#ifndef _GPXE_AOE_H
#define _GPXE_AOE_H

/** @file
 *
 * AoE protocol
 *
 */

#include <stdint.h>
#include <gpxe/list.h>
#include <gpxe/if_ether.h>
#include <gpxe/ata.h>

/** An AoE ATA command */
struct aoecmd {
	/** AoE command flags */
	uint8_t aflags;
	/** ATA error/feature register */
	uint8_t err_feat;
	/** ATA sector count register */
	uint8_t count;
	/** ATA command/status register */
	uint8_t cmd_stat;
	/** Logical block address, in little-endian order */
	union {
		uint64_t u64;
		uint8_t bytes[6];
	} lba;
	/** Data payload */
	uint8_t data[0];
} __attribute__ (( packed ));

#define AOE_FL_EXTENDED	0x40	/**< LBA48 extended addressing */
#define AOE_FL_DEV_HEAD	0x10	/**< Device/head flag */
#define AOE_FL_ASYNC	0x02	/**< Asynchronous write */
#define AOE_FL_WRITE	0x01	/**< Write command */

/** An AoE header */
struct aoehdr {
	/** Protocol version number and flags */
	uint8_t ver_flags;
	/** Error code */
	uint8_t error;
	/** Major device number, in network byte order */
	uint16_t major;
	/** Minor device number */
	uint8_t minor;
	/** Command number */
	uint8_t command;
	/** Tag, in network byte order */
	uint32_t tag;
	/** Payload */
	union {
		/** ATA command */
		struct aoecmd command[0];
	} arg;
} __attribute__ (( packed ));

#define AOE_VERSION	0x10	/**< Version 1 */
#define AOE_VERSION_MASK 0xf0	/**< Version part of ver_flags field */

#define AOE_FL_RESPONSE	0x08	/**< Message is a response */
#define AOE_FL_ERROR	0x04	/**< Command generated an error */

#define AOE_MAJOR_BROADCAST 0xffff
#define AOE_MINOR_BROADCAST 0xff

#define AOE_CMD_ATA	0x00	/**< Issue ATA command */
#define AOE_CMD_CONFIG	0x01	/**< Query Config Information */

#define AOE_ERR_BAD_COMMAND	1 /**< Unrecognised command code */
#define AOE_ERR_BAD_PARAMETER	2 /**< Bad argument parameter */
#define AOE_ERR_UNAVAILABLE	3 /**< Device unavailable */
#define AOE_ERR_CONFIG_EXISTS	4 /**< Config string present */
#define AOE_ERR_BAD_VERSION	5 /**< Unsupported version */

/** An AoE session */
struct aoe_session {
	/** List of all AoE sessions */
	struct list_head list;

	/** Network device */
	struct net_device *netdev;
	/** Major number */
	uint16_t major;
	/** Minor number */
	uint8_t minor;
	/** Target MAC address */
	uint8_t target[ETH_ALEN];

	/** Tag for current command */
	uint32_t tag;
	/** Current ATA command */
	struct ata_command *command;
	/** Status of the command */
	int status;
	/** Byte offset within command's data buffer */
	unsigned int command_offset;
};

#define AOE_STATUS_ERR_MASK	0x0f /**< Error portion of status code */ 
#define AOE_STATUS_PENDING	0x80 /**< Command pending */
#define AOE_STATUS_UNDERRUN	0x40 /**< Buffer overrun */
#define AOE_STATUS_OVERRUN	0x20 /**< Buffer underrun */

/** Maximum number of sectors per packet */
#define AOE_MAX_COUNT 2

extern void aoe_open ( struct aoe_session *aoe );
extern void aoe_close ( struct aoe_session *aoe );
extern int aoe_issue ( struct aoe_session *aoe, struct ata_command *command );
extern int aoe_issue_split ( struct aoe_session *aoe,
			     struct ata_command *command );

/** An AoE device */
struct aoe_device {
	/** ATA device interface */
	struct ata_device ata;
	/** AoE protocol instance */
	struct aoe_session aoe;
};

extern int init_aoedev ( struct aoe_device *aoedev );

#endif /* _GPXE_AOE_H */