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 <mina86@mina86.com>
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions, and the following disclaimer,
14 * without modification.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. The names of the above-listed copyright holders may not be used
19 * to endorse or promote products derived from this software without
20 * specific prior written permission.
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
27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
28 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
29 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
31 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
32 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
33 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
34 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
35 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
36 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
37 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
41 * The Mass Storage Function acts as a USB Mass Storage device,
42 * appearing to the host as a disk drive or as a CD-ROM drive. In
43 * addition to providing an example of a genuinely useful composite
44 * function for a USB device, it also illustrates a technique of
45 * double-buffering for increased throughput.
47 * Function supports multiple logical units (LUNs). Backing storage
48 * for each LUN is provided by a regular file or a block device.
49 * Access for each LUN can be limited to read-only. Moreover, the
50 * function can indicate that LUN is removable and/or CD-ROM. (The
51 * later implies read-only access.)
53 * MSF is configured by specifying a fsg_config structure. It has the
56 * nluns Number of LUNs function have (anywhere from 1
57 * to FSG_MAX_LUNS which is 8).
58 * luns An array of LUN configuration values. This
59 * should be filled for each LUN that
60 * function will include (ie. for "nluns"
61 * LUNs). Each element of the array has
62 * the following fields:
63 * ->filename The path to the backing file for the LUN.
64 * Required if LUN is not marked as
66 * ->ro Flag specifying access to the LUN shall be
67 * read-only. This is implied if CD-ROM
68 * emulation is enabled as well as when
69 * it was impossible to open "filename"
71 * ->removable Flag specifying that LUN shall be indicated as
73 * ->cdrom Flag specifying that LUN shall be reported as
75 * ->nofua Flag specifying that FUA flag in SCSI WRITE(10,12)
76 * commands for this LUN shall be ignored.
78 * lun_name_format A printf-like format for names of the LUN
79 * devices. This determines how the
80 * directory in sysfs will be named.
81 * Unless you are using several MSFs in
82 * a single gadget (as opposed to single
83 * MSF in many configurations) you may
84 * leave it as NULL (in which case
85 * "lun%d" will be used). In the format
86 * you can use "%d" to index LUNs for
87 * MSF's with more than one LUN. (Beware
88 * that there is only one integer given
89 * as an argument for the format and
90 * specifying invalid format may cause
91 * unspecified behaviour.)
92 * thread_name Name of the kernel thread process used by the
93 * MSF. You can safely set it to NULL
94 * (in which case default "file-storage"
99 * release Information used as a reply to INQUIRY
100 * request. To use default set to NULL,
101 * NULL, 0xffff respectively. The first
102 * field should be 8 and the second 16
103 * characters or less.
105 * can_stall Set to permit function to halt bulk endpoints.
106 * Disabled on some USB devices known not
107 * to work correctly. You should set it
110 * If "removable" is not set for a LUN then a backing file must be
111 * specified. If it is set, then NULL filename means the LUN's medium
112 * is not loaded (an empty string as "filename" in the fsg_config
113 * structure causes error). The CD-ROM emulation includes a single
114 * data track and no audio tracks; hence there need be only one
115 * backing file per LUN.
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 * nofua=b[,b...] Default false, booleans for ignore FUA flag
131 * in SCSI WRITE(10,12) commands
132 * luns=N Default N = number of filenames, number of
134 * stall Default determined according to the type of
135 * USB device controller (usually true),
136 * boolean to permit the driver to halt
139 * The module parameters may be prefixed with some string. You need
140 * to consult gadget's documentation or source to verify whether it is
141 * using those module parameters and if it does what are the prefixes
142 * (look for FSG_MODULE_PARAMETERS() macro usage, what's inside it is
146 * Requirements are modest; only a bulk-in and a bulk-out endpoint are
147 * needed. The memory requirement amounts to two 16K buffers, size
148 * configurable by a parameter. Support is included for both
149 * full-speed and high-speed operation.
151 * Note that the driver is slightly non-portable in that it assumes a
152 * single memory/DMA buffer will be useable for bulk-in, bulk-out, and
153 * interrupt-in endpoints. With most device controllers this isn't an
154 * issue, but there may be some with hardware restrictions that prevent
155 * a buffer from being used by more than one endpoint.
158 * The pathnames of the backing files and the ro settings are
159 * available in the attribute files "file" and "ro" in the lun<n> (or
160 * to be more precise in a directory which name comes from
161 * "lun_name_format" option!) subdirectory of the gadget's sysfs
162 * directory. If the "removable" option is set, writing to these
163 * files will simulate ejecting/loading the medium (writing an empty
164 * line means eject) and adjusting a write-enable tab. Changes to the
165 * ro setting are not allowed when the medium is loaded or if CD-ROM
166 * emulation is being used.
168 * When a LUN receive an "eject" SCSI request (Start/Stop Unit),
169 * if the LUN is removable, the backing file is released to simulate
173 * This function is heavily based on "File-backed Storage Gadget" by
174 * Alan Stern which in turn is heavily based on "Gadget Zero" by David
175 * Brownell. The driver's SCSI command interface was based on the
176 * "Information technology - Small Computer System Interface - 2"
177 * document from X3T9.2 Project 375D, Revision 10L, 7-SEP-93,
178 * available at <http://www.t10.org/ftp/t10/drafts/s2/s2-r10l.pdf>.
179 * The single exception is opcode 0x23 (READ FORMAT CAPACITIES), which
180 * was based on the "Universal Serial Bus Mass Storage Class UFI
181 * Command Specification" document, Revision 1.0, December 14, 1998,
183 * <http://www.usb.org/developers/devclass_docs/usbmass-ufi10.pdf>.
189 * The MSF is fairly straightforward. There is a main kernel
190 * thread that handles most of the work. Interrupt routines field
191 * callbacks from the controller driver: bulk- and interrupt-request
192 * completion notifications, endpoint-0 events, and disconnect events.
193 * Completion events are passed to the main thread by wakeup calls. Many
194 * ep0 requests are handled at interrupt time, but SetInterface,
195 * SetConfiguration, and device reset requests are forwarded to the
196 * thread in the form of "exceptions" using SIGUSR1 signals (since they
197 * should interrupt any ongoing file I/O operations).
199 * The thread's main routine implements the standard command/data/status
200 * parts of a SCSI interaction. It and its subroutines are full of tests
201 * for pending signals/exceptions -- all this polling is necessary since
202 * the kernel has no setjmp/longjmp equivalents. (Maybe this is an
203 * indication that the driver really wants to be running in userspace.)
204 * An important point is that so long as the thread is alive it keeps an
205 * open reference to the backing file. This will prevent unmounting
206 * the backing file's underlying filesystem and could cause problems
207 * during system shutdown, for example. To prevent such problems, the
208 * thread catches INT, TERM, and KILL signals and converts them into
211 * In normal operation the main thread is started during the gadget's
212 * fsg_bind() callback and stopped during fsg_unbind(). But it can
213 * also exit when it receives a signal, and there's no point leaving
214 * the gadget running when the thread is dead. At of this moment, MSF
215 * provides no way to deregister the gadget when thread dies -- maybe
216 * a callback functions is needed.
218 * To provide maximum throughput, the driver uses a circular pipeline of
219 * buffer heads (struct fsg_buffhd). In principle the pipeline can be
220 * arbitrarily long; in practice the benefits don't justify having more
221 * than 2 stages (i.e., double buffering). But it helps to think of the
222 * pipeline as being a long one. Each buffer head contains a bulk-in and
223 * a bulk-out request pointer (since the buffer can be used for both
224 * output and input -- directions always are given from the host's
225 * point of view) as well as a pointer to the buffer and various state
228 * Use of the pipeline follows a simple protocol. There is a variable
229 * (fsg->next_buffhd_to_fill) that points to the next buffer head to use.
230 * At any time that buffer head may still be in use from an earlier
231 * request, so each buffer head has a state variable indicating whether
232 * it is EMPTY, FULL, or BUSY. Typical use involves waiting for the
233 * buffer head to be EMPTY, filling the buffer either by file I/O or by
234 * USB I/O (during which the buffer head is BUSY), and marking the buffer
235 * head FULL when the I/O is complete. Then the buffer will be emptied
236 * (again possibly by USB I/O, during which it is marked BUSY) and
237 * finally marked EMPTY again (possibly by a completion routine).
239 * A module parameter tells the driver to avoid stalling the bulk
240 * endpoints wherever the transport specification allows. This is
241 * necessary for some UDCs like the SuperH, which cannot reliably clear a
242 * halt on a bulk endpoint. However, under certain circumstances the
243 * Bulk-only specification requires a stall. In such cases the driver
244 * will halt the endpoint and set a flag indicating that it should clear
245 * the halt in software during the next device reset. Hopefully this
246 * will permit everything to work correctly. Furthermore, although the
247 * specification allows the bulk-out endpoint to halt when the host sends
248 * too much data, implementing this would cause an unavoidable race.
249 * The driver will always use the "no-stall" approach for OUT transfers.
251 * One subtle point concerns sending status-stage responses for ep0
252 * requests. Some of these requests, such as device reset, can involve
253 * interrupting an ongoing file I/O operation, which might take an
254 * arbitrarily long time. During that delay the host might give up on
255 * the original ep0 request and issue a new one. When that happens the
256 * driver should not notify the host about completion of the original
257 * request, as the host will no longer be waiting for it. So the driver
258 * assigns to each ep0 request a unique tag, and it keeps track of the
259 * tag value of the request associated with a long-running exception
260 * (device-reset, interface-change, or configuration-change). When the
261 * exception handler is finished, the status-stage response is submitted
262 * only if the current ep0 request tag is equal to the exception request
263 * tag. Thus only the most recently received ep0 request will get a
264 * status-stage response.
266 * Warning: This driver source file is too long. It ought to be split up
267 * into a header file plus about 3 separate .c files, to handle the details
268 * of the Gadget, USB Mass Storage, and SCSI protocols.
272 /* #define VERBOSE_DEBUG */
273 /* #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>
295 #include <linux/usb/composite.h>
297 #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";
307 #define FSG_NO_DEVICE_STRINGS 1
309 #define FSG_NO_INTR_EP 1
311 #include "storage_common.c"
314 /*-------------------------------------------------------------------------*/
319 /* FSF callback functions */
320 struct fsg_operations {
322 * Callback function to call when thread exits. If no
323 * callback is set or it returns value lower then zero MSF
324 * will force eject all LUNs it operates on (including those
325 * marked as non-removable or with prevent_medium_removal flag
328 int (*thread_exits)(struct fsg_common *common);
331 * Called prior to ejection. Negative return means error,
332 * zero means to continue with ejection, positive means not to
335 int (*pre_eject)(struct fsg_common *common,
336 struct fsg_lun *lun, int num);
338 * Called after ejection. Negative return means error, zero
339 * or positive is just a success.
341 int (*post_eject)(struct fsg_common *common,
342 struct fsg_lun *lun, int num);
345 /* Data shared by all the FSG instances. */
347 struct usb_gadget *gadget;
348 struct usb_composite_dev *cdev;
349 struct fsg_dev *fsg, *new_fsg;
350 wait_queue_head_t fsg_wait;
352 /* filesem protects: backing files in use */
353 struct rw_semaphore filesem;
355 /* lock protects: state, all the req_busy's */
358 struct usb_ep *ep0; /* Copy of gadget->ep0 */
359 struct usb_request *ep0req; /* Copy of cdev->req */
360 unsigned int ep0_req_tag;
362 struct fsg_buffhd *next_buffhd_to_fill;
363 struct fsg_buffhd *next_buffhd_to_drain;
364 struct fsg_buffhd *buffhds;
367 u8 cmnd[MAX_COMMAND_SIZE];
371 struct fsg_lun *luns;
372 struct fsg_lun *curlun;
374 unsigned int bulk_out_maxpacket;
375 enum fsg_state state; /* For exception handling */
376 unsigned int exception_req_tag;
378 enum data_direction data_dir;
380 u32 data_size_from_cmnd;
385 unsigned int can_stall:1;
386 unsigned int free_storage_on_release:1;
387 unsigned int phase_error:1;
388 unsigned int short_packet_received:1;
389 unsigned int bad_lun_okay:1;
390 unsigned int running:1;
392 int thread_wakeup_needed;
393 struct completion thread_notifier;
394 struct task_struct *thread_task;
396 /* Callback functions. */
397 const struct fsg_operations *ops;
398 /* Gadget's private data. */
402 * Vendor (8 chars), product (16 chars), release (4
403 * hexadecimal digits) and NUL byte
405 char inquiry_string[8 + 16 + 4 + 1];
412 struct fsg_lun_config {
413 const char *filename;
418 } luns[FSG_MAX_LUNS];
420 const char *lun_name_format;
421 const char *thread_name;
423 /* Callback functions. */
424 const struct fsg_operations *ops;
425 /* Gadget's private data. */
428 const char *vendor_name; /* 8 characters or less */
429 const char *product_name; /* 16 characters or less */
436 struct usb_function function;
437 struct usb_gadget *gadget; /* Copy of cdev->gadget */
438 struct fsg_common *common;
440 u16 interface_number;
442 unsigned int bulk_in_enabled:1;
443 unsigned int bulk_out_enabled:1;
445 unsigned long atomic_bitflags;
446 #define IGNORE_BULK_OUT 0
448 struct usb_ep *bulk_in;
449 struct usb_ep *bulk_out;
452 static inline int __fsg_is_set(struct fsg_common *common,
453 const char *func, unsigned line)
457 ERROR(common, "common->fsg is NULL in %s at %u\n", func, line);
462 #define fsg_is_set(common) likely(__fsg_is_set(common, __func__, __LINE__))
464 static inline struct fsg_dev *fsg_from_func(struct usb_function *f)
466 return container_of(f, struct fsg_dev, function);
469 typedef void (*fsg_routine_t)(struct fsg_dev *);
471 static int exception_in_progress(struct fsg_common *common)
473 return common->state > FSG_STATE_IDLE;
476 /* Make bulk-out requests be divisible by the maxpacket size */
477 static void set_bulk_out_req_length(struct fsg_common *common,
478 struct fsg_buffhd *bh, unsigned int length)
482 bh->bulk_out_intended_length = length;
483 rem = length % common->bulk_out_maxpacket;
485 length += common->bulk_out_maxpacket - rem;
486 bh->outreq->length = length;
490 /*-------------------------------------------------------------------------*/
492 static int fsg_set_halt(struct fsg_dev *fsg, struct usb_ep *ep)
496 if (ep == fsg->bulk_in)
498 else if (ep == fsg->bulk_out)
502 DBG(fsg, "%s set halt\n", name);
503 return usb_ep_set_halt(ep);
507 /*-------------------------------------------------------------------------*/
509 /* These routines may be called in process context or in_irq */
511 /* Caller must hold fsg->lock */
512 static void wakeup_thread(struct fsg_common *common)
514 /* Tell the main thread that something has happened */
515 common->thread_wakeup_needed = 1;
516 if (common->thread_task)
517 wake_up_process(common->thread_task);
520 static void raise_exception(struct fsg_common *common, enum fsg_state new_state)
525 * Do nothing if a higher-priority exception is already in progress.
526 * If a lower-or-equal priority exception is in progress, preempt it
527 * and notify the main thread by sending it a signal.
529 spin_lock_irqsave(&common->lock, flags);
530 if (common->state <= new_state) {
531 common->exception_req_tag = common->ep0_req_tag;
532 common->state = new_state;
533 if (common->thread_task)
534 send_sig_info(SIGUSR1, SEND_SIG_FORCED,
535 common->thread_task);
537 spin_unlock_irqrestore(&common->lock, flags);
541 /*-------------------------------------------------------------------------*/
543 static int ep0_queue(struct fsg_common *common)
547 rc = usb_ep_queue(common->ep0, common->ep0req, GFP_ATOMIC);
548 common->ep0->driver_data = common;
549 if (rc != 0 && rc != -ESHUTDOWN) {
550 /* We can't do much more than wait for a reset */
551 WARNING(common, "error in submission: %s --> %d\n",
552 common->ep0->name, rc);
558 /*-------------------------------------------------------------------------*/
560 /* Completion handlers. These always run in_irq. */
562 static void bulk_in_complete(struct usb_ep *ep, struct usb_request *req)
564 struct fsg_common *common = ep->driver_data;
565 struct fsg_buffhd *bh = req->context;
567 if (req->status || req->actual != req->length)
568 DBG(common, "%s --> %d, %u/%u\n", __func__,
569 req->status, req->actual, req->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_EMPTY;
578 wakeup_thread(common);
579 spin_unlock(&common->lock);
582 static void bulk_out_complete(struct usb_ep *ep, struct usb_request *req)
584 struct fsg_common *common = ep->driver_data;
585 struct fsg_buffhd *bh = req->context;
587 dump_msg(common, "bulk-out", req->buf, req->actual);
588 if (req->status || req->actual != bh->bulk_out_intended_length)
589 DBG(common, "%s --> %d, %u/%u\n", __func__,
590 req->status, req->actual, bh->bulk_out_intended_length);
591 if (req->status == -ECONNRESET) /* Request was cancelled */
592 usb_ep_fifo_flush(ep);
594 /* Hold the lock while we update the request and buffer states */
596 spin_lock(&common->lock);
598 bh->state = BUF_STATE_FULL;
599 wakeup_thread(common);
600 spin_unlock(&common->lock);
603 static int fsg_setup(struct usb_function *f,
604 const struct usb_ctrlrequest *ctrl)
606 struct fsg_dev *fsg = fsg_from_func(f);
607 struct usb_request *req = fsg->common->ep0req;
608 u16 w_index = le16_to_cpu(ctrl->wIndex);
609 u16 w_value = le16_to_cpu(ctrl->wValue);
610 u16 w_length = le16_to_cpu(ctrl->wLength);
612 if (!fsg_is_set(fsg->common))
615 ++fsg->common->ep0_req_tag; /* Record arrival of a new request */
618 dump_msg(fsg, "ep0-setup", (u8 *) ctrl, sizeof(*ctrl));
620 switch (ctrl->bRequest) {
622 case US_BULK_RESET_REQUEST:
623 if (ctrl->bRequestType !=
624 (USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE))
626 if (w_index != fsg->interface_number || w_value != 0 ||
631 * Raise an exception to stop the current operation
632 * and reinitialize our state.
634 DBG(fsg, "bulk reset request\n");
635 raise_exception(fsg->common, FSG_STATE_RESET);
636 return DELAYED_STATUS;
638 case US_BULK_GET_MAX_LUN:
639 if (ctrl->bRequestType !=
640 (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE))
642 if (w_index != fsg->interface_number || w_value != 0 ||
645 VDBG(fsg, "get max LUN\n");
646 *(u8 *)req->buf = fsg->common->nluns - 1;
648 /* Respond with data/status */
649 req->length = min((u16)1, w_length);
650 return ep0_queue(fsg->common);
654 "unknown class-specific control req %02x.%02x v%04x i%04x l%u\n",
655 ctrl->bRequestType, ctrl->bRequest,
656 le16_to_cpu(ctrl->wValue), w_index, w_length);
661 /*-------------------------------------------------------------------------*/
663 /* All the following routines run in process context */
665 /* Use this for bulk or interrupt transfers, not ep0 */
666 static void start_transfer(struct fsg_dev *fsg, struct usb_ep *ep,
667 struct usb_request *req, int *pbusy,
668 enum fsg_buffer_state *state)
672 if (ep == fsg->bulk_in)
673 dump_msg(fsg, "bulk-in", req->buf, req->length);
675 spin_lock_irq(&fsg->common->lock);
677 *state = BUF_STATE_BUSY;
678 spin_unlock_irq(&fsg->common->lock);
679 rc = usb_ep_queue(ep, req, GFP_KERNEL);
682 *state = BUF_STATE_EMPTY;
684 /* We can't do much more than wait for a reset */
687 * Note: currently the net2280 driver fails zero-length
688 * submissions if DMA is enabled.
690 if (rc != -ESHUTDOWN &&
691 !(rc == -EOPNOTSUPP && req->length == 0))
692 WARNING(fsg, "error in submission: %s --> %d\n",
697 static bool start_in_transfer(struct fsg_common *common, struct fsg_buffhd *bh)
699 if (!fsg_is_set(common))
701 start_transfer(common->fsg, common->fsg->bulk_in,
702 bh->inreq, &bh->inreq_busy, &bh->state);
706 static bool start_out_transfer(struct fsg_common *common, struct fsg_buffhd *bh)
708 if (!fsg_is_set(common))
710 start_transfer(common->fsg, common->fsg->bulk_out,
711 bh->outreq, &bh->outreq_busy, &bh->state);
715 static int sleep_thread(struct fsg_common *common)
719 /* Wait until a signal arrives or we are woken up */
722 set_current_state(TASK_INTERRUPTIBLE);
723 if (signal_pending(current)) {
727 if (common->thread_wakeup_needed)
731 __set_current_state(TASK_RUNNING);
732 common->thread_wakeup_needed = 0;
737 /*-------------------------------------------------------------------------*/
739 static int do_read(struct fsg_common *common)
741 struct fsg_lun *curlun = common->curlun;
743 struct fsg_buffhd *bh;
746 loff_t file_offset, file_offset_tmp;
751 * Get the starting Logical Block Address and check that it's
754 if (common->cmnd[0] == READ_6)
755 lba = get_unaligned_be24(&common->cmnd[1]);
757 lba = get_unaligned_be32(&common->cmnd[2]);
760 * We allow DPO (Disable Page Out = don't save data in the
761 * cache) and FUA (Force Unit Access = don't read from the
762 * cache), but we don't implement them.
764 if ((common->cmnd[1] & ~0x18) != 0) {
765 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
769 if (lba >= curlun->num_sectors) {
770 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
773 file_offset = ((loff_t) lba) << curlun->blkbits;
775 /* Carry out the file reads */
776 amount_left = common->data_size_from_cmnd;
777 if (unlikely(amount_left == 0))
778 return -EIO; /* No default reply */
782 * Figure out how much we need to read:
783 * Try to read the remaining amount.
784 * But don't read more than the buffer size.
785 * And don't try to read past the end of the file.
787 amount = min(amount_left, FSG_BUFLEN);
788 amount = min((loff_t)amount,
789 curlun->file_length - file_offset);
791 /* Wait for the next buffer to become available */
792 bh = common->next_buffhd_to_fill;
793 while (bh->state != BUF_STATE_EMPTY) {
794 rc = sleep_thread(common);
800 * If we were asked to read past the end of file,
801 * end with an empty buffer.
805 SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
806 curlun->sense_data_info =
807 file_offset >> curlun->blkbits;
808 curlun->info_valid = 1;
809 bh->inreq->length = 0;
810 bh->state = BUF_STATE_FULL;
814 /* Perform the read */
815 file_offset_tmp = file_offset;
816 nread = vfs_read(curlun->filp,
817 (char __user *)bh->buf,
818 amount, &file_offset_tmp);
819 VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
820 (unsigned long long)file_offset, (int)nread);
821 if (signal_pending(current))
825 LDBG(curlun, "error in file read: %d\n", (int)nread);
827 } else if (nread < amount) {
828 LDBG(curlun, "partial file read: %d/%u\n",
830 nread = round_down(nread, curlun->blksize);
832 file_offset += nread;
833 amount_left -= nread;
834 common->residue -= nread;
837 * Except at the end of the transfer, nread will be
838 * equal to the buffer size, which is divisible by the
839 * bulk-in maxpacket size.
841 bh->inreq->length = nread;
842 bh->state = BUF_STATE_FULL;
844 /* If an error occurred, report it and its position */
845 if (nread < amount) {
846 curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
847 curlun->sense_data_info =
848 file_offset >> curlun->blkbits;
849 curlun->info_valid = 1;
853 if (amount_left == 0)
854 break; /* No more left to read */
856 /* Send this buffer and go read some more */
858 if (!start_in_transfer(common, bh))
859 /* Don't know what to do if common->fsg is NULL */
861 common->next_buffhd_to_fill = bh->next;
864 return -EIO; /* No default reply */
868 /*-------------------------------------------------------------------------*/
870 static int do_write(struct fsg_common *common)
872 struct fsg_lun *curlun = common->curlun;
874 struct fsg_buffhd *bh;
876 u32 amount_left_to_req, amount_left_to_write;
877 loff_t usb_offset, file_offset, file_offset_tmp;
883 curlun->sense_data = SS_WRITE_PROTECTED;
886 spin_lock(&curlun->filp->f_lock);
887 curlun->filp->f_flags &= ~O_SYNC; /* Default is not to wait */
888 spin_unlock(&curlun->filp->f_lock);
891 * Get the starting Logical Block Address and check that it's
894 if (common->cmnd[0] == WRITE_6)
895 lba = get_unaligned_be24(&common->cmnd[1]);
897 lba = get_unaligned_be32(&common->cmnd[2]);
900 * We allow DPO (Disable Page Out = don't save data in the
901 * cache) and FUA (Force Unit Access = write directly to the
902 * medium). We don't implement DPO; we implement FUA by
903 * performing synchronous output.
905 if (common->cmnd[1] & ~0x18) {
906 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
909 if (!curlun->nofua && (common->cmnd[1] & 0x08)) { /* FUA */
910 spin_lock(&curlun->filp->f_lock);
911 curlun->filp->f_flags |= O_SYNC;
912 spin_unlock(&curlun->filp->f_lock);
915 if (lba >= curlun->num_sectors) {
916 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
920 /* Carry out the file writes */
922 file_offset = usb_offset = ((loff_t) lba) << curlun->blkbits;
923 amount_left_to_req = common->data_size_from_cmnd;
924 amount_left_to_write = common->data_size_from_cmnd;
926 while (amount_left_to_write > 0) {
928 /* Queue a request for more data from the host */
929 bh = common->next_buffhd_to_fill;
930 if (bh->state == BUF_STATE_EMPTY && get_some_more) {
933 * Figure out how much we want to get:
934 * Try to get the remaining amount,
935 * but not more than the buffer size.
937 amount = min(amount_left_to_req, FSG_BUFLEN);
939 /* Beyond the end of the backing file? */
940 if (usb_offset >= curlun->file_length) {
943 SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
944 curlun->sense_data_info =
945 usb_offset >> curlun->blkbits;
946 curlun->info_valid = 1;
950 /* Get the next buffer */
951 usb_offset += amount;
952 common->usb_amount_left -= amount;
953 amount_left_to_req -= amount;
954 if (amount_left_to_req == 0)
958 * Except at the end of the transfer, amount will be
959 * equal to the buffer size, which is divisible by
960 * the bulk-out maxpacket size.
962 set_bulk_out_req_length(common, bh, amount);
963 if (!start_out_transfer(common, bh))
964 /* Dunno what to do if common->fsg is NULL */
966 common->next_buffhd_to_fill = bh->next;
970 /* Write the received data to the backing file */
971 bh = common->next_buffhd_to_drain;
972 if (bh->state == BUF_STATE_EMPTY && !get_some_more)
973 break; /* We stopped early */
974 if (bh->state == BUF_STATE_FULL) {
976 common->next_buffhd_to_drain = bh->next;
977 bh->state = BUF_STATE_EMPTY;
979 /* Did something go wrong with the transfer? */
980 if (bh->outreq->status != 0) {
981 curlun->sense_data = SS_COMMUNICATION_FAILURE;
982 curlun->sense_data_info =
983 file_offset >> curlun->blkbits;
984 curlun->info_valid = 1;
988 amount = bh->outreq->actual;
989 if (curlun->file_length - file_offset < amount) {
991 "write %u @ %llu beyond end %llu\n",
992 amount, (unsigned long long)file_offset,
993 (unsigned long long)curlun->file_length);
994 amount = curlun->file_length - file_offset;
997 /* Don't accept excess data. The spec doesn't say
998 * what to do in this case. We'll ignore the error.
1000 amount = min(amount, bh->bulk_out_intended_length);
1002 /* Don't write a partial block */
1003 amount = round_down(amount, curlun->blksize);
1007 /* Perform the write */
1008 file_offset_tmp = file_offset;
1009 nwritten = vfs_write(curlun->filp,
1010 (char __user *)bh->buf,
1011 amount, &file_offset_tmp);
1012 VLDBG(curlun, "file write %u @ %llu -> %d\n", amount,
1013 (unsigned long long)file_offset, (int)nwritten);
1014 if (signal_pending(current))
1015 return -EINTR; /* Interrupted! */
1018 LDBG(curlun, "error in file write: %d\n",
1021 } else if (nwritten < amount) {
1022 LDBG(curlun, "partial file write: %d/%u\n",
1023 (int)nwritten, amount);
1024 nwritten = round_down(nwritten, curlun->blksize);
1026 file_offset += nwritten;
1027 amount_left_to_write -= nwritten;
1028 common->residue -= nwritten;
1030 /* If an error occurred, report it and its position */
1031 if (nwritten < amount) {
1032 curlun->sense_data = SS_WRITE_ERROR;
1033 curlun->sense_data_info =
1034 file_offset >> curlun->blkbits;
1035 curlun->info_valid = 1;
1040 /* Did the host decide to stop early? */
1041 if (bh->outreq->actual < bh->bulk_out_intended_length) {
1042 common->short_packet_received = 1;
1048 /* Wait for something to happen */
1049 rc = sleep_thread(common);
1054 return -EIO; /* No default reply */
1058 /*-------------------------------------------------------------------------*/
1060 static int do_synchronize_cache(struct fsg_common *common)
1062 struct fsg_lun *curlun = common->curlun;
1065 /* We ignore the requested LBA and write out all file's
1066 * dirty data buffers. */
1067 rc = fsg_lun_fsync_sub(curlun);
1069 curlun->sense_data = SS_WRITE_ERROR;
1074 /*-------------------------------------------------------------------------*/
1076 static void invalidate_sub(struct fsg_lun *curlun)
1078 struct file *filp = curlun->filp;
1079 struct inode *inode = filp->f_path.dentry->d_inode;
1082 rc = invalidate_mapping_pages(inode->i_mapping, 0, -1);
1083 VLDBG(curlun, "invalidate_mapping_pages -> %ld\n", rc);
1086 static int do_verify(struct fsg_common *common)
1088 struct fsg_lun *curlun = common->curlun;
1090 u32 verification_length;
1091 struct fsg_buffhd *bh = common->next_buffhd_to_fill;
1092 loff_t file_offset, file_offset_tmp;
1094 unsigned int amount;
1098 * Get the starting Logical Block Address and check that it's
1101 lba = get_unaligned_be32(&common->cmnd[2]);
1102 if (lba >= curlun->num_sectors) {
1103 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1108 * We allow DPO (Disable Page Out = don't save data in the
1109 * cache) but we don't implement it.
1111 if (common->cmnd[1] & ~0x10) {
1112 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1116 verification_length = get_unaligned_be16(&common->cmnd[7]);
1117 if (unlikely(verification_length == 0))
1118 return -EIO; /* No default reply */
1120 /* Prepare to carry out the file verify */
1121 amount_left = verification_length << curlun->blkbits;
1122 file_offset = ((loff_t) lba) << curlun->blkbits;
1124 /* Write out all the dirty buffers before invalidating them */
1125 fsg_lun_fsync_sub(curlun);
1126 if (signal_pending(current))
1129 invalidate_sub(curlun);
1130 if (signal_pending(current))
1133 /* Just try to read the requested blocks */
1134 while (amount_left > 0) {
1136 * Figure out how much we need to read:
1137 * Try to read the remaining amount, but not more than
1139 * And don't try to read past the end of the file.
1141 amount = min(amount_left, FSG_BUFLEN);
1142 amount = min((loff_t)amount,
1143 curlun->file_length - file_offset);
1145 curlun->sense_data =
1146 SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1147 curlun->sense_data_info =
1148 file_offset >> curlun->blkbits;
1149 curlun->info_valid = 1;
1153 /* Perform the read */
1154 file_offset_tmp = file_offset;
1155 nread = vfs_read(curlun->filp,
1156 (char __user *) bh->buf,
1157 amount, &file_offset_tmp);
1158 VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
1159 (unsigned long long) file_offset,
1161 if (signal_pending(current))
1165 LDBG(curlun, "error in file verify: %d\n", (int)nread);
1167 } else if (nread < amount) {
1168 LDBG(curlun, "partial file verify: %d/%u\n",
1169 (int)nread, amount);
1170 nread = round_down(nread, curlun->blksize);
1173 curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
1174 curlun->sense_data_info =
1175 file_offset >> curlun->blkbits;
1176 curlun->info_valid = 1;
1179 file_offset += nread;
1180 amount_left -= nread;
1186 /*-------------------------------------------------------------------------*/
1188 static int do_inquiry(struct fsg_common *common, struct fsg_buffhd *bh)
1190 struct fsg_lun *curlun = common->curlun;
1191 u8 *buf = (u8 *) bh->buf;
1193 if (!curlun) { /* Unsupported LUNs are okay */
1194 common->bad_lun_okay = 1;
1196 buf[0] = 0x7f; /* Unsupported, no device-type */
1197 buf[4] = 31; /* Additional length */
1201 buf[0] = curlun->cdrom ? TYPE_ROM : TYPE_DISK;
1202 buf[1] = curlun->removable ? 0x80 : 0;
1203 buf[2] = 2; /* ANSI SCSI level 2 */
1204 buf[3] = 2; /* SCSI-2 INQUIRY data format */
1205 buf[4] = 31; /* Additional length */
1206 buf[5] = 0; /* No special options */
1209 memcpy(buf + 8, common->inquiry_string, sizeof common->inquiry_string);
1213 static int do_request_sense(struct fsg_common *common, struct fsg_buffhd *bh)
1215 struct fsg_lun *curlun = common->curlun;
1216 u8 *buf = (u8 *) bh->buf;
1221 * From the SCSI-2 spec., section 7.9 (Unit attention condition):
1223 * If a REQUEST SENSE command is received from an initiator
1224 * with a pending unit attention condition (before the target
1225 * generates the contingent allegiance condition), then the
1226 * target shall either:
1227 * a) report any pending sense data and preserve the unit
1228 * attention condition on the logical unit, or,
1229 * b) report the unit attention condition, may discard any
1230 * pending sense data, and clear the unit attention
1231 * condition on the logical unit for that initiator.
1233 * FSG normally uses option a); enable this code to use option b).
1236 if (curlun && curlun->unit_attention_data != SS_NO_SENSE) {
1237 curlun->sense_data = curlun->unit_attention_data;
1238 curlun->unit_attention_data = SS_NO_SENSE;
1242 if (!curlun) { /* Unsupported LUNs are okay */
1243 common->bad_lun_okay = 1;
1244 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
1248 sd = curlun->sense_data;
1249 sdinfo = curlun->sense_data_info;
1250 valid = curlun->info_valid << 7;
1251 curlun->sense_data = SS_NO_SENSE;
1252 curlun->sense_data_info = 0;
1253 curlun->info_valid = 0;
1257 buf[0] = valid | 0x70; /* Valid, current error */
1259 put_unaligned_be32(sdinfo, &buf[3]); /* Sense information */
1260 buf[7] = 18 - 8; /* Additional sense length */
1266 static int do_read_capacity(struct fsg_common *common, struct fsg_buffhd *bh)
1268 struct fsg_lun *curlun = common->curlun;
1269 u32 lba = get_unaligned_be32(&common->cmnd[2]);
1270 int pmi = common->cmnd[8];
1271 u8 *buf = (u8 *)bh->buf;
1273 /* Check the PMI and LBA fields */
1274 if (pmi > 1 || (pmi == 0 && lba != 0)) {
1275 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1279 put_unaligned_be32(curlun->num_sectors - 1, &buf[0]);
1280 /* Max logical block */
1281 put_unaligned_be32(curlun->blksize, &buf[4]);/* Block length */
1285 static int do_read_header(struct fsg_common *common, struct fsg_buffhd *bh)
1287 struct fsg_lun *curlun = common->curlun;
1288 int msf = common->cmnd[1] & 0x02;
1289 u32 lba = get_unaligned_be32(&common->cmnd[2]);
1290 u8 *buf = (u8 *)bh->buf;
1292 if (common->cmnd[1] & ~0x02) { /* Mask away MSF */
1293 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1296 if (lba >= curlun->num_sectors) {
1297 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1302 buf[0] = 0x01; /* 2048 bytes of user data, rest is EC */
1303 store_cdrom_address(&buf[4], msf, lba);
1307 static int do_read_toc(struct fsg_common *common, struct fsg_buffhd *bh)
1309 struct fsg_lun *curlun = common->curlun;
1310 int msf = common->cmnd[1] & 0x02;
1311 int start_track = common->cmnd[6];
1312 u8 *buf = (u8 *)bh->buf;
1314 if ((common->cmnd[1] & ~0x02) != 0 || /* Mask away MSF */
1316 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1321 buf[1] = (20-2); /* TOC data length */
1322 buf[2] = 1; /* First track number */
1323 buf[3] = 1; /* Last track number */
1324 buf[5] = 0x16; /* Data track, copying allowed */
1325 buf[6] = 0x01; /* Only track is number 1 */
1326 store_cdrom_address(&buf[8], msf, 0);
1328 buf[13] = 0x16; /* Lead-out track is data */
1329 buf[14] = 0xAA; /* Lead-out track number */
1330 store_cdrom_address(&buf[16], msf, curlun->num_sectors);
1334 static int do_mode_sense(struct fsg_common *common, struct fsg_buffhd *bh)
1336 struct fsg_lun *curlun = common->curlun;
1337 int mscmnd = common->cmnd[0];
1338 u8 *buf = (u8 *) bh->buf;
1341 int changeable_values, all_pages;
1345 if ((common->cmnd[1] & ~0x08) != 0) { /* Mask away DBD */
1346 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1349 pc = common->cmnd[2] >> 6;
1350 page_code = common->cmnd[2] & 0x3f;
1352 curlun->sense_data = SS_SAVING_PARAMETERS_NOT_SUPPORTED;
1355 changeable_values = (pc == 1);
1356 all_pages = (page_code == 0x3f);
1359 * Write the mode parameter header. Fixed values are: default
1360 * medium type, no cache control (DPOFUA), and no block descriptors.
1361 * The only variable value is the WriteProtect bit. We will fill in
1362 * the mode data length later.
1365 if (mscmnd == MODE_SENSE) {
1366 buf[2] = (curlun->ro ? 0x80 : 0x00); /* WP, DPOFUA */
1369 } else { /* MODE_SENSE_10 */
1370 buf[3] = (curlun->ro ? 0x80 : 0x00); /* WP, DPOFUA */
1372 limit = 65535; /* Should really be FSG_BUFLEN */
1375 /* No block descriptors */
1378 * The mode pages, in numerical order. The only page we support
1379 * is the Caching page.
1381 if (page_code == 0x08 || all_pages) {
1383 buf[0] = 0x08; /* Page code */
1384 buf[1] = 10; /* Page length */
1385 memset(buf+2, 0, 10); /* None of the fields are changeable */
1387 if (!changeable_values) {
1388 buf[2] = 0x04; /* Write cache enable, */
1389 /* Read cache not disabled */
1390 /* No cache retention priorities */
1391 put_unaligned_be16(0xffff, &buf[4]);
1392 /* Don't disable prefetch */
1393 /* Minimum prefetch = 0 */
1394 put_unaligned_be16(0xffff, &buf[8]);
1395 /* Maximum prefetch */
1396 put_unaligned_be16(0xffff, &buf[10]);
1397 /* Maximum prefetch ceiling */
1403 * Check that a valid page was requested and the mode data length
1407 if (!valid_page || len > limit) {
1408 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1412 /* Store the mode data length */
1413 if (mscmnd == MODE_SENSE)
1416 put_unaligned_be16(len - 2, buf0);
1420 static int do_start_stop(struct fsg_common *common)
1422 struct fsg_lun *curlun = common->curlun;
1427 } else if (!curlun->removable) {
1428 curlun->sense_data = SS_INVALID_COMMAND;
1430 } else if ((common->cmnd[1] & ~0x01) != 0 || /* Mask away Immed */
1431 (common->cmnd[4] & ~0x03) != 0) { /* Mask LoEj, Start */
1432 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1436 loej = common->cmnd[4] & 0x02;
1437 start = common->cmnd[4] & 0x01;
1440 * Our emulation doesn't support mounting; the medium is
1441 * available for use as soon as it is loaded.
1444 if (!fsg_lun_is_open(curlun)) {
1445 curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
1451 /* Are we allowed to unload the media? */
1452 if (curlun->prevent_medium_removal) {
1453 LDBG(curlun, "unload attempt prevented\n");
1454 curlun->sense_data = SS_MEDIUM_REMOVAL_PREVENTED;
1461 /* Simulate an unload/eject */
1462 if (common->ops && common->ops->pre_eject) {
1463 int r = common->ops->pre_eject(common, curlun,
1464 curlun - common->luns);
1465 if (unlikely(r < 0))
1471 up_read(&common->filesem);
1472 down_write(&common->filesem);
1473 fsg_lun_close(curlun);
1474 up_write(&common->filesem);
1475 down_read(&common->filesem);
1477 return common->ops && common->ops->post_eject
1478 ? min(0, common->ops->post_eject(common, curlun,
1479 curlun - common->luns))
1483 static int do_prevent_allow(struct fsg_common *common)
1485 struct fsg_lun *curlun = common->curlun;
1488 if (!common->curlun) {
1490 } else if (!common->curlun->removable) {
1491 common->curlun->sense_data = SS_INVALID_COMMAND;
1495 prevent = common->cmnd[4] & 0x01;
1496 if ((common->cmnd[4] & ~0x01) != 0) { /* Mask away Prevent */
1497 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1501 if (curlun->prevent_medium_removal && !prevent)
1502 fsg_lun_fsync_sub(curlun);
1503 curlun->prevent_medium_removal = prevent;
1507 static int do_read_format_capacities(struct fsg_common *common,
1508 struct fsg_buffhd *bh)
1510 struct fsg_lun *curlun = common->curlun;
1511 u8 *buf = (u8 *) bh->buf;
1513 buf[0] = buf[1] = buf[2] = 0;
1514 buf[3] = 8; /* Only the Current/Maximum Capacity Descriptor */
1517 put_unaligned_be32(curlun->num_sectors, &buf[0]);
1518 /* Number of blocks */
1519 put_unaligned_be32(curlun->blksize, &buf[4]);/* Block length */
1520 buf[4] = 0x02; /* Current capacity */
1524 static int do_mode_select(struct fsg_common *common, struct fsg_buffhd *bh)
1526 struct fsg_lun *curlun = common->curlun;
1528 /* We don't support MODE SELECT */
1530 curlun->sense_data = SS_INVALID_COMMAND;
1535 /*-------------------------------------------------------------------------*/
1537 static int halt_bulk_in_endpoint(struct fsg_dev *fsg)
1541 rc = fsg_set_halt(fsg, fsg->bulk_in);
1543 VDBG(fsg, "delayed bulk-in endpoint halt\n");
1545 if (rc != -EAGAIN) {
1546 WARNING(fsg, "usb_ep_set_halt -> %d\n", rc);
1551 /* Wait for a short time and then try again */
1552 if (msleep_interruptible(100) != 0)
1554 rc = usb_ep_set_halt(fsg->bulk_in);
1559 static int wedge_bulk_in_endpoint(struct fsg_dev *fsg)
1563 DBG(fsg, "bulk-in set wedge\n");
1564 rc = usb_ep_set_wedge(fsg->bulk_in);
1566 VDBG(fsg, "delayed bulk-in endpoint wedge\n");
1568 if (rc != -EAGAIN) {
1569 WARNING(fsg, "usb_ep_set_wedge -> %d\n", rc);
1574 /* Wait for a short time and then try again */
1575 if (msleep_interruptible(100) != 0)
1577 rc = usb_ep_set_wedge(fsg->bulk_in);
1582 static int throw_away_data(struct fsg_common *common)
1584 struct fsg_buffhd *bh;
1588 for (bh = common->next_buffhd_to_drain;
1589 bh->state != BUF_STATE_EMPTY || common->usb_amount_left > 0;
1590 bh = common->next_buffhd_to_drain) {
1592 /* Throw away the data in a filled buffer */
1593 if (bh->state == BUF_STATE_FULL) {
1595 bh->state = BUF_STATE_EMPTY;
1596 common->next_buffhd_to_drain = bh->next;
1598 /* A short packet or an error ends everything */
1599 if (bh->outreq->actual < bh->bulk_out_intended_length ||
1600 bh->outreq->status != 0) {
1601 raise_exception(common,
1602 FSG_STATE_ABORT_BULK_OUT);
1608 /* Try to submit another request if we need one */
1609 bh = common->next_buffhd_to_fill;
1610 if (bh->state == BUF_STATE_EMPTY
1611 && common->usb_amount_left > 0) {
1612 amount = min(common->usb_amount_left, FSG_BUFLEN);
1615 * Except at the end of the transfer, amount will be
1616 * equal to the buffer size, which is divisible by
1617 * the bulk-out maxpacket size.
1619 set_bulk_out_req_length(common, bh, amount);
1620 if (!start_out_transfer(common, bh))
1621 /* Dunno what to do if common->fsg is NULL */
1623 common->next_buffhd_to_fill = bh->next;
1624 common->usb_amount_left -= amount;
1628 /* Otherwise wait for something to happen */
1629 rc = sleep_thread(common);
1636 static int finish_reply(struct fsg_common *common)
1638 struct fsg_buffhd *bh = common->next_buffhd_to_fill;
1641 switch (common->data_dir) {
1643 break; /* Nothing to send */
1646 * If we don't know whether the host wants to read or write,
1647 * this must be CB or CBI with an unknown command. We mustn't
1648 * try to send or receive any data. So stall both bulk pipes
1649 * if we can and wait for a reset.
1651 case DATA_DIR_UNKNOWN:
1652 if (!common->can_stall) {
1654 } else if (fsg_is_set(common)) {
1655 fsg_set_halt(common->fsg, common->fsg->bulk_out);
1656 rc = halt_bulk_in_endpoint(common->fsg);
1658 /* Don't know what to do if common->fsg is NULL */
1663 /* All but the last buffer of data must have already been sent */
1664 case DATA_DIR_TO_HOST:
1665 if (common->data_size == 0) {
1666 /* Nothing to send */
1668 /* Don't know what to do if common->fsg is NULL */
1669 } else if (!fsg_is_set(common)) {
1672 /* If there's no residue, simply send the last buffer */
1673 } else if (common->residue == 0) {
1674 bh->inreq->zero = 0;
1675 if (!start_in_transfer(common, bh))
1677 common->next_buffhd_to_fill = bh->next;
1680 * For Bulk-only, mark the end of the data with a short
1681 * packet. If we are allowed to stall, halt the bulk-in
1682 * endpoint. (Note: This violates the Bulk-Only Transport
1683 * specification, which requires us to pad the data if we
1684 * don't halt the endpoint. Presumably nobody will mind.)
1687 bh->inreq->zero = 1;
1688 if (!start_in_transfer(common, bh))
1690 common->next_buffhd_to_fill = bh->next;
1691 if (common->can_stall)
1692 rc = halt_bulk_in_endpoint(common->fsg);
1697 * We have processed all we want from the data the host has sent.
1698 * There may still be outstanding bulk-out requests.
1700 case DATA_DIR_FROM_HOST:
1701 if (common->residue == 0) {
1702 /* Nothing to receive */
1704 /* Did the host stop sending unexpectedly early? */
1705 } else if (common->short_packet_received) {
1706 raise_exception(common, FSG_STATE_ABORT_BULK_OUT);
1710 * We haven't processed all the incoming data. Even though
1711 * we may be allowed to stall, doing so would cause a race.
1712 * The controller may already have ACK'ed all the remaining
1713 * bulk-out packets, in which case the host wouldn't see a
1714 * STALL. Not realizing the endpoint was halted, it wouldn't
1715 * clear the halt -- leading to problems later on.
1718 } else if (common->can_stall) {
1719 if (fsg_is_set(common))
1720 fsg_set_halt(common->fsg,
1721 common->fsg->bulk_out);
1722 raise_exception(common, FSG_STATE_ABORT_BULK_OUT);
1727 * We can't stall. Read in the excess data and throw it
1731 rc = throw_away_data(common);
1738 static int send_status(struct fsg_common *common)
1740 struct fsg_lun *curlun = common->curlun;
1741 struct fsg_buffhd *bh;
1742 struct bulk_cs_wrap *csw;
1744 u8 status = US_BULK_STAT_OK;
1747 /* Wait for the next buffer to become available */
1748 bh = common->next_buffhd_to_fill;
1749 while (bh->state != BUF_STATE_EMPTY) {
1750 rc = sleep_thread(common);
1756 sd = curlun->sense_data;
1757 sdinfo = curlun->sense_data_info;
1758 } else if (common->bad_lun_okay)
1761 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
1763 if (common->phase_error) {
1764 DBG(common, "sending phase-error status\n");
1765 status = US_BULK_STAT_PHASE;
1766 sd = SS_INVALID_COMMAND;
1767 } else if (sd != SS_NO_SENSE) {
1768 DBG(common, "sending command-failure status\n");
1769 status = US_BULK_STAT_FAIL;
1770 VDBG(common, " sense data: SK x%02x, ASC x%02x, ASCQ x%02x;"
1772 SK(sd), ASC(sd), ASCQ(sd), sdinfo);
1775 /* Store and send the Bulk-only CSW */
1776 csw = (void *)bh->buf;
1778 csw->Signature = cpu_to_le32(US_BULK_CS_SIGN);
1779 csw->Tag = common->tag;
1780 csw->Residue = cpu_to_le32(common->residue);
1781 csw->Status = status;
1783 bh->inreq->length = US_BULK_CS_WRAP_LEN;
1784 bh->inreq->zero = 0;
1785 if (!start_in_transfer(common, bh))
1786 /* Don't know what to do if common->fsg is NULL */
1789 common->next_buffhd_to_fill = bh->next;
1794 /*-------------------------------------------------------------------------*/
1797 * Check whether the command is properly formed and whether its data size
1798 * and direction agree with the values we already have.
1800 static int check_command(struct fsg_common *common, int cmnd_size,
1801 enum data_direction data_dir, unsigned int mask,
1802 int needs_medium, const char *name)
1805 int lun = common->cmnd[1] >> 5;
1806 static const char dirletter[4] = {'u', 'o', 'i', 'n'};
1808 struct fsg_lun *curlun;
1811 if (common->data_dir != DATA_DIR_UNKNOWN)
1812 sprintf(hdlen, ", H%c=%u", dirletter[(int) common->data_dir],
1814 VDBG(common, "SCSI command: %s; Dc=%d, D%c=%u; Hc=%d%s\n",
1815 name, cmnd_size, dirletter[(int) data_dir],
1816 common->data_size_from_cmnd, common->cmnd_size, hdlen);
1819 * We can't reply at all until we know the correct data direction
1822 if (common->data_size_from_cmnd == 0)
1823 data_dir = DATA_DIR_NONE;
1824 if (common->data_size < common->data_size_from_cmnd) {
1826 * Host data size < Device data size is a phase error.
1827 * Carry out the command, but only transfer as much as
1830 common->data_size_from_cmnd = common->data_size;
1831 common->phase_error = 1;
1833 common->residue = common->data_size;
1834 common->usb_amount_left = common->data_size;
1836 /* Conflicting data directions is a phase error */
1837 if (common->data_dir != data_dir && common->data_size_from_cmnd > 0) {
1838 common->phase_error = 1;
1842 /* Verify the length of the command itself */
1843 if (cmnd_size != common->cmnd_size) {
1846 * Special case workaround: There are plenty of buggy SCSI
1847 * implementations. Many have issues with cbw->Length
1848 * field passing a wrong command size. For those cases we
1849 * always try to work around the problem by using the length
1850 * sent by the host side provided it is at least as large
1851 * as the correct command length.
1852 * Examples of such cases would be MS-Windows, which issues
1853 * REQUEST SENSE with cbw->Length == 12 where it should
1854 * be 6, and xbox360 issuing INQUIRY, TEST UNIT READY and
1855 * REQUEST SENSE with cbw->Length == 10 where it should
1858 if (cmnd_size <= common->cmnd_size) {
1859 DBG(common, "%s is buggy! Expected length %d "
1860 "but we got %d\n", name,
1861 cmnd_size, common->cmnd_size);
1862 cmnd_size = common->cmnd_size;
1864 common->phase_error = 1;
1869 /* Check that the LUN values are consistent */
1870 if (common->lun != lun)
1871 DBG(common, "using LUN %d from CBW, not LUN %d from CDB\n",
1875 curlun = common->curlun;
1877 if (common->cmnd[0] != REQUEST_SENSE) {
1878 curlun->sense_data = SS_NO_SENSE;
1879 curlun->sense_data_info = 0;
1880 curlun->info_valid = 0;
1883 common->bad_lun_okay = 0;
1886 * INQUIRY and REQUEST SENSE commands are explicitly allowed
1887 * to use unsupported LUNs; all others may not.
1889 if (common->cmnd[0] != INQUIRY &&
1890 common->cmnd[0] != REQUEST_SENSE) {
1891 DBG(common, "unsupported LUN %d\n", common->lun);
1897 * If a unit attention condition exists, only INQUIRY and
1898 * REQUEST SENSE commands are allowed; anything else must fail.
1900 if (curlun && curlun->unit_attention_data != SS_NO_SENSE &&
1901 common->cmnd[0] != INQUIRY &&
1902 common->cmnd[0] != REQUEST_SENSE) {
1903 curlun->sense_data = curlun->unit_attention_data;
1904 curlun->unit_attention_data = SS_NO_SENSE;
1908 /* Check that only command bytes listed in the mask are non-zero */
1909 common->cmnd[1] &= 0x1f; /* Mask away the LUN */
1910 for (i = 1; i < cmnd_size; ++i) {
1911 if (common->cmnd[i] && !(mask & (1 << i))) {
1913 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1918 /* If the medium isn't mounted and the command needs to access
1919 * it, return an error. */
1920 if (curlun && !fsg_lun_is_open(curlun) && needs_medium) {
1921 curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
1928 /* wrapper of check_command for data size in blocks handling */
1929 static int check_command_size_in_blocks(struct fsg_common *common,
1930 int cmnd_size, enum data_direction data_dir,
1931 unsigned int mask, int needs_medium, const char *name)
1934 common->data_size_from_cmnd <<= common->curlun->blkbits;
1935 return check_command(common, cmnd_size, data_dir,
1936 mask, needs_medium, name);
1939 static int do_scsi_command(struct fsg_common *common)
1941 struct fsg_buffhd *bh;
1943 int reply = -EINVAL;
1945 static char unknown[16];
1949 /* Wait for the next buffer to become available for data or status */
1950 bh = common->next_buffhd_to_fill;
1951 common->next_buffhd_to_drain = bh;
1952 while (bh->state != BUF_STATE_EMPTY) {
1953 rc = sleep_thread(common);
1957 common->phase_error = 0;
1958 common->short_packet_received = 0;
1960 down_read(&common->filesem); /* We're using the backing file */
1961 switch (common->cmnd[0]) {
1964 common->data_size_from_cmnd = common->cmnd[4];
1965 reply = check_command(common, 6, DATA_DIR_TO_HOST,
1969 reply = do_inquiry(common, bh);
1973 common->data_size_from_cmnd = common->cmnd[4];
1974 reply = check_command(common, 6, DATA_DIR_FROM_HOST,
1978 reply = do_mode_select(common, bh);
1981 case MODE_SELECT_10:
1982 common->data_size_from_cmnd =
1983 get_unaligned_be16(&common->cmnd[7]);
1984 reply = check_command(common, 10, DATA_DIR_FROM_HOST,
1988 reply = do_mode_select(common, bh);
1992 common->data_size_from_cmnd = common->cmnd[4];
1993 reply = check_command(common, 6, DATA_DIR_TO_HOST,
1994 (1<<1) | (1<<2) | (1<<4), 0,
1997 reply = do_mode_sense(common, bh);
2001 common->data_size_from_cmnd =
2002 get_unaligned_be16(&common->cmnd[7]);
2003 reply = check_command(common, 10, DATA_DIR_TO_HOST,
2004 (1<<1) | (1<<2) | (3<<7), 0,
2007 reply = do_mode_sense(common, bh);
2010 case ALLOW_MEDIUM_REMOVAL:
2011 common->data_size_from_cmnd = 0;
2012 reply = check_command(common, 6, DATA_DIR_NONE,
2014 "PREVENT-ALLOW MEDIUM REMOVAL");
2016 reply = do_prevent_allow(common);
2020 i = common->cmnd[4];
2021 common->data_size_from_cmnd = (i == 0) ? 256 : i;
2022 reply = check_command_size_in_blocks(common, 6,
2027 reply = do_read(common);
2031 common->data_size_from_cmnd =
2032 get_unaligned_be16(&common->cmnd[7]);
2033 reply = check_command_size_in_blocks(common, 10,
2035 (1<<1) | (0xf<<2) | (3<<7), 1,
2038 reply = do_read(common);
2042 common->data_size_from_cmnd =
2043 get_unaligned_be32(&common->cmnd[6]);
2044 reply = check_command_size_in_blocks(common, 12,
2046 (1<<1) | (0xf<<2) | (0xf<<6), 1,
2049 reply = do_read(common);
2053 common->data_size_from_cmnd = 8;
2054 reply = check_command(common, 10, DATA_DIR_TO_HOST,
2055 (0xf<<2) | (1<<8), 1,
2058 reply = do_read_capacity(common, bh);
2062 if (!common->curlun || !common->curlun->cdrom)
2064 common->data_size_from_cmnd =
2065 get_unaligned_be16(&common->cmnd[7]);
2066 reply = check_command(common, 10, DATA_DIR_TO_HOST,
2067 (3<<7) | (0x1f<<1), 1,
2070 reply = do_read_header(common, bh);
2074 if (!common->curlun || !common->curlun->cdrom)
2076 common->data_size_from_cmnd =
2077 get_unaligned_be16(&common->cmnd[7]);
2078 reply = check_command(common, 10, DATA_DIR_TO_HOST,
2082 reply = do_read_toc(common, bh);
2085 case READ_FORMAT_CAPACITIES:
2086 common->data_size_from_cmnd =
2087 get_unaligned_be16(&common->cmnd[7]);
2088 reply = check_command(common, 10, DATA_DIR_TO_HOST,
2090 "READ FORMAT CAPACITIES");
2092 reply = do_read_format_capacities(common, bh);
2096 common->data_size_from_cmnd = common->cmnd[4];
2097 reply = check_command(common, 6, DATA_DIR_TO_HOST,
2101 reply = do_request_sense(common, bh);
2105 common->data_size_from_cmnd = 0;
2106 reply = check_command(common, 6, DATA_DIR_NONE,
2110 reply = do_start_stop(common);
2113 case SYNCHRONIZE_CACHE:
2114 common->data_size_from_cmnd = 0;
2115 reply = check_command(common, 10, DATA_DIR_NONE,
2116 (0xf<<2) | (3<<7), 1,
2117 "SYNCHRONIZE CACHE");
2119 reply = do_synchronize_cache(common);
2122 case TEST_UNIT_READY:
2123 common->data_size_from_cmnd = 0;
2124 reply = check_command(common, 6, DATA_DIR_NONE,
2130 * Although optional, this command is used by MS-Windows. We
2131 * support a minimal version: BytChk must be 0.
2134 common->data_size_from_cmnd = 0;
2135 reply = check_command(common, 10, DATA_DIR_NONE,
2136 (1<<1) | (0xf<<2) | (3<<7), 1,
2139 reply = do_verify(common);
2143 i = common->cmnd[4];
2144 common->data_size_from_cmnd = (i == 0) ? 256 : i;
2145 reply = check_command_size_in_blocks(common, 6,
2150 reply = do_write(common);
2154 common->data_size_from_cmnd =
2155 get_unaligned_be16(&common->cmnd[7]);
2156 reply = check_command_size_in_blocks(common, 10,
2158 (1<<1) | (0xf<<2) | (3<<7), 1,
2161 reply = do_write(common);
2165 common->data_size_from_cmnd =
2166 get_unaligned_be32(&common->cmnd[6]);
2167 reply = check_command_size_in_blocks(common, 12,
2169 (1<<1) | (0xf<<2) | (0xf<<6), 1,
2172 reply = do_write(common);
2176 * Some mandatory commands that we recognize but don't implement.
2177 * They don't mean much in this setting. It's left as an exercise
2178 * for anyone interested to implement RESERVE and RELEASE in terms
2184 case SEND_DIAGNOSTIC:
2189 common->data_size_from_cmnd = 0;
2190 sprintf(unknown, "Unknown x%02x", common->cmnd[0]);
2191 reply = check_command(common, common->cmnd_size,
2192 DATA_DIR_UNKNOWN, ~0, 0, unknown);
2194 common->curlun->sense_data = SS_INVALID_COMMAND;
2199 up_read(&common->filesem);
2201 if (reply == -EINTR || signal_pending(current))
2204 /* Set up the single reply buffer for finish_reply() */
2205 if (reply == -EINVAL)
2206 reply = 0; /* Error reply length */
2207 if (reply >= 0 && common->data_dir == DATA_DIR_TO_HOST) {
2208 reply = min((u32)reply, common->data_size_from_cmnd);
2209 bh->inreq->length = reply;
2210 bh->state = BUF_STATE_FULL;
2211 common->residue -= reply;
2212 } /* Otherwise it's already set */
2218 /*-------------------------------------------------------------------------*/
2220 static int received_cbw(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2222 struct usb_request *req = bh->outreq;
2223 struct bulk_cb_wrap *cbw = req->buf;
2224 struct fsg_common *common = fsg->common;
2226 /* Was this a real packet? Should it be ignored? */
2227 if (req->status || test_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags))
2230 /* Is the CBW valid? */
2231 if (req->actual != US_BULK_CB_WRAP_LEN ||
2232 cbw->Signature != cpu_to_le32(
2234 DBG(fsg, "invalid CBW: len %u sig 0x%x\n",
2236 le32_to_cpu(cbw->Signature));
2239 * The Bulk-only spec says we MUST stall the IN endpoint
2240 * (6.6.1), so it's unavoidable. It also says we must
2241 * retain this state until the next reset, but there's
2242 * no way to tell the controller driver it should ignore
2243 * Clear-Feature(HALT) requests.
2245 * We aren't required to halt the OUT endpoint; instead
2246 * we can simply accept and discard any data received
2247 * until the next reset.
2249 wedge_bulk_in_endpoint(fsg);
2250 set_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
2254 /* Is the CBW meaningful? */
2255 if (cbw->Lun >= FSG_MAX_LUNS || cbw->Flags & ~US_BULK_FLAG_IN ||
2256 cbw->Length <= 0 || cbw->Length > MAX_COMMAND_SIZE) {
2257 DBG(fsg, "non-meaningful CBW: lun = %u, flags = 0x%x, "
2259 cbw->Lun, cbw->Flags, cbw->Length);
2262 * We can do anything we want here, so let's stall the
2263 * bulk pipes if we are allowed to.
2265 if (common->can_stall) {
2266 fsg_set_halt(fsg, fsg->bulk_out);
2267 halt_bulk_in_endpoint(fsg);
2272 /* Save the command for later */
2273 common->cmnd_size = cbw->Length;
2274 memcpy(common->cmnd, cbw->CDB, common->cmnd_size);
2275 if (cbw->Flags & US_BULK_FLAG_IN)
2276 common->data_dir = DATA_DIR_TO_HOST;
2278 common->data_dir = DATA_DIR_FROM_HOST;
2279 common->data_size = le32_to_cpu(cbw->DataTransferLength);
2280 if (common->data_size == 0)
2281 common->data_dir = DATA_DIR_NONE;
2282 common->lun = cbw->Lun;
2283 if (common->lun >= 0 && common->lun < common->nluns)
2284 common->curlun = &common->luns[common->lun];
2286 common->curlun = NULL;
2287 common->tag = cbw->Tag;
2291 static int get_next_command(struct fsg_common *common)
2293 struct fsg_buffhd *bh;
2296 /* Wait for the next buffer to become available */
2297 bh = common->next_buffhd_to_fill;
2298 while (bh->state != BUF_STATE_EMPTY) {
2299 rc = sleep_thread(common);
2304 /* Queue a request to read a Bulk-only CBW */
2305 set_bulk_out_req_length(common, bh, US_BULK_CB_WRAP_LEN);
2306 if (!start_out_transfer(common, bh))
2307 /* Don't know what to do if common->fsg is NULL */
2311 * We will drain the buffer in software, which means we
2312 * can reuse it for the next filling. No need to advance
2313 * next_buffhd_to_fill.
2316 /* Wait for the CBW to arrive */
2317 while (bh->state != BUF_STATE_FULL) {
2318 rc = sleep_thread(common);
2323 rc = fsg_is_set(common) ? received_cbw(common->fsg, bh) : -EIO;
2324 bh->state = BUF_STATE_EMPTY;
2330 /*-------------------------------------------------------------------------*/
2332 static int alloc_request(struct fsg_common *common, struct usb_ep *ep,
2333 struct usb_request **preq)
2335 *preq = usb_ep_alloc_request(ep, GFP_ATOMIC);
2338 ERROR(common, "can't allocate request for %s\n", ep->name);
2342 /* Reset interface setting and re-init endpoint state (toggle etc). */
2343 static int do_set_interface(struct fsg_common *common, struct fsg_dev *new_fsg)
2345 struct fsg_dev *fsg;
2348 if (common->running)
2349 DBG(common, "reset interface\n");
2352 /* Deallocate the requests */
2356 for (i = 0; i < fsg_num_buffers; ++i) {
2357 struct fsg_buffhd *bh = &common->buffhds[i];
2360 usb_ep_free_request(fsg->bulk_in, bh->inreq);
2364 usb_ep_free_request(fsg->bulk_out, bh->outreq);
2369 /* Disable the endpoints */
2370 if (fsg->bulk_in_enabled) {
2371 usb_ep_disable(fsg->bulk_in);
2372 fsg->bulk_in_enabled = 0;
2374 if (fsg->bulk_out_enabled) {
2375 usb_ep_disable(fsg->bulk_out);
2376 fsg->bulk_out_enabled = 0;
2380 wake_up(&common->fsg_wait);
2383 common->running = 0;
2387 common->fsg = new_fsg;
2390 /* Enable the endpoints */
2391 rc = config_ep_by_speed(common->gadget, &(fsg->function), fsg->bulk_in);
2394 rc = usb_ep_enable(fsg->bulk_in);
2397 fsg->bulk_in->driver_data = common;
2398 fsg->bulk_in_enabled = 1;
2400 rc = config_ep_by_speed(common->gadget, &(fsg->function),
2404 rc = usb_ep_enable(fsg->bulk_out);
2407 fsg->bulk_out->driver_data = common;
2408 fsg->bulk_out_enabled = 1;
2409 common->bulk_out_maxpacket = usb_endpoint_maxp(fsg->bulk_out->desc);
2410 clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
2412 /* Allocate the requests */
2413 for (i = 0; i < fsg_num_buffers; ++i) {
2414 struct fsg_buffhd *bh = &common->buffhds[i];
2416 rc = alloc_request(common, fsg->bulk_in, &bh->inreq);
2419 rc = alloc_request(common, fsg->bulk_out, &bh->outreq);
2422 bh->inreq->buf = bh->outreq->buf = bh->buf;
2423 bh->inreq->context = bh->outreq->context = bh;
2424 bh->inreq->complete = bulk_in_complete;
2425 bh->outreq->complete = bulk_out_complete;
2428 common->running = 1;
2429 for (i = 0; i < common->nluns; ++i)
2430 common->luns[i].unit_attention_data = SS_RESET_OCCURRED;
2435 /****************************** ALT CONFIGS ******************************/
2437 static int fsg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
2439 struct fsg_dev *fsg = fsg_from_func(f);
2440 fsg->common->new_fsg = fsg;
2441 raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
2442 return USB_GADGET_DELAYED_STATUS;
2445 static void fsg_disable(struct usb_function *f)
2447 struct fsg_dev *fsg = fsg_from_func(f);
2448 fsg->common->new_fsg = NULL;
2449 raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
2453 /*-------------------------------------------------------------------------*/
2455 static void handle_exception(struct fsg_common *common)
2459 struct fsg_buffhd *bh;
2460 enum fsg_state old_state;
2461 struct fsg_lun *curlun;
2462 unsigned int exception_req_tag;
2465 * Clear the existing signals. Anything but SIGUSR1 is converted
2466 * into a high-priority EXIT exception.
2470 dequeue_signal_lock(current, ¤t->blocked, &info);
2473 if (sig != SIGUSR1) {
2474 if (common->state < FSG_STATE_EXIT)
2475 DBG(common, "Main thread exiting on signal\n");
2476 raise_exception(common, FSG_STATE_EXIT);
2480 /* Cancel all the pending transfers */
2481 if (likely(common->fsg)) {
2482 for (i = 0; i < fsg_num_buffers; ++i) {
2483 bh = &common->buffhds[i];
2485 usb_ep_dequeue(common->fsg->bulk_in, bh->inreq);
2486 if (bh->outreq_busy)
2487 usb_ep_dequeue(common->fsg->bulk_out,
2491 /* Wait until everything is idle */
2494 for (i = 0; i < fsg_num_buffers; ++i) {
2495 bh = &common->buffhds[i];
2496 num_active += bh->inreq_busy + bh->outreq_busy;
2498 if (num_active == 0)
2500 if (sleep_thread(common))
2504 /* Clear out the controller's fifos */
2505 if (common->fsg->bulk_in_enabled)
2506 usb_ep_fifo_flush(common->fsg->bulk_in);
2507 if (common->fsg->bulk_out_enabled)
2508 usb_ep_fifo_flush(common->fsg->bulk_out);
2512 * Reset the I/O buffer states and pointers, the SCSI
2513 * state, and the exception. Then invoke the handler.
2515 spin_lock_irq(&common->lock);
2517 for (i = 0; i < fsg_num_buffers; ++i) {
2518 bh = &common->buffhds[i];
2519 bh->state = BUF_STATE_EMPTY;
2521 common->next_buffhd_to_fill = &common->buffhds[0];
2522 common->next_buffhd_to_drain = &common->buffhds[0];
2523 exception_req_tag = common->exception_req_tag;
2524 old_state = common->state;
2526 if (old_state == FSG_STATE_ABORT_BULK_OUT)
2527 common->state = FSG_STATE_STATUS_PHASE;
2529 for (i = 0; i < common->nluns; ++i) {
2530 curlun = &common->luns[i];
2531 curlun->prevent_medium_removal = 0;
2532 curlun->sense_data = SS_NO_SENSE;
2533 curlun->unit_attention_data = SS_NO_SENSE;
2534 curlun->sense_data_info = 0;
2535 curlun->info_valid = 0;
2537 common->state = FSG_STATE_IDLE;
2539 spin_unlock_irq(&common->lock);
2541 /* Carry out any extra actions required for the exception */
2542 switch (old_state) {
2543 case FSG_STATE_ABORT_BULK_OUT:
2544 send_status(common);
2545 spin_lock_irq(&common->lock);
2546 if (common->state == FSG_STATE_STATUS_PHASE)
2547 common->state = FSG_STATE_IDLE;
2548 spin_unlock_irq(&common->lock);
2551 case FSG_STATE_RESET:
2553 * In case we were forced against our will to halt a
2554 * bulk endpoint, clear the halt now. (The SuperH UDC
2557 if (!fsg_is_set(common))
2559 if (test_and_clear_bit(IGNORE_BULK_OUT,
2560 &common->fsg->atomic_bitflags))
2561 usb_ep_clear_halt(common->fsg->bulk_in);
2563 if (common->ep0_req_tag == exception_req_tag)
2564 ep0_queue(common); /* Complete the status stage */
2567 * Technically this should go here, but it would only be
2568 * a waste of time. Ditto for the INTERFACE_CHANGE and
2569 * CONFIG_CHANGE cases.
2571 /* for (i = 0; i < common->nluns; ++i) */
2572 /* common->luns[i].unit_attention_data = */
2573 /* SS_RESET_OCCURRED; */
2576 case FSG_STATE_CONFIG_CHANGE:
2577 do_set_interface(common, common->new_fsg);
2578 if (common->new_fsg)
2579 usb_composite_setup_continue(common->cdev);
2582 case FSG_STATE_EXIT:
2583 case FSG_STATE_TERMINATED:
2584 do_set_interface(common, NULL); /* Free resources */
2585 spin_lock_irq(&common->lock);
2586 common->state = FSG_STATE_TERMINATED; /* Stop the thread */
2587 spin_unlock_irq(&common->lock);
2590 case FSG_STATE_INTERFACE_CHANGE:
2591 case FSG_STATE_DISCONNECT:
2592 case FSG_STATE_COMMAND_PHASE:
2593 case FSG_STATE_DATA_PHASE:
2594 case FSG_STATE_STATUS_PHASE:
2595 case FSG_STATE_IDLE:
2601 /*-------------------------------------------------------------------------*/
2603 static int fsg_main_thread(void *common_)
2605 struct fsg_common *common = common_;
2608 * Allow the thread to be killed by a signal, but set the signal mask
2609 * to block everything but INT, TERM, KILL, and USR1.
2611 allow_signal(SIGINT);
2612 allow_signal(SIGTERM);
2613 allow_signal(SIGKILL);
2614 allow_signal(SIGUSR1);
2616 /* Allow the thread to be frozen */
2620 * Arrange for userspace references to be interpreted as kernel
2621 * pointers. That way we can pass a kernel pointer to a routine
2622 * that expects a __user pointer and it will work okay.
2627 while (common->state != FSG_STATE_TERMINATED) {
2628 if (exception_in_progress(common) || signal_pending(current)) {
2629 handle_exception(common);
2633 if (!common->running) {
2634 sleep_thread(common);
2638 if (get_next_command(common))
2641 spin_lock_irq(&common->lock);
2642 if (!exception_in_progress(common))
2643 common->state = FSG_STATE_DATA_PHASE;
2644 spin_unlock_irq(&common->lock);
2646 if (do_scsi_command(common) || finish_reply(common))
2649 spin_lock_irq(&common->lock);
2650 if (!exception_in_progress(common))
2651 common->state = FSG_STATE_STATUS_PHASE;
2652 spin_unlock_irq(&common->lock);
2654 if (send_status(common))
2657 spin_lock_irq(&common->lock);
2658 if (!exception_in_progress(common))
2659 common->state = FSG_STATE_IDLE;
2660 spin_unlock_irq(&common->lock);
2663 spin_lock_irq(&common->lock);
2664 common->thread_task = NULL;
2665 spin_unlock_irq(&common->lock);
2667 if (!common->ops || !common->ops->thread_exits
2668 || common->ops->thread_exits(common) < 0) {
2669 struct fsg_lun *curlun = common->luns;
2670 unsigned i = common->nluns;
2672 down_write(&common->filesem);
2673 for (; i--; ++curlun) {
2674 if (!fsg_lun_is_open(curlun))
2677 fsg_lun_close(curlun);
2678 curlun->unit_attention_data = SS_MEDIUM_NOT_PRESENT;
2680 up_write(&common->filesem);
2683 /* Let fsg_unbind() know the thread has exited */
2684 complete_and_exit(&common->thread_notifier, 0);
2688 /*************************** DEVICE ATTRIBUTES ***************************/
2690 /* Write permission is checked per LUN in store_*() functions. */
2691 static DEVICE_ATTR(ro, 0644, fsg_show_ro, fsg_store_ro);
2692 static DEVICE_ATTR(nofua, 0644, fsg_show_nofua, fsg_store_nofua);
2693 static DEVICE_ATTR(file, 0644, fsg_show_file, fsg_store_file);
2696 /****************************** FSG COMMON ******************************/
2698 static void fsg_common_release(struct kref *ref);
2700 static void fsg_lun_release(struct device *dev)
2702 /* Nothing needs to be done */
2705 static inline void fsg_common_get(struct fsg_common *common)
2707 kref_get(&common->ref);
2710 static inline void fsg_common_put(struct fsg_common *common)
2712 kref_put(&common->ref, fsg_common_release);
2715 static struct fsg_common *fsg_common_init(struct fsg_common *common,
2716 struct usb_composite_dev *cdev,
2717 struct fsg_config *cfg)
2719 struct usb_gadget *gadget = cdev->gadget;
2720 struct fsg_buffhd *bh;
2721 struct fsg_lun *curlun;
2722 struct fsg_lun_config *lcfg;
2726 rc = fsg_num_buffers_validate();
2730 /* Find out how many LUNs there should be */
2732 if (nluns < 1 || nluns > FSG_MAX_LUNS) {
2733 dev_err(&gadget->dev, "invalid number of LUNs: %u\n", nluns);
2734 return ERR_PTR(-EINVAL);
2739 common = kzalloc(sizeof *common, GFP_KERNEL);
2741 return ERR_PTR(-ENOMEM);
2742 common->free_storage_on_release = 1;
2744 memset(common, 0, sizeof *common);
2745 common->free_storage_on_release = 0;
2748 common->buffhds = kcalloc(fsg_num_buffers,
2749 sizeof *(common->buffhds), GFP_KERNEL);
2750 if (!common->buffhds) {
2751 if (common->free_storage_on_release)
2753 return ERR_PTR(-ENOMEM);
2756 common->ops = cfg->ops;
2757 common->private_data = cfg->private_data;
2759 common->gadget = gadget;
2760 common->ep0 = gadget->ep0;
2761 common->ep0req = cdev->req;
2762 common->cdev = cdev;
2764 /* Maybe allocate device-global string IDs, and patch descriptors */
2765 if (fsg_strings[FSG_STRING_INTERFACE].id == 0) {
2766 rc = usb_string_id(cdev);
2767 if (unlikely(rc < 0))
2769 fsg_strings[FSG_STRING_INTERFACE].id = rc;
2770 fsg_intf_desc.iInterface = rc;
2774 * Create the LUNs, open their backing files, and register the
2775 * LUN devices in sysfs.
2777 curlun = kcalloc(nluns, sizeof(*curlun), GFP_KERNEL);
2778 if (unlikely(!curlun)) {
2782 common->luns = curlun;
2784 init_rwsem(&common->filesem);
2786 for (i = 0, lcfg = cfg->luns; i < nluns; ++i, ++curlun, ++lcfg) {
2787 curlun->cdrom = !!lcfg->cdrom;
2788 curlun->ro = lcfg->cdrom || lcfg->ro;
2789 curlun->initially_ro = curlun->ro;
2790 curlun->removable = lcfg->removable;
2791 curlun->dev.release = fsg_lun_release;
2792 curlun->dev.parent = &gadget->dev;
2793 /* curlun->dev.driver = &fsg_driver.driver; XXX */
2794 dev_set_drvdata(&curlun->dev, &common->filesem);
2795 dev_set_name(&curlun->dev,
2796 cfg->lun_name_format
2797 ? cfg->lun_name_format
2801 rc = device_register(&curlun->dev);
2803 INFO(common, "failed to register LUN%d: %d\n", i, rc);
2805 put_device(&curlun->dev);
2809 rc = device_create_file(&curlun->dev, &dev_attr_ro);
2812 rc = device_create_file(&curlun->dev, &dev_attr_file);
2815 rc = device_create_file(&curlun->dev, &dev_attr_nofua);
2819 if (lcfg->filename) {
2820 rc = fsg_lun_open(curlun, lcfg->filename);
2823 } else if (!curlun->removable) {
2824 ERROR(common, "no file given for LUN%d\n", i);
2829 common->nluns = nluns;
2831 /* Data buffers cyclic list */
2832 bh = common->buffhds;
2833 i = fsg_num_buffers;
2834 goto buffhds_first_it;
2839 bh->buf = kmalloc(FSG_BUFLEN, GFP_KERNEL);
2840 if (unlikely(!bh->buf)) {
2845 bh->next = common->buffhds;
2847 /* Prepare inquiryString */
2848 if (cfg->release != 0xffff) {
2851 i = usb_gadget_controller_number(gadget);
2855 WARNING(common, "controller '%s' not recognized\n",
2860 snprintf(common->inquiry_string, sizeof common->inquiry_string,
2861 "%-8s%-16s%04x", cfg->vendor_name ?: "Linux",
2862 /* Assume product name dependent on the first LUN */
2863 cfg->product_name ?: (common->luns->cdrom
2864 ? "File-Stor Gadget"
2865 : "File-CD Gadget"),
2869 * Some peripheral controllers are known not to be able to
2870 * halt bulk endpoints correctly. If one of them is present,
2873 common->can_stall = cfg->can_stall &&
2874 !(gadget_is_at91(common->gadget));
2876 spin_lock_init(&common->lock);
2877 kref_init(&common->ref);
2879 /* Tell the thread to start working */
2880 common->thread_task =
2881 kthread_create(fsg_main_thread, common,
2882 cfg->thread_name ?: "file-storage");
2883 if (IS_ERR(common->thread_task)) {
2884 rc = PTR_ERR(common->thread_task);
2887 init_completion(&common->thread_notifier);
2888 init_waitqueue_head(&common->fsg_wait);
2891 INFO(common, FSG_DRIVER_DESC ", version: " FSG_DRIVER_VERSION "\n");
2892 INFO(common, "Number of LUNs=%d\n", common->nluns);
2894 pathbuf = kmalloc(PATH_MAX, GFP_KERNEL);
2895 for (i = 0, nluns = common->nluns, curlun = common->luns;
2898 char *p = "(no medium)";
2899 if (fsg_lun_is_open(curlun)) {
2902 p = d_path(&curlun->filp->f_path,
2908 LINFO(curlun, "LUN: %s%s%sfile: %s\n",
2909 curlun->removable ? "removable " : "",
2910 curlun->ro ? "read only " : "",
2911 curlun->cdrom ? "CD-ROM " : "",
2916 DBG(common, "I/O thread pid: %d\n", task_pid_nr(common->thread_task));
2918 wake_up_process(common->thread_task);
2923 common->nluns = i + 1;
2925 common->state = FSG_STATE_TERMINATED; /* The thread is dead */
2926 /* Call fsg_common_release() directly, ref might be not initialised. */
2927 fsg_common_release(&common->ref);
2931 static void fsg_common_release(struct kref *ref)
2933 struct fsg_common *common = container_of(ref, struct fsg_common, ref);
2935 /* If the thread isn't already dead, tell it to exit now */
2936 if (common->state != FSG_STATE_TERMINATED) {
2937 raise_exception(common, FSG_STATE_EXIT);
2938 wait_for_completion(&common->thread_notifier);
2941 if (likely(common->luns)) {
2942 struct fsg_lun *lun = common->luns;
2943 unsigned i = common->nluns;
2945 /* In error recovery common->nluns may be zero. */
2946 for (; i; --i, ++lun) {
2947 device_remove_file(&lun->dev, &dev_attr_nofua);
2948 device_remove_file(&lun->dev, &dev_attr_ro);
2949 device_remove_file(&lun->dev, &dev_attr_file);
2951 device_unregister(&lun->dev);
2954 kfree(common->luns);
2958 struct fsg_buffhd *bh = common->buffhds;
2959 unsigned i = fsg_num_buffers;
2962 } while (++bh, --i);
2965 kfree(common->buffhds);
2966 if (common->free_storage_on_release)
2971 /*-------------------------------------------------------------------------*/
2973 static void fsg_unbind(struct usb_configuration *c, struct usb_function *f)
2975 struct fsg_dev *fsg = fsg_from_func(f);
2976 struct fsg_common *common = fsg->common;
2978 DBG(fsg, "unbind\n");
2979 if (fsg->common->fsg == fsg) {
2980 fsg->common->new_fsg = NULL;
2981 raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
2982 /* FIXME: make interruptible or killable somehow? */
2983 wait_event(common->fsg_wait, common->fsg != fsg);
2986 fsg_common_put(common);
2987 usb_free_descriptors(fsg->function.descriptors);
2988 usb_free_descriptors(fsg->function.hs_descriptors);
2989 usb_free_descriptors(fsg->function.ss_descriptors);
2993 static int fsg_bind(struct usb_configuration *c, struct usb_function *f)
2995 struct fsg_dev *fsg = fsg_from_func(f);
2996 struct usb_gadget *gadget = c->cdev->gadget;
3000 fsg->gadget = gadget;
3003 i = usb_interface_id(c, f);
3006 fsg_intf_desc.bInterfaceNumber = i;
3007 fsg->interface_number = i;
3009 /* Find all the endpoints we will use */
3010 ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_in_desc);
3013 ep->driver_data = fsg->common; /* claim the endpoint */
3016 ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_out_desc);
3019 ep->driver_data = fsg->common; /* claim the endpoint */
3022 /* Copy descriptors */
3023 f->descriptors = usb_copy_descriptors(fsg_fs_function);
3024 if (unlikely(!f->descriptors))
3027 if (gadget_is_dualspeed(gadget)) {
3028 /* Assume endpoint addresses are the same for both speeds */
3029 fsg_hs_bulk_in_desc.bEndpointAddress =
3030 fsg_fs_bulk_in_desc.bEndpointAddress;
3031 fsg_hs_bulk_out_desc.bEndpointAddress =
3032 fsg_fs_bulk_out_desc.bEndpointAddress;
3033 f->hs_descriptors = usb_copy_descriptors(fsg_hs_function);
3034 if (unlikely(!f->hs_descriptors)) {
3035 usb_free_descriptors(f->descriptors);
3040 if (gadget_is_superspeed(gadget)) {
3043 /* Calculate bMaxBurst, we know packet size is 1024 */
3044 max_burst = min_t(unsigned, FSG_BUFLEN / 1024, 15);
3046 fsg_ss_bulk_in_desc.bEndpointAddress =
3047 fsg_fs_bulk_in_desc.bEndpointAddress;
3048 fsg_ss_bulk_in_comp_desc.bMaxBurst = max_burst;
3050 fsg_ss_bulk_out_desc.bEndpointAddress =
3051 fsg_fs_bulk_out_desc.bEndpointAddress;
3052 fsg_ss_bulk_out_comp_desc.bMaxBurst = max_burst;
3054 f->ss_descriptors = usb_copy_descriptors(fsg_ss_function);
3055 if (unlikely(!f->ss_descriptors)) {
3056 usb_free_descriptors(f->hs_descriptors);
3057 usb_free_descriptors(f->descriptors);
3065 ERROR(fsg, "unable to autoconfigure all endpoints\n");
3070 /****************************** ADD FUNCTION ******************************/
3072 static struct usb_gadget_strings *fsg_strings_array[] = {
3077 static int fsg_bind_config(struct usb_composite_dev *cdev,
3078 struct usb_configuration *c,
3079 struct fsg_common *common)
3081 struct fsg_dev *fsg;
3084 fsg = kzalloc(sizeof *fsg, GFP_KERNEL);
3088 fsg->function.name = FSG_DRIVER_DESC;
3089 fsg->function.strings = fsg_strings_array;
3090 fsg->function.bind = fsg_bind;
3091 fsg->function.unbind = fsg_unbind;
3092 fsg->function.setup = fsg_setup;
3093 fsg->function.set_alt = fsg_set_alt;
3094 fsg->function.disable = fsg_disable;
3096 fsg->common = common;
3098 * Our caller holds a reference to common structure so we
3099 * don't have to be worry about it being freed until we return
3100 * from this function. So instead of incrementing counter now
3101 * and decrement in error recovery we increment it only when
3102 * call to usb_add_function() was successful.
3105 rc = usb_add_function(c, &fsg->function);
3109 fsg_common_get(fsg->common);
3114 /************************* Module parameters *************************/
3116 struct fsg_module_parameters {
3117 char *file[FSG_MAX_LUNS];
3118 bool ro[FSG_MAX_LUNS];
3119 bool removable[FSG_MAX_LUNS];
3120 bool cdrom[FSG_MAX_LUNS];
3121 bool nofua[FSG_MAX_LUNS];
3123 unsigned int file_count, ro_count, removable_count, cdrom_count;
3124 unsigned int nofua_count;
3125 unsigned int luns; /* nluns */
3126 bool stall; /* can_stall */
3129 #define _FSG_MODULE_PARAM_ARRAY(prefix, params, name, type, desc) \
3130 module_param_array_named(prefix ## name, params.name, type, \
3131 &prefix ## params.name ## _count, \
3133 MODULE_PARM_DESC(prefix ## name, desc)
3135 #define _FSG_MODULE_PARAM(prefix, params, name, type, desc) \
3136 module_param_named(prefix ## name, params.name, type, \
3138 MODULE_PARM_DESC(prefix ## name, desc)
3140 #define FSG_MODULE_PARAMETERS(prefix, params) \
3141 _FSG_MODULE_PARAM_ARRAY(prefix, params, file, charp, \
3142 "names of backing files or devices"); \
3143 _FSG_MODULE_PARAM_ARRAY(prefix, params, ro, bool, \
3144 "true to force read-only"); \
3145 _FSG_MODULE_PARAM_ARRAY(prefix, params, removable, bool, \
3146 "true to simulate removable media"); \
3147 _FSG_MODULE_PARAM_ARRAY(prefix, params, cdrom, bool, \
3148 "true to simulate CD-ROM instead of disk"); \
3149 _FSG_MODULE_PARAM_ARRAY(prefix, params, nofua, bool, \
3150 "true to ignore SCSI WRITE(10,12) FUA bit"); \
3151 _FSG_MODULE_PARAM(prefix, params, luns, uint, \
3152 "number of LUNs"); \
3153 _FSG_MODULE_PARAM(prefix, params, stall, bool, \
3154 "false to prevent bulk stalls")
3157 fsg_config_from_params(struct fsg_config *cfg,
3158 const struct fsg_module_parameters *params)
3160 struct fsg_lun_config *lun;
3163 /* Configure LUNs */
3165 min(params->luns ?: (params->file_count ?: 1u),
3166 (unsigned)FSG_MAX_LUNS);
3167 for (i = 0, lun = cfg->luns; i < cfg->nluns; ++i, ++lun) {
3168 lun->ro = !!params->ro[i];
3169 lun->cdrom = !!params->cdrom[i];
3170 lun->removable = /* Removable by default */
3171 params->removable_count <= i || params->removable[i];
3173 params->file_count > i && params->file[i][0]
3178 /* Let MSF use defaults */
3179 cfg->lun_name_format = 0;
3180 cfg->thread_name = 0;
3181 cfg->vendor_name = 0;
3182 cfg->product_name = 0;
3183 cfg->release = 0xffff;
3186 cfg->private_data = NULL;
3189 cfg->can_stall = params->stall;
3192 static inline struct fsg_common *
3193 fsg_common_from_params(struct fsg_common *common,
3194 struct usb_composite_dev *cdev,
3195 const struct fsg_module_parameters *params)
3196 __attribute__((unused));
3197 static inline struct fsg_common *
3198 fsg_common_from_params(struct fsg_common *common,
3199 struct usb_composite_dev *cdev,
3200 const struct fsg_module_parameters *params)
3202 struct fsg_config cfg;
3203 fsg_config_from_params(&cfg, params);
3204 return fsg_common_init(common, cdev, &cfg);