2 * f_mass_storage.c -- Mass Storage USB Composite Function
4 * Copyright (C) 2003-2008 Alan Stern
5 * Copyright (C) 2009 Samsung Electronics
6 * Author: Michal Nazarewicz <m.nazarewicz@samsung.com>
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
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13 * notice, this list of conditions, and the following disclaimer,
14 * without modification.
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20 * specific prior written permission.
22 * ALTERNATIVELY, this software may be distributed under the terms of the
23 * GNU General Public License ("GPL") as published by the Free Software
24 * Foundation, either version 2 of that License or (at your option) any
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35 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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37 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
42 * The Mass Storage Function acts as a USB Mass Storage device,
43 * appearing to the host as a disk drive or as a CD-ROM drive. In
44 * addition to providing an example of a genuinely useful composite
45 * function for a USB device, it also illustrates a technique of
46 * double-buffering for increased throughput.
48 * Function supports multiple logical units (LUNs). Backing storage
49 * for each LUN is provided by a regular file or a block device.
50 * Access for each LUN can be limited to read-only. Moreover, the
51 * function can indicate that LUN is removable and/or CD-ROM. (The
52 * later implies read-only access.)
54 * MSF is configured by specifying a fsg_config structure. It has the
57 * nluns Number of LUNs function have (anywhere from 1
58 * to FSG_MAX_LUNS which is 8).
59 * luns An array of LUN configuration values. This
60 * should be filled for each LUN that
61 * function will include (ie. for "nluns"
62 * LUNs). Each element of the array has
63 * the following fields:
64 * ->filename The path to the backing file for the LUN.
65 * Required if LUN is not marked as
67 * ->ro Flag specifying access to the LUN shall be
68 * read-only. This is implied if CD-ROM
69 * emulation is enabled as well as when
70 * it was impossible to open "filename"
72 * ->removable Flag specifying that LUN shall be indicated as
74 * ->cdrom Flag specifying that LUN shall be reported as
77 * lun_name_format A printf-like format for names of the LUN
78 * devices. This determines how the
79 * directory in sysfs will be named.
80 * Unless you are using several MSFs in
81 * a single gadget (as opposed to single
82 * MSF in many configurations) you may
83 * leave it as NULL (in which case
84 * "lun%d" will be used). In the format
85 * you can use "%d" to index LUNs for
86 * MSF's with more than one LUN. (Beware
87 * that there is only one integer given
88 * as an argument for the format and
89 * specifying invalid format may cause
90 * unspecified behaviour.)
91 * thread_name Name of the kernel thread process used by the
92 * MSF. You can safely set it to NULL
93 * (in which case default "file-storage"
98 * release Information used as a reply to INQUIRY
99 * request. To use default set to NULL,
100 * NULL, 0xffff respectively. The first
101 * field should be 8 and the second 16
102 * characters or less.
104 * can_stall Set to permit function to halt bulk endpoints.
105 * Disabled on some USB devices known not
106 * to work correctly. You should set it
109 * If "removable" is not set for a LUN then a backing file must be
110 * specified. If it is set, then NULL filename means the LUN's medium
111 * is not loaded (an empty string as "filename" in the fsg_config
112 * structure causes error). The CD-ROM emulation includes a single
113 * data track and no audio tracks; hence there need be only one
114 * backing file per LUN. Note also that the CD-ROM block length is
115 * set to 512 rather than the more common value 2048.
118 * MSF includes support for module parameters. If gadget using it
119 * decides to use it, the following module parameters will be
122 * file=filename[,filename...]
123 * Names of the files or block devices used for
125 * ro=b[,b...] Default false, boolean for read-only access.
127 * Default true, boolean for removable media.
128 * cdrom=b[,b...] Default false, boolean for whether to emulate
130 * luns=N Default N = number of filenames, number of
132 * stall Default determined according to the type of
133 * USB device controller (usually true),
134 * boolean to permit the driver to halt
137 * The module parameters may be prefixed with some string. You need
138 * to consult gadget's documentation or source to verify whether it is
139 * using those module parameters and if it does what are the prefixes
140 * (look for FSG_MODULE_PARAMETERS() macro usage, what's inside it is
144 * Requirements are modest; only a bulk-in and a bulk-out endpoint are
145 * needed. The memory requirement amounts to two 16K buffers, size
146 * configurable by a parameter. Support is included for both
147 * full-speed and high-speed operation.
149 * Note that the driver is slightly non-portable in that it assumes a
150 * single memory/DMA buffer will be useable for bulk-in, bulk-out, and
151 * interrupt-in endpoints. With most device controllers this isn't an
152 * issue, but there may be some with hardware restrictions that prevent
153 * a buffer from being used by more than one endpoint.
156 * The pathnames of the backing files and the ro settings are
157 * available in the attribute files "file" and "ro" in the lun<n> (or
158 * to be more precise in a directory which name comes from
159 * "lun_name_format" option!) subdirectory of the gadget's sysfs
160 * directory. If the "removable" option is set, writing to these
161 * files will simulate ejecting/loading the medium (writing an empty
162 * line means eject) and adjusting a write-enable tab. Changes to the
163 * ro setting are not allowed when the medium is loaded or if CD-ROM
164 * emulation is being used.
166 * When a LUN receive an "eject" SCSI request (Start/Stop Unit),
167 * if the LUN is removable, the backing file is released to simulate
171 * This function is heavily based on "File-backed Storage Gadget" by
172 * Alan Stern which in turn is heavily based on "Gadget Zero" by David
173 * Brownell. The driver's SCSI command interface was based on the
174 * "Information technology - Small Computer System Interface - 2"
175 * document from X3T9.2 Project 375D, Revision 10L, 7-SEP-93,
176 * available at <http://www.t10.org/ftp/t10/drafts/s2/s2-r10l.pdf>.
177 * The single exception is opcode 0x23 (READ FORMAT CAPACITIES), which
178 * was based on the "Universal Serial Bus Mass Storage Class UFI
179 * Command Specification" document, Revision 1.0, December 14, 1998,
181 * <http://www.usb.org/developers/devclass_docs/usbmass-ufi10.pdf>.
188 * The MSF is fairly straightforward. There is a main kernel
189 * thread that handles most of the work. Interrupt routines field
190 * callbacks from the controller driver: bulk- and interrupt-request
191 * completion notifications, endpoint-0 events, and disconnect events.
192 * Completion events are passed to the main thread by wakeup calls. Many
193 * ep0 requests are handled at interrupt time, but SetInterface,
194 * SetConfiguration, and device reset requests are forwarded to the
195 * thread in the form of "exceptions" using SIGUSR1 signals (since they
196 * should interrupt any ongoing file I/O operations).
198 * The thread's main routine implements the standard command/data/status
199 * parts of a SCSI interaction. It and its subroutines are full of tests
200 * for pending signals/exceptions -- all this polling is necessary since
201 * the kernel has no setjmp/longjmp equivalents. (Maybe this is an
202 * indication that the driver really wants to be running in userspace.)
203 * An important point is that so long as the thread is alive it keeps an
204 * open reference to the backing file. This will prevent unmounting
205 * the backing file's underlying filesystem and could cause problems
206 * during system shutdown, for example. To prevent such problems, the
207 * thread catches INT, TERM, and KILL signals and converts them into
210 * In normal operation the main thread is started during the gadget's
211 * fsg_bind() callback and stopped during fsg_unbind(). But it can
212 * also exit when it receives a signal, and there's no point leaving
213 * the gadget running when the thread is dead. At of this moment, MSF
214 * provides no way to deregister the gadget when thread dies -- maybe
215 * a callback functions is needed.
217 * To provide maximum throughput, the driver uses a circular pipeline of
218 * buffer heads (struct fsg_buffhd). In principle the pipeline can be
219 * arbitrarily long; in practice the benefits don't justify having more
220 * than 2 stages (i.e., double buffering). But it helps to think of the
221 * pipeline as being a long one. Each buffer head contains a bulk-in and
222 * a bulk-out request pointer (since the buffer can be used for both
223 * output and input -- directions always are given from the host's
224 * point of view) as well as a pointer to the buffer and various state
227 * Use of the pipeline follows a simple protocol. There is a variable
228 * (fsg->next_buffhd_to_fill) that points to the next buffer head to use.
229 * At any time that buffer head may still be in use from an earlier
230 * request, so each buffer head has a state variable indicating whether
231 * it is EMPTY, FULL, or BUSY. Typical use involves waiting for the
232 * buffer head to be EMPTY, filling the buffer either by file I/O or by
233 * USB I/O (during which the buffer head is BUSY), and marking the buffer
234 * head FULL when the I/O is complete. Then the buffer will be emptied
235 * (again possibly by USB I/O, during which it is marked BUSY) and
236 * finally marked EMPTY again (possibly by a completion routine).
238 * A module parameter tells the driver to avoid stalling the bulk
239 * endpoints wherever the transport specification allows. This is
240 * necessary for some UDCs like the SuperH, which cannot reliably clear a
241 * halt on a bulk endpoint. However, under certain circumstances the
242 * Bulk-only specification requires a stall. In such cases the driver
243 * will halt the endpoint and set a flag indicating that it should clear
244 * the halt in software during the next device reset. Hopefully this
245 * will permit everything to work correctly. Furthermore, although the
246 * specification allows the bulk-out endpoint to halt when the host sends
247 * too much data, implementing this would cause an unavoidable race.
248 * The driver will always use the "no-stall" approach for OUT transfers.
250 * One subtle point concerns sending status-stage responses for ep0
251 * requests. Some of these requests, such as device reset, can involve
252 * interrupting an ongoing file I/O operation, which might take an
253 * arbitrarily long time. During that delay the host might give up on
254 * the original ep0 request and issue a new one. When that happens the
255 * driver should not notify the host about completion of the original
256 * request, as the host will no longer be waiting for it. So the driver
257 * assigns to each ep0 request a unique tag, and it keeps track of the
258 * tag value of the request associated with a long-running exception
259 * (device-reset, interface-change, or configuration-change). When the
260 * exception handler is finished, the status-stage response is submitted
261 * only if the current ep0 request tag is equal to the exception request
262 * tag. Thus only the most recently received ep0 request will get a
263 * status-stage response.
265 * Warning: This driver source file is too long. It ought to be split up
266 * into a header file plus about 3 separate .c files, to handle the details
267 * of the Gadget, USB Mass Storage, and SCSI protocols.
271 /* #define VERBOSE_DEBUG */
272 /* #define DUMP_MSGS */
275 #include <linux/blkdev.h>
276 #include <linux/completion.h>
277 #include <linux/dcache.h>
278 #include <linux/delay.h>
279 #include <linux/device.h>
280 #include <linux/fcntl.h>
281 #include <linux/file.h>
282 #include <linux/fs.h>
283 #include <linux/kref.h>
284 #include <linux/kthread.h>
285 #include <linux/limits.h>
286 #include <linux/rwsem.h>
287 #include <linux/slab.h>
288 #include <linux/spinlock.h>
289 #include <linux/string.h>
290 #include <linux/freezer.h>
291 #include <linux/utsname.h>
293 #include <linux/usb/ch9.h>
294 #include <linux/usb/gadget.h>
296 #include "gadget_chips.h"
300 /*------------------------------------------------------------------------*/
302 #define FSG_DRIVER_DESC "Mass Storage Function"
303 #define FSG_DRIVER_VERSION "2009/09/11"
305 static const char fsg_string_interface[] = "Mass Storage";
308 #define FSG_NO_INTR_EP 1
309 #define FSG_NO_DEVICE_STRINGS 1
311 #define FSG_NO_INTR_EP 1
313 #include "storage_common.c"
316 /*-------------------------------------------------------------------------*/
321 /* Data shared by all the FSG instances. */
323 struct usb_gadget *gadget;
324 struct fsg_dev *fsg, *new_fsg;
325 wait_queue_head_t fsg_wait;
327 /* filesem protects: backing files in use */
328 struct rw_semaphore filesem;
330 /* lock protects: state, all the req_busy's */
333 struct usb_ep *ep0; /* Copy of gadget->ep0 */
334 struct usb_request *ep0req; /* Copy of cdev->req */
335 unsigned int ep0_req_tag;
337 struct fsg_buffhd *next_buffhd_to_fill;
338 struct fsg_buffhd *next_buffhd_to_drain;
339 struct fsg_buffhd buffhds[FSG_NUM_BUFFERS];
342 u8 cmnd[MAX_COMMAND_SIZE];
346 struct fsg_lun *luns;
347 struct fsg_lun *curlun;
349 unsigned int bulk_out_maxpacket;
350 enum fsg_state state; /* For exception handling */
351 unsigned int exception_req_tag;
353 enum data_direction data_dir;
355 u32 data_size_from_cmnd;
360 unsigned int can_stall:1;
361 unsigned int free_storage_on_release:1;
362 unsigned int phase_error:1;
363 unsigned int short_packet_received:1;
364 unsigned int bad_lun_okay:1;
365 unsigned int running:1;
367 int thread_wakeup_needed;
368 struct completion thread_notifier;
369 struct task_struct *thread_task;
371 /* Callback function to call when thread exits. */
372 int (*thread_exits)(struct fsg_common *common);
373 /* Gadget's private data. */
376 /* Vendor (8 chars), product (16 chars), release (4
377 * hexadecimal digits) and NUL byte */
378 char inquiry_string[8 + 16 + 4 + 1];
386 struct fsg_lun_config {
387 const char *filename;
391 } luns[FSG_MAX_LUNS];
393 const char *lun_name_format;
394 const char *thread_name;
396 /* Callback function to call when thread exits. If no
397 * callback is set or it returns value lower then zero MSF
398 * will force eject all LUNs it operates on (including those
399 * marked as non-removable or with prevent_medium_removal flag
401 int (*thread_exits)(struct fsg_common *common);
402 /* Gadget's private data. */
405 const char *vendor_name; /* 8 characters or less */
406 const char *product_name; /* 16 characters or less */
414 struct usb_function function;
415 struct usb_gadget *gadget; /* Copy of cdev->gadget */
416 struct fsg_common *common;
418 u16 interface_number;
420 unsigned int bulk_in_enabled:1;
421 unsigned int bulk_out_enabled:1;
423 unsigned long atomic_bitflags;
424 #define IGNORE_BULK_OUT 0
426 struct usb_ep *bulk_in;
427 struct usb_ep *bulk_out;
431 static inline int __fsg_is_set(struct fsg_common *common,
432 const char *func, unsigned line)
436 ERROR(common, "common->fsg is NULL in %s at %u\n", func, line);
440 #define fsg_is_set(common) likely(__fsg_is_set(common, __func__, __LINE__))
443 static inline struct fsg_dev *fsg_from_func(struct usb_function *f)
445 return container_of(f, struct fsg_dev, function);
449 typedef void (*fsg_routine_t)(struct fsg_dev *);
451 static int exception_in_progress(struct fsg_common *common)
453 return common->state > FSG_STATE_IDLE;
456 /* Make bulk-out requests be divisible by the maxpacket size */
457 static void set_bulk_out_req_length(struct fsg_common *common,
458 struct fsg_buffhd *bh, unsigned int length)
462 bh->bulk_out_intended_length = length;
463 rem = length % common->bulk_out_maxpacket;
465 length += common->bulk_out_maxpacket - rem;
466 bh->outreq->length = length;
469 /*-------------------------------------------------------------------------*/
471 static int fsg_set_halt(struct fsg_dev *fsg, struct usb_ep *ep)
475 if (ep == fsg->bulk_in)
477 else if (ep == fsg->bulk_out)
481 DBG(fsg, "%s set halt\n", name);
482 return usb_ep_set_halt(ep);
486 /*-------------------------------------------------------------------------*/
488 /* These routines may be called in process context or in_irq */
490 /* Caller must hold fsg->lock */
491 static void wakeup_thread(struct fsg_common *common)
493 /* Tell the main thread that something has happened */
494 common->thread_wakeup_needed = 1;
495 if (common->thread_task)
496 wake_up_process(common->thread_task);
500 static void raise_exception(struct fsg_common *common, enum fsg_state new_state)
504 /* Do nothing if a higher-priority exception is already in progress.
505 * If a lower-or-equal priority exception is in progress, preempt it
506 * and notify the main thread by sending it a signal. */
507 spin_lock_irqsave(&common->lock, flags);
508 if (common->state <= new_state) {
509 common->exception_req_tag = common->ep0_req_tag;
510 common->state = new_state;
511 if (common->thread_task)
512 send_sig_info(SIGUSR1, SEND_SIG_FORCED,
513 common->thread_task);
515 spin_unlock_irqrestore(&common->lock, flags);
519 /*-------------------------------------------------------------------------*/
521 static int ep0_queue(struct fsg_common *common)
525 rc = usb_ep_queue(common->ep0, common->ep0req, GFP_ATOMIC);
526 common->ep0->driver_data = common;
527 if (rc != 0 && rc != -ESHUTDOWN) {
528 /* We can't do much more than wait for a reset */
529 WARNING(common, "error in submission: %s --> %d\n",
530 common->ep0->name, rc);
535 /*-------------------------------------------------------------------------*/
537 /* Bulk and interrupt endpoint completion handlers.
538 * These always run in_irq. */
540 static void bulk_in_complete(struct usb_ep *ep, struct usb_request *req)
542 struct fsg_common *common = ep->driver_data;
543 struct fsg_buffhd *bh = req->context;
545 if (req->status || req->actual != req->length)
546 DBG(common, "%s --> %d, %u/%u\n", __func__,
547 req->status, req->actual, req->length);
548 if (req->status == -ECONNRESET) /* Request was cancelled */
549 usb_ep_fifo_flush(ep);
551 /* Hold the lock while we update the request and buffer states */
553 spin_lock(&common->lock);
555 bh->state = BUF_STATE_EMPTY;
556 wakeup_thread(common);
557 spin_unlock(&common->lock);
560 static void bulk_out_complete(struct usb_ep *ep, struct usb_request *req)
562 struct fsg_common *common = ep->driver_data;
563 struct fsg_buffhd *bh = req->context;
565 dump_msg(common, "bulk-out", req->buf, req->actual);
566 if (req->status || req->actual != bh->bulk_out_intended_length)
567 DBG(common, "%s --> %d, %u/%u\n", __func__,
568 req->status, req->actual,
569 bh->bulk_out_intended_length);
570 if (req->status == -ECONNRESET) /* Request was cancelled */
571 usb_ep_fifo_flush(ep);
573 /* Hold the lock while we update the request and buffer states */
575 spin_lock(&common->lock);
577 bh->state = BUF_STATE_FULL;
578 wakeup_thread(common);
579 spin_unlock(&common->lock);
583 /*-------------------------------------------------------------------------*/
585 /* Ep0 class-specific handlers. These always run in_irq. */
587 static int fsg_setup(struct usb_function *f,
588 const struct usb_ctrlrequest *ctrl)
590 struct fsg_dev *fsg = fsg_from_func(f);
591 struct usb_request *req = fsg->common->ep0req;
592 u16 w_index = le16_to_cpu(ctrl->wIndex);
593 u16 w_value = le16_to_cpu(ctrl->wValue);
594 u16 w_length = le16_to_cpu(ctrl->wLength);
596 if (!fsg_is_set(fsg->common))
599 switch (ctrl->bRequest) {
601 case USB_BULK_RESET_REQUEST:
602 if (ctrl->bRequestType !=
603 (USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE))
605 if (w_index != fsg->interface_number || w_value != 0)
608 /* Raise an exception to stop the current operation
609 * and reinitialize our state. */
610 DBG(fsg, "bulk reset request\n");
611 raise_exception(fsg->common, FSG_STATE_RESET);
612 return DELAYED_STATUS;
614 case USB_BULK_GET_MAX_LUN_REQUEST:
615 if (ctrl->bRequestType !=
616 (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE))
618 if (w_index != fsg->interface_number || w_value != 0)
620 VDBG(fsg, "get max LUN\n");
621 *(u8 *) req->buf = fsg->common->nluns - 1;
623 /* Respond with data/status */
624 req->length = min((u16)1, w_length);
625 return ep0_queue(fsg->common);
629 "unknown class-specific control req "
630 "%02x.%02x v%04x i%04x l%u\n",
631 ctrl->bRequestType, ctrl->bRequest,
632 le16_to_cpu(ctrl->wValue), w_index, w_length);
637 /*-------------------------------------------------------------------------*/
639 /* All the following routines run in process context */
642 /* Use this for bulk or interrupt transfers, not ep0 */
643 static void start_transfer(struct fsg_dev *fsg, struct usb_ep *ep,
644 struct usb_request *req, int *pbusy,
645 enum fsg_buffer_state *state)
649 if (ep == fsg->bulk_in)
650 dump_msg(fsg, "bulk-in", req->buf, req->length);
652 spin_lock_irq(&fsg->common->lock);
654 *state = BUF_STATE_BUSY;
655 spin_unlock_irq(&fsg->common->lock);
656 rc = usb_ep_queue(ep, req, GFP_KERNEL);
659 *state = BUF_STATE_EMPTY;
661 /* We can't do much more than wait for a reset */
663 /* Note: currently the net2280 driver fails zero-length
664 * submissions if DMA is enabled. */
665 if (rc != -ESHUTDOWN && !(rc == -EOPNOTSUPP &&
667 WARNING(fsg, "error in submission: %s --> %d\n",
672 #define START_TRANSFER_OR(common, ep_name, req, pbusy, state) \
673 if (fsg_is_set(common)) \
674 start_transfer((common)->fsg, (common)->fsg->ep_name, \
675 req, pbusy, state); \
678 #define START_TRANSFER(common, ep_name, req, pbusy, state) \
679 START_TRANSFER_OR(common, ep_name, req, pbusy, state) (void)0
683 static int sleep_thread(struct fsg_common *common)
687 /* Wait until a signal arrives or we are woken up */
690 set_current_state(TASK_INTERRUPTIBLE);
691 if (signal_pending(current)) {
695 if (common->thread_wakeup_needed)
699 __set_current_state(TASK_RUNNING);
700 common->thread_wakeup_needed = 0;
705 /*-------------------------------------------------------------------------*/
707 static int do_read(struct fsg_common *common)
709 struct fsg_lun *curlun = common->curlun;
711 struct fsg_buffhd *bh;
714 loff_t file_offset, file_offset_tmp;
716 unsigned int partial_page;
719 /* Get the starting Logical Block Address and check that it's
721 if (common->cmnd[0] == SC_READ_6)
722 lba = get_unaligned_be24(&common->cmnd[1]);
724 lba = get_unaligned_be32(&common->cmnd[2]);
726 /* We allow DPO (Disable Page Out = don't save data in the
727 * cache) and FUA (Force Unit Access = don't read from the
728 * cache), but we don't implement them. */
729 if ((common->cmnd[1] & ~0x18) != 0) {
730 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
734 if (lba >= curlun->num_sectors) {
735 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
738 file_offset = ((loff_t) lba) << 9;
740 /* Carry out the file reads */
741 amount_left = common->data_size_from_cmnd;
742 if (unlikely(amount_left == 0))
743 return -EIO; /* No default reply */
747 /* Figure out how much we need to read:
748 * Try to read the remaining amount.
749 * But don't read more than the buffer size.
750 * And don't try to read past the end of the file.
751 * Finally, if we're not at a page boundary, don't read past
753 * If this means reading 0 then we were asked to read past
754 * the end of file. */
755 amount = min(amount_left, FSG_BUFLEN);
756 amount = min((loff_t) amount,
757 curlun->file_length - file_offset);
758 partial_page = file_offset & (PAGE_CACHE_SIZE - 1);
759 if (partial_page > 0)
760 amount = min(amount, (unsigned int) PAGE_CACHE_SIZE -
763 /* Wait for the next buffer to become available */
764 bh = common->next_buffhd_to_fill;
765 while (bh->state != BUF_STATE_EMPTY) {
766 rc = sleep_thread(common);
771 /* If we were asked to read past the end of file,
772 * end with an empty buffer. */
775 SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
776 curlun->sense_data_info = file_offset >> 9;
777 curlun->info_valid = 1;
778 bh->inreq->length = 0;
779 bh->state = BUF_STATE_FULL;
783 /* Perform the read */
784 file_offset_tmp = file_offset;
785 nread = vfs_read(curlun->filp,
786 (char __user *) bh->buf,
787 amount, &file_offset_tmp);
788 VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
789 (unsigned long long) file_offset,
791 if (signal_pending(current))
795 LDBG(curlun, "error in file read: %d\n",
798 } else if (nread < amount) {
799 LDBG(curlun, "partial file read: %d/%u\n",
800 (int) nread, amount);
801 nread -= (nread & 511); /* Round down to a block */
803 file_offset += nread;
804 amount_left -= nread;
805 common->residue -= nread;
806 bh->inreq->length = nread;
807 bh->state = BUF_STATE_FULL;
809 /* If an error occurred, report it and its position */
810 if (nread < amount) {
811 curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
812 curlun->sense_data_info = file_offset >> 9;
813 curlun->info_valid = 1;
817 if (amount_left == 0)
818 break; /* No more left to read */
820 /* Send this buffer and go read some more */
822 START_TRANSFER_OR(common, bulk_in, bh->inreq,
823 &bh->inreq_busy, &bh->state)
824 /* Don't know what to do if
825 * common->fsg is NULL */
827 common->next_buffhd_to_fill = bh->next;
830 return -EIO; /* No default reply */
834 /*-------------------------------------------------------------------------*/
836 static int do_write(struct fsg_common *common)
838 struct fsg_lun *curlun = common->curlun;
840 struct fsg_buffhd *bh;
842 u32 amount_left_to_req, amount_left_to_write;
843 loff_t usb_offset, file_offset, file_offset_tmp;
845 unsigned int partial_page;
850 curlun->sense_data = SS_WRITE_PROTECTED;
853 spin_lock(&curlun->filp->f_lock);
854 curlun->filp->f_flags &= ~O_SYNC; /* Default is not to wait */
855 spin_unlock(&curlun->filp->f_lock);
857 /* Get the starting Logical Block Address and check that it's
859 if (common->cmnd[0] == SC_WRITE_6)
860 lba = get_unaligned_be24(&common->cmnd[1]);
862 lba = get_unaligned_be32(&common->cmnd[2]);
864 /* We allow DPO (Disable Page Out = don't save data in the
865 * cache) and FUA (Force Unit Access = write directly to the
866 * medium). We don't implement DPO; we implement FUA by
867 * performing synchronous output. */
868 if (common->cmnd[1] & ~0x18) {
869 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
872 if (common->cmnd[1] & 0x08) { /* FUA */
873 spin_lock(&curlun->filp->f_lock);
874 curlun->filp->f_flags |= O_SYNC;
875 spin_unlock(&curlun->filp->f_lock);
878 if (lba >= curlun->num_sectors) {
879 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
883 /* Carry out the file writes */
885 file_offset = usb_offset = ((loff_t) lba) << 9;
886 amount_left_to_req = common->data_size_from_cmnd;
887 amount_left_to_write = common->data_size_from_cmnd;
889 while (amount_left_to_write > 0) {
891 /* Queue a request for more data from the host */
892 bh = common->next_buffhd_to_fill;
893 if (bh->state == BUF_STATE_EMPTY && get_some_more) {
895 /* Figure out how much we want to get:
896 * Try to get the remaining amount.
897 * But don't get more than the buffer size.
898 * And don't try to go past the end of the file.
899 * If we're not at a page boundary,
900 * don't go past the next page.
901 * If this means getting 0, then we were asked
902 * to write past the end of file.
903 * Finally, round down to a block boundary. */
904 amount = min(amount_left_to_req, FSG_BUFLEN);
905 amount = min((loff_t) amount, curlun->file_length -
907 partial_page = usb_offset & (PAGE_CACHE_SIZE - 1);
908 if (partial_page > 0)
910 (unsigned int) PAGE_CACHE_SIZE - partial_page);
915 SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
916 curlun->sense_data_info = usb_offset >> 9;
917 curlun->info_valid = 1;
920 amount -= (amount & 511);
923 /* Why were we were asked to transfer a
929 /* Get the next buffer */
930 usb_offset += amount;
931 common->usb_amount_left -= amount;
932 amount_left_to_req -= amount;
933 if (amount_left_to_req == 0)
936 /* amount is always divisible by 512, hence by
937 * the bulk-out maxpacket size */
938 bh->outreq->length = amount;
939 bh->bulk_out_intended_length = amount;
940 bh->outreq->short_not_ok = 1;
941 START_TRANSFER_OR(common, bulk_out, bh->outreq,
942 &bh->outreq_busy, &bh->state)
943 /* Don't know what to do if
944 * common->fsg is NULL */
946 common->next_buffhd_to_fill = bh->next;
950 /* Write the received data to the backing file */
951 bh = common->next_buffhd_to_drain;
952 if (bh->state == BUF_STATE_EMPTY && !get_some_more)
953 break; /* We stopped early */
954 if (bh->state == BUF_STATE_FULL) {
956 common->next_buffhd_to_drain = bh->next;
957 bh->state = BUF_STATE_EMPTY;
959 /* Did something go wrong with the transfer? */
960 if (bh->outreq->status != 0) {
961 curlun->sense_data = SS_COMMUNICATION_FAILURE;
962 curlun->sense_data_info = file_offset >> 9;
963 curlun->info_valid = 1;
967 amount = bh->outreq->actual;
968 if (curlun->file_length - file_offset < amount) {
970 "write %u @ %llu beyond end %llu\n",
971 amount, (unsigned long long) file_offset,
972 (unsigned long long) curlun->file_length);
973 amount = curlun->file_length - file_offset;
976 /* Perform the write */
977 file_offset_tmp = file_offset;
978 nwritten = vfs_write(curlun->filp,
979 (char __user *) bh->buf,
980 amount, &file_offset_tmp);
981 VLDBG(curlun, "file write %u @ %llu -> %d\n", amount,
982 (unsigned long long) file_offset,
984 if (signal_pending(current))
985 return -EINTR; /* Interrupted! */
988 LDBG(curlun, "error in file write: %d\n",
991 } else if (nwritten < amount) {
992 LDBG(curlun, "partial file write: %d/%u\n",
993 (int) nwritten, amount);
994 nwritten -= (nwritten & 511);
995 /* Round down to a block */
997 file_offset += nwritten;
998 amount_left_to_write -= nwritten;
999 common->residue -= nwritten;
1001 /* If an error occurred, report it and its position */
1002 if (nwritten < amount) {
1003 curlun->sense_data = SS_WRITE_ERROR;
1004 curlun->sense_data_info = file_offset >> 9;
1005 curlun->info_valid = 1;
1009 /* Did the host decide to stop early? */
1010 if (bh->outreq->actual != bh->outreq->length) {
1011 common->short_packet_received = 1;
1017 /* Wait for something to happen */
1018 rc = sleep_thread(common);
1023 return -EIO; /* No default reply */
1027 /*-------------------------------------------------------------------------*/
1029 static int do_synchronize_cache(struct fsg_common *common)
1031 struct fsg_lun *curlun = common->curlun;
1034 /* We ignore the requested LBA and write out all file's
1035 * dirty data buffers. */
1036 rc = fsg_lun_fsync_sub(curlun);
1038 curlun->sense_data = SS_WRITE_ERROR;
1043 /*-------------------------------------------------------------------------*/
1045 static void invalidate_sub(struct fsg_lun *curlun)
1047 struct file *filp = curlun->filp;
1048 struct inode *inode = filp->f_path.dentry->d_inode;
1051 rc = invalidate_mapping_pages(inode->i_mapping, 0, -1);
1052 VLDBG(curlun, "invalidate_mapping_pages -> %ld\n", rc);
1055 static int do_verify(struct fsg_common *common)
1057 struct fsg_lun *curlun = common->curlun;
1059 u32 verification_length;
1060 struct fsg_buffhd *bh = common->next_buffhd_to_fill;
1061 loff_t file_offset, file_offset_tmp;
1063 unsigned int amount;
1066 /* Get the starting Logical Block Address and check that it's
1068 lba = get_unaligned_be32(&common->cmnd[2]);
1069 if (lba >= curlun->num_sectors) {
1070 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1074 /* We allow DPO (Disable Page Out = don't save data in the
1075 * cache) but we don't implement it. */
1076 if (common->cmnd[1] & ~0x10) {
1077 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1081 verification_length = get_unaligned_be16(&common->cmnd[7]);
1082 if (unlikely(verification_length == 0))
1083 return -EIO; /* No default reply */
1085 /* Prepare to carry out the file verify */
1086 amount_left = verification_length << 9;
1087 file_offset = ((loff_t) lba) << 9;
1089 /* Write out all the dirty buffers before invalidating them */
1090 fsg_lun_fsync_sub(curlun);
1091 if (signal_pending(current))
1094 invalidate_sub(curlun);
1095 if (signal_pending(current))
1098 /* Just try to read the requested blocks */
1099 while (amount_left > 0) {
1101 /* Figure out how much we need to read:
1102 * Try to read the remaining amount, but not more than
1104 * And don't try to read past the end of the file.
1105 * If this means reading 0 then we were asked to read
1106 * past the end of file. */
1107 amount = min(amount_left, FSG_BUFLEN);
1108 amount = min((loff_t) amount,
1109 curlun->file_length - file_offset);
1111 curlun->sense_data =
1112 SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1113 curlun->sense_data_info = file_offset >> 9;
1114 curlun->info_valid = 1;
1118 /* Perform the read */
1119 file_offset_tmp = file_offset;
1120 nread = vfs_read(curlun->filp,
1121 (char __user *) bh->buf,
1122 amount, &file_offset_tmp);
1123 VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
1124 (unsigned long long) file_offset,
1126 if (signal_pending(current))
1130 LDBG(curlun, "error in file verify: %d\n",
1133 } else if (nread < amount) {
1134 LDBG(curlun, "partial file verify: %d/%u\n",
1135 (int) nread, amount);
1136 nread -= (nread & 511); /* Round down to a sector */
1139 curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
1140 curlun->sense_data_info = file_offset >> 9;
1141 curlun->info_valid = 1;
1144 file_offset += nread;
1145 amount_left -= nread;
1151 /*-------------------------------------------------------------------------*/
1153 static int do_inquiry(struct fsg_common *common, struct fsg_buffhd *bh)
1155 struct fsg_lun *curlun = common->curlun;
1156 u8 *buf = (u8 *) bh->buf;
1158 if (!curlun) { /* Unsupported LUNs are okay */
1159 common->bad_lun_okay = 1;
1161 buf[0] = 0x7f; /* Unsupported, no device-type */
1162 buf[4] = 31; /* Additional length */
1166 buf[0] = curlun->cdrom ? TYPE_CDROM : TYPE_DISK;
1167 buf[1] = curlun->removable ? 0x80 : 0;
1168 buf[2] = 2; /* ANSI SCSI level 2 */
1169 buf[3] = 2; /* SCSI-2 INQUIRY data format */
1170 buf[4] = 31; /* Additional length */
1171 buf[5] = 0; /* No special options */
1174 memcpy(buf + 8, common->inquiry_string, sizeof common->inquiry_string);
1179 static int do_request_sense(struct fsg_common *common, struct fsg_buffhd *bh)
1181 struct fsg_lun *curlun = common->curlun;
1182 u8 *buf = (u8 *) bh->buf;
1187 * From the SCSI-2 spec., section 7.9 (Unit attention condition):
1189 * If a REQUEST SENSE command is received from an initiator
1190 * with a pending unit attention condition (before the target
1191 * generates the contingent allegiance condition), then the
1192 * target shall either:
1193 * a) report any pending sense data and preserve the unit
1194 * attention condition on the logical unit, or,
1195 * b) report the unit attention condition, may discard any
1196 * pending sense data, and clear the unit attention
1197 * condition on the logical unit for that initiator.
1199 * FSG normally uses option a); enable this code to use option b).
1202 if (curlun && curlun->unit_attention_data != SS_NO_SENSE) {
1203 curlun->sense_data = curlun->unit_attention_data;
1204 curlun->unit_attention_data = SS_NO_SENSE;
1208 if (!curlun) { /* Unsupported LUNs are okay */
1209 common->bad_lun_okay = 1;
1210 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
1214 sd = curlun->sense_data;
1215 sdinfo = curlun->sense_data_info;
1216 valid = curlun->info_valid << 7;
1217 curlun->sense_data = SS_NO_SENSE;
1218 curlun->sense_data_info = 0;
1219 curlun->info_valid = 0;
1223 buf[0] = valid | 0x70; /* Valid, current error */
1225 put_unaligned_be32(sdinfo, &buf[3]); /* Sense information */
1226 buf[7] = 18 - 8; /* Additional sense length */
1233 static int do_read_capacity(struct fsg_common *common, struct fsg_buffhd *bh)
1235 struct fsg_lun *curlun = common->curlun;
1236 u32 lba = get_unaligned_be32(&common->cmnd[2]);
1237 int pmi = common->cmnd[8];
1238 u8 *buf = (u8 *) bh->buf;
1240 /* Check the PMI and LBA fields */
1241 if (pmi > 1 || (pmi == 0 && lba != 0)) {
1242 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1246 put_unaligned_be32(curlun->num_sectors - 1, &buf[0]);
1247 /* Max logical block */
1248 put_unaligned_be32(512, &buf[4]); /* Block length */
1253 static int do_read_header(struct fsg_common *common, struct fsg_buffhd *bh)
1255 struct fsg_lun *curlun = common->curlun;
1256 int msf = common->cmnd[1] & 0x02;
1257 u32 lba = get_unaligned_be32(&common->cmnd[2]);
1258 u8 *buf = (u8 *) bh->buf;
1260 if (common->cmnd[1] & ~0x02) { /* Mask away MSF */
1261 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1264 if (lba >= curlun->num_sectors) {
1265 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1270 buf[0] = 0x01; /* 2048 bytes of user data, rest is EC */
1271 store_cdrom_address(&buf[4], msf, lba);
1276 static int do_read_toc(struct fsg_common *common, struct fsg_buffhd *bh)
1278 struct fsg_lun *curlun = common->curlun;
1279 int msf = common->cmnd[1] & 0x02;
1280 int start_track = common->cmnd[6];
1281 u8 *buf = (u8 *) bh->buf;
1283 if ((common->cmnd[1] & ~0x02) != 0 || /* Mask away MSF */
1285 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1290 buf[1] = (20-2); /* TOC data length */
1291 buf[2] = 1; /* First track number */
1292 buf[3] = 1; /* Last track number */
1293 buf[5] = 0x16; /* Data track, copying allowed */
1294 buf[6] = 0x01; /* Only track is number 1 */
1295 store_cdrom_address(&buf[8], msf, 0);
1297 buf[13] = 0x16; /* Lead-out track is data */
1298 buf[14] = 0xAA; /* Lead-out track number */
1299 store_cdrom_address(&buf[16], msf, curlun->num_sectors);
1304 static int do_mode_sense(struct fsg_common *common, struct fsg_buffhd *bh)
1306 struct fsg_lun *curlun = common->curlun;
1307 int mscmnd = common->cmnd[0];
1308 u8 *buf = (u8 *) bh->buf;
1311 int changeable_values, all_pages;
1315 if ((common->cmnd[1] & ~0x08) != 0) { /* Mask away DBD */
1316 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1319 pc = common->cmnd[2] >> 6;
1320 page_code = common->cmnd[2] & 0x3f;
1322 curlun->sense_data = SS_SAVING_PARAMETERS_NOT_SUPPORTED;
1325 changeable_values = (pc == 1);
1326 all_pages = (page_code == 0x3f);
1328 /* Write the mode parameter header. Fixed values are: default
1329 * medium type, no cache control (DPOFUA), and no block descriptors.
1330 * The only variable value is the WriteProtect bit. We will fill in
1331 * the mode data length later. */
1333 if (mscmnd == SC_MODE_SENSE_6) {
1334 buf[2] = (curlun->ro ? 0x80 : 0x00); /* WP, DPOFUA */
1337 } else { /* SC_MODE_SENSE_10 */
1338 buf[3] = (curlun->ro ? 0x80 : 0x00); /* WP, DPOFUA */
1340 limit = 65535; /* Should really be FSG_BUFLEN */
1343 /* No block descriptors */
1345 /* The mode pages, in numerical order. The only page we support
1346 * is the Caching page. */
1347 if (page_code == 0x08 || all_pages) {
1349 buf[0] = 0x08; /* Page code */
1350 buf[1] = 10; /* Page length */
1351 memset(buf+2, 0, 10); /* None of the fields are changeable */
1353 if (!changeable_values) {
1354 buf[2] = 0x04; /* Write cache enable, */
1355 /* Read cache not disabled */
1356 /* No cache retention priorities */
1357 put_unaligned_be16(0xffff, &buf[4]);
1358 /* Don't disable prefetch */
1359 /* Minimum prefetch = 0 */
1360 put_unaligned_be16(0xffff, &buf[8]);
1361 /* Maximum prefetch */
1362 put_unaligned_be16(0xffff, &buf[10]);
1363 /* Maximum prefetch ceiling */
1368 /* Check that a valid page was requested and the mode data length
1369 * isn't too long. */
1371 if (!valid_page || len > limit) {
1372 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1376 /* Store the mode data length */
1377 if (mscmnd == SC_MODE_SENSE_6)
1380 put_unaligned_be16(len - 2, buf0);
1385 static int do_start_stop(struct fsg_common *common)
1387 struct fsg_lun *curlun = common->curlun;
1392 } else if (!curlun->removable) {
1393 curlun->sense_data = SS_INVALID_COMMAND;
1397 loej = common->cmnd[4] & 0x02;
1398 start = common->cmnd[4] & 0x01;
1400 /* eject code from file_storage.c:do_start_stop() */
1402 if ((common->cmnd[1] & ~0x01) != 0 || /* Mask away Immed */
1403 (common->cmnd[4] & ~0x03) != 0) { /* Mask LoEj, Start */
1404 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1409 /* Are we allowed to unload the media? */
1410 if (curlun->prevent_medium_removal) {
1411 LDBG(curlun, "unload attempt prevented\n");
1412 curlun->sense_data = SS_MEDIUM_REMOVAL_PREVENTED;
1415 if (loej) { /* Simulate an unload/eject */
1416 up_read(&common->filesem);
1417 down_write(&common->filesem);
1418 fsg_lun_close(curlun);
1419 up_write(&common->filesem);
1420 down_read(&common->filesem);
1424 /* Our emulation doesn't support mounting; the medium is
1425 * available for use as soon as it is loaded. */
1426 if (!fsg_lun_is_open(curlun)) {
1427 curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
1435 static int do_prevent_allow(struct fsg_common *common)
1437 struct fsg_lun *curlun = common->curlun;
1440 if (!common->curlun) {
1442 } else if (!common->curlun->removable) {
1443 common->curlun->sense_data = SS_INVALID_COMMAND;
1447 prevent = common->cmnd[4] & 0x01;
1448 if ((common->cmnd[4] & ~0x01) != 0) { /* Mask away Prevent */
1449 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1453 if (curlun->prevent_medium_removal && !prevent)
1454 fsg_lun_fsync_sub(curlun);
1455 curlun->prevent_medium_removal = prevent;
1460 static int do_read_format_capacities(struct fsg_common *common,
1461 struct fsg_buffhd *bh)
1463 struct fsg_lun *curlun = common->curlun;
1464 u8 *buf = (u8 *) bh->buf;
1466 buf[0] = buf[1] = buf[2] = 0;
1467 buf[3] = 8; /* Only the Current/Maximum Capacity Descriptor */
1470 put_unaligned_be32(curlun->num_sectors, &buf[0]);
1471 /* Number of blocks */
1472 put_unaligned_be32(512, &buf[4]); /* Block length */
1473 buf[4] = 0x02; /* Current capacity */
1478 static int do_mode_select(struct fsg_common *common, struct fsg_buffhd *bh)
1480 struct fsg_lun *curlun = common->curlun;
1482 /* We don't support MODE SELECT */
1484 curlun->sense_data = SS_INVALID_COMMAND;
1489 /*-------------------------------------------------------------------------*/
1491 static int halt_bulk_in_endpoint(struct fsg_dev *fsg)
1495 rc = fsg_set_halt(fsg, fsg->bulk_in);
1497 VDBG(fsg, "delayed bulk-in endpoint halt\n");
1499 if (rc != -EAGAIN) {
1500 WARNING(fsg, "usb_ep_set_halt -> %d\n", rc);
1505 /* Wait for a short time and then try again */
1506 if (msleep_interruptible(100) != 0)
1508 rc = usb_ep_set_halt(fsg->bulk_in);
1513 static int wedge_bulk_in_endpoint(struct fsg_dev *fsg)
1517 DBG(fsg, "bulk-in set wedge\n");
1518 rc = usb_ep_set_wedge(fsg->bulk_in);
1520 VDBG(fsg, "delayed bulk-in endpoint wedge\n");
1522 if (rc != -EAGAIN) {
1523 WARNING(fsg, "usb_ep_set_wedge -> %d\n", rc);
1528 /* Wait for a short time and then try again */
1529 if (msleep_interruptible(100) != 0)
1531 rc = usb_ep_set_wedge(fsg->bulk_in);
1536 static int pad_with_zeros(struct fsg_dev *fsg)
1538 struct fsg_buffhd *bh = fsg->common->next_buffhd_to_fill;
1539 u32 nkeep = bh->inreq->length;
1543 bh->state = BUF_STATE_EMPTY; /* For the first iteration */
1544 fsg->common->usb_amount_left = nkeep + fsg->common->residue;
1545 while (fsg->common->usb_amount_left > 0) {
1547 /* Wait for the next buffer to be free */
1548 while (bh->state != BUF_STATE_EMPTY) {
1549 rc = sleep_thread(fsg->common);
1554 nsend = min(fsg->common->usb_amount_left, FSG_BUFLEN);
1555 memset(bh->buf + nkeep, 0, nsend - nkeep);
1556 bh->inreq->length = nsend;
1557 bh->inreq->zero = 0;
1558 start_transfer(fsg, fsg->bulk_in, bh->inreq,
1559 &bh->inreq_busy, &bh->state);
1560 bh = fsg->common->next_buffhd_to_fill = bh->next;
1561 fsg->common->usb_amount_left -= nsend;
1567 static int throw_away_data(struct fsg_common *common)
1569 struct fsg_buffhd *bh;
1573 for (bh = common->next_buffhd_to_drain;
1574 bh->state != BUF_STATE_EMPTY || common->usb_amount_left > 0;
1575 bh = common->next_buffhd_to_drain) {
1577 /* Throw away the data in a filled buffer */
1578 if (bh->state == BUF_STATE_FULL) {
1580 bh->state = BUF_STATE_EMPTY;
1581 common->next_buffhd_to_drain = bh->next;
1583 /* A short packet or an error ends everything */
1584 if (bh->outreq->actual != bh->outreq->length ||
1585 bh->outreq->status != 0) {
1586 raise_exception(common,
1587 FSG_STATE_ABORT_BULK_OUT);
1593 /* Try to submit another request if we need one */
1594 bh = common->next_buffhd_to_fill;
1595 if (bh->state == BUF_STATE_EMPTY
1596 && common->usb_amount_left > 0) {
1597 amount = min(common->usb_amount_left, FSG_BUFLEN);
1599 /* amount is always divisible by 512, hence by
1600 * the bulk-out maxpacket size */
1601 bh->outreq->length = amount;
1602 bh->bulk_out_intended_length = amount;
1603 bh->outreq->short_not_ok = 1;
1604 START_TRANSFER_OR(common, bulk_out, bh->outreq,
1605 &bh->outreq_busy, &bh->state)
1606 /* Don't know what to do if
1607 * common->fsg is NULL */
1609 common->next_buffhd_to_fill = bh->next;
1610 common->usb_amount_left -= amount;
1614 /* Otherwise wait for something to happen */
1615 rc = sleep_thread(common);
1623 static int finish_reply(struct fsg_common *common)
1625 struct fsg_buffhd *bh = common->next_buffhd_to_fill;
1628 switch (common->data_dir) {
1630 break; /* Nothing to send */
1632 /* If we don't know whether the host wants to read or write,
1633 * this must be CB or CBI with an unknown command. We mustn't
1634 * try to send or receive any data. So stall both bulk pipes
1635 * if we can and wait for a reset. */
1636 case DATA_DIR_UNKNOWN:
1637 if (!common->can_stall) {
1639 } else if (fsg_is_set(common)) {
1640 fsg_set_halt(common->fsg, common->fsg->bulk_out);
1641 rc = halt_bulk_in_endpoint(common->fsg);
1643 /* Don't know what to do if common->fsg is NULL */
1648 /* All but the last buffer of data must have already been sent */
1649 case DATA_DIR_TO_HOST:
1650 if (common->data_size == 0) {
1651 /* Nothing to send */
1653 /* If there's no residue, simply send the last buffer */
1654 } else if (common->residue == 0) {
1655 bh->inreq->zero = 0;
1656 START_TRANSFER_OR(common, bulk_in, bh->inreq,
1657 &bh->inreq_busy, &bh->state)
1659 common->next_buffhd_to_fill = bh->next;
1661 /* For Bulk-only, if we're allowed to stall then send the
1662 * short packet and halt the bulk-in endpoint. If we can't
1663 * stall, pad out the remaining data with 0's. */
1664 } else if (common->can_stall) {
1665 bh->inreq->zero = 1;
1666 START_TRANSFER_OR(common, bulk_in, bh->inreq,
1667 &bh->inreq_busy, &bh->state)
1668 /* Don't know what to do if
1669 * common->fsg is NULL */
1671 common->next_buffhd_to_fill = bh->next;
1673 rc = halt_bulk_in_endpoint(common->fsg);
1674 } else if (fsg_is_set(common)) {
1675 rc = pad_with_zeros(common->fsg);
1677 /* Don't know what to do if common->fsg is NULL */
1682 /* We have processed all we want from the data the host has sent.
1683 * There may still be outstanding bulk-out requests. */
1684 case DATA_DIR_FROM_HOST:
1685 if (common->residue == 0) {
1686 /* Nothing to receive */
1688 /* Did the host stop sending unexpectedly early? */
1689 } else if (common->short_packet_received) {
1690 raise_exception(common, FSG_STATE_ABORT_BULK_OUT);
1693 /* We haven't processed all the incoming data. Even though
1694 * we may be allowed to stall, doing so would cause a race.
1695 * The controller may already have ACK'ed all the remaining
1696 * bulk-out packets, in which case the host wouldn't see a
1697 * STALL. Not realizing the endpoint was halted, it wouldn't
1698 * clear the halt -- leading to problems later on. */
1700 } else if (common->can_stall) {
1701 if (fsg_is_set(common))
1702 fsg_set_halt(common->fsg,
1703 common->fsg->bulk_out);
1704 raise_exception(common, FSG_STATE_ABORT_BULK_OUT);
1708 /* We can't stall. Read in the excess data and throw it
1711 rc = throw_away_data(common);
1719 static int send_status(struct fsg_common *common)
1721 struct fsg_lun *curlun = common->curlun;
1722 struct fsg_buffhd *bh;
1723 struct bulk_cs_wrap *csw;
1725 u8 status = USB_STATUS_PASS;
1728 /* Wait for the next buffer to become available */
1729 bh = common->next_buffhd_to_fill;
1730 while (bh->state != BUF_STATE_EMPTY) {
1731 rc = sleep_thread(common);
1737 sd = curlun->sense_data;
1738 sdinfo = curlun->sense_data_info;
1739 } else if (common->bad_lun_okay)
1742 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
1744 if (common->phase_error) {
1745 DBG(common, "sending phase-error status\n");
1746 status = USB_STATUS_PHASE_ERROR;
1747 sd = SS_INVALID_COMMAND;
1748 } else if (sd != SS_NO_SENSE) {
1749 DBG(common, "sending command-failure status\n");
1750 status = USB_STATUS_FAIL;
1751 VDBG(common, " sense data: SK x%02x, ASC x%02x, ASCQ x%02x;"
1753 SK(sd), ASC(sd), ASCQ(sd), sdinfo);
1756 /* Store and send the Bulk-only CSW */
1757 csw = (void *)bh->buf;
1759 csw->Signature = cpu_to_le32(USB_BULK_CS_SIG);
1760 csw->Tag = common->tag;
1761 csw->Residue = cpu_to_le32(common->residue);
1762 csw->Status = status;
1764 bh->inreq->length = USB_BULK_CS_WRAP_LEN;
1765 bh->inreq->zero = 0;
1766 START_TRANSFER_OR(common, bulk_in, bh->inreq,
1767 &bh->inreq_busy, &bh->state)
1768 /* Don't know what to do if common->fsg is NULL */
1771 common->next_buffhd_to_fill = bh->next;
1776 /*-------------------------------------------------------------------------*/
1778 /* Check whether the command is properly formed and whether its data size
1779 * and direction agree with the values we already have. */
1780 static int check_command(struct fsg_common *common, int cmnd_size,
1781 enum data_direction data_dir, unsigned int mask,
1782 int needs_medium, const char *name)
1785 int lun = common->cmnd[1] >> 5;
1786 static const char dirletter[4] = {'u', 'o', 'i', 'n'};
1788 struct fsg_lun *curlun;
1791 if (common->data_dir != DATA_DIR_UNKNOWN)
1792 sprintf(hdlen, ", H%c=%u", dirletter[(int) common->data_dir],
1794 VDBG(common, "SCSI command: %s; Dc=%d, D%c=%u; Hc=%d%s\n",
1795 name, cmnd_size, dirletter[(int) data_dir],
1796 common->data_size_from_cmnd, common->cmnd_size, hdlen);
1798 /* We can't reply at all until we know the correct data direction
1800 if (common->data_size_from_cmnd == 0)
1801 data_dir = DATA_DIR_NONE;
1802 if (common->data_size < common->data_size_from_cmnd) {
1803 /* Host data size < Device data size is a phase error.
1804 * Carry out the command, but only transfer as much as
1805 * we are allowed. */
1806 common->data_size_from_cmnd = common->data_size;
1807 common->phase_error = 1;
1809 common->residue = common->data_size;
1810 common->usb_amount_left = common->data_size;
1812 /* Conflicting data directions is a phase error */
1813 if (common->data_dir != data_dir
1814 && common->data_size_from_cmnd > 0) {
1815 common->phase_error = 1;
1819 /* Verify the length of the command itself */
1820 if (cmnd_size != common->cmnd_size) {
1822 /* Special case workaround: There are plenty of buggy SCSI
1823 * implementations. Many have issues with cbw->Length
1824 * field passing a wrong command size. For those cases we
1825 * always try to work around the problem by using the length
1826 * sent by the host side provided it is at least as large
1827 * as the correct command length.
1828 * Examples of such cases would be MS-Windows, which issues
1829 * REQUEST SENSE with cbw->Length == 12 where it should
1830 * be 6, and xbox360 issuing INQUIRY, TEST UNIT READY and
1831 * REQUEST SENSE with cbw->Length == 10 where it should
1834 if (cmnd_size <= common->cmnd_size) {
1835 DBG(common, "%s is buggy! Expected length %d "
1836 "but we got %d\n", name,
1837 cmnd_size, common->cmnd_size);
1838 cmnd_size = common->cmnd_size;
1840 common->phase_error = 1;
1845 /* Check that the LUN values are consistent */
1846 if (common->lun != lun)
1847 DBG(common, "using LUN %d from CBW, not LUN %d from CDB\n",
1851 if (common->lun >= 0 && common->lun < common->nluns) {
1852 curlun = &common->luns[common->lun];
1853 common->curlun = curlun;
1854 if (common->cmnd[0] != SC_REQUEST_SENSE) {
1855 curlun->sense_data = SS_NO_SENSE;
1856 curlun->sense_data_info = 0;
1857 curlun->info_valid = 0;
1860 common->curlun = NULL;
1862 common->bad_lun_okay = 0;
1864 /* INQUIRY and REQUEST SENSE commands are explicitly allowed
1865 * to use unsupported LUNs; all others may not. */
1866 if (common->cmnd[0] != SC_INQUIRY &&
1867 common->cmnd[0] != SC_REQUEST_SENSE) {
1868 DBG(common, "unsupported LUN %d\n", common->lun);
1873 /* If a unit attention condition exists, only INQUIRY and
1874 * REQUEST SENSE commands are allowed; anything else must fail. */
1875 if (curlun && curlun->unit_attention_data != SS_NO_SENSE &&
1876 common->cmnd[0] != SC_INQUIRY &&
1877 common->cmnd[0] != SC_REQUEST_SENSE) {
1878 curlun->sense_data = curlun->unit_attention_data;
1879 curlun->unit_attention_data = SS_NO_SENSE;
1883 /* Check that only command bytes listed in the mask are non-zero */
1884 common->cmnd[1] &= 0x1f; /* Mask away the LUN */
1885 for (i = 1; i < cmnd_size; ++i) {
1886 if (common->cmnd[i] && !(mask & (1 << i))) {
1888 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1893 /* If the medium isn't mounted and the command needs to access
1894 * it, return an error. */
1895 if (curlun && !fsg_lun_is_open(curlun) && needs_medium) {
1896 curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
1904 static int do_scsi_command(struct fsg_common *common)
1906 struct fsg_buffhd *bh;
1908 int reply = -EINVAL;
1910 static char unknown[16];
1914 /* Wait for the next buffer to become available for data or status */
1915 bh = common->next_buffhd_to_fill;
1916 common->next_buffhd_to_drain = bh;
1917 while (bh->state != BUF_STATE_EMPTY) {
1918 rc = sleep_thread(common);
1922 common->phase_error = 0;
1923 common->short_packet_received = 0;
1925 down_read(&common->filesem); /* We're using the backing file */
1926 switch (common->cmnd[0]) {
1929 common->data_size_from_cmnd = common->cmnd[4];
1930 reply = check_command(common, 6, DATA_DIR_TO_HOST,
1934 reply = do_inquiry(common, bh);
1937 case SC_MODE_SELECT_6:
1938 common->data_size_from_cmnd = common->cmnd[4];
1939 reply = check_command(common, 6, DATA_DIR_FROM_HOST,
1943 reply = do_mode_select(common, bh);
1946 case SC_MODE_SELECT_10:
1947 common->data_size_from_cmnd =
1948 get_unaligned_be16(&common->cmnd[7]);
1949 reply = check_command(common, 10, DATA_DIR_FROM_HOST,
1953 reply = do_mode_select(common, bh);
1956 case SC_MODE_SENSE_6:
1957 common->data_size_from_cmnd = common->cmnd[4];
1958 reply = check_command(common, 6, DATA_DIR_TO_HOST,
1959 (1<<1) | (1<<2) | (1<<4), 0,
1962 reply = do_mode_sense(common, bh);
1965 case SC_MODE_SENSE_10:
1966 common->data_size_from_cmnd =
1967 get_unaligned_be16(&common->cmnd[7]);
1968 reply = check_command(common, 10, DATA_DIR_TO_HOST,
1969 (1<<1) | (1<<2) | (3<<7), 0,
1972 reply = do_mode_sense(common, bh);
1975 case SC_PREVENT_ALLOW_MEDIUM_REMOVAL:
1976 common->data_size_from_cmnd = 0;
1977 reply = check_command(common, 6, DATA_DIR_NONE,
1979 "PREVENT-ALLOW MEDIUM REMOVAL");
1981 reply = do_prevent_allow(common);
1985 i = common->cmnd[4];
1986 common->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
1987 reply = check_command(common, 6, DATA_DIR_TO_HOST,
1991 reply = do_read(common);
1995 common->data_size_from_cmnd =
1996 get_unaligned_be16(&common->cmnd[7]) << 9;
1997 reply = check_command(common, 10, DATA_DIR_TO_HOST,
1998 (1<<1) | (0xf<<2) | (3<<7), 1,
2001 reply = do_read(common);
2005 common->data_size_from_cmnd =
2006 get_unaligned_be32(&common->cmnd[6]) << 9;
2007 reply = check_command(common, 12, DATA_DIR_TO_HOST,
2008 (1<<1) | (0xf<<2) | (0xf<<6), 1,
2011 reply = do_read(common);
2014 case SC_READ_CAPACITY:
2015 common->data_size_from_cmnd = 8;
2016 reply = check_command(common, 10, DATA_DIR_TO_HOST,
2017 (0xf<<2) | (1<<8), 1,
2020 reply = do_read_capacity(common, bh);
2023 case SC_READ_HEADER:
2024 if (!common->curlun || !common->curlun->cdrom)
2026 common->data_size_from_cmnd =
2027 get_unaligned_be16(&common->cmnd[7]);
2028 reply = check_command(common, 10, DATA_DIR_TO_HOST,
2029 (3<<7) | (0x1f<<1), 1,
2032 reply = do_read_header(common, bh);
2036 if (!common->curlun || !common->curlun->cdrom)
2038 common->data_size_from_cmnd =
2039 get_unaligned_be16(&common->cmnd[7]);
2040 reply = check_command(common, 10, DATA_DIR_TO_HOST,
2044 reply = do_read_toc(common, bh);
2047 case SC_READ_FORMAT_CAPACITIES:
2048 common->data_size_from_cmnd =
2049 get_unaligned_be16(&common->cmnd[7]);
2050 reply = check_command(common, 10, DATA_DIR_TO_HOST,
2052 "READ FORMAT CAPACITIES");
2054 reply = do_read_format_capacities(common, bh);
2057 case SC_REQUEST_SENSE:
2058 common->data_size_from_cmnd = common->cmnd[4];
2059 reply = check_command(common, 6, DATA_DIR_TO_HOST,
2063 reply = do_request_sense(common, bh);
2066 case SC_START_STOP_UNIT:
2067 common->data_size_from_cmnd = 0;
2068 reply = check_command(common, 6, DATA_DIR_NONE,
2072 reply = do_start_stop(common);
2075 case SC_SYNCHRONIZE_CACHE:
2076 common->data_size_from_cmnd = 0;
2077 reply = check_command(common, 10, DATA_DIR_NONE,
2078 (0xf<<2) | (3<<7), 1,
2079 "SYNCHRONIZE CACHE");
2081 reply = do_synchronize_cache(common);
2084 case SC_TEST_UNIT_READY:
2085 common->data_size_from_cmnd = 0;
2086 reply = check_command(common, 6, DATA_DIR_NONE,
2091 /* Although optional, this command is used by MS-Windows. We
2092 * support a minimal version: BytChk must be 0. */
2094 common->data_size_from_cmnd = 0;
2095 reply = check_command(common, 10, DATA_DIR_NONE,
2096 (1<<1) | (0xf<<2) | (3<<7), 1,
2099 reply = do_verify(common);
2103 i = common->cmnd[4];
2104 common->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
2105 reply = check_command(common, 6, DATA_DIR_FROM_HOST,
2109 reply = do_write(common);
2113 common->data_size_from_cmnd =
2114 get_unaligned_be16(&common->cmnd[7]) << 9;
2115 reply = check_command(common, 10, DATA_DIR_FROM_HOST,
2116 (1<<1) | (0xf<<2) | (3<<7), 1,
2119 reply = do_write(common);
2123 common->data_size_from_cmnd =
2124 get_unaligned_be32(&common->cmnd[6]) << 9;
2125 reply = check_command(common, 12, DATA_DIR_FROM_HOST,
2126 (1<<1) | (0xf<<2) | (0xf<<6), 1,
2129 reply = do_write(common);
2132 /* Some mandatory commands that we recognize but don't implement.
2133 * They don't mean much in this setting. It's left as an exercise
2134 * for anyone interested to implement RESERVE and RELEASE in terms
2135 * of Posix locks. */
2136 case SC_FORMAT_UNIT:
2139 case SC_SEND_DIAGNOSTIC:
2144 common->data_size_from_cmnd = 0;
2145 sprintf(unknown, "Unknown x%02x", common->cmnd[0]);
2146 reply = check_command(common, common->cmnd_size,
2147 DATA_DIR_UNKNOWN, 0xff, 0, unknown);
2149 common->curlun->sense_data = SS_INVALID_COMMAND;
2154 up_read(&common->filesem);
2156 if (reply == -EINTR || signal_pending(current))
2159 /* Set up the single reply buffer for finish_reply() */
2160 if (reply == -EINVAL)
2161 reply = 0; /* Error reply length */
2162 if (reply >= 0 && common->data_dir == DATA_DIR_TO_HOST) {
2163 reply = min((u32) reply, common->data_size_from_cmnd);
2164 bh->inreq->length = reply;
2165 bh->state = BUF_STATE_FULL;
2166 common->residue -= reply;
2167 } /* Otherwise it's already set */
2173 /*-------------------------------------------------------------------------*/
2175 static int received_cbw(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2177 struct usb_request *req = bh->outreq;
2178 struct fsg_bulk_cb_wrap *cbw = req->buf;
2179 struct fsg_common *common = fsg->common;
2181 /* Was this a real packet? Should it be ignored? */
2182 if (req->status || test_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags))
2185 /* Is the CBW valid? */
2186 if (req->actual != USB_BULK_CB_WRAP_LEN ||
2187 cbw->Signature != cpu_to_le32(
2189 DBG(fsg, "invalid CBW: len %u sig 0x%x\n",
2191 le32_to_cpu(cbw->Signature));
2193 /* The Bulk-only spec says we MUST stall the IN endpoint
2194 * (6.6.1), so it's unavoidable. It also says we must
2195 * retain this state until the next reset, but there's
2196 * no way to tell the controller driver it should ignore
2197 * Clear-Feature(HALT) requests.
2199 * We aren't required to halt the OUT endpoint; instead
2200 * we can simply accept and discard any data received
2201 * until the next reset. */
2202 wedge_bulk_in_endpoint(fsg);
2203 set_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
2207 /* Is the CBW meaningful? */
2208 if (cbw->Lun >= FSG_MAX_LUNS || cbw->Flags & ~USB_BULK_IN_FLAG ||
2209 cbw->Length <= 0 || cbw->Length > MAX_COMMAND_SIZE) {
2210 DBG(fsg, "non-meaningful CBW: lun = %u, flags = 0x%x, "
2212 cbw->Lun, cbw->Flags, cbw->Length);
2214 /* We can do anything we want here, so let's stall the
2215 * bulk pipes if we are allowed to. */
2216 if (common->can_stall) {
2217 fsg_set_halt(fsg, fsg->bulk_out);
2218 halt_bulk_in_endpoint(fsg);
2223 /* Save the command for later */
2224 common->cmnd_size = cbw->Length;
2225 memcpy(common->cmnd, cbw->CDB, common->cmnd_size);
2226 if (cbw->Flags & USB_BULK_IN_FLAG)
2227 common->data_dir = DATA_DIR_TO_HOST;
2229 common->data_dir = DATA_DIR_FROM_HOST;
2230 common->data_size = le32_to_cpu(cbw->DataTransferLength);
2231 if (common->data_size == 0)
2232 common->data_dir = DATA_DIR_NONE;
2233 common->lun = cbw->Lun;
2234 common->tag = cbw->Tag;
2239 static int get_next_command(struct fsg_common *common)
2241 struct fsg_buffhd *bh;
2244 /* Wait for the next buffer to become available */
2245 bh = common->next_buffhd_to_fill;
2246 while (bh->state != BUF_STATE_EMPTY) {
2247 rc = sleep_thread(common);
2252 /* Queue a request to read a Bulk-only CBW */
2253 set_bulk_out_req_length(common, bh, USB_BULK_CB_WRAP_LEN);
2254 bh->outreq->short_not_ok = 1;
2255 START_TRANSFER_OR(common, bulk_out, bh->outreq,
2256 &bh->outreq_busy, &bh->state)
2257 /* Don't know what to do if common->fsg is NULL */
2260 /* We will drain the buffer in software, which means we
2261 * can reuse it for the next filling. No need to advance
2262 * next_buffhd_to_fill. */
2264 /* Wait for the CBW to arrive */
2265 while (bh->state != BUF_STATE_FULL) {
2266 rc = sleep_thread(common);
2271 rc = fsg_is_set(common) ? received_cbw(common->fsg, bh) : -EIO;
2272 bh->state = BUF_STATE_EMPTY;
2278 /*-------------------------------------------------------------------------*/
2280 static int enable_endpoint(struct fsg_common *common, struct usb_ep *ep,
2281 const struct usb_endpoint_descriptor *d)
2285 ep->driver_data = common;
2286 rc = usb_ep_enable(ep, d);
2288 ERROR(common, "can't enable %s, result %d\n", ep->name, rc);
2292 static int alloc_request(struct fsg_common *common, struct usb_ep *ep,
2293 struct usb_request **preq)
2295 *preq = usb_ep_alloc_request(ep, GFP_ATOMIC);
2298 ERROR(common, "can't allocate request for %s\n", ep->name);
2302 /* Reset interface setting and re-init endpoint state (toggle etc). */
2303 static int do_set_interface(struct fsg_common *common, struct fsg_dev *new_fsg)
2305 const struct usb_endpoint_descriptor *d;
2306 struct fsg_dev *fsg;
2309 if (common->running)
2310 DBG(common, "reset interface\n");
2313 /* Deallocate the requests */
2317 for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
2318 struct fsg_buffhd *bh = &common->buffhds[i];
2321 usb_ep_free_request(fsg->bulk_in, bh->inreq);
2325 usb_ep_free_request(fsg->bulk_out, bh->outreq);
2330 /* Disable the endpoints */
2331 if (fsg->bulk_in_enabled) {
2332 usb_ep_disable(fsg->bulk_in);
2333 fsg->bulk_in_enabled = 0;
2335 if (fsg->bulk_out_enabled) {
2336 usb_ep_disable(fsg->bulk_out);
2337 fsg->bulk_out_enabled = 0;
2341 wake_up(&common->fsg_wait);
2344 common->running = 0;
2348 common->fsg = new_fsg;
2351 /* Enable the endpoints */
2352 d = fsg_ep_desc(common->gadget,
2353 &fsg_fs_bulk_in_desc, &fsg_hs_bulk_in_desc);
2354 rc = enable_endpoint(common, fsg->bulk_in, d);
2357 fsg->bulk_in_enabled = 1;
2359 d = fsg_ep_desc(common->gadget,
2360 &fsg_fs_bulk_out_desc, &fsg_hs_bulk_out_desc);
2361 rc = enable_endpoint(common, fsg->bulk_out, d);
2364 fsg->bulk_out_enabled = 1;
2365 common->bulk_out_maxpacket = le16_to_cpu(d->wMaxPacketSize);
2366 clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
2368 /* Allocate the requests */
2369 for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
2370 struct fsg_buffhd *bh = &common->buffhds[i];
2372 rc = alloc_request(common, fsg->bulk_in, &bh->inreq);
2375 rc = alloc_request(common, fsg->bulk_out, &bh->outreq);
2378 bh->inreq->buf = bh->outreq->buf = bh->buf;
2379 bh->inreq->context = bh->outreq->context = bh;
2380 bh->inreq->complete = bulk_in_complete;
2381 bh->outreq->complete = bulk_out_complete;
2384 common->running = 1;
2385 for (i = 0; i < common->nluns; ++i)
2386 common->luns[i].unit_attention_data = SS_RESET_OCCURRED;
2391 /****************************** ALT CONFIGS ******************************/
2394 static int fsg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
2396 struct fsg_dev *fsg = fsg_from_func(f);
2397 fsg->common->new_fsg = fsg;
2398 raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
2402 static void fsg_disable(struct usb_function *f)
2404 struct fsg_dev *fsg = fsg_from_func(f);
2405 fsg->common->new_fsg = NULL;
2406 raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
2410 /*-------------------------------------------------------------------------*/
2412 static void handle_exception(struct fsg_common *common)
2416 struct fsg_buffhd *bh;
2417 enum fsg_state old_state;
2418 struct fsg_lun *curlun;
2419 unsigned int exception_req_tag;
2421 /* Clear the existing signals. Anything but SIGUSR1 is converted
2422 * into a high-priority EXIT exception. */
2425 dequeue_signal_lock(current, ¤t->blocked, &info);
2428 if (sig != SIGUSR1) {
2429 if (common->state < FSG_STATE_EXIT)
2430 DBG(common, "Main thread exiting on signal\n");
2431 raise_exception(common, FSG_STATE_EXIT);
2435 /* Cancel all the pending transfers */
2436 if (likely(common->fsg)) {
2437 for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
2438 bh = &common->buffhds[i];
2440 usb_ep_dequeue(common->fsg->bulk_in, bh->inreq);
2441 if (bh->outreq_busy)
2442 usb_ep_dequeue(common->fsg->bulk_out,
2446 /* Wait until everything is idle */
2449 for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
2450 bh = &common->buffhds[i];
2451 num_active += bh->inreq_busy + bh->outreq_busy;
2453 if (num_active == 0)
2455 if (sleep_thread(common))
2459 /* Clear out the controller's fifos */
2460 if (common->fsg->bulk_in_enabled)
2461 usb_ep_fifo_flush(common->fsg->bulk_in);
2462 if (common->fsg->bulk_out_enabled)
2463 usb_ep_fifo_flush(common->fsg->bulk_out);
2466 /* Reset the I/O buffer states and pointers, the SCSI
2467 * state, and the exception. Then invoke the handler. */
2468 spin_lock_irq(&common->lock);
2470 for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
2471 bh = &common->buffhds[i];
2472 bh->state = BUF_STATE_EMPTY;
2474 common->next_buffhd_to_fill = &common->buffhds[0];
2475 common->next_buffhd_to_drain = &common->buffhds[0];
2476 exception_req_tag = common->exception_req_tag;
2477 old_state = common->state;
2479 if (old_state == FSG_STATE_ABORT_BULK_OUT)
2480 common->state = FSG_STATE_STATUS_PHASE;
2482 for (i = 0; i < common->nluns; ++i) {
2483 curlun = &common->luns[i];
2484 curlun->prevent_medium_removal = 0;
2485 curlun->sense_data = SS_NO_SENSE;
2486 curlun->unit_attention_data = SS_NO_SENSE;
2487 curlun->sense_data_info = 0;
2488 curlun->info_valid = 0;
2490 common->state = FSG_STATE_IDLE;
2492 spin_unlock_irq(&common->lock);
2494 /* Carry out any extra actions required for the exception */
2495 switch (old_state) {
2496 case FSG_STATE_ABORT_BULK_OUT:
2497 send_status(common);
2498 spin_lock_irq(&common->lock);
2499 if (common->state == FSG_STATE_STATUS_PHASE)
2500 common->state = FSG_STATE_IDLE;
2501 spin_unlock_irq(&common->lock);
2504 case FSG_STATE_RESET:
2505 /* In case we were forced against our will to halt a
2506 * bulk endpoint, clear the halt now. (The SuperH UDC
2507 * requires this.) */
2508 if (!fsg_is_set(common))
2510 if (test_and_clear_bit(IGNORE_BULK_OUT,
2511 &common->fsg->atomic_bitflags))
2512 usb_ep_clear_halt(common->fsg->bulk_in);
2514 if (common->ep0_req_tag == exception_req_tag)
2515 ep0_queue(common); /* Complete the status stage */
2517 /* Technically this should go here, but it would only be
2518 * a waste of time. Ditto for the INTERFACE_CHANGE and
2519 * CONFIG_CHANGE cases. */
2520 /* for (i = 0; i < common->nluns; ++i) */
2521 /* common->luns[i].unit_attention_data = */
2522 /* SS_RESET_OCCURRED; */
2525 case FSG_STATE_CONFIG_CHANGE:
2526 do_set_interface(common, common->new_fsg);
2529 case FSG_STATE_EXIT:
2530 case FSG_STATE_TERMINATED:
2531 do_set_interface(common, NULL); /* Free resources */
2532 spin_lock_irq(&common->lock);
2533 common->state = FSG_STATE_TERMINATED; /* Stop the thread */
2534 spin_unlock_irq(&common->lock);
2537 case FSG_STATE_INTERFACE_CHANGE:
2538 case FSG_STATE_DISCONNECT:
2539 case FSG_STATE_COMMAND_PHASE:
2540 case FSG_STATE_DATA_PHASE:
2541 case FSG_STATE_STATUS_PHASE:
2542 case FSG_STATE_IDLE:
2548 /*-------------------------------------------------------------------------*/
2550 static int fsg_main_thread(void *common_)
2552 struct fsg_common *common = common_;
2554 /* Allow the thread to be killed by a signal, but set the signal mask
2555 * to block everything but INT, TERM, KILL, and USR1. */
2556 allow_signal(SIGINT);
2557 allow_signal(SIGTERM);
2558 allow_signal(SIGKILL);
2559 allow_signal(SIGUSR1);
2561 /* Allow the thread to be frozen */
2564 /* Arrange for userspace references to be interpreted as kernel
2565 * pointers. That way we can pass a kernel pointer to a routine
2566 * that expects a __user pointer and it will work okay. */
2570 while (common->state != FSG_STATE_TERMINATED) {
2571 if (exception_in_progress(common) || signal_pending(current)) {
2572 handle_exception(common);
2576 if (!common->running) {
2577 sleep_thread(common);
2581 if (get_next_command(common))
2584 spin_lock_irq(&common->lock);
2585 if (!exception_in_progress(common))
2586 common->state = FSG_STATE_DATA_PHASE;
2587 spin_unlock_irq(&common->lock);
2589 if (do_scsi_command(common) || finish_reply(common))
2592 spin_lock_irq(&common->lock);
2593 if (!exception_in_progress(common))
2594 common->state = FSG_STATE_STATUS_PHASE;
2595 spin_unlock_irq(&common->lock);
2597 if (send_status(common))
2600 spin_lock_irq(&common->lock);
2601 if (!exception_in_progress(common))
2602 common->state = FSG_STATE_IDLE;
2603 spin_unlock_irq(&common->lock);
2606 spin_lock_irq(&common->lock);
2607 common->thread_task = NULL;
2608 spin_unlock_irq(&common->lock);
2610 if (!common->thread_exits || common->thread_exits(common) < 0) {
2611 struct fsg_lun *curlun = common->luns;
2612 unsigned i = common->nluns;
2614 down_write(&common->filesem);
2615 for (; i--; ++curlun) {
2616 if (!fsg_lun_is_open(curlun))
2619 fsg_lun_close(curlun);
2620 curlun->unit_attention_data = SS_MEDIUM_NOT_PRESENT;
2622 up_write(&common->filesem);
2625 /* Let the unbind and cleanup routines know the thread has exited */
2626 complete_and_exit(&common->thread_notifier, 0);
2630 /*************************** DEVICE ATTRIBUTES ***************************/
2632 /* Write permission is checked per LUN in store_*() functions. */
2633 static DEVICE_ATTR(ro, 0644, fsg_show_ro, fsg_store_ro);
2634 static DEVICE_ATTR(file, 0644, fsg_show_file, fsg_store_file);
2637 /****************************** FSG COMMON ******************************/
2639 static void fsg_common_release(struct kref *ref);
2641 static void fsg_lun_release(struct device *dev)
2643 /* Nothing needs to be done */
2646 static inline void fsg_common_get(struct fsg_common *common)
2648 kref_get(&common->ref);
2651 static inline void fsg_common_put(struct fsg_common *common)
2653 kref_put(&common->ref, fsg_common_release);
2657 static struct fsg_common *fsg_common_init(struct fsg_common *common,
2658 struct usb_composite_dev *cdev,
2659 struct fsg_config *cfg)
2661 struct usb_gadget *gadget = cdev->gadget;
2662 struct fsg_buffhd *bh;
2663 struct fsg_lun *curlun;
2664 struct fsg_lun_config *lcfg;
2668 /* Find out how many LUNs there should be */
2670 if (nluns < 1 || nluns > FSG_MAX_LUNS) {
2671 dev_err(&gadget->dev, "invalid number of LUNs: %u\n", nluns);
2672 return ERR_PTR(-EINVAL);
2677 common = kzalloc(sizeof *common, GFP_KERNEL);
2679 return ERR_PTR(-ENOMEM);
2680 common->free_storage_on_release = 1;
2682 memset(common, 0, sizeof common);
2683 common->free_storage_on_release = 0;
2686 common->private_data = cfg->private_data;
2688 common->gadget = gadget;
2689 common->ep0 = gadget->ep0;
2690 common->ep0req = cdev->req;
2692 /* Maybe allocate device-global string IDs, and patch descriptors */
2693 if (fsg_strings[FSG_STRING_INTERFACE].id == 0) {
2694 rc = usb_string_id(cdev);
2695 if (unlikely(rc < 0))
2697 fsg_strings[FSG_STRING_INTERFACE].id = rc;
2698 fsg_intf_desc.iInterface = rc;
2701 /* Create the LUNs, open their backing files, and register the
2702 * LUN devices in sysfs. */
2703 curlun = kzalloc(nluns * sizeof *curlun, GFP_KERNEL);
2704 if (unlikely(!curlun)) {
2708 common->luns = curlun;
2710 init_rwsem(&common->filesem);
2712 for (i = 0, lcfg = cfg->luns; i < nluns; ++i, ++curlun, ++lcfg) {
2713 curlun->cdrom = !!lcfg->cdrom;
2714 curlun->ro = lcfg->cdrom || lcfg->ro;
2715 curlun->removable = lcfg->removable;
2716 curlun->dev.release = fsg_lun_release;
2717 curlun->dev.parent = &gadget->dev;
2718 /* curlun->dev.driver = &fsg_driver.driver; XXX */
2719 dev_set_drvdata(&curlun->dev, &common->filesem);
2720 dev_set_name(&curlun->dev,
2721 cfg->lun_name_format
2722 ? cfg->lun_name_format
2726 rc = device_register(&curlun->dev);
2728 INFO(common, "failed to register LUN%d: %d\n", i, rc);
2733 rc = device_create_file(&curlun->dev, &dev_attr_ro);
2736 rc = device_create_file(&curlun->dev, &dev_attr_file);
2740 if (lcfg->filename) {
2741 rc = fsg_lun_open(curlun, lcfg->filename);
2744 } else if (!curlun->removable) {
2745 ERROR(common, "no file given for LUN%d\n", i);
2750 common->nluns = nluns;
2753 /* Data buffers cyclic list */
2754 bh = common->buffhds;
2755 i = FSG_NUM_BUFFERS;
2756 goto buffhds_first_it;
2761 bh->buf = kmalloc(FSG_BUFLEN, GFP_KERNEL);
2762 if (unlikely(!bh->buf)) {
2767 bh->next = common->buffhds;
2770 /* Prepare inquiryString */
2771 if (cfg->release != 0xffff) {
2774 i = usb_gadget_controller_number(gadget);
2778 WARNING(common, "controller '%s' not recognized\n",
2783 #define OR(x, y) ((x) ? (x) : (y))
2784 snprintf(common->inquiry_string, sizeof common->inquiry_string,
2786 OR(cfg->vendor_name, "Linux "),
2787 /* Assume product name dependent on the first LUN */
2788 OR(cfg->product_name, common->luns->cdrom
2789 ? "File-Stor Gadget"
2790 : "File-CD Gadget "),
2794 /* Some peripheral controllers are known not to be able to
2795 * halt bulk endpoints correctly. If one of them is present,
2798 common->can_stall = cfg->can_stall &&
2799 !(gadget_is_at91(common->gadget));
2802 spin_lock_init(&common->lock);
2803 kref_init(&common->ref);
2806 /* Tell the thread to start working */
2807 common->thread_exits = cfg->thread_exits;
2808 common->thread_task =
2809 kthread_create(fsg_main_thread, common,
2810 OR(cfg->thread_name, "file-storage"));
2811 if (IS_ERR(common->thread_task)) {
2812 rc = PTR_ERR(common->thread_task);
2815 init_completion(&common->thread_notifier);
2816 init_waitqueue_head(&common->fsg_wait);
2821 INFO(common, FSG_DRIVER_DESC ", version: " FSG_DRIVER_VERSION "\n");
2822 INFO(common, "Number of LUNs=%d\n", common->nluns);
2824 pathbuf = kmalloc(PATH_MAX, GFP_KERNEL);
2825 for (i = 0, nluns = common->nluns, curlun = common->luns;
2828 char *p = "(no medium)";
2829 if (fsg_lun_is_open(curlun)) {
2832 p = d_path(&curlun->filp->f_path,
2838 LINFO(curlun, "LUN: %s%s%sfile: %s\n",
2839 curlun->removable ? "removable " : "",
2840 curlun->ro ? "read only " : "",
2841 curlun->cdrom ? "CD-ROM " : "",
2846 DBG(common, "I/O thread pid: %d\n", task_pid_nr(common->thread_task));
2848 wake_up_process(common->thread_task);
2854 common->nluns = i + 1;
2856 common->state = FSG_STATE_TERMINATED; /* The thread is dead */
2857 /* Call fsg_common_release() directly, ref might be not
2859 fsg_common_release(&common->ref);
2864 static void fsg_common_release(struct kref *ref)
2866 struct fsg_common *common = container_of(ref, struct fsg_common, ref);
2868 /* If the thread isn't already dead, tell it to exit now */
2869 if (common->state != FSG_STATE_TERMINATED) {
2870 raise_exception(common, FSG_STATE_EXIT);
2871 wait_for_completion(&common->thread_notifier);
2873 /* The cleanup routine waits for this completion also */
2874 complete(&common->thread_notifier);
2877 if (likely(common->luns)) {
2878 struct fsg_lun *lun = common->luns;
2879 unsigned i = common->nluns;
2881 /* In error recovery common->nluns may be zero. */
2882 for (; i; --i, ++lun) {
2883 device_remove_file(&lun->dev, &dev_attr_ro);
2884 device_remove_file(&lun->dev, &dev_attr_file);
2886 device_unregister(&lun->dev);
2889 kfree(common->luns);
2893 struct fsg_buffhd *bh = common->buffhds;
2894 unsigned i = FSG_NUM_BUFFERS;
2897 } while (++bh, --i);
2900 if (common->free_storage_on_release)
2905 /*-------------------------------------------------------------------------*/
2908 static void fsg_unbind(struct usb_configuration *c, struct usb_function *f)
2910 struct fsg_dev *fsg = fsg_from_func(f);
2911 struct fsg_common *common = fsg->common;
2913 DBG(fsg, "unbind\n");
2914 if (fsg->common->fsg == fsg) {
2915 fsg->common->new_fsg = NULL;
2916 raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
2917 /* FIXME: make interruptible or killable somehow? */
2918 wait_event(common->fsg_wait, common->fsg != fsg);
2921 fsg_common_put(common);
2922 usb_free_descriptors(fsg->function.descriptors);
2923 usb_free_descriptors(fsg->function.hs_descriptors);
2928 static int fsg_bind(struct usb_configuration *c, struct usb_function *f)
2930 struct fsg_dev *fsg = fsg_from_func(f);
2931 struct usb_gadget *gadget = c->cdev->gadget;
2935 fsg->gadget = gadget;
2938 i = usb_interface_id(c, f);
2941 fsg_intf_desc.bInterfaceNumber = i;
2942 fsg->interface_number = i;
2944 /* Find all the endpoints we will use */
2945 ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_in_desc);
2948 ep->driver_data = fsg->common; /* claim the endpoint */
2951 ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_out_desc);
2954 ep->driver_data = fsg->common; /* claim the endpoint */
2957 /* Copy descriptors */
2958 f->descriptors = usb_copy_descriptors(fsg_fs_function);
2959 if (unlikely(!f->descriptors))
2962 if (gadget_is_dualspeed(gadget)) {
2963 /* Assume endpoint addresses are the same for both speeds */
2964 fsg_hs_bulk_in_desc.bEndpointAddress =
2965 fsg_fs_bulk_in_desc.bEndpointAddress;
2966 fsg_hs_bulk_out_desc.bEndpointAddress =
2967 fsg_fs_bulk_out_desc.bEndpointAddress;
2968 f->hs_descriptors = usb_copy_descriptors(fsg_hs_function);
2969 if (unlikely(!f->hs_descriptors)) {
2970 usb_free_descriptors(f->descriptors);
2978 ERROR(fsg, "unable to autoconfigure all endpoints\n");
2983 /****************************** ADD FUNCTION ******************************/
2985 static struct usb_gadget_strings *fsg_strings_array[] = {
2990 static int fsg_bind_config(struct usb_composite_dev *cdev,
2991 struct usb_configuration *c,
2992 struct fsg_common *common)
2994 struct fsg_dev *fsg;
2997 fsg = kzalloc(sizeof *fsg, GFP_KERNEL);
3001 fsg->function.name = FSG_DRIVER_DESC;
3002 fsg->function.strings = fsg_strings_array;
3003 fsg->function.bind = fsg_bind;
3004 fsg->function.unbind = fsg_unbind;
3005 fsg->function.setup = fsg_setup;
3006 fsg->function.set_alt = fsg_set_alt;
3007 fsg->function.disable = fsg_disable;
3009 fsg->common = common;
3010 /* Our caller holds a reference to common structure so we
3011 * don't have to be worry about it being freed until we return
3012 * from this function. So instead of incrementing counter now
3013 * and decrement in error recovery we increment it only when
3014 * call to usb_add_function() was successful. */
3016 rc = usb_add_function(c, &fsg->function);
3020 fsg_common_get(fsg->common);
3024 static inline int __deprecated __maybe_unused
3025 fsg_add(struct usb_composite_dev *cdev,
3026 struct usb_configuration *c,
3027 struct fsg_common *common)
3029 return fsg_bind_config(cdev, c, common);
3033 /************************* Module parameters *************************/
3036 struct fsg_module_parameters {
3037 char *file[FSG_MAX_LUNS];
3038 int ro[FSG_MAX_LUNS];
3039 int removable[FSG_MAX_LUNS];
3040 int cdrom[FSG_MAX_LUNS];
3042 unsigned int file_count, ro_count, removable_count, cdrom_count;
3043 unsigned int luns; /* nluns */
3044 int stall; /* can_stall */
3048 #define _FSG_MODULE_PARAM_ARRAY(prefix, params, name, type, desc) \
3049 module_param_array_named(prefix ## name, params.name, type, \
3050 &prefix ## params.name ## _count, \
3052 MODULE_PARM_DESC(prefix ## name, desc)
3054 #define _FSG_MODULE_PARAM(prefix, params, name, type, desc) \
3055 module_param_named(prefix ## name, params.name, type, \
3057 MODULE_PARM_DESC(prefix ## name, desc)
3059 #define FSG_MODULE_PARAMETERS(prefix, params) \
3060 _FSG_MODULE_PARAM_ARRAY(prefix, params, file, charp, \
3061 "names of backing files or devices"); \
3062 _FSG_MODULE_PARAM_ARRAY(prefix, params, ro, bool, \
3063 "true to force read-only"); \
3064 _FSG_MODULE_PARAM_ARRAY(prefix, params, removable, bool, \
3065 "true to simulate removable media"); \
3066 _FSG_MODULE_PARAM_ARRAY(prefix, params, cdrom, bool, \
3067 "true to simulate CD-ROM instead of disk"); \
3068 _FSG_MODULE_PARAM(prefix, params, luns, uint, \
3069 "number of LUNs"); \
3070 _FSG_MODULE_PARAM(prefix, params, stall, bool, \
3071 "false to prevent bulk stalls")
3075 fsg_config_from_params(struct fsg_config *cfg,
3076 const struct fsg_module_parameters *params)
3078 struct fsg_lun_config *lun;
3081 /* Configure LUNs */
3083 min(params->luns ?: (params->file_count ?: 1u),
3084 (unsigned)FSG_MAX_LUNS);
3085 for (i = 0, lun = cfg->luns; i < cfg->nluns; ++i, ++lun) {
3086 lun->ro = !!params->ro[i];
3087 lun->cdrom = !!params->cdrom[i];
3088 lun->removable = /* Removable by default */
3089 params->removable_count <= i || params->removable[i];
3091 params->file_count > i && params->file[i][0]
3096 /* Let MSF use defaults */
3097 cfg->lun_name_format = 0;
3098 cfg->thread_name = 0;
3099 cfg->vendor_name = 0;
3100 cfg->product_name = 0;
3101 cfg->release = 0xffff;
3103 cfg->thread_exits = 0;
3104 cfg->private_data = 0;
3107 cfg->can_stall = params->stall;
3110 static inline struct fsg_common *
3111 fsg_common_from_params(struct fsg_common *common,
3112 struct usb_composite_dev *cdev,
3113 const struct fsg_module_parameters *params)
3114 __attribute__((unused));
3115 static inline struct fsg_common *
3116 fsg_common_from_params(struct fsg_common *common,
3117 struct usb_composite_dev *cdev,
3118 const struct fsg_module_parameters *params)
3120 struct fsg_config cfg;
3121 fsg_config_from_params(&cfg, params);
3122 return fsg_common_init(common, cdev, &cfg);