xref: /openbmc/google-ipmi-sys/cpld.cpp (revision a2056e9c)
1 // Copyright 2021 Google LLC
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 //      http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14 
15 #include "cpld.hpp"
16 
17 #include "commands.hpp"
18 #include "errors.hpp"
19 #include "handler.hpp"
20 
21 #include <cstring>
22 
23 namespace google
24 {
25 namespace ipmi
26 {
27 
28 struct CpldRequest
29 {
30     uint8_t subcommand;
31     uint8_t id;
32 } __attribute__((packed));
33 
34 struct CpldReply
35 {
36     uint8_t subcommand;
37     uint8_t major;
38     uint8_t minor;
39     uint8_t point;
40     uint8_t subpoint;
41 } __attribute__((packed));
42 
43 //
44 // Handle reading the cpld version from the tmpfs.
45 //
46 ipmi_ret_t cpldVersion(const uint8_t* reqBuf, uint8_t* replyBuf,
47                        size_t* dataLen, const HandlerInterface* handler)
48 {
49     struct CpldRequest request;
50 
51     if ((*dataLen) < sizeof(request))
52     {
53         std::fprintf(stderr, "Invalid command length: %u\n",
54                      static_cast<uint32_t>(*dataLen));
55         return IPMI_CC_REQ_DATA_LEN_INVALID;
56     }
57 
58     // reqBuf[0] is the subcommand.
59     // reqBuf[1] is the CPLD id. "/run/cpld{id}.version" is what we read.
60     // Verified that this cast actually returns the value 255 and not something
61     // negative in the case where reqBuf[1] is 0xff.  However, it looks weird
62     // since I would expect int(uint8(0xff)) to be -1.  So, just cast it
63     // unsigned. we're casting to an int width to avoid it thinking it's a
64     // letter, because it does that.
65     std::memcpy(&request, &reqBuf[0], sizeof(request));
66 
67     try
68     {
69         auto values =
70             handler->getCpldVersion(static_cast<unsigned int>(request.id));
71 
72         // Truncate if the version is too high (documented).
73         struct CpldReply reply;
74         reply.subcommand = SysCpldVersion;
75         reply.major = std::get<0>(values);
76         reply.minor = std::get<1>(values);
77         reply.point = std::get<2>(values);
78         reply.subpoint = std::get<3>(values);
79 
80         std::memcpy(&replyBuf[0], &reply, sizeof(reply));
81         (*dataLen) = sizeof(reply);
82         return IPMI_CC_OK;
83     }
84     catch (const IpmiException& e)
85     {
86         return e.getIpmiError();
87     }
88 }
89 
90 } // namespace ipmi
91 } // namespace google
92