Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Michael Kerrisk <mtk.manpages@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Dave Jones <davej@redhat.com>
		
			
				
	
	
		
			130 lines
		
	
	
	
		
			4.6 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			130 lines
		
	
	
	
		
			4.6 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
#ifndef _LINUX_VIRTIO_BLK_H
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#define _LINUX_VIRTIO_BLK_H
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/* This header is BSD licensed so anyone can use the definitions to implement
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 * compatible drivers/servers.
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions
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 * are met:
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 * 1. Redistributions of source code must retain the above copyright
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 *    notice, this list of conditions and the following disclaimer.
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 * 2. Redistributions in binary form must reproduce the above copyright
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 *    notice, this list of conditions and the following disclaimer in the
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 *    documentation and/or other materials provided with the distribution.
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 * 3. Neither the name of IBM nor the names of its contributors
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 *    may be used to endorse or promote products derived from this software
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 *    without specific prior written permission.
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND
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 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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 * ARE DISCLAIMED.  IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE
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 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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 * SUCH DAMAGE. */
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#include <linux/types.h>
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#include <linux/virtio_ids.h>
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#include <linux/virtio_config.h>
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/* Feature bits */
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#define VIRTIO_BLK_F_BARRIER	0	/* Does host support barriers? */
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#define VIRTIO_BLK_F_SIZE_MAX	1	/* Indicates maximum segment size */
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#define VIRTIO_BLK_F_SEG_MAX	2	/* Indicates maximum # of segments */
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#define VIRTIO_BLK_F_GEOMETRY	4	/* Legacy geometry available  */
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#define VIRTIO_BLK_F_RO		5	/* Disk is read-only */
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#define VIRTIO_BLK_F_BLK_SIZE	6	/* Block size of disk is available*/
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#define VIRTIO_BLK_F_SCSI	7	/* Supports scsi command passthru */
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#define VIRTIO_BLK_F_WCE	9	/* Writeback mode enabled after reset */
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#define VIRTIO_BLK_F_TOPOLOGY	10	/* Topology information is available */
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#define VIRTIO_BLK_F_CONFIG_WCE	11	/* Writeback mode available in config */
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#ifndef __KERNEL__
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/* Old (deprecated) name for VIRTIO_BLK_F_WCE. */
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#define VIRTIO_BLK_F_FLUSH VIRTIO_BLK_F_WCE
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#endif
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#define VIRTIO_BLK_ID_BYTES	20	/* ID string length */
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struct virtio_blk_config {
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	/* The capacity (in 512-byte sectors). */
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	__u64 capacity;
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	/* The maximum segment size (if VIRTIO_BLK_F_SIZE_MAX) */
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	__u32 size_max;
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	/* The maximum number of segments (if VIRTIO_BLK_F_SEG_MAX) */
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	__u32 seg_max;
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	/* geometry the device (if VIRTIO_BLK_F_GEOMETRY) */
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	struct virtio_blk_geometry {
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		__u16 cylinders;
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		__u8 heads;
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		__u8 sectors;
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	} geometry;
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	/* block size of device (if VIRTIO_BLK_F_BLK_SIZE) */
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	__u32 blk_size;
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	/* the next 4 entries are guarded by VIRTIO_BLK_F_TOPOLOGY  */
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	/* exponent for physical block per logical block. */
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	__u8 physical_block_exp;
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	/* alignment offset in logical blocks. */
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	__u8 alignment_offset;
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	/* minimum I/O size without performance penalty in logical blocks. */
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	__u16 min_io_size;
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	/* optimal sustained I/O size in logical blocks. */
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	__u32 opt_io_size;
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	/* writeback mode (if VIRTIO_BLK_F_CONFIG_WCE) */
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	__u8 wce;
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} __attribute__((packed));
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/*
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 * Command types
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 *
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 * Usage is a bit tricky as some bits are used as flags and some are not.
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 *
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 * Rules:
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 *   VIRTIO_BLK_T_OUT may be combined with VIRTIO_BLK_T_SCSI_CMD or
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 *   VIRTIO_BLK_T_BARRIER.  VIRTIO_BLK_T_FLUSH is a command of its own
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 *   and may not be combined with any of the other flags.
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 */
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/* These two define direction. */
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#define VIRTIO_BLK_T_IN		0
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#define VIRTIO_BLK_T_OUT	1
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/* This bit says it's a scsi command, not an actual read or write. */
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#define VIRTIO_BLK_T_SCSI_CMD	2
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/* Cache flush command */
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#define VIRTIO_BLK_T_FLUSH	4
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/* Get device ID command */
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#define VIRTIO_BLK_T_GET_ID    8
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/* Barrier before this op. */
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#define VIRTIO_BLK_T_BARRIER	0x80000000
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/* This is the first element of the read scatter-gather list. */
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struct virtio_blk_outhdr {
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	/* VIRTIO_BLK_T* */
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	__u32 type;
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	/* io priority. */
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	__u32 ioprio;
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	/* Sector (ie. 512 byte offset) */
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	__u64 sector;
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};
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struct virtio_scsi_inhdr {
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	__u32 errors;
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	__u32 data_len;
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	__u32 sense_len;
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	__u32 residual;
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};
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/* And this is the final byte of the write scatter-gather list. */
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#define VIRTIO_BLK_S_OK		0
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#define VIRTIO_BLK_S_IOERR	1
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#define VIRTIO_BLK_S_UNSUPP	2
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#endif /* _LINUX_VIRTIO_BLK_H */
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