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 48 struct tcmu_mailbox { 49 __u16 version; 50 __u16 flags; 51 __u32 cmdr_off; 52 __u32 cmdr_size; 53 54 __u32 cmd_head; 55 56 /* Updated by user. On its own cacheline */ 57 __u32 cmd_tail __attribute__((__aligned__(ALIGN_SIZE))); 58 59 } __packed; 60 61 enum tcmu_opcode { 62 TCMU_OP_PAD = 0, 63 TCMU_OP_CMD, 64 }; 65 66 /* 67 * Only a few opcodes, and length is 8-byte aligned, so use low bits for opcode. 68 */ 69 struct tcmu_cmd_entry_hdr { 70 __u32 len_op; 71 __u16 cmd_id; 72 __u8 kflags; 73 #define TCMU_UFLAG_UNKNOWN_OP 0x1 74 __u8 uflags; 75 76 } __packed; 77 78 #define TCMU_OP_MASK 0x7 79 80 static inline enum tcmu_opcode tcmu_hdr_get_op(__u32 len_op) 81 { 82 return len_op & TCMU_OP_MASK; 83 } 84 85 static inline void tcmu_hdr_set_op(__u32 *len_op, enum tcmu_opcode op) 86 { 87 *len_op &= ~TCMU_OP_MASK; 88 *len_op |= (op & TCMU_OP_MASK); 89 } 90 91 static inline __u32 tcmu_hdr_get_len(__u32 len_op) 92 { 93 return len_op & ~TCMU_OP_MASK; 94 } 95 96 static inline void tcmu_hdr_set_len(__u32 *len_op, __u32 len) 97 { 98 *len_op &= TCMU_OP_MASK; 99 *len_op |= len; 100 } 101 102 /* Currently the same as SCSI_SENSE_BUFFERSIZE */ 103 #define TCMU_SENSE_BUFFERSIZE 96 104 105 struct tcmu_cmd_entry { 106 struct tcmu_cmd_entry_hdr hdr; 107 108 union { 109 struct { 110 __u32 iov_cnt; 111 __u32 iov_bidi_cnt; 112 __u32 iov_dif_cnt; 113 __u64 cdb_off; 114 __u64 __pad1; 115 __u64 __pad2; 116 struct iovec iov[0]; 117 } req; 118 struct { 119 __u8 scsi_status; 120 __u8 __pad1; 121 __u16 __pad2; 122 __u32 __pad3; 123 char sense_buffer[TCMU_SENSE_BUFFERSIZE]; 124 } rsp; 125 }; 126 127 } __packed; 128 129 #define TCMU_OP_ALIGN_SIZE sizeof(__u64) 130 131 enum tcmu_genl_cmd { 132 TCMU_CMD_UNSPEC, 133 TCMU_CMD_ADDED_DEVICE, 134 TCMU_CMD_REMOVED_DEVICE, 135 TCMU_CMD_RECONFIG_DEVICE, 136 TCMU_CMD_ADDED_DEVICE_DONE, 137 TCMU_CMD_REMOVED_DEVICE_DONE, 138 TCMU_CMD_RECONFIG_DEVICE_DONE, 139 TCMU_CMD_SET_FEATURES, 140 __TCMU_CMD_MAX, 141 }; 142 #define TCMU_CMD_MAX (__TCMU_CMD_MAX - 1) 143 144 enum tcmu_genl_attr { 145 TCMU_ATTR_UNSPEC, 146 TCMU_ATTR_DEVICE, 147 TCMU_ATTR_MINOR, 148 TCMU_ATTR_PAD, 149 TCMU_ATTR_DEV_CFG, 150 TCMU_ATTR_DEV_SIZE, 151 TCMU_ATTR_WRITECACHE, 152 TCMU_ATTR_CMD_STATUS, 153 TCMU_ATTR_DEVICE_ID, 154 TCMU_ATTR_SUPP_KERN_CMD_REPLY, 155 __TCMU_ATTR_MAX, 156 }; 157 #define TCMU_ATTR_MAX (__TCMU_ATTR_MAX - 1) 158 159 #endif 160