drivers/staging/hv/Connection.c - kernel/prism - Git at Google

 /*
  *
  * Copyright (c) 2009, Microsoft Corporation.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
  * version 2, as published by the Free Software Foundation.
  *
  * This program is distributed in the hope it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  * more details.
  *
  * You should have received a copy of the GNU General Public License along with
  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  * Place - Suite 330, Boston, MA 02111-1307 USA.
  *
  * Authors:
  *   Haiyang Zhang <haiyangz@microsoft.com>
  *   Hank Janssen  <hjanssen@microsoft.com>
  *
  */
 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/vmalloc.h>
 #include "osd.h"
 #include "logging.h"
 #include "VmbusPrivate.h"


 struct VMBUS_CONNECTION gVmbusConnection = {
 	.ConnectState		= Disconnected,
 	.NextGpadlHandle	= ATOMIC_INIT(0xE1E10),
 };

 /**
  * VmbusConnect - Sends a connect request on the partition service connection
  */
 int VmbusConnect(void)
 {
 	int ret = 0;
 	struct vmbus_channel_msginfo *msgInfo = NULL;
 	struct vmbus_channel_initiate_contact *msg;
 	unsigned long flags;

 	DPRINT_ENTER(VMBUS);

 	/* Make sure we are not connecting or connected */
 	if (gVmbusConnection.ConnectState != Disconnected)
 		return -1;

 	/* Initialize the vmbus connection */
 	gVmbusConnection.ConnectState = Connecting;
 	gVmbusConnection.WorkQueue = create_workqueue("hv_vmbus_con");
 	if (!gVmbusConnection.WorkQueue) {
 		ret = -1;
 		goto Cleanup;
 	}

 	INIT_LIST_HEAD(&gVmbusConnection.ChannelMsgList);
 	spin_lock_init(&gVmbusConnection.channelmsg_lock);

 	INIT_LIST_HEAD(&gVmbusConnection.ChannelList);
 	spin_lock_init(&gVmbusConnection.channel_lock);

 	/*
 	 * Setup the vmbus event connection for channel interrupt
 	 * abstraction stuff
 	 */
 	gVmbusConnection.InterruptPage = osd_PageAlloc(1);
 	if (gVmbusConnection.InterruptPage == NULL) {
 		ret = -1;
 		goto Cleanup;
 	}

 	gVmbusConnection.RecvInterruptPage = gVmbusConnection.InterruptPage;
 	gVmbusConnection.SendInterruptPage =
 		(void *)((unsigned long)gVmbusConnection.InterruptPage +
 			(PAGE_SIZE >> 1));

 	/*
 	 * Setup the monitor notification facility. The 1st page for
 	 * parent->child and the 2nd page for child->parent
 	 */
 	gVmbusConnection.MonitorPages = osd_PageAlloc(2);
 	if (gVmbusConnection.MonitorPages == NULL) {
 		ret = -1;
 		goto Cleanup;
 	}

 	msgInfo = kzalloc(sizeof(*msgInfo) +
 			  sizeof(struct vmbus_channel_initiate_contact),
 			  GFP_KERNEL);
 	if (msgInfo == NULL) {
 		ret = -1;
 		goto Cleanup;
 	}

 	msgInfo->WaitEvent = osd_WaitEventCreate();
 	msg = (struct vmbus_channel_initiate_contact *)msgInfo->Msg;

 	msg->Header.MessageType = ChannelMessageInitiateContact;
 	msg->VMBusVersionRequested = VMBUS_REVISION_NUMBER;
 	msg->InterruptPage = virt_to_phys(gVmbusConnection.InterruptPage);
 	msg->MonitorPage1 = virt_to_phys(gVmbusConnection.MonitorPages);
 	msg->MonitorPage2 = virt_to_phys(
 			(void *)((unsigned long)gVmbusConnection.MonitorPages +
 				 PAGE_SIZE));

 	/*
 	 * Add to list before we send the request since we may
 	 * receive the response before returning from this routine
 	 */
 	spin_lock_irqsave(&gVmbusConnection.channelmsg_lock, flags);
 	list_add_tail(&msgInfo->MsgListEntry,
 		      &gVmbusConnection.ChannelMsgList);

 	spin_unlock_irqrestore(&gVmbusConnection.channelmsg_lock, flags);

 	DPRINT_DBG(VMBUS, "Vmbus connection - interrupt pfn %llx, "
 		   "monitor1 pfn %llx,, monitor2 pfn %llx",
 		   msg->InterruptPage, msg->MonitorPage1, msg->MonitorPage2);

 	DPRINT_DBG(VMBUS, "Sending channel initiate msg...");
 	ret = VmbusPostMessage(msg,
 			       sizeof(struct vmbus_channel_initiate_contact));
 	if (ret != 0) {
 		list_del(&msgInfo->MsgListEntry);
 		goto Cleanup;
 	}

 	/* Wait for the connection response */
 	osd_WaitEventWait(msgInfo->WaitEvent);

 	list_del(&msgInfo->MsgListEntry);

 	/* Check if successful */
 	if (msgInfo->Response.VersionResponse.VersionSupported) {
 		DPRINT_INFO(VMBUS, "Vmbus connected!!");
 		gVmbusConnection.ConnectState = Connected;

 	} else {
 		DPRINT_ERR(VMBUS, "Vmbus connection failed!!..."
 			   "current version (%d) not supported",
 			   VMBUS_REVISION_NUMBER);
 		ret = -1;
 		goto Cleanup;
 	}

 	kfree(msgInfo->WaitEvent);
 	kfree(msgInfo);
 	DPRINT_EXIT(VMBUS);

 	return 0;

 Cleanup:
 	gVmbusConnection.ConnectState = Disconnected;

 	if (gVmbusConnection.WorkQueue)
 		destroy_workqueue(gVmbusConnection.WorkQueue);

 	if (gVmbusConnection.InterruptPage) {
 		osd_PageFree(gVmbusConnection.InterruptPage, 1);
 		gVmbusConnection.InterruptPage = NULL;
 	}

 	if (gVmbusConnection.MonitorPages) {
 		osd_PageFree(gVmbusConnection.MonitorPages, 2);
 		gVmbusConnection.MonitorPages = NULL;
 	}

 	if (msgInfo) {
 		kfree(msgInfo->WaitEvent);
 		kfree(msgInfo);
 	}

 	DPRINT_EXIT(VMBUS);

 	return ret;
 }

 /**
  * VmbusDisconnect - Sends a disconnect request on the partition service connection
  */
 int VmbusDisconnect(void)
 {
 	int ret = 0;
 	struct vmbus_channel_message_header *msg;

 	DPRINT_ENTER(VMBUS);

 	/* Make sure we are connected */
 	if (gVmbusConnection.ConnectState != Connected)
 		return -1;

 	msg = kzalloc(sizeof(struct vmbus_channel_message_header), GFP_KERNEL);

 	msg->MessageType = ChannelMessageUnload;

 	ret = VmbusPostMessage(msg,
 			       sizeof(struct vmbus_channel_message_header));
 	if (ret != 0)
 		goto Cleanup;

 	osd_PageFree(gVmbusConnection.InterruptPage, 1);

 	/* TODO: iterate thru the msg list and free up */
 	destroy_workqueue(gVmbusConnection.WorkQueue);

 	gVmbusConnection.ConnectState = Disconnected;

 	DPRINT_INFO(VMBUS, "Vmbus disconnected!!");

 Cleanup:
 	kfree(msg);
 	DPRINT_EXIT(VMBUS);
 	return ret;
 }

 /**
  * GetChannelFromRelId - Get the channel object given its child relative id (ie channel id)
  */
 struct vmbus_channel *GetChannelFromRelId(u32 relId)
 {
 	struct vmbus_channel *channel;
 	struct vmbus_channel *foundChannel  = NULL;
 	unsigned long flags;

 	spin_lock_irqsave(&gVmbusConnection.channel_lock, flags);
 	list_for_each_entry(channel, &gVmbusConnection.ChannelList, ListEntry) {
 		if (channel->OfferMsg.ChildRelId == relId) {
 			foundChannel = channel;
 			break;
 		}
 	}
 	spin_unlock_irqrestore(&gVmbusConnection.channel_lock, flags);

 	return foundChannel;
 }

 /**
  * VmbusProcessChannelEvent - Process a channel event notification
  */
 static void VmbusProcessChannelEvent(void *context)
 {
 	struct vmbus_channel *channel;
 	u32 relId = (u32)(unsigned long)context;

 	ASSERT(relId > 0);

 	/*
 	 * Find the channel based on this relid and invokes the
 	 * channel callback to process the event
 	 */
 	channel = GetChannelFromRelId(relId);

 	if (channel) {
 		VmbusChannelOnChannelEvent(channel);
 		/*
 		 * WorkQueueQueueWorkItem(channel->dataWorkQueue,
 		 * 			  VmbusChannelOnChannelEvent,
 		 * 			  (void*)channel);
 		 */
 	} else {
 		DPRINT_ERR(VMBUS, "channel not found for relid - %d.", relId);
 	}
 }

 /**
  * VmbusOnEvents - Handler for events
  */
 void VmbusOnEvents(void)
 {
 	int dword;
 	int maxdword = MAX_NUM_CHANNELS_SUPPORTED >> 5;
 	int bit;
 	int relid;
 	u32 *recvInterruptPage = gVmbusConnection.RecvInterruptPage;

 	DPRINT_ENTER(VMBUS);

 	/* Check events */
 	if (recvInterruptPage) {
 		for (dword = 0; dword < maxdword; dword++) {
 			if (recvInterruptPage[dword]) {
 				for (bit = 0; bit < 32; bit++) {
 					if (test_and_clear_bit(bit, (unsigned long *)&recvInterruptPage[dword])) {
 						relid = (dword << 5) + bit;
 						DPRINT_DBG(VMBUS, "event detected for relid - %d", relid);

 						if (relid == 0) {
 							/* special case - vmbus channel protocol msg */
 							DPRINT_DBG(VMBUS, "invalid relid - %d", relid);
 							continue;
 						} else {
 							/* QueueWorkItem(VmbusProcessEvent, (void*)relid); */
 							/* ret = WorkQueueQueueWorkItem(gVmbusConnection.workQueue, VmbusProcessChannelEvent, (void*)relid); */
 							VmbusProcessChannelEvent((void *)(unsigned long)relid);
 						}
 					}
 				}
 			}
 		 }
 	}
 	DPRINT_EXIT(VMBUS);

 	return;
 }

 /**
  * VmbusPostMessage - Send a msg on the vmbus's message connection
  */
 int VmbusPostMessage(void *buffer, size_t bufferLen)
 {
 	union hv_connection_id connId;

 	connId.Asu32 = 0;
 	connId.u.Id = VMBUS_MESSAGE_CONNECTION_ID;
 	return HvPostMessage(connId, 1, buffer, bufferLen);
 }

 /**
  * VmbusSetEvent - Send an event notification to the parent
  */
 int VmbusSetEvent(u32 childRelId)
 {
 	int ret = 0;

 	DPRINT_ENTER(VMBUS);

 	/* Each u32 represents 32 channels */
 	set_bit(childRelId & 31,
 		(unsigned long *)gVmbusConnection.SendInterruptPage +
 		(childRelId >> 5));

 	ret = HvSignalEvent();

 	DPRINT_EXIT(VMBUS);

 	return ret;
 }
	/*
	*
	* Copyright (c) 2009, Microsoft Corporation.
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms and conditions of the GNU General Public License,
	* version 2, as published by the Free Software Foundation.
	*
	* This program is distributed in the hope it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	* more details.
	*
	* You should have received a copy of the GNU General Public License along with
	* this program; if not, write to the Free Software Foundation, Inc., 59 Temple
	* Place - Suite 330, Boston, MA 02111-1307 USA.
	*
	* Authors:
	* Haiyang Zhang <haiyangz@microsoft.com>
	* Hank Janssen <hjanssen@microsoft.com>
	*
	*/
	#include <linux/kernel.h>
	#include <linux/mm.h>
	#include <linux/vmalloc.h>
	#include "osd.h"
	#include "logging.h"
	#include "VmbusPrivate.h"


	struct VMBUS_CONNECTION gVmbusConnection = {
	.ConnectState = Disconnected,
	.NextGpadlHandle = ATOMIC_INIT(0xE1E10),
	};

	/**
	* VmbusConnect - Sends a connect request on the partition service connection
	*/
	int VmbusConnect(void)
	{
	int ret = 0;
	struct vmbus_channel_msginfo *msgInfo = NULL;
	struct vmbus_channel_initiate_contact *msg;
	unsigned long flags;

	DPRINT_ENTER(VMBUS);

	/* Make sure we are not connecting or connected */
	if (gVmbusConnection.ConnectState != Disconnected)
	return -1;

	/* Initialize the vmbus connection */
	gVmbusConnection.ConnectState = Connecting;
	gVmbusConnection.WorkQueue = create_workqueue("hv_vmbus_con");
	if (!gVmbusConnection.WorkQueue) {
	ret = -1;
	goto Cleanup;
	}

	INIT_LIST_HEAD(&gVmbusConnection.ChannelMsgList);
	spin_lock_init(&gVmbusConnection.channelmsg_lock);

	INIT_LIST_HEAD(&gVmbusConnection.ChannelList);
	spin_lock_init(&gVmbusConnection.channel_lock);

	/*
	* Setup the vmbus event connection for channel interrupt
	* abstraction stuff
	*/
	gVmbusConnection.InterruptPage = osd_PageAlloc(1);
	if (gVmbusConnection.InterruptPage == NULL) {
	ret = -1;
	goto Cleanup;
	}

	gVmbusConnection.RecvInterruptPage = gVmbusConnection.InterruptPage;
	gVmbusConnection.SendInterruptPage =
	(void *)((unsigned long)gVmbusConnection.InterruptPage +
	(PAGE_SIZE >> 1));

	/*
	* Setup the monitor notification facility. The 1st page for
	* parent->child and the 2nd page for child->parent
	*/
	gVmbusConnection.MonitorPages = osd_PageAlloc(2);
	if (gVmbusConnection.MonitorPages == NULL) {
	ret = -1;
	goto Cleanup;
	}

	msgInfo = kzalloc(sizeof(*msgInfo) +
	sizeof(struct vmbus_channel_initiate_contact),
	GFP_KERNEL);
	if (msgInfo == NULL) {
	ret = -1;
	goto Cleanup;
	}

	msgInfo->WaitEvent = osd_WaitEventCreate();
	msg = (struct vmbus_channel_initiate_contact *)msgInfo->Msg;

	msg->Header.MessageType = ChannelMessageInitiateContact;
	msg->VMBusVersionRequested = VMBUS_REVISION_NUMBER;
	msg->InterruptPage = virt_to_phys(gVmbusConnection.InterruptPage);
	msg->MonitorPage1 = virt_to_phys(gVmbusConnection.MonitorPages);
	msg->MonitorPage2 = virt_to_phys(
	(void *)((unsigned long)gVmbusConnection.MonitorPages +
	PAGE_SIZE));

	/*
	* Add to list before we send the request since we may
	* receive the response before returning from this routine
	*/
	spin_lock_irqsave(&gVmbusConnection.channelmsg_lock, flags);
	list_add_tail(&msgInfo->MsgListEntry,
	&gVmbusConnection.ChannelMsgList);

	spin_unlock_irqrestore(&gVmbusConnection.channelmsg_lock, flags);

	DPRINT_DBG(VMBUS, "Vmbus connection - interrupt pfn %llx, "
	"monitor1 pfn %llx,, monitor2 pfn %llx",
	msg->InterruptPage, msg->MonitorPage1, msg->MonitorPage2);

	DPRINT_DBG(VMBUS, "Sending channel initiate msg...");
	ret = VmbusPostMessage(msg,
	sizeof(struct vmbus_channel_initiate_contact));
	if (ret != 0) {
	list_del(&msgInfo->MsgListEntry);
	goto Cleanup;
	}

	/* Wait for the connection response */
	osd_WaitEventWait(msgInfo->WaitEvent);

	list_del(&msgInfo->MsgListEntry);

	/* Check if successful */
	if (msgInfo->Response.VersionResponse.VersionSupported) {
	DPRINT_INFO(VMBUS, "Vmbus connected!!");
	gVmbusConnection.ConnectState = Connected;

	} else {
	DPRINT_ERR(VMBUS, "Vmbus connection failed!!..."
	"current version (%d) not supported",
	VMBUS_REVISION_NUMBER);
	ret = -1;
	goto Cleanup;
	}

	kfree(msgInfo->WaitEvent);
	kfree(msgInfo);
	DPRINT_EXIT(VMBUS);

	return 0;

	Cleanup:
	gVmbusConnection.ConnectState = Disconnected;

	if (gVmbusConnection.WorkQueue)
	destroy_workqueue(gVmbusConnection.WorkQueue);

	if (gVmbusConnection.InterruptPage) {
	osd_PageFree(gVmbusConnection.InterruptPage, 1);
	gVmbusConnection.InterruptPage = NULL;
	}

	if (gVmbusConnection.MonitorPages) {
	osd_PageFree(gVmbusConnection.MonitorPages, 2);
	gVmbusConnection.MonitorPages = NULL;
	}

	if (msgInfo) {
	kfree(msgInfo->WaitEvent);
	kfree(msgInfo);
	}

	DPRINT_EXIT(VMBUS);

	return ret;
	}

	/**
	* VmbusDisconnect - Sends a disconnect request on the partition service connection
	*/
	int VmbusDisconnect(void)
	{
	int ret = 0;
	struct vmbus_channel_message_header *msg;

	DPRINT_ENTER(VMBUS);

	/* Make sure we are connected */
	if (gVmbusConnection.ConnectState != Connected)
	return -1;

	msg = kzalloc(sizeof(struct vmbus_channel_message_header), GFP_KERNEL);

	msg->MessageType = ChannelMessageUnload;

	ret = VmbusPostMessage(msg,
	sizeof(struct vmbus_channel_message_header));
	if (ret != 0)
	goto Cleanup;

	osd_PageFree(gVmbusConnection.InterruptPage, 1);

	/* TODO: iterate thru the msg list and free up */
	destroy_workqueue(gVmbusConnection.WorkQueue);

	gVmbusConnection.ConnectState = Disconnected;

	DPRINT_INFO(VMBUS, "Vmbus disconnected!!");

	Cleanup:
	kfree(msg);
	DPRINT_EXIT(VMBUS);
	return ret;
	}

	/**
	* GetChannelFromRelId - Get the channel object given its child relative id (ie channel id)
	*/
	struct vmbus_channel *GetChannelFromRelId(u32 relId)
	{
	struct vmbus_channel *channel;
	struct vmbus_channel *foundChannel = NULL;
	unsigned long flags;

	spin_lock_irqsave(&gVmbusConnection.channel_lock, flags);
	list_for_each_entry(channel, &gVmbusConnection.ChannelList, ListEntry) {
	if (channel->OfferMsg.ChildRelId == relId) {
	foundChannel = channel;
	break;
	}
	}
	spin_unlock_irqrestore(&gVmbusConnection.channel_lock, flags);

	return foundChannel;
	}

	/**
	* VmbusProcessChannelEvent - Process a channel event notification
	*/
	static void VmbusProcessChannelEvent(void *context)
	{
	struct vmbus_channel *channel;
	u32 relId = (u32)(unsigned long)context;

	ASSERT(relId > 0);

	/*
	* Find the channel based on this relid and invokes the
	* channel callback to process the event
	*/
	channel = GetChannelFromRelId(relId);

	if (channel) {
	VmbusChannelOnChannelEvent(channel);
	/*
	* WorkQueueQueueWorkItem(channel->dataWorkQueue,
	* VmbusChannelOnChannelEvent,
	* (void*)channel);
	*/
	} else {
	DPRINT_ERR(VMBUS, "channel not found for relid - %d.", relId);
	}
	}

	/**
	* VmbusOnEvents - Handler for events
	*/
	void VmbusOnEvents(void)
	{
	int dword;
	int maxdword = MAX_NUM_CHANNELS_SUPPORTED >> 5;
	int bit;
	int relid;
	u32 *recvInterruptPage = gVmbusConnection.RecvInterruptPage;

	DPRINT_ENTER(VMBUS);

	/* Check events */
	if (recvInterruptPage) {
	for (dword = 0; dword < maxdword; dword++) {
	if (recvInterruptPage[dword]) {
	for (bit = 0; bit < 32; bit++) {
	if (test_and_clear_bit(bit, (unsigned long *)&recvInterruptPage[dword])) {
	relid = (dword << 5) + bit;
	DPRINT_DBG(VMBUS, "event detected for relid - %d", relid);

	if (relid == 0) {
	/* special case - vmbus channel protocol msg */
	DPRINT_DBG(VMBUS, "invalid relid - %d", relid);
	continue;
	} else {
	/* QueueWorkItem(VmbusProcessEvent, (void)relid); /
	/* ret = WorkQueueQueueWorkItem(gVmbusConnection.workQueue, VmbusProcessChannelEvent, (void)relid); /
	VmbusProcessChannelEvent((void *)(unsigned long)relid);
	}
	}
	}
	}
	}
	}
	DPRINT_EXIT(VMBUS);

	return;
	}

	/**
	* VmbusPostMessage - Send a msg on the vmbus's message connection
	*/
	int VmbusPostMessage(void *buffer, size_t bufferLen)
	{
	union hv_connection_id connId;

	connId.Asu32 = 0;
	connId.u.Id = VMBUS_MESSAGE_CONNECTION_ID;
	return HvPostMessage(connId, 1, buffer, bufferLen);
	}

	/**
	* VmbusSetEvent - Send an event notification to the parent
	*/
	int VmbusSetEvent(u32 childRelId)
	{
	int ret = 0;

	DPRINT_ENTER(VMBUS);

	/* Each u32 represents 32 channels */
	set_bit(childRelId & 31,
	(unsigned long *)gVmbusConnection.SendInterruptPage +
	(childRelId >> 5));

	ret = HvSignalEvent();

	DPRINT_EXIT(VMBUS);

	return ret;
	}