Add expected value checking to test_csr_field macro for read-only CSR fields

Author: KushalMeghani1644

riscv/src/register/macros.rs

@@ -1048,6 +1048,11 @@ macro_rules! test_csr_field {
         assert_eq!($reg.$field(), exp_val);
     }};
 
+    // test a multi-bit bitfield for read-only CSR with expected value
+    ($reg:ident, $field:ident: [$start:expr, $end:expr], $expected:expr) => {{
+        assert_eq!($reg.$field(), $expected);
+    }};
+
     // test an enum bit field
     ($reg:ident, $field:ident: $var:expr) => {{
         $crate::paste! {

riscv/src/register/mtopi.rs

@@ -61,37 +61,26 @@ mod tests {
 
     #[test]
     fn test_mtopi_fields() {
-        // Test using helper macros as requested - follows mcounteren.rs pattern
-        let mut mtopi = Mtopi::from_bits(0);
+        let mtopi = Mtopi::from_bits(0);
 
-        // Test iid field [16:27] - using test helper macro
-        test_csr_field!(mtopi, iid: [16, 27]);
-        // Test ipid field [0:7] - using test helper macro
-        test_csr_field!(mtopi, ipid: [0, 7]);
+        test_csr_field!(mtopi, iid: [16, 27], 0x0);
+        test_csr_field!(mtopi, iprio: [0, 7], 0x0);
 
-        // Test helper methods
-        assert!(!mtopi.has_interrupt());
+        let mtopi = Mtopi::from_bits((11 << 16) | 5);
+        test_csr_field!(mtopi, iid: [16, 27], 0xB);
+        test_csr_field!(mtopi, iprio: [0, 7], 0x5);
 
-        // Test with some interrupt pending (IID = 11, IPID = 5)
-        mtopi = Mtopi::from_bits((11 << 16) | 5);
-        test_csr_field!(mtopi, iid: [16, 27]);
-        test_csr_field!(mtopi, ipid: [0, 7]);
-        assert!(mtopi.has_interrupt());
+        let mtopi = Mtopi::from_bits((0xFFF << 16) | 0xFF);
+        test_csr_field!(mtopi, iid: [16, 27], 0xFFF);
+        test_csr_field!(mtopi, iprio: [0, 7], 0xFF);
 
-        // Test maximum values for each field
-        mtopi = Mtopi::from_bits((0xFFF << 16) | 0xFF);
-        test_csr_field!(mtopi, iid: [16, 27]);
-        test_csr_field!(mtopi, ipid: [0, 7]);
-        assert!(mtopi.has_interrupt());
+        let mtopi = Mtopi::from_bits(1 << 16);
+        test_csr_field!(mtopi, iid: [16, 27], 0x1);
+        test_csr_field!(mtopi, iprio: [0, 7], 0x0);
 
-        // Test field boundaries
-        mtopi = Mtopi::from_bits(1 << 16);
-        test_csr_field!(mtopi, iid: [16, 27]);
-        test_csr_field!(mtopi, ipid: [0, 7]);
-
-        mtopi = Mtopi::from_bits(1);
-        test_csr_field!(mtopi, iid: [16, 27]);
-        test_csr_field!(mtopi, ipid: [0, 7]);
+        let mtopi = Mtopi::from_bits(1);
+        test_csr_field!(mtopi, iid: [16, 27], 0x0);
+        test_csr_field!(mtopi, iprio: [0, 7], 0x1);
     }
 
     #[test]