1 /** @file
2 A non-functional instance of the Timer Library.
3
4 Copyright (c) 2007 - 2010, 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 <PiPei.h>
16 #include <Library/BaseLib.h>
17 #include <Library/TimerLib.h>
18 #include <Library/DebugLib.h>
19 #include <Library/EmuThunkLib.h>
20 #include <Library/UefiBootServicesTableLib.h>
21 #include <Library/UefiLib.h>
22
23 #include <Protocol/Timer.h>
24
25
26 STATIC UINT64 gTimerPeriod = 0;
27 STATIC EFI_TIMER_ARCH_PROTOCOL *gTimerAp = NULL;
28 STATIC EFI_EVENT gTimerEvent = NULL;
29 STATIC VOID *gRegistration = NULL;
30
31 VOID
32 EFIAPI
RegisterTimerArchProtocol(IN EFI_EVENT Event,IN VOID * Context)33 RegisterTimerArchProtocol (
34 IN EFI_EVENT Event,
35 IN VOID *Context
36 )
37 {
38 EFI_STATUS Status;
39
40 Status = gBS->LocateProtocol (&gEfiTimerArchProtocolGuid, NULL, (VOID **)&gTimerAp);
41 if (!EFI_ERROR (Status)) {
42 Status = gTimerAp->GetTimerPeriod (gTimerAp, &gTimerPeriod);
43 ASSERT_EFI_ERROR (Status);
44
45 // Convert to Nanoseconds.
46 gTimerPeriod = MultU64x32 (gTimerPeriod, 100);
47
48 if (gTimerEvent == NULL) {
49 Status = gBS->CreateEvent (EVT_TIMER, 0, NULL, NULL, (VOID **)&gTimerEvent);
50 ASSERT_EFI_ERROR (Status);
51 }
52 }
53 }
54
55
56
57 /**
58 Stalls the CPU for at least the given number of microseconds.
59
60 Stalls the CPU for the number of microseconds specified by MicroSeconds.
61
62 @param MicroSeconds The minimum number of microseconds to delay.
63
64 @return The value of MicroSeconds inputted.
65
66 **/
67 UINTN
68 EFIAPI
MicroSecondDelay(IN UINTN MicroSeconds)69 MicroSecondDelay (
70 IN UINTN MicroSeconds
71 )
72 {
73 return NanoSecondDelay (MicroSeconds * 1000);
74 }
75
76
77 /**
78 Stalls the CPU for at least the given number of nanoseconds.
79
80 Stalls the CPU for the number of nanoseconds specified by NanoSeconds.
81
82 @param NanoSeconds The minimum number of nanoseconds to delay.
83
84 @return The value of NanoSeconds inputted.
85
86 **/
87 UINTN
88 EFIAPI
NanoSecondDelay(IN UINTN NanoSeconds)89 NanoSecondDelay (
90 IN UINTN NanoSeconds
91 )
92 {
93 EFI_STATUS Status;
94 UINT64 HundredNanoseconds;
95 UINTN Index;
96
97 if ((gTimerPeriod != 0) &&
98 ((UINT64)NanoSeconds > gTimerPeriod) &&
99 (EfiGetCurrentTpl () == TPL_APPLICATION)) {
100 //
101 // This stall is long, so use gBS->WaitForEvent () to yield CPU to DXE Core
102 //
103
104 HundredNanoseconds = DivU64x32 (NanoSeconds, 100);
105 Status = gBS->SetTimer (gTimerEvent, TimerRelative, HundredNanoseconds);
106 ASSERT_EFI_ERROR (Status);
107
108 Status = gBS->WaitForEvent (sizeof (gTimerEvent)/sizeof (EFI_EVENT), &gTimerEvent, &Index);
109 ASSERT_EFI_ERROR (Status);
110
111 } else {
112 gEmuThunk->Sleep (NanoSeconds);
113 }
114 return NanoSeconds;
115 }
116
117
118 /**
119 Retrieves the current value of a 64-bit free running performance counter.
120
121 The counter can either count up by 1 or count down by 1. If the physical
122 performance counter counts by a larger increment, then the counter values
123 must be translated. The properties of the counter can be retrieved from
124 GetPerformanceCounterProperties().
125
126 @return The current value of the free running performance counter.
127
128 **/
129 UINT64
130 EFIAPI
GetPerformanceCounter(VOID)131 GetPerformanceCounter (
132 VOID
133 )
134 {
135 return gEmuThunk->QueryPerformanceCounter ();
136 }
137
138 /**
139 Retrieves the 64-bit frequency in Hz and the range of performance counter
140 values.
141
142 If StartValue is not NULL, then the value that the performance counter starts
143 with immediately after is it rolls over is returned in StartValue. If
144 EndValue is not NULL, then the value that the performance counter end with
145 immediately before it rolls over is returned in EndValue. The 64-bit
146 frequency of the performance counter in Hz is always returned. If StartValue
147 is less than EndValue, then the performance counter counts up. If StartValue
148 is greater than EndValue, then the performance counter counts down. For
149 example, a 64-bit free running counter that counts up would have a StartValue
150 of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter
151 that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.
152
153 @param StartValue The value the performance counter starts with when it
154 rolls over.
155 @param EndValue The value that the performance counter ends with before
156 it rolls over.
157
158 @return The frequency in Hz.
159
160 **/
161 UINT64
162 EFIAPI
GetPerformanceCounterProperties(OUT UINT64 * StartValue,OPTIONAL OUT UINT64 * EndValue OPTIONAL)163 GetPerformanceCounterProperties (
164 OUT UINT64 *StartValue, OPTIONAL
165 OUT UINT64 *EndValue OPTIONAL
166 )
167 {
168
169 if (StartValue != NULL) {
170 *StartValue = 0ULL;
171 }
172 if (EndValue != NULL) {
173 *EndValue = (UINT64)-1LL;
174 }
175
176 return gEmuThunk->QueryPerformanceFrequency ();
177 }
178
179
180 /**
181 Register for the Timer AP protocol.
182
183 @param ImageHandle The firmware allocated handle for the EFI image.
184 @param SystemTable A pointer to the EFI System Table.
185
186 @retval EFI_SUCCESS The constructor always returns EFI_SUCCESS.
187
188 **/
189 EFI_STATUS
190 EFIAPI
DxeTimerLibConstructor(IN EFI_HANDLE ImageHandle,IN EFI_SYSTEM_TABLE * SystemTable)191 DxeTimerLibConstructor (
192 IN EFI_HANDLE ImageHandle,
193 IN EFI_SYSTEM_TABLE *SystemTable
194 )
195 {
196 EfiCreateProtocolNotifyEvent (
197 &gEfiTimerArchProtocolGuid,
198 TPL_CALLBACK,
199 RegisterTimerArchProtocol,
200 NULL,
201 &gRegistration
202 );
203
204 return EFI_SUCCESS;
205 }
206
207