/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 *  BSG helper library
 *
 *  Copyright (C) 2008   James Smart, Emulex Corporation
 *  Copyright (C) 2011   Red Hat, Inc.  All rights reserved.
 *  Copyright (C) 2011   Mike Christie
 */
#ifndef _BLK_BSG_
#define _BLK_BSG_

#include <linux/blkdev.h>

struct bsg_job;
struct request;
struct device;
struct scatterlist;
struct request_queue;

typedef int (bsg_job_fn) (struct bsg_job *);
typedef enum blk_eh_timer_return (bsg_timeout_fn)(struct request *);

struct bsg_buffer {
        unsigned int payload_len;
        int sg_cnt;
        struct scatterlist *sg_list;
};

struct bsg_job {
        struct device *dev;

        struct kref kref;

        unsigned int timeout;

        /* Transport/driver specific request/reply structs */
        void *request;
        void *reply;

        unsigned int request_len;
        unsigned int reply_len;
        /*
         * On entry : reply_len indicates the buffer size allocated for
         * the reply.
         *
         * Upon completion : the message handler must set reply_len
         *  to indicates the size of the reply to be returned to the
         *  caller.
         */

        /* DMA payloads for the request/response */
        struct bsg_buffer request_payload;
        struct bsg_buffer reply_payload;

        int result;
        unsigned int reply_payload_rcv_len;

        /* BIDI support */
        struct request *bidi_rq;
        struct bio *bidi_bio;

        void *dd_data;          /* Used for driver-specific storage */
};

void bsg_job_done(struct bsg_job *job, int result,
                  unsigned int reply_payload_rcv_len);
struct request_queue *bsg_setup_queue(struct device *dev, const char *name,
                struct queue_limits *lim, bsg_job_fn *job_fn,
                bsg_timeout_fn *timeout, int dd_job_size);
void bsg_remove_queue(struct request_queue *q);
void bsg_job_put(struct bsg_job *job);
int __must_check bsg_job_get(struct bsg_job *job);

#endif