[Qemu-devel] [PULL 2/3] target/mips: Implement emulation of nanoMIPS EVA instructions

Aleksandar Markovic posted 3 patches 7 years ago
Only 2 patches received!
[Qemu-devel] [PULL 2/3] target/mips: Implement emulation of nanoMIPS EVA instructions
Posted by Aleksandar Markovic 7 years ago
From: Dimitrije Nikolic <dnikolic@wavecomp.com>

Implement emulation of nanoMIPS EVA instructions. They are all
part of P.LS.E0 instruction pool, or one of its subpools.

Reviewed-by: Stefan Markovic <smarkovic@wavecomp.com>
Signed-off-by: Dimitrije Nikolic <dnikolic@wavecomp.com>
Signed-off-by: Aleksandar Markovic <amarkovic@wavecomp.com>
---
 target/mips/translate.c | 128 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 128 insertions(+)

diff --git a/target/mips/translate.c b/target/mips/translate.c
index 4338b9a..51a5488 100644
--- a/target/mips/translate.c
+++ b/target/mips/translate.c
@@ -2989,6 +2989,35 @@ static inline void check_nms(DisasContext *ctx)
     }
 }
 
+/*
+ * This code generates a "reserved instruction" exception if the
+ * Config5 NMS bit is set, and Config1 DL, Config1 IL, Config2 SL,
+ * Config2 TL, and Config5 L2C are unset.
+ */
+static inline void check_nms_dl_il_sl_tl_l2c(DisasContext *ctx)
+{
+    if (unlikely(ctx->CP0_Config5 & (1 << CP0C5_NMS)) &&
+        !(ctx->CP0_Config1 & (1 << CP0C1_DL)) &&
+        !(ctx->CP0_Config1 & (1 << CP0C1_IL)) &&
+        !(ctx->CP0_Config2 & (1 << CP0C2_SL)) &&
+        !(ctx->CP0_Config2 & (1 << CP0C2_TL)) &&
+        !(ctx->CP0_Config5 & (1 << CP0C5_L2C)))
+    {
+        generate_exception_end(ctx, EXCP_RI);
+    }
+}
+
+/*
+ * This code generates a "reserved instruction" exception if the
+ * Config5 EVA bit is NOT set.
+ */
+static inline void check_eva(DisasContext *ctx)
+{
+    if (unlikely(!(ctx->CP0_Config5 & (1 << CP0C5_EVA)))) {
+        generate_exception_end(ctx, EXCP_RI);
+    }
+}
+
 
 /* Define small wrappers for gen_load_fpr* so that we have a uniform
    calling interface for 32 and 64-bit FPRs.  No sense in changing
@@ -21218,6 +21247,105 @@ static int decode_nanomips_32_48_opc(CPUMIPSState *env, DisasContext *ctx)
                     break;
                 }
                 break;
+            case NM_P_LS_E0:
+                switch (extract32(ctx->opcode, 11, 4)) {
+                case NM_LBE:
+                    check_eva(ctx);
+                    check_cp0_enabled(ctx);
+                    gen_ld(ctx, OPC_LBE, rt, rs, s);
+                    break;
+                case NM_SBE:
+                    check_eva(ctx);
+                    check_cp0_enabled(ctx);
+                    gen_st(ctx, OPC_SBE, rt, rs, s);
+                    break;
+                case NM_LBUE:
+                    check_eva(ctx);
+                    check_cp0_enabled(ctx);
+                    gen_ld(ctx, OPC_LBUE, rt, rs, s);
+                    break;
+                case NM_P_PREFE:
+                    if (rt == 31) {
+                        /* case NM_SYNCIE */
+                        check_eva(ctx);
+                        check_cp0_enabled(ctx);
+                        /* Break the TB to be able to sync copied instructions
+                           immediately */
+                        ctx->base.is_jmp = DISAS_STOP;
+                    } else {
+                        /* case NM_PREFE */
+                        check_eva(ctx);
+                        check_cp0_enabled(ctx);
+                        /* Treat as NOP. */
+                    }
+                    break;
+                case NM_LHE:
+                    check_eva(ctx);
+                    check_cp0_enabled(ctx);
+                    gen_ld(ctx, OPC_LHE, rt, rs, s);
+                    break;
+                case NM_SHE:
+                    check_eva(ctx);
+                    check_cp0_enabled(ctx);
+                    gen_st(ctx, OPC_SHE, rt, rs, s);
+                    break;
+                case NM_LHUE:
+                    check_eva(ctx);
+                    check_cp0_enabled(ctx);
+                    gen_ld(ctx, OPC_LHUE, rt, rs, s);
+                    break;
+                case NM_CACHEE:
+                    check_nms_dl_il_sl_tl_l2c(ctx);
+                    gen_cache_operation(ctx, rt, rs, s);
+                    break;
+                case NM_LWE:
+                    check_eva(ctx);
+                    check_cp0_enabled(ctx);
+                    gen_ld(ctx, OPC_LWE, rt, rs, s);
+                    break;
+                case NM_SWE:
+                    check_eva(ctx);
+                    check_cp0_enabled(ctx);
+                    gen_st(ctx, OPC_SWE, rt, rs, s);
+                    break;
+                case NM_P_LLE:
+                    switch (extract32(ctx->opcode, 2, 2)) {
+                    case NM_LLE:
+                        check_xnp(ctx);
+                        check_eva(ctx);
+                        check_cp0_enabled(ctx);
+                        gen_ld(ctx, OPC_LLE, rt, rs, s);
+                        break;
+                    case NM_LLWPE:
+                        check_xnp(ctx);
+                        check_eva(ctx);
+                        check_cp0_enabled(ctx);
+                        gen_llwp(ctx, rs, 0, rt, extract32(ctx->opcode, 3, 5));
+                    default:
+                        generate_exception_end(ctx, EXCP_RI);
+                        break;
+                    }
+                    break;
+                case NM_P_SCE:
+                    switch (extract32(ctx->opcode, 2, 2)) {
+                    case NM_SCE:
+                        check_xnp(ctx);
+                        check_eva(ctx);
+                        check_cp0_enabled(ctx);
+                        gen_st_cond(ctx, OPC_SCE, rt, rs, s);
+                        break;
+                    case NM_SCWPE:
+                        check_xnp(ctx);
+                        check_eva(ctx);
+                        check_cp0_enabled(ctx);
+                        gen_scwp(ctx, rs, 0, rt, extract32(ctx->opcode, 3, 5));
+                    default:
+                        generate_exception_end(ctx, EXCP_RI);
+                        break;
+                    }
+                    break;
+                }
+                break;
             case NM_P_LS_WM:
             case NM_P_LS_UAWM:
                 check_nms(ctx);
-- 
2.7.4


Re: [Qemu-devel] [PULL 2/3] target/mips: Implement emulation of nanoMIPS EVA instructions
Posted by Peter Maydell 7 years ago
On 25 October 2018 at 21:19, Aleksandar Markovic
<aleksandar.markovic@rt-rk.com> wrote:
> From: Dimitrije Nikolic <dnikolic@wavecomp.com>
>
> Implement emulation of nanoMIPS EVA instructions. They are all
> part of P.LS.E0 instruction pool, or one of its subpools.
>
> Reviewed-by: Stefan Markovic <smarkovic@wavecomp.com>
> Signed-off-by: Dimitrije Nikolic <dnikolic@wavecomp.com>
> Signed-off-by: Aleksandar Markovic <amarkovic@wavecomp.com>
> --

Hi; Coverity points out (CID 1396475) that the switch
cases for NM_LLWPE and NM_SCWPE fall through without
either a 'break' statement or a '/* fall through */' comment:

> +                case NM_P_LLE:
> +                    switch (extract32(ctx->opcode, 2, 2)) {
> +                    case NM_LLE:
> +                        check_xnp(ctx);
> +                        check_eva(ctx);
> +                        check_cp0_enabled(ctx);
> +                        gen_ld(ctx, OPC_LLE, rt, rs, s);
> +                        break;
> +                    case NM_LLWPE:
> +                        check_xnp(ctx);
> +                        check_eva(ctx);
> +                        check_cp0_enabled(ctx);
> +                        gen_llwp(ctx, rs, 0, rt, extract32(ctx->opcode, 3, 5));
> +                    default:
> +                        generate_exception_end(ctx, EXCP_RI);
> +                        break;
> +                    }
> +                    break;
> +                case NM_P_SCE:
> +                    switch (extract32(ctx->opcode, 2, 2)) {
> +                    case NM_SCE:
> +                        check_xnp(ctx);
> +                        check_eva(ctx);
> +                        check_cp0_enabled(ctx);
> +                        gen_st_cond(ctx, OPC_SCE, rt, rs, s);
> +                        break;
> +                    case NM_SCWPE:
> +                        check_xnp(ctx);
> +                        check_eva(ctx);
> +                        check_cp0_enabled(ctx);
> +                        gen_scwp(ctx, rs, 0, rt, extract32(ctx->opcode, 3, 5));
> +                    default:
> +                        generate_exception_end(ctx, EXCP_RI);
> +                        break;
> +                    }
> +                    break;
> +                }
> +                break;
>              case NM_P_LS_WM:
>              case NM_P_LS_UAWM:
>                  check_nms(ctx);

Could you send a patch which adds whichever of the two is correct, please?

thanks
-- PMM

Re: [Qemu-devel] [PULL 2/3] target/mips: Implement emulation of nanoMIPS EVA instructions
Posted by Aleksandar Markovic 7 years ago
> From: Peter Maydell <peter.maydell@linaro.org>
> Sent: Monday, October 29, 2018 11:57 AM
> Subject: Re: [PULL 2/3] target/mips: Implement emulation of nanoMIPS EVA instructions
> 
> On 25 October 2018 at 21:19, Aleksandar Markovic
> <aleksandar.markovic@rt-rk.com> wrote:
> > From: Dimitrije Nikolic <dnikolic@wavecomp.com>
> >
> > Implement emulation of nanoMIPS EVA instructions. They are all
> > part of P.LS.E0 instruction pool, or one of its subpools.
> >
> > Reviewed-by: Stefan Markovic <smarkovic@wavecomp.com>
> > Signed-off-by: Dimitrije Nikolic <dnikolic@wavecomp.com>
> > Signed-off-by: Aleksandar Markovic <amarkovic@wavecomp.com>
> > --
> 
> Hi; Coverity points out (CID 1396475) that the switch
> cases for NM_LLWPE and NM_SCWPE fall through without
> either a 'break' statement or a '/* fall through */' comment:
> 
> > +                case NM_P_LLE:
> > +                    switch (extract32(ctx->opcode, 2, 2)) {
> > +                    case NM_LLE:
> > +                        check_xnp(ctx);
> > +                        check_eva(ctx);
> > +                        check_cp0_enabled(ctx);
> > +                        gen_ld(ctx, OPC_LLE, rt, rs, s);
> > +                        break;
> > +                    case NM_LLWPE:
> > +                        check_xnp(ctx);
> > +                        check_eva(ctx);
> > +                        check_cp0_enabled(ctx);
> > +                        gen_llwp(ctx, rs, 0, rt, extract32(ctx->opcode, 3, 5));
> > +                    default:
> > +                        generate_exception_end(ctx, EXCP_RI);
> > +                        break;
> > +                    }
> > +                    break;
> > +                case NM_P_SCE:
> > +                    switch (extract32(ctx->opcode, 2, 2)) {
> > +                    case NM_SCE:
> > +                        check_xnp(ctx);
> > +                        check_eva(ctx);
> > +                        check_cp0_enabled(ctx);
> > +                        gen_st_cond(ctx, OPC_SCE, rt, rs, s);
> > +                        break;
> > +                    case NM_SCWPE:
> > +                        check_xnp(ctx);
> > +                        check_eva(ctx);
> > +                        check_cp0_enabled(ctx);
> > +                        gen_scwp(ctx, rs, 0, rt, extract32(ctx->opcode, 3, 5));
> > +                    default:
> > +                        generate_exception_end(ctx, EXCP_RI);
> > +                        break;
> > +                    }
> > +                    break;
> > +                }
> > +                break;
> >              case NM_P_LS_WM:
> >              case NM_P_LS_UAWM:
> >                  check_nms(ctx);
> 
> Could you send a patch which adds whichever of the two is correct, please?
>

Sure. 'break' is missing in both cases.

Thanks,
Aleksandar

> thanks
> -- PMM