updated the comment according to latest version of MWG.
[mirror_edk2.git] / MdePkg / Library / SecPeiDxeTimerLibCpu / IpfTimerLib.c
CommitLineData
878ddf1f 1/** @file\r
ff242d40 2 Timer Library functions built upon ITC on IPF.\r
878ddf1f 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: IpfTimerLib.c\r
14\r
15**/\r
16\r
878ddf1f 17\r
878ddf1f 18\r
ed384ef3 19\r
20/**\r
21 Performs a delay measured as number of ticks.\r
22\r
23 An internal function to perform a delay measured as number of ticks. It's\r
24 invoked by MicroSecondDelay() and NanoSecondDelay().\r
25\r
26 @param Delay Number of ticks to delay.\r
27\r
28**/\r
29STATIC\r
30VOID\r
31InternalIpfDelay (\r
32 IN INT64 Delay\r
33 )\r
34{\r
35 INT64 Ticks;\r
36\r
37 //\r
38 // The target timer count is calculated here\r
39 //\r
cd4903c4 40 Ticks = IpfReadItc () + Delay;\r
ed384ef3 41\r
42 //\r
43 // Wait until time out\r
44 // Delay > 2^63 could not be handled by this function\r
45 // Timer wrap-arounds are handled correctly by this function\r
46 //\r
cd4903c4 47 while (Ticks - IpfReadItc () >= 0);\r
ed384ef3 48}\r
49\r
878ddf1f 50/**\r
51 Stalls the CPU for at least the given number of microseconds.\r
52\r
53 Stalls the CPU for the number of microseconds specified by MicroSeconds.\r
54\r
55 @param MicroSeconds The minimum number of microseconds to delay.\r
56\r
ed384ef3 57 @return MicroSeconds\r
878ddf1f 58\r
59**/\r
60UINTN\r
61EFIAPI\r
62MicroSecondDelay (\r
63 IN UINTN MicroSeconds\r
64 )\r
65{\r
ed384ef3 66 InternalIpfDelay (\r
67 GetPerformanceCounterProperties (NULL, NULL) *\r
68 MicroSeconds /\r
69 1000000\r
70 );\r
71 return MicroSeconds;\r
878ddf1f 72}\r
73\r
74/**\r
75 Stalls the CPU for at least the given number of nanoseconds.\r
76\r
77 Stalls the CPU for the number of nanoseconds specified by NanoSeconds.\r
78\r
79 @param NanoSeconds The minimum number of nanoseconds to delay.\r
80\r
ed384ef3 81 @return NanoSeconds\r
878ddf1f 82\r
83**/\r
84UINTN\r
85EFIAPI\r
86NanoSecondDelay (\r
87 IN UINTN NanoSeconds\r
88 )\r
89{\r
ed384ef3 90 InternalIpfDelay (\r
91 GetPerformanceCounterProperties (NULL, NULL) *\r
92 NanoSeconds /\r
93 1000000000\r
94 );\r
95 return NanoSeconds;\r
878ddf1f 96}\r
97\r
98/**\r
99 Retrieves the current value of a 64-bit free running performance counter.\r
100\r
101 Retrieves the current value of a 64-bit free running performance counter. The\r
102 counter can either count up by 1 or count down by 1. If the physical\r
103 performance counter counts by a larger increment, then the counter values\r
104 must be translated. The properties of the counter can be retrieved from\r
105 GetPerformanceCounterProperties().\r
106\r
107 @return The current value of the free running performance counter.\r
108\r
109**/\r
110UINT64\r
111EFIAPI\r
112GetPerformanceCounter (\r
113 VOID\r
114 )\r
115{\r
cd4903c4 116 return IpfReadItc ();\r
878ddf1f 117}\r
118\r
119/**\r
120 Retrieves the 64-bit frequency in Hz and the range of performance counter\r
121 values.\r
122\r
123 If StartValue is not NULL, then the value that the performance counter starts\r
124 with immediately after is it rolls over is returned in StartValue. If\r
125 EndValue is not NULL, then the value that the performance counter end with\r
126 immediately before it rolls over is returned in EndValue. The 64-bit\r
127 frequency of the performance counter in Hz is always returned. If StartValue\r
128 is less than EndValue, then the performance counter counts up. If StartValue\r
129 is greater than EndValue, then the performance counter counts down. For\r
130 example, a 64-bit free running counter that counts up would have a StartValue\r
131 of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter\r
132 that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.\r
133\r
134 @param StartValue The value the performance counter starts with when it\r
135 rolls over.\r
136 @param EndValue The value that the performance counter ends with before\r
137 it rolls over.\r
138\r
139 @return The frequency in Hz.\r
140\r
141**/\r
142UINT64\r
143EFIAPI\r
144GetPerformanceCounterProperties (\r
5117b83b 145 OUT UINT64 *StartValue, OPTIONAL\r
146 OUT UINT64 *EndValue OPTIONAL\r
878ddf1f 147 )\r
148{\r
149 PAL_PROC_RETURN PalRet;\r
150 UINT64 BaseFrequence;\r
151\r
e65e8d10 152 PalRet = PalCallStatic (NULL, 13, 0, 0, 0);\r
878ddf1f 153 ASSERT (PalRet.Status == 0);\r
154 BaseFrequence = PalRet.r9;\r
155\r
e65e8d10 156 PalRet = PalCallStatic (NULL, 14, 0, 0, 0);\r
878ddf1f 157 ASSERT (PalRet.Status == 0);\r
158\r
ed384ef3 159 if (StartValue != NULL) {\r
160 *StartValue = 0;\r
161 }\r
162\r
163 if (EndValue != NULL) {\r
164 *EndValue = (UINT64)(-1);\r
165 }\r
166\r
878ddf1f 167 return BaseFrequence * (PalRet.r11 >> 32) / (UINT32)PalRet.r11;\r
168}\r