Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
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
10#define TCMU_VERSION "2.0"
11
12/**
13 * DOC: Ring Design
14 * Ring Design
15 * -----------
16 *
17 * The mmaped area is divided into three parts:
18 * 1) The mailbox (struct tcmu_mailbox, below);
19 * 2) The command ring;
20 * 3) Everything beyond the command ring (data).
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
27 * userspace via UIO's interrupt mechanism.
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
44#define TCMU_MAILBOX_VERSION 2
45#define ALIGN_SIZE 64 /* Should be enough for most CPUs */
46#define TCMU_MAILBOX_FLAG_CAP_OOOC (1 << 0) /* Out-of-order completions */
47#define TCMU_MAILBOX_FLAG_CAP_READ_LEN (1 << 1) /* Read data length */
48#define TCMU_MAILBOX_FLAG_CAP_TMR (1 << 2) /* TMR notifications */
49
50struct tcmu_mailbox {
51 __u16 version;
52 __u16 flags;
53 __u32 cmdr_off;
54 __u32 cmdr_size;
55
56 __u32 cmd_head;
57
58 /* Updated by user. On its own cacheline */
59 __u32 cmd_tail __attribute__((__aligned__(ALIGN_SIZE)));
60
61} __packed;
62
63enum tcmu_opcode {
64 TCMU_OP_PAD = 0,
65 TCMU_OP_CMD,
66 TCMU_OP_TMR,
67};
68
69/*
70 * Only a few opcodes, and length is 8-byte aligned, so use low bits for opcode.
71 */
72struct tcmu_cmd_entry_hdr {
73 __u32 len_op;
74 __u16 cmd_id;
75 __u8 kflags;
76#define TCMU_UFLAG_UNKNOWN_OP 0x1
77#define TCMU_UFLAG_READ_LEN 0x2
78 __u8 uflags;
79
80} __packed;
81
82#define TCMU_OP_MASK 0x7
83
84static inline enum tcmu_opcode tcmu_hdr_get_op(__u32 len_op)
85{
86 return len_op & TCMU_OP_MASK;
87}
88
89static inline void tcmu_hdr_set_op(__u32 *len_op, enum tcmu_opcode op)
90{
91 *len_op &= ~TCMU_OP_MASK;
92 *len_op |= (op & TCMU_OP_MASK);
93}
94
95static inline __u32 tcmu_hdr_get_len(__u32 len_op)
96{
97 return len_op & ~TCMU_OP_MASK;
98}
99
100static inline void tcmu_hdr_set_len(__u32 *len_op, __u32 len)
101{
102 *len_op &= TCMU_OP_MASK;
103 *len_op |= len;
104}
105
106/* Currently the same as SCSI_SENSE_BUFFERSIZE */
107#define TCMU_SENSE_BUFFERSIZE 96
108
109struct tcmu_cmd_entry {
110 struct tcmu_cmd_entry_hdr hdr;
111
112 union {
113 struct {
114 __u32 iov_cnt;
115 __u32 iov_bidi_cnt;
116 __u32 iov_dif_cnt;
117 __u64 cdb_off;
118 __u64 __pad1;
119 __u64 __pad2;
120 struct iovec iov[0];
121 } req;
122 struct {
123 __u8 scsi_status;
124 __u8 __pad1;
125 __u16 __pad2;
126 __u32 read_len;
127 char sense_buffer[TCMU_SENSE_BUFFERSIZE];
128 } rsp;
129 };
130
131} __packed;
132
133struct tcmu_tmr_entry {
134 struct tcmu_cmd_entry_hdr hdr;
135
136#define TCMU_TMR_UNKNOWN 0
137#define TCMU_TMR_ABORT_TASK 1
138#define TCMU_TMR_ABORT_TASK_SET 2
139#define TCMU_TMR_CLEAR_ACA 3
140#define TCMU_TMR_CLEAR_TASK_SET 4
141#define TCMU_TMR_LUN_RESET 5
142#define TCMU_TMR_TARGET_WARM_RESET 6
143#define TCMU_TMR_TARGET_COLD_RESET 7
144/* Pseudo reset due to received PR OUT */
145#define TCMU_TMR_LUN_RESET_PRO 128
146 __u8 tmr_type;
147
148 __u8 __pad1;
149 __u16 __pad2;
150 __u32 cmd_cnt;
151 __u64 __pad3;
152 __u64 __pad4;
153 __u16 cmd_ids[0];
154} __packed;
155
156#define TCMU_OP_ALIGN_SIZE sizeof(__u64)
157
158enum tcmu_genl_cmd {
159 TCMU_CMD_UNSPEC,
160 TCMU_CMD_ADDED_DEVICE,
161 TCMU_CMD_REMOVED_DEVICE,
162 TCMU_CMD_RECONFIG_DEVICE,
163 TCMU_CMD_ADDED_DEVICE_DONE,
164 TCMU_CMD_REMOVED_DEVICE_DONE,
165 TCMU_CMD_RECONFIG_DEVICE_DONE,
166 TCMU_CMD_SET_FEATURES,
167 __TCMU_CMD_MAX,
168};
169#define TCMU_CMD_MAX (__TCMU_CMD_MAX - 1)
170
171enum tcmu_genl_attr {
172 TCMU_ATTR_UNSPEC,
173 TCMU_ATTR_DEVICE,
174 TCMU_ATTR_MINOR,
175 TCMU_ATTR_PAD,
176 TCMU_ATTR_DEV_CFG,
177 TCMU_ATTR_DEV_SIZE,
178 TCMU_ATTR_WRITECACHE,
179 TCMU_ATTR_CMD_STATUS,
180 TCMU_ATTR_DEVICE_ID,
181 TCMU_ATTR_SUPP_KERN_CMD_REPLY,
182 __TCMU_ATTR_MAX,
183};
184#define TCMU_ATTR_MAX (__TCMU_ATTR_MAX - 1)
185
186#endif