Staging: rtl8192u_usb: Add LG device ID 043e:7a01
[linux-2.6.git] / drivers / usb / gadget / f_mass_storage.c
1 /*
2  * f_mass_storage.c -- Mass Storage USB Composite Function
3  *
4  * Copyright (C) 2003-2008 Alan Stern
5  * Copyright (C) 2009 Samsung Electronics
6  *                    Author: Michal Nazarewicz <m.nazarewicz@samsung.com>
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions, and the following disclaimer,
14  *    without modification.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. The names of the above-listed copyright holders may not be used
19  *    to endorse or promote products derived from this software without
20  *    specific prior written permission.
21  *
22  * ALTERNATIVELY, this software may be distributed under the terms of the
23  * GNU General Public License ("GPL") as published by the Free Software
24  * Foundation, either version 2 of that License or (at your option) any
25  * later version.
26  *
27  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
28  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
29  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
30  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
31  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
32  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
33  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
34  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
35  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
36  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
37  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
38  */
39
40
41 /*
42  * The Mass Storage Function acts as a USB Mass Storage device,
43  * appearing to the host as a disk drive or as a CD-ROM drive.  In
44  * addition to providing an example of a genuinely useful composite
45  * function for a USB device, it also illustrates a technique of
46  * double-buffering for increased throughput.
47  *
48  * Function supports multiple logical units (LUNs).  Backing storage
49  * for each LUN is provided by a regular file or a block device.
50  * Access for each LUN can be limited to read-only.  Moreover, the
51  * function can indicate that LUN is removable and/or CD-ROM.  (The
52  * later implies read-only access.)
53  *
54  * MSF is configured by specifying a fsg_config structure.  It has the
55  * following fields:
56  *
57  *      nluns           Number of LUNs function have (anywhere from 1
58  *                              to FSG_MAX_LUNS which is 8).
59  *      luns            An array of LUN configuration values.  This
60  *                              should be filled for each LUN that
61  *                              function will include (ie. for "nluns"
62  *                              LUNs).  Each element of the array has
63  *                              the following fields:
64  *      ->filename      The path to the backing file for the LUN.
65  *                              Required if LUN is not marked as
66  *                              removable.
67  *      ->ro            Flag specifying access to the LUN shall be
68  *                              read-only.  This is implied if CD-ROM
69  *                              emulation is enabled as well as when
70  *                              it was impossible to open "filename"
71  *                              in R/W mode.
72  *      ->removable     Flag specifying that LUN shall be indicated as
73  *                              being removable.
74  *      ->cdrom         Flag specifying that LUN shall be reported as
75  *                              being a CD-ROM.
76  *
77  *      lun_name_format A printf-like format for names of the LUN
78  *                              devices.  This determines how the
79  *                              directory in sysfs will be named.
80  *                              Unless you are using several MSFs in
81  *                              a single gadget (as opposed to single
82  *                              MSF in many configurations) you may
83  *                              leave it as NULL (in which case
84  *                              "lun%d" will be used).  In the format
85  *                              you can use "%d" to index LUNs for
86  *                              MSF's with more than one LUN.  (Beware
87  *                              that there is only one integer given
88  *                              as an argument for the format and
89  *                              specifying invalid format may cause
90  *                              unspecified behaviour.)
91  *      thread_name     Name of the kernel thread process used by the
92  *                              MSF.  You can safely set it to NULL
93  *                              (in which case default "file-storage"
94  *                              will be used).
95  *
96  *      vendor_name
97  *      product_name
98  *      release         Information used as a reply to INQUIRY
99  *                              request.  To use default set to NULL,
100  *                              NULL, 0xffff respectively.  The first
101  *                              field should be 8 and the second 16
102  *                              characters or less.
103  *
104  *      can_stall       Set to permit function to halt bulk endpoints.
105  *                              Disabled on some USB devices known not
106  *                              to work correctly.  You should set it
107  *                              to true.
108  *
109  * If "removable" is not set for a LUN then a backing file must be
110  * specified.  If it is set, then NULL filename means the LUN's medium
111  * is not loaded (an empty string as "filename" in the fsg_config
112  * structure causes error).  The CD-ROM emulation includes a single
113  * data track and no audio tracks; hence there need be only one
114  * backing file per LUN.  Note also that the CD-ROM block length is
115  * set to 512 rather than the more common value 2048.
116  *
117  *
118  * MSF includes support for module parameters.  If gadget using it
119  * decides to use it, the following module parameters will be
120  * available:
121  *
122  *      file=filename[,filename...]
123  *                      Names of the files or block devices used for
124  *                              backing storage.
125  *      ro=b[,b...]     Default false, boolean for read-only access.
126  *      removable=b[,b...]
127  *                      Default true, boolean for removable media.
128  *      cdrom=b[,b...]  Default false, boolean for whether to emulate
129  *                              a CD-ROM drive.
130  *      luns=N          Default N = number of filenames, number of
131  *                              LUNs to support.
132  *      stall           Default determined according to the type of
133  *                              USB device controller (usually true),
134  *                              boolean to permit the driver to halt
135  *                              bulk endpoints.
136  *
137  * The module parameters may be prefixed with some string.  You need
138  * to consult gadget's documentation or source to verify whether it is
139  * using those module parameters and if it does what are the prefixes
140  * (look for FSG_MODULE_PARAMETERS() macro usage, what's inside it is
141  * the prefix).
142  *
143  *
144  * Requirements are modest; only a bulk-in and a bulk-out endpoint are
145  * needed.  The memory requirement amounts to two 16K buffers, size
146  * configurable by a parameter.  Support is included for both
147  * full-speed and high-speed operation.
148  *
149  * Note that the driver is slightly non-portable in that it assumes a
150  * single memory/DMA buffer will be useable for bulk-in, bulk-out, and
151  * interrupt-in endpoints.  With most device controllers this isn't an
152  * issue, but there may be some with hardware restrictions that prevent
153  * a buffer from being used by more than one endpoint.
154  *
155  *
156  * The pathnames of the backing files and the ro settings are
157  * available in the attribute files "file" and "ro" in the lun<n> (or
158  * to be more precise in a directory which name comes from
159  * "lun_name_format" option!) subdirectory of the gadget's sysfs
160  * directory.  If the "removable" option is set, writing to these
161  * files will simulate ejecting/loading the medium (writing an empty
162  * line means eject) and adjusting a write-enable tab.  Changes to the
163  * ro setting are not allowed when the medium is loaded or if CD-ROM
164  * emulation is being used.
165  *
166  * When a LUN receive an "eject" SCSI request (Start/Stop Unit),
167  * if the LUN is removable, the backing file is released to simulate
168  * ejection.
169  *
170  *
171  * This function is heavily based on "File-backed Storage Gadget" by
172  * Alan Stern which in turn is heavily based on "Gadget Zero" by David
173  * Brownell.  The driver's SCSI command interface was based on the
174  * "Information technology - Small Computer System Interface - 2"
175  * document from X3T9.2 Project 375D, Revision 10L, 7-SEP-93,
176  * available at <http://www.t10.org/ftp/t10/drafts/s2/s2-r10l.pdf>.
177  * The single exception is opcode 0x23 (READ FORMAT CAPACITIES), which
178  * was based on the "Universal Serial Bus Mass Storage Class UFI
179  * Command Specification" document, Revision 1.0, December 14, 1998,
180  * available at
181  * <http://www.usb.org/developers/devclass_docs/usbmass-ufi10.pdf>.
182  */
183
184
185 /*
186  *                              Driver Design
187  *
188  * The MSF is fairly straightforward.  There is a main kernel
189  * thread that handles most of the work.  Interrupt routines field
190  * callbacks from the controller driver: bulk- and interrupt-request
191  * completion notifications, endpoint-0 events, and disconnect events.
192  * Completion events are passed to the main thread by wakeup calls.  Many
193  * ep0 requests are handled at interrupt time, but SetInterface,
194  * SetConfiguration, and device reset requests are forwarded to the
195  * thread in the form of "exceptions" using SIGUSR1 signals (since they
196  * should interrupt any ongoing file I/O operations).
197  *
198  * The thread's main routine implements the standard command/data/status
199  * parts of a SCSI interaction.  It and its subroutines are full of tests
200  * for pending signals/exceptions -- all this polling is necessary since
201  * the kernel has no setjmp/longjmp equivalents.  (Maybe this is an
202  * indication that the driver really wants to be running in userspace.)
203  * An important point is that so long as the thread is alive it keeps an
204  * open reference to the backing file.  This will prevent unmounting
205  * the backing file's underlying filesystem and could cause problems
206  * during system shutdown, for example.  To prevent such problems, the
207  * thread catches INT, TERM, and KILL signals and converts them into
208  * an EXIT exception.
209  *
210  * In normal operation the main thread is started during the gadget's
211  * fsg_bind() callback and stopped during fsg_unbind().  But it can
212  * also exit when it receives a signal, and there's no point leaving
213  * the gadget running when the thread is dead.  At of this moment, MSF
214  * provides no way to deregister the gadget when thread dies -- maybe
215  * a callback functions is needed.
216  *
217  * To provide maximum throughput, the driver uses a circular pipeline of
218  * buffer heads (struct fsg_buffhd).  In principle the pipeline can be
219  * arbitrarily long; in practice the benefits don't justify having more
220  * than 2 stages (i.e., double buffering).  But it helps to think of the
221  * pipeline as being a long one.  Each buffer head contains a bulk-in and
222  * a bulk-out request pointer (since the buffer can be used for both
223  * output and input -- directions always are given from the host's
224  * point of view) as well as a pointer to the buffer and various state
225  * variables.
226  *
227  * Use of the pipeline follows a simple protocol.  There is a variable
228  * (fsg->next_buffhd_to_fill) that points to the next buffer head to use.
229  * At any time that buffer head may still be in use from an earlier
230  * request, so each buffer head has a state variable indicating whether
231  * it is EMPTY, FULL, or BUSY.  Typical use involves waiting for the
232  * buffer head to be EMPTY, filling the buffer either by file I/O or by
233  * USB I/O (during which the buffer head is BUSY), and marking the buffer
234  * head FULL when the I/O is complete.  Then the buffer will be emptied
235  * (again possibly by USB I/O, during which it is marked BUSY) and
236  * finally marked EMPTY again (possibly by a completion routine).
237  *
238  * A module parameter tells the driver to avoid stalling the bulk
239  * endpoints wherever the transport specification allows.  This is
240  * necessary for some UDCs like the SuperH, which cannot reliably clear a
241  * halt on a bulk endpoint.  However, under certain circumstances the
242  * Bulk-only specification requires a stall.  In such cases the driver
243  * will halt the endpoint and set a flag indicating that it should clear
244  * the halt in software during the next device reset.  Hopefully this
245  * will permit everything to work correctly.  Furthermore, although the
246  * specification allows the bulk-out endpoint to halt when the host sends
247  * too much data, implementing this would cause an unavoidable race.
248  * The driver will always use the "no-stall" approach for OUT transfers.
249  *
250  * One subtle point concerns sending status-stage responses for ep0
251  * requests.  Some of these requests, such as device reset, can involve
252  * interrupting an ongoing file I/O operation, which might take an
253  * arbitrarily long time.  During that delay the host might give up on
254  * the original ep0 request and issue a new one.  When that happens the
255  * driver should not notify the host about completion of the original
256  * request, as the host will no longer be waiting for it.  So the driver
257  * assigns to each ep0 request a unique tag, and it keeps track of the
258  * tag value of the request associated with a long-running exception
259  * (device-reset, interface-change, or configuration-change).  When the
260  * exception handler is finished, the status-stage response is submitted
261  * only if the current ep0 request tag is equal to the exception request
262  * tag.  Thus only the most recently received ep0 request will get a
263  * status-stage response.
264  *
265  * Warning: This driver source file is too long.  It ought to be split up
266  * into a header file plus about 3 separate .c files, to handle the details
267  * of the Gadget, USB Mass Storage, and SCSI protocols.
268  */
269
270
271 /* #define VERBOSE_DEBUG */
272 /* #define DUMP_MSGS */
273
274
275 #include <linux/blkdev.h>
276 #include <linux/completion.h>
277 #include <linux/dcache.h>
278 #include <linux/delay.h>
279 #include <linux/device.h>
280 #include <linux/fcntl.h>
281 #include <linux/file.h>
282 #include <linux/fs.h>
283 #include <linux/kref.h>
284 #include <linux/kthread.h>
285 #include <linux/limits.h>
286 #include <linux/rwsem.h>
287 #include <linux/slab.h>
288 #include <linux/spinlock.h>
289 #include <linux/string.h>
290 #include <linux/freezer.h>
291 #include <linux/utsname.h>
292
293 #include <linux/usb/ch9.h>
294 #include <linux/usb/gadget.h>
295
296 #include "gadget_chips.h"
297
298
299
300 /*------------------------------------------------------------------------*/
301
302 #define FSG_DRIVER_DESC         "Mass Storage Function"
303 #define FSG_DRIVER_VERSION      "2009/09/11"
304
305 static const char fsg_string_interface[] = "Mass Storage";
306
307
308 #define FSG_NO_INTR_EP 1
309 #define FSG_NO_DEVICE_STRINGS    1
310 #define FSG_NO_OTG               1
311 #define FSG_NO_INTR_EP           1
312
313 #include "storage_common.c"
314
315
316 /*-------------------------------------------------------------------------*/
317
318 struct fsg_dev;
319
320
321 /* Data shared by all the FSG instances. */
322 struct fsg_common {
323         struct usb_gadget       *gadget;
324         struct fsg_dev          *fsg;
325         struct fsg_dev          *prev_fsg;
326
327         /* filesem protects: backing files in use */
328         struct rw_semaphore     filesem;
329
330         /* lock protects: state, all the req_busy's */
331         spinlock_t              lock;
332
333         struct usb_ep           *ep0;           /* Copy of gadget->ep0 */
334         struct usb_request      *ep0req;        /* Copy of cdev->req */
335         unsigned int            ep0_req_tag;
336         const char              *ep0req_name;
337
338         struct fsg_buffhd       *next_buffhd_to_fill;
339         struct fsg_buffhd       *next_buffhd_to_drain;
340         struct fsg_buffhd       buffhds[FSG_NUM_BUFFERS];
341
342         int                     cmnd_size;
343         u8                      cmnd[MAX_COMMAND_SIZE];
344
345         unsigned int            nluns;
346         unsigned int            lun;
347         struct fsg_lun          *luns;
348         struct fsg_lun          *curlun;
349
350         unsigned int            bulk_out_maxpacket;
351         enum fsg_state          state;          /* For exception handling */
352         unsigned int            exception_req_tag;
353
354         u8                      config, new_config;
355         enum data_direction     data_dir;
356         u32                     data_size;
357         u32                     data_size_from_cmnd;
358         u32                     tag;
359         u32                     residue;
360         u32                     usb_amount_left;
361
362         unsigned int            can_stall:1;
363         unsigned int            free_storage_on_release:1;
364         unsigned int            phase_error:1;
365         unsigned int            short_packet_received:1;
366         unsigned int            bad_lun_okay:1;
367         unsigned int            running:1;
368
369         int                     thread_wakeup_needed;
370         struct completion       thread_notifier;
371         struct task_struct      *thread_task;
372
373         /* Callback function to call when thread exits. */
374         int                     (*thread_exits)(struct fsg_common *common);
375         /* Gadget's private data. */
376         void                    *private_data;
377
378         /* Vendor (8 chars), product (16 chars), release (4
379          * hexadecimal digits) and NUL byte */
380         char inquiry_string[8 + 16 + 4 + 1];
381
382         struct kref             ref;
383 };
384
385
386 struct fsg_config {
387         unsigned nluns;
388         struct fsg_lun_config {
389                 const char *filename;
390                 char ro;
391                 char removable;
392                 char cdrom;
393         } luns[FSG_MAX_LUNS];
394
395         const char              *lun_name_format;
396         const char              *thread_name;
397
398         /* Callback function to call when thread exits.  If no
399          * callback is set or it returns value lower then zero MSF
400          * will force eject all LUNs it operates on (including those
401          * marked as non-removable or with prevent_medium_removal flag
402          * set). */
403         int                     (*thread_exits)(struct fsg_common *common);
404         /* Gadget's private data. */
405         void                    *private_data;
406
407         const char *vendor_name;                /*  8 characters or less */
408         const char *product_name;               /* 16 characters or less */
409         u16 release;
410
411         char                    can_stall;
412 };
413
414
415 struct fsg_dev {
416         struct usb_function     function;
417         struct usb_gadget       *gadget;        /* Copy of cdev->gadget */
418         struct fsg_common       *common;
419
420         u16                     interface_number;
421
422         unsigned int            bulk_in_enabled:1;
423         unsigned int            bulk_out_enabled:1;
424
425         unsigned long           atomic_bitflags;
426 #define IGNORE_BULK_OUT         0
427
428         struct usb_ep           *bulk_in;
429         struct usb_ep           *bulk_out;
430 };
431
432
433 static inline int __fsg_is_set(struct fsg_common *common,
434                                const char *func, unsigned line)
435 {
436         if (common->fsg)
437                 return 1;
438         ERROR(common, "common->fsg is NULL in %s at %u\n", func, line);
439         return 0;
440 }
441
442 #define fsg_is_set(common) likely(__fsg_is_set(common, __func__, __LINE__))
443
444
445 static inline struct fsg_dev *fsg_from_func(struct usb_function *f)
446 {
447         return container_of(f, struct fsg_dev, function);
448 }
449
450
451 typedef void (*fsg_routine_t)(struct fsg_dev *);
452
453 static int exception_in_progress(struct fsg_common *common)
454 {
455         return common->state > FSG_STATE_IDLE;
456 }
457
458 /* Make bulk-out requests be divisible by the maxpacket size */
459 static void set_bulk_out_req_length(struct fsg_common *common,
460                 struct fsg_buffhd *bh, unsigned int length)
461 {
462         unsigned int    rem;
463
464         bh->bulk_out_intended_length = length;
465         rem = length % common->bulk_out_maxpacket;
466         if (rem > 0)
467                 length += common->bulk_out_maxpacket - rem;
468         bh->outreq->length = length;
469 }
470
471 /*-------------------------------------------------------------------------*/
472
473 static int fsg_set_halt(struct fsg_dev *fsg, struct usb_ep *ep)
474 {
475         const char      *name;
476
477         if (ep == fsg->bulk_in)
478                 name = "bulk-in";
479         else if (ep == fsg->bulk_out)
480                 name = "bulk-out";
481         else
482                 name = ep->name;
483         DBG(fsg, "%s set halt\n", name);
484         return usb_ep_set_halt(ep);
485 }
486
487
488 /*-------------------------------------------------------------------------*/
489
490 /* These routines may be called in process context or in_irq */
491
492 /* Caller must hold fsg->lock */
493 static void wakeup_thread(struct fsg_common *common)
494 {
495         /* Tell the main thread that something has happened */
496         common->thread_wakeup_needed = 1;
497         if (common->thread_task)
498                 wake_up_process(common->thread_task);
499 }
500
501
502 static void raise_exception(struct fsg_common *common, enum fsg_state new_state)
503 {
504         unsigned long           flags;
505
506         /* Do nothing if a higher-priority exception is already in progress.
507          * If a lower-or-equal priority exception is in progress, preempt it
508          * and notify the main thread by sending it a signal. */
509         spin_lock_irqsave(&common->lock, flags);
510         if (common->state <= new_state) {
511                 common->exception_req_tag = common->ep0_req_tag;
512                 common->state = new_state;
513                 if (common->thread_task)
514                         send_sig_info(SIGUSR1, SEND_SIG_FORCED,
515                                       common->thread_task);
516         }
517         spin_unlock_irqrestore(&common->lock, flags);
518 }
519
520
521 /*-------------------------------------------------------------------------*/
522
523 static int ep0_queue(struct fsg_common *common)
524 {
525         int     rc;
526
527         rc = usb_ep_queue(common->ep0, common->ep0req, GFP_ATOMIC);
528         common->ep0->driver_data = common;
529         if (rc != 0 && rc != -ESHUTDOWN) {
530                 /* We can't do much more than wait for a reset */
531                 WARNING(common, "error in submission: %s --> %d\n",
532                         common->ep0->name, rc);
533         }
534         return rc;
535 }
536
537 /*-------------------------------------------------------------------------*/
538
539 /* Bulk and interrupt endpoint completion handlers.
540  * These always run in_irq. */
541
542 static void bulk_in_complete(struct usb_ep *ep, struct usb_request *req)
543 {
544         struct fsg_common       *common = ep->driver_data;
545         struct fsg_buffhd       *bh = req->context;
546
547         if (req->status || req->actual != req->length)
548                 DBG(common, "%s --> %d, %u/%u\n", __func__,
549                                 req->status, req->actual, req->length);
550         if (req->status == -ECONNRESET)         /* Request was cancelled */
551                 usb_ep_fifo_flush(ep);
552
553         /* Hold the lock while we update the request and buffer states */
554         smp_wmb();
555         spin_lock(&common->lock);
556         bh->inreq_busy = 0;
557         bh->state = BUF_STATE_EMPTY;
558         wakeup_thread(common);
559         spin_unlock(&common->lock);
560 }
561
562 static void bulk_out_complete(struct usb_ep *ep, struct usb_request *req)
563 {
564         struct fsg_common       *common = ep->driver_data;
565         struct fsg_buffhd       *bh = req->context;
566
567         dump_msg(common, "bulk-out", req->buf, req->actual);
568         if (req->status || req->actual != bh->bulk_out_intended_length)
569                 DBG(common, "%s --> %d, %u/%u\n", __func__,
570                                 req->status, req->actual,
571                                 bh->bulk_out_intended_length);
572         if (req->status == -ECONNRESET)         /* Request was cancelled */
573                 usb_ep_fifo_flush(ep);
574
575         /* Hold the lock while we update the request and buffer states */
576         smp_wmb();
577         spin_lock(&common->lock);
578         bh->outreq_busy = 0;
579         bh->state = BUF_STATE_FULL;
580         wakeup_thread(common);
581         spin_unlock(&common->lock);
582 }
583
584
585 /*-------------------------------------------------------------------------*/
586
587 /* Ep0 class-specific handlers.  These always run in_irq. */
588
589 static int fsg_setup(struct usb_function *f,
590                 const struct usb_ctrlrequest *ctrl)
591 {
592         struct fsg_dev          *fsg = fsg_from_func(f);
593         struct usb_request      *req = fsg->common->ep0req;
594         u16                     w_index = le16_to_cpu(ctrl->wIndex);
595         u16                     w_value = le16_to_cpu(ctrl->wValue);
596         u16                     w_length = le16_to_cpu(ctrl->wLength);
597
598         if (!fsg->common->config)
599                 return -EOPNOTSUPP;
600
601         switch (ctrl->bRequest) {
602
603         case USB_BULK_RESET_REQUEST:
604                 if (ctrl->bRequestType !=
605                     (USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE))
606                         break;
607                 if (w_index != fsg->interface_number || w_value != 0)
608                         return -EDOM;
609
610                 /* Raise an exception to stop the current operation
611                  * and reinitialize our state. */
612                 DBG(fsg, "bulk reset request\n");
613                 raise_exception(fsg->common, FSG_STATE_RESET);
614                 return DELAYED_STATUS;
615
616         case USB_BULK_GET_MAX_LUN_REQUEST:
617                 if (ctrl->bRequestType !=
618                     (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE))
619                         break;
620                 if (w_index != fsg->interface_number || w_value != 0)
621                         return -EDOM;
622                 VDBG(fsg, "get max LUN\n");
623                 *(u8 *) req->buf = fsg->common->nluns - 1;
624
625                 /* Respond with data/status */
626                 req->length = min((u16)1, w_length);
627                 fsg->common->ep0req_name =
628                         ctrl->bRequestType & USB_DIR_IN ? "ep0-in" : "ep0-out";
629                 return ep0_queue(fsg->common);
630         }
631
632         VDBG(fsg,
633              "unknown class-specific control req "
634              "%02x.%02x v%04x i%04x l%u\n",
635              ctrl->bRequestType, ctrl->bRequest,
636              le16_to_cpu(ctrl->wValue), w_index, w_length);
637         return -EOPNOTSUPP;
638 }
639
640
641 /*-------------------------------------------------------------------------*/
642
643 /* All the following routines run in process context */
644
645
646 /* Use this for bulk or interrupt transfers, not ep0 */
647 static void start_transfer(struct fsg_dev *fsg, struct usb_ep *ep,
648                 struct usb_request *req, int *pbusy,
649                 enum fsg_buffer_state *state)
650 {
651         int     rc;
652
653         if (ep == fsg->bulk_in)
654                 dump_msg(fsg, "bulk-in", req->buf, req->length);
655
656         spin_lock_irq(&fsg->common->lock);
657         *pbusy = 1;
658         *state = BUF_STATE_BUSY;
659         spin_unlock_irq(&fsg->common->lock);
660         rc = usb_ep_queue(ep, req, GFP_KERNEL);
661         if (rc != 0) {
662                 *pbusy = 0;
663                 *state = BUF_STATE_EMPTY;
664
665                 /* We can't do much more than wait for a reset */
666
667                 /* Note: currently the net2280 driver fails zero-length
668                  * submissions if DMA is enabled. */
669                 if (rc != -ESHUTDOWN && !(rc == -EOPNOTSUPP &&
670                                                 req->length == 0))
671                         WARNING(fsg, "error in submission: %s --> %d\n",
672                                         ep->name, rc);
673         }
674 }
675
676 #define START_TRANSFER_OR(common, ep_name, req, pbusy, state)           \
677         if (fsg_is_set(common))                                         \
678                 start_transfer((common)->fsg, (common)->fsg->ep_name,   \
679                                req, pbusy, state);                      \
680         else
681
682 #define START_TRANSFER(common, ep_name, req, pbusy, state)              \
683         START_TRANSFER_OR(common, ep_name, req, pbusy, state) (void)0
684
685
686
687 static int sleep_thread(struct fsg_common *common)
688 {
689         int     rc = 0;
690
691         /* Wait until a signal arrives or we are woken up */
692         for (;;) {
693                 try_to_freeze();
694                 set_current_state(TASK_INTERRUPTIBLE);
695                 if (signal_pending(current)) {
696                         rc = -EINTR;
697                         break;
698                 }
699                 if (common->thread_wakeup_needed)
700                         break;
701                 schedule();
702         }
703         __set_current_state(TASK_RUNNING);
704         common->thread_wakeup_needed = 0;
705         return rc;
706 }
707
708
709 /*-------------------------------------------------------------------------*/
710
711 static int do_read(struct fsg_common *common)
712 {
713         struct fsg_lun          *curlun = common->curlun;
714         u32                     lba;
715         struct fsg_buffhd       *bh;
716         int                     rc;
717         u32                     amount_left;
718         loff_t                  file_offset, file_offset_tmp;
719         unsigned int            amount;
720         unsigned int            partial_page;
721         ssize_t                 nread;
722
723         /* Get the starting Logical Block Address and check that it's
724          * not too big */
725         if (common->cmnd[0] == SC_READ_6)
726                 lba = get_unaligned_be24(&common->cmnd[1]);
727         else {
728                 lba = get_unaligned_be32(&common->cmnd[2]);
729
730                 /* We allow DPO (Disable Page Out = don't save data in the
731                  * cache) and FUA (Force Unit Access = don't read from the
732                  * cache), but we don't implement them. */
733                 if ((common->cmnd[1] & ~0x18) != 0) {
734                         curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
735                         return -EINVAL;
736                 }
737         }
738         if (lba >= curlun->num_sectors) {
739                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
740                 return -EINVAL;
741         }
742         file_offset = ((loff_t) lba) << 9;
743
744         /* Carry out the file reads */
745         amount_left = common->data_size_from_cmnd;
746         if (unlikely(amount_left == 0))
747                 return -EIO;            /* No default reply */
748
749         for (;;) {
750
751                 /* Figure out how much we need to read:
752                  * Try to read the remaining amount.
753                  * But don't read more than the buffer size.
754                  * And don't try to read past the end of the file.
755                  * Finally, if we're not at a page boundary, don't read past
756                  *      the next page.
757                  * If this means reading 0 then we were asked to read past
758                  *      the end of file. */
759                 amount = min(amount_left, FSG_BUFLEN);
760                 amount = min((loff_t) amount,
761                                 curlun->file_length - file_offset);
762                 partial_page = file_offset & (PAGE_CACHE_SIZE - 1);
763                 if (partial_page > 0)
764                         amount = min(amount, (unsigned int) PAGE_CACHE_SIZE -
765                                         partial_page);
766
767                 /* Wait for the next buffer to become available */
768                 bh = common->next_buffhd_to_fill;
769                 while (bh->state != BUF_STATE_EMPTY) {
770                         rc = sleep_thread(common);
771                         if (rc)
772                                 return rc;
773                 }
774
775                 /* If we were asked to read past the end of file,
776                  * end with an empty buffer. */
777                 if (amount == 0) {
778                         curlun->sense_data =
779                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
780                         curlun->sense_data_info = file_offset >> 9;
781                         curlun->info_valid = 1;
782                         bh->inreq->length = 0;
783                         bh->state = BUF_STATE_FULL;
784                         break;
785                 }
786
787                 /* Perform the read */
788                 file_offset_tmp = file_offset;
789                 nread = vfs_read(curlun->filp,
790                                 (char __user *) bh->buf,
791                                 amount, &file_offset_tmp);
792                 VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
793                                 (unsigned long long) file_offset,
794                                 (int) nread);
795                 if (signal_pending(current))
796                         return -EINTR;
797
798                 if (nread < 0) {
799                         LDBG(curlun, "error in file read: %d\n",
800                                         (int) nread);
801                         nread = 0;
802                 } else if (nread < amount) {
803                         LDBG(curlun, "partial file read: %d/%u\n",
804                                         (int) nread, amount);
805                         nread -= (nread & 511); /* Round down to a block */
806                 }
807                 file_offset  += nread;
808                 amount_left  -= nread;
809                 common->residue -= nread;
810                 bh->inreq->length = nread;
811                 bh->state = BUF_STATE_FULL;
812
813                 /* If an error occurred, report it and its position */
814                 if (nread < amount) {
815                         curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
816                         curlun->sense_data_info = file_offset >> 9;
817                         curlun->info_valid = 1;
818                         break;
819                 }
820
821                 if (amount_left == 0)
822                         break;          /* No more left to read */
823
824                 /* Send this buffer and go read some more */
825                 bh->inreq->zero = 0;
826                 START_TRANSFER_OR(common, bulk_in, bh->inreq,
827                                &bh->inreq_busy, &bh->state)
828                         /* Don't know what to do if
829                          * common->fsg is NULL */
830                         return -EIO;
831                 common->next_buffhd_to_fill = bh->next;
832         }
833
834         return -EIO;            /* No default reply */
835 }
836
837
838 /*-------------------------------------------------------------------------*/
839
840 static int do_write(struct fsg_common *common)
841 {
842         struct fsg_lun          *curlun = common->curlun;
843         u32                     lba;
844         struct fsg_buffhd       *bh;
845         int                     get_some_more;
846         u32                     amount_left_to_req, amount_left_to_write;
847         loff_t                  usb_offset, file_offset, file_offset_tmp;
848         unsigned int            amount;
849         unsigned int            partial_page;
850         ssize_t                 nwritten;
851         int                     rc;
852
853         if (curlun->ro) {
854                 curlun->sense_data = SS_WRITE_PROTECTED;
855                 return -EINVAL;
856         }
857         spin_lock(&curlun->filp->f_lock);
858         curlun->filp->f_flags &= ~O_SYNC;       /* Default is not to wait */
859         spin_unlock(&curlun->filp->f_lock);
860
861         /* Get the starting Logical Block Address and check that it's
862          * not too big */
863         if (common->cmnd[0] == SC_WRITE_6)
864                 lba = get_unaligned_be24(&common->cmnd[1]);
865         else {
866                 lba = get_unaligned_be32(&common->cmnd[2]);
867
868                 /* We allow DPO (Disable Page Out = don't save data in the
869                  * cache) and FUA (Force Unit Access = write directly to the
870                  * medium).  We don't implement DPO; we implement FUA by
871                  * performing synchronous output. */
872                 if (common->cmnd[1] & ~0x18) {
873                         curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
874                         return -EINVAL;
875                 }
876                 if (common->cmnd[1] & 0x08) {   /* FUA */
877                         spin_lock(&curlun->filp->f_lock);
878                         curlun->filp->f_flags |= O_SYNC;
879                         spin_unlock(&curlun->filp->f_lock);
880                 }
881         }
882         if (lba >= curlun->num_sectors) {
883                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
884                 return -EINVAL;
885         }
886
887         /* Carry out the file writes */
888         get_some_more = 1;
889         file_offset = usb_offset = ((loff_t) lba) << 9;
890         amount_left_to_req = common->data_size_from_cmnd;
891         amount_left_to_write = common->data_size_from_cmnd;
892
893         while (amount_left_to_write > 0) {
894
895                 /* Queue a request for more data from the host */
896                 bh = common->next_buffhd_to_fill;
897                 if (bh->state == BUF_STATE_EMPTY && get_some_more) {
898
899                         /* Figure out how much we want to get:
900                          * Try to get the remaining amount.
901                          * But don't get more than the buffer size.
902                          * And don't try to go past the end of the file.
903                          * If we're not at a page boundary,
904                          *      don't go past the next page.
905                          * If this means getting 0, then we were asked
906                          *      to write past the end of file.
907                          * Finally, round down to a block boundary. */
908                         amount = min(amount_left_to_req, FSG_BUFLEN);
909                         amount = min((loff_t) amount, curlun->file_length -
910                                         usb_offset);
911                         partial_page = usb_offset & (PAGE_CACHE_SIZE - 1);
912                         if (partial_page > 0)
913                                 amount = min(amount,
914         (unsigned int) PAGE_CACHE_SIZE - partial_page);
915
916                         if (amount == 0) {
917                                 get_some_more = 0;
918                                 curlun->sense_data =
919                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
920                                 curlun->sense_data_info = usb_offset >> 9;
921                                 curlun->info_valid = 1;
922                                 continue;
923                         }
924                         amount -= (amount & 511);
925                         if (amount == 0) {
926
927                                 /* Why were we were asked to transfer a
928                                  * partial block? */
929                                 get_some_more = 0;
930                                 continue;
931                         }
932
933                         /* Get the next buffer */
934                         usb_offset += amount;
935                         common->usb_amount_left -= amount;
936                         amount_left_to_req -= amount;
937                         if (amount_left_to_req == 0)
938                                 get_some_more = 0;
939
940                         /* amount is always divisible by 512, hence by
941                          * the bulk-out maxpacket size */
942                         bh->outreq->length = amount;
943                         bh->bulk_out_intended_length = amount;
944                         bh->outreq->short_not_ok = 1;
945                         START_TRANSFER_OR(common, bulk_out, bh->outreq,
946                                           &bh->outreq_busy, &bh->state)
947                                 /* Don't know what to do if
948                                  * common->fsg is NULL */
949                                 return -EIO;
950                         common->next_buffhd_to_fill = bh->next;
951                         continue;
952                 }
953
954                 /* Write the received data to the backing file */
955                 bh = common->next_buffhd_to_drain;
956                 if (bh->state == BUF_STATE_EMPTY && !get_some_more)
957                         break;                  /* We stopped early */
958                 if (bh->state == BUF_STATE_FULL) {
959                         smp_rmb();
960                         common->next_buffhd_to_drain = bh->next;
961                         bh->state = BUF_STATE_EMPTY;
962
963                         /* Did something go wrong with the transfer? */
964                         if (bh->outreq->status != 0) {
965                                 curlun->sense_data = SS_COMMUNICATION_FAILURE;
966                                 curlun->sense_data_info = file_offset >> 9;
967                                 curlun->info_valid = 1;
968                                 break;
969                         }
970
971                         amount = bh->outreq->actual;
972                         if (curlun->file_length - file_offset < amount) {
973                                 LERROR(curlun,
974         "write %u @ %llu beyond end %llu\n",
975         amount, (unsigned long long) file_offset,
976         (unsigned long long) curlun->file_length);
977                                 amount = curlun->file_length - file_offset;
978                         }
979
980                         /* Perform the write */
981                         file_offset_tmp = file_offset;
982                         nwritten = vfs_write(curlun->filp,
983                                         (char __user *) bh->buf,
984                                         amount, &file_offset_tmp);
985                         VLDBG(curlun, "file write %u @ %llu -> %d\n", amount,
986                                         (unsigned long long) file_offset,
987                                         (int) nwritten);
988                         if (signal_pending(current))
989                                 return -EINTR;          /* Interrupted! */
990
991                         if (nwritten < 0) {
992                                 LDBG(curlun, "error in file write: %d\n",
993                                                 (int) nwritten);
994                                 nwritten = 0;
995                         } else if (nwritten < amount) {
996                                 LDBG(curlun, "partial file write: %d/%u\n",
997                                                 (int) nwritten, amount);
998                                 nwritten -= (nwritten & 511);
999                                 /* Round down to a block */
1000                         }
1001                         file_offset += nwritten;
1002                         amount_left_to_write -= nwritten;
1003                         common->residue -= nwritten;
1004
1005                         /* If an error occurred, report it and its position */
1006                         if (nwritten < amount) {
1007                                 curlun->sense_data = SS_WRITE_ERROR;
1008                                 curlun->sense_data_info = file_offset >> 9;
1009                                 curlun->info_valid = 1;
1010                                 break;
1011                         }
1012
1013                         /* Did the host decide to stop early? */
1014                         if (bh->outreq->actual != bh->outreq->length) {
1015                                 common->short_packet_received = 1;
1016                                 break;
1017                         }
1018                         continue;
1019                 }
1020
1021                 /* Wait for something to happen */
1022                 rc = sleep_thread(common);
1023                 if (rc)
1024                         return rc;
1025         }
1026
1027         return -EIO;            /* No default reply */
1028 }
1029
1030
1031 /*-------------------------------------------------------------------------*/
1032
1033 static int do_synchronize_cache(struct fsg_common *common)
1034 {
1035         struct fsg_lun  *curlun = common->curlun;
1036         int             rc;
1037
1038         /* We ignore the requested LBA and write out all file's
1039          * dirty data buffers. */
1040         rc = fsg_lun_fsync_sub(curlun);
1041         if (rc)
1042                 curlun->sense_data = SS_WRITE_ERROR;
1043         return 0;
1044 }
1045
1046
1047 /*-------------------------------------------------------------------------*/
1048
1049 static void invalidate_sub(struct fsg_lun *curlun)
1050 {
1051         struct file     *filp = curlun->filp;
1052         struct inode    *inode = filp->f_path.dentry->d_inode;
1053         unsigned long   rc;
1054
1055         rc = invalidate_mapping_pages(inode->i_mapping, 0, -1);
1056         VLDBG(curlun, "invalidate_mapping_pages -> %ld\n", rc);
1057 }
1058
1059 static int do_verify(struct fsg_common *common)
1060 {
1061         struct fsg_lun          *curlun = common->curlun;
1062         u32                     lba;
1063         u32                     verification_length;
1064         struct fsg_buffhd       *bh = common->next_buffhd_to_fill;
1065         loff_t                  file_offset, file_offset_tmp;
1066         u32                     amount_left;
1067         unsigned int            amount;
1068         ssize_t                 nread;
1069
1070         /* Get the starting Logical Block Address and check that it's
1071          * not too big */
1072         lba = get_unaligned_be32(&common->cmnd[2]);
1073         if (lba >= curlun->num_sectors) {
1074                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1075                 return -EINVAL;
1076         }
1077
1078         /* We allow DPO (Disable Page Out = don't save data in the
1079          * cache) but we don't implement it. */
1080         if (common->cmnd[1] & ~0x10) {
1081                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1082                 return -EINVAL;
1083         }
1084
1085         verification_length = get_unaligned_be16(&common->cmnd[7]);
1086         if (unlikely(verification_length == 0))
1087                 return -EIO;            /* No default reply */
1088
1089         /* Prepare to carry out the file verify */
1090         amount_left = verification_length << 9;
1091         file_offset = ((loff_t) lba) << 9;
1092
1093         /* Write out all the dirty buffers before invalidating them */
1094         fsg_lun_fsync_sub(curlun);
1095         if (signal_pending(current))
1096                 return -EINTR;
1097
1098         invalidate_sub(curlun);
1099         if (signal_pending(current))
1100                 return -EINTR;
1101
1102         /* Just try to read the requested blocks */
1103         while (amount_left > 0) {
1104
1105                 /* Figure out how much we need to read:
1106                  * Try to read the remaining amount, but not more than
1107                  * the buffer size.
1108                  * And don't try to read past the end of the file.
1109                  * If this means reading 0 then we were asked to read
1110                  * past the end of file. */
1111                 amount = min(amount_left, FSG_BUFLEN);
1112                 amount = min((loff_t) amount,
1113                                 curlun->file_length - file_offset);
1114                 if (amount == 0) {
1115                         curlun->sense_data =
1116                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1117                         curlun->sense_data_info = file_offset >> 9;
1118                         curlun->info_valid = 1;
1119                         break;
1120                 }
1121
1122                 /* Perform the read */
1123                 file_offset_tmp = file_offset;
1124                 nread = vfs_read(curlun->filp,
1125                                 (char __user *) bh->buf,
1126                                 amount, &file_offset_tmp);
1127                 VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
1128                                 (unsigned long long) file_offset,
1129                                 (int) nread);
1130                 if (signal_pending(current))
1131                         return -EINTR;
1132
1133                 if (nread < 0) {
1134                         LDBG(curlun, "error in file verify: %d\n",
1135                                         (int) nread);
1136                         nread = 0;
1137                 } else if (nread < amount) {
1138                         LDBG(curlun, "partial file verify: %d/%u\n",
1139                                         (int) nread, amount);
1140                         nread -= (nread & 511); /* Round down to a sector */
1141                 }
1142                 if (nread == 0) {
1143                         curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
1144                         curlun->sense_data_info = file_offset >> 9;
1145                         curlun->info_valid = 1;
1146                         break;
1147                 }
1148                 file_offset += nread;
1149                 amount_left -= nread;
1150         }
1151         return 0;
1152 }
1153
1154
1155 /*-------------------------------------------------------------------------*/
1156
1157 static int do_inquiry(struct fsg_common *common, struct fsg_buffhd *bh)
1158 {
1159         struct fsg_lun *curlun = common->curlun;
1160         u8      *buf = (u8 *) bh->buf;
1161
1162         if (!curlun) {          /* Unsupported LUNs are okay */
1163                 common->bad_lun_okay = 1;
1164                 memset(buf, 0, 36);
1165                 buf[0] = 0x7f;          /* Unsupported, no device-type */
1166                 buf[4] = 31;            /* Additional length */
1167                 return 36;
1168         }
1169
1170         buf[0] = curlun->cdrom ? TYPE_CDROM : TYPE_DISK;
1171         buf[1] = curlun->removable ? 0x80 : 0;
1172         buf[2] = 2;             /* ANSI SCSI level 2 */
1173         buf[3] = 2;             /* SCSI-2 INQUIRY data format */
1174         buf[4] = 31;            /* Additional length */
1175         buf[5] = 0;             /* No special options */
1176         buf[6] = 0;
1177         buf[7] = 0;
1178         memcpy(buf + 8, common->inquiry_string, sizeof common->inquiry_string);
1179         return 36;
1180 }
1181
1182
1183 static int do_request_sense(struct fsg_common *common, struct fsg_buffhd *bh)
1184 {
1185         struct fsg_lun  *curlun = common->curlun;
1186         u8              *buf = (u8 *) bh->buf;
1187         u32             sd, sdinfo;
1188         int             valid;
1189
1190         /*
1191          * From the SCSI-2 spec., section 7.9 (Unit attention condition):
1192          *
1193          * If a REQUEST SENSE command is received from an initiator
1194          * with a pending unit attention condition (before the target
1195          * generates the contingent allegiance condition), then the
1196          * target shall either:
1197          *   a) report any pending sense data and preserve the unit
1198          *      attention condition on the logical unit, or,
1199          *   b) report the unit attention condition, may discard any
1200          *      pending sense data, and clear the unit attention
1201          *      condition on the logical unit for that initiator.
1202          *
1203          * FSG normally uses option a); enable this code to use option b).
1204          */
1205 #if 0
1206         if (curlun && curlun->unit_attention_data != SS_NO_SENSE) {
1207                 curlun->sense_data = curlun->unit_attention_data;
1208                 curlun->unit_attention_data = SS_NO_SENSE;
1209         }
1210 #endif
1211
1212         if (!curlun) {          /* Unsupported LUNs are okay */
1213                 common->bad_lun_okay = 1;
1214                 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
1215                 sdinfo = 0;
1216                 valid = 0;
1217         } else {
1218                 sd = curlun->sense_data;
1219                 sdinfo = curlun->sense_data_info;
1220                 valid = curlun->info_valid << 7;
1221                 curlun->sense_data = SS_NO_SENSE;
1222                 curlun->sense_data_info = 0;
1223                 curlun->info_valid = 0;
1224         }
1225
1226         memset(buf, 0, 18);
1227         buf[0] = valid | 0x70;                  /* Valid, current error */
1228         buf[2] = SK(sd);
1229         put_unaligned_be32(sdinfo, &buf[3]);    /* Sense information */
1230         buf[7] = 18 - 8;                        /* Additional sense length */
1231         buf[12] = ASC(sd);
1232         buf[13] = ASCQ(sd);
1233         return 18;
1234 }
1235
1236
1237 static int do_read_capacity(struct fsg_common *common, struct fsg_buffhd *bh)
1238 {
1239         struct fsg_lun  *curlun = common->curlun;
1240         u32             lba = get_unaligned_be32(&common->cmnd[2]);
1241         int             pmi = common->cmnd[8];
1242         u8              *buf = (u8 *) bh->buf;
1243
1244         /* Check the PMI and LBA fields */
1245         if (pmi > 1 || (pmi == 0 && lba != 0)) {
1246                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1247                 return -EINVAL;
1248         }
1249
1250         put_unaligned_be32(curlun->num_sectors - 1, &buf[0]);
1251                                                 /* Max logical block */
1252         put_unaligned_be32(512, &buf[4]);       /* Block length */
1253         return 8;
1254 }
1255
1256
1257 static int do_read_header(struct fsg_common *common, struct fsg_buffhd *bh)
1258 {
1259         struct fsg_lun  *curlun = common->curlun;
1260         int             msf = common->cmnd[1] & 0x02;
1261         u32             lba = get_unaligned_be32(&common->cmnd[2]);
1262         u8              *buf = (u8 *) bh->buf;
1263
1264         if (common->cmnd[1] & ~0x02) {          /* Mask away MSF */
1265                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1266                 return -EINVAL;
1267         }
1268         if (lba >= curlun->num_sectors) {
1269                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1270                 return -EINVAL;
1271         }
1272
1273         memset(buf, 0, 8);
1274         buf[0] = 0x01;          /* 2048 bytes of user data, rest is EC */
1275         store_cdrom_address(&buf[4], msf, lba);
1276         return 8;
1277 }
1278
1279
1280 static int do_read_toc(struct fsg_common *common, struct fsg_buffhd *bh)
1281 {
1282         struct fsg_lun  *curlun = common->curlun;
1283         int             msf = common->cmnd[1] & 0x02;
1284         int             start_track = common->cmnd[6];
1285         u8              *buf = (u8 *) bh->buf;
1286
1287         if ((common->cmnd[1] & ~0x02) != 0 ||   /* Mask away MSF */
1288                         start_track > 1) {
1289                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1290                 return -EINVAL;
1291         }
1292
1293         memset(buf, 0, 20);
1294         buf[1] = (20-2);                /* TOC data length */
1295         buf[2] = 1;                     /* First track number */
1296         buf[3] = 1;                     /* Last track number */
1297         buf[5] = 0x16;                  /* Data track, copying allowed */
1298         buf[6] = 0x01;                  /* Only track is number 1 */
1299         store_cdrom_address(&buf[8], msf, 0);
1300
1301         buf[13] = 0x16;                 /* Lead-out track is data */
1302         buf[14] = 0xAA;                 /* Lead-out track number */
1303         store_cdrom_address(&buf[16], msf, curlun->num_sectors);
1304         return 20;
1305 }
1306
1307
1308 static int do_mode_sense(struct fsg_common *common, struct fsg_buffhd *bh)
1309 {
1310         struct fsg_lun  *curlun = common->curlun;
1311         int             mscmnd = common->cmnd[0];
1312         u8              *buf = (u8 *) bh->buf;
1313         u8              *buf0 = buf;
1314         int             pc, page_code;
1315         int             changeable_values, all_pages;
1316         int             valid_page = 0;
1317         int             len, limit;
1318
1319         if ((common->cmnd[1] & ~0x08) != 0) {   /* Mask away DBD */
1320                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1321                 return -EINVAL;
1322         }
1323         pc = common->cmnd[2] >> 6;
1324         page_code = common->cmnd[2] & 0x3f;
1325         if (pc == 3) {
1326                 curlun->sense_data = SS_SAVING_PARAMETERS_NOT_SUPPORTED;
1327                 return -EINVAL;
1328         }
1329         changeable_values = (pc == 1);
1330         all_pages = (page_code == 0x3f);
1331
1332         /* Write the mode parameter header.  Fixed values are: default
1333          * medium type, no cache control (DPOFUA), and no block descriptors.
1334          * The only variable value is the WriteProtect bit.  We will fill in
1335          * the mode data length later. */
1336         memset(buf, 0, 8);
1337         if (mscmnd == SC_MODE_SENSE_6) {
1338                 buf[2] = (curlun->ro ? 0x80 : 0x00);            /* WP, DPOFUA */
1339                 buf += 4;
1340                 limit = 255;
1341         } else {                        /* SC_MODE_SENSE_10 */
1342                 buf[3] = (curlun->ro ? 0x80 : 0x00);            /* WP, DPOFUA */
1343                 buf += 8;
1344                 limit = 65535;          /* Should really be FSG_BUFLEN */
1345         }
1346
1347         /* No block descriptors */
1348
1349         /* The mode pages, in numerical order.  The only page we support
1350          * is the Caching page. */
1351         if (page_code == 0x08 || all_pages) {
1352                 valid_page = 1;
1353                 buf[0] = 0x08;          /* Page code */
1354                 buf[1] = 10;            /* Page length */
1355                 memset(buf+2, 0, 10);   /* None of the fields are changeable */
1356
1357                 if (!changeable_values) {
1358                         buf[2] = 0x04;  /* Write cache enable, */
1359                                         /* Read cache not disabled */
1360                                         /* No cache retention priorities */
1361                         put_unaligned_be16(0xffff, &buf[4]);
1362                                         /* Don't disable prefetch */
1363                                         /* Minimum prefetch = 0 */
1364                         put_unaligned_be16(0xffff, &buf[8]);
1365                                         /* Maximum prefetch */
1366                         put_unaligned_be16(0xffff, &buf[10]);
1367                                         /* Maximum prefetch ceiling */
1368                 }
1369                 buf += 12;
1370         }
1371
1372         /* Check that a valid page was requested and the mode data length
1373          * isn't too long. */
1374         len = buf - buf0;
1375         if (!valid_page || len > limit) {
1376                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1377                 return -EINVAL;
1378         }
1379
1380         /*  Store the mode data length */
1381         if (mscmnd == SC_MODE_SENSE_6)
1382                 buf0[0] = len - 1;
1383         else
1384                 put_unaligned_be16(len - 2, buf0);
1385         return len;
1386 }
1387
1388
1389 static int do_start_stop(struct fsg_common *common)
1390 {
1391         struct fsg_lun  *curlun = common->curlun;
1392         int             loej, start;
1393
1394         if (!curlun) {
1395                 return -EINVAL;
1396         } else if (!curlun->removable) {
1397                 curlun->sense_data = SS_INVALID_COMMAND;
1398                 return -EINVAL;
1399         }
1400
1401         loej = common->cmnd[4] & 0x02;
1402         start = common->cmnd[4] & 0x01;
1403
1404         /* eject code from file_storage.c:do_start_stop() */
1405
1406         if ((common->cmnd[1] & ~0x01) != 0 ||     /* Mask away Immed */
1407                 (common->cmnd[4] & ~0x03) != 0) { /* Mask LoEj, Start */
1408                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1409                 return -EINVAL;
1410         }
1411
1412         if (!start) {
1413                 /* Are we allowed to unload the media? */
1414                 if (curlun->prevent_medium_removal) {
1415                         LDBG(curlun, "unload attempt prevented\n");
1416                         curlun->sense_data = SS_MEDIUM_REMOVAL_PREVENTED;
1417                         return -EINVAL;
1418                 }
1419                 if (loej) {     /* Simulate an unload/eject */
1420                         up_read(&common->filesem);
1421                         down_write(&common->filesem);
1422                         fsg_lun_close(curlun);
1423                         up_write(&common->filesem);
1424                         down_read(&common->filesem);
1425                 }
1426         } else {
1427
1428                 /* Our emulation doesn't support mounting; the medium is
1429                  * available for use as soon as it is loaded. */
1430                 if (!fsg_lun_is_open(curlun)) {
1431                         curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
1432                         return -EINVAL;
1433                 }
1434         }
1435         return 0;
1436 }
1437
1438
1439 static int do_prevent_allow(struct fsg_common *common)
1440 {
1441         struct fsg_lun  *curlun = common->curlun;
1442         int             prevent;
1443
1444         if (!common->curlun) {
1445                 return -EINVAL;
1446         } else if (!common->curlun->removable) {
1447                 common->curlun->sense_data = SS_INVALID_COMMAND;
1448                 return -EINVAL;
1449         }
1450
1451         prevent = common->cmnd[4] & 0x01;
1452         if ((common->cmnd[4] & ~0x01) != 0) {   /* Mask away Prevent */
1453                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1454                 return -EINVAL;
1455         }
1456
1457         if (curlun->prevent_medium_removal && !prevent)
1458                 fsg_lun_fsync_sub(curlun);
1459         curlun->prevent_medium_removal = prevent;
1460         return 0;
1461 }
1462
1463
1464 static int do_read_format_capacities(struct fsg_common *common,
1465                         struct fsg_buffhd *bh)
1466 {
1467         struct fsg_lun  *curlun = common->curlun;
1468         u8              *buf = (u8 *) bh->buf;
1469
1470         buf[0] = buf[1] = buf[2] = 0;
1471         buf[3] = 8;     /* Only the Current/Maximum Capacity Descriptor */
1472         buf += 4;
1473
1474         put_unaligned_be32(curlun->num_sectors, &buf[0]);
1475                                                 /* Number of blocks */
1476         put_unaligned_be32(512, &buf[4]);       /* Block length */
1477         buf[4] = 0x02;                          /* Current capacity */
1478         return 12;
1479 }
1480
1481
1482 static int do_mode_select(struct fsg_common *common, struct fsg_buffhd *bh)
1483 {
1484         struct fsg_lun  *curlun = common->curlun;
1485
1486         /* We don't support MODE SELECT */
1487         if (curlun)
1488                 curlun->sense_data = SS_INVALID_COMMAND;
1489         return -EINVAL;
1490 }
1491
1492
1493 /*-------------------------------------------------------------------------*/
1494
1495 static int halt_bulk_in_endpoint(struct fsg_dev *fsg)
1496 {
1497         int     rc;
1498
1499         rc = fsg_set_halt(fsg, fsg->bulk_in);
1500         if (rc == -EAGAIN)
1501                 VDBG(fsg, "delayed bulk-in endpoint halt\n");
1502         while (rc != 0) {
1503                 if (rc != -EAGAIN) {
1504                         WARNING(fsg, "usb_ep_set_halt -> %d\n", rc);
1505                         rc = 0;
1506                         break;
1507                 }
1508
1509                 /* Wait for a short time and then try again */
1510                 if (msleep_interruptible(100) != 0)
1511                         return -EINTR;
1512                 rc = usb_ep_set_halt(fsg->bulk_in);
1513         }
1514         return rc;
1515 }
1516
1517 static int wedge_bulk_in_endpoint(struct fsg_dev *fsg)
1518 {
1519         int     rc;
1520
1521         DBG(fsg, "bulk-in set wedge\n");
1522         rc = usb_ep_set_wedge(fsg->bulk_in);
1523         if (rc == -EAGAIN)
1524                 VDBG(fsg, "delayed bulk-in endpoint wedge\n");
1525         while (rc != 0) {
1526                 if (rc != -EAGAIN) {
1527                         WARNING(fsg, "usb_ep_set_wedge -> %d\n", rc);
1528                         rc = 0;
1529                         break;
1530                 }
1531
1532                 /* Wait for a short time and then try again */
1533                 if (msleep_interruptible(100) != 0)
1534                         return -EINTR;
1535                 rc = usb_ep_set_wedge(fsg->bulk_in);
1536         }
1537         return rc;
1538 }
1539
1540 static int pad_with_zeros(struct fsg_dev *fsg)
1541 {
1542         struct fsg_buffhd       *bh = fsg->common->next_buffhd_to_fill;
1543         u32                     nkeep = bh->inreq->length;
1544         u32                     nsend;
1545         int                     rc;
1546
1547         bh->state = BUF_STATE_EMPTY;            /* For the first iteration */
1548         fsg->common->usb_amount_left = nkeep + fsg->common->residue;
1549         while (fsg->common->usb_amount_left > 0) {
1550
1551                 /* Wait for the next buffer to be free */
1552                 while (bh->state != BUF_STATE_EMPTY) {
1553                         rc = sleep_thread(fsg->common);
1554                         if (rc)
1555                                 return rc;
1556                 }
1557
1558                 nsend = min(fsg->common->usb_amount_left, FSG_BUFLEN);
1559                 memset(bh->buf + nkeep, 0, nsend - nkeep);
1560                 bh->inreq->length = nsend;
1561                 bh->inreq->zero = 0;
1562                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
1563                                 &bh->inreq_busy, &bh->state);
1564                 bh = fsg->common->next_buffhd_to_fill = bh->next;
1565                 fsg->common->usb_amount_left -= nsend;
1566                 nkeep = 0;
1567         }
1568         return 0;
1569 }
1570
1571 static int throw_away_data(struct fsg_common *common)
1572 {
1573         struct fsg_buffhd       *bh;
1574         u32                     amount;
1575         int                     rc;
1576
1577         for (bh = common->next_buffhd_to_drain;
1578              bh->state != BUF_STATE_EMPTY || common->usb_amount_left > 0;
1579              bh = common->next_buffhd_to_drain) {
1580
1581                 /* Throw away the data in a filled buffer */
1582                 if (bh->state == BUF_STATE_FULL) {
1583                         smp_rmb();
1584                         bh->state = BUF_STATE_EMPTY;
1585                         common->next_buffhd_to_drain = bh->next;
1586
1587                         /* A short packet or an error ends everything */
1588                         if (bh->outreq->actual != bh->outreq->length ||
1589                                         bh->outreq->status != 0) {
1590                                 raise_exception(common,
1591                                                 FSG_STATE_ABORT_BULK_OUT);
1592                                 return -EINTR;
1593                         }
1594                         continue;
1595                 }
1596
1597                 /* Try to submit another request if we need one */
1598                 bh = common->next_buffhd_to_fill;
1599                 if (bh->state == BUF_STATE_EMPTY
1600                  && common->usb_amount_left > 0) {
1601                         amount = min(common->usb_amount_left, FSG_BUFLEN);
1602
1603                         /* amount is always divisible by 512, hence by
1604                          * the bulk-out maxpacket size */
1605                         bh->outreq->length = amount;
1606                         bh->bulk_out_intended_length = amount;
1607                         bh->outreq->short_not_ok = 1;
1608                         START_TRANSFER_OR(common, bulk_out, bh->outreq,
1609                                           &bh->outreq_busy, &bh->state)
1610                                 /* Don't know what to do if
1611                                  * common->fsg is NULL */
1612                                 return -EIO;
1613                         common->next_buffhd_to_fill = bh->next;
1614                         common->usb_amount_left -= amount;
1615                         continue;
1616                 }
1617
1618                 /* Otherwise wait for something to happen */
1619                 rc = sleep_thread(common);
1620                 if (rc)
1621                         return rc;
1622         }
1623         return 0;
1624 }
1625
1626
1627 static int finish_reply(struct fsg_common *common)
1628 {
1629         struct fsg_buffhd       *bh = common->next_buffhd_to_fill;
1630         int                     rc = 0;
1631
1632         switch (common->data_dir) {
1633         case DATA_DIR_NONE:
1634                 break;                  /* Nothing to send */
1635
1636         /* If we don't know whether the host wants to read or write,
1637          * this must be CB or CBI with an unknown command.  We mustn't
1638          * try to send or receive any data.  So stall both bulk pipes
1639          * if we can and wait for a reset. */
1640         case DATA_DIR_UNKNOWN:
1641                 if (!common->can_stall) {
1642                         /* Nothing */
1643                 } else if (fsg_is_set(common)) {
1644                         fsg_set_halt(common->fsg, common->fsg->bulk_out);
1645                         rc = halt_bulk_in_endpoint(common->fsg);
1646                 } else {
1647                         /* Don't know what to do if common->fsg is NULL */
1648                         rc = -EIO;
1649                 }
1650                 break;
1651
1652         /* All but the last buffer of data must have already been sent */
1653         case DATA_DIR_TO_HOST:
1654                 if (common->data_size == 0) {
1655                         /* Nothing to send */
1656
1657                 /* If there's no residue, simply send the last buffer */
1658                 } else if (common->residue == 0) {
1659                         bh->inreq->zero = 0;
1660                         START_TRANSFER_OR(common, bulk_in, bh->inreq,
1661                                           &bh->inreq_busy, &bh->state)
1662                                 return -EIO;
1663                         common->next_buffhd_to_fill = bh->next;
1664
1665                 /* For Bulk-only, if we're allowed to stall then send the
1666                  * short packet and halt the bulk-in endpoint.  If we can't
1667                  * stall, pad out the remaining data with 0's. */
1668                 } else if (common->can_stall) {
1669                         bh->inreq->zero = 1;
1670                         START_TRANSFER_OR(common, bulk_in, bh->inreq,
1671                                           &bh->inreq_busy, &bh->state)
1672                                 /* Don't know what to do if
1673                                  * common->fsg is NULL */
1674                                 rc = -EIO;
1675                         common->next_buffhd_to_fill = bh->next;
1676                         if (common->fsg)
1677                                 rc = halt_bulk_in_endpoint(common->fsg);
1678                 } else if (fsg_is_set(common)) {
1679                         rc = pad_with_zeros(common->fsg);
1680                 } else {
1681                         /* Don't know what to do if common->fsg is NULL */
1682                         rc = -EIO;
1683                 }
1684                 break;
1685
1686         /* We have processed all we want from the data the host has sent.
1687          * There may still be outstanding bulk-out requests. */
1688         case DATA_DIR_FROM_HOST:
1689                 if (common->residue == 0) {
1690                         /* Nothing to receive */
1691
1692                 /* Did the host stop sending unexpectedly early? */
1693                 } else if (common->short_packet_received) {
1694                         raise_exception(common, FSG_STATE_ABORT_BULK_OUT);
1695                         rc = -EINTR;
1696
1697                 /* We haven't processed all the incoming data.  Even though
1698                  * we may be allowed to stall, doing so would cause a race.
1699                  * The controller may already have ACK'ed all the remaining
1700                  * bulk-out packets, in which case the host wouldn't see a
1701                  * STALL.  Not realizing the endpoint was halted, it wouldn't
1702                  * clear the halt -- leading to problems later on. */
1703 #if 0
1704                 } else if (common->can_stall) {
1705                         if (fsg_is_set(common))
1706                                 fsg_set_halt(common->fsg,
1707                                              common->fsg->bulk_out);
1708                         raise_exception(common, FSG_STATE_ABORT_BULK_OUT);
1709                         rc = -EINTR;
1710 #endif
1711
1712                 /* We can't stall.  Read in the excess data and throw it
1713                  * all away. */
1714                 } else {
1715                         rc = throw_away_data(common);
1716                 }
1717                 break;
1718         }
1719         return rc;
1720 }
1721
1722
1723 static int send_status(struct fsg_common *common)
1724 {
1725         struct fsg_lun          *curlun = common->curlun;
1726         struct fsg_buffhd       *bh;
1727         struct bulk_cs_wrap     *csw;
1728         int                     rc;
1729         u8                      status = USB_STATUS_PASS;
1730         u32                     sd, sdinfo = 0;
1731
1732         /* Wait for the next buffer to become available */
1733         bh = common->next_buffhd_to_fill;
1734         while (bh->state != BUF_STATE_EMPTY) {
1735                 rc = sleep_thread(common);
1736                 if (rc)
1737                         return rc;
1738         }
1739
1740         if (curlun) {
1741                 sd = curlun->sense_data;
1742                 sdinfo = curlun->sense_data_info;
1743         } else if (common->bad_lun_okay)
1744                 sd = SS_NO_SENSE;
1745         else
1746                 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
1747
1748         if (common->phase_error) {
1749                 DBG(common, "sending phase-error status\n");
1750                 status = USB_STATUS_PHASE_ERROR;
1751                 sd = SS_INVALID_COMMAND;
1752         } else if (sd != SS_NO_SENSE) {
1753                 DBG(common, "sending command-failure status\n");
1754                 status = USB_STATUS_FAIL;
1755                 VDBG(common, "  sense data: SK x%02x, ASC x%02x, ASCQ x%02x;"
1756                                 "  info x%x\n",
1757                                 SK(sd), ASC(sd), ASCQ(sd), sdinfo);
1758         }
1759
1760         /* Store and send the Bulk-only CSW */
1761         csw = (void *)bh->buf;
1762
1763         csw->Signature = cpu_to_le32(USB_BULK_CS_SIG);
1764         csw->Tag = common->tag;
1765         csw->Residue = cpu_to_le32(common->residue);
1766         csw->Status = status;
1767
1768         bh->inreq->length = USB_BULK_CS_WRAP_LEN;
1769         bh->inreq->zero = 0;
1770         START_TRANSFER_OR(common, bulk_in, bh->inreq,
1771                           &bh->inreq_busy, &bh->state)
1772                 /* Don't know what to do if common->fsg is NULL */
1773                 return -EIO;
1774
1775         common->next_buffhd_to_fill = bh->next;
1776         return 0;
1777 }
1778
1779
1780 /*-------------------------------------------------------------------------*/
1781
1782 /* Check whether the command is properly formed and whether its data size
1783  * and direction agree with the values we already have. */
1784 static int check_command(struct fsg_common *common, int cmnd_size,
1785                 enum data_direction data_dir, unsigned int mask,
1786                 int needs_medium, const char *name)
1787 {
1788         int                     i;
1789         int                     lun = common->cmnd[1] >> 5;
1790         static const char       dirletter[4] = {'u', 'o', 'i', 'n'};
1791         char                    hdlen[20];
1792         struct fsg_lun          *curlun;
1793
1794         hdlen[0] = 0;
1795         if (common->data_dir != DATA_DIR_UNKNOWN)
1796                 sprintf(hdlen, ", H%c=%u", dirletter[(int) common->data_dir],
1797                                 common->data_size);
1798         VDBG(common, "SCSI command: %s;  Dc=%d, D%c=%u;  Hc=%d%s\n",
1799              name, cmnd_size, dirletter[(int) data_dir],
1800              common->data_size_from_cmnd, common->cmnd_size, hdlen);
1801
1802         /* We can't reply at all until we know the correct data direction
1803          * and size. */
1804         if (common->data_size_from_cmnd == 0)
1805                 data_dir = DATA_DIR_NONE;
1806         if (common->data_size < common->data_size_from_cmnd) {
1807                 /* Host data size < Device data size is a phase error.
1808                  * Carry out the command, but only transfer as much as
1809                  * we are allowed. */
1810                 common->data_size_from_cmnd = common->data_size;
1811                 common->phase_error = 1;
1812         }
1813         common->residue = common->data_size;
1814         common->usb_amount_left = common->data_size;
1815
1816         /* Conflicting data directions is a phase error */
1817         if (common->data_dir != data_dir
1818          && common->data_size_from_cmnd > 0) {
1819                 common->phase_error = 1;
1820                 return -EINVAL;
1821         }
1822
1823         /* Verify the length of the command itself */
1824         if (cmnd_size != common->cmnd_size) {
1825
1826                 /* Special case workaround: There are plenty of buggy SCSI
1827                  * implementations. Many have issues with cbw->Length
1828                  * field passing a wrong command size. For those cases we
1829                  * always try to work around the problem by using the length
1830                  * sent by the host side provided it is at least as large
1831                  * as the correct command length.
1832                  * Examples of such cases would be MS-Windows, which issues
1833                  * REQUEST SENSE with cbw->Length == 12 where it should
1834                  * be 6, and xbox360 issuing INQUIRY, TEST UNIT READY and
1835                  * REQUEST SENSE with cbw->Length == 10 where it should
1836                  * be 6 as well.
1837                  */
1838                 if (cmnd_size <= common->cmnd_size) {
1839                         DBG(common, "%s is buggy! Expected length %d "
1840                             "but we got %d\n", name,
1841                             cmnd_size, common->cmnd_size);
1842                         cmnd_size = common->cmnd_size;
1843                 } else {
1844                         common->phase_error = 1;
1845                         return -EINVAL;
1846                 }
1847         }
1848
1849         /* Check that the LUN values are consistent */
1850         if (common->lun != lun)
1851                 DBG(common, "using LUN %d from CBW, not LUN %d from CDB\n",
1852                     common->lun, lun);
1853
1854         /* Check the LUN */
1855         if (common->lun >= 0 && common->lun < common->nluns) {
1856                 curlun = &common->luns[common->lun];
1857                 common->curlun = curlun;
1858                 if (common->cmnd[0] != SC_REQUEST_SENSE) {
1859                         curlun->sense_data = SS_NO_SENSE;
1860                         curlun->sense_data_info = 0;
1861                         curlun->info_valid = 0;
1862                 }
1863         } else {
1864                 common->curlun = NULL;
1865                 curlun = NULL;
1866                 common->bad_lun_okay = 0;
1867
1868                 /* INQUIRY and REQUEST SENSE commands are explicitly allowed
1869                  * to use unsupported LUNs; all others may not. */
1870                 if (common->cmnd[0] != SC_INQUIRY &&
1871                     common->cmnd[0] != SC_REQUEST_SENSE) {
1872                         DBG(common, "unsupported LUN %d\n", common->lun);
1873                         return -EINVAL;
1874                 }
1875         }
1876
1877         /* If a unit attention condition exists, only INQUIRY and
1878          * REQUEST SENSE commands are allowed; anything else must fail. */
1879         if (curlun && curlun->unit_attention_data != SS_NO_SENSE &&
1880                         common->cmnd[0] != SC_INQUIRY &&
1881                         common->cmnd[0] != SC_REQUEST_SENSE) {
1882                 curlun->sense_data = curlun->unit_attention_data;
1883                 curlun->unit_attention_data = SS_NO_SENSE;
1884                 return -EINVAL;
1885         }
1886
1887         /* Check that only command bytes listed in the mask are non-zero */
1888         common->cmnd[1] &= 0x1f;                        /* Mask away the LUN */
1889         for (i = 1; i < cmnd_size; ++i) {
1890                 if (common->cmnd[i] && !(mask & (1 << i))) {
1891                         if (curlun)
1892                                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1893                         return -EINVAL;
1894                 }
1895         }
1896
1897         /* If the medium isn't mounted and the command needs to access
1898          * it, return an error. */
1899         if (curlun && !fsg_lun_is_open(curlun) && needs_medium) {
1900                 curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
1901                 return -EINVAL;
1902         }
1903
1904         return 0;
1905 }
1906
1907
1908 static int do_scsi_command(struct fsg_common *common)
1909 {
1910         struct fsg_buffhd       *bh;
1911         int                     rc;
1912         int                     reply = -EINVAL;
1913         int                     i;
1914         static char             unknown[16];
1915
1916         dump_cdb(common);
1917
1918         /* Wait for the next buffer to become available for data or status */
1919         bh = common->next_buffhd_to_fill;
1920         common->next_buffhd_to_drain = bh;
1921         while (bh->state != BUF_STATE_EMPTY) {
1922                 rc = sleep_thread(common);
1923                 if (rc)
1924                         return rc;
1925         }
1926         common->phase_error = 0;
1927         common->short_packet_received = 0;
1928
1929         down_read(&common->filesem);    /* We're using the backing file */
1930         switch (common->cmnd[0]) {
1931
1932         case SC_INQUIRY:
1933                 common->data_size_from_cmnd = common->cmnd[4];
1934                 reply = check_command(common, 6, DATA_DIR_TO_HOST,
1935                                       (1<<4), 0,
1936                                       "INQUIRY");
1937                 if (reply == 0)
1938                         reply = do_inquiry(common, bh);
1939                 break;
1940
1941         case SC_MODE_SELECT_6:
1942                 common->data_size_from_cmnd = common->cmnd[4];
1943                 reply = check_command(common, 6, DATA_DIR_FROM_HOST,
1944                                       (1<<1) | (1<<4), 0,
1945                                       "MODE SELECT(6)");
1946                 if (reply == 0)
1947                         reply = do_mode_select(common, bh);
1948                 break;
1949
1950         case SC_MODE_SELECT_10:
1951                 common->data_size_from_cmnd =
1952                         get_unaligned_be16(&common->cmnd[7]);
1953                 reply = check_command(common, 10, DATA_DIR_FROM_HOST,
1954                                       (1<<1) | (3<<7), 0,
1955                                       "MODE SELECT(10)");
1956                 if (reply == 0)
1957                         reply = do_mode_select(common, bh);
1958                 break;
1959
1960         case SC_MODE_SENSE_6:
1961                 common->data_size_from_cmnd = common->cmnd[4];
1962                 reply = check_command(common, 6, DATA_DIR_TO_HOST,
1963                                       (1<<1) | (1<<2) | (1<<4), 0,
1964                                       "MODE SENSE(6)");
1965                 if (reply == 0)
1966                         reply = do_mode_sense(common, bh);
1967                 break;
1968
1969         case SC_MODE_SENSE_10:
1970                 common->data_size_from_cmnd =
1971                         get_unaligned_be16(&common->cmnd[7]);
1972                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
1973                                       (1<<1) | (1<<2) | (3<<7), 0,
1974                                       "MODE SENSE(10)");
1975                 if (reply == 0)
1976                         reply = do_mode_sense(common, bh);
1977                 break;
1978
1979         case SC_PREVENT_ALLOW_MEDIUM_REMOVAL:
1980                 common->data_size_from_cmnd = 0;
1981                 reply = check_command(common, 6, DATA_DIR_NONE,
1982                                       (1<<4), 0,
1983                                       "PREVENT-ALLOW MEDIUM REMOVAL");
1984                 if (reply == 0)
1985                         reply = do_prevent_allow(common);
1986                 break;
1987
1988         case SC_READ_6:
1989                 i = common->cmnd[4];
1990                 common->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
1991                 reply = check_command(common, 6, DATA_DIR_TO_HOST,
1992                                       (7<<1) | (1<<4), 1,
1993                                       "READ(6)");
1994                 if (reply == 0)
1995                         reply = do_read(common);
1996                 break;
1997
1998         case SC_READ_10:
1999                 common->data_size_from_cmnd =
2000                                 get_unaligned_be16(&common->cmnd[7]) << 9;
2001                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
2002                                       (1<<1) | (0xf<<2) | (3<<7), 1,
2003                                       "READ(10)");
2004                 if (reply == 0)
2005                         reply = do_read(common);
2006                 break;
2007
2008         case SC_READ_12:
2009                 common->data_size_from_cmnd =
2010                                 get_unaligned_be32(&common->cmnd[6]) << 9;
2011                 reply = check_command(common, 12, DATA_DIR_TO_HOST,
2012                                       (1<<1) | (0xf<<2) | (0xf<<6), 1,
2013                                       "READ(12)");
2014                 if (reply == 0)
2015                         reply = do_read(common);
2016                 break;
2017
2018         case SC_READ_CAPACITY:
2019                 common->data_size_from_cmnd = 8;
2020                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
2021                                       (0xf<<2) | (1<<8), 1,
2022                                       "READ CAPACITY");
2023                 if (reply == 0)
2024                         reply = do_read_capacity(common, bh);
2025                 break;
2026
2027         case SC_READ_HEADER:
2028                 if (!common->curlun || !common->curlun->cdrom)
2029                         goto unknown_cmnd;
2030                 common->data_size_from_cmnd =
2031                         get_unaligned_be16(&common->cmnd[7]);
2032                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
2033                                       (3<<7) | (0x1f<<1), 1,
2034                                       "READ HEADER");
2035                 if (reply == 0)
2036                         reply = do_read_header(common, bh);
2037                 break;
2038
2039         case SC_READ_TOC:
2040                 if (!common->curlun || !common->curlun->cdrom)
2041                         goto unknown_cmnd;
2042                 common->data_size_from_cmnd =
2043                         get_unaligned_be16(&common->cmnd[7]);
2044                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
2045                                       (7<<6) | (1<<1), 1,
2046                                       "READ TOC");
2047                 if (reply == 0)
2048                         reply = do_read_toc(common, bh);
2049                 break;
2050
2051         case SC_READ_FORMAT_CAPACITIES:
2052                 common->data_size_from_cmnd =
2053                         get_unaligned_be16(&common->cmnd[7]);
2054                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
2055                                       (3<<7), 1,
2056                                       "READ FORMAT CAPACITIES");
2057                 if (reply == 0)
2058                         reply = do_read_format_capacities(common, bh);
2059                 break;
2060
2061         case SC_REQUEST_SENSE:
2062                 common->data_size_from_cmnd = common->cmnd[4];
2063                 reply = check_command(common, 6, DATA_DIR_TO_HOST,
2064                                       (1<<4), 0,
2065                                       "REQUEST SENSE");
2066                 if (reply == 0)
2067                         reply = do_request_sense(common, bh);
2068                 break;
2069
2070         case SC_START_STOP_UNIT:
2071                 common->data_size_from_cmnd = 0;
2072                 reply = check_command(common, 6, DATA_DIR_NONE,
2073                                       (1<<1) | (1<<4), 0,
2074                                       "START-STOP UNIT");
2075                 if (reply == 0)
2076                         reply = do_start_stop(common);
2077                 break;
2078
2079         case SC_SYNCHRONIZE_CACHE:
2080                 common->data_size_from_cmnd = 0;
2081                 reply = check_command(common, 10, DATA_DIR_NONE,
2082                                       (0xf<<2) | (3<<7), 1,
2083                                       "SYNCHRONIZE CACHE");
2084                 if (reply == 0)
2085                         reply = do_synchronize_cache(common);
2086                 break;
2087
2088         case SC_TEST_UNIT_READY:
2089                 common->data_size_from_cmnd = 0;
2090                 reply = check_command(common, 6, DATA_DIR_NONE,
2091                                 0, 1,
2092                                 "TEST UNIT READY");
2093                 break;
2094
2095         /* Although optional, this command is used by MS-Windows.  We
2096          * support a minimal version: BytChk must be 0. */
2097         case SC_VERIFY:
2098                 common->data_size_from_cmnd = 0;
2099                 reply = check_command(common, 10, DATA_DIR_NONE,
2100                                       (1<<1) | (0xf<<2) | (3<<7), 1,
2101                                       "VERIFY");
2102                 if (reply == 0)
2103                         reply = do_verify(common);
2104                 break;
2105
2106         case SC_WRITE_6:
2107                 i = common->cmnd[4];
2108                 common->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
2109                 reply = check_command(common, 6, DATA_DIR_FROM_HOST,
2110                                       (7<<1) | (1<<4), 1,
2111                                       "WRITE(6)");
2112                 if (reply == 0)
2113                         reply = do_write(common);
2114                 break;
2115
2116         case SC_WRITE_10:
2117                 common->data_size_from_cmnd =
2118                                 get_unaligned_be16(&common->cmnd[7]) << 9;
2119                 reply = check_command(common, 10, DATA_DIR_FROM_HOST,
2120                                       (1<<1) | (0xf<<2) | (3<<7), 1,
2121                                       "WRITE(10)");
2122                 if (reply == 0)
2123                         reply = do_write(common);
2124                 break;
2125
2126         case SC_WRITE_12:
2127                 common->data_size_from_cmnd =
2128                                 get_unaligned_be32(&common->cmnd[6]) << 9;
2129                 reply = check_command(common, 12, DATA_DIR_FROM_HOST,
2130                                       (1<<1) | (0xf<<2) | (0xf<<6), 1,
2131                                       "WRITE(12)");
2132                 if (reply == 0)
2133                         reply = do_write(common);
2134                 break;
2135
2136         /* Some mandatory commands that we recognize but don't implement.
2137          * They don't mean much in this setting.  It's left as an exercise
2138          * for anyone interested to implement RESERVE and RELEASE in terms
2139          * of Posix locks. */
2140         case SC_FORMAT_UNIT:
2141         case SC_RELEASE:
2142         case SC_RESERVE:
2143         case SC_SEND_DIAGNOSTIC:
2144                 /* Fall through */
2145
2146         default:
2147 unknown_cmnd:
2148                 common->data_size_from_cmnd = 0;
2149                 sprintf(unknown, "Unknown x%02x", common->cmnd[0]);
2150                 reply = check_command(common, common->cmnd_size,
2151                                       DATA_DIR_UNKNOWN, 0xff, 0, unknown);
2152                 if (reply == 0) {
2153                         common->curlun->sense_data = SS_INVALID_COMMAND;
2154                         reply = -EINVAL;
2155                 }
2156                 break;
2157         }
2158         up_read(&common->filesem);
2159
2160         if (reply == -EINTR || signal_pending(current))
2161                 return -EINTR;
2162
2163         /* Set up the single reply buffer for finish_reply() */
2164         if (reply == -EINVAL)
2165                 reply = 0;              /* Error reply length */
2166         if (reply >= 0 && common->data_dir == DATA_DIR_TO_HOST) {
2167                 reply = min((u32) reply, common->data_size_from_cmnd);
2168                 bh->inreq->length = reply;
2169                 bh->state = BUF_STATE_FULL;
2170                 common->residue -= reply;
2171         }                               /* Otherwise it's already set */
2172
2173         return 0;
2174 }
2175
2176
2177 /*-------------------------------------------------------------------------*/
2178
2179 static int received_cbw(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2180 {
2181         struct usb_request      *req = bh->outreq;
2182         struct fsg_bulk_cb_wrap *cbw = req->buf;
2183         struct fsg_common       *common = fsg->common;
2184
2185         /* Was this a real packet?  Should it be ignored? */
2186         if (req->status || test_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags))
2187                 return -EINVAL;
2188
2189         /* Is the CBW valid? */
2190         if (req->actual != USB_BULK_CB_WRAP_LEN ||
2191                         cbw->Signature != cpu_to_le32(
2192                                 USB_BULK_CB_SIG)) {
2193                 DBG(fsg, "invalid CBW: len %u sig 0x%x\n",
2194                                 req->actual,
2195                                 le32_to_cpu(cbw->Signature));
2196
2197                 /* The Bulk-only spec says we MUST stall the IN endpoint
2198                  * (6.6.1), so it's unavoidable.  It also says we must
2199                  * retain this state until the next reset, but there's
2200                  * no way to tell the controller driver it should ignore
2201                  * Clear-Feature(HALT) requests.
2202                  *
2203                  * We aren't required to halt the OUT endpoint; instead
2204                  * we can simply accept and discard any data received
2205                  * until the next reset. */
2206                 wedge_bulk_in_endpoint(fsg);
2207                 set_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
2208                 return -EINVAL;
2209         }
2210
2211         /* Is the CBW meaningful? */
2212         if (cbw->Lun >= FSG_MAX_LUNS || cbw->Flags & ~USB_BULK_IN_FLAG ||
2213                         cbw->Length <= 0 || cbw->Length > MAX_COMMAND_SIZE) {
2214                 DBG(fsg, "non-meaningful CBW: lun = %u, flags = 0x%x, "
2215                                 "cmdlen %u\n",
2216                                 cbw->Lun, cbw->Flags, cbw->Length);
2217
2218                 /* We can do anything we want here, so let's stall the
2219                  * bulk pipes if we are allowed to. */
2220                 if (common->can_stall) {
2221                         fsg_set_halt(fsg, fsg->bulk_out);
2222                         halt_bulk_in_endpoint(fsg);
2223                 }
2224                 return -EINVAL;
2225         }
2226
2227         /* Save the command for later */
2228         common->cmnd_size = cbw->Length;
2229         memcpy(common->cmnd, cbw->CDB, common->cmnd_size);
2230         if (cbw->Flags & USB_BULK_IN_FLAG)
2231                 common->data_dir = DATA_DIR_TO_HOST;
2232         else
2233                 common->data_dir = DATA_DIR_FROM_HOST;
2234         common->data_size = le32_to_cpu(cbw->DataTransferLength);
2235         if (common->data_size == 0)
2236                 common->data_dir = DATA_DIR_NONE;
2237         common->lun = cbw->Lun;
2238         common->tag = cbw->Tag;
2239         return 0;
2240 }
2241
2242
2243 static int get_next_command(struct fsg_common *common)
2244 {
2245         struct fsg_buffhd       *bh;
2246         int                     rc = 0;
2247
2248         /* Wait for the next buffer to become available */
2249         bh = common->next_buffhd_to_fill;
2250         while (bh->state != BUF_STATE_EMPTY) {
2251                 rc = sleep_thread(common);
2252                 if (rc)
2253                         return rc;
2254         }
2255
2256         /* Queue a request to read a Bulk-only CBW */
2257         set_bulk_out_req_length(common, bh, USB_BULK_CB_WRAP_LEN);
2258         bh->outreq->short_not_ok = 1;
2259         START_TRANSFER_OR(common, bulk_out, bh->outreq,
2260                           &bh->outreq_busy, &bh->state)
2261                 /* Don't know what to do if common->fsg is NULL */
2262                 return -EIO;
2263
2264         /* We will drain the buffer in software, which means we
2265          * can reuse it for the next filling.  No need to advance
2266          * next_buffhd_to_fill. */
2267
2268         /* Wait for the CBW to arrive */
2269         while (bh->state != BUF_STATE_FULL) {
2270                 rc = sleep_thread(common);
2271                 if (rc)
2272                         return rc;
2273         }
2274         smp_rmb();
2275         rc = fsg_is_set(common) ? received_cbw(common->fsg, bh) : -EIO;
2276         bh->state = BUF_STATE_EMPTY;
2277
2278         return rc;
2279 }
2280
2281
2282 /*-------------------------------------------------------------------------*/
2283
2284 static int enable_endpoint(struct fsg_common *common, struct usb_ep *ep,
2285                 const struct usb_endpoint_descriptor *d)
2286 {
2287         int     rc;
2288
2289         ep->driver_data = common;
2290         rc = usb_ep_enable(ep, d);
2291         if (rc)
2292                 ERROR(common, "can't enable %s, result %d\n", ep->name, rc);
2293         return rc;
2294 }
2295
2296 static int alloc_request(struct fsg_common *common, struct usb_ep *ep,
2297                 struct usb_request **preq)
2298 {
2299         *preq = usb_ep_alloc_request(ep, GFP_ATOMIC);
2300         if (*preq)
2301                 return 0;
2302         ERROR(common, "can't allocate request for %s\n", ep->name);
2303         return -ENOMEM;
2304 }
2305
2306 /*
2307  * Reset interface setting and re-init endpoint state (toggle etc).
2308  * Call with altsetting < 0 to disable the interface.  The only other
2309  * available altsetting is 0, which enables the interface.
2310  */
2311 static int do_set_interface(struct fsg_common *common, int altsetting)
2312 {
2313         int     rc = 0;
2314         int     i;
2315         const struct usb_endpoint_descriptor    *d;
2316
2317         if (common->running)
2318                 DBG(common, "reset interface\n");
2319
2320 reset:
2321         /* Deallocate the requests */
2322         if (common->prev_fsg) {
2323                 struct fsg_dev *fsg = common->prev_fsg;
2324
2325                 for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
2326                         struct fsg_buffhd *bh = &common->buffhds[i];
2327
2328                         if (bh->inreq) {
2329                                 usb_ep_free_request(fsg->bulk_in, bh->inreq);
2330                                 bh->inreq = NULL;
2331                         }
2332                         if (bh->outreq) {
2333                                 usb_ep_free_request(fsg->bulk_out, bh->outreq);
2334                                 bh->outreq = NULL;
2335                         }
2336                 }
2337
2338                 /* Disable the endpoints */
2339                 if (fsg->bulk_in_enabled) {
2340                         usb_ep_disable(fsg->bulk_in);
2341                         fsg->bulk_in_enabled = 0;
2342                 }
2343                 if (fsg->bulk_out_enabled) {
2344                         usb_ep_disable(fsg->bulk_out);
2345                         fsg->bulk_out_enabled = 0;
2346                 }
2347
2348                 common->prev_fsg = 0;
2349         }
2350
2351         common->running = 0;
2352         if (altsetting < 0 || rc != 0)
2353                 return rc;
2354
2355         DBG(common, "set interface %d\n", altsetting);
2356
2357         if (fsg_is_set(common)) {
2358                 struct fsg_dev *fsg = common->fsg;
2359                 common->prev_fsg = common->fsg;
2360
2361                 /* Enable the endpoints */
2362                 d = fsg_ep_desc(common->gadget,
2363                                 &fsg_fs_bulk_in_desc, &fsg_hs_bulk_in_desc);
2364                 rc = enable_endpoint(common, fsg->bulk_in, d);
2365                 if (rc)
2366                         goto reset;
2367                 fsg->bulk_in_enabled = 1;
2368
2369                 d = fsg_ep_desc(common->gadget,
2370                                 &fsg_fs_bulk_out_desc, &fsg_hs_bulk_out_desc);
2371                 rc = enable_endpoint(common, fsg->bulk_out, d);
2372                 if (rc)
2373                         goto reset;
2374                 fsg->bulk_out_enabled = 1;
2375                 common->bulk_out_maxpacket = le16_to_cpu(d->wMaxPacketSize);
2376                 clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
2377
2378                 /* Allocate the requests */
2379                 for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
2380                         struct fsg_buffhd       *bh = &common->buffhds[i];
2381
2382                         rc = alloc_request(common, fsg->bulk_in, &bh->inreq);
2383                         if (rc)
2384                                 goto reset;
2385                         rc = alloc_request(common, fsg->bulk_out, &bh->outreq);
2386                         if (rc)
2387                                 goto reset;
2388                         bh->inreq->buf = bh->outreq->buf = bh->buf;
2389                         bh->inreq->context = bh->outreq->context = bh;
2390                         bh->inreq->complete = bulk_in_complete;
2391                         bh->outreq->complete = bulk_out_complete;
2392                 }
2393
2394                 common->running = 1;
2395                 for (i = 0; i < common->nluns; ++i)
2396                         common->luns[i].unit_attention_data = SS_RESET_OCCURRED;
2397                 return rc;
2398         } else {
2399                 return -EIO;
2400         }
2401 }
2402
2403
2404 /*
2405  * Change our operational configuration.  This code must agree with the code
2406  * that returns config descriptors, and with interface altsetting code.
2407  *
2408  * It's also responsible for power management interactions.  Some
2409  * configurations might not work with our current power sources.
2410  * For now we just assume the gadget is always self-powered.
2411  */
2412 static int do_set_config(struct fsg_common *common, u8 new_config)
2413 {
2414         int     rc = 0;
2415
2416         /* Disable the single interface */
2417         if (common->config != 0) {
2418                 DBG(common, "reset config\n");
2419                 common->config = 0;
2420                 rc = do_set_interface(common, -1);
2421         }
2422
2423         /* Enable the interface */
2424         if (new_config != 0) {
2425                 common->config = new_config;
2426                 rc = do_set_interface(common, 0);
2427                 if (rc != 0)
2428                         common->config = 0;     /* Reset on errors */
2429         }
2430         return rc;
2431 }
2432
2433
2434 /****************************** ALT CONFIGS ******************************/
2435
2436
2437 static int fsg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
2438 {
2439         struct fsg_dev *fsg = fsg_from_func(f);
2440         fsg->common->prev_fsg = fsg->common->fsg;
2441         fsg->common->fsg = fsg;
2442         fsg->common->new_config = 1;
2443         raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
2444         return 0;
2445 }
2446
2447 static void fsg_disable(struct usb_function *f)
2448 {
2449         struct fsg_dev *fsg = fsg_from_func(f);
2450         fsg->common->prev_fsg = fsg->common->fsg;
2451         fsg->common->fsg = fsg;
2452         fsg->common->new_config = 0;
2453         raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
2454 }
2455
2456
2457 /*-------------------------------------------------------------------------*/
2458
2459 static void handle_exception(struct fsg_common *common)
2460 {
2461         siginfo_t               info;
2462         int                     sig;
2463         int                     i;
2464         struct fsg_buffhd       *bh;
2465         enum fsg_state          old_state;
2466         u8                      new_config;
2467         struct fsg_lun          *curlun;
2468         unsigned int            exception_req_tag;
2469         int                     rc;
2470
2471         /* Clear the existing signals.  Anything but SIGUSR1 is converted
2472          * into a high-priority EXIT exception. */
2473         for (;;) {
2474                 sig = dequeue_signal_lock(current, &current->blocked, &info);
2475                 if (!sig)
2476                         break;
2477                 if (sig != SIGUSR1) {
2478                         if (common->state < FSG_STATE_EXIT)
2479                                 DBG(common, "Main thread exiting on signal\n");
2480                         raise_exception(common, FSG_STATE_EXIT);
2481                 }
2482         }
2483
2484         /* Cancel all the pending transfers */
2485         if (fsg_is_set(common)) {
2486                 for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
2487                         bh = &common->buffhds[i];
2488                         if (bh->inreq_busy)
2489                                 usb_ep_dequeue(common->fsg->bulk_in, bh->inreq);
2490                         if (bh->outreq_busy)
2491                                 usb_ep_dequeue(common->fsg->bulk_out,
2492                                                bh->outreq);
2493                 }
2494
2495                 /* Wait until everything is idle */
2496                 for (;;) {
2497                         int num_active = 0;
2498                         for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
2499                                 bh = &common->buffhds[i];
2500                                 num_active += bh->inreq_busy + bh->outreq_busy;
2501                         }
2502                         if (num_active == 0)
2503                                 break;
2504                         if (sleep_thread(common))
2505                                 return;
2506                 }
2507
2508                 /* Clear out the controller's fifos */
2509                 if (common->fsg->bulk_in_enabled)
2510                         usb_ep_fifo_flush(common->fsg->bulk_in);
2511                 if (common->fsg->bulk_out_enabled)
2512                         usb_ep_fifo_flush(common->fsg->bulk_out);
2513         }
2514
2515         /* Reset the I/O buffer states and pointers, the SCSI
2516          * state, and the exception.  Then invoke the handler. */
2517         spin_lock_irq(&common->lock);
2518
2519         for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
2520                 bh = &common->buffhds[i];
2521                 bh->state = BUF_STATE_EMPTY;
2522         }
2523         common->next_buffhd_to_fill = &common->buffhds[0];
2524         common->next_buffhd_to_drain = &common->buffhds[0];
2525         exception_req_tag = common->exception_req_tag;
2526         new_config = common->new_config;
2527         old_state = common->state;
2528
2529         if (old_state == FSG_STATE_ABORT_BULK_OUT)
2530                 common->state = FSG_STATE_STATUS_PHASE;
2531         else {
2532                 for (i = 0; i < common->nluns; ++i) {
2533                         curlun = &common->luns[i];
2534                         curlun->prevent_medium_removal = 0;
2535                         curlun->sense_data = SS_NO_SENSE;
2536                         curlun->unit_attention_data = SS_NO_SENSE;
2537                         curlun->sense_data_info = 0;
2538                         curlun->info_valid = 0;
2539                 }
2540                 common->state = FSG_STATE_IDLE;
2541         }
2542         spin_unlock_irq(&common->lock);
2543
2544         /* Carry out any extra actions required for the exception */
2545         switch (old_state) {
2546         case FSG_STATE_ABORT_BULK_OUT:
2547                 send_status(common);
2548                 spin_lock_irq(&common->lock);
2549                 if (common->state == FSG_STATE_STATUS_PHASE)
2550                         common->state = FSG_STATE_IDLE;
2551                 spin_unlock_irq(&common->lock);
2552                 break;
2553
2554         case FSG_STATE_RESET:
2555                 /* In case we were forced against our will to halt a
2556                  * bulk endpoint, clear the halt now.  (The SuperH UDC
2557                  * requires this.) */
2558                 if (!fsg_is_set(common))
2559                         break;
2560                 if (test_and_clear_bit(IGNORE_BULK_OUT,
2561                                        &common->fsg->atomic_bitflags))
2562                         usb_ep_clear_halt(common->fsg->bulk_in);
2563
2564                 if (common->ep0_req_tag == exception_req_tag)
2565                         ep0_queue(common);      /* Complete the status stage */
2566
2567                 /* Technically this should go here, but it would only be
2568                  * a waste of time.  Ditto for the INTERFACE_CHANGE and
2569                  * CONFIG_CHANGE cases. */
2570                 /* for (i = 0; i < common->nluns; ++i) */
2571                 /*      common->luns[i].unit_attention_data = */
2572                 /*              SS_RESET_OCCURRED;  */
2573                 break;
2574
2575         case FSG_STATE_CONFIG_CHANGE:
2576                 rc = do_set_config(common, new_config);
2577                 break;
2578
2579         case FSG_STATE_EXIT:
2580         case FSG_STATE_TERMINATED:
2581                 do_set_config(common, 0);               /* Free resources */
2582                 spin_lock_irq(&common->lock);
2583                 common->state = FSG_STATE_TERMINATED;   /* Stop the thread */
2584                 spin_unlock_irq(&common->lock);
2585                 break;
2586
2587         case FSG_STATE_INTERFACE_CHANGE:
2588         case FSG_STATE_DISCONNECT:
2589         case FSG_STATE_COMMAND_PHASE:
2590         case FSG_STATE_DATA_PHASE:
2591         case FSG_STATE_STATUS_PHASE:
2592         case FSG_STATE_IDLE:
2593                 break;
2594         }
2595 }
2596
2597
2598 /*-------------------------------------------------------------------------*/
2599
2600 static int fsg_main_thread(void *common_)
2601 {
2602         struct fsg_common       *common = common_;
2603
2604         /* Allow the thread to be killed by a signal, but set the signal mask
2605          * to block everything but INT, TERM, KILL, and USR1. */
2606         allow_signal(SIGINT);
2607         allow_signal(SIGTERM);
2608         allow_signal(SIGKILL);
2609         allow_signal(SIGUSR1);
2610
2611         /* Allow the thread to be frozen */
2612         set_freezable();
2613
2614         /* Arrange for userspace references to be interpreted as kernel
2615          * pointers.  That way we can pass a kernel pointer to a routine
2616          * that expects a __user pointer and it will work okay. */
2617         set_fs(get_ds());
2618
2619         /* The main loop */
2620         while (common->state != FSG_STATE_TERMINATED) {
2621                 if (exception_in_progress(common) || signal_pending(current)) {
2622                         handle_exception(common);
2623                         continue;
2624                 }
2625
2626                 if (!common->running) {
2627                         sleep_thread(common);
2628                         continue;
2629                 }
2630
2631                 if (get_next_command(common))
2632                         continue;
2633
2634                 spin_lock_irq(&common->lock);
2635                 if (!exception_in_progress(common))
2636                         common->state = FSG_STATE_DATA_PHASE;
2637                 spin_unlock_irq(&common->lock);
2638
2639                 if (do_scsi_command(common) || finish_reply(common))
2640                         continue;
2641
2642                 spin_lock_irq(&common->lock);
2643                 if (!exception_in_progress(common))
2644                         common->state = FSG_STATE_STATUS_PHASE;
2645                 spin_unlock_irq(&common->lock);
2646
2647                 if (send_status(common))
2648                         continue;
2649
2650                 spin_lock_irq(&common->lock);
2651                 if (!exception_in_progress(common))
2652                         common->state = FSG_STATE_IDLE;
2653                 spin_unlock_irq(&common->lock);
2654         }
2655
2656         spin_lock_irq(&common->lock);
2657         common->thread_task = NULL;
2658         spin_unlock_irq(&common->lock);
2659
2660         if (!common->thread_exits || common->thread_exits(common) < 0) {
2661                 struct fsg_lun *curlun = common->luns;
2662                 unsigned i = common->nluns;
2663
2664                 down_write(&common->filesem);
2665                 for (; i--; ++curlun) {
2666                         if (!fsg_lun_is_open(curlun))
2667                                 continue;
2668
2669                         fsg_lun_close(curlun);
2670                         curlun->unit_attention_data = SS_MEDIUM_NOT_PRESENT;
2671                 }
2672                 up_write(&common->filesem);
2673         }
2674
2675         /* Let the unbind and cleanup routines know the thread has exited */
2676         complete_and_exit(&common->thread_notifier, 0);
2677 }
2678
2679
2680 /*************************** DEVICE ATTRIBUTES ***************************/
2681
2682 /* Write permission is checked per LUN in store_*() functions. */
2683 static DEVICE_ATTR(ro, 0644, fsg_show_ro, fsg_store_ro);
2684 static DEVICE_ATTR(file, 0644, fsg_show_file, fsg_store_file);
2685
2686
2687 /****************************** FSG COMMON ******************************/
2688
2689 static void fsg_common_release(struct kref *ref);
2690
2691 static void fsg_lun_release(struct device *dev)
2692 {
2693         /* Nothing needs to be done */
2694 }
2695
2696 static inline void fsg_common_get(struct fsg_common *common)
2697 {
2698         kref_get(&common->ref);
2699 }
2700
2701 static inline void fsg_common_put(struct fsg_common *common)
2702 {
2703         kref_put(&common->ref, fsg_common_release);
2704 }
2705
2706
2707 static struct fsg_common *fsg_common_init(struct fsg_common *common,
2708                                           struct usb_composite_dev *cdev,
2709                                           struct fsg_config *cfg)
2710 {
2711         struct usb_gadget *gadget = cdev->gadget;
2712         struct fsg_buffhd *bh;
2713         struct fsg_lun *curlun;
2714         struct fsg_lun_config *lcfg;
2715         int nluns, i, rc;
2716         char *pathbuf;
2717
2718         /* Find out how many LUNs there should be */
2719         nluns = cfg->nluns;
2720         if (nluns < 1 || nluns > FSG_MAX_LUNS) {
2721                 dev_err(&gadget->dev, "invalid number of LUNs: %u\n", nluns);
2722                 return ERR_PTR(-EINVAL);
2723         }
2724
2725         /* Allocate? */
2726         if (!common) {
2727                 common = kzalloc(sizeof *common, GFP_KERNEL);
2728                 if (!common)
2729                         return ERR_PTR(-ENOMEM);
2730                 common->free_storage_on_release = 1;
2731         } else {
2732                 memset(common, 0, sizeof common);
2733                 common->free_storage_on_release = 0;
2734         }
2735
2736         common->private_data = cfg->private_data;
2737
2738         common->gadget = gadget;
2739         common->ep0 = gadget->ep0;
2740         common->ep0req = cdev->req;
2741
2742         /* Maybe allocate device-global string IDs, and patch descriptors */
2743         if (fsg_strings[FSG_STRING_INTERFACE].id == 0) {
2744                 rc = usb_string_id(cdev);
2745                 if (unlikely(rc < 0))
2746                         goto error_release;
2747                 fsg_strings[FSG_STRING_INTERFACE].id = rc;
2748                 fsg_intf_desc.iInterface = rc;
2749         }
2750
2751         /* Create the LUNs, open their backing files, and register the
2752          * LUN devices in sysfs. */
2753         curlun = kzalloc(nluns * sizeof *curlun, GFP_KERNEL);
2754         if (unlikely(!curlun)) {
2755                 rc = -ENOMEM;
2756                 goto error_release;
2757         }
2758         common->luns = curlun;
2759
2760         init_rwsem(&common->filesem);
2761
2762         for (i = 0, lcfg = cfg->luns; i < nluns; ++i, ++curlun, ++lcfg) {
2763                 curlun->cdrom = !!lcfg->cdrom;
2764                 curlun->ro = lcfg->cdrom || lcfg->ro;
2765                 curlun->removable = lcfg->removable;
2766                 curlun->dev.release = fsg_lun_release;
2767                 curlun->dev.parent = &gadget->dev;
2768                 /* curlun->dev.driver = &fsg_driver.driver; XXX */
2769                 dev_set_drvdata(&curlun->dev, &common->filesem);
2770                 dev_set_name(&curlun->dev,
2771                              cfg->lun_name_format
2772                            ? cfg->lun_name_format
2773                            : "lun%d",
2774                              i);
2775
2776                 rc = device_register(&curlun->dev);
2777                 if (rc) {
2778                         INFO(common, "failed to register LUN%d: %d\n", i, rc);
2779                         common->nluns = i;
2780                         goto error_release;
2781                 }
2782
2783                 rc = device_create_file(&curlun->dev, &dev_attr_ro);
2784                 if (rc)
2785                         goto error_luns;
2786                 rc = device_create_file(&curlun->dev, &dev_attr_file);
2787                 if (rc)
2788                         goto error_luns;
2789
2790                 if (lcfg->filename) {
2791                         rc = fsg_lun_open(curlun, lcfg->filename);
2792                         if (rc)
2793                                 goto error_luns;
2794                 } else if (!curlun->removable) {
2795                         ERROR(common, "no file given for LUN%d\n", i);
2796                         rc = -EINVAL;
2797                         goto error_luns;
2798                 }
2799         }
2800         common->nluns = nluns;
2801
2802
2803         /* Data buffers cyclic list */
2804         bh = common->buffhds;
2805         i = FSG_NUM_BUFFERS;
2806         goto buffhds_first_it;
2807         do {
2808                 bh->next = bh + 1;
2809                 ++bh;
2810 buffhds_first_it:
2811                 bh->buf = kmalloc(FSG_BUFLEN, GFP_KERNEL);
2812                 if (unlikely(!bh->buf)) {
2813                         rc = -ENOMEM;
2814                         goto error_release;
2815                 }
2816         } while (--i);
2817         bh->next = common->buffhds;
2818
2819
2820         /* Prepare inquiryString */
2821         if (cfg->release != 0xffff) {
2822                 i = cfg->release;
2823         } else {
2824                 i = usb_gadget_controller_number(gadget);
2825                 if (i >= 0) {
2826                         i = 0x0300 + i;
2827                 } else {
2828                         WARNING(common, "controller '%s' not recognized\n",
2829                                 gadget->name);
2830                         i = 0x0399;
2831                 }
2832         }
2833 #define OR(x, y) ((x) ? (x) : (y))
2834         snprintf(common->inquiry_string, sizeof common->inquiry_string,
2835                  "%-8s%-16s%04x",
2836                  OR(cfg->vendor_name, "Linux   "),
2837                  /* Assume product name dependent on the first LUN */
2838                  OR(cfg->product_name, common->luns->cdrom
2839                                      ? "File-Stor Gadget"
2840                                      : "File-CD Gadget  "),
2841                  i);
2842
2843
2844         /* Some peripheral controllers are known not to be able to
2845          * halt bulk endpoints correctly.  If one of them is present,
2846          * disable stalls.
2847          */
2848         common->can_stall = cfg->can_stall &&
2849                 !(gadget_is_at91(common->gadget));
2850
2851
2852         spin_lock_init(&common->lock);
2853         kref_init(&common->ref);
2854
2855
2856         /* Tell the thread to start working */
2857         common->thread_exits = cfg->thread_exits;
2858         common->thread_task =
2859                 kthread_create(fsg_main_thread, common,
2860                                OR(cfg->thread_name, "file-storage"));
2861         if (IS_ERR(common->thread_task)) {
2862                 rc = PTR_ERR(common->thread_task);
2863                 goto error_release;
2864         }
2865         init_completion(&common->thread_notifier);
2866 #undef OR
2867
2868
2869         /* Information */
2870         INFO(common, FSG_DRIVER_DESC ", version: " FSG_DRIVER_VERSION "\n");
2871         INFO(common, "Number of LUNs=%d\n", common->nluns);
2872
2873         pathbuf = kmalloc(PATH_MAX, GFP_KERNEL);
2874         for (i = 0, nluns = common->nluns, curlun = common->luns;
2875              i < nluns;
2876              ++curlun, ++i) {
2877                 char *p = "(no medium)";
2878                 if (fsg_lun_is_open(curlun)) {
2879                         p = "(error)";
2880                         if (pathbuf) {
2881                                 p = d_path(&curlun->filp->f_path,
2882                                            pathbuf, PATH_MAX);
2883                                 if (IS_ERR(p))
2884                                         p = "(error)";
2885                         }
2886                 }
2887                 LINFO(curlun, "LUN: %s%s%sfile: %s\n",
2888                       curlun->removable ? "removable " : "",
2889                       curlun->ro ? "read only " : "",
2890                       curlun->cdrom ? "CD-ROM " : "",
2891                       p);
2892         }
2893         kfree(pathbuf);
2894
2895         DBG(common, "I/O thread pid: %d\n", task_pid_nr(common->thread_task));
2896
2897         wake_up_process(common->thread_task);
2898
2899         return common;
2900
2901
2902 error_luns:
2903         common->nluns = i + 1;
2904 error_release:
2905         common->state = FSG_STATE_TERMINATED;   /* The thread is dead */
2906         /* Call fsg_common_release() directly, ref might be not
2907          * initialised */
2908         fsg_common_release(&common->ref);
2909         return ERR_PTR(rc);
2910 }
2911
2912
2913 static void fsg_common_release(struct kref *ref)
2914 {
2915         struct fsg_common *common = container_of(ref, struct fsg_common, ref);
2916
2917         /* If the thread isn't already dead, tell it to exit now */
2918         if (common->state != FSG_STATE_TERMINATED) {
2919                 raise_exception(common, FSG_STATE_EXIT);
2920                 wait_for_completion(&common->thread_notifier);
2921
2922                 /* The cleanup routine waits for this completion also */
2923                 complete(&common->thread_notifier);
2924         }
2925
2926         if (likely(common->luns)) {
2927                 struct fsg_lun *lun = common->luns;
2928                 unsigned i = common->nluns;
2929
2930                 /* In error recovery common->nluns may be zero. */
2931                 for (; i; --i, ++lun) {
2932                         device_remove_file(&lun->dev, &dev_attr_ro);
2933                         device_remove_file(&lun->dev, &dev_attr_file);
2934                         fsg_lun_close(lun);
2935                         device_unregister(&lun->dev);
2936                 }
2937
2938                 kfree(common->luns);
2939         }
2940
2941         {
2942                 struct fsg_buffhd *bh = common->buffhds;
2943                 unsigned i = FSG_NUM_BUFFERS;
2944                 do {
2945                         kfree(bh->buf);
2946                 } while (++bh, --i);
2947         }
2948
2949         if (common->free_storage_on_release)
2950                 kfree(common);
2951 }
2952
2953
2954 /*-------------------------------------------------------------------------*/
2955
2956
2957 static void fsg_unbind(struct usb_configuration *c, struct usb_function *f)
2958 {
2959         struct fsg_dev          *fsg = fsg_from_func(f);
2960
2961         DBG(fsg, "unbind\n");
2962         fsg_common_put(fsg->common);
2963         usb_free_descriptors(fsg->function.descriptors);
2964         usb_free_descriptors(fsg->function.hs_descriptors);
2965         kfree(fsg);
2966 }
2967
2968
2969 static int fsg_bind(struct usb_configuration *c, struct usb_function *f)
2970 {
2971         struct fsg_dev          *fsg = fsg_from_func(f);
2972         struct usb_gadget       *gadget = c->cdev->gadget;
2973         int                     rc;
2974         int                     i;
2975         struct usb_ep           *ep;
2976
2977         fsg->gadget = gadget;
2978
2979         /* New interface */
2980         i = usb_interface_id(c, f);
2981         if (i < 0)
2982                 return i;
2983         fsg_intf_desc.bInterfaceNumber = i;
2984         fsg->interface_number = i;
2985
2986         /* Find all the endpoints we will use */
2987         ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_in_desc);
2988         if (!ep)
2989                 goto autoconf_fail;
2990         ep->driver_data = fsg->common;  /* claim the endpoint */
2991         fsg->bulk_in = ep;
2992
2993         ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_out_desc);
2994         if (!ep)
2995                 goto autoconf_fail;
2996         ep->driver_data = fsg->common;  /* claim the endpoint */
2997         fsg->bulk_out = ep;
2998
2999         if (gadget_is_dualspeed(gadget)) {
3000                 /* Assume endpoint addresses are the same for both speeds */
3001                 fsg_hs_bulk_in_desc.bEndpointAddress =
3002                         fsg_fs_bulk_in_desc.bEndpointAddress;
3003                 fsg_hs_bulk_out_desc.bEndpointAddress =
3004                         fsg_fs_bulk_out_desc.bEndpointAddress;
3005                 f->hs_descriptors = usb_copy_descriptors(fsg_hs_function);
3006                 if (unlikely(!f->hs_descriptors))
3007                         return -ENOMEM;
3008         }
3009
3010         return 0;
3011
3012 autoconf_fail:
3013         ERROR(fsg, "unable to autoconfigure all endpoints\n");
3014         rc = -ENOTSUPP;
3015         return rc;
3016 }
3017
3018
3019 /****************************** ADD FUNCTION ******************************/
3020
3021 static struct usb_gadget_strings *fsg_strings_array[] = {
3022         &fsg_stringtab,
3023         NULL,
3024 };
3025
3026 static int fsg_add(struct usb_composite_dev *cdev,
3027                    struct usb_configuration *c,
3028                    struct fsg_common *common)
3029 {
3030         struct fsg_dev *fsg;
3031         int rc;
3032
3033         fsg = kzalloc(sizeof *fsg, GFP_KERNEL);
3034         if (unlikely(!fsg))
3035                 return -ENOMEM;
3036
3037         fsg->function.name        = FSG_DRIVER_DESC;
3038         fsg->function.strings     = fsg_strings_array;
3039         fsg->function.descriptors = usb_copy_descriptors(fsg_fs_function);
3040         if (unlikely(!fsg->function.descriptors)) {
3041                 rc = -ENOMEM;
3042                 goto error_free_fsg;
3043         }
3044         fsg->function.bind        = fsg_bind;
3045         fsg->function.unbind      = fsg_unbind;
3046         fsg->function.setup       = fsg_setup;
3047         fsg->function.set_alt     = fsg_set_alt;
3048         fsg->function.disable     = fsg_disable;
3049
3050         fsg->common               = common;
3051         /* Our caller holds a reference to common structure so we
3052          * don't have to be worry about it being freed until we return
3053          * from this function.  So instead of incrementing counter now
3054          * and decrement in error recovery we increment it only when
3055          * call to usb_add_function() was successful. */
3056
3057         rc = usb_add_function(c, &fsg->function);
3058         if (unlikely(rc))
3059                 goto error_free_all;
3060
3061         fsg_common_get(fsg->common);
3062         return 0;
3063
3064 error_free_all:
3065         usb_free_descriptors(fsg->function.descriptors);
3066         /* fsg_bind() might have copied those; or maybe not? who cares
3067          * -- free it just in case. */
3068         usb_free_descriptors(fsg->function.hs_descriptors);
3069 error_free_fsg:
3070         kfree(fsg);
3071
3072         return rc;
3073 }
3074
3075
3076
3077 /************************* Module parameters *************************/
3078
3079
3080 struct fsg_module_parameters {
3081         char            *file[FSG_MAX_LUNS];
3082         int             ro[FSG_MAX_LUNS];
3083         int             removable[FSG_MAX_LUNS];
3084         int             cdrom[FSG_MAX_LUNS];
3085
3086         unsigned int    file_count, ro_count, removable_count, cdrom_count;
3087         unsigned int    luns;   /* nluns */
3088         int             stall;  /* can_stall */
3089 };
3090
3091
3092 #define _FSG_MODULE_PARAM_ARRAY(prefix, params, name, type, desc)       \
3093         module_param_array_named(prefix ## name, params.name, type,     \
3094                                  &prefix ## params.name ## _count,      \
3095                                  S_IRUGO);                              \
3096         MODULE_PARM_DESC(prefix ## name, desc)
3097
3098 #define _FSG_MODULE_PARAM(prefix, params, name, type, desc)             \
3099         module_param_named(prefix ## name, params.name, type,           \
3100                            S_IRUGO);                                    \
3101         MODULE_PARM_DESC(prefix ## name, desc)
3102
3103 #define FSG_MODULE_PARAMETERS(prefix, params)                           \
3104         _FSG_MODULE_PARAM_ARRAY(prefix, params, file, charp,            \
3105                                 "names of backing files or devices");   \
3106         _FSG_MODULE_PARAM_ARRAY(prefix, params, ro, bool,               \
3107                                 "true to force read-only");             \
3108         _FSG_MODULE_PARAM_ARRAY(prefix, params, removable, bool,        \
3109                                 "true to simulate removable media");    \
3110         _FSG_MODULE_PARAM_ARRAY(prefix, params, cdrom, bool,            \
3111                                 "true to simulate CD-ROM instead of disk"); \
3112         _FSG_MODULE_PARAM(prefix, params, luns, uint,                   \
3113                           "number of LUNs");                            \
3114         _FSG_MODULE_PARAM(prefix, params, stall, bool,                  \
3115                           "false to prevent bulk stalls")
3116
3117
3118 static void
3119 fsg_config_from_params(struct fsg_config *cfg,
3120                        const struct fsg_module_parameters *params)
3121 {
3122         struct fsg_lun_config *lun;
3123         unsigned i;
3124
3125         /* Configure LUNs */
3126         cfg->nluns =
3127                 min(params->luns ?: (params->file_count ?: 1u),
3128                     (unsigned)FSG_MAX_LUNS);
3129         for (i = 0, lun = cfg->luns; i < cfg->nluns; ++i, ++lun) {
3130                 lun->ro = !!params->ro[i];
3131                 lun->cdrom = !!params->cdrom[i];
3132                 lun->removable = /* Removable by default */
3133                         params->removable_count <= i || params->removable[i];
3134                 lun->filename =
3135                         params->file_count > i && params->file[i][0]
3136                         ? params->file[i]
3137                         : 0;
3138         }
3139
3140         /* Let MSF use defaults */
3141         cfg->lun_name_format = 0;
3142         cfg->thread_name = 0;
3143         cfg->vendor_name = 0;
3144         cfg->product_name = 0;
3145         cfg->release = 0xffff;
3146
3147         cfg->thread_exits = 0;
3148         cfg->private_data = 0;
3149
3150         /* Finalise */
3151         cfg->can_stall = params->stall;
3152 }
3153
3154 static inline struct fsg_common *
3155 fsg_common_from_params(struct fsg_common *common,
3156                        struct usb_composite_dev *cdev,
3157                        const struct fsg_module_parameters *params)
3158         __attribute__((unused));
3159 static inline struct fsg_common *
3160 fsg_common_from_params(struct fsg_common *common,
3161                        struct usb_composite_dev *cdev,
3162                        const struct fsg_module_parameters *params)
3163 {
3164         struct fsg_config cfg;
3165         fsg_config_from_params(&cfg, params);
3166         return fsg_common_init(common, cdev, &cfg);
3167 }
3168