wfi(env); + helper_wfi(env, 4); break; case QEMU_PSCI_0_1_FN_MIGRATE: case QEMU_PSCI_0_2_FN_MIGRATE: diff --git a/qemu/target/arm/translate-a64.c b/qemu/target/arm/translate-a64.c index 0304289d..1878cf9e 100644 --- a/qemu/target/arm/translate-a64.c +++ b/qemu/target/arm/translate-a64.c @@ -11630,17 +11630,22 @@ static void aarch64_tr_tb_stop(DisasContextBase *dcbase, CPUState *cpu) gen_helper_yield(tcg_ctx, tcg_ctx->cpu_env); break; case DISAS_WFI: + { /* This is a special case because we don't want to just halt the CPU * if trying to debug across a WFI. */ + TCGv_i32 tmp = tcg_const_i32(tcg_ctx, 4); + gen_a64_set_pc_im(dc, dc->pc); - gen_helper_wfi(tcg_ctx, tcg_ctx->cpu_env); + gen_helper_wfi(tcg_ctx, tcg_ctx->cpu_env, tmp); + tcg_temp_free_i32(tcg_ctx, tmp); /* The helper doesn't necessarily throw an exception, but we * must go back to the main loop to check for interrupts anyway. */ tcg_gen_exit_tb(tcg_ctx, 0); break; } + } } /* Functions above can change dc->pc, so re-align db->pc_next */ diff --git a/qemu/target/arm/translate.c b/qemu/target/arm/translate.c index 46c60c59..6e49602b 100644 --- a/qemu/target/arm/translate.c +++ b/qemu/target/arm/translate.c @@ -12390,6 +12390,7 @@ static void arm_tr_translate_insn(DisasContextBase *dcbase, CPUState *cpu) } insn = arm_ldl_code(env, dc->pc, dc->sctlr_b); + dc->insn = insn; dc->pc += 4; disas_arm_insn(dc, insn); @@ -12420,6 +12421,7 @@ static void thumb_tr_translate_insn(DisasContextBase *dcbase, CPUState *cpu) insn = insn << 16 | insn2; dc->pc += 2; } + dc->insn = insn; if (dc->condexec_mask && !thumb_insn_is_unconditional(dc, insn)) { uint32_t cond = dc->condexec_cond; @@ -12547,12 +12549,18 @@ static void arm_tr_tb_stop(DisasContextBase *dcbase, CPUState *cpu) /* nothing more to generate */ break; case DISAS_WFI: - gen_helper_wfi(tcg_ctx, tcg_ctx->cpu_env); + { + TCGv_i32 tmp = tcg_const_i32(tcg_ctx, (dc->thumb && + !(dc->insn & (1U << 31))) ? 2 : 4); + gen_helper_wfi(tcg_ctx, tcg_ctx->cpu_env, tmp); + tcg_temp_free_i32(tcg_ctx, tmp); + /* The helper doesn't necessarily throw an exception, but we * must go back to the main loop to check for interrupts anyway. */ tcg_gen_exit_tb(tcg_ctx, 0); break; + } case DISAS_WFE: gen_helper_wfe(tcg_ctx, tcg_ctx->cpu_env); break;