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/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
#ifndef USER_BLK_DRV_CMD_INC_H
#define USER_BLK_DRV_CMD_INC_H
#include <linux/types.h>
/* ublk server command definition */
/*
* Admin commands, issued by ublk server, and handled by ublk driver.
*/
#define UBLK_CMD_GET_QUEUE_AFFINITY 0x01
#define UBLK_CMD_GET_DEV_INFO 0x02
#define UBLK_CMD_ADD_DEV 0x04
#define UBLK_CMD_DEL_DEV 0x05
#define UBLK_CMD_START_DEV 0x06
#define UBLK_CMD_STOP_DEV 0x07
/*
* IO commands, issued by ublk server, and handled by ublk driver.
*
* FETCH_REQ: issued via sqe(URING_CMD) beforehand for fetching IO request
* from ublk driver, should be issued only when starting device. After
* the associated cqe is returned, request's tag can be retrieved via
* cqe->userdata.
*
* COMMIT_AND_FETCH_REQ: issued via sqe(URING_CMD) after ublkserver handled
* this IO request, request's handling result is committed to ublk
* driver, meantime FETCH_REQ is piggyback, and FETCH_REQ has to be
* handled before completing io request.
*/
#define UBLK_IO_FETCH_REQ 0x20
#define UBLK_IO_COMMIT_AND_FETCH_REQ 0x21
/* only ABORT means that no re-fetch */
#define UBLK_IO_RES_OK 0
#define UBLK_IO_RES_ABORT (-ENODEV)
#define UBLKSRV_CMD_BUF_OFFSET 0
#define UBLKSRV_IO_BUF_OFFSET 0x80000000
/* tag bit is 12bit, so at most 4096 IOs for each queue */
#define UBLK_MAX_QUEUE_DEPTH 4096
/*
* zero copy requires 4k block size, and can remap ublk driver's io
* request into ublksrv's vm space
*/
#define UBLK_F_SUPPORT_ZERO_COPY (1UL << 0)
/*
* Force to complete io cmd via io_uring_cmd_complete_in_task so that
* performance comparison is done easily with using task_work_add
*/
#define UBLK_F_URING_CMD_COMP_IN_TASK (1UL << 1)
/* device state */
#define UBLK_S_DEV_DEAD 0
#define UBLK_S_DEV_LIVE 1
/* shipped via sqe->cmd of io_uring command */
struct ublksrv_ctrl_cmd {
/* sent to which device, must be valid */
__u32 dev_id;
/* sent to which queue, must be -1 if the cmd isn't for queue */
__u16 queue_id;
/*
* cmd specific buffer, can be IN or OUT.
*/
__u16 len;
__u64 addr;
/* inline data */
__u64 data[2];
};
struct ublksrv_ctrl_dev_info {
__u16 nr_hw_queues;
__u16 queue_depth;
__u16 block_size;
__u16 state;
__u32 rq_max_blocks;
__u32 dev_id;
__u64 dev_blocks;
__s32 ublksrv_pid;
__s32 reserved0;
__u64 flags[2];
/* For ublksrv internal use, invisible to ublk driver */
__u64 ublksrv_flags;
__u64 reserved1[9];
};
#define UBLK_IO_OP_READ 0
#define UBLK_IO_OP_WRITE 1
#define UBLK_IO_OP_FLUSH 2
#define UBLK_IO_OP_DISCARD 3
#define UBLK_IO_OP_WRITE_SAME 4
#define UBLK_IO_OP_WRITE_ZEROES 5
#define UBLK_IO_F_FAILFAST_DEV (1U << 8)
#define UBLK_IO_F_FAILFAST_TRANSPORT (1U << 9)
#define UBLK_IO_F_FAILFAST_DRIVER (1U << 10)
#define UBLK_IO_F_META (1U << 11)
#define UBLK_IO_F_FUA (1U << 13)
#define UBLK_IO_F_NOUNMAP (1U << 15)
#define UBLK_IO_F_SWAP (1U << 16)
/*
* io cmd is described by this structure, and stored in share memory, indexed
* by request tag.
*
* The data is stored by ublk driver, and read by ublksrv after one fetch command
* returns.
*/
struct ublksrv_io_desc {
/* op: bit 0-7, flags: bit 8-31 */
__u32 op_flags;
__u32 nr_sectors;
/* start sector for this io */
__u64 start_sector;
/* buffer address in ublksrv daemon vm space, from ublk driver */
__u64 addr;
};
static inline __u8 ublksrv_get_op(const struct ublksrv_io_desc *iod)
{
return iod->op_flags & 0xff;
}
static inline __u32 ublksrv_get_flags(const struct ublksrv_io_desc *iod)
{
return iod->op_flags >> 8;
}
/* issued to ublk driver via /dev/ublkcN */
struct ublksrv_io_cmd {
__u16 q_id;
/* for fetch/commit which result */
__u16 tag;
/* io result, it is valid for COMMIT* command only */
__s32 result;
/*
* userspace buffer address in ublksrv daemon process, valid for
* FETCH* command only
*/
__u64 addr;
};
#endif
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