Merge #32

32: add user trap setup and handling registers r=almindor a=almindor

Adds CSR handlers for user trap setup and handling registers.

Also unifies common shared types.

NOTE: untested, will test on real device ASAP

Co-authored-by: Ales Katona <almindor@gmail.com>

src/register/mod.rs

@@ -13,11 +13,17 @@
 #[macro_use]
 mod macros;
 
-// TODO: User Trap Setup
-
-
-// TODO: User Trap Handling
-
+// User Trap Setup
+pub mod ustatus;
+pub mod uie;
+pub mod utvec;
+
+// User Trap Handling
+pub mod uscratch;
+pub mod uepc;
+pub mod ucause;
+pub mod utval;
+pub mod uip;
 
 // User Floating-Point CSRs
 // TODO: frm, fflags

src/register/mstatus.rs

@@ -2,6 +2,7 @@
 // TODO: Virtualization, Memory Privilege and Extension Context Fields
 
 use bit_field::BitField;
+use core::mem::size_of;
 
 /// mstatus register
 #[derive(Clone, Copy, Debug)]
@@ -80,7 +81,7 @@ impl Mstatus {
         self.bits.get_bit(5)
     }
 
-    /// User Previous Interrupt Enable
+    /// Machine Previous Interrupt Enable
     #[inline]
     pub fn mpie(&self) -> bool {
         self.bits.get_bit(7)
@@ -134,6 +135,13 @@ impl Mstatus {
             _ => unreachable!(),
         }
     }
+
+    /// Whether either the FS field or XS field
+    /// signals the presence of some dirty state
+    #[inline]
+    pub fn sd(&self) -> bool {
+        self.bits.get_bit(size_of::<usize>() * 8 - 1)
+    }
 }
 
 

src/register/scause.rs

@@ -59,7 +59,6 @@ impl Interrupt {
     }
 }
 
-
 impl Exception {
     pub fn from(nr: usize) -> Self {
         match nr {

src/register/sstatus.rs

@@ -2,6 +2,7 @@
 
 use bit_field::BitField;
 use core::mem::size_of;
+pub use super::mstatus::FS;
 
 /// Supervisor Status Register
 #[derive(Clone, Copy, Debug)]
@@ -16,15 +17,6 @@ pub enum SPP {
     User = 0,
 }
 
-/// Floating-point unit Status
-#[derive(Copy, Clone, Debug, Eq, PartialEq)]
-pub enum FS {
-    Off = 0,
-    Initial = 1,
-    Clean = 2,
-    Dirty = 3,
-}
-
 impl Sstatus {
     /// User Interrupt Enable
     #[inline]

src/register/stvec.rs

@@ -1,18 +1,13 @@
 //! stvec register
 
+pub use crate::register::mtvec::TrapMode;
+
 /// stvec register
 #[derive(Clone, Copy, Debug)]
 pub struct Stvec {
     bits: usize,
 }
 
-/// Trap mode
-#[derive(Copy, Clone, Debug, Eq, PartialEq)]
-pub enum TrapMode {
-    Direct = 0,
-    Vectored = 1,
-}
-
 impl Stvec {
     /// Returns the contents of the register as raw bits
     pub fn bits(&self) -> usize {

src/register/ucause.rs

@@ -0,0 +1,17 @@
+//! ucause register
+
+/// ucause register
+#[derive(Clone, Copy, Debug)]
+pub struct Ucause {
+    bits: usize,
+}
+
+impl Ucause {
+    /// Returns the contents of the register as raw bits
+    #[inline]
+    pub fn bits(&self) -> usize {
+        self.bits
+    }
+}
+
+read_csr_as!(Ucause, 0x042, __read_ucause);

src/register/uepc.rs

@@ -0,0 +1,4 @@
+//! uepc register
+
+read_csr_as_usize!(0x041, __read_uepc);
+write_csr_as_usize!(0x041, __write_uepc);

src/register/uie.rs

@@ -0,0 +1,49 @@
+//! uie register
+
+use bit_field::BitField;
+
+/// uie register
+#[derive(Clone, Copy, Debug)]
+pub struct Uie {
+    bits: usize,
+}
+
+impl Uie {
+    /// Returns the contents of the register as raw bits
+    #[inline]
+    pub fn bits(&self) -> usize {
+        self.bits
+    }
+
+    /// User Software Interrupt Enable
+    #[inline]
+    pub fn usoft(&self) -> bool {
+        self.bits.get_bit(0)
+    }
+
+    /// User Timer Interrupt Enable
+    #[inline]
+    pub fn utimer(&self) -> bool {
+        self.bits.get_bit(4)
+    }
+
+    /// User External Interrupt Enable
+    #[inline]
+    pub fn uext(&self) -> bool {
+        self.bits.get_bit(8)
+    }
+}
+
+read_csr_as!(Uie, 0x004, __read_uie);
+set!(0x004, __set_uie);
+clear!(0x004, __clear_uie);
+
+set_clear_csr!(
+    /// User Software Interrupt Enable
+    , set_usoft, clear_usoft, 1 << 0);
+set_clear_csr!(
+    /// User Timer Interrupt Enable
+    , set_utimer, clear_utimer, 1 << 4);
+set_clear_csr!(
+    /// User External Interrupt Enable
+    , set_uext, clear_uext, 1 << 8);

src/register/uip.rs

@@ -0,0 +1,37 @@
+//! uip register
+
+use bit_field::BitField;
+
+/// uip register
+#[derive(Clone, Copy, Debug)]
+pub struct Uip {
+    bits: usize,
+}
+
+impl Uip {
+    /// Returns the contents of the register as raw bits
+    #[inline]
+    pub fn bits(&self) -> usize {
+        self.bits
+    }
+
+    /// User Software Interrupt Pending
+    #[inline]
+    pub fn usoft(&self) -> bool {
+        self.bits.get_bit(0)
+    }
+
+    /// User Timer Interrupt Pending
+    #[inline]
+    pub fn utimer(&self) -> bool {
+        self.bits.get_bit(4)
+    }
+
+    /// User External Interrupt Pending
+    #[inline]
+    pub fn uext(&self) -> bool {
+        self.bits.get_bit(8)
+    }
+}
+
+read_csr_as!(Uip, 0x044, __read_uip);

src/register/uscratch.rs

@@ -0,0 +1,4 @@
+//! uscratch register
+
+read_csr_as_usize!(0x040, __read_uscratch);
+write_csr_as_usize!(0x040, __write_uscratch);

src/register/ustatus.rs

@@ -0,0 +1,37 @@
+//! ustatus register
+// TODO: Virtualization, Memory Privilege and Extension Context Fields
+
+use bit_field::BitField;
+
+/// ustatus register
+#[derive(Clone, Copy, Debug)]
+pub struct Ustatus {
+    bits: usize,
+}
+
+impl Ustatus {
+    /// User Interrupt Enable
+    #[inline]
+    pub fn uie(&self) -> bool {
+        self.bits.get_bit(0)
+    }
+
+    /// User Previous Interrupt Enable
+    #[inline]
+    pub fn upie(&self) -> bool {
+        self.bits.get_bit(4)
+    }
+}
+
+read_csr_as!(Ustatus, 0x000, __read_ustatus);
+write_csr!(0x000, __write_ustatus);
+set!(0x000, __set_ustatus);
+clear!(0x000, __clear_ustatus);
+
+set_clear_csr!(
+    /// User Interrupt Enable
+    , set_uie, clear_uie, 1 << 0);
+
+set_csr!(
+    /// User Previous Interrupt Enable
+    , set_upie, 1 << 4);

src/register/utval.rs

@@ -0,0 +1,3 @@
+//! utval register
+
+read_csr_as_usize!(0x043, __read_utval);

src/register/utvec.rs

@@ -0,0 +1,40 @@
+//! stvec register
+
+pub use crate::register::mtvec::TrapMode;
+
+/// stvec register
+#[derive(Clone, Copy, Debug)]
+pub struct Utvec {
+    bits: usize,
+}
+
+impl Utvec {
+    /// Returns the contents of the register as raw bits
+    pub fn bits(&self) -> usize {
+        self.bits
+    }
+
+    /// Returns the trap-vector base-address
+    pub fn address(&self) -> usize {
+        self.bits - (self.bits & 0b11)
+    }
+
+    /// Returns the trap-vector mode
+    pub fn trap_mode(&self) -> TrapMode {
+        let mode = self.bits & 0b11;
+        match mode {
+            0 => TrapMode::Direct,
+            1 => TrapMode::Vectored,
+            _ => unimplemented!()
+        }
+    }
+}
+
+read_csr_as!(Utvec, 0x005, __read_utvec);
+write_csr!(0x005, __write_utvec);
+
+/// Writes the CSR
+#[inline]
+pub unsafe fn write(addr: usize, mode: TrapMode) {
+    _write(addr + mode as usize);
+}