Re: [Qemu-devel] [Qemu-ppc] [V2 PATCH 9/9] target-ppc: Add Store Quadword Conditional

[Alexander Graf <agraf@suse.de>]

On 31.01.2014, at 20:34, Tom Musta <tommusta@gmail.com> wrote:

> This patch adds the Store Quadword Conditionl (stqcx.) instruction
> which is introduced in Power ISA 2.07.
> 
> Signed-off-by: Tom Musta <tommusta@gmail.com>
> ---
> V2: Updated linux-user/main.c to use the newly added reserve_val2.
> 
> linux-user/main.c      |   18 +++++++++++++++++-
> target-ppc/translate.c |   21 +++++++++++++++++++++
> 2 files changed, 38 insertions(+), 1 deletions(-)
> 
> diff --git a/linux-user/main.c b/linux-user/main.c
> index cabc9e1..6330427 100644
> --- a/linux-user/main.c
> +++ b/linux-user/main.c
> @@ -1490,7 +1490,7 @@ static int do_store_exclusive(CPUPPCState *env)
> {
>     target_ulong addr;
>     target_ulong page_addr;
> -    target_ulong val;
> +    target_ulong val, val2;
>     int flags;
>     int segv = 0;
> 
> @@ -1513,6 +1513,13 @@ static int do_store_exclusive(CPUPPCState *env)
>             case 4: segv = get_user_u32(val, addr); break;
> #if defined(TARGET_PPC64)
>             case 8: segv = get_user_u64(val, addr); break;
> +            case 16: {
> +                segv = get_user_u64(val, addr);
> +                if (!segv) {
> +                    segv = get_user_u64(val, addr + 8);
> +                }
> +                break;
> +            }

Does this work? After this val contains reserve_val2, but further down that one gets checked against reserve_val so the comparison is broken, no?


Alex

> #endif
>             default: abort();
>             }
> @@ -1524,6 +1531,15 @@ static int do_store_exclusive(CPUPPCState *env)
>                 case 4: segv = put_user_u32(val, addr); break;
> #if defined(TARGET_PPC64)
>                 case 8: segv = put_user_u64(val, addr); break;
> +                case 16: {
> +                    if (val2 == env->reserve_val2) {
> +                        segv = put_user_u64(val, addr);
> +                        if (!segv) {
> +                            segv = put_user_u64(val2, addr + 8);
> +                        }
> +                    }
> +                    break;
> +                }
> #endif
>                 default: abort();
>                 }
> diff --git a/target-ppc/translate.c b/target-ppc/translate.c
> index 8257dea..c883680 100644
> --- a/target-ppc/translate.c
> +++ b/target-ppc/translate.c
> @@ -3329,6 +3329,20 @@ static void gen_conditional_store(DisasContext *ctx, TCGv EA,
>         gen_qemu_st32(ctx, cpu_gpr[reg], EA);
>     } else if (size == 2) {
>         gen_qemu_st16(ctx, cpu_gpr[reg], EA);
> +#if defined(TARGET_PPC64)
> +    } else if (size == 16) {
> +        TCGv gpr1, gpr2;
> +        if (unlikely(ctx->le_mode)) {
> +            gpr1 = cpu_gpr[reg+1];
> +            gpr2 = cpu_gpr[reg];
> +        } else {
> +            gpr1 = cpu_gpr[reg];
> +            gpr2 = cpu_gpr[reg+1];
> +        }
> +        gen_qemu_st64(ctx, gpr1, EA);
> +        gen_addr_add(ctx, EA, EA, 8);
> +        gen_qemu_st64(ctx, gpr2, EA);
> +#endif
>     } else {
>         gen_qemu_st8(ctx, cpu_gpr[reg], EA);
>     }
> @@ -3341,6 +3355,11 @@ static void gen_conditional_store(DisasContext *ctx, TCGv EA,
> static void gen_##name(DisasContext *ctx)                 \
> {                                                         \
>     TCGv t0;                                              \
> +    if (unlikely((len == 16) && (rD(ctx->opcode) & 1))) { \
> +        gen_inval_exception(ctx,                          \
> +                            POWERPC_EXCP_INVAL_INVAL);    \
> +        return;                                           \
> +    }                                                     \
>     gen_set_access_type(ctx, ACCESS_RES);                 \
>     t0 = tcg_temp_local_new();                            \
>     gen_addr_reg_index(ctx, t0);                          \
> @@ -3395,6 +3414,7 @@ static void gen_lqarx(DisasContext *ctx)
> 
> /* stdcx. */
> STCX(stdcx_, 8);
> +STCX(stqcx_, 16);
> #endif /* defined(TARGET_PPC64) */
> 
> /* sync */
> @@ -9634,6 +9654,7 @@ GEN_HANDLER2(stwcx_, "stwcx.", 0x1F, 0x16, 0x04, 0x00000000, PPC_RES),
> GEN_HANDLER(ldarx, 0x1F, 0x14, 0x02, 0x00000000, PPC_64B),
> GEN_HANDLER_E(lqarx, 0x1F, 0x14, 0x08, 0, PPC_NONE, PPC2_LSQ_ISA207),
> GEN_HANDLER2(stdcx_, "stdcx.", 0x1F, 0x16, 0x06, 0x00000000, PPC_64B),
> +GEN_HANDLER_E(stqcx_, 0x1F, 0x16, 0x05, 0, PPC_NONE, PPC2_LSQ_ISA207),
> #endif
> GEN_HANDLER(sync, 0x1F, 0x16, 0x12, 0x039FF801, PPC_MEM_SYNC),
> GEN_HANDLER(wait, 0x1F, 0x1E, 0x01, 0x03FFF801, PPC_WAIT),
> -- 
> 1.7.1
> 
>