1 /*
2  * Copyright (c)  2018 Intel Corporation.
3  * Copyright (c)  2018-present Facebook.
4  *
5  * Licensed under the Apache License, Version 2.0 (the "License");
6  * you may not use this file except in compliance with the License.
7  * You may obtain a copy of the License at
8  *
9  *      http://www.apache.org/licenses/LICENSE-2.0
10  *
11  * Unless required by applicable law or agreed to in writing, software
12  * distributed under the License is distributed on an "AS IS" BASIS,
13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  * See the License for the specific language governing permissions and
15  * limitations under the License.
16  */
17 
18 #pragma once
19 #include <ipmid/api.h>
20 
21 #include <phosphor-logging/log.hpp>
22 
23 #include <cmath>
24 #include <iostream>
25 
26 namespace ipmi
27 {
28 
29 static constexpr int16_t maxInt10 = 0x1FF;
30 static constexpr int16_t minInt10 = -0x200;
31 static constexpr int8_t maxInt4 = 7;
32 static constexpr int8_t minInt4 = -8;
33 
34 enum class SensorUnits : uint8_t
35 {
36     unspecified = 0x0,
37     degreesC = 0x1,
38     volts = 0x4,
39     amps = 0x5,
40     watts = 0x6,
41     rpm = 0x12,
42 };
43 
44 enum class SensorTypeCodes : uint8_t
45 {
46     reserved = 0x0,
47     temperature = 0x1,
48     voltage = 0x2,
49     current = 0x3,
50     fan = 0x4,
51     other = 0xB,
52 };
53 
54 struct CmpStrVersion
55 {
operator ()ipmi::CmpStrVersion56     bool operator()(std::string a, std::string b) const
57     {
58         return strverscmp(a.c_str(), b.c_str()) < 0;
59     }
60 };
61 
62 using SensorSubTree = boost::container::flat_map<
63     std::string,
64     boost::container::flat_map<std::string, std::vector<std::string>>,
65     CmpStrVersion>;
66 
getSensorSubtree(SensorSubTree & subtree)67 inline static bool getSensorSubtree(SensorSubTree& subtree)
68 {
69     sd_bus* bus = NULL;
70     int ret = sd_bus_default_system(&bus);
71     if (ret < 0)
72     {
73         phosphor::logging::log<phosphor::logging::level::ERR>(
74             "Failed to connect to system bus",
75             phosphor::logging::entry("ERRNO=0x%X", -ret));
76         sd_bus_unref(bus);
77         return false;
78     }
79     sdbusplus::bus_t dbus(bus);
80     auto mapperCall =
81         dbus.new_method_call("xyz.openbmc_project.ObjectMapper",
82                              "/xyz/openbmc_project/object_mapper",
83                              "xyz.openbmc_project.ObjectMapper", "GetSubTree");
84     static constexpr const auto depth = 2;
85     static constexpr std::array<const char*, 3> interfaces = {
86         "xyz.openbmc_project.Sensor.Value",
87         "xyz.openbmc_project.Sensor.Threshold.Warning",
88         "xyz.openbmc_project.Sensor.Threshold.Critical"};
89     mapperCall.append("/xyz/openbmc_project/sensors", depth, interfaces);
90 
91     try
92     {
93         auto mapperReply = dbus.call(mapperCall);
94         subtree.clear();
95         mapperReply.read(subtree);
96     }
97     catch (sdbusplus::exception_t& e)
98     {
99         phosphor::logging::log<phosphor::logging::level::ERR>(e.what());
100         return false;
101     }
102     return true;
103 }
104 
105 // Specify the comparison required to sort and find char* map objects
106 struct CmpStr
107 {
operator ()ipmi::CmpStr108     bool operator()(const char* a, const char* b) const
109     {
110         return std::strcmp(a, b) < 0;
111     }
112 };
113 
114 const static boost::container::flat_map<const char*, SensorUnits, CmpStr>
115     sensorUnits{{{"temperature", SensorUnits::degreesC},
116                  {"voltage", SensorUnits::volts},
117                  {"current", SensorUnits::amps},
118                  {"fan_tach", SensorUnits::rpm},
119                  {"power", SensorUnits::watts}}};
120 
121 const static boost::container::flat_map<const char*, SensorTypeCodes, CmpStr>
122     sensorTypes{{{"temperature", SensorTypeCodes::temperature},
123                  {"voltage", SensorTypeCodes::voltage},
124                  {"current", SensorTypeCodes::current},
125                  {"fan_tach", SensorTypeCodes::fan},
126                  {"fan_pwm", SensorTypeCodes::fan},
127                  {"power", SensorTypeCodes::other}}};
128 
getSensorTypeStringFromPath(const std::string & path)129 inline static std::string getSensorTypeStringFromPath(const std::string& path)
130 {
131     // get sensor type string from path, path is defined as
132     // /xyz/openbmc_project/sensors/<type>/label
133     size_t typeEnd = path.rfind("/");
134     if (typeEnd == std::string::npos)
135     {
136         return path;
137     }
138     size_t typeStart = path.rfind("/", typeEnd - 1);
139     if (typeStart == std::string::npos)
140     {
141         return path;
142     }
143     // Start at the character after the '/'
144     typeStart++;
145     return path.substr(typeStart, typeEnd - typeStart);
146 }
147 
getSensorTypeFromPath(const std::string & path)148 inline static uint8_t getSensorTypeFromPath(const std::string& path)
149 {
150     uint8_t sensorType = 0;
151     std::string type = getSensorTypeStringFromPath(path);
152     auto findSensor = sensorTypes.find(type.c_str());
153     if (findSensor != sensorTypes.end())
154     {
155         sensorType = static_cast<uint8_t>(findSensor->second);
156     } // else default 0x0 RESERVED
157 
158     return sensorType;
159 }
160 
getSensorEventTypeFromPath(const std::string &)161 inline static uint8_t getSensorEventTypeFromPath(const std::string&)
162 {
163     // TODO: Add support for additional reading types as needed
164     return 0x1; // reading type = threshold
165 }
166 
getSensorAttributes(const double max,const double min,int16_t & mValue,int8_t & rExp,int16_t & bValue,int8_t & bExp,bool & bSigned)167 static inline bool getSensorAttributes(
168     const double max, const double min, int16_t& mValue, int8_t& rExp,
169     int16_t& bValue, int8_t& bExp, bool& bSigned)
170 {
171     // computing y = (10^rRexp) * (Mx + (B*(10^Bexp)))
172     // check for 0, assume always positive
173     double mDouble;
174     double bDouble;
175     if (max <= min)
176     {
177         phosphor::logging::log<phosphor::logging::level::DEBUG>(
178             "getSensorAttributes: Max must be greater than min");
179         return false;
180     }
181 
182     mDouble = (max - min) / 0xFF;
183 
184     if (min < 0)
185     {
186         bSigned = true;
187         bDouble = floor(0.5 + ((max + min) / 2));
188     }
189     else
190     {
191         bSigned = false;
192         bDouble = min;
193     }
194 
195     rExp = 0;
196 
197     // M too big for 10 bit variable
198     while (mDouble > maxInt10)
199     {
200         if (rExp >= maxInt4)
201         {
202             phosphor::logging::log<phosphor::logging::level::DEBUG>(
203                 "rExp Too big, Max and Min range too far",
204                 phosphor::logging::entry("REXP=%d", rExp));
205             return false;
206         }
207         mDouble /= 10;
208         rExp++;
209     }
210 
211     // M too small, loop until we lose less than 1 eight bit count of precision
212     while (((mDouble - floor(mDouble)) / mDouble) > (1.0 / 255))
213     {
214         if (rExp <= minInt4)
215         {
216             phosphor::logging::log<phosphor::logging::level::DEBUG>(
217                 "rExp Too Small, Max and Min range too close");
218             return false;
219         }
220         // check to see if we reached the limit of where we can adjust back the
221         // B value
222         if (bDouble / std::pow(10, rExp + minInt4 - 1) > bDouble)
223         {
224             if (mDouble < 1.0)
225             {
226                 phosphor::logging::log<phosphor::logging::level::DEBUG>(
227                     "Could not find mValue and B value with enough "
228                     "precision.");
229                 return false;
230             }
231             break;
232         }
233         // can't multiply M any more, max precision reached
234         else if (mDouble * 10 > maxInt10)
235         {
236             break;
237         }
238         mDouble *= 10;
239         rExp--;
240     }
241 
242     bDouble /= std::pow(10, rExp);
243     bExp = 0;
244 
245     // B too big for 10 bit variable
246     while (bDouble > maxInt10 || bDouble < minInt10)
247     {
248         if (bExp >= maxInt4)
249         {
250             phosphor::logging::log<phosphor::logging::level::DEBUG>(
251                 "bExp Too Big, Max and Min range need to be adjusted");
252             return false;
253         }
254         bDouble /= 10;
255         bExp++;
256     }
257 
258     while (((fabs(bDouble) - floor(fabs(bDouble))) / fabs(bDouble)) >
259            (1.0 / 255))
260     {
261         if (bExp <= minInt4)
262         {
263             phosphor::logging::log<phosphor::logging::level::DEBUG>(
264                 "bExp Too Small, Max and Min range need to be adjusted");
265             return false;
266         }
267         bDouble *= 10;
268         bExp -= 1;
269     }
270 
271     mValue = static_cast<int16_t>(mDouble) & maxInt10;
272     bValue = static_cast<int16_t>(bDouble) & maxInt10;
273 
274     return true;
275 }
276 
scaleIPMIValueFromDouble(const double value,const uint16_t mValue,const int8_t rExp,const uint16_t bValue,const int8_t bExp,const bool bSigned)277 static inline uint8_t scaleIPMIValueFromDouble(
278     const double value, const uint16_t mValue, const int8_t rExp,
279     const uint16_t bValue, const int8_t bExp, const bool bSigned)
280 {
281     uint32_t scaledValue =
282         (value - (bValue * std::pow(10, bExp) * std::pow(10, rExp))) /
283         (mValue * std::pow(10, rExp));
284 
285     if (scaledValue > std::numeric_limits<uint8_t>::max() ||
286         scaledValue < std::numeric_limits<uint8_t>::lowest())
287     {
288         throw std::out_of_range("Value out of range");
289     }
290     if (bSigned)
291     {
292         return static_cast<int8_t>(scaledValue);
293     }
294     else
295     {
296         return static_cast<uint8_t>(scaledValue);
297     }
298 }
299 
getScaledIPMIValue(const double value,const double max,const double min)300 static inline uint8_t getScaledIPMIValue(const double value, const double max,
301                                          const double min)
302 {
303     int16_t mValue = 0;
304     int8_t rExp = 0;
305     int16_t bValue = 0;
306     int8_t bExp = 0;
307     bool bSigned = 0;
308     bool result = 0;
309 
310     result = getSensorAttributes(max, min, mValue, rExp, bValue, bExp, bSigned);
311     if (!result)
312     {
313         throw std::runtime_error("Illegal sensor attributes");
314     }
315     return scaleIPMIValueFromDouble(value, mValue, rExp, bValue, bExp, bSigned);
316 }
317 } // namespace ipmi
318