text: /*
   * Copyright (c) 2012, 2014 ARM Limited
   * All rights reserved
   *
   * The license below extends only to copyright in the software and shall
   * not be construed as granting a license to any other intellectual
   * property including but not limited to intellectual property relating
   * to a hardware implementation of the functionality of the software
   * licensed hereunder.  You may use the software subject to the license
   * terms below provided that you ensure that this notice is replicated
   * unmodified and in its entirety in all distributions of the software,
   * modified or unmodified, in source code or in binary form.
   *
   * 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.
   *
   * Authors: Andreas Hansson
   */
  
  #include <sys/mman.h>
  #include <sys/types.h>
  #include <sys/user.h>
  #include <fcntl.h>
  #include <unistd.h>
  #include <zlib.h>
  
  #include <cerrno>
  #include <climits>
  #include <cstdio>
  #include <iostream>
  #include <string>
  
  #include "base/trace.hh"
  #include "debug/AddrRanges.hh"
  #include "debug/Checkpoint.hh"
  #include "mem/abstract_mem.hh"
  #include "mem/physical.hh"
  
  /**
   * On Linux, MAP_NORESERVE allow us to simulate a very large memory
   * without committing to actually providing the swap space on the
   * host. On FreeBSD or OSX the MAP_NORESERVE flag does not exist,
   * so simply make it 0.
   */
  #if defined(__APPLE__) || defined(__FreeBSD__)
  #ifndef MAP_NORESERVE
  #define MAP_NORESERVE 0
  #endif
  #endif
  
  using namespace std;
  
  PhysicalMemory::PhysicalMemory(const string& _name,
                                 const vector<AbstractMemory*>& _memories,
                                 bool mmap_using_noreserve) :
      _name(_name), rangeCache(addrMap.end()), size(0),
      mmapUsingNoReserve(mmap_using_noreserve)
  {
      if (mmap_using_noreserve)
          warn("Not reserving swap space. May cause SIGSEGV on actual usage\n");
  
      // add the memories from the system to the address map as
      // appropriate
      for (const auto& m : _memories) {
          // only add the memory if it is part of the global address map
          if (m->isInAddrMap()) {
              memories.push_back(m);
  
              // calculate the total size once and for all
              size += m->size();
  
              // add the range to our interval tree and make sure it does not
              // intersect an existing range
              fatal_if(addrMap.insert(m->getAddrRange(), m) == addrMap.end(),
                       "Memory address range for %s is overlapping\n",
                       m->name());
          } else {
              // this type of memory is used e.g. as reference memory by
              // Ruby, and they also needs a backing store, but should
              // not be part of the global address map
              DPRINTF(AddrRanges,
                      "Skipping memory %s that is not in global address map\n",
                      m->name());
  
              // sanity check
              fatal_if(m->getAddrRange().interleaved(),
                       "Memory %s that is not in the global address map cannot "
                       "be interleaved\n", m->name());
  
              // simply do it independently, also note that this kind of
              // memories are allowed to overlap in the logic address
              // map
              vector<AbstractMemory*> unmapped_mems{m};
              createBackingStore(m->getAddrRange(), unmapped_mems);
          }
      }
  
      // iterate over the increasing addresses and chunks of contiguous
      // space to be mapped to backing store, create it and inform the
      // memories
      vector<AddrRange> intlv_ranges;
      vector<AbstractMemory*> curr_memories;
      for (const auto& r : addrMap) {
          // simply skip past all memories that are null and hence do
          // not need any backing store
          if (!r.second->isNull()) {
              // if the range is interleaved then save it for now
              if (r.first.interleaved()) {
                  // if we already got interleaved ranges that are not
                  // part of the same range, then first do a merge
                  // before we add the new one
                  if (!intlv_ranges.empty() &&
                      !intlv_ranges.back().mergesWith(r.first)) {
                      AddrRange merged_range(intlv_ranges);
                      createBackingStore(merged_range, curr_memories);
                      intlv_ranges.clear();
                      curr_memories.clear();
                  }
                  intlv_ranges.push_back(r.first);
                  curr_memories.push_back(r.second);
              } else {
                  vector<AbstractMemory*> single_memory{r.second};
                  createBackingStore(r.first, single_memory);
              }
          }
      }
  
      // if there is still interleaved ranges waiting to be merged, go
      // ahead and do it
      if (!intlv_ranges.empty()) {
          AddrRange merged_range(intlv_ranges);
          createBackingStore(merged_range, curr_memories);
      }
  }
  
  void
  PhysicalMemory::createBackingStore(AddrRange range,
                                     const vector<AbstractMemory*>& _memories)
  {
      panic_if(range.interleaved(),
               "Cannot create backing store for interleaved range %s\n",
                range.to_string());
  
      // perform the actual mmap
      DPRINTF(AddrRanges, "Creating backing store for range %s with size %d\n",
              range.to_string(), range.size());
      int map_flags = MAP_ANON | MAP_PRIVATE;
  
      // to be able to simulate very large memories, the user can opt to
      // pass noreserve to mmap
      if (mmapUsingNoReserve) {
          map_flags |= MAP_NORESERVE;
      }
  
      uint8_t* pmem = (uint8_t*) mmap(NULL, range.size(),
                                      PROT_READ | PROT_WRITE,
                                      map_flags, -1, 0);
  
      if (pmem == (uint8_t*) MAP_FAILED) {
          perror("mmap");
          fatal("Could not mmap %d bytes for range %s!\n", range.size(),
                range.to_string());
      }
  
      // remember this backing store so we can checkpoint it and unmap
      // it appropriately
      backingStore.push_back(make_pair(range, pmem));
  
      // point the memories to their backing store
      for (const auto& m : _memories) {
          DPRINTF(AddrRanges, "Mapping memory %s to backing store\n",
                  m->name());
          m->setBackingStore(pmem);
      }
  }
  
  PhysicalMemory::~PhysicalMemory()
  {
      // unmap the backing store
      for (auto& s : backingStore)
          munmap((char*)s.second, s.first.size());
  }
  
  bool
  PhysicalMemory::isMemAddr(Addr addr) const
  {
      // see if the address is within the last matched range
      if (rangeCache != addrMap.end() && rangeCache->first.contains(addr)) {
          return true;
      } else {
          // lookup in the interval tree
          const auto& r = addrMap.find(addr);
          if (r == addrMap.end()) {
              // not in the cache, and not in the tree
              return false;
          }
          // the range is in the tree, update the cache
          rangeCache = r;
          return true;
      }
  }
  
  AddrRangeList
  PhysicalMemory::getConfAddrRanges() const
  {
      // this could be done once in the constructor, but since it is unlikely to
      // be called more than once the iteration should not be a problem
      AddrRangeList ranges;
      vector<AddrRange> intlv_ranges;
      for (const auto& r : addrMap) {
          if (r.second->isConfReported()) {
              // if the range is interleaved then save it for now
              if (r.first.interleaved()) {
                  // if we already got interleaved ranges that are not
                  // part of the same range, then first do a merge
                  // before we add the new one
                  if (!intlv_ranges.empty() &&
                      !intlv_ranges.back().mergesWith(r.first)) {
                      ranges.push_back(AddrRange(intlv_ranges));
                      intlv_ranges.clear();
                  }
                  intlv_ranges.push_back(r.first);
              } else {
                  // keep the current range
                  ranges.push_back(r.first);
              }
          }
      }
  
      // if there is still interleaved ranges waiting to be merged,
      // go ahead and do it
      if (!intlv_ranges.empty()) {
          ranges.push_back(AddrRange(intlv_ranges));
      }
  
      return ranges;
  }
  
  void
  PhysicalMemory::access(PacketPtr pkt)
  {
      assert(pkt->isRequest());
      Addr addr = pkt->getAddr();
      if (rangeCache != addrMap.end() && rangeCache->first.contains(addr)) {
          rangeCache->second->access(pkt);
      } else {
          // do not update the cache here, as we typically call
          // isMemAddr before calling access
          const auto& m = addrMap.find(addr);
          assert(m != addrMap.end());
          m->second->access(pkt);
      }
  }
  
  void
  PhysicalMemory::functionalAccess(PacketPtr pkt)
  {
      assert(pkt->isRequest());
      Addr addr = pkt->getAddr();
      if (rangeCache != addrMap.end() && rangeCache->first.contains(addr)) {
          rangeCache->second->functionalAccess(pkt);
      } else {
          // do not update the cache here, as we typically call
          // isMemAddr before calling functionalAccess
          const auto& m = addrMap.find(addr);
          assert(m != addrMap.end());
          m->second->functionalAccess(pkt);
      }
  }
  
  void
  PhysicalMemory::serialize(CheckpointOut &cp) const
  {
      // serialize all the locked addresses and their context ids
      vector<Addr> lal_addr;
      vector<ContextID> lal_cid;
  
      for (auto& m : memories) {
          const list<LockedAddr>& locked_addrs = m->getLockedAddrList();
          for (const auto& l : locked_addrs) {
              lal_addr.push_back(l.addr);
              lal_cid.push_back(l.contextId);
          }
      }
  
      SERIALIZE_CONTAINER(lal_addr);
      SERIALIZE_CONTAINER(lal_cid);
  
      // serialize the backing stores
      unsigned int nbr_of_stores = backingStore.size();
      SERIALIZE_SCALAR(nbr_of_stores);
  
      unsigned int store_id = 0;
      // store each backing store memory segment in a file
      for (auto& s : backingStore) {
          ScopedCheckpointSection sec(cp, csprintf("store%d", store_id));
          serializeStore(cp, store_id++, s.first, s.second);
      }
  }
  
  void
  PhysicalMemory::serializeStore(CheckpointOut &cp, unsigned int store_id,
                                 AddrRange range, uint8_t* pmem) const
  {
      // we cannot use the address range for the name as the
      // memories that are not part of the address map can overlap
      string filename = name() + ".store" + to_string(store_id) + ".pmem";
      long range_size = range.size();
  
      DPRINTF(Checkpoint, "Serializing physical memory %s with size %d\n",
              filename, range_size);
  
      SERIALIZE_SCALAR(store_id);
      SERIALIZE_SCALAR(filename);
      SERIALIZE_SCALAR(range_size);
  
      // write memory file
      string filepath = CheckpointIn::dir() + "/" + filename.c_str();
      gzFile compressed_mem = gzopen(filepath.c_str(), "wb");
      if (compressed_mem == NULL)
          fatal("Can't open physical memory checkpoint file '%s'\n",
                filename);
  
      uint64_t pass_size = 0;
  
      // gzwrite fails if (int)len < 0 (gzwrite returns int)
      for (uint64_t written = 0; written < range.size();
           written += pass_size) {
          pass_size = (uint64_t)INT_MAX < (range.size() - written) ?
              (uint64_t)INT_MAX : (range.size() - written);
  
          if (gzwrite(compressed_mem, pmem + written,
                      (unsigned int) pass_size) != (int) pass_size) {
              fatal("Write failed on physical memory checkpoint file '%s'\n",
                    filename);
          }
      }
  
      // close the compressed stream and check that the exit status
      // is zero
      if (gzclose(compressed_mem))
          fatal("Close failed on physical memory checkpoint file '%s'\n",
                filename);
  
  }
  
  void
  PhysicalMemory::unserialize(CheckpointIn &cp)
  {
      // unserialize the locked addresses and map them to the
      // appropriate memory controller
      vector<Addr> lal_addr;
      vector<ContextID> lal_cid;
      UNSERIALIZE_CONTAINER(lal_addr);
      UNSERIALIZE_CONTAINER(lal_cid);
      for (size_t i = 0; i < lal_addr.size(); ++i) {
          const auto& m = addrMap.find(lal_addr[i]);
          m->second->addLockedAddr(LockedAddr(lal_addr[i], lal_cid[i]));
      }
  
      // unserialize the backing stores
      unsigned int nbr_of_stores;
      UNSERIALIZE_SCALAR(nbr_of_stores);
  
      for (unsigned int i = 0; i < nbr_of_stores; ++i) {
          ScopedCheckpointSection sec(cp, csprintf("store%d", i));
          unserializeStore(cp);
      }
  
  }
  
  void
  PhysicalMemory::unserializeStore(CheckpointIn &cp)
  {
      const uint32_t chunk_size = 16384;
  
      unsigned int store_id;
      UNSERIALIZE_SCALAR(store_id);
  
      string filename;
      UNSERIALIZE_SCALAR(filename);
      string filepath = cp.cptDir + "/" + filename;
  
      // mmap memoryfile
      gzFile compressed_mem = gzopen(filepath.c_str(), "rb");
      if (compressed_mem == NULL)
          fatal("Can't open physical memory checkpoint file '%s'", filename);
  
      // we've already got the actual backing store mapped
      uint8_t* pmem = backingStore[store_id].second;
      AddrRange range = backingStore[store_id].first;
  
      long range_size;
      UNSERIALIZE_SCALAR(range_size);
  
      DPRINTF(Checkpoint, "Unserializing physical memory %s with size %d\n",
              filename, range_size);
  
      if (range_size != range.size())
          fatal("Memory range size has changed! Saw %lld, expected %lld\n",
                range_size, range.size());
  
      uint64_t curr_size = 0;
      long* temp_page = new long[chunk_size];
      long* pmem_current;
      uint32_t bytes_read;
      while (curr_size < range.size()) {
          bytes_read = gzread(compressed_mem, temp_page, chunk_size);
          if (bytes_read == 0)
              break;
  
          assert(bytes_read % sizeof(long) == 0);
  
          for (uint32_t x = 0; x < bytes_read / sizeof(long); x++) {
              // Only copy bytes that are non-zero, so we don't give
              // the VM system hell
              if (*(temp_page + x) != 0) {
                  pmem_current = (long*)(pmem + curr_size + x * sizeof(long));
                  *pmem_current = *(temp_page + x);
              }
          }
          curr_size += bytes_read;
      }
  
      delete[] temp_page;
  
      if (gzclose(compressed_mem))
          fatal("Close failed on physical memory checkpoint file '%s'\n",
                filename);
  }
  