include/scsi/scsi_transport.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   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
  16 struct 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 */
  56 static inline void
  57 scsi_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 }
  63 static inline void
  64 scsi_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 }
  70 static inline void *
  71 scsi_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 }
  78 static inline void *
  79 scsi_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
  86 void __scsi_init_queue(struct Scsi_Host *shost, struct request_queue *q);
  87
  88 #endif /* SCSI_TRANSPORT_H */