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1 '\" te
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6 .TH USCSI 7I "May 29, 2007"
7 .SH NAME
8 uscsi \- user SCSI command interface
9 .SH SYNOPSIS
10 .LP
11 .nf
12 #include <sys/scsi/impl/uscsi.h>
14 \fB\fR\fBioctl\fR(\fBint\fR \fIfildes\fR, \fBint\fR \fIrequest\fR, \fBstruct uscsi_cmd *\fR\fIcmd\fR);
15 .fi
17 .SH DESCRIPTION
18 .sp
19 .LP
20 The \fBuscsi\fR command is very powerful and somewhat dangerous; therefore it
21 has some permission restrictions. See \fBWARNINGS\fR for more details.
22 .sp
23 .LP
24 Drivers supporting this \fBioctl\fR(2) provide a general interface allowing
25 user-level applications to cause individual \fBSCSI\fR commands to be directed
26 to a particular \fBSCSI\fR or \fBATAPI\fR device under control of that driver.
27 The \fBuscsi\fR command is supported by the \fBsd\fR driver for \fBSCSI\fR
28 disks and \fBATAPI\fR CD-ROM drives, and by the \fBst\fR driver for \fBSCSI\fR
29 tape drives. \fBuscsi\fR may also be supported by other device drivers; see the
30 specific device driver manual page for complete information.
31 .sp
32 .LP
33 Applications must not assume that all Solaris disk device drivers support the
34 \fBuscsi\fR ioctl command. The \fBSCSI\fR command may include a data transfer
35 to or from that device, if appropriate for that command. Upon completion of the
36 command, the user application can determine how many bytes were transferred and
37 the status returned by the device. Also, optionally, if the command returns a
38 Check Condition status, the driver will automatically issue a Request Sense
39 command and return the sense data along with the original status. See the
40 \fBUSCSI_RQENABLE\fR flag below for this Request Sense processing. The
41 \fBuscsi_cmd\fR structure is defined in \fB<sys/scsi/impl/uscsi.h>\fR and
42 includes the following members:
43 .sp
44 .in +2
45 .nf
46 int uscsi_flags; /* read, write, etc. see below */
47 short uscsi_status; /* resulting status */
48 short uscsi_timeout; /* Command Timeout */
49 caddr_t uscsi_cdb /* CDB to send to target */
50 caddr_t uscsi_bufaddr; /* i/o source/destination */
51 size_t uscsi_buflen; /* size of i/o to take place*/
52 size_t uscsi_resid; /* resid from i/o operation */
53 uchar_t uscsi_cdblen; /* # of valid CDB bytes */
54 uchar_t uscsi_rqlen; /* size of uscsi_rqbuf */
55 uchar_t uscsi_rqstatus; /* status of request sense cmd */
56 uchar_t uscsi_rqresid; /* resid of request sense cmd */
57 caddr_t uscsi_rqbuf; /* request sense buffer */
58 void *uscsi_reserved_5; /* Reserved for future use */
59 .fi
60 .in -2
62 .sp
63 .LP
64 The fields of the \fBuscsi_cmd\fR structure have the following meanings:
65 .sp
66 .ne 2
67 .na
68 \fB\fBuscsi_flags\fR\fR
69 .ad
70 .RS 20n
71 The \fBI/O\fR direction and other details of how to carry out the \fBSCSI\fR
72 command. Possible values are described below.
73 .RE
75 .sp
76 .ne 2
77 .na
78 \fB\fBuscsi_status\fR\fR
79 .ad
80 .RS 20n
81 The \fBSCSI\fR status byte returned by the device is returned in this field.
82 .RE
84 .sp
85 .ne 2
86 .na
87 \fB\fBuscsi_timeout\fR\fR
88 .ad
89 .RS 20n
90 Time in seconds to allow for completion of the command.
91 .RE
93 .sp
94 .ne 2
95 .na
96 \fB\fBuscsi_cdb\fR\fR
97 .ad
98 .RS 20n
99 A pointer to the \fBSCSI\fR CDB (command descriptor block) to be transferred to
100 the device in command phase.
101 .RE
103 .sp
104 .ne 2
105 .na
106 \fB\fBuscsi_bufaddr\fR\fR
107 .ad
108 .RS 20n
109 The user buffer containing the data to be read from or written to the device.
110 .RE
112 .sp
113 .ne 2
114 .na
115 \fB\fBuscsi_buflen\fR\fR
116 .ad
117 .RS 20n
118 The length of \fBuscsi_bufaddr\fR.
119 .RE
121 .sp
122 .ne 2
123 .na
124 \fB\fBuscsi_resid\fR\fR
125 .ad
126 .RS 20n
127 If a data transfer terminates without transferring the entire requested amount,
128 the remainder, or residue, is returned in this field.
129 .RE
131 .sp
132 .ne 2
133 .na
134 \fB\fBuscsi_cdblen\fR\fR
135 .ad
136 .RS 20n
137 The length of the \fBSCSI\fR CDB to be transferred to the device in command
138 phase.
139 .RE
141 .sp
142 .ne 2
143 .na
144 \fB\fBuscsi_rqlen\fR\fR
145 .ad
146 .RS 20n
147 The length of \fBuscsi_rqbuf\fR, the application's Request Sense buffer.
148 .RE
150 .sp
151 .ne 2
152 .na
153 \fB\fBuscsi_rqstatus\fR\fR
154 .ad
155 .RS 20n
156 The \fBSCSI\fR status byte returned for the Request Sense command executed
157 automatically by the driver in response to a Check Condition status return.
158 .RE
160 .sp
161 .ne 2
162 .na
163 \fB\fBuscsi_rqresid\fR\fR
164 .ad
165 .RS 20n
166 The residue, or untransferred data length, of the Request Sense data transfer
167 (the number of bytes, less than or equal to \fBuscsi_rqlen\fR, which were not
168 filled with sense data).
169 .RE
171 .sp
172 .ne 2
173 .na
174 \fB\fBuscsi_rqbuf\fR\fR
175 .ad
176 .RS 20n
177 Points to a buffer in application address space to which the results of an
178 automatic Request Sense command are written.
179 .RE
181 .sp
182 .ne 2
183 .na
184 \fB\fBuscsi_reserved_5\fR\fR
185 .ad
186 .RS 20n
187 Reserved for future use.
188 .RE
190 .sp
191 .LP
192 The \fBuscsi_flags\fR field defines the following:
193 .sp
194 .in +2
195 .nf
196 USCSI_WRITE /* send data to device */
197 USCSI_SILENT /* no error messages */
198 USCSI_DIAGNOSE /* fail if any error occurs */
199 USCSI_ISOLATE /* isolate from normal commands */
200 USCSI_READ /* get data from device */
201 USCSI_ASYNC /* set bus to asynchronous mode */
202 USCSI_SYNC /* return bus to sync mode if possible */
203 USCSI_RESET /* reset target */
204 USCSI_RESET_TARGET /* reset target */
205 USCSI_RESET_LUN /* reset logical unit */
206 USCSI_RESET_ALL /* reset all targets */
207 USCSI_RQENABLE /* enable request sense extensions */
208 USCSI_RENEGOT /* renegotiate wide/sync on next I/O */
209 .fi
210 .in -2
212 .sp
213 .LP
214 The \fBuscsi_flags\fR bits have the following interpretation:
215 .sp
216 .ne 2
217 .na
218 \fB\fBUSCSI_WRITE\fR\fR
219 .ad
220 .RS 22n
221 Data will be written from the initiator to the target.
222 .RE
224 .sp
225 .ne 2
226 .na
227 \fB\fBUSCSI_SILENT\fR\fR
228 .ad
229 .RS 22n
230 The driver should not print any console error messages or warnings regarding
231 failures associated with this \fBSCSI\fR command.
232 .RE
234 .sp
235 .ne 2
236 .na
237 \fB\fBUSCSI_DIAGNOSE\fR\fR
238 .ad
239 .RS 22n
240 The driver should not attempt any retries or other recovery mechanisms if this
241 \fBSCSI\fR command terminates abnormally in any way.
242 .RE
244 .sp
245 .ne 2
246 .na
247 \fB\fBUSCSI_ISOLATE\fR\fR
248 .ad
249 .RS 22n
250 This \fBSCSI\fR command should not be executed with other commands.
251 .RE
253 .sp
254 .ne 2
255 .na
256 \fB\fBUSCSI_READ\fR\fR
257 .ad
258 .RS 22n
259 Data will be read from the target to the initiator.
260 .RE
262 .sp
263 .ne 2
264 .na
265 \fB\fBUSCSI_ASYNC\fR\fR
266 .ad
267 .RS 22n
268 Set the \fBSCSI\fR bus to asynchronous mode before running this command.
269 .RE
271 .sp
272 .ne 2
273 .na
274 \fB\fBUSCSI_SYNC\fR\fR
275 .ad
276 .RS 22n
277 Set the \fBSCSI\fR bus to synchronous mode before running this command.
278 .RE
280 .sp
281 .ne 2
282 .na
283 \fB\fBUSCSI_RESET\fR\fR
284 .ad
285 .RS 22n
286 Send a \fBSCSI\fR bus device reset message to this target.
287 .RE
289 .sp
290 .ne 2
291 .na
292 \fB\fBUSCSI_RESET_TARGET\fR\fR
293 .ad
294 .RS 22n
295 Same as USCSI_RESET. Use this flag to request TARGET RESET. (USCSI_RESET is
296 maintained only for compatibility with old applications).
297 .RE
299 .sp
300 .ne 2
301 .na
302 \fB\fBUSCSI_RESET_LUN\fR\fR
303 .ad
304 .RS 22n
305 Send a \fBSCSI\fR logical unit reset message to this target.
306 .RE
308 .sp
309 .ne 2
310 .na
311 \fB\fBUSCSI_RESET_ALL\fR\fR
312 .ad
313 .RS 22n
314 USCSI_RESET_ALL, USCSI_RESET/USCSI_RESET_TARGET and USCSI_RESET_LUN are
315 mutually exclusive options and issuing them in any simultaneous combination
316 will result in implementation-dependent behavior
317 .sp
318 When a USCSI reset request is combined with other \fBSCSI\fR commands, the
319 following semantics take effect:
320 .sp
321 If the USCSI RESET flag is specified, the other fields (other than uscsi_flags)
322 in the uscsi_cmd are ignored. The uscsi_cdblen \fBmust\fR be set to zero.
323 .RE
325 .sp
326 .ne 2
327 .na
328 \fB\fBUSCSI_RQENABLE\fR\fR
329 .ad
330 .RS 22n
331 Enable Request Sense extensions. If the user application is prepared to receive
332 sense data, this bit must be set, the fields \fBuscsi_rqbuf\fR and
333 \fBuscsi_rqbuflen\fR must be non-zero, and the \fBuscsi_rqbuf\fR must point to
334 memory writable by the application.
335 .RE
337 .sp
338 .ne 2
339 .na
340 \fB\fBUSCSI_RENEGOT\fR\fR
341 .ad
342 .RS 22n
343 Tells USCSI to renegotiate wide mode and synchronous transfer speed before the
344 transmitted SCSI command is executed. This flag in effects tells the target
345 driver to pass the \fBFLAG_RENEGOTIATE_WIDE_SYNC\fR flag in the SCSI packet
346 before passing the command to an adapter driver for transport.
347 .sp
348 See the \fBscsi_pkt\fR(9S) flag \fBFLAG_RENEGOTIATE_WIDE_SYNC\fR for more
349 information.
350 .RE
352 .SH IOCTLS
353 .sp
354 .LP
355 The \fBioctl\fR supported by drivers providing the \fBuscsi\fR interface is:
356 .sp
357 .ne 2
358 .na
359 \fB\fBUSCSICMD\fR\fR
360 .ad
361 .RS 12n
362 The argument is a pointer to a \fBuscsi_cmd\fR structure. The \fBSCSI\fR device
363 addressed by that driver is selected, and given the \fBSCSI\fR command
364 addressed by \fBuscsi_cdb\fR. If this command requires a data phase, the
365 \fBuscsi_buflen\fR and \fBuscsi_bufaddr\fR fields must be set appropriately; if
366 data phase occurs, the \fBuscsi_resid\fR is returned as the number of bytes not
367 transferred. The status of the command, as returned by the device, is returned
368 in the \fBuscsi_status\fR field. If the command terminates with Check Condition
369 status, and Request Sense is enabled, the sense data itself is returned in
370 \fBuscsi_rqbuf\fR. The \fBuscsi_rqresid\fR provides the residue of the Request
371 Sense data transfer.
372 .RE
374 .SH ERRORS
375 .sp
376 .ne 2
377 .na
378 \fB\fBEINVAL\fR\fR
379 .ad
380 .RS 10n
381 A parameter has an incorrect, or unsupported, value.
382 .RE
384 .sp
385 .ne 2
386 .na
387 \fB\fBEIO\fR\fR
388 .ad
389 .RS 10n
390 An error occurred during the execution of the command.
391 .RE
393 .sp
394 .ne 2
395 .na
396 \fB\fBEPERM\fR\fR
397 .ad
398 .RS 10n
399 A process without root credentials tried to execute the \fBUSCSICMD\fR ioctl.
400 .RE
402 .sp
403 .ne 2
404 .na
405 \fB\fBEFAULT\fR\fR
406 .ad
407 .RS 10n
408 The \fBuscsi_cmd\fR itself, the \fBuscsi_cdb\fR, the \fBuscsi_buf\fR, or the
409 \fBuscsi_rqbuf\fR point to an invalid address.
410 .RE
412 .SH ATTRIBUTES
413 .sp
414 .LP
415 See \fBattributes\fR(5) for descriptions of the following attributes:
416 .sp
418 .sp
419 .TS
420 box;
421 c | c
422 l | l .
423 ATTRIBUTE TYPE ATTRIBUTE VALUE
424 _
425 Interface Stability Committed
426 .TE
428 .SH SEE ALSO
429 .sp
430 .LP
431 \fBioctl\fR(2), \fBattributes\fR(5), \fBsd\fR(7D), \fBst\fR(7D)
432 .sp
433 .LP
434 \fIANSI Small Computer System Interface-2 (SCSI-2)\fR
435 .SH WARNINGS
436 .sp
437 .LP
438 The \fBuscsi\fR command is very powerful, but somewhat dangerous, and so its
439 use is restricted to processes running as root, regardless of the file
440 permissions on the device node. The device driver code expects to own the
441 device state, and \fBuscsi\fR commands can change the state of the device and
442 confuse the device driver. It is best to use \fBuscsi\fR commands only with no
443 side effects, and avoid commands such as Mode Select, as they may cause damage
444 to data stored on the drive or system panics. Also, as the commands are not
445 checked in any way by the device driver, any block may be overwritten, and the
446 block numbers are absolute block numbers on the drive regardless of which slice
447 number is used to send the command.
448 .sp
449 .LP
450 The \fBuscsi\fR interface is not recommended for very large data transfers
451 (typically more than 16MB). If the requested transfer size exceeds the maximum
452 transfer size of the DMA engine, it will not be broken up into multiple
453 transfers and DMA errors may result.
454 .sp
455 .LP
456 The \fBUSCSICMD\fR ioctl associates a \fBstruct uscsi_cmd\fR with a device by
457 using an open file descriptor to the device. Other APIs might provide the same
458 \fBstruct uscsi_cmd\fR programming interface, but perform device association in
459 some other manner.