From cbdece176953cf2be63b322f53600e2136b94744 Mon Sep 17 00:00:00 2001
From: Sami Mujawar <sami.mujawar@arm.com>
Date: Thu, 3 Mar 2016 15:28:16 +0000
Subject: [PATCH] ArmPkg/ArchArmTimerLib: refactor MultU64xN and TimerFreq
 definitions

This refactors some timer code to define MultU64xN as a preprocessor
symbol rather than a function pointer, and to factor out the code that
obtains the timer frequency into GetPlatformTimerFreq ().

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Evan Lloyd <evan.lloyd@arm.com>
Reviewed-by: Ryan Harkin <ryan.harkin@linaro.org>

Contributed-under: TianoCore Contribution Agreement 1.0
[ard.biesheuvel: split off from 'add GetTimeInNanoSecond() to ArmArchTimerLib']
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 .../Library/ArmArchTimerLib/ArmArchTimerLib.c | 49 ++++++++++++-------
 1 file changed, 31 insertions(+), 18 deletions(-)

diff --git a/ArmPkg/Library/ArmArchTimerLib/ArmArchTimerLib.c b/ArmPkg/Library/ArmArchTimerLib/ArmArchTimerLib.c
index a0e4f5804b..4361905e14 100644
--- a/ArmPkg/Library/ArmArchTimerLib/ArmArchTimerLib.c
+++ b/ArmPkg/Library/ArmArchTimerLib/ArmArchTimerLib.c
@@ -24,6 +24,14 @@
 
 #define TICKS_PER_MICRO_SEC     (PcdGet32 (PcdArmArchTimerFreqInHz)/1000000U)
 
+// Select appropriate multiply function for platform architecture.
+#ifdef MDE_CPU_ARM
+#define MultU64xN MultU64x32
+#else
+#define MultU64xN MultU64x64
+#endif
+
+
 RETURN_STATUS
 EFIAPI
 TimerConstructor (
@@ -76,6 +84,28 @@ TimerConstructor (
   return RETURN_SUCCESS;
 }
 
+/**
+  A local utility function that returns the PCD value, if specified.
+  Otherwise it defaults to ArmGenericTimerGetTimerFreq.
+
+  @return The timer frequency.
+
+**/
+STATIC
+UINTN
+EFIAPI
+GetPlatformTimerFreq (
+  )
+{
+  UINTN TimerFreq;
+
+  TimerFreq = PcdGet32 (PcdArmArchTimerFreqInHz);
+  if (TimerFreq == 0) {
+    TimerFreq = ArmGenericTimerGetTimerFreq ();
+  }
+  return TimerFreq;
+}
+
 
 /**
   Stalls the CPU for the number of microseconds specified by MicroSeconds.
@@ -93,23 +123,6 @@ MicroSecondDelay (
 {
   UINT64 TimerTicks64;
   UINT64 SystemCounterVal;
-  UINT64 (EFIAPI
-          *MultU64xN) (
-            IN UINT64 Multiplicand,
-            IN UINTN  Multiplier
-            );
-  UINTN TimerFreq;
-
-#ifdef MDE_CPU_ARM
-  MultU64xN = MultU64x32;
-#else
-  MultU64xN = MultU64x64;
-#endif
-
-  TimerFreq = PcdGet32 (PcdArmArchTimerFreqInHz);
-  if (TimerFreq == 0) {
-    TimerFreq = ArmGenericTimerGetTimerFreq ();
-  }
 
   // Calculate counter ticks that can represent requested delay:
   //  = MicroSeconds x TICKS_PER_MICRO_SEC
@@ -117,7 +130,7 @@ MicroSecondDelay (
   TimerTicks64 = DivU64x32 (
                    MultU64xN (
                      MicroSeconds,
-                     TimerFreq
+                     GetPlatformTimerFreq ()
                      ),
                    1000000U
                    );