Ruby: Remove store buffer

This patch removes the store buffer from Ruby. It is not in use currently.
Since libruby is being and store buffer makes calls to libruby, it is not
possible to maintain it until substantial changes are made.

1 files changed, 0 insertions, 299 deletions

diff --git a/src/mem/ruby/storebuffer/storebuffer.cc b/src/mem/ruby/storebuffer/storebuffer.cc
deleted file mode 100644
index 0accf138d..000000000
--- a/src/mem/ruby/storebuffer/storebuffer.cc
+++ /dev/null
@@ -1,299 +0,0 @@
-/*
- * Copyright (c) 1999-2008 Mark D. Hill and David A. Wood
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met: redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer;
- * redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution;
- * neither the name of the copyright holders nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#include <cassert>
-#include <cstdio>
-#include <map>
-
-#include "base/trace.hh"
-#include "mem/ruby/common/Global.hh"
-#include "mem/ruby/storebuffer/storebuffer.hh"
-
-using namespace std;
-
-#define SYSTEM_EXIT assert(0)
-
-// global map of request id_s to map them back to storebuffer pointers
-map<uint64_t, StoreBuffer *> request_map;
-
-void
-hit(int64_t id)
-{
-    if (request_map.find(id) == request_map.end()) {
-        panic("Request ID %d not found in the map\n", id);
-    } else {
-        request_map[id]->complete(id);
-        request_map.erase(id);
-    }
-}
-
-StoreBuffer::StoreBuffer(uint32 id, uint32 block_bits, int storebuffer_size)
-{
-    iseq = 0;
-    tso_iseq = 0;
-    char name [] = "Sequencer_";
-    char port_name [13];
-    sprintf(port_name, "%s%d", name, id);
-    m_hit_callback = NULL;
-    assert(storebuffer_size >= 0);
-    m_storebuffer_size = storebuffer_size;
-    m_id = id;
-    m_block_size = 1 << block_bits;
-    m_block_mask = ~(m_block_size - 1);
-    m_buffer_size = 0;
-    m_storebuffer_full = false;
-    m_storebuffer_flushing = false;
-    m_stalled_issue = true;
-}
-
-StoreBuffer::~StoreBuffer()
-{
-}
-
-void
-StoreBuffer::registerHitCallback(void (*hit_callback)(int64_t request_id))
-{
-    assert(m_hit_callback == NULL); // can't assign hit_callback twice
-    m_hit_callback = hit_callback;
-}
-
-
-void
-StoreBuffer::addToStoreBuffer(RubyRequest request)
-{
-    buffer.push_front(SBEntry(request, NULL));
-
-    m_buffer_size++;
-
-    if (m_buffer_size >= m_storebuffer_size) {
-        m_storebuffer_full = true;
-    } else if (m_stalled_issue) {
-        m_stalled_issue = false;
-        issueNextStore();
-    }
-
-    iseq++;
-}
-
-
-// Return value of -2 indicates that the load request was satisfied by
-// the store buffer
-// Return value of -3 indicates a partial match, so the load has to
-// retry until NO_MATCH
-// Alternatively we could satisfy the partial match, but tso gets
-// complicated and more races
-int64_t
-StoreBuffer::handleLoad(RubyRequest request)
-{
-    load_match match = checkForLoadHit(request);
-    if (match == FULL_MATCH) {
-        // fill data
-        returnMatchedData(request);
-        iseq++;
-        return -2;
-    } else { // partial match
-        return -3;
-    }
-}
-
-// This function will fill the data array if any match is found
-load_match
-StoreBuffer::checkForLoadHit(RubyRequest request)
-{
-    physical_address_t physical_address = request.paddr;
-    int len = request.len;
-
-    uint8_t * data = new uint8_t[64];
-    memset(data, 0, 64);
-    for (int i = physical_address % 64; i < len; i++)
-        data[i] = 1;
-
-    bool found = false;
-    physical_address_t lineaddr = physical_address & m_block_mask;
-
-    // iterate over the buffer looking for hits
-    deque<SBEntry>::iterator it = buffer.begin();
-    for (; it != buffer.end(); it++) {
-        RubyRequest &req = it->m_request;
-        if ((req.paddr & m_block_mask) != lineaddr)
-            continue;
-
-        found = true;
-        for (int i = req.paddr % 64; i < req.len; i++)
-            data[i] = 0;
-    }
-
-    // if any matching entry is found, determine if all the
-    // requested bytes have been matched
-    if (found) {
-        assert(m_buffer_size > 0);
-        int unmatched_bytes = 0;
-        for (int i = physical_address%64; i < len; i++) {
-            unmatched_bytes = unmatched_bytes + data[i];
-        }
-        if (unmatched_bytes == 0) {
-            delete data;
-            return FULL_MATCH;
-        } else {
-            delete data;
-            return PARTIAL_MATCH;
-        }
-    } else {
-        delete data;
-        return NO_MATCH;
-    }
-}
-
-void
-StoreBuffer::returnMatchedData(RubyRequest request)
-{
-    if (!m_use_storebuffer) {
-        panic("returnMatchedData called while write buffer is not in use\n");
-    }
-
-    uint8_t * data = new uint8_t[64];
-    memset(data, 0, 64);
-    uint8_t * written = new uint8_t[64];
-    memset(written, 0, 64);
-
-    physical_address_t physical_address = request.paddr;
-    int len = request.len;
-
-    assert(checkForLoadHit(request) != NO_MATCH);
-    physical_address_t lineaddr = physical_address & m_block_mask;
-    bool found = false;
-    deque<SBEntry>::iterator satisfying_store;
-    deque<SBEntry>::iterator it = buffer.begin();
-    for (; it != buffer.end(); it++) {
-        if ((it->m_request.paddr & m_block_mask) == lineaddr) {
-            if (!found) {
-                found = true;
-            }
-            uint8_t * dataPtr = it->m_request.data;
-            int offset = it->m_request.paddr%64;
-            for (int i = offset; i < it->m_request.len; i++) {
-                if (!written[i]) { // don't overwrite data with earlier data
-                    data[i] = dataPtr[i-offset];
-                    written[i] = 1;
-                }
-            }
-        }
-    }
-
-    int i = physical_address%64;
-    for (int j = 0; (i < physical_address%64 + len) && (j < len); i++, j++) {
-        if (written[i]) {
-            request.data[j] = data[i];
-        }
-    }
-
-    delete data;
-    delete written;
-}
-
-void
-StoreBuffer::flushStoreBuffer()
-{
-    if (!m_use_storebuffer) {
-        // do nothing
-        return;
-    }
-
-    m_storebuffer_flushing = (m_buffer_size > 0);
-}
-
-void
-StoreBuffer::issueNextStore()
-{
-}
-
-void
-StoreBuffer::complete(uint64_t id)
-{
-    if (!m_use_storebuffer) {
-        m_hit_callback(id);
-        return;
-    }
-
-    assert(outstanding_requests.find(id) != outstanding_requests.end());
-    physical_address_t physical_address =
-        outstanding_requests.find(id)->second.paddr;
-    RubyRequestType type = outstanding_requests.find(id)->second.type;
-
-    if (type == RubyRequestType_ST) {
-        physical_address_t lineaddr = physical_address & m_block_mask;
-
-        // Note fastpath hits are handled like regular requests - they
-        // must remove the WB entry!
-        if (lineaddr != physical_address) {
-            warn("error: StoreBuffer: ruby returns pa 0x%0llx "
-                      "which is not a cache line: 0x%0llx\n",
-                      physical_address, lineaddr);
-        }
-
-        SBEntry from_buffer = buffer.back();
-        if ((from_buffer.m_request.paddr & m_block_mask) == lineaddr &&
-                from_buffer.m_request.type == type) {
-            buffer.pop_back();
-            m_buffer_size--;
-            assert(m_buffer_size >= 0);
-
-            // schedule the next request
-            if (m_buffer_size > 0) {
-                issueNextStore();
-            } else if (m_buffer_size == 0) {
-                m_storebuffer_flushing = false;
-                m_stalled_issue = true;
-            }
-
-            m_storebuffer_full = false;
-        } else {
-            panic("[%d] error: StoreBuffer: at complete, address 0x%0llx "
-                 "not found.\n"
-                 "StoreBuffer:: complete FAILS\n",
-                 m_id, lineaddr);
-        }
-
-    } else if (type == RubyRequestType_LD) {
-        m_hit_callback(id);
-    }
-
-    // LD, ST or FETCH hit callback
-    outstanding_requests.erase(id);
-}
-
-void
-StoreBuffer::print()
-{
-    DPRINTF(RubyStorebuffer, "[%d] StoreBuffer: Total entries: %d "
-            "Outstanding: %d\n",
-            m_id, m_storebuffer_size, m_buffer_size);
-
-    if (!m_use_storebuffer)
-        DPRINTF(RubyStorebuffer, "\t WRITE BUFFER NOT USED\n");
-}