kill unused invalidate_inode_pages helper
[linux-2.6.git] / drivers / usb / gadget / f_mass_storage.c
1 /*
2  * f_mass_storage.c -- Mass Storage USB Composite Function
3  *
4  * Copyright (C) 2003-2008 Alan Stern
5  * Copyright (C) 2009 Samsung Electronics
6  *                    Author: Michal Nazarewicz <m.nazarewicz@samsung.com>
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions, and the following disclaimer,
14  *    without modification.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. The names of the above-listed copyright holders may not be used
19  *    to endorse or promote products derived from this software without
20  *    specific prior written permission.
21  *
22  * ALTERNATIVELY, this software may be distributed under the terms of the
23  * GNU General Public License ("GPL") as published by the Free Software
24  * Foundation, either version 2 of that License or (at your option) any
25  * later version.
26  *
27  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
28  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
29  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
30  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
31  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
32  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
33  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
34  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
35  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
36  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
37  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
38  */
39
40
41 /*
42  * The Mass Storage Function acts as a USB Mass Storage device,
43  * appearing to the host as a disk drive or as a CD-ROM drive.  In
44  * addition to providing an example of a genuinely useful composite
45  * function for a USB device, it also illustrates a technique of
46  * double-buffering for increased throughput.
47  *
48  * Function supports multiple logical units (LUNs).  Backing storage
49  * for each LUN is provided by a regular file or a block device.
50  * Access for each LUN can be limited to read-only.  Moreover, the
51  * function can indicate that LUN is removable and/or CD-ROM.  (The
52  * later implies read-only access.)
53  *
54  * MSF is configured by specifying a fsg_config structure.  It has the
55  * following fields:
56  *
57  *      nluns           Number of LUNs function have (anywhere from 1
58  *                              to FSG_MAX_LUNS which is 8).
59  *      luns            An array of LUN configuration values.  This
60  *                              should be filled for each LUN that
61  *                              function will include (ie. for "nluns"
62  *                              LUNs).  Each element of the array has
63  *                              the following fields:
64  *      ->filename      The path to the backing file for the LUN.
65  *                              Required if LUN is not marked as
66  *                              removable.
67  *      ->ro            Flag specifying access to the LUN shall be
68  *                              read-only.  This is implied if CD-ROM
69  *                              emulation is enabled as well as when
70  *                              it was impossible to open "filename"
71  *                              in R/W mode.
72  *      ->removable     Flag specifying that LUN shall be indicated as
73  *                              being removable.
74  *      ->cdrom         Flag specifying that LUN shall be reported as
75  *                              being a CD-ROM.
76  *
77  *      lun_name_format A printf-like format for names of the LUN
78  *                              devices.  This determines how the
79  *                              directory in sysfs will be named.
80  *                              Unless you are using several MSFs in
81  *                              a single gadget (as opposed to single
82  *                              MSF in many configurations) you may
83  *                              leave it as NULL (in which case
84  *                              "lun%d" will be used).  In the format
85  *                              you can use "%d" to index LUNs for
86  *                              MSF's with more than one LUN.  (Beware
87  *                              that there is only one integer given
88  *                              as an argument for the format and
89  *                              specifying invalid format may cause
90  *                              unspecified behaviour.)
91  *      thread_name     Name of the kernel thread process used by the
92  *                              MSF.  You can safely set it to NULL
93  *                              (in which case default "file-storage"
94  *                              will be used).
95  *
96  *      vendor_name
97  *      product_name
98  *      release         Information used as a reply to INQUIRY
99  *                              request.  To use default set to NULL,
100  *                              NULL, 0xffff respectively.  The first
101  *                              field should be 8 and the second 16
102  *                              characters or less.
103  *
104  *      can_stall       Set to permit function to halt bulk endpoints.
105  *                              Disabled on some USB devices known not
106  *                              to work correctly.  You should set it
107  *                              to true.
108  *
109  * If "removable" is not set for a LUN then a backing file must be
110  * specified.  If it is set, then NULL filename means the LUN's medium
111  * is not loaded (an empty string as "filename" in the fsg_config
112  * structure causes error).  The CD-ROM emulation includes a single
113  * data track and no audio tracks; hence there need be only one
114  * backing file per LUN.  Note also that the CD-ROM block length is
115  * set to 512 rather than the more common value 2048.
116  *
117  *
118  * MSF includes support for module parameters.  If gadget using it
119  * decides to use it, the following module parameters will be
120  * available:
121  *
122  *      file=filename[,filename...]
123  *                      Names of the files or block devices used for
124  *                              backing storage.
125  *      ro=b[,b...]     Default false, boolean for read-only access.
126  *      removable=b[,b...]
127  *                      Default true, boolean for removable media.
128  *      cdrom=b[,b...]  Default false, boolean for whether to emulate
129  *                              a CD-ROM drive.
130  *      luns=N          Default N = number of filenames, number of
131  *                              LUNs to support.
132  *      stall           Default determined according to the type of
133  *                              USB device controller (usually true),
134  *                              boolean to permit the driver to halt
135  *                              bulk endpoints.
136  *
137  * The module parameters may be prefixed with some string.  You need
138  * to consult gadget's documentation or source to verify whether it is
139  * using those module parameters and if it does what are the prefixes
140  * (look for FSG_MODULE_PARAMETERS() macro usage, what's inside it is
141  * the prefix).
142  *
143  *
144  * Requirements are modest; only a bulk-in and a bulk-out endpoint are
145  * needed.  The memory requirement amounts to two 16K buffers, size
146  * configurable by a parameter.  Support is included for both
147  * full-speed and high-speed operation.
148  *
149  * Note that the driver is slightly non-portable in that it assumes a
150  * single memory/DMA buffer will be useable for bulk-in, bulk-out, and
151  * interrupt-in endpoints.  With most device controllers this isn't an
152  * issue, but there may be some with hardware restrictions that prevent
153  * a buffer from being used by more than one endpoint.
154  *
155  *
156  * The pathnames of the backing files and the ro settings are
157  * available in the attribute files "file" and "ro" in the lun<n> (or
158  * to be more precise in a directory which name comes from
159  * "lun_name_format" option!) subdirectory of the gadget's sysfs
160  * directory.  If the "removable" option is set, writing to these
161  * files will simulate ejecting/loading the medium (writing an empty
162  * line means eject) and adjusting a write-enable tab.  Changes to the
163  * ro setting are not allowed when the medium is loaded or if CD-ROM
164  * emulation is being used.
165  *
166  *
167  * This function is heavily based on "File-backed Storage Gadget" by
168  * Alan Stern which in turn is heavily based on "Gadget Zero" by David
169  * Brownell.  The driver's SCSI command interface was based on the
170  * "Information technology - Small Computer System Interface - 2"
171  * document from X3T9.2 Project 375D, Revision 10L, 7-SEP-93,
172  * available at <http://www.t10.org/ftp/t10/drafts/s2/s2-r10l.pdf>.
173  * The single exception is opcode 0x23 (READ FORMAT CAPACITIES), which
174  * was based on the "Universal Serial Bus Mass Storage Class UFI
175  * Command Specification" document, Revision 1.0, December 14, 1998,
176  * available at
177  * <http://www.usb.org/developers/devclass_docs/usbmass-ufi10.pdf>.
178  */
179
180
181 /*
182  *                              Driver Design
183  *
184  * The MSF is fairly straightforward.  There is a main kernel
185  * thread that handles most of the work.  Interrupt routines field
186  * callbacks from the controller driver: bulk- and interrupt-request
187  * completion notifications, endpoint-0 events, and disconnect events.
188  * Completion events are passed to the main thread by wakeup calls.  Many
189  * ep0 requests are handled at interrupt time, but SetInterface,
190  * SetConfiguration, and device reset requests are forwarded to the
191  * thread in the form of "exceptions" using SIGUSR1 signals (since they
192  * should interrupt any ongoing file I/O operations).
193  *
194  * The thread's main routine implements the standard command/data/status
195  * parts of a SCSI interaction.  It and its subroutines are full of tests
196  * for pending signals/exceptions -- all this polling is necessary since
197  * the kernel has no setjmp/longjmp equivalents.  (Maybe this is an
198  * indication that the driver really wants to be running in userspace.)
199  * An important point is that so long as the thread is alive it keeps an
200  * open reference to the backing file.  This will prevent unmounting
201  * the backing file's underlying filesystem and could cause problems
202  * during system shutdown, for example.  To prevent such problems, the
203  * thread catches INT, TERM, and KILL signals and converts them into
204  * an EXIT exception.
205  *
206  * In normal operation the main thread is started during the gadget's
207  * fsg_bind() callback and stopped during fsg_unbind().  But it can
208  * also exit when it receives a signal, and there's no point leaving
209  * the gadget running when the thread is dead.  At of this moment, MSF
210  * provides no way to deregister the gadget when thread dies -- maybe
211  * a callback functions is needed.
212  *
213  * To provide maximum throughput, the driver uses a circular pipeline of
214  * buffer heads (struct fsg_buffhd).  In principle the pipeline can be
215  * arbitrarily long; in practice the benefits don't justify having more
216  * than 2 stages (i.e., double buffering).  But it helps to think of the
217  * pipeline as being a long one.  Each buffer head contains a bulk-in and
218  * a bulk-out request pointer (since the buffer can be used for both
219  * output and input -- directions always are given from the host's
220  * point of view) as well as a pointer to the buffer and various state
221  * variables.
222  *
223  * Use of the pipeline follows a simple protocol.  There is a variable
224  * (fsg->next_buffhd_to_fill) that points to the next buffer head to use.
225  * At any time that buffer head may still be in use from an earlier
226  * request, so each buffer head has a state variable indicating whether
227  * it is EMPTY, FULL, or BUSY.  Typical use involves waiting for the
228  * buffer head to be EMPTY, filling the buffer either by file I/O or by
229  * USB I/O (during which the buffer head is BUSY), and marking the buffer
230  * head FULL when the I/O is complete.  Then the buffer will be emptied
231  * (again possibly by USB I/O, during which it is marked BUSY) and
232  * finally marked EMPTY again (possibly by a completion routine).
233  *
234  * A module parameter tells the driver to avoid stalling the bulk
235  * endpoints wherever the transport specification allows.  This is
236  * necessary for some UDCs like the SuperH, which cannot reliably clear a
237  * halt on a bulk endpoint.  However, under certain circumstances the
238  * Bulk-only specification requires a stall.  In such cases the driver
239  * will halt the endpoint and set a flag indicating that it should clear
240  * the halt in software during the next device reset.  Hopefully this
241  * will permit everything to work correctly.  Furthermore, although the
242  * specification allows the bulk-out endpoint to halt when the host sends
243  * too much data, implementing this would cause an unavoidable race.
244  * The driver will always use the "no-stall" approach for OUT transfers.
245  *
246  * One subtle point concerns sending status-stage responses for ep0
247  * requests.  Some of these requests, such as device reset, can involve
248  * interrupting an ongoing file I/O operation, which might take an
249  * arbitrarily long time.  During that delay the host might give up on
250  * the original ep0 request and issue a new one.  When that happens the
251  * driver should not notify the host about completion of the original
252  * request, as the host will no longer be waiting for it.  So the driver
253  * assigns to each ep0 request a unique tag, and it keeps track of the
254  * tag value of the request associated with a long-running exception
255  * (device-reset, interface-change, or configuration-change).  When the
256  * exception handler is finished, the status-stage response is submitted
257  * only if the current ep0 request tag is equal to the exception request
258  * tag.  Thus only the most recently received ep0 request will get a
259  * status-stage response.
260  *
261  * Warning: This driver source file is too long.  It ought to be split up
262  * into a header file plus about 3 separate .c files, to handle the details
263  * of the Gadget, USB Mass Storage, and SCSI protocols.
264  */
265
266
267 /* #define VERBOSE_DEBUG */
268 /* #define DUMP_MSGS */
269
270
271 #include <linux/blkdev.h>
272 #include <linux/completion.h>
273 #include <linux/dcache.h>
274 #include <linux/delay.h>
275 #include <linux/device.h>
276 #include <linux/fcntl.h>
277 #include <linux/file.h>
278 #include <linux/fs.h>
279 #include <linux/kref.h>
280 #include <linux/kthread.h>
281 #include <linux/limits.h>
282 #include <linux/rwsem.h>
283 #include <linux/slab.h>
284 #include <linux/spinlock.h>
285 #include <linux/string.h>
286 #include <linux/freezer.h>
287 #include <linux/utsname.h>
288
289 #include <linux/usb/ch9.h>
290 #include <linux/usb/gadget.h>
291
292 #include "gadget_chips.h"
293
294
295
296 /*------------------------------------------------------------------------*/
297
298 #define FSG_DRIVER_DESC         "Mass Storage Function"
299 #define FSG_DRIVER_VERSION      "2009/09/11"
300
301 static const char fsg_string_interface[] = "Mass Storage";
302
303
304 #define FSG_NO_INTR_EP 1
305 #define FSG_BUFFHD_STATIC_BUFFER 1
306 #define FSG_NO_DEVICE_STRINGS    1
307 #define FSG_NO_OTG               1
308 #define FSG_NO_INTR_EP           1
309
310 #include "storage_common.c"
311
312
313 /*-------------------------------------------------------------------------*/
314
315 struct fsg_dev;
316
317
318 /* Data shared by all the FSG instances. */
319 struct fsg_common {
320         struct usb_gadget       *gadget;
321         struct fsg_dev          *fsg;
322         struct fsg_dev          *prev_fsg;
323
324         /* filesem protects: backing files in use */
325         struct rw_semaphore     filesem;
326
327         /* lock protects: state, all the req_busy's */
328         spinlock_t              lock;
329
330         struct usb_ep           *ep0;           /* Copy of gadget->ep0 */
331         struct usb_request      *ep0req;        /* Copy of cdev->req */
332         unsigned int            ep0_req_tag;
333         const char              *ep0req_name;
334
335         struct fsg_buffhd       *next_buffhd_to_fill;
336         struct fsg_buffhd       *next_buffhd_to_drain;
337         struct fsg_buffhd       buffhds[FSG_NUM_BUFFERS];
338
339         int                     cmnd_size;
340         u8                      cmnd[MAX_COMMAND_SIZE];
341
342         unsigned int            nluns;
343         unsigned int            lun;
344         struct fsg_lun          *luns;
345         struct fsg_lun          *curlun;
346
347         unsigned int            bulk_out_maxpacket;
348         enum fsg_state          state;          /* For exception handling */
349         unsigned int            exception_req_tag;
350
351         u8                      config, new_config;
352         enum data_direction     data_dir;
353         u32                     data_size;
354         u32                     data_size_from_cmnd;
355         u32                     tag;
356         u32                     residue;
357         u32                     usb_amount_left;
358
359         unsigned int            can_stall:1;
360         unsigned int            free_storage_on_release:1;
361         unsigned int            phase_error:1;
362         unsigned int            short_packet_received:1;
363         unsigned int            bad_lun_okay:1;
364         unsigned int            running:1;
365
366         int                     thread_wakeup_needed;
367         struct completion       thread_notifier;
368         struct task_struct      *thread_task;
369
370         /* Callback function to call when thread exits. */
371         void                    (*thread_exits)(struct fsg_common *common);
372         /* Gadget's private data. */
373         void                    *private_data;
374
375         /* Vendor (8 chars), product (16 chars), release (4
376          * hexadecimal digits) and NUL byte */
377         char inquiry_string[8 + 16 + 4 + 1];
378
379         struct kref             ref;
380 };
381
382
383 struct fsg_config {
384         unsigned nluns;
385         struct fsg_lun_config {
386                 const char *filename;
387                 char ro;
388                 char removable;
389                 char cdrom;
390         } luns[FSG_MAX_LUNS];
391
392         const char              *lun_name_format;
393         const char              *thread_name;
394
395         /* Callback function to call when thread exits. */
396         void                    (*thread_exits)(struct fsg_common *common);
397         /* Gadget's private data. */
398         void                    *private_data;
399
400         const char *vendor_name;                /*  8 characters or less */
401         const char *product_name;               /* 16 characters or less */
402         u16 release;
403
404         char                    can_stall;
405 };
406
407
408 struct fsg_dev {
409         struct usb_function     function;
410         struct usb_gadget       *gadget;        /* Copy of cdev->gadget */
411         struct fsg_common       *common;
412
413         u16                     interface_number;
414
415         unsigned int            bulk_in_enabled:1;
416         unsigned int            bulk_out_enabled:1;
417
418         unsigned long           atomic_bitflags;
419 #define IGNORE_BULK_OUT         0
420
421         struct usb_ep           *bulk_in;
422         struct usb_ep           *bulk_out;
423 };
424
425
426 static inline int __fsg_is_set(struct fsg_common *common,
427                                const char *func, unsigned line)
428 {
429         if (common->fsg)
430                 return 1;
431         ERROR(common, "common->fsg is NULL in %s at %u\n", func, line);
432         return 0;
433 }
434
435 #define fsg_is_set(common) likely(__fsg_is_set(common, __func__, __LINE__))
436
437
438 static inline struct fsg_dev *fsg_from_func(struct usb_function *f)
439 {
440         return container_of(f, struct fsg_dev, function);
441 }
442
443
444 typedef void (*fsg_routine_t)(struct fsg_dev *);
445
446 static int exception_in_progress(struct fsg_common *common)
447 {
448         return common->state > FSG_STATE_IDLE;
449 }
450
451 /* Make bulk-out requests be divisible by the maxpacket size */
452 static void set_bulk_out_req_length(struct fsg_common *common,
453                 struct fsg_buffhd *bh, unsigned int length)
454 {
455         unsigned int    rem;
456
457         bh->bulk_out_intended_length = length;
458         rem = length % common->bulk_out_maxpacket;
459         if (rem > 0)
460                 length += common->bulk_out_maxpacket - rem;
461         bh->outreq->length = length;
462 }
463
464 /*-------------------------------------------------------------------------*/
465
466 static int fsg_set_halt(struct fsg_dev *fsg, struct usb_ep *ep)
467 {
468         const char      *name;
469
470         if (ep == fsg->bulk_in)
471                 name = "bulk-in";
472         else if (ep == fsg->bulk_out)
473                 name = "bulk-out";
474         else
475                 name = ep->name;
476         DBG(fsg, "%s set halt\n", name);
477         return usb_ep_set_halt(ep);
478 }
479
480
481 /*-------------------------------------------------------------------------*/
482
483 /* These routines may be called in process context or in_irq */
484
485 /* Caller must hold fsg->lock */
486 static void wakeup_thread(struct fsg_common *common)
487 {
488         /* Tell the main thread that something has happened */
489         common->thread_wakeup_needed = 1;
490         if (common->thread_task)
491                 wake_up_process(common->thread_task);
492 }
493
494
495 static void raise_exception(struct fsg_common *common, enum fsg_state new_state)
496 {
497         unsigned long           flags;
498
499         /* Do nothing if a higher-priority exception is already in progress.
500          * If a lower-or-equal priority exception is in progress, preempt it
501          * and notify the main thread by sending it a signal. */
502         spin_lock_irqsave(&common->lock, flags);
503         if (common->state <= new_state) {
504                 common->exception_req_tag = common->ep0_req_tag;
505                 common->state = new_state;
506                 if (common->thread_task)
507                         send_sig_info(SIGUSR1, SEND_SIG_FORCED,
508                                       common->thread_task);
509         }
510         spin_unlock_irqrestore(&common->lock, flags);
511 }
512
513
514 /*-------------------------------------------------------------------------*/
515
516 static int ep0_queue(struct fsg_common *common)
517 {
518         int     rc;
519
520         rc = usb_ep_queue(common->ep0, common->ep0req, GFP_ATOMIC);
521         common->ep0->driver_data = common;
522         if (rc != 0 && rc != -ESHUTDOWN) {
523                 /* We can't do much more than wait for a reset */
524                 WARNING(common, "error in submission: %s --> %d\n",
525                         common->ep0->name, rc);
526         }
527         return rc;
528 }
529
530 /*-------------------------------------------------------------------------*/
531
532 /* Bulk and interrupt endpoint completion handlers.
533  * These always run in_irq. */
534
535 static void bulk_in_complete(struct usb_ep *ep, struct usb_request *req)
536 {
537         struct fsg_common       *common = ep->driver_data;
538         struct fsg_buffhd       *bh = req->context;
539
540         if (req->status || req->actual != req->length)
541                 DBG(common, "%s --> %d, %u/%u\n", __func__,
542                                 req->status, req->actual, req->length);
543         if (req->status == -ECONNRESET)         /* Request was cancelled */
544                 usb_ep_fifo_flush(ep);
545
546         /* Hold the lock while we update the request and buffer states */
547         smp_wmb();
548         spin_lock(&common->lock);
549         bh->inreq_busy = 0;
550         bh->state = BUF_STATE_EMPTY;
551         wakeup_thread(common);
552         spin_unlock(&common->lock);
553 }
554
555 static void bulk_out_complete(struct usb_ep *ep, struct usb_request *req)
556 {
557         struct fsg_common       *common = ep->driver_data;
558         struct fsg_buffhd       *bh = req->context;
559
560         dump_msg(common, "bulk-out", req->buf, req->actual);
561         if (req->status || req->actual != bh->bulk_out_intended_length)
562                 DBG(common, "%s --> %d, %u/%u\n", __func__,
563                                 req->status, req->actual,
564                                 bh->bulk_out_intended_length);
565         if (req->status == -ECONNRESET)         /* Request was cancelled */
566                 usb_ep_fifo_flush(ep);
567
568         /* Hold the lock while we update the request and buffer states */
569         smp_wmb();
570         spin_lock(&common->lock);
571         bh->outreq_busy = 0;
572         bh->state = BUF_STATE_FULL;
573         wakeup_thread(common);
574         spin_unlock(&common->lock);
575 }
576
577
578 /*-------------------------------------------------------------------------*/
579
580 /* Ep0 class-specific handlers.  These always run in_irq. */
581
582 static int fsg_setup(struct usb_function *f,
583                 const struct usb_ctrlrequest *ctrl)
584 {
585         struct fsg_dev          *fsg = fsg_from_func(f);
586         struct usb_request      *req = fsg->common->ep0req;
587         u16                     w_index = le16_to_cpu(ctrl->wIndex);
588         u16                     w_value = le16_to_cpu(ctrl->wValue);
589         u16                     w_length = le16_to_cpu(ctrl->wLength);
590
591         if (!fsg->common->config)
592                 return -EOPNOTSUPP;
593
594         switch (ctrl->bRequest) {
595
596         case USB_BULK_RESET_REQUEST:
597                 if (ctrl->bRequestType !=
598                     (USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE))
599                         break;
600                 if (w_index != fsg->interface_number || w_value != 0)
601                         return -EDOM;
602
603                 /* Raise an exception to stop the current operation
604                  * and reinitialize our state. */
605                 DBG(fsg, "bulk reset request\n");
606                 raise_exception(fsg->common, FSG_STATE_RESET);
607                 return DELAYED_STATUS;
608
609         case USB_BULK_GET_MAX_LUN_REQUEST:
610                 if (ctrl->bRequestType !=
611                     (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE))
612                         break;
613                 if (w_index != fsg->interface_number || w_value != 0)
614                         return -EDOM;
615                 VDBG(fsg, "get max LUN\n");
616                 *(u8 *) req->buf = fsg->common->nluns - 1;
617                 return 1;
618         }
619
620         VDBG(fsg,
621              "unknown class-specific control req "
622              "%02x.%02x v%04x i%04x l%u\n",
623              ctrl->bRequestType, ctrl->bRequest,
624              le16_to_cpu(ctrl->wValue), w_index, w_length);
625         return -EOPNOTSUPP;
626 }
627
628
629 /*-------------------------------------------------------------------------*/
630
631 /* All the following routines run in process context */
632
633
634 /* Use this for bulk or interrupt transfers, not ep0 */
635 static void start_transfer(struct fsg_dev *fsg, struct usb_ep *ep,
636                 struct usb_request *req, int *pbusy,
637                 enum fsg_buffer_state *state)
638 {
639         int     rc;
640
641         if (ep == fsg->bulk_in)
642                 dump_msg(fsg, "bulk-in", req->buf, req->length);
643
644         spin_lock_irq(&fsg->common->lock);
645         *pbusy = 1;
646         *state = BUF_STATE_BUSY;
647         spin_unlock_irq(&fsg->common->lock);
648         rc = usb_ep_queue(ep, req, GFP_KERNEL);
649         if (rc != 0) {
650                 *pbusy = 0;
651                 *state = BUF_STATE_EMPTY;
652
653                 /* We can't do much more than wait for a reset */
654
655                 /* Note: currently the net2280 driver fails zero-length
656                  * submissions if DMA is enabled. */
657                 if (rc != -ESHUTDOWN && !(rc == -EOPNOTSUPP &&
658                                                 req->length == 0))
659                         WARNING(fsg, "error in submission: %s --> %d\n",
660                                         ep->name, rc);
661         }
662 }
663
664 #define START_TRANSFER_OR(common, ep_name, req, pbusy, state)           \
665         if (fsg_is_set(common))                                         \
666                 start_transfer((common)->fsg, (common)->fsg->ep_name,   \
667                                req, pbusy, state);                      \
668         else
669
670 #define START_TRANSFER(common, ep_name, req, pbusy, state)              \
671         START_TRANSFER_OR(common, ep_name, req, pbusy, state) (void)0
672
673
674
675 static int sleep_thread(struct fsg_common *common)
676 {
677         int     rc = 0;
678
679         /* Wait until a signal arrives or we are woken up */
680         for (;;) {
681                 try_to_freeze();
682                 set_current_state(TASK_INTERRUPTIBLE);
683                 if (signal_pending(current)) {
684                         rc = -EINTR;
685                         break;
686                 }
687                 if (common->thread_wakeup_needed)
688                         break;
689                 schedule();
690         }
691         __set_current_state(TASK_RUNNING);
692         common->thread_wakeup_needed = 0;
693         return rc;
694 }
695
696
697 /*-------------------------------------------------------------------------*/
698
699 static int do_read(struct fsg_common *common)
700 {
701         struct fsg_lun          *curlun = common->curlun;
702         u32                     lba;
703         struct fsg_buffhd       *bh;
704         int                     rc;
705         u32                     amount_left;
706         loff_t                  file_offset, file_offset_tmp;
707         unsigned int            amount;
708         unsigned int            partial_page;
709         ssize_t                 nread;
710
711         /* Get the starting Logical Block Address and check that it's
712          * not too big */
713         if (common->cmnd[0] == SC_READ_6)
714                 lba = get_unaligned_be24(&common->cmnd[1]);
715         else {
716                 lba = get_unaligned_be32(&common->cmnd[2]);
717
718                 /* We allow DPO (Disable Page Out = don't save data in the
719                  * cache) and FUA (Force Unit Access = don't read from the
720                  * cache), but we don't implement them. */
721                 if ((common->cmnd[1] & ~0x18) != 0) {
722                         curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
723                         return -EINVAL;
724                 }
725         }
726         if (lba >= curlun->num_sectors) {
727                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
728                 return -EINVAL;
729         }
730         file_offset = ((loff_t) lba) << 9;
731
732         /* Carry out the file reads */
733         amount_left = common->data_size_from_cmnd;
734         if (unlikely(amount_left == 0))
735                 return -EIO;            /* No default reply */
736
737         for (;;) {
738
739                 /* Figure out how much we need to read:
740                  * Try to read the remaining amount.
741                  * But don't read more than the buffer size.
742                  * And don't try to read past the end of the file.
743                  * Finally, if we're not at a page boundary, don't read past
744                  *      the next page.
745                  * If this means reading 0 then we were asked to read past
746                  *      the end of file. */
747                 amount = min(amount_left, FSG_BUFLEN);
748                 amount = min((loff_t) amount,
749                                 curlun->file_length - file_offset);
750                 partial_page = file_offset & (PAGE_CACHE_SIZE - 1);
751                 if (partial_page > 0)
752                         amount = min(amount, (unsigned int) PAGE_CACHE_SIZE -
753                                         partial_page);
754
755                 /* Wait for the next buffer to become available */
756                 bh = common->next_buffhd_to_fill;
757                 while (bh->state != BUF_STATE_EMPTY) {
758                         rc = sleep_thread(common);
759                         if (rc)
760                                 return rc;
761                 }
762
763                 /* If we were asked to read past the end of file,
764                  * end with an empty buffer. */
765                 if (amount == 0) {
766                         curlun->sense_data =
767                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
768                         curlun->sense_data_info = file_offset >> 9;
769                         curlun->info_valid = 1;
770                         bh->inreq->length = 0;
771                         bh->state = BUF_STATE_FULL;
772                         break;
773                 }
774
775                 /* Perform the read */
776                 file_offset_tmp = file_offset;
777                 nread = vfs_read(curlun->filp,
778                                 (char __user *) bh->buf,
779                                 amount, &file_offset_tmp);
780                 VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
781                                 (unsigned long long) file_offset,
782                                 (int) nread);
783                 if (signal_pending(current))
784                         return -EINTR;
785
786                 if (nread < 0) {
787                         LDBG(curlun, "error in file read: %d\n",
788                                         (int) nread);
789                         nread = 0;
790                 } else if (nread < amount) {
791                         LDBG(curlun, "partial file read: %d/%u\n",
792                                         (int) nread, amount);
793                         nread -= (nread & 511); /* Round down to a block */
794                 }
795                 file_offset  += nread;
796                 amount_left  -= nread;
797                 common->residue -= nread;
798                 bh->inreq->length = nread;
799                 bh->state = BUF_STATE_FULL;
800
801                 /* If an error occurred, report it and its position */
802                 if (nread < amount) {
803                         curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
804                         curlun->sense_data_info = file_offset >> 9;
805                         curlun->info_valid = 1;
806                         break;
807                 }
808
809                 if (amount_left == 0)
810                         break;          /* No more left to read */
811
812                 /* Send this buffer and go read some more */
813                 bh->inreq->zero = 0;
814                 START_TRANSFER_OR(common, bulk_in, bh->inreq,
815                                &bh->inreq_busy, &bh->state)
816                         /* Don't know what to do if
817                          * common->fsg is NULL */
818                         return -EIO;
819                 common->next_buffhd_to_fill = bh->next;
820         }
821
822         return -EIO;            /* No default reply */
823 }
824
825
826 /*-------------------------------------------------------------------------*/
827
828 static int do_write(struct fsg_common *common)
829 {
830         struct fsg_lun          *curlun = common->curlun;
831         u32                     lba;
832         struct fsg_buffhd       *bh;
833         int                     get_some_more;
834         u32                     amount_left_to_req, amount_left_to_write;
835         loff_t                  usb_offset, file_offset, file_offset_tmp;
836         unsigned int            amount;
837         unsigned int            partial_page;
838         ssize_t                 nwritten;
839         int                     rc;
840
841         if (curlun->ro) {
842                 curlun->sense_data = SS_WRITE_PROTECTED;
843                 return -EINVAL;
844         }
845         spin_lock(&curlun->filp->f_lock);
846         curlun->filp->f_flags &= ~O_SYNC;       /* Default is not to wait */
847         spin_unlock(&curlun->filp->f_lock);
848
849         /* Get the starting Logical Block Address and check that it's
850          * not too big */
851         if (common->cmnd[0] == SC_WRITE_6)
852                 lba = get_unaligned_be24(&common->cmnd[1]);
853         else {
854                 lba = get_unaligned_be32(&common->cmnd[2]);
855
856                 /* We allow DPO (Disable Page Out = don't save data in the
857                  * cache) and FUA (Force Unit Access = write directly to the
858                  * medium).  We don't implement DPO; we implement FUA by
859                  * performing synchronous output. */
860                 if (common->cmnd[1] & ~0x18) {
861                         curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
862                         return -EINVAL;
863                 }
864                 if (common->cmnd[1] & 0x08) {   /* FUA */
865                         spin_lock(&curlun->filp->f_lock);
866                         curlun->filp->f_flags |= O_SYNC;
867                         spin_unlock(&curlun->filp->f_lock);
868                 }
869         }
870         if (lba >= curlun->num_sectors) {
871                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
872                 return -EINVAL;
873         }
874
875         /* Carry out the file writes */
876         get_some_more = 1;
877         file_offset = usb_offset = ((loff_t) lba) << 9;
878         amount_left_to_req = common->data_size_from_cmnd;
879         amount_left_to_write = common->data_size_from_cmnd;
880
881         while (amount_left_to_write > 0) {
882
883                 /* Queue a request for more data from the host */
884                 bh = common->next_buffhd_to_fill;
885                 if (bh->state == BUF_STATE_EMPTY && get_some_more) {
886
887                         /* Figure out how much we want to get:
888                          * Try to get the remaining amount.
889                          * But don't get more than the buffer size.
890                          * And don't try to go past the end of the file.
891                          * If we're not at a page boundary,
892                          *      don't go past the next page.
893                          * If this means getting 0, then we were asked
894                          *      to write past the end of file.
895                          * Finally, round down to a block boundary. */
896                         amount = min(amount_left_to_req, FSG_BUFLEN);
897                         amount = min((loff_t) amount, curlun->file_length -
898                                         usb_offset);
899                         partial_page = usb_offset & (PAGE_CACHE_SIZE - 1);
900                         if (partial_page > 0)
901                                 amount = min(amount,
902         (unsigned int) PAGE_CACHE_SIZE - partial_page);
903
904                         if (amount == 0) {
905                                 get_some_more = 0;
906                                 curlun->sense_data =
907                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
908                                 curlun->sense_data_info = usb_offset >> 9;
909                                 curlun->info_valid = 1;
910                                 continue;
911                         }
912                         amount -= (amount & 511);
913                         if (amount == 0) {
914
915                                 /* Why were we were asked to transfer a
916                                  * partial block? */
917                                 get_some_more = 0;
918                                 continue;
919                         }
920
921                         /* Get the next buffer */
922                         usb_offset += amount;
923                         common->usb_amount_left -= amount;
924                         amount_left_to_req -= amount;
925                         if (amount_left_to_req == 0)
926                                 get_some_more = 0;
927
928                         /* amount is always divisible by 512, hence by
929                          * the bulk-out maxpacket size */
930                         bh->outreq->length = amount;
931                         bh->bulk_out_intended_length = amount;
932                         bh->outreq->short_not_ok = 1;
933                         START_TRANSFER_OR(common, bulk_out, bh->outreq,
934                                           &bh->outreq_busy, &bh->state)
935                                 /* Don't know what to do if
936                                  * common->fsg is NULL */
937                                 return -EIO;
938                         common->next_buffhd_to_fill = bh->next;
939                         continue;
940                 }
941
942                 /* Write the received data to the backing file */
943                 bh = common->next_buffhd_to_drain;
944                 if (bh->state == BUF_STATE_EMPTY && !get_some_more)
945                         break;                  /* We stopped early */
946                 if (bh->state == BUF_STATE_FULL) {
947                         smp_rmb();
948                         common->next_buffhd_to_drain = bh->next;
949                         bh->state = BUF_STATE_EMPTY;
950
951                         /* Did something go wrong with the transfer? */
952                         if (bh->outreq->status != 0) {
953                                 curlun->sense_data = SS_COMMUNICATION_FAILURE;
954                                 curlun->sense_data_info = file_offset >> 9;
955                                 curlun->info_valid = 1;
956                                 break;
957                         }
958
959                         amount = bh->outreq->actual;
960                         if (curlun->file_length - file_offset < amount) {
961                                 LERROR(curlun,
962         "write %u @ %llu beyond end %llu\n",
963         amount, (unsigned long long) file_offset,
964         (unsigned long long) curlun->file_length);
965                                 amount = curlun->file_length - file_offset;
966                         }
967
968                         /* Perform the write */
969                         file_offset_tmp = file_offset;
970                         nwritten = vfs_write(curlun->filp,
971                                         (char __user *) bh->buf,
972                                         amount, &file_offset_tmp);
973                         VLDBG(curlun, "file write %u @ %llu -> %d\n", amount,
974                                         (unsigned long long) file_offset,
975                                         (int) nwritten);
976                         if (signal_pending(current))
977                                 return -EINTR;          /* Interrupted! */
978
979                         if (nwritten < 0) {
980                                 LDBG(curlun, "error in file write: %d\n",
981                                                 (int) nwritten);
982                                 nwritten = 0;
983                         } else if (nwritten < amount) {
984                                 LDBG(curlun, "partial file write: %d/%u\n",
985                                                 (int) nwritten, amount);
986                                 nwritten -= (nwritten & 511);
987                                 /* Round down to a block */
988                         }
989                         file_offset += nwritten;
990                         amount_left_to_write -= nwritten;
991                         common->residue -= nwritten;
992
993                         /* If an error occurred, report it and its position */
994                         if (nwritten < amount) {
995                                 curlun->sense_data = SS_WRITE_ERROR;
996                                 curlun->sense_data_info = file_offset >> 9;
997                                 curlun->info_valid = 1;
998                                 break;
999                         }
1000
1001                         /* Did the host decide to stop early? */
1002                         if (bh->outreq->actual != bh->outreq->length) {
1003                                 common->short_packet_received = 1;
1004                                 break;
1005                         }
1006                         continue;
1007                 }
1008
1009                 /* Wait for something to happen */
1010                 rc = sleep_thread(common);
1011                 if (rc)
1012                         return rc;
1013         }
1014
1015         return -EIO;            /* No default reply */
1016 }
1017
1018
1019 /*-------------------------------------------------------------------------*/
1020
1021 static int do_synchronize_cache(struct fsg_common *common)
1022 {
1023         struct fsg_lun  *curlun = common->curlun;
1024         int             rc;
1025
1026         /* We ignore the requested LBA and write out all file's
1027          * dirty data buffers. */
1028         rc = fsg_lun_fsync_sub(curlun);
1029         if (rc)
1030                 curlun->sense_data = SS_WRITE_ERROR;
1031         return 0;
1032 }
1033
1034
1035 /*-------------------------------------------------------------------------*/
1036
1037 static void invalidate_sub(struct fsg_lun *curlun)
1038 {
1039         struct file     *filp = curlun->filp;
1040         struct inode    *inode = filp->f_path.dentry->d_inode;
1041         unsigned long   rc;
1042
1043         rc = invalidate_mapping_pages(inode->i_mapping, 0, -1);
1044         VLDBG(curlun, "invalidate_mapping_pages -> %ld\n", rc);
1045 }
1046
1047 static int do_verify(struct fsg_common *common)
1048 {
1049         struct fsg_lun          *curlun = common->curlun;
1050         u32                     lba;
1051         u32                     verification_length;
1052         struct fsg_buffhd       *bh = common->next_buffhd_to_fill;
1053         loff_t                  file_offset, file_offset_tmp;
1054         u32                     amount_left;
1055         unsigned int            amount;
1056         ssize_t                 nread;
1057
1058         /* Get the starting Logical Block Address and check that it's
1059          * not too big */
1060         lba = get_unaligned_be32(&common->cmnd[2]);
1061         if (lba >= curlun->num_sectors) {
1062                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1063                 return -EINVAL;
1064         }
1065
1066         /* We allow DPO (Disable Page Out = don't save data in the
1067          * cache) but we don't implement it. */
1068         if (common->cmnd[1] & ~0x10) {
1069                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1070                 return -EINVAL;
1071         }
1072
1073         verification_length = get_unaligned_be16(&common->cmnd[7]);
1074         if (unlikely(verification_length == 0))
1075                 return -EIO;            /* No default reply */
1076
1077         /* Prepare to carry out the file verify */
1078         amount_left = verification_length << 9;
1079         file_offset = ((loff_t) lba) << 9;
1080
1081         /* Write out all the dirty buffers before invalidating them */
1082         fsg_lun_fsync_sub(curlun);
1083         if (signal_pending(current))
1084                 return -EINTR;
1085
1086         invalidate_sub(curlun);
1087         if (signal_pending(current))
1088                 return -EINTR;
1089
1090         /* Just try to read the requested blocks */
1091         while (amount_left > 0) {
1092
1093                 /* Figure out how much we need to read:
1094                  * Try to read the remaining amount, but not more than
1095                  * the buffer size.
1096                  * And don't try to read past the end of the file.
1097                  * If this means reading 0 then we were asked to read
1098                  * past the end of file. */
1099                 amount = min(amount_left, FSG_BUFLEN);
1100                 amount = min((loff_t) amount,
1101                                 curlun->file_length - file_offset);
1102                 if (amount == 0) {
1103                         curlun->sense_data =
1104                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1105                         curlun->sense_data_info = file_offset >> 9;
1106                         curlun->info_valid = 1;
1107                         break;
1108                 }
1109
1110                 /* Perform the read */
1111                 file_offset_tmp = file_offset;
1112                 nread = vfs_read(curlun->filp,
1113                                 (char __user *) bh->buf,
1114                                 amount, &file_offset_tmp);
1115                 VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
1116                                 (unsigned long long) file_offset,
1117                                 (int) nread);
1118                 if (signal_pending(current))
1119                         return -EINTR;
1120
1121                 if (nread < 0) {
1122                         LDBG(curlun, "error in file verify: %d\n",
1123                                         (int) nread);
1124                         nread = 0;
1125                 } else if (nread < amount) {
1126                         LDBG(curlun, "partial file verify: %d/%u\n",
1127                                         (int) nread, amount);
1128                         nread -= (nread & 511); /* Round down to a sector */
1129                 }
1130                 if (nread == 0) {
1131                         curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
1132                         curlun->sense_data_info = file_offset >> 9;
1133                         curlun->info_valid = 1;
1134                         break;
1135                 }
1136                 file_offset += nread;
1137                 amount_left -= nread;
1138         }
1139         return 0;
1140 }
1141
1142
1143 /*-------------------------------------------------------------------------*/
1144
1145 static int do_inquiry(struct fsg_common *common, struct fsg_buffhd *bh)
1146 {
1147         struct fsg_lun *curlun = common->curlun;
1148         u8      *buf = (u8 *) bh->buf;
1149
1150         if (!curlun) {          /* Unsupported LUNs are okay */
1151                 common->bad_lun_okay = 1;
1152                 memset(buf, 0, 36);
1153                 buf[0] = 0x7f;          /* Unsupported, no device-type */
1154                 buf[4] = 31;            /* Additional length */
1155                 return 36;
1156         }
1157
1158         buf[0] = curlun->cdrom ? TYPE_CDROM : TYPE_DISK;
1159         buf[1] = curlun->removable ? 0x80 : 0;
1160         buf[2] = 2;             /* ANSI SCSI level 2 */
1161         buf[3] = 2;             /* SCSI-2 INQUIRY data format */
1162         buf[4] = 31;            /* Additional length */
1163         buf[5] = 0;             /* No special options */
1164         buf[6] = 0;
1165         buf[7] = 0;
1166         memcpy(buf + 8, common->inquiry_string, sizeof common->inquiry_string);
1167         return 36;
1168 }
1169
1170
1171 static int do_request_sense(struct fsg_common *common, struct fsg_buffhd *bh)
1172 {
1173         struct fsg_lun  *curlun = common->curlun;
1174         u8              *buf = (u8 *) bh->buf;
1175         u32             sd, sdinfo;
1176         int             valid;
1177
1178         /*
1179          * From the SCSI-2 spec., section 7.9 (Unit attention condition):
1180          *
1181          * If a REQUEST SENSE command is received from an initiator
1182          * with a pending unit attention condition (before the target
1183          * generates the contingent allegiance condition), then the
1184          * target shall either:
1185          *   a) report any pending sense data and preserve the unit
1186          *      attention condition on the logical unit, or,
1187          *   b) report the unit attention condition, may discard any
1188          *      pending sense data, and clear the unit attention
1189          *      condition on the logical unit for that initiator.
1190          *
1191          * FSG normally uses option a); enable this code to use option b).
1192          */
1193 #if 0
1194         if (curlun && curlun->unit_attention_data != SS_NO_SENSE) {
1195                 curlun->sense_data = curlun->unit_attention_data;
1196                 curlun->unit_attention_data = SS_NO_SENSE;
1197         }
1198 #endif
1199
1200         if (!curlun) {          /* Unsupported LUNs are okay */
1201                 common->bad_lun_okay = 1;
1202                 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
1203                 sdinfo = 0;
1204                 valid = 0;
1205         } else {
1206                 sd = curlun->sense_data;
1207                 sdinfo = curlun->sense_data_info;
1208                 valid = curlun->info_valid << 7;
1209                 curlun->sense_data = SS_NO_SENSE;
1210                 curlun->sense_data_info = 0;
1211                 curlun->info_valid = 0;
1212         }
1213
1214         memset(buf, 0, 18);
1215         buf[0] = valid | 0x70;                  /* Valid, current error */
1216         buf[2] = SK(sd);
1217         put_unaligned_be32(sdinfo, &buf[3]);    /* Sense information */
1218         buf[7] = 18 - 8;                        /* Additional sense length */
1219         buf[12] = ASC(sd);
1220         buf[13] = ASCQ(sd);
1221         return 18;
1222 }
1223
1224
1225 static int do_read_capacity(struct fsg_common *common, struct fsg_buffhd *bh)
1226 {
1227         struct fsg_lun  *curlun = common->curlun;
1228         u32             lba = get_unaligned_be32(&common->cmnd[2]);
1229         int             pmi = common->cmnd[8];
1230         u8              *buf = (u8 *) bh->buf;
1231
1232         /* Check the PMI and LBA fields */
1233         if (pmi > 1 || (pmi == 0 && lba != 0)) {
1234                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1235                 return -EINVAL;
1236         }
1237
1238         put_unaligned_be32(curlun->num_sectors - 1, &buf[0]);
1239                                                 /* Max logical block */
1240         put_unaligned_be32(512, &buf[4]);       /* Block length */
1241         return 8;
1242 }
1243
1244
1245 static int do_read_header(struct fsg_common *common, struct fsg_buffhd *bh)
1246 {
1247         struct fsg_lun  *curlun = common->curlun;
1248         int             msf = common->cmnd[1] & 0x02;
1249         u32             lba = get_unaligned_be32(&common->cmnd[2]);
1250         u8              *buf = (u8 *) bh->buf;
1251
1252         if (common->cmnd[1] & ~0x02) {          /* Mask away MSF */
1253                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1254                 return -EINVAL;
1255         }
1256         if (lba >= curlun->num_sectors) {
1257                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1258                 return -EINVAL;
1259         }
1260
1261         memset(buf, 0, 8);
1262         buf[0] = 0x01;          /* 2048 bytes of user data, rest is EC */
1263         store_cdrom_address(&buf[4], msf, lba);
1264         return 8;
1265 }
1266
1267
1268 static int do_read_toc(struct fsg_common *common, struct fsg_buffhd *bh)
1269 {
1270         struct fsg_lun  *curlun = common->curlun;
1271         int             msf = common->cmnd[1] & 0x02;
1272         int             start_track = common->cmnd[6];
1273         u8              *buf = (u8 *) bh->buf;
1274
1275         if ((common->cmnd[1] & ~0x02) != 0 ||   /* Mask away MSF */
1276                         start_track > 1) {
1277                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1278                 return -EINVAL;
1279         }
1280
1281         memset(buf, 0, 20);
1282         buf[1] = (20-2);                /* TOC data length */
1283         buf[2] = 1;                     /* First track number */
1284         buf[3] = 1;                     /* Last track number */
1285         buf[5] = 0x16;                  /* Data track, copying allowed */
1286         buf[6] = 0x01;                  /* Only track is number 1 */
1287         store_cdrom_address(&buf[8], msf, 0);
1288
1289         buf[13] = 0x16;                 /* Lead-out track is data */
1290         buf[14] = 0xAA;                 /* Lead-out track number */
1291         store_cdrom_address(&buf[16], msf, curlun->num_sectors);
1292         return 20;
1293 }
1294
1295
1296 static int do_mode_sense(struct fsg_common *common, struct fsg_buffhd *bh)
1297 {
1298         struct fsg_lun  *curlun = common->curlun;
1299         int             mscmnd = common->cmnd[0];
1300         u8              *buf = (u8 *) bh->buf;
1301         u8              *buf0 = buf;
1302         int             pc, page_code;
1303         int             changeable_values, all_pages;
1304         int             valid_page = 0;
1305         int             len, limit;
1306
1307         if ((common->cmnd[1] & ~0x08) != 0) {   /* Mask away DBD */
1308                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1309                 return -EINVAL;
1310         }
1311         pc = common->cmnd[2] >> 6;
1312         page_code = common->cmnd[2] & 0x3f;
1313         if (pc == 3) {
1314                 curlun->sense_data = SS_SAVING_PARAMETERS_NOT_SUPPORTED;
1315                 return -EINVAL;
1316         }
1317         changeable_values = (pc == 1);
1318         all_pages = (page_code == 0x3f);
1319
1320         /* Write the mode parameter header.  Fixed values are: default
1321          * medium type, no cache control (DPOFUA), and no block descriptors.
1322          * The only variable value is the WriteProtect bit.  We will fill in
1323          * the mode data length later. */
1324         memset(buf, 0, 8);
1325         if (mscmnd == SC_MODE_SENSE_6) {
1326                 buf[2] = (curlun->ro ? 0x80 : 0x00);            /* WP, DPOFUA */
1327                 buf += 4;
1328                 limit = 255;
1329         } else {                        /* SC_MODE_SENSE_10 */
1330                 buf[3] = (curlun->ro ? 0x80 : 0x00);            /* WP, DPOFUA */
1331                 buf += 8;
1332                 limit = 65535;          /* Should really be FSG_BUFLEN */
1333         }
1334
1335         /* No block descriptors */
1336
1337         /* The mode pages, in numerical order.  The only page we support
1338          * is the Caching page. */
1339         if (page_code == 0x08 || all_pages) {
1340                 valid_page = 1;
1341                 buf[0] = 0x08;          /* Page code */
1342                 buf[1] = 10;            /* Page length */
1343                 memset(buf+2, 0, 10);   /* None of the fields are changeable */
1344
1345                 if (!changeable_values) {
1346                         buf[2] = 0x04;  /* Write cache enable, */
1347                                         /* Read cache not disabled */
1348                                         /* No cache retention priorities */
1349                         put_unaligned_be16(0xffff, &buf[4]);
1350                                         /* Don't disable prefetch */
1351                                         /* Minimum prefetch = 0 */
1352                         put_unaligned_be16(0xffff, &buf[8]);
1353                                         /* Maximum prefetch */
1354                         put_unaligned_be16(0xffff, &buf[10]);
1355                                         /* Maximum prefetch ceiling */
1356                 }
1357                 buf += 12;
1358         }
1359
1360         /* Check that a valid page was requested and the mode data length
1361          * isn't too long. */
1362         len = buf - buf0;
1363         if (!valid_page || len > limit) {
1364                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1365                 return -EINVAL;
1366         }
1367
1368         /*  Store the mode data length */
1369         if (mscmnd == SC_MODE_SENSE_6)
1370                 buf0[0] = len - 1;
1371         else
1372                 put_unaligned_be16(len - 2, buf0);
1373         return len;
1374 }
1375
1376
1377 static int do_start_stop(struct fsg_common *common)
1378 {
1379         if (!common->curlun) {
1380                 return -EINVAL;
1381         } else if (!common->curlun->removable) {
1382                 common->curlun->sense_data = SS_INVALID_COMMAND;
1383                 return -EINVAL;
1384         }
1385         return 0;
1386 }
1387
1388
1389 static int do_prevent_allow(struct fsg_common *common)
1390 {
1391         struct fsg_lun  *curlun = common->curlun;
1392         int             prevent;
1393
1394         if (!common->curlun) {
1395                 return -EINVAL;
1396         } else if (!common->curlun->removable) {
1397                 common->curlun->sense_data = SS_INVALID_COMMAND;
1398                 return -EINVAL;
1399         }
1400
1401         prevent = common->cmnd[4] & 0x01;
1402         if ((common->cmnd[4] & ~0x01) != 0) {   /* Mask away Prevent */
1403                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1404                 return -EINVAL;
1405         }
1406
1407         if (curlun->prevent_medium_removal && !prevent)
1408                 fsg_lun_fsync_sub(curlun);
1409         curlun->prevent_medium_removal = prevent;
1410         return 0;
1411 }
1412
1413
1414 static int do_read_format_capacities(struct fsg_common *common,
1415                         struct fsg_buffhd *bh)
1416 {
1417         struct fsg_lun  *curlun = common->curlun;
1418         u8              *buf = (u8 *) bh->buf;
1419
1420         buf[0] = buf[1] = buf[2] = 0;
1421         buf[3] = 8;     /* Only the Current/Maximum Capacity Descriptor */
1422         buf += 4;
1423
1424         put_unaligned_be32(curlun->num_sectors, &buf[0]);
1425                                                 /* Number of blocks */
1426         put_unaligned_be32(512, &buf[4]);       /* Block length */
1427         buf[4] = 0x02;                          /* Current capacity */
1428         return 12;
1429 }
1430
1431
1432 static int do_mode_select(struct fsg_common *common, struct fsg_buffhd *bh)
1433 {
1434         struct fsg_lun  *curlun = common->curlun;
1435
1436         /* We don't support MODE SELECT */
1437         if (curlun)
1438                 curlun->sense_data = SS_INVALID_COMMAND;
1439         return -EINVAL;
1440 }
1441
1442
1443 /*-------------------------------------------------------------------------*/
1444
1445 static int halt_bulk_in_endpoint(struct fsg_dev *fsg)
1446 {
1447         int     rc;
1448
1449         rc = fsg_set_halt(fsg, fsg->bulk_in);
1450         if (rc == -EAGAIN)
1451                 VDBG(fsg, "delayed bulk-in endpoint halt\n");
1452         while (rc != 0) {
1453                 if (rc != -EAGAIN) {
1454                         WARNING(fsg, "usb_ep_set_halt -> %d\n", rc);
1455                         rc = 0;
1456                         break;
1457                 }
1458
1459                 /* Wait for a short time and then try again */
1460                 if (msleep_interruptible(100) != 0)
1461                         return -EINTR;
1462                 rc = usb_ep_set_halt(fsg->bulk_in);
1463         }
1464         return rc;
1465 }
1466
1467 static int wedge_bulk_in_endpoint(struct fsg_dev *fsg)
1468 {
1469         int     rc;
1470
1471         DBG(fsg, "bulk-in set wedge\n");
1472         rc = usb_ep_set_wedge(fsg->bulk_in);
1473         if (rc == -EAGAIN)
1474                 VDBG(fsg, "delayed bulk-in endpoint wedge\n");
1475         while (rc != 0) {
1476                 if (rc != -EAGAIN) {
1477                         WARNING(fsg, "usb_ep_set_wedge -> %d\n", rc);
1478                         rc = 0;
1479                         break;
1480                 }
1481
1482                 /* Wait for a short time and then try again */
1483                 if (msleep_interruptible(100) != 0)
1484                         return -EINTR;
1485                 rc = usb_ep_set_wedge(fsg->bulk_in);
1486         }
1487         return rc;
1488 }
1489
1490 static int pad_with_zeros(struct fsg_dev *fsg)
1491 {
1492         struct fsg_buffhd       *bh = fsg->common->next_buffhd_to_fill;
1493         u32                     nkeep = bh->inreq->length;
1494         u32                     nsend;
1495         int                     rc;
1496
1497         bh->state = BUF_STATE_EMPTY;            /* For the first iteration */
1498         fsg->common->usb_amount_left = nkeep + fsg->common->residue;
1499         while (fsg->common->usb_amount_left > 0) {
1500
1501                 /* Wait for the next buffer to be free */
1502                 while (bh->state != BUF_STATE_EMPTY) {
1503                         rc = sleep_thread(fsg->common);
1504                         if (rc)
1505                                 return rc;
1506                 }
1507
1508                 nsend = min(fsg->common->usb_amount_left, FSG_BUFLEN);
1509                 memset(bh->buf + nkeep, 0, nsend - nkeep);
1510                 bh->inreq->length = nsend;
1511                 bh->inreq->zero = 0;
1512                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
1513                                 &bh->inreq_busy, &bh->state);
1514                 bh = fsg->common->next_buffhd_to_fill = bh->next;
1515                 fsg->common->usb_amount_left -= nsend;
1516                 nkeep = 0;
1517         }
1518         return 0;
1519 }
1520
1521 static int throw_away_data(struct fsg_common *common)
1522 {
1523         struct fsg_buffhd       *bh;
1524         u32                     amount;
1525         int                     rc;
1526
1527         for (bh = common->next_buffhd_to_drain;
1528              bh->state != BUF_STATE_EMPTY || common->usb_amount_left > 0;
1529              bh = common->next_buffhd_to_drain) {
1530
1531                 /* Throw away the data in a filled buffer */
1532                 if (bh->state == BUF_STATE_FULL) {
1533                         smp_rmb();
1534                         bh->state = BUF_STATE_EMPTY;
1535                         common->next_buffhd_to_drain = bh->next;
1536
1537                         /* A short packet or an error ends everything */
1538                         if (bh->outreq->actual != bh->outreq->length ||
1539                                         bh->outreq->status != 0) {
1540                                 raise_exception(common,
1541                                                 FSG_STATE_ABORT_BULK_OUT);
1542                                 return -EINTR;
1543                         }
1544                         continue;
1545                 }
1546
1547                 /* Try to submit another request if we need one */
1548                 bh = common->next_buffhd_to_fill;
1549                 if (bh->state == BUF_STATE_EMPTY
1550                  && common->usb_amount_left > 0) {
1551                         amount = min(common->usb_amount_left, FSG_BUFLEN);
1552
1553                         /* amount is always divisible by 512, hence by
1554                          * the bulk-out maxpacket size */
1555                         bh->outreq->length = amount;
1556                         bh->bulk_out_intended_length = amount;
1557                         bh->outreq->short_not_ok = 1;
1558                         START_TRANSFER_OR(common, bulk_out, bh->outreq,
1559                                           &bh->outreq_busy, &bh->state)
1560                                 /* Don't know what to do if
1561                                  * common->fsg is NULL */
1562                                 return -EIO;
1563                         common->next_buffhd_to_fill = bh->next;
1564                         common->usb_amount_left -= amount;
1565                         continue;
1566                 }
1567
1568                 /* Otherwise wait for something to happen */
1569                 rc = sleep_thread(common);
1570                 if (rc)
1571                         return rc;
1572         }
1573         return 0;
1574 }
1575
1576
1577 static int finish_reply(struct fsg_common *common)
1578 {
1579         struct fsg_buffhd       *bh = common->next_buffhd_to_fill;
1580         int                     rc = 0;
1581
1582         switch (common->data_dir) {
1583         case DATA_DIR_NONE:
1584                 break;                  /* Nothing to send */
1585
1586         /* If we don't know whether the host wants to read or write,
1587          * this must be CB or CBI with an unknown command.  We mustn't
1588          * try to send or receive any data.  So stall both bulk pipes
1589          * if we can and wait for a reset. */
1590         case DATA_DIR_UNKNOWN:
1591                 if (!common->can_stall) {
1592                         /* Nothing */
1593                 } else if (fsg_is_set(common)) {
1594                         fsg_set_halt(common->fsg, common->fsg->bulk_out);
1595                         rc = halt_bulk_in_endpoint(common->fsg);
1596                 } else {
1597                         /* Don't know what to do if common->fsg is NULL */
1598                         rc = -EIO;
1599                 }
1600                 break;
1601
1602         /* All but the last buffer of data must have already been sent */
1603         case DATA_DIR_TO_HOST:
1604                 if (common->data_size == 0) {
1605                         /* Nothing to send */
1606
1607                 /* If there's no residue, simply send the last buffer */
1608                 } else if (common->residue == 0) {
1609                         bh->inreq->zero = 0;
1610                         START_TRANSFER_OR(common, bulk_in, bh->inreq,
1611                                           &bh->inreq_busy, &bh->state)
1612                                 return -EIO;
1613                         common->next_buffhd_to_fill = bh->next;
1614
1615                 /* For Bulk-only, if we're allowed to stall then send the
1616                  * short packet and halt the bulk-in endpoint.  If we can't
1617                  * stall, pad out the remaining data with 0's. */
1618                 } else if (common->can_stall) {
1619                         bh->inreq->zero = 1;
1620                         START_TRANSFER_OR(common, bulk_in, bh->inreq,
1621                                           &bh->inreq_busy, &bh->state)
1622                                 /* Don't know what to do if
1623                                  * common->fsg is NULL */
1624                                 rc = -EIO;
1625                         common->next_buffhd_to_fill = bh->next;
1626                         if (common->fsg)
1627                                 rc = halt_bulk_in_endpoint(common->fsg);
1628                 } else if (fsg_is_set(common)) {
1629                         rc = pad_with_zeros(common->fsg);
1630                 } else {
1631                         /* Don't know what to do if common->fsg is NULL */
1632                         rc = -EIO;
1633                 }
1634                 break;
1635
1636         /* We have processed all we want from the data the host has sent.
1637          * There may still be outstanding bulk-out requests. */
1638         case DATA_DIR_FROM_HOST:
1639                 if (common->residue == 0) {
1640                         /* Nothing to receive */
1641
1642                 /* Did the host stop sending unexpectedly early? */
1643                 } else if (common->short_packet_received) {
1644                         raise_exception(common, FSG_STATE_ABORT_BULK_OUT);
1645                         rc = -EINTR;
1646
1647                 /* We haven't processed all the incoming data.  Even though
1648                  * we may be allowed to stall, doing so would cause a race.
1649                  * The controller may already have ACK'ed all the remaining
1650                  * bulk-out packets, in which case the host wouldn't see a
1651                  * STALL.  Not realizing the endpoint was halted, it wouldn't
1652                  * clear the halt -- leading to problems later on. */
1653 #if 0
1654                 } else if (common->can_stall) {
1655                         if (fsg_is_set(common))
1656                                 fsg_set_halt(common->fsg,
1657                                              common->fsg->bulk_out);
1658                         raise_exception(common, FSG_STATE_ABORT_BULK_OUT);
1659                         rc = -EINTR;
1660 #endif
1661
1662                 /* We can't stall.  Read in the excess data and throw it
1663                  * all away. */
1664                 } else {
1665                         rc = throw_away_data(common);
1666                 }
1667                 break;
1668         }
1669         return rc;
1670 }
1671
1672
1673 static int send_status(struct fsg_common *common)
1674 {
1675         struct fsg_lun          *curlun = common->curlun;
1676         struct fsg_buffhd       *bh;
1677         struct bulk_cs_wrap     *csw;
1678         int                     rc;
1679         u8                      status = USB_STATUS_PASS;
1680         u32                     sd, sdinfo = 0;
1681
1682         /* Wait for the next buffer to become available */
1683         bh = common->next_buffhd_to_fill;
1684         while (bh->state != BUF_STATE_EMPTY) {
1685                 rc = sleep_thread(common);
1686                 if (rc)
1687                         return rc;
1688         }
1689
1690         if (curlun) {
1691                 sd = curlun->sense_data;
1692                 sdinfo = curlun->sense_data_info;
1693         } else if (common->bad_lun_okay)
1694                 sd = SS_NO_SENSE;
1695         else
1696                 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
1697
1698         if (common->phase_error) {
1699                 DBG(common, "sending phase-error status\n");
1700                 status = USB_STATUS_PHASE_ERROR;
1701                 sd = SS_INVALID_COMMAND;
1702         } else if (sd != SS_NO_SENSE) {
1703                 DBG(common, "sending command-failure status\n");
1704                 status = USB_STATUS_FAIL;
1705                 VDBG(common, "  sense data: SK x%02x, ASC x%02x, ASCQ x%02x;"
1706                                 "  info x%x\n",
1707                                 SK(sd), ASC(sd), ASCQ(sd), sdinfo);
1708         }
1709
1710         /* Store and send the Bulk-only CSW */
1711         csw = (void *)bh->buf;
1712
1713         csw->Signature = cpu_to_le32(USB_BULK_CS_SIG);
1714         csw->Tag = common->tag;
1715         csw->Residue = cpu_to_le32(common->residue);
1716         csw->Status = status;
1717
1718         bh->inreq->length = USB_BULK_CS_WRAP_LEN;
1719         bh->inreq->zero = 0;
1720         START_TRANSFER_OR(common, bulk_in, bh->inreq,
1721                           &bh->inreq_busy, &bh->state)
1722                 /* Don't know what to do if common->fsg is NULL */
1723                 return -EIO;
1724
1725         common->next_buffhd_to_fill = bh->next;
1726         return 0;
1727 }
1728
1729
1730 /*-------------------------------------------------------------------------*/
1731
1732 /* Check whether the command is properly formed and whether its data size
1733  * and direction agree with the values we already have. */
1734 static int check_command(struct fsg_common *common, int cmnd_size,
1735                 enum data_direction data_dir, unsigned int mask,
1736                 int needs_medium, const char *name)
1737 {
1738         int                     i;
1739         int                     lun = common->cmnd[1] >> 5;
1740         static const char       dirletter[4] = {'u', 'o', 'i', 'n'};
1741         char                    hdlen[20];
1742         struct fsg_lun          *curlun;
1743
1744         hdlen[0] = 0;
1745         if (common->data_dir != DATA_DIR_UNKNOWN)
1746                 sprintf(hdlen, ", H%c=%u", dirletter[(int) common->data_dir],
1747                                 common->data_size);
1748         VDBG(common, "SCSI command: %s;  Dc=%d, D%c=%u;  Hc=%d%s\n",
1749              name, cmnd_size, dirletter[(int) data_dir],
1750              common->data_size_from_cmnd, common->cmnd_size, hdlen);
1751
1752         /* We can't reply at all until we know the correct data direction
1753          * and size. */
1754         if (common->data_size_from_cmnd == 0)
1755                 data_dir = DATA_DIR_NONE;
1756         if (common->data_size < common->data_size_from_cmnd) {
1757                 /* Host data size < Device data size is a phase error.
1758                  * Carry out the command, but only transfer as much as
1759                  * we are allowed. */
1760                 common->data_size_from_cmnd = common->data_size;
1761                 common->phase_error = 1;
1762         }
1763         common->residue = common->data_size;
1764         common->usb_amount_left = common->data_size;
1765
1766         /* Conflicting data directions is a phase error */
1767         if (common->data_dir != data_dir
1768          && common->data_size_from_cmnd > 0) {
1769                 common->phase_error = 1;
1770                 return -EINVAL;
1771         }
1772
1773         /* Verify the length of the command itself */
1774         if (cmnd_size != common->cmnd_size) {
1775
1776                 /* Special case workaround: There are plenty of buggy SCSI
1777                  * implementations. Many have issues with cbw->Length
1778                  * field passing a wrong command size. For those cases we
1779                  * always try to work around the problem by using the length
1780                  * sent by the host side provided it is at least as large
1781                  * as the correct command length.
1782                  * Examples of such cases would be MS-Windows, which issues
1783                  * REQUEST SENSE with cbw->Length == 12 where it should
1784                  * be 6, and xbox360 issuing INQUIRY, TEST UNIT READY and
1785                  * REQUEST SENSE with cbw->Length == 10 where it should
1786                  * be 6 as well.
1787                  */
1788                 if (cmnd_size <= common->cmnd_size) {
1789                         DBG(common, "%s is buggy! Expected length %d "
1790                             "but we got %d\n", name,
1791                             cmnd_size, common->cmnd_size);
1792                         cmnd_size = common->cmnd_size;
1793                 } else {
1794                         common->phase_error = 1;
1795                         return -EINVAL;
1796                 }
1797         }
1798
1799         /* Check that the LUN values are consistent */
1800         if (common->lun != lun)
1801                 DBG(common, "using LUN %d from CBW, not LUN %d from CDB\n",
1802                     common->lun, lun);
1803
1804         /* Check the LUN */
1805         if (common->lun >= 0 && common->lun < common->nluns) {
1806                 curlun = &common->luns[common->lun];
1807                 common->curlun = curlun;
1808                 if (common->cmnd[0] != SC_REQUEST_SENSE) {
1809                         curlun->sense_data = SS_NO_SENSE;
1810                         curlun->sense_data_info = 0;
1811                         curlun->info_valid = 0;
1812                 }
1813         } else {
1814                 common->curlun = NULL;
1815                 curlun = NULL;
1816                 common->bad_lun_okay = 0;
1817
1818                 /* INQUIRY and REQUEST SENSE commands are explicitly allowed
1819                  * to use unsupported LUNs; all others may not. */
1820                 if (common->cmnd[0] != SC_INQUIRY &&
1821                     common->cmnd[0] != SC_REQUEST_SENSE) {
1822                         DBG(common, "unsupported LUN %d\n", common->lun);
1823                         return -EINVAL;
1824                 }
1825         }
1826
1827         /* If a unit attention condition exists, only INQUIRY and
1828          * REQUEST SENSE commands are allowed; anything else must fail. */
1829         if (curlun && curlun->unit_attention_data != SS_NO_SENSE &&
1830                         common->cmnd[0] != SC_INQUIRY &&
1831                         common->cmnd[0] != SC_REQUEST_SENSE) {
1832                 curlun->sense_data = curlun->unit_attention_data;
1833                 curlun->unit_attention_data = SS_NO_SENSE;
1834                 return -EINVAL;
1835         }
1836
1837         /* Check that only command bytes listed in the mask are non-zero */
1838         common->cmnd[1] &= 0x1f;                        /* Mask away the LUN */
1839         for (i = 1; i < cmnd_size; ++i) {
1840                 if (common->cmnd[i] && !(mask & (1 << i))) {
1841                         if (curlun)
1842                                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1843                         return -EINVAL;
1844                 }
1845         }
1846
1847         /* If the medium isn't mounted and the command needs to access
1848          * it, return an error. */
1849         if (curlun && !fsg_lun_is_open(curlun) && needs_medium) {
1850                 curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
1851                 return -EINVAL;
1852         }
1853
1854         return 0;
1855 }
1856
1857
1858 static int do_scsi_command(struct fsg_common *common)
1859 {
1860         struct fsg_buffhd       *bh;
1861         int                     rc;
1862         int                     reply = -EINVAL;
1863         int                     i;
1864         static char             unknown[16];
1865
1866         dump_cdb(common);
1867
1868         /* Wait for the next buffer to become available for data or status */
1869         bh = common->next_buffhd_to_fill;
1870         common->next_buffhd_to_drain = bh;
1871         while (bh->state != BUF_STATE_EMPTY) {
1872                 rc = sleep_thread(common);
1873                 if (rc)
1874                         return rc;
1875         }
1876         common->phase_error = 0;
1877         common->short_packet_received = 0;
1878
1879         down_read(&common->filesem);    /* We're using the backing file */
1880         switch (common->cmnd[0]) {
1881
1882         case SC_INQUIRY:
1883                 common->data_size_from_cmnd = common->cmnd[4];
1884                 reply = check_command(common, 6, DATA_DIR_TO_HOST,
1885                                       (1<<4), 0,
1886                                       "INQUIRY");
1887                 if (reply == 0)
1888                         reply = do_inquiry(common, bh);
1889                 break;
1890
1891         case SC_MODE_SELECT_6:
1892                 common->data_size_from_cmnd = common->cmnd[4];
1893                 reply = check_command(common, 6, DATA_DIR_FROM_HOST,
1894                                       (1<<1) | (1<<4), 0,
1895                                       "MODE SELECT(6)");
1896                 if (reply == 0)
1897                         reply = do_mode_select(common, bh);
1898                 break;
1899
1900         case SC_MODE_SELECT_10:
1901                 common->data_size_from_cmnd =
1902                         get_unaligned_be16(&common->cmnd[7]);
1903                 reply = check_command(common, 10, DATA_DIR_FROM_HOST,
1904                                       (1<<1) | (3<<7), 0,
1905                                       "MODE SELECT(10)");
1906                 if (reply == 0)
1907                         reply = do_mode_select(common, bh);
1908                 break;
1909
1910         case SC_MODE_SENSE_6:
1911                 common->data_size_from_cmnd = common->cmnd[4];
1912                 reply = check_command(common, 6, DATA_DIR_TO_HOST,
1913                                       (1<<1) | (1<<2) | (1<<4), 0,
1914                                       "MODE SENSE(6)");
1915                 if (reply == 0)
1916                         reply = do_mode_sense(common, bh);
1917                 break;
1918
1919         case SC_MODE_SENSE_10:
1920                 common->data_size_from_cmnd =
1921                         get_unaligned_be16(&common->cmnd[7]);
1922                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
1923                                       (1<<1) | (1<<2) | (3<<7), 0,
1924                                       "MODE SENSE(10)");
1925                 if (reply == 0)
1926                         reply = do_mode_sense(common, bh);
1927                 break;
1928
1929         case SC_PREVENT_ALLOW_MEDIUM_REMOVAL:
1930                 common->data_size_from_cmnd = 0;
1931                 reply = check_command(common, 6, DATA_DIR_NONE,
1932                                       (1<<4), 0,
1933                                       "PREVENT-ALLOW MEDIUM REMOVAL");
1934                 if (reply == 0)
1935                         reply = do_prevent_allow(common);
1936                 break;
1937
1938         case SC_READ_6:
1939                 i = common->cmnd[4];
1940                 common->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
1941                 reply = check_command(common, 6, DATA_DIR_TO_HOST,
1942                                       (7<<1) | (1<<4), 1,
1943                                       "READ(6)");
1944                 if (reply == 0)
1945                         reply = do_read(common);
1946                 break;
1947
1948         case SC_READ_10:
1949                 common->data_size_from_cmnd =
1950                                 get_unaligned_be16(&common->cmnd[7]) << 9;
1951                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
1952                                       (1<<1) | (0xf<<2) | (3<<7), 1,
1953                                       "READ(10)");
1954                 if (reply == 0)
1955                         reply = do_read(common);
1956                 break;
1957
1958         case SC_READ_12:
1959                 common->data_size_from_cmnd =
1960                                 get_unaligned_be32(&common->cmnd[6]) << 9;
1961                 reply = check_command(common, 12, DATA_DIR_TO_HOST,
1962                                       (1<<1) | (0xf<<2) | (0xf<<6), 1,
1963                                       "READ(12)");
1964                 if (reply == 0)
1965                         reply = do_read(common);
1966                 break;
1967
1968         case SC_READ_CAPACITY:
1969                 common->data_size_from_cmnd = 8;
1970                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
1971                                       (0xf<<2) | (1<<8), 1,
1972                                       "READ CAPACITY");
1973                 if (reply == 0)
1974                         reply = do_read_capacity(common, bh);
1975                 break;
1976
1977         case SC_READ_HEADER:
1978                 if (!common->curlun || !common->curlun->cdrom)
1979                         goto unknown_cmnd;
1980                 common->data_size_from_cmnd =
1981                         get_unaligned_be16(&common->cmnd[7]);
1982                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
1983                                       (3<<7) | (0x1f<<1), 1,
1984                                       "READ HEADER");
1985                 if (reply == 0)
1986                         reply = do_read_header(common, bh);
1987                 break;
1988
1989         case SC_READ_TOC:
1990                 if (!common->curlun || !common->curlun->cdrom)
1991                         goto unknown_cmnd;
1992                 common->data_size_from_cmnd =
1993                         get_unaligned_be16(&common->cmnd[7]);
1994                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
1995                                       (7<<6) | (1<<1), 1,
1996                                       "READ TOC");
1997                 if (reply == 0)
1998                         reply = do_read_toc(common, bh);
1999                 break;
2000
2001         case SC_READ_FORMAT_CAPACITIES:
2002                 common->data_size_from_cmnd =
2003                         get_unaligned_be16(&common->cmnd[7]);
2004                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
2005                                       (3<<7), 1,
2006                                       "READ FORMAT CAPACITIES");
2007                 if (reply == 0)
2008                         reply = do_read_format_capacities(common, bh);
2009                 break;
2010
2011         case SC_REQUEST_SENSE:
2012                 common->data_size_from_cmnd = common->cmnd[4];
2013                 reply = check_command(common, 6, DATA_DIR_TO_HOST,
2014                                       (1<<4), 0,
2015                                       "REQUEST SENSE");
2016                 if (reply == 0)
2017                         reply = do_request_sense(common, bh);
2018                 break;
2019
2020         case SC_START_STOP_UNIT:
2021                 common->data_size_from_cmnd = 0;
2022                 reply = check_command(common, 6, DATA_DIR_NONE,
2023                                       (1<<1) | (1<<4), 0,
2024                                       "START-STOP UNIT");
2025                 if (reply == 0)
2026                         reply = do_start_stop(common);
2027                 break;
2028
2029         case SC_SYNCHRONIZE_CACHE:
2030                 common->data_size_from_cmnd = 0;
2031                 reply = check_command(common, 10, DATA_DIR_NONE,
2032                                       (0xf<<2) | (3<<7), 1,
2033                                       "SYNCHRONIZE CACHE");
2034                 if (reply == 0)
2035                         reply = do_synchronize_cache(common);
2036                 break;
2037
2038         case SC_TEST_UNIT_READY:
2039                 common->data_size_from_cmnd = 0;
2040                 reply = check_command(common, 6, DATA_DIR_NONE,
2041                                 0, 1,
2042                                 "TEST UNIT READY");
2043                 break;
2044
2045         /* Although optional, this command is used by MS-Windows.  We
2046          * support a minimal version: BytChk must be 0. */
2047         case SC_VERIFY:
2048                 common->data_size_from_cmnd = 0;
2049                 reply = check_command(common, 10, DATA_DIR_NONE,
2050                                       (1<<1) | (0xf<<2) | (3<<7), 1,
2051                                       "VERIFY");
2052                 if (reply == 0)
2053                         reply = do_verify(common);
2054                 break;
2055
2056         case SC_WRITE_6:
2057                 i = common->cmnd[4];
2058                 common->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
2059                 reply = check_command(common, 6, DATA_DIR_FROM_HOST,
2060                                       (7<<1) | (1<<4), 1,
2061                                       "WRITE(6)");
2062                 if (reply == 0)
2063                         reply = do_write(common);
2064                 break;
2065
2066         case SC_WRITE_10:
2067                 common->data_size_from_cmnd =
2068                                 get_unaligned_be16(&common->cmnd[7]) << 9;
2069                 reply = check_command(common, 10, DATA_DIR_FROM_HOST,
2070                                       (1<<1) | (0xf<<2) | (3<<7), 1,
2071                                       "WRITE(10)");
2072                 if (reply == 0)
2073                         reply = do_write(common);
2074                 break;
2075
2076         case SC_WRITE_12:
2077                 common->data_size_from_cmnd =
2078                                 get_unaligned_be32(&common->cmnd[6]) << 9;
2079                 reply = check_command(common, 12, DATA_DIR_FROM_HOST,
2080                                       (1<<1) | (0xf<<2) | (0xf<<6), 1,
2081                                       "WRITE(12)");
2082                 if (reply == 0)
2083                         reply = do_write(common);
2084                 break;
2085
2086         /* Some mandatory commands that we recognize but don't implement.
2087          * They don't mean much in this setting.  It's left as an exercise
2088          * for anyone interested to implement RESERVE and RELEASE in terms
2089          * of Posix locks. */
2090         case SC_FORMAT_UNIT:
2091         case SC_RELEASE:
2092         case SC_RESERVE:
2093         case SC_SEND_DIAGNOSTIC:
2094                 /* Fall through */
2095
2096         default:
2097 unknown_cmnd:
2098                 common->data_size_from_cmnd = 0;
2099                 sprintf(unknown, "Unknown x%02x", common->cmnd[0]);
2100                 reply = check_command(common, common->cmnd_size,
2101                                       DATA_DIR_UNKNOWN, 0xff, 0, unknown);
2102                 if (reply == 0) {
2103                         common->curlun->sense_data = SS_INVALID_COMMAND;
2104                         reply = -EINVAL;
2105                 }
2106                 break;
2107         }
2108         up_read(&common->filesem);
2109
2110         if (reply == -EINTR || signal_pending(current))
2111                 return -EINTR;
2112
2113         /* Set up the single reply buffer for finish_reply() */
2114         if (reply == -EINVAL)
2115                 reply = 0;              /* Error reply length */
2116         if (reply >= 0 && common->data_dir == DATA_DIR_TO_HOST) {
2117                 reply = min((u32) reply, common->data_size_from_cmnd);
2118                 bh->inreq->length = reply;
2119                 bh->state = BUF_STATE_FULL;
2120                 common->residue -= reply;
2121         }                               /* Otherwise it's already set */
2122
2123         return 0;
2124 }
2125
2126
2127 /*-------------------------------------------------------------------------*/
2128
2129 static int received_cbw(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2130 {
2131         struct usb_request      *req = bh->outreq;
2132         struct fsg_bulk_cb_wrap *cbw = req->buf;
2133         struct fsg_common       *common = fsg->common;
2134
2135         /* Was this a real packet?  Should it be ignored? */
2136         if (req->status || test_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags))
2137                 return -EINVAL;
2138
2139         /* Is the CBW valid? */
2140         if (req->actual != USB_BULK_CB_WRAP_LEN ||
2141                         cbw->Signature != cpu_to_le32(
2142                                 USB_BULK_CB_SIG)) {
2143                 DBG(fsg, "invalid CBW: len %u sig 0x%x\n",
2144                                 req->actual,
2145                                 le32_to_cpu(cbw->Signature));
2146
2147                 /* The Bulk-only spec says we MUST stall the IN endpoint
2148                  * (6.6.1), so it's unavoidable.  It also says we must
2149                  * retain this state until the next reset, but there's
2150                  * no way to tell the controller driver it should ignore
2151                  * Clear-Feature(HALT) requests.
2152                  *
2153                  * We aren't required to halt the OUT endpoint; instead
2154                  * we can simply accept and discard any data received
2155                  * until the next reset. */
2156                 wedge_bulk_in_endpoint(fsg);
2157                 set_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
2158                 return -EINVAL;
2159         }
2160
2161         /* Is the CBW meaningful? */
2162         if (cbw->Lun >= FSG_MAX_LUNS || cbw->Flags & ~USB_BULK_IN_FLAG ||
2163                         cbw->Length <= 0 || cbw->Length > MAX_COMMAND_SIZE) {
2164                 DBG(fsg, "non-meaningful CBW: lun = %u, flags = 0x%x, "
2165                                 "cmdlen %u\n",
2166                                 cbw->Lun, cbw->Flags, cbw->Length);
2167
2168                 /* We can do anything we want here, so let's stall the
2169                  * bulk pipes if we are allowed to. */
2170                 if (common->can_stall) {
2171                         fsg_set_halt(fsg, fsg->bulk_out);
2172                         halt_bulk_in_endpoint(fsg);
2173                 }
2174                 return -EINVAL;
2175         }
2176
2177         /* Save the command for later */
2178         common->cmnd_size = cbw->Length;
2179         memcpy(common->cmnd, cbw->CDB, common->cmnd_size);
2180         if (cbw->Flags & USB_BULK_IN_FLAG)
2181                 common->data_dir = DATA_DIR_TO_HOST;
2182         else
2183                 common->data_dir = DATA_DIR_FROM_HOST;
2184         common->data_size = le32_to_cpu(cbw->DataTransferLength);
2185         if (common->data_size == 0)
2186                 common->data_dir = DATA_DIR_NONE;
2187         common->lun = cbw->Lun;
2188         common->tag = cbw->Tag;
2189         return 0;
2190 }
2191
2192
2193 static int get_next_command(struct fsg_common *common)
2194 {
2195         struct fsg_buffhd       *bh;
2196         int                     rc = 0;
2197
2198         /* Wait for the next buffer to become available */
2199         bh = common->next_buffhd_to_fill;
2200         while (bh->state != BUF_STATE_EMPTY) {
2201                 rc = sleep_thread(common);
2202                 if (rc)
2203                         return rc;
2204         }
2205
2206         /* Queue a request to read a Bulk-only CBW */
2207         set_bulk_out_req_length(common, bh, USB_BULK_CB_WRAP_LEN);
2208         bh->outreq->short_not_ok = 1;
2209         START_TRANSFER_OR(common, bulk_out, bh->outreq,
2210                           &bh->outreq_busy, &bh->state)
2211                 /* Don't know what to do if common->fsg is NULL */
2212                 return -EIO;
2213
2214         /* We will drain the buffer in software, which means we
2215          * can reuse it for the next filling.  No need to advance
2216          * next_buffhd_to_fill. */
2217
2218         /* Wait for the CBW to arrive */
2219         while (bh->state != BUF_STATE_FULL) {
2220                 rc = sleep_thread(common);
2221                 if (rc)
2222                         return rc;
2223         }
2224         smp_rmb();
2225         rc = fsg_is_set(common) ? received_cbw(common->fsg, bh) : -EIO;
2226         bh->state = BUF_STATE_EMPTY;
2227
2228         return rc;
2229 }
2230
2231
2232 /*-------------------------------------------------------------------------*/
2233
2234 static int enable_endpoint(struct fsg_common *common, struct usb_ep *ep,
2235                 const struct usb_endpoint_descriptor *d)
2236 {
2237         int     rc;
2238
2239         ep->driver_data = common;
2240         rc = usb_ep_enable(ep, d);
2241         if (rc)
2242                 ERROR(common, "can't enable %s, result %d\n", ep->name, rc);
2243         return rc;
2244 }
2245
2246 static int alloc_request(struct fsg_common *common, struct usb_ep *ep,
2247                 struct usb_request **preq)
2248 {
2249         *preq = usb_ep_alloc_request(ep, GFP_ATOMIC);
2250         if (*preq)
2251                 return 0;
2252         ERROR(common, "can't allocate request for %s\n", ep->name);
2253         return -ENOMEM;
2254 }
2255
2256 /*
2257  * Reset interface setting and re-init endpoint state (toggle etc).
2258  * Call with altsetting < 0 to disable the interface.  The only other
2259  * available altsetting is 0, which enables the interface.
2260  */
2261 static int do_set_interface(struct fsg_common *common, int altsetting)
2262 {
2263         int     rc = 0;
2264         int     i;
2265         const struct usb_endpoint_descriptor    *d;
2266
2267         if (common->running)
2268                 DBG(common, "reset interface\n");
2269
2270 reset:
2271         /* Deallocate the requests */
2272         if (common->prev_fsg) {
2273                 struct fsg_dev *fsg = common->prev_fsg;
2274
2275                 for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
2276                         struct fsg_buffhd *bh = &common->buffhds[i];
2277
2278                         if (bh->inreq) {
2279                                 usb_ep_free_request(fsg->bulk_in, bh->inreq);
2280                                 bh->inreq = NULL;
2281                         }
2282                         if (bh->outreq) {
2283                                 usb_ep_free_request(fsg->bulk_out, bh->outreq);
2284                                 bh->outreq = NULL;
2285                         }
2286                 }
2287
2288                 /* Disable the endpoints */
2289                 if (fsg->bulk_in_enabled) {
2290                         usb_ep_disable(fsg->bulk_in);
2291                         fsg->bulk_in_enabled = 0;
2292                 }
2293                 if (fsg->bulk_out_enabled) {
2294                         usb_ep_disable(fsg->bulk_out);
2295                         fsg->bulk_out_enabled = 0;
2296                 }
2297
2298                 common->prev_fsg = 0;
2299         }
2300
2301         common->running = 0;
2302         if (altsetting < 0 || rc != 0)
2303                 return rc;
2304
2305         DBG(common, "set interface %d\n", altsetting);
2306
2307         if (fsg_is_set(common)) {
2308                 struct fsg_dev *fsg = common->fsg;
2309                 common->prev_fsg = common->fsg;
2310
2311                 /* Enable the endpoints */
2312                 d = fsg_ep_desc(common->gadget,
2313                                 &fsg_fs_bulk_in_desc, &fsg_hs_bulk_in_desc);
2314                 rc = enable_endpoint(common, fsg->bulk_in, d);
2315                 if (rc)
2316                         goto reset;
2317                 fsg->bulk_in_enabled = 1;
2318
2319                 d = fsg_ep_desc(common->gadget,
2320                                 &fsg_fs_bulk_out_desc, &fsg_hs_bulk_out_desc);
2321                 rc = enable_endpoint(common, fsg->bulk_out, d);
2322                 if (rc)
2323                         goto reset;
2324                 fsg->bulk_out_enabled = 1;
2325                 common->bulk_out_maxpacket = le16_to_cpu(d->wMaxPacketSize);
2326                 clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
2327
2328                 /* Allocate the requests */
2329                 for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
2330                         struct fsg_buffhd       *bh = &common->buffhds[i];
2331
2332                         rc = alloc_request(common, fsg->bulk_in, &bh->inreq);
2333                         if (rc)
2334                                 goto reset;
2335                         rc = alloc_request(common, fsg->bulk_out, &bh->outreq);
2336                         if (rc)
2337                                 goto reset;
2338                         bh->inreq->buf = bh->outreq->buf = bh->buf;
2339                         bh->inreq->context = bh->outreq->context = bh;
2340                         bh->inreq->complete = bulk_in_complete;
2341                         bh->outreq->complete = bulk_out_complete;
2342                 }
2343
2344                 common->running = 1;
2345                 for (i = 0; i < common->nluns; ++i)
2346                         common->luns[i].unit_attention_data = SS_RESET_OCCURRED;
2347                 return rc;
2348         } else {
2349                 return -EIO;
2350         }
2351 }
2352
2353
2354 /*
2355  * Change our operational configuration.  This code must agree with the code
2356  * that returns config descriptors, and with interface altsetting code.
2357  *
2358  * It's also responsible for power management interactions.  Some
2359  * configurations might not work with our current power sources.
2360  * For now we just assume the gadget is always self-powered.
2361  */
2362 static int do_set_config(struct fsg_common *common, u8 new_config)
2363 {
2364         int     rc = 0;
2365
2366         /* Disable the single interface */
2367         if (common->config != 0) {
2368                 DBG(common, "reset config\n");
2369                 common->config = 0;
2370                 rc = do_set_interface(common, -1);
2371         }
2372
2373         /* Enable the interface */
2374         if (new_config != 0) {
2375                 common->config = new_config;
2376                 rc = do_set_interface(common, 0);
2377                 if (rc != 0)
2378                         common->config = 0;     /* Reset on errors */
2379         }
2380         return rc;
2381 }
2382
2383
2384 /****************************** ALT CONFIGS ******************************/
2385
2386
2387 static int fsg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
2388 {
2389         struct fsg_dev *fsg = fsg_from_func(f);
2390         fsg->common->prev_fsg = fsg->common->fsg;
2391         fsg->common->fsg = fsg;
2392         fsg->common->new_config = 1;
2393         raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
2394         return 0;
2395 }
2396
2397 static void fsg_disable(struct usb_function *f)
2398 {
2399         struct fsg_dev *fsg = fsg_from_func(f);
2400         fsg->common->prev_fsg = fsg->common->fsg;
2401         fsg->common->fsg = fsg;
2402         fsg->common->new_config = 0;
2403         raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
2404 }
2405
2406
2407 /*-------------------------------------------------------------------------*/
2408
2409 static void handle_exception(struct fsg_common *common)
2410 {
2411         siginfo_t               info;
2412         int                     sig;
2413         int                     i;
2414         struct fsg_buffhd       *bh;
2415         enum fsg_state          old_state;
2416         u8                      new_config;
2417         struct fsg_lun          *curlun;
2418         unsigned int            exception_req_tag;
2419         int                     rc;
2420
2421         /* Clear the existing signals.  Anything but SIGUSR1 is converted
2422          * into a high-priority EXIT exception. */
2423         for (;;) {
2424                 sig = dequeue_signal_lock(current, &current->blocked, &info);
2425                 if (!sig)
2426                         break;
2427                 if (sig != SIGUSR1) {
2428                         if (common->state < FSG_STATE_EXIT)
2429                                 DBG(common, "Main thread exiting on signal\n");
2430                         raise_exception(common, FSG_STATE_EXIT);
2431                 }
2432         }
2433
2434         /* Cancel all the pending transfers */
2435         if (fsg_is_set(common)) {
2436                 for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
2437                         bh = &common->buffhds[i];
2438                         if (bh->inreq_busy)
2439                                 usb_ep_dequeue(common->fsg->bulk_in, bh->inreq);
2440                         if (bh->outreq_busy)
2441                                 usb_ep_dequeue(common->fsg->bulk_out,
2442                                                bh->outreq);
2443                 }
2444
2445                 /* Wait until everything is idle */
2446                 for (;;) {
2447                         int num_active = 0;
2448                         for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
2449                                 bh = &common->buffhds[i];
2450                                 num_active += bh->inreq_busy + bh->outreq_busy;
2451                         }
2452                         if (num_active == 0)
2453                                 break;
2454                         if (sleep_thread(common))
2455                                 return;
2456                 }
2457
2458                 /* Clear out the controller's fifos */
2459                 if (common->fsg->bulk_in_enabled)
2460                         usb_ep_fifo_flush(common->fsg->bulk_in);
2461                 if (common->fsg->bulk_out_enabled)
2462                         usb_ep_fifo_flush(common->fsg->bulk_out);
2463         }
2464
2465         /* Reset the I/O buffer states and pointers, the SCSI
2466          * state, and the exception.  Then invoke the handler. */
2467         spin_lock_irq(&common->lock);
2468
2469         for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
2470                 bh = &common->buffhds[i];
2471                 bh->state = BUF_STATE_EMPTY;
2472         }
2473         common->next_buffhd_to_fill = &common->buffhds[0];
2474         common->next_buffhd_to_drain = &common->buffhds[0];
2475         exception_req_tag = common->exception_req_tag;
2476         new_config = common->new_config;
2477         old_state = common->state;
2478
2479         if (old_state == FSG_STATE_ABORT_BULK_OUT)
2480                 common->state = FSG_STATE_STATUS_PHASE;
2481         else {
2482                 for (i = 0; i < common->nluns; ++i) {
2483                         curlun = &common->luns[i];
2484                         curlun->prevent_medium_removal = 0;
2485                         curlun->sense_data = SS_NO_SENSE;
2486                         curlun->unit_attention_data = SS_NO_SENSE;
2487                         curlun->sense_data_info = 0;
2488                         curlun->info_valid = 0;
2489                 }
2490                 common->state = FSG_STATE_IDLE;
2491         }
2492         spin_unlock_irq(&common->lock);
2493
2494         /* Carry out any extra actions required for the exception */
2495         switch (old_state) {
2496         case FSG_STATE_ABORT_BULK_OUT:
2497                 send_status(common);
2498                 spin_lock_irq(&common->lock);
2499                 if (common->state == FSG_STATE_STATUS_PHASE)
2500                         common->state = FSG_STATE_IDLE;
2501                 spin_unlock_irq(&common->lock);
2502                 break;
2503
2504         case FSG_STATE_RESET:
2505                 /* In case we were forced against our will to halt a
2506                  * bulk endpoint, clear the halt now.  (The SuperH UDC
2507                  * requires this.) */
2508                 if (!fsg_is_set(common))
2509                         break;
2510                 if (test_and_clear_bit(IGNORE_BULK_OUT,
2511                                        &common->fsg->atomic_bitflags))
2512                         usb_ep_clear_halt(common->fsg->bulk_in);
2513
2514                 if (common->ep0_req_tag == exception_req_tag)
2515                         ep0_queue(common);      /* Complete the status stage */
2516
2517                 /* Technically this should go here, but it would only be
2518                  * a waste of time.  Ditto for the INTERFACE_CHANGE and
2519                  * CONFIG_CHANGE cases. */
2520                 /* for (i = 0; i < common->nluns; ++i) */
2521                 /*      common->luns[i].unit_attention_data = */
2522                 /*              SS_RESET_OCCURRED;  */
2523                 break;
2524
2525         case FSG_STATE_CONFIG_CHANGE:
2526                 rc = do_set_config(common, new_config);
2527                 if (common->ep0_req_tag != exception_req_tag)
2528                         break;
2529                 if (rc != 0) {                  /* STALL on errors */
2530                         DBG(common, "ep0 set halt\n");
2531                         usb_ep_set_halt(common->ep0);
2532                 } else {                        /* Complete the status stage */
2533                         ep0_queue(common);
2534                 }
2535                 break;
2536
2537         case FSG_STATE_EXIT:
2538         case FSG_STATE_TERMINATED:
2539                 do_set_config(common, 0);               /* Free resources */
2540                 spin_lock_irq(&common->lock);
2541                 common->state = FSG_STATE_TERMINATED;   /* Stop the thread */
2542                 spin_unlock_irq(&common->lock);
2543                 break;
2544
2545         case FSG_STATE_INTERFACE_CHANGE:
2546         case FSG_STATE_DISCONNECT:
2547         case FSG_STATE_COMMAND_PHASE:
2548         case FSG_STATE_DATA_PHASE:
2549         case FSG_STATE_STATUS_PHASE:
2550         case FSG_STATE_IDLE:
2551                 break;
2552         }
2553 }
2554
2555
2556 /*-------------------------------------------------------------------------*/
2557
2558 static int fsg_main_thread(void *common_)
2559 {
2560         struct fsg_common       *common = common_;
2561
2562         /* Allow the thread to be killed by a signal, but set the signal mask
2563          * to block everything but INT, TERM, KILL, and USR1. */
2564         allow_signal(SIGINT);
2565         allow_signal(SIGTERM);
2566         allow_signal(SIGKILL);
2567         allow_signal(SIGUSR1);
2568
2569         /* Allow the thread to be frozen */
2570         set_freezable();
2571
2572         /* Arrange for userspace references to be interpreted as kernel
2573          * pointers.  That way we can pass a kernel pointer to a routine
2574          * that expects a __user pointer and it will work okay. */
2575         set_fs(get_ds());
2576
2577         /* The main loop */
2578         while (common->state != FSG_STATE_TERMINATED) {
2579                 if (exception_in_progress(common) || signal_pending(current)) {
2580                         handle_exception(common);
2581                         continue;
2582                 }
2583
2584                 if (!common->running) {
2585                         sleep_thread(common);
2586                         continue;
2587                 }
2588
2589                 if (get_next_command(common))
2590                         continue;
2591
2592                 spin_lock_irq(&common->lock);
2593                 if (!exception_in_progress(common))
2594                         common->state = FSG_STATE_DATA_PHASE;
2595                 spin_unlock_irq(&common->lock);
2596
2597                 if (do_scsi_command(common) || finish_reply(common))
2598                         continue;
2599
2600                 spin_lock_irq(&common->lock);
2601                 if (!exception_in_progress(common))
2602                         common->state = FSG_STATE_STATUS_PHASE;
2603                 spin_unlock_irq(&common->lock);
2604
2605                 if (send_status(common))
2606                         continue;
2607
2608                 spin_lock_irq(&common->lock);
2609                 if (!exception_in_progress(common))
2610                         common->state = FSG_STATE_IDLE;
2611                 spin_unlock_irq(&common->lock);
2612         }
2613
2614         spin_lock_irq(&common->lock);
2615         common->thread_task = NULL;
2616         spin_unlock_irq(&common->lock);
2617
2618         if (common->thread_exits)
2619                 common->thread_exits(common);
2620
2621         /* Let the unbind and cleanup routines know the thread has exited */
2622         complete_and_exit(&common->thread_notifier, 0);
2623 }
2624
2625
2626 /*************************** DEVICE ATTRIBUTES ***************************/
2627
2628 /* Write permission is checked per LUN in store_*() functions. */
2629 static DEVICE_ATTR(ro, 0644, fsg_show_ro, fsg_store_ro);
2630 static DEVICE_ATTR(file, 0644, fsg_show_file, fsg_store_file);
2631
2632
2633 /****************************** FSG COMMON ******************************/
2634
2635 static void fsg_common_release(struct kref *ref);
2636
2637 static void fsg_lun_release(struct device *dev)
2638 {
2639         /* Nothing needs to be done */
2640 }
2641
2642 static inline void fsg_common_get(struct fsg_common *common)
2643 {
2644         kref_get(&common->ref);
2645 }
2646
2647 static inline void fsg_common_put(struct fsg_common *common)
2648 {
2649         kref_put(&common->ref, fsg_common_release);
2650 }
2651
2652
2653 static struct fsg_common *fsg_common_init(struct fsg_common *common,
2654                                           struct usb_composite_dev *cdev,
2655                                           struct fsg_config *cfg)
2656 {
2657         struct usb_gadget *gadget = cdev->gadget;
2658         struct fsg_buffhd *bh;
2659         struct fsg_lun *curlun;
2660         struct fsg_lun_config *lcfg;
2661         int nluns, i, rc;
2662         char *pathbuf;
2663
2664         /* Find out how many LUNs there should be */
2665         nluns = cfg->nluns;
2666         if (nluns < 1 || nluns > FSG_MAX_LUNS) {
2667                 dev_err(&gadget->dev, "invalid number of LUNs: %u\n", nluns);
2668                 return ERR_PTR(-EINVAL);
2669         }
2670
2671         /* Allocate? */
2672         if (!common) {
2673                 common = kzalloc(sizeof *common, GFP_KERNEL);
2674                 if (!common)
2675                         return ERR_PTR(-ENOMEM);
2676                 common->free_storage_on_release = 1;
2677         } else {
2678                 memset(common, 0, sizeof common);
2679                 common->free_storage_on_release = 0;
2680         }
2681
2682         common->private_data = cfg->private_data;
2683
2684         common->gadget = gadget;
2685         common->ep0 = gadget->ep0;
2686         common->ep0req = cdev->req;
2687
2688         /* Maybe allocate device-global string IDs, and patch descriptors */
2689         if (fsg_strings[FSG_STRING_INTERFACE].id == 0) {
2690                 rc = usb_string_id(cdev);
2691                 if (rc < 0) {
2692                         kfree(common);
2693                         return ERR_PTR(rc);
2694                 }
2695                 fsg_strings[FSG_STRING_INTERFACE].id = rc;
2696                 fsg_intf_desc.iInterface = rc;
2697         }
2698
2699         /* Create the LUNs, open their backing files, and register the
2700          * LUN devices in sysfs. */
2701         curlun = kzalloc(nluns * sizeof *curlun, GFP_KERNEL);
2702         if (!curlun) {
2703                 kfree(common);
2704                 return ERR_PTR(-ENOMEM);
2705         }
2706         common->luns = curlun;
2707
2708         init_rwsem(&common->filesem);
2709
2710         for (i = 0, lcfg = cfg->luns; i < nluns; ++i, ++curlun, ++lcfg) {
2711                 curlun->cdrom = !!lcfg->cdrom;
2712                 curlun->ro = lcfg->cdrom || lcfg->ro;
2713                 curlun->removable = lcfg->removable;
2714                 curlun->dev.release = fsg_lun_release;
2715                 curlun->dev.parent = &gadget->dev;
2716                 /* curlun->dev.driver = &fsg_driver.driver; XXX */
2717                 dev_set_drvdata(&curlun->dev, &common->filesem);
2718                 dev_set_name(&curlun->dev,
2719                              cfg->lun_name_format
2720                            ? cfg->lun_name_format
2721                            : "lun%d",
2722                              i);
2723
2724                 rc = device_register(&curlun->dev);
2725                 if (rc) {
2726                         INFO(common, "failed to register LUN%d: %d\n", i, rc);
2727                         common->nluns = i;
2728                         goto error_release;
2729                 }
2730
2731                 rc = device_create_file(&curlun->dev, &dev_attr_ro);
2732                 if (rc)
2733                         goto error_luns;
2734                 rc = device_create_file(&curlun->dev, &dev_attr_file);
2735                 if (rc)
2736                         goto error_luns;
2737
2738                 if (lcfg->filename) {
2739                         rc = fsg_lun_open(curlun, lcfg->filename);
2740                         if (rc)
2741                                 goto error_luns;
2742                 } else if (!curlun->removable) {
2743                         ERROR(common, "no file given for LUN%d\n", i);
2744                         rc = -EINVAL;
2745                         goto error_luns;
2746                 }
2747         }
2748         common->nluns = nluns;
2749
2750
2751         /* Data buffers cyclic list */
2752         /* Buffers in buffhds are static -- no need for additional
2753          * allocation. */
2754         bh = common->buffhds;
2755         i = FSG_NUM_BUFFERS - 1;
2756         do {
2757                 bh->next = bh + 1;
2758         } while (++bh, --i);
2759         bh->next = common->buffhds;
2760
2761
2762         /* Prepare inquiryString */
2763         if (cfg->release != 0xffff) {
2764                 i = cfg->release;
2765         } else {
2766                 /* The sa1100 controller is not supported */
2767                 i = gadget_is_sa1100(gadget)
2768                         ? -1
2769                         : usb_gadget_controller_number(gadget);
2770                 if (i >= 0) {
2771                         i = 0x0300 + i;
2772                 } else {
2773                         WARNING(common, "controller '%s' not recognized\n",
2774                                 gadget->name);
2775                         i = 0x0399;
2776                 }
2777         }
2778 #define OR(x, y) ((x) ? (x) : (y))
2779         snprintf(common->inquiry_string, sizeof common->inquiry_string,
2780                  "%-8s%-16s%04x",
2781                  OR(cfg->vendor_name, "Linux   "),
2782                  /* Assume product name dependent on the first LUN */
2783                  OR(cfg->product_name, common->luns->cdrom
2784                                      ? "File-Stor Gadget"
2785                                      : "File-CD Gadget  "),
2786                  i);
2787
2788
2789         /* Some peripheral controllers are known not to be able to
2790          * halt bulk endpoints correctly.  If one of them is present,
2791          * disable stalls.
2792          */
2793         common->can_stall = cfg->can_stall &&
2794                 !(gadget_is_sh(common->gadget) ||
2795                   gadget_is_at91(common->gadget));
2796
2797
2798         spin_lock_init(&common->lock);
2799         kref_init(&common->ref);
2800
2801
2802         /* Tell the thread to start working */
2803         common->thread_exits = cfg->thread_exits;
2804         common->thread_task =
2805                 kthread_create(fsg_main_thread, common,
2806                                OR(cfg->thread_name, "file-storage"));
2807         if (IS_ERR(common->thread_task)) {
2808                 rc = PTR_ERR(common->thread_task);
2809                 goto error_release;
2810         }
2811         init_completion(&common->thread_notifier);
2812 #undef OR
2813
2814
2815         /* Information */
2816         INFO(common, FSG_DRIVER_DESC ", version: " FSG_DRIVER_VERSION "\n");
2817         INFO(common, "Number of LUNs=%d\n", common->nluns);
2818
2819         pathbuf = kmalloc(PATH_MAX, GFP_KERNEL);
2820         for (i = 0, nluns = common->nluns, curlun = common->luns;
2821              i < nluns;
2822              ++curlun, ++i) {
2823                 char *p = "(no medium)";
2824                 if (fsg_lun_is_open(curlun)) {
2825                         p = "(error)";
2826                         if (pathbuf) {
2827                                 p = d_path(&curlun->filp->f_path,
2828                                            pathbuf, PATH_MAX);
2829                                 if (IS_ERR(p))
2830                                         p = "(error)";
2831                         }
2832                 }
2833                 LINFO(curlun, "LUN: %s%s%sfile: %s\n",
2834                       curlun->removable ? "removable " : "",
2835                       curlun->ro ? "read only " : "",
2836                       curlun->cdrom ? "CD-ROM " : "",
2837                       p);
2838         }
2839         kfree(pathbuf);
2840
2841         DBG(common, "I/O thread pid: %d\n", task_pid_nr(common->thread_task));
2842
2843         wake_up_process(common->thread_task);
2844
2845         return common;
2846
2847
2848 error_luns:
2849         common->nluns = i + 1;
2850 error_release:
2851         common->state = FSG_STATE_TERMINATED;   /* The thread is dead */
2852         /* Call fsg_common_release() directly, ref might be not
2853          * initialised */
2854         fsg_common_release(&common->ref);
2855         complete(&common->thread_notifier);
2856         return ERR_PTR(rc);
2857 }
2858
2859
2860 static void fsg_common_release(struct kref *ref)
2861 {
2862         struct fsg_common *common =
2863                 container_of(ref, struct fsg_common, ref);
2864         unsigned i = common->nluns;
2865         struct fsg_lun *lun = common->luns;
2866
2867         /* If the thread isn't already dead, tell it to exit now */
2868         if (common->state != FSG_STATE_TERMINATED) {
2869                 raise_exception(common, FSG_STATE_EXIT);
2870                 wait_for_completion(&common->thread_notifier);
2871
2872                 /* The cleanup routine waits for this completion also */
2873                 complete(&common->thread_notifier);
2874         }
2875
2876         /* Beware tempting for -> do-while optimization: when in error
2877          * recovery nluns may be zero. */
2878
2879         for (; i; --i, ++lun) {
2880                 device_remove_file(&lun->dev, &dev_attr_ro);
2881                 device_remove_file(&lun->dev, &dev_attr_file);
2882                 fsg_lun_close(lun);
2883                 device_unregister(&lun->dev);
2884         }
2885
2886         kfree(common->luns);
2887         if (common->free_storage_on_release)
2888                 kfree(common);
2889 }
2890
2891
2892 /*-------------------------------------------------------------------------*/
2893
2894
2895 static void fsg_unbind(struct usb_configuration *c, struct usb_function *f)
2896 {
2897         struct fsg_dev          *fsg = fsg_from_func(f);
2898
2899         DBG(fsg, "unbind\n");
2900         fsg_common_put(fsg->common);
2901         kfree(fsg);
2902 }
2903
2904
2905 static int fsg_bind(struct usb_configuration *c, struct usb_function *f)
2906 {
2907         struct fsg_dev          *fsg = fsg_from_func(f);
2908         struct usb_gadget       *gadget = c->cdev->gadget;
2909         int                     rc;
2910         int                     i;
2911         struct usb_ep           *ep;
2912
2913         fsg->gadget = gadget;
2914
2915         /* New interface */
2916         i = usb_interface_id(c, f);
2917         if (i < 0)
2918                 return i;
2919         fsg_intf_desc.bInterfaceNumber = i;
2920         fsg->interface_number = i;
2921
2922         /* Find all the endpoints we will use */
2923         ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_in_desc);
2924         if (!ep)
2925                 goto autoconf_fail;
2926         ep->driver_data = fsg->common;  /* claim the endpoint */
2927         fsg->bulk_in = ep;
2928
2929         ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_out_desc);
2930         if (!ep)
2931                 goto autoconf_fail;
2932         ep->driver_data = fsg->common;  /* claim the endpoint */
2933         fsg->bulk_out = ep;
2934
2935         if (gadget_is_dualspeed(gadget)) {
2936                 /* Assume endpoint addresses are the same for both speeds */
2937                 fsg_hs_bulk_in_desc.bEndpointAddress =
2938                         fsg_fs_bulk_in_desc.bEndpointAddress;
2939                 fsg_hs_bulk_out_desc.bEndpointAddress =
2940                         fsg_fs_bulk_out_desc.bEndpointAddress;
2941                 f->hs_descriptors = fsg_hs_function;
2942         }
2943
2944         return 0;
2945
2946 autoconf_fail:
2947         ERROR(fsg, "unable to autoconfigure all endpoints\n");
2948         rc = -ENOTSUPP;
2949         fsg_unbind(c, f);
2950         return rc;
2951 }
2952
2953
2954 /****************************** ADD FUNCTION ******************************/
2955
2956 static struct usb_gadget_strings *fsg_strings_array[] = {
2957         &fsg_stringtab,
2958         NULL,
2959 };
2960
2961 static int fsg_add(struct usb_composite_dev *cdev,
2962                    struct usb_configuration *c,
2963                    struct fsg_common *common)
2964 {
2965         struct fsg_dev *fsg;
2966         int rc;
2967
2968         fsg = kzalloc(sizeof *fsg, GFP_KERNEL);
2969         if (unlikely(!fsg))
2970                 return -ENOMEM;
2971
2972         fsg->function.name        = FSG_DRIVER_DESC;
2973         fsg->function.strings     = fsg_strings_array;
2974         fsg->function.descriptors = fsg_fs_function;
2975         fsg->function.bind        = fsg_bind;
2976         fsg->function.unbind      = fsg_unbind;
2977         fsg->function.setup       = fsg_setup;
2978         fsg->function.set_alt     = fsg_set_alt;
2979         fsg->function.disable     = fsg_disable;
2980
2981         fsg->common               = common;
2982         /* Our caller holds a reference to common structure so we
2983          * don't have to be worry about it being freed until we return
2984          * from this function.  So instead of incrementing counter now
2985          * and decrement in error recovery we increment it only when
2986          * call to usb_add_function() was successful. */
2987
2988         rc = usb_add_function(c, &fsg->function);
2989
2990         if (likely(rc == 0))
2991                 fsg_common_get(fsg->common);
2992         else
2993                 kfree(fsg);
2994
2995         return rc;
2996 }
2997
2998
2999
3000 /************************* Module parameters *************************/
3001
3002
3003 struct fsg_module_parameters {
3004         char            *file[FSG_MAX_LUNS];
3005         int             ro[FSG_MAX_LUNS];
3006         int             removable[FSG_MAX_LUNS];
3007         int             cdrom[FSG_MAX_LUNS];
3008
3009         unsigned int    file_count, ro_count, removable_count, cdrom_count;
3010         unsigned int    luns;   /* nluns */
3011         int             stall;  /* can_stall */
3012 };
3013
3014
3015 #define _FSG_MODULE_PARAM_ARRAY(prefix, params, name, type, desc)       \
3016         module_param_array_named(prefix ## name, params.name, type,     \
3017                                  &prefix ## params.name ## _count,      \
3018                                  S_IRUGO);                              \
3019         MODULE_PARM_DESC(prefix ## name, desc)
3020
3021 #define _FSG_MODULE_PARAM(prefix, params, name, type, desc)             \
3022         module_param_named(prefix ## name, params.name, type,           \
3023                            S_IRUGO);                                    \
3024         MODULE_PARM_DESC(prefix ## name, desc)
3025
3026 #define FSG_MODULE_PARAMETERS(prefix, params)                           \
3027         _FSG_MODULE_PARAM_ARRAY(prefix, params, file, charp,            \
3028                                 "names of backing files or devices");   \
3029         _FSG_MODULE_PARAM_ARRAY(prefix, params, ro, bool,               \
3030                                 "true to force read-only");             \
3031         _FSG_MODULE_PARAM_ARRAY(prefix, params, removable, bool,        \
3032                                 "true to simulate removable media");    \
3033         _FSG_MODULE_PARAM_ARRAY(prefix, params, cdrom, bool,            \
3034                                 "true to simulate CD-ROM instead of disk"); \
3035         _FSG_MODULE_PARAM(prefix, params, luns, uint,                   \
3036                           "number of LUNs");                            \
3037         _FSG_MODULE_PARAM(prefix, params, stall, bool,                  \
3038                           "false to prevent bulk stalls")
3039
3040
3041 static void
3042 fsg_config_from_params(struct fsg_config *cfg,
3043                        const struct fsg_module_parameters *params)
3044 {
3045         struct fsg_lun_config *lun;
3046         unsigned i;
3047
3048         /* Configure LUNs */
3049         cfg->nluns =
3050                 min(params->luns ?: (params->file_count ?: 1u),
3051                     (unsigned)FSG_MAX_LUNS);
3052         for (i = 0, lun = cfg->luns; i < cfg->nluns; ++i, ++lun) {
3053                 lun->ro = !!params->ro[i];
3054                 lun->cdrom = !!params->cdrom[i];
3055                 lun->removable = /* Removable by default */
3056                         params->removable_count <= i || params->removable[i];
3057                 lun->filename =
3058                         params->file_count > i && params->file[i][0]
3059                         ? params->file[i]
3060                         : 0;
3061         }
3062
3063         /* Let MSF use defaults */
3064         cfg->lun_name_format = 0;
3065         cfg->thread_name = 0;
3066         cfg->vendor_name = 0;
3067         cfg->product_name = 0;
3068         cfg->release = 0xffff;
3069
3070         cfg->thread_exits = 0;
3071         cfg->private_data = 0;
3072
3073         /* Finalise */
3074         cfg->can_stall = params->stall;
3075 }
3076
3077 static inline struct fsg_common *
3078 fsg_common_from_params(struct fsg_common *common,
3079                        struct usb_composite_dev *cdev,
3080                        const struct fsg_module_parameters *params)
3081         __attribute__((unused));
3082 static inline struct fsg_common *
3083 fsg_common_from_params(struct fsg_common *common,
3084                        struct usb_composite_dev *cdev,
3085                        const struct fsg_module_parameters *params)
3086 {
3087         struct fsg_config cfg;
3088         fsg_config_from_params(&cfg, params);
3089         return fsg_common_init(common, cdev, &cfg);
3090 }
3091