1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
|
/*
* hosts.h Copyright (C) 1992 Drew Eckhardt
* Copyright (C) 1993, 1994, 1995 Eric Youngdale
*
* mid to low-level SCSI driver interface header
* Initial versions: Drew Eckhardt
* Subsequent revisions: Eric Youngdale
*
* <drew@colorado.edu>
*
* Modified by Eric Youngdale eric@aib.com to
* add scatter-gather, multiple outstanding request, and other
* enhancements.
*
* Further modified by Eric Youngdale to support multiple host adapters
* of the same type.
*/
#ifndef _HOSTS_H
#define _HOSTS_H
/*
$Header: cvs/gnumach/linux/src/drivers/scsi/Attic/hosts.h,v 1.1 1999/04/26 05:54:41 tb Exp $
*/
#include <linux/proc_fs.h>
/* It is senseless to set SG_ALL any higher than this - the performance
* does not get any better, and it wastes memory
*/
#define SG_NONE 0
#define SG_ALL 0xff
#define DISABLE_CLUSTERING 0
#define ENABLE_CLUSTERING 1
/* The various choices mean:
* NONE: Self evident. Host adapter is not capable of scatter-gather.
* ALL: Means that the host adapter module can do scatter-gather,
* and that there is no limit to the size of the table to which
* we scatter/gather data.
* Anything else: Indicates the maximum number of chains that can be
* used in one scatter-gather request.
*/
/*
* The Scsi_Host_Template type has all that is needed to interface with a SCSI
* host in a device independent matter. There is one entry for each different
* type of host adapter that is supported on the system.
*/
typedef struct scsi_disk Disk;
typedef struct SHT
{
/* Used with loadable modules so we can construct a linked list. */
struct SHT * next;
/* Used with loadable modules so that we know when it is safe to unload */
long * usage_count;
/* The pointer to the /proc/scsi directory entry */
struct proc_dir_entry *proc_dir;
/* proc-fs info function.
* Can be used to export driver statistics and other infos to the world
* outside the kernel ie. userspace and it also provides an interface
* to feed the driver with information. Check eata_dma_proc.c for reference
*/
int (*proc_info)(char *, char **, off_t, int, int, int);
/*
* The name pointer is a pointer to the name of the SCSI
* device detected.
*/
const char *name;
/*
* The detect function shall return non zero on detection,
* indicating the number of host adapters of this particular
* type were found. It should also
* initialize all data necessary for this particular
* SCSI driver. It is passed the host number, so this host
* knows where the first entry is in the scsi_hosts[] array.
*
* Note that the detect routine MUST not call any of the mid level
* functions to queue commands because things are not guaranteed
* to be set up yet. The detect routine can send commands to
* the host adapter as long as the program control will not be
* passed to scsi.c in the processing of the command. Note
* especially that scsi_malloc/scsi_free must not be called.
*/
int (* detect)(struct SHT *);
/* Used with loadable modules to unload the host structures. Note:
* there is a default action built into the modules code which may
* be sufficient for most host adapters. Thus you may not have to supply
* this at all.
*/
int (*release)(struct Scsi_Host *);
/*
* The info function will return whatever useful
* information the developer sees fit. If not provided, then
* the name field will be used instead.
*/
const char *(* info)(struct Scsi_Host *);
/*
* The command function takes a target, a command (this is a SCSI
* command formatted as per the SCSI spec, nothing strange), a
* data buffer pointer, and data buffer length pointer. The return
* is a status int, bit fielded as follows :
* Byte What
* 0 SCSI status code
* 1 SCSI 1 byte message
* 2 host error return.
* 3 mid level error return
*/
int (* command)(Scsi_Cmnd *);
/*
* The QueueCommand function works in a similar manner
* to the command function. It takes an additional parameter,
* void (* done)(int host, int code) which is passed the host
* # and exit result when the command is complete.
* Host number is the POSITION IN THE hosts array of THIS
* host adapter.
*/
int (* queuecommand)(Scsi_Cmnd *, void (*done)(Scsi_Cmnd *));
/*
* Since the mid level driver handles time outs, etc, we want to
* be able to abort the current command. Abort returns 0 if the
* abortion was successful. The field SCpnt->abort reason
* can be filled in with the appropriate reason why we wanted
* the abort in the first place, and this will be used
* in the mid-level code instead of the host_byte().
* If non-zero, the code passed to it
* will be used as the return code, otherwise
* DID_ABORT should be returned.
*
* Note that the scsi driver should "clean up" after itself,
* resetting the bus, etc. if necessary.
*/
int (* abort)(Scsi_Cmnd *);
/*
* The reset function will reset the SCSI bus. Any executing
* commands should fail with a DID_RESET in the host byte.
* The Scsi_Cmnd is passed so that the reset routine can figure
* out which host adapter should be reset, and also which command
* within the command block was responsible for the reset in
* the first place. Some hosts do not implement a reset function,
* and these hosts must call scsi_request_sense(SCpnt) to keep
* the command alive.
*/
int (* reset)(Scsi_Cmnd *, unsigned int);
/*
* This function is used to select synchronous communications,
* which will result in a higher data throughput. Not implemented
* yet.
*/
int (* slave_attach)(int, int);
/*
* This function determines the bios parameters for a given
* harddisk. These tend to be numbers that are made up by
* the host adapter. Parameters:
* size, device number, list (heads, sectors, cylinders)
*/
int (* bios_param)(Disk *, kdev_t, int []);
/*
* This determines if we will use a non-interrupt driven
* or an interrupt driven scheme, It is set to the maximum number
* of simultaneous commands a given host adapter will accept.
*/
int can_queue;
/*
* In many instances, especially where disconnect / reconnect are
* supported, our host also has an ID on the SCSI bus. If this is
* the case, then it must be reserved. Please set this_id to -1 if
* your setup is in single initiator mode, and the host lacks an
* ID.
*/
int this_id;
/*
* This determines the degree to which the host adapter is capable
* of scatter-gather.
*/
short unsigned int sg_tablesize;
/*
* True if this host adapter can make good use of linked commands.
* This will allow more than one command to be queued to a given
* unit on a given host. Set this to the maximum number of command
* blocks to be provided for each device. Set this to 1 for one
* command block per lun, 2 for two, etc. Do not set this to 0.
* You should make sure that the host adapter will do the right thing
* before you try setting this above 1.
*/
short cmd_per_lun;
/*
* present contains counter indicating how many boards of this
* type were found when we did the scan.
*/
unsigned char present;
/*
* true if this host adapter uses unchecked DMA onto an ISA bus.
*/
unsigned unchecked_isa_dma:1;
/*
* true if this host adapter can make good use of clustering.
* I originally thought that if the tablesize was large that it
* was a waste of CPU cycles to prepare a cluster list, but
* it works out that the Buslogic is faster if you use a smaller
* number of segments (i.e. use clustering). I guess it is
* inefficient.
*/
unsigned use_clustering:1;
} Scsi_Host_Template;
/*
* The scsi_hosts array is the array containing the data for all
* possible <supported> scsi hosts. This is similar to the
* Scsi_Host_Template, except that we have one entry for each
* actual physical host adapter on the system, stored as a linked
* list. Note that if there are 2 aha1542 boards, then there will
* be two Scsi_Host entries, but only 1 Scsi_Host_Template entry.
*/
struct Scsi_Host
{
struct Scsi_Host * next;
unsigned short extra_bytes;
volatile unsigned char host_busy;
char host_no; /* Used for IOCTL_GET_IDLUN, /proc/scsi et al. */
unsigned long last_reset;
struct wait_queue *host_wait;
Scsi_Cmnd *host_queue;
Scsi_Host_Template * hostt;
/*
* These three parameters can be used to allow for wide scsi,
* and for host adapters that support multiple busses
* The first two should be set to 1 more than the actual max id
* or lun (i.e. 8 for normal systems).
*/
unsigned int max_id;
unsigned int max_lun;
unsigned int max_channel;
/*
* Pointer to a circularly linked list - this indicates the hosts
* that should be locked out of performing I/O while we have an active
* command on this host.
*/
struct Scsi_Host * block;
unsigned wish_block:1;
/* These parameters should be set by the detect routine */
unsigned char *base;
unsigned int io_port;
unsigned char n_io_port;
unsigned char irq;
unsigned char dma_channel;
/*
* This is a unique identifier that must be assigned so that we
* have some way of identifying each detected host adapter properly
* and uniquely. For hosts that do not support more than one card
* in the system at one time, this does not need to be set. It is
* initialized to 0 in scsi_register.
*/
unsigned int unique_id;
/*
* The rest can be copied from the template, or specifically
* initialized, as required.
*/
int this_id;
int can_queue;
short cmd_per_lun;
short unsigned int sg_tablesize;
unsigned unchecked_isa_dma:1;
unsigned use_clustering:1;
/*
* True if this host was loaded as a loadable module
*/
unsigned loaded_as_module:1;
void (*select_queue_depths)(struct Scsi_Host *, Scsi_Device *);
unsigned long hostdata[0]; /* Used for storage of host specific stuff */
};
extern struct Scsi_Host * scsi_hostlist;
extern struct Scsi_Device_Template * scsi_devicelist;
extern Scsi_Host_Template * scsi_hosts;
extern void build_proc_dir_entries(Scsi_Host_Template *);
/*
* scsi_init initializes the scsi hosts.
*/
/*
* We use these goofy things because the MM is not set up when we init
* the scsi subsystem. By using these functions we can write code that
* looks normal. Also, it makes it possible to use the same code for a
* loadable module.
*/
extern void * scsi_init_malloc(unsigned int size, int priority);
extern void scsi_init_free(char * ptr, unsigned int size);
extern int next_scsi_host;
extern int scsi_loadable_module_flag;
unsigned int scsi_init(void);
extern struct Scsi_Host * scsi_register(Scsi_Host_Template *, int j);
extern void scsi_unregister(struct Scsi_Host * i);
#define BLANK_HOST {"", 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
struct Scsi_Device_Template
{
struct Scsi_Device_Template * next;
const char * name;
const char * tag;
long * usage_count; /* Used for loadable modules */
unsigned char scsi_type;
unsigned char major;
unsigned char nr_dev; /* Number currently attached */
unsigned char dev_noticed; /* Number of devices detected. */
unsigned char dev_max; /* Current size of arrays */
unsigned blk:1; /* 0 if character device */
int (*detect)(Scsi_Device *); /* Returns 1 if we can attach this device */
int (*init)(void); /* Sizes arrays based upon number of devices
* detected */
void (*finish)(void); /* Perform initialization after attachment */
int (*attach)(Scsi_Device *); /* Attach devices to arrays */
void (*detach)(Scsi_Device *);
};
extern struct Scsi_Device_Template sd_template;
extern struct Scsi_Device_Template st_template;
extern struct Scsi_Device_Template sr_template;
extern struct Scsi_Device_Template sg_template;
int scsi_register_device(struct Scsi_Device_Template * sdpnt);
/* These are used by loadable modules */
extern int scsi_register_module(int, void *);
extern void scsi_unregister_module(int, void *);
/* The different types of modules that we can load and unload */
#define MODULE_SCSI_HA 1
#define MODULE_SCSI_CONST 2
#define MODULE_SCSI_IOCTL 3
#define MODULE_SCSI_DEV 4
/*
* This is an ugly hack. If we expect to be able to load devices at run time,
* we need to leave extra room in some of the data structures. Doing a
* realloc to enlarge the structures would be riddled with race conditions,
* so until a better solution is discovered, we use this crude approach
*/
#define SD_EXTRA_DEVS 2
#define ST_EXTRA_DEVS 2
#define SR_EXTRA_DEVS 2
#define SG_EXTRA_DEVS (SD_EXTRA_DEVS + SR_EXTRA_DEVS + ST_EXTRA_DEVS)
#endif
/*
* Overrides for Emacs so that we follow Linus's tabbing style.
* Emacs will notice this stuff at the end of the file and automatically
* adjust the settings for this buffer only. This must remain at the end
* of the file.
* ---------------------------------------------------------------------------
* Local variables:
* c-indent-level: 4
* c-brace-imaginary-offset: 0
* c-brace-offset: -4
* c-argdecl-indent: 4
* c-label-offset: -4
* c-continued-statement-offset: 4
* c-continued-brace-offset: 0
* indent-tabs-mode: nil
* tab-width: 8
* End:
*/
|