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 /* request queue sizes */
60 #define I2O_BLOCK_REQ_MEMPOOL_SIZE		32
61 
62 #define KERNEL_SECTOR_SHIFT 9
63 #define KERNEL_SECTOR_SIZE (1 << KERNEL_SECTOR_SHIFT)
64 
65 /* I2O Block OSM mempool struct */
66 struct i2o_block_mempool {
67 	struct kmem_cache *slab;
68 	mempool_t *pool;
69 };
70 
71 /* I2O Block device descriptor */
72 struct i2o_block_device {
73 	struct i2o_device *i2o_dev;	/* pointer to I2O device */
74 	struct gendisk *gd;
75 	spinlock_t lock;	/* queue lock */
76 	struct list_head open_queue;	/* list of transferred, but unfinished
77 					   requests */
78 	unsigned int open_queue_depth;	/* number of requests in the queue */
79 
80 	int rcache;		/* read cache flags */
81 	int wcache;		/* write cache flags */
82 	int flags;
83 	u16 power;		/* power state */
84 	int media_change_flag;	/* media changed flag */
85 };
86 
87 /* I2O Block device request */
88 struct i2o_block_request {
89 	struct list_head queue;
90 	struct request *req;	/* corresponding request */
91 	struct i2o_block_device *i2o_blk_dev;	/* I2O block device */
92 	struct device *dev;	/* device used for DMA */
93 	int sg_nents;		/* number of SG elements */
94 	struct scatterlist sg_table[I2O_MAX_PHYS_SEGMENTS];	/* SG table */
95 };
96 
97 /* I2O Block device delayed request */
98 struct i2o_block_delayed_request {
99 	struct delayed_work work;
100 	struct request_queue *queue;
101 };
102 
103 #endif
104