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         /* The size of the specific transport attribute structure (a
  33          * space of this size will be left at the end of the
  34          * scsi_* structure */
  35         int     device_size;
  36         int     device_private_offset;
  37         int     target_size;
  38         int     target_private_offset;
  39         int     host_size;
  40         /* no private offset for the host; there's an alternative mechanism */
  41
  42         /*
  43          * True if the transport wants to use a host-based work-queue
  44          */
  45         unsigned int create_work_queue : 1;
  46 };
  47
  48 #define transport_class_to_shost(tc) \
  49         dev_to_shost((tc)->dev)
  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 #endif /* SCSI_TRANSPORT_H */