1 Kernel driver fam15h_power
2 ==========================
3
4 Supported chips:
5
6 * AMD Family 15h Processors
7
8 * AMD Family 16h Processors
9
10 Prefix: 'fam15h_power'
11
12 Addresses scanned: PCI space
13
14 Datasheets:
15
16 - BIOS and Kernel Developer's Guide (BKDG) F
17 - BIOS and Kernel Developer's Guide (BKDG) F
18 - AMD64 Architecture Programmer's Manual Vol
19
20 Author: Andreas Herrmann <herrmann.der.user@goo
21
22 Description
23 -----------
24
25 1) Processor TDP (Thermal design power)
26
27 Given a fixed frequency and voltage, the power
28 processor varies based on the workload being e
29 is the power consumed when running a specific
30 design power (TDP) is an example of derated po
31
32 This driver permits reading of registers provi
33 of AMD Family 15h and 16h processors via TDP a
34
35 For AMD Family 15h and 16h processors the foll
36 be calculated using different processor northb
37 registers:
38
39 * BasePwrWatts:
40 Specifies in watts the maximum amount of p
41 consumed by the processor for NB and logic
42
43 * ProcessorPwrWatts:
44 Specifies in watts the maximum amount of p
45 the processor can support.
46 * CurrPwrWatts:
47 Specifies in watts the current amount of p
48 consumed by the processor.
49
50 This driver provides ProcessorPwrWatts and Cur
51
52 * power1_crit (ProcessorPwrWatts)
53 * power1_input (CurrPwrWatts)
54
55 On multi-node processors the calculated value
56 package and not for a single node. Thus the dr
57 attributes only for internal node0 of a multi-
58
59 2) Accumulated Power Mechanism
60
61 This driver also introduces an algorithm that
62 calculate the average power consumed by a proc
63 measurement interval Tm. The feature of accumu
64 indicated by CPUID Fn8000_0007_EDX[12].
65
66 * Tsample:
67 compute unit power accumulator sample
68
69 * Tref:
70 the PTSC counter period
71
72 * PTSC:
73 performance timestamp counter
74
75 * N:
76 the ratio of compute unit power accumu
77 PTSC period
78
79 * Jmax:
80 max compute unit accumulated power whi
81 MaxCpuSwPwrAcc MSR C001007b
82
83 * Jx/Jy:
84 compute unit accumulated power which i
85 CpuSwPwrAcc MSR C001007a
86 * Tx/Ty:
87 the value of performance timestamp cou
88 by CU_PTSC MSR C0010280
89
90 * PwrCPUave:
91 CPU average power
92
93 i. Determine the ratio of Tsample to Tref by e
94
95 N = value of CPUID Fn8000_0007_ECX[Cpu
96
97 ii. Read the full range of the cumulative ener
98 MSR MaxCpuSwPwrAcc.
99
100 Jmax = value returned.
101
102 iii. At time x, SW reads CpuSwPwrAcc MSR and s
103
104 Jx = value read from CpuSwPwrAcc and T
105
106 iv. At time y, SW reads CpuSwPwrAcc MSR and sa
107
108 Jy = value read from CpuSwPwrAcc and T
109
110 v. Calculate the average power consumption for
111 time period (y-x). Unit of result is uWatt:
112
113 if (Jy < Jx) // Rollover has occurred
114 Jdelta = (Jy + Jmax) - Jx
115 else
116 Jdelta = Jy - Jx
117 PwrCPUave = N * Jdelta * 1000 / (Ty -
118
119 This driver provides PwrCPUave and interval(de
120 and maximum is 1 second):
121
122 * power1_average (PwrCPUave)
123 * power1_average_interval (Interval)
124
125 The power1_average_interval can be updated at
126 as below:
127
128 chip `fam15h_power-*`
129 set power1_average_interval 0.01
130
131 Then save it with "sensors -s".
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