/*
 *
 * 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>
 *
 */


#ifndef _NETVSC_H_
#define _NETVSC_H_

#include <linux/list.h>
#include "VmbusPacketFormat.h"
#include "VmbusChannelInterface.h"
#include "NetVscApi.h"


#define NVSP_INVALID_PROTOCOL_VERSION	((u32)0xFFFFFFFF)

#define NVSP_PROTOCOL_VERSION_1		2
#define NVSP_MIN_PROTOCOL_VERSION	NVSP_PROTOCOL_VERSION_1
#define NVSP_MAX_PROTOCOL_VERSION	NVSP_PROTOCOL_VERSION_1

enum {
	NvspMessageTypeNone = 0,

	/* Init Messages */
	NvspMessageTypeInit			= 1,
	NvspMessageTypeInitComplete		= 2,

	NvspVersionMessageStart			= 100,

	/* Version 1 Messages */
	NvspMessage1TypeSendNdisVersion		= NvspVersionMessageStart,

	NvspMessage1TypeSendReceiveBuffer,
	NvspMessage1TypeSendReceiveBufferComplete,
	NvspMessage1TypeRevokeReceiveBuffer,

	NvspMessage1TypeSendSendBuffer,
	NvspMessage1TypeSendSendBufferComplete,
	NvspMessage1TypeRevokeSendBuffer,

	NvspMessage1TypeSendRNDISPacket,
	NvspMessage1TypeSendRNDISPacketComplete,

	/*
	 * This should be set to the number of messages for the version with
	 * the maximum number of messages.
	 */
	NvspNumMessagePerVersion		= 9,
};

enum {
	NvspStatusNone = 0,
	NvspStatusSuccess,
	NvspStatusFailure,
	NvspStatusProtocolVersionRangeTooNew,
	NvspStatusProtocolVersionRangeTooOld,
	NvspStatusInvalidRndisPacket,
	NvspStatusBusy,
	NvspStatusMax,
};

struct nvsp_message_header {
	u32 MessageType;
};

/* Init Messages */

/*
 * This message is used by the VSC to initialize the channel after the channels
 * has been opened. This message should never include anything other then
 * versioning (i.e. this message will be the same for ever).
 */
struct nvsp_message_init {
	u32 MinProtocolVersion;
	u32 MaxProtocolVersion;
} __attribute__((packed));

/*
 * This message is used by the VSP to complete the initialization of the
 * channel. This message should never include anything other then versioning
 * (i.e. this message will be the same for ever).
 */
struct nvsp_message_init_complete {
	u32 NegotiatedProtocolVersion;
	u32 MaximumMdlChainLength;
	u32 Status;
} __attribute__((packed));

union nvsp_message_init_uber {
	struct nvsp_message_init Init;
	struct nvsp_message_init_complete InitComplete;
} __attribute__((packed));

/* Version 1 Messages */

/*
 * This message is used by the VSC to send the NDIS version to the VSP. The VSP
 * can use this information when handling OIDs sent by the VSC.
 */
struct nvsp_1_message_send_ndis_version {
	u32 NdisMajorVersion;
	u32 NdisMinorVersion;
} __attribute__((packed));

/*
 * This message is used by the VSC to send a receive buffer to the VSP. The VSP
 * can then use the receive buffer to send data to the VSC.
 */
struct nvsp_1_message_send_receive_buffer {
	u32 GpadlHandle;
	u16 Id;
} __attribute__((packed));

struct nvsp_1_receive_buffer_section {
	u32 Offset;
	u32 SubAllocationSize;
	u32 NumSubAllocations;
	u32 EndOffset;
} __attribute__((packed));

/*
 * This message is used by the VSP to acknowledge a receive buffer send by the
 * VSC. This message must be sent by the VSP before the VSP uses the receive
 * buffer.
 */
struct nvsp_1_message_send_receive_buffer_complete {
	u32 Status;
	u32 NumSections;

	/*
	 * The receive buffer is split into two parts, a large suballocation
	 * section and a small suballocation section. These sections are then
	 * suballocated by a certain size.
	 */

	/*
	 * For example, the following break up of the receive buffer has 6
	 * large suballocations and 10 small suballocations.
	 */

	/*
	 * |            Large Section          |  |   Small Section   |
	 * ------------------------------------------------------------
	 * |     |     |     |     |     |     |  | | | | | | | | | | |
	 * |                                      |
	 *  LargeOffset                            SmallOffset
	 */

	struct nvsp_1_receive_buffer_section Sections[1];
} __attribute__((packed));

/*
 * This message is sent by the VSC to revoke the receive buffer.  After the VSP
 * completes this transaction, the vsp should never use the receive buffer
 * again.
 */
struct nvsp_1_message_revoke_receive_buffer {
	u16 Id;
};

/*
 * This message is used by the VSC to send a send buffer to the VSP. The VSC
 * can then use the send buffer to send data to the VSP.
 */
struct nvsp_1_message_send_send_buffer {
	u32 GpadlHandle;
	u16 Id;
} __attribute__((packed));

/*
 * This message is used by the VSP to acknowledge a send buffer sent by the
 * VSC. This message must be sent by the VSP before the VSP uses the sent
 * buffer.
 */
struct nvsp_1_message_send_send_buffer_complete {
	u32 Status;

	/*
	 * The VSC gets to choose the size of the send buffer and the VSP gets
	 * to choose the sections size of the buffer.  This was done to enable
	 * dynamic reconfigurations when the cost of GPA-direct buffers
	 * decreases.
	 */
	u32 SectionSize;
} __attribute__((packed));

/*
 * This message is sent by the VSC to revoke the send buffer.  After the VSP
 * completes this transaction, the vsp should never use the send buffer again.
 */
struct nvsp_1_message_revoke_send_buffer {
	u16 Id;
};

/*
 * This message is used by both the VSP and the VSC to send a RNDIS message to
 * the opposite channel endpoint.
 */
struct nvsp_1_message_send_rndis_packet {
	/*
	 * This field is specified by RNIDS. They assume there's two different
	 * channels of communication. However, the Network VSP only has one.
	 * Therefore, the channel travels with the RNDIS packet.
	 */
	u32 ChannelType;

	/*
	 * This field is used to send part or all of the data through a send
	 * buffer. This values specifies an index into the send buffer. If the
	 * index is 0xFFFFFFFF, then the send buffer is not being used and all
	 * of the data was sent through other VMBus mechanisms.
	 */
	u32 SendBufferSectionIndex;
	u32 SendBufferSectionSize;
} __attribute__((packed));

/*
 * This message is used by both the VSP and the VSC to complete a RNDIS message
 * to the opposite channel endpoint. At this point, the initiator of this
 * message cannot use any resources associated with the original RNDIS packet.
 */
struct nvsp_1_message_send_rndis_packet_complete {
	u32 Status;
};

union nvsp_1_message_uber {
	struct nvsp_1_message_send_ndis_version SendNdisVersion;

	struct nvsp_1_message_send_receive_buffer SendReceiveBuffer;
	struct nvsp_1_message_send_receive_buffer_complete
						SendReceiveBufferComplete;
	struct nvsp_1_message_revoke_receive_buffer RevokeReceiveBuffer;

	struct nvsp_1_message_send_send_buffer SendSendBuffer;
	struct nvsp_1_message_send_send_buffer_complete SendSendBufferComplete;
	struct nvsp_1_message_revoke_send_buffer RevokeSendBuffer;

	struct nvsp_1_message_send_rndis_packet SendRNDISPacket;
	struct nvsp_1_message_send_rndis_packet_complete
						SendRNDISPacketComplete;
} __attribute__((packed));

union nvsp_all_messages {
	union nvsp_message_init_uber InitMessages;
	union nvsp_1_message_uber Version1Messages;
} __attribute__((packed));

/* ALL Messages */
struct nvsp_message {
	struct nvsp_message_header Header;
	union nvsp_all_messages Messages;
} __attribute__((packed));


/* #define NVSC_MIN_PROTOCOL_VERSION		1 */
/* #define NVSC_MAX_PROTOCOL_VERSION		1 */

#define NETVSC_SEND_BUFFER_SIZE			(64*1024)	/* 64K */
#define NETVSC_SEND_BUFFER_ID			0xface


#define NETVSC_RECEIVE_BUFFER_SIZE		(1024*1024)	/* 1MB */

#define NETVSC_RECEIVE_BUFFER_ID		0xcafe

#define NETVSC_RECEIVE_SG_COUNT			1

/* Preallocated receive packets */
#define NETVSC_RECEIVE_PACKETLIST_COUNT		256


/* Per netvsc channel-specific */
struct netvsc_device {
	struct hv_device *Device;

	atomic_t RefCount;
	atomic_t NumOutstandingSends;
	/*
	 * List of free preallocated hv_netvsc_packet to represent receive
	 * packet
	 */
	struct list_head ReceivePacketList;
	spinlock_t receive_packet_list_lock;

	/* Send buffer allocated by us but manages by NetVSP */
	void *SendBuffer;
	u32 SendBufferSize;
	u32 SendBufferGpadlHandle;
	u32 SendSectionSize;

	/* Receive buffer allocated by us but manages by NetVSP */
	void *ReceiveBuffer;
	u32 ReceiveBufferSize;
	u32 ReceiveBufferGpadlHandle;
	u32 ReceiveSectionCount;
	struct nvsp_1_receive_buffer_section *ReceiveSections;

	/* Used for NetVSP initialization protocol */
	struct osd_waitevent *ChannelInitEvent;
	struct nvsp_message ChannelInitPacket;

	struct nvsp_message RevokePacket;
	/* unsigned char HwMacAddr[HW_MACADDR_LEN]; */

	/* Holds rndis device info */
	void *Extension;
};

#endif /* _NETVSC_H_ */