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 45/* See https://gcc.gnu.org/onlinedocs/cpp/Stringification.html */ 46#define xstr(s) str(s) 47#define str(s) #s 48 49struct 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 62enum 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 */ 70struct tcmu_cmd_entry_hdr { 71 __u32 len_op; 72 __u16 cmd_id; 73 __u8 kflags; 74#define TCMU_UFLAG_UNKNOWN_OP 0x1 75 __u8 uflags; 76 77} __packed; 78 79#define TCMU_OP_MASK 0x7 80 81static inline enum tcmu_opcode tcmu_hdr_get_op(__u32 len_op) 82{ 83 return len_op & TCMU_OP_MASK; 84} 85 86static inline void tcmu_hdr_set_op(__u32 *len_op, enum tcmu_opcode op) 87{ 88 *len_op &= ~TCMU_OP_MASK; 89 *len_op |= (op & TCMU_OP_MASK); 90} 91 92static inline __u32 tcmu_hdr_get_len(__u32 len_op) 93{ 94 return len_op & ~TCMU_OP_MASK; 95} 96 97static inline void tcmu_hdr_set_len(__u32 *len_op, __u32 len) 98{ 99 *len_op &= TCMU_OP_MASK; 100 *len_op |= len; 101} 102 103/* Currently the same as SCSI_SENSE_BUFFERSIZE */ 104#define TCMU_SENSE_BUFFERSIZE 96 105 106struct tcmu_cmd_entry { 107 struct tcmu_cmd_entry_hdr hdr; 108 109 union { 110 struct { 111 uint32_t iov_cnt; 112 uint32_t iov_bidi_cnt; 113 uint32_t iov_dif_cnt; 114 uint64_t cdb_off; 115 uint64_t __pad1; 116 uint64_t __pad2; 117 struct iovec iov[0]; 118 } req; 119 struct { 120 uint8_t scsi_status; 121 uint8_t __pad1; 122 uint16_t __pad2; 123 uint32_t __pad3; 124 char sense_buffer[TCMU_SENSE_BUFFERSIZE]; 125 } rsp; 126 }; 127 128} __packed; 129 130#define TCMU_OP_ALIGN_SIZE sizeof(uint64_t) 131 132enum tcmu_genl_cmd { 133 TCMU_CMD_UNSPEC, 134 TCMU_CMD_ADDED_DEVICE, 135 TCMU_CMD_REMOVED_DEVICE, 136 __TCMU_CMD_MAX, 137}; 138#define TCMU_CMD_MAX (__TCMU_CMD_MAX - 1) 139 140enum tcmu_genl_attr { 141 TCMU_ATTR_UNSPEC, 142 TCMU_ATTR_DEVICE, 143 TCMU_ATTR_MINOR, 144 __TCMU_ATTR_MAX, 145}; 146#define TCMU_ATTR_MAX (__TCMU_ATTR_MAX - 1) 147 148#endif 149