Merge tag 'char-misc-4.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc updates from Greg KH:
 "Here is the big char/misc driver update for 4.6-rc1.

  The majority of the patches here is hwtracing and some new mic
  drivers, but there's a lot of other driver updates as well.  Full
  details in the shortlog.

  All have been in linux-next for a while with no reported issues"

* tag 'char-misc-4.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (238 commits)
  goldfish: Fix build error of missing ioremap on UM
  nvmem: mediatek: Fix later provider initialization
  nvmem: imx-ocotp: Fix return value of imx_ocotp_read
  nvmem: Fix dependencies for !HAS_IOMEM archs
  char: genrtc: replace blacklist with whitelist
  drivers/hwtracing: make coresight-etm-perf.c explicitly non-modular
  drivers: char: mem: fix IS_ERROR_VALUE usage
  char: xillybus: Fix internal data structure initialization
  pch_phub: return -ENODATA if ROM can't be mapped
  Drivers: hv: vmbus: Support kexec on ws2012 r2 and above
  Drivers: hv: vmbus: Support handling messages on multiple CPUs
  Drivers: hv: utils: Remove util transport handler from list if registration fails
  Drivers: hv: util: Pass the channel information during the init call
  Drivers: hv: vmbus: avoid unneeded compiler optimizations in vmbus_wait_for_unload()
  Drivers: hv: vmbus: remove code duplication in message handling
  Drivers: hv: vmbus: avoid wait_for_completion() on crash
  Drivers: hv: vmbus: don't loose HVMSG_TIMER_EXPIRED messages
  misc: at24: replace memory_accessor with nvmem_device_read
  eeprom: 93xx46: extend driver to plug into the NVMEM framework
  eeprom: at25: extend driver to plug into the NVMEM framework
  ...

12 files changed, 377 insertions, 171 deletions

diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index 1161d68a1863..56dd261f7142 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -219,6 +219,21 @@ error0:
 }
 EXPORT_SYMBOL_GPL(vmbus_open);
 
+/* Used for Hyper-V Socket: a guest client's connect() to the host */
+int vmbus_send_tl_connect_request(const uuid_le *shv_guest_servie_id,
+				  const uuid_le *shv_host_servie_id)
+{
+	struct vmbus_channel_tl_connect_request conn_msg;
+
+	memset(&conn_msg, 0, sizeof(conn_msg));
+	conn_msg.header.msgtype = CHANNELMSG_TL_CONNECT_REQUEST;
+	conn_msg.guest_endpoint_id = *shv_guest_servie_id;
+	conn_msg.host_service_id = *shv_host_servie_id;
+
+	return vmbus_post_msg(&conn_msg, sizeof(conn_msg));
+}
+EXPORT_SYMBOL_GPL(vmbus_send_tl_connect_request);
+
 /*
  * create_gpadl_header - Creates a gpadl for the specified buffer
  */
@@ -624,6 +639,7 @@ int vmbus_sendpacket_ctl(struct vmbus_channel *channel, void *buffer,
 	u64 aligned_data = 0;
 	int ret;
 	bool signal = false;
+	bool lock = channel->acquire_ring_lock;
 	int num_vecs = ((bufferlen != 0) ? 3 : 1);
 
 
@@ -643,7 +659,7 @@ 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);
+				  &signal, lock);
 
 	/*
 	 * Signalling the host is conditional on many factors:
@@ -659,6 +675,9 @@ int vmbus_sendpacket_ctl(struct vmbus_channel *channel, void *buffer,
 	 * If we cannot write to the ring-buffer; signal the host
 	 * even if we may not have written anything. This is a rare
 	 * enough condition that it should not matter.
+	 * NOTE: in this case, the hvsock channel is an exception, because
+	 * it looks the host side's hvsock implementation has a throttling
+	 * mechanism which can hurt the performance otherwise.
 	 */
 
 	if (channel->signal_policy)
@@ -666,7 +685,8 @@ int vmbus_sendpacket_ctl(struct vmbus_channel *channel, void *buffer,
 	else
 		kick_q = true;
 
-	if (((ret == 0) && kick_q && signal) || (ret))
+	if (((ret == 0) && kick_q && signal) ||
+	    (ret && !is_hvsock_channel(channel)))
 		vmbus_setevent(channel);
 
 	return ret;
@@ -719,6 +739,7 @@ int vmbus_sendpacket_pagebuffer_ctl(struct vmbus_channel *channel,
 	struct kvec bufferlist[3];
 	u64 aligned_data = 0;
 	bool signal = false;
+	bool lock = channel->acquire_ring_lock;
 
 	if (pagecount > MAX_PAGE_BUFFER_COUNT)
 		return -EINVAL;
@@ -755,7 +776,8 @@ int vmbus_sendpacket_pagebuffer_ctl(struct vmbus_channel *channel,
 	bufferlist[2].iov_base = &aligned_data;
 	bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 
-	ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
+	ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3,
+				  &signal, lock);
 
 	/*
 	 * Signalling the host is conditional on many factors:
@@ -818,6 +840,7 @@ int vmbus_sendpacket_mpb_desc(struct vmbus_channel *channel,
 	struct kvec bufferlist[3];
 	u64 aligned_data = 0;
 	bool signal = false;
+	bool lock = channel->acquire_ring_lock;
 
 	packetlen = desc_size + bufferlen;
 	packetlen_aligned = ALIGN(packetlen, sizeof(u64));
@@ -837,7 +860,8 @@ int vmbus_sendpacket_mpb_desc(struct vmbus_channel *channel,
 	bufferlist[2].iov_base = &aligned_data;
 	bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 
-	ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
+	ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3,
+				  &signal, lock);
 
 	if (ret == 0 && signal)
 		vmbus_setevent(channel);
@@ -862,6 +886,7 @@ int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
 	struct kvec bufferlist[3];
 	u64 aligned_data = 0;
 	bool signal = false;
+	bool lock = channel->acquire_ring_lock;
 	u32 pfncount = NUM_PAGES_SPANNED(multi_pagebuffer->offset,
 					 multi_pagebuffer->len);
 
@@ -900,7 +925,8 @@ int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
 	bufferlist[2].iov_base = &aligned_data;
 	bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 
-	ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3, &signal);
+	ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3,
+				  &signal, lock);
 
 	if (ret == 0 && signal)
 		vmbus_setevent(channel);
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index 1c1ad47042c5..38b682bab85a 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -28,12 +28,127 @@
 #include <linux/list.h>
 #include <linux/module.h>
 #include <linux/completion.h>
+#include <linux/delay.h>
 #include <linux/hyperv.h>
 
 #include "hyperv_vmbus.h"
 
-static void init_vp_index(struct vmbus_channel *channel,
-			  const uuid_le *type_guid);
+static void init_vp_index(struct vmbus_channel *channel, u16 dev_type);
+
+static const struct vmbus_device vmbus_devs[] = {
+	/* IDE */
+	{ .dev_type = HV_IDE,
+	  HV_IDE_GUID,
+	  .perf_device = true,
+	},
+
+	/* SCSI */
+	{ .dev_type = HV_SCSI,
+	  HV_SCSI_GUID,
+	  .perf_device = true,
+	},
+
+	/* Fibre Channel */
+	{ .dev_type = HV_FC,
+	  HV_SYNTHFC_GUID,
+	  .perf_device = true,
+	},
+
+	/* Synthetic NIC */
+	{ .dev_type = HV_NIC,
+	  HV_NIC_GUID,
+	  .perf_device = true,
+	},
+
+	/* Network Direct */
+	{ .dev_type = HV_ND,
+	  HV_ND_GUID,
+	  .perf_device = true,
+	},
+
+	/* PCIE */
+	{ .dev_type = HV_PCIE,
+	  HV_PCIE_GUID,
+	  .perf_device = true,
+	},
+
+	/* Synthetic Frame Buffer */
+	{ .dev_type = HV_FB,
+	  HV_SYNTHVID_GUID,
+	  .perf_device = false,
+	},
+
+	/* Synthetic Keyboard */
+	{ .dev_type = HV_KBD,
+	  HV_KBD_GUID,
+	  .perf_device = false,
+	},
+
+	/* Synthetic MOUSE */
+	{ .dev_type = HV_MOUSE,
+	  HV_MOUSE_GUID,
+	  .perf_device = false,
+	},
+
+	/* KVP */
+	{ .dev_type = HV_KVP,
+	  HV_KVP_GUID,
+	  .perf_device = false,
+	},
+
+	/* Time Synch */
+	{ .dev_type = HV_TS,
+	  HV_TS_GUID,
+	  .perf_device = false,
+	},
+
+	/* Heartbeat */
+	{ .dev_type = HV_HB,
+	  HV_HEART_BEAT_GUID,
+	  .perf_device = false,
+	},
+
+	/* Shutdown */
+	{ .dev_type = HV_SHUTDOWN,
+	  HV_SHUTDOWN_GUID,
+	  .perf_device = false,
+	},
+
+	/* File copy */
+	{ .dev_type = HV_FCOPY,
+	  HV_FCOPY_GUID,
+	  .perf_device = false,
+	},
+
+	/* Backup */
+	{ .dev_type = HV_BACKUP,
+	  HV_VSS_GUID,
+	  .perf_device = false,
+	},
+
+	/* Dynamic Memory */
+	{ .dev_type = HV_DM,
+	  HV_DM_GUID,
+	  .perf_device = false,
+	},
+
+	/* Unknown GUID */
+	{ .dev_type = HV_UNKOWN,
+	  .perf_device = false,
+	},
+};
+
+static u16 hv_get_dev_type(const uuid_le *guid)
+{
+	u16 i;
+
+	for (i = HV_IDE; i < HV_UNKOWN; i++) {
+		if (!uuid_le_cmp(*guid, vmbus_devs[i].guid))
+			return i;
+	}
+	pr_info("Unknown GUID: %pUl\n", guid);
+	return i;
+}
 
 /**
  * vmbus_prep_negotiate_resp() - Create default response for Hyper-V Negotiate message
@@ -144,6 +259,7 @@ static struct vmbus_channel *alloc_channel(void)
 		return NULL;
 
 	channel->id = atomic_inc_return(&chan_num);
+	channel->acquire_ring_lock = true;
 	spin_lock_init(&channel->inbound_lock);
 	spin_lock_init(&channel->lock);
 
@@ -195,6 +311,7 @@ void hv_process_channel_removal(struct vmbus_channel *channel, u32 relid)
 	vmbus_release_relid(relid);
 
 	BUG_ON(!channel->rescind);
+	BUG_ON(!mutex_is_locked(&vmbus_connection.channel_mutex));
 
 	if (channel->target_cpu != get_cpu()) {
 		put_cpu();
@@ -206,9 +323,7 @@ void hv_process_channel_removal(struct vmbus_channel *channel, u32 relid)
 	}
 
 	if (channel->primary_channel == NULL) {
-		mutex_lock(&vmbus_connection.channel_mutex);
 		list_del(&channel->listentry);
-		mutex_unlock(&vmbus_connection.channel_mutex);
 
 		primary_channel = channel;
 	} else {
@@ -251,6 +366,8 @@ static void vmbus_process_offer(struct vmbus_channel *newchannel)
 	struct vmbus_channel *channel;
 	bool fnew = true;
 	unsigned long flags;
+	u16 dev_type;
+	int ret;
 
 	/* Make sure this is a new offer */
 	mutex_lock(&vmbus_connection.channel_mutex);
@@ -288,7 +405,9 @@ static void vmbus_process_offer(struct vmbus_channel *newchannel)
 			goto err_free_chan;
 	}
 
-	init_vp_index(newchannel, &newchannel->offermsg.offer.if_type);
+	dev_type = hv_get_dev_type(&newchannel->offermsg.offer.if_type);
+
+	init_vp_index(newchannel, dev_type);
 
 	if (newchannel->target_cpu != get_cpu()) {
 		put_cpu();
@@ -325,12 +444,17 @@ static void vmbus_process_offer(struct vmbus_channel *newchannel)
 	if (!newchannel->device_obj)
 		goto err_deq_chan;
 
+	newchannel->device_obj->device_id = dev_type;
 	/*
 	 * Add the new device to the bus. This will kick off device-driver
 	 * binding which eventually invokes the device driver's AddDevice()
 	 * method.
 	 */
-	if (vmbus_device_register(newchannel->device_obj) != 0) {
+	mutex_lock(&vmbus_connection.channel_mutex);
+	ret = vmbus_device_register(newchannel->device_obj);
+	mutex_unlock(&vmbus_connection.channel_mutex);
+
+	if (ret != 0) {
 		pr_err("unable to add child device object (relid %d)\n",
 			newchannel->offermsg.child_relid);
 		kfree(newchannel->device_obj);
@@ -358,37 +482,6 @@ err_free_chan:
 	free_channel(newchannel);
 }
 
-enum {
-	IDE = 0,
-	SCSI,
-	FC,
-	NIC,
-	ND_NIC,
-	PCIE,
-	MAX_PERF_CHN,
-};
-
-/*
- * This is an array of device_ids (device types) that are performance critical.
- * We attempt to distribute the interrupt load for these devices across
- * all available CPUs.
- */
-static const struct hv_vmbus_device_id hp_devs[] = {
-	/* IDE */
-	{ HV_IDE_GUID, },
-	/* Storage - SCSI */
-	{ HV_SCSI_GUID, },
-	/* Storage - FC */
-	{ HV_SYNTHFC_GUID, },
-	/* Network */
-	{ HV_NIC_GUID, },
-	/* NetworkDirect Guest RDMA */
-	{ HV_ND_GUID, },
-	/* PCI Express Pass Through */
-	{ HV_PCIE_GUID, },
-};
-
-
 /*
  * We use this state to statically distribute the channel interrupt load.
  */
@@ -405,22 +498,15 @@ static int next_numa_node_id;
  * For pre-win8 hosts or non-performance critical channels we assign the
  * first CPU in the first NUMA node.
  */
-static void init_vp_index(struct vmbus_channel *channel, const uuid_le *type_guid)
+static void init_vp_index(struct vmbus_channel *channel, u16 dev_type)
 {
 	u32 cur_cpu;
-	int i;
-	bool perf_chn = false;
+	bool perf_chn = vmbus_devs[dev_type].perf_device;
 	struct vmbus_channel *primary = channel->primary_channel;
 	int next_node;
 	struct cpumask available_mask;
 	struct cpumask *alloced_mask;
 
-	for (i = IDE; i < MAX_PERF_CHN; i++) {
-		if (!uuid_le_cmp(*type_guid, hp_devs[i].guid)) {
-			perf_chn = true;
-			break;
-		}
-	}
 	if ((vmbus_proto_version == VERSION_WS2008) ||
 	    (vmbus_proto_version == VERSION_WIN7) || (!perf_chn)) {
 		/*
@@ -469,6 +555,17 @@ static void init_vp_index(struct vmbus_channel *channel, const uuid_le *type_gui
 		    cpumask_of_node(primary->numa_node));
 
 	cur_cpu = -1;
+
+	/*
+	 * Normally Hyper-V host doesn't create more subchannels than there
+	 * are VCPUs on the node but it is possible when not all present VCPUs
+	 * on the node are initialized by guest. Clear the alloced_cpus_in_node
+	 * to start over.
+	 */
+	if (cpumask_equal(&primary->alloced_cpus_in_node,
+			  cpumask_of_node(primary->numa_node)))
+		cpumask_clear(&primary->alloced_cpus_in_node);
+
 	while (true) {
 		cur_cpu = cpumask_next(cur_cpu, &available_mask);
 		if (cur_cpu >= nr_cpu_ids) {
@@ -498,6 +595,32 @@ static void init_vp_index(struct vmbus_channel *channel, const uuid_le *type_gui
 	channel->target_vp = hv_context.vp_index[cur_cpu];
 }
 
+static void vmbus_wait_for_unload(void)
+{
+	int cpu = smp_processor_id();
+	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;
+	bool unloaded = false;
+
+	while (1) {
+		if (READ_ONCE(msg->header.message_type) == HVMSG_NONE) {
+			mdelay(10);
+			continue;
+		}
+
+		hdr = (struct vmbus_channel_message_header *)msg->u.payload;
+		if (hdr->msgtype == CHANNELMSG_UNLOAD_RESPONSE)
+			unloaded = true;
+
+		vmbus_signal_eom(msg);
+
+		if (unloaded)
+			break;
+	}
+}
+
 /*
  * vmbus_unload_response - Handler for the unload response.
  */
@@ -510,7 +633,7 @@ static void vmbus_unload_response(struct vmbus_channel_message_header *hdr)
 	complete(&vmbus_connection.unload_event);
 }
 
-void vmbus_initiate_unload(void)
+void vmbus_initiate_unload(bool crash)
 {
 	struct vmbus_channel_message_header hdr;
 
@@ -523,7 +646,14 @@ void vmbus_initiate_unload(void)
 	hdr.msgtype = CHANNELMSG_UNLOAD;
 	vmbus_post_msg(&hdr, sizeof(struct vmbus_channel_message_header));
 
-	wait_for_completion(&vmbus_connection.unload_event);
+	/*
+	 * vmbus_initiate_unload() is also called on crash and the crash can be
+	 * happening in an interrupt context, where scheduling is impossible.
+	 */
+	if (!crash)
+		wait_for_completion(&vmbus_connection.unload_event);
+	else
+		vmbus_wait_for_unload();
 }
 
 /*
@@ -592,6 +722,8 @@ static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr)
 	struct device *dev;
 
 	rescind = (struct vmbus_channel_rescind_offer *)hdr;
+
+	mutex_lock(&vmbus_connection.channel_mutex);
 	channel = relid2channel(rescind->child_relid);
 
 	if (channel == NULL) {
@@ -600,7 +732,7 @@ static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr)
 		 * vmbus_process_offer(), we have already invoked
 		 * vmbus_release_relid() on error.
 		 */
-		return;
+		goto out;
 	}
 
 	spin_lock_irqsave(&channel->lock, flags);
@@ -608,6 +740,10 @@ static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr)
 	spin_unlock_irqrestore(&channel->lock, flags);
 
 	if (channel->device_obj) {
+		if (channel->chn_rescind_callback) {
+			channel->chn_rescind_callback(channel);
+			goto out;
+		}
 		/*
 		 * We will have to unregister this device from the
 		 * driver core.
@@ -621,7 +757,24 @@ static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr)
 		hv_process_channel_removal(channel,
 			channel->offermsg.child_relid);
 	}
+
+out:
+	mutex_unlock(&vmbus_connection.channel_mutex);
+}
+
+void vmbus_hvsock_device_unregister(struct vmbus_channel *channel)
+{
+	mutex_lock(&vmbus_connection.channel_mutex);
+
+	BUG_ON(!is_hvsock_channel(channel));
+
+	channel->rescind = true;
+	vmbus_device_unregister(channel->device_obj);
+
+	mutex_unlock(&vmbus_connection.channel_mutex);
 }
+EXPORT_SYMBOL_GPL(vmbus_hvsock_device_unregister);
+
 
 /*
  * vmbus_onoffers_delivered -
@@ -825,6 +978,10 @@ struct vmbus_channel_message_table_entry
 	{CHANNELMSG_VERSION_RESPONSE,		1, vmbus_onversion_response},
 	{CHANNELMSG_UNLOAD,			0, NULL},
 	{CHANNELMSG_UNLOAD_RESPONSE,		1, vmbus_unload_response},
+	{CHANNELMSG_18,				0, NULL},
+	{CHANNELMSG_19,				0, NULL},
+	{CHANNELMSG_20,				0, NULL},
+	{CHANNELMSG_TL_CONNECT_REQUEST,		0, NULL},
 };
 
 /*
@@ -973,3 +1130,10 @@ bool vmbus_are_subchannels_present(struct vmbus_channel *primary)
 	return ret;
 }
 EXPORT_SYMBOL_GPL(vmbus_are_subchannels_present);
+
+void vmbus_set_chn_rescind_callback(struct vmbus_channel *channel,
+		void (*chn_rescind_cb)(struct vmbus_channel *))
+{
+	channel->chn_rescind_callback = chn_rescind_cb;
+}
+EXPORT_SYMBOL_GPL(vmbus_set_chn_rescind_callback);
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index 3dc5a9c7fad6..d02f1373dd98 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -88,8 +88,16 @@ static int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo,
 	 * This has been the behavior pre-win8. This is not
 	 * perf issue and having all channel messages delivered on CPU 0
 	 * would be ok.
+	 * For post win8 hosts, we support receiving channel messagges on
+	 * all the CPUs. This is needed for kexec to work correctly where
+	 * the CPU attempting to connect may not be CPU 0.
 	 */
-	msg->target_vcpu = 0;
+	if (version >= VERSION_WIN8_1) {
+		msg->target_vcpu = hv_context.vp_index[get_cpu()];
+		put_cpu();
+	} else {
+		msg->target_vcpu = 0;
+	}
 
 	/*
 	 * Add to list before we send the request since we may
@@ -236,7 +244,7 @@ void vmbus_disconnect(void)
 	/*
 	 * First send the unload request to the host.
 	 */
-	vmbus_initiate_unload();
+	vmbus_initiate_unload(false);
 
 	if (vmbus_connection.work_queue) {
 		drain_workqueue(vmbus_connection.work_queue);
@@ -288,7 +296,8 @@ struct vmbus_channel *relid2channel(u32 relid)
 	struct list_head *cur, *tmp;
 	struct vmbus_channel *cur_sc;
 
-	mutex_lock(&vmbus_connection.channel_mutex);
+	BUG_ON(!mutex_is_locked(&vmbus_connection.channel_mutex));
+
 	list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
 		if (channel->offermsg.child_relid == relid) {
 			found_channel = channel;
@@ -307,7 +316,6 @@ struct vmbus_channel *relid2channel(u32 relid)
 			}
 		}
 	}
-	mutex_unlock(&vmbus_connection.channel_mutex);
 
 	return found_channel;
 }
@@ -474,7 +482,7 @@ int vmbus_post_msg(void *buffer, size_t buflen)
 /*
  * vmbus_set_event - Send an event notification to the parent
  */
-int vmbus_set_event(struct vmbus_channel *channel)
+void vmbus_set_event(struct vmbus_channel *channel)
 {
 	u32 child_relid = channel->offermsg.child_relid;
 
@@ -485,5 +493,5 @@ int vmbus_set_event(struct vmbus_channel *channel)
 			(child_relid >> 5));
 	}
 
-	return hv_signal_event(channel->sig_event);
+	hv_do_hypercall(HVCALL_SIGNAL_EVENT, channel->sig_event, NULL);
 }
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index 11bca51ef5ff..a1c086ba3b9a 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -204,6 +204,8 @@ int hv_init(void)
 	       sizeof(int) * NR_CPUS);
 	memset(hv_context.event_dpc, 0,
 	       sizeof(void *) * NR_CPUS);
+	memset(hv_context.msg_dpc, 0,
+	       sizeof(void *) * NR_CPUS);
 	memset(hv_context.clk_evt, 0,
 	       sizeof(void *) * NR_CPUS);
 
@@ -295,8 +297,14 @@ void hv_cleanup(void)
 	 * Cleanup the TSC page based CS.
 	 */
 	if (ms_hyperv.features & HV_X64_MSR_REFERENCE_TSC_AVAILABLE) {
-		clocksource_change_rating(&hyperv_cs_tsc, 10);
-		clocksource_unregister(&hyperv_cs_tsc);
+		/*
+		 * Crash can happen in an interrupt context and unregistering
+		 * a clocksource is impossible and redundant in this case.
+		 */
+		if (!oops_in_progress) {
+			clocksource_change_rating(&hyperv_cs_tsc, 10);
+			clocksource_unregister(&hyperv_cs_tsc);
+		}
 
 		hypercall_msr.as_uint64 = 0;
 		wrmsrl(HV_X64_MSR_REFERENCE_TSC, hypercall_msr.as_uint64);
@@ -337,22 +345,6 @@ int hv_post_message(union hv_connection_id connection_id,
 	return status & 0xFFFF;
 }
 
-
-/*
- * hv_signal_event -
- * Signal an event on the specified connection using the hypervisor event IPC.
- *
- * This involves a hypercall.
- */
-int hv_signal_event(void *con_id)
-{
-	u64 status;
-
-	status = hv_do_hypercall(HVCALL_SIGNAL_EVENT, con_id, NULL);
-
-	return status & 0xFFFF;
-}
-
 static int hv_ce_set_next_event(unsigned long delta,
 				struct clock_event_device *evt)
 {
@@ -425,6 +417,13 @@ int hv_synic_alloc(void)
 		}
 		tasklet_init(hv_context.event_dpc[cpu], vmbus_on_event, cpu);
 
+		hv_context.msg_dpc[cpu] = kmalloc(size, GFP_ATOMIC);
+		if (hv_context.msg_dpc[cpu] == NULL) {
+			pr_err("Unable to allocate event dpc\n");
+			goto err;
+		}
+		tasklet_init(hv_context.msg_dpc[cpu], vmbus_on_msg_dpc, cpu);
+
 		hv_context.clk_evt[cpu] = kzalloc(ced_size, GFP_ATOMIC);
 		if (hv_context.clk_evt[cpu] == NULL) {
 			pr_err("Unable to allocate clock event device\n");
@@ -466,6 +465,7 @@ err:
 static void hv_synic_free_cpu(int cpu)
 {
 	kfree(hv_context.event_dpc[cpu]);
+	kfree(hv_context.msg_dpc[cpu]);
 	kfree(hv_context.clk_evt[cpu]);
 	if (hv_context.synic_event_page[cpu])
 		free_page((unsigned long)hv_context.synic_event_page[cpu]);
diff --git a/drivers/hv/hv_fcopy.c b/drivers/hv/hv_fcopy.c
index c37a71e13de0..23c70799ad8a 100644
--- a/drivers/hv/hv_fcopy.c
+++ b/drivers/hv/hv_fcopy.c
@@ -251,7 +251,6 @@ void hv_fcopy_onchannelcallback(void *context)
 		 */
 
 		fcopy_transaction.recv_len = recvlen;
-		fcopy_transaction.recv_channel = channel;
 		fcopy_transaction.recv_req_id = requestid;
 		fcopy_transaction.fcopy_msg = fcopy_msg;
 
@@ -317,6 +316,7 @@ static void fcopy_on_reset(void)
 int hv_fcopy_init(struct hv_util_service *srv)
 {
 	recv_buffer = srv->recv_buffer;
+	fcopy_transaction.recv_channel = srv->channel;
 
 	/*
 	 * When this driver loads, the user level daemon that
diff --git a/drivers/hv/hv_kvp.c b/drivers/hv/hv_kvp.c
index d4ab81bcd515..9b9b370fe22a 100644
--- a/drivers/hv/hv_kvp.c
+++ b/drivers/hv/hv_kvp.c
@@ -639,7 +639,6 @@ void hv_kvp_onchannelcallback(void *context)
 			 */
 
 			kvp_transaction.recv_len = recvlen;
-			kvp_transaction.recv_channel = channel;
 			kvp_transaction.recv_req_id = requestid;
 			kvp_transaction.kvp_msg = kvp_msg;
 
@@ -688,6 +687,7 @@ int
 hv_kvp_init(struct hv_util_service *srv)
 {
 	recv_buffer = srv->recv_buffer;
+	kvp_transaction.recv_channel = srv->channel;
 
 	/*
 	 * When this driver loads, the user level daemon that
diff --git a/drivers/hv/hv_snapshot.c b/drivers/hv/hv_snapshot.c
index 67def4a831c8..3fba14e88f03 100644
--- a/drivers/hv/hv_snapshot.c
+++ b/drivers/hv/hv_snapshot.c
@@ -263,7 +263,6 @@ void hv_vss_onchannelcallback(void *context)
 			 */
 
 			vss_transaction.recv_len = recvlen;
-			vss_transaction.recv_channel = channel;
 			vss_transaction.recv_req_id = requestid;
 			vss_transaction.msg = (struct hv_vss_msg *)vss_msg;
 
@@ -337,6 +336,7 @@ hv_vss_init(struct hv_util_service *srv)
 		return -ENOTSUPP;
 	}
 	recv_buffer = srv->recv_buffer;
+	vss_transaction.recv_channel = srv->channel;
 
 	/*
 	 * When this driver loads, the user level daemon that
diff --git a/drivers/hv/hv_util.c b/drivers/hv/hv_util.c
index 7994ec2e4151..d5acaa2d8e61 100644
--- a/drivers/hv/hv_util.c
+++ b/drivers/hv/hv_util.c
@@ -322,6 +322,7 @@ static int util_probe(struct hv_device *dev,
 	srv->recv_buffer = kmalloc(PAGE_SIZE * 4, GFP_KERNEL);
 	if (!srv->recv_buffer)
 		return -ENOMEM;
+	srv->channel = dev->channel;
 	if (srv->util_init) {
 		ret = srv->util_init(srv);
 		if (ret) {
diff --git a/drivers/hv/hv_utils_transport.c b/drivers/hv/hv_utils_transport.c
index 4f42c0e20c20..9a9983fa4531 100644
--- a/drivers/hv/hv_utils_transport.c
+++ b/drivers/hv/hv_utils_transport.c
@@ -310,6 +310,9 @@ struct hvutil_transport *hvutil_transport_init(const char *name,
 	return hvt;
 
 err_free_hvt:
+	spin_lock(&hvt_list_lock);
+	list_del(&hvt->list);
+	spin_unlock(&hvt_list_lock);
 	kfree(hvt);
 	return NULL;
 }
diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index 2f8c0f40930b..12321b93a756 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -443,10 +443,11 @@ struct hv_context {
 	u32 vp_index[NR_CPUS];
 	/*
 	 * Starting with win8, we can take channel interrupts on any CPU;
-	 * we will manage the tasklet that handles events on a per CPU
+	 * we will manage the tasklet that handles events messages on a per CPU
 	 * basis.
 	 */
 	struct tasklet_struct *event_dpc[NR_CPUS];
+	struct tasklet_struct *msg_dpc[NR_CPUS];
 	/*
 	 * To optimize the mapping of relid to channel, maintain
 	 * per-cpu list of the channels based on their CPU affinity.
@@ -495,8 +496,6 @@ extern int hv_post_message(union hv_connection_id connection_id,
 			 enum hv_message_type message_type,
 			 void *payload, size_t payload_size);
 
-extern int hv_signal_event(void *con_id);
-
 extern int hv_synic_alloc(void);
 
 extern void hv_synic_free(void);
@@ -525,7 +524,7 @@ void hv_ringbuffer_cleanup(struct hv_ring_buffer_info *ring_info);
 
 int hv_ringbuffer_write(struct hv_ring_buffer_info *ring_info,
 		    struct kvec *kv_list,
-		    u32 kv_count, bool *signal);
+		    u32 kv_count, bool *signal, bool lock);
 
 int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info,
 		       void *buffer, u32 buflen, u32 *buffer_actual_len,
@@ -620,6 +619,30 @@ struct vmbus_channel_message_table_entry {
 extern struct vmbus_channel_message_table_entry
 	channel_message_table[CHANNELMSG_COUNT];
 
+/* Free the message slot and signal end-of-message if required */
+static inline void vmbus_signal_eom(struct hv_message *msg)
+{
+	msg->header.message_type = HVMSG_NONE;
+
+	/*
+	 * Make sure the write to MessageType (ie set to
+	 * HVMSG_NONE) happens before we read the
+	 * MessagePending and EOMing. Otherwise, the EOMing
+	 * will not deliver any more messages since there is
+	 * no empty slot
+	 */
+	mb();
+
+	if (msg->header.message_flags.msg_pending) {
+		/*
+		 * This will cause message queue rescan to
+		 * possibly deliver another msg from the
+		 * hypervisor
+		 */
+		wrmsrl(HV_X64_MSR_EOM, 0);
+	}
+}
+
 /* General vmbus interface */
 
 struct hv_device *vmbus_device_create(const uuid_le *type,
@@ -644,9 +667,10 @@ void vmbus_disconnect(void);
 
 int vmbus_post_msg(void *buffer, size_t buflen);
 
-int vmbus_set_event(struct vmbus_channel *channel);
+void vmbus_set_event(struct vmbus_channel *channel);
 
 void vmbus_on_event(unsigned long data);
+void vmbus_on_msg_dpc(unsigned long data);
 
 int hv_kvp_init(struct hv_util_service *);
 void hv_kvp_deinit(void);
@@ -659,7 +683,7 @@ void hv_vss_onchannelcallback(void *);
 int hv_fcopy_init(struct hv_util_service *);
 void hv_fcopy_deinit(void);
 void hv_fcopy_onchannelcallback(void *);
-void vmbus_initiate_unload(void);
+void vmbus_initiate_unload(bool crash);
 
 static inline void hv_poll_channel(struct vmbus_channel *channel,
 				   void (*cb)(void *))
diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c
index b53702ce692f..5613e2b5cff7 100644
--- a/drivers/hv/ring_buffer.c
+++ b/drivers/hv/ring_buffer.c
@@ -314,7 +314,7 @@ void hv_ringbuffer_cleanup(struct hv_ring_buffer_info *ring_info)
 
 /* Write to the ring buffer. */
 int hv_ringbuffer_write(struct hv_ring_buffer_info *outring_info,
-		    struct kvec *kv_list, u32 kv_count, bool *signal)
+		    struct kvec *kv_list, u32 kv_count, bool *signal, bool lock)
 {
 	int i = 0;
 	u32 bytes_avail_towrite;
@@ -324,14 +324,15 @@ int hv_ringbuffer_write(struct hv_ring_buffer_info *outring_info,
 	u32 next_write_location;
 	u32 old_write;
 	u64 prev_indices = 0;
-	unsigned long flags;
+	unsigned long flags = 0;
 
 	for (i = 0; i < kv_count; i++)
 		totalbytes_towrite += kv_list[i].iov_len;
 
 	totalbytes_towrite += sizeof(u64);
 
-	spin_lock_irqsave(&outring_info->ring_lock, flags);
+	if (lock)
+		spin_lock_irqsave(&outring_info->ring_lock, flags);
 
 	hv_get_ringbuffer_availbytes(outring_info,
 				&bytes_avail_toread,
@@ -343,7 +344,8 @@ int hv_ringbuffer_write(struct hv_ring_buffer_info *outring_info,
 	 * is empty since the read index == write index.
 	 */
 	if (bytes_avail_towrite <= totalbytes_towrite) {
-		spin_unlock_irqrestore(&outring_info->ring_lock, flags);
+		if (lock)
+			spin_unlock_irqrestore(&outring_info->ring_lock, flags);
 		return -EAGAIN;
 	}
 
@@ -374,7 +376,8 @@ int hv_ringbuffer_write(struct hv_ring_buffer_info *outring_info,
 	hv_set_next_write_location(outring_info, next_write_location);
 
 
-	spin_unlock_irqrestore(&outring_info->ring_lock, flags);
+	if (lock)
+		spin_unlock_irqrestore(&outring_info->ring_lock, flags);
 
 	*signal = hv_need_to_signal(old_write, outring_info);
 	return 0;
@@ -388,7 +391,6 @@ int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info,
 	u32 bytes_avail_toread;
 	u32 next_read_location = 0;
 	u64 prev_indices = 0;
-	unsigned long flags;
 	struct vmpacket_descriptor desc;
 	u32 offset;
 	u32 packetlen;
@@ -397,7 +399,6 @@ int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info,
 	if (buflen <= 0)
 		return -EINVAL;
 
-	spin_lock_irqsave(&inring_info->ring_lock, flags);
 
 	*buffer_actual_len = 0;
 	*requestid = 0;
@@ -412,7 +413,7 @@ int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info,
 		 * No error is set when there is even no header, drivers are
 		 * supposed to analyze buffer_actual_len.
 		 */
-		goto out_unlock;
+		return ret;
 	}
 
 	next_read_location = hv_get_next_read_location(inring_info);
@@ -425,15 +426,11 @@ int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info,
 	*buffer_actual_len = packetlen;
 	*requestid = desc.trans_id;
 
-	if (bytes_avail_toread < packetlen + offset) {
-		ret = -EAGAIN;
-		goto out_unlock;
-	}
+	if (bytes_avail_toread < packetlen + offset)
+		return -EAGAIN;
 
-	if (packetlen > buflen) {
-		ret = -ENOBUFS;
-		goto out_unlock;
-	}
+	if (packetlen > buflen)
+		return -ENOBUFS;
 
 	next_read_location =
 		hv_get_next_readlocation_withoffset(inring_info, offset);
@@ -460,7 +457,5 @@ int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info,
 
 	*signal = hv_need_to_signal_on_read(bytes_avail_towrite, inring_info);
 
-out_unlock:
-	spin_unlock_irqrestore(&inring_info->ring_lock, flags);
 	return ret;
 }
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 328e4c3808e0..64713ff47e36 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -45,7 +45,6 @@
 
 static struct acpi_device  *hv_acpi_dev;
 
-static struct tasklet_struct msg_dpc;
 static struct completion probe_event;
 
 
@@ -477,6 +476,24 @@ static ssize_t channel_vp_mapping_show(struct device *dev,
 }
 static DEVICE_ATTR_RO(channel_vp_mapping);
 
+static ssize_t vendor_show(struct device *dev,
+			   struct device_attribute *dev_attr,
+			   char *buf)
+{
+	struct hv_device *hv_dev = device_to_hv_device(dev);
+	return sprintf(buf, "0x%x\n", hv_dev->vendor_id);
+}
+static DEVICE_ATTR_RO(vendor);
+
+static ssize_t device_show(struct device *dev,
+			   struct device_attribute *dev_attr,
+			   char *buf)
+{
+	struct hv_device *hv_dev = device_to_hv_device(dev);
+	return sprintf(buf, "0x%x\n", hv_dev->device_id);
+}
+static DEVICE_ATTR_RO(device);
+
 /* Set up per device attributes in /sys/bus/vmbus/devices/<bus device> */
 static struct attribute *vmbus_attrs[] = {
 	&dev_attr_id.attr,
@@ -502,6 +519,8 @@ static struct attribute *vmbus_attrs[] = {
 	&dev_attr_in_read_bytes_avail.attr,
 	&dev_attr_in_write_bytes_avail.attr,
 	&dev_attr_channel_vp_mapping.attr,
+	&dev_attr_vendor.attr,
+	&dev_attr_device.attr,
 	NULL,
 };
 ATTRIBUTE_GROUPS(vmbus);
@@ -562,6 +581,10 @@ static int vmbus_match(struct device *device, struct device_driver *driver)
 	struct hv_driver *drv = drv_to_hv_drv(driver);
 	struct hv_device *hv_dev = device_to_hv_device(device);
 
+	/* The hv_sock driver handles all hv_sock offers. */
+	if (is_hvsock_channel(hv_dev->channel))
+		return drv->hvsock;
+
 	if (hv_vmbus_get_id(drv->id_table, &hv_dev->dev_type))
 		return 1;
 
@@ -685,28 +708,10 @@ static void hv_process_timer_expiration(struct hv_message *msg, int cpu)
 	if (dev->event_handler)
 		dev->event_handler(dev);
 
-	msg->header.message_type = HVMSG_NONE;
-
-	/*
-	 * Make sure the write to MessageType (ie set to
-	 * HVMSG_NONE) happens before we read the
-	 * MessagePending and EOMing. Otherwise, the EOMing
-	 * will not deliver any more messages since there is
-	 * no empty slot
-	 */
-	mb();
-
-	if (msg->header.message_flags.msg_pending) {
-		/*
-		 * This will cause message queue rescan to
-		 * possibly deliver another msg from the
-		 * hypervisor
-		 */
-		wrmsrl(HV_X64_MSR_EOM, 0);
-	}
+	vmbus_signal_eom(msg);
 }
 
-static void vmbus_on_msg_dpc(unsigned long data)
+void vmbus_on_msg_dpc(unsigned long data)
 {
 	int cpu = smp_processor_id();
 	void *page_addr = hv_context.synic_message_page[cpu];
@@ -716,52 +721,32 @@ static void vmbus_on_msg_dpc(unsigned long data)
 	struct vmbus_channel_message_table_entry *entry;
 	struct onmessage_work_context *ctx;
 
-	while (1) {
-		if (msg->header.message_type == HVMSG_NONE)
-			/* no msg */
-			break;
+	if (msg->header.message_type == HVMSG_NONE)
+		/* no msg */
+		return;
 
-		hdr = (struct vmbus_channel_message_header *)msg->u.payload;
+	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;
-		}
+	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;
+	entry = &channel_message_table[hdr->msgtype];
+	if (entry->handler_type	== VMHT_BLOCKING) {
+		ctx = kmalloc(sizeof(*ctx), GFP_ATOMIC);
+		if (ctx == NULL)
+			return;
 
-			INIT_WORK(&ctx->work, vmbus_onmessage_work);
-			memcpy(&ctx->msg, msg, sizeof(*msg));
+		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);
+		queue_work(vmbus_connection.work_queue, &ctx->work);
+	} else
+		entry->message_handler(hdr);
 
 msg_handled:
-		msg->header.message_type = HVMSG_NONE;
-
-		/*
-		 * Make sure the write to MessageType (ie set to
-		 * HVMSG_NONE) happens before we read the
-		 * MessagePending and EOMing. Otherwise, the EOMing
-		 * will not deliver any more messages since there is
-		 * no empty slot
-		 */
-		mb();
-
-		if (msg->header.message_flags.msg_pending) {
-			/*
-			 * This will cause message queue rescan to
-			 * possibly deliver another msg from the
-			 * hypervisor
-			 */
-			wrmsrl(HV_X64_MSR_EOM, 0);
-		}
-	}
+	vmbus_signal_eom(msg);
 }
 
 static void vmbus_isr(void)
@@ -814,7 +799,7 @@ static void vmbus_isr(void)
 		if (msg->header.message_type == HVMSG_TIMER_EXPIRED)
 			hv_process_timer_expiration(msg, cpu);
 		else
-			tasklet_schedule(&msg_dpc);
+			tasklet_schedule(hv_context.msg_dpc[cpu]);
 	}
 }
 
@@ -838,8 +823,6 @@ static int vmbus_bus_init(void)
 		return ret;
 	}
 
-	tasklet_init(&msg_dpc, vmbus_on_msg_dpc, 0);
-
 	ret = bus_register(&hv_bus);
 	if (ret)
 		goto err_cleanup;
@@ -957,6 +940,7 @@ struct hv_device *vmbus_device_create(const uuid_le *type,
 	memcpy(&child_device_obj->dev_type, type, sizeof(uuid_le));
 	memcpy(&child_device_obj->dev_instance, instance,
 	       sizeof(uuid_le));
+	child_device_obj->vendor_id = 0x1414; /* MSFT vendor ID */
 
 
 	return child_device_obj;
@@ -1268,7 +1252,7 @@ static void hv_kexec_handler(void)
 	int cpu;
 
 	hv_synic_clockevents_cleanup();
-	vmbus_initiate_unload();
+	vmbus_initiate_unload(false);
 	for_each_online_cpu(cpu)
 		smp_call_function_single(cpu, hv_synic_cleanup, NULL, 1);
 	hv_cleanup();
@@ -1276,7 +1260,7 @@ static void hv_kexec_handler(void)
 
 static void hv_crash_handler(struct pt_regs *regs)
 {
-	vmbus_initiate_unload();
+	vmbus_initiate_unload(true);
 	/*
 	 * In crash handler we can't schedule synic cleanup for all CPUs,
 	 * doing the cleanup for current CPU only. This should be sufficient
@@ -1334,7 +1318,8 @@ static void __exit vmbus_exit(void)
 	hv_synic_clockevents_cleanup();
 	vmbus_disconnect();
 	hv_remove_vmbus_irq();
-	tasklet_kill(&msg_dpc);
+	for_each_online_cpu(cpu)
+		tasklet_kill(hv_context.msg_dpc[cpu]);
 	vmbus_free_channels();
 	if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
 		unregister_die_notifier(&hyperv_die_block);