/*
 *
 * 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>
 *
 */


#ifndef _NETVSC_H_
#define _NETVSC_H_

#include <linux/list.h>
#include "vmbus_packet_format.h"
#include "vmbus_channel_interface.h"
#include "netvsc_api.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 {
	NVSP_MSG_TYPE_NONE = 0,

	/* Init Messages */
	NVSP_MSG_TYPE_INIT			= 1,
	NVSP_MSG_TYPE_INIT_COMPLETE		= 2,

	NVSP_VERSION_MSG_START			= 100,

	/* Version 1 Messages */
	NVSP_MSG1_TYPE_SEND_NDIS_VER		= NVSP_VERSION_MSG_START,

	NVSP_MSG1_TYPE_SEND_RECV_BUF,
	NVSP_MSG1_TYPE_SEND_RECV_BUF_COMPLETE,
	NVSP_MSG1_TYPE_REVOKE_RECV_BUF,

	NVSP_MSG1_TYPE_SEND_SEND_BUF,
	NVSP_MSG1_TYPE_SEND_SEND_BUF_COMPLETE,
	NVSP_MSG1_TYPE_REVOKE_SEND_BUF,

	NVSP_MSG1_TYPE_SEND_RNDIS_PKT,
	NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE,

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

enum {
	NVSP_STAT_NONE = 0,
	NVSP_STAT_SUCCESS,
	NVSP_STAT_FAIL,
	NVSP_STAT_PROTOCOL_TOO_NEW,
	NVSP_STAT_PROTOCOL_TOO_OLD,
	NVSP_STAT_INVALID_RNDIS_PKT,
	NVSP_STAT_BUSY,
	NVSP_STAT_MAX,
};

struct nvsp_message_header {
	u32 msg_type;
};

/* 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 min_protocol_ver;
	u32 max_protocol_ver;
} __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 negotiated_protocol_ver;
	u32 max_mdl_chain_len;
	u32 status;
} __packed;

union nvsp_message_init_uber {
	struct nvsp_message_init init;
	struct nvsp_message_init_complete init_complete;
} __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 ndis_major_ver;
	u32 ndis_minor_ver;
} __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 gpadl_handle;
	u16 id;
} __packed;

struct nvsp_1_receive_buffer_section {
	u32 offset;
	u32 sub_alloc_size;
	u32 num_sub_allocs;
	u32 end_offset;
} __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 num_sections;

	/*
	 * 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];
} __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 gpadl_handle;
	u16 id;
} __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 section_size;
} __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 channel_type;

	/*
	 * 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 send_buf_section_index;
	u32 send_buf_section_size;
} __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 send_ndis_ver;

	struct nvsp_1_message_send_receive_buffer send_recv_buf;
	struct nvsp_1_message_send_receive_buffer_complete
						send_recv_buf_complete;
	struct nvsp_1_message_revoke_receive_buffer revoke_recv_buf;

	struct nvsp_1_message_send_send_buffer send_send_buf;
	struct nvsp_1_message_send_send_buffer_complete send_send_buf_complete;
	struct nvsp_1_message_revoke_send_buffer revoke_send_buf;

	struct nvsp_1_message_send_rndis_packet send_rndis_pkt;
	struct nvsp_1_message_send_rndis_packet_complete
						send_rndis_pkt_complete;
} __packed;

union nvsp_all_messages {
	union nvsp_message_init_uber init_msg;
	union nvsp_1_message_uber v1_msg;
} __packed;

/* ALL Messages */
struct nvsp_message {
	struct nvsp_message_header hdr;
	union nvsp_all_messages msg;
} __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

#define NETVSC_PACKET_SIZE                      2048

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

	atomic_t refcnt;
	atomic_t num_outstanding_sends;
	/*
	 * List of free preallocated hv_netvsc_packet to represent receive
	 * packet
	 */
	struct list_head recv_pkt_list;
	spinlock_t recv_pkt_list_lock;

	/* Send buffer allocated by us but manages by NetVSP */
	void *send_buf;
	u32 send_buf_size;
	u32 send_buf_gpadl_handle;
	u32 send_section_size;

	/* Receive buffer allocated by us but manages by NetVSP */
	void *recv_buf;
	u32 recv_buf_size;
	u32 recv_buf_gpadl_handle;
	u32 recv_section_cnt;
	struct nvsp_1_receive_buffer_section *recv_section;

	/* Used for NetVSP initialization protocol */
	int wait_condition;
	wait_queue_head_t channel_init_wait;
	struct nvsp_message channel_init_pkt;

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

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

#endif /* _NETVSC_H_ */