From: Aleksandar Rikalo <arikalo@wavecomp.com>

Add a field in hflags for XNP bit, and a function check_xnp().

Reviewed-by: Aleksandar Markovic <amarkovic@wavecomp.com>
Signed-off-by: Aleksandar Markovic <amarkovic@wavecomp.com>
Signed-off-by: Stefan Markovic <smarkovic@wavecomp.com>
---
 target/mips/cpu.h       |  3 ++-
 target/mips/internal.h  |  5 ++++-
 target/mips/translate.c | 12 ++++++++++++
 3 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/target/mips/cpu.h b/target/mips/cpu.h
index 009202c..02ea91e 100644
--- a/target/mips/cpu.h
+++ b/target/mips/cpu.h
@@ -554,7 +554,7 @@ struct CPUMIPSState {
 #define EXCP_INST_NOTAVAIL 0x2 /* No valid instruction word for BadInstr */
     uint32_t hflags;    /* CPU State */
     /* TMASK defines different execution modes */
-#define MIPS_HFLAG_TMASK  0x1F5807FF
+#define MIPS_HFLAG_TMASK  0x3F5807FF
 #define MIPS_HFLAG_MODE   0x00007 /* execution modes                    */
     /* The KSU flags must be the lowest bits in hflags. The flag order
        must be the same as defined for CP0 Status. This allows to use
@@ -605,6 +605,7 @@ struct CPUMIPSState {
 #define MIPS_HFLAG_ELPA  0x4000000
 #define MIPS_HFLAG_ITC_CACHE  0x8000000 /* CACHE instr. operates on ITC tag */
 #define MIPS_HFLAG_ERL   0x10000000 /* error level flag */
+#define MIPS_HFLAG_XNP   0x20000000
     target_ulong btarget;        /* Jump / branch target               */
     target_ulong bcond;          /* Branch condition (if needed)       */
 
diff --git a/target/mips/internal.h b/target/mips/internal.h
index e41051f..97485da 100644
--- a/target/mips/internal.h
+++ b/target/mips/internal.h
@@ -308,7 +308,7 @@ static inline void compute_hflags(CPUMIPSState *env)
                      MIPS_HFLAG_F64 | MIPS_HFLAG_FPU | MIPS_HFLAG_KSU |
                      MIPS_HFLAG_AWRAP | MIPS_HFLAG_DSP | MIPS_HFLAG_DSPR2 |
                      MIPS_HFLAG_SBRI | MIPS_HFLAG_MSA | MIPS_HFLAG_FRE |
-                     MIPS_HFLAG_ELPA | MIPS_HFLAG_ERL);
+                     MIPS_HFLAG_ELPA | MIPS_HFLAG_ERL | MIPS_HFLAG_XNP);
     if (env->CP0_Status & (1 << CP0St_ERL)) {
         env->hflags |= MIPS_HFLAG_ERL;
     }
@@ -402,6 +402,9 @@ static inline void compute_hflags(CPUMIPSState *env)
             env->hflags |= MIPS_HFLAG_ELPA;
         }
     }
+    if (env->CP0_Config5 & (1 << CP0C5_XNP)) {
+        env->hflags |= MIPS_HFLAG_XNP;
+    }
 }
 
 void cpu_mips_tlb_flush(CPUMIPSState *env);
diff --git a/target/mips/translate.c b/target/mips/translate.c
index ae3aaab..35342e2 100644
--- a/target/mips/translate.c
+++ b/target/mips/translate.c
@@ -1902,6 +1902,18 @@ static inline void check_mvh(DisasContext *ctx)
 }
 #endif
 
+/*
+ * This code generates a "reserved instruction" exception if the
+ * Config5 XNP bit is set.
+ */
+static inline void check_xnp(DisasContext *ctx)
+{
+    if (unlikely(ctx->hflags & MIPS_HFLAG_XNP)) {
+        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
    all callers for gen_load_fpr32 when we need the CTX parameter for
-- 
2.7.4