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git.proxmox.com Git - mirror_edk2.git/blob - MdePkg/Library/SecPeiDxeTimerLibCpu/IpfTimerLib.c
2 Timer Library functions built upon ITC on IPF.
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.
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.
16 #include <Library/TimerLib.h>
17 #include <Library/BaseLib.h>
18 #include <Library/PalLib.h>
22 Performs a delay measured as number of ticks.
24 An internal function to perform a delay measured as number of ticks. It's
25 invoked by MicroSecondDelay() and NanoSecondDelay().
27 @param Delay The number of ticks to delay.
39 // The target timer count is calculated here
41 Ticks
= (INT64
)AsmReadItc () + Delay
;
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
48 while (Ticks
- (INT64
)AsmReadItc() >= 0);
52 Stalls the CPU for at least the given number of microseconds.
54 Stalls the CPU for the number of microseconds specified by MicroSeconds.
56 @param MicroSeconds The minimum number of microseconds to delay.
58 @return The value of MicroSeconds inputted.
68 GetPerformanceCounterProperties (NULL
, NULL
) *
76 Stalls the CPU for at least the given number of nanoseconds.
78 Stalls the CPU for the number of nanoseconds specified by NanoSeconds.
80 @param NanoSeconds The minimum number of nanoseconds to delay.
82 @return The value of NanoSeconds inputted.
92 GetPerformanceCounterProperties (NULL
, NULL
) *
100 Retrieves the current value of a 64-bit free running performance counter.
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().
107 @return The current value of the free running performance counter.
112 GetPerformanceCounter (
116 return AsmReadItc ();
120 Retrieves the 64-bit frequency in Hz and the range of performance counter
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.
134 @param StartValue The value the performance counter starts with when it
136 @param EndValue The value that the performance counter ends with before
139 @return The frequency in Hz.
144 GetPerformanceCounterProperties (
145 OUT UINT64
*StartValue
, OPTIONAL
146 OUT UINT64
*EndValue OPTIONAL
149 PAL_CALL_RETURN PalRet
;
150 UINT64 BaseFrequence
;
152 if (StartValue
!= NULL
) {
156 if (EndValue
!= NULL
) {
157 *EndValue
= (UINT64
)(-1);
160 PalRet
= PalCall (PAL_FREQ_BASE
, 0, 0, 0);
161 if (PalRet
.Status
!= 0) {
164 BaseFrequence
= PalRet
.r9
;
166 PalRet
= PalCall (PAL_FREQ_RATIOS
, 0, 0, 0);
167 if (PalRet
.Status
!= 0) {
171 return BaseFrequence
* (PalRet
.r11
>> 32) / (UINT32
)PalRet
.r11
;
175 Converts elapsed ticks of performance counter to time in nanoseconds.
177 This function converts the elapsed ticks of running performance counter to
178 time value in unit of nanoseconds.
180 @param Ticks The number of elapsed ticks of running performance counter.
182 @return The elapsed time in nanoseconds.
187 GetTimeInNanoSecond (
196 Frequency
= GetPerformanceCounterProperties (NULL
, NULL
);
200 // Time = --------- x 1,000,000,000
203 NanoSeconds
= MultU64x32 (DivU64x64Remainder (Ticks
, Frequency
, &Remainder
), 1000000000u);
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.
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
);