staging: unisys: remove MEMORYBARRIER AND VolatileBarrier from commontypes

Remove the MEMORYBARRIER and VolatileBarrier() defines from commontypes.h and
convert the spots that used this to mb(). Add comments to each use to indicate
that the barrier is used to ensure channel synchronization between guests.

Signed-off-by: Benjamin Romer <benjamin.romer@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/unisys/channels/channel.c

@@ -75,7 +75,7 @@ visor_signal_insert(CHANNEL_HEADER __iomem *pChannel, u32 Queue, void *pSignal)
 		(head * readl(&pqhdr->SignalSize));
 	memcpy_toio(psignal, pSignal, readl(&pqhdr->SignalSize));
 
-	VolatileBarrier();
+	mb(); /* channel synch */
 	writel(head, &pqhdr->Head);
 
 	writeq(readq(&pqhdr->NumSignalsSent) + 1, &pqhdr->NumSignalsSent);
@@ -128,7 +128,7 @@ visor_signal_remove(CHANNEL_HEADER __iomem *pChannel, u32 Queue, void *pSignal)
 		(tail * readl(&pqhdr->SignalSize));
 	memcpy_fromio(pSignal, psource, readl(&pqhdr->SignalSize));
 
-	VolatileBarrier();
+	mb(); /* channel synch */
 	writel(tail, &pqhdr->Tail);
 
 	writeq(readq(&pqhdr->NumSignalsReceived) + 1,
@@ -186,7 +186,7 @@ SignalRemoveAll(pCHANNEL_HEADER pChannel, u32 Queue, void *pSignal)
 		memcpy((char *) pSignal + (pqhdr->SignalSize * signalCount),
 		       psource, pqhdr->SignalSize);
 
-		VolatileBarrier();
+		mb(); /* channel synch */
 		pqhdr->Tail = tail;
 
 		signalCount++;

drivers/staging/unisys/common-spar/include/channels/channel.h

@@ -157,7 +157,7 @@ ULTRA_CHANNELCLI_STRING(u32 v)
 			      PathName_Last_N_Nodes(__FILE__, 4), __LINE__); \
 		writel(newstate, &((CHANNEL_HEADER __iomem *) \
 				   (pChan))->CliStateOS);		\
-		MEMORYBARRIER;						\
+		mb(); /* required for channel synch */			\
 	} while (0)
 
 #define ULTRA_CHANNEL_CLIENT_ACQUIRE_OS(pChan, chanId, logCtx)	\
@@ -458,7 +458,7 @@ ULTRA_channel_client_acquire_os(void __iomem *pChannel, u8 *chanId,
 			      CHANNELCLI_OWNED,
 			      PathName_Last_N_Nodes((u8 *) file, 4), line);
 		writel(CHANNELCLI_OWNED, &pChan->CliStateOS);
-		MEMORYBARRIER;
+		mb(); /* required for channel synch */
 	}
 	if (readl(&pChan->CliStateOS) == CHANNELCLI_OWNED) {
 		if (readb(&pChan->CliErrorOS) != 0) {
@@ -502,7 +502,7 @@ ULTRA_channel_client_acquire_os(void __iomem *pChannel, u8 *chanId,
 		return 0;
 	}
 	writel(CHANNELCLI_BUSY, &pChan->CliStateOS);
-	MEMORYBARRIER;
+	mb(); /* required for channel synch */
 	if (readl(&pChan->CliStateBoot) == CHANNELCLI_BUSY) {
 		if ((readb(&pChan->CliErrorOS)
 		     & ULTRA_CLIERROROS_THROTTLEMSG_BUSY) == 0) {
@@ -521,7 +521,7 @@ ULTRA_channel_client_acquire_os(void __iomem *pChannel, u8 *chanId,
 		}
 		/* reset busy */
 		writel(CHANNELCLI_ATTACHED, &pChan->CliStateOS);
-		MEMORYBARRIER;
+		mb(); /* required for channel synch */
 		return 0;
 	}
 	if (readb(&pChan->CliErrorOS) != 0) {

drivers/staging/unisys/include/commontypes.h

@@ -30,8 +30,6 @@ typedef u64 GUEST_PHYSICAL_ADDRESS;
 #define INLINE inline
 #define OFFSETOF offsetof
 
-#define MEMORYBARRIER mb()
-
 #define CHANNEL_GUID_MISMATCH(chType, chName, field, expected, actual, fil, \
 			      lin, logCtx)				\
 	do {								\
@@ -63,7 +61,5 @@ typedef u64 GUEST_PHYSICAL_ADDRESS;
 		      LineNumber, Str, args...)				\
 	pr_info(Str, ## args)
 
-#define VolatileBarrier() MEMORYBARRIER
-
 #endif
 

drivers/staging/unisys/visorchannel/visorchannel_funcs.c

@@ -424,7 +424,7 @@ visorchannel_signalremove(VISORCHANNEL *channel, u32 queue, void *msg)
 	/* For each data field in SIGNAL_QUEUE_HEADER that was modified,
 	 * update host memory.
 	 */
-	MEMORYBARRIER;
+	mb(); /* required for channel synch */
 	if (!SIG_WRITE_FIELD(channel, queue, &sig_hdr, Tail)) {
 		ERRDRV("visor_memregion_write of Tail failed: (status=%d)\n",
 		       rc);
@@ -477,7 +477,7 @@ visorchannel_signalinsert(VISORCHANNEL *channel, u32 queue, void *msg)
 	/* For each data field in SIGNAL_QUEUE_HEADER that was modified,
 	 * update host memory.
 	 */
-	MEMORYBARRIER;
+	mb(); /* required for channel synch */
 	if (!SIG_WRITE_FIELD(channel, queue, &sig_hdr, Head)) {
 		ERRDRV("visor_memregion_write of Head failed: (status=%d)\n",
 		       rc);