MdePkg/BaseSynchronizationLib: Add volatile Interlocked*() APIs

[mirror_edk2.git] / MdePkg / Library / BaseSynchronizationLib / Synchronization.c

diff --git a/MdePkg/Library/BaseSynchronizationLib/Synchronization.c b/MdePkg/Library/BaseSynchronizationLib/Synchronization.c
index 4475b85667301a6a3abb1ef3c14e8816c16efb56..4f2e21bcb32110789ad57bf549a7cd2d3b274feb 100644 (file)
--- a/MdePkg/Library/BaseSynchronizationLib/Synchronization.c
+++ b/MdePkg/Library/BaseSynchronizationLib/Synchronization.c
@@ -1,11 +1,11 @@
 /** @file\r
   Implementation of synchronization functions.\r
 \r
-  Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>\r
+  Copyright (c) 2006 - 2016, 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
+  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
@@ -22,8 +22,8 @@
   optimal spin lock performance.\r
 \r
   This function retrieves the spin lock alignment requirements for optimal\r
-  performance on a given CPU architecture. The spin lock alignment must be a\r
-  power of two and is returned by this function. If there are no alignment\r
+  performance on a given CPU architecture. The spin lock alignment is byte alignment. \r
+  It must be a power of two and is returned by this function. If there are no alignment\r
   requirements, then 1 must be returned. The spin lock synchronization\r
   functions must function correctly if the spin lock size and alignment values\r
   returned by this function are not used at all. These values are hints to the\r
@@ -55,7 +55,7 @@ GetSpinLockProperties (
   @param  SpinLock  A pointer to the spin lock to initialize to the released\r
                     state.\r
 \r
-  @return SpinLock in release state.\r
+  @return SpinLock is in release state.\r
 \r
 **/\r
 SPIN_LOCK *\r
@@ -86,7 +86,7 @@ InitializeSpinLock (
 \r
   @param  SpinLock  A pointer to the spin lock to place in the acquired state.\r
 \r
-  @return SpinLock acquired lock.\r
+  @return SpinLock acquired the lock.\r
 \r
 **/\r
 SPIN_LOCK *\r
@@ -104,7 +104,11 @@ AcquireSpinLock (
   INT64   Cycle;\r
   INT64   Delta;\r
 \r
-  if (PcdGet32 (PcdSpinLockTimeout) > 0) {\r
+  if (PcdGet32 (PcdSpinLockTimeout) == 0) {\r
+    while (!AcquireSpinLockOrFail (SpinLock)) {\r
+      CpuPause ();\r
+    }\r
+  } else if (!AcquireSpinLockOrFail (SpinLock)) {\r
     //\r
     // Get the current timer value\r
     //\r
@@ -148,10 +152,6 @@ AcquireSpinLock (
       Total += Delta;\r
       ASSERT (Total < Timeout);\r
     }\r
-  } else {\r
-    while (!AcquireSpinLockOrFail (SpinLock)) {\r
-      CpuPause ();\r
-    }\r
   }\r
   return SpinLock;\r
 }\r
@@ -244,7 +244,7 @@ ReleaseSpinLock (
 UINT32\r
 EFIAPI\r
 InterlockedIncrement (\r
-  IN      UINT32                    *Value\r
+  IN      volatile UINT32           *Value\r
   )\r
 {\r
   ASSERT (Value != NULL);\r
@@ -269,13 +269,44 @@ InterlockedIncrement (
 UINT32\r
 EFIAPI\r
 InterlockedDecrement (\r
-  IN      UINT32                    *Value\r
+  IN      volatile UINT32           *Value\r
   )\r
 {\r
   ASSERT (Value != NULL);\r
   return InternalSyncDecrement (Value);\r
 }\r
 \r
+/**\r
+  Performs an atomic compare exchange operation on a 16-bit unsigned integer.\r
+\r
+  Performs an atomic compare exchange operation on the 16-bit unsigned integer\r
+  specified by Value.  If Value is equal to CompareValue, then Value is set to\r
+  ExchangeValue and CompareValue is returned.  If Value is not equal to CompareValue,\r
+  then Value is returned.  The compare exchange operation must be performed using\r
+  MP safe mechanisms.\r
+\r
+  If Value is NULL, then ASSERT().\r
+\r
+  @param  Value         A pointer to the 16-bit value for the compare exchange\r
+                        operation.\r
+  @param  CompareValue  16-bit value used in compare operation.\r
+  @param  ExchangeValue 16-bit value used in exchange operation.\r
+\r
+  @return The original *Value before exchange.\r
+\r
+**/\r
+UINT16\r
+EFIAPI\r
+InterlockedCompareExchange16 (\r
+  IN OUT  volatile UINT16           *Value,\r
+  IN      UINT16                    CompareValue,\r
+  IN      UINT16                    ExchangeValue\r
+  )\r
+{\r
+  ASSERT (Value != NULL);\r
+  return InternalSyncCompareExchange16 (Value, CompareValue, ExchangeValue);\r
+}\r
+\r
 /**\r
   Performs an atomic compare exchange operation on a 32-bit unsigned integer.\r
 \r
@@ -298,7 +329,7 @@ InterlockedDecrement (
 UINT32\r
 EFIAPI\r
 InterlockedCompareExchange32 (\r
-  IN OUT  UINT32                    *Value,\r
+  IN OUT  volatile UINT32           *Value,\r
   IN      UINT32                    CompareValue,\r
   IN      UINT32                    ExchangeValue\r
   )\r
@@ -328,7 +359,7 @@ InterlockedCompareExchange32 (
 UINT64\r
 EFIAPI\r
 InterlockedCompareExchange64 (\r
-  IN OUT  UINT64                    *Value,\r
+  IN OUT  volatile UINT64           *Value,\r
   IN      UINT64                    CompareValue,\r
   IN      UINT64                    ExchangeValue\r
   )\r
@@ -358,7 +389,7 @@ InterlockedCompareExchange64 (
 VOID *\r
 EFIAPI\r
 InterlockedCompareExchangePointer (\r
-  IN OUT  VOID                      **Value,\r
+  IN OUT  VOID                      * volatile *Value,\r
   IN      VOID                      *CompareValue,\r
   IN      VOID                      *ExchangeValue\r
   )\r
@@ -370,13 +401,13 @@ InterlockedCompareExchangePointer (
   switch (SizeOfValue) {\r
     case sizeof (UINT32):\r
       return (VOID*)(UINTN)InterlockedCompareExchange32 (\r
-                             (UINT32*)Value,\r
+                             (volatile UINT32 *)Value,\r
                              (UINT32)(UINTN)CompareValue,\r
                              (UINT32)(UINTN)ExchangeValue\r
                              );\r
     case sizeof (UINT64):\r
       return (VOID*)(UINTN)InterlockedCompareExchange64 (\r
-                             (UINT64*)Value,\r
+                             (volatile UINT64 *)Value,\r
                              (UINT64)(UINTN)CompareValue,\r
                              (UINT64)(UINTN)ExchangeValue\r
                              );\r