[Qemu-devel] [PATCH v2 7/7] target/mips: Implement emulation of nanoMIPS EVA instructions

[Aleksandar Markovic <aleksandar.markovic@rt-rk.com>]

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.

Signed-off-by: Aleksandar Markovic <amarkovic@wavecomp.com>
---
 target/mips/translate.c | 79 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 79 insertions(+)

diff --git a/target/mips/translate.c b/target/mips/translate.c
index b0b2f40..3adf31f 100644
--- a/target/mips/translate.c
+++ b/target/mips/translate.c
@@ -1979,6 +1979,17 @@ static inline void check_nms(DisasContext *ctx)
     }
 }
 
+/*
+ * 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
@@ -20011,6 +20022,74 @@ static int decode_nanomips_32_48_opc(CPUMIPSState *env, DisasContext *ctx)
                     break;
                 }
                 break;
+            case NM_P_LS_E0:
+                check_eva(ctx);
+                switch (extract32(ctx->opcode, 11, 4)) {
+                case NM_LBE:
+                    gen_ld(ctx, OPC_LBE, rt, rs, s);
+                    break;
+                case NM_SBE:
+                    gen_st(ctx, OPC_SBE, rt, rs, s);
+                    break;
+                case NM_LBUE:
+                    gen_ld(ctx, OPC_LBUE, rt, rs, s);
+                    break;
+                case NM_P_PREFE:
+                    if (rt == 31) {
+                        /* SYNCIE */
+                        /* Break the TB to be able to sync copied instructions
+                           immediately */
+                        ctx->base.is_jmp = DISAS_STOP;
+                    } else {
+                        /* PREF */
+                        /* Treat as NOP. */
+                    }
+                    break;
+                case NM_LHE:
+                    gen_ld(ctx, OPC_LHE, rt, rs, s);
+                    break;
+                case NM_SHE:
+                    gen_st(ctx, OPC_SHE, rt, rs, s);
+                    break;
+                case NM_LHUE:
+                    gen_ld(ctx, OPC_LHUE, rt, rs, s);
+                    break;
+                case NM_CACHEE:
+                    /* Treat as no-op */
+                    if (ctx->hflags & MIPS_HFLAG_ITC_CACHE) {
+                        gen_cache_operation(ctx, rt, rs, s);
+                    }
+                    break;
+                case NM_LWE:
+                    gen_ld(ctx, OPC_LWE, rt, rs, s);
+                    break;
+                case NM_SWE:
+                    gen_st(ctx, OPC_SWE, rt, rs, s);
+                    break;
+                case NM_P_LLE:
+                    switch (extract32(ctx->opcode, 2, 2)) {
+                    case NM_LL:
+                        gen_ld(ctx, OPC_LLE, rt, rs, s);
+                        break;
+                    case NM_LLWP:
+                    default:
+                        generate_exception_end(ctx, EXCP_RI);
+                        break;
+                    }
+                    break;
+                case NM_P_SCE:
+                    switch (extract32(ctx->opcode, 2, 2)) {
+                    case NM_SC:
+                        gen_st_cond(ctx, OPC_SCE, rt, rs, s);
+                        break;
+                    case NM_SCWP:
+                    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