include/linux/bsg-lib.h

   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
  14 struct bsg_job;
  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                 struct queue_limits *lim, bsg_job_fn *job_fn,
  69                 bsg_timeout_fn *timeout, int dd_job_size);
  70 void bsg_remove_queue(struct request_queue *q);
  71 void bsg_job_put(struct bsg_job *job);
  72 int __must_check bsg_job_get(struct bsg_job *job);
  73
  74 #endif