Add comments on the definition of SPIN_LOCK_RELEASED & SPIN_LOCK_ACQUIRED

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

diff --git a/MdePkg/Library/BaseLib/Synchronization.c b/MdePkg/Library/BaseLib/Synchronization.c
index 0457f3ab89cf42d5da212ed678aebc2df26630d7..59919a7f03b1ac1955d1075fd30585d060e10c94 100644 (file)
--- a/MdePkg/Library/BaseLib/Synchronization.c
+++ b/MdePkg/Library/BaseLib/Synchronization.c
@@ -14,95 +14,14 @@
 \r
 **/\r
 \r
-#define SPIN_LOCK_RELEASED          ((SPIN_LOCK)1)\r
-#define SPIN_LOCK_ACQUIRED          ((SPIN_LOCK)2)\r
+#include "BaseLibInternals.h"\r
 \r
-/**\r
-  Performs an atomic increment of an 32-bit unsigned integer.\r
-\r
-  Performs an atomic increment of the 32-bit unsigned integer specified by\r
-  Value and returns the incremented value. The increment operation must be\r
-  performed using MP safe mechanisms. The state of the return value is not\r
-  guaranteed to be MP safe.\r
-\r
-  @param  Value A pointer to the 32-bit value to increment.\r
-\r
-  @return The incremented value.\r
-\r
-**/\r
-UINT32\r
-EFIAPI\r
-InternalSyncIncrement (\r
-  IN      volatile UINT32           *Value\r
-  );\r
-\r
-/**\r
-  Performs an atomic decrement of an 32-bit unsigned integer.\r
-\r
-  Performs an atomic decrement of the 32-bit unsigned integer specified by\r
-  Value and returns the decrement value. The decrement operation must be\r
-  performed using MP safe mechanisms. The state of the return value is not\r
-  guaranteed to be MP safe.\r
-\r
-  @param  Value A pointer to the 32-bit value to decrement.\r
-\r
-  @return The decrement value.\r
-\r
-**/\r
-UINT32\r
-EFIAPI\r
-InternalSyncDecrement (\r
-  IN      volatile UINT32           *Value\r
-  );\r
-\r
-/**\r
-  Performs an atomic compare exchange operation on a 32-bit unsigned integer.\r
-\r
-  Performs an atomic compare exchange operation on the 32-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
-  @param  Value         A pointer to the 32-bit value for the compare exchange\r
-                        operation.\r
-  @param  CompareValue  32-bit value used in compare operation.\r
-  @param  ExchangeValue 32-bit value used in exchange operation.\r
-\r
-  @return The original *Value before exchange.\r
-\r
-**/\r
-UINT32\r
-EFIAPI\r
-InternalSyncCompareExchange32 (\r
-  IN      volatile UINT32           *Value,\r
-  IN      UINT32                    CompareValue,\r
-  IN      UINT32                    ExchangeValue\r
-  );\r
-\r
-/**\r
-  Performs an atomic compare exchange operation on a 64-bit unsigned integer.\r
-\r
-  Performs an atomic compare exchange operation on the 64-bit unsigned integer specified \r
-  by Value.  If Value is equal to CompareValue, then Value is set to ExchangeValue and \r
-  CompareValue is returned.  If Value is not equal to CompareValue, then Value is returned. \r
-  The compare exchange operation must be performed using MP safe mechanisms.\r
-\r
-  @param  Value         A pointer to the 64-bit value for the compare exchange\r
-                        operation.\r
-  @param  CompareValue  64-bit value used in compare operation.\r
-  @param  ExchangeValue 64-bit value used in exchange operation.\r
-\r
-  @return The original *Value before exchange.\r
-\r
-**/\r
-UINT64\r
-EFIAPI\r
-InternalSyncCompareExchange64 (\r
-  IN      volatile UINT64           *Value,\r
-  IN      UINT64                    CompareValue,\r
-  IN      UINT64                    ExchangeValue\r
-  );\r
+//\r
+// SPIN_LOCK_RELEASED & SPIN_LOCK_ACQUIRED should belong to type "SPIN_LOCK".\r
+// Here we use type-case "UINTN" to avoid "volatile" modifier on const integers.\r
+//\r
+#define SPIN_LOCK_RELEASED          ((UINTN) 1)\r
+#define SPIN_LOCK_ACQUIRED          ((UINTN) 2)\r
 \r
 /**\r
   Retrieves the architecture specific spin lock alignment requirements for\r
@@ -236,7 +155,7 @@ AcquireSpinLockOrFail (
   IN OUT  SPIN_LOCK                 *SpinLock\r
   )\r
 {\r
-  volatile SPIN_LOCK    LockValue;\r
+  SPIN_LOCK    LockValue;\r
 \r
   ASSERT (SpinLock != NULL);\r
 \r
@@ -419,7 +338,11 @@ InterlockedCompareExchangePointer (
   IN      VOID                      *ExchangeValue\r
   )\r
 {\r
-  switch (sizeof (*Value)) {\r
+  UINT8  SizeOfValue;\r
+\r
+  SizeOfValue = sizeof (*Value);\r
+\r
+  switch (SizeOfValue) {\r
     case sizeof (UINT32):\r
       return (VOID*)(UINTN)InterlockedCompareExchange32 (\r
                              (UINT32*)Value,\r