diff options
| author | bbahnsen <bbahnsen@6f19259b-4bc3-4df7-8a09-765794883524> | 2006-04-21 22:54:32 +0000 |
|---|---|---|
| committer | bbahnsen <bbahnsen@6f19259b-4bc3-4df7-8a09-765794883524> | 2006-04-21 22:54:32 +0000 |
| commit | 878ddf1fc3540a715f63594ed22b6929e881afb4 (patch) | |
| tree | c56c44dac138137b510e1fba7c3efe5e4d84bea2 /MdePkg/Library/BaseTimerLibLocalApic/x86TimerLib.c | |
| download | edk2-platforms-878ddf1fc3540a715f63594ed22b6929e881afb4.tar.xz | |
Initial import.
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@3 6f19259b-4bc3-4df7-8a09-765794883524
Diffstat (limited to 'MdePkg/Library/BaseTimerLibLocalApic/x86TimerLib.c')
| -rw-r--r-- | MdePkg/Library/BaseTimerLibLocalApic/x86TimerLib.c | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/MdePkg/Library/BaseTimerLibLocalApic/x86TimerLib.c b/MdePkg/Library/BaseTimerLibLocalApic/x86TimerLib.c new file mode 100644 index 0000000000..6f78e4e4fd --- /dev/null +++ b/MdePkg/Library/BaseTimerLibLocalApic/x86TimerLib.c @@ -0,0 +1,168 @@ +/** @file
+ Timer Library functions built upon local APIC on IA32/x64.
+
+ @bug Should use PCD to retrieve all the constants including index of
+ the IA32_APIC_BASE MSR, the offsets of InitialCount, CorrentCount
+ and DivideConfiguration.
+
+ Copyright (c) 2006, Intel Corporation<BR>
+ All rights reserved. This program and the accompanying materials
+ are licensed and made available under the terms and conditions of the BSD License
+ which accompanies this distribution. The full text of the license may be found at
+ http://opensource.org/licenses/bsd-license.php
+
+ THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+ Module Name: x86TimerLib.c
+
+**/
+
+static
+UINTN
+EFIAPI
+DelayWorker (
+ IN UINT64 NDelay
+ )
+{
+ UINTN Ticks;
+
+ Ticks = (UINTN)GetPerformanceCounter ();
+ Ticks -= (UINTN)DivU64x32 (
+ MultU64x64 (
+ GetPerformanceCounterProperties (NULL, NULL),
+ NDelay
+ ),
+ 1000000000u
+ );
+ while (Ticks >= GetPerformanceCounter ());
+ return Ticks;
+}
+
+/**
+ Stalls the CPU for at least the given number of microseconds.
+
+ Stalls the CPU for the number of microseconds specified by MicroSeconds.
+
+ @param MicroSeconds The minimum number of microseconds to delay.
+
+ @return Return value depends on implementation.
+
+**/
+UINTN
+EFIAPI
+MicroSecondDelay (
+ IN UINTN MicroSeconds
+ )
+{
+ return DelayWorker (MicroSeconds * 1000ull);
+}
+
+/**
+ Stalls the CPU for at least the given number of nanoseconds.
+
+ Stalls the CPU for the number of nanoseconds specified by NanoSeconds.
+
+ @param NanoSeconds The minimum number of nanoseconds to delay.
+
+ @return Return value depends on implementation.
+
+**/
+UINTN
+EFIAPI
+NanoSecondDelay (
+ IN UINTN NanoSeconds
+ )
+{
+ return DelayWorker (NanoSeconds);
+}
+
+static
+UINTN
+EFIAPI
+GetApicBase (
+ VOID
+ )
+{
+ return (UINTN)AsmMsrBitFieldRead64 (27, 12, 35) << 12;
+}
+
+/**
+ Retrieves the current value of a 64-bit free running performance counter.
+
+ Retrieves the current value of a 64-bit free running performance counter. The
+ counter can either count up by 1 or count down by 1. If the physical
+ performance counter counts by a larger increment, then the counter values
+ must be translated. The properties of the counter can be retrieved from
+ GetPerformanceCounterProperties().
+
+ @return The current value of the free running performance counter.
+
+**/
+UINT64
+EFIAPI
+GetPerformanceCounter (
+ VOID
+ )
+{
+ return MmioRead32 (GetApicBase () + 0x390);
+}
+
+/**
+ Retrieves the 64-bit frequency in Hz and the range of performance counter
+ values.
+
+ If StartValue is not NULL, then the value that the performance counter starts
+ with immediately after is it rolls over is returned in StartValue. If
+ EndValue is not NULL, then the value that the performance counter end with
+ immediately before it rolls over is returned in EndValue. The 64-bit
+ frequency of the performance counter in Hz is always returned. If StartValue
+ is less than EndValue, then the performance counter counts up. If StartValue
+ is greater than EndValue, then the performance counter counts down. For
+ example, a 64-bit free running counter that counts up would have a StartValue
+ of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter
+ that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.
+
+ @param StartValue The value the performance counter starts with when it
+ rolls over.
+ @param EndValue The value that the performance counter ends with before
+ it rolls over.
+
+ @return The frequency in Hz.
+
+**/
+UINT64
+EFIAPI
+GetPerformanceCounterProperties (
+ IN UINT64 *StartValue,
+ IN UINT64 *EndValue
+ )
+{
+ static const UINT32 mFrequencies[] = {
+ 100000000,
+ 133000000,
+ 200000000,
+ 166000000
+ };
+ static const UINT8 mDivisor[] = {
+ 0x02, 0x04, 0x08, 0x10,
+ 0x02, 0x04, 0x08, 0x10,
+ 0x20, 0x40, 0x80, 0x01,
+ 0x20, 0x40, 0x80, 0x01
+ };
+
+ UINTN ApicBase;
+
+ ApicBase = GetApicBase ();
+
+ if (StartValue != NULL) {
+ *StartValue = MmioRead32 (ApicBase + 0x380);
+ }
+
+ if (EndValue != NULL) {
+ *EndValue = 0;
+ }
+
+ return mFrequencies[AsmMsrBitFieldRead32 (44, 16, 18)] /
+ mDivisor[MmioBitFieldRead32 (ApicBase + 0x3e0, 0, 3)];
+}
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