1 /*
2  * Copyright 2018 Google Inc.
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *     http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include "data.hpp"
18 #include "pci_handler.hpp"
19 
20 #include <fcntl.h>
21 
22 #include <cstdint>
23 #include <cstring>
24 #include <string>
25 #include <vector>
26 
27 namespace ipmi_flash
28 {
29 
30 bool PciDataHandler::open()
31 {
32     static constexpr auto devmem = "/dev/mem";
33 
34     mappedFd = sys->open(devmem, O_RDWR | O_SYNC);
35     if (mappedFd == -1)
36     {
37         std::fprintf(stderr, "PciDataHandler::Unable to open /dev/mem");
38         return false;
39     }
40 
41     mapped = reinterpret_cast<uint8_t*>(sys->mmap(
42         0, memoryRegionSize, PROT_READ, MAP_SHARED, mappedFd, regionAddress));
43     if (mapped == MAP_FAILED)
44     {
45         sys->close(mappedFd);
46         mappedFd = -1;
47         mapped = nullptr;
48 
49         std::fprintf(stderr, "PciDataHandler::Unable to map region");
50         return false;
51     }
52 
53     return true;
54 }
55 
56 bool PciDataHandler::close()
57 {
58     /* TODO: Turn off the P2A bridge and region to disable host-side access.
59      */
60     if (mapped)
61     {
62         sys->munmap(mapped, memoryRegionSize);
63         mapped = nullptr;
64     }
65 
66     if (mappedFd != -1)
67     {
68         sys->close(mappedFd);
69         mappedFd = -1;
70     }
71 
72     return true;
73 }
74 
75 std::vector<std::uint8_t> PciDataHandler::copyFrom(std::uint32_t length)
76 {
77     std::vector<std::uint8_t> results(length);
78     std::memcpy(results.data(), mapped, length);
79 
80     return results;
81 }
82 
83 bool PciDataHandler::writeMeta(const std::vector<std::uint8_t>&)
84 {
85     /* PCI handler doesn't require configuration write, only read. */
86     return false;
87 }
88 
89 std::vector<std::uint8_t> PciDataHandler::readMeta()
90 {
91     /* PCI handler does require returning a configuration from read. */
92     struct PciConfigResponse reply;
93     reply.address = regionAddress;
94 
95     std::vector<std::uint8_t> bytes;
96     bytes.resize(sizeof(reply));
97     std::memcpy(bytes.data(), &reply, sizeof(reply));
98 
99     return bytes;
100 }
101 
102 } // namespace ipmi_flash
103