[linux-2.6-block.git] / include / uapi / linux / target_core_user.h

#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>

#ifndef __packed
#define __packed                        __attribute__((packed))
#endif

#define TCMU_VERSION "1.0"

/*
 * 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 1
#define ALIGN_SIZE 64 /* Should be enough for most CPUs */

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;
} __packed;

#define TCMU_OP_MASK 0x7

static inline enum tcmu_opcode tcmu_hdr_get_op(struct tcmu_cmd_entry_hdr *hdr)
{
	return hdr->len_op & TCMU_OP_MASK;
}

static inline void tcmu_hdr_set_op(struct tcmu_cmd_entry_hdr *hdr, enum tcmu_opcode op)
{
	hdr->len_op &= ~TCMU_OP_MASK;
	hdr->len_op |= (op & TCMU_OP_MASK);
}

static inline __u32 tcmu_hdr_get_len(struct tcmu_cmd_entry_hdr *hdr)
{
	return hdr->len_op & ~TCMU_OP_MASK;
}

static inline void tcmu_hdr_set_len(struct tcmu_cmd_entry_hdr *hdr, __u32 len)
{
	hdr->len_op &= TCMU_OP_MASK;
	hdr->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;

	uint16_t cmd_id;
	uint16_t __pad1;

	union {
		struct {
			uint64_t cdb_off;
			uint64_t iov_cnt;
			struct iovec iov[0];
		} req;
		struct {
			uint8_t scsi_status;
			uint8_t __pad1;
			uint16_t __pad2;
			uint32_t __pad3;
			char sense_buffer[TCMU_SENSE_BUFFERSIZE];
		} rsp;
	};

} __packed;

#define TCMU_OP_ALIGN_SIZE sizeof(uint64_t)

enum tcmu_genl_cmd {
	TCMU_CMD_UNSPEC,
	TCMU_CMD_ADDED_DEVICE,
	TCMU_CMD_REMOVED_DEVICE,
	__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_MAX,
};
#define TCMU_ATTR_MAX (__TCMU_ATTR_MAX - 1)

#endif
Commit	Line	Data
7c9e7a6f AG	1	#ifndef __TARGET_CORE_USER_H
	2	#define __TARGET_CORE_USER_H
	3
	4	/* This header will be used by application too */
	5
	6	#include <linux/types.h>
	7	#include <linux/uio.h>
	8
	9	#ifndef __packed
	10	#define __packed __attribute__((packed))
	11	#endif
	12
	13	#define TCMU_VERSION "1.0"
	14
	15	/*
	16	* Ring Design
	17	* -----------
	18	*
	19	* The mmaped area is divided into three parts:
	20	* 1) The mailbox (struct tcmu_mailbox, below)
	21	* 2) The command ring
	22	* 3) Everything beyond the command ring (data)
	23	*
	24	* The mailbox tells userspace the offset of the command ring from the
	25	* start of the shared memory region, and how big the command ring is.
	26	*
	27	* The kernel passes SCSI commands to userspace by putting a struct
	28	* tcmu_cmd_entry in the ring, updating mailbox->cmd_head, and poking
	29	* userspace via uio's interrupt mechanism.
	30	*
	31	* tcmu_cmd_entry contains a header. If the header type is PAD,
	32	* userspace should skip hdr->length bytes (mod cmdr_size) to find the
	33	* next cmd_entry.
	34	*
	35	* Otherwise, the entry will contain offsets into the mmaped area that
	36	* contain the cdb and data buffers -- the latter accessible via the
	37	* iov array. iov addresses are also offsets into the shared area.
	38	*
	39	* When userspace is completed handling the command, set
	40	* entry->rsp.scsi_status, fill in rsp.sense_buffer if appropriate,
	41	* and also set mailbox->cmd_tail equal to the old cmd_tail plus
	42	* hdr->length, mod cmdr_size. If cmd_tail doesn't equal cmd_head, it
	43	* should process the next packet the same way, and so on.
	44	*/
	45
	46	#define TCMU_MAILBOX_VERSION 1
	47	#define ALIGN_SIZE 64 /* Should be enough for most CPUs */
	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 {
71	__u32 len_op;
72	} __packed;
73
74	#define TCMU_OP_MASK 0x7
75
76	static inline enum tcmu_opcode tcmu_hdr_get_op(struct tcmu_cmd_entry_hdr *hdr)
77	{
78	return hdr->len_op & TCMU_OP_MASK;
79	}
80
81	static inline void tcmu_hdr_set_op(struct tcmu_cmd_entry_hdr *hdr, enum tcmu_opcode op)
82	{
83	hdr->len_op &= ~TCMU_OP_MASK;
84	hdr->len_op \|= (op & TCMU_OP_MASK);
85	}
86
87	static inline __u32 tcmu_hdr_get_len(struct tcmu_cmd_entry_hdr *hdr)
88	{
89	return hdr->len_op & ~TCMU_OP_MASK;
90	}
91
92	static inline void tcmu_hdr_set_len(struct tcmu_cmd_entry_hdr *hdr, __u32 len)
93	{
94	hdr->len_op &= TCMU_OP_MASK;
95	hdr->len_op \|= len;
96	}
97
98	/* Currently the same as SCSI_SENSE_BUFFERSIZE */
99	#define TCMU_SENSE_BUFFERSIZE 96
100
101	struct tcmu_cmd_entry {
102	struct tcmu_cmd_entry_hdr hdr;
103
104	uint16_t cmd_id;
105	uint16_t __pad1;
106
107	union {
108	struct {
109	uint64_t cdb_off;
110	uint64_t iov_cnt;
111	struct iovec iov[0];
112	} req;
113	struct {
114	uint8_t scsi_status;
115	uint8_t __pad1;
116	uint16_t __pad2;
117	uint32_t __pad3;
118	char sense_buffer[TCMU_SENSE_BUFFERSIZE];
119	} rsp;
120	};
121
122	} __packed;
123
124	#define TCMU_OP_ALIGN_SIZE sizeof(uint64_t)
125
126	enum tcmu_genl_cmd {
127	TCMU_CMD_UNSPEC,
128	TCMU_CMD_ADDED_DEVICE,
129	TCMU_CMD_REMOVED_DEVICE,
130	__TCMU_CMD_MAX,
131	};
132	#define TCMU_CMD_MAX (__TCMU_CMD_MAX - 1)
133
134	enum tcmu_genl_attr {
135	TCMU_ATTR_UNSPEC,
136	TCMU_ATTR_DEVICE,
137	TCMU_ATTR_MINOR,
138	__TCMU_ATTR_MAX,
139	};
140	#define TCMU_ATTR_MAX (__TCMU_ATTR_MAX - 1)
141
142	#endif