i2o_block.h

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/*
 *  Block OSM structures/API
 *
 *  Copyright (C) 1999-2002 Red Hat Software
 *
 *  Written by Alan Cox, Building Number Three Ltd
 *
 *  This program is free software; you can redistribute it and/or modify it
 *  under the terms of the GNU General Public License as published by the
 *  Free Software Foundation; either version 2 of the License, or (at your
 *  option) any later version.
 *
 *  This program is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  General Public License for more details.
 *
 *  For the purpose of avoiding doubt the preferred form of the work
 *  for making modifications shall be a standards compliant form such
 *  gzipped tar and not one requiring a proprietary or patent encumbered
 *  tool to unpack.
 *
 *  Fixes/additions:
 *      Steve Ralston:
 *          Multiple device handling error fixes,
 *          Added a queue depth.
 *      Alan Cox:
 *          FC920 has an rmw bug. Dont or in the end marker.
 *          Removed queue walk, fixed for 64bitness.
 *          Rewrote much of the code over time
 *          Added indirect block lists
 *          Handle 64K limits on many controllers
 *          Don't use indirects on the Promise (breaks)
 *          Heavily chop down the queue depths
 *      Deepak Saxena:
 *          Independent queues per IOP
 *          Support for dynamic device creation/deletion
 *          Code cleanup
 *              Support for larger I/Os through merge* functions
 *          (taken from DAC960 driver)
 *      Boji T Kannanthanam:
 *          Set the I2O Block devices to be detected in increasing
 *          order of TIDs during boot.
 *          Search and set the I2O block device that we boot off
 *          from as the first device to be claimed (as /dev/i2o/hda)
 *          Properly attach/detach I2O gendisk structure from the
 *          system gendisk list. The I2O block devices now appear in
 *          /proc/partitions.
 *      Markus Lidel <[email protected]>:
 *          Minor bugfixes for 2.6.
 */

#ifndef I2O_BLOCK_OSM_H
#define I2O_BLOCK_OSM_H

#define I2O_BLOCK_RETRY_TIME HZ/4
#define I2O_BLOCK_MAX_OPEN_REQUESTS 50

/* request queue sizes */
#define I2O_BLOCK_REQ_MEMPOOL_SIZE      32

#define KERNEL_SECTOR_SHIFT 9
#define KERNEL_SECTOR_SIZE (1 << KERNEL_SECTOR_SHIFT)

/* I2O Block OSM mempool struct */
struct i2o_block_mempool {
    struct kmem_cache *slab;
    mempool_t *pool;
};

/* I2O Block device descriptor */
struct i2o_block_device {
    struct i2o_device *i2o_dev; /* pointer to I2O device */
    struct gendisk *gd;
    spinlock_t lock;    /* queue lock */
    struct list_head open_queue;    /* list of transferred, but unfinished
                       requests */
    unsigned int open_queue_depth;  /* number of requests in the queue */

    int rcache;     /* read cache flags */
    int wcache;     /* write cache flags */
    int flags;
    u16 power;      /* power state */
    int media_change_flag;  /* media changed flag */
};

/* I2O Block device request */
struct i2o_block_request {
    struct list_head queue;
    struct request *req;    /* corresponding request */
    struct i2o_block_device *i2o_blk_dev;   /* I2O block device */
    struct device *dev; /* device used for DMA */
    int sg_nents;       /* number of SG elements */
    struct scatterlist sg_table[I2O_MAX_PHYS_SEGMENTS]; /* SG table */
};

/* I2O Block device delayed request */
struct i2o_block_delayed_request {
    struct delayed_work work;
    struct request_queue *queue;
};

#endif