LXR linux/include/scsi/scsi

   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 <linux/blkdev.h>
  25#include <linux/bug.h>
  26#include <scsi/scsi_host.h>
  27#include <scsi/scsi_device.h>
  28
  29struct scsi_transport_template {
  30        /* the attribute containers */
  31        struct transport_container host_attrs;
  32        struct transport_container target_attrs;
  33        struct transport_container device_attrs;
  34
  35        /*
  36         * If set, called from sysfs and legacy procfs rescanning code.
  37         */
  38        int (*user_scan)(struct Scsi_Host *, uint, uint, 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         * Allows a transport to override the default error handler.
  57         */
  58        void (* eh_strategy_handler)(struct Scsi_Host *);
  59
  60        /*
  61         * This is an optional routine that allows the transport to become
  62         * involved when a scsi io timer fires. The return value tells the
  63         * timer routine how to finish the io timeout handling:
  64         * EH_HANDLED:          I fixed the error, please complete the command
  65         * EH_RESET_TIMER:      I need more time, reset the timer and
  66         *                      begin counting again
  67         * EH_NOT_HANDLED       Begin normal error recovery
  68         */
  69        enum blk_eh_timer_return (*eh_timed_out)(struct scsi_cmnd *);
  70
  71        /*
  72         * Used as callback for the completion of i_t_nexus request
  73         * for target drivers.
  74         */
  75        int (* it_nexus_response)(struct Scsi_Host *, u64, int);
  76
  77        /*
  78         * Used as callback for the completion of task management
  79         * request for target drivers.
  80         */
  81        int (* tsk_mgmt_response)(struct Scsi_Host *, u64, u64, int);
  82};
  83
  84#define transport_class_to_shost(tc) \
  85        dev_to_shost((tc)->parent)
  86
  87
  88/* Private area maintenance. The driver requested allocations come
  89 * directly after the transport class allocations (if any).  The idea
  90 * is that you *must* call these only once.  The code assumes that the
  91 * initial values are the ones the transport specific code requires */
  92static inline void
  93scsi_transport_reserve_target(struct scsi_transport_template * t, int space)
  94{
  95        BUG_ON(t->target_private_offset != 0);
  96        t->target_private_offset = ALIGN(t->target_size, sizeof(void *));
  97        t->target_size = t->target_private_offset + space;
  98}
  99static inline void
 100scsi_transport_reserve_device(struct scsi_transport_template * t, int space)
 101{
 102        BUG_ON(t->device_private_offset != 0);
 103        t->device_private_offset = ALIGN(t->device_size, sizeof(void *));
 104        t->device_size = t->device_private_offset + space;
 105}
 106static inline void *
 107scsi_transport_target_data(struct scsi_target *starget)
 108{
 109        struct Scsi_Host *shost = dev_to_shost(&starget->dev);
 110        return (u8 *)starget->starget_data
 111                + shost->transportt->target_private_offset;
 112
 113}
 114static inline void *
 115scsi_transport_device_data(struct scsi_device *sdev)
 116{
 117        struct Scsi_Host *shost = sdev->host;
 118        return (u8 *)sdev->sdev_data
 119                + shost->transportt->device_private_offset;
 120}
 121
 122#endif /* SCSI_TRANSPORT_H */
 123