1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  *  BSG helper library
4  *
5  *  Copyright (C) 2008   James Smart, Emulex Corporation
6  *  Copyright (C) 2011   Red Hat, Inc.  All rights reserved.
7  *  Copyright (C) 2011   Mike Christie
8  */
9 #ifndef _BLK_BSG_
10 #define _BLK_BSG_
11 
12 #include <linux/blkdev.h>
13 #include <scsi/scsi_request.h>
14 
15 struct request;
16 struct device;
17 struct scatterlist;
18 struct request_queue;
19 
20 typedef int (bsg_job_fn) (struct bsg_job *);
21 typedef enum blk_eh_timer_return (bsg_timeout_fn)(struct request *);
22 
23 struct bsg_buffer {
24 	unsigned int payload_len;
25 	int sg_cnt;
26 	struct scatterlist *sg_list;
27 };
28 
29 struct bsg_job {
30 	struct device *dev;
31 
32 	struct kref kref;
33 
34 	unsigned int timeout;
35 
36 	/* Transport/driver specific request/reply structs */
37 	void *request;
38 	void *reply;
39 
40 	unsigned int request_len;
41 	unsigned int reply_len;
42 	/*
43 	 * On entry : reply_len indicates the buffer size allocated for
44 	 * the reply.
45 	 *
46 	 * Upon completion : the message handler must set reply_len
47 	 *  to indicates the size of the reply to be returned to the
48 	 *  caller.
49 	 */
50 
51 	/* DMA payloads for the request/response */
52 	struct bsg_buffer request_payload;
53 	struct bsg_buffer reply_payload;
54 
55 	int result;
56 	unsigned int reply_payload_rcv_len;
57 
58 	/* BIDI support */
59 	struct request *bidi_rq;
60 	struct bio *bidi_bio;
61 
62 	void *dd_data;		/* Used for driver-specific storage */
63 };
64 
65 void bsg_job_done(struct bsg_job *job, int result,
66 		  unsigned int reply_payload_rcv_len);
67 struct request_queue *bsg_setup_queue(struct device *dev, const char *name,
68 		bsg_job_fn *job_fn, bsg_timeout_fn *timeout, int dd_job_size);
69 void bsg_remove_queue(struct request_queue *q);
70 void bsg_job_put(struct bsg_job *job);
71 int __must_check bsg_job_get(struct bsg_job *job);
72 
73 #endif
74