Staging: hv: add the Hyper-V virtual block driver

/*

 *

 * 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:

 *   Hank Janssen  <hjanssen@microsoft.com>

 *

 */

#include "../storvsc/StorVsc.c"

static const char* gBlkDriverName="blkvsc";

//{32412632-86cb-44a2-9b5c-50d1417354f5}

static const GUID gBlkVscDeviceType={

	.Data = {0x32, 0x26, 0x41, 0x32, 0xcb, 0x86, 0xa2, 0x44, 0x9b, 0x5c, 0x50, 0xd1, 0x41, 0x73, 0x54, 0xf5}

};

// Static routines

static int

BlkVscOnDeviceAdd(

	DEVICE_OBJECT	*Device,

	void			*AdditionalInfo

	);

int

BlkVscInitialize(

	DRIVER_OBJECT *Driver

	)

{

	STORVSC_DRIVER_OBJECT* storDriver = (STORVSC_DRIVER_OBJECT*)Driver;

	int ret=0;

	DPRINT_ENTER(BLKVSC);

	// Make sure we are at least 2 pages since 1 page is used for control

	ASSERT(storDriver->RingBufferSize >= (PAGE_SIZE << 1));

	Driver->name = gBlkDriverName;

	memcpy(&Driver->deviceType, &gBlkVscDeviceType, sizeof(GUID));

	storDriver->RequestExtSize			= sizeof(STORVSC_REQUEST_EXTENSION);

	// Divide the ring buffer data size (which is 1 page less than the ring buffer size since that page is reserved for the ring buffer indices)

	// by the max request size (which is VMBUS_CHANNEL_PACKET_MULITPAGE_BUFFER + VSTOR_PACKET + UINT64)

	storDriver->MaxOutstandingRequestsPerChannel =

		((storDriver->RingBufferSize - PAGE_SIZE) / ALIGN_UP(MAX_MULTIPAGE_BUFFER_PACKET + sizeof(VSTOR_PACKET) + sizeof(UINT64),sizeof(UINT64)));

	DPRINT_INFO(BLKVSC, "max io outstd %u", storDriver->MaxOutstandingRequestsPerChannel);

	// Setup the dispatch table

	storDriver->Base.OnDeviceAdd		= BlkVscOnDeviceAdd;

	storDriver->Base.OnDeviceRemove		= StorVscOnDeviceRemove;

	storDriver->Base.OnCleanup			= StorVscOnCleanup;

	storDriver->OnIORequest				= StorVscOnIORequest;

	DPRINT_EXIT(BLKVSC);

	return ret;

}

int

BlkVscOnDeviceAdd(

	DEVICE_OBJECT	*Device,

	void			*AdditionalInfo

	)

{

	int ret=0;

	STORVSC_DEVICE_INFO *deviceInfo = (STORVSC_DEVICE_INFO*)AdditionalInfo;

	DPRINT_ENTER(BLKVSC);

	ret = StorVscOnDeviceAdd(Device, AdditionalInfo);

	if (ret != 0)

	{

		DPRINT_EXIT(BLKVSC);

		return ret;

	}

	// We need to use the device instance guid to set the path and target id. For IDE devices, the

	// device instance id is formatted as <bus id> - <device id> - 8899 - 000000000000.

	deviceInfo->PathId = Device->deviceInstance.Data[3] << 24 | Device->deviceInstance.Data[2] << 16 |

		Device->deviceInstance.Data[1] << 8 |Device->deviceInstance.Data[0];

	deviceInfo->TargetId = Device->deviceInstance.Data[5] << 8 | Device->deviceInstance.Data[4];

	DPRINT_EXIT(BLKVSC);

	return ret;

}