/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ #ifndef __TARGET_CORE_USER_H #define __TARGET_CORE_USER_H /* This header will be used by application too */ #include <linux/types.h> #include <linux/uio.h> #define TCMU_VERSION … /** * DOC: Ring Design * Ring Design * ----------- * * The mmaped area is divided into three parts: * 1) The mailbox (struct tcmu_mailbox, below); * 2) The command ring; * 3) Everything beyond the command ring (data). * * The mailbox tells userspace the offset of the command ring from the * start of the shared memory region, and how big the command ring is. * * The kernel passes SCSI commands to userspace by putting a struct * tcmu_cmd_entry in the ring, updating mailbox->cmd_head, and poking * userspace via UIO's interrupt mechanism. * * tcmu_cmd_entry contains a header. If the header type is PAD, * userspace should skip hdr->length bytes (mod cmdr_size) to find the * next cmd_entry. * * Otherwise, the entry will contain offsets into the mmaped area that * contain the cdb and data buffers -- the latter accessible via the * iov array. iov addresses are also offsets into the shared area. * * When userspace is completed handling the command, set * entry->rsp.scsi_status, fill in rsp.sense_buffer if appropriate, * and also set mailbox->cmd_tail equal to the old cmd_tail plus * hdr->length, mod cmdr_size. If cmd_tail doesn't equal cmd_head, it * should process the next packet the same way, and so on. */ #define TCMU_MAILBOX_VERSION … #define ALIGN_SIZE … #define TCMU_MAILBOX_FLAG_CAP_OOOC … #define TCMU_MAILBOX_FLAG_CAP_READ_LEN … #define TCMU_MAILBOX_FLAG_CAP_TMR … #define TCMU_MAILBOX_FLAG_CAP_KEEP_BUF … struct tcmu_mailbox { … } __packed; enum tcmu_opcode { … }; /* * Only a few opcodes, and length is 8-byte aligned, so use low bits for opcode. */ struct tcmu_cmd_entry_hdr { … } __packed; #define TCMU_OP_MASK … static inline enum tcmu_opcode tcmu_hdr_get_op(__u32 len_op) { … } static inline void tcmu_hdr_set_op(__u32 *len_op, enum tcmu_opcode op) { … } static inline __u32 tcmu_hdr_get_len(__u32 len_op) { … } static inline void tcmu_hdr_set_len(__u32 *len_op, __u32 len) { … } /* Currently the same as SCSI_SENSE_BUFFERSIZE */ #define TCMU_SENSE_BUFFERSIZE … struct tcmu_cmd_entry { … } __packed; struct tcmu_tmr_entry { … } __packed; #define TCMU_OP_ALIGN_SIZE … enum tcmu_genl_cmd { … }; #define TCMU_CMD_MAX … enum tcmu_genl_attr { … }; #define TCMU_ATTR_MAX … #endif
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