[PATCH v7 3/4] target/riscv: smstateen check for fcsr

[Mayuresh Chitale <mchitale@ventanamicro.com>]

If smstateen is implemented and sstateen0.fcsr is clear then the
floating point operations must return illegal instruction exception.

Signed-off-by: Mayuresh Chitale <mchitale@ventanamicro.com>
---
 target/riscv/csr.c                        | 23 +++++++++++++
 target/riscv/insn_trans/trans_rvf.c.inc   | 40 +++++++++++++++++++++--
 target/riscv/insn_trans/trans_rvzfh.c.inc | 12 +++++++
 3 files changed, 72 insertions(+), 3 deletions(-)

diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index 011d6c5976..0512391220 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -79,6 +79,10 @@ static RISCVException fs(CPURISCVState *env, int csrno)
         !RISCV_CPU(env_cpu(env))->cfg.ext_zfinx) {
         return RISCV_EXCP_ILLEGAL_INST;
     }
+
+    if (!env->debugger && !riscv_cpu_fp_enabled(env)) {
+        return smstateen_acc_ok(env, 0, SMSTATEEN0_FCSR);
+    }
 #endif
     return RISCV_EXCP_NONE;
 }
@@ -1866,6 +1870,9 @@ static RISCVException write_mstateen0(CPURISCVState *env, int csrno,
                                       target_ulong new_val)
 {
     uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
+    if (!riscv_has_ext(env, RVF)) {
+        wr_mask |= SMSTATEEN0_FCSR;
+    }
 
     return write_mstateen(env, csrno, wr_mask, new_val);
 }
@@ -1914,6 +1921,10 @@ static RISCVException write_mstateen0h(CPURISCVState *env, int csrno,
 {
     uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
 
+    if (!riscv_has_ext(env, RVF)) {
+        wr_mask |= SMSTATEEN0_FCSR;
+    }
+
     return write_mstateenh(env, csrno, wr_mask, new_val);
 }
 
@@ -1963,6 +1974,10 @@ static RISCVException write_hstateen0(CPURISCVState *env, int csrno,
 {
     uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
 
+    if (!riscv_has_ext(env, RVF)) {
+        wr_mask |= SMSTATEEN0_FCSR;
+    }
+
     return write_hstateen(env, csrno, wr_mask, new_val);
 }
 
@@ -2014,6 +2029,10 @@ static RISCVException write_hstateen0h(CPURISCVState *env, int csrno,
 {
     uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
 
+    if (!riscv_has_ext(env, RVF)) {
+        wr_mask |= SMSTATEEN0_FCSR;
+    }
+
     return write_hstateenh(env, csrno, wr_mask, new_val);
 }
 
@@ -2073,6 +2092,10 @@ static RISCVException write_sstateen0(CPURISCVState *env, int csrno,
 {
     uint64_t wr_mask = SMSTATEEN_STATEEN | SMSTATEEN0_HSENVCFG;
 
+    if (!riscv_has_ext(env, RVF)) {
+        wr_mask |= SMSTATEEN0_FCSR;
+    }
+
     return write_sstateen(env, csrno, wr_mask, new_val);
 }
 
diff --git a/target/riscv/insn_trans/trans_rvf.c.inc b/target/riscv/insn_trans/trans_rvf.c.inc
index a1d3eb52ad..ce8a0cc34b 100644
--- a/target/riscv/insn_trans/trans_rvf.c.inc
+++ b/target/riscv/insn_trans/trans_rvf.c.inc
@@ -24,9 +24,43 @@
             return false; \
 } while (0)
 
-#define REQUIRE_ZFINX_OR_F(ctx) do {\
-    if (!ctx->cfg_ptr->ext_zfinx) { \
-        REQUIRE_EXT(ctx, RVF); \
+#ifndef CONFIG_USER_ONLY
+static inline bool smstateen_check(DisasContext *ctx, int index)
+{
+    CPUState *cpu = ctx->cs;
+    CPURISCVState *env = cpu->env_ptr;
+    uint64_t stateen = env->mstateen[index];
+
+    if (!ctx->cfg_ptr->ext_smstateen || env->priv == PRV_M) {
+        return true;
+    }
+
+    if (ctx->virt_enabled) {
+        stateen &= env->hstateen[index];
+    }
+
+    if (env->priv == PRV_U && has_ext(ctx, RVS)) {
+        stateen &= env->sstateen[index];
+    }
+
+    if (!(stateen & SMSTATEEN0_FCSR)) {
+        return false;
+    }
+
+    return true;
+}
+#else
+#define smstateen_check(ctx, index) (true)
+#endif
+
+#define REQUIRE_ZFINX_OR_F(ctx) do { \
+    if (!has_ext(ctx, RVF)) { \
+        if (!ctx->cfg_ptr->ext_zfinx) { \
+            return false; \
+        } \
+        if (!smstateen_check(ctx, 0)) { \
+            return false; \
+        } \
     } \
 } while (0)
 
diff --git a/target/riscv/insn_trans/trans_rvzfh.c.inc b/target/riscv/insn_trans/trans_rvzfh.c.inc
index 5d07150cd0..44d962c920 100644
--- a/target/riscv/insn_trans/trans_rvzfh.c.inc
+++ b/target/riscv/insn_trans/trans_rvzfh.c.inc
@@ -20,18 +20,27 @@
     if (!ctx->cfg_ptr->ext_zfh) {      \
         return false;         \
     }                         \
+    if (!smstateen_check(ctx, 0)) { \
+        return false; \
+    } \
 } while (0)
 
 #define REQUIRE_ZHINX_OR_ZFH(ctx) do { \
     if (!ctx->cfg_ptr->ext_zhinx && !ctx->cfg_ptr->ext_zfh) { \
         return false;                  \
     }                                  \
+    if (!smstateen_check(ctx, 0)) { \
+        return false; \
+    } \
 } while (0)
 
 #define REQUIRE_ZFH_OR_ZFHMIN(ctx) do {       \
     if (!(ctx->cfg_ptr->ext_zfh || ctx->cfg_ptr->ext_zfhmin)) { \
         return false;                         \
     }                                         \
+    if (!smstateen_check(ctx, 0)) { \
+        return false; \
+    } \
 } while (0)
 
 #define REQUIRE_ZFH_OR_ZFHMIN_OR_ZHINX_OR_ZHINXMIN(ctx) do { \
@@ -39,6 +48,9 @@
           ctx->cfg_ptr->ext_zhinx || ctx->cfg_ptr->ext_zhinxmin)) {     \
         return false;                                        \
     }                                                        \
+    if (!smstateen_check(ctx, 0)) { \
+        return false; \
+    } \
 } while (0)
 
 static bool trans_flh(DisasContext *ctx, arg_flh *a)
-- 
2.25.1