From 210fff77d5ec0ab172aee309323168a052d489c3 Mon Sep 17 00:00:00 2001
From: David Li <li.davidm96@gmail.com>
Date: Sun, 17 Jan 2016 17:11:25 -0700
Subject: Distinguish between memory and cache at type level

---
 src/memory.rs    | 42 ++++++++++++++++++++++++++++++++++++++++++
 src/simulator.rs |  6 +++---
 2 files changed, 45 insertions(+), 3 deletions(-)

diff --git a/src/memory.rs b/src/memory.rs
index 052ffb7..958ef21 100644
--- a/src/memory.rs
+++ b/src/memory.rs
@@ -123,7 +123,23 @@ pub trait MemoryInterface {
     }
 }
 
+pub struct CacheMetadata {
+    /// How many sets are in the cache
+    pub num_sets: usize,
+    /// How many ways are in a set
+    pub num_ways: usize,
+    /// How many words are in a block/line
+    pub num_block_words: usize,
+    /// The tags currently in the cache, in order of set, then way
+    pub tags: Vec<Option<isa::Address>>,
+}
+
+pub trait CacheInterface : MemoryInterface {
+    fn cache_metadata(&self) -> CacheMetadata;
+}
+
 pub type SharedMemory<'a> = Rc<RefCell<MemoryInterface + 'a>>;
+pub type SharedCache<'a> = Rc<RefCell<CacheInterface + 'a>>;
 
 pub trait Mmu {
     fn translate(&self, address: isa::Address) -> isa::Address;
@@ -441,3 +457,29 @@ impl<'a> MemoryInterface for DirectMappedCache<'a> {
         }
     }
 }
+
+impl<'a> CacheInterface for DirectMappedCache<'a> {
+    fn cache_metadata(&self) -> CacheMetadata {
+        let tags = {
+            let mut tags = Vec::new();
+
+            for set in self.cache.iter() {
+                if set.valid {
+                    tags.push(Some(isa::Word(set.tag)));
+                }
+                else {
+                    tags.push(None);
+                }
+            }
+
+            tags
+        };
+
+        CacheMetadata {
+            num_sets: self.num_sets as usize,
+            num_ways: 1,
+            num_block_words: self.block_words as usize,
+            tags: tags,
+        }
+    }
+}
diff --git a/src/simulator.rs b/src/simulator.rs
index 8e2a0a5..9071599 100644
--- a/src/simulator.rs
+++ b/src/simulator.rs
@@ -16,7 +16,7 @@
 
 use isa;
 use isa::IsaType;
-use memory::{MemoryInterface, MemoryError, Mmu, SharedMemory};
+use memory::{MemoryInterface, MemoryError, Mmu, SharedCache, SharedMemory};
 use register_file::RegisterFile;
 use syscall::SyscallHandler;
 use trap::Trap;
@@ -27,7 +27,7 @@ pub struct Core<'a> {
     registers: RegisterFile,
     stall: u32,
     running: bool,
-    cache: SharedMemory<'a>,
+    cache: SharedCache<'a>,
     mmu: Box<Mmu + 'a>,
     cycle_count: u32,
     stall_count: u32,
@@ -53,7 +53,7 @@ pub struct Simulator<'a, T: SyscallHandler> {
 impl<'a> Core<'a> {
     // TODO: take Rc<RefCell<>> to Memory as well?
     pub fn new(id: usize, entry: isa::Address, sp: isa::Address,
-               cache: SharedMemory<'a>, mmu: Box<Mmu + 'a>) -> Core<'a> {
+               cache: SharedCache<'a>, mmu: Box<Mmu + 'a>) -> Core<'a> {
         let mut registers = RegisterFile::new();
         registers.write_word(isa::Register::X2, sp);
         Core {
-- 
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