X-Git-Url: https://git.proxmox.com/?p=mirror_edk2.git;a=blobdiff_plain;f=MdePkg%2FLibrary%2FBaseTimerLibLocalApic%2FIpf%2FIpfTimerLib.c;h=65b58bc54945ec96ff2187c5ad50020505ef2fcf;hp=3814534607d924913f90021c0a3281223a804668;hb=cd4903c497c9ace4016efb340d6e9cfd561a9833;hpb=e65e8d103dbadc85c3fe3cce50cd98069a75e72f

diff --git a/MdePkg/Library/BaseTimerLibLocalApic/Ipf/IpfTimerLib.c b/MdePkg/Library/BaseTimerLibLocalApic/Ipf/IpfTimerLib.c
index 3814534607..65b58bc549 100644
--- a/MdePkg/Library/BaseTimerLibLocalApic/Ipf/IpfTimerLib.c
+++ b/MdePkg/Library/BaseTimerLibLocalApic/Ipf/IpfTimerLib.c
@@ -18,26 +18,38 @@
 
 **/
 
-UINT64
-ReadItc (
-  VOID
-  );
-
-typedef struct {
-  UINT64                            Status;
-  UINT64                            r9;
-  UINT64                            r10;
-  UINT64                            r11;
-} PAL_PROC_RETURN;
-
-PAL_PROC_RETURN
-PalCallStatic (
-  IN      CONST VOID                *PalEntryPoint,
-  IN      UINT64                    Arg1,
-  IN      UINT64                    Arg2,
-  IN      UINT64                    Arg3,
-  IN      UINT64                    Arg4
-  );
+
+
+
+/**
+  Performs a delay measured as number of ticks.
+
+  An internal function to perform a delay measured as number of ticks. It's
+  invoked by MicroSecondDelay() and NanoSecondDelay().
+
+  @param  Delay Number of ticks to delay.
+
+**/
+STATIC
+VOID
+InternalIpfDelay (
+  IN      INT64                     Delay
+  )
+{
+  INT64                             Ticks;
+
+  //
+  // The target timer count is calculated here
+  //
+  Ticks = IpfReadItc () + Delay;
+
+  //
+  // Wait until time out
+  // Delay > 2^63 could not be handled by this function
+  // Timer wrap-arounds are handled correctly by this function
+  //
+  while (Ticks - IpfReadItc () >= 0);
+}
 
 /**
   Stalls the CPU for at least the given number of microseconds.
@@ -46,7 +58,7 @@ PalCallStatic (
 
   @param  MicroSeconds  The minimum number of microseconds to delay.
 
-  @return The ticks delayed actually.
+  @return MicroSeconds
 
 **/
 UINTN
@@ -55,13 +67,12 @@ MicroSecondDelay (
   IN      UINTN                     MicroSeconds
   )
 {
-  UINT64                            Ticks;
-  UINT64                            Delay;
-
-  Ticks = GetPerformanceCounter ();
-  Delay = GetPerformanceCounterProperties (NULL, NULL) * MicroSeconds / 1000000;
-  while (Ticks + Delay >= GetPerformanceCounter ());
-  return (UINTN)Delay;
+  InternalIpfDelay (
+    GetPerformanceCounterProperties (NULL, NULL) *
+    MicroSeconds /
+    1000000
+    );
+  return MicroSeconds;
 }
 
 /**
@@ -71,7 +82,7 @@ MicroSecondDelay (
 
   @param  NanoSeconds The minimum number of nanoseconds to delay.
 
-  @return The ticks delayed actually.
+  @return NanoSeconds
 
 **/
 UINTN
@@ -80,13 +91,12 @@ NanoSecondDelay (
   IN      UINTN                     NanoSeconds
   )
 {
-  UINT64                            Ticks;
-  UINT64                            Delay;
-
-  Ticks = GetPerformanceCounter ();
-  Delay = GetPerformanceCounterProperties (NULL, NULL) * NanoSeconds / 1000000000;
-  while (Ticks + Delay >= GetPerformanceCounter ());
-  return (UINTN)Delay;
+  InternalIpfDelay (
+    GetPerformanceCounterProperties (NULL, NULL) *
+    NanoSeconds /
+    1000000000
+    );
+  return NanoSeconds;
 }
 
 /**
@@ -107,7 +117,7 @@ GetPerformanceCounter (
   VOID
   )
 {
-  return ReadItc ();
+  return IpfReadItc ();
 }
 
 /**
@@ -136,8 +146,8 @@ GetPerformanceCounter (
 UINT64
 EFIAPI
 GetPerformanceCounterProperties (
-  IN      UINT64                    *StartValue,
-  IN      UINT64                    *EndValue
+  OUT      UINT64                    *StartValue,  OPTIONAL
+  OUT      UINT64                    *EndValue     OPTIONAL
   )
 {
   PAL_PROC_RETURN                   PalRet;
@@ -150,7 +160,13 @@ GetPerformanceCounterProperties (
   PalRet = PalCallStatic (NULL, 14, 0, 0, 0);
   ASSERT (PalRet.Status == 0);
 
-  *StartValue = 0;
-  *EndValue = (UINT64)(-1);
+  if (StartValue != NULL) {
+    *StartValue = 0;
+  }
+
+  if (EndValue != NULL) {
+    *EndValue = (UINT64)(-1);
+  }
+
   return BaseFrequence * (PalRet.r11 >> 32) / (UINT32)PalRet.r11;
 }