--- /dev/null
+/** @file\r
+ Timer Library functions built upon local APIC on IA32/x64.\r
+\r
+ This library uses the local APIC library so that it supports x2APIC mode.\r
+ \r
+ Copyright (c) 2010, Intel Corporation. All rights reserved.<BR>\r
+ This program and the accompanying materials\r
+ are licensed and made available under the terms and conditions of the BSD License\r
+ which accompanies this distribution. The full text of the license may be found at\r
+ http://opensource.org/licenses/bsd-license.php.\r
+\r
+ THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
+ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
+\r
+**/\r
+\r
+#include <Base.h>\r
+#include <Library/TimerLib.h>\r
+#include <Library/BaseLib.h>\r
+#include <Library/PcdLib.h>\r
+#include <Library/DebugLib.h>\r
+#include <Library/LocalApicLib.h>\r
+\r
+/**\r
+ Internal function to return the frequency of the local APIC timer.\r
+\r
+ @return The frequency of the timer in Hz.\r
+\r
+**/\r
+UINT32\r
+EFIAPI\r
+InternalX86GetTimerFrequency (\r
+ VOID\r
+ )\r
+{\r
+ UINTN Divisor;\r
+\r
+ GetApicTimerState (&Divisor, NULL, NULL);\r
+ return PcdGet32(PcdFSBClock) / (UINT32)Divisor;\r
+}\r
+\r
+/**\r
+ Stalls the CPU for at least the given number of ticks.\r
+\r
+ Stalls the CPU for at least the given number of ticks. It's invoked by\r
+ MicroSecondDelay() and NanoSecondDelay().\r
+\r
+ @param Delay A period of time to delay in ticks.\r
+\r
+**/\r
+VOID\r
+EFIAPI\r
+InternalX86Delay (\r
+ IN UINT32 Delay\r
+ )\r
+{\r
+ INT32 Ticks;\r
+ UINT32 PowerOfTwoCounter;\r
+\r
+ //\r
+ // The target timer count is calculated here\r
+ //\r
+ Ticks = GetApicTimerCurrentCount () - Delay;\r
+\r
+ //\r
+ // Wait until time out\r
+ // Delay > 2^31 could not be handled by this function\r
+ // Timer wrap-arounds are handled correctly by this function\r
+ //\r
+ PowerOfTwoCounter = GetPowerOfTwo32 (GetApicTimerInitCount ());\r
+ while (((UINT32)(GetApicTimerCurrentCount () - Ticks) & PowerOfTwoCounter) == 0) {\r
+ CpuPause ();\r
+ }\r
+}\r
+\r
+/**\r
+ Stalls the CPU for at least the given number of microseconds.\r
+\r
+ Stalls the CPU for the number of microseconds specified by MicroSeconds.\r
+\r
+ @param MicroSeconds The minimum number of microseconds to delay.\r
+\r
+ @return The value of MicroSeconds inputted.\r
+\r
+**/\r
+UINTN\r
+EFIAPI\r
+MicroSecondDelay (\r
+ IN UINTN MicroSeconds\r
+ )\r
+{\r
+ InternalX86Delay (\r
+ (UINT32)DivU64x32 (\r
+ MultU64x64 (\r
+ InternalX86GetTimerFrequency (),\r
+ MicroSeconds\r
+ ),\r
+ 1000000u\r
+ )\r
+ );\r
+ return MicroSeconds;\r
+}\r
+\r
+/**\r
+ Stalls the CPU for at least the given number of nanoseconds.\r
+\r
+ Stalls the CPU for the number of nanoseconds specified by NanoSeconds.\r
+\r
+ @param NanoSeconds The minimum number of nanoseconds to delay.\r
+\r
+ @return The value of NanoSeconds inputted.\r
+\r
+**/\r
+UINTN\r
+EFIAPI\r
+NanoSecondDelay (\r
+ IN UINTN NanoSeconds\r
+ )\r
+{\r
+ InternalX86Delay (\r
+ (UINT32)DivU64x32 (\r
+ MultU64x64 (\r
+ InternalX86GetTimerFrequency (),\r
+ NanoSeconds\r
+ ),\r
+ 1000000000u\r
+ )\r
+ );\r
+ return NanoSeconds;\r
+}\r
+\r
+/**\r
+ Retrieves the current value of a 64-bit free running performance counter.\r
+\r
+ The counter can either count up by 1 or count down by 1. If the physical\r
+ performance counter counts by a larger increment, then the counter values\r
+ must be translated. The properties of the counter can be retrieved from\r
+ GetPerformanceCounterProperties().\r
+\r
+ @return The current value of the free running performance counter.\r
+\r
+**/\r
+UINT64\r
+EFIAPI\r
+GetPerformanceCounter (\r
+ VOID\r
+ )\r
+{\r
+ return (UINT64)GetApicTimerCurrentCount ();\r
+}\r
+\r
+/**\r
+ Retrieves the 64-bit frequency in Hz and the range of performance counter\r
+ values.\r
+\r
+ If StartValue is not NULL, then the value that the performance counter starts\r
+ with immediately after is it rolls over is returned in StartValue. If\r
+ EndValue is not NULL, then the value that the performance counter end with\r
+ immediately before it rolls over is returned in EndValue. The 64-bit\r
+ frequency of the performance counter in Hz is always returned. If StartValue\r
+ is less than EndValue, then the performance counter counts up. If StartValue\r
+ is greater than EndValue, then the performance counter counts down. For\r
+ example, a 64-bit free running counter that counts up would have a StartValue\r
+ of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter\r
+ that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.\r
+\r
+ @param StartValue The value the performance counter starts with when it\r
+ rolls over.\r
+ @param EndValue The value that the performance counter ends with before\r
+ it rolls over.\r
+\r
+ @return The frequency in Hz.\r
+\r
+**/\r
+UINT64\r
+EFIAPI\r
+GetPerformanceCounterProperties (\r
+ OUT UINT64 *StartValue, OPTIONAL\r
+ OUT UINT64 *EndValue OPTIONAL\r
+ )\r
+{\r
+ if (StartValue != NULL) {\r
+ *StartValue = (UINT64)GetApicTimerInitCount ();\r
+ //\r
+ // make sure StartValue is all 1s from High Bit\r
+ //\r
+ ASSERT ((*StartValue & (*StartValue + 1)) == 0);\r
+ }\r
+\r
+ if (EndValue != NULL) {\r
+ *EndValue = 0;\r
+ }\r
+\r
+ return (UINT64) InternalX86GetTimerFrequency ();\r
+}\r
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