[linux-block.git] / include / uapi / linux / target_core_user.h

/* 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 */
#define TCMU_MAILBOX_FLAG_CAP_READ_LEN (1 << 1) /* Read data length */

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
#define TCMU_UFLAG_READ_LEN   0x2
	__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 read_len;
			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
Commit	Line	Data
6f52b16c	1	/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
7c9e7a6f AG	2	#ifndef __TARGET_CORE_USER_H
	3	#define __TARGET_CORE_USER_H
	4
	5	/* This header will be used by application too */
	6
	7	#include <linux/types.h>
	8	#include <linux/uio.h>
	9
0ad46af8	10	#define TCMU_VERSION "2.0"
7c9e7a6f	11
572ccdab RD	12	/**
572ccdab RD	13	* DOC: Ring Design
7c9e7a6f AG	14	* Ring Design
	15	* -----------
	16	*
	17	* The mmaped area is divided into three parts:
572ccdab RD	18	* 1) The mailbox (struct tcmu_mailbox, below);
	19	* 2) The command ring;
	20	* 3) Everything beyond the command ring (data).
7c9e7a6f AG	21	*
	22	* The mailbox tells userspace the offset of the command ring from the
	23	* start of the shared memory region, and how big the command ring is.
	24	*
	25	* The kernel passes SCSI commands to userspace by putting a struct
	26	* tcmu_cmd_entry in the ring, updating mailbox->cmd_head, and poking
572ccdab	27	* userspace via UIO's interrupt mechanism.
7c9e7a6f AG	28	*
	29	* tcmu_cmd_entry contains a header. If the header type is PAD,
	30	* userspace should skip hdr->length bytes (mod cmdr_size) to find the
	31	* next cmd_entry.
	32	*
	33	* Otherwise, the entry will contain offsets into the mmaped area that
	34	* contain the cdb and data buffers -- the latter accessible via the
	35	* iov array. iov addresses are also offsets into the shared area.
	36	*
	37	* When userspace is completed handling the command, set
	38	* entry->rsp.scsi_status, fill in rsp.sense_buffer if appropriate,
	39	* and also set mailbox->cmd_tail equal to the old cmd_tail plus
	40	* hdr->length, mod cmdr_size. If cmd_tail doesn't equal cmd_head, it
	41	* should process the next packet the same way, and so on.
	42	*/
	43
0ad46af8	44	#define TCMU_MAILBOX_VERSION 2
7c9e7a6f	45	#define ALIGN_SIZE 64 /* Should be enough for most CPUs */
32c76de3	46	#define TCMU_MAILBOX_FLAG_CAP_OOOC (1 << 0) /* Out-of-order completions */
6c3796d1	47	#define TCMU_MAILBOX_FLAG_CAP_READ_LEN (1 << 1) /* Read data length */
7c9e7a6f AG	48
	49	struct tcmu_mailbox {
	50	__u16 version;
	51	__u16 flags;
	52	__u32 cmdr_off;
	53	__u32 cmdr_size;
	54
	55	__u32 cmd_head;
	56
	57	/* Updated by user. On its own cacheline */
	58	__u32 cmd_tail __attribute__((__aligned__(ALIGN_SIZE)));
	59
	60	} __packed;
	61
	62	enum tcmu_opcode {
	63	TCMU_OP_PAD = 0,
	64	TCMU_OP_CMD,
	65	};
	66
	67	/*
	68	* Only a few opcodes, and length is 8-byte aligned, so use low bits for opcode.
	69	*/
	70	struct tcmu_cmd_entry_hdr {
0ad46af8 AG	71	__u32 len_op;
	72	__u16 cmd_id;
	73	__u8 kflags;
	74	#define TCMU_UFLAG_UNKNOWN_OP 0x1
6c3796d1	75	#define TCMU_UFLAG_READ_LEN 0x2
0ad46af8 AG	76	__u8 uflags;
0ad46af8 AG	77
7c9e7a6f AG	78	} __packed;
	79
	80	#define TCMU_OP_MASK 0x7
	81
0ad46af8	82	static inline enum tcmu_opcode tcmu_hdr_get_op(__u32 len_op)
7c9e7a6f	83	{
0ad46af8	84	return len_op & TCMU_OP_MASK;
7c9e7a6f AG	85	}
7c9e7a6f AG	86
0ad46af8	87	static inline void tcmu_hdr_set_op(__u32 *len_op, enum tcmu_opcode op)
7c9e7a6f	88	{
0ad46af8 AG	89	*len_op &= ~TCMU_OP_MASK;
0ad46af8 AG	90	*len_op \|= (op & TCMU_OP_MASK);
7c9e7a6f AG	91	}
7c9e7a6f AG	92
0ad46af8	93	static inline __u32 tcmu_hdr_get_len(__u32 len_op)
7c9e7a6f	94	{
0ad46af8	95	return len_op & ~TCMU_OP_MASK;
7c9e7a6f AG	96	}
7c9e7a6f AG	97
0ad46af8	98	static inline void tcmu_hdr_set_len(__u32 *len_op, __u32 len)
7c9e7a6f	99	{
0ad46af8 AG	100	*len_op &= TCMU_OP_MASK;
0ad46af8 AG	101	*len_op \|= len;
7c9e7a6f AG	102	}
	103
	104	/* Currently the same as SCSI_SENSE_BUFFERSIZE */
	105	#define TCMU_SENSE_BUFFERSIZE 96
	106
	107	struct tcmu_cmd_entry {
	108	struct tcmu_cmd_entry_hdr hdr;
	109
7c9e7a6f AG	110	union {
7c9e7a6f AG	111	struct {
762b6f00 DL	112	__u32 iov_cnt;
	113	__u32 iov_bidi_cnt;
	114	__u32 iov_dif_cnt;
	115	__u64 cdb_off;
	116	__u64 __pad1;
	117	__u64 __pad2;
7c9e7a6f AG	118	struct iovec iov[0];
	119	} req;
	120	struct {
762b6f00 DL	121	__u8 scsi_status;
	122	__u8 __pad1;
	123	__u16 __pad2;
6c3796d1	124	__u32 read_len;
7c9e7a6f AG	125	char sense_buffer[TCMU_SENSE_BUFFERSIZE];
	126	} rsp;
	127	};
	128
	129	} __packed;
	130
762b6f00	131	#define TCMU_OP_ALIGN_SIZE sizeof(__u64)
7c9e7a6f AG	132
	133	enum tcmu_genl_cmd {
	134	TCMU_CMD_UNSPEC,
	135	TCMU_CMD_ADDED_DEVICE,
	136	TCMU_CMD_REMOVED_DEVICE,
1068be7b	137	TCMU_CMD_RECONFIG_DEVICE,
b3af66e2 MC	138	TCMU_CMD_ADDED_DEVICE_DONE,
	139	TCMU_CMD_REMOVED_DEVICE_DONE,
	140	TCMU_CMD_RECONFIG_DEVICE_DONE,
	141	TCMU_CMD_SET_FEATURES,
7c9e7a6f AG	142	__TCMU_CMD_MAX,
	143	};
	144	#define TCMU_CMD_MAX (__TCMU_CMD_MAX - 1)
	145
	146	enum tcmu_genl_attr {
	147	TCMU_ATTR_UNSPEC,
	148	TCMU_ATTR_DEVICE,
	149	TCMU_ATTR_MINOR,
2d76443e MC	150	TCMU_ATTR_PAD,
	151	TCMU_ATTR_DEV_CFG,
	152	TCMU_ATTR_DEV_SIZE,
	153	TCMU_ATTR_WRITECACHE,
b3af66e2 MC	154	TCMU_ATTR_CMD_STATUS,
	155	TCMU_ATTR_DEVICE_ID,
	156	TCMU_ATTR_SUPP_KERN_CMD_REPLY,
7c9e7a6f AG	157	__TCMU_ATTR_MAX,
	158	};
	159	#define TCMU_ATTR_MAX (__TCMU_ATTR_MAX - 1)
	160
	161	#endif