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target_core_user.h (4651B) - Raw


      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 #define TCMU_MAILBOX_FLAG_CAP_TMR (1 << 2) /* TMR notifications */
     49 #define TCMU_MAILBOX_FLAG_CAP_KEEP_BUF (1<<3) /* Keep buf after cmd completion */
     50 
     51 struct tcmu_mailbox {
     52 	__u16 version;
     53 	__u16 flags;
     54 	__u32 cmdr_off;
     55 	__u32 cmdr_size;
     56 
     57 	__u32 cmd_head;
     58 
     59 	/* Updated by user. On its own cacheline */
     60 	__u32 cmd_tail __attribute__((__aligned__(ALIGN_SIZE)));
     61 
     62 } __attribute__((packed));
     63 
     64 enum tcmu_opcode {
     65 	TCMU_OP_PAD = 0,
     66 	TCMU_OP_CMD,
     67 	TCMU_OP_TMR,
     68 };
     69 
     70 /*
     71  * Only a few opcodes, and length is 8-byte aligned, so use low bits for opcode.
     72  */
     73 struct tcmu_cmd_entry_hdr {
     74 	__u32 len_op;
     75 	__u16 cmd_id;
     76 	__u8 kflags;
     77 #define TCMU_UFLAG_UNKNOWN_OP 0x1
     78 #define TCMU_UFLAG_READ_LEN   0x2
     79 #define TCMU_UFLAG_KEEP_BUF   0x4
     80 	__u8 uflags;
     81 
     82 } __attribute__((packed));
     83 
     84 #define TCMU_OP_MASK 0x7
     85 
     86 static __inline__ enum tcmu_opcode tcmu_hdr_get_op(__u32 len_op)
     87 {
     88 	return len_op & TCMU_OP_MASK;
     89 }
     90 
     91 static __inline__ void tcmu_hdr_set_op(__u32 *len_op, enum tcmu_opcode op)
     92 {
     93 	*len_op &= ~TCMU_OP_MASK;
     94 	*len_op |= (op & TCMU_OP_MASK);
     95 }
     96 
     97 static __inline__ __u32 tcmu_hdr_get_len(__u32 len_op)
     98 {
     99 	return len_op & ~TCMU_OP_MASK;
    100 }
    101 
    102 static __inline__ void tcmu_hdr_set_len(__u32 *len_op, __u32 len)
    103 {
    104 	*len_op &= TCMU_OP_MASK;
    105 	*len_op |= len;
    106 }
    107 
    108 /* Currently the same as SCSI_SENSE_BUFFERSIZE */
    109 #define TCMU_SENSE_BUFFERSIZE 96
    110 
    111 struct tcmu_cmd_entry {
    112 	struct tcmu_cmd_entry_hdr hdr;
    113 
    114 	union {
    115 		struct {
    116 			__u32 iov_cnt;
    117 			__u32 iov_bidi_cnt;
    118 			__u32 iov_dif_cnt;
    119 			__u64 cdb_off;
    120 			__u64 __pad1;
    121 			__u64 __pad2;
    122 			__DECLARE_FLEX_ARRAY(struct iovec, iov);
    123 		} req;
    124 		struct {
    125 			__u8 scsi_status;
    126 			__u8 __pad1;
    127 			__u16 __pad2;
    128 			__u32 read_len;
    129 			char sense_buffer[TCMU_SENSE_BUFFERSIZE];
    130 		} rsp;
    131 	};
    132 
    133 } __attribute__((packed));
    134 
    135 struct tcmu_tmr_entry {
    136 	struct tcmu_cmd_entry_hdr hdr;
    137 
    138 #define TCMU_TMR_UNKNOWN		0
    139 #define TCMU_TMR_ABORT_TASK		1
    140 #define TCMU_TMR_ABORT_TASK_SET		2
    141 #define TCMU_TMR_CLEAR_ACA		3
    142 #define TCMU_TMR_CLEAR_TASK_SET		4
    143 #define TCMU_TMR_LUN_RESET		5
    144 #define TCMU_TMR_TARGET_WARM_RESET	6
    145 #define TCMU_TMR_TARGET_COLD_RESET	7
    146 /* Pseudo reset due to received PR OUT */
    147 #define TCMU_TMR_LUN_RESET_PRO		128
    148 	__u8 tmr_type;
    149 
    150 	__u8 __pad1;
    151 	__u16 __pad2;
    152 	__u32 cmd_cnt;
    153 	__u64 __pad3;
    154 	__u64 __pad4;
    155 	__u16 cmd_ids[];
    156 } __attribute__((packed));
    157 
    158 #define TCMU_OP_ALIGN_SIZE sizeof(__u64)
    159 
    160 enum tcmu_genl_cmd {
    161 	TCMU_CMD_UNSPEC,
    162 	TCMU_CMD_ADDED_DEVICE,
    163 	TCMU_CMD_REMOVED_DEVICE,
    164 	TCMU_CMD_RECONFIG_DEVICE,
    165 	TCMU_CMD_ADDED_DEVICE_DONE,
    166 	TCMU_CMD_REMOVED_DEVICE_DONE,
    167 	TCMU_CMD_RECONFIG_DEVICE_DONE,
    168 	TCMU_CMD_SET_FEATURES,
    169 	__TCMU_CMD_MAX,
    170 };
    171 #define TCMU_CMD_MAX (__TCMU_CMD_MAX - 1)
    172 
    173 enum tcmu_genl_attr {
    174 	TCMU_ATTR_UNSPEC,
    175 	TCMU_ATTR_DEVICE,
    176 	TCMU_ATTR_MINOR,
    177 	TCMU_ATTR_PAD,
    178 	TCMU_ATTR_DEV_CFG,
    179 	TCMU_ATTR_DEV_SIZE,
    180 	TCMU_ATTR_WRITECACHE,
    181 	TCMU_ATTR_CMD_STATUS,
    182 	TCMU_ATTR_DEVICE_ID,
    183 	TCMU_ATTR_SUPP_KERN_CMD_REPLY,
    184 	__TCMU_ATTR_MAX,
    185 };
    186 #define TCMU_ATTR_MAX (__TCMU_ATTR_MAX - 1)
    187 
    188 #endif