Re: [Qemu-devel] [PATCH 03/13] target/ppc: Use atomic store for STQ

[David Gibson <david@gibson.dropbear.id.au>]

[-- Attachment #1: Type: text/plain, Size: 5158 bytes --]

On Tue, Jun 26, 2018 at 09:19:11AM -0700, Richard Henderson wrote:
> Section 1.4 of the Power ISA v3.0B states that this insn is
> single-copy atomic.  As we cannot (yet) issue 128-bit loads
> within TCG, use the generic helpers provided.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Applied to ppc-for-3.0, thanks.

> ---
>  target/ppc/helper.h     |  4 ++++
>  target/ppc/mem_helper.c | 14 ++++++++++++++
>  target/ppc/translate.c  | 35 +++++++++++++++++++++++++++--------
>  3 files changed, 45 insertions(+), 8 deletions(-)
> 
> diff --git a/target/ppc/helper.h b/target/ppc/helper.h
> index 3f451a5d7e..cbc1228570 100644
> --- a/target/ppc/helper.h
> +++ b/target/ppc/helper.h
> @@ -803,4 +803,8 @@ DEF_HELPER_FLAGS_1(fixup_thrm, TCG_CALL_NO_RWG, void, env)
>  #if defined(TARGET_PPC64) && defined(CONFIG_ATOMIC128)
>  DEF_HELPER_FLAGS_3(lq_le_parallel, TCG_CALL_NO_WG, i64, env, tl, i32)
>  DEF_HELPER_FLAGS_3(lq_be_parallel, TCG_CALL_NO_WG, i64, env, tl, i32)
> +DEF_HELPER_FLAGS_5(stq_le_parallel, TCG_CALL_NO_WG,
> +                   void, env, tl, i64, i64, i32)
> +DEF_HELPER_FLAGS_5(stq_be_parallel, TCG_CALL_NO_WG,
> +                   void, env, tl, i64, i64, i32)
>  #endif
> diff --git a/target/ppc/mem_helper.c b/target/ppc/mem_helper.c
> index 44a8f3445a..57e301edc3 100644
> --- a/target/ppc/mem_helper.c
> +++ b/target/ppc/mem_helper.c
> @@ -231,6 +231,20 @@ uint64_t helper_lq_be_parallel(CPUPPCState *env, target_ulong addr,
>      env->retxh = int128_gethi(ret);
>      return int128_getlo(ret);
>  }
> +
> +void helper_stq_le_parallel(CPUPPCState *env, target_ulong addr,
> +                            uint64_t lo, uint64_t hi, uint32_t opidx)
> +{
> +    Int128 val = int128_make128(lo, hi);
> +    helper_atomic_sto_le_mmu(env, addr, val, opidx, GETPC());
> +}
> +
> +void helper_stq_be_parallel(CPUPPCState *env, target_ulong addr,
> +                            uint64_t lo, uint64_t hi, uint32_t opidx)
> +{
> +    Int128 val = int128_make128(lo, hi);
> +    helper_atomic_sto_be_mmu(env, addr, val, opidx, GETPC());
> +}
>  #endif
>  
>  /*****************************************************************************/
> diff --git a/target/ppc/translate.c b/target/ppc/translate.c
> index 0923cc24e3..3d63a62269 100644
> --- a/target/ppc/translate.c
> +++ b/target/ppc/translate.c
> @@ -2760,6 +2760,7 @@ static void gen_std(DisasContext *ctx)
>      if ((ctx->opcode & 0x3) == 0x2) { /* stq */
>          bool legal_in_user_mode = (ctx->insns_flags2 & PPC2_LSQ_ISA207) != 0;
>          bool le_is_supported = (ctx->insns_flags2 & PPC2_LSQ_ISA207) != 0;
> +        TCGv hi, lo;
>  
>          if (!(ctx->insns_flags & PPC_64BX)) {
>              gen_inval_exception(ctx, POWERPC_EXCP_INVAL_INVAL);
> @@ -2783,20 +2784,38 @@ static void gen_std(DisasContext *ctx)
>          EA = tcg_temp_new();
>          gen_addr_imm_index(ctx, EA, 0x03);
>  
> -        /* We only need to swap high and low halves. gen_qemu_st64_i64 does
> -           necessary 64-bit byteswap already. */
> -        if (unlikely(ctx->le_mode)) {
> -            gen_qemu_st64_i64(ctx, cpu_gpr[rs + 1], EA);
> +        /* Note that the low part is always in RS+1, even in LE mode.  */
> +        lo = cpu_gpr[rs + 1];
> +        hi = cpu_gpr[rs];
> +
> +        if (tb_cflags(ctx->base.tb) & CF_PARALLEL) {
> +#ifdef CONFIG_ATOMIC128
> +            TCGv_i32 oi = tcg_temp_new_i32();
> +            if (ctx->le_mode) {
> +                tcg_gen_movi_i32(oi, make_memop_idx(MO_LEQ, ctx->mem_idx));
> +                gen_helper_stq_le_parallel(cpu_env, EA, lo, hi, oi);
> +            } else {
> +                tcg_gen_movi_i32(oi, make_memop_idx(MO_BEQ, ctx->mem_idx));
> +                gen_helper_stq_be_parallel(cpu_env, EA, lo, hi, oi);
> +            }
> +            tcg_temp_free_i32(oi);
> +#else
> +            /* Restart with exclusive lock.  */
> +            gen_helper_exit_atomic(cpu_env);
> +            ctx->base.is_jmp = DISAS_NORETURN;
> +#endif
> +        } else if (ctx->le_mode) {
> +            tcg_gen_qemu_st_i64(lo, EA, ctx->mem_idx, MO_LEQ);
>              gen_addr_add(ctx, EA, EA, 8);
> -            gen_qemu_st64_i64(ctx, cpu_gpr[rs], EA);
> +            tcg_gen_qemu_st_i64(hi, EA, ctx->mem_idx, MO_LEQ);
>          } else {
> -            gen_qemu_st64_i64(ctx, cpu_gpr[rs], EA);
> +            tcg_gen_qemu_st_i64(hi, EA, ctx->mem_idx, MO_BEQ);
>              gen_addr_add(ctx, EA, EA, 8);
> -            gen_qemu_st64_i64(ctx, cpu_gpr[rs + 1], EA);
> +            tcg_gen_qemu_st_i64(lo, EA, ctx->mem_idx, MO_BEQ);
>          }
>          tcg_temp_free(EA);
>      } else {
> -        /* std / stdu*/
> +        /* std / stdu */
>          if (Rc(ctx->opcode)) {
>              if (unlikely(rA(ctx->opcode) == 0)) {
>                  gen_inval_exception(ctx, POWERPC_EXCP_INVAL_INVAL);

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]