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.
48 #include <linux/slab.h>
49 #include <linux/module.h>
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 #include <scsi/scsi_host.h>
61 #include "transport.h"
64 /***********************************************************************
66 ***********************************************************************/
68 static const char* host_info(struct Scsi_Host *host)
70 return "SCSI emulation for USB Mass Storage devices";
73 static int slave_alloc (struct scsi_device *sdev)
76 * Set default bflags. These can be overridden for individual
77 * models and vendors via the scsi devinfo mechanism. The only
78 * flag we need is to force 36-byte INQUIRYs; we don't use any
79 * of the extra data and many devices choke if asked for more or
82 sdev->sdev_bflags = BLIST_INQUIRY_36;
87 static int slave_configure(struct scsi_device *sdev)
89 struct us_data *us = (struct us_data *) sdev->host->hostdata[0];
91 /* Scatter-gather buffers (all but the last) must have a length
92 * divisible by the bulk maxpacket size. Otherwise a data packet
93 * would end up being short, causing a premature end to the data
94 * transfer. Since high-speed bulk pipes have a maxpacket size
95 * of 512, we'll use that as the scsi device queue's DMA alignment
96 * mask. Guaranteeing proper alignment of the first buffer will
97 * have the desired effect because, except at the beginning and
98 * the end, scatter-gather buffers follow page boundaries. */
99 blk_queue_dma_alignment(sdev->request_queue, (512 - 1));
101 /* According to the technical support people at Genesys Logic,
102 * devices using their chips have problems transferring more than
103 * 32 KB at a time. In practice people have found that 64 KB
104 * works okay and that's what Windows does. But we'll be
105 * conservative; people can always use the sysfs interface to
106 * increase max_sectors. */
107 if (us->pusb_dev->descriptor.idVendor == USB_VENDOR_ID_GENESYS &&
108 sdev->request_queue->max_sectors > 64)
109 blk_queue_max_sectors(sdev->request_queue, 64);
111 /* We can't put these settings in slave_alloc() because that gets
112 * called before the device type is known. Consequently these
113 * settings can't be overridden via the scsi devinfo mechanism. */
114 if (sdev->type == TYPE_DISK) {
116 /* Disk-type devices use MODE SENSE(6) if the protocol
117 * (SubClass) is Transparent SCSI, otherwise they use
119 if (us->subclass != US_SC_SCSI)
120 sdev->use_10_for_ms = 1;
122 /* Many disks only accept MODE SENSE transfer lengths of
123 * 192 bytes (that's what Windows uses). */
124 sdev->use_192_bytes_for_3f = 1;
126 /* A number of devices have problems with MODE SENSE for
127 * page x08, so we will skip it. */
128 sdev->skip_ms_page_8 = 1;
130 #ifndef CONFIG_USB_STORAGE_RW_DETECT
131 /* Some devices may not like MODE SENSE with page=0x3f.
132 * Now that we're using 192-byte transfers this may no
133 * longer be a problem. So this will be a configuration
135 sdev->skip_ms_page_3f = 1;
140 /* Non-disk-type devices don't need to blacklist any pages
141 * or to force 192-byte transfer lengths for MODE SENSE.
142 * But they do need to use MODE SENSE(10). */
143 sdev->use_10_for_ms = 1;
146 /* this is to satisfy the compiler, tho I don't think the
147 * return code is ever checked anywhere. */
151 /* queue a command */
152 /* This is always called with scsi_lock(srb->host) held */
153 static int queuecommand(struct scsi_cmnd *srb,
154 void (*done)(struct scsi_cmnd *))
156 struct us_data *us = (struct us_data *)srb->device->host->hostdata[0];
158 US_DEBUGP("%s called\n", __FUNCTION__);
159 srb->host_scribble = (unsigned char *)us;
161 /* enqueue the command */
162 if (us->sm_state != US_STATE_IDLE || us->srb != NULL) {
163 printk(KERN_ERR USB_STORAGE "Error in %s: "
164 "state = %d, us->srb = %p\n",
165 __FUNCTION__, us->sm_state, us->srb);
166 return SCSI_MLQUEUE_HOST_BUSY;
169 srb->scsi_done = done;
172 /* wake up the process task */
178 /***********************************************************************
179 * Error handling functions
180 ***********************************************************************/
183 /* This is always called with scsi_lock(srb->host) held */
184 static int command_abort(struct scsi_cmnd *srb )
186 struct Scsi_Host *host = srb->device->host;
187 struct us_data *us = (struct us_data *) host->hostdata[0];
189 US_DEBUGP("%s called\n", __FUNCTION__);
191 /* Is this command still active? */
192 if (us->srb != srb) {
193 US_DEBUGP ("-- nothing to abort\n");
197 /* Normally the current state is RUNNING. If the control thread
198 * hasn't even started processing this command, the state will be
199 * IDLE. Anything else is a bug. */
200 if (us->sm_state != US_STATE_RUNNING
201 && us->sm_state != US_STATE_IDLE) {
202 printk(KERN_ERR USB_STORAGE "Error in %s: "
203 "invalid state %d\n", __FUNCTION__, us->sm_state);
207 /* Set state to ABORTING and set the ABORTING bit, but only if
208 * a device reset isn't already in progress (to avoid interfering
209 * with the reset). To prevent races with auto-reset, we must
210 * stop any ongoing USB transfers while still holding the host
212 us->sm_state = US_STATE_ABORTING;
213 if (!test_bit(US_FLIDX_RESETTING, &us->flags)) {
214 set_bit(US_FLIDX_ABORTING, &us->flags);
215 usb_stor_stop_transport(us);
219 /* Wait for the aborted command to finish */
220 wait_for_completion(&us->notify);
222 /* Reacquire the lock and allow USB transfers to resume */
224 clear_bit(US_FLIDX_ABORTING, &us->flags);
228 /* This invokes the transport reset mechanism to reset the state of the
230 /* This is always called with scsi_lock(srb->host) held */
231 static int device_reset(struct scsi_cmnd *srb)
233 struct us_data *us = (struct us_data *)srb->device->host->hostdata[0];
236 US_DEBUGP("%s called\n", __FUNCTION__);
237 if (us->sm_state != US_STATE_IDLE) {
238 printk(KERN_ERR USB_STORAGE "Error in %s: "
239 "invalid state %d\n", __FUNCTION__, us->sm_state);
243 /* set the state and release the lock */
244 us->sm_state = US_STATE_RESETTING;
245 scsi_unlock(srb->device->host);
247 /* lock the device pointers and do the reset */
248 down(&(us->dev_semaphore));
249 if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) {
251 US_DEBUGP("No reset during disconnect\n");
253 result = us->transport_reset(us);
254 up(&(us->dev_semaphore));
256 /* lock access to the state and clear it */
257 scsi_lock(srb->device->host);
258 us->sm_state = US_STATE_IDLE;
262 /* This resets the device's USB port. */
263 /* It refuses to work if there's more than one interface in
264 * the device, so that other users are not affected. */
265 /* This is always called with scsi_lock(srb->host) held */
266 static int bus_reset(struct scsi_cmnd *srb)
268 struct us_data *us = (struct us_data *)srb->device->host->hostdata[0];
271 US_DEBUGP("%s called\n", __FUNCTION__);
272 if (us->sm_state != US_STATE_IDLE) {
273 printk(KERN_ERR USB_STORAGE "Error in %s: "
274 "invalid state %d\n", __FUNCTION__, us->sm_state);
278 /* set the state and release the lock */
279 us->sm_state = US_STATE_RESETTING;
280 scsi_unlock(srb->device->host);
282 /* The USB subsystem doesn't handle synchronisation between
283 * a device's several drivers. Therefore we reset only devices
284 * with just one interface, which we of course own. */
286 down(&(us->dev_semaphore));
287 if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) {
289 US_DEBUGP("No reset during disconnect\n");
290 } else if (us->pusb_dev->actconfig->desc.bNumInterfaces != 1) {
292 US_DEBUGP("Refusing to reset a multi-interface device\n");
294 result = usb_reset_device(us->pusb_dev);
295 US_DEBUGP("usb_reset_device returns %d\n", result);
297 up(&(us->dev_semaphore));
299 /* lock access to the state and clear it */
300 scsi_lock(srb->device->host);
301 us->sm_state = US_STATE_IDLE;
302 return result < 0 ? FAILED : SUCCESS;
305 /* Report a driver-initiated device reset to the SCSI layer.
306 * Calling this for a SCSI-initiated reset is unnecessary but harmless.
307 * The caller must own the SCSI host lock. */
308 void usb_stor_report_device_reset(struct us_data *us)
312 scsi_report_device_reset(us->host, 0, 0);
313 if (us->flags & US_FL_SCM_MULT_TARG) {
314 for (i = 1; i < us->host->max_id; ++i)
315 scsi_report_device_reset(us->host, 0, i);
319 /***********************************************************************
320 * /proc/scsi/ functions
321 ***********************************************************************/
323 /* we use this macro to help us write into the buffer */
325 #define SPRINTF(args...) \
326 do { if (pos < buffer+length) pos += sprintf(pos, ## args); } while (0)
328 do { if (us->flags & US_FL_##a) pos += sprintf(pos, " " #a); } while(0)
330 static int proc_info (struct Scsi_Host *hostptr, char *buffer, char **start, off_t offset,
331 int length, int inout)
336 /* if someone is sending us data, just throw it away */
340 us = (struct us_data*)hostptr->hostdata[0];
342 /* print the controller name */
343 SPRINTF(" Host scsi%d: usb-storage\n", hostptr->host_no);
345 /* print product, vendor, and serial number strings */
346 SPRINTF(" Vendor: %s\n", us->vendor);
347 SPRINTF(" Product: %s\n", us->product);
348 SPRINTF("Serial Number: %s\n", us->serial);
350 /* show the protocol and transport */
351 SPRINTF(" Protocol: %s\n", us->protocol_name);
352 SPRINTF(" Transport: %s\n", us->transport_name);
354 /* show the device flags */
355 if (pos < buffer + length) {
356 pos += sprintf(pos, " Quirks:");
359 DO_FLAG(SCM_MULT_TARG);
360 DO_FLAG(FIX_INQUIRY);
361 DO_FLAG(FIX_CAPACITY);
367 * Calculate start of next buffer, and return value.
369 *start = buffer + offset;
371 if ((pos - buffer) < offset)
373 else if ((pos - buffer - offset) < length)
374 return (pos - buffer - offset);
379 /***********************************************************************
381 ***********************************************************************/
383 /* Output routine for the sysfs max_sectors file */
384 static ssize_t show_max_sectors(struct device *dev, char *buf)
386 struct scsi_device *sdev = to_scsi_device(dev);
388 return sprintf(buf, "%u\n", sdev->request_queue->max_sectors);
391 /* Input routine for the sysfs max_sectors file */
392 static ssize_t store_max_sectors(struct device *dev, const char *buf,
395 struct scsi_device *sdev = to_scsi_device(dev);
398 if (sscanf(buf, "%hu", &ms) > 0 && ms <= SCSI_DEFAULT_MAX_SECTORS) {
399 blk_queue_max_sectors(sdev->request_queue, ms);
405 static DEVICE_ATTR(max_sectors, S_IRUGO | S_IWUSR, show_max_sectors,
408 static struct device_attribute *sysfs_device_attr_list[] = {
409 &dev_attr_max_sectors,
414 * this defines our host template, with which we'll allocate hosts
417 struct scsi_host_template usb_stor_host_template = {
418 /* basic userland interface stuff */
419 .name = "usb-storage",
420 .proc_name = "usb-storage",
421 .proc_info = proc_info,
424 /* command interface -- queued only */
425 .queuecommand = queuecommand,
427 /* error and abort handlers */
428 .eh_abort_handler = command_abort,
429 .eh_device_reset_handler = device_reset,
430 .eh_bus_reset_handler = bus_reset,
432 /* queue commands only, only one command per LUN */
436 /* unknown initiator id */
439 .slave_alloc = slave_alloc,
440 .slave_configure = slave_configure,
442 /* lots of sg segments can be handled */
443 .sg_tablesize = SG_ALL,
445 /* limit the total size of a transfer to 120 KB */
448 /* merge commands... this seems to help performance, but
449 * periodically someone should test to see which setting is more
457 /* we do our own delay after a device or bus reset */
458 .skip_settle_delay = 1,
460 /* sysfs device attributes */
461 .sdev_attrs = sysfs_device_attr_list,
463 /* module management */
464 .module = THIS_MODULE
467 /* For a device that is "Not Ready" */
468 unsigned char usb_stor_sense_notready[18] = {
469 [0] = 0x70, /* current error */
470 [2] = 0x02, /* not ready */
471 [7] = 0x0a, /* additional length */
472 [12] = 0x04, /* not ready */
473 [13] = 0x03 /* manual intervention */
476 /* To Report "Illegal Request: Invalid Field in CDB */
477 unsigned char usb_stor_sense_invalidCDB[18] = {
478 [0] = 0x70, /* current error */
479 [2] = ILLEGAL_REQUEST, /* Illegal Request = 0x05 */
480 [7] = 0x0a, /* additional length */
481 [12] = 0x24 /* Invalid Field in CDB */