1 /* Driver for USB Mass Storage compliant devices
4 * $Id: scsiglue.c,v 1.26 2002/04/22 03:39:43 mdharm Exp $
6 * Current development and maintenance by:
7 * (c) 1999-2002 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
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)
14 * (c) 1999 Michael Gee (michael@linuxspecific.com)
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.
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.
27 * Also, for certain devices, the interrupt endpoint is used to convey
28 * status of a command.
30 * Please see http://www.one-eyed-alien.net/~mdharm/linux-usb for more
31 * information about this driver.
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
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.
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.
50 #include "transport.h"
53 #include <linux/slab.h>
54 #include <linux/module.h>
55 #include <scsi/scsi_devinfo.h>
56 #include <scsi/scsi_host.h>
58 /***********************************************************************
60 ***********************************************************************/
62 static const char* host_info(struct Scsi_Host *host)
64 return "SCSI emulation for USB Mass Storage devices";
67 static int slave_alloc (struct scsi_device *sdev)
70 * Set default bflags. These can be overridden for individual
71 * models and vendors via the scsi devinfo mechanism. The only
72 * flag we need is to force 36-byte INQUIRYs; we don't use any
73 * of the extra data and many devices choke if asked for more or
76 sdev->sdev_bflags = BLIST_INQUIRY_36;
81 static int slave_configure(struct scsi_device *sdev)
83 struct us_data *us = (struct us_data *) sdev->host->hostdata[0];
85 /* Scatter-gather buffers (all but the last) must have a length
86 * divisible by the bulk maxpacket size. Otherwise a data packet
87 * would end up being short, causing a premature end to the data
88 * transfer. Since high-speed bulk pipes have a maxpacket size
89 * of 512, we'll use that as the scsi device queue's DMA alignment
90 * mask. Guaranteeing proper alignment of the first buffer will
91 * have the desired effect because, except at the beginning and
92 * the end, scatter-gather buffers follow page boundaries. */
93 blk_queue_dma_alignment(sdev->request_queue, (512 - 1));
95 /* According to the technical support people at Genesys Logic,
96 * devices using their chips have problems transferring more than
97 * 32 KB at a time. In practice people have found that 64 KB
98 * works okay and that's what Windows does. But we'll be
99 * conservative; people can always use the sysfs interface to
100 * increase max_sectors. */
101 if (us->pusb_dev->descriptor.idVendor == USB_VENDOR_ID_GENESYS &&
102 sdev->request_queue->max_sectors > 64)
103 blk_queue_max_sectors(sdev->request_queue, 64);
105 /* We can't put these settings in slave_alloc() because that gets
106 * called before the device type is known. Consequently these
107 * settings can't be overridden via the scsi devinfo mechanism. */
108 if (sdev->type == TYPE_DISK) {
110 /* Disk-type devices use MODE SENSE(6) if the protocol
111 * (SubClass) is Transparent SCSI, otherwise they use
113 if (us->subclass != US_SC_SCSI)
114 sdev->use_10_for_ms = 1;
116 /* Many disks only accept MODE SENSE transfer lengths of
117 * 192 bytes (that's what Windows uses). */
118 sdev->use_192_bytes_for_3f = 1;
120 /* A number of devices have problems with MODE SENSE for
121 * page x08, so we will skip it. */
122 sdev->skip_ms_page_8 = 1;
124 #ifndef CONFIG_USB_STORAGE_RW_DETECT
125 /* Some devices may not like MODE SENSE with page=0x3f.
126 * Now that we're using 192-byte transfers this may no
127 * longer be a problem. So this will be a configuration
129 sdev->skip_ms_page_3f = 1;
134 /* Non-disk-type devices don't need to blacklist any pages
135 * or to force 192-byte transfer lengths for MODE SENSE.
136 * But they do need to use MODE SENSE(10). */
137 sdev->use_10_for_ms = 1;
140 /* this is to satisfy the compiler, tho I don't think the
141 * return code is ever checked anywhere. */
145 /* queue a command */
146 /* This is always called with scsi_lock(srb->host) held */
147 static int queuecommand( Scsi_Cmnd *srb , void (*done)(Scsi_Cmnd *))
149 struct us_data *us = (struct us_data *)srb->device->host->hostdata[0];
151 US_DEBUGP("%s called\n", __FUNCTION__);
152 srb->host_scribble = (unsigned char *)us;
154 /* enqueue the command */
155 if (us->sm_state != US_STATE_IDLE || us->srb != NULL) {
156 printk(KERN_ERR USB_STORAGE "Error in %s: "
157 "state = %d, us->srb = %p\n",
158 __FUNCTION__, us->sm_state, us->srb);
159 return SCSI_MLQUEUE_HOST_BUSY;
162 srb->scsi_done = done;
165 /* wake up the process task */
171 /***********************************************************************
172 * Error handling functions
173 ***********************************************************************/
176 /* This is always called with scsi_lock(srb->host) held */
177 static int command_abort( Scsi_Cmnd *srb )
179 struct Scsi_Host *host = srb->device->host;
180 struct us_data *us = (struct us_data *) host->hostdata[0];
182 US_DEBUGP("%s called\n", __FUNCTION__);
184 /* Is this command still active? */
185 if (us->srb != srb) {
186 US_DEBUGP ("-- nothing to abort\n");
190 /* Normally the current state is RUNNING. If the control thread
191 * hasn't even started processing this command, the state will be
192 * IDLE. Anything else is a bug. */
193 if (us->sm_state != US_STATE_RUNNING
194 && us->sm_state != US_STATE_IDLE) {
195 printk(KERN_ERR USB_STORAGE "Error in %s: "
196 "invalid state %d\n", __FUNCTION__, us->sm_state);
200 /* Set state to ABORTING and set the ABORTING bit, but only if
201 * a device reset isn't already in progress (to avoid interfering
202 * with the reset). To prevent races with auto-reset, we must
203 * stop any ongoing USB transfers while still holding the host
205 us->sm_state = US_STATE_ABORTING;
206 if (!test_bit(US_FLIDX_RESETTING, &us->flags)) {
207 set_bit(US_FLIDX_ABORTING, &us->flags);
208 usb_stor_stop_transport(us);
212 /* Wait for the aborted command to finish */
213 wait_for_completion(&us->notify);
215 /* Reacquire the lock and allow USB transfers to resume */
217 clear_bit(US_FLIDX_ABORTING, &us->flags);
221 /* This invokes the transport reset mechanism to reset the state of the
223 /* This is always called with scsi_lock(srb->host) held */
224 static int device_reset( Scsi_Cmnd *srb )
226 struct us_data *us = (struct us_data *)srb->device->host->hostdata[0];
229 US_DEBUGP("%s called\n", __FUNCTION__);
230 if (us->sm_state != US_STATE_IDLE) {
231 printk(KERN_ERR USB_STORAGE "Error in %s: "
232 "invalid state %d\n", __FUNCTION__, us->sm_state);
236 /* set the state and release the lock */
237 us->sm_state = US_STATE_RESETTING;
238 scsi_unlock(srb->device->host);
240 /* lock the device pointers and do the reset */
241 down(&(us->dev_semaphore));
242 if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) {
244 US_DEBUGP("No reset during disconnect\n");
246 result = us->transport_reset(us);
247 up(&(us->dev_semaphore));
249 /* lock access to the state and clear it */
250 scsi_lock(srb->device->host);
251 us->sm_state = US_STATE_IDLE;
255 /* This resets the device's USB port. */
256 /* It refuses to work if there's more than one interface in
257 * the device, so that other users are not affected. */
258 /* This is always called with scsi_lock(srb->host) held */
259 static int bus_reset( Scsi_Cmnd *srb )
261 struct us_data *us = (struct us_data *)srb->device->host->hostdata[0];
264 US_DEBUGP("%s called\n", __FUNCTION__);
265 if (us->sm_state != US_STATE_IDLE) {
266 printk(KERN_ERR USB_STORAGE "Error in %s: "
267 "invalid state %d\n", __FUNCTION__, us->sm_state);
271 /* set the state and release the lock */
272 us->sm_state = US_STATE_RESETTING;
273 scsi_unlock(srb->device->host);
275 /* The USB subsystem doesn't handle synchronisation between
276 * a device's several drivers. Therefore we reset only devices
277 * with just one interface, which we of course own. */
279 down(&(us->dev_semaphore));
280 if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) {
282 US_DEBUGP("No reset during disconnect\n");
283 } else if (us->pusb_dev->actconfig->desc.bNumInterfaces != 1) {
285 US_DEBUGP("Refusing to reset a multi-interface device\n");
287 result = usb_reset_device(us->pusb_dev);
288 US_DEBUGP("usb_reset_device returns %d\n", result);
290 up(&(us->dev_semaphore));
292 /* lock access to the state and clear it */
293 scsi_lock(srb->device->host);
294 us->sm_state = US_STATE_IDLE;
295 return result < 0 ? FAILED : SUCCESS;
298 /* Report a driver-initiated device reset to the SCSI layer.
299 * Calling this for a SCSI-initiated reset is unnecessary but harmless.
300 * The caller must own the SCSI host lock. */
301 void usb_stor_report_device_reset(struct us_data *us)
305 scsi_report_device_reset(us->host, 0, 0);
306 if (us->flags & US_FL_SCM_MULT_TARG) {
307 for (i = 1; i < us->host->max_id; ++i)
308 scsi_report_device_reset(us->host, 0, i);
312 /***********************************************************************
313 * /proc/scsi/ functions
314 ***********************************************************************/
316 /* we use this macro to help us write into the buffer */
318 #define SPRINTF(args...) \
319 do { if (pos < buffer+length) pos += sprintf(pos, ## args); } while (0)
321 do { if (us->flags & US_FL_##a) pos += sprintf(pos, " " #a); } while(0)
323 static int proc_info (struct Scsi_Host *hostptr, char *buffer, char **start, off_t offset,
324 int length, int inout)
329 /* if someone is sending us data, just throw it away */
333 us = (struct us_data*)hostptr->hostdata[0];
335 /* print the controller name */
336 SPRINTF(" Host scsi%d: usb-storage\n", hostptr->host_no);
338 /* print product, vendor, and serial number strings */
339 SPRINTF(" Vendor: %s\n", us->vendor);
340 SPRINTF(" Product: %s\n", us->product);
341 SPRINTF("Serial Number: %s\n", us->serial);
343 /* show the protocol and transport */
344 SPRINTF(" Protocol: %s\n", us->protocol_name);
345 SPRINTF(" Transport: %s\n", us->transport_name);
347 /* show the device flags */
348 if (pos < buffer + length) {
349 pos += sprintf(pos, " Quirks:");
352 DO_FLAG(SCM_MULT_TARG);
353 DO_FLAG(FIX_INQUIRY);
354 DO_FLAG(FIX_CAPACITY);
360 * Calculate start of next buffer, and return value.
362 *start = buffer + offset;
364 if ((pos - buffer) < offset)
366 else if ((pos - buffer - offset) < length)
367 return (pos - buffer - offset);
372 /***********************************************************************
374 ***********************************************************************/
376 /* Output routine for the sysfs max_sectors file */
377 static ssize_t show_max_sectors(struct device *dev, char *buf)
379 struct scsi_device *sdev = to_scsi_device(dev);
381 return sprintf(buf, "%u\n", sdev->request_queue->max_sectors);
384 /* Input routine for the sysfs max_sectors file */
385 static ssize_t store_max_sectors(struct device *dev, const char *buf,
388 struct scsi_device *sdev = to_scsi_device(dev);
391 if (sscanf(buf, "%hu", &ms) > 0 && ms <= SCSI_DEFAULT_MAX_SECTORS) {
392 blk_queue_max_sectors(sdev->request_queue, ms);
398 static DEVICE_ATTR(max_sectors, S_IRUGO | S_IWUSR, show_max_sectors,
401 static struct device_attribute *sysfs_device_attr_list[] = {
402 &dev_attr_max_sectors,
407 * this defines our host template, with which we'll allocate hosts
410 struct scsi_host_template usb_stor_host_template = {
411 /* basic userland interface stuff */
412 .name = "usb-storage",
413 .proc_name = "usb-storage",
414 .proc_info = proc_info,
417 /* command interface -- queued only */
418 .queuecommand = queuecommand,
420 /* error and abort handlers */
421 .eh_abort_handler = command_abort,
422 .eh_device_reset_handler = device_reset,
423 .eh_bus_reset_handler = bus_reset,
425 /* queue commands only, only one command per LUN */
429 /* unknown initiator id */
432 .slave_alloc = slave_alloc,
433 .slave_configure = slave_configure,
435 /* lots of sg segments can be handled */
436 .sg_tablesize = SG_ALL,
438 /* limit the total size of a transfer to 120 KB */
441 /* merge commands... this seems to help performance, but
442 * periodically someone should test to see which setting is more
445 .use_clustering = TRUE,
450 /* we do our own delay after a device or bus reset */
451 .skip_settle_delay = 1,
453 /* sysfs device attributes */
454 .sdev_attrs = sysfs_device_attr_list,
456 /* module management */
457 .module = THIS_MODULE
460 /* For a device that is "Not Ready" */
461 unsigned char usb_stor_sense_notready[18] = {
462 [0] = 0x70, /* current error */
463 [2] = 0x02, /* not ready */
464 [7] = 0x0a, /* additional length */
465 [12] = 0x04, /* not ready */
466 [13] = 0x03 /* manual intervention */
469 /* To Report "Illegal Request: Invalid Field in CDB */
470 unsigned char usb_stor_sense_invalidCDB[18] = {
471 [0] = 0x70, /* current error */
472 [2] = ILLEGAL_REQUEST, /* Illegal Request = 0x05 */
473 [7] = 0x0a, /* additional length */
474 [12] = 0x24 /* Invalid Field in CDB */