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 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 __u16 cmd_id; 73 __u8 kflags; 74 #define TCMU_UFLAG_UNKNOWN_OP 0x1 75 #define TCMU_UFLAG_READ_LEN 0x2 76 __u8 uflags; 77 78 } __packed; 79 80 #define TCMU_OP_MASK 0x7 81 82 static inline enum tcmu_opcode tcmu_hdr_get_op(__u32 len_op) 83 { 84 return len_op & TCMU_OP_MASK; 85 } 86 87 static inline void tcmu_hdr_set_op(__u32 *len_op, enum tcmu_opcode op) 88 { 89 *len_op &= ~TCMU_OP_MASK; 90 *len_op |= (op & TCMU_OP_MASK); 91 } 92 93 static inline __u32 tcmu_hdr_get_len(__u32 len_op) 94 { 95 return len_op & ~TCMU_OP_MASK; 96 } 97 98 static inline void tcmu_hdr_set_len(__u32 *len_op, __u32 len) 99 { 100 *len_op &= TCMU_OP_MASK; 101 *len_op |= len; 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; 109 110 union { 111 struct { 112 __u32 iov_cnt; 113 __u32 iov_bidi_cnt; 114 __u32 iov_dif_cnt; 115 __u64 cdb_off; 116 __u64 __pad1; 117 __u64 __pad2; 118 struct iovec iov[0]; 119 } req; 120 struct { 121 __u8 scsi_status; 122 __u8 __pad1; 123 __u16 __pad2; 124 __u32 read_len; 125 char sense_buffer[TCMU_SENSE_BUFFERSIZE]; 126 } rsp; 127 }; 128 129 } __packed; 130 131 #define TCMU_OP_ALIGN_SIZE sizeof(__u64) 132 133 enum tcmu_genl_cmd { 134 TCMU_CMD_UNSPEC, 135 TCMU_CMD_ADDED_DEVICE, 136 TCMU_CMD_REMOVED_DEVICE, 137 TCMU_CMD_RECONFIG_DEVICE, 138 TCMU_CMD_ADDED_DEVICE_DONE, 139 TCMU_CMD_REMOVED_DEVICE_DONE, 140 TCMU_CMD_RECONFIG_DEVICE_DONE, 141 TCMU_CMD_SET_FEATURES, 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, 150 TCMU_ATTR_PAD, 151 TCMU_ATTR_DEV_CFG, 152 TCMU_ATTR_DEV_SIZE, 153 TCMU_ATTR_WRITECACHE, 154 TCMU_ATTR_CMD_STATUS, 155 TCMU_ATTR_DEVICE_ID, 156 TCMU_ATTR_SUPP_KERN_CMD_REPLY, 157 __TCMU_ATTR_MAX, 158 }; 159 #define TCMU_ATTR_MAX (__TCMU_ATTR_MAX - 1) 160 161 #endif 162