From f4802209e59da759b2d1bfcf136d6855984a5d05 Mon Sep 17 00:00:00 2001 From: Tuomas Tynkkynen Date: Mon, 15 Oct 2018 02:21:11 -0700 Subject: virtio: Add block driver support This adds virtio block device driver support. Signed-off-by: Tuomas Tynkkynen Signed-off-by: Bin Meng Reviewed-by: Simon Glass --- drivers/virtio/virtio_blk.h | 129 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 129 insertions(+) create mode 100644 drivers/virtio/virtio_blk.h (limited to 'drivers/virtio/virtio_blk.h') diff --git a/drivers/virtio/virtio_blk.h b/drivers/virtio/virtio_blk.h new file mode 100644 index 0000000000..8d8e02fa2e --- /dev/null +++ b/drivers/virtio/virtio_blk.h @@ -0,0 +1,129 @@ +/* SPDX-License-Identifier: BSD-3-Clause */ +/* + * Copyright (C) 2018, Tuomas Tynkkynen + * Copyright (C) 2018, Bin Meng + * + * From Linux kernel include/uapi/linux/virtio_blk.h + */ + +#ifndef _LINUX_VIRTIO_BLK_H +#define _LINUX_VIRTIO_BLK_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 */ +#ifndef __KERNEL__ +/* Old (deprecated) name for VIRTIO_BLK_F_FLUSH */ +#define VIRTIO_BLK_F_WCE VIRTIO_BLK_F_FLUSH +#endif +#endif /* !VIRTIO_BLK_NO_LEGACY */ + +#define VIRTIO_BLK_ID_BYTES 20 /* ID string length */ + +struct __packed 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; +}; + +/* + * 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 */ -- cgit v1.2.3