Staging: hv: make Channel->InboundLock a real spinlock

Don't use the wrapper functions for this lock, make it a real
lock so that we know what is going on.

I don't think we really want to be doing a irqsave for this code, but I
left it alone to preserve the original codepath.  It should be reviewed
later.

Cc: Hank Janssen <hjanssen@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/hv/Channel.c

@@ -991,18 +991,19 @@ VmbusChannelRecvPacket(
 	u32 packetLen;
 	u32 userLen;
 	int ret;
+	unsigned long flags;
 
 	DPRINT_ENTER(VMBUS);
 
 	*BufferActualLen = 0;
 	*RequestId = 0;
 
-	SpinlockAcquire(Channel->InboundLock);
+	spin_lock_irqsave(&Channel->inbound_lock, flags);
 
 	ret = RingBufferPeek(&Channel->Inbound, &desc, sizeof(VMPACKET_DESCRIPTOR));
 	if (ret != 0)
 	{
-		SpinlockRelease(Channel->InboundLock);
+		spin_unlock_irqrestore(&Channel->inbound_lock, flags);
 
 		//DPRINT_DBG(VMBUS, "nothing to read!!");
 		DPRINT_EXIT(VMBUS);
@@ -1026,7 +1027,7 @@ VmbusChannelRecvPacket(
 
 	if (userLen > BufferLen)
 	{
-		SpinlockRelease(Channel->InboundLock);
+		spin_unlock_irqrestore(&Channel->inbound_lock, flags);
 
 		DPRINT_ERR(VMBUS, "buffer too small - got %d needs %d", BufferLen, userLen);
 		DPRINT_EXIT(VMBUS);
@@ -1039,7 +1040,7 @@ VmbusChannelRecvPacket(
 	// Copy over the packet to the user buffer
 	ret = RingBufferRead(&Channel->Inbound, Buffer, userLen, (desc.DataOffset8 << 3));
 
-	SpinlockRelease(Channel->InboundLock);
+	spin_unlock_irqrestore(&Channel->inbound_lock, flags);
 
 	DPRINT_EXIT(VMBUS);
 
@@ -1068,18 +1069,19 @@ VmbusChannelRecvPacketRaw(
 	u32 packetLen;
 	u32 userLen;
 	int ret;
+	unsigned long flags;
 
 	DPRINT_ENTER(VMBUS);
 
 	*BufferActualLen = 0;
 	*RequestId = 0;
 
-	SpinlockAcquire(Channel->InboundLock);
+	spin_lock_irqsave(&Channel->inbound_lock, flags);
 
 	ret = RingBufferPeek(&Channel->Inbound, &desc, sizeof(VMPACKET_DESCRIPTOR));
 	if (ret != 0)
 	{
-		SpinlockRelease(Channel->InboundLock);
+		spin_unlock_irqrestore(&Channel->inbound_lock, flags);
 
 		//DPRINT_DBG(VMBUS, "nothing to read!!");
 		DPRINT_EXIT(VMBUS);
@@ -1102,7 +1104,7 @@ VmbusChannelRecvPacketRaw(
 
 	if (packetLen > BufferLen)
 	{
-		SpinlockRelease(Channel->InboundLock);
+		spin_unlock_irqrestore(&Channel->inbound_lock, flags);
 
 		DPRINT_ERR(VMBUS, "buffer too small - needed %d bytes but got space for only %d bytes", packetLen, BufferLen);
 		DPRINT_EXIT(VMBUS);
@@ -1114,7 +1116,7 @@ VmbusChannelRecvPacketRaw(
 	// Copy over the entire packet to the user buffer
 	ret = RingBufferRead(&Channel->Inbound, Buffer, packetLen, 0);
 
-	SpinlockRelease(Channel->InboundLock);
+	spin_unlock_irqrestore(&Channel->inbound_lock, flags);
 
 	DPRINT_EXIT(VMBUS);
 

drivers/staging/hv/ChannelMgmt.c

@@ -149,17 +149,11 @@ VMBUS_CHANNEL* AllocVmbusChannel(void)
 		return NULL;
 	}
 
-	channel->InboundLock = SpinlockCreate();
-	if (!channel->InboundLock)
-	{
-		kfree(channel);
-		return NULL;
-	}
+	spin_lock_init(&channel->inbound_lock);
 
 	channel->PollTimer = TimerCreate(VmbusChannelOnTimer, channel);
 	if (!channel->PollTimer)
 	{
-		SpinlockClose(channel->InboundLock);
 		kfree(channel);
 		return NULL;
 	}
@@ -169,7 +163,6 @@ VMBUS_CHANNEL* AllocVmbusChannel(void)
 	if (!channel->ControlWQ)
 	{
 		TimerClose(channel->PollTimer);
-		SpinlockClose(channel->InboundLock);
 		kfree(channel);
 		return NULL;
 	}
@@ -212,7 +205,6 @@ static inline void ReleaseVmbusChannel(void* Context)
 --*/
 void FreeVmbusChannel(VMBUS_CHANNEL* Channel)
 {
-	SpinlockClose(Channel->InboundLock);
 	TimerClose(Channel->PollTimer);
 
 	// We have to release the channel's workqueue/thread in the vmbus's workqueue/thread context

drivers/staging/hv/ChannelMgmt.h

@@ -63,7 +63,7 @@ typedef struct _VMBUS_CHANNEL {
 	u32						RingBufferPageCount;
 	RING_BUFFER_INFO			Outbound;	// send to parent
 	RING_BUFFER_INFO			Inbound;	// receive from parent
-	HANDLE						InboundLock;
+	spinlock_t inbound_lock;
 	HANDLE						ControlWQ;
 
 	// Channel callback are invoked in this workqueue context