include: add local virtio_blk.h

#ifndef _LINUX_VIRTIO_BLK_H

#define _LINUX_VIRTIO_BLK_H

/* This header is BSD licensed so anyone can use the definitions to implement

 * compatible drivers/servers.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 * 3. Neither the name of IBM nor the names of its contributors

 *    may be used to endorse or promote products derived from this software

 *    without specific prior written permission.

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND

 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED.  IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE

 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

 * SUCH DAMAGE. */

#include <linux/types.h>

#include <linux/virtio_ids.h>

#include <linux/virtio_config.h>

#include <linux/virtio_types.h>

/* Feature bits */

#define VIRTIO_BLK_F_SIZE_MAX	1	/* Indicates maximum segment size */

#define VIRTIO_BLK_F_SEG_MAX	2	/* Indicates maximum # of segments */

#define VIRTIO_BLK_F_GEOMETRY	4	/* Legacy geometry available  */

#define VIRTIO_BLK_F_RO		5	/* Disk is read-only */

#define VIRTIO_BLK_F_BLK_SIZE	6	/* Block size of disk is available */

#define VIRTIO_BLK_F_TOPOLOGY	10	/* Topology information is available */

#define VIRTIO_BLK_F_MQ		12	/* support more than one vq */

/* Legacy feature bits */

#ifndef VIRTIO_BLK_NO_LEGACY

#define VIRTIO_BLK_F_BARRIER	0	/* Does host support barriers? */

#define VIRTIO_BLK_F_SCSI	7	/* Supports scsi command passthru */

#define VIRTIO_BLK_F_FLUSH	9	/* Flush command supported */

#define VIRTIO_BLK_F_CONFIG_WCE	11	/* Writeback mode available in config */

/* Old (deprecated) name for VIRTIO_BLK_F_FLUSH. */

#define VIRTIO_BLK_F_WCE VIRTIO_BLK_F_FLUSH

#endif /* !VIRTIO_BLK_NO_LEGACY */

#define VIRTIO_BLK_ID_BYTES	20	/* ID string length */

struct virtio_blk_config {

	/* The capacity (in 512-byte sectors). */

	__u64 capacity;

	/* The maximum segment size (if VIRTIO_BLK_F_SIZE_MAX) */

	__u32 size_max;

	/* The maximum number of segments (if VIRTIO_BLK_F_SEG_MAX) */

	__u32 seg_max;

	/* geometry of the device (if VIRTIO_BLK_F_GEOMETRY) */

	struct virtio_blk_geometry {

		__u16 cylinders;

		__u8 heads;

		__u8 sectors;

	} geometry;

	/* block size of device (if VIRTIO_BLK_F_BLK_SIZE) */

	__u32 blk_size;

	/* the next 4 entries are guarded by VIRTIO_BLK_F_TOPOLOGY  */

	/* exponent for physical block per logical block. */

	__u8 physical_block_exp;

	/* alignment offset in logical blocks. */

	__u8 alignment_offset;

	/* minimum I/O size without performance penalty in logical blocks. */

	__u16 min_io_size;

	/* optimal sustained I/O size in logical blocks. */

	__u32 opt_io_size;

	/* writeback mode (if VIRTIO_BLK_F_CONFIG_WCE) */

	__u8 wce;

	__u8 unused;

	/* number of vqs, only available when VIRTIO_BLK_F_MQ is set */

	__u16 num_queues;

} __attribute__((packed));

/*

 * Command types

 *

 * Usage is a bit tricky as some bits are used as flags and some are not.

 *

 * Rules:

 *   VIRTIO_BLK_T_OUT may be combined with VIRTIO_BLK_T_SCSI_CMD or

 *   VIRTIO_BLK_T_BARRIER.  VIRTIO_BLK_T_FLUSH is a command of its own

 *   and may not be combined with any of the other flags.

 */

/* These two define direction. */

#define VIRTIO_BLK_T_IN		0

#define VIRTIO_BLK_T_OUT	1

#ifndef VIRTIO_BLK_NO_LEGACY

/* This bit says it's a scsi command, not an actual read or write. */

#define VIRTIO_BLK_T_SCSI_CMD	2

#endif /* VIRTIO_BLK_NO_LEGACY */

/* Cache flush command */

#define VIRTIO_BLK_T_FLUSH	4

/* Get device ID command */

#define VIRTIO_BLK_T_GET_ID    8

#ifndef VIRTIO_BLK_NO_LEGACY

/* Barrier before this op. */

#define VIRTIO_BLK_T_BARRIER	0x80000000

#endif /* !VIRTIO_BLK_NO_LEGACY */

/*

 * This comes first in the read scatter-gather list.

 * For legacy virtio, if VIRTIO_F_ANY_LAYOUT is not negotiated,

 * this is the first element of the read scatter-gather list.

 */

struct virtio_blk_outhdr {

	/* VIRTIO_BLK_T* */

	__virtio32 type;

	/* io priority. */

	__virtio32 ioprio;

	/* Sector (ie. 512 byte offset) */

	__virtio64 sector;

};

#ifndef VIRTIO_BLK_NO_LEGACY

struct virtio_scsi_inhdr {

	__virtio32 errors;

	__virtio32 data_len;

	__virtio32 sense_len;

	__virtio32 residual;

};

#endif /* !VIRTIO_BLK_NO_LEGACY */

/* And this is the final byte of the write scatter-gather list. */

#define VIRTIO_BLK_S_OK		0

#define VIRTIO_BLK_S_IOERR	1

#define VIRTIO_BLK_S_UNSUPP	2

#endif /* _LINUX_VIRTIO_BLK_H */