LXR linux/include/scsi/scsi

   1/* SPDX-License-Identifier: GPL-2.0 */
   2/* 
   3 *  Transport specific attributes.
   4 *
   5 *  Copyright (c) 2003 Silicon Graphics, Inc.  All rights reserved.
   6 */
   7#ifndef SCSI_TRANSPORT_H
   8#define SCSI_TRANSPORT_H
   9
  10#include <linux/transport_class.h>
  11#include <linux/blkdev.h>
  12#include <linux/bug.h>
  13#include <scsi/scsi_host.h>
  14#include <scsi/scsi_device.h>
  15
  16struct scsi_transport_template {
  17        /* the attribute containers */
  18        struct transport_container host_attrs;
  19        struct transport_container target_attrs;
  20        struct transport_container device_attrs;
  21
  22        /*
  23         * If set, called from sysfs and legacy procfs rescanning code.
  24         */
  25        int (*user_scan)(struct Scsi_Host *, uint, uint, u64);
  26
  27        /* The size of the specific transport attribute structure (a
  28         * space of this size will be left at the end of the
  29         * scsi_* structure */
  30        int     device_size;
  31        int     device_private_offset;
  32        int     target_size;
  33        int     target_private_offset;
  34        int     host_size;
  35        /* no private offset for the host; there's an alternative mechanism */
  36
  37        /*
  38         * True if the transport wants to use a host-based work-queue
  39         */
  40        unsigned int create_work_queue : 1;
  41
  42        /*
  43         * Allows a transport to override the default error handler.
  44         */
  45        void (* eh_strategy_handler)(struct Scsi_Host *);
  46};
  47
  48#define transport_class_to_shost(tc) \
  49        dev_to_shost((tc)->parent)
  50
  51
  52/* Private area maintenance. The driver requested allocations come
  53 * directly after the transport class allocations (if any).  The idea
  54 * is that you *must* call these only once.  The code assumes that the
  55 * initial values are the ones the transport specific code requires */
  56static inline void
  57scsi_transport_reserve_target(struct scsi_transport_template * t, int space)
  58{
  59        BUG_ON(t->target_private_offset != 0);
  60        t->target_private_offset = ALIGN(t->target_size, sizeof(void *));
  61        t->target_size = t->target_private_offset + space;
  62}
  63static inline void
  64scsi_transport_reserve_device(struct scsi_transport_template * t, int space)
  65{
  66        BUG_ON(t->device_private_offset != 0);
  67        t->device_private_offset = ALIGN(t->device_size, sizeof(void *));
  68        t->device_size = t->device_private_offset + space;
  69}
  70static inline void *
  71scsi_transport_target_data(struct scsi_target *starget)
  72{
  73        struct Scsi_Host *shost = dev_to_shost(&starget->dev);
  74        return (u8 *)starget->starget_data
  75                + shost->transportt->target_private_offset;
  76
  77}
  78static inline void *
  79scsi_transport_device_data(struct scsi_device *sdev)
  80{
  81        struct Scsi_Host *shost = sdev->host;
  82        return (u8 *)sdev->sdev_data
  83                + shost->transportt->device_private_offset;
  84}
  85
  86void __scsi_init_queue(struct Scsi_Host *shost, struct request_queue *q);
  87
  88#endif /* SCSI_TRANSPORT_H */
  89