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 * Ring Design 14 * ----------- 15 * 16 * The mmaped area is divided into three parts: 17 * 1) The mailbox (struct tcmu_mailbox, below) 18 * 2) The command ring 19 * 3) Everything beyond the command ring (data) 20 * 21 * The mailbox tells userspace the offset of the command ring from the 22 * start of the shared memory region, and how big the command ring is. 23 * 24 * The kernel passes SCSI commands to userspace by putting a struct 25 * tcmu_cmd_entry in the ring, updating mailbox->cmd_head, and poking 26 * userspace via uio's interrupt mechanism. 27 * 28 * tcmu_cmd_entry contains a header. If the header type is PAD, 29 * userspace should skip hdr->length bytes (mod cmdr_size) to find the 30 * next cmd_entry. 31 * 32 * Otherwise, the entry will contain offsets into the mmaped area that 33 * contain the cdb and data buffers -- the latter accessible via the 34 * iov array. iov addresses are also offsets into the shared area. 35 * 36 * When userspace is completed handling the command, set 37 * entry->rsp.scsi_status, fill in rsp.sense_buffer if appropriate, 38 * and also set mailbox->cmd_tail equal to the old cmd_tail plus 39 * hdr->length, mod cmdr_size. If cmd_tail doesn't equal cmd_head, it 40 * should process the next packet the same way, and so on. 41 */ 42 43#define TCMU_MAILBOX_VERSION 2 44#define ALIGN_SIZE 64 /* Should be enough for most CPUs */ 45#define TCMU_MAILBOX_FLAG_CAP_OOOC (1 << 0) /* Out-of-order completions */ 46 47struct tcmu_mailbox { 48 __u16 version; 49 __u16 flags; 50 __u32 cmdr_off; 51 __u32 cmdr_size; 52 53 __u32 cmd_head; 54 55 /* Updated by user. On its own cacheline */ 56 __u32 cmd_tail __attribute__((__aligned__(ALIGN_SIZE))); 57 58} __packed; 59 60enum tcmu_opcode { 61 TCMU_OP_PAD = 0, 62 TCMU_OP_CMD, 63}; 64 65/* 66 * Only a few opcodes, and length is 8-byte aligned, so use low bits for opcode. 67 */ 68struct tcmu_cmd_entry_hdr { 69 __u32 len_op; 70 __u16 cmd_id; 71 __u8 kflags; 72#define TCMU_UFLAG_UNKNOWN_OP 0x1 73 __u8 uflags; 74 75} __packed; 76 77#define TCMU_OP_MASK 0x7 78 79static inline enum tcmu_opcode tcmu_hdr_get_op(__u32 len_op) 80{ 81 return len_op & TCMU_OP_MASK; 82} 83 84static inline void tcmu_hdr_set_op(__u32 *len_op, enum tcmu_opcode op) 85{ 86 *len_op &= ~TCMU_OP_MASK; 87 *len_op |= (op & TCMU_OP_MASK); 88} 89 90static inline __u32 tcmu_hdr_get_len(__u32 len_op) 91{ 92 return len_op & ~TCMU_OP_MASK; 93} 94 95static inline void tcmu_hdr_set_len(__u32 *len_op, __u32 len) 96{ 97 *len_op &= TCMU_OP_MASK; 98 *len_op |= len; 99} 100 101/* Currently the same as SCSI_SENSE_BUFFERSIZE */ 102#define TCMU_SENSE_BUFFERSIZE 96 103 104struct tcmu_cmd_entry { 105 struct tcmu_cmd_entry_hdr hdr; 106 107 union { 108 struct { 109 __u32 iov_cnt; 110 __u32 iov_bidi_cnt; 111 __u32 iov_dif_cnt; 112 __u64 cdb_off; 113 __u64 __pad1; 114 __u64 __pad2; 115 struct iovec iov[0]; 116 } req; 117 struct { 118 __u8 scsi_status; 119 __u8 __pad1; 120 __u16 __pad2; 121 __u32 __pad3; 122 char sense_buffer[TCMU_SENSE_BUFFERSIZE]; 123 } rsp; 124 }; 125 126} __packed; 127 128#define TCMU_OP_ALIGN_SIZE sizeof(__u64) 129 130enum tcmu_genl_cmd { 131 TCMU_CMD_UNSPEC, 132 TCMU_CMD_ADDED_DEVICE, 133 TCMU_CMD_REMOVED_DEVICE, 134 TCMU_CMD_RECONFIG_DEVICE, 135 TCMU_CMD_ADDED_DEVICE_DONE, 136 TCMU_CMD_REMOVED_DEVICE_DONE, 137 TCMU_CMD_RECONFIG_DEVICE_DONE, 138 TCMU_CMD_SET_FEATURES, 139 __TCMU_CMD_MAX, 140}; 141#define TCMU_CMD_MAX (__TCMU_CMD_MAX - 1) 142 143enum tcmu_genl_attr { 144 TCMU_ATTR_UNSPEC, 145 TCMU_ATTR_DEVICE, 146 TCMU_ATTR_MINOR, 147 TCMU_ATTR_PAD, 148 TCMU_ATTR_DEV_CFG, 149 TCMU_ATTR_DEV_SIZE, 150 TCMU_ATTR_WRITECACHE, 151 TCMU_ATTR_CMD_STATUS, 152 TCMU_ATTR_DEVICE_ID, 153 TCMU_ATTR_SUPP_KERN_CMD_REPLY, 154 __TCMU_ATTR_MAX, 155}; 156#define TCMU_ATTR_MAX (__TCMU_ATTR_MAX - 1) 157 158#endif 159