1 #ifndef _LINUX_VIRTIO_BLK_H 2 #define _LINUX_VIRTIO_BLK_H 3 /* This header is BSD licensed so anyone can use the definitions to implement 4 * compatible drivers/servers. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. Neither the name of IBM nor the names of its contributors 15 * may be used to endorse or promote products derived from this software 16 * without specific prior written permission. 17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. */ 28 #if 0 29 #include <linux/types.h> 30 #include <linux/virtio_ids.h> 31 #include <linux/virtio_config.h> 32 #endif 33 34 /* Feature bits */ 35 #define VIRTIO_BLK_F_BARRIER 0 /* Does host support barriers? */ 36 #define VIRTIO_BLK_F_SIZE_MAX 1 /* Indicates maximum segment size */ 37 #define VIRTIO_BLK_F_SEG_MAX 2 /* Indicates maximum # of segments */ 38 #define VIRTIO_BLK_F_GEOMETRY 4 /* Legacy geometry available */ 39 #define VIRTIO_BLK_F_RO 5 /* Disk is read-only */ 40 #define VIRTIO_BLK_F_BLK_SIZE 6 /* Block size of disk is available*/ 41 #define VIRTIO_BLK_F_SCSI 7 /* Supports scsi command passthru */ 42 #define VIRTIO_BLK_F_FLUSH 9 /* Cache flush command support */ 43 #define VIRTIO_BLK_F_TOPOLOGY 10 /* Topology information is available */ 44 45 #define VIRTIO_BLK_ID_BYTES 20 /* ID string length */ 46 47 struct virtio_blk_config { 48 /* The capacity (in 512-byte sectors). */ 49 u64_t capacity; 50 /* The maximum segment size (if VIRTIO_BLK_F_SIZE_MAX) */ 51 u32_t size_max; 52 /* The maximum number of segments (if VIRTIO_BLK_F_SEG_MAX) */ 53 u32_t seg_max; 54 /* geometry the device (if VIRTIO_BLK_F_GEOMETRY) */ 55 struct virtio_blk_geometry { 56 u16_t cylinders; 57 u8_t heads; 58 u8_t sectors; 59 } geometry; 60 61 /* block size of device (if VIRTIO_BLK_F_BLK_SIZE) */ 62 u32_t blk_size; 63 64 /* the next 4 entries are guarded by VIRTIO_BLK_F_TOPOLOGY */ 65 /* exponent for physical block per logical block. */ 66 u8_t physical_block_exp; 67 /* alignment offset in logical blocks. */ 68 u8_t alignment_offset; 69 /* minimum I/O size without performance penalty in logical blocks. */ 70 u16_t min_io_size; 71 /* optimal sustained I/O size in logical blocks. */ 72 u32_t opt_io_size; 73 74 } __attribute__((packed)); 75 76 /* 77 * Command types 78 * 79 * Usage is a bit tricky as some bits are used as flags and some are not. 80 * 81 * Rules: 82 * VIRTIO_BLK_T_OUT may be combined with VIRTIO_BLK_T_SCSI_CMD or 83 * VIRTIO_BLK_T_BARRIER. VIRTIO_BLK_T_FLUSH is a command of its own 84 * and may not be combined with any of the other flags. 85 */ 86 87 /* These two define direction. */ 88 #define VIRTIO_BLK_T_IN 0 89 #define VIRTIO_BLK_T_OUT 1 90 91 /* This bit says it's a scsi command, not an actual read or write. */ 92 #define VIRTIO_BLK_T_SCSI_CMD 2 93 94 /* Cache flush command */ 95 #define VIRTIO_BLK_T_FLUSH 4 96 97 /* Get device ID command */ 98 #define VIRTIO_BLK_T_GET_ID 8 99 100 /* Barrier before this op. */ 101 #define VIRTIO_BLK_T_BARRIER 0x80000000 102 103 /* This is the first element of the read scatter-gather list. */ 104 struct virtio_blk_outhdr { 105 /* VIRTIO_BLK_T* */ 106 u32_t type; 107 /* io priority. */ 108 u32_t ioprio; 109 /* Sector (ie. 512 byte offset) */ 110 u64_t sector; 111 }; 112 113 struct virtio_scsi_inhdr { 114 u32_t errors; 115 u32_t data_len; 116 u32_t sense_len; 117 u32_t residual; 118 }; 119 120 /* And this is the final byte of the write scatter-gather list. */ 121 #define VIRTIO_BLK_S_OK 0 122 #define VIRTIO_BLK_S_IOERR 1 123 #define VIRTIO_BLK_S_UNSUPP 2 124 #endif /* _LINUX_VIRTIO_BLK_H */ 125