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
|
/** @file
Timer Library functions built upon ITC on IPF.
Copyright (c) 2006 - 2008, Intel Corporation<BR>
All rights reserved. This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution. The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
**/
#include <Base.h>
#include <Library/TimerLib.h>
#include <Library/BaseLib.h>
#include <Library/PalLib.h>
/**
Performs a delay measured as number of ticks.
An internal function to perform a delay measured as number of ticks. It's
invoked by MicroSecondDelay() and NanoSecondDelay().
@param Delay Number of ticks to delay.
**/
VOID
EFIAPI
InternalIpfDelay (
IN INT64 Delay
)
{
INT64 Ticks;
//
// The target timer count is calculated here
//
Ticks = (INT64)AsmReadItc () + Delay;
//
// Wait until time out
// Delay > 2^63 could not be handled by this function
// Timer wrap-arounds are handled correctly by this function
//
while (Ticks - (INT64)AsmReadItc() >= 0);
}
/**
Stalls the CPU for at least the given number of microseconds.
Stalls the CPU for the number of microseconds specified by MicroSeconds.
@param MicroSeconds The minimum number of microseconds to delay.
@return The value of MicroSeconds inputted.
**/
UINTN
EFIAPI
MicroSecondDelay (
IN UINTN MicroSeconds
)
{
InternalIpfDelay (
GetPerformanceCounterProperties (NULL, NULL) *
MicroSeconds /
1000000
);
return MicroSeconds;
}
/**
Stalls the CPU for at least the given number of nanoseconds.
Stalls the CPU for the number of nanoseconds specified by NanoSeconds.
@param NanoSeconds The minimum number of nanoseconds to delay.
@return The value of NanoSeconds inputted.
**/
UINTN
EFIAPI
NanoSecondDelay (
IN UINTN NanoSeconds
)
{
InternalIpfDelay (
GetPerformanceCounterProperties (NULL, NULL) *
NanoSeconds /
1000000000
);
return NanoSeconds;
}
/**
Retrieves the current value of a 64-bit free running performance counter.
The counter can either count up by 1 or count down by 1. If the physical
performance counter counts by a larger increment, then the counter values
must be translated. The properties of the counter can be retrieved from
GetPerformanceCounterProperties().
@return The current value of the free running performance counter.
**/
UINT64
EFIAPI
GetPerformanceCounter (
VOID
)
{
return AsmReadItc ();
}
/**
Retrieves the 64-bit frequency in Hz and the range of performance counter
values.
If StartValue is not NULL, then the value that the performance counter starts
with immediately after is it rolls over is returned in StartValue. If
EndValue is not NULL, then the value that the performance counter end with
immediately before it rolls over is returned in EndValue. The 64-bit
frequency of the performance counter in Hz is always returned. If StartValue
is less than EndValue, then the performance counter counts up. If StartValue
is greater than EndValue, then the performance counter counts down. For
example, a 64-bit free running counter that counts up would have a StartValue
of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter
that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.
@param StartValue The value the performance counter starts with when it
rolls over.
@param EndValue The value that the performance counter ends with before
it rolls over.
@return The frequency in Hz.
**/
UINT64
EFIAPI
GetPerformanceCounterProperties (
OUT UINT64 *StartValue, OPTIONAL
OUT UINT64 *EndValue OPTIONAL
)
{
PAL_CALL_RETURN PalRet;
UINT64 BaseFrequence;
if (StartValue != NULL) {
*StartValue = 0;
}
if (EndValue != NULL) {
*EndValue = (UINT64)(-1);
}
PalRet = PalCall (PAL_FREQ_BASE, 0, 0, 0);
if (PalRet.Status != 0) {
return 1000000;
}
BaseFrequence = PalRet.r9;
PalRet = PalCall (PAL_FREQ_RATIOS, 0, 0, 0);
if (PalRet.Status != 0) {
return 1000000;
}
return BaseFrequence * (PalRet.r11 >> 32) / (UINT32)PalRet.r11;
}
|
