Update macros.rs to add read_write_csr_as_usize and update dscratch0 and dcsratch1 to use them instead of read_write_csr macro

Author: KushalMeghani1644

riscv/src/register/dscratch0.rs

@@ -1,10 +1,6 @@
 //! dscratch0
 
-read_write_csr! {
-    /// Debug scratch register 0
-    Dscratch0: 0x7b2,
-    mask: usize::MAX,
-}
+read_write_csr_as_usize!(Dscratch0, 0x7b2);
 
 #[cfg(test)]
 mod tests {

riscv/src/register/dscratch1.rs

@@ -1,10 +1,6 @@
 //! dscratch1
 
-read_write_csr! {
-    /// Debug scratch register 1
-    Dscratch1: 0x7b3,
-    mask: usize::MAX,
-}
+read_write_csr_as_usize!(Dscratch1, 0x7b3);
 
 #[cfg(test)]
 mod tests {

riscv/src/register/macros.rs

@@ -301,6 +301,30 @@ macro_rules! write_csr_as_usize_rv32 {
     };
 }
 
+/// Convenience macro to provide combined read/write of a CSR as a `usize`.
+///
+/// This composes [`read_csr_as_usize`] and [`write_csr_as_usize`]. Use the
+/// `safe` form to get safe wrappers instead of unsafe.
+#[macro_export]
+macro_rules! read_write_csr_as_usize {
+    ($csr_number:literal) => {
+        $crate::read_csr_as_usize!($csr_number);
+        $crate::write_csr_as_usize!($csr_number);
+    };
+    (safe $csr_number:literal) => {
+        $crate::read_csr_as_usize!($csr_number);
+        $crate::write_csr_as_usize!(safe $csr_number);
+    };
+    ($csr_number:literal, $($cfg:meta),*) => {
+        $crate::read_csr_as_usize!($csr_number, $($cfg),*);
+        $crate::write_csr_as_usize!($csr_number, $($cfg),*);
+    };
+    (safe $csr_number:literal, $($cfg:meta),*) => {
+        $crate::read_csr_as_usize!($csr_number, $($cfg),*);
+        $crate::write_csr_as_usize!(safe $csr_number, $($cfg),*);
+    };
+}
+
 /// Convenience macro around the `csrrs` assembly instruction to set the CSR register.
 ///
 /// This macro is intended for use with the [set_csr](crate::set_csr) or [set_clear_csr](crate::set_clear_csr) macros.