uapi/linux/target_core_user.h

0001 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
0002 #ifndef __TARGET_CORE_USER_H
0003 #define __TARGET_CORE_USER_H
0004
0005 /* This header will be used by application too */
0006
0007 #include <linux/types.h>
0008 #include <linux/uio.h>
0009
0010 #define TCMU_VERSION "2.0"
0011
0012 /**
0013  * DOC: Ring Design
0014  * Ring Design
0015  * -----------
0016  *
0017  * The mmaped area is divided into three parts:
0018  * 1) The mailbox (struct tcmu_mailbox, below);
0019  * 2) The command ring;
0020  * 3) Everything beyond the command ring (data).
0021  *
0022  * The mailbox tells userspace the offset of the command ring from the
0023  * start of the shared memory region, and how big the command ring is.
0024  *
0025  * The kernel passes SCSI commands to userspace by putting a struct
0026  * tcmu_cmd_entry in the ring, updating mailbox->cmd_head, and poking
0027  * userspace via UIO's interrupt mechanism.
0028  *
0029  * tcmu_cmd_entry contains a header. If the header type is PAD,
0030  * userspace should skip hdr->length bytes (mod cmdr_size) to find the
0031  * next cmd_entry.
0032  *
0033  * Otherwise, the entry will contain offsets into the mmaped area that
0034  * contain the cdb and data buffers -- the latter accessible via the
0035  * iov array. iov addresses are also offsets into the shared area.
0036  *
0037  * When userspace is completed handling the command, set
0038  * entry->rsp.scsi_status, fill in rsp.sense_buffer if appropriate,
0039  * and also set mailbox->cmd_tail equal to the old cmd_tail plus
0040  * hdr->length, mod cmdr_size. If cmd_tail doesn't equal cmd_head, it
0041  * should process the next packet the same way, and so on.
0042  */
0043
0044 #define TCMU_MAILBOX_VERSION 2
0045 #define ALIGN_SIZE 64 /* Should be enough for most CPUs */
0046 #define TCMU_MAILBOX_FLAG_CAP_OOOC (1 << 0) /* Out-of-order completions */
0047 #define TCMU_MAILBOX_FLAG_CAP_READ_LEN (1 << 1) /* Read data length */
0048 #define TCMU_MAILBOX_FLAG_CAP_TMR (1 << 2) /* TMR notifications */
0049 #define TCMU_MAILBOX_FLAG_CAP_KEEP_BUF (1<<3) /* Keep buf after cmd completion */
0050
0051 struct tcmu_mailbox {
0052     __u16 version;
0053     __u16 flags;
0054     __u32 cmdr_off;
0055     __u32 cmdr_size;
0056
0057     __u32 cmd_head;
0058
0059     /* Updated by user. On its own cacheline */
0060     __u32 cmd_tail __attribute__((__aligned__(ALIGN_SIZE)));
0061
0062 } __packed;
0063
0064 enum tcmu_opcode {
0065     TCMU_OP_PAD = 0,
0066     TCMU_OP_CMD,
0067     TCMU_OP_TMR,
0068 };
0069
0070 /*
0071  * Only a few opcodes, and length is 8-byte aligned, so use low bits for opcode.
0072  */
0073 struct tcmu_cmd_entry_hdr {
0074     __u32 len_op;
0075     __u16 cmd_id;
0076     __u8 kflags;
0077 #define TCMU_UFLAG_UNKNOWN_OP 0x1
0078 #define TCMU_UFLAG_READ_LEN   0x2
0079 #define TCMU_UFLAG_KEEP_BUF   0x4
0080     __u8 uflags;
0081
0082 } __packed;
0083
0084 #define TCMU_OP_MASK 0x7
0085
0086 static inline enum tcmu_opcode tcmu_hdr_get_op(__u32 len_op)
0087 {
0088     return len_op & TCMU_OP_MASK;
0089 }
0090
0091 static inline void tcmu_hdr_set_op(__u32 *len_op, enum tcmu_opcode op)
0092 {
0093     *len_op &= ~TCMU_OP_MASK;
0094     *len_op |= (op & TCMU_OP_MASK);
0095 }
0096
0097 static inline __u32 tcmu_hdr_get_len(__u32 len_op)
0098 {
0099     return len_op & ~TCMU_OP_MASK;
0100 }
0101
0102 static inline void tcmu_hdr_set_len(__u32 *len_op, __u32 len)
0103 {
0104     *len_op &= TCMU_OP_MASK;
0105     *len_op |= len;
0106 }
0107
0108 /* Currently the same as SCSI_SENSE_BUFFERSIZE */
0109 #define TCMU_SENSE_BUFFERSIZE 96
0110
0111 struct tcmu_cmd_entry {
0112     struct tcmu_cmd_entry_hdr hdr;
0113
0114     union {
0115         struct {
0116             __u32 iov_cnt;
0117             __u32 iov_bidi_cnt;
0118             __u32 iov_dif_cnt;
0119             __u64 cdb_off;
0120             __u64 __pad1;
0121             __u64 __pad2;
0122             struct iovec iov[0];
0123         } req;
0124         struct {
0125             __u8 scsi_status;
0126             __u8 __pad1;
0127             __u16 __pad2;
0128             __u32 read_len;
0129             char sense_buffer[TCMU_SENSE_BUFFERSIZE];
0130         } rsp;
0131     };
0132
0133 } __packed;
0134
0135 struct tcmu_tmr_entry {
0136     struct tcmu_cmd_entry_hdr hdr;
0137
0138 #define TCMU_TMR_UNKNOWN        0
0139 #define TCMU_TMR_ABORT_TASK     1
0140 #define TCMU_TMR_ABORT_TASK_SET     2
0141 #define TCMU_TMR_CLEAR_ACA      3
0142 #define TCMU_TMR_CLEAR_TASK_SET     4
0143 #define TCMU_TMR_LUN_RESET      5
0144 #define TCMU_TMR_TARGET_WARM_RESET  6
0145 #define TCMU_TMR_TARGET_COLD_RESET  7
0146 /* Pseudo reset due to received PR OUT */
0147 #define TCMU_TMR_LUN_RESET_PRO      128
0148     __u8 tmr_type;
0149
0150     __u8 __pad1;
0151     __u16 __pad2;
0152     __u32 cmd_cnt;
0153     __u64 __pad3;
0154     __u64 __pad4;
0155     __u16 cmd_ids[];
0156 } __packed;
0157
0158 #define TCMU_OP_ALIGN_SIZE sizeof(__u64)
0159
0160 enum tcmu_genl_cmd {
0161     TCMU_CMD_UNSPEC,
0162     TCMU_CMD_ADDED_DEVICE,
0163     TCMU_CMD_REMOVED_DEVICE,
0164     TCMU_CMD_RECONFIG_DEVICE,
0165     TCMU_CMD_ADDED_DEVICE_DONE,
0166     TCMU_CMD_REMOVED_DEVICE_DONE,
0167     TCMU_CMD_RECONFIG_DEVICE_DONE,
0168     TCMU_CMD_SET_FEATURES,
0169     __TCMU_CMD_MAX,
0170 };
0171 #define TCMU_CMD_MAX (__TCMU_CMD_MAX - 1)
0172
0173 enum tcmu_genl_attr {
0174     TCMU_ATTR_UNSPEC,
0175     TCMU_ATTR_DEVICE,
0176     TCMU_ATTR_MINOR,
0177     TCMU_ATTR_PAD,
0178     TCMU_ATTR_DEV_CFG,
0179     TCMU_ATTR_DEV_SIZE,
0180     TCMU_ATTR_WRITECACHE,
0181     TCMU_ATTR_CMD_STATUS,
0182     TCMU_ATTR_DEVICE_ID,
0183     TCMU_ATTR_SUPP_KERN_CMD_REPLY,
0184     __TCMU_ATTR_MAX,
0185 };
0186 #define TCMU_ATTR_MAX (__TCMU_ATTR_MAX - 1)
0187
0188 #endif