svn commit: r299889 - head/sys/dev/hyperv/vmbus

[Sepherosa Ziehau]

Author: sephe
Date: Mon May 16 03:48:00 2016
New Revision: 299889
URL: https://svnweb.freebsd.org/changeset/base/299889

Log:
  hyperv/vmbus: Simplify event processing
  
  While I'm here, remove useless comment and unnecessary return.
  
  MFC after:	1 week
  Sponsored by:	Microsoft OSTC
  Differential Revision:	https://reviews.freebsd.org/D6332

Modified:
  head/sys/dev/hyperv/vmbus/hv_connection.c

Modified: head/sys/dev/hyperv/vmbus/hv_connection.c
==============================================================================
--- head/sys/dev/hyperv/vmbus/hv_connection.c	Mon May 16 03:26:16 2016	(r299888)
+++ head/sys/dev/hyperv/vmbus/hv_connection.c	Mon May 16 03:48:00 2016	(r299889)
@@ -300,7 +300,6 @@ hv_vmbus_on_events(int cpu)
 	int rel_id;
 	int maxdword;
 	hv_vmbus_synic_event_flags *event;
-	/* int maxdword = PAGE_SIZE >> 3; */
 
 	KASSERT(cpu <= mp_maxid, ("VMBUS: hv_vmbus_on_events: "
 	    "cpu out of range!"));
@@ -314,9 +313,12 @@ hv_vmbus_on_events(int cpu)
 		/*
 		 * receive size is 1/2 page and divide that by 4 bytes
 		 */
-		if (synch_test_and_clear_bit(0, &event->flags32[0]))
+		if (synch_test_and_clear_bit(0, &event->flags32[0])) {
 			recv_interrupt_page =
 			    hv_vmbus_g_connection.recv_interrupt_page;
+		} else {
+			return;
+		}
 	} else {
 		/*
 		 * On Host with Win8 or above, the event page can be
@@ -330,36 +332,32 @@ hv_vmbus_on_events(int cpu)
 	/*
 	 * Check events
 	 */
-	if (recv_interrupt_page != NULL) {
-	    for (dword = 0; dword < maxdword; dword++) {
-		if (recv_interrupt_page[dword]) {
-		    for (bit = 0; bit < HV_CHANNEL_DWORD_LEN; bit++) {
-			if (synch_test_and_clear_bit(bit,
-			    (uint32_t *) &recv_interrupt_page[dword])) {
-			    rel_id = (dword << 5) + bit;
-			    if (rel_id == 0) {
-				/*
-				 * Special case -
-				 * vmbus channel protocol msg.
-				 */
-				continue;
-			    } else {
-				hv_vmbus_channel * channel = hv_vmbus_g_connection.channels[rel_id];
-				/* if channel is closed or closing */
-				if (channel == NULL || channel->rxq == NULL)
-					continue;
-
-				if (channel->batched_reading)
-					hv_ring_buffer_read_begin(&channel->inbound);
-				taskqueue_enqueue(channel->rxq, &channel->channel_task);
-			    }
-			}
-		    }
-		}
+	for (dword = 0; dword < maxdword; dword++) {
+	    if (recv_interrupt_page[dword]) {
+	        for (bit = 0; bit < HV_CHANNEL_DWORD_LEN; bit++) {
+	    	if (synch_test_and_clear_bit(bit,
+	    	    (uint32_t *) &recv_interrupt_page[dword])) {
+	    	    rel_id = (dword << 5) + bit;
+	    	    if (rel_id == 0) {
+	    		/*
+	    		 * Special case -
+	    		 * vmbus channel protocol msg.
+	    		 */
+	    		continue;
+	    	    } else {
+	    		hv_vmbus_channel * channel = hv_vmbus_g_connection.channels[rel_id];
+	    		/* if channel is closed or closing */
+	    		if (channel == NULL || channel->rxq == NULL)
+	    			continue;
+
+	    		if (channel->batched_reading)
+	    			hv_ring_buffer_read_begin(&channel->inbound);
+	    		taskqueue_enqueue(channel->rxq, &channel->channel_task);
+	    	    }
+	    	}
+	        }
 	    }
 	}
-
-	return;
 }
 
 /**