src/sim/vma.cc

   1 /*
   2  * Copyright (c) 2017-2020 Advanced Micro Devices, Inc.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are
   7  * met: redistributions of source code must retain the above copyright
   8  * notice, this list of conditions and the following disclaimer;
   9  * redistributions in binary form must reproduce the above copyright
  10  * notice, this list of conditions and the following disclaimer in the
  11  * documentation and/or other materials provided with the distribution;
  12  * neither the name of the copyright holders nor the names of its
  13  * contributors may be used to endorse or promote products derived from
  14  * this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  17  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  18  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  19  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  20  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  21  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  22  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  26  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 #include "sim/vma.hh"
  30
  31 #include <sys/mman.h>
  32 #include <sys/stat.h>
  33
  34 #include "base/types.hh"
  35 #include "config/the_isa.hh"
  36
  37 void
  38 VMA::fillMemPages(Addr start, Addr size, PortProxy &port) const
  39 {
  40     auto offset = start - _addrRange.start();
  41
  42     /**
  43      * Try to copy a full page, but don't overrun the size of the file.
  44      */
  45     if (offset < _hostBufLen) {
  46         auto size = std::min(_hostBufLen - offset, _pageBytes);
  47         port.writeBlob(start, (uint8_t*)_hostBuf + offset, size);
  48     }
  49 }
  50
  51 bool
  52 VMA::isStrictSuperset(const AddrRange &r) const
  53 {
  54     return (r.start() > _addrRange.start() && r.end() < _addrRange.end());
  55 }
  56
  57 void
  58 VMA::sliceRegionRight(Addr slice_addr)
  59 {
  60     if (hasHostBuf()) {
  61         auto nonoverlap_len = slice_addr - _addrRange.start();
  62         _hostBufLen = std::min(_hostBufLen, nonoverlap_len);
  63     }
  64
  65     _addrRange = AddrRange(_addrRange.start(), slice_addr);
  66
  67     DPRINTF(Vma, "slice right vma start %#x end %#x\n", _addrRange.start(),
  68             _addrRange.end());
  69
  70     sanityCheck();
  71 }
  72
  73 void
  74 VMA::sliceRegionLeft(Addr slice_addr)
  75 {
  76     if (hasHostBuf()) {
  77         auto overlap_len = slice_addr - _addrRange.start();
  78
  79         if (overlap_len >= _hostBufLen) {
  80             _hostBufLen = 0;
  81             _hostBuf = nullptr;
  82             _origHostBuf = nullptr;
  83         } else {
  84             _hostBufLen -= overlap_len;
  85         }
  86
  87         _hostBuf = (void *)((uint8_t *)_hostBuf + overlap_len);
  88     }
  89
  90     _addrRange = AddrRange(slice_addr, _addrRange.end());
  91
  92     DPRINTF(Vma, "slice left vma start %#x end %#x\n", _addrRange.start(),
  93             _addrRange.end());
  94
  95     sanityCheck();
  96 }
  97
  98 void
  99 VMA::sanityCheck()
 100 {
 101     /**
 102      * Avoid regions without a length.
 103      */
 104     assert(_addrRange.start() != _addrRange.end());
 105
 106     /**
 107      * Avoid regions with an end point before the start point
 108      */
 109     assert(_addrRange.start() < _addrRange.end());
 110
 111     /**
 112      *  Avoid non-aligned regions; we assume in the code that the
 113      *  regions are page aligned so consider this to be a bug.
 114      */
 115     assert((_addrRange.start() % _pageBytes) == 0);
 116     assert((_addrRange.end() % _pageBytes) == 0);
 117 }
 118
 119 VMA::MappedFileBuffer::MappedFileBuffer(int fd, size_t length,
 120                                         off_t offset)
 121     : _buffer(nullptr), _length(length)
 122 {
 123     panic_if(_length == 0, "Tried to mmap file of length zero");
 124
 125     struct stat file_stat;
 126     if (fstat(fd, &file_stat) > 0) {
 127         panic("Cannot stat file: %s\n", strerror(errno));
 128     }
 129
 130     // Don't bother mapping more than the actual file size
 131     panic_if(offset > file_stat.st_size,
 132              "Tried to mmap with offset greater than file size");
 133     _length = std::min((size_t)(file_stat.st_size - offset), _length);
 134
 135     // cannot call mmap with _length == 0
 136     if (_length) {
 137         _buffer = mmap(NULL, _length, PROT_READ,
 138                                  MAP_PRIVATE, fd, offset);
 139         if (_buffer == MAP_FAILED) {
 140             panic("Failed to map file into host address space: %s",
 141                   strerror(errno));
 142         }
 143     } else {
 144         panic("Tried to mmap 0 bytes");
 145     }
 146 }
 147
 148 VMA::MappedFileBuffer::~MappedFileBuffer()
 149 {
 150     if (_buffer) {
 151         panic_if(munmap(_buffer, _length) == -1,
 152                  "mmap: failed to unmap file-backed host memory: %s",
 153                  strerror(errno));
 154     }
 155 }