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>

4 files changed, 9 insertions, 13 deletions

diff --git a/drivers/staging/unisys/channels/channel.c b/drivers/staging/unisys/channels/channel.c
index ade2fe0..b4bdee4 100644
--- a/drivers/staging/unisys/channels/channel.c
+++ b/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++;
diff --git a/drivers/staging/unisys/common-spar/include/channels/channel.h b/drivers/staging/unisys/common-spar/include/channels/channel.h
index 15a8d6b..bc92333 100644
--- a/drivers/staging/unisys/common-spar/include/channels/channel.h
+++ b/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) {
diff --git a/drivers/staging/unisys/include/commontypes.h b/drivers/staging/unisys/include/commontypes.h
index 53ac770..34b31ad 100644
--- a/drivers/staging/unisys/include/commontypes.h
+++ b/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
 
diff --git a/drivers/staging/unisys/visorchannel/visorchannel_funcs.c b/drivers/staging/unisys/visorchannel/visorchannel_funcs.c
index 62ec928..947b23c 100644
--- a/drivers/staging/unisys/visorchannel/visorchannel_funcs.c
+++ b/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);