[POWERPC] viopath: Use completion

Use a completion instead of abusing a semaphore for hypervisor event
completion in viopath.

Signed-off-by: Christoph Hellwig <[e-mail]>
Acked-by: Stephen Rothwell <[e-mail]>
Signed-off-by: Paul Mackerras <[e-mail]>

arch/powerpc/platforms/iseries/viopath.c

···
 #include <linux/wait.h>
 #include <linux/seq_file.h>
 #include <linux/interrupt.h>
+#include <linux/completion.h>
 
 #include <asm/system.h>
 #include <asm/uaccess.h>
···
 	u16 vlanMap;
 	dma_addr_t handle;
 	HvLpEvent_Rc hvrc;
-	DECLARE_MUTEX_LOCKED(Semaphore);
+	DECLARE_COMPLETION(done);
 	struct device_node *node;
 	const char *sysid;
 
···
 			HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
 			viopath_sourceinst(viopath_hostLp),
 			viopath_targetinst(viopath_hostLp),
-			(u64)(unsigned long)&Semaphore, VIOVERSION << 16,
+			(u64)(unsigned long)&done, VIOVERSION << 16,
 			((u64)handle) << 32, HW_PAGE_SIZE, 0, 0);
 
 	if (hvrc != HvLpEvent_Rc_Good)
 		printk(VIOPATH_KERN_WARN "hv error on op %d\n", (int)hvrc);
 
-	down(&Semaphore);
+	wait_for_completion(&done);
 
 	vlanMap = HvLpConfig_getVirtualLanIndexMap();
 
···
 		return;
 	}
 
-	up((struct semaphore *)event->xCorrelationToken);
+	complete((struct completion *)event->xCorrelationToken);
 }
 
 /*