7467bc5e4df6a0e98b811a9b693d8d0b7ce7ff12
[mirror_edk2.git] / MdePkg / Library / SecPeiDxeTimerLibCpu / x86TimerLib.c
1 /** @file
2 Timer Library functions built upon local APIC on IA32/x64.
3
4 @bug Should use PCD to retrieve all the constants including index of
5 the IA32_APIC_BASE MSR, the offsets of InitialCount, CorrentCount
6 and DivideConfiguration.
7
8 Copyright (c) 2006 - 2007, Intel Corporation<BR>
9 All rights reserved. This program and the accompanying materials
10 are licensed and made available under the terms and conditions of the BSD License
11 which accompanies this distribution. The full text of the license may be found at
12 http://opensource.org/licenses/bsd-license.php
13
14 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
15 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
16
17 Module Name: x86TimerLib.c
18
19 **/
20
21 //
22 // The following array is used in calculating the frequency of local APIC
23 // timer. Refer to IA-32 developers' manual for more details.
24 //
25 GLOBAL_REMOVE_IF_UNREFERENCED
26 CONST UINT8 mTimerLibLocalApicDivisor[] = {
27 0x02, 0x04, 0x08, 0x10,
28 0x02, 0x04, 0x08, 0x10,
29 0x20, 0x40, 0x80, 0x01,
30 0x20, 0x40, 0x80, 0x01
31 };
32
33 /**
34 Internal function to retrieve the base address of local APIC.
35
36 Internal function to retrieve the base address of local APIC.
37
38 @return The base address of local APIC
39
40 **/
41 STATIC
42 UINTN
43 InternalX86GetApicBase (
44 VOID
45 )
46 {
47 return (UINTN)AsmMsrBitFieldRead64 (27, 12, 35) << 12;
48 }
49
50 /**
51 Internal function to return the frequency of the local APIC timer.
52
53 Internal function to return the frequency of the local APIC timer.
54
55 @param ApicBase The base address of memory mapped registers of local APIC.
56
57 @return The frequency of the timer in Hz.
58
59 **/
60 STATIC
61 UINT32
62 InternalX86GetTimerFrequency (
63 IN UINTN ApicBase
64 )
65 {
66 return
67 PcdGet32(PcdFSBClock) /
68 mTimerLibLocalApicDivisor[MmioBitFieldRead32 (ApicBase + 0x3e0, 0, 3)];
69 }
70
71 /**
72 Internal function to read the current tick counter of local APIC.
73
74 Internal function to read the current tick counter of local APIC.
75
76 @param ApicBase The base address of memory mapped registers of local APIC.
77
78 @return The tick counter read.
79
80 **/
81 STATIC
82 INT32
83 InternalX86GetTimerTick (
84 IN UINTN ApicBase
85 )
86 {
87 return MmioRead32 (ApicBase + 0x390);
88 }
89
90 /**
91 Stalls the CPU for at least the given number of ticks.
92
93 Stalls the CPU for at least the given number of ticks. It's invoked by
94 MicroSecondDelay() and NanoSecondDelay().
95
96 @param ApicBase The base address of memory mapped registers of local APIC.
97 @param Delay A period of time to delay in ticks.
98
99 **/
100 STATIC
101 VOID
102 InternalX86Delay (
103 IN UINTN ApicBase,
104 IN UINT32 Delay
105 )
106 {
107 INT32 Ticks;
108
109 //
110 // The target timer count is calculated here
111 //
112 Ticks = InternalX86GetTimerTick (ApicBase) - Delay;
113
114 //
115 // Wait until time out
116 // Delay > 2^31 could not be handled by this function
117 // Timer wrap-arounds are handled correctly by this function
118 //
119 while (InternalX86GetTimerTick (ApicBase) - Ticks >= 0);
120 }
121
122 /**
123 Stalls the CPU for at least the given number of microseconds.
124
125 Stalls the CPU for the number of microseconds specified by MicroSeconds.
126
127 @param MicroSeconds The minimum number of microseconds to delay.
128
129 @return MicroSeconds
130
131 **/
132 UINTN
133 EFIAPI
134 MicroSecondDelay (
135 IN UINTN MicroSeconds
136 )
137 {
138 UINTN ApicBase;
139
140 ApicBase = InternalX86GetApicBase ();
141 InternalX86Delay (
142 ApicBase,
143 (UINT32)DivU64x32 (
144 MultU64x64 (
145 InternalX86GetTimerFrequency (ApicBase),
146 MicroSeconds
147 ),
148 1000000u
149 )
150 );
151 return MicroSeconds;
152 }
153
154 /**
155 Stalls the CPU for at least the given number of nanoseconds.
156
157 Stalls the CPU for the number of nanoseconds specified by NanoSeconds.
158
159 @param NanoSeconds The minimum number of nanoseconds to delay.
160
161 @return NanoSeconds
162
163 **/
164 UINTN
165 EFIAPI
166 NanoSecondDelay (
167 IN UINTN NanoSeconds
168 )
169 {
170 UINTN ApicBase;
171
172 ApicBase = InternalX86GetApicBase ();
173 InternalX86Delay (
174 ApicBase,
175 (UINT32)DivU64x32 (
176 MultU64x64 (
177 InternalX86GetTimerFrequency (ApicBase),
178 NanoSeconds
179 ),
180 1000000000u
181 )
182 );
183 return NanoSeconds;
184 }
185
186 /**
187 Retrieves the current value of a 64-bit free running performance counter.
188
189 Retrieves the current value of a 64-bit free running performance counter. The
190 counter can either count up by 1 or count down by 1. If the physical
191 performance counter counts by a larger increment, then the counter values
192 must be translated. The properties of the counter can be retrieved from
193 GetPerformanceCounterProperties().
194
195 @return The current value of the free running performance counter.
196
197 **/
198 UINT64
199 EFIAPI
200 GetPerformanceCounter (
201 VOID
202 )
203 {
204 return (UINT64)(UINT32)InternalX86GetTimerTick (InternalX86GetApicBase ());
205 }
206
207 /**
208 Retrieves the 64-bit frequency in Hz and the range of performance counter
209 values.
210
211 If StartValue is not NULL, then the value that the performance counter starts
212 with immediately after is it rolls over is returned in StartValue. If
213 EndValue is not NULL, then the value that the performance counter end with
214 immediately before it rolls over is returned in EndValue. The 64-bit
215 frequency of the performance counter in Hz is always returned. If StartValue
216 is less than EndValue, then the performance counter counts up. If StartValue
217 is greater than EndValue, then the performance counter counts down. For
218 example, a 64-bit free running counter that counts up would have a StartValue
219 of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter
220 that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.
221
222 @param StartValue The value the performance counter starts with when it
223 rolls over.
224 @param EndValue The value that the performance counter ends with before
225 it rolls over.
226
227 @return The frequency in Hz.
228
229 **/
230 UINT64
231 EFIAPI
232 GetPerformanceCounterProperties (
233 OUT UINT64 *StartValue, OPTIONAL
234 OUT UINT64 *EndValue OPTIONAL
235 )
236 {
237 UINTN ApicBase;
238
239 ApicBase = InternalX86GetApicBase ();
240
241 if (StartValue != NULL) {
242 *StartValue = MmioRead32 (ApicBase + 0x380);
243 }
244
245 if (EndValue != NULL) {
246 *EndValue = 0;
247 }
248
249 return (UINT64) InternalX86GetTimerFrequency (ApicBase);;
250 }