updated the comment according to latest version of MWG.
[mirror_edk2.git] / MdePkg / Library / SecPeiDxeTimerLibCpu / x86TimerLib.c
CommitLineData
878ddf1f 1/** @file\r
2 Timer Library functions built upon local APIC on IA32/x64.\r
3\r
4faa5028 4 Copyright (c) 2006 - 2007, Intel Corporation<BR>\r
878ddf1f 5 All rights reserved. This program and the accompanying materials\r
6 are licensed and made available under the terms and conditions of the BSD License\r
7 which accompanies this distribution. The full text of the license may be found at\r
8 http://opensource.org/licenses/bsd-license.php\r
9\r
10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
12\r
13 Module Name: x86TimerLib.c\r
14\r
15**/\r
16\r
ed384ef3 17//\r
b219108e 18// The following array is used in calculating the frequency of local APIC\r
ed384ef3 19// timer. Refer to IA-32 developers' manual for more details.\r
20//\r
ed384ef3 21GLOBAL_REMOVE_IF_UNREFERENCED\r
22CONST UINT8 mTimerLibLocalApicDivisor[] = {\r
23 0x02, 0x04, 0x08, 0x10,\r
24 0x02, 0x04, 0x08, 0x10,\r
25 0x20, 0x40, 0x80, 0x01,\r
26 0x20, 0x40, 0x80, 0x01\r
27};\r
28\r
29/**\r
30 Internal function to retrieve the base address of local APIC.\r
31\r
32 Internal function to retrieve the base address of local APIC.\r
33\r
34 @return The base address of local APIC\r
35\r
36**/\r
37STATIC\r
878ddf1f 38UINTN\r
ed384ef3 39InternalX86GetApicBase (\r
40 VOID\r
41 )\r
42{\r
43 return (UINTN)AsmMsrBitFieldRead64 (27, 12, 35) << 12;\r
44}\r
45\r
46/**\r
47 Internal function to return the frequency of the local APIC timer.\r
48\r
49 Internal function to return the frequency of the local APIC timer.\r
50\r
51 @param ApicBase The base address of memory mapped registers of local APIC.\r
52\r
53 @return The frequency of the timer in Hz.\r
54\r
55**/\r
56STATIC\r
57UINT32\r
58InternalX86GetTimerFrequency (\r
59 IN UINTN ApicBase\r
60 )\r
61{\r
62 return\r
885dc4d8 63 PcdGet32(PcdFSBClock) /\r
ed384ef3 64 mTimerLibLocalApicDivisor[MmioBitFieldRead32 (ApicBase + 0x3e0, 0, 3)];\r
65}\r
66\r
67/**\r
68 Internal function to read the current tick counter of local APIC.\r
69\r
70 Internal function to read the current tick counter of local APIC.\r
71\r
72 @param ApicBase The base address of memory mapped registers of local APIC.\r
73\r
74 @return The tick counter read.\r
75\r
76**/\r
77STATIC\r
78INT32\r
79InternalX86GetTimerTick (\r
80 IN UINTN ApicBase\r
878ddf1f 81 )\r
82{\r
ed384ef3 83 return MmioRead32 (ApicBase + 0x390);\r
84}\r
85\r
86/**\r
87 Stalls the CPU for at least the given number of ticks.\r
88\r
89 Stalls the CPU for at least the given number of ticks. It's invoked by\r
90 MicroSecondDelay() and NanoSecondDelay().\r
91\r
92 @param ApicBase The base address of memory mapped registers of local APIC.\r
93 @param Delay A period of time to delay in ticks.\r
94\r
95**/\r
96STATIC\r
97VOID\r
98InternalX86Delay (\r
99 IN UINTN ApicBase,\r
100 IN UINT32 Delay\r
101 )\r
102{\r
103 INT32 Ticks;\r
104\r
ed384ef3 105 //\r
106 // The target timer count is calculated here\r
107 //\r
108 Ticks = InternalX86GetTimerTick (ApicBase) - Delay;\r
109\r
110 //\r
111 // Wait until time out\r
112 // Delay > 2^31 could not be handled by this function\r
113 // Timer wrap-arounds are handled correctly by this function\r
114 //\r
115 while (InternalX86GetTimerTick (ApicBase) - Ticks >= 0);\r
878ddf1f 116}\r
117\r
118/**\r
119 Stalls the CPU for at least the given number of microseconds.\r
120\r
121 Stalls the CPU for the number of microseconds specified by MicroSeconds.\r
122\r
123 @param MicroSeconds The minimum number of microseconds to delay.\r
124\r
ed384ef3 125 @return MicroSeconds\r
878ddf1f 126\r
127**/\r
128UINTN\r
129EFIAPI\r
130MicroSecondDelay (\r
131 IN UINTN MicroSeconds\r
132 )\r
133{\r
ed384ef3 134 UINTN ApicBase;\r
135\r
136 ApicBase = InternalX86GetApicBase ();\r
137 InternalX86Delay (\r
138 ApicBase,\r
139 (UINT32)DivU64x32 (\r
140 MultU64x64 (\r
141 InternalX86GetTimerFrequency (ApicBase),\r
142 MicroSeconds\r
143 ),\r
144 1000000u\r
145 )\r
146 );\r
147 return MicroSeconds;\r
878ddf1f 148}\r
149\r
150/**\r
151 Stalls the CPU for at least the given number of nanoseconds.\r
152\r
153 Stalls the CPU for the number of nanoseconds specified by NanoSeconds.\r
154\r
155 @param NanoSeconds The minimum number of nanoseconds to delay.\r
156\r
ed384ef3 157 @return NanoSeconds\r
878ddf1f 158\r
159**/\r
160UINTN\r
161EFIAPI\r
162NanoSecondDelay (\r
163 IN UINTN NanoSeconds\r
164 )\r
165{\r
ed384ef3 166 UINTN ApicBase;\r
878ddf1f 167\r
ed384ef3 168 ApicBase = InternalX86GetApicBase ();\r
169 InternalX86Delay (\r
170 ApicBase,\r
171 (UINT32)DivU64x32 (\r
172 MultU64x64 (\r
173 InternalX86GetTimerFrequency (ApicBase),\r
174 NanoSeconds\r
175 ),\r
176 1000000000u\r
177 )\r
178 );\r
179 return NanoSeconds;\r
878ddf1f 180}\r
181\r
182/**\r
183 Retrieves the current value of a 64-bit free running performance counter.\r
184\r
185 Retrieves the current value of a 64-bit free running performance counter. The\r
186 counter can either count up by 1 or count down by 1. If the physical\r
187 performance counter counts by a larger increment, then the counter values\r
188 must be translated. The properties of the counter can be retrieved from\r
189 GetPerformanceCounterProperties().\r
190\r
191 @return The current value of the free running performance counter.\r
192\r
193**/\r
194UINT64\r
195EFIAPI\r
196GetPerformanceCounter (\r
197 VOID\r
198 )\r
199{\r
34913f24 200 return (UINT64)(UINT32)InternalX86GetTimerTick (InternalX86GetApicBase ());\r
878ddf1f 201}\r
202\r
203/**\r
204 Retrieves the 64-bit frequency in Hz and the range of performance counter\r
205 values.\r
206\r
207 If StartValue is not NULL, then the value that the performance counter starts\r
208 with immediately after is it rolls over is returned in StartValue. If\r
209 EndValue is not NULL, then the value that the performance counter end with\r
210 immediately before it rolls over is returned in EndValue. The 64-bit\r
211 frequency of the performance counter in Hz is always returned. If StartValue\r
212 is less than EndValue, then the performance counter counts up. If StartValue\r
213 is greater than EndValue, then the performance counter counts down. For\r
214 example, a 64-bit free running counter that counts up would have a StartValue\r
215 of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter\r
216 that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.\r
217\r
218 @param StartValue The value the performance counter starts with when it\r
219 rolls over.\r
220 @param EndValue The value that the performance counter ends with before\r
221 it rolls over.\r
222\r
223 @return The frequency in Hz.\r
224\r
225**/\r
226UINT64\r
227EFIAPI\r
228GetPerformanceCounterProperties (\r
5117b83b 229 OUT UINT64 *StartValue, OPTIONAL\r
230 OUT UINT64 *EndValue OPTIONAL\r
878ddf1f 231 )\r
232{\r
878ddf1f 233 UINTN ApicBase;\r
234\r
ed384ef3 235 ApicBase = InternalX86GetApicBase ();\r
878ddf1f 236\r
237 if (StartValue != NULL) {\r
238 *StartValue = MmioRead32 (ApicBase + 0x380);\r
239 }\r
240\r
241 if (EndValue != NULL) {\r
242 *EndValue = 0;\r
243 }\r
244\r
83b3efca 245 return (UINT64) InternalX86GetTimerFrequency (ApicBase);;\r
878ddf1f 246}\r