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.
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_INTR_EP 1
308 #define FSG_NO_DEVICE_STRINGS 1
310 #define FSG_NO_INTR_EP 1
312 #include "storage_common.c"
315 /*-------------------------------------------------------------------------*/
320 /* FSF callback functions */
321 struct fsg_operations {
323 * Callback function to call when thread exits. If no
324 * callback is set or it returns value lower then zero MSF
325 * will force eject all LUNs it operates on (including those
326 * marked as non-removable or with prevent_medium_removal flag
329 int (*thread_exits)(struct fsg_common *common);
332 * Called prior to ejection. Negative return means error,
333 * zero means to continue with ejection, positive means not to
336 int (*pre_eject)(struct fsg_common *common,
337 struct fsg_lun *lun, int num);
339 * Called after ejection. Negative return means error, zero
340 * or positive is just a success.
342 int (*post_eject)(struct fsg_common *common,
343 struct fsg_lun *lun, int num);
346 /* Data shared by all the FSG instances. */
348 struct usb_gadget *gadget;
349 struct usb_composite_dev *cdev;
350 struct fsg_dev *fsg, *new_fsg;
351 wait_queue_head_t fsg_wait;
353 /* filesem protects: backing files in use */
354 struct rw_semaphore filesem;
356 /* lock protects: state, all the req_busy's */
359 struct usb_ep *ep0; /* Copy of gadget->ep0 */
360 struct usb_request *ep0req; /* Copy of cdev->req */
361 unsigned int ep0_req_tag;
363 struct fsg_buffhd *next_buffhd_to_fill;
364 struct fsg_buffhd *next_buffhd_to_drain;
365 struct fsg_buffhd *buffhds;
368 u8 cmnd[MAX_COMMAND_SIZE];
372 struct fsg_lun *luns;
373 struct fsg_lun *curlun;
375 unsigned int bulk_out_maxpacket;
376 enum fsg_state state; /* For exception handling */
377 unsigned int exception_req_tag;
379 enum data_direction data_dir;
381 u32 data_size_from_cmnd;
386 unsigned int can_stall:1;
387 unsigned int free_storage_on_release:1;
388 unsigned int phase_error:1;
389 unsigned int short_packet_received:1;
390 unsigned int bad_lun_okay:1;
391 unsigned int running:1;
393 int thread_wakeup_needed;
394 struct completion thread_notifier;
395 struct task_struct *thread_task;
397 /* Callback functions. */
398 const struct fsg_operations *ops;
399 /* Gadget's private data. */
403 * Vendor (8 chars), product (16 chars), release (4
404 * hexadecimal digits) and NUL byte
406 char inquiry_string[8 + 16 + 4 + 1];
413 struct fsg_lun_config {
414 const char *filename;
419 } luns[FSG_MAX_LUNS];
421 const char *lun_name_format;
422 const char *thread_name;
424 /* Callback functions. */
425 const struct fsg_operations *ops;
426 /* Gadget's private data. */
429 const char *vendor_name; /* 8 characters or less */
430 const char *product_name; /* 16 characters or less */
437 struct usb_function function;
438 struct usb_gadget *gadget; /* Copy of cdev->gadget */
439 struct fsg_common *common;
441 u16 interface_number;
443 unsigned int bulk_in_enabled:1;
444 unsigned int bulk_out_enabled:1;
446 unsigned long atomic_bitflags;
447 #define IGNORE_BULK_OUT 0
449 struct usb_ep *bulk_in;
450 struct usb_ep *bulk_out;
453 static inline int __fsg_is_set(struct fsg_common *common,
454 const char *func, unsigned line)
458 ERROR(common, "common->fsg is NULL in %s at %u\n", func, line);
463 #define fsg_is_set(common) likely(__fsg_is_set(common, __func__, __LINE__))
465 static inline struct fsg_dev *fsg_from_func(struct usb_function *f)
467 return container_of(f, struct fsg_dev, function);
470 typedef void (*fsg_routine_t)(struct fsg_dev *);
472 static int exception_in_progress(struct fsg_common *common)
474 return common->state > FSG_STATE_IDLE;
477 /* Make bulk-out requests be divisible by the maxpacket size */
478 static void set_bulk_out_req_length(struct fsg_common *common,
479 struct fsg_buffhd *bh, unsigned int length)
483 bh->bulk_out_intended_length = length;
484 rem = length % common->bulk_out_maxpacket;
486 length += common->bulk_out_maxpacket - rem;
487 bh->outreq->length = length;
491 /*-------------------------------------------------------------------------*/
493 static int fsg_set_halt(struct fsg_dev *fsg, struct usb_ep *ep)
497 if (ep == fsg->bulk_in)
499 else if (ep == fsg->bulk_out)
503 DBG(fsg, "%s set halt\n", name);
504 return usb_ep_set_halt(ep);
508 /*-------------------------------------------------------------------------*/
510 /* These routines may be called in process context or in_irq */
512 /* Caller must hold fsg->lock */
513 static void wakeup_thread(struct fsg_common *common)
515 smp_wmb(); /* ensure the write of bh->state is complete */
516 /* Tell the main thread that something has happened */
517 common->thread_wakeup_needed = 1;
518 if (common->thread_task)
519 wake_up_process(common->thread_task);
522 static void raise_exception(struct fsg_common *common, enum fsg_state new_state)
527 * Do nothing if a higher-priority exception is already in progress.
528 * If a lower-or-equal priority exception is in progress, preempt it
529 * and notify the main thread by sending it a signal.
531 spin_lock_irqsave(&common->lock, flags);
532 if (common->state <= new_state) {
533 common->exception_req_tag = common->ep0_req_tag;
534 common->state = new_state;
535 if (common->thread_task)
536 send_sig_info(SIGUSR1, SEND_SIG_FORCED,
537 common->thread_task);
539 spin_unlock_irqrestore(&common->lock, flags);
543 /*-------------------------------------------------------------------------*/
545 static int ep0_queue(struct fsg_common *common)
549 rc = usb_ep_queue(common->ep0, common->ep0req, GFP_ATOMIC);
550 common->ep0->driver_data = common;
551 if (rc != 0 && rc != -ESHUTDOWN) {
552 /* We can't do much more than wait for a reset */
553 WARNING(common, "error in submission: %s --> %d\n",
554 common->ep0->name, rc);
560 /*-------------------------------------------------------------------------*/
562 /* Completion handlers. These always run in_irq. */
564 static void bulk_in_complete(struct usb_ep *ep, struct usb_request *req)
566 struct fsg_common *common = ep->driver_data;
567 struct fsg_buffhd *bh = req->context;
569 if (req->status || req->actual != req->length)
570 DBG(common, "%s --> %d, %u/%u\n", __func__,
571 req->status, req->actual, req->length);
572 if (req->status == -ECONNRESET) /* Request was cancelled */
573 usb_ep_fifo_flush(ep);
575 /* Hold the lock while we update the request and buffer states */
577 spin_lock(&common->lock);
579 bh->state = BUF_STATE_EMPTY;
580 wakeup_thread(common);
581 spin_unlock(&common->lock);
584 static void bulk_out_complete(struct usb_ep *ep, struct usb_request *req)
586 struct fsg_common *common = ep->driver_data;
587 struct fsg_buffhd *bh = req->context;
589 dump_msg(common, "bulk-out", req->buf, req->actual);
590 if (req->status || req->actual != bh->bulk_out_intended_length)
591 DBG(common, "%s --> %d, %u/%u\n", __func__,
592 req->status, req->actual, bh->bulk_out_intended_length);
593 if (req->status == -ECONNRESET) /* Request was cancelled */
594 usb_ep_fifo_flush(ep);
596 /* Hold the lock while we update the request and buffer states */
598 spin_lock(&common->lock);
600 bh->state = BUF_STATE_FULL;
601 wakeup_thread(common);
602 spin_unlock(&common->lock);
605 static int fsg_setup(struct usb_function *f,
606 const struct usb_ctrlrequest *ctrl)
608 struct fsg_dev *fsg = fsg_from_func(f);
609 struct usb_request *req = fsg->common->ep0req;
610 u16 w_index = le16_to_cpu(ctrl->wIndex);
611 u16 w_value = le16_to_cpu(ctrl->wValue);
612 u16 w_length = le16_to_cpu(ctrl->wLength);
614 if (!fsg_is_set(fsg->common))
617 ++fsg->common->ep0_req_tag; /* Record arrival of a new request */
620 dump_msg(fsg, "ep0-setup", (u8 *) ctrl, sizeof(*ctrl));
622 switch (ctrl->bRequest) {
624 case USB_BULK_RESET_REQUEST:
625 if (ctrl->bRequestType !=
626 (USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE))
628 if (w_index != fsg->interface_number || w_value != 0 ||
633 * Raise an exception to stop the current operation
634 * and reinitialize our state.
636 DBG(fsg, "bulk reset request\n");
637 raise_exception(fsg->common, FSG_STATE_RESET);
638 return DELAYED_STATUS;
640 case USB_BULK_GET_MAX_LUN_REQUEST:
641 if (ctrl->bRequestType !=
642 (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE))
644 if (w_index != fsg->interface_number || w_value != 0 ||
647 VDBG(fsg, "get max LUN\n");
648 *(u8 *)req->buf = fsg->common->nluns - 1;
650 /* Respond with data/status */
651 req->length = min((u16)1, w_length);
652 return ep0_queue(fsg->common);
656 "unknown class-specific control req %02x.%02x v%04x i%04x l%u\n",
657 ctrl->bRequestType, ctrl->bRequest,
658 le16_to_cpu(ctrl->wValue), w_index, w_length);
663 /*-------------------------------------------------------------------------*/
665 /* All the following routines run in process context */
667 /* Use this for bulk or interrupt transfers, not ep0 */
668 static void start_transfer(struct fsg_dev *fsg, struct usb_ep *ep,
669 struct usb_request *req, int *pbusy,
670 enum fsg_buffer_state *state)
674 if (ep == fsg->bulk_in)
675 dump_msg(fsg, "bulk-in", req->buf, req->length);
677 spin_lock_irq(&fsg->common->lock);
679 *state = BUF_STATE_BUSY;
680 spin_unlock_irq(&fsg->common->lock);
681 rc = usb_ep_queue(ep, req, GFP_KERNEL);
684 *state = BUF_STATE_EMPTY;
686 /* We can't do much more than wait for a reset */
689 * Note: currently the net2280 driver fails zero-length
690 * submissions if DMA is enabled.
692 if (rc != -ESHUTDOWN &&
693 !(rc == -EOPNOTSUPP && req->length == 0))
694 WARNING(fsg, "error in submission: %s --> %d\n",
699 static bool start_in_transfer(struct fsg_common *common, struct fsg_buffhd *bh)
701 if (!fsg_is_set(common))
703 start_transfer(common->fsg, common->fsg->bulk_in,
704 bh->inreq, &bh->inreq_busy, &bh->state);
708 static bool start_out_transfer(struct fsg_common *common, struct fsg_buffhd *bh)
710 if (!fsg_is_set(common))
712 start_transfer(common->fsg, common->fsg->bulk_out,
713 bh->outreq, &bh->outreq_busy, &bh->state);
717 static int sleep_thread(struct fsg_common *common)
721 /* Wait until a signal arrives or we are woken up */
724 set_current_state(TASK_INTERRUPTIBLE);
725 if (signal_pending(current)) {
729 if (common->thread_wakeup_needed)
733 __set_current_state(TASK_RUNNING);
734 common->thread_wakeup_needed = 0;
735 smp_rmb(); /* ensure the latest bh->state is visible */
740 /*-------------------------------------------------------------------------*/
742 static int do_read(struct fsg_common *common)
744 struct fsg_lun *curlun = common->curlun;
746 struct fsg_buffhd *bh;
749 loff_t file_offset, file_offset_tmp;
754 * Get the starting Logical Block Address and check that it's
757 if (common->cmnd[0] == READ_6)
758 lba = get_unaligned_be24(&common->cmnd[1]);
760 lba = get_unaligned_be32(&common->cmnd[2]);
763 * We allow DPO (Disable Page Out = don't save data in the
764 * cache) and FUA (Force Unit Access = don't read from the
765 * cache), but we don't implement them.
767 if ((common->cmnd[1] & ~0x18) != 0) {
768 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
772 if (lba >= curlun->num_sectors) {
773 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
776 file_offset = ((loff_t) lba) << curlun->blkbits;
778 /* Carry out the file reads */
779 amount_left = common->data_size_from_cmnd;
780 if (unlikely(amount_left == 0))
781 return -EIO; /* No default reply */
785 * Figure out how much we need to read:
786 * Try to read the remaining amount.
787 * But don't read more than the buffer size.
788 * And don't try to read past the end of the file.
790 amount = min(amount_left, FSG_BUFLEN);
791 amount = min((loff_t)amount,
792 curlun->file_length - file_offset);
794 /* Wait for the next buffer to become available */
795 bh = common->next_buffhd_to_fill;
796 while (bh->state != BUF_STATE_EMPTY) {
797 rc = sleep_thread(common);
803 * If we were asked to read past the end of file,
804 * end with an empty buffer.
808 SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
809 curlun->sense_data_info =
810 file_offset >> curlun->blkbits;
811 curlun->info_valid = 1;
812 bh->inreq->length = 0;
813 bh->state = BUF_STATE_FULL;
817 /* Perform the read */
818 file_offset_tmp = file_offset;
819 nread = vfs_read(curlun->filp,
820 (char __user *)bh->buf,
821 amount, &file_offset_tmp);
822 VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
823 (unsigned long long)file_offset, (int)nread);
824 if (signal_pending(current))
828 LDBG(curlun, "error in file read: %d\n", (int)nread);
830 } else if (nread < amount) {
831 LDBG(curlun, "partial file read: %d/%u\n",
833 nread = round_down(nread, curlun->blksize);
835 file_offset += nread;
836 amount_left -= nread;
837 common->residue -= nread;
840 * Except at the end of the transfer, nread will be
841 * equal to the buffer size, which is divisible by the
842 * bulk-in maxpacket size.
844 bh->inreq->length = nread;
845 bh->state = BUF_STATE_FULL;
847 /* If an error occurred, report it and its position */
848 if (nread < amount) {
849 curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
850 curlun->sense_data_info =
851 file_offset >> curlun->blkbits;
852 curlun->info_valid = 1;
856 if (amount_left == 0)
857 break; /* No more left to read */
859 /* Send this buffer and go read some more */
861 if (!start_in_transfer(common, bh))
862 /* Don't know what to do if common->fsg is NULL */
864 common->next_buffhd_to_fill = bh->next;
867 return -EIO; /* No default reply */
871 /*-------------------------------------------------------------------------*/
873 static int do_write(struct fsg_common *common)
875 struct fsg_lun *curlun = common->curlun;
877 struct fsg_buffhd *bh;
879 u32 amount_left_to_req, amount_left_to_write;
880 loff_t usb_offset, file_offset, file_offset_tmp;
886 curlun->sense_data = SS_WRITE_PROTECTED;
889 spin_lock(&curlun->filp->f_lock);
890 curlun->filp->f_flags &= ~O_SYNC; /* Default is not to wait */
891 spin_unlock(&curlun->filp->f_lock);
894 * Get the starting Logical Block Address and check that it's
897 if (common->cmnd[0] == WRITE_6)
898 lba = get_unaligned_be24(&common->cmnd[1]);
900 lba = get_unaligned_be32(&common->cmnd[2]);
903 * We allow DPO (Disable Page Out = don't save data in the
904 * cache) and FUA (Force Unit Access = write directly to the
905 * medium). We don't implement DPO; we implement FUA by
906 * performing synchronous output.
908 if (common->cmnd[1] & ~0x18) {
909 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
912 if (!curlun->nofua && (common->cmnd[1] & 0x08)) { /* FUA */
913 spin_lock(&curlun->filp->f_lock);
914 curlun->filp->f_flags |= O_SYNC;
915 spin_unlock(&curlun->filp->f_lock);
918 if (lba >= curlun->num_sectors) {
919 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
923 /* Carry out the file writes */
925 file_offset = usb_offset = ((loff_t) lba) << curlun->blkbits;
926 amount_left_to_req = common->data_size_from_cmnd;
927 amount_left_to_write = common->data_size_from_cmnd;
929 while (amount_left_to_write > 0) {
931 /* Queue a request for more data from the host */
932 bh = common->next_buffhd_to_fill;
933 if (bh->state == BUF_STATE_EMPTY && get_some_more) {
936 * Figure out how much we want to get:
937 * Try to get the remaining amount,
938 * but not more than the buffer size.
940 amount = min(amount_left_to_req, FSG_BUFLEN);
942 /* Beyond the end of the backing file? */
943 if (usb_offset >= curlun->file_length) {
946 SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
947 curlun->sense_data_info =
948 usb_offset >> curlun->blkbits;
949 curlun->info_valid = 1;
953 /* Get the next buffer */
954 usb_offset += amount;
955 common->usb_amount_left -= amount;
956 amount_left_to_req -= amount;
957 if (amount_left_to_req == 0)
961 * Except at the end of the transfer, amount will be
962 * equal to the buffer size, which is divisible by
963 * the bulk-out maxpacket size.
965 set_bulk_out_req_length(common, bh, amount);
966 if (!start_out_transfer(common, bh))
967 /* Dunno what to do if common->fsg is NULL */
969 common->next_buffhd_to_fill = bh->next;
973 /* Write the received data to the backing file */
974 bh = common->next_buffhd_to_drain;
975 if (bh->state == BUF_STATE_EMPTY && !get_some_more)
976 break; /* We stopped early */
977 if (bh->state == BUF_STATE_FULL) {
979 common->next_buffhd_to_drain = bh->next;
980 bh->state = BUF_STATE_EMPTY;
982 /* Did something go wrong with the transfer? */
983 if (bh->outreq->status != 0) {
984 curlun->sense_data = SS_COMMUNICATION_FAILURE;
985 curlun->sense_data_info =
986 file_offset >> curlun->blkbits;
987 curlun->info_valid = 1;
991 amount = bh->outreq->actual;
992 if (curlun->file_length - file_offset < amount) {
994 "write %u @ %llu beyond end %llu\n",
995 amount, (unsigned long long)file_offset,
996 (unsigned long long)curlun->file_length);
997 amount = curlun->file_length - file_offset;
1000 /* Don't accept excess data. The spec doesn't say
1001 * what to do in this case. We'll ignore the error.
1003 amount = min(amount, bh->bulk_out_intended_length);
1005 /* Don't write a partial block */
1006 amount = round_down(amount, curlun->blksize);
1010 /* Perform the write */
1011 file_offset_tmp = file_offset;
1012 nwritten = vfs_write(curlun->filp,
1013 (char __user *)bh->buf,
1014 amount, &file_offset_tmp);
1015 VLDBG(curlun, "file write %u @ %llu -> %d\n", amount,
1016 (unsigned long long)file_offset, (int)nwritten);
1017 if (signal_pending(current))
1018 return -EINTR; /* Interrupted! */
1021 LDBG(curlun, "error in file write: %d\n",
1024 } else if (nwritten < amount) {
1025 LDBG(curlun, "partial file write: %d/%u\n",
1026 (int)nwritten, amount);
1027 nwritten = round_down(nwritten, curlun->blksize);
1029 file_offset += nwritten;
1030 amount_left_to_write -= nwritten;
1031 common->residue -= nwritten;
1033 /* If an error occurred, report it and its position */
1034 if (nwritten < amount) {
1035 curlun->sense_data = SS_WRITE_ERROR;
1036 curlun->sense_data_info =
1037 file_offset >> curlun->blkbits;
1038 curlun->info_valid = 1;
1043 /* Did the host decide to stop early? */
1044 if (bh->outreq->actual < bh->bulk_out_intended_length) {
1045 common->short_packet_received = 1;
1051 /* Wait for something to happen */
1052 rc = sleep_thread(common);
1057 return -EIO; /* No default reply */
1061 /*-------------------------------------------------------------------------*/
1063 static int do_synchronize_cache(struct fsg_common *common)
1065 struct fsg_lun *curlun = common->curlun;
1068 /* We ignore the requested LBA and write out all file's
1069 * dirty data buffers. */
1070 rc = fsg_lun_fsync_sub(curlun);
1072 curlun->sense_data = SS_WRITE_ERROR;
1077 /*-------------------------------------------------------------------------*/
1079 static void invalidate_sub(struct fsg_lun *curlun)
1081 struct file *filp = curlun->filp;
1082 struct inode *inode = filp->f_path.dentry->d_inode;
1085 rc = invalidate_mapping_pages(inode->i_mapping, 0, -1);
1086 VLDBG(curlun, "invalidate_mapping_pages -> %ld\n", rc);
1089 static int do_verify(struct fsg_common *common)
1091 struct fsg_lun *curlun = common->curlun;
1093 u32 verification_length;
1094 struct fsg_buffhd *bh = common->next_buffhd_to_fill;
1095 loff_t file_offset, file_offset_tmp;
1097 unsigned int amount;
1101 * Get the starting Logical Block Address and check that it's
1104 lba = get_unaligned_be32(&common->cmnd[2]);
1105 if (lba >= curlun->num_sectors) {
1106 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1111 * We allow DPO (Disable Page Out = don't save data in the
1112 * cache) but we don't implement it.
1114 if (common->cmnd[1] & ~0x10) {
1115 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1119 verification_length = get_unaligned_be16(&common->cmnd[7]);
1120 if (unlikely(verification_length == 0))
1121 return -EIO; /* No default reply */
1123 /* Prepare to carry out the file verify */
1124 amount_left = verification_length << curlun->blkbits;
1125 file_offset = ((loff_t) lba) << curlun->blkbits;
1127 /* Write out all the dirty buffers before invalidating them */
1128 fsg_lun_fsync_sub(curlun);
1129 if (signal_pending(current))
1132 invalidate_sub(curlun);
1133 if (signal_pending(current))
1136 /* Just try to read the requested blocks */
1137 while (amount_left > 0) {
1139 * Figure out how much we need to read:
1140 * Try to read the remaining amount, but not more than
1142 * And don't try to read past the end of the file.
1144 amount = min(amount_left, FSG_BUFLEN);
1145 amount = min((loff_t)amount,
1146 curlun->file_length - file_offset);
1148 curlun->sense_data =
1149 SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1150 curlun->sense_data_info =
1151 file_offset >> curlun->blkbits;
1152 curlun->info_valid = 1;
1156 /* Perform the read */
1157 file_offset_tmp = file_offset;
1158 nread = vfs_read(curlun->filp,
1159 (char __user *) bh->buf,
1160 amount, &file_offset_tmp);
1161 VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
1162 (unsigned long long) file_offset,
1164 if (signal_pending(current))
1168 LDBG(curlun, "error in file verify: %d\n", (int)nread);
1170 } else if (nread < amount) {
1171 LDBG(curlun, "partial file verify: %d/%u\n",
1172 (int)nread, amount);
1173 nread = round_down(nread, curlun->blksize);
1176 curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
1177 curlun->sense_data_info =
1178 file_offset >> curlun->blkbits;
1179 curlun->info_valid = 1;
1182 file_offset += nread;
1183 amount_left -= nread;
1189 /*-------------------------------------------------------------------------*/
1191 static int do_inquiry(struct fsg_common *common, struct fsg_buffhd *bh)
1193 struct fsg_lun *curlun = common->curlun;
1194 u8 *buf = (u8 *) bh->buf;
1196 if (!curlun) { /* Unsupported LUNs are okay */
1197 common->bad_lun_okay = 1;
1199 buf[0] = 0x7f; /* Unsupported, no device-type */
1200 buf[4] = 31; /* Additional length */
1204 buf[0] = curlun->cdrom ? TYPE_ROM : TYPE_DISK;
1205 buf[1] = curlun->removable ? 0x80 : 0;
1206 buf[2] = 2; /* ANSI SCSI level 2 */
1207 buf[3] = 2; /* SCSI-2 INQUIRY data format */
1208 buf[4] = 31; /* Additional length */
1209 buf[5] = 0; /* No special options */
1212 memcpy(buf + 8, common->inquiry_string, sizeof common->inquiry_string);
1216 static int do_request_sense(struct fsg_common *common, struct fsg_buffhd *bh)
1218 struct fsg_lun *curlun = common->curlun;
1219 u8 *buf = (u8 *) bh->buf;
1224 * From the SCSI-2 spec., section 7.9 (Unit attention condition):
1226 * If a REQUEST SENSE command is received from an initiator
1227 * with a pending unit attention condition (before the target
1228 * generates the contingent allegiance condition), then the
1229 * target shall either:
1230 * a) report any pending sense data and preserve the unit
1231 * attention condition on the logical unit, or,
1232 * b) report the unit attention condition, may discard any
1233 * pending sense data, and clear the unit attention
1234 * condition on the logical unit for that initiator.
1236 * FSG normally uses option a); enable this code to use option b).
1239 if (curlun && curlun->unit_attention_data != SS_NO_SENSE) {
1240 curlun->sense_data = curlun->unit_attention_data;
1241 curlun->unit_attention_data = SS_NO_SENSE;
1245 if (!curlun) { /* Unsupported LUNs are okay */
1246 common->bad_lun_okay = 1;
1247 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
1251 sd = curlun->sense_data;
1252 sdinfo = curlun->sense_data_info;
1253 valid = curlun->info_valid << 7;
1254 curlun->sense_data = SS_NO_SENSE;
1255 curlun->sense_data_info = 0;
1256 curlun->info_valid = 0;
1260 buf[0] = valid | 0x70; /* Valid, current error */
1262 put_unaligned_be32(sdinfo, &buf[3]); /* Sense information */
1263 buf[7] = 18 - 8; /* Additional sense length */
1269 static int do_read_capacity(struct fsg_common *common, struct fsg_buffhd *bh)
1271 struct fsg_lun *curlun = common->curlun;
1272 u32 lba = get_unaligned_be32(&common->cmnd[2]);
1273 int pmi = common->cmnd[8];
1274 u8 *buf = (u8 *)bh->buf;
1276 /* Check the PMI and LBA fields */
1277 if (pmi > 1 || (pmi == 0 && lba != 0)) {
1278 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1282 put_unaligned_be32(curlun->num_sectors - 1, &buf[0]);
1283 /* Max logical block */
1284 put_unaligned_be32(curlun->blksize, &buf[4]);/* Block length */
1288 static int do_read_header(struct fsg_common *common, struct fsg_buffhd *bh)
1290 struct fsg_lun *curlun = common->curlun;
1291 int msf = common->cmnd[1] & 0x02;
1292 u32 lba = get_unaligned_be32(&common->cmnd[2]);
1293 u8 *buf = (u8 *)bh->buf;
1295 if (common->cmnd[1] & ~0x02) { /* Mask away MSF */
1296 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1299 if (lba >= curlun->num_sectors) {
1300 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1305 buf[0] = 0x01; /* 2048 bytes of user data, rest is EC */
1306 store_cdrom_address(&buf[4], msf, lba);
1310 static int do_read_toc(struct fsg_common *common, struct fsg_buffhd *bh)
1312 struct fsg_lun *curlun = common->curlun;
1313 int msf = common->cmnd[1] & 0x02;
1314 int start_track = common->cmnd[6];
1315 u8 *buf = (u8 *)bh->buf;
1317 if ((common->cmnd[1] & ~0x02) != 0 || /* Mask away MSF */
1319 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1324 buf[1] = (20-2); /* TOC data length */
1325 buf[2] = 1; /* First track number */
1326 buf[3] = 1; /* Last track number */
1327 buf[5] = 0x16; /* Data track, copying allowed */
1328 buf[6] = 0x01; /* Only track is number 1 */
1329 store_cdrom_address(&buf[8], msf, 0);
1331 buf[13] = 0x16; /* Lead-out track is data */
1332 buf[14] = 0xAA; /* Lead-out track number */
1333 store_cdrom_address(&buf[16], msf, curlun->num_sectors);
1337 static int do_mode_sense(struct fsg_common *common, struct fsg_buffhd *bh)
1339 struct fsg_lun *curlun = common->curlun;
1340 int mscmnd = common->cmnd[0];
1341 u8 *buf = (u8 *) bh->buf;
1344 int changeable_values, all_pages;
1348 if ((common->cmnd[1] & ~0x08) != 0) { /* Mask away DBD */
1349 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1352 pc = common->cmnd[2] >> 6;
1353 page_code = common->cmnd[2] & 0x3f;
1355 curlun->sense_data = SS_SAVING_PARAMETERS_NOT_SUPPORTED;
1358 changeable_values = (pc == 1);
1359 all_pages = (page_code == 0x3f);
1362 * Write the mode parameter header. Fixed values are: default
1363 * medium type, no cache control (DPOFUA), and no block descriptors.
1364 * The only variable value is the WriteProtect bit. We will fill in
1365 * the mode data length later.
1368 if (mscmnd == MODE_SENSE) {
1369 buf[2] = (curlun->ro ? 0x80 : 0x00); /* WP, DPOFUA */
1372 } else { /* MODE_SENSE_10 */
1373 buf[3] = (curlun->ro ? 0x80 : 0x00); /* WP, DPOFUA */
1375 limit = 65535; /* Should really be FSG_BUFLEN */
1378 /* No block descriptors */
1381 * The mode pages, in numerical order. The only page we support
1382 * is the Caching page.
1384 if (page_code == 0x08 || all_pages) {
1386 buf[0] = 0x08; /* Page code */
1387 buf[1] = 10; /* Page length */
1388 memset(buf+2, 0, 10); /* None of the fields are changeable */
1390 if (!changeable_values) {
1391 buf[2] = 0x04; /* Write cache enable, */
1392 /* Read cache not disabled */
1393 /* No cache retention priorities */
1394 put_unaligned_be16(0xffff, &buf[4]);
1395 /* Don't disable prefetch */
1396 /* Minimum prefetch = 0 */
1397 put_unaligned_be16(0xffff, &buf[8]);
1398 /* Maximum prefetch */
1399 put_unaligned_be16(0xffff, &buf[10]);
1400 /* Maximum prefetch ceiling */
1406 * Check that a valid page was requested and the mode data length
1410 if (!valid_page || len > limit) {
1411 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1415 /* Store the mode data length */
1416 if (mscmnd == MODE_SENSE)
1419 put_unaligned_be16(len - 2, buf0);
1423 static int do_start_stop(struct fsg_common *common)
1425 struct fsg_lun *curlun = common->curlun;
1430 } else if (!curlun->removable) {
1431 curlun->sense_data = SS_INVALID_COMMAND;
1433 } else if ((common->cmnd[1] & ~0x01) != 0 || /* Mask away Immed */
1434 (common->cmnd[4] & ~0x03) != 0) { /* Mask LoEj, Start */
1435 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1439 loej = common->cmnd[4] & 0x02;
1440 start = common->cmnd[4] & 0x01;
1443 * Our emulation doesn't support mounting; the medium is
1444 * available for use as soon as it is loaded.
1447 if (!fsg_lun_is_open(curlun)) {
1448 curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
1454 /* Are we allowed to unload the media? */
1455 if (curlun->prevent_medium_removal) {
1456 LDBG(curlun, "unload attempt prevented\n");
1457 curlun->sense_data = SS_MEDIUM_REMOVAL_PREVENTED;
1464 /* Simulate an unload/eject */
1465 if (common->ops && common->ops->pre_eject) {
1466 int r = common->ops->pre_eject(common, curlun,
1467 curlun - common->luns);
1468 if (unlikely(r < 0))
1474 up_read(&common->filesem);
1475 down_write(&common->filesem);
1476 fsg_lun_close(curlun);
1477 up_write(&common->filesem);
1478 down_read(&common->filesem);
1480 return common->ops && common->ops->post_eject
1481 ? min(0, common->ops->post_eject(common, curlun,
1482 curlun - common->luns))
1486 static int do_prevent_allow(struct fsg_common *common)
1488 struct fsg_lun *curlun = common->curlun;
1491 if (!common->curlun) {
1493 } else if (!common->curlun->removable) {
1494 common->curlun->sense_data = SS_INVALID_COMMAND;
1498 prevent = common->cmnd[4] & 0x01;
1499 if ((common->cmnd[4] & ~0x01) != 0) { /* Mask away Prevent */
1500 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1504 if (curlun->prevent_medium_removal && !prevent)
1505 fsg_lun_fsync_sub(curlun);
1506 curlun->prevent_medium_removal = prevent;
1510 static int do_read_format_capacities(struct fsg_common *common,
1511 struct fsg_buffhd *bh)
1513 struct fsg_lun *curlun = common->curlun;
1514 u8 *buf = (u8 *) bh->buf;
1516 buf[0] = buf[1] = buf[2] = 0;
1517 buf[3] = 8; /* Only the Current/Maximum Capacity Descriptor */
1520 put_unaligned_be32(curlun->num_sectors, &buf[0]);
1521 /* Number of blocks */
1522 put_unaligned_be32(curlun->blksize, &buf[4]);/* Block length */
1523 buf[4] = 0x02; /* Current capacity */
1527 static int do_mode_select(struct fsg_common *common, struct fsg_buffhd *bh)
1529 struct fsg_lun *curlun = common->curlun;
1531 /* We don't support MODE SELECT */
1533 curlun->sense_data = SS_INVALID_COMMAND;
1538 /*-------------------------------------------------------------------------*/
1540 static int halt_bulk_in_endpoint(struct fsg_dev *fsg)
1544 rc = fsg_set_halt(fsg, fsg->bulk_in);
1546 VDBG(fsg, "delayed bulk-in endpoint halt\n");
1548 if (rc != -EAGAIN) {
1549 WARNING(fsg, "usb_ep_set_halt -> %d\n", rc);
1554 /* Wait for a short time and then try again */
1555 if (msleep_interruptible(100) != 0)
1557 rc = usb_ep_set_halt(fsg->bulk_in);
1562 static int wedge_bulk_in_endpoint(struct fsg_dev *fsg)
1566 DBG(fsg, "bulk-in set wedge\n");
1567 rc = usb_ep_set_wedge(fsg->bulk_in);
1569 VDBG(fsg, "delayed bulk-in endpoint wedge\n");
1571 if (rc != -EAGAIN) {
1572 WARNING(fsg, "usb_ep_set_wedge -> %d\n", rc);
1577 /* Wait for a short time and then try again */
1578 if (msleep_interruptible(100) != 0)
1580 rc = usb_ep_set_wedge(fsg->bulk_in);
1585 static int throw_away_data(struct fsg_common *common)
1587 struct fsg_buffhd *bh;
1591 for (bh = common->next_buffhd_to_drain;
1592 bh->state != BUF_STATE_EMPTY || common->usb_amount_left > 0;
1593 bh = common->next_buffhd_to_drain) {
1595 /* Throw away the data in a filled buffer */
1596 if (bh->state == BUF_STATE_FULL) {
1598 bh->state = BUF_STATE_EMPTY;
1599 common->next_buffhd_to_drain = bh->next;
1601 /* A short packet or an error ends everything */
1602 if (bh->outreq->actual < bh->bulk_out_intended_length ||
1603 bh->outreq->status != 0) {
1604 raise_exception(common,
1605 FSG_STATE_ABORT_BULK_OUT);
1611 /* Try to submit another request if we need one */
1612 bh = common->next_buffhd_to_fill;
1613 if (bh->state == BUF_STATE_EMPTY
1614 && common->usb_amount_left > 0) {
1615 amount = min(common->usb_amount_left, FSG_BUFLEN);
1618 * Except at the end of the transfer, amount will be
1619 * equal to the buffer size, which is divisible by
1620 * the bulk-out maxpacket size.
1622 set_bulk_out_req_length(common, bh, amount);
1623 if (!start_out_transfer(common, bh))
1624 /* Dunno what to do if common->fsg is NULL */
1626 common->next_buffhd_to_fill = bh->next;
1627 common->usb_amount_left -= amount;
1631 /* Otherwise wait for something to happen */
1632 rc = sleep_thread(common);
1639 static int finish_reply(struct fsg_common *common)
1641 struct fsg_buffhd *bh = common->next_buffhd_to_fill;
1644 switch (common->data_dir) {
1646 break; /* Nothing to send */
1649 * If we don't know whether the host wants to read or write,
1650 * this must be CB or CBI with an unknown command. We mustn't
1651 * try to send or receive any data. So stall both bulk pipes
1652 * if we can and wait for a reset.
1654 case DATA_DIR_UNKNOWN:
1655 if (!common->can_stall) {
1657 } else if (fsg_is_set(common)) {
1658 fsg_set_halt(common->fsg, common->fsg->bulk_out);
1659 rc = halt_bulk_in_endpoint(common->fsg);
1661 /* Don't know what to do if common->fsg is NULL */
1666 /* All but the last buffer of data must have already been sent */
1667 case DATA_DIR_TO_HOST:
1668 if (common->data_size == 0) {
1669 /* Nothing to send */
1671 /* Don't know what to do if common->fsg is NULL */
1672 } else if (!fsg_is_set(common)) {
1675 /* If there's no residue, simply send the last buffer */
1676 } else if (common->residue == 0) {
1677 bh->inreq->zero = 0;
1678 if (!start_in_transfer(common, bh))
1680 common->next_buffhd_to_fill = bh->next;
1683 * For Bulk-only, mark the end of the data with a short
1684 * packet. If we are allowed to stall, halt the bulk-in
1685 * endpoint. (Note: This violates the Bulk-Only Transport
1686 * specification, which requires us to pad the data if we
1687 * don't halt the endpoint. Presumably nobody will mind.)
1690 bh->inreq->zero = 1;
1691 if (!start_in_transfer(common, bh))
1693 common->next_buffhd_to_fill = bh->next;
1694 if (common->can_stall)
1695 rc = halt_bulk_in_endpoint(common->fsg);
1700 * We have processed all we want from the data the host has sent.
1701 * There may still be outstanding bulk-out requests.
1703 case DATA_DIR_FROM_HOST:
1704 if (common->residue == 0) {
1705 /* Nothing to receive */
1707 /* Did the host stop sending unexpectedly early? */
1708 } else if (common->short_packet_received) {
1709 raise_exception(common, FSG_STATE_ABORT_BULK_OUT);
1713 * We haven't processed all the incoming data. Even though
1714 * we may be allowed to stall, doing so would cause a race.
1715 * The controller may already have ACK'ed all the remaining
1716 * bulk-out packets, in which case the host wouldn't see a
1717 * STALL. Not realizing the endpoint was halted, it wouldn't
1718 * clear the halt -- leading to problems later on.
1721 } else if (common->can_stall) {
1722 if (fsg_is_set(common))
1723 fsg_set_halt(common->fsg,
1724 common->fsg->bulk_out);
1725 raise_exception(common, FSG_STATE_ABORT_BULK_OUT);
1730 * We can't stall. Read in the excess data and throw it
1734 rc = throw_away_data(common);
1741 static int send_status(struct fsg_common *common)
1743 struct fsg_lun *curlun = common->curlun;
1744 struct fsg_buffhd *bh;
1745 struct bulk_cs_wrap *csw;
1747 u8 status = USB_STATUS_PASS;
1750 /* Wait for the next buffer to become available */
1751 bh = common->next_buffhd_to_fill;
1752 while (bh->state != BUF_STATE_EMPTY) {
1753 rc = sleep_thread(common);
1759 sd = curlun->sense_data;
1760 sdinfo = curlun->sense_data_info;
1761 } else if (common->bad_lun_okay)
1764 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
1766 if (common->phase_error) {
1767 DBG(common, "sending phase-error status\n");
1768 status = USB_STATUS_PHASE_ERROR;
1769 sd = SS_INVALID_COMMAND;
1770 } else if (sd != SS_NO_SENSE) {
1771 DBG(common, "sending command-failure status\n");
1772 status = USB_STATUS_FAIL;
1773 VDBG(common, " sense data: SK x%02x, ASC x%02x, ASCQ x%02x;"
1775 SK(sd), ASC(sd), ASCQ(sd), sdinfo);
1778 /* Store and send the Bulk-only CSW */
1779 csw = (void *)bh->buf;
1781 csw->Signature = cpu_to_le32(USB_BULK_CS_SIG);
1782 csw->Tag = common->tag;
1783 csw->Residue = cpu_to_le32(common->residue);
1784 csw->Status = status;
1786 bh->inreq->length = USB_BULK_CS_WRAP_LEN;
1787 bh->inreq->zero = 0;
1788 if (!start_in_transfer(common, bh))
1789 /* Don't know what to do if common->fsg is NULL */
1792 common->next_buffhd_to_fill = bh->next;
1797 /*-------------------------------------------------------------------------*/
1800 * Check whether the command is properly formed and whether its data size
1801 * and direction agree with the values we already have.
1803 static int check_command(struct fsg_common *common, int cmnd_size,
1804 enum data_direction data_dir, unsigned int mask,
1805 int needs_medium, const char *name)
1808 int lun = common->cmnd[1] >> 5;
1809 static const char dirletter[4] = {'u', 'o', 'i', 'n'};
1811 struct fsg_lun *curlun;
1814 if (common->data_dir != DATA_DIR_UNKNOWN)
1815 sprintf(hdlen, ", H%c=%u", dirletter[(int) common->data_dir],
1817 VDBG(common, "SCSI command: %s; Dc=%d, D%c=%u; Hc=%d%s\n",
1818 name, cmnd_size, dirletter[(int) data_dir],
1819 common->data_size_from_cmnd, common->cmnd_size, hdlen);
1822 * We can't reply at all until we know the correct data direction
1825 if (common->data_size_from_cmnd == 0)
1826 data_dir = DATA_DIR_NONE;
1827 if (common->data_size < common->data_size_from_cmnd) {
1829 * Host data size < Device data size is a phase error.
1830 * Carry out the command, but only transfer as much as
1833 common->data_size_from_cmnd = common->data_size;
1834 common->phase_error = 1;
1836 common->residue = common->data_size;
1837 common->usb_amount_left = common->data_size;
1839 /* Conflicting data directions is a phase error */
1840 if (common->data_dir != data_dir && common->data_size_from_cmnd > 0) {
1841 common->phase_error = 1;
1845 /* Verify the length of the command itself */
1846 if (cmnd_size != common->cmnd_size) {
1849 * Special case workaround: There are plenty of buggy SCSI
1850 * implementations. Many have issues with cbw->Length
1851 * field passing a wrong command size. For those cases we
1852 * always try to work around the problem by using the length
1853 * sent by the host side provided it is at least as large
1854 * as the correct command length.
1855 * Examples of such cases would be MS-Windows, which issues
1856 * REQUEST SENSE with cbw->Length == 12 where it should
1857 * be 6, and xbox360 issuing INQUIRY, TEST UNIT READY and
1858 * REQUEST SENSE with cbw->Length == 10 where it should
1861 if (cmnd_size <= common->cmnd_size) {
1862 DBG(common, "%s is buggy! Expected length %d "
1863 "but we got %d\n", name,
1864 cmnd_size, common->cmnd_size);
1865 cmnd_size = common->cmnd_size;
1867 common->phase_error = 1;
1872 /* Check that the LUN values are consistent */
1873 if (common->lun != lun)
1874 DBG(common, "using LUN %d from CBW, not LUN %d from CDB\n",
1878 if (common->lun < common->nluns) {
1879 curlun = &common->luns[common->lun];
1880 common->curlun = curlun;
1881 if (common->cmnd[0] != REQUEST_SENSE) {
1882 curlun->sense_data = SS_NO_SENSE;
1883 curlun->sense_data_info = 0;
1884 curlun->info_valid = 0;
1887 common->curlun = NULL;
1889 common->bad_lun_okay = 0;
1892 * INQUIRY and REQUEST SENSE commands are explicitly allowed
1893 * to use unsupported LUNs; all others may not.
1895 if (common->cmnd[0] != INQUIRY &&
1896 common->cmnd[0] != REQUEST_SENSE) {
1897 DBG(common, "unsupported LUN %d\n", common->lun);
1903 * If a unit attention condition exists, only INQUIRY and
1904 * REQUEST SENSE commands are allowed; anything else must fail.
1906 if (curlun && curlun->unit_attention_data != SS_NO_SENSE &&
1907 common->cmnd[0] != INQUIRY &&
1908 common->cmnd[0] != REQUEST_SENSE) {
1909 curlun->sense_data = curlun->unit_attention_data;
1910 curlun->unit_attention_data = SS_NO_SENSE;
1914 /* Check that only command bytes listed in the mask are non-zero */
1915 common->cmnd[1] &= 0x1f; /* Mask away the LUN */
1916 for (i = 1; i < cmnd_size; ++i) {
1917 if (common->cmnd[i] && !(mask & (1 << i))) {
1919 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1924 /* If the medium isn't mounted and the command needs to access
1925 * it, return an error. */
1926 if (curlun && !fsg_lun_is_open(curlun) && needs_medium) {
1927 curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
1934 static int do_scsi_command(struct fsg_common *common)
1936 struct fsg_buffhd *bh;
1938 int reply = -EINVAL;
1940 static char unknown[16];
1944 /* Wait for the next buffer to become available for data or status */
1945 bh = common->next_buffhd_to_fill;
1946 common->next_buffhd_to_drain = bh;
1947 while (bh->state != BUF_STATE_EMPTY) {
1948 rc = sleep_thread(common);
1952 common->phase_error = 0;
1953 common->short_packet_received = 0;
1955 down_read(&common->filesem); /* We're using the backing file */
1956 switch (common->cmnd[0]) {
1959 common->data_size_from_cmnd = common->cmnd[4];
1960 reply = check_command(common, 6, DATA_DIR_TO_HOST,
1964 reply = do_inquiry(common, bh);
1968 common->data_size_from_cmnd = common->cmnd[4];
1969 reply = check_command(common, 6, DATA_DIR_FROM_HOST,
1973 reply = do_mode_select(common, bh);
1976 case MODE_SELECT_10:
1977 common->data_size_from_cmnd =
1978 get_unaligned_be16(&common->cmnd[7]);
1979 reply = check_command(common, 10, DATA_DIR_FROM_HOST,
1983 reply = do_mode_select(common, bh);
1987 common->data_size_from_cmnd = common->cmnd[4];
1988 reply = check_command(common, 6, DATA_DIR_TO_HOST,
1989 (1<<1) | (1<<2) | (1<<4), 0,
1992 reply = do_mode_sense(common, bh);
1996 common->data_size_from_cmnd =
1997 get_unaligned_be16(&common->cmnd[7]);
1998 reply = check_command(common, 10, DATA_DIR_TO_HOST,
1999 (1<<1) | (1<<2) | (3<<7), 0,
2002 reply = do_mode_sense(common, bh);
2005 case ALLOW_MEDIUM_REMOVAL:
2006 common->data_size_from_cmnd = 0;
2007 reply = check_command(common, 6, DATA_DIR_NONE,
2009 "PREVENT-ALLOW MEDIUM REMOVAL");
2011 reply = do_prevent_allow(common);
2015 i = common->cmnd[4];
2016 common->data_size_from_cmnd = (i == 0 ? 256 : i) <<
2017 common->curlun->blkbits;
2018 reply = check_command(common, 6, DATA_DIR_TO_HOST,
2022 reply = do_read(common);
2026 common->data_size_from_cmnd =
2027 get_unaligned_be16(&common->cmnd[7]) <<
2028 common->curlun->blkbits;
2029 reply = check_command(common, 10, DATA_DIR_TO_HOST,
2030 (1<<1) | (0xf<<2) | (3<<7), 1,
2033 reply = do_read(common);
2037 common->data_size_from_cmnd =
2038 get_unaligned_be32(&common->cmnd[6]) <<
2039 common->curlun->blkbits;
2040 reply = check_command(common, 12, DATA_DIR_TO_HOST,
2041 (1<<1) | (0xf<<2) | (0xf<<6), 1,
2044 reply = do_read(common);
2048 common->data_size_from_cmnd = 8;
2049 reply = check_command(common, 10, DATA_DIR_TO_HOST,
2050 (0xf<<2) | (1<<8), 1,
2053 reply = do_read_capacity(common, bh);
2057 if (!common->curlun || !common->curlun->cdrom)
2059 common->data_size_from_cmnd =
2060 get_unaligned_be16(&common->cmnd[7]);
2061 reply = check_command(common, 10, DATA_DIR_TO_HOST,
2062 (3<<7) | (0x1f<<1), 1,
2065 reply = do_read_header(common, bh);
2069 if (!common->curlun || !common->curlun->cdrom)
2071 common->data_size_from_cmnd =
2072 get_unaligned_be16(&common->cmnd[7]);
2073 reply = check_command(common, 10, DATA_DIR_TO_HOST,
2077 reply = do_read_toc(common, bh);
2080 case READ_FORMAT_CAPACITIES:
2081 common->data_size_from_cmnd =
2082 get_unaligned_be16(&common->cmnd[7]);
2083 reply = check_command(common, 10, DATA_DIR_TO_HOST,
2085 "READ FORMAT CAPACITIES");
2087 reply = do_read_format_capacities(common, bh);
2091 common->data_size_from_cmnd = common->cmnd[4];
2092 reply = check_command(common, 6, DATA_DIR_TO_HOST,
2096 reply = do_request_sense(common, bh);
2100 common->data_size_from_cmnd = 0;
2101 reply = check_command(common, 6, DATA_DIR_NONE,
2105 reply = do_start_stop(common);
2108 case SYNCHRONIZE_CACHE:
2109 common->data_size_from_cmnd = 0;
2110 reply = check_command(common, 10, DATA_DIR_NONE,
2111 (0xf<<2) | (3<<7), 1,
2112 "SYNCHRONIZE CACHE");
2114 reply = do_synchronize_cache(common);
2117 case TEST_UNIT_READY:
2118 common->data_size_from_cmnd = 0;
2119 reply = check_command(common, 6, DATA_DIR_NONE,
2125 * Although optional, this command is used by MS-Windows. We
2126 * support a minimal version: BytChk must be 0.
2129 common->data_size_from_cmnd = 0;
2130 reply = check_command(common, 10, DATA_DIR_NONE,
2131 (1<<1) | (0xf<<2) | (3<<7), 1,
2134 reply = do_verify(common);
2138 i = common->cmnd[4];
2139 common->data_size_from_cmnd = (i == 0 ? 256 : i) <<
2140 common->curlun->blkbits;
2141 reply = check_command(common, 6, DATA_DIR_FROM_HOST,
2145 reply = do_write(common);
2149 common->data_size_from_cmnd =
2150 get_unaligned_be16(&common->cmnd[7]) <<
2151 common->curlun->blkbits;
2152 reply = check_command(common, 10, DATA_DIR_FROM_HOST,
2153 (1<<1) | (0xf<<2) | (3<<7), 1,
2156 reply = do_write(common);
2160 common->data_size_from_cmnd =
2161 get_unaligned_be32(&common->cmnd[6]) <<
2162 common->curlun->blkbits;
2163 reply = check_command(common, 12, DATA_DIR_FROM_HOST,
2164 (1<<1) | (0xf<<2) | (0xf<<6), 1,
2167 reply = do_write(common);
2171 * Some mandatory commands that we recognize but don't implement.
2172 * They don't mean much in this setting. It's left as an exercise
2173 * for anyone interested to implement RESERVE and RELEASE in terms
2179 case SEND_DIAGNOSTIC:
2184 common->data_size_from_cmnd = 0;
2185 sprintf(unknown, "Unknown x%02x", common->cmnd[0]);
2186 reply = check_command(common, common->cmnd_size,
2187 DATA_DIR_UNKNOWN, ~0, 0, unknown);
2189 common->curlun->sense_data = SS_INVALID_COMMAND;
2194 up_read(&common->filesem);
2196 if (reply == -EINTR || signal_pending(current))
2199 /* Set up the single reply buffer for finish_reply() */
2200 if (reply == -EINVAL)
2201 reply = 0; /* Error reply length */
2202 if (reply >= 0 && common->data_dir == DATA_DIR_TO_HOST) {
2203 reply = min((u32)reply, common->data_size_from_cmnd);
2204 bh->inreq->length = reply;
2205 bh->state = BUF_STATE_FULL;
2206 common->residue -= reply;
2207 } /* Otherwise it's already set */
2213 /*-------------------------------------------------------------------------*/
2215 static int received_cbw(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2217 struct usb_request *req = bh->outreq;
2218 struct fsg_bulk_cb_wrap *cbw = req->buf;
2219 struct fsg_common *common = fsg->common;
2221 /* Was this a real packet? Should it be ignored? */
2222 if (req->status || test_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags))
2225 /* Is the CBW valid? */
2226 if (req->actual != USB_BULK_CB_WRAP_LEN ||
2227 cbw->Signature != cpu_to_le32(
2229 DBG(fsg, "invalid CBW: len %u sig 0x%x\n",
2231 le32_to_cpu(cbw->Signature));
2234 * The Bulk-only spec says we MUST stall the IN endpoint
2235 * (6.6.1), so it's unavoidable. It also says we must
2236 * retain this state until the next reset, but there's
2237 * no way to tell the controller driver it should ignore
2238 * Clear-Feature(HALT) requests.
2240 * We aren't required to halt the OUT endpoint; instead
2241 * we can simply accept and discard any data received
2242 * until the next reset.
2244 wedge_bulk_in_endpoint(fsg);
2245 set_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
2249 /* Is the CBW meaningful? */
2250 if (cbw->Lun >= FSG_MAX_LUNS || cbw->Flags & ~USB_BULK_IN_FLAG ||
2251 cbw->Length <= 0 || cbw->Length > MAX_COMMAND_SIZE) {
2252 DBG(fsg, "non-meaningful CBW: lun = %u, flags = 0x%x, "
2254 cbw->Lun, cbw->Flags, cbw->Length);
2257 * We can do anything we want here, so let's stall the
2258 * bulk pipes if we are allowed to.
2260 if (common->can_stall) {
2261 fsg_set_halt(fsg, fsg->bulk_out);
2262 halt_bulk_in_endpoint(fsg);
2267 /* Save the command for later */
2268 common->cmnd_size = cbw->Length;
2269 memcpy(common->cmnd, cbw->CDB, common->cmnd_size);
2270 if (cbw->Flags & USB_BULK_IN_FLAG)
2271 common->data_dir = DATA_DIR_TO_HOST;
2273 common->data_dir = DATA_DIR_FROM_HOST;
2274 common->data_size = le32_to_cpu(cbw->DataTransferLength);
2275 if (common->data_size == 0)
2276 common->data_dir = DATA_DIR_NONE;
2277 common->lun = cbw->Lun;
2278 common->tag = cbw->Tag;
2282 static int get_next_command(struct fsg_common *common)
2284 struct fsg_buffhd *bh;
2287 /* Wait for the next buffer to become available */
2288 bh = common->next_buffhd_to_fill;
2289 while (bh->state != BUF_STATE_EMPTY) {
2290 rc = sleep_thread(common);
2295 /* Queue a request to read a Bulk-only CBW */
2296 set_bulk_out_req_length(common, bh, USB_BULK_CB_WRAP_LEN);
2297 if (!start_out_transfer(common, bh))
2298 /* Don't know what to do if common->fsg is NULL */
2302 * We will drain the buffer in software, which means we
2303 * can reuse it for the next filling. No need to advance
2304 * next_buffhd_to_fill.
2307 /* Wait for the CBW to arrive */
2308 while (bh->state != BUF_STATE_FULL) {
2309 rc = sleep_thread(common);
2314 rc = fsg_is_set(common) ? received_cbw(common->fsg, bh) : -EIO;
2315 bh->state = BUF_STATE_EMPTY;
2321 /*-------------------------------------------------------------------------*/
2323 static int alloc_request(struct fsg_common *common, struct usb_ep *ep,
2324 struct usb_request **preq)
2326 *preq = usb_ep_alloc_request(ep, GFP_ATOMIC);
2329 ERROR(common, "can't allocate request for %s\n", ep->name);
2333 /* Reset interface setting and re-init endpoint state (toggle etc). */
2334 static int do_set_interface(struct fsg_common *common, struct fsg_dev *new_fsg)
2336 struct fsg_dev *fsg;
2339 if (common->running)
2340 DBG(common, "reset interface\n");
2343 /* Deallocate the requests */
2347 for (i = 0; i < fsg_num_buffers; ++i) {
2348 struct fsg_buffhd *bh = &common->buffhds[i];
2351 usb_ep_free_request(fsg->bulk_in, bh->inreq);
2355 usb_ep_free_request(fsg->bulk_out, bh->outreq);
2360 /* Disable the endpoints */
2361 if (fsg->bulk_in_enabled) {
2362 usb_ep_disable(fsg->bulk_in);
2363 fsg->bulk_in_enabled = 0;
2365 if (fsg->bulk_out_enabled) {
2366 usb_ep_disable(fsg->bulk_out);
2367 fsg->bulk_out_enabled = 0;
2371 wake_up(&common->fsg_wait);
2374 common->running = 0;
2378 common->fsg = new_fsg;
2381 /* Enable the endpoints */
2382 rc = config_ep_by_speed(common->gadget, &(fsg->function), fsg->bulk_in);
2385 rc = usb_ep_enable(fsg->bulk_in);
2388 fsg->bulk_in->driver_data = common;
2389 fsg->bulk_in_enabled = 1;
2391 rc = config_ep_by_speed(common->gadget, &(fsg->function),
2395 rc = usb_ep_enable(fsg->bulk_out);
2398 fsg->bulk_out->driver_data = common;
2399 fsg->bulk_out_enabled = 1;
2400 common->bulk_out_maxpacket = usb_endpoint_maxp(fsg->bulk_out->desc);
2401 clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
2403 /* Allocate the requests */
2404 for (i = 0; i < fsg_num_buffers; ++i) {
2405 struct fsg_buffhd *bh = &common->buffhds[i];
2407 rc = alloc_request(common, fsg->bulk_in, &bh->inreq);
2410 rc = alloc_request(common, fsg->bulk_out, &bh->outreq);
2413 bh->inreq->buf = bh->outreq->buf = bh->buf;
2414 bh->inreq->context = bh->outreq->context = bh;
2415 bh->inreq->complete = bulk_in_complete;
2416 bh->outreq->complete = bulk_out_complete;
2419 common->running = 1;
2420 for (i = 0; i < common->nluns; ++i)
2421 common->luns[i].unit_attention_data = SS_RESET_OCCURRED;
2426 /****************************** ALT CONFIGS ******************************/
2428 static int fsg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
2430 struct fsg_dev *fsg = fsg_from_func(f);
2431 fsg->common->new_fsg = fsg;
2432 raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
2433 return USB_GADGET_DELAYED_STATUS;
2436 static void fsg_disable(struct usb_function *f)
2438 struct fsg_dev *fsg = fsg_from_func(f);
2439 fsg->common->new_fsg = NULL;
2440 raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
2444 /*-------------------------------------------------------------------------*/
2446 static void handle_exception(struct fsg_common *common)
2450 struct fsg_buffhd *bh;
2451 enum fsg_state old_state;
2452 struct fsg_lun *curlun;
2453 unsigned int exception_req_tag;
2456 * Clear the existing signals. Anything but SIGUSR1 is converted
2457 * into a high-priority EXIT exception.
2461 dequeue_signal_lock(current, ¤t->blocked, &info);
2464 if (sig != SIGUSR1) {
2465 if (common->state < FSG_STATE_EXIT)
2466 DBG(common, "Main thread exiting on signal\n");
2467 raise_exception(common, FSG_STATE_EXIT);
2471 /* Cancel all the pending transfers */
2472 if (likely(common->fsg)) {
2473 for (i = 0; i < fsg_num_buffers; ++i) {
2474 bh = &common->buffhds[i];
2476 usb_ep_dequeue(common->fsg->bulk_in, bh->inreq);
2477 if (bh->outreq_busy)
2478 usb_ep_dequeue(common->fsg->bulk_out,
2482 /* Wait until everything is idle */
2485 for (i = 0; i < fsg_num_buffers; ++i) {
2486 bh = &common->buffhds[i];
2487 num_active += bh->inreq_busy + bh->outreq_busy;
2489 if (num_active == 0)
2491 if (sleep_thread(common))
2495 /* Clear out the controller's fifos */
2496 if (common->fsg->bulk_in_enabled)
2497 usb_ep_fifo_flush(common->fsg->bulk_in);
2498 if (common->fsg->bulk_out_enabled)
2499 usb_ep_fifo_flush(common->fsg->bulk_out);
2503 * Reset the I/O buffer states and pointers, the SCSI
2504 * state, and the exception. Then invoke the handler.
2506 spin_lock_irq(&common->lock);
2508 for (i = 0; i < fsg_num_buffers; ++i) {
2509 bh = &common->buffhds[i];
2510 bh->state = BUF_STATE_EMPTY;
2512 common->next_buffhd_to_fill = &common->buffhds[0];
2513 common->next_buffhd_to_drain = &common->buffhds[0];
2514 exception_req_tag = common->exception_req_tag;
2515 old_state = common->state;
2517 if (old_state == FSG_STATE_ABORT_BULK_OUT)
2518 common->state = FSG_STATE_STATUS_PHASE;
2520 for (i = 0; i < common->nluns; ++i) {
2521 curlun = &common->luns[i];
2522 curlun->prevent_medium_removal = 0;
2523 curlun->sense_data = SS_NO_SENSE;
2524 curlun->unit_attention_data = SS_NO_SENSE;
2525 curlun->sense_data_info = 0;
2526 curlun->info_valid = 0;
2528 common->state = FSG_STATE_IDLE;
2530 spin_unlock_irq(&common->lock);
2532 /* Carry out any extra actions required for the exception */
2533 switch (old_state) {
2534 case FSG_STATE_ABORT_BULK_OUT:
2535 send_status(common);
2536 spin_lock_irq(&common->lock);
2537 if (common->state == FSG_STATE_STATUS_PHASE)
2538 common->state = FSG_STATE_IDLE;
2539 spin_unlock_irq(&common->lock);
2542 case FSG_STATE_RESET:
2544 * In case we were forced against our will to halt a
2545 * bulk endpoint, clear the halt now. (The SuperH UDC
2548 if (!fsg_is_set(common))
2550 if (test_and_clear_bit(IGNORE_BULK_OUT,
2551 &common->fsg->atomic_bitflags))
2552 usb_ep_clear_halt(common->fsg->bulk_in);
2554 if (common->ep0_req_tag == exception_req_tag)
2555 ep0_queue(common); /* Complete the status stage */
2558 * Technically this should go here, but it would only be
2559 * a waste of time. Ditto for the INTERFACE_CHANGE and
2560 * CONFIG_CHANGE cases.
2562 /* for (i = 0; i < common->nluns; ++i) */
2563 /* common->luns[i].unit_attention_data = */
2564 /* SS_RESET_OCCURRED; */
2567 case FSG_STATE_CONFIG_CHANGE:
2568 do_set_interface(common, common->new_fsg);
2569 if (common->new_fsg)
2570 usb_composite_setup_continue(common->cdev);
2573 case FSG_STATE_EXIT:
2574 case FSG_STATE_TERMINATED:
2575 do_set_interface(common, NULL); /* Free resources */
2576 spin_lock_irq(&common->lock);
2577 common->state = FSG_STATE_TERMINATED; /* Stop the thread */
2578 spin_unlock_irq(&common->lock);
2581 case FSG_STATE_INTERFACE_CHANGE:
2582 case FSG_STATE_DISCONNECT:
2583 case FSG_STATE_COMMAND_PHASE:
2584 case FSG_STATE_DATA_PHASE:
2585 case FSG_STATE_STATUS_PHASE:
2586 case FSG_STATE_IDLE:
2592 /*-------------------------------------------------------------------------*/
2594 static int fsg_main_thread(void *common_)
2596 struct fsg_common *common = common_;
2599 * Allow the thread to be killed by a signal, but set the signal mask
2600 * to block everything but INT, TERM, KILL, and USR1.
2602 allow_signal(SIGINT);
2603 allow_signal(SIGTERM);
2604 allow_signal(SIGKILL);
2605 allow_signal(SIGUSR1);
2607 /* Allow the thread to be frozen */
2611 * Arrange for userspace references to be interpreted as kernel
2612 * pointers. That way we can pass a kernel pointer to a routine
2613 * that expects a __user pointer and it will work okay.
2618 while (common->state != FSG_STATE_TERMINATED) {
2619 if (exception_in_progress(common) || signal_pending(current)) {
2620 handle_exception(common);
2624 if (!common->running) {
2625 sleep_thread(common);
2629 if (get_next_command(common))
2632 spin_lock_irq(&common->lock);
2633 if (!exception_in_progress(common))
2634 common->state = FSG_STATE_DATA_PHASE;
2635 spin_unlock_irq(&common->lock);
2637 if (do_scsi_command(common) || finish_reply(common))
2640 spin_lock_irq(&common->lock);
2641 if (!exception_in_progress(common))
2642 common->state = FSG_STATE_STATUS_PHASE;
2643 spin_unlock_irq(&common->lock);
2645 if (send_status(common))
2648 spin_lock_irq(&common->lock);
2649 if (!exception_in_progress(common))
2650 common->state = FSG_STATE_IDLE;
2651 spin_unlock_irq(&common->lock);
2654 spin_lock_irq(&common->lock);
2655 common->thread_task = NULL;
2656 spin_unlock_irq(&common->lock);
2658 if (!common->ops || !common->ops->thread_exits
2659 || common->ops->thread_exits(common) < 0) {
2660 struct fsg_lun *curlun = common->luns;
2661 unsigned i = common->nluns;
2663 down_write(&common->filesem);
2664 for (; i--; ++curlun) {
2665 if (!fsg_lun_is_open(curlun))
2668 fsg_lun_close(curlun);
2669 curlun->unit_attention_data = SS_MEDIUM_NOT_PRESENT;
2671 up_write(&common->filesem);
2674 /* Let fsg_unbind() know the thread has exited */
2675 complete_and_exit(&common->thread_notifier, 0);
2679 /*************************** DEVICE ATTRIBUTES ***************************/
2681 /* Write permission is checked per LUN in store_*() functions. */
2682 static DEVICE_ATTR(ro, 0644, fsg_show_ro, fsg_store_ro);
2683 static DEVICE_ATTR(nofua, 0644, fsg_show_nofua, fsg_store_nofua);
2684 static DEVICE_ATTR(file, 0644, fsg_show_file, fsg_store_file);
2687 /****************************** FSG COMMON ******************************/
2689 static void fsg_common_release(struct kref *ref);
2691 static void fsg_lun_release(struct device *dev)
2693 /* Nothing needs to be done */
2696 static inline void fsg_common_get(struct fsg_common *common)
2698 kref_get(&common->ref);
2701 static inline void fsg_common_put(struct fsg_common *common)
2703 kref_put(&common->ref, fsg_common_release);
2706 static struct fsg_common *fsg_common_init(struct fsg_common *common,
2707 struct usb_composite_dev *cdev,
2708 struct fsg_config *cfg)
2710 struct usb_gadget *gadget = cdev->gadget;
2711 struct fsg_buffhd *bh;
2712 struct fsg_lun *curlun;
2713 struct fsg_lun_config *lcfg;
2717 rc = fsg_num_buffers_validate();
2721 /* Find out how many LUNs there should be */
2723 if (nluns < 1 || nluns > FSG_MAX_LUNS) {
2724 dev_err(&gadget->dev, "invalid number of LUNs: %u\n", nluns);
2725 return ERR_PTR(-EINVAL);
2730 common = kzalloc(sizeof *common, GFP_KERNEL);
2732 return ERR_PTR(-ENOMEM);
2733 common->free_storage_on_release = 1;
2735 memset(common, 0, sizeof *common);
2736 common->free_storage_on_release = 0;
2739 common->buffhds = kcalloc(fsg_num_buffers,
2740 sizeof *(common->buffhds), GFP_KERNEL);
2741 if (!common->buffhds) {
2742 if (common->free_storage_on_release)
2744 return ERR_PTR(-ENOMEM);
2747 common->ops = cfg->ops;
2748 common->private_data = cfg->private_data;
2750 common->gadget = gadget;
2751 common->ep0 = gadget->ep0;
2752 common->ep0req = cdev->req;
2753 common->cdev = cdev;
2755 /* Maybe allocate device-global string IDs, and patch descriptors */
2756 if (fsg_strings[FSG_STRING_INTERFACE].id == 0) {
2757 rc = usb_string_id(cdev);
2758 if (unlikely(rc < 0))
2760 fsg_strings[FSG_STRING_INTERFACE].id = rc;
2761 fsg_intf_desc.iInterface = rc;
2765 * Create the LUNs, open their backing files, and register the
2766 * LUN devices in sysfs.
2768 curlun = kzalloc(nluns * sizeof *curlun, GFP_KERNEL);
2769 if (unlikely(!curlun)) {
2773 common->luns = curlun;
2775 init_rwsem(&common->filesem);
2777 for (i = 0, lcfg = cfg->luns; i < nluns; ++i, ++curlun, ++lcfg) {
2778 curlun->cdrom = !!lcfg->cdrom;
2779 curlun->ro = lcfg->cdrom || lcfg->ro;
2780 curlun->initially_ro = curlun->ro;
2781 curlun->removable = lcfg->removable;
2782 curlun->dev.release = fsg_lun_release;
2783 curlun->dev.parent = &gadget->dev;
2784 /* curlun->dev.driver = &fsg_driver.driver; XXX */
2785 dev_set_drvdata(&curlun->dev, &common->filesem);
2786 dev_set_name(&curlun->dev,
2787 cfg->lun_name_format
2788 ? cfg->lun_name_format
2792 rc = device_register(&curlun->dev);
2794 INFO(common, "failed to register LUN%d: %d\n", i, rc);
2796 put_device(&curlun->dev);
2800 rc = device_create_file(&curlun->dev, &dev_attr_ro);
2803 rc = device_create_file(&curlun->dev, &dev_attr_file);
2806 rc = device_create_file(&curlun->dev, &dev_attr_nofua);
2810 if (lcfg->filename) {
2811 rc = fsg_lun_open(curlun, lcfg->filename);
2814 } else if (!curlun->removable) {
2815 ERROR(common, "no file given for LUN%d\n", i);
2820 common->nluns = nluns;
2822 /* Data buffers cyclic list */
2823 bh = common->buffhds;
2824 i = fsg_num_buffers;
2825 goto buffhds_first_it;
2830 bh->buf = kmalloc(FSG_BUFLEN, GFP_KERNEL);
2831 if (unlikely(!bh->buf)) {
2836 bh->next = common->buffhds;
2838 /* Prepare inquiryString */
2839 if (cfg->release != 0xffff) {
2842 i = usb_gadget_controller_number(gadget);
2846 WARNING(common, "controller '%s' not recognized\n",
2851 snprintf(common->inquiry_string, sizeof common->inquiry_string,
2852 "%-8s%-16s%04x", cfg->vendor_name ?: "Linux",
2853 /* Assume product name dependent on the first LUN */
2854 cfg->product_name ?: (common->luns->cdrom
2855 ? "File-Stor Gadget"
2856 : "File-CD Gadget"),
2860 * Some peripheral controllers are known not to be able to
2861 * halt bulk endpoints correctly. If one of them is present,
2864 common->can_stall = cfg->can_stall &&
2865 !(gadget_is_at91(common->gadget));
2867 spin_lock_init(&common->lock);
2868 kref_init(&common->ref);
2870 /* Tell the thread to start working */
2871 common->thread_task =
2872 kthread_create(fsg_main_thread, common,
2873 cfg->thread_name ?: "file-storage");
2874 if (IS_ERR(common->thread_task)) {
2875 rc = PTR_ERR(common->thread_task);
2878 init_completion(&common->thread_notifier);
2879 init_waitqueue_head(&common->fsg_wait);
2882 INFO(common, FSG_DRIVER_DESC ", version: " FSG_DRIVER_VERSION "\n");
2883 INFO(common, "Number of LUNs=%d\n", common->nluns);
2885 pathbuf = kmalloc(PATH_MAX, GFP_KERNEL);
2886 for (i = 0, nluns = common->nluns, curlun = common->luns;
2889 char *p = "(no medium)";
2890 if (fsg_lun_is_open(curlun)) {
2893 p = d_path(&curlun->filp->f_path,
2899 LINFO(curlun, "LUN: %s%s%sfile: %s\n",
2900 curlun->removable ? "removable " : "",
2901 curlun->ro ? "read only " : "",
2902 curlun->cdrom ? "CD-ROM " : "",
2907 DBG(common, "I/O thread pid: %d\n", task_pid_nr(common->thread_task));
2909 wake_up_process(common->thread_task);
2914 common->nluns = i + 1;
2916 common->state = FSG_STATE_TERMINATED; /* The thread is dead */
2917 /* Call fsg_common_release() directly, ref might be not initialised. */
2918 fsg_common_release(&common->ref);
2922 static void fsg_common_release(struct kref *ref)
2924 struct fsg_common *common = container_of(ref, struct fsg_common, ref);
2926 /* If the thread isn't already dead, tell it to exit now */
2927 if (common->state != FSG_STATE_TERMINATED) {
2928 raise_exception(common, FSG_STATE_EXIT);
2929 wait_for_completion(&common->thread_notifier);
2932 if (likely(common->luns)) {
2933 struct fsg_lun *lun = common->luns;
2934 unsigned i = common->nluns;
2936 /* In error recovery common->nluns may be zero. */
2937 for (; i; --i, ++lun) {
2938 device_remove_file(&lun->dev, &dev_attr_nofua);
2939 device_remove_file(&lun->dev, &dev_attr_ro);
2940 device_remove_file(&lun->dev, &dev_attr_file);
2942 device_unregister(&lun->dev);
2945 kfree(common->luns);
2949 struct fsg_buffhd *bh = common->buffhds;
2950 unsigned i = fsg_num_buffers;
2953 } while (++bh, --i);
2956 kfree(common->buffhds);
2957 if (common->free_storage_on_release)
2962 /*-------------------------------------------------------------------------*/
2964 static void fsg_unbind(struct usb_configuration *c, struct usb_function *f)
2966 struct fsg_dev *fsg = fsg_from_func(f);
2967 struct fsg_common *common = fsg->common;
2969 DBG(fsg, "unbind\n");
2970 if (fsg->common->fsg == fsg) {
2971 fsg->common->new_fsg = NULL;
2972 raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
2973 /* FIXME: make interruptible or killable somehow? */
2974 wait_event(common->fsg_wait, common->fsg != fsg);
2977 fsg_common_put(common);
2978 usb_free_descriptors(fsg->function.descriptors);
2979 usb_free_descriptors(fsg->function.hs_descriptors);
2980 usb_free_descriptors(fsg->function.ss_descriptors);
2984 static int fsg_bind(struct usb_configuration *c, struct usb_function *f)
2986 struct fsg_dev *fsg = fsg_from_func(f);
2987 struct usb_gadget *gadget = c->cdev->gadget;
2991 fsg->gadget = gadget;
2994 i = usb_interface_id(c, f);
2997 fsg_intf_desc.bInterfaceNumber = i;
2998 fsg->interface_number = i;
3000 /* Find all the endpoints we will use */
3001 ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_in_desc);
3004 ep->driver_data = fsg->common; /* claim the endpoint */
3007 ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_out_desc);
3010 ep->driver_data = fsg->common; /* claim the endpoint */
3013 /* Copy descriptors */
3014 f->descriptors = usb_copy_descriptors(fsg_fs_function);
3015 if (unlikely(!f->descriptors))
3018 if (gadget_is_dualspeed(gadget)) {
3019 /* Assume endpoint addresses are the same for both speeds */
3020 fsg_hs_bulk_in_desc.bEndpointAddress =
3021 fsg_fs_bulk_in_desc.bEndpointAddress;
3022 fsg_hs_bulk_out_desc.bEndpointAddress =
3023 fsg_fs_bulk_out_desc.bEndpointAddress;
3024 f->hs_descriptors = usb_copy_descriptors(fsg_hs_function);
3025 if (unlikely(!f->hs_descriptors)) {
3026 usb_free_descriptors(f->descriptors);
3031 if (gadget_is_superspeed(gadget)) {
3034 /* Calculate bMaxBurst, we know packet size is 1024 */
3035 max_burst = min_t(unsigned, FSG_BUFLEN / 1024, 15);
3037 fsg_ss_bulk_in_desc.bEndpointAddress =
3038 fsg_fs_bulk_in_desc.bEndpointAddress;
3039 fsg_ss_bulk_in_comp_desc.bMaxBurst = max_burst;
3041 fsg_ss_bulk_out_desc.bEndpointAddress =
3042 fsg_fs_bulk_out_desc.bEndpointAddress;
3043 fsg_ss_bulk_out_comp_desc.bMaxBurst = max_burst;
3045 f->ss_descriptors = usb_copy_descriptors(fsg_ss_function);
3046 if (unlikely(!f->ss_descriptors)) {
3047 usb_free_descriptors(f->hs_descriptors);
3048 usb_free_descriptors(f->descriptors);
3056 ERROR(fsg, "unable to autoconfigure all endpoints\n");
3061 /****************************** ADD FUNCTION ******************************/
3063 static struct usb_gadget_strings *fsg_strings_array[] = {
3068 static int fsg_bind_config(struct usb_composite_dev *cdev,
3069 struct usb_configuration *c,
3070 struct fsg_common *common)
3072 struct fsg_dev *fsg;
3075 fsg = kzalloc(sizeof *fsg, GFP_KERNEL);
3079 fsg->function.name = FSG_DRIVER_DESC;
3080 fsg->function.strings = fsg_strings_array;
3081 fsg->function.bind = fsg_bind;
3082 fsg->function.unbind = fsg_unbind;
3083 fsg->function.setup = fsg_setup;
3084 fsg->function.set_alt = fsg_set_alt;
3085 fsg->function.disable = fsg_disable;
3087 fsg->common = common;
3089 * Our caller holds a reference to common structure so we
3090 * don't have to be worry about it being freed until we return
3091 * from this function. So instead of incrementing counter now
3092 * and decrement in error recovery we increment it only when
3093 * call to usb_add_function() was successful.
3096 rc = usb_add_function(c, &fsg->function);
3100 fsg_common_get(fsg->common);
3104 static inline int __deprecated __maybe_unused
3105 fsg_add(struct usb_composite_dev *cdev, struct usb_configuration *c,
3106 struct fsg_common *common)
3108 return fsg_bind_config(cdev, c, common);
3112 /************************* Module parameters *************************/
3114 struct fsg_module_parameters {
3115 char *file[FSG_MAX_LUNS];
3116 bool ro[FSG_MAX_LUNS];
3117 bool removable[FSG_MAX_LUNS];
3118 bool cdrom[FSG_MAX_LUNS];
3119 bool nofua[FSG_MAX_LUNS];
3121 unsigned int file_count, ro_count, removable_count, cdrom_count;
3122 unsigned int nofua_count;
3123 unsigned int luns; /* nluns */
3124 bool stall; /* can_stall */
3127 #define _FSG_MODULE_PARAM_ARRAY(prefix, params, name, type, desc) \
3128 module_param_array_named(prefix ## name, params.name, type, \
3129 &prefix ## params.name ## _count, \
3131 MODULE_PARM_DESC(prefix ## name, desc)
3133 #define _FSG_MODULE_PARAM(prefix, params, name, type, desc) \
3134 module_param_named(prefix ## name, params.name, type, \
3136 MODULE_PARM_DESC(prefix ## name, desc)
3138 #define FSG_MODULE_PARAMETERS(prefix, params) \
3139 _FSG_MODULE_PARAM_ARRAY(prefix, params, file, charp, \
3140 "names of backing files or devices"); \
3141 _FSG_MODULE_PARAM_ARRAY(prefix, params, ro, bool, \
3142 "true to force read-only"); \
3143 _FSG_MODULE_PARAM_ARRAY(prefix, params, removable, bool, \
3144 "true to simulate removable media"); \
3145 _FSG_MODULE_PARAM_ARRAY(prefix, params, cdrom, bool, \
3146 "true to simulate CD-ROM instead of disk"); \
3147 _FSG_MODULE_PARAM_ARRAY(prefix, params, nofua, bool, \
3148 "true to ignore SCSI WRITE(10,12) FUA bit"); \
3149 _FSG_MODULE_PARAM(prefix, params, luns, uint, \
3150 "number of LUNs"); \
3151 _FSG_MODULE_PARAM(prefix, params, stall, bool, \
3152 "false to prevent bulk stalls")
3155 fsg_config_from_params(struct fsg_config *cfg,
3156 const struct fsg_module_parameters *params)
3158 struct fsg_lun_config *lun;
3161 /* Configure LUNs */
3163 min(params->luns ?: (params->file_count ?: 1u),
3164 (unsigned)FSG_MAX_LUNS);
3165 for (i = 0, lun = cfg->luns; i < cfg->nluns; ++i, ++lun) {
3166 lun->ro = !!params->ro[i];
3167 lun->cdrom = !!params->cdrom[i];
3168 lun->removable = /* Removable by default */
3169 params->removable_count <= i || params->removable[i];
3171 params->file_count > i && params->file[i][0]
3176 /* Let MSF use defaults */
3177 cfg->lun_name_format = 0;
3178 cfg->thread_name = 0;
3179 cfg->vendor_name = 0;
3180 cfg->product_name = 0;
3181 cfg->release = 0xffff;
3184 cfg->private_data = NULL;
3187 cfg->can_stall = params->stall;
3190 static inline struct fsg_common *
3191 fsg_common_from_params(struct fsg_common *common,
3192 struct usb_composite_dev *cdev,
3193 const struct fsg_module_parameters *params)
3194 __attribute__((unused));
3195 static inline struct fsg_common *
3196 fsg_common_from_params(struct fsg_common *common,
3197 struct usb_composite_dev *cdev,
3198 const struct fsg_module_parameters *params)
3200 struct fsg_config cfg;
3201 fsg_config_from_params(&cfg, params);
3202 return fsg_common_init(common, cdev, &cfg);