714b99eec41431a6fca7fedfd29098df2d9d9346
[mirror_edk2.git] / UefiCpuPkg / Library / SecPeiDxeTimerLibUefiCpu / IpfTimerLib.c
1 /** @file
2 Timer Library functions built upon ITC on IPF.
3
4 Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR>
5 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 **/
14
15 #include <Base.h>
16 #include <Library/TimerLib.h>
17 #include <Library/BaseLib.h>
18 #include <Library/PalLib.h>
19
20
21 /**
22 Performs a delay measured as number of ticks.
23
24 An internal function to perform a delay measured as number of ticks. It's
25 invoked by MicroSecondDelay() and NanoSecondDelay().
26
27 @param Delay The number of ticks to delay.
28
29 **/
30 VOID
31 EFIAPI
32 InternalIpfDelay (
33 IN INT64 Delay
34 )
35 {
36 INT64 Ticks;
37
38 //
39 // The target timer count is calculated here
40 //
41 Ticks = (INT64)AsmReadItc () + Delay;
42
43 //
44 // Wait until time out
45 // Delay > 2^63 could not be handled by this function
46 // Timer wrap-arounds are handled correctly by this function
47 //
48 while (Ticks - (INT64)AsmReadItc() >= 0);
49 }
50
51 /**
52 Stalls the CPU for at least the given number of microseconds.
53
54 Stalls the CPU for the number of microseconds specified by MicroSeconds.
55
56 @param MicroSeconds The minimum number of microseconds to delay.
57
58 @return The value of MicroSeconds inputted.
59
60 **/
61 UINTN
62 EFIAPI
63 MicroSecondDelay (
64 IN UINTN MicroSeconds
65 )
66 {
67 InternalIpfDelay (
68 GetPerformanceCounterProperties (NULL, NULL) *
69 MicroSeconds /
70 1000000
71 );
72 return MicroSeconds;
73 }
74
75 /**
76 Stalls the CPU for at least the given number of nanoseconds.
77
78 Stalls the CPU for the number of nanoseconds specified by NanoSeconds.
79
80 @param NanoSeconds The minimum number of nanoseconds to delay.
81
82 @return The value of NanoSeconds inputted.
83
84 **/
85 UINTN
86 EFIAPI
87 NanoSecondDelay (
88 IN UINTN NanoSeconds
89 )
90 {
91 InternalIpfDelay (
92 GetPerformanceCounterProperties (NULL, NULL) *
93 NanoSeconds /
94 1000000000
95 );
96 return NanoSeconds;
97 }
98
99 /**
100 Retrieves the current value of a 64-bit free running performance counter.
101
102 The 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 AsmReadItc ();
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_CALL_RETURN PalRet;
150 UINT64 BaseFrequence;
151
152 if (StartValue != NULL) {
153 *StartValue = 0;
154 }
155
156 if (EndValue != NULL) {
157 *EndValue = (UINT64)(-1);
158 }
159
160 PalRet = PalCall (PAL_FREQ_BASE, 0, 0, 0);
161 if (PalRet.Status != 0) {
162 return 1000000;
163 }
164 BaseFrequence = PalRet.r9;
165
166 PalRet = PalCall (PAL_FREQ_RATIOS, 0, 0, 0);
167 if (PalRet.Status != 0) {
168 return 1000000;
169 }
170
171 return BaseFrequence * (PalRet.r11 >> 32) / (UINT32)PalRet.r11;
172 }
173
174 /**
175 Converts elapsed ticks of performance counter to time in nanoseconds.
176
177 This function converts the elapsed ticks of running performance counter to
178 time value in unit of nanoseconds.
179
180 @param Ticks The number of elapsed ticks of running performance counter.
181
182 @return The elapsed time in nanoseconds.
183
184 **/
185 UINT64
186 EFIAPI
187 GetTimeInNanoSecond (
188 IN UINT64 Ticks
189 )
190 {
191 UINT64 Frequency;
192 UINT64 NanoSeconds;
193 UINT64 Remainder;
194 INTN Shift;
195
196 Frequency = GetPerformanceCounterProperties (NULL, NULL);
197
198 //
199 // Ticks
200 // Time = --------- x 1,000,000,000
201 // Frequency
202 //
203 NanoSeconds = MultU64x32 (DivU64x64Remainder (Ticks, Frequency, &Remainder), 1000000000u);
204
205 //
206 // Ensure (Remainder * 1,000,000,000) will not overflow 64-bit.
207 // Since 2^29 < 1,000,000,000 = 0x3B9ACA00 < 2^30, Remainder should < 2^(64-30) = 2^34,
208 // i.e. highest bit set in Remainder should <= 33.
209 //
210 Shift = MAX (0, HighBitSet64 (Remainder) - 33);
211 Remainder = RShiftU64 (Remainder, (UINTN) Shift);
212 Frequency = RShiftU64 (Frequency, (UINTN) Shift);
213 NanoSeconds += DivU64x64Remainder (MultU64x32 (Remainder, 1000000000u), Frequency, NULL);
214
215 return NanoSeconds;
216 }