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		4cb2ea28c5
		
	
	
	
	
		
			
			Add virtio-blk device id (s/n) support via virtio request. Signed-off-by: john cooper <john.cooper@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
		
			
				
	
	
		
			100 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			100 lines
		
	
	
		
			2.9 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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| #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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| 
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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_FLUSH	9	/* Cache flush command support */
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| #define VIRTIO_BLK_F_TOPOLOGY	10	/* Topology information is available */
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| 
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| #define VIRTIO_BLK_ID_BYTES	20	/* ID string length */
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| 
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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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| 
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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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| 
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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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| 
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| } __attribute__((packed));
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| 
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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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| 
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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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| 
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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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| 
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| /* Cache flush command */
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| #define VIRTIO_BLK_T_FLUSH	4
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| 
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| /* Get device ID command */
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| #define VIRTIO_BLK_T_GET_ID    8
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| 
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| /* Barrier before this op. */
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| #define VIRTIO_BLK_T_BARRIER	0x80000000
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| 
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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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| 
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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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| 
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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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