| Message ID | 20170710192128.9048-5-alex.bennee@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | arm: fixes for eret, isb and DISAS_UPDATE handling | expand |
On 07/10/2017 09:21 AM, Alex Bennée wrote: > - s->is_jmp = DISAS_UPDATE; > + gen_a64_set_pc_im(s->pc); > + s->is_jmp = DISAS_JUMP; Better would be gen_goto_tb. The destination is known, so there's no need to go through lookup_and_goto_ptr. You still get the icount_decr check at the start of the linked TB, which is what you're looking for. Interesting that a64's gen_goto_tb sets is_jmp, but a32 does not... r~
Richard Henderson <rth@twiddle.net> writes: > On 07/10/2017 09:21 AM, Alex Bennée wrote: >> - s->is_jmp = DISAS_UPDATE; >> + gen_a64_set_pc_im(s->pc); >> + s->is_jmp = DISAS_JUMP; > > Better would be gen_goto_tb. The destination is known, so there's no > need to go through lookup_and_goto_ptr. You still get the icount_decr > check at the start of the linked TB, which is what you're looking for. > > Interesting that a64's gen_goto_tb sets is_jmp, but a32 does not... Hmm the only caller that is not already in the exit path sets it. Maybe I should push the s->is_jmp to the a32 gen_goto_tb? I can then do the same in both. -- Alex Bennée
On 07/10/2017 10:27 PM, Alex Bennée wrote: > > Richard Henderson <rth@twiddle.net> writes: > >> On 07/10/2017 09:21 AM, Alex Bennée wrote: >>> - s->is_jmp = DISAS_UPDATE; >>> + gen_a64_set_pc_im(s->pc); >>> + s->is_jmp = DISAS_JUMP; >> >> Better would be gen_goto_tb. The destination is known, so there's no >> need to go through lookup_and_goto_ptr. You still get the icount_decr >> check at the start of the linked TB, which is what you're looking for. >> >> Interesting that a64's gen_goto_tb sets is_jmp, but a32 does not... > > Hmm the only caller that is not already in the exit path sets it. Maybe > I should push the s->is_jmp to the a32 gen_goto_tb? I can then do the > same in both. Sounds reasonable. r~
diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c index 66139b6046..ad46d84efb 100644 --- a/target/arm/translate-a64.c +++ b/target/arm/translate-a64.c @@ -1393,7 +1393,8 @@ static void handle_sync(DisasContext *s, uint32_t insn, * a self-modified code correctly and also to take * any pending interrupts immediately. */ - s->is_jmp = DISAS_UPDATE; + gen_a64_set_pc_im(s->pc); + s->is_jmp = DISAS_JUMP; return; default: unallocated_encoding(s); diff --git a/target/arm/translate.c b/target/arm/translate.c index ccc4768b2e..94aa4bbb4d 100644 --- a/target/arm/translate.c +++ b/target/arm/translate.c @@ -1201,6 +1201,15 @@ static inline void gen_lookup_tb(DisasContext *s) s->is_jmp = DISAS_EXIT; } +/* End the current block and force a TB lookup. We may chain to the + * next TB but exit_req will be immediately checked so we will exit to + * the main loop if we need to */ +static inline void gen_jump_tb(DisasContext *s) +{ + tcg_gen_movi_i32(cpu_R[15], s->pc & ~1); + s->is_jmp = DISAS_JUMP; +} + static inline void gen_hlt(DisasContext *s, int imm) { /* HLT. This has two purposes. @@ -8165,7 +8174,7 @@ static void disas_arm_insn(DisasContext *s, unsigned int insn) * self-modifying code correctly and also to take * any pending interrupts immediately. */ - gen_lookup_tb(s); + gen_jump_tb(s); return; default: goto illegal_op; @@ -10558,7 +10567,7 @@ static int disas_thumb2_insn(CPUARMState *env, DisasContext *s, uint16_t insn_hw * and also to take any pending interrupts * immediately. */ - gen_lookup_tb(s); + gen_jump_tb(s); break; default: goto illegal_op;
While an ISB will ensure any raised IRQs happen on the next instruction it doesn't cause any to get raised by itself. We can therefor use DISAS_JUMP for ISB instructions and rely on the exit_request check at the top of each TB to deal with exiting if needed. Signed-off-by: Alex Bennée <alex.bennee@linaro.org> --- target/arm/translate-a64.c | 3 ++- target/arm/translate.c | 13 +++++++++++-- 2 files changed, 13 insertions(+), 3 deletions(-) -- 2.13.0