| /* |
| * Copyright (c) 2016 Advanced Micro Devices, Inc. |
| * All rights reserved. |
| * |
| * For use for simulation and test purposes only |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are met: |
| * |
| * 1. Redistributions of source code must retain the above copyright notice, |
| * this list of conditions and the following disclaimer. |
| * |
| * 2. 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. |
| * |
| * 3. Neither the name of the copyright holder 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 HOLDER 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: Michael LeBeane |
| */ |
| |
| #ifndef __BASE_MAPPED_BUF_HH__ |
| #define __BASE_MAPPED_BUF_HH__ |
| |
| #include <sys/mman.h> |
| #include <sys/stat.h> |
| |
| #include "base/logging.hh" |
| #include "base/types.hh" |
| |
| /** |
| * MappedFileBuffer is a wrapper around a region of host memory backed by a |
| * file. The constructor attempts to map a file from host memory, and the |
| * destructor attempts to unmap it. If there is a problem with the host |
| * mapping/unmapping, then we panic. |
| */ |
| struct MappedFileBuffer |
| { |
| char *buf; // Host buffer ptr |
| uint64_t len; // Length of host ptr |
| |
| MappedFileBuffer(int fd, uint64_t length, uint64_t offset) |
| : buf(nullptr), len(0) |
| { |
| struct stat file_stat; |
| if (fstat(fd, &file_stat) > 0) |
| panic("mmap: cannot stat file"); |
| // Don't bother mapping more than the actual file size |
| len = std::min((uint64_t)file_stat.st_size - offset, length); |
| // cannot call mmap with len == 0 |
| if (len) { |
| buf = (char *)mmap(NULL, len, PROT_READ, MAP_PRIVATE, fd, offset); |
| if (buf == MAP_FAILED) |
| panic("mmap: failed to map file into host address space"); |
| } |
| } |
| |
| ~MappedFileBuffer() |
| { |
| if (buf) |
| if (munmap(buf, len) == -1) |
| panic("mmap: failed to unmap file-backed host memory"); |
| } |
| }; |
| |
| #endif // __BASE_MAPPED_BUF_HH__ |