LXR linux/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#include <scsi/scsi_request.h>
  14
  15struct request;
  16struct device;
  17struct scatterlist;
  18struct request_queue;
  19
  20typedef int (bsg_job_fn) (struct bsg_job *);
  21typedef enum blk_eh_timer_return (bsg_timeout_fn)(struct request *);
  22
  23struct bsg_buffer {
  24        unsigned int payload_len;
  25        int sg_cnt;
  26        struct scatterlist *sg_list;
  27};
  28
  29struct 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
  65void bsg_job_done(struct bsg_job *job, int result,
  66                  unsigned int reply_payload_rcv_len);
  67struct 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);
  69void bsg_remove_queue(struct request_queue *q);
  70void bsg_job_put(struct bsg_job *job);
  71int __must_check bsg_job_get(struct bsg_job *job);
  72
  73#endif
  74