USB: g_mass_storage: testing code from f_mass_storage.c removed
[linux-2.6.git] / drivers / usb / gadget / f_mass_storage.c
1 /*
2  * file_storage.c -- File-backed USB Storage Gadget, for USB development
3  *
4  * Copyright (C) 2003-2008 Alan Stern
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions, and the following disclaimer,
12  *    without modification.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. The names of the above-listed copyright holders may not be used
17  *    to endorse or promote products derived from this software without
18  *    specific prior written permission.
19  *
20  * ALTERNATIVELY, this software may be distributed under the terms of the
21  * GNU General Public License ("GPL") as published by the Free Software
22  * Foundation, either version 2 of that License or (at your option) any
23  * later version.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
26  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
27  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
29  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
30  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
31  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
32  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
33  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
34  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
35  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36  */
37
38
39 /*
40  * The File-backed Storage Gadget acts as a USB Mass Storage device,
41  * appearing to the host as a disk drive or as a CD-ROM drive.  In addition
42  * to providing an example of a genuinely useful gadget driver for a USB
43  * device, it also illustrates a technique of double-buffering for increased
44  * throughput.  Last but not least, it gives an easy way to probe the
45  * behavior of the Mass Storage drivers in a USB host.
46  *
47  * Backing storage is provided by a regular file or a block device, specified
48  * by the "file" module parameter.  Access can be limited to read-only by
49  * setting the optional "ro" module parameter.  (For CD-ROM emulation,
50  * access is always read-only.)  The gadget will indicate that it has
51  * removable media if the optional "removable" module parameter is set.
52  *
53  * There is support for multiple logical units (LUNs), each of which has
54  * its own backing file.  The number of LUNs can be set using the optional
55  * "luns" module parameter (anywhere from 1 to 8), and the corresponding
56  * files are specified using comma-separated lists for "file" and "ro".
57  * The default number of LUNs is taken from the number of "file" elements;
58  * it is 1 if "file" is not given.  If "removable" is not set then a backing
59  * file must be specified for each LUN.  If it is set, then an unspecified
60  * or empty backing filename means the LUN's medium is not loaded.  Ideally
61  * each LUN would be settable independently as a disk drive or a CD-ROM
62  * drive, but currently all LUNs have to be the same type.  The CD-ROM
63  * emulation includes a single data track and no audio tracks; hence there
64  * need be only one backing file per LUN.  Note also that the CD-ROM block
65  * length is set to 512 rather than the more common value 2048.
66  *
67  * Requirements are modest; only a bulk-in and a bulk-out endpoint are
68  * needed (an interrupt-out endpoint is also needed for CBI).  The memory
69  * requirement amounts to two 16K buffers, size configurable by a parameter.
70  * Support is included for both full-speed and high-speed operation.
71  *
72  * Note that the driver is slightly non-portable in that it assumes a
73  * single memory/DMA buffer will be useable for bulk-in, bulk-out, and
74  * interrupt-in endpoints.  With most device controllers this isn't an
75  * issue, but there may be some with hardware restrictions that prevent
76  * a buffer from being used by more than one endpoint.
77  *
78  * Module options:
79  *
80  *      file=filename[,filename...]
81  *                              Required if "removable" is not set, names of
82  *                                      the files or block devices used for
83  *                                      backing storage
84  *      ro=b[,b...]             Default false, booleans for read-only access
85  *      removable               Default false, boolean for removable media
86  *      luns=N                  Default N = number of filenames, number of
87  *                                      LUNs to support
88  *      stall                   Default determined according to the type of
89  *                                      USB device controller (usually true),
90  *                                      boolean to permit the driver to halt
91  *                                      bulk endpoints
92  *      cdrom                   Default false, boolean for whether to emulate
93  *                                      a CD-ROM drive
94  *
95  * The pathnames of the backing files and the ro settings are available in
96  * the attribute files "file" and "ro" in the lun<n> subdirectory of the
97  * gadget's sysfs directory.  If the "removable" option is set, writing to
98  * these files will simulate ejecting/loading the medium (writing an empty
99  * line means eject) and adjusting a write-enable tab.  Changes to the ro
100  * setting are not allowed when the medium is loaded or if CD-ROM emulation
101  * is being used.
102  *
103  * This gadget driver is heavily based on "Gadget Zero" by David Brownell.
104  * The driver's SCSI command interface was based on the "Information
105  * technology - Small Computer System Interface - 2" document from
106  * X3T9.2 Project 375D, Revision 10L, 7-SEP-93, available at
107  * <http://www.t10.org/ftp/t10/drafts/s2/s2-r10l.pdf>.  The single exception
108  * is opcode 0x23 (READ FORMAT CAPACITIES), which was based on the
109  * "Universal Serial Bus Mass Storage Class UFI Command Specification"
110  * document, Revision 1.0, December 14, 1998, available at
111  * <http://www.usb.org/developers/devclass_docs/usbmass-ufi10.pdf>.
112  */
113
114
115 /*
116  *                              Driver Design
117  *
118  * The FSG driver is fairly straightforward.  There is a main kernel
119  * thread that handles most of the work.  Interrupt routines field
120  * callbacks from the controller driver: bulk- and interrupt-request
121  * completion notifications, endpoint-0 events, and disconnect events.
122  * Completion events are passed to the main thread by wakeup calls.  Many
123  * ep0 requests are handled at interrupt time, but SetInterface,
124  * SetConfiguration, and device reset requests are forwarded to the
125  * thread in the form of "exceptions" using SIGUSR1 signals (since they
126  * should interrupt any ongoing file I/O operations).
127  *
128  * The thread's main routine implements the standard command/data/status
129  * parts of a SCSI interaction.  It and its subroutines are full of tests
130  * for pending signals/exceptions -- all this polling is necessary since
131  * the kernel has no setjmp/longjmp equivalents.  (Maybe this is an
132  * indication that the driver really wants to be running in userspace.)
133  * An important point is that so long as the thread is alive it keeps an
134  * open reference to the backing file.  This will prevent unmounting
135  * the backing file's underlying filesystem and could cause problems
136  * during system shutdown, for example.  To prevent such problems, the
137  * thread catches INT, TERM, and KILL signals and converts them into
138  * an EXIT exception.
139  *
140  * In normal operation the main thread is started during the gadget's
141  * fsg_bind() callback and stopped during fsg_unbind().  But it can also
142  * exit when it receives a signal, and there's no point leaving the
143  * gadget running when the thread is dead.  So just before the thread
144  * exits, it deregisters the gadget driver.  This makes things a little
145  * tricky: The driver is deregistered at two places, and the exiting
146  * thread can indirectly call fsg_unbind() which in turn can tell the
147  * thread to exit.  The first problem is resolved through the use of the
148  * REGISTERED atomic bitflag; the driver will only be deregistered once.
149  * The second problem is resolved by having fsg_unbind() check
150  * fsg->state; it won't try to stop the thread if the state is already
151  * FSG_STATE_TERMINATED.
152  *
153  * To provide maximum throughput, the driver uses a circular pipeline of
154  * buffer heads (struct fsg_buffhd).  In principle the pipeline can be
155  * arbitrarily long; in practice the benefits don't justify having more
156  * than 2 stages (i.e., double buffering).  But it helps to think of the
157  * pipeline as being a long one.  Each buffer head contains a bulk-in and
158  * a bulk-out request pointer (since the buffer can be used for both
159  * output and input -- directions always are given from the host's
160  * point of view) as well as a pointer to the buffer and various state
161  * variables.
162  *
163  * Use of the pipeline follows a simple protocol.  There is a variable
164  * (fsg->next_buffhd_to_fill) that points to the next buffer head to use.
165  * At any time that buffer head may still be in use from an earlier
166  * request, so each buffer head has a state variable indicating whether
167  * it is EMPTY, FULL, or BUSY.  Typical use involves waiting for the
168  * buffer head to be EMPTY, filling the buffer either by file I/O or by
169  * USB I/O (during which the buffer head is BUSY), and marking the buffer
170  * head FULL when the I/O is complete.  Then the buffer will be emptied
171  * (again possibly by USB I/O, during which it is marked BUSY) and
172  * finally marked EMPTY again (possibly by a completion routine).
173  *
174  * A module parameter tells the driver to avoid stalling the bulk
175  * endpoints wherever the transport specification allows.  This is
176  * necessary for some UDCs like the SuperH, which cannot reliably clear a
177  * halt on a bulk endpoint.  However, under certain circumstances the
178  * Bulk-only specification requires a stall.  In such cases the driver
179  * will halt the endpoint and set a flag indicating that it should clear
180  * the halt in software during the next device reset.  Hopefully this
181  * will permit everything to work correctly.  Furthermore, although the
182  * specification allows the bulk-out endpoint to halt when the host sends
183  * too much data, implementing this would cause an unavoidable race.
184  * The driver will always use the "no-stall" approach for OUT transfers.
185  *
186  * One subtle point concerns sending status-stage responses for ep0
187  * requests.  Some of these requests, such as device reset, can involve
188  * interrupting an ongoing file I/O operation, which might take an
189  * arbitrarily long time.  During that delay the host might give up on
190  * the original ep0 request and issue a new one.  When that happens the
191  * driver should not notify the host about completion of the original
192  * request, as the host will no longer be waiting for it.  So the driver
193  * assigns to each ep0 request a unique tag, and it keeps track of the
194  * tag value of the request associated with a long-running exception
195  * (device-reset, interface-change, or configuration-change).  When the
196  * exception handler is finished, the status-stage response is submitted
197  * only if the current ep0 request tag is equal to the exception request
198  * tag.  Thus only the most recently received ep0 request will get a
199  * status-stage response.
200  *
201  * Warning: This driver source file is too long.  It ought to be split up
202  * into a header file plus about 3 separate .c files, to handle the details
203  * of the Gadget, USB Mass Storage, and SCSI protocols.
204  */
205
206
207 /* #define VERBOSE_DEBUG */
208 /* #define DUMP_MSGS */
209
210
211 #include <linux/blkdev.h>
212 #include <linux/completion.h>
213 #include <linux/dcache.h>
214 #include <linux/delay.h>
215 #include <linux/device.h>
216 #include <linux/fcntl.h>
217 #include <linux/file.h>
218 #include <linux/fs.h>
219 #include <linux/kref.h>
220 #include <linux/kthread.h>
221 #include <linux/limits.h>
222 #include <linux/rwsem.h>
223 #include <linux/slab.h>
224 #include <linux/spinlock.h>
225 #include <linux/string.h>
226 #include <linux/freezer.h>
227 #include <linux/utsname.h>
228
229 #include <linux/usb/ch9.h>
230 #include <linux/usb/gadget.h>
231
232 #include "gadget_chips.h"
233
234
235
236 /*
237  * Kbuild is not very cooperative with respect to linking separately
238  * compiled library objects into one module.  So for now we won't use
239  * separate compilation ... ensuring init/exit sections work to shrink
240  * the runtime footprint, and giving us at least some parts of what
241  * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
242  */
243 #include "usbstring.c"
244 #include "config.c"
245 #include "epautoconf.c"
246
247 /*-------------------------------------------------------------------------*/
248
249 #define DRIVER_DESC             "File-backed Storage Gadget"
250 #define DRIVER_NAME             "g_file_storage"
251 #define DRIVER_VERSION          "20 November 2008"
252
253 static       char fsg_string_manufacturer[64];
254 static const char fsg_string_product[] = DRIVER_DESC;
255 static       char fsg_string_serial[13];
256 static const char fsg_string_config[] = "Self-powered";
257 static const char fsg_string_interface[] = "Mass Storage";
258
259
260 #define FSG_NO_INTR_EP 1
261
262 #include "storage_common.c"
263
264
265 MODULE_DESCRIPTION(DRIVER_DESC);
266 MODULE_AUTHOR("Alan Stern");
267 MODULE_LICENSE("Dual BSD/GPL");
268
269 /*
270  * This driver assumes self-powered hardware and has no way for users to
271  * trigger remote wakeup.  It uses autoconfiguration to select endpoints
272  * and endpoint addresses.
273  */
274
275
276 /*-------------------------------------------------------------------------*/
277
278
279 /* Encapsulate the module parameter settings */
280
281 static struct {
282         char            *file[FSG_MAX_LUNS];
283         int             ro[FSG_MAX_LUNS];
284         unsigned int    num_filenames;
285         unsigned int    num_ros;
286         unsigned int    nluns;
287
288         int             removable;
289         int             can_stall;
290         int             cdrom;
291
292         unsigned short  release;
293 } mod_data = {                                  // Default values
294         .removable              = 0,
295         .can_stall              = 1,
296         .cdrom                  = 0,
297         };
298
299
300 module_param_array_named(file, mod_data.file, charp, &mod_data.num_filenames,
301                 S_IRUGO);
302 MODULE_PARM_DESC(file, "names of backing files or devices");
303
304 module_param_array_named(ro, mod_data.ro, bool, &mod_data.num_ros, S_IRUGO);
305 MODULE_PARM_DESC(ro, "true to force read-only");
306
307 module_param_named(luns, mod_data.nluns, uint, S_IRUGO);
308 MODULE_PARM_DESC(luns, "number of LUNs");
309
310 module_param_named(removable, mod_data.removable, bool, S_IRUGO);
311 MODULE_PARM_DESC(removable, "true to simulate removable media");
312
313 module_param_named(stall, mod_data.can_stall, bool, S_IRUGO);
314 MODULE_PARM_DESC(stall, "false to prevent bulk stalls");
315
316 module_param_named(cdrom, mod_data.cdrom, bool, S_IRUGO);
317 MODULE_PARM_DESC(cdrom, "true to emulate cdrom instead of disk");
318
319
320 /*-------------------------------------------------------------------------*/
321
322
323 struct fsg_dev {
324         /* lock protects: state, all the req_busy's, and cbbuf_cmnd */
325         spinlock_t              lock;
326         struct usb_gadget       *gadget;
327
328         /* filesem protects: backing files in use */
329         struct rw_semaphore     filesem;
330
331         /* reference counting: wait until all LUNs are released */
332         struct kref             ref;
333
334         struct usb_ep           *ep0;           // Handy copy of gadget->ep0
335         struct usb_request      *ep0req;        // For control responses
336         unsigned int            ep0_req_tag;
337         const char              *ep0req_name;
338
339         unsigned int            bulk_out_maxpacket;
340         enum fsg_state          state;          // For exception handling
341         unsigned int            exception_req_tag;
342
343         u8                      config, new_config;
344
345         unsigned int            running : 1;
346         unsigned int            bulk_in_enabled : 1;
347         unsigned int            bulk_out_enabled : 1;
348         unsigned int            phase_error : 1;
349         unsigned int            short_packet_received : 1;
350         unsigned int            bad_lun_okay : 1;
351
352         unsigned long           atomic_bitflags;
353 #define REGISTERED              0
354 #define IGNORE_BULK_OUT         1
355
356         struct usb_ep           *bulk_in;
357         struct usb_ep           *bulk_out;
358
359         struct fsg_buffhd       *next_buffhd_to_fill;
360         struct fsg_buffhd       *next_buffhd_to_drain;
361         struct fsg_buffhd       buffhds[FSG_NUM_BUFFERS];
362
363         int                     thread_wakeup_needed;
364         struct completion       thread_notifier;
365         struct task_struct      *thread_task;
366
367         int                     cmnd_size;
368         u8                      cmnd[MAX_COMMAND_SIZE];
369         enum data_direction     data_dir;
370         u32                     data_size;
371         u32                     data_size_from_cmnd;
372         u32                     tag;
373         unsigned int            lun;
374         u32                     residue;
375         u32                     usb_amount_left;
376
377         unsigned int            nluns;
378         struct fsg_lun          *luns;
379         struct fsg_lun          *curlun;
380 };
381
382 typedef void (*fsg_routine_t)(struct fsg_dev *);
383
384 static int exception_in_progress(struct fsg_dev *fsg)
385 {
386         return (fsg->state > FSG_STATE_IDLE);
387 }
388
389 /* Make bulk-out requests be divisible by the maxpacket size */
390 static void set_bulk_out_req_length(struct fsg_dev *fsg,
391                 struct fsg_buffhd *bh, unsigned int length)
392 {
393         unsigned int    rem;
394
395         bh->bulk_out_intended_length = length;
396         rem = length % fsg->bulk_out_maxpacket;
397         if (rem > 0)
398                 length += fsg->bulk_out_maxpacket - rem;
399         bh->outreq->length = length;
400 }
401
402 static struct fsg_dev                   *the_fsg;
403 static struct usb_gadget_driver         fsg_driver;
404
405
406 /*-------------------------------------------------------------------------*/
407
408 static int fsg_set_halt(struct fsg_dev *fsg, struct usb_ep *ep)
409 {
410         const char      *name;
411
412         if (ep == fsg->bulk_in)
413                 name = "bulk-in";
414         else if (ep == fsg->bulk_out)
415                 name = "bulk-out";
416         else
417                 name = ep->name;
418         DBG(fsg, "%s set halt\n", name);
419         return usb_ep_set_halt(ep);
420 }
421
422
423 /*-------------------------------------------------------------------------*/
424
425 /*
426  * DESCRIPTORS ... most are static, but strings and (full) configuration
427  * descriptors are built on demand.  Also the (static) config and interface
428  * descriptors are adjusted during fsg_bind().
429  */
430
431 /* There is only one configuration. */
432 #define CONFIG_VALUE            1
433
434 static struct usb_device_descriptor
435 device_desc = {
436         .bLength =              sizeof device_desc,
437         .bDescriptorType =      USB_DT_DEVICE,
438
439         .bcdUSB =               cpu_to_le16(0x0200),
440         .bDeviceClass =         USB_CLASS_PER_INTERFACE,
441
442         /* The next three values can be overridden by module parameters */
443         .idVendor =             cpu_to_le16(FSG_VENDOR_ID),
444         .idProduct =            cpu_to_le16(FSG_PRODUCT_ID),
445         .bcdDevice =            cpu_to_le16(0xffff),
446
447         .iManufacturer =        FSG_STRING_MANUFACTURER,
448         .iProduct =             FSG_STRING_PRODUCT,
449         .iSerialNumber =        FSG_STRING_SERIAL,
450         .bNumConfigurations =   1,
451 };
452
453 static struct usb_config_descriptor
454 config_desc = {
455         .bLength =              sizeof config_desc,
456         .bDescriptorType =      USB_DT_CONFIG,
457
458         /* wTotalLength computed by usb_gadget_config_buf() */
459         .bNumInterfaces =       1,
460         .bConfigurationValue =  CONFIG_VALUE,
461         .iConfiguration =       FSG_STRING_CONFIG,
462         .bmAttributes =         USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER,
463         .bMaxPower =            CONFIG_USB_GADGET_VBUS_DRAW / 2,
464 };
465
466
467 static struct usb_qualifier_descriptor
468 dev_qualifier = {
469         .bLength =              sizeof dev_qualifier,
470         .bDescriptorType =      USB_DT_DEVICE_QUALIFIER,
471
472         .bcdUSB =               cpu_to_le16(0x0200),
473         .bDeviceClass =         USB_CLASS_PER_INTERFACE,
474
475         .bNumConfigurations =   1,
476 };
477
478
479
480 /*
481  * Config descriptors must agree with the code that sets configurations
482  * and with code managing interfaces and their altsettings.  They must
483  * also handle different speeds and other-speed requests.
484  */
485 static int populate_config_buf(struct usb_gadget *gadget,
486                 u8 *buf, u8 type, unsigned index)
487 {
488         enum usb_device_speed                   speed = gadget->speed;
489         int                                     len;
490         const struct usb_descriptor_header      **function;
491
492         if (index > 0)
493                 return -EINVAL;
494
495         if (gadget_is_dualspeed(gadget) && type == USB_DT_OTHER_SPEED_CONFIG)
496                 speed = (USB_SPEED_FULL + USB_SPEED_HIGH) - speed;
497         if (gadget_is_dualspeed(gadget) && speed == USB_SPEED_HIGH)
498                 function = fsg_hs_function;
499         else
500                 function = fsg_fs_function;
501
502         /* for now, don't advertise srp-only devices */
503         if (!gadget_is_otg(gadget))
504                 function++;
505
506         len = usb_gadget_config_buf(&config_desc, buf, EP0_BUFSIZE, function);
507         ((struct usb_config_descriptor *) buf)->bDescriptorType = type;
508         return len;
509 }
510
511
512 /*-------------------------------------------------------------------------*/
513
514 /* These routines may be called in process context or in_irq */
515
516 /* Caller must hold fsg->lock */
517 static void wakeup_thread(struct fsg_dev *fsg)
518 {
519         /* Tell the main thread that something has happened */
520         fsg->thread_wakeup_needed = 1;
521         if (fsg->thread_task)
522                 wake_up_process(fsg->thread_task);
523 }
524
525
526 static void raise_exception(struct fsg_dev *fsg, enum fsg_state new_state)
527 {
528         unsigned long           flags;
529
530         /* Do nothing if a higher-priority exception is already in progress.
531          * If a lower-or-equal priority exception is in progress, preempt it
532          * and notify the main thread by sending it a signal. */
533         spin_lock_irqsave(&fsg->lock, flags);
534         if (fsg->state <= new_state) {
535                 fsg->exception_req_tag = fsg->ep0_req_tag;
536                 fsg->state = new_state;
537                 if (fsg->thread_task)
538                         send_sig_info(SIGUSR1, SEND_SIG_FORCED,
539                                         fsg->thread_task);
540         }
541         spin_unlock_irqrestore(&fsg->lock, flags);
542 }
543
544
545 /*-------------------------------------------------------------------------*/
546
547 /* The disconnect callback and ep0 routines.  These always run in_irq,
548  * except that ep0_queue() is called in the main thread to acknowledge
549  * completion of various requests: set config, set interface, and
550  * Bulk-only device reset. */
551
552 static void fsg_disconnect(struct usb_gadget *gadget)
553 {
554         struct fsg_dev          *fsg = get_gadget_data(gadget);
555
556         DBG(fsg, "disconnect or port reset\n");
557         raise_exception(fsg, FSG_STATE_DISCONNECT);
558 }
559
560
561 static int ep0_queue(struct fsg_dev *fsg)
562 {
563         int     rc;
564
565         rc = usb_ep_queue(fsg->ep0, fsg->ep0req, GFP_ATOMIC);
566         if (rc != 0 && rc != -ESHUTDOWN) {
567
568                 /* We can't do much more than wait for a reset */
569                 WARNING(fsg, "error in submission: %s --> %d\n",
570                                 fsg->ep0->name, rc);
571         }
572         return rc;
573 }
574
575 static void ep0_complete(struct usb_ep *ep, struct usb_request *req)
576 {
577         struct fsg_dev          *fsg = ep->driver_data;
578
579         if (req->actual > 0)
580                 dump_msg(fsg, fsg->ep0req_name, req->buf, req->actual);
581         if (req->status || req->actual != req->length)
582                 DBG(fsg, "%s --> %d, %u/%u\n", __func__,
583                                 req->status, req->actual, req->length);
584         if (req->status == -ECONNRESET)         // Request was cancelled
585                 usb_ep_fifo_flush(ep);
586
587         if (req->status == 0 && req->context)
588                 ((fsg_routine_t) (req->context))(fsg);
589 }
590
591
592 /*-------------------------------------------------------------------------*/
593
594 /* Bulk and interrupt endpoint completion handlers.
595  * These always run in_irq. */
596
597 static void bulk_in_complete(struct usb_ep *ep, struct usb_request *req)
598 {
599         struct fsg_dev          *fsg = ep->driver_data;
600         struct fsg_buffhd       *bh = req->context;
601
602         if (req->status || req->actual != req->length)
603                 DBG(fsg, "%s --> %d, %u/%u\n", __func__,
604                                 req->status, req->actual, req->length);
605         if (req->status == -ECONNRESET)         // Request was cancelled
606                 usb_ep_fifo_flush(ep);
607
608         /* Hold the lock while we update the request and buffer states */
609         smp_wmb();
610         spin_lock(&fsg->lock);
611         bh->inreq_busy = 0;
612         bh->state = BUF_STATE_EMPTY;
613         wakeup_thread(fsg);
614         spin_unlock(&fsg->lock);
615 }
616
617 static void bulk_out_complete(struct usb_ep *ep, struct usb_request *req)
618 {
619         struct fsg_dev          *fsg = ep->driver_data;
620         struct fsg_buffhd       *bh = req->context;
621
622         dump_msg(fsg, "bulk-out", req->buf, req->actual);
623         if (req->status || req->actual != bh->bulk_out_intended_length)
624                 DBG(fsg, "%s --> %d, %u/%u\n", __func__,
625                                 req->status, req->actual,
626                                 bh->bulk_out_intended_length);
627         if (req->status == -ECONNRESET)         // Request was cancelled
628                 usb_ep_fifo_flush(ep);
629
630         /* Hold the lock while we update the request and buffer states */
631         smp_wmb();
632         spin_lock(&fsg->lock);
633         bh->outreq_busy = 0;
634         bh->state = BUF_STATE_FULL;
635         wakeup_thread(fsg);
636         spin_unlock(&fsg->lock);
637 }
638
639
640 /*-------------------------------------------------------------------------*/
641
642 /* Ep0 class-specific handlers.  These always run in_irq. */
643
644 static int class_setup_req(struct fsg_dev *fsg,
645                 const struct usb_ctrlrequest *ctrl)
646 {
647         struct usb_request      *req = fsg->ep0req;
648         u16                     w_index = le16_to_cpu(ctrl->wIndex);
649         u16                     w_value = le16_to_cpu(ctrl->wValue);
650         u16                     w_length = le16_to_cpu(ctrl->wLength);
651
652         if (!fsg->config)
653                 return -EOPNOTSUPP;
654
655         switch (ctrl->bRequest) {
656
657         case USB_BULK_RESET_REQUEST:
658                 if (ctrl->bRequestType !=
659                     (USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE))
660                         break;
661                 if (w_index != 0 || w_value != 0)
662                         return -EDOM;
663
664                 /* Raise an exception to stop the current operation
665                  * and reinitialize our state. */
666                 DBG(fsg, "bulk reset request\n");
667                 raise_exception(fsg, FSG_STATE_RESET);
668                 return DELAYED_STATUS;
669
670         case USB_BULK_GET_MAX_LUN_REQUEST:
671                 if (ctrl->bRequestType !=
672                     (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE))
673                         break;
674                 if (w_index != 0 || w_value != 0)
675                         return -EDOM;
676                 VDBG(fsg, "get max LUN\n");
677                 *(u8 *) req->buf = fsg->nluns - 1;
678                 return 1;
679         }
680
681         VDBG(fsg,
682              "unknown class-specific control req "
683              "%02x.%02x v%04x i%04x l%u\n",
684              ctrl->bRequestType, ctrl->bRequest,
685              le16_to_cpu(ctrl->wValue), w_index, w_length);
686         return -EOPNOTSUPP;
687 }
688
689
690 /*-------------------------------------------------------------------------*/
691
692 /* Ep0 standard request handlers.  These always run in_irq. */
693
694 static int standard_setup_req(struct fsg_dev *fsg,
695                 const struct usb_ctrlrequest *ctrl)
696 {
697         struct usb_request      *req = fsg->ep0req;
698         int                     value = -EOPNOTSUPP;
699         u16                     w_index = le16_to_cpu(ctrl->wIndex);
700         u16                     w_value = le16_to_cpu(ctrl->wValue);
701
702         /* Usually this just stores reply data in the pre-allocated ep0 buffer,
703          * but config change events will also reconfigure hardware. */
704         switch (ctrl->bRequest) {
705
706         case USB_REQ_GET_DESCRIPTOR:
707                 if (ctrl->bRequestType != (USB_DIR_IN | USB_TYPE_STANDARD |
708                                 USB_RECIP_DEVICE))
709                         break;
710                 switch (w_value >> 8) {
711
712                 case USB_DT_DEVICE:
713                         VDBG(fsg, "get device descriptor\n");
714                         value = sizeof device_desc;
715                         memcpy(req->buf, &device_desc, value);
716                         break;
717                 case USB_DT_DEVICE_QUALIFIER:
718                         VDBG(fsg, "get device qualifier\n");
719                         if (!gadget_is_dualspeed(fsg->gadget))
720                                 break;
721                         value = sizeof dev_qualifier;
722                         memcpy(req->buf, &dev_qualifier, value);
723                         break;
724
725                 case USB_DT_OTHER_SPEED_CONFIG:
726                         VDBG(fsg, "get other-speed config descriptor\n");
727                         if (!gadget_is_dualspeed(fsg->gadget))
728                                 break;
729                         goto get_config;
730                 case USB_DT_CONFIG:
731                         VDBG(fsg, "get configuration descriptor\n");
732 get_config:
733                         value = populate_config_buf(fsg->gadget,
734                                         req->buf,
735                                         w_value >> 8,
736                                         w_value & 0xff);
737                         break;
738
739                 case USB_DT_STRING:
740                         VDBG(fsg, "get string descriptor\n");
741
742                         /* wIndex == language code */
743                         value = usb_gadget_get_string(&fsg_stringtab,
744                                         w_value & 0xff, req->buf);
745                         break;
746                 }
747                 break;
748
749         /* One config, two speeds */
750         case USB_REQ_SET_CONFIGURATION:
751                 if (ctrl->bRequestType != (USB_DIR_OUT | USB_TYPE_STANDARD |
752                                 USB_RECIP_DEVICE))
753                         break;
754                 VDBG(fsg, "set configuration\n");
755                 if (w_value == CONFIG_VALUE || w_value == 0) {
756                         fsg->new_config = w_value;
757
758                         /* Raise an exception to wipe out previous transaction
759                          * state (queued bufs, etc) and set the new config. */
760                         raise_exception(fsg, FSG_STATE_CONFIG_CHANGE);
761                         value = DELAYED_STATUS;
762                 }
763                 break;
764         case USB_REQ_GET_CONFIGURATION:
765                 if (ctrl->bRequestType != (USB_DIR_IN | USB_TYPE_STANDARD |
766                                 USB_RECIP_DEVICE))
767                         break;
768                 VDBG(fsg, "get configuration\n");
769                 *(u8 *) req->buf = fsg->config;
770                 value = 1;
771                 break;
772
773         case USB_REQ_SET_INTERFACE:
774                 if (ctrl->bRequestType != (USB_DIR_OUT| USB_TYPE_STANDARD |
775                                 USB_RECIP_INTERFACE))
776                         break;
777                 if (fsg->config && w_index == 0) {
778
779                         /* Raise an exception to wipe out previous transaction
780                          * state (queued bufs, etc) and install the new
781                          * interface altsetting. */
782                         raise_exception(fsg, FSG_STATE_INTERFACE_CHANGE);
783                         value = DELAYED_STATUS;
784                 }
785                 break;
786         case USB_REQ_GET_INTERFACE:
787                 if (ctrl->bRequestType != (USB_DIR_IN | USB_TYPE_STANDARD |
788                                 USB_RECIP_INTERFACE))
789                         break;
790                 if (!fsg->config)
791                         break;
792                 if (w_index != 0) {
793                         value = -EDOM;
794                         break;
795                 }
796                 VDBG(fsg, "get interface\n");
797                 *(u8 *) req->buf = 0;
798                 value = 1;
799                 break;
800
801         default:
802                 VDBG(fsg,
803                         "unknown control req %02x.%02x v%04x i%04x l%u\n",
804                         ctrl->bRequestType, ctrl->bRequest,
805                         w_value, w_index, le16_to_cpu(ctrl->wLength));
806         }
807
808         return value;
809 }
810
811
812 static int fsg_setup(struct usb_gadget *gadget,
813                 const struct usb_ctrlrequest *ctrl)
814 {
815         struct fsg_dev          *fsg = get_gadget_data(gadget);
816         int                     rc;
817         int                     w_length = le16_to_cpu(ctrl->wLength);
818
819         ++fsg->ep0_req_tag;             // Record arrival of a new request
820         fsg->ep0req->context = NULL;
821         fsg->ep0req->length = 0;
822         dump_msg(fsg, "ep0-setup", (u8 *) ctrl, sizeof(*ctrl));
823
824         if ((ctrl->bRequestType & USB_TYPE_MASK) == USB_TYPE_CLASS)
825                 rc = class_setup_req(fsg, ctrl);
826         else
827                 rc = standard_setup_req(fsg, ctrl);
828
829         /* Respond with data/status or defer until later? */
830         if (rc >= 0 && rc != DELAYED_STATUS) {
831                 rc = min(rc, w_length);
832                 fsg->ep0req->length = rc;
833                 fsg->ep0req->zero = rc < w_length;
834                 fsg->ep0req_name = (ctrl->bRequestType & USB_DIR_IN ?
835                                 "ep0-in" : "ep0-out");
836                 rc = ep0_queue(fsg);
837         }
838
839         /* Device either stalls (rc < 0) or reports success */
840         return rc;
841 }
842
843
844 /*-------------------------------------------------------------------------*/
845
846 /* All the following routines run in process context */
847
848
849 /* Use this for bulk or interrupt transfers, not ep0 */
850 static void start_transfer(struct fsg_dev *fsg, struct usb_ep *ep,
851                 struct usb_request *req, int *pbusy,
852                 enum fsg_buffer_state *state)
853 {
854         int     rc;
855
856         if (ep == fsg->bulk_in)
857                 dump_msg(fsg, "bulk-in", req->buf, req->length);
858
859         spin_lock_irq(&fsg->lock);
860         *pbusy = 1;
861         *state = BUF_STATE_BUSY;
862         spin_unlock_irq(&fsg->lock);
863         rc = usb_ep_queue(ep, req, GFP_KERNEL);
864         if (rc != 0) {
865                 *pbusy = 0;
866                 *state = BUF_STATE_EMPTY;
867
868                 /* We can't do much more than wait for a reset */
869
870                 /* Note: currently the net2280 driver fails zero-length
871                  * submissions if DMA is enabled. */
872                 if (rc != -ESHUTDOWN && !(rc == -EOPNOTSUPP &&
873                                                 req->length == 0))
874                         WARNING(fsg, "error in submission: %s --> %d\n",
875                                         ep->name, rc);
876         }
877 }
878
879
880 static int sleep_thread(struct fsg_dev *fsg)
881 {
882         int     rc = 0;
883
884         /* Wait until a signal arrives or we are woken up */
885         for (;;) {
886                 try_to_freeze();
887                 set_current_state(TASK_INTERRUPTIBLE);
888                 if (signal_pending(current)) {
889                         rc = -EINTR;
890                         break;
891                 }
892                 if (fsg->thread_wakeup_needed)
893                         break;
894                 schedule();
895         }
896         __set_current_state(TASK_RUNNING);
897         fsg->thread_wakeup_needed = 0;
898         return rc;
899 }
900
901
902 /*-------------------------------------------------------------------------*/
903
904 static int do_read(struct fsg_dev *fsg)
905 {
906         struct fsg_lun          *curlun = fsg->curlun;
907         u32                     lba;
908         struct fsg_buffhd       *bh;
909         int                     rc;
910         u32                     amount_left;
911         loff_t                  file_offset, file_offset_tmp;
912         unsigned int            amount;
913         unsigned int            partial_page;
914         ssize_t                 nread;
915
916         /* Get the starting Logical Block Address and check that it's
917          * not too big */
918         if (fsg->cmnd[0] == SC_READ_6)
919                 lba = get_unaligned_be24(&fsg->cmnd[1]);
920         else {
921                 lba = get_unaligned_be32(&fsg->cmnd[2]);
922
923                 /* We allow DPO (Disable Page Out = don't save data in the
924                  * cache) and FUA (Force Unit Access = don't read from the
925                  * cache), but we don't implement them. */
926                 if ((fsg->cmnd[1] & ~0x18) != 0) {
927                         curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
928                         return -EINVAL;
929                 }
930         }
931         if (lba >= curlun->num_sectors) {
932                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
933                 return -EINVAL;
934         }
935         file_offset = ((loff_t) lba) << 9;
936
937         /* Carry out the file reads */
938         amount_left = fsg->data_size_from_cmnd;
939         if (unlikely(amount_left == 0))
940                 return -EIO;            // No default reply
941
942         for (;;) {
943
944                 /* Figure out how much we need to read:
945                  * Try to read the remaining amount.
946                  * But don't read more than the buffer size.
947                  * And don't try to read past the end of the file.
948                  * Finally, if we're not at a page boundary, don't read past
949                  *      the next page.
950                  * If this means reading 0 then we were asked to read past
951                  *      the end of file. */
952                 amount = min(amount_left, FSG_BUFLEN);
953                 amount = min((loff_t) amount,
954                                 curlun->file_length - file_offset);
955                 partial_page = file_offset & (PAGE_CACHE_SIZE - 1);
956                 if (partial_page > 0)
957                         amount = min(amount, (unsigned int) PAGE_CACHE_SIZE -
958                                         partial_page);
959
960                 /* Wait for the next buffer to become available */
961                 bh = fsg->next_buffhd_to_fill;
962                 while (bh->state != BUF_STATE_EMPTY) {
963                         rc = sleep_thread(fsg);
964                         if (rc)
965                                 return rc;
966                 }
967
968                 /* If we were asked to read past the end of file,
969                  * end with an empty buffer. */
970                 if (amount == 0) {
971                         curlun->sense_data =
972                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
973                         curlun->sense_data_info = file_offset >> 9;
974                         curlun->info_valid = 1;
975                         bh->inreq->length = 0;
976                         bh->state = BUF_STATE_FULL;
977                         break;
978                 }
979
980                 /* Perform the read */
981                 file_offset_tmp = file_offset;
982                 nread = vfs_read(curlun->filp,
983                                 (char __user *) bh->buf,
984                                 amount, &file_offset_tmp);
985                 VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
986                                 (unsigned long long) file_offset,
987                                 (int) nread);
988                 if (signal_pending(current))
989                         return -EINTR;
990
991                 if (nread < 0) {
992                         LDBG(curlun, "error in file read: %d\n",
993                                         (int) nread);
994                         nread = 0;
995                 } else if (nread < amount) {
996                         LDBG(curlun, "partial file read: %d/%u\n",
997                                         (int) nread, amount);
998                         nread -= (nread & 511); // Round down to a block
999                 }
1000                 file_offset  += nread;
1001                 amount_left  -= nread;
1002                 fsg->residue -= nread;
1003                 bh->inreq->length = nread;
1004                 bh->state = BUF_STATE_FULL;
1005
1006                 /* If an error occurred, report it and its position */
1007                 if (nread < amount) {
1008                         curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
1009                         curlun->sense_data_info = file_offset >> 9;
1010                         curlun->info_valid = 1;
1011                         break;
1012                 }
1013
1014                 if (amount_left == 0)
1015                         break;          // No more left to read
1016
1017                 /* Send this buffer and go read some more */
1018                 bh->inreq->zero = 0;
1019                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
1020                                 &bh->inreq_busy, &bh->state);
1021                 fsg->next_buffhd_to_fill = bh->next;
1022         }
1023
1024         return -EIO;            // No default reply
1025 }
1026
1027
1028 /*-------------------------------------------------------------------------*/
1029
1030 static int do_write(struct fsg_dev *fsg)
1031 {
1032         struct fsg_lun          *curlun = fsg->curlun;
1033         u32                     lba;
1034         struct fsg_buffhd       *bh;
1035         int                     get_some_more;
1036         u32                     amount_left_to_req, amount_left_to_write;
1037         loff_t                  usb_offset, file_offset, file_offset_tmp;
1038         unsigned int            amount;
1039         unsigned int            partial_page;
1040         ssize_t                 nwritten;
1041         int                     rc;
1042
1043         if (curlun->ro) {
1044                 curlun->sense_data = SS_WRITE_PROTECTED;
1045                 return -EINVAL;
1046         }
1047         spin_lock(&curlun->filp->f_lock);
1048         curlun->filp->f_flags &= ~O_SYNC;       // Default is not to wait
1049         spin_unlock(&curlun->filp->f_lock);
1050
1051         /* Get the starting Logical Block Address and check that it's
1052          * not too big */
1053         if (fsg->cmnd[0] == SC_WRITE_6)
1054                 lba = get_unaligned_be24(&fsg->cmnd[1]);
1055         else {
1056                 lba = get_unaligned_be32(&fsg->cmnd[2]);
1057
1058                 /* We allow DPO (Disable Page Out = don't save data in the
1059                  * cache) and FUA (Force Unit Access = write directly to the
1060                  * medium).  We don't implement DPO; we implement FUA by
1061                  * performing synchronous output. */
1062                 if ((fsg->cmnd[1] & ~0x18) != 0) {
1063                         curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1064                         return -EINVAL;
1065                 }
1066                 if (fsg->cmnd[1] & 0x08) {      // FUA
1067                         spin_lock(&curlun->filp->f_lock);
1068                         curlun->filp->f_flags |= O_SYNC;
1069                         spin_unlock(&curlun->filp->f_lock);
1070                 }
1071         }
1072         if (lba >= curlun->num_sectors) {
1073                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1074                 return -EINVAL;
1075         }
1076
1077         /* Carry out the file writes */
1078         get_some_more = 1;
1079         file_offset = usb_offset = ((loff_t) lba) << 9;
1080         amount_left_to_req = amount_left_to_write = fsg->data_size_from_cmnd;
1081
1082         while (amount_left_to_write > 0) {
1083
1084                 /* Queue a request for more data from the host */
1085                 bh = fsg->next_buffhd_to_fill;
1086                 if (bh->state == BUF_STATE_EMPTY && get_some_more) {
1087
1088                         /* Figure out how much we want to get:
1089                          * Try to get the remaining amount.
1090                          * But don't get more than the buffer size.
1091                          * And don't try to go past the end of the file.
1092                          * If we're not at a page boundary,
1093                          *      don't go past the next page.
1094                          * If this means getting 0, then we were asked
1095                          *      to write past the end of file.
1096                          * Finally, round down to a block boundary. */
1097                         amount = min(amount_left_to_req, FSG_BUFLEN);
1098                         amount = min((loff_t) amount, curlun->file_length -
1099                                         usb_offset);
1100                         partial_page = usb_offset & (PAGE_CACHE_SIZE - 1);
1101                         if (partial_page > 0)
1102                                 amount = min(amount,
1103         (unsigned int) PAGE_CACHE_SIZE - partial_page);
1104
1105                         if (amount == 0) {
1106                                 get_some_more = 0;
1107                                 curlun->sense_data =
1108                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1109                                 curlun->sense_data_info = usb_offset >> 9;
1110                                 curlun->info_valid = 1;
1111                                 continue;
1112                         }
1113                         amount -= (amount & 511);
1114                         if (amount == 0) {
1115
1116                                 /* Why were we were asked to transfer a
1117                                  * partial block? */
1118                                 get_some_more = 0;
1119                                 continue;
1120                         }
1121
1122                         /* Get the next buffer */
1123                         usb_offset += amount;
1124                         fsg->usb_amount_left -= amount;
1125                         amount_left_to_req -= amount;
1126                         if (amount_left_to_req == 0)
1127                                 get_some_more = 0;
1128
1129                         /* amount is always divisible by 512, hence by
1130                          * the bulk-out maxpacket size */
1131                         bh->outreq->length = bh->bulk_out_intended_length =
1132                                         amount;
1133                         bh->outreq->short_not_ok = 1;
1134                         start_transfer(fsg, fsg->bulk_out, bh->outreq,
1135                                         &bh->outreq_busy, &bh->state);
1136                         fsg->next_buffhd_to_fill = bh->next;
1137                         continue;
1138                 }
1139
1140                 /* Write the received data to the backing file */
1141                 bh = fsg->next_buffhd_to_drain;
1142                 if (bh->state == BUF_STATE_EMPTY && !get_some_more)
1143                         break;                  // We stopped early
1144                 if (bh->state == BUF_STATE_FULL) {
1145                         smp_rmb();
1146                         fsg->next_buffhd_to_drain = bh->next;
1147                         bh->state = BUF_STATE_EMPTY;
1148
1149                         /* Did something go wrong with the transfer? */
1150                         if (bh->outreq->status != 0) {
1151                                 curlun->sense_data = SS_COMMUNICATION_FAILURE;
1152                                 curlun->sense_data_info = file_offset >> 9;
1153                                 curlun->info_valid = 1;
1154                                 break;
1155                         }
1156
1157                         amount = bh->outreq->actual;
1158                         if (curlun->file_length - file_offset < amount) {
1159                                 LERROR(curlun,
1160         "write %u @ %llu beyond end %llu\n",
1161         amount, (unsigned long long) file_offset,
1162         (unsigned long long) curlun->file_length);
1163                                 amount = curlun->file_length - file_offset;
1164                         }
1165
1166                         /* Perform the write */
1167                         file_offset_tmp = file_offset;
1168                         nwritten = vfs_write(curlun->filp,
1169                                         (char __user *) bh->buf,
1170                                         amount, &file_offset_tmp);
1171                         VLDBG(curlun, "file write %u @ %llu -> %d\n", amount,
1172                                         (unsigned long long) file_offset,
1173                                         (int) nwritten);
1174                         if (signal_pending(current))
1175                                 return -EINTR;          // Interrupted!
1176
1177                         if (nwritten < 0) {
1178                                 LDBG(curlun, "error in file write: %d\n",
1179                                                 (int) nwritten);
1180                                 nwritten = 0;
1181                         } else if (nwritten < amount) {
1182                                 LDBG(curlun, "partial file write: %d/%u\n",
1183                                                 (int) nwritten, amount);
1184                                 nwritten -= (nwritten & 511);
1185                                                 // Round down to a block
1186                         }
1187                         file_offset += nwritten;
1188                         amount_left_to_write -= nwritten;
1189                         fsg->residue -= nwritten;
1190
1191                         /* If an error occurred, report it and its position */
1192                         if (nwritten < amount) {
1193                                 curlun->sense_data = SS_WRITE_ERROR;
1194                                 curlun->sense_data_info = file_offset >> 9;
1195                                 curlun->info_valid = 1;
1196                                 break;
1197                         }
1198
1199                         /* Did the host decide to stop early? */
1200                         if (bh->outreq->actual != bh->outreq->length) {
1201                                 fsg->short_packet_received = 1;
1202                                 break;
1203                         }
1204                         continue;
1205                 }
1206
1207                 /* Wait for something to happen */
1208                 rc = sleep_thread(fsg);
1209                 if (rc)
1210                         return rc;
1211         }
1212
1213         return -EIO;            // No default reply
1214 }
1215
1216
1217 /*-------------------------------------------------------------------------*/
1218
1219 static int do_synchronize_cache(struct fsg_dev *fsg)
1220 {
1221         struct fsg_lun  *curlun = fsg->curlun;
1222         int             rc;
1223
1224         /* We ignore the requested LBA and write out all file's
1225          * dirty data buffers. */
1226         rc = fsg_lun_fsync_sub(curlun);
1227         if (rc)
1228                 curlun->sense_data = SS_WRITE_ERROR;
1229         return 0;
1230 }
1231
1232
1233 /*-------------------------------------------------------------------------*/
1234
1235 static void invalidate_sub(struct fsg_lun *curlun)
1236 {
1237         struct file     *filp = curlun->filp;
1238         struct inode    *inode = filp->f_path.dentry->d_inode;
1239         unsigned long   rc;
1240
1241         rc = invalidate_mapping_pages(inode->i_mapping, 0, -1);
1242         VLDBG(curlun, "invalidate_inode_pages -> %ld\n", rc);
1243 }
1244
1245 static int do_verify(struct fsg_dev *fsg)
1246 {
1247         struct fsg_lun          *curlun = fsg->curlun;
1248         u32                     lba;
1249         u32                     verification_length;
1250         struct fsg_buffhd       *bh = fsg->next_buffhd_to_fill;
1251         loff_t                  file_offset, file_offset_tmp;
1252         u32                     amount_left;
1253         unsigned int            amount;
1254         ssize_t                 nread;
1255
1256         /* Get the starting Logical Block Address and check that it's
1257          * not too big */
1258         lba = get_unaligned_be32(&fsg->cmnd[2]);
1259         if (lba >= curlun->num_sectors) {
1260                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1261                 return -EINVAL;
1262         }
1263
1264         /* We allow DPO (Disable Page Out = don't save data in the
1265          * cache) but we don't implement it. */
1266         if ((fsg->cmnd[1] & ~0x10) != 0) {
1267                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1268                 return -EINVAL;
1269         }
1270
1271         verification_length = get_unaligned_be16(&fsg->cmnd[7]);
1272         if (unlikely(verification_length == 0))
1273                 return -EIO;            // No default reply
1274
1275         /* Prepare to carry out the file verify */
1276         amount_left = verification_length << 9;
1277         file_offset = ((loff_t) lba) << 9;
1278
1279         /* Write out all the dirty buffers before invalidating them */
1280         fsg_lun_fsync_sub(curlun);
1281         if (signal_pending(current))
1282                 return -EINTR;
1283
1284         invalidate_sub(curlun);
1285         if (signal_pending(current))
1286                 return -EINTR;
1287
1288         /* Just try to read the requested blocks */
1289         while (amount_left > 0) {
1290
1291                 /* Figure out how much we need to read:
1292                  * Try to read the remaining amount, but not more than
1293                  * the buffer size.
1294                  * And don't try to read past the end of the file.
1295                  * If this means reading 0 then we were asked to read
1296                  * past the end of file. */
1297                 amount = min(amount_left, FSG_BUFLEN);
1298                 amount = min((loff_t) amount,
1299                                 curlun->file_length - file_offset);
1300                 if (amount == 0) {
1301                         curlun->sense_data =
1302                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1303                         curlun->sense_data_info = file_offset >> 9;
1304                         curlun->info_valid = 1;
1305                         break;
1306                 }
1307
1308                 /* Perform the read */
1309                 file_offset_tmp = file_offset;
1310                 nread = vfs_read(curlun->filp,
1311                                 (char __user *) bh->buf,
1312                                 amount, &file_offset_tmp);
1313                 VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
1314                                 (unsigned long long) file_offset,
1315                                 (int) nread);
1316                 if (signal_pending(current))
1317                         return -EINTR;
1318
1319                 if (nread < 0) {
1320                         LDBG(curlun, "error in file verify: %d\n",
1321                                         (int) nread);
1322                         nread = 0;
1323                 } else if (nread < amount) {
1324                         LDBG(curlun, "partial file verify: %d/%u\n",
1325                                         (int) nread, amount);
1326                         nread -= (nread & 511); // Round down to a sector
1327                 }
1328                 if (nread == 0) {
1329                         curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
1330                         curlun->sense_data_info = file_offset >> 9;
1331                         curlun->info_valid = 1;
1332                         break;
1333                 }
1334                 file_offset += nread;
1335                 amount_left -= nread;
1336         }
1337         return 0;
1338 }
1339
1340
1341 /*-------------------------------------------------------------------------*/
1342
1343 static int do_inquiry(struct fsg_dev *fsg, struct fsg_buffhd *bh)
1344 {
1345         u8      *buf = (u8 *) bh->buf;
1346
1347         static char vendor_id[] = "Linux   ";
1348         static char product_disk_id[] = "File-Stor Gadget";
1349         static char product_cdrom_id[] = "File-CD Gadget  ";
1350
1351         if (!fsg->curlun) {             // Unsupported LUNs are okay
1352                 fsg->bad_lun_okay = 1;
1353                 memset(buf, 0, 36);
1354                 buf[0] = 0x7f;          // Unsupported, no device-type
1355                 buf[4] = 31;            // Additional length
1356                 return 36;
1357         }
1358
1359         memset(buf, 0, 8);
1360         buf[0] = (mod_data.cdrom ? TYPE_CDROM : TYPE_DISK);
1361         if (mod_data.removable)
1362                 buf[1] = 0x80;
1363         buf[2] = 2;             // ANSI SCSI level 2
1364         buf[3] = 2;             // SCSI-2 INQUIRY data format
1365         buf[4] = 31;            // Additional length
1366                                 // No special options
1367         sprintf(buf + 8, "%-8s%-16s%04x", vendor_id,
1368                         (mod_data.cdrom ? product_cdrom_id :
1369                                 product_disk_id),
1370                         mod_data.release);
1371         return 36;
1372 }
1373
1374
1375 static int do_request_sense(struct fsg_dev *fsg, struct fsg_buffhd *bh)
1376 {
1377         struct fsg_lun  *curlun = fsg->curlun;
1378         u8              *buf = (u8 *) bh->buf;
1379         u32             sd, sdinfo;
1380         int             valid;
1381
1382         /*
1383          * From the SCSI-2 spec., section 7.9 (Unit attention condition):
1384          *
1385          * If a REQUEST SENSE command is received from an initiator
1386          * with a pending unit attention condition (before the target
1387          * generates the contingent allegiance condition), then the
1388          * target shall either:
1389          *   a) report any pending sense data and preserve the unit
1390          *      attention condition on the logical unit, or,
1391          *   b) report the unit attention condition, may discard any
1392          *      pending sense data, and clear the unit attention
1393          *      condition on the logical unit for that initiator.
1394          *
1395          * FSG normally uses option a); enable this code to use option b).
1396          */
1397 #if 0
1398         if (curlun && curlun->unit_attention_data != SS_NO_SENSE) {
1399                 curlun->sense_data = curlun->unit_attention_data;
1400                 curlun->unit_attention_data = SS_NO_SENSE;
1401         }
1402 #endif
1403
1404         if (!curlun) {          // Unsupported LUNs are okay
1405                 fsg->bad_lun_okay = 1;
1406                 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
1407                 sdinfo = 0;
1408                 valid = 0;
1409         } else {
1410                 sd = curlun->sense_data;
1411                 sdinfo = curlun->sense_data_info;
1412                 valid = curlun->info_valid << 7;
1413                 curlun->sense_data = SS_NO_SENSE;
1414                 curlun->sense_data_info = 0;
1415                 curlun->info_valid = 0;
1416         }
1417
1418         memset(buf, 0, 18);
1419         buf[0] = valid | 0x70;                  // Valid, current error
1420         buf[2] = SK(sd);
1421         put_unaligned_be32(sdinfo, &buf[3]);    /* Sense information */
1422         buf[7] = 18 - 8;                        // Additional sense length
1423         buf[12] = ASC(sd);
1424         buf[13] = ASCQ(sd);
1425         return 18;
1426 }
1427
1428
1429 static int do_read_capacity(struct fsg_dev *fsg, struct fsg_buffhd *bh)
1430 {
1431         struct fsg_lun  *curlun = fsg->curlun;
1432         u32             lba = get_unaligned_be32(&fsg->cmnd[2]);
1433         int             pmi = fsg->cmnd[8];
1434         u8              *buf = (u8 *) bh->buf;
1435
1436         /* Check the PMI and LBA fields */
1437         if (pmi > 1 || (pmi == 0 && lba != 0)) {
1438                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1439                 return -EINVAL;
1440         }
1441
1442         put_unaligned_be32(curlun->num_sectors - 1, &buf[0]);
1443                                                 /* Max logical block */
1444         put_unaligned_be32(512, &buf[4]);       /* Block length */
1445         return 8;
1446 }
1447
1448
1449 static int do_read_header(struct fsg_dev *fsg, struct fsg_buffhd *bh)
1450 {
1451         struct fsg_lun  *curlun = fsg->curlun;
1452         int             msf = fsg->cmnd[1] & 0x02;
1453         u32             lba = get_unaligned_be32(&fsg->cmnd[2]);
1454         u8              *buf = (u8 *) bh->buf;
1455
1456         if ((fsg->cmnd[1] & ~0x02) != 0) {              /* Mask away MSF */
1457                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1458                 return -EINVAL;
1459         }
1460         if (lba >= curlun->num_sectors) {
1461                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1462                 return -EINVAL;
1463         }
1464
1465         memset(buf, 0, 8);
1466         buf[0] = 0x01;          /* 2048 bytes of user data, rest is EC */
1467         store_cdrom_address(&buf[4], msf, lba);
1468         return 8;
1469 }
1470
1471
1472 static int do_read_toc(struct fsg_dev *fsg, struct fsg_buffhd *bh)
1473 {
1474         struct fsg_lun  *curlun = fsg->curlun;
1475         int             msf = fsg->cmnd[1] & 0x02;
1476         int             start_track = fsg->cmnd[6];
1477         u8              *buf = (u8 *) bh->buf;
1478
1479         if ((fsg->cmnd[1] & ~0x02) != 0 ||              /* Mask away MSF */
1480                         start_track > 1) {
1481                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1482                 return -EINVAL;
1483         }
1484
1485         memset(buf, 0, 20);
1486         buf[1] = (20-2);                /* TOC data length */
1487         buf[2] = 1;                     /* First track number */
1488         buf[3] = 1;                     /* Last track number */
1489         buf[5] = 0x16;                  /* Data track, copying allowed */
1490         buf[6] = 0x01;                  /* Only track is number 1 */
1491         store_cdrom_address(&buf[8], msf, 0);
1492
1493         buf[13] = 0x16;                 /* Lead-out track is data */
1494         buf[14] = 0xAA;                 /* Lead-out track number */
1495         store_cdrom_address(&buf[16], msf, curlun->num_sectors);
1496         return 20;
1497 }
1498
1499
1500 static int do_mode_sense(struct fsg_dev *fsg, struct fsg_buffhd *bh)
1501 {
1502         struct fsg_lun  *curlun = fsg->curlun;
1503         int             mscmnd = fsg->cmnd[0];
1504         u8              *buf = (u8 *) bh->buf;
1505         u8              *buf0 = buf;
1506         int             pc, page_code;
1507         int             changeable_values, all_pages;
1508         int             valid_page = 0;
1509         int             len, limit;
1510
1511         if ((fsg->cmnd[1] & ~0x08) != 0) {              // Mask away DBD
1512                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1513                 return -EINVAL;
1514         }
1515         pc = fsg->cmnd[2] >> 6;
1516         page_code = fsg->cmnd[2] & 0x3f;
1517         if (pc == 3) {
1518                 curlun->sense_data = SS_SAVING_PARAMETERS_NOT_SUPPORTED;
1519                 return -EINVAL;
1520         }
1521         changeable_values = (pc == 1);
1522         all_pages = (page_code == 0x3f);
1523
1524         /* Write the mode parameter header.  Fixed values are: default
1525          * medium type, no cache control (DPOFUA), and no block descriptors.
1526          * The only variable value is the WriteProtect bit.  We will fill in
1527          * the mode data length later. */
1528         memset(buf, 0, 8);
1529         if (mscmnd == SC_MODE_SENSE_6) {
1530                 buf[2] = (curlun->ro ? 0x80 : 0x00);            // WP, DPOFUA
1531                 buf += 4;
1532                 limit = 255;
1533         } else {                        // SC_MODE_SENSE_10
1534                 buf[3] = (curlun->ro ? 0x80 : 0x00);            // WP, DPOFUA
1535                 buf += 8;
1536                 limit = 65535;          // Should really be FSG_BUFLEN
1537         }
1538
1539         /* No block descriptors */
1540
1541         /* The mode pages, in numerical order.  The only page we support
1542          * is the Caching page. */
1543         if (page_code == 0x08 || all_pages) {
1544                 valid_page = 1;
1545                 buf[0] = 0x08;          // Page code
1546                 buf[1] = 10;            // Page length
1547                 memset(buf+2, 0, 10);   // None of the fields are changeable
1548
1549                 if (!changeable_values) {
1550                         buf[2] = 0x04;  // Write cache enable,
1551                                         // Read cache not disabled
1552                                         // No cache retention priorities
1553                         put_unaligned_be16(0xffff, &buf[4]);
1554                                         /* Don't disable prefetch */
1555                                         /* Minimum prefetch = 0 */
1556                         put_unaligned_be16(0xffff, &buf[8]);
1557                                         /* Maximum prefetch */
1558                         put_unaligned_be16(0xffff, &buf[10]);
1559                                         /* Maximum prefetch ceiling */
1560                 }
1561                 buf += 12;
1562         }
1563
1564         /* Check that a valid page was requested and the mode data length
1565          * isn't too long. */
1566         len = buf - buf0;
1567         if (!valid_page || len > limit) {
1568                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1569                 return -EINVAL;
1570         }
1571
1572         /*  Store the mode data length */
1573         if (mscmnd == SC_MODE_SENSE_6)
1574                 buf0[0] = len - 1;
1575         else
1576                 put_unaligned_be16(len - 2, buf0);
1577         return len;
1578 }
1579
1580
1581 static int do_start_stop(struct fsg_dev *fsg)
1582 {
1583         if (!mod_data.removable) {
1584                 fsg->curlun->sense_data = SS_INVALID_COMMAND;
1585                 return -EINVAL;
1586         }
1587         return 0;
1588 }
1589
1590
1591 static int do_prevent_allow(struct fsg_dev *fsg)
1592 {
1593         struct fsg_lun  *curlun = fsg->curlun;
1594         int             prevent;
1595
1596         if (!mod_data.removable) {
1597                 curlun->sense_data = SS_INVALID_COMMAND;
1598                 return -EINVAL;
1599         }
1600
1601         prevent = fsg->cmnd[4] & 0x01;
1602         if ((fsg->cmnd[4] & ~0x01) != 0) {              // Mask away Prevent
1603                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1604                 return -EINVAL;
1605         }
1606
1607         if (curlun->prevent_medium_removal && !prevent)
1608                 fsg_lun_fsync_sub(curlun);
1609         curlun->prevent_medium_removal = prevent;
1610         return 0;
1611 }
1612
1613
1614 static int do_read_format_capacities(struct fsg_dev *fsg,
1615                         struct fsg_buffhd *bh)
1616 {
1617         struct fsg_lun  *curlun = fsg->curlun;
1618         u8              *buf = (u8 *) bh->buf;
1619
1620         buf[0] = buf[1] = buf[2] = 0;
1621         buf[3] = 8;             // Only the Current/Maximum Capacity Descriptor
1622         buf += 4;
1623
1624         put_unaligned_be32(curlun->num_sectors, &buf[0]);
1625                                                 /* Number of blocks */
1626         put_unaligned_be32(512, &buf[4]);       /* Block length */
1627         buf[4] = 0x02;                          /* Current capacity */
1628         return 12;
1629 }
1630
1631
1632 static int do_mode_select(struct fsg_dev *fsg, struct fsg_buffhd *bh)
1633 {
1634         struct fsg_lun  *curlun = fsg->curlun;
1635
1636         /* We don't support MODE SELECT */
1637         curlun->sense_data = SS_INVALID_COMMAND;
1638         return -EINVAL;
1639 }
1640
1641
1642 /*-------------------------------------------------------------------------*/
1643
1644 static int halt_bulk_in_endpoint(struct fsg_dev *fsg)
1645 {
1646         int     rc;
1647
1648         rc = fsg_set_halt(fsg, fsg->bulk_in);
1649         if (rc == -EAGAIN)
1650                 VDBG(fsg, "delayed bulk-in endpoint halt\n");
1651         while (rc != 0) {
1652                 if (rc != -EAGAIN) {
1653                         WARNING(fsg, "usb_ep_set_halt -> %d\n", rc);
1654                         rc = 0;
1655                         break;
1656                 }
1657
1658                 /* Wait for a short time and then try again */
1659                 if (msleep_interruptible(100) != 0)
1660                         return -EINTR;
1661                 rc = usb_ep_set_halt(fsg->bulk_in);
1662         }
1663         return rc;
1664 }
1665
1666 static int wedge_bulk_in_endpoint(struct fsg_dev *fsg)
1667 {
1668         int     rc;
1669
1670         DBG(fsg, "bulk-in set wedge\n");
1671         rc = usb_ep_set_wedge(fsg->bulk_in);
1672         if (rc == -EAGAIN)
1673                 VDBG(fsg, "delayed bulk-in endpoint wedge\n");
1674         while (rc != 0) {
1675                 if (rc != -EAGAIN) {
1676                         WARNING(fsg, "usb_ep_set_wedge -> %d\n", rc);
1677                         rc = 0;
1678                         break;
1679                 }
1680
1681                 /* Wait for a short time and then try again */
1682                 if (msleep_interruptible(100) != 0)
1683                         return -EINTR;
1684                 rc = usb_ep_set_wedge(fsg->bulk_in);
1685         }
1686         return rc;
1687 }
1688
1689 static int pad_with_zeros(struct fsg_dev *fsg)
1690 {
1691         struct fsg_buffhd       *bh = fsg->next_buffhd_to_fill;
1692         u32                     nkeep = bh->inreq->length;
1693         u32                     nsend;
1694         int                     rc;
1695
1696         bh->state = BUF_STATE_EMPTY;            // For the first iteration
1697         fsg->usb_amount_left = nkeep + fsg->residue;
1698         while (fsg->usb_amount_left > 0) {
1699
1700                 /* Wait for the next buffer to be free */
1701                 while (bh->state != BUF_STATE_EMPTY) {
1702                         rc = sleep_thread(fsg);
1703                         if (rc)
1704                                 return rc;
1705                 }
1706
1707                 nsend = min(fsg->usb_amount_left, FSG_BUFLEN);
1708                 memset(bh->buf + nkeep, 0, nsend - nkeep);
1709                 bh->inreq->length = nsend;
1710                 bh->inreq->zero = 0;
1711                 start_transfer(fsg, fsg->bulk_in, bh->inreq,
1712                                 &bh->inreq_busy, &bh->state);
1713                 bh = fsg->next_buffhd_to_fill = bh->next;
1714                 fsg->usb_amount_left -= nsend;
1715                 nkeep = 0;
1716         }
1717         return 0;
1718 }
1719
1720 static int throw_away_data(struct fsg_dev *fsg)
1721 {
1722         struct fsg_buffhd       *bh;
1723         u32                     amount;
1724         int                     rc;
1725
1726         while ((bh = fsg->next_buffhd_to_drain)->state != BUF_STATE_EMPTY ||
1727                         fsg->usb_amount_left > 0) {
1728
1729                 /* Throw away the data in a filled buffer */
1730                 if (bh->state == BUF_STATE_FULL) {
1731                         smp_rmb();
1732                         bh->state = BUF_STATE_EMPTY;
1733                         fsg->next_buffhd_to_drain = bh->next;
1734
1735                         /* A short packet or an error ends everything */
1736                         if (bh->outreq->actual != bh->outreq->length ||
1737                                         bh->outreq->status != 0) {
1738                                 raise_exception(fsg, FSG_STATE_ABORT_BULK_OUT);
1739                                 return -EINTR;
1740                         }
1741                         continue;
1742                 }
1743
1744                 /* Try to submit another request if we need one */
1745                 bh = fsg->next_buffhd_to_fill;
1746                 if (bh->state == BUF_STATE_EMPTY && fsg->usb_amount_left > 0) {
1747                         amount = min(fsg->usb_amount_left, FSG_BUFLEN);
1748
1749                         /* amount is always divisible by 512, hence by
1750                          * the bulk-out maxpacket size */
1751                         bh->outreq->length = bh->bulk_out_intended_length =
1752                                         amount;
1753                         bh->outreq->short_not_ok = 1;
1754                         start_transfer(fsg, fsg->bulk_out, bh->outreq,
1755                                         &bh->outreq_busy, &bh->state);
1756                         fsg->next_buffhd_to_fill = bh->next;
1757                         fsg->usb_amount_left -= amount;
1758                         continue;
1759                 }
1760
1761                 /* Otherwise wait for something to happen */
1762                 rc = sleep_thread(fsg);
1763                 if (rc)
1764                         return rc;
1765         }
1766         return 0;
1767 }
1768
1769
1770 static int finish_reply(struct fsg_dev *fsg)
1771 {
1772         struct fsg_buffhd       *bh = fsg->next_buffhd_to_fill;
1773         int                     rc = 0;
1774
1775         switch (fsg->data_dir) {
1776         case DATA_DIR_NONE:
1777                 break;                  // Nothing to send
1778
1779         /* If we don't know whether the host wants to read or write,
1780          * this must be CB or CBI with an unknown command.  We mustn't
1781          * try to send or receive any data.  So stall both bulk pipes
1782          * if we can and wait for a reset. */
1783         case DATA_DIR_UNKNOWN:
1784                 if (mod_data.can_stall) {
1785                         fsg_set_halt(fsg, fsg->bulk_out);
1786                         rc = halt_bulk_in_endpoint(fsg);
1787                 }
1788                 break;
1789
1790         /* All but the last buffer of data must have already been sent */
1791         case DATA_DIR_TO_HOST:
1792                 if (fsg->data_size == 0) {
1793                         /* Nothing to send */
1794
1795                 /* If there's no residue, simply send the last buffer */
1796                 } else if (fsg->residue == 0) {
1797                         bh->inreq->zero = 0;
1798                         start_transfer(fsg, fsg->bulk_in, bh->inreq,
1799                                         &bh->inreq_busy, &bh->state);
1800                         fsg->next_buffhd_to_fill = bh->next;
1801
1802                 /* For Bulk-only, if we're allowed to stall then send the
1803                  * short packet and halt the bulk-in endpoint.  If we can't
1804                  * stall, pad out the remaining data with 0's. */
1805                 } else if (mod_data.can_stall) {
1806                         bh->inreq->zero = 1;
1807                         start_transfer(fsg, fsg->bulk_in, bh->inreq,
1808                                        &bh->inreq_busy, &bh->state);
1809                         fsg->next_buffhd_to_fill = bh->next;
1810                         rc = halt_bulk_in_endpoint(fsg);
1811                 } else {
1812                         rc = pad_with_zeros(fsg);
1813                 }
1814                 break;
1815
1816         /* We have processed all we want from the data the host has sent.
1817          * There may still be outstanding bulk-out requests. */
1818         case DATA_DIR_FROM_HOST:
1819                 if (fsg->residue == 0)
1820                         ;               // Nothing to receive
1821
1822                 /* Did the host stop sending unexpectedly early? */
1823                 else if (fsg->short_packet_received) {
1824                         raise_exception(fsg, FSG_STATE_ABORT_BULK_OUT);
1825                         rc = -EINTR;
1826                 }
1827
1828                 /* We haven't processed all the incoming data.  Even though
1829                  * we may be allowed to stall, doing so would cause a race.
1830                  * The controller may already have ACK'ed all the remaining
1831                  * bulk-out packets, in which case the host wouldn't see a
1832                  * STALL.  Not realizing the endpoint was halted, it wouldn't
1833                  * clear the halt -- leading to problems later on. */
1834 #if 0
1835                 else if (mod_data.can_stall) {
1836                         fsg_set_halt(fsg, fsg->bulk_out);
1837                         raise_exception(fsg, FSG_STATE_ABORT_BULK_OUT);
1838                         rc = -EINTR;
1839                 }
1840 #endif
1841
1842                 /* We can't stall.  Read in the excess data and throw it
1843                  * all away. */
1844                 else
1845                         rc = throw_away_data(fsg);
1846                 break;
1847         }
1848         return rc;
1849 }
1850
1851
1852 static int send_status(struct fsg_dev *fsg)
1853 {
1854         struct fsg_lun          *curlun = fsg->curlun;
1855         struct fsg_buffhd       *bh;
1856         struct bulk_cs_wrap     *csw;
1857         int                     rc;
1858         u8                      status = USB_STATUS_PASS;
1859         u32                     sd, sdinfo = 0;
1860
1861         /* Wait for the next buffer to become available */
1862         bh = fsg->next_buffhd_to_fill;
1863         while (bh->state != BUF_STATE_EMPTY) {
1864                 rc = sleep_thread(fsg);
1865                 if (rc)
1866                         return rc;
1867         }
1868
1869         if (curlun) {
1870                 sd = curlun->sense_data;
1871                 sdinfo = curlun->sense_data_info;
1872         } else if (fsg->bad_lun_okay)
1873                 sd = SS_NO_SENSE;
1874         else
1875                 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
1876
1877         if (fsg->phase_error) {
1878                 DBG(fsg, "sending phase-error status\n");
1879                 status = USB_STATUS_PHASE_ERROR;
1880                 sd = SS_INVALID_COMMAND;
1881         } else if (sd != SS_NO_SENSE) {
1882                 DBG(fsg, "sending command-failure status\n");
1883                 status = USB_STATUS_FAIL;
1884                 VDBG(fsg, "  sense data: SK x%02x, ASC x%02x, ASCQ x%02x;"
1885                                 "  info x%x\n",
1886                                 SK(sd), ASC(sd), ASCQ(sd), sdinfo);
1887         }
1888
1889
1890         /* Store and send the Bulk-only CSW */
1891         csw = bh->buf;
1892
1893         csw->Signature = cpu_to_le32(USB_BULK_CS_SIG);
1894         csw->Tag = fsg->tag;
1895         csw->Residue = cpu_to_le32(fsg->residue);
1896         csw->Status = status;
1897
1898         bh->inreq->length = USB_BULK_CS_WRAP_LEN;
1899         bh->inreq->zero = 0;
1900         start_transfer(fsg, fsg->bulk_in, bh->inreq,
1901                        &bh->inreq_busy, &bh->state);
1902
1903         fsg->next_buffhd_to_fill = bh->next;
1904         return 0;
1905 }
1906
1907
1908 /*-------------------------------------------------------------------------*/
1909
1910 /* Check whether the command is properly formed and whether its data size
1911  * and direction agree with the values we already have. */
1912 static int check_command(struct fsg_dev *fsg, int cmnd_size,
1913                 enum data_direction data_dir, unsigned int mask,
1914                 int needs_medium, const char *name)
1915 {
1916         int                     i;
1917         int                     lun = fsg->cmnd[1] >> 5;
1918         static const char       dirletter[4] = {'u', 'o', 'i', 'n'};
1919         char                    hdlen[20];
1920         struct fsg_lun          *curlun;
1921
1922         hdlen[0] = 0;
1923         if (fsg->data_dir != DATA_DIR_UNKNOWN)
1924                 sprintf(hdlen, ", H%c=%u", dirletter[(int) fsg->data_dir],
1925                                 fsg->data_size);
1926         VDBG(fsg, "SCSI command: %s;  Dc=%d, D%c=%u;  Hc=%d%s\n",
1927                         name, cmnd_size, dirletter[(int) data_dir],
1928                         fsg->data_size_from_cmnd, fsg->cmnd_size, hdlen);
1929
1930         /* We can't reply at all until we know the correct data direction
1931          * and size. */
1932         if (fsg->data_size_from_cmnd == 0)
1933                 data_dir = DATA_DIR_NONE;
1934         if (fsg->data_dir == DATA_DIR_UNKNOWN) {        // CB or CBI
1935                 fsg->data_dir = data_dir;
1936                 fsg->data_size = fsg->data_size_from_cmnd;
1937
1938         } else {                                        // Bulk-only
1939                 if (fsg->data_size < fsg->data_size_from_cmnd) {
1940
1941                         /* Host data size < Device data size is a phase error.
1942                          * Carry out the command, but only transfer as much
1943                          * as we are allowed. */
1944                         fsg->data_size_from_cmnd = fsg->data_size;
1945                         fsg->phase_error = 1;
1946                 }
1947         }
1948         fsg->residue = fsg->usb_amount_left = fsg->data_size;
1949
1950         /* Conflicting data directions is a phase error */
1951         if (fsg->data_dir != data_dir && fsg->data_size_from_cmnd > 0) {
1952                 fsg->phase_error = 1;
1953                 return -EINVAL;
1954         }
1955
1956         /* Verify the length of the command itself */
1957         if (cmnd_size != fsg->cmnd_size) {
1958
1959                 /* Special case workaround: There are plenty of buggy SCSI
1960                  * implementations. Many have issues with cbw->Length
1961                  * field passing a wrong command size. For those cases we
1962                  * always try to work around the problem by using the length
1963                  * sent by the host side provided it is at least as large
1964                  * as the correct command length.
1965                  * Examples of such cases would be MS-Windows, which issues
1966                  * REQUEST SENSE with cbw->Length == 12 where it should
1967                  * be 6, and xbox360 issuing INQUIRY, TEST UNIT READY and
1968                  * REQUEST SENSE with cbw->Length == 10 where it should
1969                  * be 6 as well.
1970                  */
1971                 if (cmnd_size <= fsg->cmnd_size) {
1972                         DBG(fsg, "%s is buggy! Expected length %d "
1973                                         "but we got %d\n", name,
1974                                         cmnd_size, fsg->cmnd_size);
1975                         cmnd_size = fsg->cmnd_size;
1976                 } else {
1977                         fsg->phase_error = 1;
1978                         return -EINVAL;
1979                 }
1980         }
1981
1982         /* Check that the LUN values are consistent */
1983         if (fsg->lun != lun)
1984                 DBG(fsg, "using LUN %d from CBW, not LUN %d from CDB\n",
1985                     fsg->lun, lun);
1986
1987         /* Check the LUN */
1988         if (fsg->lun >= 0 && fsg->lun < fsg->nluns) {
1989                 fsg->curlun = curlun = &fsg->luns[fsg->lun];
1990                 if (fsg->cmnd[0] != SC_REQUEST_SENSE) {
1991                         curlun->sense_data = SS_NO_SENSE;
1992                         curlun->sense_data_info = 0;
1993                         curlun->info_valid = 0;
1994                 }
1995         } else {
1996                 fsg->curlun = curlun = NULL;
1997                 fsg->bad_lun_okay = 0;
1998
1999                 /* INQUIRY and REQUEST SENSE commands are explicitly allowed
2000                  * to use unsupported LUNs; all others may not. */
2001                 if (fsg->cmnd[0] != SC_INQUIRY &&
2002                                 fsg->cmnd[0] != SC_REQUEST_SENSE) {
2003                         DBG(fsg, "unsupported LUN %d\n", fsg->lun);
2004                         return -EINVAL;
2005                 }
2006         }
2007
2008         /* If a unit attention condition exists, only INQUIRY and
2009          * REQUEST SENSE commands are allowed; anything else must fail. */
2010         if (curlun && curlun->unit_attention_data != SS_NO_SENSE &&
2011                         fsg->cmnd[0] != SC_INQUIRY &&
2012                         fsg->cmnd[0] != SC_REQUEST_SENSE) {
2013                 curlun->sense_data = curlun->unit_attention_data;
2014                 curlun->unit_attention_data = SS_NO_SENSE;
2015                 return -EINVAL;
2016         }
2017
2018         /* Check that only command bytes listed in the mask are non-zero */
2019         fsg->cmnd[1] &= 0x1f;                   // Mask away the LUN
2020         for (i = 1; i < cmnd_size; ++i) {
2021                 if (fsg->cmnd[i] && !(mask & (1 << i))) {
2022                         if (curlun)
2023                                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
2024                         return -EINVAL;
2025                 }
2026         }
2027
2028         /* If the medium isn't mounted and the command needs to access
2029          * it, return an error. */
2030         if (curlun && !fsg_lun_is_open(curlun) && needs_medium) {
2031                 curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
2032                 return -EINVAL;
2033         }
2034
2035         return 0;
2036 }
2037
2038
2039 static int do_scsi_command(struct fsg_dev *fsg)
2040 {
2041         struct fsg_buffhd       *bh;
2042         int                     rc;
2043         int                     reply = -EINVAL;
2044         int                     i;
2045         static char             unknown[16];
2046
2047         dump_cdb(fsg);
2048
2049         /* Wait for the next buffer to become available for data or status */
2050         bh = fsg->next_buffhd_to_drain = fsg->next_buffhd_to_fill;
2051         while (bh->state != BUF_STATE_EMPTY) {
2052                 rc = sleep_thread(fsg);
2053                 if (rc)
2054                         return rc;
2055         }
2056         fsg->phase_error = 0;
2057         fsg->short_packet_received = 0;
2058
2059         down_read(&fsg->filesem);       // We're using the backing file
2060         switch (fsg->cmnd[0]) {
2061
2062         case SC_INQUIRY:
2063                 fsg->data_size_from_cmnd = fsg->cmnd[4];
2064                 if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
2065                                 (1<<4), 0,
2066                                 "INQUIRY")) == 0)
2067                         reply = do_inquiry(fsg, bh);
2068                 break;
2069
2070         case SC_MODE_SELECT_6:
2071                 fsg->data_size_from_cmnd = fsg->cmnd[4];
2072                 if ((reply = check_command(fsg, 6, DATA_DIR_FROM_HOST,
2073                                 (1<<1) | (1<<4), 0,
2074                                 "MODE SELECT(6)")) == 0)
2075                         reply = do_mode_select(fsg, bh);
2076                 break;
2077
2078         case SC_MODE_SELECT_10:
2079                 fsg->data_size_from_cmnd = get_unaligned_be16(&fsg->cmnd[7]);
2080                 if ((reply = check_command(fsg, 10, DATA_DIR_FROM_HOST,
2081                                 (1<<1) | (3<<7), 0,
2082                                 "MODE SELECT(10)")) == 0)
2083                         reply = do_mode_select(fsg, bh);
2084                 break;
2085
2086         case SC_MODE_SENSE_6:
2087                 fsg->data_size_from_cmnd = fsg->cmnd[4];
2088                 if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
2089                                 (1<<1) | (1<<2) | (1<<4), 0,
2090                                 "MODE SENSE(6)")) == 0)
2091                         reply = do_mode_sense(fsg, bh);
2092                 break;
2093
2094         case SC_MODE_SENSE_10:
2095                 fsg->data_size_from_cmnd = get_unaligned_be16(&fsg->cmnd[7]);
2096                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2097                                 (1<<1) | (1<<2) | (3<<7), 0,
2098                                 "MODE SENSE(10)")) == 0)
2099                         reply = do_mode_sense(fsg, bh);
2100                 break;
2101
2102         case SC_PREVENT_ALLOW_MEDIUM_REMOVAL:
2103                 fsg->data_size_from_cmnd = 0;
2104                 if ((reply = check_command(fsg, 6, DATA_DIR_NONE,
2105                                 (1<<4), 0,
2106                                 "PREVENT-ALLOW MEDIUM REMOVAL")) == 0)
2107                         reply = do_prevent_allow(fsg);
2108                 break;
2109
2110         case SC_READ_6:
2111                 i = fsg->cmnd[4];
2112                 fsg->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
2113                 if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
2114                                 (7<<1) | (1<<4), 1,
2115                                 "READ(6)")) == 0)
2116                         reply = do_read(fsg);
2117                 break;
2118
2119         case SC_READ_10:
2120                 fsg->data_size_from_cmnd =
2121                                 get_unaligned_be16(&fsg->cmnd[7]) << 9;
2122                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2123                                 (1<<1) | (0xf<<2) | (3<<7), 1,
2124                                 "READ(10)")) == 0)
2125                         reply = do_read(fsg);
2126                 break;
2127
2128         case SC_READ_12:
2129                 fsg->data_size_from_cmnd =
2130                                 get_unaligned_be32(&fsg->cmnd[6]) << 9;
2131                 if ((reply = check_command(fsg, 12, DATA_DIR_TO_HOST,
2132                                 (1<<1) | (0xf<<2) | (0xf<<6), 1,
2133                                 "READ(12)")) == 0)
2134                         reply = do_read(fsg);
2135                 break;
2136
2137         case SC_READ_CAPACITY:
2138                 fsg->data_size_from_cmnd = 8;
2139                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2140                                 (0xf<<2) | (1<<8), 1,
2141                                 "READ CAPACITY")) == 0)
2142                         reply = do_read_capacity(fsg, bh);
2143                 break;
2144
2145         case SC_READ_HEADER:
2146                 if (!mod_data.cdrom)
2147                         goto unknown_cmnd;
2148                 fsg->data_size_from_cmnd = get_unaligned_be16(&fsg->cmnd[7]);
2149                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2150                                 (3<<7) | (0x1f<<1), 1,
2151                                 "READ HEADER")) == 0)
2152                         reply = do_read_header(fsg, bh);
2153                 break;
2154
2155         case SC_READ_TOC:
2156                 if (!mod_data.cdrom)
2157                         goto unknown_cmnd;
2158                 fsg->data_size_from_cmnd = get_unaligned_be16(&fsg->cmnd[7]);
2159                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2160                                 (7<<6) | (1<<1), 1,
2161                                 "READ TOC")) == 0)
2162                         reply = do_read_toc(fsg, bh);
2163                 break;
2164
2165         case SC_READ_FORMAT_CAPACITIES:
2166                 fsg->data_size_from_cmnd = get_unaligned_be16(&fsg->cmnd[7]);
2167                 if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST,
2168                                 (3<<7), 1,
2169                                 "READ FORMAT CAPACITIES")) == 0)
2170                         reply = do_read_format_capacities(fsg, bh);
2171                 break;
2172
2173         case SC_REQUEST_SENSE:
2174                 fsg->data_size_from_cmnd = fsg->cmnd[4];
2175                 if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST,
2176                                 (1<<4), 0,
2177                                 "REQUEST SENSE")) == 0)
2178                         reply = do_request_sense(fsg, bh);
2179                 break;
2180
2181         case SC_START_STOP_UNIT:
2182                 fsg->data_size_from_cmnd = 0;
2183                 if ((reply = check_command(fsg, 6, DATA_DIR_NONE,
2184                                 (1<<1) | (1<<4), 0,
2185                                 "START-STOP UNIT")) == 0)
2186                         reply = do_start_stop(fsg);
2187                 break;
2188
2189         case SC_SYNCHRONIZE_CACHE:
2190                 fsg->data_size_from_cmnd = 0;
2191                 if ((reply = check_command(fsg, 10, DATA_DIR_NONE,
2192                                 (0xf<<2) | (3<<7), 1,
2193                                 "SYNCHRONIZE CACHE")) == 0)
2194                         reply = do_synchronize_cache(fsg);
2195                 break;
2196
2197         case SC_TEST_UNIT_READY:
2198                 fsg->data_size_from_cmnd = 0;
2199                 reply = check_command(fsg, 6, DATA_DIR_NONE,
2200                                 0, 1,
2201                                 "TEST UNIT READY");
2202                 break;
2203
2204         /* Although optional, this command is used by MS-Windows.  We
2205          * support a minimal version: BytChk must be 0. */
2206         case SC_VERIFY:
2207                 fsg->data_size_from_cmnd = 0;
2208                 if ((reply = check_command(fsg, 10, DATA_DIR_NONE,
2209                                 (1<<1) | (0xf<<2) | (3<<7), 1,
2210                                 "VERIFY")) == 0)
2211                         reply = do_verify(fsg);
2212                 break;
2213
2214         case SC_WRITE_6:
2215                 i = fsg->cmnd[4];
2216                 fsg->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
2217                 if ((reply = check_command(fsg, 6, DATA_DIR_FROM_HOST,
2218                                 (7<<1) | (1<<4), 1,
2219                                 "WRITE(6)")) == 0)
2220                         reply = do_write(fsg);
2221                 break;
2222
2223         case SC_WRITE_10:
2224                 fsg->data_size_from_cmnd =
2225                                 get_unaligned_be16(&fsg->cmnd[7]) << 9;
2226                 if ((reply = check_command(fsg, 10, DATA_DIR_FROM_HOST,
2227                                 (1<<1) | (0xf<<2) | (3<<7), 1,
2228                                 "WRITE(10)")) == 0)
2229                         reply = do_write(fsg);
2230                 break;
2231
2232         case SC_WRITE_12:
2233                 fsg->data_size_from_cmnd =
2234                                 get_unaligned_be32(&fsg->cmnd[6]) << 9;
2235                 if ((reply = check_command(fsg, 12, DATA_DIR_FROM_HOST,
2236                                 (1<<1) | (0xf<<2) | (0xf<<6), 1,
2237                                 "WRITE(12)")) == 0)
2238                         reply = do_write(fsg);
2239                 break;
2240
2241         /* Some mandatory commands that we recognize but don't implement.
2242          * They don't mean much in this setting.  It's left as an exercise
2243          * for anyone interested to implement RESERVE and RELEASE in terms
2244          * of Posix locks. */
2245         case SC_FORMAT_UNIT:
2246         case SC_RELEASE:
2247         case SC_RESERVE:
2248         case SC_SEND_DIAGNOSTIC:
2249                 // Fall through
2250
2251         default:
2252  unknown_cmnd:
2253                 fsg->data_size_from_cmnd = 0;
2254                 sprintf(unknown, "Unknown x%02x", fsg->cmnd[0]);
2255                 if ((reply = check_command(fsg, fsg->cmnd_size,
2256                                 DATA_DIR_UNKNOWN, 0xff, 0, unknown)) == 0) {
2257                         fsg->curlun->sense_data = SS_INVALID_COMMAND;
2258                         reply = -EINVAL;
2259                 }
2260                 break;
2261         }
2262         up_read(&fsg->filesem);
2263
2264         if (reply == -EINTR || signal_pending(current))
2265                 return -EINTR;
2266
2267         /* Set up the single reply buffer for finish_reply() */
2268         if (reply == -EINVAL)
2269                 reply = 0;              // Error reply length
2270         if (reply >= 0 && fsg->data_dir == DATA_DIR_TO_HOST) {
2271                 reply = min((u32) reply, fsg->data_size_from_cmnd);
2272                 bh->inreq->length = reply;
2273                 bh->state = BUF_STATE_FULL;
2274                 fsg->residue -= reply;
2275         }                               // Otherwise it's already set
2276
2277         return 0;
2278 }
2279
2280
2281 /*-------------------------------------------------------------------------*/
2282
2283 static int received_cbw(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2284 {
2285         struct usb_request              *req = bh->outreq;
2286         struct fsg_bulk_cb_wrap *cbw = req->buf;
2287
2288         /* Was this a real packet?  Should it be ignored? */
2289         if (req->status || test_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags))
2290                 return -EINVAL;
2291
2292         /* Is the CBW valid? */
2293         if (req->actual != USB_BULK_CB_WRAP_LEN ||
2294                         cbw->Signature != cpu_to_le32(
2295                                 USB_BULK_CB_SIG)) {
2296                 DBG(fsg, "invalid CBW: len %u sig 0x%x\n",
2297                                 req->actual,
2298                                 le32_to_cpu(cbw->Signature));
2299
2300                 /* The Bulk-only spec says we MUST stall the IN endpoint
2301                  * (6.6.1), so it's unavoidable.  It also says we must
2302                  * retain this state until the next reset, but there's
2303                  * no way to tell the controller driver it should ignore
2304                  * Clear-Feature(HALT) requests.
2305                  *
2306                  * We aren't required to halt the OUT endpoint; instead
2307                  * we can simply accept and discard any data received
2308                  * until the next reset. */
2309                 wedge_bulk_in_endpoint(fsg);
2310                 set_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
2311                 return -EINVAL;
2312         }
2313
2314         /* Is the CBW meaningful? */
2315         if (cbw->Lun >= FSG_MAX_LUNS || cbw->Flags & ~USB_BULK_IN_FLAG ||
2316                         cbw->Length <= 0 || cbw->Length > MAX_COMMAND_SIZE) {
2317                 DBG(fsg, "non-meaningful CBW: lun = %u, flags = 0x%x, "
2318                                 "cmdlen %u\n",
2319                                 cbw->Lun, cbw->Flags, cbw->Length);
2320
2321                 /* We can do anything we want here, so let's stall the
2322                  * bulk pipes if we are allowed to. */
2323                 if (mod_data.can_stall) {
2324                         fsg_set_halt(fsg, fsg->bulk_out);
2325                         halt_bulk_in_endpoint(fsg);
2326                 }
2327                 return -EINVAL;
2328         }
2329
2330         /* Save the command for later */
2331         fsg->cmnd_size = cbw->Length;
2332         memcpy(fsg->cmnd, cbw->CDB, fsg->cmnd_size);
2333         if (cbw->Flags & USB_BULK_IN_FLAG)
2334                 fsg->data_dir = DATA_DIR_TO_HOST;
2335         else
2336                 fsg->data_dir = DATA_DIR_FROM_HOST;
2337         fsg->data_size = le32_to_cpu(cbw->DataTransferLength);
2338         if (fsg->data_size == 0)
2339                 fsg->data_dir = DATA_DIR_NONE;
2340         fsg->lun = cbw->Lun;
2341         fsg->tag = cbw->Tag;
2342         return 0;
2343 }
2344
2345
2346 static int get_next_command(struct fsg_dev *fsg)
2347 {
2348         struct fsg_buffhd       *bh;
2349         int                     rc = 0;
2350
2351         /* Wait for the next buffer to become available */
2352         bh = fsg->next_buffhd_to_fill;
2353         while (bh->state != BUF_STATE_EMPTY) {
2354                 rc = sleep_thread(fsg);
2355                 if (rc)
2356                         return rc;
2357         }
2358
2359         /* Queue a request to read a Bulk-only CBW */
2360         set_bulk_out_req_length(fsg, bh, USB_BULK_CB_WRAP_LEN);
2361         bh->outreq->short_not_ok = 1;
2362         start_transfer(fsg, fsg->bulk_out, bh->outreq,
2363                        &bh->outreq_busy, &bh->state);
2364
2365         /* We will drain the buffer in software, which means we
2366          * can reuse it for the next filling.  No need to advance
2367          * next_buffhd_to_fill. */
2368
2369         /* Wait for the CBW to arrive */
2370         while (bh->state != BUF_STATE_FULL) {
2371                 rc = sleep_thread(fsg);
2372                 if (rc)
2373                         return rc;
2374         }
2375         smp_rmb();
2376         rc = received_cbw(fsg, bh);
2377         bh->state = BUF_STATE_EMPTY;
2378
2379         return rc;
2380 }
2381
2382
2383 /*-------------------------------------------------------------------------*/
2384
2385 static int enable_endpoint(struct fsg_dev *fsg, struct usb_ep *ep,
2386                 const struct usb_endpoint_descriptor *d)
2387 {
2388         int     rc;
2389
2390         ep->driver_data = fsg;
2391         rc = usb_ep_enable(ep, d);
2392         if (rc)
2393                 ERROR(fsg, "can't enable %s, result %d\n", ep->name, rc);
2394         return rc;
2395 }
2396
2397 static int alloc_request(struct fsg_dev *fsg, struct usb_ep *ep,
2398                 struct usb_request **preq)
2399 {
2400         *preq = usb_ep_alloc_request(ep, GFP_ATOMIC);
2401         if (*preq)
2402                 return 0;
2403         ERROR(fsg, "can't allocate request for %s\n", ep->name);
2404         return -ENOMEM;
2405 }
2406
2407 /*
2408  * Reset interface setting and re-init endpoint state (toggle etc).
2409  * Call with altsetting < 0 to disable the interface.  The only other
2410  * available altsetting is 0, which enables the interface.
2411  */
2412 static int do_set_interface(struct fsg_dev *fsg, int altsetting)
2413 {
2414         int     rc = 0;
2415         int     i;
2416         const struct usb_endpoint_descriptor    *d;
2417
2418         if (fsg->running)
2419                 DBG(fsg, "reset interface\n");
2420
2421 reset:
2422         /* Deallocate the requests */
2423         for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
2424                 struct fsg_buffhd *bh = &fsg->buffhds[i];
2425
2426                 if (bh->inreq) {
2427                         usb_ep_free_request(fsg->bulk_in, bh->inreq);
2428                         bh->inreq = NULL;
2429                 }
2430                 if (bh->outreq) {
2431                         usb_ep_free_request(fsg->bulk_out, bh->outreq);
2432                         bh->outreq = NULL;
2433                 }
2434         }
2435
2436         /* Disable the endpoints */
2437         if (fsg->bulk_in_enabled) {
2438                 usb_ep_disable(fsg->bulk_in);
2439                 fsg->bulk_in_enabled = 0;
2440         }
2441         if (fsg->bulk_out_enabled) {
2442                 usb_ep_disable(fsg->bulk_out);
2443                 fsg->bulk_out_enabled = 0;
2444         }
2445
2446         fsg->running = 0;
2447         if (altsetting < 0 || rc != 0)
2448                 return rc;
2449
2450         DBG(fsg, "set interface %d\n", altsetting);
2451
2452         /* Enable the endpoints */
2453         d = fsg_ep_desc(fsg->gadget,
2454                         &fsg_fs_bulk_in_desc, &fsg_hs_bulk_in_desc);
2455         if ((rc = enable_endpoint(fsg, fsg->bulk_in, d)) != 0)
2456                 goto reset;
2457         fsg->bulk_in_enabled = 1;
2458
2459         d = fsg_ep_desc(fsg->gadget,
2460                         &fsg_fs_bulk_out_desc, &fsg_hs_bulk_out_desc);
2461         if ((rc = enable_endpoint(fsg, fsg->bulk_out, d)) != 0)
2462                 goto reset;
2463         fsg->bulk_out_enabled = 1;
2464         fsg->bulk_out_maxpacket = le16_to_cpu(d->wMaxPacketSize);
2465         clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
2466
2467         /* Allocate the requests */
2468         for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
2469                 struct fsg_buffhd       *bh = &fsg->buffhds[i];
2470
2471                 if ((rc = alloc_request(fsg, fsg->bulk_in, &bh->inreq)) != 0)
2472                         goto reset;
2473                 if ((rc = alloc_request(fsg, fsg->bulk_out, &bh->outreq)) != 0)
2474                         goto reset;
2475                 bh->inreq->buf = bh->outreq->buf = bh->buf;
2476                 bh->inreq->context = bh->outreq->context = bh;
2477                 bh->inreq->complete = bulk_in_complete;
2478                 bh->outreq->complete = bulk_out_complete;
2479         }
2480
2481         fsg->running = 1;
2482         for (i = 0; i < fsg->nluns; ++i)
2483                 fsg->luns[i].unit_attention_data = SS_RESET_OCCURRED;
2484         return rc;
2485 }
2486
2487
2488 /*
2489  * Change our operational configuration.  This code must agree with the code
2490  * that returns config descriptors, and with interface altsetting code.
2491  *
2492  * It's also responsible for power management interactions.  Some
2493  * configurations might not work with our current power sources.
2494  * For now we just assume the gadget is always self-powered.
2495  */
2496 static int do_set_config(struct fsg_dev *fsg, u8 new_config)
2497 {
2498         int     rc = 0;
2499
2500         /* Disable the single interface */
2501         if (fsg->config != 0) {
2502                 DBG(fsg, "reset config\n");
2503                 fsg->config = 0;
2504                 rc = do_set_interface(fsg, -1);
2505         }
2506
2507         /* Enable the interface */
2508         if (new_config != 0) {
2509                 fsg->config = new_config;
2510                 if ((rc = do_set_interface(fsg, 0)) != 0)
2511                         fsg->config = 0;        // Reset on errors
2512                 else {
2513                         char *speed;
2514
2515                         switch (fsg->gadget->speed) {
2516                         case USB_SPEED_LOW:     speed = "low";  break;
2517                         case USB_SPEED_FULL:    speed = "full"; break;
2518                         case USB_SPEED_HIGH:    speed = "high"; break;
2519                         default:                speed = "?";    break;
2520                         }
2521                         INFO(fsg, "%s speed config #%d\n", speed, fsg->config);
2522                 }
2523         }
2524         return rc;
2525 }
2526
2527
2528 /*-------------------------------------------------------------------------*/
2529
2530 static void handle_exception(struct fsg_dev *fsg)
2531 {
2532         siginfo_t               info;
2533         int                     sig;
2534         int                     i;
2535         int                     num_active;
2536         struct fsg_buffhd       *bh;
2537         enum fsg_state          old_state;
2538         u8                      new_config;
2539         struct fsg_lun          *curlun;
2540         unsigned int            exception_req_tag;
2541         int                     rc;
2542
2543         /* Clear the existing signals.  Anything but SIGUSR1 is converted
2544          * into a high-priority EXIT exception. */
2545         for (;;) {
2546                 sig = dequeue_signal_lock(current, &current->blocked, &info);
2547                 if (!sig)
2548                         break;
2549                 if (sig != SIGUSR1) {
2550                         if (fsg->state < FSG_STATE_EXIT)
2551                                 DBG(fsg, "Main thread exiting on signal\n");
2552                         raise_exception(fsg, FSG_STATE_EXIT);
2553                 }
2554         }
2555
2556         /* Cancel all the pending transfers */
2557         for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
2558                 bh = &fsg->buffhds[i];
2559                 if (bh->inreq_busy)
2560                         usb_ep_dequeue(fsg->bulk_in, bh->inreq);
2561                 if (bh->outreq_busy)
2562                         usb_ep_dequeue(fsg->bulk_out, bh->outreq);
2563         }
2564
2565         /* Wait until everything is idle */
2566         for (;;) {
2567                 num_active = 0;
2568                 for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
2569                         bh = &fsg->buffhds[i];
2570                         num_active += bh->inreq_busy + bh->outreq_busy;
2571                 }
2572                 if (num_active == 0)
2573                         break;
2574                 if (sleep_thread(fsg))
2575                         return;
2576         }
2577
2578         /* Clear out the controller's fifos */
2579         if (fsg->bulk_in_enabled)
2580                 usb_ep_fifo_flush(fsg->bulk_in);
2581         if (fsg->bulk_out_enabled)
2582                 usb_ep_fifo_flush(fsg->bulk_out);
2583
2584         /* Reset the I/O buffer states and pointers, the SCSI
2585          * state, and the exception.  Then invoke the handler. */
2586         spin_lock_irq(&fsg->lock);
2587
2588         for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
2589                 bh = &fsg->buffhds[i];
2590                 bh->state = BUF_STATE_EMPTY;
2591         }
2592         fsg->next_buffhd_to_fill = fsg->next_buffhd_to_drain =
2593                         &fsg->buffhds[0];
2594
2595         exception_req_tag = fsg->exception_req_tag;
2596         new_config = fsg->new_config;
2597         old_state = fsg->state;
2598
2599         if (old_state == FSG_STATE_ABORT_BULK_OUT)
2600                 fsg->state = FSG_STATE_STATUS_PHASE;
2601         else {
2602                 for (i = 0; i < fsg->nluns; ++i) {
2603                         curlun = &fsg->luns[i];
2604                         curlun->prevent_medium_removal = 0;
2605                         curlun->sense_data = curlun->unit_attention_data =
2606                                         SS_NO_SENSE;
2607                         curlun->sense_data_info = 0;
2608                         curlun->info_valid = 0;
2609                 }
2610                 fsg->state = FSG_STATE_IDLE;
2611         }
2612         spin_unlock_irq(&fsg->lock);
2613
2614         /* Carry out any extra actions required for the exception */
2615         switch (old_state) {
2616         default:
2617                 break;
2618
2619         case FSG_STATE_ABORT_BULK_OUT:
2620                 send_status(fsg);
2621                 spin_lock_irq(&fsg->lock);
2622                 if (fsg->state == FSG_STATE_STATUS_PHASE)
2623                         fsg->state = FSG_STATE_IDLE;
2624                 spin_unlock_irq(&fsg->lock);
2625                 break;
2626
2627         case FSG_STATE_RESET:
2628                 /* In case we were forced against our will to halt a
2629                  * bulk endpoint, clear the halt now.  (The SuperH UDC
2630                  * requires this.) */
2631                 if (test_and_clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags))
2632                         usb_ep_clear_halt(fsg->bulk_in);
2633
2634                 if (fsg->ep0_req_tag == exception_req_tag)
2635                         ep0_queue(fsg); // Complete the status stage
2636
2637                 /* Technically this should go here, but it would only be
2638                  * a waste of time.  Ditto for the INTERFACE_CHANGE and
2639                  * CONFIG_CHANGE cases. */
2640                 // for (i = 0; i < fsg->nluns; ++i)
2641                 //      fsg->luns[i].unit_attention_data = SS_RESET_OCCURRED;
2642                 break;
2643
2644         case FSG_STATE_INTERFACE_CHANGE:
2645                 rc = do_set_interface(fsg, 0);
2646                 if (fsg->ep0_req_tag != exception_req_tag)
2647                         break;
2648                 if (rc != 0)                    // STALL on errors
2649                         fsg_set_halt(fsg, fsg->ep0);
2650                 else                            // Complete the status stage
2651                         ep0_queue(fsg);
2652                 break;
2653
2654         case FSG_STATE_CONFIG_CHANGE:
2655                 rc = do_set_config(fsg, new_config);
2656                 if (fsg->ep0_req_tag != exception_req_tag)
2657                         break;
2658                 if (rc != 0)                    // STALL on errors
2659                         fsg_set_halt(fsg, fsg->ep0);
2660                 else                            // Complete the status stage
2661                         ep0_queue(fsg);
2662                 break;
2663
2664         case FSG_STATE_DISCONNECT:
2665                 for (i = 0; i < fsg->nluns; ++i)
2666                         fsg_lun_fsync_sub(fsg->luns + i);
2667                 do_set_config(fsg, 0);          // Unconfigured state
2668                 break;
2669
2670         case FSG_STATE_EXIT:
2671         case FSG_STATE_TERMINATED:
2672                 do_set_config(fsg, 0);                  // Free resources
2673                 spin_lock_irq(&fsg->lock);
2674                 fsg->state = FSG_STATE_TERMINATED;      // Stop the thread
2675                 spin_unlock_irq(&fsg->lock);
2676                 break;
2677         }
2678 }
2679
2680
2681 /*-------------------------------------------------------------------------*/
2682
2683 static int fsg_main_thread(void *fsg_)
2684 {
2685         struct fsg_dev          *fsg = fsg_;
2686
2687         /* Allow the thread to be killed by a signal, but set the signal mask
2688          * to block everything but INT, TERM, KILL, and USR1. */
2689         allow_signal(SIGINT);
2690         allow_signal(SIGTERM);
2691         allow_signal(SIGKILL);
2692         allow_signal(SIGUSR1);
2693
2694         /* Allow the thread to be frozen */
2695         set_freezable();
2696
2697         /* Arrange for userspace references to be interpreted as kernel
2698          * pointers.  That way we can pass a kernel pointer to a routine
2699          * that expects a __user pointer and it will work okay. */
2700         set_fs(get_ds());
2701
2702         /* The main loop */
2703         while (fsg->state != FSG_STATE_TERMINATED) {
2704                 if (exception_in_progress(fsg) || signal_pending(current)) {
2705                         handle_exception(fsg);
2706                         continue;
2707                 }
2708
2709                 if (!fsg->running) {
2710                         sleep_thread(fsg);
2711                         continue;
2712                 }
2713
2714                 if (get_next_command(fsg))
2715                         continue;
2716
2717                 spin_lock_irq(&fsg->lock);
2718                 if (!exception_in_progress(fsg))
2719                         fsg->state = FSG_STATE_DATA_PHASE;
2720                 spin_unlock_irq(&fsg->lock);
2721
2722                 if (do_scsi_command(fsg) || finish_reply(fsg))
2723                         continue;
2724
2725                 spin_lock_irq(&fsg->lock);
2726                 if (!exception_in_progress(fsg))
2727                         fsg->state = FSG_STATE_STATUS_PHASE;
2728                 spin_unlock_irq(&fsg->lock);
2729
2730                 if (send_status(fsg))
2731                         continue;
2732
2733                 spin_lock_irq(&fsg->lock);
2734                 if (!exception_in_progress(fsg))
2735                         fsg->state = FSG_STATE_IDLE;
2736                 spin_unlock_irq(&fsg->lock);
2737                 }
2738
2739         spin_lock_irq(&fsg->lock);
2740         fsg->thread_task = NULL;
2741         spin_unlock_irq(&fsg->lock);
2742
2743         /* If we are exiting because of a signal, unregister the
2744          * gadget driver. */
2745         if (test_and_clear_bit(REGISTERED, &fsg->atomic_bitflags))
2746                 usb_gadget_unregister_driver(&fsg_driver);
2747
2748         /* Let the unbind and cleanup routines know the thread has exited */
2749         complete_and_exit(&fsg->thread_notifier, 0);
2750 }
2751
2752
2753 /*-------------------------------------------------------------------------*/
2754
2755
2756 /* The write permissions and store_xxx pointers are set in fsg_bind() */
2757 static DEVICE_ATTR(ro, 0444, fsg_show_ro, NULL);
2758 static DEVICE_ATTR(file, 0444, fsg_show_file, NULL);
2759
2760
2761 /*-------------------------------------------------------------------------*/
2762
2763 static void fsg_release(struct kref *ref)
2764 {
2765         struct fsg_dev  *fsg = container_of(ref, struct fsg_dev, ref);
2766
2767         kfree(fsg->luns);
2768         kfree(fsg);
2769 }
2770
2771 static void lun_release(struct device *dev)
2772 {
2773         struct rw_semaphore     *filesem = dev_get_drvdata(dev);
2774         struct fsg_dev          *fsg =
2775                 container_of(filesem, struct fsg_dev, filesem);
2776
2777         kref_put(&fsg->ref, fsg_release);
2778 }
2779
2780 static void /* __init_or_exit */ fsg_unbind(struct usb_gadget *gadget)
2781 {
2782         struct fsg_dev          *fsg = get_gadget_data(gadget);
2783         int                     i;
2784         struct fsg_lun          *curlun;
2785         struct usb_request      *req = fsg->ep0req;
2786
2787         DBG(fsg, "unbind\n");
2788         clear_bit(REGISTERED, &fsg->atomic_bitflags);
2789
2790         /* Unregister the sysfs attribute files and the LUNs */
2791         for (i = 0; i < fsg->nluns; ++i) {
2792                 curlun = &fsg->luns[i];
2793                 if (curlun->registered) {
2794                         device_remove_file(&curlun->dev, &dev_attr_ro);
2795                         device_remove_file(&curlun->dev, &dev_attr_file);
2796                         fsg_lun_close(curlun);
2797                         device_unregister(&curlun->dev);
2798                         curlun->registered = 0;
2799                 }
2800         }
2801
2802         /* If the thread isn't already dead, tell it to exit now */
2803         if (fsg->state != FSG_STATE_TERMINATED) {
2804                 raise_exception(fsg, FSG_STATE_EXIT);
2805                 wait_for_completion(&fsg->thread_notifier);
2806
2807                 /* The cleanup routine waits for this completion also */
2808                 complete(&fsg->thread_notifier);
2809         }
2810
2811         /* Free the data buffers */
2812         for (i = 0; i < FSG_NUM_BUFFERS; ++i)
2813                 kfree(fsg->buffhds[i].buf);
2814
2815         /* Free the request and buffer for endpoint 0 */
2816         if (req) {
2817                 kfree(req->buf);
2818                 usb_ep_free_request(fsg->ep0, req);
2819         }
2820
2821         set_gadget_data(gadget, NULL);
2822 }
2823
2824
2825 static int __init check_parameters(struct fsg_dev *fsg)
2826 {
2827         int     gcnum;
2828
2829         /* Some peripheral controllers are known not to be able to
2830          * halt bulk endpoints correctly.  If one of them is present,
2831          * disable stalls.
2832          */
2833         if (gadget_is_sh(fsg->gadget) || gadget_is_at91(fsg->gadget))
2834                 mod_data.can_stall = 0;
2835
2836         if (mod_data.release == 0xffff) {       // Parameter wasn't set
2837                 /* The sa1100 controller is not supported */
2838                 if (gadget_is_sa1100(fsg->gadget))
2839                         gcnum = -1;
2840                 else
2841                         gcnum = usb_gadget_controller_number(fsg->gadget);
2842                 if (gcnum >= 0)
2843                         mod_data.release = 0x0300 + gcnum;
2844                 else {
2845                         WARNING(fsg, "controller '%s' not recognized\n",
2846                                 fsg->gadget->name);
2847                         mod_data.release = 0x0399;
2848                 }
2849         }
2850
2851         return 0;
2852 }
2853
2854
2855 static int __init fsg_bind(struct usb_gadget *gadget)
2856 {
2857         struct fsg_dev          *fsg = the_fsg;
2858         int                     rc;
2859         int                     i;
2860         struct fsg_lun          *curlun;
2861         struct usb_ep           *ep;
2862         struct usb_request      *req;
2863         char                    *pathbuf, *p;
2864
2865         fsg->gadget = gadget;
2866         set_gadget_data(gadget, fsg);
2867         fsg->ep0 = gadget->ep0;
2868         fsg->ep0->driver_data = fsg;
2869
2870         if ((rc = check_parameters(fsg)) != 0)
2871                 goto out;
2872
2873         if (mod_data.removable) {       // Enable the store_xxx attributes
2874                 dev_attr_file.attr.mode = 0644;
2875                 dev_attr_file.store = fsg_store_file;
2876                 if (!mod_data.cdrom) {
2877                         dev_attr_ro.attr.mode = 0644;
2878                         dev_attr_ro.store = fsg_store_ro;
2879                 }
2880         }
2881
2882         /* Find out how many LUNs there should be */
2883         i = mod_data.nluns;
2884         if (i == 0)
2885                 i = max(mod_data.num_filenames, 1u);
2886         if (i > FSG_MAX_LUNS) {
2887                 ERROR(fsg, "invalid number of LUNs: %d\n", i);
2888                 rc = -EINVAL;
2889                 goto out;
2890         }
2891
2892         /* Create the LUNs, open their backing files, and register the
2893          * LUN devices in sysfs. */
2894         fsg->luns = kzalloc(i * sizeof(struct fsg_lun), GFP_KERNEL);
2895         if (!fsg->luns) {
2896                 rc = -ENOMEM;
2897                 goto out;
2898         }
2899         fsg->nluns = i;
2900
2901         for (i = 0; i < fsg->nluns; ++i) {
2902                 curlun = &fsg->luns[i];
2903                 curlun->cdrom = !!mod_data.cdrom;
2904                 curlun->ro = mod_data.cdrom || mod_data.ro[i];
2905                 curlun->initially_ro = curlun->ro;
2906                 curlun->removable = mod_data.removable;
2907                 curlun->dev.release = lun_release;
2908                 curlun->dev.parent = &gadget->dev;
2909                 curlun->dev.driver = &fsg_driver.driver;
2910                 dev_set_drvdata(&curlun->dev, &fsg->filesem);
2911                 dev_set_name(&curlun->dev,"%s-lun%d",
2912                              dev_name(&gadget->dev), i);
2913
2914                 if ((rc = device_register(&curlun->dev)) != 0) {
2915                         INFO(fsg, "failed to register LUN%d: %d\n", i, rc);
2916                         goto out;
2917                 }
2918                 if ((rc = device_create_file(&curlun->dev,
2919                                         &dev_attr_ro)) != 0 ||
2920                                 (rc = device_create_file(&curlun->dev,
2921                                         &dev_attr_file)) != 0) {
2922                         device_unregister(&curlun->dev);
2923                         goto out;
2924                 }
2925                 curlun->registered = 1;
2926                 kref_get(&fsg->ref);
2927
2928                 if (mod_data.file[i] && *mod_data.file[i]) {
2929                         if ((rc = fsg_lun_open(curlun,
2930                                         mod_data.file[i])) != 0)
2931                                 goto out;
2932                 } else if (!mod_data.removable) {
2933                         ERROR(fsg, "no file given for LUN%d\n", i);
2934                         rc = -EINVAL;
2935                         goto out;
2936                 }
2937         }
2938
2939         /* Find all the endpoints we will use */
2940         usb_ep_autoconfig_reset(gadget);
2941         ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_in_desc);
2942         if (!ep)
2943                 goto autoconf_fail;
2944         ep->driver_data = fsg;          // claim the endpoint
2945         fsg->bulk_in = ep;
2946
2947         ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_out_desc);
2948         if (!ep)
2949                 goto autoconf_fail;
2950         ep->driver_data = fsg;          // claim the endpoint
2951         fsg->bulk_out = ep;
2952
2953         /* Fix up the descriptors */
2954         device_desc.bMaxPacketSize0 = fsg->ep0->maxpacket;
2955         device_desc.bcdDevice = cpu_to_le16(mod_data.release);
2956
2957         if (gadget_is_dualspeed(gadget)) {
2958                 /* Assume ep0 uses the same maxpacket value for both speeds */
2959                 dev_qualifier.bMaxPacketSize0 = fsg->ep0->maxpacket;
2960
2961                 /* Assume endpoint addresses are the same for both speeds */
2962                 fsg_hs_bulk_in_desc.bEndpointAddress =
2963                         fsg_fs_bulk_in_desc.bEndpointAddress;
2964                 fsg_hs_bulk_out_desc.bEndpointAddress =
2965                         fsg_fs_bulk_out_desc.bEndpointAddress;
2966         }
2967
2968         if (gadget_is_otg(gadget))
2969                 fsg_otg_desc.bmAttributes |= USB_OTG_HNP;
2970
2971         rc = -ENOMEM;
2972
2973         /* Allocate the request and buffer for endpoint 0 */
2974         fsg->ep0req = req = usb_ep_alloc_request(fsg->ep0, GFP_KERNEL);
2975         if (!req)
2976                 goto out;
2977         req->buf = kmalloc(EP0_BUFSIZE, GFP_KERNEL);
2978         if (!req->buf)
2979                 goto out;
2980         req->complete = ep0_complete;
2981
2982         /* Allocate the data buffers */
2983         for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
2984                 struct fsg_buffhd       *bh = &fsg->buffhds[i];
2985
2986                 /* Allocate for the bulk-in endpoint.  We assume that
2987                  * the buffer will also work with the bulk-out (and
2988                  * interrupt-in) endpoint. */
2989                 bh->buf = kmalloc(FSG_BUFLEN, GFP_KERNEL);
2990                 if (!bh->buf)
2991                         goto out;
2992                 bh->next = bh + 1;
2993         }
2994         fsg->buffhds[FSG_NUM_BUFFERS - 1].next = &fsg->buffhds[0];
2995
2996         /* This should reflect the actual gadget power source */
2997         usb_gadget_set_selfpowered(gadget);
2998
2999         snprintf(fsg_string_manufacturer, sizeof fsg_string_manufacturer,
3000                         "%s %s with %s",
3001                         init_utsname()->sysname, init_utsname()->release,
3002                         gadget->name);
3003
3004         /* On a real device, serial[] would be loaded from permanent
3005          * storage.  We just encode it from the driver version string. */
3006         for (i = 0; i < sizeof fsg_string_serial - 2; i += 2) {
3007                 unsigned char           c = DRIVER_VERSION[i / 2];
3008
3009                 if (!c)
3010                         break;
3011                 sprintf(&fsg_string_serial[i], "%02X", c);
3012         }
3013
3014         fsg->thread_task = kthread_create(fsg_main_thread, fsg,
3015                         "file-storage-gadget");
3016         if (IS_ERR(fsg->thread_task)) {