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/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
#ifndef __TARGET_CORE_USER_H
#define __TARGET_CORE_USER_H
/* This header will be used by application too */
#include <linux/types.h>
#include <linux/uio.h>
#define TCMU_VERSION "2.0"
/**
* DOC: Ring Design
* Ring Design
* -----------
*
* The mmaped area is divided into three parts:
* 1) The mailbox (struct tcmu_mailbox, below);
* 2) The command ring;
* 3) Everything beyond the command ring (data).
*
* The mailbox tells userspace the offset of the command ring from the
* start of the shared memory region, and how big the command ring is.
*
* The kernel passes SCSI commands to userspace by putting a struct
* tcmu_cmd_entry in the ring, updating mailbox->cmd_head, and poking
* userspace via UIO's interrupt mechanism.
*
* tcmu_cmd_entry contains a header. If the header type is PAD,
* userspace should skip hdr->length bytes (mod cmdr_size) to find the
* next cmd_entry.
*
* Otherwise, the entry will contain offsets into the mmaped area that
* contain the cdb and data buffers -- the latter accessible via the
* iov array. iov addresses are also offsets into the shared area.
*
* When userspace is completed handling the command, set
* entry->rsp.scsi_status, fill in rsp.sense_buffer if appropriate,
* and also set mailbox->cmd_tail equal to the old cmd_tail plus
* hdr->length, mod cmdr_size. If cmd_tail doesn't equal cmd_head, it
* should process the next packet the same way, and so on.
*/
#define TCMU_MAILBOX_VERSION 2
#define ALIGN_SIZE 64 /* Should be enough for most CPUs */
#define TCMU_MAILBOX_FLAG_CAP_OOOC (1 << 0) /* Out-of-order completions */
struct tcmu_mailbox {
__u16 version;
__u16 flags;
__u32 cmdr_off;
__u32 cmdr_size;
__u32 cmd_head;
/* Updated by user. On its own cacheline */
__u32 cmd_tail __attribute__((__aligned__(ALIGN_SIZE)));
} __packed;
enum tcmu_opcode {
TCMU_OP_PAD = 0,
TCMU_OP_CMD,
};
/*
* Only a few opcodes, and length is 8-byte aligned, so use low bits for opcode.
*/
struct tcmu_cmd_entry_hdr {
__u32 len_op;
__u16 cmd_id;
__u8 kflags;
#define TCMU_UFLAG_UNKNOWN_OP 0x1
__u8 uflags;
} __packed;
#define TCMU_OP_MASK 0x7
static inline enum tcmu_opcode tcmu_hdr_get_op(__u32 len_op)
{
return len_op & TCMU_OP_MASK;
}
static inline void tcmu_hdr_set_op(__u32 *len_op, enum tcmu_opcode op)
{
*len_op &= ~TCMU_OP_MASK;
*len_op |= (op & TCMU_OP_MASK);
}
static inline __u32 tcmu_hdr_get_len(__u32 len_op)
{
return len_op & ~TCMU_OP_MASK;
}
static inline void tcmu_hdr_set_len(__u32 *len_op, __u32 len)
{
*len_op &= TCMU_OP_MASK;
*len_op |= len;
}
/* Currently the same as SCSI_SENSE_BUFFERSIZE */
#define TCMU_SENSE_BUFFERSIZE 96
struct tcmu_cmd_entry {
struct tcmu_cmd_entry_hdr hdr;
union {
struct {
__u32 iov_cnt;
__u32 iov_bidi_cnt;
__u32 iov_dif_cnt;
__u64 cdb_off;
__u64 __pad1;
__u64 __pad2;
struct iovec iov[0];
} req;
struct {
__u8 scsi_status;
__u8 __pad1;
__u16 __pad2;
__u32 __pad3;
char sense_buffer[TCMU_SENSE_BUFFERSIZE];
} rsp;
};
} __packed;
#define TCMU_OP_ALIGN_SIZE sizeof(__u64)
enum tcmu_genl_cmd {
TCMU_CMD_UNSPEC,
TCMU_CMD_ADDED_DEVICE,
TCMU_CMD_REMOVED_DEVICE,
TCMU_CMD_RECONFIG_DEVICE,
TCMU_CMD_ADDED_DEVICE_DONE,
TCMU_CMD_REMOVED_DEVICE_DONE,
TCMU_CMD_RECONFIG_DEVICE_DONE,
TCMU_CMD_SET_FEATURES,
__TCMU_CMD_MAX,
};
#define TCMU_CMD_MAX (__TCMU_CMD_MAX - 1)
enum tcmu_genl_attr {
TCMU_ATTR_UNSPEC,
TCMU_ATTR_DEVICE,
TCMU_ATTR_MINOR,
TCMU_ATTR_PAD,
TCMU_ATTR_DEV_CFG,
TCMU_ATTR_DEV_SIZE,
TCMU_ATTR_WRITECACHE,
TCMU_ATTR_CMD_STATUS,
TCMU_ATTR_DEVICE_ID,
TCMU_ATTR_SUPP_KERN_CMD_REPLY,
__TCMU_ATTR_MAX,
};
#define TCMU_ATTR_MAX (__TCMU_ATTR_MAX - 1)
#endif
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