xref: /openbmc/google-ipmi-sys/pcie_i2c.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 "pcie_i2c.hpp"
16 
17 #include "commands.hpp"
18 
19 #include <cstdint>
20 #include <cstring>
21 #include <string>
22 #include <tuple>
23 #include <vector>
24 
25 namespace google
26 {
27 namespace ipmi
28 {
29 
30 #ifndef MAX_IPMI_BUFFER
31 #define MAX_IPMI_BUFFER 64
32 #endif
33 
34 struct PcieSlotCountRequest
35 {
36     uint8_t subcommand;
37 } __attribute__((packed));
38 
39 struct PcieSlotCountReply
40 {
41     uint8_t subcommand;
42     uint8_t value;
43 } __attribute__((packed));
44 
45 struct PcieSlotI2cBusMappingRequest
46 {
47     uint8_t subcommand;
48     uint8_t entry;
49 } __attribute__((packed));
50 
51 struct PcieSlotI2cBusMappingReply
52 {
53     uint8_t subcommand;
54     uint8_t i2c_bus_number;
55     uint8_t pcie_slot_name_len;
56 } __attribute__((packed));
57 
58 ipmi_ret_t pcieSlotCount(const uint8_t*, uint8_t* replyBuf, size_t* dataLen,
59                          HandlerInterface* handler)
60 {
61     if ((*dataLen) < sizeof(struct PcieSlotCountRequest))
62     {
63         std::fprintf(stderr, "Invalid command length: %u\n",
64                      static_cast<uint32_t>(*dataLen));
65         return IPMI_CC_REQ_DATA_LEN_INVALID;
66     }
67 
68     // If there are already entries in the vector, clear them.
69     handler->buildI2cPcieMapping();
70 
71     struct PcieSlotCountReply reply;
72     reply.subcommand = SysPcieSlotCount;
73     // Fill the pcie slot count as the number of entries in the vector.
74     reply.value = handler->getI2cPcieMappingSize();
75 
76     std::memcpy(&replyBuf[0], &reply, sizeof(reply));
77 
78     // Return the subcommand and the result.
79     (*dataLen) = sizeof(reply);
80 
81     return IPMI_CC_OK;
82 }
83 
84 ipmi_ret_t pcieSlotI2cBusMapping(const uint8_t* reqBuf, uint8_t* replyBuf,
85                                  size_t* dataLen, HandlerInterface* handler)
86 {
87     struct PcieSlotI2cBusMappingRequest request;
88 
89     if ((*dataLen) < sizeof(request))
90     {
91         std::fprintf(stderr, "Invalid command length: %u\n",
92                      static_cast<uint32_t>(*dataLen));
93         return IPMI_CC_REQ_DATA_LEN_INVALID;
94     }
95 
96     // If there are no entries in the vector return error.
97     size_t mapSize = handler->getI2cPcieMappingSize();
98     if (mapSize == 0)
99     {
100         return IPMI_CC_INVALID_RESERVATION_ID;
101     }
102 
103     std::memcpy(&request, &reqBuf[0], sizeof(request));
104 
105     // The valid entries range from 0 to N - 1, N being the total number of
106     // entries in the vector.
107     if (request.entry >= mapSize)
108     {
109         return IPMI_CC_PARM_OUT_OF_RANGE;
110     }
111 
112     // Get the i2c bus number and the pcie slot name from the vector.
113     auto i2cEntry = handler->getI2cEntry(request.entry);
114     uint32_t i2c_bus_number = std::get<0>(i2cEntry);
115     std::string pcie_slot_name = std::get<1>(i2cEntry);
116 
117     int length =
118         sizeof(struct PcieSlotI2cBusMappingReply) + pcie_slot_name.length();
119 
120     // TODO (jaghu) : Add a way to dynamically receive the MAX_IPMI_BUFFER
121     // value and change error to IPMI_CC_REQUESTED_TOO_MANY_BYTES.
122     if (length > MAX_IPMI_BUFFER)
123     {
124         std::fprintf(stderr, "Response would overflow response buffer\n");
125         return IPMI_CC_INVALID;
126     }
127 
128     auto reply =
129         reinterpret_cast<struct PcieSlotI2cBusMappingReply*>(&replyBuf[0]);
130     reply->subcommand = SysPcieSlotI2cBusMapping;
131     // Copy the i2c bus number and the pcie slot name to the reply struct.
132     reply->i2c_bus_number = i2c_bus_number;
133     reply->pcie_slot_name_len = pcie_slot_name.length();
134     std::memcpy(reply + 1, pcie_slot_name.c_str(), pcie_slot_name.length());
135 
136     // Return the subcommand and the result.
137     (*dataLen) = length;
138     return IPMI_CC_OK;
139 }
140 } // namespace ipmi
141 } // namespace google
142