From 7457359d5dd35a7e1021e87355686ca05ecb04a8 Mon Sep 17 00:00:00 2001
From: Cameron Gutman <aicommander@gmail.com>
Date: Fri, 8 Jan 2010 18:21:52 +0000
Subject: [PATCH]  - Use a spin lock to protect the port bitmap instead of a
 fast mutex

svn path=/branches/aicom-network-branch/; revision=45006
---
 drivers/network/tcpip/include/ports.h |  2 +-
 lib/drivers/ip/network/ports.c        | 27 ++++++++++++++++-----------
 2 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/drivers/network/tcpip/include/ports.h b/drivers/network/tcpip/include/ports.h
index 700682937e3..3be359097fb 100644
--- a/drivers/network/tcpip/include/ports.h
+++ b/drivers/network/tcpip/include/ports.h
@@ -16,7 +16,7 @@ typedef struct _PORT_SET {
     PVOID ProtoBitBuffer;
     UINT StartingPort;
     UINT PortsToOversee;
-    FAST_MUTEX Mutex;
+    KSPIN_LOCK Lock;
 } PORT_SET, *PPORT_SET;
 
 NTSTATUS PortsStartup( PPORT_SET PortSet,
diff --git a/lib/drivers/ip/network/ports.c b/lib/drivers/ip/network/ports.c
index cd9dbd2f05f..0da272260cd 100644
--- a/lib/drivers/ip/network/ports.c
+++ b/lib/drivers/ip/network/ports.c
@@ -24,7 +24,7 @@ NTSTATUS PortsStartup( PPORT_SET PortSet,
 			 PortSet->ProtoBitBuffer,
 			 PortSet->PortsToOversee );
     RtlClearAllBits( &PortSet->ProtoBitmap );
-    ExInitializeFastMutex( &PortSet->Mutex );
+    KeInitializeSpinLock( &PortSet->Lock );
     return STATUS_SUCCESS;
 }
 
@@ -33,17 +33,20 @@ VOID PortsShutdown( PPORT_SET PortSet ) {
 }
 
 VOID DeallocatePort( PPORT_SET PortSet, ULONG Port ) {
+    KIRQL OldIrql;
+
     Port = htons(Port);
     ASSERT(Port >= PortSet->StartingPort);
     ASSERT(Port < PortSet->StartingPort + PortSet->PortsToOversee);
 
-    ExAcquireFastMutex( &PortSet->Mutex );
+    KeAcquireSpinLock( &PortSet->Lock, &OldIrql );
     RtlClearBits( &PortSet->ProtoBitmap, Port - PortSet->StartingPort, 1 );
-    ExReleaseFastMutex( &PortSet->Mutex );
+    KeReleaseSpinLock( &PortSet->Lock, OldIrql );
 }
 
 BOOLEAN AllocatePort( PPORT_SET PortSet, ULONG Port ) {
     BOOLEAN Clear;
+    KIRQL OldIrql;
 
     Port = htons(Port);
 
@@ -55,32 +58,34 @@ BOOLEAN AllocatePort( PPORT_SET PortSet, ULONG Port ) {
 
     Port -= PortSet->StartingPort;
 
-    ExAcquireFastMutex( &PortSet->Mutex );
+    KeAcquireSpinLock( &PortSet->Lock, &OldIrql );
     Clear = RtlAreBitsClear( &PortSet->ProtoBitmap, Port, 1 );
     if( Clear ) RtlSetBits( &PortSet->ProtoBitmap, Port, 1 );
-    ExReleaseFastMutex( &PortSet->Mutex );
+    KeReleaseSpinLock( &PortSet->Lock, OldIrql );
 
     return Clear;
 }
 
 ULONG AllocateAnyPort( PPORT_SET PortSet ) {
     ULONG AllocatedPort;
+    KIRQL OldIrql;
 
-    ExAcquireFastMutex( &PortSet->Mutex );
+    KeAcquireSpinLock( &PortSet->Lock, &OldIrql );
     AllocatedPort = RtlFindClearBits( &PortSet->ProtoBitmap, 1, 0 );
     if( AllocatedPort != (ULONG)-1 ) {
 	RtlSetBit( &PortSet->ProtoBitmap, AllocatedPort );
 	AllocatedPort += PortSet->StartingPort;
-	ExReleaseFastMutex( &PortSet->Mutex );
+	KeReleaseSpinLock( &PortSet->Lock, OldIrql );
 	return htons(AllocatedPort);
     }
-    ExReleaseFastMutex( &PortSet->Mutex );
+    KeReleaseSpinLock( &PortSet->Lock, OldIrql );
 
     return -1;
 }
 
 ULONG AllocatePortFromRange( PPORT_SET PortSet, ULONG Lowest, ULONG Highest ) {
     ULONG AllocatedPort;
+    KIRQL OldIrql;
 
     if ((Lowest < PortSet->StartingPort) ||
         (Highest >= PortSet->StartingPort + PortSet->PortsToOversee))
@@ -91,15 +96,15 @@ ULONG AllocatePortFromRange( PPORT_SET PortSet, ULONG Lowest, ULONG Highest ) {
     Lowest -= PortSet->StartingPort;
     Highest -= PortSet->StartingPort;
 
-    ExAcquireFastMutex( &PortSet->Mutex );
+    KeAcquireSpinLock( &PortSet->Lock, &OldIrql );
     AllocatedPort = RtlFindClearBits( &PortSet->ProtoBitmap, 1, Lowest );
     if( AllocatedPort != (ULONG)-1 && AllocatedPort <= Highest) {
 	RtlSetBit( &PortSet->ProtoBitmap, AllocatedPort );
 	AllocatedPort += PortSet->StartingPort;
-	ExReleaseFastMutex( &PortSet->Mutex );
+	KeReleaseSpinLock( &PortSet->Lock, OldIrql );
 	return htons(AllocatedPort);
     }
-    ExReleaseFastMutex( &PortSet->Mutex );
+    KeReleaseSpinLock( &PortSet->Lock, OldIrql );
 
     return -1;
 }
-- 
2.17.1