target: clean up kernel-doc and add driver-api document

@@ -1654,7 +1654,7 @@ static bool target_lookup_lun_from_tag(s
  * @se_sess: associated se_sess for endpoint
  * @sense: pointer to SCSI sense buffer
  * @unpacked_lun: unpacked LUN to reference for struct se_lun
- * @fabric_context: fabric context for TMR req
+ * @fabric_tmr_ptr: fabric context for TMR req
  * @tm_type: Type of TM request
  * @gfp: gfp type for caller
  * @tag: referenced task tag for TMR_ABORT_TASK

@@ -1431,7 +1431,7 @@ transport_generic_map_mem_to_cmd(struct
 	return 0;
 }
 
-/*
+/**
  * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
  * 			 se_cmd + use pre-allocated SGL memory.
  *

@@ -1441,7 +1441,7 @@ transport_generic_map_mem_to_cmd(struct
  * @sense: pointer to SCSI sense buffer
  * @unpacked_lun: unpacked LUN to reference for struct se_lun
  * @data_length: fabric expected data transfer length
- * @task_addr: SAM task attribute
+ * @task_attr: SAM task attribute
  * @data_dir: DMA data direction
  * @flags: flags for command submission from target_sc_flags_tables
  * @sgl: struct scatterlist memory for unidirectional mapping

@@ -1578,7 +1578,7 @@ int target_submit_cmd_map_sgls(struct se
 }
 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
 
-/*
+/**
  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
  *
  * @se_cmd: command descriptor to submit

@@ -1587,7 +1587,7 @@ EXPORT_SYMBOL(target_submit_cmd_map_sgls
  * @sense: pointer to SCSI sense buffer
  * @unpacked_lun: unpacked LUN to reference for struct se_lun
  * @data_length: fabric expected data transfer length
- * @task_addr: SAM task attribute
+ * @task_attr: SAM task attribute
  * @data_dir: DMA data direction
  * @flags: flags for command submission from target_sc_flags_tables
  *

@@ -2606,7 +2606,8 @@ int transport_generic_free_cmd(struct se
 }
 EXPORT_SYMBOL(transport_generic_free_cmd);
 
-/* target_get_sess_cmd - Add command to active ->sess_cmd_list
+/**
+ * target_get_sess_cmd - Add command to active ->sess_cmd_list
  * @se_cmd:	command descriptor to add
  * @ack_kref:	Signal that fabric will perform an ack target_put_sess_cmd()
  */

@@ -2800,7 +2801,8 @@ void target_show_cmd(const char *pfx, st
 }
 EXPORT_SYMBOL(target_show_cmd);
 
-/* target_sess_cmd_list_set_waiting - Flag all commands in
+/**
+ * target_sess_cmd_list_set_waiting - Flag all commands in
  *         sess_cmd_list to complete cmd_wait_comp.  Set
  *         sess_tearing_down so no more commands are queued.
  * @se_sess:	session to flag

@@ -2835,7 +2837,8 @@ void target_sess_cmd_list_set_waiting(st
 }
 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
 
-/* target_wait_for_sess_cmds - Wait for outstanding descriptors
+/**
+ * target_wait_for_sess_cmds - Wait for outstanding descriptors
  * @se_sess:    session to wait for active I/O
  */
 void target_wait_for_sess_cmds(struct se_session *se_sess)

@@ -42,7 +42,11 @@
 
 #include <linux/target_core_user.h>
 
-/*
+/**
+ * DOC: Userspace I/O
+ * Userspace I/O
+ * -------------
+ *
  * Define a shared-memory interface for LIO to pass SCSI commands and
  * data to userspace for processing. This is to allow backends that
  * are too complex for in-kernel support to be possible.

@@ -53,7 +57,7 @@
  * See the .h file for how the ring is laid out. Note that while the
  * command ring is defined, the particulars of the data area are
  * not. Offset values in the command entry point to other locations
- * internal to the mmap()ed area. There is separate space outside the
+ * internal to the mmap-ed area. There is separate space outside the
  * command ring for data buffers. This leaves maximum flexibility for
  * moving buffer allocations, or even page flipping or other
  * allocation techniques, without altering the command ring layout.

@@ -9,21 +9,22 @@
 
 #define TCMU_VERSION "2.0"
 
-/*
+/**
+ * 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)
+ * 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.
+ * 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