From efaf4844e51bd47f9385cedfc3f1392f04af2f42 Mon Sep 17 00:00:00 2001
From: David Li <li.davidm96@gmail.com>
Date: Mon, 25 Jan 2016 14:46:40 -0500
Subject: feat(memory): write cache tag info to global status structs

---
 src/globals.rs | 87 ++++++++++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 76 insertions(+), 11 deletions(-)

(limited to 'src/globals.rs')

diff --git a/src/globals.rs b/src/globals.rs
index dc96403..3a661e4 100644
--- a/src/globals.rs
+++ b/src/globals.rs
@@ -1,6 +1,8 @@
 use std::cell::RefCell;
+use std::fmt;
 use std::rc::Rc;
 
+use rustv::cache;
 use rustv::isa::{self, IsaType};
 use rustv::memory::{MemoryInterface, Mmu};
 
@@ -10,18 +12,33 @@ pub const HOME_STATUS: isa::Address = isa::Word(0xFFF00);
 
 /// Update the various global data structures as requested by other
 /// subsystems.
-// Intended to be passed around as &'a GlobalsUpdater
-pub struct GlobalsUpdater<'a> {
+// Intended to be passed around as &'a Updater
+pub struct Updater<'a> {
     // TODO: weak reference?
     memory: Rc<RefCell<MemoryTracker>>,
     mmu1: Box<Mmu + 'a>,
     mmu2: Box<Mmu + 'a>,
 }
 
-impl<'a> GlobalsUpdater<'a> {
+#[derive(Clone,Copy)]
+pub enum Player {
+    One,
+    Two,
+}
+
+impl fmt::Display for Player {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match *self {
+            Player::One => write!(f, "Player 1"),
+            Player::Two => write!(f, "Player 2"),
+        }
+    }
+}
+
+impl<'a> Updater<'a> {
     pub fn new(memory: Rc<RefCell<MemoryTracker>>,
-               mmu1: Box<Mmu + 'a>, mmu2: Box<Mmu + 'a>) -> GlobalsUpdater<'a> {
-        GlobalsUpdater {
+               mmu1: Box<Mmu + 'a>, mmu2: Box<Mmu + 'a>) -> Updater<'a> {
+        Updater {
             memory: memory,
             mmu1: mmu1,
             mmu2: mmu2,
@@ -42,18 +59,66 @@ impl<'a> GlobalsUpdater<'a> {
         }
     }
 
-    // TODO: how to distinguish which player?
-    // TODO: we want virtual addresses? or physical ones?
-    pub fn fetch_tag(&self, tag: isa::Address, index: u32) {
-        // TODO: assert index is 0 or 1
-        let address = HOME_STATUS;
+    /// Update the player's status struct with the physical address of
+    /// a tag that has been fetched.
+    pub fn finish_tag(&self, player: Player, tag: u32, index: u32) {
+        debug_assert!(index == 0 || index == 1);
+        let address = HOME_STATUS + isa::Word(index * 4);
+        let address = match player {
+            Player::One => self.mmu1.translate(address),
+            Player::Two => self.mmu2.translate(address),
+        };
+
+        match self.memory.borrow_mut().write_word(address, isa::Word(tag)) {
+            Ok(()) => {},
+            Err(e) => panic!("Could not update memory with cache tag: {:?}", e),
+        }
     }
 
-    pub fn finish_tag(&self, tag: isa::Address, index: u32) {
+    /// Update the player's status struct with the physical address of
+    /// a tag that has been requested.
+    pub fn fetch_tag(&self, player: Player, tag: u32, index: u32) {
+        debug_assert!(index == 0 || index == 1);
+        let address = HOME_STATUS + isa::Word(8 + index * 4);
+        let address = match player {
+            Player::One => self.mmu1.translate(address),
+            Player::Two => self.mmu2.translate(address),
+        };
 
+        match self.memory.borrow_mut().write_word(address, isa::Word(tag)) {
+            Ok(()) => {},
+            Err(e) => panic!("Could not update memory with cache tag: {:?}", e),
+        }
     }
 
     pub fn update_score(&self, player1: i64, player2: i64) {
 
     }
 }
+
+pub struct CacheEventHandler<'a> {
+    player: Player,
+    updater: &'a Updater<'a>,
+}
+
+impl<'a> CacheEventHandler<'a> {
+    pub fn new(updater: &'a Updater<'a>, player: Player)
+               -> CacheEventHandler<'a> {
+        CacheEventHandler {
+            player: player,
+            updater: updater,
+        }
+    }
+}
+
+impl<'a> cache::EventHandler for CacheEventHandler<'a> {
+    fn block_fetched(&self, location: cache::CacheLocation) {
+        // TODO: need to snoop cache
+        info!("[memory] [cache] {}: tag {:x} fetched", self.player, location.tag);
+        self.updater.finish_tag(self.player, location.tag, location.index);
+    }
+
+    fn block_requested(&self, location: cache::CacheLocation) {
+        self.updater.fetch_tag(self.player, location.tag, location.index);
+    }
+}
-- 
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