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 /* Devices using Genesys Logic chips cause a lot of trouble for
96 * high-speed transfers; they die unpredictably when given more
97 * than 64 KB of data at a time. If we detect such a device,
98 * reduce the maximum transfer size to 64 KB = 128 sectors. */
100 #define USB_VENDOR_ID_GENESYS 0x05e3 // Needs a standard location
102 if (us->pusb_dev->descriptor.idVendor == USB_VENDOR_ID_GENESYS &&
103 us->pusb_dev->speed == USB_SPEED_HIGH &&
104 sdev->request_queue->max_sectors > 128)
105 blk_queue_max_sectors(sdev->request_queue, 128);
107 /* We can't put these settings in slave_alloc() because that gets
108 * called before the device type is known. Consequently these
109 * settings can't be overridden via the scsi devinfo mechanism. */
110 if (sdev->type == TYPE_DISK) {
112 /* Disk-type devices use MODE SENSE(6) if the protocol
113 * (SubClass) is Transparent SCSI, otherwise they use
115 if (us->subclass != US_SC_SCSI)
116 sdev->use_10_for_ms = 1;
118 /* Many disks only accept MODE SENSE transfer lengths of
119 * 192 bytes (that's what Windows uses). */
120 sdev->use_192_bytes_for_3f = 1;
122 /* A number of devices have problems with MODE SENSE for
123 * page x08, so we will skip it. */
124 sdev->skip_ms_page_8 = 1;
126 #ifndef CONFIG_USB_STORAGE_RW_DETECT
127 /* Some devices may not like MODE SENSE with page=0x3f.
128 * Now that we're using 192-byte transfers this may no
129 * longer be a problem. So this will be a configuration
131 sdev->skip_ms_page_3f = 1;
136 /* Non-disk-type devices don't need to blacklist any pages
137 * or to force 192-byte transfer lengths for MODE SENSE.
138 * But they do need to use MODE SENSE(10). */
139 sdev->use_10_for_ms = 1;
142 /* this is to satisfy the compiler, tho I don't think the
143 * return code is ever checked anywhere. */
147 /* queue a command */
148 /* This is always called with scsi_lock(srb->host) held */
149 static int queuecommand( Scsi_Cmnd *srb , void (*done)(Scsi_Cmnd *))
151 struct us_data *us = (struct us_data *)srb->device->host->hostdata[0];
153 US_DEBUGP("%s called\n", __FUNCTION__);
154 srb->host_scribble = (unsigned char *)us;
156 /* enqueue the command */
157 if (us->sm_state != US_STATE_IDLE || us->srb != NULL) {
158 printk(KERN_ERR USB_STORAGE "Error in %s: "
159 "state = %d, us->srb = %p\n",
160 __FUNCTION__, us->sm_state, us->srb);
161 return SCSI_MLQUEUE_HOST_BUSY;
164 srb->scsi_done = done;
167 /* wake up the process task */
173 /***********************************************************************
174 * Error handling functions
175 ***********************************************************************/
178 /* This is always called with scsi_lock(srb->host) held */
179 static int command_abort( Scsi_Cmnd *srb )
181 struct Scsi_Host *host = srb->device->host;
182 struct us_data *us = (struct us_data *) host->hostdata[0];
184 US_DEBUGP("%s called\n", __FUNCTION__);
186 /* Is this command still active? */
187 if (us->srb != srb) {
188 US_DEBUGP ("-- nothing to abort\n");
192 /* Normally the current state is RUNNING. If the control thread
193 * hasn't even started processing this command, the state will be
194 * IDLE. Anything else is a bug. */
195 if (us->sm_state != US_STATE_RUNNING
196 && us->sm_state != US_STATE_IDLE) {
197 printk(KERN_ERR USB_STORAGE "Error in %s: "
198 "invalid state %d\n", __FUNCTION__, us->sm_state);
202 /* Set state to ABORTING and set the ABORTING bit, but only if
203 * a device reset isn't already in progress (to avoid interfering
204 * with the reset). To prevent races with auto-reset, we must
205 * stop any ongoing USB transfers while still holding the host
207 us->sm_state = US_STATE_ABORTING;
208 if (!test_bit(US_FLIDX_RESETTING, &us->flags)) {
209 set_bit(US_FLIDX_ABORTING, &us->flags);
210 usb_stor_stop_transport(us);
214 /* Wait for the aborted command to finish */
215 wait_for_completion(&us->notify);
217 /* Reacquire the lock and allow USB transfers to resume */
219 clear_bit(US_FLIDX_ABORTING, &us->flags);
223 /* This invokes the transport reset mechanism to reset the state of the
225 /* This is always called with scsi_lock(srb->host) held */
226 static int device_reset( Scsi_Cmnd *srb )
228 struct us_data *us = (struct us_data *)srb->device->host->hostdata[0];
231 US_DEBUGP("%s called\n", __FUNCTION__);
232 if (us->sm_state != US_STATE_IDLE) {
233 printk(KERN_ERR USB_STORAGE "Error in %s: "
234 "invalid state %d\n", __FUNCTION__, us->sm_state);
238 /* set the state and release the lock */
239 us->sm_state = US_STATE_RESETTING;
240 scsi_unlock(srb->device->host);
242 /* lock the device pointers and do the reset */
243 down(&(us->dev_semaphore));
244 if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) {
246 US_DEBUGP("No reset during disconnect\n");
248 result = us->transport_reset(us);
249 up(&(us->dev_semaphore));
251 /* lock access to the state and clear it */
252 scsi_lock(srb->device->host);
253 us->sm_state = US_STATE_IDLE;
257 /* This resets the device's USB port. */
258 /* It refuses to work if there's more than one interface in
259 * the device, so that other users are not affected. */
260 /* This is always called with scsi_lock(srb->host) held */
261 static int bus_reset( Scsi_Cmnd *srb )
263 struct us_data *us = (struct us_data *)srb->device->host->hostdata[0];
266 US_DEBUGP("%s called\n", __FUNCTION__);
267 if (us->sm_state != US_STATE_IDLE) {
268 printk(KERN_ERR USB_STORAGE "Error in %s: "
269 "invalid state %d\n", __FUNCTION__, us->sm_state);
273 /* set the state and release the lock */
274 us->sm_state = US_STATE_RESETTING;
275 scsi_unlock(srb->device->host);
277 /* The USB subsystem doesn't handle synchronisation between
278 * a device's several drivers. Therefore we reset only devices
279 * with just one interface, which we of course own. */
281 down(&(us->dev_semaphore));
282 if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) {
284 US_DEBUGP("No reset during disconnect\n");
285 } else if (us->pusb_dev->actconfig->desc.bNumInterfaces != 1) {
287 US_DEBUGP("Refusing to reset a multi-interface device\n");
289 result = usb_reset_device(us->pusb_dev);
290 US_DEBUGP("usb_reset_device returns %d\n", result);
292 up(&(us->dev_semaphore));
294 /* lock access to the state and clear it */
295 scsi_lock(srb->device->host);
296 us->sm_state = US_STATE_IDLE;
297 return result < 0 ? FAILED : SUCCESS;
300 /* Report a driver-initiated device reset to the SCSI layer.
301 * Calling this for a SCSI-initiated reset is unnecessary but harmless.
302 * The caller must own the SCSI host lock. */
303 void usb_stor_report_device_reset(struct us_data *us)
307 scsi_report_device_reset(us->host, 0, 0);
308 if (us->flags & US_FL_SCM_MULT_TARG) {
309 for (i = 1; i < us->host->max_id; ++i)
310 scsi_report_device_reset(us->host, 0, i);
314 /***********************************************************************
315 * /proc/scsi/ functions
316 ***********************************************************************/
318 /* we use this macro to help us write into the buffer */
320 #define SPRINTF(args...) \
321 do { if (pos < buffer+length) pos += sprintf(pos, ## args); } while (0)
323 do { if (us->flags & US_FL_##a) pos += sprintf(pos, " " #a); } while(0)
325 static int proc_info (struct Scsi_Host *hostptr, char *buffer, char **start, off_t offset,
326 int length, int inout)
331 /* if someone is sending us data, just throw it away */
335 us = (struct us_data*)hostptr->hostdata[0];
337 /* print the controller name */
338 SPRINTF(" Host scsi%d: usb-storage\n", hostptr->host_no);
340 /* print product, vendor, and serial number strings */
341 SPRINTF(" Vendor: %s\n", us->vendor);
342 SPRINTF(" Product: %s\n", us->product);
343 SPRINTF("Serial Number: %s\n", us->serial);
345 /* show the protocol and transport */
346 SPRINTF(" Protocol: %s\n", us->protocol_name);
347 SPRINTF(" Transport: %s\n", us->transport_name);
349 /* show the device flags */
350 if (pos < buffer + length) {
351 pos += sprintf(pos, " Quirks:");
354 DO_FLAG(SCM_MULT_TARG);
355 DO_FLAG(FIX_INQUIRY);
356 DO_FLAG(FIX_CAPACITY);
362 * Calculate start of next buffer, and return value.
364 *start = buffer + offset;
366 if ((pos - buffer) < offset)
368 else if ((pos - buffer - offset) < length)
369 return (pos - buffer - offset);
374 /***********************************************************************
376 ***********************************************************************/
378 /* Output routine for the sysfs max_sectors file */
379 static ssize_t show_max_sectors(struct device *dev, char *buf)
381 struct scsi_device *sdev = to_scsi_device(dev);
383 return sprintf(buf, "%u\n", sdev->request_queue->max_sectors);
386 /* Input routine for the sysfs max_sectors file */
387 static ssize_t store_max_sectors(struct device *dev, const char *buf,
390 struct scsi_device *sdev = to_scsi_device(dev);
393 if (sscanf(buf, "%hu", &ms) > 0 && ms <= SCSI_DEFAULT_MAX_SECTORS) {
394 blk_queue_max_sectors(sdev->request_queue, ms);
400 static DEVICE_ATTR(max_sectors, S_IRUGO | S_IWUSR, show_max_sectors,
403 static struct device_attribute *sysfs_device_attr_list[] = {
404 &dev_attr_max_sectors,
409 * this defines our host template, with which we'll allocate hosts
412 struct scsi_host_template usb_stor_host_template = {
413 /* basic userland interface stuff */
414 .name = "usb-storage",
415 .proc_name = "usb-storage",
416 .proc_info = proc_info,
419 /* command interface -- queued only */
420 .queuecommand = queuecommand,
422 /* error and abort handlers */
423 .eh_abort_handler = command_abort,
424 .eh_device_reset_handler = device_reset,
425 .eh_bus_reset_handler = bus_reset,
427 /* queue commands only, only one command per LUN */
431 /* unknown initiator id */
434 .slave_alloc = slave_alloc,
435 .slave_configure = slave_configure,
437 /* lots of sg segments can be handled */
438 .sg_tablesize = SG_ALL,
440 /* limit the total size of a transfer to 120 KB */
443 /* merge commands... this seems to help performance, but
444 * periodically someone should test to see which setting is more
447 .use_clustering = TRUE,
452 /* we do our own delay after a device or bus reset */
453 .skip_settle_delay = 1,
455 /* sysfs device attributes */
456 .sdev_attrs = sysfs_device_attr_list,
458 /* module management */
459 .module = THIS_MODULE
462 /* For a device that is "Not Ready" */
463 unsigned char usb_stor_sense_notready[18] = {
464 [0] = 0x70, /* current error */
465 [2] = 0x02, /* not ready */
466 [7] = 0x0a, /* additional length */
467 [12] = 0x04, /* not ready */
468 [13] = 0x03 /* manual intervention */
471 /* To Report "Illegal Request: Invalid Field in CDB */
472 unsigned char usb_stor_sense_invalidCDB[18] = {
473 [0] = 0x70, /* current error */
474 [2] = ILLEGAL_REQUEST, /* Illegal Request = 0x05 */
475 [7] = 0x0a, /* additional length */
476 [12] = 0x24 /* Invalid Field in CDB */