drivers/message/i2o/i2o_block.h

   1 /*
   2  *      Block OSM structures/API
   3  *
   4  *      Copyright (C) 1999-2002 Red Hat Software
   5  *
   6  *      Written by Alan Cox, Building Number Three Ltd
   7  *
   8  *      This program is free software; you can redistribute it and/or modify it
   9  *      under the terms of the GNU General Public License as published by the
  10  *      Free Software Foundation; either version 2 of the License, or (at your
  11  *      option) any later version.
  12  *
  13  *      This program is distributed in the hope that it will be useful, but
  14  *      WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  *      General Public License for more details.
  17  *
  18  *      For the purpose of avoiding doubt the preferred form of the work
  19  *      for making modifications shall be a standards compliant form such
  20  *      gzipped tar and not one requiring a proprietary or patent encumbered
  21  *      tool to unpack.
  22  *
  23  *      Fixes/additions:
  24  *              Steve Ralston:
  25  *                      Multiple device handling error fixes,
  26  *                      Added a queue depth.
  27  *              Alan Cox:
  28  *                      FC920 has an rmw bug. Dont or in the end marker.
  29  *                      Removed queue walk, fixed for 64bitness.
  30  *                      Rewrote much of the code over time
  31  *                      Added indirect block lists
  32  *                      Handle 64K limits on many controllers
  33  *                      Don't use indirects on the Promise (breaks)
  34  *                      Heavily chop down the queue depths
  35  *              Deepak Saxena:
  36  *                      Independent queues per IOP
  37  *                      Support for dynamic device creation/deletion
  38  *                      Code cleanup
  39  *                      Support for larger I/Os through merge* functions
  40  *                      (taken from DAC960 driver)
  41  *              Boji T Kannanthanam:
  42  *                      Set the I2O Block devices to be detected in increasing
  43  *                      order of TIDs during boot.
  44  *                      Search and set the I2O block device that we boot off
  45  *                      from as the first device to be claimed (as /dev/i2o/hda)
  46  *                      Properly attach/detach I2O gendisk structure from the
  47  *                      system gendisk list. The I2O block devices now appear in
  48  *                      /proc/partitions.
  49  *              Markus Lidel <Markus.Lidel@shadowconnect.com>:
  50  *                      Minor bugfixes for 2.6.
  51  */
  52
  53 #ifndef I2O_BLOCK_OSM_H
  54 #define I2O_BLOCK_OSM_H
  55
  56 #define I2O_BLOCK_RETRY_TIME HZ/4
  57 #define I2O_BLOCK_MAX_OPEN_REQUESTS 50
  58
  59 /* I2O Block OSM mempool struct */
  60 struct i2o_block_mempool {
  61         kmem_cache_t    *slab;
  62         mempool_t       *pool;
  63 };
  64
  65 /* I2O Block device descriptor */
  66 struct i2o_block_device {
  67         struct i2o_device *i2o_dev;     /* pointer to I2O device */
  68         struct gendisk *gd;
  69         spinlock_t lock;                /* queue lock */
  70         struct list_head open_queue;    /* list of transfered, but unfinished
  71                                            requests */
  72         unsigned int open_queue_depth;  /* number of requests in the queue */
  73
  74         int rcache;                     /* read cache flags */
  75         int wcache;                     /* write cache flags */
  76         int flags;
  77         int power;                      /* power state */
  78         int media_change_flag;          /* media changed flag */
  79 };
  80
  81 /* I2O Block device request */
  82 struct i2o_block_request
  83 {
  84         struct list_head queue;
  85         struct request *req;            /* corresponding request */
  86         struct i2o_block_device *i2o_blk_dev;   /* I2O block device */
  87         int sg_dma_direction;           /* direction of DMA buffer read/write */
  88         int sg_nents;                   /* number of SG elements */
  89         struct scatterlist sg_table[I2O_MAX_SEGMENTS]; /* SG table */
  90 };
  91
  92 /* I2O Block device delayed request */
  93 struct i2o_block_delayed_request
  94 {
  95         struct work_struct work;
  96         struct request_queue *queue;
  97 };
  98
  99 #endif