Merge branch 'stable-3.2' into pandora-3.2
[pandora-kernel.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  * The Mass Storage Function acts as a USB Mass Storage device,
42  * appearing to the host as a disk drive or as a CD-ROM drive.  In
43  * addition to providing an example of a genuinely useful composite
44  * function for a USB device, it also illustrates a technique of
45  * double-buffering for increased throughput.
46  *
47  * Function supports multiple logical units (LUNs).  Backing storage
48  * for each LUN is provided by a regular file or a block device.
49  * Access for each LUN can be limited to read-only.  Moreover, the
50  * function can indicate that LUN is removable and/or CD-ROM.  (The
51  * later implies read-only access.)
52  *
53  * MSF is configured by specifying a fsg_config structure.  It has the
54  * following fields:
55  *
56  *      nluns           Number of LUNs function have (anywhere from 1
57  *                              to FSG_MAX_LUNS which is 8).
58  *      luns            An array of LUN configuration values.  This
59  *                              should be filled for each LUN that
60  *                              function will include (ie. for "nluns"
61  *                              LUNs).  Each element of the array has
62  *                              the following fields:
63  *      ->filename      The path to the backing file for the LUN.
64  *                              Required if LUN is not marked as
65  *                              removable.
66  *      ->ro            Flag specifying access to the LUN shall be
67  *                              read-only.  This is implied if CD-ROM
68  *                              emulation is enabled as well as when
69  *                              it was impossible to open "filename"
70  *                              in R/W mode.
71  *      ->removable     Flag specifying that LUN shall be indicated as
72  *                              being removable.
73  *      ->cdrom         Flag specifying that LUN shall be reported as
74  *                              being a CD-ROM.
75  *      ->nofua         Flag specifying that FUA flag in SCSI WRITE(10,12)
76  *                              commands for this LUN shall be ignored.
77  *
78  *      lun_name_format A printf-like format for names of the LUN
79  *                              devices.  This determines how the
80  *                              directory in sysfs will be named.
81  *                              Unless you are using several MSFs in
82  *                              a single gadget (as opposed to single
83  *                              MSF in many configurations) you may
84  *                              leave it as NULL (in which case
85  *                              "lun%d" will be used).  In the format
86  *                              you can use "%d" to index LUNs for
87  *                              MSF's with more than one LUN.  (Beware
88  *                              that there is only one integer given
89  *                              as an argument for the format and
90  *                              specifying invalid format may cause
91  *                              unspecified behaviour.)
92  *      thread_name     Name of the kernel thread process used by the
93  *                              MSF.  You can safely set it to NULL
94  *                              (in which case default "file-storage"
95  *                              will be used).
96  *
97  *      vendor_name
98  *      product_name
99  *      release         Information used as a reply to INQUIRY
100  *                              request.  To use default set to NULL,
101  *                              NULL, 0xffff respectively.  The first
102  *                              field should be 8 and the second 16
103  *                              characters or less.
104  *
105  *      can_stall       Set to permit function to halt bulk endpoints.
106  *                              Disabled on some USB devices known not
107  *                              to work correctly.  You should set it
108  *                              to true.
109  *
110  * If "removable" is not set for a LUN then a backing file must be
111  * specified.  If it is set, then NULL filename means the LUN's medium
112  * is not loaded (an empty string as "filename" in the fsg_config
113  * structure causes error).  The CD-ROM emulation includes a single
114  * data track and no audio tracks; hence there need be only one
115  * backing file per LUN.
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  *      nofua=b[,b...]  Default false, booleans for ignore FUA flag
131  *                              in SCSI WRITE(10,12) commands
132  *      luns=N          Default N = number of filenames, number of
133  *                              LUNs to support.
134  *      stall           Default determined according to the type of
135  *                              USB device controller (usually true),
136  *                              boolean to permit the driver to halt
137  *                              bulk endpoints.
138  *
139  * The module parameters may be prefixed with some string.  You need
140  * to consult gadget's documentation or source to verify whether it is
141  * using those module parameters and if it does what are the prefixes
142  * (look for FSG_MODULE_PARAMETERS() macro usage, what's inside it is
143  * the prefix).
144  *
145  *
146  * Requirements are modest; only a bulk-in and a bulk-out endpoint are
147  * needed.  The memory requirement amounts to two 16K buffers, size
148  * configurable by a parameter.  Support is included for both
149  * full-speed and high-speed operation.
150  *
151  * Note that the driver is slightly non-portable in that it assumes a
152  * single memory/DMA buffer will be useable for bulk-in, bulk-out, and
153  * interrupt-in endpoints.  With most device controllers this isn't an
154  * issue, but there may be some with hardware restrictions that prevent
155  * a buffer from being used by more than one endpoint.
156  *
157  *
158  * The pathnames of the backing files and the ro settings are
159  * available in the attribute files "file" and "ro" in the lun<n> (or
160  * to be more precise in a directory which name comes from
161  * "lun_name_format" option!) subdirectory of the gadget's sysfs
162  * directory.  If the "removable" option is set, writing to these
163  * files will simulate ejecting/loading the medium (writing an empty
164  * line means eject) and adjusting a write-enable tab.  Changes to the
165  * ro setting are not allowed when the medium is loaded or if CD-ROM
166  * emulation is being used.
167  *
168  * When a LUN receive an "eject" SCSI request (Start/Stop Unit),
169  * if the LUN is removable, the backing file is released to simulate
170  * ejection.
171  *
172  *
173  * This function is heavily based on "File-backed Storage Gadget" by
174  * Alan Stern which in turn is heavily based on "Gadget Zero" by David
175  * Brownell.  The driver's SCSI command interface was based on the
176  * "Information technology - Small Computer System Interface - 2"
177  * document from X3T9.2 Project 375D, Revision 10L, 7-SEP-93,
178  * available at <http://www.t10.org/ftp/t10/drafts/s2/s2-r10l.pdf>.
179  * The single exception is opcode 0x23 (READ FORMAT CAPACITIES), which
180  * was based on the "Universal Serial Bus Mass Storage Class UFI
181  * Command Specification" document, Revision 1.0, December 14, 1998,
182  * available at
183  * <http://www.usb.org/developers/devclass_docs/usbmass-ufi10.pdf>.
184  */
185
186 /*
187  *                              Driver Design
188  *
189  * The MSF is fairly straightforward.  There is a main kernel
190  * thread that handles most of the work.  Interrupt routines field
191  * callbacks from the controller driver: bulk- and interrupt-request
192  * completion notifications, endpoint-0 events, and disconnect events.
193  * Completion events are passed to the main thread by wakeup calls.  Many
194  * ep0 requests are handled at interrupt time, but SetInterface,
195  * SetConfiguration, and device reset requests are forwarded to the
196  * thread in the form of "exceptions" using SIGUSR1 signals (since they
197  * should interrupt any ongoing file I/O operations).
198  *
199  * The thread's main routine implements the standard command/data/status
200  * parts of a SCSI interaction.  It and its subroutines are full of tests
201  * for pending signals/exceptions -- all this polling is necessary since
202  * the kernel has no setjmp/longjmp equivalents.  (Maybe this is an
203  * indication that the driver really wants to be running in userspace.)
204  * An important point is that so long as the thread is alive it keeps an
205  * open reference to the backing file.  This will prevent unmounting
206  * the backing file's underlying filesystem and could cause problems
207  * during system shutdown, for example.  To prevent such problems, the
208  * thread catches INT, TERM, and KILL signals and converts them into
209  * an EXIT exception.
210  *
211  * In normal operation the main thread is started during the gadget's
212  * fsg_bind() callback and stopped during fsg_unbind().  But it can
213  * also exit when it receives a signal, and there's no point leaving
214  * the gadget running when the thread is dead.  At of this moment, MSF
215  * provides no way to deregister the gadget when thread dies -- maybe
216  * a callback functions is needed.
217  *
218  * To provide maximum throughput, the driver uses a circular pipeline of
219  * buffer heads (struct fsg_buffhd).  In principle the pipeline can be
220  * arbitrarily long; in practice the benefits don't justify having more
221  * than 2 stages (i.e., double buffering).  But it helps to think of the
222  * pipeline as being a long one.  Each buffer head contains a bulk-in and
223  * a bulk-out request pointer (since the buffer can be used for both
224  * output and input -- directions always are given from the host's
225  * point of view) as well as a pointer to the buffer and various state
226  * variables.
227  *
228  * Use of the pipeline follows a simple protocol.  There is a variable
229  * (fsg->next_buffhd_to_fill) that points to the next buffer head to use.
230  * At any time that buffer head may still be in use from an earlier
231  * request, so each buffer head has a state variable indicating whether
232  * it is EMPTY, FULL, or BUSY.  Typical use involves waiting for the
233  * buffer head to be EMPTY, filling the buffer either by file I/O or by
234  * USB I/O (during which the buffer head is BUSY), and marking the buffer
235  * head FULL when the I/O is complete.  Then the buffer will be emptied
236  * (again possibly by USB I/O, during which it is marked BUSY) and
237  * finally marked EMPTY again (possibly by a completion routine).
238  *
239  * A module parameter tells the driver to avoid stalling the bulk
240  * endpoints wherever the transport specification allows.  This is
241  * necessary for some UDCs like the SuperH, which cannot reliably clear a
242  * halt on a bulk endpoint.  However, under certain circumstances the
243  * Bulk-only specification requires a stall.  In such cases the driver
244  * will halt the endpoint and set a flag indicating that it should clear
245  * the halt in software during the next device reset.  Hopefully this
246  * will permit everything to work correctly.  Furthermore, although the
247  * specification allows the bulk-out endpoint to halt when the host sends
248  * too much data, implementing this would cause an unavoidable race.
249  * The driver will always use the "no-stall" approach for OUT transfers.
250  *
251  * One subtle point concerns sending status-stage responses for ep0
252  * requests.  Some of these requests, such as device reset, can involve
253  * interrupting an ongoing file I/O operation, which might take an
254  * arbitrarily long time.  During that delay the host might give up on
255  * the original ep0 request and issue a new one.  When that happens the
256  * driver should not notify the host about completion of the original
257  * request, as the host will no longer be waiting for it.  So the driver
258  * assigns to each ep0 request a unique tag, and it keeps track of the
259  * tag value of the request associated with a long-running exception
260  * (device-reset, interface-change, or configuration-change).  When the
261  * exception handler is finished, the status-stage response is submitted
262  * only if the current ep0 request tag is equal to the exception request
263  * tag.  Thus only the most recently received ep0 request will get a
264  * status-stage response.
265  *
266  * Warning: This driver source file is too long.  It ought to be split up
267  * into a header file plus about 3 separate .c files, to handle the details
268  * of the Gadget, USB Mass Storage, and SCSI protocols.
269  */
270
271
272 /* #define VERBOSE_DEBUG */
273 /* #define DUMP_MSGS */
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 #include <linux/usb/composite.h>
296
297 #include "gadget_chips.h"
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 #define FSG_NO_INTR_EP 1
308 #define FSG_NO_DEVICE_STRINGS    1
309 #define FSG_NO_OTG               1
310 #define FSG_NO_INTR_EP           1
311
312 #include "storage_common.c"
313
314
315 /*-------------------------------------------------------------------------*/
316
317 struct fsg_dev;
318 struct fsg_common;
319
320 /* FSF callback functions */
321 struct fsg_operations {
322         /*
323          * Callback function to call when thread exits.  If no
324          * callback is set or it returns value lower then zero MSF
325          * will force eject all LUNs it operates on (including those
326          * marked as non-removable or with prevent_medium_removal flag
327          * set).
328          */
329         int (*thread_exits)(struct fsg_common *common);
330
331         /*
332          * Called prior to ejection.  Negative return means error,
333          * zero means to continue with ejection, positive means not to
334          * eject.
335          */
336         int (*pre_eject)(struct fsg_common *common,
337                          struct fsg_lun *lun, int num);
338         /*
339          * Called after ejection.  Negative return means error, zero
340          * or positive is just a success.
341          */
342         int (*post_eject)(struct fsg_common *common,
343                           struct fsg_lun *lun, int num);
344 };
345
346 /* Data shared by all the FSG instances. */
347 struct fsg_common {
348         struct usb_gadget       *gadget;
349         struct usb_composite_dev *cdev;
350         struct fsg_dev          *fsg, *new_fsg;
351         wait_queue_head_t       fsg_wait;
352
353         /* filesem protects: backing files in use */
354         struct rw_semaphore     filesem;
355
356         /* lock protects: state, all the req_busy's */
357         spinlock_t              lock;
358
359         struct usb_ep           *ep0;           /* Copy of gadget->ep0 */
360         struct usb_request      *ep0req;        /* Copy of cdev->req */
361         unsigned int            ep0_req_tag;
362
363         struct fsg_buffhd       *next_buffhd_to_fill;
364         struct fsg_buffhd       *next_buffhd_to_drain;
365         struct fsg_buffhd       *buffhds;
366
367         int                     cmnd_size;
368         u8                      cmnd[MAX_COMMAND_SIZE];
369
370         unsigned int            nluns;
371         unsigned int            lun;
372         struct fsg_lun          *luns;
373         struct fsg_lun          *curlun;
374
375         unsigned int            bulk_out_maxpacket;
376         enum fsg_state          state;          /* For exception handling */
377         unsigned int            exception_req_tag;
378
379         enum data_direction     data_dir;
380         u32                     data_size;
381         u32                     data_size_from_cmnd;
382         u32                     tag;
383         u32                     residue;
384         u32                     usb_amount_left;
385
386         unsigned int            can_stall:1;
387         unsigned int            free_storage_on_release:1;
388         unsigned int            phase_error:1;
389         unsigned int            short_packet_received:1;
390         unsigned int            bad_lun_okay:1;
391         unsigned int            running:1;
392
393         int                     thread_wakeup_needed;
394         struct completion       thread_notifier;
395         struct task_struct      *thread_task;
396
397         /* Callback functions. */
398         const struct fsg_operations     *ops;
399         /* Gadget's private data. */
400         void                    *private_data;
401
402         /*
403          * Vendor (8 chars), product (16 chars), release (4
404          * hexadecimal digits) and NUL byte
405          */
406         char inquiry_string[8 + 16 + 4 + 1];
407
408         struct kref             ref;
409 };
410
411 struct fsg_config {
412         unsigned nluns;
413         struct fsg_lun_config {
414                 const char *filename;
415                 char ro;
416                 char removable;
417                 char cdrom;
418                 char nofua;
419         } luns[FSG_MAX_LUNS];
420
421         const char              *lun_name_format;
422         const char              *thread_name;
423
424         /* Callback functions. */
425         const struct fsg_operations     *ops;
426         /* Gadget's private data. */
427         void                    *private_data;
428
429         const char *vendor_name;                /*  8 characters or less */
430         const char *product_name;               /* 16 characters or less */
431         u16 release;
432
433         char                    can_stall;
434 };
435
436 struct fsg_dev {
437         struct usb_function     function;
438         struct usb_gadget       *gadget;        /* Copy of cdev->gadget */
439         struct fsg_common       *common;
440
441         u16                     interface_number;
442
443         unsigned int            bulk_in_enabled:1;
444         unsigned int            bulk_out_enabled:1;
445
446         unsigned long           atomic_bitflags;
447 #define IGNORE_BULK_OUT         0
448
449         struct usb_ep           *bulk_in;
450         struct usb_ep           *bulk_out;
451 };
452
453 static inline int __fsg_is_set(struct fsg_common *common,
454                                const char *func, unsigned line)
455 {
456         if (common->fsg)
457                 return 1;
458         ERROR(common, "common->fsg is NULL in %s at %u\n", func, line);
459         WARN_ON(1);
460         return 0;
461 }
462
463 #define fsg_is_set(common) likely(__fsg_is_set(common, __func__, __LINE__))
464
465 static inline struct fsg_dev *fsg_from_func(struct usb_function *f)
466 {
467         return container_of(f, struct fsg_dev, function);
468 }
469
470 typedef void (*fsg_routine_t)(struct fsg_dev *);
471
472 static int exception_in_progress(struct fsg_common *common)
473 {
474         return common->state > FSG_STATE_IDLE;
475 }
476
477 /* Make bulk-out requests be divisible by the maxpacket size */
478 static void set_bulk_out_req_length(struct fsg_common *common,
479                                     struct fsg_buffhd *bh, unsigned int length)
480 {
481         unsigned int    rem;
482
483         bh->bulk_out_intended_length = length;
484         rem = length % common->bulk_out_maxpacket;
485         if (rem > 0)
486                 length += common->bulk_out_maxpacket - rem;
487         bh->outreq->length = length;
488 }
489
490
491 /*-------------------------------------------------------------------------*/
492
493 static int fsg_set_halt(struct fsg_dev *fsg, struct usb_ep *ep)
494 {
495         const char      *name;
496
497         if (ep == fsg->bulk_in)
498                 name = "bulk-in";
499         else if (ep == fsg->bulk_out)
500                 name = "bulk-out";
501         else
502                 name = ep->name;
503         DBG(fsg, "%s set halt\n", name);
504         return usb_ep_set_halt(ep);
505 }
506
507
508 /*-------------------------------------------------------------------------*/
509
510 /* These routines may be called in process context or in_irq */
511
512 /* Caller must hold fsg->lock */
513 static void wakeup_thread(struct fsg_common *common)
514 {
515         /*
516          * Ensure the reading of thread_wakeup_needed
517          * and the writing of bh->state are completed
518          */
519         smp_mb();
520         /* Tell the main thread that something has happened */
521         common->thread_wakeup_needed = 1;
522         if (common->thread_task)
523                 wake_up_process(common->thread_task);
524 }
525
526 static void raise_exception(struct fsg_common *common, enum fsg_state new_state)
527 {
528         unsigned long           flags;
529
530         /*
531          * Do nothing if a higher-priority exception is already in progress.
532          * If a lower-or-equal priority exception is in progress, preempt it
533          * and notify the main thread by sending it a signal.
534          */
535         spin_lock_irqsave(&common->lock, flags);
536         if (common->state <= new_state) {
537                 common->exception_req_tag = common->ep0_req_tag;
538                 common->state = new_state;
539                 if (common->thread_task)
540                         send_sig_info(SIGUSR1, SEND_SIG_FORCED,
541                                       common->thread_task);
542         }
543         spin_unlock_irqrestore(&common->lock, flags);
544 }
545
546
547 /*-------------------------------------------------------------------------*/
548
549 static int ep0_queue(struct fsg_common *common)
550 {
551         int     rc;
552
553         rc = usb_ep_queue(common->ep0, common->ep0req, GFP_ATOMIC);
554         common->ep0->driver_data = common;
555         if (rc != 0 && rc != -ESHUTDOWN) {
556                 /* We can't do much more than wait for a reset */
557                 WARNING(common, "error in submission: %s --> %d\n",
558                         common->ep0->name, rc);
559         }
560         return rc;
561 }
562
563
564 /*-------------------------------------------------------------------------*/
565
566 /* Completion handlers. These always run in_irq. */
567
568 static void bulk_in_complete(struct usb_ep *ep, struct usb_request *req)
569 {
570         struct fsg_common       *common = ep->driver_data;
571         struct fsg_buffhd       *bh = req->context;
572
573         if (req->status || req->actual != req->length)
574                 DBG(common, "%s --> %d, %u/%u\n", __func__,
575                     req->status, req->actual, req->length);
576         if (req->status == -ECONNRESET)         /* Request was cancelled */
577                 usb_ep_fifo_flush(ep);
578
579         /* Hold the lock while we update the request and buffer states */
580         smp_wmb();
581         spin_lock(&common->lock);
582         bh->inreq_busy = 0;
583         bh->state = BUF_STATE_EMPTY;
584         wakeup_thread(common);
585         spin_unlock(&common->lock);
586 }
587
588 static void bulk_out_complete(struct usb_ep *ep, struct usb_request *req)
589 {
590         struct fsg_common       *common = ep->driver_data;
591         struct fsg_buffhd       *bh = req->context;
592
593         dump_msg(common, "bulk-out", req->buf, req->actual);
594         if (req->status || req->actual != bh->bulk_out_intended_length)
595                 DBG(common, "%s --> %d, %u/%u\n", __func__,
596                     req->status, req->actual, bh->bulk_out_intended_length);
597         if (req->status == -ECONNRESET)         /* Request was cancelled */
598                 usb_ep_fifo_flush(ep);
599
600         /* Hold the lock while we update the request and buffer states */
601         smp_wmb();
602         spin_lock(&common->lock);
603         bh->outreq_busy = 0;
604         bh->state = BUF_STATE_FULL;
605         wakeup_thread(common);
606         spin_unlock(&common->lock);
607 }
608
609 static int fsg_setup(struct usb_function *f,
610                      const struct usb_ctrlrequest *ctrl)
611 {
612         struct fsg_dev          *fsg = fsg_from_func(f);
613         struct usb_request      *req = fsg->common->ep0req;
614         u16                     w_index = le16_to_cpu(ctrl->wIndex);
615         u16                     w_value = le16_to_cpu(ctrl->wValue);
616         u16                     w_length = le16_to_cpu(ctrl->wLength);
617
618         if (!fsg_is_set(fsg->common))
619                 return -EOPNOTSUPP;
620
621         ++fsg->common->ep0_req_tag;     /* Record arrival of a new request */
622         req->context = NULL;
623         req->length = 0;
624         dump_msg(fsg, "ep0-setup", (u8 *) ctrl, sizeof(*ctrl));
625
626         switch (ctrl->bRequest) {
627
628         case USB_BULK_RESET_REQUEST:
629                 if (ctrl->bRequestType !=
630                     (USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE))
631                         break;
632                 if (w_index != fsg->interface_number || w_value != 0 ||
633                                 w_length != 0)
634                         return -EDOM;
635
636                 /*
637                  * Raise an exception to stop the current operation
638                  * and reinitialize our state.
639                  */
640                 DBG(fsg, "bulk reset request\n");
641                 raise_exception(fsg->common, FSG_STATE_RESET);
642                 return DELAYED_STATUS;
643
644         case USB_BULK_GET_MAX_LUN_REQUEST:
645                 if (ctrl->bRequestType !=
646                     (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE))
647                         break;
648                 if (w_index != fsg->interface_number || w_value != 0 ||
649                                 w_length != 1)
650                         return -EDOM;
651                 VDBG(fsg, "get max LUN\n");
652                 *(u8 *)req->buf = fsg->common->nluns - 1;
653
654                 /* Respond with data/status */
655                 req->length = min((u16)1, w_length);
656                 return ep0_queue(fsg->common);
657         }
658
659         VDBG(fsg,
660              "unknown class-specific control req %02x.%02x v%04x i%04x l%u\n",
661              ctrl->bRequestType, ctrl->bRequest,
662              le16_to_cpu(ctrl->wValue), w_index, w_length);
663         return -EOPNOTSUPP;
664 }
665
666
667 /*-------------------------------------------------------------------------*/
668
669 /* All the following routines run in process context */
670
671 /* Use this for bulk or interrupt transfers, not ep0 */
672 static void start_transfer(struct fsg_dev *fsg, struct usb_ep *ep,
673                            struct usb_request *req, int *pbusy,
674                            enum fsg_buffer_state *state)
675 {
676         int     rc;
677
678         if (ep == fsg->bulk_in)
679                 dump_msg(fsg, "bulk-in", req->buf, req->length);
680
681         spin_lock_irq(&fsg->common->lock);
682         *pbusy = 1;
683         *state = BUF_STATE_BUSY;
684         spin_unlock_irq(&fsg->common->lock);
685         rc = usb_ep_queue(ep, req, GFP_KERNEL);
686         if (rc != 0) {
687                 *pbusy = 0;
688                 *state = BUF_STATE_EMPTY;
689
690                 /* We can't do much more than wait for a reset */
691
692                 /*
693                  * Note: currently the net2280 driver fails zero-length
694                  * submissions if DMA is enabled.
695                  */
696                 if (rc != -ESHUTDOWN &&
697                     !(rc == -EOPNOTSUPP && req->length == 0))
698                         WARNING(fsg, "error in submission: %s --> %d\n",
699                                 ep->name, rc);
700         }
701 }
702
703 static bool start_in_transfer(struct fsg_common *common, struct fsg_buffhd *bh)
704 {
705         if (!fsg_is_set(common))
706                 return false;
707         start_transfer(common->fsg, common->fsg->bulk_in,
708                        bh->inreq, &bh->inreq_busy, &bh->state);
709         return true;
710 }
711
712 static bool start_out_transfer(struct fsg_common *common, struct fsg_buffhd *bh)
713 {
714         if (!fsg_is_set(common))
715                 return false;
716         start_transfer(common->fsg, common->fsg->bulk_out,
717                        bh->outreq, &bh->outreq_busy, &bh->state);
718         return true;
719 }
720
721 static int sleep_thread(struct fsg_common *common)
722 {
723         int     rc = 0;
724
725         /* Wait until a signal arrives or we are woken up */
726         for (;;) {
727                 try_to_freeze();
728                 set_current_state(TASK_INTERRUPTIBLE);
729                 if (signal_pending(current)) {
730                         rc = -EINTR;
731                         break;
732                 }
733                 if (common->thread_wakeup_needed)
734                         break;
735                 schedule();
736         }
737         __set_current_state(TASK_RUNNING);
738         common->thread_wakeup_needed = 0;
739
740         /*
741          * Ensure the writing of thread_wakeup_needed
742          * and the reading of bh->state are completed
743          */
744         smp_mb();
745         return rc;
746 }
747
748
749 /*-------------------------------------------------------------------------*/
750
751 static int do_read(struct fsg_common *common)
752 {
753         struct fsg_lun          *curlun = common->curlun;
754         u32                     lba;
755         struct fsg_buffhd       *bh;
756         int                     rc;
757         u32                     amount_left;
758         loff_t                  file_offset, file_offset_tmp;
759         unsigned int            amount;
760         ssize_t                 nread;
761
762         /*
763          * Get the starting Logical Block Address and check that it's
764          * not too big.
765          */
766         if (common->cmnd[0] == READ_6)
767                 lba = get_unaligned_be24(&common->cmnd[1]);
768         else {
769                 lba = get_unaligned_be32(&common->cmnd[2]);
770
771                 /*
772                  * We allow DPO (Disable Page Out = don't save data in the
773                  * cache) and FUA (Force Unit Access = don't read from the
774                  * cache), but we don't implement them.
775                  */
776                 if ((common->cmnd[1] & ~0x18) != 0) {
777                         curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
778                         return -EINVAL;
779                 }
780         }
781         if (lba >= curlun->num_sectors) {
782                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
783                 return -EINVAL;
784         }
785         file_offset = ((loff_t) lba) << curlun->blkbits;
786
787         /* Carry out the file reads */
788         amount_left = common->data_size_from_cmnd;
789         if (unlikely(amount_left == 0))
790                 return -EIO;            /* No default reply */
791
792         for (;;) {
793                 /*
794                  * Figure out how much we need to read:
795                  * Try to read the remaining amount.
796                  * But don't read more than the buffer size.
797                  * And don't try to read past the end of the file.
798                  */
799                 amount = min(amount_left, FSG_BUFLEN);
800                 amount = min((loff_t)amount,
801                              curlun->file_length - file_offset);
802
803                 /* Wait for the next buffer to become available */
804                 bh = common->next_buffhd_to_fill;
805                 while (bh->state != BUF_STATE_EMPTY) {
806                         rc = sleep_thread(common);
807                         if (rc)
808                                 return rc;
809                 }
810
811                 /*
812                  * If we were asked to read past the end of file,
813                  * end with an empty buffer.
814                  */
815                 if (amount == 0) {
816                         curlun->sense_data =
817                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
818                         curlun->sense_data_info =
819                                         file_offset >> curlun->blkbits;
820                         curlun->info_valid = 1;
821                         bh->inreq->length = 0;
822                         bh->state = BUF_STATE_FULL;
823                         break;
824                 }
825
826                 /* Perform the read */
827                 file_offset_tmp = file_offset;
828                 nread = vfs_read(curlun->filp,
829                                  (char __user *)bh->buf,
830                                  amount, &file_offset_tmp);
831                 VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
832                       (unsigned long long)file_offset, (int)nread);
833                 if (signal_pending(current))
834                         return -EINTR;
835
836                 if (nread < 0) {
837                         LDBG(curlun, "error in file read: %d\n", (int)nread);
838                         nread = 0;
839                 } else if (nread < amount) {
840                         LDBG(curlun, "partial file read: %d/%u\n",
841                              (int)nread, amount);
842                         nread = round_down(nread, curlun->blksize);
843                 }
844                 file_offset  += nread;
845                 amount_left  -= nread;
846                 common->residue -= nread;
847
848                 /*
849                  * Except at the end of the transfer, nread will be
850                  * equal to the buffer size, which is divisible by the
851                  * bulk-in maxpacket size.
852                  */
853                 bh->inreq->length = nread;
854                 bh->state = BUF_STATE_FULL;
855
856                 /* If an error occurred, report it and its position */
857                 if (nread < amount) {
858                         curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
859                         curlun->sense_data_info =
860                                         file_offset >> curlun->blkbits;
861                         curlun->info_valid = 1;
862                         break;
863                 }
864
865                 if (amount_left == 0)
866                         break;          /* No more left to read */
867
868                 /* Send this buffer and go read some more */
869                 bh->inreq->zero = 0;
870                 if (!start_in_transfer(common, bh))
871                         /* Don't know what to do if common->fsg is NULL */
872                         return -EIO;
873                 common->next_buffhd_to_fill = bh->next;
874         }
875
876         return -EIO;            /* No default reply */
877 }
878
879
880 /*-------------------------------------------------------------------------*/
881
882 static int do_write(struct fsg_common *common)
883 {
884         struct fsg_lun          *curlun = common->curlun;
885         u32                     lba;
886         struct fsg_buffhd       *bh;
887         int                     get_some_more;
888         u32                     amount_left_to_req, amount_left_to_write;
889         loff_t                  usb_offset, file_offset, file_offset_tmp;
890         unsigned int            amount;
891         ssize_t                 nwritten;
892         int                     rc;
893
894         if (curlun->ro) {
895                 curlun->sense_data = SS_WRITE_PROTECTED;
896                 return -EINVAL;
897         }
898         spin_lock(&curlun->filp->f_lock);
899         curlun->filp->f_flags &= ~O_SYNC;       /* Default is not to wait */
900         spin_unlock(&curlun->filp->f_lock);
901
902         /*
903          * Get the starting Logical Block Address and check that it's
904          * not too big
905          */
906         if (common->cmnd[0] == WRITE_6)
907                 lba = get_unaligned_be24(&common->cmnd[1]);
908         else {
909                 lba = get_unaligned_be32(&common->cmnd[2]);
910
911                 /*
912                  * We allow DPO (Disable Page Out = don't save data in the
913                  * cache) and FUA (Force Unit Access = write directly to the
914                  * medium).  We don't implement DPO; we implement FUA by
915                  * performing synchronous output.
916                  */
917                 if (common->cmnd[1] & ~0x18) {
918                         curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
919                         return -EINVAL;
920                 }
921                 if (!curlun->nofua && (common->cmnd[1] & 0x08)) { /* FUA */
922                         spin_lock(&curlun->filp->f_lock);
923                         curlun->filp->f_flags |= O_SYNC;
924                         spin_unlock(&curlun->filp->f_lock);
925                 }
926         }
927         if (lba >= curlun->num_sectors) {
928                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
929                 return -EINVAL;
930         }
931
932         /* Carry out the file writes */
933         get_some_more = 1;
934         file_offset = usb_offset = ((loff_t) lba) << curlun->blkbits;
935         amount_left_to_req = common->data_size_from_cmnd;
936         amount_left_to_write = common->data_size_from_cmnd;
937
938         while (amount_left_to_write > 0) {
939
940                 /* Queue a request for more data from the host */
941                 bh = common->next_buffhd_to_fill;
942                 if (bh->state == BUF_STATE_EMPTY && get_some_more) {
943
944                         /*
945                          * Figure out how much we want to get:
946                          * Try to get the remaining amount,
947                          * but not more than the buffer size.
948                          */
949                         amount = min(amount_left_to_req, FSG_BUFLEN);
950
951                         /* Beyond the end of the backing file? */
952                         if (usb_offset >= curlun->file_length) {
953                                 get_some_more = 0;
954                                 curlun->sense_data =
955                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
956                                 curlun->sense_data_info =
957                                         usb_offset >> curlun->blkbits;
958                                 curlun->info_valid = 1;
959                                 continue;
960                         }
961
962                         /* Get the next buffer */
963                         usb_offset += amount;
964                         common->usb_amount_left -= amount;
965                         amount_left_to_req -= amount;
966                         if (amount_left_to_req == 0)
967                                 get_some_more = 0;
968
969                         /*
970                          * Except at the end of the transfer, amount will be
971                          * equal to the buffer size, which is divisible by
972                          * the bulk-out maxpacket size.
973                          */
974                         set_bulk_out_req_length(common, bh, amount);
975                         if (!start_out_transfer(common, bh))
976                                 /* Dunno what to do if common->fsg is NULL */
977                                 return -EIO;
978                         common->next_buffhd_to_fill = bh->next;
979                         continue;
980                 }
981
982                 /* Write the received data to the backing file */
983                 bh = common->next_buffhd_to_drain;
984                 if (bh->state == BUF_STATE_EMPTY && !get_some_more)
985                         break;                  /* We stopped early */
986                 if (bh->state == BUF_STATE_FULL) {
987                         smp_rmb();
988                         common->next_buffhd_to_drain = bh->next;
989                         bh->state = BUF_STATE_EMPTY;
990
991                         /* Did something go wrong with the transfer? */
992                         if (bh->outreq->status != 0) {
993                                 curlun->sense_data = SS_COMMUNICATION_FAILURE;
994                                 curlun->sense_data_info =
995                                         file_offset >> curlun->blkbits;
996                                 curlun->info_valid = 1;
997                                 break;
998                         }
999
1000                         amount = bh->outreq->actual;
1001                         if (curlun->file_length - file_offset < amount) {
1002                                 LERROR(curlun,
1003                                        "write %u @ %llu beyond end %llu\n",
1004                                        amount, (unsigned long long)file_offset,
1005                                        (unsigned long long)curlun->file_length);
1006                                 amount = curlun->file_length - file_offset;
1007                         }
1008
1009                         /* Don't accept excess data.  The spec doesn't say
1010                          * what to do in this case.  We'll ignore the error.
1011                          */
1012                         amount = min(amount, bh->bulk_out_intended_length);
1013
1014                         /* Don't write a partial block */
1015                         amount = round_down(amount, curlun->blksize);
1016                         if (amount == 0)
1017                                 goto empty_write;
1018
1019                         /* Perform the write */
1020                         file_offset_tmp = file_offset;
1021                         nwritten = vfs_write(curlun->filp,
1022                                              (char __user *)bh->buf,
1023                                              amount, &file_offset_tmp);
1024                         VLDBG(curlun, "file write %u @ %llu -> %d\n", amount,
1025                               (unsigned long long)file_offset, (int)nwritten);
1026                         if (signal_pending(current))
1027                                 return -EINTR;          /* Interrupted! */
1028
1029                         if (nwritten < 0) {
1030                                 LDBG(curlun, "error in file write: %d\n",
1031                                      (int)nwritten);
1032                                 nwritten = 0;
1033                         } else if (nwritten < amount) {
1034                                 LDBG(curlun, "partial file write: %d/%u\n",
1035                                      (int)nwritten, amount);
1036                                 nwritten = round_down(nwritten, curlun->blksize);
1037                         }
1038                         file_offset += nwritten;
1039                         amount_left_to_write -= nwritten;
1040                         common->residue -= nwritten;
1041
1042                         /* If an error occurred, report it and its position */
1043                         if (nwritten < amount) {
1044                                 curlun->sense_data = SS_WRITE_ERROR;
1045                                 curlun->sense_data_info =
1046                                         file_offset >> curlun->blkbits;
1047                                 curlun->info_valid = 1;
1048                                 break;
1049                         }
1050
1051  empty_write:
1052                         /* Did the host decide to stop early? */
1053                         if (bh->outreq->actual < bh->bulk_out_intended_length) {
1054                                 common->short_packet_received = 1;
1055                                 break;
1056                         }
1057                         continue;
1058                 }
1059
1060                 /* Wait for something to happen */
1061                 rc = sleep_thread(common);
1062                 if (rc)
1063                         return rc;
1064         }
1065
1066         return -EIO;            /* No default reply */
1067 }
1068
1069
1070 /*-------------------------------------------------------------------------*/
1071
1072 static int do_synchronize_cache(struct fsg_common *common)
1073 {
1074         struct fsg_lun  *curlun = common->curlun;
1075         int             rc;
1076
1077         /* We ignore the requested LBA and write out all file's
1078          * dirty data buffers. */
1079         rc = fsg_lun_fsync_sub(curlun);
1080         if (rc)
1081                 curlun->sense_data = SS_WRITE_ERROR;
1082         return 0;
1083 }
1084
1085
1086 /*-------------------------------------------------------------------------*/
1087
1088 static void invalidate_sub(struct fsg_lun *curlun)
1089 {
1090         struct file     *filp = curlun->filp;
1091         struct inode    *inode = filp->f_path.dentry->d_inode;
1092         unsigned long   rc;
1093
1094         rc = invalidate_mapping_pages(inode->i_mapping, 0, -1);
1095         VLDBG(curlun, "invalidate_mapping_pages -> %ld\n", rc);
1096 }
1097
1098 static int do_verify(struct fsg_common *common)
1099 {
1100         struct fsg_lun          *curlun = common->curlun;
1101         u32                     lba;
1102         u32                     verification_length;
1103         struct fsg_buffhd       *bh = common->next_buffhd_to_fill;
1104         loff_t                  file_offset, file_offset_tmp;
1105         u32                     amount_left;
1106         unsigned int            amount;
1107         ssize_t                 nread;
1108
1109         /*
1110          * Get the starting Logical Block Address and check that it's
1111          * not too big.
1112          */
1113         lba = get_unaligned_be32(&common->cmnd[2]);
1114         if (lba >= curlun->num_sectors) {
1115                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1116                 return -EINVAL;
1117         }
1118
1119         /*
1120          * We allow DPO (Disable Page Out = don't save data in the
1121          * cache) but we don't implement it.
1122          */
1123         if (common->cmnd[1] & ~0x10) {
1124                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1125                 return -EINVAL;
1126         }
1127
1128         verification_length = get_unaligned_be16(&common->cmnd[7]);
1129         if (unlikely(verification_length == 0))
1130                 return -EIO;            /* No default reply */
1131
1132         /* Prepare to carry out the file verify */
1133         amount_left = verification_length << curlun->blkbits;
1134         file_offset = ((loff_t) lba) << curlun->blkbits;
1135
1136         /* Write out all the dirty buffers before invalidating them */
1137         fsg_lun_fsync_sub(curlun);
1138         if (signal_pending(current))
1139                 return -EINTR;
1140
1141         invalidate_sub(curlun);
1142         if (signal_pending(current))
1143                 return -EINTR;
1144
1145         /* Just try to read the requested blocks */
1146         while (amount_left > 0) {
1147                 /*
1148                  * Figure out how much we need to read:
1149                  * Try to read the remaining amount, but not more than
1150                  * the buffer size.
1151                  * And don't try to read past the end of the file.
1152                  */
1153                 amount = min(amount_left, FSG_BUFLEN);
1154                 amount = min((loff_t)amount,
1155                              curlun->file_length - file_offset);
1156                 if (amount == 0) {
1157                         curlun->sense_data =
1158                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1159                         curlun->sense_data_info =
1160                                 file_offset >> curlun->blkbits;
1161                         curlun->info_valid = 1;
1162                         break;
1163                 }
1164
1165                 /* Perform the read */
1166                 file_offset_tmp = file_offset;
1167                 nread = vfs_read(curlun->filp,
1168                                 (char __user *) bh->buf,
1169                                 amount, &file_offset_tmp);
1170                 VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
1171                                 (unsigned long long) file_offset,
1172                                 (int) nread);
1173                 if (signal_pending(current))
1174                         return -EINTR;
1175
1176                 if (nread < 0) {
1177                         LDBG(curlun, "error in file verify: %d\n", (int)nread);
1178                         nread = 0;
1179                 } else if (nread < amount) {
1180                         LDBG(curlun, "partial file verify: %d/%u\n",
1181                              (int)nread, amount);
1182                         nread = round_down(nread, curlun->blksize);
1183                 }
1184                 if (nread == 0) {
1185                         curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
1186                         curlun->sense_data_info =
1187                                 file_offset >> curlun->blkbits;
1188                         curlun->info_valid = 1;
1189                         break;
1190                 }
1191                 file_offset += nread;
1192                 amount_left -= nread;
1193         }
1194         return 0;
1195 }
1196
1197
1198 /*-------------------------------------------------------------------------*/
1199
1200 static int do_inquiry(struct fsg_common *common, struct fsg_buffhd *bh)
1201 {
1202         struct fsg_lun *curlun = common->curlun;
1203         u8      *buf = (u8 *) bh->buf;
1204
1205         if (!curlun) {          /* Unsupported LUNs are okay */
1206                 common->bad_lun_okay = 1;
1207                 memset(buf, 0, 36);
1208                 buf[0] = 0x7f;          /* Unsupported, no device-type */
1209                 buf[4] = 31;            /* Additional length */
1210                 return 36;
1211         }
1212
1213         buf[0] = curlun->cdrom ? TYPE_ROM : TYPE_DISK;
1214         buf[1] = curlun->removable ? 0x80 : 0;
1215         buf[2] = 2;             /* ANSI SCSI level 2 */
1216         buf[3] = 2;             /* SCSI-2 INQUIRY data format */
1217         buf[4] = 31;            /* Additional length */
1218         buf[5] = 0;             /* No special options */
1219         buf[6] = 0;
1220         buf[7] = 0;
1221         memcpy(buf + 8, common->inquiry_string, sizeof common->inquiry_string);
1222         return 36;
1223 }
1224
1225 static int do_request_sense(struct fsg_common *common, struct fsg_buffhd *bh)
1226 {
1227         struct fsg_lun  *curlun = common->curlun;
1228         u8              *buf = (u8 *) bh->buf;
1229         u32             sd, sdinfo;
1230         int             valid;
1231
1232         /*
1233          * From the SCSI-2 spec., section 7.9 (Unit attention condition):
1234          *
1235          * If a REQUEST SENSE command is received from an initiator
1236          * with a pending unit attention condition (before the target
1237          * generates the contingent allegiance condition), then the
1238          * target shall either:
1239          *   a) report any pending sense data and preserve the unit
1240          *      attention condition on the logical unit, or,
1241          *   b) report the unit attention condition, may discard any
1242          *      pending sense data, and clear the unit attention
1243          *      condition on the logical unit for that initiator.
1244          *
1245          * FSG normally uses option a); enable this code to use option b).
1246          */
1247 #if 0
1248         if (curlun && curlun->unit_attention_data != SS_NO_SENSE) {
1249                 curlun->sense_data = curlun->unit_attention_data;
1250                 curlun->unit_attention_data = SS_NO_SENSE;
1251         }
1252 #endif
1253
1254         if (!curlun) {          /* Unsupported LUNs are okay */
1255                 common->bad_lun_okay = 1;
1256                 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
1257                 sdinfo = 0;
1258                 valid = 0;
1259         } else {
1260                 sd = curlun->sense_data;
1261                 sdinfo = curlun->sense_data_info;
1262                 valid = curlun->info_valid << 7;
1263                 curlun->sense_data = SS_NO_SENSE;
1264                 curlun->sense_data_info = 0;
1265                 curlun->info_valid = 0;
1266         }
1267
1268         memset(buf, 0, 18);
1269         buf[0] = valid | 0x70;                  /* Valid, current error */
1270         buf[2] = SK(sd);
1271         put_unaligned_be32(sdinfo, &buf[3]);    /* Sense information */
1272         buf[7] = 18 - 8;                        /* Additional sense length */
1273         buf[12] = ASC(sd);
1274         buf[13] = ASCQ(sd);
1275         return 18;
1276 }
1277
1278 static int do_read_capacity(struct fsg_common *common, struct fsg_buffhd *bh)
1279 {
1280         struct fsg_lun  *curlun = common->curlun;
1281         u32             lba = get_unaligned_be32(&common->cmnd[2]);
1282         int             pmi = common->cmnd[8];
1283         u8              *buf = (u8 *)bh->buf;
1284
1285         /* Check the PMI and LBA fields */
1286         if (pmi > 1 || (pmi == 0 && lba != 0)) {
1287                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1288                 return -EINVAL;
1289         }
1290
1291         put_unaligned_be32(curlun->num_sectors - 1, &buf[0]);
1292                                                 /* Max logical block */
1293         put_unaligned_be32(curlun->blksize, &buf[4]);/* Block length */
1294         return 8;
1295 }
1296
1297 static int do_read_header(struct fsg_common *common, struct fsg_buffhd *bh)
1298 {
1299         struct fsg_lun  *curlun = common->curlun;
1300         int             msf = common->cmnd[1] & 0x02;
1301         u32             lba = get_unaligned_be32(&common->cmnd[2]);
1302         u8              *buf = (u8 *)bh->buf;
1303
1304         if (common->cmnd[1] & ~0x02) {          /* Mask away MSF */
1305                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1306                 return -EINVAL;
1307         }
1308         if (lba >= curlun->num_sectors) {
1309                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1310                 return -EINVAL;
1311         }
1312
1313         memset(buf, 0, 8);
1314         buf[0] = 0x01;          /* 2048 bytes of user data, rest is EC */
1315         store_cdrom_address(&buf[4], msf, lba);
1316         return 8;
1317 }
1318
1319 static int do_read_toc(struct fsg_common *common, struct fsg_buffhd *bh)
1320 {
1321         struct fsg_lun  *curlun = common->curlun;
1322         int             msf = common->cmnd[1] & 0x02;
1323         int             start_track = common->cmnd[6];
1324         u8              *buf = (u8 *)bh->buf;
1325
1326         if ((common->cmnd[1] & ~0x02) != 0 ||   /* Mask away MSF */
1327                         start_track > 1) {
1328                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1329                 return -EINVAL;
1330         }
1331
1332         memset(buf, 0, 20);
1333         buf[1] = (20-2);                /* TOC data length */
1334         buf[2] = 1;                     /* First track number */
1335         buf[3] = 1;                     /* Last track number */
1336         buf[5] = 0x16;                  /* Data track, copying allowed */
1337         buf[6] = 0x01;                  /* Only track is number 1 */
1338         store_cdrom_address(&buf[8], msf, 0);
1339
1340         buf[13] = 0x16;                 /* Lead-out track is data */
1341         buf[14] = 0xAA;                 /* Lead-out track number */
1342         store_cdrom_address(&buf[16], msf, curlun->num_sectors);
1343         return 20;
1344 }
1345
1346 static int do_mode_sense(struct fsg_common *common, struct fsg_buffhd *bh)
1347 {
1348         struct fsg_lun  *curlun = common->curlun;
1349         int             mscmnd = common->cmnd[0];
1350         u8              *buf = (u8 *) bh->buf;
1351         u8              *buf0 = buf;
1352         int             pc, page_code;
1353         int             changeable_values, all_pages;
1354         int             valid_page = 0;
1355         int             len, limit;
1356
1357         if ((common->cmnd[1] & ~0x08) != 0) {   /* Mask away DBD */
1358                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1359                 return -EINVAL;
1360         }
1361         pc = common->cmnd[2] >> 6;
1362         page_code = common->cmnd[2] & 0x3f;
1363         if (pc == 3) {
1364                 curlun->sense_data = SS_SAVING_PARAMETERS_NOT_SUPPORTED;
1365                 return -EINVAL;
1366         }
1367         changeable_values = (pc == 1);
1368         all_pages = (page_code == 0x3f);
1369
1370         /*
1371          * Write the mode parameter header.  Fixed values are: default
1372          * medium type, no cache control (DPOFUA), and no block descriptors.
1373          * The only variable value is the WriteProtect bit.  We will fill in
1374          * the mode data length later.
1375          */
1376         memset(buf, 0, 8);
1377         if (mscmnd == MODE_SENSE) {
1378                 buf[2] = (curlun->ro ? 0x80 : 0x00);            /* WP, DPOFUA */
1379                 buf += 4;
1380                 limit = 255;
1381         } else {                        /* MODE_SENSE_10 */
1382                 buf[3] = (curlun->ro ? 0x80 : 0x00);            /* WP, DPOFUA */
1383                 buf += 8;
1384                 limit = 65535;          /* Should really be FSG_BUFLEN */
1385         }
1386
1387         /* No block descriptors */
1388
1389         /*
1390          * The mode pages, in numerical order.  The only page we support
1391          * is the Caching page.
1392          */
1393         if (page_code == 0x08 || all_pages) {
1394                 valid_page = 1;
1395                 buf[0] = 0x08;          /* Page code */
1396                 buf[1] = 10;            /* Page length */
1397                 memset(buf+2, 0, 10);   /* None of the fields are changeable */
1398
1399                 if (!changeable_values) {
1400                         buf[2] = 0x04;  /* Write cache enable, */
1401                                         /* Read cache not disabled */
1402                                         /* No cache retention priorities */
1403                         put_unaligned_be16(0xffff, &buf[4]);
1404                                         /* Don't disable prefetch */
1405                                         /* Minimum prefetch = 0 */
1406                         put_unaligned_be16(0xffff, &buf[8]);
1407                                         /* Maximum prefetch */
1408                         put_unaligned_be16(0xffff, &buf[10]);
1409                                         /* Maximum prefetch ceiling */
1410                 }
1411                 buf += 12;
1412         }
1413
1414         /*
1415          * Check that a valid page was requested and the mode data length
1416          * isn't too long.
1417          */
1418         len = buf - buf0;
1419         if (!valid_page || len > limit) {
1420                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1421                 return -EINVAL;
1422         }
1423
1424         /*  Store the mode data length */
1425         if (mscmnd == MODE_SENSE)
1426                 buf0[0] = len - 1;
1427         else
1428                 put_unaligned_be16(len - 2, buf0);
1429         return len;
1430 }
1431
1432 static int do_start_stop(struct fsg_common *common)
1433 {
1434         struct fsg_lun  *curlun = common->curlun;
1435         int             loej, start;
1436
1437         if (!curlun) {
1438                 return -EINVAL;
1439         } else if (!curlun->removable) {
1440                 curlun->sense_data = SS_INVALID_COMMAND;
1441                 return -EINVAL;
1442         } else if ((common->cmnd[1] & ~0x01) != 0 || /* Mask away Immed */
1443                    (common->cmnd[4] & ~0x03) != 0) { /* Mask LoEj, Start */
1444                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1445                 return -EINVAL;
1446         }
1447
1448         loej  = common->cmnd[4] & 0x02;
1449         start = common->cmnd[4] & 0x01;
1450
1451         /*
1452          * Our emulation doesn't support mounting; the medium is
1453          * available for use as soon as it is loaded.
1454          */
1455         if (start) {
1456                 if (!fsg_lun_is_open(curlun)) {
1457                         curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
1458                         return -EINVAL;
1459                 }
1460                 return 0;
1461         }
1462
1463         /* Are we allowed to unload the media? */
1464         if (curlun->prevent_medium_removal) {
1465                 LDBG(curlun, "unload attempt prevented\n");
1466                 curlun->sense_data = SS_MEDIUM_REMOVAL_PREVENTED;
1467                 return -EINVAL;
1468         }
1469
1470         if (!loej)
1471                 return 0;
1472
1473         /* Simulate an unload/eject */
1474         if (common->ops && common->ops->pre_eject) {
1475                 int r = common->ops->pre_eject(common, curlun,
1476                                                curlun - common->luns);
1477                 if (unlikely(r < 0))
1478                         return r;
1479                 else if (r)
1480                         return 0;
1481         }
1482
1483         up_read(&common->filesem);
1484         down_write(&common->filesem);
1485         fsg_lun_close(curlun);
1486         up_write(&common->filesem);
1487         down_read(&common->filesem);
1488
1489         return common->ops && common->ops->post_eject
1490                 ? min(0, common->ops->post_eject(common, curlun,
1491                                                  curlun - common->luns))
1492                 : 0;
1493 }
1494
1495 static int do_prevent_allow(struct fsg_common *common)
1496 {
1497         struct fsg_lun  *curlun = common->curlun;
1498         int             prevent;
1499
1500         if (!common->curlun) {
1501                 return -EINVAL;
1502         } else if (!common->curlun->removable) {
1503                 common->curlun->sense_data = SS_INVALID_COMMAND;
1504                 return -EINVAL;
1505         }
1506
1507         prevent = common->cmnd[4] & 0x01;
1508         if ((common->cmnd[4] & ~0x01) != 0) {   /* Mask away Prevent */
1509                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1510                 return -EINVAL;
1511         }
1512
1513         if (curlun->prevent_medium_removal && !prevent)
1514                 fsg_lun_fsync_sub(curlun);
1515         curlun->prevent_medium_removal = prevent;
1516         return 0;
1517 }
1518
1519 static int do_read_format_capacities(struct fsg_common *common,
1520                         struct fsg_buffhd *bh)
1521 {
1522         struct fsg_lun  *curlun = common->curlun;
1523         u8              *buf = (u8 *) bh->buf;
1524
1525         buf[0] = buf[1] = buf[2] = 0;
1526         buf[3] = 8;     /* Only the Current/Maximum Capacity Descriptor */
1527         buf += 4;
1528
1529         put_unaligned_be32(curlun->num_sectors, &buf[0]);
1530                                                 /* Number of blocks */
1531         put_unaligned_be32(curlun->blksize, &buf[4]);/* Block length */
1532         buf[4] = 0x02;                          /* Current capacity */
1533         return 12;
1534 }
1535
1536 static int do_mode_select(struct fsg_common *common, struct fsg_buffhd *bh)
1537 {
1538         struct fsg_lun  *curlun = common->curlun;
1539
1540         /* We don't support MODE SELECT */
1541         if (curlun)
1542                 curlun->sense_data = SS_INVALID_COMMAND;
1543         return -EINVAL;
1544 }
1545
1546
1547 /*-------------------------------------------------------------------------*/
1548
1549 static int halt_bulk_in_endpoint(struct fsg_dev *fsg)
1550 {
1551         int     rc;
1552
1553         rc = fsg_set_halt(fsg, fsg->bulk_in);
1554         if (rc == -EAGAIN)
1555                 VDBG(fsg, "delayed bulk-in endpoint halt\n");
1556         while (rc != 0) {
1557                 if (rc != -EAGAIN) {
1558                         WARNING(fsg, "usb_ep_set_halt -> %d\n", rc);
1559                         rc = 0;
1560                         break;
1561                 }
1562
1563                 /* Wait for a short time and then try again */
1564                 if (msleep_interruptible(100) != 0)
1565                         return -EINTR;
1566                 rc = usb_ep_set_halt(fsg->bulk_in);
1567         }
1568         return rc;
1569 }
1570
1571 static int wedge_bulk_in_endpoint(struct fsg_dev *fsg)
1572 {
1573         int     rc;
1574
1575         DBG(fsg, "bulk-in set wedge\n");
1576         rc = usb_ep_set_wedge(fsg->bulk_in);
1577         if (rc == -EAGAIN)
1578                 VDBG(fsg, "delayed bulk-in endpoint wedge\n");
1579         while (rc != 0) {
1580                 if (rc != -EAGAIN) {
1581                         WARNING(fsg, "usb_ep_set_wedge -> %d\n", rc);
1582                         rc = 0;
1583                         break;
1584                 }
1585
1586                 /* Wait for a short time and then try again */
1587                 if (msleep_interruptible(100) != 0)
1588                         return -EINTR;
1589                 rc = usb_ep_set_wedge(fsg->bulk_in);
1590         }
1591         return rc;
1592 }
1593
1594 static int throw_away_data(struct fsg_common *common)
1595 {
1596         struct fsg_buffhd       *bh;
1597         u32                     amount;
1598         int                     rc;
1599
1600         for (bh = common->next_buffhd_to_drain;
1601              bh->state != BUF_STATE_EMPTY || common->usb_amount_left > 0;
1602              bh = common->next_buffhd_to_drain) {
1603
1604                 /* Throw away the data in a filled buffer */
1605                 if (bh->state == BUF_STATE_FULL) {
1606                         smp_rmb();
1607                         bh->state = BUF_STATE_EMPTY;
1608                         common->next_buffhd_to_drain = bh->next;
1609
1610                         /* A short packet or an error ends everything */
1611                         if (bh->outreq->actual < bh->bulk_out_intended_length ||
1612                             bh->outreq->status != 0) {
1613                                 raise_exception(common,
1614                                                 FSG_STATE_ABORT_BULK_OUT);
1615                                 return -EINTR;
1616                         }
1617                         continue;
1618                 }
1619
1620                 /* Try to submit another request if we need one */
1621                 bh = common->next_buffhd_to_fill;
1622                 if (bh->state == BUF_STATE_EMPTY
1623                  && common->usb_amount_left > 0) {
1624                         amount = min(common->usb_amount_left, FSG_BUFLEN);
1625
1626                         /*
1627                          * Except at the end of the transfer, amount will be
1628                          * equal to the buffer size, which is divisible by
1629                          * the bulk-out maxpacket size.
1630                          */
1631                         set_bulk_out_req_length(common, bh, amount);
1632                         if (!start_out_transfer(common, bh))
1633                                 /* Dunno what to do if common->fsg is NULL */
1634                                 return -EIO;
1635                         common->next_buffhd_to_fill = bh->next;
1636                         common->usb_amount_left -= amount;
1637                         continue;
1638                 }
1639
1640                 /* Otherwise wait for something to happen */
1641                 rc = sleep_thread(common);
1642                 if (rc)
1643                         return rc;
1644         }
1645         return 0;
1646 }
1647
1648 static int finish_reply(struct fsg_common *common)
1649 {
1650         struct fsg_buffhd       *bh = common->next_buffhd_to_fill;
1651         int                     rc = 0;
1652
1653         switch (common->data_dir) {
1654         case DATA_DIR_NONE:
1655                 break;                  /* Nothing to send */
1656
1657         /*
1658          * If we don't know whether the host wants to read or write,
1659          * this must be CB or CBI with an unknown command.  We mustn't
1660          * try to send or receive any data.  So stall both bulk pipes
1661          * if we can and wait for a reset.
1662          */
1663         case DATA_DIR_UNKNOWN:
1664                 if (!common->can_stall) {
1665                         /* Nothing */
1666                 } else if (fsg_is_set(common)) {
1667                         fsg_set_halt(common->fsg, common->fsg->bulk_out);
1668                         rc = halt_bulk_in_endpoint(common->fsg);
1669                 } else {
1670                         /* Don't know what to do if common->fsg is NULL */
1671                         rc = -EIO;
1672                 }
1673                 break;
1674
1675         /* All but the last buffer of data must have already been sent */
1676         case DATA_DIR_TO_HOST:
1677                 if (common->data_size == 0) {
1678                         /* Nothing to send */
1679
1680                 /* Don't know what to do if common->fsg is NULL */
1681                 } else if (!fsg_is_set(common)) {
1682                         rc = -EIO;
1683
1684                 /* If there's no residue, simply send the last buffer */
1685                 } else if (common->residue == 0) {
1686                         bh->inreq->zero = 0;
1687                         if (!start_in_transfer(common, bh))
1688                                 return -EIO;
1689                         common->next_buffhd_to_fill = bh->next;
1690
1691                 /*
1692                  * For Bulk-only, mark the end of the data with a short
1693                  * packet.  If we are allowed to stall, halt the bulk-in
1694                  * endpoint.  (Note: This violates the Bulk-Only Transport
1695                  * specification, which requires us to pad the data if we
1696                  * don't halt the endpoint.  Presumably nobody will mind.)
1697                  */
1698                 } else {
1699                         bh->inreq->zero = 1;
1700                         if (!start_in_transfer(common, bh))
1701                                 rc = -EIO;
1702                         common->next_buffhd_to_fill = bh->next;
1703                         if (common->can_stall)
1704                                 rc = halt_bulk_in_endpoint(common->fsg);
1705                 }
1706                 break;
1707
1708         /*
1709          * We have processed all we want from the data the host has sent.
1710          * There may still be outstanding bulk-out requests.
1711          */
1712         case DATA_DIR_FROM_HOST:
1713                 if (common->residue == 0) {
1714                         /* Nothing to receive */
1715
1716                 /* Did the host stop sending unexpectedly early? */
1717                 } else if (common->short_packet_received) {
1718                         raise_exception(common, FSG_STATE_ABORT_BULK_OUT);
1719                         rc = -EINTR;
1720
1721                 /*
1722                  * We haven't processed all the incoming data.  Even though
1723                  * we may be allowed to stall, doing so would cause a race.
1724                  * The controller may already have ACK'ed all the remaining
1725                  * bulk-out packets, in which case the host wouldn't see a
1726                  * STALL.  Not realizing the endpoint was halted, it wouldn't
1727                  * clear the halt -- leading to problems later on.
1728                  */
1729 #if 0
1730                 } else if (common->can_stall) {
1731                         if (fsg_is_set(common))
1732                                 fsg_set_halt(common->fsg,
1733                                              common->fsg->bulk_out);
1734                         raise_exception(common, FSG_STATE_ABORT_BULK_OUT);
1735                         rc = -EINTR;
1736 #endif
1737
1738                 /*
1739                  * We can't stall.  Read in the excess data and throw it
1740                  * all away.
1741                  */
1742                 } else {
1743                         rc = throw_away_data(common);
1744                 }
1745                 break;
1746         }
1747         return rc;
1748 }
1749
1750 static int send_status(struct fsg_common *common)
1751 {
1752         struct fsg_lun          *curlun = common->curlun;
1753         struct fsg_buffhd       *bh;
1754         struct bulk_cs_wrap     *csw;
1755         int                     rc;
1756         u8                      status = USB_STATUS_PASS;
1757         u32                     sd, sdinfo = 0;
1758
1759         /* Wait for the next buffer to become available */
1760         bh = common->next_buffhd_to_fill;
1761         while (bh->state != BUF_STATE_EMPTY) {
1762                 rc = sleep_thread(common);
1763                 if (rc)
1764                         return rc;
1765         }
1766
1767         if (curlun) {
1768                 sd = curlun->sense_data;
1769                 sdinfo = curlun->sense_data_info;
1770         } else if (common->bad_lun_okay)
1771                 sd = SS_NO_SENSE;
1772         else
1773                 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
1774
1775         if (common->phase_error) {
1776                 DBG(common, "sending phase-error status\n");
1777                 status = USB_STATUS_PHASE_ERROR;
1778                 sd = SS_INVALID_COMMAND;
1779         } else if (sd != SS_NO_SENSE) {
1780                 DBG(common, "sending command-failure status\n");
1781                 status = USB_STATUS_FAIL;
1782                 VDBG(common, "  sense data: SK x%02x, ASC x%02x, ASCQ x%02x;"
1783                                 "  info x%x\n",
1784                                 SK(sd), ASC(sd), ASCQ(sd), sdinfo);
1785         }
1786
1787         /* Store and send the Bulk-only CSW */
1788         csw = (void *)bh->buf;
1789
1790         csw->Signature = cpu_to_le32(USB_BULK_CS_SIG);
1791         csw->Tag = common->tag;
1792         csw->Residue = cpu_to_le32(common->residue);
1793         csw->Status = status;
1794
1795         bh->inreq->length = USB_BULK_CS_WRAP_LEN;
1796         bh->inreq->zero = 0;
1797         if (!start_in_transfer(common, bh))
1798                 /* Don't know what to do if common->fsg is NULL */
1799                 return -EIO;
1800
1801         common->next_buffhd_to_fill = bh->next;
1802         return 0;
1803 }
1804
1805
1806 /*-------------------------------------------------------------------------*/
1807
1808 /*
1809  * Check whether the command is properly formed and whether its data size
1810  * and direction agree with the values we already have.
1811  */
1812 static int check_command(struct fsg_common *common, int cmnd_size,
1813                          enum data_direction data_dir, unsigned int mask,
1814                          int needs_medium, const char *name)
1815 {
1816         int                     i;
1817         int                     lun = common->cmnd[1] >> 5;
1818         static const char       dirletter[4] = {'u', 'o', 'i', 'n'};
1819         char                    hdlen[20];
1820         struct fsg_lun          *curlun;
1821
1822         hdlen[0] = 0;
1823         if (common->data_dir != DATA_DIR_UNKNOWN)
1824                 sprintf(hdlen, ", H%c=%u", dirletter[(int) common->data_dir],
1825                         common->data_size);
1826         VDBG(common, "SCSI command: %s;  Dc=%d, D%c=%u;  Hc=%d%s\n",
1827              name, cmnd_size, dirletter[(int) data_dir],
1828              common->data_size_from_cmnd, common->cmnd_size, hdlen);
1829
1830         /*
1831          * We can't reply at all until we know the correct data direction
1832          * and size.
1833          */
1834         if (common->data_size_from_cmnd == 0)
1835                 data_dir = DATA_DIR_NONE;
1836         if (common->data_size < common->data_size_from_cmnd) {
1837                 /*
1838                  * Host data size < Device data size is a phase error.
1839                  * Carry out the command, but only transfer as much as
1840                  * we are allowed.
1841                  */
1842                 common->data_size_from_cmnd = common->data_size;
1843                 common->phase_error = 1;
1844         }
1845         common->residue = common->data_size;
1846         common->usb_amount_left = common->data_size;
1847
1848         /* Conflicting data directions is a phase error */
1849         if (common->data_dir != data_dir && common->data_size_from_cmnd > 0) {
1850                 common->phase_error = 1;
1851                 return -EINVAL;
1852         }
1853
1854         /* Verify the length of the command itself */
1855         if (cmnd_size != common->cmnd_size) {
1856
1857                 /*
1858                  * Special case workaround: There are plenty of buggy SCSI
1859                  * implementations. Many have issues with cbw->Length
1860                  * field passing a wrong command size. For those cases we
1861                  * always try to work around the problem by using the length
1862                  * sent by the host side provided it is at least as large
1863                  * as the correct command length.
1864                  * Examples of such cases would be MS-Windows, which issues
1865                  * REQUEST SENSE with cbw->Length == 12 where it should
1866                  * be 6, and xbox360 issuing INQUIRY, TEST UNIT READY and
1867                  * REQUEST SENSE with cbw->Length == 10 where it should
1868                  * be 6 as well.
1869                  */
1870                 if (cmnd_size <= common->cmnd_size) {
1871                         DBG(common, "%s is buggy! Expected length %d "
1872                             "but we got %d\n", name,
1873                             cmnd_size, common->cmnd_size);
1874                         cmnd_size = common->cmnd_size;
1875                 } else {
1876                         common->phase_error = 1;
1877                         return -EINVAL;
1878                 }
1879         }
1880
1881         /* Check that the LUN values are consistent */
1882         if (common->lun != lun)
1883                 DBG(common, "using LUN %d from CBW, not LUN %d from CDB\n",
1884                     common->lun, lun);
1885
1886         /* Check the LUN */
1887         if (common->lun < common->nluns) {
1888                 curlun = &common->luns[common->lun];
1889                 common->curlun = curlun;
1890                 if (common->cmnd[0] != REQUEST_SENSE) {
1891                         curlun->sense_data = SS_NO_SENSE;
1892                         curlun->sense_data_info = 0;
1893                         curlun->info_valid = 0;
1894                 }
1895         } else {
1896                 common->curlun = NULL;
1897                 curlun = NULL;
1898                 common->bad_lun_okay = 0;
1899
1900                 /*
1901                  * INQUIRY and REQUEST SENSE commands are explicitly allowed
1902                  * to use unsupported LUNs; all others may not.
1903                  */
1904                 if (common->cmnd[0] != INQUIRY &&
1905                     common->cmnd[0] != REQUEST_SENSE) {
1906                         DBG(common, "unsupported LUN %d\n", common->lun);
1907                         return -EINVAL;
1908                 }
1909         }
1910
1911         /*
1912          * If a unit attention condition exists, only INQUIRY and
1913          * REQUEST SENSE commands are allowed; anything else must fail.
1914          */
1915         if (curlun && curlun->unit_attention_data != SS_NO_SENSE &&
1916             common->cmnd[0] != INQUIRY &&
1917             common->cmnd[0] != REQUEST_SENSE) {
1918                 curlun->sense_data = curlun->unit_attention_data;
1919                 curlun->unit_attention_data = SS_NO_SENSE;
1920                 return -EINVAL;
1921         }
1922
1923         /* Check that only command bytes listed in the mask are non-zero */
1924         common->cmnd[1] &= 0x1f;                        /* Mask away the LUN */
1925         for (i = 1; i < cmnd_size; ++i) {
1926                 if (common->cmnd[i] && !(mask & (1 << i))) {
1927                         if (curlun)
1928                                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1929                         return -EINVAL;
1930                 }
1931         }
1932
1933         /* If the medium isn't mounted and the command needs to access
1934          * it, return an error. */
1935         if (curlun && !fsg_lun_is_open(curlun) && needs_medium) {
1936                 curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
1937                 return -EINVAL;
1938         }
1939
1940         return 0;
1941 }
1942
1943 static int do_scsi_command(struct fsg_common *common)
1944 {
1945         struct fsg_buffhd       *bh;
1946         int                     rc;
1947         int                     reply = -EINVAL;
1948         int                     i;
1949         static char             unknown[16];
1950
1951         dump_cdb(common);
1952
1953         /* Wait for the next buffer to become available for data or status */
1954         bh = common->next_buffhd_to_fill;
1955         common->next_buffhd_to_drain = bh;
1956         while (bh->state != BUF_STATE_EMPTY) {
1957                 rc = sleep_thread(common);
1958                 if (rc)
1959                         return rc;
1960         }
1961         common->phase_error = 0;
1962         common->short_packet_received = 0;
1963
1964         down_read(&common->filesem);    /* We're using the backing file */
1965         switch (common->cmnd[0]) {
1966
1967         case INQUIRY:
1968                 common->data_size_from_cmnd = common->cmnd[4];
1969                 reply = check_command(common, 6, DATA_DIR_TO_HOST,
1970                                       (1<<4), 0,
1971                                       "INQUIRY");
1972                 if (reply == 0)
1973                         reply = do_inquiry(common, bh);
1974                 break;
1975
1976         case MODE_SELECT:
1977                 common->data_size_from_cmnd = common->cmnd[4];
1978                 reply = check_command(common, 6, DATA_DIR_FROM_HOST,
1979                                       (1<<1) | (1<<4), 0,
1980                                       "MODE SELECT(6)");
1981                 if (reply == 0)
1982                         reply = do_mode_select(common, bh);
1983                 break;
1984
1985         case MODE_SELECT_10:
1986                 common->data_size_from_cmnd =
1987                         get_unaligned_be16(&common->cmnd[7]);
1988                 reply = check_command(common, 10, DATA_DIR_FROM_HOST,
1989                                       (1<<1) | (3<<7), 0,
1990                                       "MODE SELECT(10)");
1991                 if (reply == 0)
1992                         reply = do_mode_select(common, bh);
1993                 break;
1994
1995         case MODE_SENSE:
1996                 common->data_size_from_cmnd = common->cmnd[4];
1997                 reply = check_command(common, 6, DATA_DIR_TO_HOST,
1998                                       (1<<1) | (1<<2) | (1<<4), 0,
1999                                       "MODE SENSE(6)");
2000                 if (reply == 0)
2001                         reply = do_mode_sense(common, bh);
2002                 break;
2003
2004         case MODE_SENSE_10:
2005                 common->data_size_from_cmnd =
2006                         get_unaligned_be16(&common->cmnd[7]);
2007                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
2008                                       (1<<1) | (1<<2) | (3<<7), 0,
2009                                       "MODE SENSE(10)");
2010                 if (reply == 0)
2011                         reply = do_mode_sense(common, bh);
2012                 break;
2013
2014         case ALLOW_MEDIUM_REMOVAL:
2015                 common->data_size_from_cmnd = 0;
2016                 reply = check_command(common, 6, DATA_DIR_NONE,
2017                                       (1<<4), 0,
2018                                       "PREVENT-ALLOW MEDIUM REMOVAL");
2019                 if (reply == 0)
2020                         reply = do_prevent_allow(common);
2021                 break;
2022
2023         case READ_6:
2024                 i = common->cmnd[4];
2025                 common->data_size_from_cmnd = (i == 0 ? 256 : i) <<
2026                                 common->curlun->blkbits;
2027                 reply = check_command(common, 6, DATA_DIR_TO_HOST,
2028                                       (7<<1) | (1<<4), 1,
2029                                       "READ(6)");
2030                 if (reply == 0)
2031                         reply = do_read(common);
2032                 break;
2033
2034         case READ_10:
2035                 common->data_size_from_cmnd =
2036                                 get_unaligned_be16(&common->cmnd[7]) <<
2037                                                 common->curlun->blkbits;
2038                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
2039                                       (1<<1) | (0xf<<2) | (3<<7), 1,
2040                                       "READ(10)");
2041                 if (reply == 0)
2042                         reply = do_read(common);
2043                 break;
2044
2045         case READ_12:
2046                 common->data_size_from_cmnd =
2047                                 get_unaligned_be32(&common->cmnd[6]) <<
2048                                                 common->curlun->blkbits;
2049                 reply = check_command(common, 12, DATA_DIR_TO_HOST,
2050                                       (1<<1) | (0xf<<2) | (0xf<<6), 1,
2051                                       "READ(12)");
2052                 if (reply == 0)
2053                         reply = do_read(common);
2054                 break;
2055
2056         case READ_CAPACITY:
2057                 common->data_size_from_cmnd = 8;
2058                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
2059                                       (0xf<<2) | (1<<8), 1,
2060                                       "READ CAPACITY");
2061                 if (reply == 0)
2062                         reply = do_read_capacity(common, bh);
2063                 break;
2064
2065         case READ_HEADER:
2066                 if (!common->curlun || !common->curlun->cdrom)
2067                         goto unknown_cmnd;
2068                 common->data_size_from_cmnd =
2069                         get_unaligned_be16(&common->cmnd[7]);
2070                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
2071                                       (3<<7) | (0x1f<<1), 1,
2072                                       "READ HEADER");
2073                 if (reply == 0)
2074                         reply = do_read_header(common, bh);
2075                 break;
2076
2077         case READ_TOC:
2078                 if (!common->curlun || !common->curlun->cdrom)
2079                         goto unknown_cmnd;
2080                 common->data_size_from_cmnd =
2081                         get_unaligned_be16(&common->cmnd[7]);
2082                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
2083                                       (7<<6) | (1<<1), 1,
2084                                       "READ TOC");
2085                 if (reply == 0)
2086                         reply = do_read_toc(common, bh);
2087                 break;
2088
2089         case READ_FORMAT_CAPACITIES:
2090                 common->data_size_from_cmnd =
2091                         get_unaligned_be16(&common->cmnd[7]);
2092                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
2093                                       (3<<7), 1,
2094                                       "READ FORMAT CAPACITIES");
2095                 if (reply == 0)
2096                         reply = do_read_format_capacities(common, bh);
2097                 break;
2098
2099         case REQUEST_SENSE:
2100                 common->data_size_from_cmnd = common->cmnd[4];
2101                 reply = check_command(common, 6, DATA_DIR_TO_HOST,
2102                                       (1<<4), 0,
2103                                       "REQUEST SENSE");
2104                 if (reply == 0)
2105                         reply = do_request_sense(common, bh);
2106                 break;
2107
2108         case START_STOP:
2109                 common->data_size_from_cmnd = 0;
2110                 reply = check_command(common, 6, DATA_DIR_NONE,
2111                                       (1<<1) | (1<<4), 0,
2112                                       "START-STOP UNIT");
2113                 if (reply == 0)
2114                         reply = do_start_stop(common);
2115                 break;
2116
2117         case SYNCHRONIZE_CACHE:
2118                 common->data_size_from_cmnd = 0;
2119                 reply = check_command(common, 10, DATA_DIR_NONE,
2120                                       (0xf<<2) | (3<<7), 1,
2121                                       "SYNCHRONIZE CACHE");
2122                 if (reply == 0)
2123                         reply = do_synchronize_cache(common);
2124                 break;
2125
2126         case TEST_UNIT_READY:
2127                 common->data_size_from_cmnd = 0;
2128                 reply = check_command(common, 6, DATA_DIR_NONE,
2129                                 0, 1,
2130                                 "TEST UNIT READY");
2131                 break;
2132
2133         /*
2134          * Although optional, this command is used by MS-Windows.  We
2135          * support a minimal version: BytChk must be 0.
2136          */
2137         case VERIFY:
2138                 common->data_size_from_cmnd = 0;
2139                 reply = check_command(common, 10, DATA_DIR_NONE,
2140                                       (1<<1) | (0xf<<2) | (3<<7), 1,
2141                                       "VERIFY");
2142                 if (reply == 0)
2143                         reply = do_verify(common);
2144                 break;
2145
2146         case WRITE_6:
2147                 i = common->cmnd[4];
2148                 common->data_size_from_cmnd = (i == 0 ? 256 : i) <<
2149                                         common->curlun->blkbits;
2150                 reply = check_command(common, 6, DATA_DIR_FROM_HOST,
2151                                       (7<<1) | (1<<4), 1,
2152                                       "WRITE(6)");
2153                 if (reply == 0)
2154                         reply = do_write(common);
2155                 break;
2156
2157         case WRITE_10:
2158                 common->data_size_from_cmnd =
2159                                 get_unaligned_be16(&common->cmnd[7]) <<
2160                                                 common->curlun->blkbits;
2161                 reply = check_command(common, 10, DATA_DIR_FROM_HOST,
2162                                       (1<<1) | (0xf<<2) | (3<<7), 1,
2163                                       "WRITE(10)");
2164                 if (reply == 0)
2165                         reply = do_write(common);
2166                 break;
2167
2168         case WRITE_12:
2169                 common->data_size_from_cmnd =
2170                                 get_unaligned_be32(&common->cmnd[6]) <<
2171                                                 common->curlun->blkbits;
2172                 reply = check_command(common, 12, DATA_DIR_FROM_HOST,
2173                                       (1<<1) | (0xf<<2) | (0xf<<6), 1,
2174                                       "WRITE(12)");
2175                 if (reply == 0)
2176                         reply = do_write(common);
2177                 break;
2178
2179         /*
2180          * Some mandatory commands that we recognize but don't implement.
2181          * They don't mean much in this setting.  It's left as an exercise
2182          * for anyone interested to implement RESERVE and RELEASE in terms
2183          * of Posix locks.
2184          */
2185         case FORMAT_UNIT:
2186         case RELEASE:
2187         case RESERVE:
2188         case SEND_DIAGNOSTIC:
2189                 /* Fall through */
2190
2191         default:
2192 unknown_cmnd:
2193                 common->data_size_from_cmnd = 0;
2194                 sprintf(unknown, "Unknown x%02x", common->cmnd[0]);
2195                 reply = check_command(common, common->cmnd_size,
2196                                       DATA_DIR_UNKNOWN, ~0, 0, unknown);
2197                 if (reply == 0) {
2198                         common->curlun->sense_data = SS_INVALID_COMMAND;
2199                         reply = -EINVAL;
2200                 }
2201                 break;
2202         }
2203         up_read(&common->filesem);
2204
2205         if (reply == -EINTR || signal_pending(current))
2206                 return -EINTR;
2207
2208         /* Set up the single reply buffer for finish_reply() */
2209         if (reply == -EINVAL)
2210                 reply = 0;              /* Error reply length */
2211         if (reply >= 0 && common->data_dir == DATA_DIR_TO_HOST) {
2212                 reply = min((u32)reply, common->data_size_from_cmnd);
2213                 bh->inreq->length = reply;
2214                 bh->state = BUF_STATE_FULL;
2215                 common->residue -= reply;
2216         }                               /* Otherwise it's already set */
2217
2218         return 0;
2219 }
2220
2221
2222 /*-------------------------------------------------------------------------*/
2223
2224 static int received_cbw(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2225 {
2226         struct usb_request      *req = bh->outreq;
2227         struct fsg_bulk_cb_wrap *cbw = req->buf;
2228         struct fsg_common       *common = fsg->common;
2229
2230         /* Was this a real packet?  Should it be ignored? */
2231         if (req->status || test_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags))
2232                 return -EINVAL;
2233
2234         /* Is the CBW valid? */
2235         if (req->actual != USB_BULK_CB_WRAP_LEN ||
2236                         cbw->Signature != cpu_to_le32(
2237                                 USB_BULK_CB_SIG)) {
2238                 DBG(fsg, "invalid CBW: len %u sig 0x%x\n",
2239                                 req->actual,
2240                                 le32_to_cpu(cbw->Signature));
2241
2242                 /*
2243                  * The Bulk-only spec says we MUST stall the IN endpoint
2244                  * (6.6.1), so it's unavoidable.  It also says we must
2245                  * retain this state until the next reset, but there's
2246                  * no way to tell the controller driver it should ignore
2247                  * Clear-Feature(HALT) requests.
2248                  *
2249                  * We aren't required to halt the OUT endpoint; instead
2250                  * we can simply accept and discard any data received
2251                  * until the next reset.
2252                  */
2253                 wedge_bulk_in_endpoint(fsg);
2254                 set_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
2255                 return -EINVAL;
2256         }
2257
2258         /* Is the CBW meaningful? */
2259         if (cbw->Lun >= FSG_MAX_LUNS || cbw->Flags & ~USB_BULK_IN_FLAG ||
2260                         cbw->Length <= 0 || cbw->Length > MAX_COMMAND_SIZE) {
2261                 DBG(fsg, "non-meaningful CBW: lun = %u, flags = 0x%x, "
2262                                 "cmdlen %u\n",
2263                                 cbw->Lun, cbw->Flags, cbw->Length);
2264
2265                 /*
2266                  * We can do anything we want here, so let's stall the
2267                  * bulk pipes if we are allowed to.
2268                  */
2269                 if (common->can_stall) {
2270                         fsg_set_halt(fsg, fsg->bulk_out);
2271                         halt_bulk_in_endpoint(fsg);
2272                 }
2273                 return -EINVAL;
2274         }
2275
2276         /* Save the command for later */
2277         common->cmnd_size = cbw->Length;
2278         memcpy(common->cmnd, cbw->CDB, common->cmnd_size);
2279         if (cbw->Flags & USB_BULK_IN_FLAG)
2280                 common->data_dir = DATA_DIR_TO_HOST;
2281         else
2282                 common->data_dir = DATA_DIR_FROM_HOST;
2283         common->data_size = le32_to_cpu(cbw->DataTransferLength);
2284         if (common->data_size == 0)
2285                 common->data_dir = DATA_DIR_NONE;
2286         common->lun = cbw->Lun;
2287         common->tag = cbw->Tag;
2288         return 0;
2289 }
2290
2291 static int get_next_command(struct fsg_common *common)
2292 {
2293         struct fsg_buffhd       *bh;
2294         int                     rc = 0;
2295
2296         /* Wait for the next buffer to become available */
2297         bh = common->next_buffhd_to_fill;
2298         while (bh->state != BUF_STATE_EMPTY) {
2299                 rc = sleep_thread(common);
2300                 if (rc)
2301                         return rc;
2302         }
2303
2304         /* Queue a request to read a Bulk-only CBW */
2305         set_bulk_out_req_length(common, bh, USB_BULK_CB_WRAP_LEN);
2306         if (!start_out_transfer(common, bh))
2307                 /* Don't know what to do if common->fsg is NULL */
2308                 return -EIO;
2309
2310         /*
2311          * We will drain the buffer in software, which means we
2312          * can reuse it for the next filling.  No need to advance
2313          * next_buffhd_to_fill.
2314          */
2315
2316         /* Wait for the CBW to arrive */
2317         while (bh->state != BUF_STATE_FULL) {
2318                 rc = sleep_thread(common);
2319                 if (rc)
2320                         return rc;
2321         }
2322         smp_rmb();
2323         rc = fsg_is_set(common) ? received_cbw(common->fsg, bh) : -EIO;
2324         bh->state = BUF_STATE_EMPTY;
2325
2326         return rc;
2327 }
2328
2329
2330 /*-------------------------------------------------------------------------*/
2331
2332 static int alloc_request(struct fsg_common *common, struct usb_ep *ep,
2333                 struct usb_request **preq)
2334 {
2335         *preq = usb_ep_alloc_request(ep, GFP_ATOMIC);
2336         if (*preq)
2337                 return 0;
2338         ERROR(common, "can't allocate request for %s\n", ep->name);
2339         return -ENOMEM;
2340 }
2341
2342 /* Reset interface setting and re-init endpoint state (toggle etc). */
2343 static int do_set_interface(struct fsg_common *common, struct fsg_dev *new_fsg)
2344 {
2345         struct fsg_dev *fsg;
2346         int i, rc = 0;
2347
2348         if (common->running)
2349                 DBG(common, "reset interface\n");
2350
2351 reset:
2352         /* Deallocate the requests */
2353         if (common->fsg) {
2354                 fsg = common->fsg;
2355
2356                 for (i = 0; i < fsg_num_buffers; ++i) {
2357                         struct fsg_buffhd *bh = &common->buffhds[i];
2358
2359                         if (bh->inreq) {
2360                                 usb_ep_free_request(fsg->bulk_in, bh->inreq);
2361                                 bh->inreq = NULL;
2362                         }
2363                         if (bh->outreq) {
2364                                 usb_ep_free_request(fsg->bulk_out, bh->outreq);
2365                                 bh->outreq = NULL;
2366                         }
2367                 }
2368
2369                 /* Disable the endpoints */
2370                 if (fsg->bulk_in_enabled) {
2371                         usb_ep_disable(fsg->bulk_in);
2372                         fsg->bulk_in_enabled = 0;
2373                 }
2374                 if (fsg->bulk_out_enabled) {
2375                         usb_ep_disable(fsg->bulk_out);
2376                         fsg->bulk_out_enabled = 0;
2377                 }
2378
2379                 common->fsg = NULL;
2380                 wake_up(&common->fsg_wait);
2381         }
2382
2383         common->running = 0;
2384         if (!new_fsg || rc)
2385                 return rc;
2386
2387         common->fsg = new_fsg;
2388         fsg = common->fsg;
2389
2390         /* Enable the endpoints */
2391         rc = config_ep_by_speed(common->gadget, &(fsg->function), fsg->bulk_in);
2392         if (rc)
2393                 goto reset;
2394         rc = usb_ep_enable(fsg->bulk_in);
2395         if (rc)
2396                 goto reset;
2397         fsg->bulk_in->driver_data = common;
2398         fsg->bulk_in_enabled = 1;
2399
2400         rc = config_ep_by_speed(common->gadget, &(fsg->function),
2401                                 fsg->bulk_out);
2402         if (rc)
2403                 goto reset;
2404         rc = usb_ep_enable(fsg->bulk_out);
2405         if (rc)
2406                 goto reset;
2407         fsg->bulk_out->driver_data = common;
2408         fsg->bulk_out_enabled = 1;
2409         common->bulk_out_maxpacket = usb_endpoint_maxp(fsg->bulk_out->desc);
2410         clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
2411
2412         /* Allocate the requests */
2413         for (i = 0; i < fsg_num_buffers; ++i) {
2414                 struct fsg_buffhd       *bh = &common->buffhds[i];
2415
2416                 rc = alloc_request(common, fsg->bulk_in, &bh->inreq);
2417                 if (rc)
2418                         goto reset;
2419                 rc = alloc_request(common, fsg->bulk_out, &bh->outreq);
2420                 if (rc)
2421                         goto reset;
2422                 bh->inreq->buf = bh->outreq->buf = bh->buf;
2423                 bh->inreq->context = bh->outreq->context = bh;
2424                 bh->inreq->complete = bulk_in_complete;
2425                 bh->outreq->complete = bulk_out_complete;
2426         }
2427
2428         common->running = 1;
2429         for (i = 0; i < common->nluns; ++i)
2430                 common->luns[i].unit_attention_data = SS_RESET_OCCURRED;
2431         return rc;
2432 }
2433
2434
2435 /****************************** ALT CONFIGS ******************************/
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->new_fsg = fsg;
2441         raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
2442         return USB_GADGET_DELAYED_STATUS;
2443 }
2444
2445 static void fsg_disable(struct usb_function *f)
2446 {
2447         struct fsg_dev *fsg = fsg_from_func(f);
2448         fsg->common->new_fsg = NULL;
2449         raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
2450 }
2451
2452
2453 /*-------------------------------------------------------------------------*/
2454
2455 static void handle_exception(struct fsg_common *common)
2456 {
2457         siginfo_t               info;
2458         int                     i;
2459         struct fsg_buffhd       *bh;
2460         enum fsg_state          old_state;
2461         struct fsg_lun          *curlun;
2462         unsigned int            exception_req_tag;
2463
2464         /*
2465          * Clear the existing signals.  Anything but SIGUSR1 is converted
2466          * into a high-priority EXIT exception.
2467          */
2468         for (;;) {
2469                 int sig =
2470                         dequeue_signal_lock(current, &current->blocked, &info);
2471                 if (!sig)
2472                         break;
2473                 if (sig != SIGUSR1) {
2474                         if (common->state < FSG_STATE_EXIT)
2475                                 DBG(common, "Main thread exiting on signal\n");
2476                         raise_exception(common, FSG_STATE_EXIT);
2477                 }
2478         }
2479
2480         /* Cancel all the pending transfers */
2481         if (likely(common->fsg)) {
2482                 for (i = 0; i < fsg_num_buffers; ++i) {
2483                         bh = &common->buffhds[i];
2484                         if (bh->inreq_busy)
2485                                 usb_ep_dequeue(common->fsg->bulk_in, bh->inreq);
2486                         if (bh->outreq_busy)
2487                                 usb_ep_dequeue(common->fsg->bulk_out,
2488                                                bh->outreq);
2489                 }
2490
2491                 /* Wait until everything is idle */
2492                 for (;;) {
2493                         int num_active = 0;
2494                         for (i = 0; i < fsg_num_buffers; ++i) {
2495                                 bh = &common->buffhds[i];
2496                                 num_active += bh->inreq_busy + bh->outreq_busy;
2497                         }
2498                         if (num_active == 0)
2499                                 break;
2500                         if (sleep_thread(common))
2501                                 return;
2502                 }
2503
2504                 /* Clear out the controller's fifos */
2505                 if (common->fsg->bulk_in_enabled)
2506                         usb_ep_fifo_flush(common->fsg->bulk_in);
2507                 if (common->fsg->bulk_out_enabled)
2508                         usb_ep_fifo_flush(common->fsg->bulk_out);
2509         }
2510
2511         /*
2512          * Reset the I/O buffer states and pointers, the SCSI
2513          * state, and the exception.  Then invoke the handler.
2514          */
2515         spin_lock_irq(&common->lock);
2516
2517         for (i = 0; i < fsg_num_buffers; ++i) {
2518                 bh = &common->buffhds[i];
2519                 bh->state = BUF_STATE_EMPTY;
2520         }
2521         common->next_buffhd_to_fill = &common->buffhds[0];
2522         common->next_buffhd_to_drain = &common->buffhds[0];
2523         exception_req_tag = common->exception_req_tag;
2524         old_state = common->state;
2525
2526         if (old_state == FSG_STATE_ABORT_BULK_OUT)
2527                 common->state = FSG_STATE_STATUS_PHASE;
2528         else {
2529                 for (i = 0; i < common->nluns; ++i) {
2530                         curlun = &common->luns[i];
2531                         curlun->prevent_medium_removal = 0;
2532                         curlun->sense_data = SS_NO_SENSE;
2533                         curlun->unit_attention_data = SS_NO_SENSE;
2534                         curlun->sense_data_info = 0;
2535                         curlun->info_valid = 0;
2536                 }
2537                 common->state = FSG_STATE_IDLE;
2538         }
2539         spin_unlock_irq(&common->lock);
2540
2541         /* Carry out any extra actions required for the exception */
2542         switch (old_state) {
2543         case FSG_STATE_ABORT_BULK_OUT:
2544                 send_status(common);
2545                 spin_lock_irq(&common->lock);
2546                 if (common->state == FSG_STATE_STATUS_PHASE)
2547                         common->state = FSG_STATE_IDLE;
2548                 spin_unlock_irq(&common->lock);
2549                 break;
2550
2551         case FSG_STATE_RESET:
2552                 /*
2553                  * In case we were forced against our will to halt a
2554                  * bulk endpoint, clear the halt now.  (The SuperH UDC
2555                  * requires this.)
2556                  */
2557                 if (!fsg_is_set(common))
2558                         break;
2559                 if (test_and_clear_bit(IGNORE_BULK_OUT,
2560                                        &common->fsg->atomic_bitflags))
2561                         usb_ep_clear_halt(common->fsg->bulk_in);
2562
2563                 if (common->ep0_req_tag == exception_req_tag)
2564                         ep0_queue(common);      /* Complete the status stage */
2565
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                  */
2571                 /* for (i = 0; i < common->nluns; ++i) */
2572                 /*      common->luns[i].unit_attention_data = */
2573                 /*              SS_RESET_OCCURRED;  */
2574                 break;
2575
2576         case FSG_STATE_CONFIG_CHANGE:
2577                 do_set_interface(common, common->new_fsg);
2578                 if (common->new_fsg)
2579                         usb_composite_setup_continue(common->cdev);
2580                 break;
2581
2582         case FSG_STATE_EXIT:
2583         case FSG_STATE_TERMINATED:
2584                 do_set_interface(common, NULL);         /* Free resources */
2585                 spin_lock_irq(&common->lock);
2586                 common->state = FSG_STATE_TERMINATED;   /* Stop the thread */
2587                 spin_unlock_irq(&common->lock);
2588                 break;
2589
2590         case FSG_STATE_INTERFACE_CHANGE:
2591         case FSG_STATE_DISCONNECT:
2592         case FSG_STATE_COMMAND_PHASE:
2593         case FSG_STATE_DATA_PHASE:
2594         case FSG_STATE_STATUS_PHASE:
2595         case FSG_STATE_IDLE:
2596                 break;
2597         }
2598 }
2599
2600
2601 /*-------------------------------------------------------------------------*/
2602
2603 static int fsg_main_thread(void *common_)
2604 {
2605         struct fsg_common       *common = common_;
2606
2607         /*
2608          * Allow the thread to be killed by a signal, but set the signal mask
2609          * to block everything but INT, TERM, KILL, and USR1.
2610          */
2611         allow_signal(SIGINT);
2612         allow_signal(SIGTERM);
2613         allow_signal(SIGKILL);
2614         allow_signal(SIGUSR1);
2615
2616         /* Allow the thread to be frozen */
2617         set_freezable();
2618
2619         /*
2620          * Arrange for userspace references to be interpreted as kernel
2621          * pointers.  That way we can pass a kernel pointer to a routine
2622          * that expects a __user pointer and it will work okay.
2623          */
2624         set_fs(get_ds());
2625
2626         /* The main loop */
2627         while (common->state != FSG_STATE_TERMINATED) {
2628                 if (exception_in_progress(common) || signal_pending(current)) {
2629                         handle_exception(common);
2630                         continue;
2631                 }
2632
2633                 if (!common->running) {
2634                         sleep_thread(common);
2635                         continue;
2636                 }
2637
2638                 if (get_next_command(common))
2639                         continue;
2640
2641                 spin_lock_irq(&common->lock);
2642                 if (!exception_in_progress(common))
2643                         common->state = FSG_STATE_DATA_PHASE;
2644                 spin_unlock_irq(&common->lock);
2645
2646                 if (do_scsi_command(common) || finish_reply(common))
2647                         continue;
2648
2649                 spin_lock_irq(&common->lock);
2650                 if (!exception_in_progress(common))
2651                         common->state = FSG_STATE_STATUS_PHASE;
2652                 spin_unlock_irq(&common->lock);
2653
2654                 if (send_status(common))
2655                         continue;
2656
2657                 spin_lock_irq(&common->lock);
2658                 if (!exception_in_progress(common))
2659                         common->state = FSG_STATE_IDLE;
2660                 spin_unlock_irq(&common->lock);
2661         }
2662
2663         spin_lock_irq(&common->lock);
2664         common->thread_task = NULL;
2665         spin_unlock_irq(&common->lock);
2666
2667         if (!common->ops || !common->ops->thread_exits
2668          || common->ops->thread_exits(common) < 0) {
2669                 struct fsg_lun *curlun = common->luns;
2670                 unsigned i = common->nluns;
2671
2672                 down_write(&common->filesem);
2673                 for (; i--; ++curlun) {
2674                         if (!fsg_lun_is_open(curlun))
2675                                 continue;
2676
2677                         fsg_lun_close(curlun);
2678                         curlun->unit_attention_data = SS_MEDIUM_NOT_PRESENT;
2679                 }
2680                 up_write(&common->filesem);
2681         }
2682
2683         /* Let fsg_unbind() know the thread has exited */
2684         complete_and_exit(&common->thread_notifier, 0);
2685 }
2686
2687
2688 /*************************** DEVICE ATTRIBUTES ***************************/
2689
2690 /* Write permission is checked per LUN in store_*() functions. */
2691 static DEVICE_ATTR(ro, 0644, fsg_show_ro, fsg_store_ro);
2692 static DEVICE_ATTR(nofua, 0644, fsg_show_nofua, fsg_store_nofua);
2693 static DEVICE_ATTR(file, 0644, fsg_show_file, fsg_store_file);
2694
2695
2696 /****************************** FSG COMMON ******************************/
2697
2698 static void fsg_common_release(struct kref *ref);
2699
2700 static void fsg_lun_release(struct device *dev)
2701 {
2702         /* Nothing needs to be done */
2703 }
2704
2705 static inline void fsg_common_get(struct fsg_common *common)
2706 {
2707         kref_get(&common->ref);
2708 }
2709
2710 static inline void fsg_common_put(struct fsg_common *common)
2711 {
2712         kref_put(&common->ref, fsg_common_release);
2713 }
2714
2715 static struct fsg_common *fsg_common_init(struct fsg_common *common,
2716                                           struct usb_composite_dev *cdev,
2717                                           struct fsg_config *cfg)
2718 {
2719         struct usb_gadget *gadget = cdev->gadget;
2720         struct fsg_buffhd *bh;
2721         struct fsg_lun *curlun;
2722         struct fsg_lun_config *lcfg;
2723         int nluns, i, rc;
2724         char *pathbuf;
2725
2726         rc = fsg_num_buffers_validate();
2727         if (rc != 0)
2728                 return ERR_PTR(rc);
2729
2730         /* Find out how many LUNs there should be */
2731         nluns = cfg->nluns;
2732         if (nluns < 1 || nluns > FSG_MAX_LUNS) {
2733                 dev_err(&gadget->dev, "invalid number of LUNs: %u\n", nluns);
2734                 return ERR_PTR(-EINVAL);
2735         }
2736
2737         /* Allocate? */
2738         if (!common) {
2739                 common = kzalloc(sizeof *common, GFP_KERNEL);
2740                 if (!common)
2741                         return ERR_PTR(-ENOMEM);
2742                 common->free_storage_on_release = 1;
2743         } else {
2744                 memset(common, 0, sizeof *common);
2745                 common->free_storage_on_release = 0;
2746         }
2747
2748         common->buffhds = kcalloc(fsg_num_buffers,
2749                                   sizeof *(common->buffhds), GFP_KERNEL);
2750         if (!common->buffhds) {
2751                 if (common->free_storage_on_release)
2752                         kfree(common);
2753                 return ERR_PTR(-ENOMEM);
2754         }
2755
2756         common->ops = cfg->ops;
2757         common->private_data = cfg->private_data;
2758
2759         common->gadget = gadget;
2760         common->ep0 = gadget->ep0;
2761         common->ep0req = cdev->req;
2762         common->cdev = cdev;
2763
2764         /* Maybe allocate device-global string IDs, and patch descriptors */
2765         if (fsg_strings[FSG_STRING_INTERFACE].id == 0) {
2766                 rc = usb_string_id(cdev);
2767                 if (unlikely(rc < 0))
2768                         goto error_release;
2769                 fsg_strings[FSG_STRING_INTERFACE].id = rc;
2770                 fsg_intf_desc.iInterface = rc;
2771         }
2772
2773         /*
2774          * Create the LUNs, open their backing files, and register the
2775          * LUN devices in sysfs.
2776          */
2777         curlun = kzalloc(nluns * sizeof *curlun, GFP_KERNEL);
2778         if (unlikely(!curlun)) {
2779                 rc = -ENOMEM;
2780                 goto error_release;
2781         }
2782         common->luns = curlun;
2783
2784         init_rwsem(&common->filesem);
2785
2786         for (i = 0, lcfg = cfg->luns; i < nluns; ++i, ++curlun, ++lcfg) {
2787                 curlun->cdrom = !!lcfg->cdrom;
2788                 curlun->ro = lcfg->cdrom || lcfg->ro;
2789                 curlun->initially_ro = curlun->ro;
2790                 curlun->removable = lcfg->removable;
2791                 curlun->dev.release = fsg_lun_release;
2792                 curlun->dev.parent = &gadget->dev;
2793                 /* curlun->dev.driver = &fsg_driver.driver; XXX */
2794                 dev_set_drvdata(&curlun->dev, &common->filesem);
2795                 dev_set_name(&curlun->dev,
2796                              cfg->lun_name_format
2797                            ? cfg->lun_name_format
2798                            : "lun%d",
2799                              i);
2800
2801                 rc = device_register(&curlun->dev);
2802                 if (rc) {
2803                         INFO(common, "failed to register LUN%d: %d\n", i, rc);
2804                         common->nluns = i;
2805                         put_device(&curlun->dev);
2806                         goto error_release;
2807                 }
2808
2809                 rc = device_create_file(&curlun->dev, &dev_attr_ro);
2810                 if (rc)
2811                         goto error_luns;
2812                 rc = device_create_file(&curlun->dev, &dev_attr_file);
2813                 if (rc)
2814                         goto error_luns;
2815                 rc = device_create_file(&curlun->dev, &dev_attr_nofua);
2816                 if (rc)
2817                         goto error_luns;
2818
2819                 if (lcfg->filename) {
2820                         rc = fsg_lun_open(curlun, lcfg->filename);
2821                         if (rc)
2822                                 goto error_luns;
2823                 } else if (!curlun->removable) {
2824                         ERROR(common, "no file given for LUN%d\n", i);
2825                         rc = -EINVAL;
2826                         goto error_luns;
2827                 }
2828         }
2829         common->nluns = nluns;
2830
2831         /* Data buffers cyclic list */
2832         bh = common->buffhds;
2833         i = fsg_num_buffers;
2834         goto buffhds_first_it;
2835         do {
2836                 bh->next = bh + 1;
2837                 ++bh;
2838 buffhds_first_it:
2839                 bh->buf = kmalloc(FSG_BUFLEN, GFP_KERNEL);
2840                 if (unlikely(!bh->buf)) {
2841                         rc = -ENOMEM;
2842                         goto error_release;
2843                 }
2844         } while (--i);
2845         bh->next = common->buffhds;
2846
2847         /* Prepare inquiryString */
2848         if (cfg->release != 0xffff) {
2849                 i = cfg->release;
2850         } else {
2851                 i = usb_gadget_controller_number(gadget);
2852                 if (i >= 0) {
2853                         i = 0x0300 + i;
2854                 } else {
2855                         WARNING(common, "controller '%s' not recognized\n",
2856                                 gadget->name);
2857                         i = 0x0399;
2858                 }
2859         }
2860         snprintf(common->inquiry_string, sizeof common->inquiry_string,
2861                  "%-8s%-16s%04x", cfg->vendor_name ?: "Linux",
2862                  /* Assume product name dependent on the first LUN */
2863                  cfg->product_name ?: (common->luns->cdrom
2864                                      ? "File-Stor Gadget"
2865                                      : "File-CD Gadget"),
2866                  i);
2867
2868         /*
2869          * Some peripheral controllers are known not to be able to
2870          * halt bulk endpoints correctly.  If one of them is present,
2871          * disable stalls.
2872          */
2873         common->can_stall = cfg->can_stall &&
2874                 !(gadget_is_at91(common->gadget));
2875
2876         spin_lock_init(&common->lock);