Removed unnecessary MSR access in InternalX86Delay()
[mirror_edk2.git] / MdePkg / Library / BaseTimerLibLocalApic / x86TimerLib.c
CommitLineData
878ddf1f 1/** @file\r
2 Timer Library functions built upon local APIC on IA32/x64.\r
3\r
4 @bug Should use PCD to retrieve all the constants including index of\r
5 the IA32_APIC_BASE MSR, the offsets of InitialCount, CorrentCount\r
6 and DivideConfiguration.\r
7\r
8 Copyright (c) 2006, Intel Corporation<BR>\r
9 All rights reserved. This program and the accompanying materials\r
10 are licensed and made available under the terms and conditions of the BSD License\r
11 which accompanies this distribution. The full text of the license may be found at\r
12 http://opensource.org/licenses/bsd-license.php\r
13\r
14 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
15 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
16\r
17 Module Name: x86TimerLib.c\r
18\r
19**/\r
20\r
ed384ef3 21//\r
22// The following 2 arrays are used in calculating the frequency of local APIC\r
23// timer. Refer to IA-32 developers' manual for more details.\r
24//\r
25\r
26GLOBAL_REMOVE_IF_UNREFERENCED\r
27CONST UINT32 mTimerLibLocalApicFrequencies[] = {\r
28 100000000,\r
29 133000000,\r
30 200000000,\r
31 166000000\r
32};\r
33\r
34GLOBAL_REMOVE_IF_UNREFERENCED\r
35CONST UINT8 mTimerLibLocalApicDivisor[] = {\r
36 0x02, 0x04, 0x08, 0x10,\r
37 0x02, 0x04, 0x08, 0x10,\r
38 0x20, 0x40, 0x80, 0x01,\r
39 0x20, 0x40, 0x80, 0x01\r
40};\r
41\r
42/**\r
43 Internal function to retrieve the base address of local APIC.\r
44\r
45 Internal function to retrieve the base address of local APIC.\r
46\r
47 @return The base address of local APIC\r
48\r
49**/\r
50STATIC\r
878ddf1f 51UINTN\r
ed384ef3 52InternalX86GetApicBase (\r
53 VOID\r
54 )\r
55{\r
56 return (UINTN)AsmMsrBitFieldRead64 (27, 12, 35) << 12;\r
57}\r
58\r
59/**\r
60 Internal function to return the frequency of the local APIC timer.\r
61\r
62 Internal function to return the frequency of the local APIC timer.\r
63\r
64 @param ApicBase The base address of memory mapped registers of local APIC.\r
65\r
66 @return The frequency of the timer in Hz.\r
67\r
68**/\r
69STATIC\r
70UINT32\r
71InternalX86GetTimerFrequency (\r
72 IN UINTN ApicBase\r
73 )\r
74{\r
75 return\r
76 mTimerLibLocalApicFrequencies[AsmMsrBitFieldRead32 (44, 16, 18)] /\r
77 mTimerLibLocalApicDivisor[MmioBitFieldRead32 (ApicBase + 0x3e0, 0, 3)];\r
78}\r
79\r
80/**\r
81 Internal function to read the current tick counter of local APIC.\r
82\r
83 Internal function to read the current tick counter of local APIC.\r
84\r
85 @param ApicBase The base address of memory mapped registers of local APIC.\r
86\r
87 @return The tick counter read.\r
88\r
89**/\r
90STATIC\r
91INT32\r
92InternalX86GetTimerTick (\r
93 IN UINTN ApicBase\r
878ddf1f 94 )\r
95{\r
ed384ef3 96 return MmioRead32 (ApicBase + 0x390);\r
97}\r
98\r
99/**\r
100 Stalls the CPU for at least the given number of ticks.\r
101\r
102 Stalls the CPU for at least the given number of ticks. It's invoked by\r
103 MicroSecondDelay() and NanoSecondDelay().\r
104\r
105 @param ApicBase The base address of memory mapped registers of local APIC.\r
106 @param Delay A period of time to delay in ticks.\r
107\r
108**/\r
109STATIC\r
110VOID\r
111InternalX86Delay (\r
112 IN UINTN ApicBase,\r
113 IN UINT32 Delay\r
114 )\r
115{\r
116 INT32 Ticks;\r
117\r
ed384ef3 118 //\r
119 // The target timer count is calculated here\r
120 //\r
121 Ticks = InternalX86GetTimerTick (ApicBase) - Delay;\r
122\r
123 //\r
124 // Wait until time out\r
125 // Delay > 2^31 could not be handled by this function\r
126 // Timer wrap-arounds are handled correctly by this function\r
127 //\r
128 while (InternalX86GetTimerTick (ApicBase) - Ticks >= 0);\r
878ddf1f 129}\r
130\r
131/**\r
132 Stalls the CPU for at least the given number of microseconds.\r
133\r
134 Stalls the CPU for the number of microseconds specified by MicroSeconds.\r
135\r
136 @param MicroSeconds The minimum number of microseconds to delay.\r
137\r
ed384ef3 138 @return MicroSeconds\r
878ddf1f 139\r
140**/\r
141UINTN\r
142EFIAPI\r
143MicroSecondDelay (\r
144 IN UINTN MicroSeconds\r
145 )\r
146{\r
ed384ef3 147 UINTN ApicBase;\r
148\r
149 ApicBase = InternalX86GetApicBase ();\r
150 InternalX86Delay (\r
151 ApicBase,\r
152 (UINT32)DivU64x32 (\r
153 MultU64x64 (\r
154 InternalX86GetTimerFrequency (ApicBase),\r
155 MicroSeconds\r
156 ),\r
157 1000000u\r
158 )\r
159 );\r
160 return MicroSeconds;\r
878ddf1f 161}\r
162\r
163/**\r
164 Stalls the CPU for at least the given number of nanoseconds.\r
165\r
166 Stalls the CPU for the number of nanoseconds specified by NanoSeconds.\r
167\r
168 @param NanoSeconds The minimum number of nanoseconds to delay.\r
169\r
ed384ef3 170 @return NanoSeconds\r
878ddf1f 171\r
172**/\r
173UINTN\r
174EFIAPI\r
175NanoSecondDelay (\r
176 IN UINTN NanoSeconds\r
177 )\r
178{\r
ed384ef3 179 UINTN ApicBase;\r
878ddf1f 180\r
ed384ef3 181 ApicBase = InternalX86GetApicBase ();\r
182 InternalX86Delay (\r
183 ApicBase,\r
184 (UINT32)DivU64x32 (\r
185 MultU64x64 (\r
186 InternalX86GetTimerFrequency (ApicBase),\r
187 NanoSeconds\r
188 ),\r
189 1000000000u\r
190 )\r
191 );\r
192 return NanoSeconds;\r
878ddf1f 193}\r
194\r
195/**\r
196 Retrieves the current value of a 64-bit free running performance counter.\r
197\r
198 Retrieves the current value of a 64-bit free running performance counter. The\r
199 counter can either count up by 1 or count down by 1. If the physical\r
200 performance counter counts by a larger increment, then the counter values\r
201 must be translated. The properties of the counter can be retrieved from\r
202 GetPerformanceCounterProperties().\r
203\r
204 @return The current value of the free running performance counter.\r
205\r
206**/\r
207UINT64\r
208EFIAPI\r
209GetPerformanceCounter (\r
210 VOID\r
211 )\r
212{\r
ed384ef3 213 return InternalX86GetTimerTick (InternalX86GetApicBase ());\r
878ddf1f 214}\r
215\r
216/**\r
217 Retrieves the 64-bit frequency in Hz and the range of performance counter\r
218 values.\r
219\r
220 If StartValue is not NULL, then the value that the performance counter starts\r
221 with immediately after is it rolls over is returned in StartValue. If\r
222 EndValue is not NULL, then the value that the performance counter end with\r
223 immediately before it rolls over is returned in EndValue. The 64-bit\r
224 frequency of the performance counter in Hz is always returned. If StartValue\r
225 is less than EndValue, then the performance counter counts up. If StartValue\r
226 is greater than EndValue, then the performance counter counts down. For\r
227 example, a 64-bit free running counter that counts up would have a StartValue\r
228 of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter\r
229 that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.\r
230\r
231 @param StartValue The value the performance counter starts with when it\r
232 rolls over.\r
233 @param EndValue The value that the performance counter ends with before\r
234 it rolls over.\r
235\r
236 @return The frequency in Hz.\r
237\r
238**/\r
239UINT64\r
240EFIAPI\r
241GetPerformanceCounterProperties (\r
242 IN UINT64 *StartValue,\r
243 IN UINT64 *EndValue\r
244 )\r
245{\r
878ddf1f 246 UINTN ApicBase;\r
247\r
ed384ef3 248 ApicBase = InternalX86GetApicBase ();\r
878ddf1f 249\r
250 if (StartValue != NULL) {\r
251 *StartValue = MmioRead32 (ApicBase + 0x380);\r
252 }\r
253\r
254 if (EndValue != NULL) {\r
255 *EndValue = 0;\r
256 }\r
257\r
ed384ef3 258 return InternalX86GetTimerFrequency (ApicBase);\r
878ddf1f 259}\r