target/riscv: Use RISCVException enum for CSR access

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Message-id: 302b208f40373557fa11b351b5c9f43039ca8ea3.1617290165.git.alistair.francis@wdc.com

4 files changed, 38 insertions, 36 deletions

diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
index a7b8876ea0..842d3ab810 100644
--- a/target/riscv/cpu.h
+++ b/target/riscv/cpu.h
@@ -454,10 +454,13 @@ static inline void cpu_get_tb_cpu_state(CPURISCVState *env, target_ulong *pc,
     *pflags = flags;
 }
 
-int riscv_csrrw(CPURISCVState *env, int csrno, target_ulong *ret_value,
-                target_ulong new_value, target_ulong write_mask);
-int riscv_csrrw_debug(CPURISCVState *env, int csrno, target_ulong *ret_value,
-                      target_ulong new_value, target_ulong write_mask);
+RISCVException riscv_csrrw(CPURISCVState *env, int csrno,
+                           target_ulong *ret_value,
+                           target_ulong new_value, target_ulong write_mask);
+RISCVException riscv_csrrw_debug(CPURISCVState *env, int csrno,
+                                 target_ulong *ret_value,
+                                 target_ulong new_value,
+                                 target_ulong write_mask);
 
 static inline void riscv_csr_write(CPURISCVState *env, int csrno,
                                    target_ulong val)
diff --git a/target/riscv/csr.c b/target/riscv/csr.c
index f67eaf4042..f0a74f0eb8 100644
--- a/target/riscv/csr.c
+++ b/target/riscv/csr.c
@@ -1382,10 +1382,11 @@ static RISCVException write_pmpaddr(CPURISCVState *env, int csrno,
  * csrrc  <->  riscv_csrrw(env, csrno, ret_value, 0, value);
  */
 
-int riscv_csrrw(CPURISCVState *env, int csrno, target_ulong *ret_value,
-                target_ulong new_value, target_ulong write_mask)
+RISCVException riscv_csrrw(CPURISCVState *env, int csrno,
+                           target_ulong *ret_value,
+                           target_ulong new_value, target_ulong write_mask)
 {
-    int ret;
+    RISCVException ret;
     target_ulong old_value;
     RISCVCPU *cpu = env_archcpu(env);
 
@@ -1407,41 +1408,37 @@ int riscv_csrrw(CPURISCVState *env, int csrno, target_ulong *ret_value,
 
     if ((write_mask && read_only) ||
         (!env->debugger && (effective_priv < get_field(csrno, 0x300)))) {
-        return -RISCV_EXCP_ILLEGAL_INST;
+        return RISCV_EXCP_ILLEGAL_INST;
     }
 #endif
 
     /* ensure the CSR extension is enabled. */
     if (!cpu->cfg.ext_icsr) {
-        return -RISCV_EXCP_ILLEGAL_INST;
+        return RISCV_EXCP_ILLEGAL_INST;
     }
 
     /* check predicate */
     if (!csr_ops[csrno].predicate) {
-        return -RISCV_EXCP_ILLEGAL_INST;
+        return RISCV_EXCP_ILLEGAL_INST;
     }
     ret = csr_ops[csrno].predicate(env, csrno);
     if (ret != RISCV_EXCP_NONE) {
-        return -ret;
+        return ret;
     }
 
     /* execute combined read/write operation if it exists */
     if (csr_ops[csrno].op) {
-        ret = csr_ops[csrno].op(env, csrno, ret_value, new_value, write_mask);
-        if (ret != RISCV_EXCP_NONE) {
-            return -ret;
-        }
-        return 0;
+        return csr_ops[csrno].op(env, csrno, ret_value, new_value, write_mask);
     }
 
     /* if no accessor exists then return failure */
     if (!csr_ops[csrno].read) {
-        return -RISCV_EXCP_ILLEGAL_INST;
+        return RISCV_EXCP_ILLEGAL_INST;
     }
     /* read old value */
     ret = csr_ops[csrno].read(env, csrno, &old_value);
     if (ret != RISCV_EXCP_NONE) {
-        return -ret;
+        return ret;
     }
 
     /* write value if writable and write mask set, otherwise drop writes */
@@ -1450,7 +1447,7 @@ int riscv_csrrw(CPURISCVState *env, int csrno, target_ulong *ret_value,
         if (csr_ops[csrno].write) {
             ret = csr_ops[csrno].write(env, csrno, new_value);
             if (ret != RISCV_EXCP_NONE) {
-                return -ret;
+                return ret;
             }
         }
     }
@@ -1460,17 +1457,19 @@ int riscv_csrrw(CPURISCVState *env, int csrno, target_ulong *ret_value,
         *ret_value = old_value;
     }
 
-    return 0;
+    return RISCV_EXCP_NONE;
 }
 
 /*
  * Debugger support.  If not in user mode, set env->debugger before the
  * riscv_csrrw call and clear it after the call.
  */
-int riscv_csrrw_debug(CPURISCVState *env, int csrno, target_ulong *ret_value,
-                target_ulong new_value, target_ulong write_mask)
+RISCVException riscv_csrrw_debug(CPURISCVState *env, int csrno,
+                                 target_ulong *ret_value,
+                                 target_ulong new_value,
+                                 target_ulong write_mask)
 {
-    int ret;
+    RISCVException ret;
 #if !defined(CONFIG_USER_ONLY)
     env->debugger = true;
 #endif
diff --git a/target/riscv/gdbstub.c b/target/riscv/gdbstub.c
index 5f96b7ea2a..ca78682cf4 100644
--- a/target/riscv/gdbstub.c
+++ b/target/riscv/gdbstub.c
@@ -71,7 +71,7 @@ static int riscv_gdb_get_fpu(CPURISCVState *env, GByteArray *buf, int n)
          */
         result = riscv_csrrw_debug(env, n - 32, &val,
                                    0, 0);
-        if (result == 0) {
+        if (result == RISCV_EXCP_NONE) {
             return gdb_get_regl(buf, val);
         }
     }
@@ -94,7 +94,7 @@ static int riscv_gdb_set_fpu(CPURISCVState *env, uint8_t *mem_buf, int n)
          */
         result = riscv_csrrw_debug(env, n - 32, NULL,
                                    val, -1);
-        if (result == 0) {
+        if (result == RISCV_EXCP_NONE) {
             return sizeof(target_ulong);
         }
     }
@@ -108,7 +108,7 @@ static int riscv_gdb_get_csr(CPURISCVState *env, GByteArray *buf, int n)
         int result;
 
         result = riscv_csrrw_debug(env, n, &val, 0, 0);
-        if (result == 0) {
+        if (result == RISCV_EXCP_NONE) {
             return gdb_get_regl(buf, val);
         }
     }
@@ -122,7 +122,7 @@ static int riscv_gdb_set_csr(CPURISCVState *env, uint8_t *mem_buf, int n)
         int result;
 
         result = riscv_csrrw_debug(env, n, NULL, val, -1);
-        if (result == 0) {
+        if (result == RISCV_EXCP_NONE) {
             return sizeof(target_ulong);
         }
     }
diff --git a/target/riscv/op_helper.c b/target/riscv/op_helper.c
index f0bbd73ca5..170b494227 100644
--- a/target/riscv/op_helper.c
+++ b/target/riscv/op_helper.c
@@ -41,10 +41,10 @@ target_ulong helper_csrrw(CPURISCVState *env, target_ulong src,
         target_ulong csr)
 {
     target_ulong val = 0;
-    int ret = riscv_csrrw(env, csr, &val, src, -1);
+    RISCVException ret = riscv_csrrw(env, csr, &val, src, -1);
 
-    if (ret < 0) {
-        riscv_raise_exception(env, -ret, GETPC());
+    if (ret != RISCV_EXCP_NONE) {
+        riscv_raise_exception(env, ret, GETPC());
     }
     return val;
 }
@@ -53,10 +53,10 @@ target_ulong helper_csrrs(CPURISCVState *env, target_ulong src,
         target_ulong csr, target_ulong rs1_pass)
 {
     target_ulong val = 0;
-    int ret = riscv_csrrw(env, csr, &val, -1, rs1_pass ? src : 0);
+    RISCVException ret = riscv_csrrw(env, csr, &val, -1, rs1_pass ? src : 0);
 
-    if (ret < 0) {
-        riscv_raise_exception(env, -ret, GETPC());
+    if (ret != RISCV_EXCP_NONE) {
+        riscv_raise_exception(env, ret, GETPC());
     }
     return val;
 }
@@ -65,10 +65,10 @@ target_ulong helper_csrrc(CPURISCVState *env, target_ulong src,
         target_ulong csr, target_ulong rs1_pass)
 {
     target_ulong val = 0;
-    int ret = riscv_csrrw(env, csr, &val, 0, rs1_pass ? src : 0);
+    RISCVException ret = riscv_csrrw(env, csr, &val, 0, rs1_pass ? src : 0);
 
-    if (ret < 0) {
-        riscv_raise_exception(env, -ret, GETPC());
+    if (ret != RISCV_EXCP_NONE) {
+        riscv_raise_exception(env, ret, GETPC());
     }
     return val;
 }