1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
|
/* IBM_PROLOG_BEGIN_TAG */
/* This is an automatically generated prolog. */
/* */
/* $Source: src/usr/hwpf/hwp/tod_init/TodSvc.H $ */
/* */
/* OpenPOWER HostBoot Project */
/* */
/* COPYRIGHT International Business Machines Corp. 2013,2014 */
/* */
/* Licensed under the Apache License, Version 2.0 (the "License"); */
/* you may not use this file except in compliance with the License. */
/* You may obtain a copy of the License at */
/* */
/* http://www.apache.org/licenses/LICENSE-2.0 */
/* */
/* Unless required by applicable law or agreed to in writing, software */
/* distributed under the License is distributed on an "AS IS" BASIS, */
/* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or */
/* implied. See the License for the specific language governing */
/* permissions and limitations under the License. */
/* */
/* IBM_PROLOG_END_TAG */
#ifndef TODSVC_H
#define TODSVC_H
/**
* @file TodSvc.H
*
* @brief Defines the TodSvc class that provides the Time Of Day service
* The TodSvc class is a thread-safe singleton.
*
* HWP_IGNORE_VERSION_CHECK
*
*/
#include <util/singleton.H>
namespace TOD
{
/**
* @class TodSvc
*
* @brief Time Of Day service entry point
*/
class TodSvc
{
public:
/**
* @brief Get singleton instance of this class.
*
* @return the (one and only) instance of TodSvc
*/
static TodSvc& getTheInstance();
/**
* @brief This interface should be called during IPL to setup the
* time of day logic on the P8 processors sitting on the system.
*
* @par Detailed Description:
* All processors of a symmetric multiprocessor model must appear to
* have the same time. This is in order to ensure that time stamps
* accurately reflect the sequence of events occuring on these procs.
*
* To achieve this, each proc has a hardware time of day (TOD) logic.
* A TOD oscillator(a fixed frequency clock) can send out signals to
* keep the TOD clocks on the various procs in sync.
*
* Since the procs are connected by fabric buses, a signal sent out by
* the oscillator will reach the procs at different times. Besides,
* there are multiple bus paths to propagate TOD signals. To solve these
* issues, we (FSP HWSV) need to create a TOD topology. A TOD topology
* has a single Master Drawer Master TOD processor chip (MDMT), which
* receives input directly from the oscillator. The MDMT will propagate
* signals to other procs, MDSTs (Master Drawer Slave TOD Chips),
* in the fabric node/physical drawer in which it's contained, via X
* buses. This group of procs will be part of a TOD drawer. Inter TOD
* drawer communications will be via A buses. Via A bus, the MDMT will
* propagate TOD signals to designated masters in other drawers, SDMTs
* (Slave Drawer Master TOD Chips). In the their respective TOD
* drawers, SDMTs, like the MDMT, will use X buses to propagate signals
* to other SDSTs (Slave Drawer Slave TOD Chips).
*
* We will create a primary topology and a secondary topology, for
* redundancy. Once we create the topologies, the same will be passed
* on to a hardware procedure. The procedure will set bits in the TOD
* registers of the procs, to indicate the topology. THe procedure will
* also compute "delays", to be introduced to signals sent out by the
* oscillator. MDMT will have the longest delay and the furthest proc
* from the oscillator will have 0 delay. This helps ensuring that TOD
* signals are received at the same wall clock time.
*
* At runtime, PHYP will be able to read the TOD registers and
* determine the TOD topolgies. It will use the primary topology as the
* active topology for timekeeping. On detecting errors in the active
* topology, it can switch to the secondary and ask us to reconfigure a
* backup.
*
* @return Error log handle indicating the status of the request.
* @retval NULL if successful
* @retval !NULL if failed to setup TOD
*
* Error log handle points to a valid error log object whose primary
* SRC reason code (pError->getSRC()->reasonCode()) indicates the type
* of error.
*
* @note It is up to the caller to change the severity of the
* returned error based on what it decides to do with it. By default
* any returned error created by this function will be a non-reported
* tracing event error log.
*
* @note TOD setup is not allowed at FSP runtime
* @note Presence of a secondary topology is not critical to
* to TOD functionality, so an error in creating the same
* will be noted but not returned.
*/
errlHndl_t todSetup();
/**
* @brief This interface should be called during IPL to set the TOD
* into running state
*
* @return Error log handle indicating the status of the request.
* @retval NULL if successful
* @retval !NULL if failed to setup TOD
*
* Error log handle points to a valid error log object whose primary
* SRC reason code (pError->getSRC()->reasonCode()) indicates the type
* of error.
*
* @note It is up to the caller to change the severity of the
* returned error based on what it decides to do with it. By default
* any returned error created by this function will be a non-reported
* tracing event error log.
*/
errlHndl_t todInit();
/**
* @brief Reads the Time Of Day (TOD) value from the TOD register on
* the processor chip and returns the same.
*
* @par Detailed Description:
* This interface will read the TOD value from the TOD value register.
* We could read this from any of the processor that's part of the
* TOD topology, since the TOD value should be in sync across procs,
* so we'll read this from the MDMT's register.
*
* @param[out] o_todValue
* 64-bit contents of the TOD value register will be copied here
* in a big-endian format. Will be 0 on error.
*
* @return Error log handle indicating the status of the request.
* @retval NULL if successful
* @retval !NULL if failed to read TOD value
*
* Error log handle points to a valid error log object whose primary
* SRC reason code (pError->getSRC()->reasonCode()) indicates the type
* of error.
*
* @note It is up to the caller to change the severity of the
* returned error based on what it decides to do with it. By default
* any returned error created by this function will be a non-reported
* tracing event error log.
*/
errlHndl_t readTod(uint64_t& o_todValue) const;
protected:
/**
* @brief Constructor.
*
* @note This is protected so that only SingletonHolder can call.
*/
TodSvc();
/**
* @brief Destructor.
*
* @note This is protected so that only SingletonHolder can call.
*/
~TodSvc();
private:
//Disabled copy constructor and assignment operator
TodSvc(const TodSvc& rhs);
TodSvc& operator=(const TodSvc& rhs);
//Indicates if we've already setup TOD
bool iv_todSetup;
};
} //namespace TOD
#endif //TODSVC_H
|
