/*
 *
 * 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 "logging.h"
#include "VersionInfo.h"
#include "VmbusPrivate.h"

//
// Globals
//
static const char* gDriverName="vmbus";

// Windows vmbus does not defined this. We defined this to be consistent with other devices
//{c5295816-f63a-4d5f-8d1a-4daf999ca185}
static const GUID gVmbusDeviceType={
	.Data = {0x16, 0x58, 0x29, 0xc5, 0x3a, 0xf6, 0x5f, 0x4d, 0x8d, 0x1a, 0x4d, 0xaf, 0x99, 0x9c, 0xa1, 0x85}
};

//{ac3760fc-9adf-40aa-9427-a70ed6de95c5}
static const GUID gVmbusDeviceId={
	.Data = {0xfc, 0x60, 0x37, 0xac, 0xdf, 0x9a, 0xaa, 0x40, 0x94, 0x27, 0xa7, 0x0e, 0xd6, 0xde, 0x95, 0xc5}
};

static DRIVER_OBJECT* gDriver; // vmbus driver object
static DEVICE_OBJECT* gDevice; // vmbus root device


//
// Internal routines
//

static void
VmbusGetChannelInterface(
	VMBUS_CHANNEL_INTERFACE *Interface
	);

static void
VmbusGetChannelInfo(
	DEVICE_OBJECT	*DeviceObject,
	DEVICE_INFO		*DeviceInfo
	);

static void
VmbusGetChannelOffers(
	void
	);

static int
VmbusOnDeviceAdd(
	DEVICE_OBJECT	*Device,
	void			*AdditionalInfo
	);

static int
VmbusOnDeviceRemove(
	DEVICE_OBJECT* dev
	);

static void
VmbusOnCleanup(
	DRIVER_OBJECT* drv
	);

static int
VmbusOnISR(
	DRIVER_OBJECT* drv
	);

static void
VmbusOnMsgDPC(
	DRIVER_OBJECT* drv
	);

static void
VmbusOnEventDPC(
	DRIVER_OBJECT* drv
	);

/*++;

Name:
	VmbusInitialize()

Description:
	Main entry point

--*/
int
VmbusInitialize(
	DRIVER_OBJECT* drv
	)
{
	VMBUS_DRIVER_OBJECT* driver = (VMBUS_DRIVER_OBJECT*)drv;
	int ret=0;

	DPRINT_ENTER(VMBUS);

	DPRINT_INFO(VMBUS, "+++++++ Build Date=%s %s +++++++", VersionDate, VersionTime);
	DPRINT_INFO(VMBUS, "+++++++ Build Description=%s +++++++", VersionDesc);

	DPRINT_INFO(VMBUS, "+++++++ Vmbus supported version = %d +++++++", VMBUS_REVISION_NUMBER);
	DPRINT_INFO(VMBUS, "+++++++ Vmbus using SINT %d +++++++", VMBUS_MESSAGE_SINT);

	DPRINT_DBG(VMBUS, "sizeof(VMBUS_CHANNEL_PACKET_PAGE_BUFFER)=%d, sizeof(VMBUS_CHANNEL_PACKET_MULITPAGE_BUFFER)=%d",
		sizeof(VMBUS_CHANNEL_PACKET_PAGE_BUFFER), sizeof(VMBUS_CHANNEL_PACKET_MULITPAGE_BUFFER));

	drv->name = gDriverName;
	memcpy(&drv->deviceType, &gVmbusDeviceType, sizeof(GUID));

	// Setup dispatch table
	driver->Base.OnDeviceAdd		= VmbusOnDeviceAdd;
	driver->Base.OnDeviceRemove		= VmbusOnDeviceRemove;
	driver->Base.OnCleanup			= VmbusOnCleanup;
	driver->OnIsr					= VmbusOnISR;
	driver->OnMsgDpc				= VmbusOnMsgDPC;
	driver->OnEventDpc				= VmbusOnEventDPC;
	driver->GetChannelOffers		= VmbusGetChannelOffers;
	driver->GetChannelInterface		= VmbusGetChannelInterface;
	driver->GetChannelInfo			= VmbusGetChannelInfo;

	// Hypervisor initialization...setup hypercall page..etc
	ret = HvInit();
	if (ret != 0)
	{
		DPRINT_ERR(VMBUS, "Unable to initialize the hypervisor - 0x%x", ret);
	}

	gDriver = drv;

	DPRINT_EXIT(VMBUS);

	return ret;
}


/*++;

Name:
	VmbusGetChannelOffers()

Description:
	Retrieve the channel offers from the parent partition

--*/

static void
VmbusGetChannelOffers(void)
{
	DPRINT_ENTER(VMBUS);
	VmbusChannelRequestOffers();
	DPRINT_EXIT(VMBUS);
}


/*++;

Name:
	VmbusGetChannelInterface()

Description:
	Get the channel interface

--*/
static void
VmbusGetChannelInterface(
	VMBUS_CHANNEL_INTERFACE *Interface
	)
{
	GetChannelInterface(Interface);
}


/*++;

Name:
	VmbusGetChannelInterface()

Description:
	Get the device info for the specified device object

--*/
static void
VmbusGetChannelInfo(
	DEVICE_OBJECT	*DeviceObject,
	DEVICE_INFO		*DeviceInfo
	)
{
	GetChannelInfo(DeviceObject, DeviceInfo);
}



/*++

Name:
	VmbusCreateChildDevice()

Description:
	Creates the child device on the bus that represents the channel offer

--*/

DEVICE_OBJECT*
VmbusChildDeviceCreate(
	GUID DeviceType,
	GUID DeviceInstance,
	void *Context)
{
	VMBUS_DRIVER_OBJECT* vmbusDriver = (VMBUS_DRIVER_OBJECT*)gDriver;

	return vmbusDriver->OnChildDeviceCreate(
		DeviceType,
		DeviceInstance,
		Context);
}


/*++

Name:
	VmbusChildDeviceAdd()

Description:
	Registers the child device with the vmbus

--*/
int
VmbusChildDeviceAdd(
   DEVICE_OBJECT* ChildDevice)
{
	VMBUS_DRIVER_OBJECT* vmbusDriver = (VMBUS_DRIVER_OBJECT*)gDriver;

	return vmbusDriver->OnChildDeviceAdd(gDevice, ChildDevice);
}


/*++

Name:
	VmbusChildDeviceRemove()

Description:
	Unregisters the child device from the vmbus

--*/
void
VmbusChildDeviceRemove(
   DEVICE_OBJECT* ChildDevice)
{
	VMBUS_DRIVER_OBJECT* vmbusDriver = (VMBUS_DRIVER_OBJECT*)gDriver;

	vmbusDriver->OnChildDeviceRemove(ChildDevice);
}

/*++

Name:
	VmbusChildDeviceDestroy()

Description:
	Release the child device from the vmbus

--*/
//void
//VmbusChildDeviceDestroy(
//	DEVICE_OBJECT* ChildDevice
//	)
//{
//	VMBUS_DRIVER_OBJECT* vmbusDriver = (VMBUS_DRIVER_OBJECT*)gDriver;
//
//	vmbusDriver->OnChildDeviceDestroy(ChildDevice);
//}

/*++

Name:
	VmbusOnDeviceAdd()

Description:
	Callback when the root bus device is added

--*/
static int
VmbusOnDeviceAdd(
	DEVICE_OBJECT	*dev,
	void			*AdditionalInfo
	)
{
	UINT32 *irqvector = (UINT32*) AdditionalInfo;
	int ret=0;

	DPRINT_ENTER(VMBUS);

	gDevice = dev;

	memcpy(&gDevice->deviceType, &gVmbusDeviceType, sizeof(GUID));
	memcpy(&gDevice->deviceInstance, &gVmbusDeviceId, sizeof(GUID));

	//strcpy(dev->name, "vmbus");
	// SynIC setup...
	ret = HvSynicInit(*irqvector);

	// Connect to VMBus in the root partition
	ret = VmbusConnect();

	//VmbusSendEvent(device->localPortId+1);
	DPRINT_EXIT(VMBUS);

	return ret;
}


/*++

Name:
	VmbusOnDeviceRemove()

Description:
	Callback when the root bus device is removed

--*/
int VmbusOnDeviceRemove(
	DEVICE_OBJECT* dev
	)
{
	int ret=0;

	DPRINT_ENTER(VMBUS);

	VmbusChannelReleaseUnattachedChannels();

	VmbusDisconnect();

	HvSynicCleanup();

	DPRINT_EXIT(VMBUS);

	return ret;
}


/*++

Name:
	VmbusOnCleanup()

Description:
	Perform any cleanup when the driver is removed

--*/
void
VmbusOnCleanup(
	DRIVER_OBJECT* drv
	)
{
	//VMBUS_DRIVER_OBJECT* driver = (VMBUS_DRIVER_OBJECT*)drv;

	DPRINT_ENTER(VMBUS);

	HvCleanup();

	DPRINT_EXIT(VMBUS);
}


/*++

Name:
	VmbusOnMsgDPC()

Description:
	DPC routine to handle messages from the hypervisior

--*/
void
VmbusOnMsgDPC(
	DRIVER_OBJECT* drv
	)
{
	void *page_addr = gHvContext.synICMessagePage[0];

	HV_MESSAGE* msg = (HV_MESSAGE*)page_addr + VMBUS_MESSAGE_SINT;
	HV_MESSAGE *copied;
	while (1)
	{
		if (msg->Header.MessageType == HvMessageTypeNone) // no msg
		{
			break;
		}
		else
		{
			copied = MemAllocAtomic(sizeof(HV_MESSAGE));
			if (copied == NULL)
			{
				continue;
			}

			memcpy(copied, msg, sizeof(HV_MESSAGE));
			WorkQueueQueueWorkItem(gVmbusConnection.WorkQueue, VmbusOnChannelMessage, (void*)copied);
		}

		msg->Header.MessageType = HvMessageTypeNone;

		// Make sure the write to MessageType (ie set to HvMessageTypeNone) happens
		// before we read the MessagePending and EOMing. Otherwise, the EOMing will not deliver
		// any more messages since there is no empty slot
		MemoryFence();

		if (msg->Header.MessageFlags.MessagePending)
		{
			// This will cause message queue rescan to possibly deliver another msg from the hypervisor
			WriteMsr(HV_X64_MSR_EOM, 0);
		}
	}
}

/*++

Name:
	VmbusOnEventDPC()

Description:
	DPC routine to handle events from the hypervisior

--*/
void
VmbusOnEventDPC(
	DRIVER_OBJECT* drv
	)
{
	// TODO: Process any events
	VmbusOnEvents();
}


/*++

Name:
	VmbusOnISR()

Description:
	ISR routine

--*/
int
VmbusOnISR(
	DRIVER_OBJECT* drv
	)
{
	//VMBUS_DRIVER_OBJECT* driver = (VMBUS_DRIVER_OBJECT*)drv;

	int ret=0;
	//struct page* page;
	void *page_addr;
	HV_MESSAGE* msg;
	HV_SYNIC_EVENT_FLAGS* event;

	//page = SynICMessagePage[0];
	//page_addr = page_address(page);
	page_addr = gHvContext.synICMessagePage[0];
	msg = (HV_MESSAGE*)page_addr + VMBUS_MESSAGE_SINT;

	DPRINT_ENTER(VMBUS);

	// Check if there are actual msgs to be process
	if (msg->Header.MessageType != HvMessageTypeNone)
    {
		DPRINT_DBG(VMBUS, "received msg type %d size %d", msg->Header.MessageType, msg->Header.PayloadSize);
		ret |= 0x1;
    }

	// TODO: Check if there are events to be process
	page_addr = gHvContext.synICEventPage[0];
	event = (HV_SYNIC_EVENT_FLAGS*)page_addr + VMBUS_MESSAGE_SINT;

	// Since we are a child, we only need to check bit 0
	if (BitTestAndClear(&event->Flags32[0], 0))
	{
		DPRINT_DBG(VMBUS, "received event %d", event->Flags32[0]);
		ret |= 0x2;
	}

	DPRINT_EXIT(VMBUS);
	return ret;
}

// eof