[PULL 39/59] target/riscv: Allow debugger to access {h, s}stateen CSRs

[Palmer Dabbelt]

From: Bin Meng <bmeng@tinylab.org>

At present {h,s}stateen CSRs are not reported in the CSR XML
hence gdb cannot access them.

Fix it by adjusting their predicate() routine logic so that the
static config check comes before the run-time check, as well as
adding a debugger check.

Signed-off-by: Bin Meng <bmeng@tinylab.org>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
Message-ID: <20230228104035.1879882-16-bmeng@tinylab.org>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
---
 target/riscv/csr.c | 22 ++++++++++++++++++++--
 1 file changed, 20 insertions(+), 2 deletions(-)

diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index 15b23b9b5a..a0e70f5ba0 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -337,13 +337,22 @@ static RISCVException hstateen_pred(CPURISCVState *env, 
int csrno, int base)
         return RISCV_EXCP_ILLEGAL_INST;
     }
 
+    RISCVException ret = hmode(env, csrno);
+    if (ret != RISCV_EXCP_NONE) {
+        return ret;
+    }
+
+    if (env->debugger) {
+        return RISCV_EXCP_NONE;
+    }
+
     if (env->priv < PRV_M) {
         if (!(env->mstateen[csrno - base] & SMSTATEEN_STATEEN)) {
             return RISCV_EXCP_ILLEGAL_INST;
         }
     }
 
-    return hmode(env, csrno);
+    return RISCV_EXCP_NONE;
 }
 
 static RISCVException hstateen(CPURISCVState *env, int csrno)
@@ -366,6 +375,15 @@ static RISCVException sstateen(CPURISCVState *env, int 
csrno)
         return RISCV_EXCP_ILLEGAL_INST;
     }
 
+    RISCVException ret = smode(env, csrno);
+    if (ret != RISCV_EXCP_NONE) {
+        return ret;
+    }
+
+    if (env->debugger) {
+        return RISCV_EXCP_NONE;
+    }
+
     if (env->priv < PRV_M) {
         if (!(env->mstateen[index] & SMSTATEEN_STATEEN)) {
             return RISCV_EXCP_ILLEGAL_INST;
@@ -378,7 +396,7 @@ static RISCVException sstateen(CPURISCVState *env, int 
csrno)
         }
     }
 
-    return smode(env, csrno);
+    return RISCV_EXCP_NONE;
 }
 
 /* Checks if PointerMasking registers could be accessed */
-- 
2.39.2