From 9857dfcd7dbe93901c38f5c517d5e561ea98cae4 Mon Sep 17 00:00:00 2001
From: whitequark <whitequark@whitequark.org>
Date: Fri, 4 May 2018 18:26:12 +0000
Subject: [PATCH] firmware: add irq::Exception to libboard.

---
 artiq/firmware/libboard/lib.rs      |  2 +-
 artiq/firmware/libboard/or1k/irq.rs | 84 ++++++++++++++++++++++++++++-
 artiq/firmware/libboard/or1k/spr.rs |  2 +
 3 files changed, 86 insertions(+), 2 deletions(-)

diff --git a/artiq/firmware/libboard/lib.rs b/artiq/firmware/libboard/lib.rs
index a685f5252..369a38d8c 100644
--- a/artiq/firmware/libboard/lib.rs
+++ b/artiq/firmware/libboard/lib.rs
@@ -1,5 +1,5 @@
 #![no_std]
-#![feature(compiler_builtins_lib, asm)]
+#![feature(compiler_builtins_lib, asm, try_from)]
 
 extern crate compiler_builtins;
 extern crate byteorder;
diff --git a/artiq/firmware/libboard/or1k/irq.rs b/artiq/firmware/libboard/or1k/irq.rs
index ad9c917b9..bc745ae02 100644
--- a/artiq/firmware/libboard/or1k/irq.rs
+++ b/artiq/firmware/libboard/or1k/irq.rs
@@ -1,9 +1,76 @@
+use core::{fmt, convert};
+
 use super::spr::*;
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+pub enum Exception {
+    Reset = 0x1,
+    BusError = 0x2,
+    DataPageFault = 0x3,
+    InsnPageFault = 0x4,
+    Tick = 0x5,
+    Alignment = 0x6,
+    IllegalInsn = 0x7,
+    Interrupt = 0x8,
+    DtlbMiss = 0x9,
+    ItlbMiss = 0xa,
+    Range = 0xb,
+    Syscall = 0xc,
+    FloatingPoint = 0xd,
+    Trap = 0xe,
+}
+
+impl fmt::Display for Exception {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match *self {
+            Exception::Reset         => write!(f, "reset"),
+            Exception::BusError      => write!(f, "bus error"),
+            Exception::DataPageFault => write!(f, "data page fault"),
+            Exception::InsnPageFault => write!(f, "instruction page fault"),
+            Exception::Tick          => write!(f, "tick"),
+            Exception::Alignment     => write!(f, "alignment"),
+            Exception::IllegalInsn   => write!(f, "illegal instruction"),
+            Exception::Interrupt     => write!(f, "interrupt"),
+            Exception::DtlbMiss      => write!(f, "D-TLB miss"),
+            Exception::ItlbMiss      => write!(f, "I-TLB miss"),
+            Exception::Range         => write!(f, "range"),
+            Exception::Syscall       => write!(f, "system call"),
+            Exception::FloatingPoint => write!(f, "floating point"),
+            Exception::Trap          => write!(f, "trap"),
+        }
+    }
+}
+
+impl convert::TryFrom<u32> for Exception {
+    type Error = ();
+
+    fn try_from(num: u32) -> Result<Self, Self::Error> {
+        match num {
+            0x1 => Ok(Exception::Reset),
+            0x2 => Ok(Exception::BusError),
+            0x3 => Ok(Exception::DataPageFault),
+            0x4 => Ok(Exception::InsnPageFault),
+            0x5 => Ok(Exception::Tick),
+            0x6 => Ok(Exception::Alignment),
+            0x7 => Ok(Exception::IllegalInsn),
+            0x8 => Ok(Exception::Interrupt),
+            0x9 => Ok(Exception::DtlbMiss),
+            0xa => Ok(Exception::ItlbMiss),
+            0xb => Ok(Exception::Range),
+            0xc => Ok(Exception::Syscall),
+            0xd => Ok(Exception::FloatingPoint),
+            0xe => Ok(Exception::Trap),
+            _ => Err(())
+        }
+    }
+}
+
+#[inline]
 pub fn get_ie() -> bool {
     unsafe { mfspr(SPR_SR) & SPR_SR_IEE != 0 }
 }
 
+#[inline]
 pub fn set_ie(ie: bool) {
     if ie {
         unsafe { mtspr(SPR_SR, mfspr(SPR_SR) | SPR_SR_IEE) }
@@ -12,14 +79,29 @@ pub fn set_ie(ie: bool) {
     }
 }
 
+#[inline]
 pub fn get_mask() -> u32 {
     unsafe { mfspr(SPR_PICMR) }
 }
 
+#[inline]
 pub fn set_mask(mask: u32) {
     unsafe { mtspr(SPR_PICMR, mask) }
 }
 
-pub fn pending() -> u32 {
+#[inline]
+pub fn pending_mask() -> u32 {
     unsafe { mfspr(SPR_PICSR) }
 }
+
+pub fn enable(irq: u32) {
+    set_mask(get_mask() | (1 << irq))
+}
+
+pub fn disable(irq: u32) {
+    set_mask(get_mask() & !(1 << irq))
+}
+
+pub fn is_pending(irq: u32) -> bool {
+    get_mask() & (1 << irq) != 0
+}
diff --git a/artiq/firmware/libboard/or1k/spr.rs b/artiq/firmware/libboard/or1k/spr.rs
index 8f011a564..14bb5ae3d 100644
--- a/artiq/firmware/libboard/or1k/spr.rs
+++ b/artiq/firmware/libboard/or1k/spr.rs
@@ -1,9 +1,11 @@
+#[inline(always)]
 pub unsafe fn mfspr(reg: u32) -> u32 {
     let value: u32;
     asm!("l.mfspr $0, $1, 0" : "=r"(value) : "r"(reg) : : "volatile");
     value
 }
 
+#[inline(always)]
 pub unsafe fn mtspr(reg: u32, value: u32) {
     asm!("l.mtspr $0, $1, 0" : : "r"(reg), "r"(value) : : "volatile")
 }