1 files changed, 68 insertions, 80 deletions

diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index 56dd261f7142..16f91c8490fe 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -43,7 +43,12 @@ static void vmbus_setevent(struct vmbus_channel *channel)
 {
 	struct hv_monitor_page *monitorpage;
 
-	if (channel->offermsg.monitor_allocated) {
+	/*
+	 * For channels marked as in "low latency" mode
+	 * bypass the monitor page mechanism.
+	 */
+	if ((channel->offermsg.monitor_allocated) &&
+	    (!channel->low_latency)) {
 		/* Each u32 represents 32 channels */
 		sync_set_bit(channel->offermsg.child_relid & 31,
 			(unsigned long *) vmbus_connection.send_int_page +
@@ -70,12 +75,14 @@ int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
 {
 	struct vmbus_channel_open_channel *open_msg;
 	struct vmbus_channel_msginfo *open_info = NULL;
-	void *in, *out;
 	unsigned long flags;
 	int ret, err = 0;
-	unsigned long t;
 	struct page *page;
 
+	if (send_ringbuffer_size % PAGE_SIZE ||
+	    recv_ringbuffer_size % PAGE_SIZE)
+		return -EINVAL;
+
 	spin_lock_irqsave(&newchannel->lock, flags);
 	if (newchannel->state == CHANNEL_OPEN_STATE) {
 		newchannel->state = CHANNEL_OPENING_STATE;
@@ -95,36 +102,33 @@ int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
 				recv_ringbuffer_size));
 
 	if (!page)
-		out = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO,
-					       get_order(send_ringbuffer_size +
-					       recv_ringbuffer_size));
-	else
-		out = (void *)page_address(page);
+		page = alloc_pages(GFP_KERNEL|__GFP_ZERO,
+				   get_order(send_ringbuffer_size +
+					     recv_ringbuffer_size));
 
-	if (!out) {
+	if (!page) {
 		err = -ENOMEM;
-		goto error0;
+		goto error_set_chnstate;
 	}
 
-	in = (void *)((unsigned long)out + send_ringbuffer_size);
-
-	newchannel->ringbuffer_pages = out;
+	newchannel->ringbuffer_pages = page_address(page);
 	newchannel->ringbuffer_pagecount = (send_ringbuffer_size +
 					   recv_ringbuffer_size) >> PAGE_SHIFT;
 
-	ret = hv_ringbuffer_init(
-		&newchannel->outbound, out, send_ringbuffer_size);
+	ret = hv_ringbuffer_init(&newchannel->outbound, page,
+				 send_ringbuffer_size >> PAGE_SHIFT);
 
 	if (ret != 0) {
 		err = ret;
-		goto error0;
+		goto error_free_pages;
 	}
 
-	ret = hv_ringbuffer_init(
-		&newchannel->inbound, in, recv_ringbuffer_size);
+	ret = hv_ringbuffer_init(&newchannel->inbound,
+				 &page[send_ringbuffer_size >> PAGE_SHIFT],
+				 recv_ringbuffer_size >> PAGE_SHIFT);
 	if (ret != 0) {
 		err = ret;
-		goto error0;
+		goto error_free_pages;
 	}
 
 
@@ -132,14 +136,14 @@ int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
 	newchannel->ringbuffer_gpadlhandle = 0;
 
 	ret = vmbus_establish_gpadl(newchannel,
-					 newchannel->outbound.ring_buffer,
-					 send_ringbuffer_size +
-					 recv_ringbuffer_size,
-					 &newchannel->ringbuffer_gpadlhandle);
+				    page_address(page),
+				    send_ringbuffer_size +
+				    recv_ringbuffer_size,
+				    &newchannel->ringbuffer_gpadlhandle);
 
 	if (ret != 0) {
 		err = ret;
-		goto error0;
+		goto error_free_pages;
 	}
 
 	/* Create and init the channel open message */
@@ -148,7 +152,7 @@ int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
 			   GFP_KERNEL);
 	if (!open_info) {
 		err = -ENOMEM;
-		goto error_gpadl;
+		goto error_free_gpadl;
 	}
 
 	init_completion(&open_info->waitevent);
@@ -164,7 +168,7 @@ int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
 
 	if (userdatalen > MAX_USER_DEFINED_BYTES) {
 		err = -EINVAL;
-		goto error_gpadl;
+		goto error_free_gpadl;
 	}
 
 	if (userdatalen)
@@ -180,14 +184,10 @@ int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
 
 	if (ret != 0) {
 		err = ret;
-		goto error1;
+		goto error_clean_msglist;
 	}
 
-	t = wait_for_completion_timeout(&open_info->waitevent, 5*HZ);
-	if (t == 0) {
-		err = -ETIMEDOUT;
-		goto error1;
-	}
+	wait_for_completion(&open_info->waitevent);
 
 	spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 	list_del(&open_info->msglistentry);
@@ -195,25 +195,27 @@ int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
 
 	if (open_info->response.open_result.status) {
 		err = -EAGAIN;
-		goto error_gpadl;
+		goto error_free_gpadl;
 	}
 
 	newchannel->state = CHANNEL_OPENED_STATE;
 	kfree(open_info);
 	return 0;
 
-error1:
+error_clean_msglist:
 	spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 	list_del(&open_info->msglistentry);
 	spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
 
-error_gpadl:
+error_free_gpadl:
 	vmbus_teardown_gpadl(newchannel, newchannel->ringbuffer_gpadlhandle);
-
-error0:
-	free_pages((unsigned long)out,
-		get_order(send_ringbuffer_size + recv_ringbuffer_size));
 	kfree(open_info);
+error_free_pages:
+	hv_ringbuffer_cleanup(&newchannel->outbound);
+	hv_ringbuffer_cleanup(&newchannel->inbound);
+	__free_pages(page,
+		     get_order(send_ringbuffer_size + recv_ringbuffer_size));
+error_set_chnstate:
 	newchannel->state = CHANNEL_OPEN_STATE;
 	return err;
 }
@@ -238,8 +240,7 @@ EXPORT_SYMBOL_GPL(vmbus_send_tl_connect_request);
  * create_gpadl_header - Creates a gpadl for the specified buffer
  */
 static int create_gpadl_header(void *kbuffer, u32 size,
-					 struct vmbus_channel_msginfo **msginfo,
-					 u32 *messagecount)
+			       struct vmbus_channel_msginfo **msginfo)
 {
 	int i;
 	int pagecount;
@@ -283,7 +284,6 @@ static int create_gpadl_header(void *kbuffer, u32 size,
 			gpadl_header->range[0].pfn_array[i] = slow_virt_to_phys(
 				kbuffer + PAGE_SIZE * i) >> PAGE_SHIFT;
 		*msginfo = msgheader;
-		*messagecount = 1;
 
 		pfnsum = pfncount;
 		pfnleft = pagecount - pfncount;
@@ -323,7 +323,6 @@ static int create_gpadl_header(void *kbuffer, u32 size,
 			}
 
 			msgbody->msgsize = msgsize;
-			(*messagecount)++;
 			gpadl_body =
 				(struct vmbus_channel_gpadl_body *)msgbody->msg;
 
@@ -352,6 +351,8 @@ static int create_gpadl_header(void *kbuffer, u32 size,
 		msgheader = kzalloc(msgsize, GFP_KERNEL);
 		if (msgheader == NULL)
 			goto nomem;
+
+		INIT_LIST_HEAD(&msgheader->submsglist);
 		msgheader->msgsize = msgsize;
 
 		gpadl_header = (struct vmbus_channel_gpadl_header *)
@@ -366,7 +367,6 @@ static int create_gpadl_header(void *kbuffer, u32 size,
 				kbuffer + PAGE_SIZE * i) >> PAGE_SHIFT;
 
 		*msginfo = msgheader;
-		*messagecount = 1;
 	}
 
 	return 0;
@@ -390,8 +390,7 @@ int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
 	struct vmbus_channel_gpadl_header *gpadlmsg;
 	struct vmbus_channel_gpadl_body *gpadl_body;
 	struct vmbus_channel_msginfo *msginfo = NULL;
-	struct vmbus_channel_msginfo *submsginfo;
-	u32 msgcount;
+	struct vmbus_channel_msginfo *submsginfo, *tmp;
 	struct list_head *curr;
 	u32 next_gpadl_handle;
 	unsigned long flags;
@@ -400,7 +399,7 @@ int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
 	next_gpadl_handle =
 		(atomic_inc_return(&vmbus_connection.next_gpadl_handle) - 1);
 
-	ret = create_gpadl_header(kbuffer, size, &msginfo, &msgcount);
+	ret = create_gpadl_header(kbuffer, size, &msginfo);
 	if (ret)
 		return ret;
 
@@ -423,24 +422,21 @@ int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
 	if (ret != 0)
 		goto cleanup;
 
-	if (msgcount > 1) {
-		list_for_each(curr, &msginfo->submsglist) {
-
-			submsginfo = (struct vmbus_channel_msginfo *)curr;
-			gpadl_body =
-			     (struct vmbus_channel_gpadl_body *)submsginfo->msg;
+	list_for_each(curr, &msginfo->submsglist) {
+		submsginfo = (struct vmbus_channel_msginfo *)curr;
+		gpadl_body =
+			(struct vmbus_channel_gpadl_body *)submsginfo->msg;
 
-			gpadl_body->header.msgtype =
-				CHANNELMSG_GPADL_BODY;
-			gpadl_body->gpadl = next_gpadl_handle;
+		gpadl_body->header.msgtype =
+			CHANNELMSG_GPADL_BODY;
+		gpadl_body->gpadl = next_gpadl_handle;
 
-			ret = vmbus_post_msg(gpadl_body,
-					       submsginfo->msgsize -
-					       sizeof(*submsginfo));
-			if (ret != 0)
-				goto cleanup;
+		ret = vmbus_post_msg(gpadl_body,
+				     submsginfo->msgsize -
+				     sizeof(*submsginfo));
+		if (ret != 0)
+			goto cleanup;
 
-		}
 	}
 	wait_for_completion(&msginfo->waitevent);
 
@@ -451,6 +447,10 @@ cleanup:
 	spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
 	list_del(&msginfo->msglistentry);
 	spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
+	list_for_each_entry_safe(submsginfo, tmp, &msginfo->submsglist,
+				 msglistentry) {
+		kfree(submsginfo);
+	}
 
 	kfree(msginfo);
 	return ret;
@@ -512,7 +512,6 @@ static void reset_channel_cb(void *arg)
 static int vmbus_close_internal(struct vmbus_channel *channel)
 {
 	struct vmbus_channel_close_channel *msg;
-	struct tasklet_struct *tasklet;
 	int ret;
 
 	/*
@@ -524,8 +523,7 @@ static int vmbus_close_internal(struct vmbus_channel *channel)
 	 * To resolve the race, we can serialize them by disabling the
 	 * tasklet when the latter is running here.
 	 */
-	tasklet = hv_context.event_dpc[channel->target_cpu];
-	tasklet_disable(tasklet);
+	hv_event_tasklet_disable(channel);
 
 	/*
 	 * In case a device driver's probe() fails (e.g.,
@@ -591,7 +589,7 @@ static int vmbus_close_internal(struct vmbus_channel *channel)
 		get_order(channel->ringbuffer_pagecount * PAGE_SIZE));
 
 out:
-	tasklet_enable(tasklet);
+	hv_event_tasklet_enable(channel);
 
 	return ret;
 }
@@ -659,7 +657,7 @@ int vmbus_sendpacket_ctl(struct vmbus_channel *channel, void *buffer,
 	bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 
 	ret = hv_ringbuffer_write(&channel->outbound, bufferlist, num_vecs,
-				  &signal, lock);
+				  &signal, lock, channel->signal_policy);
 
 	/*
 	 * Signalling the host is conditional on many factors:
@@ -680,11 +678,6 @@ int vmbus_sendpacket_ctl(struct vmbus_channel *channel, void *buffer,
 	 * mechanism which can hurt the performance otherwise.
 	 */
 
-	if (channel->signal_policy)
-		signal = true;
-	else
-		kick_q = true;
-
 	if (((ret == 0) && kick_q && signal) ||
 	    (ret && !is_hvsock_channel(channel)))
 		vmbus_setevent(channel);
@@ -777,7 +770,7 @@ int vmbus_sendpacket_pagebuffer_ctl(struct vmbus_channel *channel,
 	bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 
 	ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3,
-				  &signal, lock);
+				  &signal, lock, channel->signal_policy);
 
 	/*
 	 * Signalling the host is conditional on many factors:
@@ -795,11 +788,6 @@ int vmbus_sendpacket_pagebuffer_ctl(struct vmbus_channel *channel,
 	 * enough condition that it should not matter.
 	 */
 
-	if (channel->signal_policy)
-		signal = true;
-	else
-		kick_q = true;
-
 	if (((ret == 0) && kick_q && signal) || (ret))
 		vmbus_setevent(channel);
 
@@ -861,7 +849,7 @@ int vmbus_sendpacket_mpb_desc(struct vmbus_channel *channel,
 	bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 
 	ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3,
-				  &signal, lock);
+				  &signal, lock, channel->signal_policy);
 
 	if (ret == 0 && signal)
 		vmbus_setevent(channel);
@@ -926,7 +914,7 @@ int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
 	bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 
 	ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3,
-				  &signal, lock);
+				  &signal, lock, channel->signal_policy);
 
 	if (ret == 0 && signal)
 		vmbus_setevent(channel);