Drivers: hv: Miscellaneous cleanups and bug fixes

index bb39705..287f07b 100644
@@ -33,11 +33,6 @@
 
 #include "hyperv_vmbus.h"
 
-struct vmbus_channel_message_table_entry {
-	enum vmbus_channel_message_type message_type;
-	void (*message_handler)(struct vmbus_channel_message_header *msg);
-};
-
 struct vmbus_rescind_work {
 	struct work_struct work;
 	struct vmbus_channel *channel;

@@ -827,25 +822,25 @@ static void vmbus_onversion_response(
 }
 
 /* Channel message dispatch table */
-static struct vmbus_channel_message_table_entry
+struct vmbus_channel_message_table_entry
 	channel_message_table[CHANNELMSG_COUNT] = {
-	{CHANNELMSG_INVALID,			NULL},
-	{CHANNELMSG_OFFERCHANNEL,		vmbus_onoffer},
-	{CHANNELMSG_RESCIND_CHANNELOFFER,	vmbus_onoffer_rescind},
-	{CHANNELMSG_REQUESTOFFERS,		NULL},
-	{CHANNELMSG_ALLOFFERS_DELIVERED,	vmbus_onoffers_delivered},
-	{CHANNELMSG_OPENCHANNEL,		NULL},
-	{CHANNELMSG_OPENCHANNEL_RESULT,	vmbus_onopen_result},
-	{CHANNELMSG_CLOSECHANNEL,		NULL},
-	{CHANNELMSG_GPADL_HEADER,		NULL},
-	{CHANNELMSG_GPADL_BODY,		NULL},
-	{CHANNELMSG_GPADL_CREATED,		vmbus_ongpadl_created},
-	{CHANNELMSG_GPADL_TEARDOWN,		NULL},
-	{CHANNELMSG_GPADL_TORNDOWN,		vmbus_ongpadl_torndown},
-	{CHANNELMSG_RELID_RELEASED,		NULL},
-	{CHANNELMSG_INITIATE_CONTACT,		NULL},
-	{CHANNELMSG_VERSION_RESPONSE,		vmbus_onversion_response},
-	{CHANNELMSG_UNLOAD,			NULL},
+	{CHANNELMSG_INVALID,			0, NULL},
+	{CHANNELMSG_OFFERCHANNEL,		0, vmbus_onoffer},
+	{CHANNELMSG_RESCIND_CHANNELOFFER,	0, vmbus_onoffer_rescind},
+	{CHANNELMSG_REQUESTOFFERS,		0, NULL},
+	{CHANNELMSG_ALLOFFERS_DELIVERED,	1, vmbus_onoffers_delivered},
+	{CHANNELMSG_OPENCHANNEL,		0, NULL},
+	{CHANNELMSG_OPENCHANNEL_RESULT,		1, vmbus_onopen_result},
+	{CHANNELMSG_CLOSECHANNEL,		0, NULL},
+	{CHANNELMSG_GPADL_HEADER,		0, NULL},
+	{CHANNELMSG_GPADL_BODY,			0, NULL},
+	{CHANNELMSG_GPADL_CREATED,		1, vmbus_ongpadl_created},
+	{CHANNELMSG_GPADL_TEARDOWN,		0, NULL},
+	{CHANNELMSG_GPADL_TORNDOWN,		1, vmbus_ongpadl_torndown},
+	{CHANNELMSG_RELID_RELEASED,		0, NULL},
+	{CHANNELMSG_INITIATE_CONTACT,		0, NULL},
+	{CHANNELMSG_VERSION_RESPONSE,		1, vmbus_onversion_response},
+	{CHANNELMSG_UNLOAD,			0, NULL},
 };
 
 /*

index c8e27e0..f40a5a9 100644
@@ -685,6 +685,23 @@ struct vmbus_msginfo {
 
 extern struct vmbus_connection vmbus_connection;
 
+enum vmbus_message_handler_type {
+	/* The related handler can sleep. */
+	VMHT_BLOCKING = 0,
+
+	/* The related handler must NOT sleep. */
+	VMHT_NON_BLOCKING = 1,
+};
+
+struct vmbus_channel_message_table_entry {
+	enum vmbus_channel_message_type message_type;
+	enum vmbus_message_handler_type handler_type;
+	void (*message_handler)(struct vmbus_channel_message_header *msg);
+};
+
+extern struct vmbus_channel_message_table_entry
+	channel_message_table[CHANNELMSG_COUNT];
+
 /* General vmbus interface */
 
 struct hv_device *vmbus_device_create(const uuid_le *type,

index 8313e25..c85235e 100644
@@ -657,21 +657,36 @@ static void vmbus_on_msg_dpc(unsigned long data)
 	void *page_addr = hv_context.synic_message_page[cpu];
 	struct hv_message *msg = (struct hv_message *)page_addr +
 				  VMBUS_MESSAGE_SINT;
+	struct vmbus_channel_message_header *hdr;
+	struct vmbus_channel_message_table_entry *entry;
 	struct onmessage_work_context *ctx;
 
 	while (1) {
-		if (msg->header.message_type == HVMSG_NONE) {
+		if (msg->header.message_type == HVMSG_NONE)
 			/* no msg */
 			break;
-		} else {
+
+		hdr = (struct vmbus_channel_message_header *)msg->u.payload;
+
+		if (hdr->msgtype >= CHANNELMSG_COUNT) {
+			WARN_ONCE(1, "unknown msgtype=%d\n", hdr->msgtype);
+			goto msg_handled;
+		}
+
+		entry = &channel_message_table[hdr->msgtype];
+		if (entry->handler_type	== VMHT_BLOCKING) {
 			ctx = kmalloc(sizeof(*ctx), GFP_ATOMIC);
 			if (ctx == NULL)
 				continue;
+
 			INIT_WORK(&ctx->work, vmbus_onmessage_work);
 			memcpy(&ctx->msg, msg, sizeof(*msg));
+
 			queue_work(vmbus_connection.work_queue, &ctx->work);
-		}
+		} else
+			entry->message_handler(hdr);
 
+msg_handled:
 		msg->header.message_type = HVMSG_NONE;
 
 		/*

index 287f07b..d69864d 100644
@@ -23,7 +23,6 @@
 #include <linux/kernel.h>
 #include <linux/sched.h>
 #include <linux/wait.h>
-#include <linux/delay.h>
 #include <linux/mm.h>
 #include <linux/slab.h>
 #include <linux/list.h>

@@ -33,11 +32,6 @@
 
 #include "hyperv_vmbus.h"
 
-struct vmbus_rescind_work {
-	struct work_struct work;
-	struct vmbus_channel *channel;
-};
-
 /**
  * vmbus_prep_negotiate_resp() - Create default response for Hyper-V Negotiate message
  * @icmsghdrp: Pointer to msg header structure

@@ -134,20 +128,6 @@ fw_error:
 
 EXPORT_SYMBOL_GPL(vmbus_prep_negotiate_resp);
 
-static void vmbus_sc_creation_cb(struct work_struct *work)
-{
-	struct vmbus_channel *newchannel = container_of(work,
-							struct vmbus_channel,
-							work);
-	struct vmbus_channel *primary_channel = newchannel->primary_channel;
-
-	/*
-	 * On entry sc_creation_callback has been already verified to
-	 * be non-NULL.
-	 */
-	primary_channel->sc_creation_callback(newchannel);
-}
-
 /*
  * alloc_channel - Allocate and initialize a vmbus channel object
  */

@@ -206,40 +186,6 @@ static void free_channel(struct vmbus_channel *channel)
 	queue_work(vmbus_connection.work_queue, &channel->work);
 }
 
-static void process_rescind_fn(struct work_struct *work)
-{
-	struct vmbus_rescind_work *rc_work;
-	struct vmbus_channel *channel;
-	struct device *dev;
-
-	rc_work = container_of(work, struct vmbus_rescind_work, work);
-	channel = rc_work->channel;
-
-	/*
-	 * We have already acquired a reference on the channel
-	 * and so it cannot vanish underneath us.
-	 * It is possible (while very unlikely) that we may
-	 * get here while the processing of the initial offer
-	 * is still not complete. Deal with this situation by
-	 * just waiting until the channel is in the correct state.
-	 */
-
-	while (channel->work.func != release_channel)
-		msleep(1000);
-
-	if (channel->device_obj) {
-		dev = get_device(&channel->device_obj->device);
-		if (dev) {
-			vmbus_device_unregister(channel->device_obj);
-			put_device(dev);
-		}
-	} else {
-		hv_process_channel_removal(channel,
-					   channel->offermsg.child_relid);
-	}
-	kfree(work);
-}
-
 static void percpu_channel_enq(void *arg)
 {
 	struct vmbus_channel *channel = arg;

@@ -302,46 +248,6 @@ void vmbus_free_channels(void)
 	}
 }
 
-static void vmbus_do_device_register(struct work_struct *work)
-{
-	struct hv_device *device_obj;
-	int ret;
-	unsigned long flags;
-	struct vmbus_channel *newchannel = container_of(work,
-						     struct vmbus_channel,
-						     work);
-
-	ret = vmbus_device_register(newchannel->device_obj);
-	if (ret != 0) {
-		pr_err("unable to add child device object (relid %d)\n",
-			newchannel->offermsg.child_relid);
-		spin_lock_irqsave(&vmbus_connection.channel_lock, flags);
-		list_del(&newchannel->listentry);
-		device_obj = newchannel->device_obj;
-		newchannel->device_obj = NULL;
-		spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
-
-		if (newchannel->target_cpu != get_cpu()) {
-			put_cpu();
-			smp_call_function_single(newchannel->target_cpu,
-					 percpu_channel_deq, newchannel, true);
-		} else {
-			percpu_channel_deq(newchannel);
-			put_cpu();
-		}
-
-		kfree(device_obj);
-		if (!newchannel->rescind) {
-			free_channel(newchannel);
-			return;
-		}
-	}
-	/*
-	 * The next state for this channel is to be freed.
-	 */
-	INIT_WORK(&newchannel->work, release_channel);
-}
-
 /*
  * vmbus_process_offer - Process the offer by creating a channel/device
  * associated with this offer

@@ -410,19 +316,8 @@ static void vmbus_process_offer(struct vmbus_channel *newchannel)
 
 			newchannel->state = CHANNEL_OPEN_STATE;
 			channel->num_sc++;
-			if (channel->sc_creation_callback != NULL) {
-				/*
-				 * We need to invoke the sub-channel creation
-				 * callback; invoke this in a seperate work
-				 * context since we are currently running on
-				 * the global work context in which we handle
-				 * messages from the host.
-				 */
-				INIT_WORK(&newchannel->work,
-					  vmbus_sc_creation_cb);
-				queue_work(newchannel->controlwq,
-					   &newchannel->work);
-			}
+			if (channel->sc_creation_callback != NULL)
+				channel->sc_creation_callback(newchannel);
 
 			return;
 		}

@@ -453,13 +348,13 @@ static void vmbus_process_offer(struct vmbus_channel *newchannel)
 	 * Add the new device to the bus. This will kick off device-driver
 	 * binding which eventually invokes the device driver's AddDevice()
 	 * method.
-	 * Invoke this call on the per-channel work context.
-	 * Until we return from this function, rescind offer message
-	 * cannot be processed as we are running on the global message
-	 * handling work.
 	 */
-	INIT_WORK(&newchannel->work, vmbus_do_device_register);
-	queue_work(newchannel->controlwq, &newchannel->work);
+	if (vmbus_device_register(newchannel->device_obj) != 0) {
+		pr_err("unable to add child device object (relid %d)\n",
+			newchannel->offermsg.child_relid);
+		kfree(newchannel->device_obj);
+		goto err_deq_chan;
+	}
 	return;
 
 err_deq_chan:

@@ -613,31 +508,35 @@ static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr)
 {
 	struct vmbus_channel_rescind_offer *rescind;
 	struct vmbus_channel *channel;
-	struct vmbus_rescind_work *rc_work;
+	unsigned long flags;
+	struct device *dev;
 
 	rescind = (struct vmbus_channel_rescind_offer *)hdr;
-	channel = relid2channel(rescind->child_relid, true);
+	channel = relid2channel(rescind->child_relid);
 
 	if (channel == NULL) {
 		hv_process_channel_removal(NULL, rescind->child_relid);
 		return;
 	}
 
-	/*
-	 * We have acquired a reference on the channel and have posted
-	 * the rescind state. Perform further cleanup in a work context
-	 * that is different from the global work context in which
-	 * we process messages from the host (we are currently executing
-	 * on that global context.
-	 */
-	rc_work = kzalloc(sizeof(struct vmbus_rescind_work), GFP_KERNEL);
-	if (!rc_work) {
-		pr_err("Unable to allocate memory for rescind processing ");
-		return;
+	spin_lock_irqsave(&channel->lock, flags);
+	channel->rescind = true;
+	spin_unlock_irqrestore(&channel->lock, flags);
+
+	if (channel->device_obj) {
+		/*
+		 * We will have to unregister this device from the
+		 * driver core.
+		 */
+		dev = get_device(&channel->device_obj->device);
+		if (dev) {
+			vmbus_device_unregister(channel->device_obj);
+			put_device(dev);
+		}
+	} else {
+		hv_process_channel_removal(channel,
+			channel->offermsg.child_relid);
 	}
-	rc_work->channel = channel;
-	INIT_WORK(&rc_work->work, process_rescind_fn);
-	schedule_work(&rc_work->work);
 }
 
 /*

index 8bcd307..583d7d4 100644
@@ -270,7 +270,7 @@ static struct vmbus_channel *pcpu_relid2channel(u32 relid)
  * relid2channel - Get the channel object given its
  * child relative id (ie channel id)
  */
-struct vmbus_channel *relid2channel(u32 relid, bool rescind)
+struct vmbus_channel *relid2channel(u32 relid)
 {
 	struct vmbus_channel *channel;
 	struct vmbus_channel *found_channel  = NULL;

@@ -282,8 +282,6 @@ struct vmbus_channel *relid2channel(u32 relid, bool rescind)
 	list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
 		if (channel->offermsg.child_relid == relid) {
 			found_channel = channel;
-			if (rescind)
-				found_channel->rescind = true;
 			break;
 		} else if (!list_empty(&channel->sc_list)) {
 			/*

@@ -294,8 +292,6 @@ struct vmbus_channel *relid2channel(u32 relid, bool rescind)
 							sc_list);
 				if (cur_sc->offermsg.child_relid == relid) {
 					found_channel = cur_sc;
-					if (rescind)
-						found_channel->rescind = true;
 					break;
 				}
 			}

index f40a5a9..887287a 100644
@@ -715,7 +715,7 @@ void vmbus_device_unregister(struct hv_device *device_obj);
 /* VmbusChildDeviceDestroy( */
 /* struct hv_device *); */
 
-struct vmbus_channel *relid2channel(u32 relid, bool rescind);
+struct vmbus_channel *relid2channel(u32 relid);
 
 void vmbus_free_channels(void);
 

index d69864d..0eeb1b3 100644
@@ -147,43 +147,15 @@ static struct vmbus_channel *alloc_channel(void)
 	INIT_LIST_HEAD(&channel->sc_list);
 	INIT_LIST_HEAD(&channel->percpu_list);
 
-	channel->controlwq = alloc_workqueue("hv_vmbus_ctl/%d", WQ_MEM_RECLAIM,
-					     1, channel->id);
-	if (!channel->controlwq) {
-		kfree(channel);
-		return NULL;
-	}
-
 	return channel;
 }
 
 /*
- * release_hannel - Release the vmbus channel object itself
- */
-static void release_channel(struct work_struct *work)
-{
-	struct vmbus_channel *channel = container_of(work,
-						     struct vmbus_channel,
-						     work);
-
-	destroy_workqueue(channel->controlwq);
-
-	kfree(channel);
-}
-
-/*
  * free_channel - Release the resources used by the vmbus channel object
  */
 static void free_channel(struct vmbus_channel *channel)
 {
-
-	/*
-	 * We have to release the channel's workqueue/thread in the vmbus's
-	 * workqueue/thread context
-	 * ie we can't destroy ourselves.
-	 */
-	INIT_WORK(&channel->work, release_channel);
-	queue_work(vmbus_connection.work_queue, &channel->work);
+	kfree(channel);
 }
 
 static void percpu_channel_enq(void *arg)

index 80e444b..902c37a 100644
@@ -653,8 +653,6 @@ struct vmbus_channel {
 
 	struct hv_device *device_obj;
 
-	struct work_struct work;
-
 	enum vmbus_channel_state state;
 
 	struct vmbus_channel_offer_channel offermsg;

@@ -675,7 +673,6 @@ struct vmbus_channel {
 	struct hv_ring_buffer_info outbound;	/* send to parent */
 	struct hv_ring_buffer_info inbound;	/* receive from parent */
 	spinlock_t inbound_lock;
-	struct workqueue_struct *controlwq;
 
 	struct vmbus_close_msg close_msg;
 

index 014256a..99afef9 100644
@@ -778,7 +778,17 @@ static unsigned long handle_pg_range(unsigned long pg_start,
 			pgs_ol = has->ha_end_pfn - start_pfn;
 			if (pgs_ol > pfn_cnt)
 				pgs_ol = pfn_cnt;
-			hv_bring_pgs_online(start_pfn, pgs_ol);
+
+			/*
+			 * Check if the corresponding memory block is already
+			 * online by checking its last previously backed page.
+			 * In case it is we need to bring rest (which was not
+			 * backed previously) online too.
+			 */
+			if (start_pfn > has->start_pfn &&
+			    !PageReserved(pfn_to_page(start_pfn - 1)))
+				hv_bring_pgs_online(start_pfn, pgs_ol);
+
 			has->covered_end_pfn +=  pgs_ol;
 			pfn_cnt -= pgs_ol;
 		}

index 99afef9..4f5323c 100644
@@ -976,8 +976,8 @@ static unsigned long compute_balloon_floor(void)
 	 *     128        72    (1/2)
 	 *     512       168    (1/4)
 	 *    2048       360    (1/8)
-	 *    8192       768    (1/16)
-	 *   32768      1536	(1/32)
+	 *    8192       744    (1/16)
+	 *   32768      1512	(1/32)
 	 */
 	if (totalram_pages < MB2PAGES(128))
 		min_pages = MB2PAGES(8) + (totalram_pages >> 1);

@@ -986,9 +986,9 @@ static unsigned long compute_balloon_floor(void)
 	else if (totalram_pages < MB2PAGES(2048))
 		min_pages = MB2PAGES(104) + (totalram_pages >> 3);
 	else if (totalram_pages < MB2PAGES(8192))
-		min_pages = MB2PAGES(256) + (totalram_pages >> 4);
+		min_pages = MB2PAGES(232) + (totalram_pages >> 4);
 	else
-		min_pages = MB2PAGES(512) + (totalram_pages >> 5);
+		min_pages = MB2PAGES(488) + (totalram_pages >> 5);
 #undef MB2PAGES
 	return min_pages;
 }

index 4f5323c..74312c8 100644
@@ -1081,9 +1081,9 @@ static void free_balloon_pages(struct hv_dynmem_device *dm,
 
 
 
-static int  alloc_balloon_pages(struct hv_dynmem_device *dm, int num_pages,
-			 struct dm_balloon_response *bl_resp, int alloc_unit,
-			 bool *alloc_error)
+static int alloc_balloon_pages(struct hv_dynmem_device *dm, int num_pages,
+			       struct dm_balloon_response *bl_resp,
+			       int alloc_unit)
 {
 	int i = 0;
 	struct page *pg;

@@ -1104,11 +1104,8 @@ static int  alloc_balloon_pages(struct hv_dynmem_device *dm, int num_pages,
 				__GFP_NOMEMALLOC | __GFP_NOWARN,
 				get_order(alloc_unit << PAGE_SHIFT));
 
-		if (!pg) {
-			*alloc_error = true;
+		if (!pg)
 			return i * alloc_unit;
-		}
-
 
 		dm->num_pages_ballooned += alloc_unit;
 

@@ -1140,7 +1137,6 @@ static void balloon_up(struct work_struct *dummy)
 	struct dm_balloon_response *bl_resp;
 	int alloc_unit;
 	int ret;
-	bool alloc_error;
 	bool done = false;
 	int i;
 	struct sysinfo val;

@@ -1173,18 +1169,15 @@ static void balloon_up(struct work_struct *dummy)
 
 
 		num_pages -= num_ballooned;
-		alloc_error = false;
 		num_ballooned = alloc_balloon_pages(&dm_device, num_pages,
-						bl_resp, alloc_unit,
-						 &alloc_error);
+						    bl_resp, alloc_unit);
 
 		if (alloc_unit != 1 && num_ballooned == 0) {
 			alloc_unit = 1;
 			continue;
 		}
 
-		if ((alloc_unit == 1 && alloc_error) ||
-			(num_ballooned == num_pages)) {
+		if (num_ballooned == 0 || num_ballooned == num_pages) {
 			bl_resp->more_pages = 0;
 			done = true;
 			dm_device.state = DM_INITIALIZED;

index 583d7d4..b27220a 100644
@@ -422,6 +422,7 @@ int vmbus_post_msg(void *buffer, size_t buflen)
 	union hv_connection_id conn_id;
 	int ret = 0;
 	int retries = 0;
+	u32 msec = 1;
 
 	conn_id.asu32 = 0;
 	conn_id.u.id = VMBUS_MESSAGE_CONNECTION_ID;

@@ -431,7 +432,7 @@ int vmbus_post_msg(void *buffer, size_t buflen)
 	 * insufficient resources. Retry the operation a couple of
 	 * times before giving up.
 	 */
-	while (retries < 10) {
+	while (retries < 20) {
 		ret = hv_post_message(conn_id, 1, buffer, buflen);
 
 		switch (ret) {

@@ -454,7 +455,9 @@ int vmbus_post_msg(void *buffer, size_t buflen)
 		}
 
 		retries++;
-		msleep(1000);
+		msleep(msec);
+		if (msec < 2048)
+			msec *= 2;
 	}
 	return ret;
 }