From aea14095ea91f792ee43ee52fe6032cd8cdd7190 Mon Sep 17 00:00:00 2001
From: Leon Alrae <leon.alrae@imgtec.com>
Date: Mon, 7 Jul 2014 11:24:01 +0100
Subject: target-mips: add BadInstr and BadInstrP support

BadInstr Register (CP0 Register 8, Select 1)
The BadInstr register is a read-only register that capture the most recent
instruction which caused an exception.

BadInstrP Register (CP0 Register 8, Select 2)
The BadInstrP register contains the prior branch instruction, when the
faulting instruction is in a branch delay slot.

Using error_code to indicate whether AdEL or TLBL was triggered during
instruction fetch, in this case BadInstr is not updated as valid instruction
word is not available.

Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
Reviewed-by: Yongbok Kim <yongbok.kim@imgtec.com>
---
 target-mips/translate.c | 76 +++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 70 insertions(+), 6 deletions(-)

(limited to 'target-mips/translate.c')

diff --git a/target-mips/translate.c b/target-mips/translate.c
index fdb61be8d3..3e6e99026a 100644
--- a/target-mips/translate.c
+++ b/target-mips/translate.c
@@ -1175,6 +1175,8 @@ typedef struct DisasContext {
     int kscrexist;
     bool rxi;
     int ie;
+    bool bi;
+    bool bp;
 } DisasContext;
 
 enum {
@@ -4828,9 +4830,25 @@ static void gen_mfc0(DisasContext *ctx, TCGv arg, int reg, int sel)
             tcg_gen_ext32s_tl(arg, arg);
             rn = "BadVAddr";
             break;
+        case 1:
+            if (ctx->bi) {
+                gen_mfc0_load32(arg, offsetof(CPUMIPSState, CP0_BadInstr));
+                rn = "BadInstr";
+            } else {
+                gen_mfc0_unimplemented(ctx, arg);
+            }
+            break;
+        case 2:
+            if (ctx->bp) {
+                gen_mfc0_load32(arg, offsetof(CPUMIPSState, CP0_BadInstrP));
+                rn = "BadInstrP";
+            } else {
+                gen_mfc0_unimplemented(ctx, arg);
+            }
+            break;
         default:
             goto die;
-       }
+        }
         break;
     case 9:
         switch (sel) {
@@ -5428,8 +5446,22 @@ static void gen_mtc0(DisasContext *ctx, TCGv arg, int reg, int sel)
         }
         break;
     case 8:
-        /* ignored */
-        rn = "BadVAddr";
+        switch (sel) {
+        case 0:
+            /* ignored */
+            rn = "BadVAddr";
+            break;
+        case 1:
+            /* ignored */
+            rn = "BadInstr";
+            break;
+        case 2:
+            /* ignored */
+            rn = "BadInstrP";
+            break;
+        default:
+            goto die;
+        }
         break;
     case 9:
         switch (sel) {
@@ -6054,6 +6086,22 @@ static void gen_dmfc0(DisasContext *ctx, TCGv arg, int reg, int sel)
             tcg_gen_ld_tl(arg, cpu_env, offsetof(CPUMIPSState, CP0_BadVAddr));
             rn = "BadVAddr";
             break;
+        case 1:
+            if (ctx->bi) {
+                gen_mfc0_load32(arg, offsetof(CPUMIPSState, CP0_BadInstr));
+                rn = "BadInstr";
+            } else {
+                gen_mfc0_unimplemented(ctx, arg);
+            }
+            break;
+        case 2:
+            if (ctx->bp) {
+                gen_mfc0_load32(arg, offsetof(CPUMIPSState, CP0_BadInstrP));
+                rn = "BadInstrP";
+            } else {
+                gen_mfc0_unimplemented(ctx, arg);
+            }
+            break;
         default:
             goto die;
         }
@@ -6639,8 +6687,22 @@ static void gen_dmtc0(DisasContext *ctx, TCGv arg, int reg, int sel)
         }
         break;
     case 8:
-        /* ignored */
-        rn = "BadVAddr";
+        switch (sel) {
+        case 0:
+            /* ignored */
+            rn = "BadVAddr";
+            break;
+        case 1:
+            /* ignored */
+            rn = "BadInstr";
+            break;
+        case 2:
+            /* ignored */
+            rn = "BadInstrP";
+            break;
+        default:
+            goto die;
+        }
         break;
     case 9:
         switch (sel) {
@@ -16862,7 +16924,7 @@ static void decode_opc (CPUMIPSState *env, DisasContext *ctx)
     /* make sure instructions are on a word boundary */
     if (ctx->pc & 0x3) {
         env->CP0_BadVAddr = ctx->pc;
-        generate_exception(ctx, EXCP_AdEL);
+        generate_exception_err(ctx, EXCP_AdEL, EXCP_INST_NOTAVAIL);
         return;
     }
 
@@ -17500,6 +17562,8 @@ gen_intermediate_code_internal(MIPSCPU *cpu, TranslationBlock *tb,
     ctx.kscrexist = (env->CP0_Config4 >> CP0C4_KScrExist) & 0xff;
     ctx.rxi = (env->CP0_Config3 >> CP0C3_RXI) & 1;
     ctx.ie = (env->CP0_Config4 >> CP0C4_IE) & 3;
+    ctx.bi = (env->CP0_Config3 >> CP0C3_BI) & 1;
+    ctx.bp = (env->CP0_Config3 >> CP0C3_BP) & 1;
     /* Restore delay slot state from the tb context.  */
     ctx.hflags = (uint32_t)tb->flags; /* FIXME: maybe use 64 bits here? */
     ctx.ulri = env->CP0_Config3 & (1 << CP0C3_ULRI);
-- 
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