1 #ifndef __TARGET_CORE_USER_H 2 #define __TARGET_CORE_USER_H 3 4 /* This header will be used by application too */ 5 6 #include <linux/types.h> 7 #include <linux/uio.h> 8 9 #define TCMU_VERSION "2.0" 10 11 /* 12 * Ring Design 13 * ----------- 14 * 15 * The mmaped area is divided into three parts: 16 * 1) The mailbox (struct tcmu_mailbox, below) 17 * 2) The command ring 18 * 3) Everything beyond the command ring (data) 19 * 20 * The mailbox tells userspace the offset of the command ring from the 21 * start of the shared memory region, and how big the command ring is. 22 * 23 * The kernel passes SCSI commands to userspace by putting a struct 24 * tcmu_cmd_entry in the ring, updating mailbox->cmd_head, and poking 25 * userspace via uio's interrupt mechanism. 26 * 27 * tcmu_cmd_entry contains a header. If the header type is PAD, 28 * userspace should skip hdr->length bytes (mod cmdr_size) to find the 29 * next cmd_entry. 30 * 31 * Otherwise, the entry will contain offsets into the mmaped area that 32 * contain the cdb and data buffers -- the latter accessible via the 33 * iov array. iov addresses are also offsets into the shared area. 34 * 35 * When userspace is completed handling the command, set 36 * entry->rsp.scsi_status, fill in rsp.sense_buffer if appropriate, 37 * and also set mailbox->cmd_tail equal to the old cmd_tail plus 38 * hdr->length, mod cmdr_size. If cmd_tail doesn't equal cmd_head, it 39 * should process the next packet the same way, and so on. 40 */ 41 42 #define TCMU_MAILBOX_VERSION 2 43 #define ALIGN_SIZE 64 /* Should be enough for most CPUs */ 44 #define TCMU_MAILBOX_FLAG_CAP_OOOC (1 << 0) /* Out-of-order completions */ 45 46 struct tcmu_mailbox { 47 __u16 version; 48 __u16 flags; 49 __u32 cmdr_off; 50 __u32 cmdr_size; 51 52 __u32 cmd_head; 53 54 /* Updated by user. On its own cacheline */ 55 __u32 cmd_tail __attribute__((__aligned__(ALIGN_SIZE))); 56 57 } __packed; 58 59 enum tcmu_opcode { 60 TCMU_OP_PAD = 0, 61 TCMU_OP_CMD, 62 }; 63 64 /* 65 * Only a few opcodes, and length is 8-byte aligned, so use low bits for opcode. 66 */ 67 struct tcmu_cmd_entry_hdr { 68 __u32 len_op; 69 __u16 cmd_id; 70 __u8 kflags; 71 #define TCMU_UFLAG_UNKNOWN_OP 0x1 72 __u8 uflags; 73 74 } __packed; 75 76 #define TCMU_OP_MASK 0x7 77 78 static inline enum tcmu_opcode tcmu_hdr_get_op(__u32 len_op) 79 { 80 return len_op & TCMU_OP_MASK; 81 } 82 83 static inline void tcmu_hdr_set_op(__u32 *len_op, enum tcmu_opcode op) 84 { 85 *len_op &= ~TCMU_OP_MASK; 86 *len_op |= (op & TCMU_OP_MASK); 87 } 88 89 static inline __u32 tcmu_hdr_get_len(__u32 len_op) 90 { 91 return len_op & ~TCMU_OP_MASK; 92 } 93 94 static inline void tcmu_hdr_set_len(__u32 *len_op, __u32 len) 95 { 96 *len_op &= TCMU_OP_MASK; 97 *len_op |= len; 98 } 99 100 /* Currently the same as SCSI_SENSE_BUFFERSIZE */ 101 #define TCMU_SENSE_BUFFERSIZE 96 102 103 struct tcmu_cmd_entry { 104 struct tcmu_cmd_entry_hdr hdr; 105 106 union { 107 struct { 108 __u32 iov_cnt; 109 __u32 iov_bidi_cnt; 110 __u32 iov_dif_cnt; 111 __u64 cdb_off; 112 __u64 __pad1; 113 __u64 __pad2; 114 struct iovec iov[0]; 115 } req; 116 struct { 117 __u8 scsi_status; 118 __u8 __pad1; 119 __u16 __pad2; 120 __u32 __pad3; 121 char sense_buffer[TCMU_SENSE_BUFFERSIZE]; 122 } rsp; 123 }; 124 125 } __packed; 126 127 #define TCMU_OP_ALIGN_SIZE sizeof(__u64) 128 129 enum tcmu_genl_cmd { 130 TCMU_CMD_UNSPEC, 131 TCMU_CMD_ADDED_DEVICE, 132 TCMU_CMD_REMOVED_DEVICE, 133 TCMU_CMD_RECONFIG_DEVICE, 134 TCMU_CMD_ADDED_DEVICE_DONE, 135 TCMU_CMD_REMOVED_DEVICE_DONE, 136 TCMU_CMD_RECONFIG_DEVICE_DONE, 137 TCMU_CMD_SET_FEATURES, 138 __TCMU_CMD_MAX, 139 }; 140 #define TCMU_CMD_MAX (__TCMU_CMD_MAX - 1) 141 142 enum tcmu_genl_attr { 143 TCMU_ATTR_UNSPEC, 144 TCMU_ATTR_DEVICE, 145 TCMU_ATTR_MINOR, 146 TCMU_ATTR_PAD, 147 TCMU_ATTR_DEV_CFG, 148 TCMU_ATTR_DEV_SIZE, 149 TCMU_ATTR_WRITECACHE, 150 TCMU_ATTR_CMD_STATUS, 151 TCMU_ATTR_DEVICE_ID, 152 TCMU_ATTR_SUPP_KERN_CMD_REPLY, 153 __TCMU_ATTR_MAX, 154 }; 155 #define TCMU_ATTR_MAX (__TCMU_ATTR_MAX - 1) 156 157 #endif 158