9049fef997fe3249ccbb98527a28f0fc2f572468
[mirror_edk2.git] / MdePkg / Library / SecPeiDxeTimerLibCpu / IpfTimerLib.c
1 /** @file
2 Timer Library functions built upon ITC on IA32/x64.
3
4 Copyright (c) 2006 - 2007, Intel Corporation<BR>
5 All rights reserved. This program and the accompanying materials
6 are licensed and made available under the terms and conditions of the BSD License
7 which accompanies this distribution. The full text of the license may be found at
8 http://opensource.org/licenses/bsd-license.php
9
10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
12
13 Module Name: IpfTimerLib.c
14
15 **/
16
17
18
19
20 /**
21 Performs a delay measured as number of ticks.
22
23 An internal function to perform a delay measured as number of ticks. It's
24 invoked by MicroSecondDelay() and NanoSecondDelay().
25
26 @param Delay Number of ticks to delay.
27
28 **/
29 STATIC
30 VOID
31 InternalIpfDelay (
32 IN INT64 Delay
33 )
34 {
35 INT64 Ticks;
36
37 //
38 // The target timer count is calculated here
39 //
40 Ticks = IpfReadItc () + Delay;
41
42 //
43 // Wait until time out
44 // Delay > 2^63 could not be handled by this function
45 // Timer wrap-arounds are handled correctly by this function
46 //
47 while (Ticks - IpfReadItc () >= 0);
48 }
49
50 /**
51 Stalls the CPU for at least the given number of microseconds.
52
53 Stalls the CPU for the number of microseconds specified by MicroSeconds.
54
55 @param MicroSeconds The minimum number of microseconds to delay.
56
57 @return MicroSeconds
58
59 **/
60 UINTN
61 EFIAPI
62 MicroSecondDelay (
63 IN UINTN MicroSeconds
64 )
65 {
66 InternalIpfDelay (
67 GetPerformanceCounterProperties (NULL, NULL) *
68 MicroSeconds /
69 1000000
70 );
71 return MicroSeconds;
72 }
73
74 /**
75 Stalls the CPU for at least the given number of nanoseconds.
76
77 Stalls the CPU for the number of nanoseconds specified by NanoSeconds.
78
79 @param NanoSeconds The minimum number of nanoseconds to delay.
80
81 @return NanoSeconds
82
83 **/
84 UINTN
85 EFIAPI
86 NanoSecondDelay (
87 IN UINTN NanoSeconds
88 )
89 {
90 InternalIpfDelay (
91 GetPerformanceCounterProperties (NULL, NULL) *
92 NanoSeconds /
93 1000000000
94 );
95 return NanoSeconds;
96 }
97
98 /**
99 Retrieves the current value of a 64-bit free running performance counter.
100
101 Retrieves the current value of a 64-bit free running performance counter. The
102 counter can either count up by 1 or count down by 1. If the physical
103 performance counter counts by a larger increment, then the counter values
104 must be translated. The properties of the counter can be retrieved from
105 GetPerformanceCounterProperties().
106
107 @return The current value of the free running performance counter.
108
109 **/
110 UINT64
111 EFIAPI
112 GetPerformanceCounter (
113 VOID
114 )
115 {
116 return IpfReadItc ();
117 }
118
119 /**
120 Retrieves the 64-bit frequency in Hz and the range of performance counter
121 values.
122
123 If StartValue is not NULL, then the value that the performance counter starts
124 with immediately after is it rolls over is returned in StartValue. If
125 EndValue is not NULL, then the value that the performance counter end with
126 immediately before it rolls over is returned in EndValue. The 64-bit
127 frequency of the performance counter in Hz is always returned. If StartValue
128 is less than EndValue, then the performance counter counts up. If StartValue
129 is greater than EndValue, then the performance counter counts down. For
130 example, a 64-bit free running counter that counts up would have a StartValue
131 of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter
132 that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.
133
134 @param StartValue The value the performance counter starts with when it
135 rolls over.
136 @param EndValue The value that the performance counter ends with before
137 it rolls over.
138
139 @return The frequency in Hz.
140
141 **/
142 UINT64
143 EFIAPI
144 GetPerformanceCounterProperties (
145 OUT UINT64 *StartValue, OPTIONAL
146 OUT UINT64 *EndValue OPTIONAL
147 )
148 {
149 PAL_PROC_RETURN PalRet;
150 UINT64 BaseFrequence;
151
152 PalRet = PalCallStatic (NULL, 13, 0, 0, 0);
153 ASSERT (PalRet.Status == 0);
154 BaseFrequence = PalRet.r9;
155
156 PalRet = PalCallStatic (NULL, 14, 0, 0, 0);
157 ASSERT (PalRet.Status == 0);
158
159 if (StartValue != NULL) {
160 *StartValue = 0;
161 }
162
163 if (EndValue != NULL) {
164 *EndValue = (UINT64)(-1);
165 }
166
167 return BaseFrequence * (PalRet.r11 >> 32) / (UINT32)PalRet.r11;
168 }