include/scsi/scsi_transport.h

   1 /*
   2  *  Transport specific attributes.
   3  *
   4  *  Copyright (c) 2003 Silicon Graphics, Inc.  All rights reserved.
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, write to the Free Software
  18  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20 #ifndef SCSI_TRANSPORT_H
  21 #define SCSI_TRANSPORT_H
  22
  23 #include <linux/transport_class.h>
  24 #include <scsi/scsi_host.h>
  25
  26 struct scsi_transport_template {
  27         /* the attribute containers */
  28         struct transport_container host_attrs;
  29         struct transport_container target_attrs;
  30         struct transport_container device_attrs;
  31
  32         /*
  33          * If set, call target_parent prior to allocating a scsi_target,
  34          * so we get the appropriate parent for the target. This function
  35          * is required for transports like FC and iSCSI that do not put the
  36          * scsi_target under scsi_host.
  37          */
  38         struct device *(*target_parent)(struct Scsi_Host *, int, uint);
  39
  40         /* The size of the specific transport attribute structure (a
  41          * space of this size will be left at the end of the
  42          * scsi_* structure */
  43         int     device_size;
  44         int     device_private_offset;
  45         int     target_size;
  46         int     target_private_offset;
  47         int     host_size;
  48         /* no private offset for the host; there's an alternative mechanism */
  49
  50         /*
  51          * True if the transport wants to use a host-based work-queue
  52          */
  53         unsigned int create_work_queue : 1;
  54 };
  55
  56 #define transport_class_to_shost(tc) \
  57         dev_to_shost((tc)->dev)
  58
  59
  60 /* Private area maintenance. The driver requested allocations come
  61  * directly after the transport class allocations (if any).  The idea
  62  * is that you *must* call these only once.  The code assumes that the
  63  * initial values are the ones the transport specific code requires */
  64 static inline void
  65 scsi_transport_reserve_target(struct scsi_transport_template * t, int space)
  66 {
  67         BUG_ON(t->target_private_offset != 0);
  68         t->target_private_offset = ALIGN(t->target_size, sizeof(void *));
  69         t->target_size = t->target_private_offset + space;
  70 }
  71 static inline void
  72 scsi_transport_reserve_device(struct scsi_transport_template * t, int space)
  73 {
  74         BUG_ON(t->device_private_offset != 0);
  75         t->device_private_offset = ALIGN(t->device_size, sizeof(void *));
  76         t->device_size = t->device_private_offset + space;
  77 }
  78 static inline void *
  79 scsi_transport_target_data(struct scsi_target *starget)
  80 {
  81         struct Scsi_Host *shost = dev_to_shost(&starget->dev);
  82         return (u8 *)starget->starget_data
  83                 + shost->transportt->target_private_offset;
  84
  85 }
  86 static inline void *
  87 scsi_transport_device_data(struct scsi_device *sdev)
  88 {
  89         struct Scsi_Host *shost = sdev->host;
  90         return (u8 *)sdev->sdev_data
  91                 + shost->transportt->device_private_offset;
  92 }
  93
  94 #endif /* SCSI_TRANSPORT_H */