git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@905 6f19259b...

[mirror_edk2.git] / MdePkg / Library / BasePciExpressLib / PciLib.c

diff --git a/MdePkg/Library/BasePciExpressLib/PciLib.c b/MdePkg/Library/BasePciExpressLib/PciLib.c
index e027955ceb6ddad741bdae814c095edc67c4edb2..771c18f811d106ac0bd47a1a4b79cac238fe81b2 100644 (file)
--- a/MdePkg/Library/BasePciExpressLib/PciLib.c
+++ b/MdePkg/Library/BasePciExpressLib/PciLib.c
@@ -1174,8 +1174,7 @@ PciExpressBitFieldAndThenOr32 (
 \r
   If StartAddress > 0x0FFFFFFF, then ASSERT().\r
   If ((StartAddress & 0xFFF) + Size) > 0x1000, then ASSERT().\r
-  If (StartAddress + Size - 1)  > 0x0FFFFFFF, then ASSERT().\r
-  If Buffer is NULL, then ASSERT().\r
+  If Size > 0 and Buffer is NULL, then ASSERT().\r
 \r
   @param  StartAddress  Starting address that encodes the PCI Bus, Device,\r
                         Function and Register.\r
@@ -1193,58 +1192,70 @@ PciExpressReadBuffer (
   OUT     VOID                      *Buffer\r
   )\r
 {\r
-  UINTN                             EndAddress;\r
+  UINTN                             ReturnValue;\r
 \r
   ASSERT_INVALID_PCI_ADDRESS (StartAddress);\r
   ASSERT (((StartAddress & 0xFFF) + Size) <= 0x1000);\r
+\r
+  if (Size == 0) {\r
+    return Size;\r
+  }\r
+\r
   ASSERT (Buffer != NULL);\r
 \r
-  EndAddress = StartAddress + Size;\r
+  //\r
+  // Save Size for return\r
+  //\r
+  ReturnValue = Size;\r
 \r
-  if (StartAddress < EndAddress && (StartAddress & 1)) {\r
+  if ((StartAddress & 1) != 0) {\r
     //\r
     // Read a byte if StartAddress is byte aligned\r
     //\r
     *(UINT8*)Buffer = PciExpressRead8 (StartAddress);\r
     StartAddress += sizeof (UINT8);\r
+    Size -= sizeof (UINT8);\r
     Buffer = (UINT8*)Buffer + 1;\r
   }\r
 \r
-  if (StartAddress < EndAddress && (StartAddress & 2)) {\r
+  if (Size >= sizeof (UINT16) && (StartAddress & 2) != 0) {\r
     //\r
     // Read a word if StartAddress is word aligned\r
     //\r
     *(UINT16*)Buffer = PciExpressRead16 (StartAddress);\r
     StartAddress += sizeof (UINT16);\r
+    Size -= sizeof (UINT16);\r
     Buffer = (UINT16*)Buffer + 1;\r
   }\r
 \r
-  while (EndAddress - StartAddress >= 4) {\r
+  while (Size >= sizeof (UINT32)) {\r
     //\r
     // Read as many double words as possible\r
     //\r
     *(UINT32*)Buffer = PciExpressRead32 (StartAddress);\r
     StartAddress += sizeof (UINT32);\r
+    Size -= sizeof (UINT32);\r
     Buffer = (UINT32*)Buffer + 1;\r
   }\r
 \r
-  if ((EndAddress & 2) != 0) {\r
+  if (Size >= sizeof (UINT16)) {\r
     //\r
     // Read the last remaining word if exist\r
     //\r
     *(UINT16*)Buffer = PciExpressRead16 (StartAddress);\r
     StartAddress += sizeof (UINT16);\r
+    Size -= sizeof (UINT16);\r
     Buffer = (UINT16*)Buffer + 1;\r
   }\r
 \r
-  if (EndAddress & 1) {\r
+  if (Size >= sizeof (UINT8)) {\r
     //\r
     // Read the last remaining byte if exist\r
     //\r
     *(UINT8*)Buffer = PciExpressRead8 (StartAddress);\r
   }\r
 \r
-  return Size;\r
+  return ReturnValue;\r
 }\r
 \r
 /**\r
@@ -1261,8 +1272,7 @@ PciExpressReadBuffer (
 \r
   If StartAddress > 0x0FFFFFFF, then ASSERT().\r
   If ((StartAddress & 0xFFF) + Size) > 0x1000, then ASSERT().\r
-  If (StartAddress + Size - 1)  > 0x0FFFFFFF, then ASSERT().\r
-  If Buffer is NULL, then ASSERT().\r
+  If Size > 0 and Buffer is NULL, then ASSERT().\r
 \r
   @param  StartAddress  Starting address that encodes the PCI Bus, Device,\r
                         Function and Register.\r
@@ -1280,56 +1290,68 @@ PciExpressWriteBuffer (
   IN      VOID                      *Buffer\r
   )\r
 {\r
-  UINTN                             EndAddress;\r
+  UINTN                             ReturnValue;\r
 \r
   ASSERT_INVALID_PCI_ADDRESS (StartAddress);\r
   ASSERT (((StartAddress & 0xFFF) + Size) <= 0x1000);\r
+\r
+  if (Size == 0) {\r
+    return 0;\r
+  }\r
+\r
   ASSERT (Buffer != NULL);\r
 \r
-  EndAddress = StartAddress + Size;\r
+  //\r
+  // Save Size for return\r
+  //\r
+  ReturnValue = Size;\r
 \r
-  if ((StartAddress < EndAddress) && ((StartAddress & 1)!= 0)) {\r
+  if ((StartAddress & 1) != 0) {\r
     //\r
     // Write a byte if StartAddress is byte aligned\r
     //\r
     PciExpressWrite8 (StartAddress, *(UINT8*)Buffer);\r
     StartAddress += sizeof (UINT8);\r
+    Size -= sizeof (UINT8);\r
     Buffer = (UINT8*)Buffer + 1;\r
   }\r
 \r
-  if (StartAddress < EndAddress && (StartAddress & 2)) {\r
+  if (Size >= sizeof (UINT16) && (StartAddress & 2) != 0) {\r
     //\r
     // Write a word if StartAddress is word aligned\r
     //\r
     PciExpressWrite16 (StartAddress, *(UINT16*)Buffer);\r
     StartAddress += sizeof (UINT16);\r
+    Size -= sizeof (UINT16);\r
     Buffer = (UINT16*)Buffer + 1;\r
   }\r
 \r
-  while (EndAddress - StartAddress >= 4) {\r
+  while (Size >= sizeof (UINT32)) {\r
     //\r
     // Write as many double words as possible\r
     //\r
     PciExpressWrite32 (StartAddress, *(UINT32*)Buffer);\r
     StartAddress += sizeof (UINT32);\r
+    Size -= sizeof (UINT32);\r
     Buffer = (UINT32*)Buffer + 1;\r
   }\r
 \r
-  if (EndAddress & 2) {\r
+  if (Size >= sizeof (UINT16)) {\r
     //\r
     // Write the last remaining word if exist\r
     //\r
     PciExpressWrite16 (StartAddress, *(UINT16*)Buffer);\r
     StartAddress += sizeof (UINT16);\r
+    Size -= sizeof (UINT16);\r
     Buffer = (UINT16*)Buffer + 1;\r
   }\r
 \r
-  if (EndAddress & 1) {\r
+  if (Size >= sizeof (UINT8)) {\r
     //\r
     // Write the last remaining byte if exist\r
     //\r
     PciExpressWrite8 (StartAddress, *(UINT8*)Buffer);\r
   }\r
 \r
-  return Size;\r
+  return ReturnValue;\r
 }\r