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1da177e4 LT |
1 | /* Driver for USB Mass Storage compliant devices |
2 | * SCSI layer glue code | |
3 | * | |
4 | * $Id: scsiglue.c,v 1.26 2002/04/22 03:39:43 mdharm Exp $ | |
5 | * | |
6 | * Current development and maintenance by: | |
7 | * (c) 1999-2002 Matthew Dharm (mdharm-usb@one-eyed-alien.net) | |
8 | * | |
9 | * Developed with the assistance of: | |
10 | * (c) 2000 David L. Brown, Jr. (usb-storage@davidb.org) | |
11 | * (c) 2000 Stephen J. Gowdy (SGowdy@lbl.gov) | |
12 | * | |
13 | * Initial work by: | |
14 | * (c) 1999 Michael Gee (michael@linuxspecific.com) | |
15 | * | |
16 | * This driver is based on the 'USB Mass Storage Class' document. This | |
17 | * describes in detail the protocol used to communicate with such | |
18 | * devices. Clearly, the designers had SCSI and ATAPI commands in | |
19 | * mind when they created this document. The commands are all very | |
20 | * similar to commands in the SCSI-II and ATAPI specifications. | |
21 | * | |
22 | * It is important to note that in a number of cases this class | |
23 | * exhibits class-specific exemptions from the USB specification. | |
24 | * Notably the usage of NAK, STALL and ACK differs from the norm, in | |
25 | * that they are used to communicate wait, failed and OK on commands. | |
26 | * | |
27 | * Also, for certain devices, the interrupt endpoint is used to convey | |
28 | * status of a command. | |
29 | * | |
30 | * Please see http://www.one-eyed-alien.net/~mdharm/linux-usb for more | |
31 | * information about this driver. | |
32 | * | |
33 | * This program is free software; you can redistribute it and/or modify it | |
34 | * under the terms of the GNU General Public License as published by the | |
35 | * Free Software Foundation; either version 2, or (at your option) any | |
36 | * later version. | |
37 | * | |
38 | * This program is distributed in the hope that it will be useful, but | |
39 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
40 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
41 | * General Public License for more details. | |
42 | * | |
43 | * You should have received a copy of the GNU General Public License along | |
44 | * with this program; if not, write to the Free Software Foundation, Inc., | |
45 | * 675 Mass Ave, Cambridge, MA 02139, USA. | |
46 | */ | |
47 | ||
48 | #include <linux/slab.h> | |
49 | #include <linux/module.h> | |
50 | ||
51 | #include <scsi/scsi.h> | |
52 | #include <scsi/scsi_cmnd.h> | |
53 | #include <scsi/scsi_devinfo.h> | |
54 | #include <scsi/scsi_device.h> | |
55 | #include <scsi/scsi_eh.h> | |
56 | ||
57 | #include "usb.h" | |
58 | #include "scsiglue.h" | |
59 | #include "debug.h" | |
60 | #include "transport.h" | |
61 | #include "protocol.h" | |
62 | ||
63 | /*********************************************************************** | |
64 | * Host functions | |
65 | ***********************************************************************/ | |
66 | ||
67 | static const char* host_info(struct Scsi_Host *host) | |
68 | { | |
69 | return "SCSI emulation for USB Mass Storage devices"; | |
70 | } | |
71 | ||
72 | static int slave_alloc (struct scsi_device *sdev) | |
73 | { | |
74 | /* | |
75 | * Set the INQUIRY transfer length to 36. We don't use any of | |
76 | * the extra data and many devices choke if asked for more or | |
77 | * less than 36 bytes. | |
78 | */ | |
79 | sdev->inquiry_len = 36; | |
80 | return 0; | |
81 | } | |
82 | ||
83 | static int slave_configure(struct scsi_device *sdev) | |
84 | { | |
85 | struct us_data *us = host_to_us(sdev->host); | |
86 | ||
87 | /* Scatter-gather buffers (all but the last) must have a length | |
88 | * divisible by the bulk maxpacket size. Otherwise a data packet | |
89 | * would end up being short, causing a premature end to the data | |
90 | * transfer. Since high-speed bulk pipes have a maxpacket size | |
91 | * of 512, we'll use that as the scsi device queue's DMA alignment | |
92 | * mask. Guaranteeing proper alignment of the first buffer will | |
93 | * have the desired effect because, except at the beginning and | |
94 | * the end, scatter-gather buffers follow page boundaries. */ | |
95 | blk_queue_dma_alignment(sdev->request_queue, (512 - 1)); | |
96 | ||
97 | /* Set the SCSI level to at least 2. We'll leave it at 3 if that's | |
98 | * what is originally reported. We need this to avoid confusing | |
99 | * the SCSI layer with devices that report 0 or 1, but need 10-byte | |
100 | * commands (ala ATAPI devices behind certain bridges, or devices | |
101 | * which simply have broken INQUIRY data). | |
102 | * | |
103 | * NOTE: This means /dev/sg programs (ala cdrecord) will get the | |
104 | * actual information. This seems to be the preference for | |
105 | * programs like that. | |
106 | * | |
107 | * NOTE: This also means that /proc/scsi/scsi and sysfs may report | |
108 | * the actual value or the modified one, depending on where the | |
109 | * data comes from. | |
110 | */ | |
111 | if (sdev->scsi_level < SCSI_2) | |
112 | sdev->scsi_level = SCSI_2; | |
113 | ||
114 | /* According to the technical support people at Genesys Logic, | |
115 | * devices using their chips have problems transferring more than | |
116 | * 32 KB at a time. In practice people have found that 64 KB | |
117 | * works okay and that's what Windows does. But we'll be | |
118 | * conservative; people can always use the sysfs interface to | |
119 | * increase max_sectors. */ | |
120 | if (le16_to_cpu(us->pusb_dev->descriptor.idVendor) == USB_VENDOR_ID_GENESYS && | |
121 | sdev->request_queue->max_sectors > 64) | |
122 | blk_queue_max_sectors(sdev->request_queue, 64); | |
123 | ||
124 | /* We can't put these settings in slave_alloc() because that gets | |
125 | * called before the device type is known. Consequently these | |
126 | * settings can't be overridden via the scsi devinfo mechanism. */ | |
127 | if (sdev->type == TYPE_DISK) { | |
128 | ||
129 | /* Disk-type devices use MODE SENSE(6) if the protocol | |
130 | * (SubClass) is Transparent SCSI, otherwise they use | |
131 | * MODE SENSE(10). */ | |
132 | if (us->subclass != US_SC_SCSI) | |
133 | sdev->use_10_for_ms = 1; | |
134 | ||
135 | /* Many disks only accept MODE SENSE transfer lengths of | |
136 | * 192 bytes (that's what Windows uses). */ | |
137 | sdev->use_192_bytes_for_3f = 1; | |
138 | ||
139 | /* Some devices don't like MODE SENSE with page=0x3f, | |
140 | * which is the command used for checking if a device | |
141 | * is write-protected. Now that we tell the sd driver | |
142 | * to do a 192-byte transfer with this command the | |
143 | * majority of devices work fine, but a few still can't | |
144 | * handle it. The sd driver will simply assume those | |
145 | * devices are write-enabled. */ | |
146 | if (us->flags & US_FL_NO_WP_DETECT) | |
147 | sdev->skip_ms_page_3f = 1; | |
148 | ||
149 | /* A number of devices have problems with MODE SENSE for | |
150 | * page x08, so we will skip it. */ | |
151 | sdev->skip_ms_page_8 = 1; | |
152 | ||
153 | /* Some disks return the total number of blocks in response | |
154 | * to READ CAPACITY rather than the highest block number. | |
155 | * If this device makes that mistake, tell the sd driver. */ | |
156 | if (us->flags & US_FL_FIX_CAPACITY) | |
157 | sdev->fix_capacity = 1; | |
158 | } else { | |
159 | ||
160 | /* Non-disk-type devices don't need to blacklist any pages | |
161 | * or to force 192-byte transfer lengths for MODE SENSE. | |
162 | * But they do need to use MODE SENSE(10). */ | |
163 | sdev->use_10_for_ms = 1; | |
164 | } | |
165 | ||
166 | /* Some devices choke when they receive a PREVENT-ALLOW MEDIUM | |
167 | * REMOVAL command, so suppress those commands. */ | |
168 | if (us->flags & US_FL_NOT_LOCKABLE) | |
169 | sdev->lockable = 0; | |
170 | ||
171 | /* this is to satisfy the compiler, tho I don't think the | |
172 | * return code is ever checked anywhere. */ | |
173 | return 0; | |
174 | } | |
175 | ||
176 | /* queue a command */ | |
177 | /* This is always called with scsi_lock(host) held */ | |
178 | static int queuecommand(struct scsi_cmnd *srb, | |
179 | void (*done)(struct scsi_cmnd *)) | |
180 | { | |
181 | struct us_data *us = host_to_us(srb->device->host); | |
182 | ||
183 | US_DEBUGP("%s called\n", __FUNCTION__); | |
184 | ||
185 | /* check for state-transition errors */ | |
186 | if (us->srb != NULL) { | |
187 | printk(KERN_ERR USB_STORAGE "Error in %s: us->srb = %p\n", | |
188 | __FUNCTION__, us->srb); | |
189 | return SCSI_MLQUEUE_HOST_BUSY; | |
190 | } | |
191 | ||
192 | /* fail the command if we are disconnecting */ | |
193 | if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) { | |
194 | US_DEBUGP("Fail command during disconnect\n"); | |
195 | srb->result = DID_NO_CONNECT << 16; | |
196 | done(srb); | |
197 | return 0; | |
198 | } | |
199 | ||
200 | /* enqueue the command and wake up the control thread */ | |
201 | srb->scsi_done = done; | |
202 | us->srb = srb; | |
203 | up(&(us->sema)); | |
204 | ||
205 | return 0; | |
206 | } | |
207 | ||
208 | /*********************************************************************** | |
209 | * Error handling functions | |
210 | ***********************************************************************/ | |
211 | ||
212 | /* Command timeout and abort */ | |
213 | /* This is always called with scsi_lock(host) held */ | |
214 | static int command_abort(struct scsi_cmnd *srb) | |
215 | { | |
216 | struct us_data *us = host_to_us(srb->device->host); | |
217 | ||
218 | US_DEBUGP("%s called\n", __FUNCTION__); | |
219 | ||
220 | /* Is this command still active? */ | |
221 | if (us->srb != srb) { | |
222 | US_DEBUGP ("-- nothing to abort\n"); | |
223 | return FAILED; | |
224 | } | |
225 | ||
226 | /* Set the TIMED_OUT bit. Also set the ABORTING bit, but only if | |
227 | * a device reset isn't already in progress (to avoid interfering | |
228 | * with the reset). To prevent races with auto-reset, we must | |
229 | * stop any ongoing USB transfers while still holding the host | |
230 | * lock. */ | |
231 | set_bit(US_FLIDX_TIMED_OUT, &us->flags); | |
232 | if (!test_bit(US_FLIDX_RESETTING, &us->flags)) { | |
233 | set_bit(US_FLIDX_ABORTING, &us->flags); | |
234 | usb_stor_stop_transport(us); | |
235 | } | |
1da177e4 LT |
236 | |
237 | /* Wait for the aborted command to finish */ | |
238 | wait_for_completion(&us->notify); | |
239 | ||
240 | /* Reacquire the lock and allow USB transfers to resume */ | |
1da177e4 LT |
241 | clear_bit(US_FLIDX_ABORTING, &us->flags); |
242 | clear_bit(US_FLIDX_TIMED_OUT, &us->flags); | |
243 | return SUCCESS; | |
244 | } | |
245 | ||
246 | /* This invokes the transport reset mechanism to reset the state of the | |
247 | * device */ | |
248 | /* This is always called with scsi_lock(host) held */ | |
249 | static int device_reset(struct scsi_cmnd *srb) | |
250 | { | |
251 | struct us_data *us = host_to_us(srb->device->host); | |
252 | int result; | |
253 | ||
254 | US_DEBUGP("%s called\n", __FUNCTION__); | |
255 | ||
256 | scsi_unlock(us_to_host(us)); | |
257 | ||
258 | /* lock the device pointers and do the reset */ | |
259 | down(&(us->dev_semaphore)); | |
260 | if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) { | |
261 | result = FAILED; | |
262 | US_DEBUGP("No reset during disconnect\n"); | |
263 | } else | |
264 | result = us->transport_reset(us); | |
265 | up(&(us->dev_semaphore)); | |
266 | ||
267 | /* lock the host for the return */ | |
268 | scsi_lock(us_to_host(us)); | |
269 | return result; | |
270 | } | |
271 | ||
272 | /* This resets the device's USB port. */ | |
273 | /* It refuses to work if there's more than one interface in | |
274 | * the device, so that other users are not affected. */ | |
275 | /* This is always called with scsi_lock(host) held */ | |
276 | static int bus_reset(struct scsi_cmnd *srb) | |
277 | { | |
278 | struct us_data *us = host_to_us(srb->device->host); | |
279 | int result, rc; | |
280 | ||
281 | US_DEBUGP("%s called\n", __FUNCTION__); | |
282 | ||
283 | scsi_unlock(us_to_host(us)); | |
284 | ||
285 | /* The USB subsystem doesn't handle synchronisation between | |
286 | * a device's several drivers. Therefore we reset only devices | |
287 | * with just one interface, which we of course own. */ | |
288 | ||
289 | down(&(us->dev_semaphore)); | |
290 | if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) { | |
291 | result = -EIO; | |
292 | US_DEBUGP("No reset during disconnect\n"); | |
293 | } else if (us->pusb_dev->actconfig->desc.bNumInterfaces != 1) { | |
294 | result = -EBUSY; | |
295 | US_DEBUGP("Refusing to reset a multi-interface device\n"); | |
296 | } else { | |
297 | rc = usb_lock_device_for_reset(us->pusb_dev, us->pusb_intf); | |
298 | if (rc < 0) { | |
299 | US_DEBUGP("unable to lock device for reset: %d\n", rc); | |
300 | result = rc; | |
301 | } else { | |
302 | result = usb_reset_device(us->pusb_dev); | |
303 | if (rc) | |
304 | usb_unlock_device(us->pusb_dev); | |
305 | US_DEBUGP("usb_reset_device returns %d\n", result); | |
306 | } | |
307 | } | |
308 | up(&(us->dev_semaphore)); | |
309 | ||
310 | /* lock the host for the return */ | |
311 | scsi_lock(us_to_host(us)); | |
312 | return result < 0 ? FAILED : SUCCESS; | |
313 | } | |
314 | ||
315 | /* Report a driver-initiated device reset to the SCSI layer. | |
316 | * Calling this for a SCSI-initiated reset is unnecessary but harmless. | |
317 | * The caller must own the SCSI host lock. */ | |
318 | void usb_stor_report_device_reset(struct us_data *us) | |
319 | { | |
320 | int i; | |
321 | struct Scsi_Host *host = us_to_host(us); | |
322 | ||
323 | scsi_report_device_reset(host, 0, 0); | |
324 | if (us->flags & US_FL_SCM_MULT_TARG) { | |
325 | for (i = 1; i < host->max_id; ++i) | |
326 | scsi_report_device_reset(host, 0, i); | |
327 | } | |
328 | } | |
329 | ||
330 | /*********************************************************************** | |
331 | * /proc/scsi/ functions | |
332 | ***********************************************************************/ | |
333 | ||
334 | /* we use this macro to help us write into the buffer */ | |
335 | #undef SPRINTF | |
336 | #define SPRINTF(args...) \ | |
337 | do { if (pos < buffer+length) pos += sprintf(pos, ## args); } while (0) | |
338 | ||
339 | static int proc_info (struct Scsi_Host *host, char *buffer, | |
340 | char **start, off_t offset, int length, int inout) | |
341 | { | |
342 | struct us_data *us = host_to_us(host); | |
343 | char *pos = buffer; | |
344 | const char *string; | |
345 | ||
346 | /* if someone is sending us data, just throw it away */ | |
347 | if (inout) | |
348 | return length; | |
349 | ||
350 | /* print the controller name */ | |
351 | SPRINTF(" Host scsi%d: usb-storage\n", host->host_no); | |
352 | ||
353 | /* print product, vendor, and serial number strings */ | |
354 | if (us->pusb_dev->manufacturer) | |
355 | string = us->pusb_dev->manufacturer; | |
356 | else if (us->unusual_dev->vendorName) | |
357 | string = us->unusual_dev->vendorName; | |
358 | else | |
359 | string = "Unknown"; | |
360 | SPRINTF(" Vendor: %s\n", string); | |
361 | if (us->pusb_dev->product) | |
362 | string = us->pusb_dev->product; | |
363 | else if (us->unusual_dev->productName) | |
364 | string = us->unusual_dev->productName; | |
365 | else | |
366 | string = "Unknown"; | |
367 | SPRINTF(" Product: %s\n", string); | |
368 | if (us->pusb_dev->serial) | |
369 | string = us->pusb_dev->serial; | |
370 | else | |
371 | string = "None"; | |
372 | SPRINTF("Serial Number: %s\n", string); | |
373 | ||
374 | /* show the protocol and transport */ | |
375 | SPRINTF(" Protocol: %s\n", us->protocol_name); | |
376 | SPRINTF(" Transport: %s\n", us->transport_name); | |
377 | ||
378 | /* show the device flags */ | |
379 | if (pos < buffer + length) { | |
380 | pos += sprintf(pos, " Quirks:"); | |
381 | ||
382 | #define US_FLAG(name, value) \ | |
383 | if (us->flags & value) pos += sprintf(pos, " " #name); | |
384 | US_DO_ALL_FLAGS | |
385 | #undef US_FLAG | |
386 | ||
387 | *(pos++) = '\n'; | |
388 | } | |
389 | ||
390 | /* | |
391 | * Calculate start of next buffer, and return value. | |
392 | */ | |
393 | *start = buffer + offset; | |
394 | ||
395 | if ((pos - buffer) < offset) | |
396 | return (0); | |
397 | else if ((pos - buffer - offset) < length) | |
398 | return (pos - buffer - offset); | |
399 | else | |
400 | return (length); | |
401 | } | |
402 | ||
403 | /*********************************************************************** | |
404 | * Sysfs interface | |
405 | ***********************************************************************/ | |
406 | ||
407 | /* Output routine for the sysfs max_sectors file */ | |
408 | static ssize_t show_max_sectors(struct device *dev, char *buf) | |
409 | { | |
410 | struct scsi_device *sdev = to_scsi_device(dev); | |
411 | ||
412 | return sprintf(buf, "%u\n", sdev->request_queue->max_sectors); | |
413 | } | |
414 | ||
415 | /* Input routine for the sysfs max_sectors file */ | |
416 | static ssize_t store_max_sectors(struct device *dev, const char *buf, | |
417 | size_t count) | |
418 | { | |
419 | struct scsi_device *sdev = to_scsi_device(dev); | |
420 | unsigned short ms; | |
421 | ||
422 | if (sscanf(buf, "%hu", &ms) > 0 && ms <= SCSI_DEFAULT_MAX_SECTORS) { | |
423 | blk_queue_max_sectors(sdev->request_queue, ms); | |
424 | return strlen(buf); | |
425 | } | |
426 | return -EINVAL; | |
427 | } | |
428 | ||
429 | static DEVICE_ATTR(max_sectors, S_IRUGO | S_IWUSR, show_max_sectors, | |
430 | store_max_sectors); | |
431 | ||
432 | static struct device_attribute *sysfs_device_attr_list[] = { | |
433 | &dev_attr_max_sectors, | |
434 | NULL, | |
435 | }; | |
436 | ||
437 | /* | |
438 | * this defines our host template, with which we'll allocate hosts | |
439 | */ | |
440 | ||
441 | struct scsi_host_template usb_stor_host_template = { | |
442 | /* basic userland interface stuff */ | |
443 | .name = "usb-storage", | |
444 | .proc_name = "usb-storage", | |
445 | .proc_info = proc_info, | |
446 | .info = host_info, | |
447 | ||
448 | /* command interface -- queued only */ | |
449 | .queuecommand = queuecommand, | |
450 | ||
451 | /* error and abort handlers */ | |
452 | .eh_abort_handler = command_abort, | |
453 | .eh_device_reset_handler = device_reset, | |
454 | .eh_bus_reset_handler = bus_reset, | |
455 | ||
456 | /* queue commands only, only one command per LUN */ | |
457 | .can_queue = 1, | |
458 | .cmd_per_lun = 1, | |
459 | ||
460 | /* unknown initiator id */ | |
461 | .this_id = -1, | |
462 | ||
463 | .slave_alloc = slave_alloc, | |
464 | .slave_configure = slave_configure, | |
465 | ||
466 | /* lots of sg segments can be handled */ | |
467 | .sg_tablesize = SG_ALL, | |
468 | ||
469 | /* limit the total size of a transfer to 120 KB */ | |
470 | .max_sectors = 240, | |
471 | ||
472 | /* merge commands... this seems to help performance, but | |
473 | * periodically someone should test to see which setting is more | |
474 | * optimal. | |
475 | */ | |
476 | .use_clustering = 1, | |
477 | ||
478 | /* emulated HBA */ | |
479 | .emulated = 1, | |
480 | ||
481 | /* we do our own delay after a device or bus reset */ | |
482 | .skip_settle_delay = 1, | |
483 | ||
484 | /* sysfs device attributes */ | |
485 | .sdev_attrs = sysfs_device_attr_list, | |
486 | ||
487 | /* module management */ | |
488 | .module = THIS_MODULE | |
489 | }; | |
490 | ||
491 | /* To Report "Illegal Request: Invalid Field in CDB */ | |
492 | unsigned char usb_stor_sense_invalidCDB[18] = { | |
493 | [0] = 0x70, /* current error */ | |
494 | [2] = ILLEGAL_REQUEST, /* Illegal Request = 0x05 */ | |
495 | [7] = 0x0a, /* additional length */ | |
496 | [12] = 0x24 /* Invalid Field in CDB */ | |
497 | }; | |
498 |