Fix timeout logic in AcquireSpinLock(). It could fail if the end time computed was larger than the roll over value of the performance counter. The timeout logic now accumulates the total time elapsed to determine if the timeout has been exceeded.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@4345 6f19259b-4bc3-4df7-8a09-765794883524

3 files changed, 141 insertions, 48 deletions

diff --git a/MdePkg/Library/BaseLib/Synchronization.c b/MdePkg/Library/BaseLib/Synchronization.c
index b7c89732e0..f1565db3fd 100644
--- a/MdePkg/Library/BaseLib/Synchronization.c
+++ b/MdePkg/Library/BaseLib/Synchronization.c
@@ -101,15 +101,32 @@ AcquireSpinLock (
   IN OUT  SPIN_LOCK                 *SpinLock

   )

 {

-  UINT64                            Tick;

-  UINT64                            Start, End;

-  UINT64                            Timeout;

+  UINT64  Current;

+  UINT64  Previous;

+  UINT64  Total;

+  UINT64  Start;

+  UINT64  End;

+  UINT64  Timeout;

+  INT64   Cycle;

+  INT64   Delta;

 

-  Tick = 0;

-  Start = 0;

-  End = 0;

   if (PcdGet32 (PcdSpinLockTimeout) > 0) {

-    Tick = GetPerformanceCounter ();

+    //

+    // Get the current timer value

+    //

+    Current = GetPerformanceCounter();

+

+    //

+    // Initialize local variables

+    //

+    Start = 0;

+    End   = 0;

+    Total = 0;

+

+    //

+    // Retrieve the performance counter properties and compute the number of performance

+    // counter ticks required to reach the timeout

+    //

     Timeout = DivU64x32 (

                 MultU64x32 (

                   GetPerformanceCounterProperties (&Start, &End),

@@ -117,16 +134,30 @@ AcquireSpinLock (
                   ),

                 1000000

                 );

-    if (Start < End) {

-      Tick += Timeout;

-    } else {

-      Tick -= Timeout;

+    Cycle = End - Start;

+    if (Cycle < 0) {

+      Cycle = -Cycle;

+    }

+    Cycle++;

+

+    while (!AcquireSpinLockOrFail (SpinLock)) {

+      CpuPause ();

+      Previous = Current;

+      Current  = GetPerformanceCounter();

+      Delta = (INT64) (Current - Previous);

+      if (Start > End) {

+        Delta = -Delta;

+      }

+      if (Delta < 0) {

+        Delta += Cycle;

+      }

+      Total += Delta;

+      ASSERT (Total < Timeout);

+    }

+  } else {

+    while (!AcquireSpinLockOrFail (SpinLock)) {

+      CpuPause ();

     }

-  }

-

-  while (!AcquireSpinLockOrFail (SpinLock)) {

-    CpuPause ();

-    ASSERT ((Start < End) ^ (Tick <= GetPerformanceCounter ()));

   }

   return SpinLock;

 }

diff --git a/MdePkg/Library/BaseLib/SynchronizationGcc.c b/MdePkg/Library/BaseLib/SynchronizationGcc.c
index 1681b4cf44..4c30dbc4b1 100644
--- a/MdePkg/Library/BaseLib/SynchronizationGcc.c
+++ b/MdePkg/Library/BaseLib/SynchronizationGcc.c
@@ -110,15 +110,32 @@ AcquireSpinLock (
   IN OUT  SPIN_LOCK                 *SpinLock

   )

 {

-  UINT64                            Tick;

-  UINT64                            Start, End;

-  UINT64                            Timeout;

+  UINT64  Current;

+  UINT64  Previous;

+  UINT64  Total;

+  UINT64  Start;

+  UINT64  End;

+  UINT64  Timeout;

+  INT64   Cycle;

+  INT64   Delta;

 

-  Tick = 0;

-  Start = 0;

-  End = 0;

   if (PcdGet32 (PcdSpinLockTimeout) > 0) {

-    Tick = GetPerformanceCounter ();

+    //

+    // Get the current timer value

+    //

+    Current = GetPerformanceCounter();

+

+    //

+    // Initialize local variables

+    //

+    Start = 0;

+    End   = 0;

+    Total = 0;

+

+    //

+    // Retrieve the performance counter properties and compute the number of performance

+    // counter ticks required to reach the timeout

+    //

     Timeout = DivU64x32 (

                 MultU64x32 (

                   GetPerformanceCounterProperties (&Start, &End),

@@ -126,16 +143,30 @@ AcquireSpinLock (
                   ),

                 1000000

                 );

-    if (Start < End) {

-      Tick += Timeout;

-    } else {

-      Tick -= Timeout;

+    Cycle = End - Start;

+    if (Cycle < 0) {

+      Cycle = -Cycle;

+    }

+    Cycle++;

+

+    while (!AcquireSpinLockOrFail (SpinLock)) {

+      CpuPause ();

+      Previous = Current;

+      Current  = GetPerformanceCounter();

+      Delta = (INT64) (Current - Previous);

+      if (Start > End) {

+        Delta = -Delta;

+      }

+      if (Delta < 0) {

+        Delta += Cycle;

+      }

+      Total += Delta;

+      ASSERT (Total < Timeout);

+    }

+  } else {

+    while (!AcquireSpinLockOrFail (SpinLock)) {

+      CpuPause ();

     }

-  }

-

-  while (!AcquireSpinLockOrFail (SpinLock)) {

-    CpuPause ();

-    ASSERT ((Start < End) ^ (Tick <= GetPerformanceCounter ()));

   }

   return SpinLock;

 }

diff --git a/MdePkg/Library/BaseLib/SynchronizationMsc.c b/MdePkg/Library/BaseLib/SynchronizationMsc.c
index 9f1ec19383..0bc60259b1 100644
--- a/MdePkg/Library/BaseLib/SynchronizationMsc.c
+++ b/MdePkg/Library/BaseLib/SynchronizationMsc.c
@@ -112,15 +112,32 @@ AcquireSpinLock (
   IN OUT  SPIN_LOCK                 *SpinLock

   )

 {

-  UINT64                            Tick;

-  UINT64                            Start, End;

-  UINT64                            Timeout;

+  UINT64  Current;

+  UINT64  Previous;

+  UINT64  Total;

+  UINT64  Start;

+  UINT64  End;

+  UINT64  Timeout;

+  INT64   Cycle;

+  INT64   Delta;

 

-  Tick = 0;

-  Start = 0;

-  End = 0;

   if (PcdGet32 (PcdSpinLockTimeout) > 0) {

-    Tick = GetPerformanceCounter ();

+    //

+    // Get the current timer value

+    //

+    Current = GetPerformanceCounter();

+

+    //

+    // Initialize local variables

+    //

+    Start = 0;

+    End   = 0;

+    Total = 0;

+

+    //

+    // Retrieve the performance counter properties and compute the number of performance

+    // counter ticks required to reach the timeout

+    //

     Timeout = DivU64x32 (

                 MultU64x32 (

                   GetPerformanceCounterProperties (&Start, &End),

@@ -128,16 +145,30 @@ AcquireSpinLock (
                   ),

                 1000000

                 );

-    if (Start < End) {

-      Tick += Timeout;

-    } else {

-      Tick -= Timeout;

+    Cycle = End - Start;

+    if (Cycle < 0) {

+      Cycle = -Cycle;

+    }

+    Cycle++;

+

+    while (!AcquireSpinLockOrFail (SpinLock)) {

+      CpuPause ();

+      Previous = Current;

+      Current  = GetPerformanceCounter();

+      Delta = (INT64) (Current - Previous);

+      if (Start > End) {

+        Delta = -Delta;

+      }

+      if (Delta < 0) {

+        Delta += Cycle;

+      }

+      Total += Delta;

+      ASSERT (Total < Timeout);

+    }

+  } else {

+    while (!AcquireSpinLockOrFail (SpinLock)) {

+      CpuPause ();

     }

-  }

-

-  while (!AcquireSpinLockOrFail (SpinLock)) {

-    CpuPause ();

-    ASSERT ((Start < End) ^ (Tick <= GetPerformanceCounter ()));

   }

   return SpinLock;

 }