sam-t2/sam/cpus/vonk/ss/lib/csr/src/SS_BaseCsr.cc

// ========== Copyright Header Begin ==========================================
//
// OpenSPARC T2 Processor File: SS_BaseCsr.cc
// Copyright (c) 2006 Sun Microsystems, Inc.  All Rights Reserved.
// DO NOT ALTER OR REMOVE COPYRIGHT NOTICES.
//
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// modify it under the terms of the GNU General Public
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// General Public License for more details.
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// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
//
// ========== Copyright Header End ============================================
/************************************************************************
**
**  Copyright (C) 2006, Sun Microsystems, Inc.
**
**  Sun considers its source code as an unpublished, proprietary
**  trade secret and it is available only under strict license provisions.
**  This copyright notice is placed here only to protect Sun in the event
**  the source is deemed a published work. Disassembly, decompilation,
**  or other means of reducing the object code to human readable form
**  is prohibited by the license agreement under which this code is
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*************************************************************************/
#include <sstream>
#include <list>
#include "SS_BaseCsr.h"
#include "SS_Memory.h"
#include "SS_AddressMap.h"

using namespace std;

//======================================================================
//======================================================================
void
SS_BaseCsr::access( void* obj,
                    uint_t sid,
                    SS_Access::Type type,
                    SS_Paddr addr,
                    uint_t size,
                    uint64_t* data)
{
  SS_BaseCsr* self = (SS_BaseCsr*)obj;
  switch (type)
  {
  case SS_Access::LOAD:
    self->read64(addr, data, MemoryTransaction::READ, sid);
    break;
  case SS_Access::STORE:
    self->write64(addr, *data, MemoryTransaction::WRITE, sid);
    break;
  }
}

//======================================================================
//======================================================================
int64_t
SS_BaseCsr::findAttributeEntryNdx(SS_Paddr paddr,
                                  const RegisterAttribute* attributeTable,
                                  int entries)
{
    for (int i = 0; i < entries; i++) {
        if (attributeTable[i].startAddr <= paddr && paddr <= attributeTable[i].endAddr) {
            if (((paddr - attributeTable[i].startAddr) & (attributeTable[i].stride - 1)) == 0) {
                return i;
            }
        }
    }
    return ENTRY_NOT_FOUND;
}

//======================================================================
//======================================================================
const RegisterAttribute* const
SS_BaseCsr::findAttributeEntry(SS_Paddr paddr,
                               const RegisterAttribute* attributeTable,
                               int entries)
{
    uint64_t ndx = findAttributeEntryNdx(paddr, attributeTable, entries);
    return ndx == ENTRY_NOT_FOUND ? NULL: &attributeTable[ndx];
}

//======================================================================
//======================================================================
void
SS_BaseCsr::warmReset(vector<vector<RegisterValue>*>* values,
                      int nrAttributeEntries)
{
  //TODO  if a register has different por and warm-reset values, and
  //      the register is never referenced up to this point, such that it
  //      is not in the table yet, then we won't create a register with
  //      warm-reset value for it, the next access to the register will
  //      return its por value, which is wrong. 11/29/05
  for (int i = 0; i < nrAttributeEntries; i++)
  {
    // CSR entries, has 1-to-1 mapping with RegisterAttribute table
    vector<vector<RegisterValue>*> nodes = values[i];
    for (int j = 0; j < nodes.size(); j++)
    {
      // each entry points to a vector of registers belong to a particulat node
      if (nodes[j] != NULL)
      {
        vector<RegisterValue>& regs = *nodes[j];
        for (int k = 0; k < regs.size(); k++)
        {
          // registers, of a particular node and a particular CSR entry
          if (regs[k].valid())
          {
            if (regs[k].attribute->maskWarm == 0x0)
            {
              // if no warm-reset mask, just use warm-reset value
              regs[k].set_data(regs[k].attribute->warmReset);
            }
            else
            {
              // otherwise, use warm-reset mask on current data to produce
              // the new data.
              regs[k].set_data(regs[k].data() & regs[k].attribute->maskWarm);
            }
          }
        }
      }
    }
  }
}

//=============================================================================
// this function assumes value is always 8-byte
//=============================================================================
uint64_t
SS_BaseCsr::reverseByteOrder(uint64_t value, bool littleEndian)
{
  if (littleEndian)
  {
    int size = 8;
    uint8_t *byteArr = (uint8_t*)&value;
    uint64_t revValue = 0;
    uint8_t *revByteArr = (uint8_t*)&revValue;

    int revIdx = sizeof( value ) - size;
    int topByte = sizeof( value ) - 1;
    for ( int byte = topByte; byte > topByte - size; --byte )
    {
      revByteArr[revIdx] = byteArr[byte];
      ++revIdx;
    }
    return revValue;
  }
  else
  {
    return value;
  }
}

//=============================================================================
// mainly used by follow-me, allow writing into any bits except reserved ones,
// ignore RW1C and RW1S masking. If the data is in littleEndian, then the
// reserved-mask must be reversed before doing the masking.
//=============================================================================
uint64_t
SS_BaseCsr::forceWrite(uint64_t inputData,
                       const RegisterAttribute* attribute,
                       int access)
{
  bool littleEndian = (access & MemoryTransaction::LITTLE_ENDIAN) ? true : false;
    return (inputData & ~(reverseByteOrder(attribute->maskRSVD, littleEndian)));
}

//=============================================================================
// normal write operation, take all masking into account.
//
// exclude_maskRW = maskRW & ~(maskRW1C | maskRW1S)
// new_data = (input_data & exclude_maskRW) |
//            (input_data & maskRW1S) |
//            (old_data & ~(exclde_maskRW | (input_data & maskRW1C)))
// newData = normalWrite(inputData, oldData, attribute, littleEndian);
//=============================================================================
uint64_t
SS_BaseCsr::normalWrite(uint64_t inputData,
                        uint64_t oldData,
                        const RegisterAttribute* attribute,
                        int access)
{
  bool littleEndian = (access & MemoryTransaction::LITTLE_ENDIAN) ? true : false;
    uint64_t maskRW_exc = attribute->maskRW & ~(attribute->maskRW1C | attribute->maskRW1S);
    uint64_t newData = (inputData & reverseByteOrder(maskRW_exc, littleEndian)) |
        (inputData & reverseByteOrder(attribute->maskRW1S, littleEndian)) |
        (oldData & ~(reverseByteOrder(maskRW_exc, littleEndian) | (inputData & reverseByteOrder(attribute->maskRW1C, littleEndian))));

    return newData;
}

//=============================================================================
//=============================================================================
void
SS_BaseCsr::registerAddressSpace(RegisterAttribute *attributeTable,
                                 uint_t tableSize,
                                 const string &description)
{
  //TODO  this routine does not take localvs global I/O address into account

    uint64_t start = ULLONG_MAX;
    uint64_t end = 0;

    for (uint_t tableNdx = 0; tableNdx < tableSize; ++tableNdx) {
        if (attributeTable[tableNdx].startAddr < start) {
            start = attributeTable[tableNdx].startAddr;
        }
        if (attributeTable[tableNdx].endAddr > end) {
            // Be sure to cover the entire address range
            end = attributeTable[tableNdx].endAddr +
                attributeTable[tableNdx].stride - 1;

            // Die if the stride and the count don't match the
            // endAddr
            if (end + 1 < attributeTable[tableNdx].startAddr +
                attributeTable[tableNdx].stride *
                attributeTable[tableNdx].count) {
                ostringstream os;
                os << "SS_BaseCsr::registerAddressSpace: " <<
                    "bad RegisterAttribute ranges: endAddr 0x" <<
                    hex  << end <<
                    " startAddr 0x" << attributeTable[tableNdx].startAddr <<
                    " stride " << dec << attributeTable[tableNdx].stride <<
                    " count\n" << dec << attributeTable[tableNdx].count <<
                    "\n";

                fprintf(stderr, "ERROR: %s\n", os.str().c_str());
            }
        }
    }
#ifndef COMPILE_FOR_COSIM
    //TODO  we don't have strand pointer here, cannot access sim_state.cosim()
    //if (!s->sim_state.cosim())
    SS_Io::io.add(start, end, this, SS_AddressMap::ABS, SS_BaseCsr::access);
#endif
}

//=============================================================================
// when mem==NULL, a paddr that does not match any supported CSR will
// return INVALID value, this is mainly used by callback corresponding
// to asi_read.  when access.getInternal()==true, it means the
// read64() is invoked by callback// corresponding to asi_read, the
// read64() will return INVALID for non-matched paddr, and it will
// remove a matched entry after the value is returned.
//=============================================================================
//======================================================================
// THIS IS READ64
//======================================================================
int
SS_BaseCsr::read64( SS_Paddr paddr, uint64_t* data, int access, int sid )
{
  // for N2, there is only one cpu (i.e., node), so local I/O address is
  // equal to global I/O address.

  // In general strands in the same cpu use the same global I/O address, but
  // for CSR follow-me, each strand can have its own follow-me value, so we
  // need strand-id in follow-me matching up.

  SS_Paddr laddr;
  SS_Paddr gaddr;
  if (is_global_addr(paddr))
  {
    laddr = global2local(paddr);
    gaddr = paddr;
  }
  else if (sid < 0)
  {
    // if it is not a global address, then we need a real strand-id to
    // convert the address to global address, otherwise it is an error.
    fprintf(stderr, "ERROR: SS_BaseCsr::read64( paddr=%#llx, sid=%d ): paddr not a global addr\n", paddr, sid);
    *data = 0;
    return SS_Io::NOP;
  }
  else
  {
    laddr = paddr;
    gaddr = local2global(paddr, sid);
  }
  SS_Paddr baddr = addr_node0(paddr);
  int nid = get_node_id(gaddr);

  // for any read, look at follow-me list first, if a match can be found,
  // use it (and then discard the entry), otherwise go to real register area.
  if ((access & SS_BaseCsr::NO_FOLLOW_ME) == 0)
  {
    list<FollowMeData>::iterator iter = followme_.begin();
    for (; iter != followme_.end(); iter++)
    {
      // if either side of sid is -1, then pick the first entry that has a
      // matching addr
      if (((*iter).addr == gaddr) &&
          (((*iter).sid == sid) || ((*iter).sid < 0) || (sid < 0)))
      {
        *data = (*iter).data;
        followme_.erase(iter);
        return SS_Io::FOLLOWME;
      }
    }
  }

  // no matching follow-me, search real CSR
  uint64_t attributeNdx =
    findAttributeEntryNdx(baddr, attributeTable_, nrAttributeEntries_);
  if (attributeNdx != ENTRY_NOT_FOUND)
  {
    // attribute table uses node0 addr as keyword, 'value' vector has an
    // 1-on-1 mapping with attribute table, so node0 addr has to be used.
    const RegisterAttribute* attribute = &attributeTable_[attributeNdx];
    RegisterValue *value = attribute->find(baddr, values_[attributeNdx], nid);
    if (value == NULL)
    {
      // this is an error
      fprintf(stderr, "ERROR: SS_BaseCsr::read64( paddr=%#llx, sid=%d ): null RegisterValue pointer\n", paddr, sid);
      *data = 0;
      return SS_Io::NOP;
    }
    else
    {
      if (!value->valid())
      {
        // no valid data for this entry yet, generate it
        uint64_t init_data;
        // first, see if the addr has a valid data in mem.image (sometimes
        // uses this approach to provide a csr's init value other then its
        // pre-defined por value).
        int state = read_memimage(gaddr, laddr, &init_data);
        init_data &= attribute->maskRSVD;
        if (init_data == 0x0)
        {
          // when read_memimage() returns 0, we consider that means no data
          // for this addr is available in mem.image, so we use the por value
          // in CSR attribute table.
          //TODO  this can be troublesome, if a real 0x0 value is set for the
          //      addr in mem.image, then we will mistake it as not available,
          //      and use por value instead (wrongly), do we have a way of
          //      knowing whether a valid data is available in mem.image?
          init_data = attribute->por;
        }
        RegisterValue newValue(baddr, init_data, attribute, sid);
        *value = newValue;
      }
      *data = value->data();
    }
  }
  else
  {
    // not in csr attribute list, use global addr for non-csr
    return read64_notCsr( gaddr, laddr, data );
  }
  return SS_Io::OK;
}

//=============================================================================
// read64_notCsr() reads any non-CSR address
//=============================================================================
int
SS_BaseCsr::read64_notCsr( SS_Paddr gaddr, SS_Paddr laddr, uint64_t* data )
{
  // for addr not in csr list, just read it from memory
  return read_memimage(gaddr, laddr, data);
}

//=============================================================================
// when mem==NULL, a paddr that does not match any supported CSR will
// be silently dropped, this is mainly used by asi_read function.
// when access.getInternal()==true, it means allwoing write to RO
// non-reserved field(s) of a register, this is to mimic hardware
// writing to RO non-reserved field(s).
//=============================================================================
int
SS_BaseCsr::write64( SS_Paddr paddr, uint64_t data, int access, int sid )
{
  SS_Paddr laddr;
  SS_Paddr gaddr;
  if (is_global_addr(paddr))
  {
    laddr = global2local(paddr);
    gaddr = paddr;
  }
  else if (sid < 0)
  {
    // if it is not a global address, then we need a real strand-id to
    // convert the address to global address, otherwise it is an error.
    fprintf(stderr, "ERROR: SS_BaseCsr::write64( paddr=%#llx, sid=%d ): paddr not a global addr\n", paddr, sid);
    return SS_Io::NOP;
  }
  else
  {
    laddr = paddr;
    gaddr = local2global(paddr, sid);
  }
  SS_Paddr baddr = addr_node0(paddr);
  int nid = get_node_id(gaddr);

  if (access & MemoryTransaction::FOLLOW_ME)
  {
    // this is a follow-me write, keep the value in followme_ list
    FollowMeData fm(gaddr, data, sid);
    followme_.push_back(fm);
    return SS_Io::OK;
  }
  else
  {
    uint64_t attributeNdx =
      findAttributeEntryNdx(baddr, attributeTable_, nrAttributeEntries_);
    if (attributeNdx != ENTRY_NOT_FOUND)
    {
      const RegisterAttribute* attribute = &attributeTable_[attributeNdx];
      RegisterValue *value = attribute->find(baddr, values_[attributeNdx], nid);
      if (value == NULL)
      {
        // this is an error
        fprintf(stderr, "ERROR: SS_BaseCsr::write64( paddr=%#llx, sid=%d ): null RegisterValue pointer\n", paddr, sid);
        return SS_Io::NOP;
      }
      else
      {
        uint64_t new_data;
        uint64_t old_data = attribute->por;
        if (value->valid())
        {
          old_data = value->data();
        }
        if ((access & MemoryTransaction::INTERNAL) ||
            (access & MemoryTransaction::MEM_SLAM))
        {
          // allow writing into any non-reserved bits
          new_data = forceWrite(data, attribute, access);
        }
        else
        {
          if (attribute->protect != RegisterAttribute::RO)
          {
            // can only write into W bits (e.g., WO, RW, RW1C, RW1S, etc)
            new_data = normalWrite(data, old_data, attribute, access);
          }
          else
          {
            fprintf(stderr, "WARNING: %s::write64(): paddr=%#llx (gaddr=%#llx) is read-only, data=%#llx is NOT committed\n", className_.c_str(), paddr, gaddr, data);
            return SS_Io::NOP;
          }
        }
        if (!value->valid())
        {
          // the entry is not available yet, create it
          RegisterValue newValue(baddr, new_data, attribute, sid);
          *value = newValue;
        }
        else
        {
          value->set_data(new_data);
        }
      }
    }
    else
    {
      // paddr not in csr list
      return write64_notCsr( gaddr, data );
    }
  }
  return SS_Io::OK;
}

//=============================================================================
// write64_notCsr() reads any non-CSR address
//=============================================================================
int
SS_BaseCsr::write64_notCsr( SS_Paddr gaddr, uint64_t data )
{
  // for addr not in csr list, just write it to memory using global-addr
#ifndef COMPILE_FOR_SAM
  SS_Memory::memory.poke64(gaddr, data);
  return SS_Io::OK;
#else
  extern SS_Memory *mm1;
  mm1->st64(gaddr, data);
  return SS_Io::OK;
#endif
}

//=============================================================================
// even if an addr in question is in CSR list, a diag may have the addr's
// initial value in mem.image, it can use either local or global addr, so
// look for those first. Always start with global addr, as that is specific
// to each node, local addr is shared among nodes. If none is found, then use
// the pre-defined por value (if one is available). (yes, it is messy, but
// verification diag wants the flexibility).
//=============================================================================
int
SS_BaseCsr::read_memimage( SS_Paddr gaddr, SS_Paddr laddr, uint64_t* data )
{
#ifndef COMPILE_FOR_SAM
  *data = SS_Memory::memory.peek64(gaddr);
#else
  extern SS_Memory *mm1;
  *data = mm1->ld64(gaddr);
#endif
  if ((*data == 0x0) && (gaddr != laddr))
  {
    // if not match with global addr, try local addr
    //TODO  this is not perfect, returned value of 0x0 can be
    //      (1) the addr is not in mem.image, (2) the addr is in
    //      mem.image with value 0x0. In here we assume 0x0 means
    //      not in mem.image.
#ifndef COMPILE_FOR_SAM
    *data = SS_Memory::memory.peek64(laddr);
#else
  extern SS_Memory *mm1;
  *data = mm1->ld64(laddr);
#endif
  }
  return SS_Io::OK;
}