X-Git-Url: https://git.proxmox.com/?p=mirror_edk2.git;a=blobdiff_plain;f=MdePkg%2FLibrary%2FBasePciExpressLib%2FPciLib.c;h=771c18f811d106ac0bd47a1a4b79cac238fe81b2;hp=acd31034835f90d56efc381afbb92889a3766c0f;hb=9748aecca6cad6a4a1782b415445d086af4e2bba;hpb=ace425da363ca731aa174bcf1975429f9e1531ab

diff --git a/MdePkg/Library/BasePciExpressLib/PciLib.c b/MdePkg/Library/BasePciExpressLib/PciLib.c
index acd3103483..771c18f811 100644
--- a/MdePkg/Library/BasePciExpressLib/PciLib.c
+++ b/MdePkg/Library/BasePciExpressLib/PciLib.c
@@ -1192,18 +1192,21 @@ PciExpressReadBuffer (
   OUT     VOID                      *Buffer
   )
 {
-  UINTN                             EndAddress;
+  UINTN                             ReturnValue;
 
   ASSERT_INVALID_PCI_ADDRESS (StartAddress);
   ASSERT (((StartAddress & 0xFFF) + Size) <= 0x1000);
 
   if (Size == 0) {
-    return 0;
+    return Size;
   }
 
   ASSERT (Buffer != NULL);
 
-  EndAddress = StartAddress + Size;
+  //
+  // Save Size for return
+  //
+  ReturnValue = Size;
 
   if ((StartAddress & 1) != 0) {
     //
@@ -1211,44 +1214,48 @@ PciExpressReadBuffer (
     //
     *(UINT8*)Buffer = PciExpressRead8 (StartAddress);
     StartAddress += sizeof (UINT8);
+    Size -= sizeof (UINT8);
     Buffer = (UINT8*)Buffer + 1;
   }
 
-  if ((StartAddress < EndAddress) && ((StartAddress & 2) != 0)) {
+  if (Size >= sizeof (UINT16) && (StartAddress & 2) != 0) {
     //
     // Read a word if StartAddress is word aligned
     //
     *(UINT16*)Buffer = PciExpressRead16 (StartAddress);
     StartAddress += sizeof (UINT16);
+    Size -= sizeof (UINT16);
     Buffer = (UINT16*)Buffer + 1;
   }
 
-  while ((EndAddress - StartAddress) >= 4) {
+  while (Size >= sizeof (UINT32)) {
     //
     // Read as many double words as possible
     //
     *(UINT32*)Buffer = PciExpressRead32 (StartAddress);
     StartAddress += sizeof (UINT32);
+    Size -= sizeof (UINT32);
     Buffer = (UINT32*)Buffer + 1;
   }
 
-  if ((EndAddress & 2) != 0) {
+  if (Size >= sizeof (UINT16)) {
     //
     // Read the last remaining word if exist
     //
     *(UINT16*)Buffer = PciExpressRead16 (StartAddress);
     StartAddress += sizeof (UINT16);
+    Size -= sizeof (UINT16);
     Buffer = (UINT16*)Buffer + 1;
   }
 
-  if ((EndAddress & 1) != 0) {
+  if (Size >= sizeof (UINT8)) {
     //
     // Read the last remaining byte if exist
     //
     *(UINT8*)Buffer = PciExpressRead8 (StartAddress);
   }
 
-  return Size;
+  return ReturnValue;
 }
 
 /**
@@ -1283,7 +1290,7 @@ PciExpressWriteBuffer (
   IN      VOID                      *Buffer
   )
 {
-  UINTN                             EndAddress;
+  UINTN                             ReturnValue;
 
   ASSERT_INVALID_PCI_ADDRESS (StartAddress);
   ASSERT (((StartAddress & 0xFFF) + Size) <= 0x1000);
@@ -1294,7 +1301,10 @@ PciExpressWriteBuffer (
 
   ASSERT (Buffer != NULL);
 
-  EndAddress = StartAddress + Size;
+  //
+  // Save Size for return
+  //
+  ReturnValue = Size;
 
   if ((StartAddress & 1) != 0) {
     //
@@ -1302,42 +1312,46 @@ PciExpressWriteBuffer (
     //
     PciExpressWrite8 (StartAddress, *(UINT8*)Buffer);
     StartAddress += sizeof (UINT8);
+    Size -= sizeof (UINT8);
     Buffer = (UINT8*)Buffer + 1;
   }
 
-  if ((StartAddress < EndAddress) && ((StartAddress & 2) != 0)) {
+  if (Size >= sizeof (UINT16) && (StartAddress & 2) != 0) {
     //
     // Write a word if StartAddress is word aligned
     //
     PciExpressWrite16 (StartAddress, *(UINT16*)Buffer);
     StartAddress += sizeof (UINT16);
+    Size -= sizeof (UINT16);
     Buffer = (UINT16*)Buffer + 1;
   }
 
-  while ((EndAddress - StartAddress) >= 4) {
+  while (Size >= sizeof (UINT32)) {
     //
     // Write as many double words as possible
     //
     PciExpressWrite32 (StartAddress, *(UINT32*)Buffer);
     StartAddress += sizeof (UINT32);
+    Size -= sizeof (UINT32);
     Buffer = (UINT32*)Buffer + 1;
   }
 
-  if ((EndAddress & 2) != 0) {
+  if (Size >= sizeof (UINT16)) {
     //
     // Write the last remaining word if exist
     //
     PciExpressWrite16 (StartAddress, *(UINT16*)Buffer);
     StartAddress += sizeof (UINT16);
+    Size -= sizeof (UINT16);
     Buffer = (UINT16*)Buffer + 1;
   }
 
-  if ((EndAddress & 1) != 0) {
+  if (Size >= sizeof (UINT8)) {
     //
     // Write the last remaining byte if exist
     //
     PciExpressWrite8 (StartAddress, *(UINT8*)Buffer);
   }
 
-  return Size;
+  return ReturnValue;
 }