1 // SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause
2 /*
3  * f_mass_storage.c -- Mass Storage USB Composite Function
4  *
5  * Copyright (C) 2003-2008 Alan Stern
6  * Copyright (C) 2009 Samsung Electronics
7  *                    Author: Michal Nazarewicz <m.nazarewicz@samsung.com>
8  * All rights reserved.
9  */
10 
11 /*
12  * The Mass Storage Function acts as a USB Mass Storage device,
13  * appearing to the host as a disk drive or as a CD-ROM drive.  In
14  * addition to providing an example of a genuinely useful composite
15  * function for a USB device, it also illustrates a technique of
16  * double-buffering for increased throughput.
17  *
18  * Function supports multiple logical units (LUNs).  Backing storage
19  * for each LUN is provided by a regular file or a block device.
20  * Access for each LUN can be limited to read-only.  Moreover, the
21  * function can indicate that LUN is removable and/or CD-ROM.  (The
22  * later implies read-only access.)
23  *
24  * MSF is configured by specifying a fsg_config structure.  It has the
25  * following fields:
26  *
27  *	nluns		Number of LUNs function have (anywhere from 1
28  *				to FSG_MAX_LUNS which is 8).
29  *	luns		An array of LUN configuration values.  This
30  *				should be filled for each LUN that
31  *				function will include (ie. for "nluns"
32  *				LUNs).  Each element of the array has
33  *				the following fields:
34  *	->filename	The path to the backing file for the LUN.
35  *				Required if LUN is not marked as
36  *				removable.
37  *	->ro		Flag specifying access to the LUN shall be
38  *				read-only.  This is implied if CD-ROM
39  *				emulation is enabled as well as when
40  *				it was impossible to open "filename"
41  *				in R/W mode.
42  *	->removable	Flag specifying that LUN shall be indicated as
43  *				being removable.
44  *	->cdrom		Flag specifying that LUN shall be reported as
45  *				being a CD-ROM.
46  *
47  *	lun_name_format	A printf-like format for names of the LUN
48  *				devices.  This determines how the
49  *				directory in sysfs will be named.
50  *				Unless you are using several MSFs in
51  *				a single gadget (as opposed to single
52  *				MSF in many configurations) you may
53  *				leave it as NULL (in which case
54  *				"lun%d" will be used).  In the format
55  *				you can use "%d" to index LUNs for
56  *				MSF's with more than one LUN.  (Beware
57  *				that there is only one integer given
58  *				as an argument for the format and
59  *				specifying invalid format may cause
60  *				unspecified behaviour.)
61  *	thread_name	Name of the kernel thread process used by the
62  *				MSF.  You can safely set it to NULL
63  *				(in which case default "file-storage"
64  *				will be used).
65  *
66  *	vendor_name
67  *	product_name
68  *	release		Information used as a reply to INQUIRY
69  *				request.  To use default set to NULL,
70  *				NULL, 0xffff respectively.  The first
71  *				field should be 8 and the second 16
72  *				characters or less.
73  *
74  *	can_stall	Set to permit function to halt bulk endpoints.
75  *				Disabled on some USB devices known not
76  *				to work correctly.  You should set it
77  *				to true.
78  *
79  * If "removable" is not set for a LUN then a backing file must be
80  * specified.  If it is set, then NULL filename means the LUN's medium
81  * is not loaded (an empty string as "filename" in the fsg_config
82  * structure causes error).  The CD-ROM emulation includes a single
83  * data track and no audio tracks; hence there need be only one
84  * backing file per LUN.  Note also that the CD-ROM block length is
85  * set to 512 rather than the more common value 2048.
86  *
87  *
88  * MSF includes support for module parameters.  If gadget using it
89  * decides to use it, the following module parameters will be
90  * available:
91  *
92  *	file=filename[,filename...]
93  *			Names of the files or block devices used for
94  *				backing storage.
95  *	ro=b[,b...]	Default false, boolean for read-only access.
96  *	removable=b[,b...]
97  *			Default true, boolean for removable media.
98  *	cdrom=b[,b...]	Default false, boolean for whether to emulate
99  *				a CD-ROM drive.
100  *	luns=N		Default N = number of filenames, number of
101  *				LUNs to support.
102  *	stall		Default determined according to the type of
103  *				USB device controller (usually true),
104  *				boolean to permit the driver to halt
105  *				bulk endpoints.
106  *
107  * The module parameters may be prefixed with some string.  You need
108  * to consult gadget's documentation or source to verify whether it is
109  * using those module parameters and if it does what are the prefixes
110  * (look for FSG_MODULE_PARAMETERS() macro usage, what's inside it is
111  * the prefix).
112  *
113  *
114  * Requirements are modest; only a bulk-in and a bulk-out endpoint are
115  * needed.  The memory requirement amounts to two 16K buffers, size
116  * configurable by a parameter.  Support is included for both
117  * full-speed and high-speed operation.
118  *
119  * Note that the driver is slightly non-portable in that it assumes a
120  * single memory/DMA buffer will be useable for bulk-in, bulk-out, and
121  * interrupt-in endpoints.  With most device controllers this isn't an
122  * issue, but there may be some with hardware restrictions that prevent
123  * a buffer from being used by more than one endpoint.
124  *
125  *
126  * The pathnames of the backing files and the ro settings are
127  * available in the attribute files "file" and "ro" in the lun<n> (or
128  * to be more precise in a directory which name comes from
129  * "lun_name_format" option!) subdirectory of the gadget's sysfs
130  * directory.  If the "removable" option is set, writing to these
131  * files will simulate ejecting/loading the medium (writing an empty
132  * line means eject) and adjusting a write-enable tab.  Changes to the
133  * ro setting are not allowed when the medium is loaded or if CD-ROM
134  * emulation is being used.
135  *
136  * When a LUN receive an "eject" SCSI request (Start/Stop Unit),
137  * if the LUN is removable, the backing file is released to simulate
138  * ejection.
139  *
140  *
141  * This function is heavily based on "File-backed Storage Gadget" by
142  * Alan Stern which in turn is heavily based on "Gadget Zero" by David
143  * Brownell.  The driver's SCSI command interface was based on the
144  * "Information technology - Small Computer System Interface - 2"
145  * document from X3T9.2 Project 375D, Revision 10L, 7-SEP-93,
146  * available at <http://www.t10.org/ftp/t10/drafts/s2/s2-r10l.pdf>.
147  * The single exception is opcode 0x23 (READ FORMAT CAPACITIES), which
148  * was based on the "Universal Serial Bus Mass Storage Class UFI
149  * Command Specification" document, Revision 1.0, December 14, 1998,
150  * available at
151  * <http://www.usb.org/developers/devclass_docs/usbmass-ufi10.pdf>.
152  */
153 
154 /*
155  *				Driver Design
156  *
157  * The MSF is fairly straightforward.  There is a main kernel
158  * thread that handles most of the work.  Interrupt routines field
159  * callbacks from the controller driver: bulk- and interrupt-request
160  * completion notifications, endpoint-0 events, and disconnect events.
161  * Completion events are passed to the main thread by wakeup calls.  Many
162  * ep0 requests are handled at interrupt time, but SetInterface,
163  * SetConfiguration, and device reset requests are forwarded to the
164  * thread in the form of "exceptions" using SIGUSR1 signals (since they
165  * should interrupt any ongoing file I/O operations).
166  *
167  * The thread's main routine implements the standard command/data/status
168  * parts of a SCSI interaction.  It and its subroutines are full of tests
169  * for pending signals/exceptions -- all this polling is necessary since
170  * the kernel has no setjmp/longjmp equivalents.  (Maybe this is an
171  * indication that the driver really wants to be running in userspace.)
172  * An important point is that so long as the thread is alive it keeps an
173  * open reference to the backing file.  This will prevent unmounting
174  * the backing file's underlying filesystem and could cause problems
175  * during system shutdown, for example.  To prevent such problems, the
176  * thread catches INT, TERM, and KILL signals and converts them into
177  * an EXIT exception.
178  *
179  * In normal operation the main thread is started during the gadget's
180  * fsg_bind() callback and stopped during fsg_unbind().  But it can
181  * also exit when it receives a signal, and there's no point leaving
182  * the gadget running when the thread is dead.  At of this moment, MSF
183  * provides no way to deregister the gadget when thread dies -- maybe
184  * a callback functions is needed.
185  *
186  * To provide maximum throughput, the driver uses a circular pipeline of
187  * buffer heads (struct fsg_buffhd).  In principle the pipeline can be
188  * arbitrarily long; in practice the benefits don't justify having more
189  * than 2 stages (i.e., double buffering).  But it helps to think of the
190  * pipeline as being a long one.  Each buffer head contains a bulk-in and
191  * a bulk-out request pointer (since the buffer can be used for both
192  * output and input -- directions always are given from the host's
193  * point of view) as well as a pointer to the buffer and various state
194  * variables.
195  *
196  * Use of the pipeline follows a simple protocol.  There is a variable
197  * (fsg->next_buffhd_to_fill) that points to the next buffer head to use.
198  * At any time that buffer head may still be in use from an earlier
199  * request, so each buffer head has a state variable indicating whether
200  * it is EMPTY, FULL, or BUSY.  Typical use involves waiting for the
201  * buffer head to be EMPTY, filling the buffer either by file I/O or by
202  * USB I/O (during which the buffer head is BUSY), and marking the buffer
203  * head FULL when the I/O is complete.  Then the buffer will be emptied
204  * (again possibly by USB I/O, during which it is marked BUSY) and
205  * finally marked EMPTY again (possibly by a completion routine).
206  *
207  * A module parameter tells the driver to avoid stalling the bulk
208  * endpoints wherever the transport specification allows.  This is
209  * necessary for some UDCs like the SuperH, which cannot reliably clear a
210  * halt on a bulk endpoint.  However, under certain circumstances the
211  * Bulk-only specification requires a stall.  In such cases the driver
212  * will halt the endpoint and set a flag indicating that it should clear
213  * the halt in software during the next device reset.  Hopefully this
214  * will permit everything to work correctly.  Furthermore, although the
215  * specification allows the bulk-out endpoint to halt when the host sends
216  * too much data, implementing this would cause an unavoidable race.
217  * The driver will always use the "no-stall" approach for OUT transfers.
218  *
219  * One subtle point concerns sending status-stage responses for ep0
220  * requests.  Some of these requests, such as device reset, can involve
221  * interrupting an ongoing file I/O operation, which might take an
222  * arbitrarily long time.  During that delay the host might give up on
223  * the original ep0 request and issue a new one.  When that happens the
224  * driver should not notify the host about completion of the original
225  * request, as the host will no longer be waiting for it.  So the driver
226  * assigns to each ep0 request a unique tag, and it keeps track of the
227  * tag value of the request associated with a long-running exception
228  * (device-reset, interface-change, or configuration-change).  When the
229  * exception handler is finished, the status-stage response is submitted
230  * only if the current ep0 request tag is equal to the exception request
231  * tag.  Thus only the most recently received ep0 request will get a
232  * status-stage response.
233  *
234  * Warning: This driver source file is too long.  It ought to be split up
235  * into a header file plus about 3 separate .c files, to handle the details
236  * of the Gadget, USB Mass Storage, and SCSI protocols.
237  */
238 
239 /* #define VERBOSE_DEBUG */
240 /* #define DUMP_MSGS */
241 
242 #include <config.h>
243 #include <hexdump.h>
244 #include <malloc.h>
245 #include <common.h>
246 #include <console.h>
247 #include <g_dnl.h>
248 
249 #include <linux/err.h>
250 #include <linux/usb/ch9.h>
251 #include <linux/usb/gadget.h>
252 #include <usb_mass_storage.h>
253 
254 #include <asm/unaligned.h>
255 #include <linux/bitops.h>
256 #include <linux/usb/gadget.h>
257 #include <linux/usb/gadget.h>
258 #include <linux/usb/composite.h>
259 #include <usb/lin_gadget_compat.h>
260 #include <g_dnl.h>
261 
262 /*------------------------------------------------------------------------*/
263 
264 #define FSG_DRIVER_DESC	"Mass Storage Function"
265 #define FSG_DRIVER_VERSION	"2012/06/5"
266 
267 static const char fsg_string_interface[] = "Mass Storage";
268 
269 #define FSG_NO_INTR_EP 1
270 #define FSG_NO_DEVICE_STRINGS    1
271 #define FSG_NO_OTG               1
272 #define FSG_NO_INTR_EP           1
273 
274 #include "storage_common.c"
275 
276 /*-------------------------------------------------------------------------*/
277 
278 #define GFP_ATOMIC ((gfp_t) 0)
279 #define PAGE_CACHE_SHIFT	12
280 #define PAGE_CACHE_SIZE		(1 << PAGE_CACHE_SHIFT)
281 #define kthread_create(...)	__builtin_return_address(0)
282 #define wait_for_completion(...) do {} while (0)
283 
284 struct kref {int x; };
285 struct completion {int x; };
286 
287 struct fsg_dev;
288 struct fsg_common;
289 
290 /* Data shared by all the FSG instances. */
291 struct fsg_common {
292 	struct usb_gadget	*gadget;
293 	struct fsg_dev		*fsg, *new_fsg;
294 
295 	struct usb_ep		*ep0;		/* Copy of gadget->ep0 */
296 	struct usb_request	*ep0req;	/* Copy of cdev->req */
297 	unsigned int		ep0_req_tag;
298 
299 	struct fsg_buffhd	*next_buffhd_to_fill;
300 	struct fsg_buffhd	*next_buffhd_to_drain;
301 	struct fsg_buffhd	buffhds[FSG_NUM_BUFFERS];
302 
303 	int			cmnd_size;
304 	u8			cmnd[MAX_COMMAND_SIZE];
305 
306 	unsigned int		nluns;
307 	unsigned int		lun;
308 	struct fsg_lun          luns[FSG_MAX_LUNS];
309 
310 	unsigned int		bulk_out_maxpacket;
311 	enum fsg_state		state;		/* For exception handling */
312 	unsigned int		exception_req_tag;
313 
314 	enum data_direction	data_dir;
315 	u32			data_size;
316 	u32			data_size_from_cmnd;
317 	u32			tag;
318 	u32			residue;
319 	u32			usb_amount_left;
320 
321 	unsigned int		can_stall:1;
322 	unsigned int		free_storage_on_release:1;
323 	unsigned int		phase_error:1;
324 	unsigned int		short_packet_received:1;
325 	unsigned int		bad_lun_okay:1;
326 	unsigned int		running:1;
327 
328 	int			thread_wakeup_needed;
329 	struct completion	thread_notifier;
330 	struct task_struct	*thread_task;
331 
332 	/* Callback functions. */
333 	const struct fsg_operations	*ops;
334 	/* Gadget's private data. */
335 	void			*private_data;
336 
337 	const char *vendor_name;		/*  8 characters or less */
338 	const char *product_name;		/* 16 characters or less */
339 	u16 release;
340 
341 	/* Vendor (8 chars), product (16 chars), release (4
342 	 * hexadecimal digits) and NUL byte */
343 	char inquiry_string[8 + 16 + 4 + 1];
344 
345 	struct kref		ref;
346 };
347 
348 struct fsg_config {
349 	unsigned nluns;
350 	struct fsg_lun_config {
351 		const char *filename;
352 		char ro;
353 		char removable;
354 		char cdrom;
355 		char nofua;
356 	} luns[FSG_MAX_LUNS];
357 
358 	/* Callback functions. */
359 	const struct fsg_operations     *ops;
360 	/* Gadget's private data. */
361 	void			*private_data;
362 
363 	const char *vendor_name;		/*  8 characters or less */
364 	const char *product_name;		/* 16 characters or less */
365 
366 	char			can_stall;
367 };
368 
369 struct fsg_dev {
370 	struct usb_function	function;
371 	struct usb_gadget	*gadget;	/* Copy of cdev->gadget */
372 	struct fsg_common	*common;
373 
374 	u16			interface_number;
375 
376 	unsigned int		bulk_in_enabled:1;
377 	unsigned int		bulk_out_enabled:1;
378 
379 	unsigned long		atomic_bitflags;
380 #define IGNORE_BULK_OUT		0
381 
382 	struct usb_ep		*bulk_in;
383 	struct usb_ep		*bulk_out;
384 };
385 
386 
387 static inline int __fsg_is_set(struct fsg_common *common,
388 			       const char *func, unsigned line)
389 {
390 	if (common->fsg)
391 		return 1;
392 	ERROR(common, "common->fsg is NULL in %s at %u\n", func, line);
393 	WARN_ON(1);
394 	return 0;
395 }
396 
397 #define fsg_is_set(common) likely(__fsg_is_set(common, __func__, __LINE__))
398 
399 
400 static inline struct fsg_dev *fsg_from_func(struct usb_function *f)
401 {
402 	return container_of(f, struct fsg_dev, function);
403 }
404 
405 
406 typedef void (*fsg_routine_t)(struct fsg_dev *);
407 
408 static int exception_in_progress(struct fsg_common *common)
409 {
410 	return common->state > FSG_STATE_IDLE;
411 }
412 
413 /* Make bulk-out requests be divisible by the maxpacket size */
414 static void set_bulk_out_req_length(struct fsg_common *common,
415 		struct fsg_buffhd *bh, unsigned int length)
416 {
417 	unsigned int	rem;
418 
419 	bh->bulk_out_intended_length = length;
420 	rem = length % common->bulk_out_maxpacket;
421 	if (rem > 0)
422 		length += common->bulk_out_maxpacket - rem;
423 	bh->outreq->length = length;
424 }
425 
426 /*-------------------------------------------------------------------------*/
427 
428 static struct ums *ums;
429 static int ums_count;
430 static struct fsg_common *the_fsg_common;
431 
432 static int fsg_set_halt(struct fsg_dev *fsg, struct usb_ep *ep)
433 {
434 	const char	*name;
435 
436 	if (ep == fsg->bulk_in)
437 		name = "bulk-in";
438 	else if (ep == fsg->bulk_out)
439 		name = "bulk-out";
440 	else
441 		name = ep->name;
442 	DBG(fsg, "%s set halt\n", name);
443 	return usb_ep_set_halt(ep);
444 }
445 
446 /*-------------------------------------------------------------------------*/
447 
448 /* These routines may be called in process context or in_irq */
449 
450 /* Caller must hold fsg->lock */
451 static void wakeup_thread(struct fsg_common *common)
452 {
453 	common->thread_wakeup_needed = 1;
454 }
455 
456 static void raise_exception(struct fsg_common *common, enum fsg_state new_state)
457 {
458 	/* Do nothing if a higher-priority exception is already in progress.
459 	 * If a lower-or-equal priority exception is in progress, preempt it
460 	 * and notify the main thread by sending it a signal. */
461 	if (common->state <= new_state) {
462 		common->exception_req_tag = common->ep0_req_tag;
463 		common->state = new_state;
464 		common->thread_wakeup_needed = 1;
465 	}
466 }
467 
468 /*-------------------------------------------------------------------------*/
469 
470 static int ep0_queue(struct fsg_common *common)
471 {
472 	int	rc;
473 
474 	rc = usb_ep_queue(common->ep0, common->ep0req, GFP_ATOMIC);
475 	common->ep0->driver_data = common;
476 	if (rc != 0 && rc != -ESHUTDOWN) {
477 		/* We can't do much more than wait for a reset */
478 		WARNING(common, "error in submission: %s --> %d\n",
479 			common->ep0->name, rc);
480 	}
481 	return rc;
482 }
483 
484 /*-------------------------------------------------------------------------*/
485 
486 /* Bulk and interrupt endpoint completion handlers.
487  * These always run in_irq. */
488 
489 static void bulk_in_complete(struct usb_ep *ep, struct usb_request *req)
490 {
491 	struct fsg_common	*common = ep->driver_data;
492 	struct fsg_buffhd	*bh = req->context;
493 
494 	if (req->status || req->actual != req->length)
495 		DBG(common, "%s --> %d, %u/%u\n", __func__,
496 				req->status, req->actual, req->length);
497 	if (req->status == -ECONNRESET)		/* Request was cancelled */
498 		usb_ep_fifo_flush(ep);
499 
500 	/* Hold the lock while we update the request and buffer states */
501 	bh->inreq_busy = 0;
502 	bh->state = BUF_STATE_EMPTY;
503 	wakeup_thread(common);
504 }
505 
506 static void bulk_out_complete(struct usb_ep *ep, struct usb_request *req)
507 {
508 	struct fsg_common	*common = ep->driver_data;
509 	struct fsg_buffhd	*bh = req->context;
510 
511 	dump_msg(common, "bulk-out", req->buf, req->actual);
512 	if (req->status || req->actual != bh->bulk_out_intended_length)
513 		DBG(common, "%s --> %d, %u/%u\n", __func__,
514 				req->status, req->actual,
515 				bh->bulk_out_intended_length);
516 	if (req->status == -ECONNRESET)		/* Request was cancelled */
517 		usb_ep_fifo_flush(ep);
518 
519 	/* Hold the lock while we update the request and buffer states */
520 	bh->outreq_busy = 0;
521 	bh->state = BUF_STATE_FULL;
522 	wakeup_thread(common);
523 }
524 
525 /*-------------------------------------------------------------------------*/
526 
527 /* Ep0 class-specific handlers.  These always run in_irq. */
528 
529 static int fsg_setup(struct usb_function *f,
530 		const struct usb_ctrlrequest *ctrl)
531 {
532 	struct fsg_dev		*fsg = fsg_from_func(f);
533 	struct usb_request	*req = fsg->common->ep0req;
534 	u16			w_index = get_unaligned_le16(&ctrl->wIndex);
535 	u16			w_value = get_unaligned_le16(&ctrl->wValue);
536 	u16			w_length = get_unaligned_le16(&ctrl->wLength);
537 
538 	if (!fsg_is_set(fsg->common))
539 		return -EOPNOTSUPP;
540 
541 	switch (ctrl->bRequest) {
542 
543 	case USB_BULK_RESET_REQUEST:
544 		if (ctrl->bRequestType !=
545 		    (USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE))
546 			break;
547 		if (w_index != fsg->interface_number || w_value != 0)
548 			return -EDOM;
549 
550 		/* Raise an exception to stop the current operation
551 		 * and reinitialize our state. */
552 		DBG(fsg, "bulk reset request\n");
553 		raise_exception(fsg->common, FSG_STATE_RESET);
554 		return DELAYED_STATUS;
555 
556 	case USB_BULK_GET_MAX_LUN_REQUEST:
557 		if (ctrl->bRequestType !=
558 		    (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE))
559 			break;
560 		if (w_index != fsg->interface_number || w_value != 0)
561 			return -EDOM;
562 		VDBG(fsg, "get max LUN\n");
563 		*(u8 *) req->buf = fsg->common->nluns - 1;
564 
565 		/* Respond with data/status */
566 		req->length = min((u16)1, w_length);
567 		return ep0_queue(fsg->common);
568 	}
569 
570 	VDBG(fsg,
571 	     "unknown class-specific control req "
572 	     "%02x.%02x v%04x i%04x l%u\n",
573 	     ctrl->bRequestType, ctrl->bRequest,
574 	     get_unaligned_le16(&ctrl->wValue), w_index, w_length);
575 	return -EOPNOTSUPP;
576 }
577 
578 /*-------------------------------------------------------------------------*/
579 
580 /* All the following routines run in process context */
581 
582 /* Use this for bulk or interrupt transfers, not ep0 */
583 static void start_transfer(struct fsg_dev *fsg, struct usb_ep *ep,
584 		struct usb_request *req, int *pbusy,
585 		enum fsg_buffer_state *state)
586 {
587 	int	rc;
588 
589 	if (ep == fsg->bulk_in)
590 		dump_msg(fsg, "bulk-in", req->buf, req->length);
591 
592 	*pbusy = 1;
593 	*state = BUF_STATE_BUSY;
594 	rc = usb_ep_queue(ep, req, GFP_KERNEL);
595 	if (rc != 0) {
596 		*pbusy = 0;
597 		*state = BUF_STATE_EMPTY;
598 
599 		/* We can't do much more than wait for a reset */
600 
601 		/* Note: currently the net2280 driver fails zero-length
602 		 * submissions if DMA is enabled. */
603 		if (rc != -ESHUTDOWN && !(rc == -EOPNOTSUPP &&
604 						req->length == 0))
605 			WARNING(fsg, "error in submission: %s --> %d\n",
606 					ep->name, rc);
607 	}
608 }
609 
610 #define START_TRANSFER_OR(common, ep_name, req, pbusy, state)		\
611 	if (fsg_is_set(common))						\
612 		start_transfer((common)->fsg, (common)->fsg->ep_name,	\
613 			       req, pbusy, state);			\
614 	else
615 
616 #define START_TRANSFER(common, ep_name, req, pbusy, state)		\
617 	START_TRANSFER_OR(common, ep_name, req, pbusy, state) (void)0
618 
619 static void busy_indicator(void)
620 {
621 	static int state;
622 
623 	switch (state) {
624 	case 0:
625 		puts("\r|"); break;
626 	case 1:
627 		puts("\r/"); break;
628 	case 2:
629 		puts("\r-"); break;
630 	case 3:
631 		puts("\r\\"); break;
632 	case 4:
633 		puts("\r|"); break;
634 	case 5:
635 		puts("\r/"); break;
636 	case 6:
637 		puts("\r-"); break;
638 	case 7:
639 		puts("\r\\"); break;
640 	default:
641 		state = 0;
642 	}
643 	if (state++ == 8)
644 		state = 0;
645 }
646 
647 static int sleep_thread(struct fsg_common *common)
648 {
649 	int	rc = 0;
650 	int i = 0, k = 0;
651 
652 	/* Wait until a signal arrives or we are woken up */
653 	for (;;) {
654 		if (common->thread_wakeup_needed)
655 			break;
656 
657 		if (++i == 20000) {
658 			busy_indicator();
659 			i = 0;
660 			k++;
661 		}
662 
663 		if (k == 10) {
664 			/* Handle CTRL+C */
665 			if (ctrlc())
666 				return -EPIPE;
667 
668 			/* Check cable connection */
669 			if (!g_dnl_board_usb_cable_connected())
670 				return -EIO;
671 
672 			k = 0;
673 		}
674 
675 		usb_gadget_handle_interrupts(0);
676 	}
677 	common->thread_wakeup_needed = 0;
678 	return rc;
679 }
680 
681 /*-------------------------------------------------------------------------*/
682 
683 static int do_read(struct fsg_common *common)
684 {
685 	struct fsg_lun		*curlun = &common->luns[common->lun];
686 	u32			lba;
687 	struct fsg_buffhd	*bh;
688 	int			rc;
689 	u32			amount_left;
690 	loff_t			file_offset;
691 	unsigned int		amount;
692 	unsigned int		partial_page;
693 	ssize_t			nread;
694 
695 	/* Get the starting Logical Block Address and check that it's
696 	 * not too big */
697 	if (common->cmnd[0] == SC_READ_6)
698 		lba = get_unaligned_be24(&common->cmnd[1]);
699 	else {
700 		lba = get_unaligned_be32(&common->cmnd[2]);
701 
702 		/* We allow DPO (Disable Page Out = don't save data in the
703 		 * cache) and FUA (Force Unit Access = don't read from the
704 		 * cache), but we don't implement them. */
705 		if ((common->cmnd[1] & ~0x18) != 0) {
706 			curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
707 			return -EINVAL;
708 		}
709 	}
710 	if (lba >= curlun->num_sectors) {
711 		curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
712 		return -EINVAL;
713 	}
714 	file_offset = ((loff_t) lba) << 9;
715 
716 	/* Carry out the file reads */
717 	amount_left = common->data_size_from_cmnd;
718 	if (unlikely(amount_left == 0))
719 		return -EIO;		/* No default reply */
720 
721 	for (;;) {
722 
723 		/* Figure out how much we need to read:
724 		 * Try to read the remaining amount.
725 		 * But don't read more than the buffer size.
726 		 * And don't try to read past the end of the file.
727 		 * Finally, if we're not at a page boundary, don't read past
728 		 *	the next page.
729 		 * If this means reading 0 then we were asked to read past
730 		 *	the end of file. */
731 		amount = min(amount_left, FSG_BUFLEN);
732 		partial_page = file_offset & (PAGE_CACHE_SIZE - 1);
733 		if (partial_page > 0)
734 			amount = min(amount, (unsigned int) PAGE_CACHE_SIZE -
735 					partial_page);
736 
737 		/* Wait for the next buffer to become available */
738 		bh = common->next_buffhd_to_fill;
739 		while (bh->state != BUF_STATE_EMPTY) {
740 			rc = sleep_thread(common);
741 			if (rc)
742 				return rc;
743 		}
744 
745 		/* If we were asked to read past the end of file,
746 		 * end with an empty buffer. */
747 		if (amount == 0) {
748 			curlun->sense_data =
749 					SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
750 			curlun->info_valid = 1;
751 			bh->inreq->length = 0;
752 			bh->state = BUF_STATE_FULL;
753 			break;
754 		}
755 
756 		/* Perform the read */
757 		rc = ums[common->lun].read_sector(&ums[common->lun],
758 				      file_offset / SECTOR_SIZE,
759 				      amount / SECTOR_SIZE,
760 				      (char __user *)bh->buf);
761 		if (!rc)
762 			return -EIO;
763 
764 		nread = rc * SECTOR_SIZE;
765 
766 		VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
767 				(unsigned long long) file_offset,
768 				(int) nread);
769 
770 		if (nread < 0) {
771 			LDBG(curlun, "error in file read: %d\n",
772 					(int) nread);
773 			nread = 0;
774 		} else if (nread < amount) {
775 			LDBG(curlun, "partial file read: %d/%u\n",
776 					(int) nread, amount);
777 			nread -= (nread & 511);	/* Round down to a block */
778 		}
779 		file_offset  += nread;
780 		amount_left  -= nread;
781 		common->residue -= nread;
782 		bh->inreq->length = nread;
783 		bh->state = BUF_STATE_FULL;
784 
785 		/* If an error occurred, report it and its position */
786 		if (nread < amount) {
787 			curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
788 			curlun->info_valid = 1;
789 			break;
790 		}
791 
792 		if (amount_left == 0)
793 			break;		/* No more left to read */
794 
795 		/* Send this buffer and go read some more */
796 		bh->inreq->zero = 0;
797 		START_TRANSFER_OR(common, bulk_in, bh->inreq,
798 			       &bh->inreq_busy, &bh->state)
799 			/* Don't know what to do if
800 			 * common->fsg is NULL */
801 			return -EIO;
802 		common->next_buffhd_to_fill = bh->next;
803 	}
804 
805 	return -EIO;		/* No default reply */
806 }
807 
808 /*-------------------------------------------------------------------------*/
809 
810 static int do_write(struct fsg_common *common)
811 {
812 	struct fsg_lun		*curlun = &common->luns[common->lun];
813 	u32			lba;
814 	struct fsg_buffhd	*bh;
815 	int			get_some_more;
816 	u32			amount_left_to_req, amount_left_to_write;
817 	loff_t			usb_offset, file_offset;
818 	unsigned int		amount;
819 	unsigned int		partial_page;
820 	ssize_t			nwritten;
821 	int			rc;
822 
823 	if (curlun->ro) {
824 		curlun->sense_data = SS_WRITE_PROTECTED;
825 		return -EINVAL;
826 	}
827 
828 	/* Get the starting Logical Block Address and check that it's
829 	 * not too big */
830 	if (common->cmnd[0] == SC_WRITE_6)
831 		lba = get_unaligned_be24(&common->cmnd[1]);
832 	else {
833 		lba = get_unaligned_be32(&common->cmnd[2]);
834 
835 		/* We allow DPO (Disable Page Out = don't save data in the
836 		 * cache) and FUA (Force Unit Access = write directly to the
837 		 * medium).  We don't implement DPO; we implement FUA by
838 		 * performing synchronous output. */
839 		if (common->cmnd[1] & ~0x18) {
840 			curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
841 			return -EINVAL;
842 		}
843 	}
844 	if (lba >= curlun->num_sectors) {
845 		curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
846 		return -EINVAL;
847 	}
848 
849 	/* Carry out the file writes */
850 	get_some_more = 1;
851 	file_offset = usb_offset = ((loff_t) lba) << 9;
852 	amount_left_to_req = common->data_size_from_cmnd;
853 	amount_left_to_write = common->data_size_from_cmnd;
854 
855 	while (amount_left_to_write > 0) {
856 
857 		/* Queue a request for more data from the host */
858 		bh = common->next_buffhd_to_fill;
859 		if (bh->state == BUF_STATE_EMPTY && get_some_more) {
860 
861 			/* Figure out how much we want to get:
862 			 * Try to get the remaining amount.
863 			 * But don't get more than the buffer size.
864 			 * And don't try to go past the end of the file.
865 			 * If we're not at a page boundary,
866 			 *	don't go past the next page.
867 			 * If this means getting 0, then we were asked
868 			 *	to write past the end of file.
869 			 * Finally, round down to a block boundary. */
870 			amount = min(amount_left_to_req, FSG_BUFLEN);
871 			partial_page = usb_offset & (PAGE_CACHE_SIZE - 1);
872 			if (partial_page > 0)
873 				amount = min(amount,
874 	(unsigned int) PAGE_CACHE_SIZE - partial_page);
875 
876 			if (amount == 0) {
877 				get_some_more = 0;
878 				curlun->sense_data =
879 					SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
880 				curlun->info_valid = 1;
881 				continue;
882 			}
883 			amount -= (amount & 511);
884 			if (amount == 0) {
885 
886 				/* Why were we were asked to transfer a
887 				 * partial block? */
888 				get_some_more = 0;
889 				continue;
890 			}
891 
892 			/* Get the next buffer */
893 			usb_offset += amount;
894 			common->usb_amount_left -= amount;
895 			amount_left_to_req -= amount;
896 			if (amount_left_to_req == 0)
897 				get_some_more = 0;
898 
899 			/* amount is always divisible by 512, hence by
900 			 * the bulk-out maxpacket size */
901 			bh->outreq->length = amount;
902 			bh->bulk_out_intended_length = amount;
903 			bh->outreq->short_not_ok = 1;
904 			START_TRANSFER_OR(common, bulk_out, bh->outreq,
905 					  &bh->outreq_busy, &bh->state)
906 				/* Don't know what to do if
907 				 * common->fsg is NULL */
908 				return -EIO;
909 			common->next_buffhd_to_fill = bh->next;
910 			continue;
911 		}
912 
913 		/* Write the received data to the backing file */
914 		bh = common->next_buffhd_to_drain;
915 		if (bh->state == BUF_STATE_EMPTY && !get_some_more)
916 			break;			/* We stopped early */
917 		if (bh->state == BUF_STATE_FULL) {
918 			common->next_buffhd_to_drain = bh->next;
919 			bh->state = BUF_STATE_EMPTY;
920 
921 			/* Did something go wrong with the transfer? */
922 			if (bh->outreq->status != 0) {
923 				curlun->sense_data = SS_COMMUNICATION_FAILURE;
924 				curlun->info_valid = 1;
925 				break;
926 			}
927 
928 			amount = bh->outreq->actual;
929 
930 			/* Perform the write */
931 			rc = ums[common->lun].write_sector(&ums[common->lun],
932 					       file_offset / SECTOR_SIZE,
933 					       amount / SECTOR_SIZE,
934 					       (char __user *)bh->buf);
935 			if (!rc)
936 				return -EIO;
937 			nwritten = rc * SECTOR_SIZE;
938 
939 			VLDBG(curlun, "file write %u @ %llu -> %d\n", amount,
940 					(unsigned long long) file_offset,
941 					(int) nwritten);
942 
943 			if (nwritten < 0) {
944 				LDBG(curlun, "error in file write: %d\n",
945 						(int) nwritten);
946 				nwritten = 0;
947 			} else if (nwritten < amount) {
948 				LDBG(curlun, "partial file write: %d/%u\n",
949 						(int) nwritten, amount);
950 				nwritten -= (nwritten & 511);
951 				/* Round down to a block */
952 			}
953 			file_offset += nwritten;
954 			amount_left_to_write -= nwritten;
955 			common->residue -= nwritten;
956 
957 			/* If an error occurred, report it and its position */
958 			if (nwritten < amount) {
959 				printf("nwritten:%zd amount:%u\n", nwritten,
960 				       amount);
961 				curlun->sense_data = SS_WRITE_ERROR;
962 				curlun->info_valid = 1;
963 				break;
964 			}
965 
966 			/* Did the host decide to stop early? */
967 			if (bh->outreq->actual != bh->outreq->length) {
968 				common->short_packet_received = 1;
969 				break;
970 			}
971 			continue;
972 		}
973 
974 		/* Wait for something to happen */
975 		rc = sleep_thread(common);
976 		if (rc)
977 			return rc;
978 	}
979 
980 	return -EIO;		/* No default reply */
981 }
982 
983 /*-------------------------------------------------------------------------*/
984 
985 static int do_synchronize_cache(struct fsg_common *common)
986 {
987 	return 0;
988 }
989 
990 /*-------------------------------------------------------------------------*/
991 
992 static int do_verify(struct fsg_common *common)
993 {
994 	struct fsg_lun		*curlun = &common->luns[common->lun];
995 	u32			lba;
996 	u32			verification_length;
997 	struct fsg_buffhd	*bh = common->next_buffhd_to_fill;
998 	loff_t			file_offset;
999 	u32			amount_left;
1000 	unsigned int		amount;
1001 	ssize_t			nread;
1002 	int			rc;
1003 
1004 	/* Get the starting Logical Block Address and check that it's
1005 	 * not too big */
1006 	lba = get_unaligned_be32(&common->cmnd[2]);
1007 	if (lba >= curlun->num_sectors) {
1008 		curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1009 		return -EINVAL;
1010 	}
1011 
1012 	/* We allow DPO (Disable Page Out = don't save data in the
1013 	 * cache) but we don't implement it. */
1014 	if (common->cmnd[1] & ~0x10) {
1015 		curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1016 		return -EINVAL;
1017 	}
1018 
1019 	verification_length = get_unaligned_be16(&common->cmnd[7]);
1020 	if (unlikely(verification_length == 0))
1021 		return -EIO;		/* No default reply */
1022 
1023 	/* Prepare to carry out the file verify */
1024 	amount_left = verification_length << 9;
1025 	file_offset = ((loff_t) lba) << 9;
1026 
1027 	/* Write out all the dirty buffers before invalidating them */
1028 
1029 	/* Just try to read the requested blocks */
1030 	while (amount_left > 0) {
1031 
1032 		/* Figure out how much we need to read:
1033 		 * Try to read the remaining amount, but not more than
1034 		 * the buffer size.
1035 		 * And don't try to read past the end of the file.
1036 		 * If this means reading 0 then we were asked to read
1037 		 * past the end of file. */
1038 		amount = min(amount_left, FSG_BUFLEN);
1039 		if (amount == 0) {
1040 			curlun->sense_data =
1041 					SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1042 			curlun->info_valid = 1;
1043 			break;
1044 		}
1045 
1046 		/* Perform the read */
1047 		rc = ums[common->lun].read_sector(&ums[common->lun],
1048 				      file_offset / SECTOR_SIZE,
1049 				      amount / SECTOR_SIZE,
1050 				      (char __user *)bh->buf);
1051 		if (!rc)
1052 			return -EIO;
1053 		nread = rc * SECTOR_SIZE;
1054 
1055 		VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
1056 				(unsigned long long) file_offset,
1057 				(int) nread);
1058 		if (nread < 0) {
1059 			LDBG(curlun, "error in file verify: %d\n",
1060 					(int) nread);
1061 			nread = 0;
1062 		} else if (nread < amount) {
1063 			LDBG(curlun, "partial file verify: %d/%u\n",
1064 					(int) nread, amount);
1065 			nread -= (nread & 511);	/* Round down to a sector */
1066 		}
1067 		if (nread == 0) {
1068 			curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
1069 			curlun->info_valid = 1;
1070 			break;
1071 		}
1072 		file_offset += nread;
1073 		amount_left -= nread;
1074 	}
1075 	return 0;
1076 }
1077 
1078 /*-------------------------------------------------------------------------*/
1079 
1080 static int do_inquiry(struct fsg_common *common, struct fsg_buffhd *bh)
1081 {
1082 	struct fsg_lun *curlun = &common->luns[common->lun];
1083 	static const char vendor_id[] = "Linux   ";
1084 	u8	*buf = (u8 *) bh->buf;
1085 
1086 	if (!curlun) {		/* Unsupported LUNs are okay */
1087 		common->bad_lun_okay = 1;
1088 		memset(buf, 0, 36);
1089 		buf[0] = 0x7f;		/* Unsupported, no device-type */
1090 		buf[4] = 31;		/* Additional length */
1091 		return 36;
1092 	}
1093 
1094 	memset(buf, 0, 8);
1095 	buf[0] = TYPE_DISK;
1096 	buf[1] = curlun->removable ? 0x80 : 0;
1097 	buf[2] = 2;		/* ANSI SCSI level 2 */
1098 	buf[3] = 2;		/* SCSI-2 INQUIRY data format */
1099 	buf[4] = 31;		/* Additional length */
1100 				/* No special options */
1101 	sprintf((char *) (buf + 8), "%-8s%-16s%04x", (char*) vendor_id ,
1102 			ums[common->lun].name, (u16) 0xffff);
1103 
1104 	return 36;
1105 }
1106 
1107 
1108 static int do_request_sense(struct fsg_common *common, struct fsg_buffhd *bh)
1109 {
1110 	struct fsg_lun	*curlun = &common->luns[common->lun];
1111 	u8		*buf = (u8 *) bh->buf;
1112 	u32		sd, sdinfo;
1113 	int		valid;
1114 
1115 	/*
1116 	 * From the SCSI-2 spec., section 7.9 (Unit attention condition):
1117 	 *
1118 	 * If a REQUEST SENSE command is received from an initiator
1119 	 * with a pending unit attention condition (before the target
1120 	 * generates the contingent allegiance condition), then the
1121 	 * target shall either:
1122 	 *   a) report any pending sense data and preserve the unit
1123 	 *	attention condition on the logical unit, or,
1124 	 *   b) report the unit attention condition, may discard any
1125 	 *	pending sense data, and clear the unit attention
1126 	 *	condition on the logical unit for that initiator.
1127 	 *
1128 	 * FSG normally uses option a); enable this code to use option b).
1129 	 */
1130 #if 0
1131 	if (curlun && curlun->unit_attention_data != SS_NO_SENSE) {
1132 		curlun->sense_data = curlun->unit_attention_data;
1133 		curlun->unit_attention_data = SS_NO_SENSE;
1134 	}
1135 #endif
1136 
1137 	if (!curlun) {		/* Unsupported LUNs are okay */
1138 		common->bad_lun_okay = 1;
1139 		sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
1140 		sdinfo = 0;
1141 		valid = 0;
1142 	} else {
1143 		sd = curlun->sense_data;
1144 		valid = curlun->info_valid << 7;
1145 		curlun->sense_data = SS_NO_SENSE;
1146 		curlun->info_valid = 0;
1147 	}
1148 
1149 	memset(buf, 0, 18);
1150 	buf[0] = valid | 0x70;			/* Valid, current error */
1151 	buf[2] = SK(sd);
1152 	put_unaligned_be32(sdinfo, &buf[3]);	/* Sense information */
1153 	buf[7] = 18 - 8;			/* Additional sense length */
1154 	buf[12] = ASC(sd);
1155 	buf[13] = ASCQ(sd);
1156 	return 18;
1157 }
1158 
1159 static int do_read_capacity(struct fsg_common *common, struct fsg_buffhd *bh)
1160 {
1161 	struct fsg_lun	*curlun = &common->luns[common->lun];
1162 	u32		lba = get_unaligned_be32(&common->cmnd[2]);
1163 	int		pmi = common->cmnd[8];
1164 	u8		*buf = (u8 *) bh->buf;
1165 
1166 	/* Check the PMI and LBA fields */
1167 	if (pmi > 1 || (pmi == 0 && lba != 0)) {
1168 		curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1169 		return -EINVAL;
1170 	}
1171 
1172 	put_unaligned_be32(curlun->num_sectors - 1, &buf[0]);
1173 						/* Max logical block */
1174 	put_unaligned_be32(512, &buf[4]);	/* Block length */
1175 	return 8;
1176 }
1177 
1178 static int do_read_header(struct fsg_common *common, struct fsg_buffhd *bh)
1179 {
1180 	struct fsg_lun	*curlun = &common->luns[common->lun];
1181 	int		msf = common->cmnd[1] & 0x02;
1182 	u32		lba = get_unaligned_be32(&common->cmnd[2]);
1183 	u8		*buf = (u8 *) bh->buf;
1184 
1185 	if (common->cmnd[1] & ~0x02) {		/* Mask away MSF */
1186 		curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1187 		return -EINVAL;
1188 	}
1189 	if (lba >= curlun->num_sectors) {
1190 		curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1191 		return -EINVAL;
1192 	}
1193 
1194 	memset(buf, 0, 8);
1195 	buf[0] = 0x01;		/* 2048 bytes of user data, rest is EC */
1196 	store_cdrom_address(&buf[4], msf, lba);
1197 	return 8;
1198 }
1199 
1200 
1201 static int do_read_toc(struct fsg_common *common, struct fsg_buffhd *bh)
1202 {
1203 	struct fsg_lun	*curlun = &common->luns[common->lun];
1204 	int		msf = common->cmnd[1] & 0x02;
1205 	int		start_track = common->cmnd[6];
1206 	u8		*buf = (u8 *) bh->buf;
1207 
1208 	if ((common->cmnd[1] & ~0x02) != 0 ||	/* Mask away MSF */
1209 			start_track > 1) {
1210 		curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1211 		return -EINVAL;
1212 	}
1213 
1214 	memset(buf, 0, 20);
1215 	buf[1] = (20-2);		/* TOC data length */
1216 	buf[2] = 1;			/* First track number */
1217 	buf[3] = 1;			/* Last track number */
1218 	buf[5] = 0x16;			/* Data track, copying allowed */
1219 	buf[6] = 0x01;			/* Only track is number 1 */
1220 	store_cdrom_address(&buf[8], msf, 0);
1221 
1222 	buf[13] = 0x16;			/* Lead-out track is data */
1223 	buf[14] = 0xAA;			/* Lead-out track number */
1224 	store_cdrom_address(&buf[16], msf, curlun->num_sectors);
1225 
1226 	return 20;
1227 }
1228 
1229 static int do_mode_sense(struct fsg_common *common, struct fsg_buffhd *bh)
1230 {
1231 	struct fsg_lun	*curlun = &common->luns[common->lun];
1232 	int		mscmnd = common->cmnd[0];
1233 	u8		*buf = (u8 *) bh->buf;
1234 	u8		*buf0 = buf;
1235 	int		pc, page_code;
1236 	int		changeable_values, all_pages;
1237 	int		valid_page = 0;
1238 	int		len, limit;
1239 
1240 	if ((common->cmnd[1] & ~0x08) != 0) {	/* Mask away DBD */
1241 		curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1242 		return -EINVAL;
1243 	}
1244 	pc = common->cmnd[2] >> 6;
1245 	page_code = common->cmnd[2] & 0x3f;
1246 	if (pc == 3) {
1247 		curlun->sense_data = SS_SAVING_PARAMETERS_NOT_SUPPORTED;
1248 		return -EINVAL;
1249 	}
1250 	changeable_values = (pc == 1);
1251 	all_pages = (page_code == 0x3f);
1252 
1253 	/* Write the mode parameter header.  Fixed values are: default
1254 	 * medium type, no cache control (DPOFUA), and no block descriptors.
1255 	 * The only variable value is the WriteProtect bit.  We will fill in
1256 	 * the mode data length later. */
1257 	memset(buf, 0, 8);
1258 	if (mscmnd == SC_MODE_SENSE_6) {
1259 		buf[2] = (curlun->ro ? 0x80 : 0x00);		/* WP, DPOFUA */
1260 		buf += 4;
1261 		limit = 255;
1262 	} else {			/* SC_MODE_SENSE_10 */
1263 		buf[3] = (curlun->ro ? 0x80 : 0x00);		/* WP, DPOFUA */
1264 		buf += 8;
1265 		limit = 65535;		/* Should really be FSG_BUFLEN */
1266 	}
1267 
1268 	/* No block descriptors */
1269 
1270 	/* The mode pages, in numerical order.  The only page we support
1271 	 * is the Caching page. */
1272 	if (page_code == 0x08 || all_pages) {
1273 		valid_page = 1;
1274 		buf[0] = 0x08;		/* Page code */
1275 		buf[1] = 10;		/* Page length */
1276 		memset(buf+2, 0, 10);	/* None of the fields are changeable */
1277 
1278 		if (!changeable_values) {
1279 			buf[2] = 0x04;	/* Write cache enable, */
1280 					/* Read cache not disabled */
1281 					/* No cache retention priorities */
1282 			put_unaligned_be16(0xffff, &buf[4]);
1283 					/* Don't disable prefetch */
1284 					/* Minimum prefetch = 0 */
1285 			put_unaligned_be16(0xffff, &buf[8]);
1286 					/* Maximum prefetch */
1287 			put_unaligned_be16(0xffff, &buf[10]);
1288 					/* Maximum prefetch ceiling */
1289 		}
1290 		buf += 12;
1291 	}
1292 
1293 	/* Check that a valid page was requested and the mode data length
1294 	 * isn't too long. */
1295 	len = buf - buf0;
1296 	if (!valid_page || len > limit) {
1297 		curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1298 		return -EINVAL;
1299 	}
1300 
1301 	/*  Store the mode data length */
1302 	if (mscmnd == SC_MODE_SENSE_6)
1303 		buf0[0] = len - 1;
1304 	else
1305 		put_unaligned_be16(len - 2, buf0);
1306 	return len;
1307 }
1308 
1309 
1310 static int do_start_stop(struct fsg_common *common)
1311 {
1312 	struct fsg_lun	*curlun = &common->luns[common->lun];
1313 
1314 	if (!curlun) {
1315 		return -EINVAL;
1316 	} else if (!curlun->removable) {
1317 		curlun->sense_data = SS_INVALID_COMMAND;
1318 		return -EINVAL;
1319 	}
1320 
1321 	return 0;
1322 }
1323 
1324 static int do_prevent_allow(struct fsg_common *common)
1325 {
1326 	struct fsg_lun	*curlun = &common->luns[common->lun];
1327 	int		prevent;
1328 
1329 	if (!curlun->removable) {
1330 		curlun->sense_data = SS_INVALID_COMMAND;
1331 		return -EINVAL;
1332 	}
1333 
1334 	prevent = common->cmnd[4] & 0x01;
1335 	if ((common->cmnd[4] & ~0x01) != 0) {	/* Mask away Prevent */
1336 		curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1337 		return -EINVAL;
1338 	}
1339 
1340 	if (curlun->prevent_medium_removal && !prevent)
1341 		fsg_lun_fsync_sub(curlun);
1342 	curlun->prevent_medium_removal = prevent;
1343 	return 0;
1344 }
1345 
1346 
1347 static int do_read_format_capacities(struct fsg_common *common,
1348 			struct fsg_buffhd *bh)
1349 {
1350 	struct fsg_lun	*curlun = &common->luns[common->lun];
1351 	u8		*buf = (u8 *) bh->buf;
1352 
1353 	buf[0] = buf[1] = buf[2] = 0;
1354 	buf[3] = 8;	/* Only the Current/Maximum Capacity Descriptor */
1355 	buf += 4;
1356 
1357 	put_unaligned_be32(curlun->num_sectors, &buf[0]);
1358 						/* Number of blocks */
1359 	put_unaligned_be32(512, &buf[4]);	/* Block length */
1360 	buf[4] = 0x02;				/* Current capacity */
1361 	return 12;
1362 }
1363 
1364 
1365 static int do_mode_select(struct fsg_common *common, struct fsg_buffhd *bh)
1366 {
1367 	struct fsg_lun	*curlun = &common->luns[common->lun];
1368 
1369 	/* We don't support MODE SELECT */
1370 	if (curlun)
1371 		curlun->sense_data = SS_INVALID_COMMAND;
1372 	return -EINVAL;
1373 }
1374 
1375 
1376 /*-------------------------------------------------------------------------*/
1377 
1378 static int halt_bulk_in_endpoint(struct fsg_dev *fsg)
1379 {
1380 	int	rc;
1381 
1382 	rc = fsg_set_halt(fsg, fsg->bulk_in);
1383 	if (rc == -EAGAIN)
1384 		VDBG(fsg, "delayed bulk-in endpoint halt\n");
1385 	while (rc != 0) {
1386 		if (rc != -EAGAIN) {
1387 			WARNING(fsg, "usb_ep_set_halt -> %d\n", rc);
1388 			rc = 0;
1389 			break;
1390 		}
1391 
1392 		rc = usb_ep_set_halt(fsg->bulk_in);
1393 	}
1394 	return rc;
1395 }
1396 
1397 static int wedge_bulk_in_endpoint(struct fsg_dev *fsg)
1398 {
1399 	int	rc;
1400 
1401 	DBG(fsg, "bulk-in set wedge\n");
1402 	rc = 0; /* usb_ep_set_wedge(fsg->bulk_in); */
1403 	if (rc == -EAGAIN)
1404 		VDBG(fsg, "delayed bulk-in endpoint wedge\n");
1405 	while (rc != 0) {
1406 		if (rc != -EAGAIN) {
1407 			WARNING(fsg, "usb_ep_set_wedge -> %d\n", rc);
1408 			rc = 0;
1409 			break;
1410 		}
1411 	}
1412 	return rc;
1413 }
1414 
1415 static int pad_with_zeros(struct fsg_dev *fsg)
1416 {
1417 	struct fsg_buffhd	*bh = fsg->common->next_buffhd_to_fill;
1418 	u32			nkeep = bh->inreq->length;
1419 	u32			nsend;
1420 	int			rc;
1421 
1422 	bh->state = BUF_STATE_EMPTY;		/* For the first iteration */
1423 	fsg->common->usb_amount_left = nkeep + fsg->common->residue;
1424 	while (fsg->common->usb_amount_left > 0) {
1425 
1426 		/* Wait for the next buffer to be free */
1427 		while (bh->state != BUF_STATE_EMPTY) {
1428 			rc = sleep_thread(fsg->common);
1429 			if (rc)
1430 				return rc;
1431 		}
1432 
1433 		nsend = min(fsg->common->usb_amount_left, FSG_BUFLEN);
1434 		memset(bh->buf + nkeep, 0, nsend - nkeep);
1435 		bh->inreq->length = nsend;
1436 		bh->inreq->zero = 0;
1437 		start_transfer(fsg, fsg->bulk_in, bh->inreq,
1438 				&bh->inreq_busy, &bh->state);
1439 		bh = fsg->common->next_buffhd_to_fill = bh->next;
1440 		fsg->common->usb_amount_left -= nsend;
1441 		nkeep = 0;
1442 	}
1443 	return 0;
1444 }
1445 
1446 static int throw_away_data(struct fsg_common *common)
1447 {
1448 	struct fsg_buffhd	*bh;
1449 	u32			amount;
1450 	int			rc;
1451 
1452 	for (bh = common->next_buffhd_to_drain;
1453 	     bh->state != BUF_STATE_EMPTY || common->usb_amount_left > 0;
1454 	     bh = common->next_buffhd_to_drain) {
1455 
1456 		/* Throw away the data in a filled buffer */
1457 		if (bh->state == BUF_STATE_FULL) {
1458 			bh->state = BUF_STATE_EMPTY;
1459 			common->next_buffhd_to_drain = bh->next;
1460 
1461 			/* A short packet or an error ends everything */
1462 			if (bh->outreq->actual != bh->outreq->length ||
1463 					bh->outreq->status != 0) {
1464 				raise_exception(common,
1465 						FSG_STATE_ABORT_BULK_OUT);
1466 				return -EINTR;
1467 			}
1468 			continue;
1469 		}
1470 
1471 		/* Try to submit another request if we need one */
1472 		bh = common->next_buffhd_to_fill;
1473 		if (bh->state == BUF_STATE_EMPTY
1474 		 && common->usb_amount_left > 0) {
1475 			amount = min(common->usb_amount_left, FSG_BUFLEN);
1476 
1477 			/* amount is always divisible by 512, hence by
1478 			 * the bulk-out maxpacket size */
1479 			bh->outreq->length = amount;
1480 			bh->bulk_out_intended_length = amount;
1481 			bh->outreq->short_not_ok = 1;
1482 			START_TRANSFER_OR(common, bulk_out, bh->outreq,
1483 					  &bh->outreq_busy, &bh->state)
1484 				/* Don't know what to do if
1485 				 * common->fsg is NULL */
1486 				return -EIO;
1487 			common->next_buffhd_to_fill = bh->next;
1488 			common->usb_amount_left -= amount;
1489 			continue;
1490 		}
1491 
1492 		/* Otherwise wait for something to happen */
1493 		rc = sleep_thread(common);
1494 		if (rc)
1495 			return rc;
1496 	}
1497 	return 0;
1498 }
1499 
1500 
1501 static int finish_reply(struct fsg_common *common)
1502 {
1503 	struct fsg_buffhd	*bh = common->next_buffhd_to_fill;
1504 	int			rc = 0;
1505 
1506 	switch (common->data_dir) {
1507 	case DATA_DIR_NONE:
1508 		break;			/* Nothing to send */
1509 
1510 	/* If we don't know whether the host wants to read or write,
1511 	 * this must be CB or CBI with an unknown command.  We mustn't
1512 	 * try to send or receive any data.  So stall both bulk pipes
1513 	 * if we can and wait for a reset. */
1514 	case DATA_DIR_UNKNOWN:
1515 		if (!common->can_stall) {
1516 			/* Nothing */
1517 		} else if (fsg_is_set(common)) {
1518 			fsg_set_halt(common->fsg, common->fsg->bulk_out);
1519 			rc = halt_bulk_in_endpoint(common->fsg);
1520 		} else {
1521 			/* Don't know what to do if common->fsg is NULL */
1522 			rc = -EIO;
1523 		}
1524 		break;
1525 
1526 	/* All but the last buffer of data must have already been sent */
1527 	case DATA_DIR_TO_HOST:
1528 		if (common->data_size == 0) {
1529 			/* Nothing to send */
1530 
1531 		/* If there's no residue, simply send the last buffer */
1532 		} else if (common->residue == 0) {
1533 			bh->inreq->zero = 0;
1534 			START_TRANSFER_OR(common, bulk_in, bh->inreq,
1535 					  &bh->inreq_busy, &bh->state)
1536 				return -EIO;
1537 			common->next_buffhd_to_fill = bh->next;
1538 
1539 		/* For Bulk-only, if we're allowed to stall then send the
1540 		 * short packet and halt the bulk-in endpoint.  If we can't
1541 		 * stall, pad out the remaining data with 0's. */
1542 		} else if (common->can_stall) {
1543 			bh->inreq->zero = 1;
1544 			START_TRANSFER_OR(common, bulk_in, bh->inreq,
1545 					  &bh->inreq_busy, &bh->state)
1546 				/* Don't know what to do if
1547 				 * common->fsg is NULL */
1548 				rc = -EIO;
1549 			common->next_buffhd_to_fill = bh->next;
1550 			if (common->fsg)
1551 				rc = halt_bulk_in_endpoint(common->fsg);
1552 		} else if (fsg_is_set(common)) {
1553 			rc = pad_with_zeros(common->fsg);
1554 		} else {
1555 			/* Don't know what to do if common->fsg is NULL */
1556 			rc = -EIO;
1557 		}
1558 		break;
1559 
1560 	/* We have processed all we want from the data the host has sent.
1561 	 * There may still be outstanding bulk-out requests. */
1562 	case DATA_DIR_FROM_HOST:
1563 		if (common->residue == 0) {
1564 			/* Nothing to receive */
1565 
1566 		/* Did the host stop sending unexpectedly early? */
1567 		} else if (common->short_packet_received) {
1568 			raise_exception(common, FSG_STATE_ABORT_BULK_OUT);
1569 			rc = -EINTR;
1570 
1571 		/* We haven't processed all the incoming data.  Even though
1572 		 * we may be allowed to stall, doing so would cause a race.
1573 		 * The controller may already have ACK'ed all the remaining
1574 		 * bulk-out packets, in which case the host wouldn't see a
1575 		 * STALL.  Not realizing the endpoint was halted, it wouldn't
1576 		 * clear the halt -- leading to problems later on. */
1577 #if 0
1578 		} else if (common->can_stall) {
1579 			if (fsg_is_set(common))
1580 				fsg_set_halt(common->fsg,
1581 					     common->fsg->bulk_out);
1582 			raise_exception(common, FSG_STATE_ABORT_BULK_OUT);
1583 			rc = -EINTR;
1584 #endif
1585 
1586 		/* We can't stall.  Read in the excess data and throw it
1587 		 * all away. */
1588 		} else {
1589 			rc = throw_away_data(common);
1590 		}
1591 		break;
1592 	}
1593 	return rc;
1594 }
1595 
1596 
1597 static int send_status(struct fsg_common *common)
1598 {
1599 	struct fsg_lun		*curlun = &common->luns[common->lun];
1600 	struct fsg_buffhd	*bh;
1601 	struct bulk_cs_wrap	*csw;
1602 	int			rc;
1603 	u8			status = USB_STATUS_PASS;
1604 	u32			sd, sdinfo = 0;
1605 
1606 	/* Wait for the next buffer to become available */
1607 	bh = common->next_buffhd_to_fill;
1608 	while (bh->state != BUF_STATE_EMPTY) {
1609 		rc = sleep_thread(common);
1610 		if (rc)
1611 			return rc;
1612 	}
1613 
1614 	if (curlun)
1615 		sd = curlun->sense_data;
1616 	else if (common->bad_lun_okay)
1617 		sd = SS_NO_SENSE;
1618 	else
1619 		sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
1620 
1621 	if (common->phase_error) {
1622 		DBG(common, "sending phase-error status\n");
1623 		status = USB_STATUS_PHASE_ERROR;
1624 		sd = SS_INVALID_COMMAND;
1625 	} else if (sd != SS_NO_SENSE) {
1626 		DBG(common, "sending command-failure status\n");
1627 		status = USB_STATUS_FAIL;
1628 		VDBG(common, "  sense data: SK x%02x, ASC x%02x, ASCQ x%02x;"
1629 			"  info x%x\n",
1630 			SK(sd), ASC(sd), ASCQ(sd), sdinfo);
1631 	}
1632 
1633 	/* Store and send the Bulk-only CSW */
1634 	csw = (void *)bh->buf;
1635 
1636 	csw->Signature = cpu_to_le32(USB_BULK_CS_SIG);
1637 	csw->Tag = common->tag;
1638 	csw->Residue = cpu_to_le32(common->residue);
1639 	csw->Status = status;
1640 
1641 	bh->inreq->length = USB_BULK_CS_WRAP_LEN;
1642 	bh->inreq->zero = 0;
1643 	START_TRANSFER_OR(common, bulk_in, bh->inreq,
1644 			  &bh->inreq_busy, &bh->state)
1645 		/* Don't know what to do if common->fsg is NULL */
1646 		return -EIO;
1647 
1648 	common->next_buffhd_to_fill = bh->next;
1649 	return 0;
1650 }
1651 
1652 
1653 /*-------------------------------------------------------------------------*/
1654 
1655 /* Check whether the command is properly formed and whether its data size
1656  * and direction agree with the values we already have. */
1657 static int check_command(struct fsg_common *common, int cmnd_size,
1658 		enum data_direction data_dir, unsigned int mask,
1659 		int needs_medium, const char *name)
1660 {
1661 	int			i;
1662 	int			lun = common->cmnd[1] >> 5;
1663 	static const char	dirletter[4] = {'u', 'o', 'i', 'n'};
1664 	char			hdlen[20];
1665 	struct fsg_lun		*curlun;
1666 
1667 	hdlen[0] = 0;
1668 	if (common->data_dir != DATA_DIR_UNKNOWN)
1669 		sprintf(hdlen, ", H%c=%u", dirletter[(int) common->data_dir],
1670 				common->data_size);
1671 	VDBG(common, "SCSI command: %s;  Dc=%d, D%c=%u;  Hc=%d%s\n",
1672 	     name, cmnd_size, dirletter[(int) data_dir],
1673 	     common->data_size_from_cmnd, common->cmnd_size, hdlen);
1674 
1675 	/* We can't reply at all until we know the correct data direction
1676 	 * and size. */
1677 	if (common->data_size_from_cmnd == 0)
1678 		data_dir = DATA_DIR_NONE;
1679 	if (common->data_size < common->data_size_from_cmnd) {
1680 		/* Host data size < Device data size is a phase error.
1681 		 * Carry out the command, but only transfer as much as
1682 		 * we are allowed. */
1683 		common->data_size_from_cmnd = common->data_size;
1684 		common->phase_error = 1;
1685 	}
1686 	common->residue = common->data_size;
1687 	common->usb_amount_left = common->data_size;
1688 
1689 	/* Conflicting data directions is a phase error */
1690 	if (common->data_dir != data_dir
1691 	 && common->data_size_from_cmnd > 0) {
1692 		common->phase_error = 1;
1693 		return -EINVAL;
1694 	}
1695 
1696 	/* Verify the length of the command itself */
1697 	if (cmnd_size != common->cmnd_size) {
1698 
1699 		/* Special case workaround: There are plenty of buggy SCSI
1700 		 * implementations. Many have issues with cbw->Length
1701 		 * field passing a wrong command size. For those cases we
1702 		 * always try to work around the problem by using the length
1703 		 * sent by the host side provided it is at least as large
1704 		 * as the correct command length.
1705 		 * Examples of such cases would be MS-Windows, which issues
1706 		 * REQUEST SENSE with cbw->Length == 12 where it should
1707 		 * be 6, and xbox360 issuing INQUIRY, TEST UNIT READY and
1708 		 * REQUEST SENSE with cbw->Length == 10 where it should
1709 		 * be 6 as well.
1710 		 */
1711 		if (cmnd_size <= common->cmnd_size) {
1712 			DBG(common, "%s is buggy! Expected length %d "
1713 			    "but we got %d\n", name,
1714 			    cmnd_size, common->cmnd_size);
1715 			cmnd_size = common->cmnd_size;
1716 		} else {
1717 			common->phase_error = 1;
1718 			return -EINVAL;
1719 		}
1720 	}
1721 
1722 	/* Check that the LUN values are consistent */
1723 	if (common->lun != lun)
1724 		DBG(common, "using LUN %d from CBW, not LUN %d from CDB\n",
1725 		    common->lun, lun);
1726 
1727 	/* Check the LUN */
1728 	if (common->lun < common->nluns) {
1729 		curlun = &common->luns[common->lun];
1730 		if (common->cmnd[0] != SC_REQUEST_SENSE) {
1731 			curlun->sense_data = SS_NO_SENSE;
1732 			curlun->info_valid = 0;
1733 		}
1734 	} else {
1735 		curlun = NULL;
1736 		common->bad_lun_okay = 0;
1737 
1738 		/* INQUIRY and REQUEST SENSE commands are explicitly allowed
1739 		 * to use unsupported LUNs; all others may not. */
1740 		if (common->cmnd[0] != SC_INQUIRY &&
1741 		    common->cmnd[0] != SC_REQUEST_SENSE) {
1742 			DBG(common, "unsupported LUN %d\n", common->lun);
1743 			return -EINVAL;
1744 		}
1745 	}
1746 #if 0
1747 	/* If a unit attention condition exists, only INQUIRY and
1748 	 * REQUEST SENSE commands are allowed; anything else must fail. */
1749 	if (curlun && curlun->unit_attention_data != SS_NO_SENSE &&
1750 			common->cmnd[0] != SC_INQUIRY &&
1751 			common->cmnd[0] != SC_REQUEST_SENSE) {
1752 		curlun->sense_data = curlun->unit_attention_data;
1753 		curlun->unit_attention_data = SS_NO_SENSE;
1754 		return -EINVAL;
1755 	}
1756 #endif
1757 	/* Check that only command bytes listed in the mask are non-zero */
1758 	common->cmnd[1] &= 0x1f;			/* Mask away the LUN */
1759 	for (i = 1; i < cmnd_size; ++i) {
1760 		if (common->cmnd[i] && !(mask & (1 << i))) {
1761 			if (curlun)
1762 				curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1763 			return -EINVAL;
1764 		}
1765 	}
1766 
1767 	return 0;
1768 }
1769 
1770 
1771 static int do_scsi_command(struct fsg_common *common)
1772 {
1773 	struct fsg_buffhd	*bh;
1774 	int			rc;
1775 	int			reply = -EINVAL;
1776 	int			i;
1777 	static char		unknown[16];
1778 	struct fsg_lun		*curlun = &common->luns[common->lun];
1779 
1780 	dump_cdb(common);
1781 
1782 	/* Wait for the next buffer to become available for data or status */
1783 	bh = common->next_buffhd_to_fill;
1784 	common->next_buffhd_to_drain = bh;
1785 	while (bh->state != BUF_STATE_EMPTY) {
1786 		rc = sleep_thread(common);
1787 		if (rc)
1788 			return rc;
1789 	}
1790 	common->phase_error = 0;
1791 	common->short_packet_received = 0;
1792 
1793 	down_read(&common->filesem);	/* We're using the backing file */
1794 	switch (common->cmnd[0]) {
1795 
1796 	case SC_INQUIRY:
1797 		common->data_size_from_cmnd = common->cmnd[4];
1798 		reply = check_command(common, 6, DATA_DIR_TO_HOST,
1799 				      (1<<4), 0,
1800 				      "INQUIRY");
1801 		if (reply == 0)
1802 			reply = do_inquiry(common, bh);
1803 		break;
1804 
1805 	case SC_MODE_SELECT_6:
1806 		common->data_size_from_cmnd = common->cmnd[4];
1807 		reply = check_command(common, 6, DATA_DIR_FROM_HOST,
1808 				      (1<<1) | (1<<4), 0,
1809 				      "MODE SELECT(6)");
1810 		if (reply == 0)
1811 			reply = do_mode_select(common, bh);
1812 		break;
1813 
1814 	case SC_MODE_SELECT_10:
1815 		common->data_size_from_cmnd =
1816 			get_unaligned_be16(&common->cmnd[7]);
1817 		reply = check_command(common, 10, DATA_DIR_FROM_HOST,
1818 				      (1<<1) | (3<<7), 0,
1819 				      "MODE SELECT(10)");
1820 		if (reply == 0)
1821 			reply = do_mode_select(common, bh);
1822 		break;
1823 
1824 	case SC_MODE_SENSE_6:
1825 		common->data_size_from_cmnd = common->cmnd[4];
1826 		reply = check_command(common, 6, DATA_DIR_TO_HOST,
1827 				      (1<<1) | (1<<2) | (1<<4), 0,
1828 				      "MODE SENSE(6)");
1829 		if (reply == 0)
1830 			reply = do_mode_sense(common, bh);
1831 		break;
1832 
1833 	case SC_MODE_SENSE_10:
1834 		common->data_size_from_cmnd =
1835 			get_unaligned_be16(&common->cmnd[7]);
1836 		reply = check_command(common, 10, DATA_DIR_TO_HOST,
1837 				      (1<<1) | (1<<2) | (3<<7), 0,
1838 				      "MODE SENSE(10)");
1839 		if (reply == 0)
1840 			reply = do_mode_sense(common, bh);
1841 		break;
1842 
1843 	case SC_PREVENT_ALLOW_MEDIUM_REMOVAL:
1844 		common->data_size_from_cmnd = 0;
1845 		reply = check_command(common, 6, DATA_DIR_NONE,
1846 				      (1<<4), 0,
1847 				      "PREVENT-ALLOW MEDIUM REMOVAL");
1848 		if (reply == 0)
1849 			reply = do_prevent_allow(common);
1850 		break;
1851 
1852 	case SC_READ_6:
1853 		i = common->cmnd[4];
1854 		common->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
1855 		reply = check_command(common, 6, DATA_DIR_TO_HOST,
1856 				      (7<<1) | (1<<4), 1,
1857 				      "READ(6)");
1858 		if (reply == 0)
1859 			reply = do_read(common);
1860 		break;
1861 
1862 	case SC_READ_10:
1863 		common->data_size_from_cmnd =
1864 				get_unaligned_be16(&common->cmnd[7]) << 9;
1865 		reply = check_command(common, 10, DATA_DIR_TO_HOST,
1866 				      (1<<1) | (0xf<<2) | (3<<7), 1,
1867 				      "READ(10)");
1868 		if (reply == 0)
1869 			reply = do_read(common);
1870 		break;
1871 
1872 	case SC_READ_12:
1873 		common->data_size_from_cmnd =
1874 				get_unaligned_be32(&common->cmnd[6]) << 9;
1875 		reply = check_command(common, 12, DATA_DIR_TO_HOST,
1876 				      (1<<1) | (0xf<<2) | (0xf<<6), 1,
1877 				      "READ(12)");
1878 		if (reply == 0)
1879 			reply = do_read(common);
1880 		break;
1881 
1882 	case SC_READ_CAPACITY:
1883 		common->data_size_from_cmnd = 8;
1884 		reply = check_command(common, 10, DATA_DIR_TO_HOST,
1885 				      (0xf<<2) | (1<<8), 1,
1886 				      "READ CAPACITY");
1887 		if (reply == 0)
1888 			reply = do_read_capacity(common, bh);
1889 		break;
1890 
1891 	case SC_READ_HEADER:
1892 		if (!common->luns[common->lun].cdrom)
1893 			goto unknown_cmnd;
1894 		common->data_size_from_cmnd =
1895 			get_unaligned_be16(&common->cmnd[7]);
1896 		reply = check_command(common, 10, DATA_DIR_TO_HOST,
1897 				      (3<<7) | (0x1f<<1), 1,
1898 				      "READ HEADER");
1899 		if (reply == 0)
1900 			reply = do_read_header(common, bh);
1901 		break;
1902 
1903 	case SC_READ_TOC:
1904 		if (!common->luns[common->lun].cdrom)
1905 			goto unknown_cmnd;
1906 		common->data_size_from_cmnd =
1907 			get_unaligned_be16(&common->cmnd[7]);
1908 		reply = check_command(common, 10, DATA_DIR_TO_HOST,
1909 				      (7<<6) | (1<<1), 1,
1910 				      "READ TOC");
1911 		if (reply == 0)
1912 			reply = do_read_toc(common, bh);
1913 		break;
1914 
1915 	case SC_READ_FORMAT_CAPACITIES:
1916 		common->data_size_from_cmnd =
1917 			get_unaligned_be16(&common->cmnd[7]);
1918 		reply = check_command(common, 10, DATA_DIR_TO_HOST,
1919 				      (3<<7), 1,
1920 				      "READ FORMAT CAPACITIES");
1921 		if (reply == 0)
1922 			reply = do_read_format_capacities(common, bh);
1923 		break;
1924 
1925 	case SC_REQUEST_SENSE:
1926 		common->data_size_from_cmnd = common->cmnd[4];
1927 		reply = check_command(common, 6, DATA_DIR_TO_HOST,
1928 				      (1<<4), 0,
1929 				      "REQUEST SENSE");
1930 		if (reply == 0)
1931 			reply = do_request_sense(common, bh);
1932 		break;
1933 
1934 	case SC_START_STOP_UNIT:
1935 		common->data_size_from_cmnd = 0;
1936 		reply = check_command(common, 6, DATA_DIR_NONE,
1937 				      (1<<1) | (1<<4), 0,
1938 				      "START-STOP UNIT");
1939 		if (reply == 0)
1940 			reply = do_start_stop(common);
1941 		break;
1942 
1943 	case SC_SYNCHRONIZE_CACHE:
1944 		common->data_size_from_cmnd = 0;
1945 		reply = check_command(common, 10, DATA_DIR_NONE,
1946 				      (0xf<<2) | (3<<7), 1,
1947 				      "SYNCHRONIZE CACHE");
1948 		if (reply == 0)
1949 			reply = do_synchronize_cache(common);
1950 		break;
1951 
1952 	case SC_TEST_UNIT_READY:
1953 		common->data_size_from_cmnd = 0;
1954 		reply = check_command(common, 6, DATA_DIR_NONE,
1955 				0, 1,
1956 				"TEST UNIT READY");
1957 		break;
1958 
1959 	/* Although optional, this command is used by MS-Windows.  We
1960 	 * support a minimal version: BytChk must be 0. */
1961 	case SC_VERIFY:
1962 		common->data_size_from_cmnd = 0;
1963 		reply = check_command(common, 10, DATA_DIR_NONE,
1964 				      (1<<1) | (0xf<<2) | (3<<7), 1,
1965 				      "VERIFY");
1966 		if (reply == 0)
1967 			reply = do_verify(common);
1968 		break;
1969 
1970 	case SC_WRITE_6:
1971 		i = common->cmnd[4];
1972 		common->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
1973 		reply = check_command(common, 6, DATA_DIR_FROM_HOST,
1974 				      (7<<1) | (1<<4), 1,
1975 				      "WRITE(6)");
1976 		if (reply == 0)
1977 			reply = do_write(common);
1978 		break;
1979 
1980 	case SC_WRITE_10:
1981 		common->data_size_from_cmnd =
1982 				get_unaligned_be16(&common->cmnd[7]) << 9;
1983 		reply = check_command(common, 10, DATA_DIR_FROM_HOST,
1984 				      (1<<1) | (0xf<<2) | (3<<7), 1,
1985 				      "WRITE(10)");
1986 		if (reply == 0)
1987 			reply = do_write(common);
1988 		break;
1989 
1990 	case SC_WRITE_12:
1991 		common->data_size_from_cmnd =
1992 				get_unaligned_be32(&common->cmnd[6]) << 9;
1993 		reply = check_command(common, 12, DATA_DIR_FROM_HOST,
1994 				      (1<<1) | (0xf<<2) | (0xf<<6), 1,
1995 				      "WRITE(12)");
1996 		if (reply == 0)
1997 			reply = do_write(common);
1998 		break;
1999 
2000 	/* Some mandatory commands that we recognize but don't implement.
2001 	 * They don't mean much in this setting.  It's left as an exercise
2002 	 * for anyone interested to implement RESERVE and RELEASE in terms
2003 	 * of Posix locks. */
2004 	case SC_FORMAT_UNIT:
2005 	case SC_RELEASE:
2006 	case SC_RESERVE:
2007 	case SC_SEND_DIAGNOSTIC:
2008 		/* Fall through */
2009 
2010 	default:
2011 unknown_cmnd:
2012 		common->data_size_from_cmnd = 0;
2013 		sprintf(unknown, "Unknown x%02x", common->cmnd[0]);
2014 		reply = check_command(common, common->cmnd_size,
2015 				      DATA_DIR_UNKNOWN, 0xff, 0, unknown);
2016 		if (reply == 0) {
2017 			curlun->sense_data = SS_INVALID_COMMAND;
2018 			reply = -EINVAL;
2019 		}
2020 		break;
2021 	}
2022 	up_read(&common->filesem);
2023 
2024 	if (reply == -EINTR)
2025 		return -EINTR;
2026 
2027 	/* Set up the single reply buffer for finish_reply() */
2028 	if (reply == -EINVAL)
2029 		reply = 0;		/* Error reply length */
2030 	if (reply >= 0 && common->data_dir == DATA_DIR_TO_HOST) {
2031 		reply = min((u32) reply, common->data_size_from_cmnd);
2032 		bh->inreq->length = reply;
2033 		bh->state = BUF_STATE_FULL;
2034 		common->residue -= reply;
2035 	}				/* Otherwise it's already set */
2036 
2037 	return 0;
2038 }
2039 
2040 /*-------------------------------------------------------------------------*/
2041 
2042 static int received_cbw(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2043 {
2044 	struct usb_request	*req = bh->outreq;
2045 	struct fsg_bulk_cb_wrap	*cbw = req->buf;
2046 	struct fsg_common	*common = fsg->common;
2047 
2048 	/* Was this a real packet?  Should it be ignored? */
2049 	if (req->status || test_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags))
2050 		return -EINVAL;
2051 
2052 	/* Is the CBW valid? */
2053 	if (req->actual != USB_BULK_CB_WRAP_LEN ||
2054 			cbw->Signature != cpu_to_le32(
2055 				USB_BULK_CB_SIG)) {
2056 		DBG(fsg, "invalid CBW: len %u sig 0x%x\n",
2057 				req->actual,
2058 				le32_to_cpu(cbw->Signature));
2059 
2060 		/* The Bulk-only spec says we MUST stall the IN endpoint
2061 		 * (6.6.1), so it's unavoidable.  It also says we must
2062 		 * retain this state until the next reset, but there's
2063 		 * no way to tell the controller driver it should ignore
2064 		 * Clear-Feature(HALT) requests.
2065 		 *
2066 		 * We aren't required to halt the OUT endpoint; instead
2067 		 * we can simply accept and discard any data received
2068 		 * until the next reset. */
2069 		wedge_bulk_in_endpoint(fsg);
2070 		generic_set_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
2071 		return -EINVAL;
2072 	}
2073 
2074 	/* Is the CBW meaningful? */
2075 	if (cbw->Lun >= FSG_MAX_LUNS || cbw->Flags & ~USB_BULK_IN_FLAG ||
2076 			cbw->Length <= 0 || cbw->Length > MAX_COMMAND_SIZE) {
2077 		DBG(fsg, "non-meaningful CBW: lun = %u, flags = 0x%x, "
2078 				"cmdlen %u\n",
2079 				cbw->Lun, cbw->Flags, cbw->Length);
2080 
2081 		/* We can do anything we want here, so let's stall the
2082 		 * bulk pipes if we are allowed to. */
2083 		if (common->can_stall) {
2084 			fsg_set_halt(fsg, fsg->bulk_out);
2085 			halt_bulk_in_endpoint(fsg);
2086 		}
2087 		return -EINVAL;
2088 	}
2089 
2090 	/* Save the command for later */
2091 	common->cmnd_size = cbw->Length;
2092 	memcpy(common->cmnd, cbw->CDB, common->cmnd_size);
2093 	if (cbw->Flags & USB_BULK_IN_FLAG)
2094 		common->data_dir = DATA_DIR_TO_HOST;
2095 	else
2096 		common->data_dir = DATA_DIR_FROM_HOST;
2097 	common->data_size = le32_to_cpu(cbw->DataTransferLength);
2098 	if (common->data_size == 0)
2099 		common->data_dir = DATA_DIR_NONE;
2100 	common->lun = cbw->Lun;
2101 	common->tag = cbw->Tag;
2102 	return 0;
2103 }
2104 
2105 
2106 static int get_next_command(struct fsg_common *common)
2107 {
2108 	struct fsg_buffhd	*bh;
2109 	int			rc = 0;
2110 
2111 	/* Wait for the next buffer to become available */
2112 	bh = common->next_buffhd_to_fill;
2113 	while (bh->state != BUF_STATE_EMPTY) {
2114 		rc = sleep_thread(common);
2115 		if (rc)
2116 			return rc;
2117 	}
2118 
2119 	/* Queue a request to read a Bulk-only CBW */
2120 	set_bulk_out_req_length(common, bh, USB_BULK_CB_WRAP_LEN);
2121 	bh->outreq->short_not_ok = 1;
2122 	START_TRANSFER_OR(common, bulk_out, bh->outreq,
2123 			  &bh->outreq_busy, &bh->state)
2124 		/* Don't know what to do if common->fsg is NULL */
2125 		return -EIO;
2126 
2127 	/* We will drain the buffer in software, which means we
2128 	 * can reuse it for the next filling.  No need to advance
2129 	 * next_buffhd_to_fill. */
2130 
2131 	/* Wait for the CBW to arrive */
2132 	while (bh->state != BUF_STATE_FULL) {
2133 		rc = sleep_thread(common);
2134 		if (rc)
2135 			return rc;
2136 	}
2137 
2138 	rc = fsg_is_set(common) ? received_cbw(common->fsg, bh) : -EIO;
2139 	bh->state = BUF_STATE_EMPTY;
2140 
2141 	return rc;
2142 }
2143 
2144 
2145 /*-------------------------------------------------------------------------*/
2146 
2147 static int enable_endpoint(struct fsg_common *common, struct usb_ep *ep,
2148 		const struct usb_endpoint_descriptor *d)
2149 {
2150 	int	rc;
2151 
2152 	ep->driver_data = common;
2153 	rc = usb_ep_enable(ep, d);
2154 	if (rc)
2155 		ERROR(common, "can't enable %s, result %d\n", ep->name, rc);
2156 	return rc;
2157 }
2158 
2159 static int alloc_request(struct fsg_common *common, struct usb_ep *ep,
2160 		struct usb_request **preq)
2161 {
2162 	*preq = usb_ep_alloc_request(ep, GFP_ATOMIC);
2163 	if (*preq)
2164 		return 0;
2165 	ERROR(common, "can't allocate request for %s\n", ep->name);
2166 	return -ENOMEM;
2167 }
2168 
2169 /* Reset interface setting and re-init endpoint state (toggle etc). */
2170 static int do_set_interface(struct fsg_common *common, struct fsg_dev *new_fsg)
2171 {
2172 	const struct usb_endpoint_descriptor *d;
2173 	struct fsg_dev *fsg;
2174 	int i, rc = 0;
2175 
2176 	if (common->running)
2177 		DBG(common, "reset interface\n");
2178 
2179 reset:
2180 	/* Deallocate the requests */
2181 	if (common->fsg) {
2182 		fsg = common->fsg;
2183 
2184 		for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
2185 			struct fsg_buffhd *bh = &common->buffhds[i];
2186 
2187 			if (bh->inreq) {
2188 				usb_ep_free_request(fsg->bulk_in, bh->inreq);
2189 				bh->inreq = NULL;
2190 			}
2191 			if (bh->outreq) {
2192 				usb_ep_free_request(fsg->bulk_out, bh->outreq);
2193 				bh->outreq = NULL;
2194 			}
2195 		}
2196 
2197 		/* Disable the endpoints */
2198 		if (fsg->bulk_in_enabled) {
2199 			usb_ep_disable(fsg->bulk_in);
2200 			fsg->bulk_in_enabled = 0;
2201 		}
2202 		if (fsg->bulk_out_enabled) {
2203 			usb_ep_disable(fsg->bulk_out);
2204 			fsg->bulk_out_enabled = 0;
2205 		}
2206 
2207 		common->fsg = NULL;
2208 		/* wake_up(&common->fsg_wait); */
2209 	}
2210 
2211 	common->running = 0;
2212 	if (!new_fsg || rc)
2213 		return rc;
2214 
2215 	common->fsg = new_fsg;
2216 	fsg = common->fsg;
2217 
2218 	/* Enable the endpoints */
2219 	d = fsg_ep_desc(common->gadget,
2220 			&fsg_fs_bulk_in_desc, &fsg_hs_bulk_in_desc);
2221 	rc = enable_endpoint(common, fsg->bulk_in, d);
2222 	if (rc)
2223 		goto reset;
2224 	fsg->bulk_in_enabled = 1;
2225 
2226 	d = fsg_ep_desc(common->gadget,
2227 			&fsg_fs_bulk_out_desc, &fsg_hs_bulk_out_desc);
2228 	rc = enable_endpoint(common, fsg->bulk_out, d);
2229 	if (rc)
2230 		goto reset;
2231 	fsg->bulk_out_enabled = 1;
2232 	common->bulk_out_maxpacket =
2233 				le16_to_cpu(get_unaligned(&d->wMaxPacketSize));
2234 	generic_clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
2235 
2236 	/* Allocate the requests */
2237 	for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
2238 		struct fsg_buffhd	*bh = &common->buffhds[i];
2239 
2240 		rc = alloc_request(common, fsg->bulk_in, &bh->inreq);
2241 		if (rc)
2242 			goto reset;
2243 		rc = alloc_request(common, fsg->bulk_out, &bh->outreq);
2244 		if (rc)
2245 			goto reset;
2246 		bh->inreq->buf = bh->outreq->buf = bh->buf;
2247 		bh->inreq->context = bh->outreq->context = bh;
2248 		bh->inreq->complete = bulk_in_complete;
2249 		bh->outreq->complete = bulk_out_complete;
2250 	}
2251 
2252 	common->running = 1;
2253 
2254 	return rc;
2255 }
2256 
2257 
2258 /****************************** ALT CONFIGS ******************************/
2259 
2260 
2261 static int fsg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
2262 {
2263 	struct fsg_dev *fsg = fsg_from_func(f);
2264 	fsg->common->new_fsg = fsg;
2265 	raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
2266 	return 0;
2267 }
2268 
2269 static void fsg_disable(struct usb_function *f)
2270 {
2271 	struct fsg_dev *fsg = fsg_from_func(f);
2272 	fsg->common->new_fsg = NULL;
2273 	raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
2274 }
2275 
2276 /*-------------------------------------------------------------------------*/
2277 
2278 static void handle_exception(struct fsg_common *common)
2279 {
2280 	int			i;
2281 	struct fsg_buffhd	*bh;
2282 	enum fsg_state		old_state;
2283 	struct fsg_lun		*curlun;
2284 	unsigned int		exception_req_tag;
2285 
2286 	/* Cancel all the pending transfers */
2287 	if (common->fsg) {
2288 		for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
2289 			bh = &common->buffhds[i];
2290 			if (bh->inreq_busy)
2291 				usb_ep_dequeue(common->fsg->bulk_in, bh->inreq);
2292 			if (bh->outreq_busy)
2293 				usb_ep_dequeue(common->fsg->bulk_out,
2294 					       bh->outreq);
2295 		}
2296 
2297 		/* Wait until everything is idle */
2298 		for (;;) {
2299 			int num_active = 0;
2300 			for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
2301 				bh = &common->buffhds[i];
2302 				num_active += bh->inreq_busy + bh->outreq_busy;
2303 			}
2304 			if (num_active == 0)
2305 				break;
2306 			if (sleep_thread(common))
2307 				return;
2308 		}
2309 
2310 		/* Clear out the controller's fifos */
2311 		if (common->fsg->bulk_in_enabled)
2312 			usb_ep_fifo_flush(common->fsg->bulk_in);
2313 		if (common->fsg->bulk_out_enabled)
2314 			usb_ep_fifo_flush(common->fsg->bulk_out);
2315 	}
2316 
2317 	/* Reset the I/O buffer states and pointers, the SCSI
2318 	 * state, and the exception.  Then invoke the handler. */
2319 
2320 	for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
2321 		bh = &common->buffhds[i];
2322 		bh->state = BUF_STATE_EMPTY;
2323 	}
2324 	common->next_buffhd_to_fill = &common->buffhds[0];
2325 	common->next_buffhd_to_drain = &common->buffhds[0];
2326 	exception_req_tag = common->exception_req_tag;
2327 	old_state = common->state;
2328 
2329 	if (old_state == FSG_STATE_ABORT_BULK_OUT)
2330 		common->state = FSG_STATE_STATUS_PHASE;
2331 	else {
2332 		for (i = 0; i < common->nluns; ++i) {
2333 			curlun = &common->luns[i];
2334 			curlun->sense_data = SS_NO_SENSE;
2335 			curlun->info_valid = 0;
2336 		}
2337 		common->state = FSG_STATE_IDLE;
2338 	}
2339 
2340 	/* Carry out any extra actions required for the exception */
2341 	switch (old_state) {
2342 	case FSG_STATE_ABORT_BULK_OUT:
2343 		send_status(common);
2344 
2345 		if (common->state == FSG_STATE_STATUS_PHASE)
2346 			common->state = FSG_STATE_IDLE;
2347 		break;
2348 
2349 	case FSG_STATE_RESET:
2350 		/* In case we were forced against our will to halt a
2351 		 * bulk endpoint, clear the halt now.  (The SuperH UDC
2352 		 * requires this.) */
2353 		if (!fsg_is_set(common))
2354 			break;
2355 		if (test_and_clear_bit(IGNORE_BULK_OUT,
2356 				       &common->fsg->atomic_bitflags))
2357 			usb_ep_clear_halt(common->fsg->bulk_in);
2358 
2359 		if (common->ep0_req_tag == exception_req_tag)
2360 			ep0_queue(common);	/* Complete the status stage */
2361 
2362 		break;
2363 
2364 	case FSG_STATE_CONFIG_CHANGE:
2365 		do_set_interface(common, common->new_fsg);
2366 		break;
2367 
2368 	case FSG_STATE_EXIT:
2369 	case FSG_STATE_TERMINATED:
2370 		do_set_interface(common, NULL);		/* Free resources */
2371 		common->state = FSG_STATE_TERMINATED;	/* Stop the thread */
2372 		break;
2373 
2374 	case FSG_STATE_INTERFACE_CHANGE:
2375 	case FSG_STATE_DISCONNECT:
2376 	case FSG_STATE_COMMAND_PHASE:
2377 	case FSG_STATE_DATA_PHASE:
2378 	case FSG_STATE_STATUS_PHASE:
2379 	case FSG_STATE_IDLE:
2380 		break;
2381 	}
2382 }
2383 
2384 /*-------------------------------------------------------------------------*/
2385 
2386 int fsg_main_thread(void *common_)
2387 {
2388 	int ret;
2389 	struct fsg_common	*common = the_fsg_common;
2390 	/* The main loop */
2391 	do {
2392 		if (exception_in_progress(common)) {
2393 			handle_exception(common);
2394 			continue;
2395 		}
2396 
2397 		if (!common->running) {
2398 			ret = sleep_thread(common);
2399 			if (ret)
2400 				return ret;
2401 
2402 			continue;
2403 		}
2404 
2405 		ret = get_next_command(common);
2406 		if (ret)
2407 			return ret;
2408 
2409 		if (!exception_in_progress(common))
2410 			common->state = FSG_STATE_DATA_PHASE;
2411 
2412 		if (do_scsi_command(common) || finish_reply(common))
2413 			continue;
2414 
2415 		if (!exception_in_progress(common))
2416 			common->state = FSG_STATE_STATUS_PHASE;
2417 
2418 		if (send_status(common))
2419 			continue;
2420 
2421 		if (!exception_in_progress(common))
2422 			common->state = FSG_STATE_IDLE;
2423 	} while (0);
2424 
2425 	common->thread_task = NULL;
2426 
2427 	return 0;
2428 }
2429 
2430 static void fsg_common_release(struct kref *ref);
2431 
2432 static struct fsg_common *fsg_common_init(struct fsg_common *common,
2433 					  struct usb_composite_dev *cdev)
2434 {
2435 	struct usb_gadget *gadget = cdev->gadget;
2436 	struct fsg_buffhd *bh;
2437 	struct fsg_lun *curlun;
2438 	int nluns, i, rc;
2439 
2440 	/* Find out how many LUNs there should be */
2441 	nluns = ums_count;
2442 	if (nluns < 1 || nluns > FSG_MAX_LUNS) {
2443 		printf("invalid number of LUNs: %u\n", nluns);
2444 		return ERR_PTR(-EINVAL);
2445 	}
2446 
2447 	/* Allocate? */
2448 	if (!common) {
2449 		common = calloc(sizeof(*common), 1);
2450 		if (!common)
2451 			return ERR_PTR(-ENOMEM);
2452 		common->free_storage_on_release = 1;
2453 	} else {
2454 		memset(common, 0, sizeof(*common));
2455 		common->free_storage_on_release = 0;
2456 	}
2457 
2458 	common->ops = NULL;
2459 	common->private_data = NULL;
2460 
2461 	common->gadget = gadget;
2462 	common->ep0 = gadget->ep0;
2463 	common->ep0req = cdev->req;
2464 
2465 	/* Maybe allocate device-global string IDs, and patch descriptors */
2466 	if (fsg_strings[FSG_STRING_INTERFACE].id == 0) {
2467 		rc = usb_string_id(cdev);
2468 		if (unlikely(rc < 0))
2469 			goto error_release;
2470 		fsg_strings[FSG_STRING_INTERFACE].id = rc;
2471 		fsg_intf_desc.iInterface = rc;
2472 	}
2473 
2474 	/* Create the LUNs, open their backing files, and register the
2475 	 * LUN devices in sysfs. */
2476 	curlun = calloc(nluns, sizeof *curlun);
2477 	if (!curlun) {
2478 		rc = -ENOMEM;
2479 		goto error_release;
2480 	}
2481 	common->nluns = nluns;
2482 
2483 	for (i = 0; i < nluns; i++) {
2484 		common->luns[i].removable = 1;
2485 
2486 		rc = fsg_lun_open(&common->luns[i], ums[i].num_sectors, "");
2487 		if (rc)
2488 			goto error_luns;
2489 	}
2490 	common->lun = 0;
2491 
2492 	/* Data buffers cyclic list */
2493 	bh = common->buffhds;
2494 
2495 	i = FSG_NUM_BUFFERS;
2496 	goto buffhds_first_it;
2497 	do {
2498 		bh->next = bh + 1;
2499 		++bh;
2500 buffhds_first_it:
2501 		bh->inreq_busy = 0;
2502 		bh->outreq_busy = 0;
2503 		bh->buf = memalign(CONFIG_SYS_CACHELINE_SIZE, FSG_BUFLEN);
2504 		if (unlikely(!bh->buf)) {
2505 			rc = -ENOMEM;
2506 			goto error_release;
2507 		}
2508 	} while (--i);
2509 	bh->next = common->buffhds;
2510 
2511 	snprintf(common->inquiry_string, sizeof common->inquiry_string,
2512 		 "%-8s%-16s%04x",
2513 		 "Linux   ",
2514 		 "File-Store Gadget",
2515 		 0xffff);
2516 
2517 	/* Some peripheral controllers are known not to be able to
2518 	 * halt bulk endpoints correctly.  If one of them is present,
2519 	 * disable stalls.
2520 	 */
2521 
2522 	/* Tell the thread to start working */
2523 	common->thread_task =
2524 		kthread_create(fsg_main_thread, common,
2525 			       OR(cfg->thread_name, "file-storage"));
2526 	if (IS_ERR(common->thread_task)) {
2527 		rc = PTR_ERR(common->thread_task);
2528 		goto error_release;
2529 	}
2530 
2531 #undef OR
2532 	/* Information */
2533 	INFO(common, FSG_DRIVER_DESC ", version: " FSG_DRIVER_VERSION "\n");
2534 	INFO(common, "Number of LUNs=%d\n", common->nluns);
2535 
2536 	return common;
2537 
2538 error_luns:
2539 	common->nluns = i + 1;
2540 error_release:
2541 	common->state = FSG_STATE_TERMINATED;	/* The thread is dead */
2542 	/* Call fsg_common_release() directly, ref might be not
2543 	 * initialised */
2544 	fsg_common_release(&common->ref);
2545 	return ERR_PTR(rc);
2546 }
2547 
2548 static void fsg_common_release(struct kref *ref)
2549 {
2550 	struct fsg_common *common = container_of(ref, struct fsg_common, ref);
2551 
2552 	/* If the thread isn't already dead, tell it to exit now */
2553 	if (common->state != FSG_STATE_TERMINATED) {
2554 		raise_exception(common, FSG_STATE_EXIT);
2555 		wait_for_completion(&common->thread_notifier);
2556 	}
2557 
2558 	if (likely(common->luns)) {
2559 		struct fsg_lun *lun = common->luns;
2560 		unsigned i = common->nluns;
2561 
2562 		/* In error recovery common->nluns may be zero. */
2563 		for (; i; --i, ++lun)
2564 			fsg_lun_close(lun);
2565 
2566 		kfree(common->luns);
2567 	}
2568 
2569 	{
2570 		struct fsg_buffhd *bh = common->buffhds;
2571 		unsigned i = FSG_NUM_BUFFERS;
2572 		do {
2573 			kfree(bh->buf);
2574 		} while (++bh, --i);
2575 	}
2576 
2577 	if (common->free_storage_on_release)
2578 		kfree(common);
2579 }
2580 
2581 
2582 /*-------------------------------------------------------------------------*/
2583 
2584 /**
2585  * usb_copy_descriptors - copy a vector of USB descriptors
2586  * @src: null-terminated vector to copy
2587  * Context: initialization code, which may sleep
2588  *
2589  * This makes a copy of a vector of USB descriptors.  Its primary use
2590  * is to support usb_function objects which can have multiple copies,
2591  * each needing different descriptors.  Functions may have static
2592  * tables of descriptors, which are used as templates and customized
2593  * with identifiers (for interfaces, strings, endpoints, and more)
2594  * as needed by a given function instance.
2595  */
2596 struct usb_descriptor_header **
2597 usb_copy_descriptors(struct usb_descriptor_header **src)
2598 {
2599 	struct usb_descriptor_header **tmp;
2600 	unsigned bytes;
2601 	unsigned n_desc;
2602 	void *mem;
2603 	struct usb_descriptor_header **ret;
2604 
2605 	/* count descriptors and their sizes; then add vector size */
2606 	for (bytes = 0, n_desc = 0, tmp = src; *tmp; tmp++, n_desc++)
2607 		bytes += (*tmp)->bLength;
2608 	bytes += (n_desc + 1) * sizeof(*tmp);
2609 
2610 	mem = memalign(CONFIG_SYS_CACHELINE_SIZE, bytes);
2611 	if (!mem)
2612 		return NULL;
2613 
2614 	/* fill in pointers starting at "tmp",
2615 	 * to descriptors copied starting at "mem";
2616 	 * and return "ret"
2617 	 */
2618 	tmp = mem;
2619 	ret = mem;
2620 	mem += (n_desc + 1) * sizeof(*tmp);
2621 	while (*src) {
2622 		memcpy(mem, *src, (*src)->bLength);
2623 		*tmp = mem;
2624 		tmp++;
2625 		mem += (*src)->bLength;
2626 		src++;
2627 	}
2628 	*tmp = NULL;
2629 
2630 	return ret;
2631 }
2632 
2633 static void fsg_unbind(struct usb_configuration *c, struct usb_function *f)
2634 {
2635 	struct fsg_dev		*fsg = fsg_from_func(f);
2636 
2637 	DBG(fsg, "unbind\n");
2638 	if (fsg->common->fsg == fsg) {
2639 		fsg->common->new_fsg = NULL;
2640 		raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
2641 	}
2642 
2643 	free(fsg->function.descriptors);
2644 	free(fsg->function.hs_descriptors);
2645 	kfree(fsg);
2646 }
2647 
2648 static int fsg_bind(struct usb_configuration *c, struct usb_function *f)
2649 {
2650 	struct fsg_dev		*fsg = fsg_from_func(f);
2651 	struct usb_gadget	*gadget = c->cdev->gadget;
2652 	int			i;
2653 	struct usb_ep		*ep;
2654 	fsg->gadget = gadget;
2655 
2656 	/* New interface */
2657 	i = usb_interface_id(c, f);
2658 	if (i < 0)
2659 		return i;
2660 	fsg_intf_desc.bInterfaceNumber = i;
2661 	fsg->interface_number = i;
2662 
2663 	/* Find all the endpoints we will use */
2664 	ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_in_desc);
2665 	if (!ep)
2666 		goto autoconf_fail;
2667 	ep->driver_data = fsg->common;	/* claim the endpoint */
2668 	fsg->bulk_in = ep;
2669 
2670 	ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_out_desc);
2671 	if (!ep)
2672 		goto autoconf_fail;
2673 	ep->driver_data = fsg->common;	/* claim the endpoint */
2674 	fsg->bulk_out = ep;
2675 
2676 	/* Copy descriptors */
2677 	f->descriptors = usb_copy_descriptors(fsg_fs_function);
2678 	if (unlikely(!f->descriptors))
2679 		return -ENOMEM;
2680 
2681 	if (gadget_is_dualspeed(gadget)) {
2682 		/* Assume endpoint addresses are the same for both speeds */
2683 		fsg_hs_bulk_in_desc.bEndpointAddress =
2684 			fsg_fs_bulk_in_desc.bEndpointAddress;
2685 		fsg_hs_bulk_out_desc.bEndpointAddress =
2686 			fsg_fs_bulk_out_desc.bEndpointAddress;
2687 		f->hs_descriptors = usb_copy_descriptors(fsg_hs_function);
2688 		if (unlikely(!f->hs_descriptors)) {
2689 			free(f->descriptors);
2690 			return -ENOMEM;
2691 		}
2692 	}
2693 	return 0;
2694 
2695 autoconf_fail:
2696 	ERROR(fsg, "unable to autoconfigure all endpoints\n");
2697 	return -ENOTSUPP;
2698 }
2699 
2700 
2701 /****************************** ADD FUNCTION ******************************/
2702 
2703 static struct usb_gadget_strings *fsg_strings_array[] = {
2704 	&fsg_stringtab,
2705 	NULL,
2706 };
2707 
2708 static int fsg_bind_config(struct usb_composite_dev *cdev,
2709 			   struct usb_configuration *c,
2710 			   struct fsg_common *common)
2711 {
2712 	struct fsg_dev *fsg;
2713 	int rc;
2714 
2715 	fsg = calloc(1, sizeof *fsg);
2716 	if (!fsg)
2717 		return -ENOMEM;
2718 	fsg->function.name        = FSG_DRIVER_DESC;
2719 	fsg->function.strings     = fsg_strings_array;
2720 	fsg->function.bind        = fsg_bind;
2721 	fsg->function.unbind      = fsg_unbind;
2722 	fsg->function.setup       = fsg_setup;
2723 	fsg->function.set_alt     = fsg_set_alt;
2724 	fsg->function.disable     = fsg_disable;
2725 
2726 	fsg->common               = common;
2727 	common->fsg               = fsg;
2728 	/* Our caller holds a reference to common structure so we
2729 	 * don't have to be worry about it being freed until we return
2730 	 * from this function.  So instead of incrementing counter now
2731 	 * and decrement in error recovery we increment it only when
2732 	 * call to usb_add_function() was successful. */
2733 
2734 	rc = usb_add_function(c, &fsg->function);
2735 
2736 	if (rc)
2737 		kfree(fsg);
2738 
2739 	return rc;
2740 }
2741 
2742 int fsg_add(struct usb_configuration *c)
2743 {
2744 	struct fsg_common *fsg_common;
2745 
2746 	fsg_common = fsg_common_init(NULL, c->cdev);
2747 
2748 	fsg_common->vendor_name = 0;
2749 	fsg_common->product_name = 0;
2750 	fsg_common->release = 0xffff;
2751 
2752 	fsg_common->ops = NULL;
2753 	fsg_common->private_data = NULL;
2754 
2755 	the_fsg_common = fsg_common;
2756 
2757 	return fsg_bind_config(c->cdev, c, fsg_common);
2758 }
2759 
2760 int fsg_init(struct ums *ums_devs, int count)
2761 {
2762 	ums = ums_devs;
2763 	ums_count = count;
2764 
2765 	return 0;
2766 }
2767 
2768 DECLARE_GADGET_BIND_CALLBACK(usb_dnl_ums, fsg_add);
2769