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1 | /** @file\r | |
2 | SMM Timer feature support\r | |
3 | \r | |
4 | Copyright (c) 2009 - 2015, Intel Corporation. All rights reserved.<BR>\r | |
5 | SPDX-License-Identifier: BSD-2-Clause-Patent\r | |
6 | \r | |
7 | **/\r | |
8 | \r | |
9 | #include "PiSmmCpuDxeSmm.h"\r | |
10 | \r | |
11 | UINT64 mTimeoutTicker = 0;\r | |
12 | //\r | |
13 | // Number of counts in a roll-over cycle of the performance counter.\r | |
14 | //\r | |
15 | UINT64 mCycle = 0;\r | |
16 | //\r | |
17 | // Flag to indicate the performance counter is count-up or count-down.\r | |
18 | //\r | |
19 | BOOLEAN mCountDown;\r | |
20 | \r | |
21 | /**\r | |
22 | Initialize Timer for SMM AP Sync.\r | |
23 | \r | |
24 | **/\r | |
25 | VOID\r | |
26 | InitializeSmmTimer (\r | |
27 | VOID\r | |
28 | )\r | |
29 | {\r | |
30 | UINT64 TimerFrequency;\r | |
31 | UINT64 Start;\r | |
32 | UINT64 End;\r | |
33 | \r | |
34 | TimerFrequency = GetPerformanceCounterProperties (&Start, &End);\r | |
35 | mTimeoutTicker = DivU64x32 (\r | |
36 | MultU64x64 (TimerFrequency, PcdGet64 (PcdCpuSmmApSyncTimeout)),\r | |
37 | 1000 * 1000\r | |
38 | );\r | |
39 | if (End < Start) {\r | |
40 | mCountDown = TRUE;\r | |
41 | mCycle = Start - End;\r | |
42 | } else {\r | |
43 | mCountDown = FALSE;\r | |
44 | mCycle = End - Start;\r | |
45 | }\r | |
46 | }\r | |
47 | \r | |
48 | /**\r | |
49 | Start Timer for SMM AP Sync.\r | |
50 | \r | |
51 | **/\r | |
52 | UINT64\r | |
53 | EFIAPI\r | |
54 | StartSyncTimer (\r | |
55 | VOID\r | |
56 | )\r | |
57 | {\r | |
58 | return GetPerformanceCounter ();\r | |
59 | }\r | |
60 | \r | |
61 | /**\r | |
62 | Check if the SMM AP Sync timer is timeout.\r | |
63 | \r | |
64 | @param Timer The start timer from the begin.\r | |
65 | \r | |
66 | **/\r | |
67 | BOOLEAN\r | |
68 | EFIAPI\r | |
69 | IsSyncTimerTimeout (\r | |
70 | IN UINT64 Timer\r | |
71 | )\r | |
72 | {\r | |
73 | UINT64 CurrentTimer;\r | |
74 | UINT64 Delta;\r | |
75 | \r | |
76 | CurrentTimer = GetPerformanceCounter ();\r | |
77 | //\r | |
78 | // We need to consider the case that CurrentTimer is equal to Timer\r | |
79 | // when some timer runs too slow and CPU runs fast. We think roll over\r | |
80 | // condition does not happen on this case.\r | |
81 | //\r | |
82 | if (mCountDown) {\r | |
83 | //\r | |
84 | // The performance counter counts down. Check for roll over condition.\r | |
85 | //\r | |
86 | if (CurrentTimer <= Timer) {\r | |
87 | Delta = Timer - CurrentTimer;\r | |
88 | } else {\r | |
89 | //\r | |
90 | // Handle one roll-over.\r | |
91 | //\r | |
92 | Delta = mCycle - (CurrentTimer - Timer) + 1;\r | |
93 | }\r | |
94 | } else {\r | |
95 | //\r | |
96 | // The performance counter counts up. Check for roll over condition.\r | |
97 | //\r | |
98 | if (CurrentTimer >= Timer) {\r | |
99 | Delta = CurrentTimer - Timer;\r | |
100 | } else {\r | |
101 | //\r | |
102 | // Handle one roll-over.\r | |
103 | //\r | |
104 | Delta = mCycle - (Timer - CurrentTimer) + 1;\r | |
105 | }\r | |
106 | }\r | |
107 | \r | |
108 | return (BOOLEAN)(Delta >= mTimeoutTicker);\r | |
109 | }\r |