drivers/usb/gadget/function/f_mass_storage.c

   1 /*
   2  * f_mass_storage.c -- Mass Storage USB Composite Function
   3  *
   4  * Copyright (C) 2003-2008 Alan Stern
   5  * Copyright (C) 2009 Samsung Electronics
   6  *                    Author: Michal Nazarewicz <mina86@mina86.com>
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  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.
  21  *
  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
  25  * later version.
  26  *
  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.
  38  */
  39
  40 /*
  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.
  46  *
  47  * For more information about MSF and in particular its module
  48  * parameters and sysfs interface read the
  49  * <Documentation/usb/mass-storage.txt> file.
  50  */
  51
  52 /*
  53  * MSF is configured by specifying a fsg_config structure.  It has the
  54  * following fields:
  55  *
  56  *      nluns           Number of LUNs function have (anywhere from 1
  57  *                              to FSG_MAX_LUNS).
  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
  65  *                              removable.
  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"
  70  *                              in R/W mode.
  71  *      ->removable     Flag specifying that LUN shall be indicated as
  72  *                              being removable.
  73  *      ->cdrom         Flag specifying that LUN shall be reported as
  74  *                              being a CD-ROM.
  75  *      ->nofua         Flag specifying that FUA flag in SCSI WRITE(10,12)
  76  *                              commands for this LUN shall be ignored.
  77  *
  78  *      vendor_name
  79  *      product_name
  80  *      release         Information used as a reply to INQUIRY
  81  *                              request.  To use default set to NULL,
  82  *                              NULL, 0xffff respectively.  The first
  83  *                              field should be 8 and the second 16
  84  *                              characters or less.
  85  *
  86  *      can_stall       Set to permit function to halt bulk endpoints.
  87  *                              Disabled on some USB devices known not
  88  *                              to work correctly.  You should set it
  89  *                              to true.
  90  *
  91  * If "removable" is not set for a LUN then a backing file must be
  92  * specified.  If it is set, then NULL filename means the LUN's medium
  93  * is not loaded (an empty string as "filename" in the fsg_config
  94  * structure causes error).  The CD-ROM emulation includes a single
  95  * data track and no audio tracks; hence there need be only one
  96  * backing file per LUN.
  97  *
  98  * This function is heavily based on "File-backed Storage Gadget" by
  99  * Alan Stern which in turn is heavily based on "Gadget Zero" by David
 100  * Brownell.  The driver's SCSI command interface was based on the
 101  * "Information technology - Small Computer System Interface - 2"
 102  * document from X3T9.2 Project 375D, Revision 10L, 7-SEP-93,
 103  * available at <http://www.t10.org/ftp/t10/drafts/s2/s2-r10l.pdf>.
 104  * The single exception is opcode 0x23 (READ FORMAT CAPACITIES), which
 105  * was based on the "Universal Serial Bus Mass Storage Class UFI
 106  * Command Specification" document, Revision 1.0, December 14, 1998,
 107  * available at
 108  * <http://www.usb.org/developers/devclass_docs/usbmass-ufi10.pdf>.
 109  */
 110
 111 /*
 112  *                              Driver Design
 113  *
 114  * The MSF is fairly straightforward.  There is a main kernel
 115  * thread that handles most of the work.  Interrupt routines field
 116  * callbacks from the controller driver: bulk- and interrupt-request
 117  * completion notifications, endpoint-0 events, and disconnect events.
 118  * Completion events are passed to the main thread by wakeup calls.  Many
 119  * ep0 requests are handled at interrupt time, but SetInterface,
 120  * SetConfiguration, and device reset requests are forwarded to the
 121  * thread in the form of "exceptions" using SIGUSR1 signals (since they
 122  * should interrupt any ongoing file I/O operations).
 123  *
 124  * The thread's main routine implements the standard command/data/status
 125  * parts of a SCSI interaction.  It and its subroutines are full of tests
 126  * for pending signals/exceptions -- all this polling is necessary since
 127  * the kernel has no setjmp/longjmp equivalents.  (Maybe this is an
 128  * indication that the driver really wants to be running in userspace.)
 129  * An important point is that so long as the thread is alive it keeps an
 130  * open reference to the backing file.  This will prevent unmounting
 131  * the backing file's underlying filesystem and could cause problems
 132  * during system shutdown, for example.  To prevent such problems, the
 133  * thread catches INT, TERM, and KILL signals and converts them into
 134  * an EXIT exception.
 135  *
 136  * In normal operation the main thread is started during the gadget's
 137  * fsg_bind() callback and stopped during fsg_unbind().  But it can
 138  * also exit when it receives a signal, and there's no point leaving
 139  * the gadget running when the thread is dead.  As of this moment, MSF
 140  * provides no way to deregister the gadget when thread dies -- maybe
 141  * a callback functions is needed.
 142  *
 143  * To provide maximum throughput, the driver uses a circular pipeline of
 144  * buffer heads (struct fsg_buffhd).  In principle the pipeline can be
 145  * arbitrarily long; in practice the benefits don't justify having more
 146  * than 2 stages (i.e., double buffering).  But it helps to think of the
 147  * pipeline as being a long one.  Each buffer head contains a bulk-in and
 148  * a bulk-out request pointer (since the buffer can be used for both
 149  * output and input -- directions always are given from the host's
 150  * point of view) as well as a pointer to the buffer and various state
 151  * variables.
 152  *
 153  * Use of the pipeline follows a simple protocol.  There is a variable
 154  * (fsg->next_buffhd_to_fill) that points to the next buffer head to use.
 155  * At any time that buffer head may still be in use from an earlier
 156  * request, so each buffer head has a state variable indicating whether
 157  * it is EMPTY, FULL, or BUSY.  Typical use involves waiting for the
 158  * buffer head to be EMPTY, filling the buffer either by file I/O or by
 159  * USB I/O (during which the buffer head is BUSY), and marking the buffer
 160  * head FULL when the I/O is complete.  Then the buffer will be emptied
 161  * (again possibly by USB I/O, during which it is marked BUSY) and
 162  * finally marked EMPTY again (possibly by a completion routine).
 163  *
 164  * A module parameter tells the driver to avoid stalling the bulk
 165  * endpoints wherever the transport specification allows.  This is
 166  * necessary for some UDCs like the SuperH, which cannot reliably clear a
 167  * halt on a bulk endpoint.  However, under certain circumstances the
 168  * Bulk-only specification requires a stall.  In such cases the driver
 169  * will halt the endpoint and set a flag indicating that it should clear
 170  * the halt in software during the next device reset.  Hopefully this
 171  * will permit everything to work correctly.  Furthermore, although the
 172  * specification allows the bulk-out endpoint to halt when the host sends
 173  * too much data, implementing this would cause an unavoidable race.
 174  * The driver will always use the "no-stall" approach for OUT transfers.
 175  *
 176  * One subtle point concerns sending status-stage responses for ep0
 177  * requests.  Some of these requests, such as device reset, can involve
 178  * interrupting an ongoing file I/O operation, which might take an
 179  * arbitrarily long time.  During that delay the host might give up on
 180  * the original ep0 request and issue a new one.  When that happens the
 181  * driver should not notify the host about completion of the original
 182  * request, as the host will no longer be waiting for it.  So the driver
 183  * assigns to each ep0 request a unique tag, and it keeps track of the
 184  * tag value of the request associated with a long-running exception
 185  * (device-reset, interface-change, or configuration-change).  When the
 186  * exception handler is finished, the status-stage response is submitted
 187  * only if the current ep0 request tag is equal to the exception request
 188  * tag.  Thus only the most recently received ep0 request will get a
 189  * status-stage response.
 190  *
 191  * Warning: This driver source file is too long.  It ought to be split up
 192  * into a header file plus about 3 separate .c files, to handle the details
 193  * of the Gadget, USB Mass Storage, and SCSI protocols.
 194  */
 195
 196
 197 /* #define VERBOSE_DEBUG */
 198 /* #define DUMP_MSGS */
 199
 200 #include <linux/blkdev.h>
 201 #include <linux/completion.h>
 202 #include <linux/dcache.h>
 203 #include <linux/delay.h>
 204 #include <linux/device.h>
 205 #include <linux/fcntl.h>
 206 #include <linux/file.h>
 207 #include <linux/fs.h>
 208 #include <linux/kref.h>
 209 #include <linux/kthread.h>
 210 #include <linux/limits.h>
 211 #include <linux/rwsem.h>
 212 #include <linux/slab.h>
 213 #include <linux/spinlock.h>
 214 #include <linux/string.h>
 215 #include <linux/freezer.h>
 216 #include <linux/module.h>
 217 #include <linux/uaccess.h>
 218
 219 #include <linux/usb/ch9.h>
 220 #include <linux/usb/gadget.h>
 221 #include <linux/usb/composite.h>
 222
 223 #include <linux/nospec.h>
 224
 225 #include "configfs.h"
 226
 227
 228 /*------------------------------------------------------------------------*/
 229
 230 #define FSG_DRIVER_DESC         "Mass Storage Function"
 231 #define FSG_DRIVER_VERSION      "2009/09/11"
 232
 233 static const char fsg_string_interface[] = "Mass Storage";
 234
 235 #include "storage_common.h"
 236 #include "f_mass_storage.h"
 237
 238 /* Static strings, in UTF-8 (for simplicity we use only ASCII characters) */
 239 static struct usb_string                fsg_strings[] = {
 240         {FSG_STRING_INTERFACE,          fsg_string_interface},
 241         {}
 242 };
 243
 244 static struct usb_gadget_strings        fsg_stringtab = {
 245         .language       = 0x0409,               /* en-us */
 246         .strings        = fsg_strings,
 247 };
 248
 249 static struct usb_gadget_strings *fsg_strings_array[] = {
 250         &fsg_stringtab,
 251         NULL,
 252 };
 253
 254 /*-------------------------------------------------------------------------*/
 255
 256 struct fsg_dev;
 257 struct fsg_common;
 258
 259 /* Data shared by all the FSG instances. */
 260 struct fsg_common {
 261         struct usb_gadget       *gadget;
 262         struct usb_composite_dev *cdev;
 263         struct fsg_dev          *fsg, *new_fsg;
 264         wait_queue_head_t       fsg_wait;
 265
 266         /* filesem protects: backing files in use */
 267         struct rw_semaphore     filesem;
 268
 269         /* lock protects: state, all the req_busy's */
 270         spinlock_t              lock;
 271
 272         struct usb_ep           *ep0;           /* Copy of gadget->ep0 */
 273         struct usb_request      *ep0req;        /* Copy of cdev->req */
 274         unsigned int            ep0_req_tag;
 275
 276         struct fsg_buffhd       *next_buffhd_to_fill;
 277         struct fsg_buffhd       *next_buffhd_to_drain;
 278         struct fsg_buffhd       *buffhds;
 279         unsigned int            fsg_num_buffers;
 280
 281         int                     cmnd_size;
 282         u8                      cmnd[MAX_COMMAND_SIZE];
 283
 284         unsigned int            lun;
 285         struct fsg_lun          *luns[FSG_MAX_LUNS];
 286         struct fsg_lun          *curlun;
 287
 288         unsigned int            bulk_out_maxpacket;
 289         enum fsg_state          state;          /* For exception handling */
 290         unsigned int            exception_req_tag;
 291
 292         enum data_direction     data_dir;
 293         u32                     data_size;
 294         u32                     data_size_from_cmnd;
 295         u32                     tag;
 296         u32                     residue;
 297         u32                     usb_amount_left;
 298
 299         unsigned int            can_stall:1;
 300         unsigned int            free_storage_on_release:1;
 301         unsigned int            phase_error:1;
 302         unsigned int            short_packet_received:1;
 303         unsigned int            bad_lun_okay:1;
 304         unsigned int            running:1;
 305         unsigned int            sysfs:1;
 306
 307         int                     thread_wakeup_needed;
 308         struct completion       thread_notifier;
 309         struct task_struct      *thread_task;
 310
 311         /* Gadget's private data. */
 312         void                    *private_data;
 313
 314         char inquiry_string[INQUIRY_STRING_LEN];
 315
 316         struct kref             ref;
 317 };
 318
 319 struct fsg_dev {
 320         struct usb_function     function;
 321         struct usb_gadget       *gadget;        /* Copy of cdev->gadget */
 322         struct fsg_common       *common;
 323
 324         u16                     interface_number;
 325
 326         unsigned int            bulk_in_enabled:1;
 327         unsigned int            bulk_out_enabled:1;
 328
 329         unsigned long           atomic_bitflags;
 330 #define IGNORE_BULK_OUT         0
 331
 332         struct usb_ep           *bulk_in;
 333         struct usb_ep           *bulk_out;
 334 };
 335
 336 static inline int __fsg_is_set(struct fsg_common *common,
 337                                const char *func, unsigned line)
 338 {
 339         if (common->fsg)
 340                 return 1;
 341         ERROR(common, "common->fsg is NULL in %s at %u\n", func, line);
 342         WARN_ON(1);
 343         return 0;
 344 }
 345
 346 #define fsg_is_set(common) likely(__fsg_is_set(common, __func__, __LINE__))
 347
 348 static inline struct fsg_dev *fsg_from_func(struct usb_function *f)
 349 {
 350         return container_of(f, struct fsg_dev, function);
 351 }
 352
 353 typedef void (*fsg_routine_t)(struct fsg_dev *);
 354
 355 static int exception_in_progress(struct fsg_common *common)
 356 {
 357         return common->state > FSG_STATE_IDLE;
 358 }
 359
 360 /* Make bulk-out requests be divisible by the maxpacket size */
 361 static void set_bulk_out_req_length(struct fsg_common *common,
 362                                     struct fsg_buffhd *bh, unsigned int length)
 363 {
 364         unsigned int    rem;
 365
 366         bh->bulk_out_intended_length = length;
 367         rem = length % common->bulk_out_maxpacket;
 368         if (rem > 0)
 369                 length += common->bulk_out_maxpacket - rem;
 370         bh->outreq->length = length;
 371 }
 372
 373
 374 /*-------------------------------------------------------------------------*/
 375
 376 static int fsg_set_halt(struct fsg_dev *fsg, struct usb_ep *ep)
 377 {
 378         const char      *name;
 379
 380         if (ep == fsg->bulk_in)
 381                 name = "bulk-in";
 382         else if (ep == fsg->bulk_out)
 383                 name = "bulk-out";
 384         else
 385                 name = ep->name;
 386         DBG(fsg, "%s set halt\n", name);
 387         return usb_ep_set_halt(ep);
 388 }
 389
 390
 391 /*-------------------------------------------------------------------------*/
 392
 393 /* These routines may be called in process context or in_irq */
 394
 395 /* Caller must hold fsg->lock */
 396 static void wakeup_thread(struct fsg_common *common)
 397 {
 398         /*
 399          * Ensure the reading of thread_wakeup_needed
 400          * and the writing of bh->state are completed
 401          */
 402         smp_mb();
 403         /* Tell the main thread that something has happened */
 404         common->thread_wakeup_needed = 1;
 405         if (common->thread_task)
 406                 wake_up_process(common->thread_task);
 407 }
 408
 409 static void raise_exception(struct fsg_common *common, enum fsg_state new_state)
 410 {
 411         unsigned long           flags;
 412
 413         /*
 414          * Do nothing if a higher-priority exception is already in progress.
 415          * If a lower-or-equal priority exception is in progress, preempt it
 416          * and notify the main thread by sending it a signal.
 417          */
 418         spin_lock_irqsave(&common->lock, flags);
 419         if (common->state <= new_state) {
 420                 common->exception_req_tag = common->ep0_req_tag;
 421                 common->state = new_state;
 422                 if (common->thread_task)
 423                         send_sig_info(SIGUSR1, SEND_SIG_FORCED,
 424                                       common->thread_task);
 425         }
 426         spin_unlock_irqrestore(&common->lock, flags);
 427 }
 428
 429
 430 /*-------------------------------------------------------------------------*/
 431
 432 static int ep0_queue(struct fsg_common *common)
 433 {
 434         int     rc;
 435
 436         rc = usb_ep_queue(common->ep0, common->ep0req, GFP_ATOMIC);
 437         common->ep0->driver_data = common;
 438         if (rc != 0 && rc != -ESHUTDOWN) {
 439                 /* We can't do much more than wait for a reset */
 440                 WARNING(common, "error in submission: %s --> %d\n",
 441                         common->ep0->name, rc);
 442         }
 443         return rc;
 444 }
 445
 446
 447 /*-------------------------------------------------------------------------*/
 448
 449 /* Completion handlers. These always run in_irq. */
 450
 451 static void bulk_in_complete(struct usb_ep *ep, struct usb_request *req)
 452 {
 453         struct fsg_common       *common = ep->driver_data;
 454         struct fsg_buffhd       *bh = req->context;
 455
 456         if (req->status || req->actual != req->length)
 457                 DBG(common, "%s --> %d, %u/%u\n", __func__,
 458                     req->status, req->actual, req->length);
 459         if (req->status == -ECONNRESET)         /* Request was cancelled */
 460                 usb_ep_fifo_flush(ep);
 461
 462         /* Hold the lock while we update the request and buffer states */
 463         smp_wmb();
 464         spin_lock(&common->lock);
 465         bh->inreq_busy = 0;
 466         bh->state = BUF_STATE_EMPTY;
 467         wakeup_thread(common);
 468         spin_unlock(&common->lock);
 469 }
 470
 471 static void bulk_out_complete(struct usb_ep *ep, struct usb_request *req)
 472 {
 473         struct fsg_common       *common = ep->driver_data;
 474         struct fsg_buffhd       *bh = req->context;
 475
 476         dump_msg(common, "bulk-out", req->buf, req->actual);
 477         if (req->status || req->actual != bh->bulk_out_intended_length)
 478                 DBG(common, "%s --> %d, %u/%u\n", __func__,
 479                     req->status, req->actual, bh->bulk_out_intended_length);
 480         if (req->status == -ECONNRESET)         /* Request was cancelled */
 481                 usb_ep_fifo_flush(ep);
 482
 483         /* Hold the lock while we update the request and buffer states */
 484         smp_wmb();
 485         spin_lock(&common->lock);
 486         bh->outreq_busy = 0;
 487         bh->state = BUF_STATE_FULL;
 488         wakeup_thread(common);
 489         spin_unlock(&common->lock);
 490 }
 491
 492 static int _fsg_common_get_max_lun(struct fsg_common *common)
 493 {
 494         int i = ARRAY_SIZE(common->luns) - 1;
 495
 496         while (i >= 0 && !common->luns[i])
 497                 --i;
 498
 499         return i;
 500 }
 501
 502 static int fsg_setup(struct usb_function *f,
 503                      const struct usb_ctrlrequest *ctrl)
 504 {
 505         struct fsg_dev          *fsg = fsg_from_func(f);
 506         struct usb_request      *req = fsg->common->ep0req;
 507         u16                     w_index = le16_to_cpu(ctrl->wIndex);
 508         u16                     w_value = le16_to_cpu(ctrl->wValue);
 509         u16                     w_length = le16_to_cpu(ctrl->wLength);
 510
 511         if (!fsg_is_set(fsg->common))
 512                 return -EOPNOTSUPP;
 513
 514         ++fsg->common->ep0_req_tag;     /* Record arrival of a new request */
 515         req->context = NULL;
 516         req->length = 0;
 517         dump_msg(fsg, "ep0-setup", (u8 *) ctrl, sizeof(*ctrl));
 518
 519         switch (ctrl->bRequest) {
 520
 521         case US_BULK_RESET_REQUEST:
 522                 if (ctrl->bRequestType !=
 523                     (USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE))
 524                         break;
 525                 if (w_index != fsg->interface_number || w_value != 0 ||
 526                                 w_length != 0)
 527                         return -EDOM;
 528
 529                 /*
 530                  * Raise an exception to stop the current operation
 531                  * and reinitialize our state.
 532                  */
 533                 DBG(fsg, "bulk reset request\n");
 534                 raise_exception(fsg->common, FSG_STATE_RESET);
 535                 return USB_GADGET_DELAYED_STATUS;
 536
 537         case US_BULK_GET_MAX_LUN:
 538                 if (ctrl->bRequestType !=
 539                     (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE))
 540                         break;
 541                 if (w_index != fsg->interface_number || w_value != 0 ||
 542                                 w_length != 1)
 543                         return -EDOM;
 544                 VDBG(fsg, "get max LUN\n");
 545                 *(u8 *)req->buf = _fsg_common_get_max_lun(fsg->common);
 546
 547                 /* Respond with data/status */
 548                 req->length = min((u16)1, w_length);
 549                 return ep0_queue(fsg->common);
 550         }
 551
 552         VDBG(fsg,
 553              "unknown class-specific control req %02x.%02x v%04x i%04x l%u\n",
 554              ctrl->bRequestType, ctrl->bRequest,
 555              le16_to_cpu(ctrl->wValue), w_index, w_length);
 556         return -EOPNOTSUPP;
 557 }
 558
 559
 560 /*-------------------------------------------------------------------------*/
 561
 562 /* All the following routines run in process context */
 563
 564 /* Use this for bulk or interrupt transfers, not ep0 */
 565 static void start_transfer(struct fsg_dev *fsg, struct usb_ep *ep,
 566                            struct usb_request *req, int *pbusy,
 567                            enum fsg_buffer_state *state)
 568 {
 569         int     rc;
 570
 571         if (ep == fsg->bulk_in)
 572                 dump_msg(fsg, "bulk-in", req->buf, req->length);
 573
 574         spin_lock_irq(&fsg->common->lock);
 575         *pbusy = 1;
 576         *state = BUF_STATE_BUSY;
 577         spin_unlock_irq(&fsg->common->lock);
 578
 579         rc = usb_ep_queue(ep, req, GFP_KERNEL);
 580         if (rc == 0)
 581                 return;  /* All good, we're done */
 582
 583         *pbusy = 0;
 584         *state = BUF_STATE_EMPTY;
 585
 586         /* We can't do much more than wait for a reset */
 587
 588         /*
 589          * Note: currently the net2280 driver fails zero-length
 590          * submissions if DMA is enabled.
 591          */
 592         if (rc != -ESHUTDOWN && !(rc == -EOPNOTSUPP && req->length == 0))
 593                 WARNING(fsg, "error in submission: %s --> %d\n", ep->name, rc);
 594 }
 595
 596 static bool start_in_transfer(struct fsg_common *common, struct fsg_buffhd *bh)
 597 {
 598         if (!fsg_is_set(common))
 599                 return false;
 600         start_transfer(common->fsg, common->fsg->bulk_in,
 601                        bh->inreq, &bh->inreq_busy, &bh->state);
 602         return true;
 603 }
 604
 605 static bool start_out_transfer(struct fsg_common *common, struct fsg_buffhd *bh)
 606 {
 607         if (!fsg_is_set(common))
 608                 return false;
 609         start_transfer(common->fsg, common->fsg->bulk_out,
 610                        bh->outreq, &bh->outreq_busy, &bh->state);
 611         return true;
 612 }
 613
 614 static int sleep_thread(struct fsg_common *common, bool can_freeze)
 615 {
 616         int     rc = 0;
 617
 618         /* Wait until a signal arrives or we are woken up */
 619         for (;;) {
 620                 if (can_freeze)
 621                         try_to_freeze();
 622                 set_current_state(TASK_INTERRUPTIBLE);
 623                 if (signal_pending(current)) {
 624                         rc = -EINTR;
 625                         break;
 626                 }
 627                 if (common->thread_wakeup_needed)
 628                         break;
 629                 schedule();
 630         }
 631         __set_current_state(TASK_RUNNING);
 632         common->thread_wakeup_needed = 0;
 633
 634         /*
 635          * Ensure the writing of thread_wakeup_needed
 636          * and the reading of bh->state are completed
 637          */
 638         smp_mb();
 639         return rc;
 640 }
 641
 642
 643 /*-------------------------------------------------------------------------*/
 644
 645 static int do_read(struct fsg_common *common)
 646 {
 647         struct fsg_lun          *curlun = common->curlun;
 648         u32                     lba;
 649         struct fsg_buffhd       *bh;
 650         int                     rc;
 651         u32                     amount_left;
 652         loff_t                  file_offset, file_offset_tmp;
 653         unsigned int            amount;
 654         ssize_t                 nread;
 655
 656         /*
 657          * Get the starting Logical Block Address and check that it's
 658          * not too big.
 659          */
 660         if (common->cmnd[0] == READ_6)
 661                 lba = get_unaligned_be24(&common->cmnd[1]);
 662         else {
 663                 lba = get_unaligned_be32(&common->cmnd[2]);
 664
 665                 /*
 666                  * We allow DPO (Disable Page Out = don't save data in the
 667                  * cache) and FUA (Force Unit Access = don't read from the
 668                  * cache), but we don't implement them.
 669                  */
 670                 if ((common->cmnd[1] & ~0x18) != 0) {
 671                         curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
 672                         return -EINVAL;
 673                 }
 674         }
 675         if (lba >= curlun->num_sectors) {
 676                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
 677                 return -EINVAL;
 678         }
 679         file_offset = ((loff_t) lba) << curlun->blkbits;
 680
 681         /* Carry out the file reads */
 682         amount_left = common->data_size_from_cmnd;
 683         if (unlikely(amount_left == 0))
 684                 return -EIO;            /* No default reply */
 685
 686         for (;;) {
 687                 /*
 688                  * Figure out how much we need to read:
 689                  * Try to read the remaining amount.
 690                  * But don't read more than the buffer size.
 691                  * And don't try to read past the end of the file.
 692                  */
 693                 amount = min(amount_left, FSG_BUFLEN);
 694                 amount = min((loff_t)amount,
 695                              curlun->file_length - file_offset);
 696
 697                 /* Wait for the next buffer to become available */
 698                 bh = common->next_buffhd_to_fill;
 699                 while (bh->state != BUF_STATE_EMPTY) {
 700                         rc = sleep_thread(common, false);
 701                         if (rc)
 702                                 return rc;
 703                 }
 704
 705                 /*
 706                  * If we were asked to read past the end of file,
 707                  * end with an empty buffer.
 708                  */
 709                 if (amount == 0) {
 710                         curlun->sense_data =
 711                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
 712                         curlun->sense_data_info =
 713                                         file_offset >> curlun->blkbits;
 714                         curlun->info_valid = 1;
 715                         bh->inreq->length = 0;
 716                         bh->state = BUF_STATE_FULL;
 717                         break;
 718                 }
 719
 720                 /* Perform the read */
 721                 file_offset_tmp = file_offset;
 722                 nread = vfs_read(curlun->filp,
 723                                  (char __user *)bh->buf,
 724                                  amount, &file_offset_tmp);
 725                 VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
 726                       (unsigned long long)file_offset, (int)nread);
 727                 if (signal_pending(current))
 728                         return -EINTR;
 729
 730                 if (nread < 0) {
 731                         LDBG(curlun, "error in file read: %d\n", (int)nread);
 732                         nread = 0;
 733                 } else if (nread < amount) {
 734                         LDBG(curlun, "partial file read: %d/%u\n",
 735                              (int)nread, amount);
 736                         nread = round_down(nread, curlun->blksize);
 737                 }
 738                 file_offset  += nread;
 739                 amount_left  -= nread;
 740                 common->residue -= nread;
 741
 742                 /*
 743                  * Except at the end of the transfer, nread will be
 744                  * equal to the buffer size, which is divisible by the
 745                  * bulk-in maxpacket size.
 746                  */
 747                 bh->inreq->length = nread;
 748                 bh->state = BUF_STATE_FULL;
 749
 750                 /* If an error occurred, report it and its position */
 751                 if (nread < amount) {
 752                         curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
 753                         curlun->sense_data_info =
 754                                         file_offset >> curlun->blkbits;
 755                         curlun->info_valid = 1;
 756                         break;
 757                 }
 758
 759                 if (amount_left == 0)
 760                         break;          /* No more left to read */
 761
 762                 /* Send this buffer and go read some more */
 763                 bh->inreq->zero = 0;
 764                 if (!start_in_transfer(common, bh))
 765                         /* Don't know what to do if common->fsg is NULL */
 766                         return -EIO;
 767                 common->next_buffhd_to_fill = bh->next;
 768         }
 769
 770         return -EIO;            /* No default reply */
 771 }
 772
 773
 774 /*-------------------------------------------------------------------------*/
 775
 776 static int do_write(struct fsg_common *common)
 777 {
 778         struct fsg_lun          *curlun = common->curlun;
 779         u32                     lba;
 780         struct fsg_buffhd       *bh;
 781         int                     get_some_more;
 782         u32                     amount_left_to_req, amount_left_to_write;
 783         loff_t                  usb_offset, file_offset, file_offset_tmp;
 784         unsigned int            amount;
 785         ssize_t                 nwritten;
 786         int                     rc;
 787
 788         if (curlun->ro) {
 789                 curlun->sense_data = SS_WRITE_PROTECTED;
 790                 return -EINVAL;
 791         }
 792         spin_lock(&curlun->filp->f_lock);
 793         curlun->filp->f_flags &= ~O_SYNC;       /* Default is not to wait */
 794         spin_unlock(&curlun->filp->f_lock);
 795
 796         /*
 797          * Get the starting Logical Block Address and check that it's
 798          * not too big
 799          */
 800         if (common->cmnd[0] == WRITE_6)
 801                 lba = get_unaligned_be24(&common->cmnd[1]);
 802         else {
 803                 lba = get_unaligned_be32(&common->cmnd[2]);
 804
 805                 /*
 806                  * We allow DPO (Disable Page Out = don't save data in the
 807                  * cache) and FUA (Force Unit Access = write directly to the
 808                  * medium).  We don't implement DPO; we implement FUA by
 809                  * performing synchronous output.
 810                  */
 811                 if (common->cmnd[1] & ~0x18) {
 812                         curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
 813                         return -EINVAL;
 814                 }
 815                 if (!curlun->nofua && (common->cmnd[1] & 0x08)) { /* FUA */
 816                         spin_lock(&curlun->filp->f_lock);
 817                         curlun->filp->f_flags |= O_SYNC;
 818                         spin_unlock(&curlun->filp->f_lock);
 819                 }
 820         }
 821         if (lba >= curlun->num_sectors) {
 822                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
 823                 return -EINVAL;
 824         }
 825
 826         /* Carry out the file writes */
 827         get_some_more = 1;
 828         file_offset = usb_offset = ((loff_t) lba) << curlun->blkbits;
 829         amount_left_to_req = common->data_size_from_cmnd;
 830         amount_left_to_write = common->data_size_from_cmnd;
 831
 832         while (amount_left_to_write > 0) {
 833
 834                 /* Queue a request for more data from the host */
 835                 bh = common->next_buffhd_to_fill;
 836                 if (bh->state == BUF_STATE_EMPTY && get_some_more) {
 837
 838                         /*
 839                          * Figure out how much we want to get:
 840                          * Try to get the remaining amount,
 841                          * but not more than the buffer size.
 842                          */
 843                         amount = min(amount_left_to_req, FSG_BUFLEN);
 844
 845                         /* Beyond the end of the backing file? */
 846                         if (usb_offset >= curlun->file_length) {
 847                                 get_some_more = 0;
 848                                 curlun->sense_data =
 849                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
 850                                 curlun->sense_data_info =
 851                                         usb_offset >> curlun->blkbits;
 852                                 curlun->info_valid = 1;
 853                                 continue;
 854                         }
 855
 856                         /* Get the next buffer */
 857                         usb_offset += amount;
 858                         common->usb_amount_left -= amount;
 859                         amount_left_to_req -= amount;
 860                         if (amount_left_to_req == 0)
 861                                 get_some_more = 0;
 862
 863                         /*
 864                          * Except at the end of the transfer, amount will be
 865                          * equal to the buffer size, which is divisible by
 866                          * the bulk-out maxpacket size.
 867                          */
 868                         set_bulk_out_req_length(common, bh, amount);
 869                         if (!start_out_transfer(common, bh))
 870                                 /* Dunno what to do if common->fsg is NULL */
 871                                 return -EIO;
 872                         common->next_buffhd_to_fill = bh->next;
 873                         continue;
 874                 }
 875
 876                 /* Write the received data to the backing file */
 877                 bh = common->next_buffhd_to_drain;
 878                 if (bh->state == BUF_STATE_EMPTY && !get_some_more)
 879                         break;                  /* We stopped early */
 880                 if (bh->state == BUF_STATE_FULL) {
 881                         smp_rmb();
 882                         common->next_buffhd_to_drain = bh->next;
 883                         bh->state = BUF_STATE_EMPTY;
 884
 885                         /* Did something go wrong with the transfer? */
 886                         if (bh->outreq->status != 0) {
 887                                 curlun->sense_data = SS_COMMUNICATION_FAILURE;
 888                                 curlun->sense_data_info =
 889                                         file_offset >> curlun->blkbits;
 890                                 curlun->info_valid = 1;
 891                                 break;
 892                         }
 893
 894                         amount = bh->outreq->actual;
 895                         if (curlun->file_length - file_offset < amount) {
 896                                 LERROR(curlun,
 897                                        "write %u @ %llu beyond end %llu\n",
 898                                        amount, (unsigned long long)file_offset,
 899                                        (unsigned long long)curlun->file_length);
 900                                 amount = curlun->file_length - file_offset;
 901                         }
 902
 903                         /* Don't accept excess data.  The spec doesn't say
 904                          * what to do in this case.  We'll ignore the error.
 905                          */
 906                         amount = min(amount, bh->bulk_out_intended_length);
 907
 908                         /* Don't write a partial block */
 909                         amount = round_down(amount, curlun->blksize);
 910                         if (amount == 0)
 911                                 goto empty_write;
 912
 913                         /* Perform the write */
 914                         file_offset_tmp = file_offset;
 915                         nwritten = vfs_write(curlun->filp,
 916                                              (char __user *)bh->buf,
 917                                              amount, &file_offset_tmp);
 918                         VLDBG(curlun, "file write %u @ %llu -> %d\n", amount,
 919                               (unsigned long long)file_offset, (int)nwritten);
 920                         if (signal_pending(current))
 921                                 return -EINTR;          /* Interrupted! */
 922
 923                         if (nwritten < 0) {
 924                                 LDBG(curlun, "error in file write: %d\n",
 925                                      (int)nwritten);
 926                                 nwritten = 0;
 927                         } else if (nwritten < amount) {
 928                                 LDBG(curlun, "partial file write: %d/%u\n",
 929                                      (int)nwritten, amount);
 930                                 nwritten = round_down(nwritten, curlun->blksize);
 931                         }
 932                         file_offset += nwritten;
 933                         amount_left_to_write -= nwritten;
 934                         common->residue -= nwritten;
 935
 936                         /* If an error occurred, report it and its position */
 937                         if (nwritten < amount) {
 938                                 curlun->sense_data = SS_WRITE_ERROR;
 939                                 curlun->sense_data_info =
 940                                         file_offset >> curlun->blkbits;
 941                                 curlun->info_valid = 1;
 942                                 break;
 943                         }
 944
 945  empty_write:
 946                         /* Did the host decide to stop early? */
 947                         if (bh->outreq->actual < bh->bulk_out_intended_length) {
 948                                 common->short_packet_received = 1;
 949                                 break;
 950                         }
 951                         continue;
 952                 }
 953
 954                 /* Wait for something to happen */
 955                 rc = sleep_thread(common, false);
 956                 if (rc)
 957                         return rc;
 958         }
 959
 960         return -EIO;            /* No default reply */
 961 }
 962
 963
 964 /*-------------------------------------------------------------------------*/
 965
 966 static int do_synchronize_cache(struct fsg_common *common)
 967 {
 968         struct fsg_lun  *curlun = common->curlun;
 969         int             rc;
 970
 971         /* We ignore the requested LBA and write out all file's
 972          * dirty data buffers. */
 973         rc = fsg_lun_fsync_sub(curlun);
 974         if (rc)
 975                 curlun->sense_data = SS_WRITE_ERROR;
 976         return 0;
 977 }
 978
 979
 980 /*-------------------------------------------------------------------------*/
 981
 982 static void invalidate_sub(struct fsg_lun *curlun)
 983 {
 984         struct file     *filp = curlun->filp;
 985         struct inode    *inode = file_inode(filp);
 986         unsigned long   rc;
 987
 988         rc = invalidate_mapping_pages(inode->i_mapping, 0, -1);
 989         VLDBG(curlun, "invalidate_mapping_pages -> %ld\n", rc);
 990 }
 991
 992 static int do_verify(struct fsg_common *common)
 993 {
 994         struct fsg_lun          *curlun = common->curlun;
 995         u32                     lba;
 996         u32                     verification_length;
 997         struct fsg_buffhd       *bh = common->next_buffhd_to_fill;
 998         loff_t                  file_offset, file_offset_tmp;
 999         u32                     amount_left;
1000         unsigned int            amount;
1001         ssize_t                 nread;
1002
1003         /*
1004          * Get the starting Logical Block Address and check that it's
1005          * not too big.
1006          */
1007         lba = get_unaligned_be32(&common->cmnd[2]);
1008         if (lba >= curlun->num_sectors) {
1009                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1010                 return -EINVAL;
1011         }
1012
1013         /*
1014          * We allow DPO (Disable Page Out = don't save data in the
1015          * cache) but we don't implement it.
1016          */
1017         if (common->cmnd[1] & ~0x10) {
1018                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1019                 return -EINVAL;
1020         }
1021
1022         verification_length = get_unaligned_be16(&common->cmnd[7]);
1023         if (unlikely(verification_length == 0))
1024                 return -EIO;            /* No default reply */
1025
1026         /* Prepare to carry out the file verify */
1027         amount_left = verification_length << curlun->blkbits;
1028         file_offset = ((loff_t) lba) << curlun->blkbits;
1029
1030         /* Write out all the dirty buffers before invalidating them */
1031         fsg_lun_fsync_sub(curlun);
1032         if (signal_pending(current))
1033                 return -EINTR;
1034
1035         invalidate_sub(curlun);
1036         if (signal_pending(current))
1037                 return -EINTR;
1038
1039         /* Just try to read the requested blocks */
1040         while (amount_left > 0) {
1041                 /*
1042                  * Figure out how much we need to read:
1043                  * Try to read the remaining amount, but not more than
1044                  * the buffer size.
1045                  * And don't try to read past the end of the file.
1046                  */
1047                 amount = min(amount_left, FSG_BUFLEN);
1048                 amount = min((loff_t)amount,
1049                              curlun->file_length - file_offset);
1050                 if (amount == 0) {
1051                         curlun->sense_data =
1052                                         SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1053                         curlun->sense_data_info =
1054                                 file_offset >> curlun->blkbits;
1055                         curlun->info_valid = 1;
1056                         break;
1057                 }
1058
1059                 /* Perform the read */
1060                 file_offset_tmp = file_offset;
1061                 nread = vfs_read(curlun->filp,
1062                                 (char __user *) bh->buf,
1063                                 amount, &file_offset_tmp);
1064                 VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
1065                                 (unsigned long long) file_offset,
1066                                 (int) nread);
1067                 if (signal_pending(current))
1068                         return -EINTR;
1069
1070                 if (nread < 0) {
1071                         LDBG(curlun, "error in file verify: %d\n", (int)nread);
1072                         nread = 0;
1073                 } else if (nread < amount) {
1074                         LDBG(curlun, "partial file verify: %d/%u\n",
1075                              (int)nread, amount);
1076                         nread = round_down(nread, curlun->blksize);
1077                 }
1078                 if (nread == 0) {
1079                         curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
1080                         curlun->sense_data_info =
1081                                 file_offset >> curlun->blkbits;
1082                         curlun->info_valid = 1;
1083                         break;
1084                 }
1085                 file_offset += nread;
1086                 amount_left -= nread;
1087         }
1088         return 0;
1089 }
1090
1091
1092 /*-------------------------------------------------------------------------*/
1093
1094 static int do_inquiry(struct fsg_common *common, struct fsg_buffhd *bh)
1095 {
1096         struct fsg_lun *curlun = common->curlun;
1097         u8      *buf = (u8 *) bh->buf;
1098
1099         if (!curlun) {          /* Unsupported LUNs are okay */
1100                 common->bad_lun_okay = 1;
1101                 memset(buf, 0, 36);
1102                 buf[0] = TYPE_NO_LUN;   /* Unsupported, no device-type */
1103                 buf[4] = 31;            /* Additional length */
1104                 return 36;
1105         }
1106
1107         buf[0] = curlun->cdrom ? TYPE_ROM : TYPE_DISK;
1108         buf[1] = curlun->removable ? 0x80 : 0;
1109         buf[2] = 2;             /* ANSI SCSI level 2 */
1110         buf[3] = 2;             /* SCSI-2 INQUIRY data format */
1111         buf[4] = 31;            /* Additional length */
1112         buf[5] = 0;             /* No special options */
1113         buf[6] = 0;
1114         buf[7] = 0;
1115         if (curlun->inquiry_string[0])
1116                 memcpy(buf + 8, curlun->inquiry_string,
1117                        sizeof(curlun->inquiry_string));
1118         else
1119                 memcpy(buf + 8, common->inquiry_string,
1120                        sizeof(common->inquiry_string));
1121         return 36;
1122 }
1123
1124 static int do_request_sense(struct fsg_common *common, struct fsg_buffhd *bh)
1125 {
1126         struct fsg_lun  *curlun = common->curlun;
1127         u8              *buf = (u8 *) bh->buf;
1128         u32             sd, sdinfo;
1129         int             valid;
1130
1131         /*
1132          * From the SCSI-2 spec., section 7.9 (Unit attention condition):
1133          *
1134          * If a REQUEST SENSE command is received from an initiator
1135          * with a pending unit attention condition (before the target
1136          * generates the contingent allegiance condition), then the
1137          * target shall either:
1138          *   a) report any pending sense data and preserve the unit
1139          *      attention condition on the logical unit, or,
1140          *   b) report the unit attention condition, may discard any
1141          *      pending sense data, and clear the unit attention
1142          *      condition on the logical unit for that initiator.
1143          *
1144          * FSG normally uses option a); enable this code to use option b).
1145          */
1146 #if 0
1147         if (curlun && curlun->unit_attention_data != SS_NO_SENSE) {
1148                 curlun->sense_data = curlun->unit_attention_data;
1149                 curlun->unit_attention_data = SS_NO_SENSE;
1150         }
1151 #endif
1152
1153         if (!curlun) {          /* Unsupported LUNs are okay */
1154                 common->bad_lun_okay = 1;
1155                 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
1156                 sdinfo = 0;
1157                 valid = 0;
1158         } else {
1159                 sd = curlun->sense_data;
1160                 sdinfo = curlun->sense_data_info;
1161                 valid = curlun->info_valid << 7;
1162                 curlun->sense_data = SS_NO_SENSE;
1163                 curlun->sense_data_info = 0;
1164                 curlun->info_valid = 0;
1165         }
1166
1167         memset(buf, 0, 18);
1168         buf[0] = valid | 0x70;                  /* Valid, current error */
1169         buf[2] = SK(sd);
1170         put_unaligned_be32(sdinfo, &buf[3]);    /* Sense information */
1171         buf[7] = 18 - 8;                        /* Additional sense length */
1172         buf[12] = ASC(sd);
1173         buf[13] = ASCQ(sd);
1174         return 18;
1175 }
1176
1177 static int do_read_capacity(struct fsg_common *common, struct fsg_buffhd *bh)
1178 {
1179         struct fsg_lun  *curlun = common->curlun;
1180         u32             lba = get_unaligned_be32(&common->cmnd[2]);
1181         int             pmi = common->cmnd[8];
1182         u8              *buf = (u8 *)bh->buf;
1183
1184         /* Check the PMI and LBA fields */
1185         if (pmi > 1 || (pmi == 0 && lba != 0)) {
1186                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1187                 return -EINVAL;
1188         }
1189
1190         put_unaligned_be32(curlun->num_sectors - 1, &buf[0]);
1191                                                 /* Max logical block */
1192         put_unaligned_be32(curlun->blksize, &buf[4]);/* Block length */
1193         return 8;
1194 }
1195
1196 static int do_read_header(struct fsg_common *common, struct fsg_buffhd *bh)
1197 {
1198         struct fsg_lun  *curlun = common->curlun;
1199         int             msf = common->cmnd[1] & 0x02;
1200         u32             lba = get_unaligned_be32(&common->cmnd[2]);
1201         u8              *buf = (u8 *)bh->buf;
1202
1203         if (common->cmnd[1] & ~0x02) {          /* Mask away MSF */
1204                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1205                 return -EINVAL;
1206         }
1207         if (lba >= curlun->num_sectors) {
1208                 curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1209                 return -EINVAL;
1210         }
1211
1212         memset(buf, 0, 8);
1213         buf[0] = 0x01;          /* 2048 bytes of user data, rest is EC */
1214         store_cdrom_address(&buf[4], msf, lba);
1215         return 8;
1216 }
1217
1218 static int do_read_toc(struct fsg_common *common, struct fsg_buffhd *bh)
1219 {
1220         struct fsg_lun  *curlun = common->curlun;
1221         int             msf = common->cmnd[1] & 0x02;
1222         int             start_track = common->cmnd[6];
1223         u8              *buf = (u8 *)bh->buf;
1224
1225         if ((common->cmnd[1] & ~0x02) != 0 ||   /* Mask away MSF */
1226                         start_track > 1) {
1227                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1228                 return -EINVAL;
1229         }
1230
1231         memset(buf, 0, 20);
1232         buf[1] = (20-2);                /* TOC data length */
1233         buf[2] = 1;                     /* First track number */
1234         buf[3] = 1;                     /* Last track number */
1235         buf[5] = 0x16;                  /* Data track, copying allowed */
1236         buf[6] = 0x01;                  /* Only track is number 1 */
1237         store_cdrom_address(&buf[8], msf, 0);
1238
1239         buf[13] = 0x16;                 /* Lead-out track is data */
1240         buf[14] = 0xAA;                 /* Lead-out track number */
1241         store_cdrom_address(&buf[16], msf, curlun->num_sectors);
1242         return 20;
1243 }
1244
1245 static int do_mode_sense(struct fsg_common *common, struct fsg_buffhd *bh)
1246 {
1247         struct fsg_lun  *curlun = common->curlun;
1248         int             mscmnd = common->cmnd[0];
1249         u8              *buf = (u8 *) bh->buf;
1250         u8              *buf0 = buf;
1251         int             pc, page_code;
1252         int             changeable_values, all_pages;
1253         int             valid_page = 0;
1254         int             len, limit;
1255
1256         if ((common->cmnd[1] & ~0x08) != 0) {   /* Mask away DBD */
1257                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1258                 return -EINVAL;
1259         }
1260         pc = common->cmnd[2] >> 6;
1261         page_code = common->cmnd[2] & 0x3f;
1262         if (pc == 3) {
1263                 curlun->sense_data = SS_SAVING_PARAMETERS_NOT_SUPPORTED;
1264                 return -EINVAL;
1265         }
1266         changeable_values = (pc == 1);
1267         all_pages = (page_code == 0x3f);
1268
1269         /*
1270          * Write the mode parameter header.  Fixed values are: default
1271          * medium type, no cache control (DPOFUA), and no block descriptors.
1272          * The only variable value is the WriteProtect bit.  We will fill in
1273          * the mode data length later.
1274          */
1275         memset(buf, 0, 8);
1276         if (mscmnd == MODE_SENSE) {
1277                 buf[2] = (curlun->ro ? 0x80 : 0x00);            /* WP, DPOFUA */
1278                 buf += 4;
1279                 limit = 255;
1280         } else {                        /* MODE_SENSE_10 */
1281                 buf[3] = (curlun->ro ? 0x80 : 0x00);            /* WP, DPOFUA */
1282                 buf += 8;
1283                 limit = 65535;          /* Should really be FSG_BUFLEN */
1284         }
1285
1286         /* No block descriptors */
1287
1288         /*
1289          * The mode pages, in numerical order.  The only page we support
1290          * is the Caching page.
1291          */
1292         if (page_code == 0x08 || all_pages) {
1293                 valid_page = 1;
1294                 buf[0] = 0x08;          /* Page code */
1295                 buf[1] = 10;            /* Page length */
1296                 memset(buf+2, 0, 10);   /* None of the fields are changeable */
1297
1298                 if (!changeable_values) {
1299                         buf[2] = 0x04;  /* Write cache enable, */
1300                                         /* Read cache not disabled */
1301                                         /* No cache retention priorities */
1302                         put_unaligned_be16(0xffff, &buf[4]);
1303                                         /* Don't disable prefetch */
1304                                         /* Minimum prefetch = 0 */
1305                         put_unaligned_be16(0xffff, &buf[8]);
1306                                         /* Maximum prefetch */
1307                         put_unaligned_be16(0xffff, &buf[10]);
1308                                         /* Maximum prefetch ceiling */
1309                 }
1310                 buf += 12;
1311         }
1312
1313         /*
1314          * Check that a valid page was requested and the mode data length
1315          * isn't too long.
1316          */
1317         len = buf - buf0;
1318         if (!valid_page || len > limit) {
1319                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1320                 return -EINVAL;
1321         }
1322
1323         /*  Store the mode data length */
1324         if (mscmnd == MODE_SENSE)
1325                 buf0[0] = len - 1;
1326         else
1327                 put_unaligned_be16(len - 2, buf0);
1328         return len;
1329 }
1330
1331 static int do_start_stop(struct fsg_common *common)
1332 {
1333         struct fsg_lun  *curlun = common->curlun;
1334         int             loej, start;
1335
1336         if (!curlun) {
1337                 return -EINVAL;
1338         } else if (!curlun->removable) {
1339                 curlun->sense_data = SS_INVALID_COMMAND;
1340                 return -EINVAL;
1341         } else if ((common->cmnd[1] & ~0x01) != 0 || /* Mask away Immed */
1342                    (common->cmnd[4] & ~0x03) != 0) { /* Mask LoEj, Start */
1343                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1344                 return -EINVAL;
1345         }
1346
1347         loej  = common->cmnd[4] & 0x02;
1348         start = common->cmnd[4] & 0x01;
1349
1350         /*
1351          * Our emulation doesn't support mounting; the medium is
1352          * available for use as soon as it is loaded.
1353          */
1354         if (start) {
1355                 if (!fsg_lun_is_open(curlun)) {
1356                         curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
1357                         return -EINVAL;
1358                 }
1359                 return 0;
1360         }
1361
1362         /* Are we allowed to unload the media? */
1363         if (curlun->prevent_medium_removal) {
1364                 LDBG(curlun, "unload attempt prevented\n");
1365                 curlun->sense_data = SS_MEDIUM_REMOVAL_PREVENTED;
1366                 return -EINVAL;
1367         }
1368
1369         if (!loej)
1370                 return 0;
1371
1372         up_read(&common->filesem);
1373         down_write(&common->filesem);
1374         fsg_lun_close(curlun);
1375         up_write(&common->filesem);
1376         down_read(&common->filesem);
1377
1378         return 0;
1379 }
1380
1381 static int do_prevent_allow(struct fsg_common *common)
1382 {
1383         struct fsg_lun  *curlun = common->curlun;
1384         int             prevent;
1385
1386         if (!common->curlun) {
1387                 return -EINVAL;
1388         } else if (!common->curlun->removable) {
1389                 common->curlun->sense_data = SS_INVALID_COMMAND;
1390                 return -EINVAL;
1391         }
1392
1393         prevent = common->cmnd[4] & 0x01;
1394         if ((common->cmnd[4] & ~0x01) != 0) {   /* Mask away Prevent */
1395                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1396                 return -EINVAL;
1397         }
1398
1399         if (curlun->prevent_medium_removal && !prevent)
1400                 fsg_lun_fsync_sub(curlun);
1401         curlun->prevent_medium_removal = prevent;
1402         return 0;
1403 }
1404
1405 static int do_read_format_capacities(struct fsg_common *common,
1406                         struct fsg_buffhd *bh)
1407 {
1408         struct fsg_lun  *curlun = common->curlun;
1409         u8              *buf = (u8 *) bh->buf;
1410
1411         buf[0] = buf[1] = buf[2] = 0;
1412         buf[3] = 8;     /* Only the Current/Maximum Capacity Descriptor */
1413         buf += 4;
1414
1415         put_unaligned_be32(curlun->num_sectors, &buf[0]);
1416                                                 /* Number of blocks */
1417         put_unaligned_be32(curlun->blksize, &buf[4]);/* Block length */
1418         buf[4] = 0x02;                          /* Current capacity */
1419         return 12;
1420 }
1421
1422 static int do_mode_select(struct fsg_common *common, struct fsg_buffhd *bh)
1423 {
1424         struct fsg_lun  *curlun = common->curlun;
1425
1426         /* We don't support MODE SELECT */
1427         if (curlun)
1428                 curlun->sense_data = SS_INVALID_COMMAND;
1429         return -EINVAL;
1430 }
1431
1432
1433 /*-------------------------------------------------------------------------*/
1434
1435 static int halt_bulk_in_endpoint(struct fsg_dev *fsg)
1436 {
1437         int     rc;
1438
1439         rc = fsg_set_halt(fsg, fsg->bulk_in);
1440         if (rc == -EAGAIN)
1441                 VDBG(fsg, "delayed bulk-in endpoint halt\n");
1442         while (rc != 0) {
1443                 if (rc != -EAGAIN) {
1444                         WARNING(fsg, "usb_ep_set_halt -> %d\n", rc);
1445                         rc = 0;
1446                         break;
1447                 }
1448
1449                 /* Wait for a short time and then try again */
1450                 if (msleep_interruptible(100) != 0)
1451                         return -EINTR;
1452                 rc = usb_ep_set_halt(fsg->bulk_in);
1453         }
1454         return rc;
1455 }
1456
1457 static int wedge_bulk_in_endpoint(struct fsg_dev *fsg)
1458 {
1459         int     rc;
1460
1461         DBG(fsg, "bulk-in set wedge\n");
1462         rc = usb_ep_set_wedge(fsg->bulk_in);
1463         if (rc == -EAGAIN)
1464                 VDBG(fsg, "delayed bulk-in endpoint wedge\n");
1465         while (rc != 0) {
1466                 if (rc != -EAGAIN) {
1467                         WARNING(fsg, "usb_ep_set_wedge -> %d\n", rc);
1468                         rc = 0;
1469                         break;
1470                 }
1471
1472                 /* Wait for a short time and then try again */
1473                 if (msleep_interruptible(100) != 0)
1474                         return -EINTR;
1475                 rc = usb_ep_set_wedge(fsg->bulk_in);
1476         }
1477         return rc;
1478 }
1479
1480 static int throw_away_data(struct fsg_common *common)
1481 {
1482         struct fsg_buffhd       *bh;
1483         u32                     amount;
1484         int                     rc;
1485
1486         for (bh = common->next_buffhd_to_drain;
1487              bh->state != BUF_STATE_EMPTY || common->usb_amount_left > 0;
1488              bh = common->next_buffhd_to_drain) {
1489
1490                 /* Throw away the data in a filled buffer */
1491                 if (bh->state == BUF_STATE_FULL) {
1492                         smp_rmb();
1493                         bh->state = BUF_STATE_EMPTY;
1494                         common->next_buffhd_to_drain = bh->next;
1495
1496                         /* A short packet or an error ends everything */
1497                         if (bh->outreq->actual < bh->bulk_out_intended_length ||
1498                             bh->outreq->status != 0) {
1499                                 raise_exception(common,
1500                                                 FSG_STATE_ABORT_BULK_OUT);
1501                                 return -EINTR;
1502                         }
1503                         continue;
1504                 }
1505
1506                 /* Try to submit another request if we need one */
1507                 bh = common->next_buffhd_to_fill;
1508                 if (bh->state == BUF_STATE_EMPTY
1509                  && common->usb_amount_left > 0) {
1510                         amount = min(common->usb_amount_left, FSG_BUFLEN);
1511
1512                         /*
1513                          * Except at the end of the transfer, amount will be
1514                          * equal to the buffer size, which is divisible by
1515                          * the bulk-out maxpacket size.
1516                          */
1517                         set_bulk_out_req_length(common, bh, amount);
1518                         if (!start_out_transfer(common, bh))
1519                                 /* Dunno what to do if common->fsg is NULL */
1520                                 return -EIO;
1521                         common->next_buffhd_to_fill = bh->next;
1522                         common->usb_amount_left -= amount;
1523                         continue;
1524                 }
1525
1526                 /* Otherwise wait for something to happen */
1527                 rc = sleep_thread(common, true);
1528                 if (rc)
1529                         return rc;
1530         }
1531         return 0;
1532 }
1533
1534 static int finish_reply(struct fsg_common *common)
1535 {
1536         struct fsg_buffhd       *bh = common->next_buffhd_to_fill;
1537         int                     rc = 0;
1538
1539         switch (common->data_dir) {
1540         case DATA_DIR_NONE:
1541                 break;                  /* Nothing to send */
1542
1543         /*
1544          * If we don't know whether the host wants to read or write,
1545          * this must be CB or CBI with an unknown command.  We mustn't
1546          * try to send or receive any data.  So stall both bulk pipes
1547          * if we can and wait for a reset.
1548          */
1549         case DATA_DIR_UNKNOWN:
1550                 if (!common->can_stall) {
1551                         /* Nothing */
1552                 } else if (fsg_is_set(common)) {
1553                         fsg_set_halt(common->fsg, common->fsg->bulk_out);
1554                         rc = halt_bulk_in_endpoint(common->fsg);
1555                 } else {
1556                         /* Don't know what to do if common->fsg is NULL */
1557                         rc = -EIO;
1558                 }
1559                 break;
1560
1561         /* All but the last buffer of data must have already been sent */
1562         case DATA_DIR_TO_HOST:
1563                 if (common->data_size == 0) {
1564                         /* Nothing to send */
1565
1566                 /* Don't know what to do if common->fsg is NULL */
1567                 } else if (!fsg_is_set(common)) {
1568                         rc = -EIO;
1569
1570                 /* If there's no residue, simply send the last buffer */
1571                 } else if (common->residue == 0) {
1572                         bh->inreq->zero = 0;
1573                         if (!start_in_transfer(common, bh))
1574                                 return -EIO;
1575                         common->next_buffhd_to_fill = bh->next;
1576
1577                 /*
1578                  * For Bulk-only, mark the end of the data with a short
1579                  * packet.  If we are allowed to stall, halt the bulk-in
1580                  * endpoint.  (Note: This violates the Bulk-Only Transport
1581                  * specification, which requires us to pad the data if we
1582                  * don't halt the endpoint.  Presumably nobody will mind.)
1583                  */
1584                 } else {
1585                         bh->inreq->zero = 1;
1586                         if (!start_in_transfer(common, bh))
1587                                 rc = -EIO;
1588                         common->next_buffhd_to_fill = bh->next;
1589                         if (common->can_stall)
1590                                 rc = halt_bulk_in_endpoint(common->fsg);
1591                 }
1592                 break;
1593
1594         /*
1595          * We have processed all we want from the data the host has sent.
1596          * There may still be outstanding bulk-out requests.
1597          */
1598         case DATA_DIR_FROM_HOST:
1599                 if (common->residue == 0) {
1600                         /* Nothing to receive */
1601
1602                 /* Did the host stop sending unexpectedly early? */
1603                 } else if (common->short_packet_received) {
1604                         raise_exception(common, FSG_STATE_ABORT_BULK_OUT);
1605                         rc = -EINTR;
1606
1607                 /*
1608                  * We haven't processed all the incoming data.  Even though
1609                  * we may be allowed to stall, doing so would cause a race.
1610                  * The controller may already have ACK'ed all the remaining
1611                  * bulk-out packets, in which case the host wouldn't see a
1612                  * STALL.  Not realizing the endpoint was halted, it wouldn't
1613                  * clear the halt -- leading to problems later on.
1614                  */
1615 #if 0
1616                 } else if (common->can_stall) {
1617                         if (fsg_is_set(common))
1618                                 fsg_set_halt(common->fsg,
1619                                              common->fsg->bulk_out);
1620                         raise_exception(common, FSG_STATE_ABORT_BULK_OUT);
1621                         rc = -EINTR;
1622 #endif
1623
1624                 /*
1625                  * We can't stall.  Read in the excess data and throw it
1626                  * all away.
1627                  */
1628                 } else {
1629                         rc = throw_away_data(common);
1630                 }
1631                 break;
1632         }
1633         return rc;
1634 }
1635
1636 static int send_status(struct fsg_common *common)
1637 {
1638         struct fsg_lun          *curlun = common->curlun;
1639         struct fsg_buffhd       *bh;
1640         struct bulk_cs_wrap     *csw;
1641         int                     rc;
1642         u8                      status = US_BULK_STAT_OK;
1643         u32                     sd, sdinfo = 0;
1644
1645         /* Wait for the next buffer to become available */
1646         bh = common->next_buffhd_to_fill;
1647         while (bh->state != BUF_STATE_EMPTY) {
1648                 rc = sleep_thread(common, true);
1649                 if (rc)
1650                         return rc;
1651         }
1652
1653         if (curlun) {
1654                 sd = curlun->sense_data;
1655                 sdinfo = curlun->sense_data_info;
1656         } else if (common->bad_lun_okay)
1657                 sd = SS_NO_SENSE;
1658         else
1659                 sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
1660
1661         if (common->phase_error) {
1662                 DBG(common, "sending phase-error status\n");
1663                 status = US_BULK_STAT_PHASE;
1664                 sd = SS_INVALID_COMMAND;
1665         } else if (sd != SS_NO_SENSE) {
1666                 DBG(common, "sending command-failure status\n");
1667                 status = US_BULK_STAT_FAIL;
1668                 VDBG(common, "  sense data: SK x%02x, ASC x%02x, ASCQ x%02x;"
1669                                 "  info x%x\n",
1670                                 SK(sd), ASC(sd), ASCQ(sd), sdinfo);
1671         }
1672
1673         /* Store and send the Bulk-only CSW */
1674         csw = (void *)bh->buf;
1675
1676         csw->Signature = cpu_to_le32(US_BULK_CS_SIGN);
1677         csw->Tag = common->tag;
1678         csw->Residue = cpu_to_le32(common->residue);
1679         csw->Status = status;
1680
1681         bh->inreq->length = US_BULK_CS_WRAP_LEN;
1682         bh->inreq->zero = 0;
1683         if (!start_in_transfer(common, bh))
1684                 /* Don't know what to do if common->fsg is NULL */
1685                 return -EIO;
1686
1687         common->next_buffhd_to_fill = bh->next;
1688         return 0;
1689 }
1690
1691
1692 /*-------------------------------------------------------------------------*/
1693
1694 /*
1695  * Check whether the command is properly formed and whether its data size
1696  * and direction agree with the values we already have.
1697  */
1698 static int check_command(struct fsg_common *common, int cmnd_size,
1699                          enum data_direction data_dir, unsigned int mask,
1700                          int needs_medium, const char *name)
1701 {
1702         int                     i;
1703         unsigned int            lun = common->cmnd[1] >> 5;
1704         static const char       dirletter[4] = {'u', 'o', 'i', 'n'};
1705         char                    hdlen[20];
1706         struct fsg_lun          *curlun;
1707
1708         hdlen[0] = 0;
1709         if (common->data_dir != DATA_DIR_UNKNOWN)
1710                 sprintf(hdlen, ", H%c=%u", dirletter[(int) common->data_dir],
1711                         common->data_size);
1712         VDBG(common, "SCSI command: %s;  Dc=%d, D%c=%u;  Hc=%d%s\n",
1713              name, cmnd_size, dirletter[(int) data_dir],
1714              common->data_size_from_cmnd, common->cmnd_size, hdlen);
1715
1716         /*
1717          * We can't reply at all until we know the correct data direction
1718          * and size.
1719          */
1720         if (common->data_size_from_cmnd == 0)
1721                 data_dir = DATA_DIR_NONE;
1722         if (common->data_size < common->data_size_from_cmnd) {
1723                 /*
1724                  * Host data size < Device data size is a phase error.
1725                  * Carry out the command, but only transfer as much as
1726                  * we are allowed.
1727                  */
1728                 common->data_size_from_cmnd = common->data_size;
1729                 common->phase_error = 1;
1730         }
1731         common->residue = common->data_size;
1732         common->usb_amount_left = common->data_size;
1733
1734         /* Conflicting data directions is a phase error */
1735         if (common->data_dir != data_dir && common->data_size_from_cmnd > 0) {
1736                 common->phase_error = 1;
1737                 return -EINVAL;
1738         }
1739
1740         /* Verify the length of the command itself */
1741         if (cmnd_size != common->cmnd_size) {
1742
1743                 /*
1744                  * Special case workaround: There are plenty of buggy SCSI
1745                  * implementations. Many have issues with cbw->Length
1746                  * field passing a wrong command size. For those cases we
1747                  * always try to work around the problem by using the length
1748                  * sent by the host side provided it is at least as large
1749                  * as the correct command length.
1750                  * Examples of such cases would be MS-Windows, which issues
1751                  * REQUEST SENSE with cbw->Length == 12 where it should
1752                  * be 6, and xbox360 issuing INQUIRY, TEST UNIT READY and
1753                  * REQUEST SENSE with cbw->Length == 10 where it should
1754                  * be 6 as well.
1755                  */
1756                 if (cmnd_size <= common->cmnd_size) {
1757                         DBG(common, "%s is buggy! Expected length %d "
1758                             "but we got %d\n", name,
1759                             cmnd_size, common->cmnd_size);
1760                         cmnd_size = common->cmnd_size;
1761                 } else {
1762                         common->phase_error = 1;
1763                         return -EINVAL;
1764                 }
1765         }
1766
1767         /* Check that the LUN values are consistent */
1768         if (common->lun != lun)
1769                 DBG(common, "using LUN %u from CBW, not LUN %u from CDB\n",
1770                     common->lun, lun);
1771
1772         /* Check the LUN */
1773         curlun = common->curlun;
1774         if (curlun) {
1775                 if (common->cmnd[0] != REQUEST_SENSE) {
1776                         curlun->sense_data = SS_NO_SENSE;
1777                         curlun->sense_data_info = 0;
1778                         curlun->info_valid = 0;
1779                 }
1780         } else {
1781                 common->bad_lun_okay = 0;
1782
1783                 /*
1784                  * INQUIRY and REQUEST SENSE commands are explicitly allowed
1785                  * to use unsupported LUNs; all others may not.
1786                  */
1787                 if (common->cmnd[0] != INQUIRY &&
1788                     common->cmnd[0] != REQUEST_SENSE) {
1789                         DBG(common, "unsupported LUN %u\n", common->lun);
1790                         return -EINVAL;
1791                 }
1792         }
1793
1794         /*
1795          * If a unit attention condition exists, only INQUIRY and
1796          * REQUEST SENSE commands are allowed; anything else must fail.
1797          */
1798         if (curlun && curlun->unit_attention_data != SS_NO_SENSE &&
1799             common->cmnd[0] != INQUIRY &&
1800             common->cmnd[0] != REQUEST_SENSE) {
1801                 curlun->sense_data = curlun->unit_attention_data;
1802                 curlun->unit_attention_data = SS_NO_SENSE;
1803                 return -EINVAL;
1804         }
1805
1806         /* Check that only command bytes listed in the mask are non-zero */
1807         common->cmnd[1] &= 0x1f;                        /* Mask away the LUN */
1808         for (i = 1; i < cmnd_size; ++i) {
1809                 if (common->cmnd[i] && !(mask & (1 << i))) {
1810                         if (curlun)
1811                                 curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1812                         return -EINVAL;
1813                 }
1814         }
1815
1816         /* If the medium isn't mounted and the command needs to access
1817          * it, return an error. */
1818         if (curlun && !fsg_lun_is_open(curlun) && needs_medium) {
1819                 curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
1820                 return -EINVAL;
1821         }
1822
1823         return 0;
1824 }
1825
1826 /* wrapper of check_command for data size in blocks handling */
1827 static int check_command_size_in_blocks(struct fsg_common *common,
1828                 int cmnd_size, enum data_direction data_dir,
1829                 unsigned int mask, int needs_medium, const char *name)
1830 {
1831         if (common->curlun)
1832                 common->data_size_from_cmnd <<= common->curlun->blkbits;
1833         return check_command(common, cmnd_size, data_dir,
1834                         mask, needs_medium, name);
1835 }
1836
1837 static int do_scsi_command(struct fsg_common *common)
1838 {
1839         struct fsg_buffhd       *bh;
1840         int                     rc;
1841         int                     reply = -EINVAL;
1842         int                     i;
1843         static char             unknown[16];
1844
1845         dump_cdb(common);
1846
1847         /* Wait for the next buffer to become available for data or status */
1848         bh = common->next_buffhd_to_fill;
1849         common->next_buffhd_to_drain = bh;
1850         while (bh->state != BUF_STATE_EMPTY) {
1851                 rc = sleep_thread(common, true);
1852                 if (rc)
1853                         return rc;
1854         }
1855         common->phase_error = 0;
1856         common->short_packet_received = 0;
1857
1858         down_read(&common->filesem);    /* We're using the backing file */
1859         switch (common->cmnd[0]) {
1860
1861         case INQUIRY:
1862                 common->data_size_from_cmnd = common->cmnd[4];
1863                 reply = check_command(common, 6, DATA_DIR_TO_HOST,
1864                                       (1<<4), 0,
1865                                       "INQUIRY");
1866                 if (reply == 0)
1867                         reply = do_inquiry(common, bh);
1868                 break;
1869
1870         case MODE_SELECT:
1871                 common->data_size_from_cmnd = common->cmnd[4];
1872                 reply = check_command(common, 6, DATA_DIR_FROM_HOST,
1873                                       (1<<1) | (1<<4), 0,
1874                                       "MODE SELECT(6)");
1875                 if (reply == 0)
1876                         reply = do_mode_select(common, bh);
1877                 break;
1878
1879         case MODE_SELECT_10:
1880                 common->data_size_from_cmnd =
1881                         get_unaligned_be16(&common->cmnd[7]);
1882                 reply = check_command(common, 10, DATA_DIR_FROM_HOST,
1883                                       (1<<1) | (3<<7), 0,
1884                                       "MODE SELECT(10)");
1885                 if (reply == 0)
1886                         reply = do_mode_select(common, bh);
1887                 break;
1888
1889         case MODE_SENSE:
1890                 common->data_size_from_cmnd = common->cmnd[4];
1891                 reply = check_command(common, 6, DATA_DIR_TO_HOST,
1892                                       (1<<1) | (1<<2) | (1<<4), 0,
1893                                       "MODE SENSE(6)");
1894                 if (reply == 0)
1895                         reply = do_mode_sense(common, bh);
1896                 break;
1897
1898         case MODE_SENSE_10:
1899                 common->data_size_from_cmnd =
1900                         get_unaligned_be16(&common->cmnd[7]);
1901                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
1902                                       (1<<1) | (1<<2) | (3<<7), 0,
1903                                       "MODE SENSE(10)");
1904                 if (reply == 0)
1905                         reply = do_mode_sense(common, bh);
1906                 break;
1907
1908         case ALLOW_MEDIUM_REMOVAL:
1909                 common->data_size_from_cmnd = 0;
1910                 reply = check_command(common, 6, DATA_DIR_NONE,
1911                                       (1<<4), 0,
1912                                       "PREVENT-ALLOW MEDIUM REMOVAL");
1913                 if (reply == 0)
1914                         reply = do_prevent_allow(common);
1915                 break;
1916
1917         case READ_6:
1918                 i = common->cmnd[4];
1919                 common->data_size_from_cmnd = (i == 0) ? 256 : i;
1920                 reply = check_command_size_in_blocks(common, 6,
1921                                       DATA_DIR_TO_HOST,
1922                                       (7<<1) | (1<<4), 1,
1923                                       "READ(6)");
1924                 if (reply == 0)
1925                         reply = do_read(common);
1926                 break;
1927
1928         case READ_10:
1929                 common->data_size_from_cmnd =
1930                                 get_unaligned_be16(&common->cmnd[7]);
1931                 reply = check_command_size_in_blocks(common, 10,
1932                                       DATA_DIR_TO_HOST,
1933                                       (1<<1) | (0xf<<2) | (3<<7), 1,
1934                                       "READ(10)");
1935                 if (reply == 0)
1936                         reply = do_read(common);
1937                 break;
1938
1939         case READ_12:
1940                 common->data_size_from_cmnd =
1941                                 get_unaligned_be32(&common->cmnd[6]);
1942                 reply = check_command_size_in_blocks(common, 12,
1943                                       DATA_DIR_TO_HOST,
1944                                       (1<<1) | (0xf<<2) | (0xf<<6), 1,
1945                                       "READ(12)");
1946                 if (reply == 0)
1947                         reply = do_read(common);
1948                 break;
1949
1950         case READ_CAPACITY:
1951                 common->data_size_from_cmnd = 8;
1952                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
1953                                       (0xf<<2) | (1<<8), 1,
1954                                       "READ CAPACITY");
1955                 if (reply == 0)
1956                         reply = do_read_capacity(common, bh);
1957                 break;
1958
1959         case READ_HEADER:
1960                 if (!common->curlun || !common->curlun->cdrom)
1961                         goto unknown_cmnd;
1962                 common->data_size_from_cmnd =
1963                         get_unaligned_be16(&common->cmnd[7]);
1964                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
1965                                       (3<<7) | (0x1f<<1), 1,
1966                                       "READ HEADER");
1967                 if (reply == 0)
1968                         reply = do_read_header(common, bh);
1969                 break;
1970
1971         case READ_TOC:
1972                 if (!common->curlun || !common->curlun->cdrom)
1973                         goto unknown_cmnd;
1974                 common->data_size_from_cmnd =
1975                         get_unaligned_be16(&common->cmnd[7]);
1976                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
1977                                       (7<<6) | (1<<1), 1,
1978                                       "READ TOC");
1979                 if (reply == 0)
1980                         reply = do_read_toc(common, bh);
1981                 break;
1982
1983         case READ_FORMAT_CAPACITIES:
1984                 common->data_size_from_cmnd =
1985                         get_unaligned_be16(&common->cmnd[7]);
1986                 reply = check_command(common, 10, DATA_DIR_TO_HOST,
1987                                       (3<<7), 1,
1988                                       "READ FORMAT CAPACITIES");
1989                 if (reply == 0)
1990                         reply = do_read_format_capacities(common, bh);
1991                 break;
1992
1993         case REQUEST_SENSE:
1994                 common->data_size_from_cmnd = common->cmnd[4];
1995                 reply = check_command(common, 6, DATA_DIR_TO_HOST,
1996                                       (1<<4), 0,
1997                                       "REQUEST SENSE");
1998                 if (reply == 0)
1999                         reply = do_request_sense(common, bh);
2000                 break;
2001
2002         case START_STOP:
2003                 common->data_size_from_cmnd = 0;
2004                 reply = check_command(common, 6, DATA_DIR_NONE,
2005                                       (1<<1) | (1<<4), 0,
2006                                       "START-STOP UNIT");
2007                 if (reply == 0)
2008                         reply = do_start_stop(common);
2009                 break;
2010
2011         case SYNCHRONIZE_CACHE:
2012                 common->data_size_from_cmnd = 0;
2013                 reply = check_command(common, 10, DATA_DIR_NONE,
2014                                       (0xf<<2) | (3<<7), 1,
2015                                       "SYNCHRONIZE CACHE");
2016                 if (reply == 0)
2017                         reply = do_synchronize_cache(common);
2018                 break;
2019
2020         case TEST_UNIT_READY:
2021                 common->data_size_from_cmnd = 0;
2022                 reply = check_command(common, 6, DATA_DIR_NONE,
2023                                 0, 1,
2024                                 "TEST UNIT READY");
2025                 break;
2026
2027         /*
2028          * Although optional, this command is used by MS-Windows.  We
2029          * support a minimal version: BytChk must be 0.
2030          */
2031         case VERIFY:
2032                 common->data_size_from_cmnd = 0;
2033                 reply = check_command(common, 10, DATA_DIR_NONE,
2034                                       (1<<1) | (0xf<<2) | (3<<7), 1,
2035                                       "VERIFY");
2036                 if (reply == 0)
2037                         reply = do_verify(common);
2038                 break;
2039
2040         case WRITE_6:
2041                 i = common->cmnd[4];
2042                 common->data_size_from_cmnd = (i == 0) ? 256 : i;
2043                 reply = check_command_size_in_blocks(common, 6,
2044                                       DATA_DIR_FROM_HOST,
2045                                       (7<<1) | (1<<4), 1,
2046                                       "WRITE(6)");
2047                 if (reply == 0)
2048                         reply = do_write(common);
2049                 break;
2050
2051         case WRITE_10:
2052                 common->data_size_from_cmnd =
2053                                 get_unaligned_be16(&common->cmnd[7]);
2054                 reply = check_command_size_in_blocks(common, 10,
2055                                       DATA_DIR_FROM_HOST,
2056                                       (1<<1) | (0xf<<2) | (3<<7), 1,
2057                                       "WRITE(10)");
2058                 if (reply == 0)
2059                         reply = do_write(common);
2060                 break;
2061
2062         case WRITE_12:
2063                 common->data_size_from_cmnd =
2064                                 get_unaligned_be32(&common->cmnd[6]);
2065                 reply = check_command_size_in_blocks(common, 12,
2066                                       DATA_DIR_FROM_HOST,
2067                                       (1<<1) | (0xf<<2) | (0xf<<6), 1,
2068                                       "WRITE(12)");
2069                 if (reply == 0)
2070                         reply = do_write(common);
2071                 break;
2072
2073         /*
2074          * Some mandatory commands that we recognize but don't implement.
2075          * They don't mean much in this setting.  It's left as an exercise
2076          * for anyone interested to implement RESERVE and RELEASE in terms
2077          * of Posix locks.
2078          */
2079         case FORMAT_UNIT:
2080         case RELEASE:
2081         case RESERVE:
2082         case SEND_DIAGNOSTIC:
2083                 /* Fall through */
2084
2085         default:
2086 unknown_cmnd:
2087                 common->data_size_from_cmnd = 0;
2088                 sprintf(unknown, "Unknown x%02x", common->cmnd[0]);
2089                 reply = check_command(common, common->cmnd_size,
2090                                       DATA_DIR_UNKNOWN, ~0, 0, unknown);
2091                 if (reply == 0) {
2092                         common->curlun->sense_data = SS_INVALID_COMMAND;
2093                         reply = -EINVAL;
2094                 }
2095                 break;
2096         }
2097         up_read(&common->filesem);
2098
2099         if (reply == -EINTR || signal_pending(current))
2100                 return -EINTR;
2101
2102         /* Set up the single reply buffer for finish_reply() */
2103         if (reply == -EINVAL)
2104                 reply = 0;              /* Error reply length */
2105         if (reply >= 0 && common->data_dir == DATA_DIR_TO_HOST) {
2106                 reply = min((u32)reply, common->data_size_from_cmnd);
2107                 bh->inreq->length = reply;
2108                 bh->state = BUF_STATE_FULL;
2109                 common->residue -= reply;
2110         }                               /* Otherwise it's already set */
2111
2112         return 0;
2113 }
2114
2115
2116 /*-------------------------------------------------------------------------*/
2117
2118 static int received_cbw(struct fsg_dev *fsg, struct fsg_buffhd *bh)
2119 {
2120         struct usb_request      *req = bh->outreq;
2121         struct bulk_cb_wrap     *cbw = req->buf;
2122         struct fsg_common       *common = fsg->common;
2123
2124         /* Was this a real packet?  Should it be ignored? */
2125         if (req->status || test_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags))
2126                 return -EINVAL;
2127
2128         /* Is the CBW valid? */
2129         if (req->actual != US_BULK_CB_WRAP_LEN ||
2130                         cbw->Signature != cpu_to_le32(
2131                                 US_BULK_CB_SIGN)) {
2132                 DBG(fsg, "invalid CBW: len %u sig 0x%x\n",
2133                                 req->actual,
2134                                 le32_to_cpu(cbw->Signature));
2135
2136                 /*
2137                  * The Bulk-only spec says we MUST stall the IN endpoint
2138                  * (6.6.1), so it's unavoidable.  It also says we must
2139                  * retain this state until the next reset, but there's
2140                  * no way to tell the controller driver it should ignore
2141                  * Clear-Feature(HALT) requests.
2142                  *
2143                  * We aren't required to halt the OUT endpoint; instead
2144                  * we can simply accept and discard any data received
2145                  * until the next reset.
2146                  */
2147                 wedge_bulk_in_endpoint(fsg);
2148                 set_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
2149                 return -EINVAL;
2150         }
2151
2152         /* Is the CBW meaningful? */
2153         if (cbw->Lun >= ARRAY_SIZE(common->luns) ||
2154             cbw->Flags & ~US_BULK_FLAG_IN || cbw->Length <= 0 ||
2155             cbw->Length > MAX_COMMAND_SIZE) {
2156                 DBG(fsg, "non-meaningful CBW: lun = %u, flags = 0x%x, "
2157                                 "cmdlen %u\n",
2158                                 cbw->Lun, cbw->Flags, cbw->Length);
2159
2160                 /*
2161                  * We can do anything we want here, so let's stall the
2162                  * bulk pipes if we are allowed to.
2163                  */
2164                 if (common->can_stall) {
2165                         fsg_set_halt(fsg, fsg->bulk_out);
2166                         halt_bulk_in_endpoint(fsg);
2167                 }
2168                 return -EINVAL;
2169         }
2170
2171         /* Save the command for later */
2172         common->cmnd_size = cbw->Length;
2173         memcpy(common->cmnd, cbw->CDB, common->cmnd_size);
2174         if (cbw->Flags & US_BULK_FLAG_IN)
2175                 common->data_dir = DATA_DIR_TO_HOST;
2176         else
2177                 common->data_dir = DATA_DIR_FROM_HOST;
2178         common->data_size = le32_to_cpu(cbw->DataTransferLength);
2179         if (common->data_size == 0)
2180                 common->data_dir = DATA_DIR_NONE;
2181         common->lun = cbw->Lun;
2182         if (common->lun < ARRAY_SIZE(common->luns))
2183                 common->curlun = common->luns[common->lun];
2184         else
2185                 common->curlun = NULL;
2186         common->tag = cbw->Tag;
2187         return 0;
2188 }
2189
2190 static int get_next_command(struct fsg_common *common)
2191 {
2192         struct fsg_buffhd       *bh;
2193         int                     rc = 0;
2194
2195         /* Wait for the next buffer to become available */
2196         bh = common->next_buffhd_to_fill;
2197         while (bh->state != BUF_STATE_EMPTY) {
2198                 rc = sleep_thread(common, true);
2199                 if (rc)
2200                         return rc;
2201         }
2202
2203         /* Queue a request to read a Bulk-only CBW */
2204         set_bulk_out_req_length(common, bh, US_BULK_CB_WRAP_LEN);
2205         if (!start_out_transfer(common, bh))
2206                 /* Don't know what to do if common->fsg is NULL */
2207                 return -EIO;
2208
2209         /*
2210          * We will drain the buffer in software, which means we
2211          * can reuse it for the next filling.  No need to advance
2212          * next_buffhd_to_fill.
2213          */
2214
2215         /* Wait for the CBW to arrive */
2216         while (bh->state != BUF_STATE_FULL) {
2217                 rc = sleep_thread(common, true);
2218                 if (rc)
2219                         return rc;
2220         }
2221         smp_rmb();
2222         rc = fsg_is_set(common) ? received_cbw(common->fsg, bh) : -EIO;
2223         bh->state = BUF_STATE_EMPTY;
2224
2225         return rc;
2226 }
2227
2228
2229 /*-------------------------------------------------------------------------*/
2230
2231 static int alloc_request(struct fsg_common *common, struct usb_ep *ep,
2232                 struct usb_request **preq)
2233 {
2234         *preq = usb_ep_alloc_request(ep, GFP_ATOMIC);
2235         if (*preq)
2236                 return 0;
2237         ERROR(common, "can't allocate request for %s\n", ep->name);
2238         return -ENOMEM;
2239 }
2240
2241 /* Reset interface setting and re-init endpoint state (toggle etc). */
2242 static int do_set_interface(struct fsg_common *common, struct fsg_dev *new_fsg)
2243 {
2244         struct fsg_dev *fsg;
2245         int i, rc = 0;
2246
2247         if (common->running)
2248                 DBG(common, "reset interface\n");
2249
2250 reset:
2251         /* Deallocate the requests */
2252         if (common->fsg) {
2253                 fsg = common->fsg;
2254
2255                 for (i = 0; i < common->fsg_num_buffers; ++i) {
2256                         struct fsg_buffhd *bh = &common->buffhds[i];
2257
2258                         if (bh->inreq) {
2259                                 usb_ep_free_request(fsg->bulk_in, bh->inreq);
2260                                 bh->inreq = NULL;
2261                         }
2262                         if (bh->outreq) {
2263                                 usb_ep_free_request(fsg->bulk_out, bh->outreq);
2264                                 bh->outreq = NULL;
2265                         }
2266                 }
2267
2268                 /* Disable the endpoints */
2269                 if (fsg->bulk_in_enabled) {
2270                         usb_ep_disable(fsg->bulk_in);
2271                         fsg->bulk_in_enabled = 0;
2272                 }
2273                 if (fsg->bulk_out_enabled) {
2274                         usb_ep_disable(fsg->bulk_out);
2275                         fsg->bulk_out_enabled = 0;
2276                 }
2277
2278                 common->fsg = NULL;
2279                 wake_up(&common->fsg_wait);
2280         }
2281
2282         common->running = 0;
2283         if (!new_fsg || rc)
2284                 return rc;
2285
2286         common->fsg = new_fsg;
2287         fsg = common->fsg;
2288
2289         /* Enable the endpoints */
2290         rc = config_ep_by_speed(common->gadget, &(fsg->function), fsg->bulk_in);
2291         if (rc)
2292                 goto reset;
2293         rc = usb_ep_enable(fsg->bulk_in);
2294         if (rc)
2295                 goto reset;
2296         fsg->bulk_in->driver_data = common;
2297         fsg->bulk_in_enabled = 1;
2298
2299         rc = config_ep_by_speed(common->gadget, &(fsg->function),
2300                                 fsg->bulk_out);
2301         if (rc)
2302                 goto reset;
2303         rc = usb_ep_enable(fsg->bulk_out);
2304         if (rc)
2305                 goto reset;
2306         fsg->bulk_out->driver_data = common;
2307         fsg->bulk_out_enabled = 1;
2308         common->bulk_out_maxpacket = usb_endpoint_maxp(fsg->bulk_out->desc);
2309         clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
2310
2311         /* Allocate the requests */
2312         for (i = 0; i < common->fsg_num_buffers; ++i) {
2313                 struct fsg_buffhd       *bh = &common->buffhds[i];
2314
2315                 rc = alloc_request(common, fsg->bulk_in, &bh->inreq);
2316                 if (rc)
2317                         goto reset;
2318                 rc = alloc_request(common, fsg->bulk_out, &bh->outreq);
2319                 if (rc)
2320                         goto reset;
2321                 bh->inreq->buf = bh->outreq->buf = bh->buf;
2322                 bh->inreq->context = bh->outreq->context = bh;
2323                 bh->inreq->complete = bulk_in_complete;
2324                 bh->outreq->complete = bulk_out_complete;
2325         }
2326
2327         common->running = 1;
2328         for (i = 0; i < ARRAY_SIZE(common->luns); ++i)
2329                 if (common->luns[i])
2330                         common->luns[i]->unit_attention_data =
2331                                 SS_RESET_OCCURRED;
2332         return rc;
2333 }
2334
2335
2336 /****************************** ALT CONFIGS ******************************/
2337
2338 static int fsg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
2339 {
2340         struct fsg_dev *fsg = fsg_from_func(f);
2341         fsg->common->new_fsg = fsg;
2342         raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
2343         return USB_GADGET_DELAYED_STATUS;
2344 }
2345
2346 static void fsg_disable(struct usb_function *f)
2347 {
2348         struct fsg_dev *fsg = fsg_from_func(f);
2349         fsg->common->new_fsg = NULL;
2350         raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
2351 }
2352
2353
2354 /*-------------------------------------------------------------------------*/
2355
2356 static void handle_exception(struct fsg_common *common)
2357 {
2358         int                     i;
2359         struct fsg_buffhd       *bh;
2360         enum fsg_state          old_state;
2361         struct fsg_lun          *curlun;
2362         unsigned int            exception_req_tag;
2363
2364         /*
2365          * Clear the existing signals.  Anything but SIGUSR1 is converted
2366          * into a high-priority EXIT exception.
2367          */
2368         for (;;) {
2369                 int sig = kernel_dequeue_signal(NULL);
2370                 if (!sig)
2371                         break;
2372                 if (sig != SIGUSR1) {
2373                         if (common->state < FSG_STATE_EXIT)
2374                                 DBG(common, "Main thread exiting on signal\n");
2375                         raise_exception(common, FSG_STATE_EXIT);
2376                 }
2377         }
2378
2379         /* Cancel all the pending transfers */
2380         if (likely(common->fsg)) {
2381                 for (i = 0; i < common->fsg_num_buffers; ++i) {
2382                         bh = &common->buffhds[i];
2383                         if (bh->inreq_busy)
2384                                 usb_ep_dequeue(common->fsg->bulk_in, bh->inreq);
2385                         if (bh->outreq_busy)
2386                                 usb_ep_dequeue(common->fsg->bulk_out,
2387                                                bh->outreq);
2388                 }
2389
2390                 /* Wait until everything is idle */
2391                 for (;;) {
2392                         int num_active = 0;
2393                         for (i = 0; i < common->fsg_num_buffers; ++i) {
2394                                 bh = &common->buffhds[i];
2395                                 num_active += bh->inreq_busy + bh->outreq_busy;
2396                         }
2397                         if (num_active == 0)
2398                                 break;
2399                         if (sleep_thread(common, true))
2400                                 return;
2401                 }
2402
2403                 /* Clear out the controller's fifos */
2404                 if (common->fsg->bulk_in_enabled)
2405                         usb_ep_fifo_flush(common->fsg->bulk_in);
2406                 if (common->fsg->bulk_out_enabled)
2407                         usb_ep_fifo_flush(common->fsg->bulk_out);
2408         }
2409
2410         /*
2411          * Reset the I/O buffer states and pointers, the SCSI
2412          * state, and the exception.  Then invoke the handler.
2413          */
2414         spin_lock_irq(&common->lock);
2415
2416         for (i = 0; i < common->fsg_num_buffers; ++i) {
2417                 bh = &common->buffhds[i];
2418                 bh->state = BUF_STATE_EMPTY;
2419         }
2420         common->next_buffhd_to_fill = &common->buffhds[0];
2421         common->next_buffhd_to_drain = &common->buffhds[0];
2422         exception_req_tag = common->exception_req_tag;
2423         old_state = common->state;
2424
2425         if (old_state == FSG_STATE_ABORT_BULK_OUT)
2426                 common->state = FSG_STATE_STATUS_PHASE;
2427         else {
2428                 for (i = 0; i < ARRAY_SIZE(common->luns); ++i) {
2429                         curlun = common->luns[i];
2430                         if (!curlun)
2431                                 continue;
2432                         curlun->prevent_medium_removal = 0;
2433                         curlun->sense_data = SS_NO_SENSE;
2434                         curlun->unit_attention_data = SS_NO_SENSE;
2435                         curlun->sense_data_info = 0;
2436                         curlun->info_valid = 0;
2437                 }
2438                 common->state = FSG_STATE_IDLE;
2439         }
2440         spin_unlock_irq(&common->lock);
2441
2442         /* Carry out any extra actions required for the exception */
2443         switch (old_state) {
2444         case FSG_STATE_ABORT_BULK_OUT:
2445                 send_status(common);
2446                 spin_lock_irq(&common->lock);
2447                 if (common->state == FSG_STATE_STATUS_PHASE)
2448                         common->state = FSG_STATE_IDLE;
2449                 spin_unlock_irq(&common->lock);
2450                 break;
2451
2452         case FSG_STATE_RESET:
2453                 /*
2454                  * In case we were forced against our will to halt a
2455                  * bulk endpoint, clear the halt now.  (The SuperH UDC
2456                  * requires this.)
2457                  */
2458                 if (!fsg_is_set(common))
2459                         break;
2460                 if (test_and_clear_bit(IGNORE_BULK_OUT,
2461                                        &common->fsg->atomic_bitflags))
2462                         usb_ep_clear_halt(common->fsg->bulk_in);
2463
2464                 if (common->ep0_req_tag == exception_req_tag)
2465                         ep0_queue(common);      /* Complete the status stage */
2466
2467                 /*
2468                  * Technically this should go here, but it would only be
2469                  * a waste of time.  Ditto for the INTERFACE_CHANGE and
2470                  * CONFIG_CHANGE cases.
2471                  */
2472                 /* for (i = 0; i < common->ARRAY_SIZE(common->luns); ++i) */
2473                 /*      if (common->luns[i]) */
2474                 /*              common->luns[i]->unit_attention_data = */
2475                 /*                      SS_RESET_OCCURRED;  */
2476                 break;
2477
2478         case FSG_STATE_CONFIG_CHANGE:
2479                 do_set_interface(common, common->new_fsg);
2480                 if (common->new_fsg)
2481                         usb_composite_setup_continue(common->cdev);
2482                 break;
2483
2484         case FSG_STATE_EXIT:
2485         case FSG_STATE_TERMINATED:
2486                 do_set_interface(common, NULL);         /* Free resources */
2487                 spin_lock_irq(&common->lock);
2488                 common->state = FSG_STATE_TERMINATED;   /* Stop the thread */
2489                 spin_unlock_irq(&common->lock);
2490                 break;
2491
2492         case FSG_STATE_INTERFACE_CHANGE:
2493         case FSG_STATE_DISCONNECT:
2494         case FSG_STATE_COMMAND_PHASE:
2495         case FSG_STATE_DATA_PHASE:
2496         case FSG_STATE_STATUS_PHASE:
2497         case FSG_STATE_IDLE:
2498                 break;
2499         }
2500 }
2501
2502
2503 /*-------------------------------------------------------------------------*/
2504
2505 static int fsg_main_thread(void *common_)
2506 {
2507         struct fsg_common       *common = common_;
2508         int                     i;
2509
2510         /*
2511          * Allow the thread to be killed by a signal, but set the signal mask
2512          * to block everything but INT, TERM, KILL, and USR1.
2513          */
2514         allow_signal(SIGINT);
2515         allow_signal(SIGTERM);
2516         allow_signal(SIGKILL);
2517         allow_signal(SIGUSR1);
2518
2519         /* Allow the thread to be frozen */
2520         set_freezable();
2521
2522         /*
2523          * Arrange for userspace references to be interpreted as kernel
2524          * pointers.  That way we can pass a kernel pointer to a routine
2525          * that expects a __user pointer and it will work okay.
2526          */
2527         set_fs(get_ds());
2528
2529         /* The main loop */
2530         while (common->state != FSG_STATE_TERMINATED) {
2531                 if (exception_in_progress(common) || signal_pending(current)) {
2532                         handle_exception(common);
2533                         continue;
2534                 }
2535
2536                 if (!common->running) {
2537                         sleep_thread(common, true);
2538                         continue;
2539                 }
2540
2541                 if (get_next_command(common))
2542                         continue;
2543
2544                 spin_lock_irq(&common->lock);
2545                 if (!exception_in_progress(common))
2546                         common->state = FSG_STATE_DATA_PHASE;
2547                 spin_unlock_irq(&common->lock);
2548
2549                 if (do_scsi_command(common) || finish_reply(common))
2550                         continue;
2551
2552                 spin_lock_irq(&common->lock);
2553                 if (!exception_in_progress(common))
2554                         common->state = FSG_STATE_STATUS_PHASE;
2555                 spin_unlock_irq(&common->lock);
2556
2557                 if (send_status(common))
2558                         continue;
2559
2560                 spin_lock_irq(&common->lock);
2561                 if (!exception_in_progress(common))
2562                         common->state = FSG_STATE_IDLE;
2563                 spin_unlock_irq(&common->lock);
2564         }
2565
2566         spin_lock_irq(&common->lock);
2567         common->thread_task = NULL;
2568         spin_unlock_irq(&common->lock);
2569
2570         /* Eject media from all LUNs */
2571
2572         down_write(&common->filesem);
2573         for (i = 0; i < ARRAY_SIZE(common->luns); i++) {
2574                 struct fsg_lun *curlun = common->luns[i];
2575
2576                 if (curlun && fsg_lun_is_open(curlun))
2577                         fsg_lun_close(curlun);
2578         }
2579         up_write(&common->filesem);
2580
2581         /* Let fsg_unbind() know the thread has exited */
2582         complete_and_exit(&common->thread_notifier, 0);
2583 }
2584
2585
2586 /*************************** DEVICE ATTRIBUTES ***************************/
2587
2588 static ssize_t ro_show(struct device *dev, struct device_attribute *attr, char *buf)
2589 {
2590         struct fsg_lun          *curlun = fsg_lun_from_dev(dev);
2591
2592         return fsg_show_ro(curlun, buf);
2593 }
2594
2595 static ssize_t nofua_show(struct device *dev, struct device_attribute *attr,
2596                           char *buf)
2597 {
2598         struct fsg_lun          *curlun = fsg_lun_from_dev(dev);
2599
2600         return fsg_show_nofua(curlun, buf);
2601 }
2602
2603 static ssize_t file_show(struct device *dev, struct device_attribute *attr,
2604                          char *buf)
2605 {
2606         struct fsg_lun          *curlun = fsg_lun_from_dev(dev);
2607         struct rw_semaphore     *filesem = dev_get_drvdata(dev);
2608
2609         return fsg_show_file(curlun, filesem, buf);
2610 }
2611
2612 static ssize_t ro_store(struct device *dev, struct device_attribute *attr,
2613                         const char *buf, size_t count)
2614 {
2615         struct fsg_lun          *curlun = fsg_lun_from_dev(dev);
2616         struct rw_semaphore     *filesem = dev_get_drvdata(dev);
2617
2618         return fsg_store_ro(curlun, filesem, buf, count);
2619 }
2620
2621 static ssize_t nofua_store(struct device *dev, struct device_attribute *attr,
2622                            const char *buf, size_t count)
2623 {
2624         struct fsg_lun          *curlun = fsg_lun_from_dev(dev);
2625
2626         return fsg_store_nofua(curlun, buf, count);
2627 }
2628
2629 static ssize_t file_store(struct device *dev, struct device_attribute *attr,
2630                           const char *buf, size_t count)
2631 {
2632         struct fsg_lun          *curlun = fsg_lun_from_dev(dev);
2633         struct rw_semaphore     *filesem = dev_get_drvdata(dev);
2634
2635         return fsg_store_file(curlun, filesem, buf, count);
2636 }
2637
2638 static DEVICE_ATTR_RW(nofua);
2639 /* mode wil be set in fsg_lun_attr_is_visible() */
2640 static DEVICE_ATTR(ro, 0, ro_show, ro_store);
2641 static DEVICE_ATTR(file, 0, file_show, file_store);
2642
2643 /****************************** FSG COMMON ******************************/
2644
2645 static void fsg_common_release(struct kref *ref);
2646
2647 static void fsg_lun_release(struct device *dev)
2648 {
2649         /* Nothing needs to be done */
2650 }
2651
2652 void fsg_common_get(struct fsg_common *common)
2653 {
2654         kref_get(&common->ref);
2655 }
2656 EXPORT_SYMBOL_GPL(fsg_common_get);
2657
2658 void fsg_common_put(struct fsg_common *common)
2659 {
2660         kref_put(&common->ref, fsg_common_release);
2661 }
2662 EXPORT_SYMBOL_GPL(fsg_common_put);
2663
2664 static struct fsg_common *fsg_common_setup(struct fsg_common *common)
2665 {
2666         if (!common) {
2667                 common = kzalloc(sizeof(*common), GFP_KERNEL);
2668                 if (!common)
2669                         return ERR_PTR(-ENOMEM);
2670                 common->free_storage_on_release = 1;
2671         } else {
2672                 common->free_storage_on_release = 0;
2673         }
2674         init_rwsem(&common->filesem);
2675         spin_lock_init(&common->lock);
2676         kref_init(&common->ref);
2677         init_completion(&common->thread_notifier);
2678         init_waitqueue_head(&common->fsg_wait);
2679         common->state = FSG_STATE_TERMINATED;
2680         memset(common->luns, 0, sizeof(common->luns));
2681
2682         return common;
2683 }
2684
2685 void fsg_common_set_sysfs(struct fsg_common *common, bool sysfs)
2686 {
2687         common->sysfs = sysfs;
2688 }
2689 EXPORT_SYMBOL_GPL(fsg_common_set_sysfs);
2690
2691 static void _fsg_common_free_buffers(struct fsg_buffhd *buffhds, unsigned n)
2692 {
2693         if (buffhds) {
2694                 struct fsg_buffhd *bh = buffhds;
2695                 while (n--) {
2696                         kfree(bh->buf);
2697                         ++bh;
2698                 }
2699                 kfree(buffhds);
2700         }
2701 }
2702
2703 int fsg_common_set_num_buffers(struct fsg_common *common, unsigned int n)
2704 {
2705         struct fsg_buffhd *bh, *buffhds;
2706         int i;
2707
2708         buffhds = kcalloc(n, sizeof(*buffhds), GFP_KERNEL);
2709         if (!buffhds)
2710                 return -ENOMEM;
2711
2712         /* Data buffers cyclic list */
2713         bh = buffhds;
2714         i = n;
2715         goto buffhds_first_it;
2716         do {
2717                 bh->next = bh + 1;
2718                 ++bh;
2719 buffhds_first_it:
2720                 bh->buf = kmalloc(FSG_BUFLEN, GFP_KERNEL);
2721                 if (unlikely(!bh->buf))
2722                         goto error_release;
2723         } while (--i);
2724         bh->next = buffhds;
2725
2726         _fsg_common_free_buffers(common->buffhds, common->fsg_num_buffers);
2727         common->fsg_num_buffers = n;
2728         common->buffhds = buffhds;
2729
2730         return 0;
2731
2732 error_release:
2733         /*
2734          * "buf"s pointed to by heads after n - i are NULL
2735          * so releasing them won't hurt
2736          */
2737         _fsg_common_free_buffers(buffhds, n);
2738
2739         return -ENOMEM;
2740 }
2741 EXPORT_SYMBOL_GPL(fsg_common_set_num_buffers);
2742
2743 void fsg_common_remove_lun(struct fsg_lun *lun)
2744 {
2745         if (device_is_registered(&lun->dev))
2746                 device_unregister(&lun->dev);
2747         fsg_lun_close(lun);
2748         kfree(lun);
2749 }
2750 EXPORT_SYMBOL_GPL(fsg_common_remove_lun);
2751
2752 static void _fsg_common_remove_luns(struct fsg_common *common, int n)
2753 {
2754         int i;
2755
2756         for (i = 0; i < n; ++i)
2757                 if (common->luns[i]) {
2758                         fsg_common_remove_lun(common->luns[i]);
2759                         common->luns[i] = NULL;
2760                 }
2761 }
2762
2763 void fsg_common_remove_luns(struct fsg_common *common)
2764 {
2765         _fsg_common_remove_luns(common, ARRAY_SIZE(common->luns));
2766 }
2767 EXPORT_SYMBOL_GPL(fsg_common_remove_luns);
2768
2769 void fsg_common_free_buffers(struct fsg_common *common)
2770 {
2771         _fsg_common_free_buffers(common->buffhds, common->fsg_num_buffers);
2772         common->buffhds = NULL;
2773 }
2774 EXPORT_SYMBOL_GPL(fsg_common_free_buffers);
2775
2776 int fsg_common_set_cdev(struct fsg_common *common,
2777                          struct usb_composite_dev *cdev, bool can_stall)
2778 {
2779         struct usb_string *us;
2780
2781         common->gadget = cdev->gadget;
2782         common->ep0 = cdev->gadget->ep0;
2783         common->ep0req = cdev->req;
2784         common->cdev = cdev;
2785
2786         us = usb_gstrings_attach(cdev, fsg_strings_array,
2787                                  ARRAY_SIZE(fsg_strings));
2788         if (IS_ERR(us))
2789                 return PTR_ERR(us);
2790
2791         fsg_intf_desc.iInterface = us[FSG_STRING_INTERFACE].id;
2792
2793         /*
2794          * Some peripheral controllers are known not to be able to
2795          * halt bulk endpoints correctly.  If one of them is present,
2796          * disable stalls.
2797          */
2798         common->can_stall = can_stall &&
2799                         gadget_is_stall_supported(common->gadget);
2800
2801         return 0;
2802 }
2803 EXPORT_SYMBOL_GPL(fsg_common_set_cdev);
2804
2805 static struct attribute *fsg_lun_dev_attrs[] = {
2806         &dev_attr_ro.attr,
2807         &dev_attr_file.attr,
2808         &dev_attr_nofua.attr,
2809         NULL
2810 };
2811
2812 static umode_t fsg_lun_dev_is_visible(struct kobject *kobj,
2813                                       struct attribute *attr, int idx)
2814 {
2815         struct device *dev = kobj_to_dev(kobj);
2816         struct fsg_lun *lun = fsg_lun_from_dev(dev);
2817
2818         if (attr == &dev_attr_ro.attr)
2819                 return lun->cdrom ? S_IRUGO : (S_IWUSR | S_IRUGO);
2820         if (attr == &dev_attr_file.attr)
2821                 return lun->removable ? (S_IWUSR | S_IRUGO) : S_IRUGO;
2822         return attr->mode;
2823 }
2824
2825 static const struct attribute_group fsg_lun_dev_group = {
2826         .attrs = fsg_lun_dev_attrs,
2827         .is_visible = fsg_lun_dev_is_visible,
2828 };
2829
2830 static const struct attribute_group *fsg_lun_dev_groups[] = {
2831         &fsg_lun_dev_group,
2832         NULL
2833 };
2834
2835 int fsg_common_create_lun(struct fsg_common *common, struct fsg_lun_config *cfg,
2836                           unsigned int id, const char *name,
2837                           const char **name_pfx)
2838 {
2839         struct fsg_lun *lun;
2840         char *pathbuf, *p;
2841         int rc = -ENOMEM;
2842
2843         if (id >= ARRAY_SIZE(common->luns))
2844                 return -ENODEV;
2845
2846         if (common->luns[id])
2847                 return -EBUSY;
2848
2849         if (!cfg->filename && !cfg->removable) {
2850                 pr_err("no file given for LUN%d\n", id);
2851                 return -EINVAL;
2852         }
2853
2854         lun = kzalloc(sizeof(*lun), GFP_KERNEL);
2855         if (!lun)
2856                 return -ENOMEM;
2857
2858         lun->name_pfx = name_pfx;
2859
2860         lun->cdrom = !!cfg->cdrom;
2861         lun->ro = cfg->cdrom || cfg->ro;
2862         lun->initially_ro = lun->ro;
2863         lun->removable = !!cfg->removable;
2864
2865         if (!common->sysfs) {
2866                 /* we DON'T own the name!*/
2867                 lun->name = name;
2868         } else {
2869                 lun->dev.release = fsg_lun_release;
2870                 lun->dev.parent = &common->gadget->dev;
2871                 lun->dev.groups = fsg_lun_dev_groups;
2872                 dev_set_drvdata(&lun->dev, &common->filesem);
2873                 dev_set_name(&lun->dev, "%s", name);
2874                 lun->name = dev_name(&lun->dev);
2875
2876                 rc = device_register(&lun->dev);
2877                 if (rc) {
2878                         pr_info("failed to register LUN%d: %d\n", id, rc);
2879                         put_device(&lun->dev);
2880                         goto error_sysfs;
2881                 }
2882         }
2883
2884         common->luns[id] = lun;
2885
2886         if (cfg->filename) {
2887                 rc = fsg_lun_open(lun, cfg->filename);
2888                 if (rc)
2889                         goto error_lun;
2890         }
2891
2892         pathbuf = kmalloc(PATH_MAX, GFP_KERNEL);
2893         p = "(no medium)";
2894         if (fsg_lun_is_open(lun)) {
2895                 p = "(error)";
2896                 if (pathbuf) {
2897                         p = file_path(lun->filp, pathbuf, PATH_MAX);
2898                         if (IS_ERR(p))
2899                                 p = "(error)";
2900                 }
2901         }
2902         pr_info("LUN: %s%s%sfile: %s\n",
2903               lun->removable ? "removable " : "",
2904               lun->ro ? "read only " : "",
2905               lun->cdrom ? "CD-ROM " : "",
2906               p);
2907         kfree(pathbuf);
2908
2909         return 0;
2910
2911 error_lun:
2912         if (device_is_registered(&lun->dev))
2913                 device_unregister(&lun->dev);
2914         fsg_lun_close(lun);
2915         common->luns[id] = NULL;
2916 error_sysfs:
2917         kfree(lun);
2918         return rc;
2919 }
2920 EXPORT_SYMBOL_GPL(fsg_common_create_lun);
2921
2922 int fsg_common_create_luns(struct fsg_common *common, struct fsg_config *cfg)
2923 {
2924         char buf[8]; /* enough for 100000000 different numbers, decimal */
2925         int i, rc;
2926
2927         fsg_common_remove_luns(common);
2928
2929         for (i = 0; i < cfg->nluns; ++i) {
2930                 snprintf(buf, sizeof(buf), "lun%d", i);
2931                 rc = fsg_common_create_lun(common, &cfg->luns[i], i, buf, NULL);
2932                 if (rc)
2933                         goto fail;
2934         }
2935
2936         pr_info("Number of LUNs=%d\n", cfg->nluns);
2937
2938         return 0;
2939
2940 fail:
2941         _fsg_common_remove_luns(common, i);
2942         return rc;
2943 }
2944 EXPORT_SYMBOL_GPL(fsg_common_create_luns);
2945
2946 void fsg_common_set_inquiry_string(struct fsg_common *common, const char *vn,
2947                                    const char *pn)
2948 {
2949         int i;
2950
2951         /* Prepare inquiryString */
2952         i = get_default_bcdDevice();
2953         snprintf(common->inquiry_string, sizeof(common->inquiry_string),
2954                  "%-8s%-16s%04x", vn ?: "Linux",
2955                  /* Assume product name dependent on the first LUN */
2956                  pn ?: ((*common->luns)->cdrom
2957                      ? "File-CD Gadget"
2958                      : "File-Stor Gadget"),
2959                  i);
2960 }
2961 EXPORT_SYMBOL_GPL(fsg_common_set_inquiry_string);
2962
2963 static void fsg_common_release(struct kref *ref)
2964 {
2965         struct fsg_common *common = container_of(ref, struct fsg_common, ref);
2966         int i;
2967
2968         /* If the thread isn't already dead, tell it to exit now */
2969         if (common->state != FSG_STATE_TERMINATED) {
2970                 raise_exception(common, FSG_STATE_EXIT);
2971                 wait_for_completion(&common->thread_notifier);
2972                 common->thread_task = NULL;
2973         }
2974
2975         for (i = 0; i < ARRAY_SIZE(common->luns); ++i) {
2976                 struct fsg_lun *lun = common->luns[i];
2977                 if (!lun)
2978                         continue;
2979                 fsg_lun_close(lun);
2980                 if (device_is_registered(&lun->dev))
2981                         device_unregister(&lun->dev);
2982                 kfree(lun);
2983         }
2984
2985         _fsg_common_free_buffers(common->buffhds, common->fsg_num_buffers);
2986         if (common->free_storage_on_release)
2987                 kfree(common);
2988 }
2989
2990
2991 /*-------------------------------------------------------------------------*/
2992
2993 static int fsg_bind(struct usb_configuration *c, struct usb_function *f)
2994 {
2995         struct fsg_dev          *fsg = fsg_from_func(f);
2996         struct fsg_common       *common = fsg->common;
2997         struct usb_gadget       *gadget = c->cdev->gadget;
2998         int                     i;
2999         struct usb_ep           *ep;
3000         unsigned                max_burst;
3001         int                     ret;
3002         struct fsg_opts         *opts;
3003
3004         /* Don't allow to bind if we don't have at least one LUN */
3005         ret = _fsg_common_get_max_lun(common);
3006         if (ret < 0) {
3007                 pr_err("There should be at least one LUN.\n");
3008                 return -EINVAL;
3009         }
3010
3011         opts = fsg_opts_from_func_inst(f->fi);
3012         if (!opts->no_configfs) {
3013                 ret = fsg_common_set_cdev(fsg->common, c->cdev,
3014                                           fsg->common->can_stall);
3015                 if (ret)
3016                         return ret;
3017                 fsg_common_set_inquiry_string(fsg->common, NULL, NULL);
3018         }
3019
3020         if (!common->thread_task) {
3021                 common->state = FSG_STATE_IDLE;
3022                 common->thread_task =
3023                         kthread_create(fsg_main_thread, common, "file-storage");
3024                 if (IS_ERR(common->thread_task)) {
3025                         int ret = PTR_ERR(common->thread_task);
3026                         common->thread_task = NULL;
3027                         common->state = FSG_STATE_TERMINATED;
3028                         return ret;
3029                 }
3030                 DBG(common, "I/O thread pid: %d\n",
3031                     task_pid_nr(common->thread_task));
3032                 wake_up_process(common->thread_task);
3033         }
3034
3035         fsg->gadget = gadget;
3036
3037         /* New interface */
3038         i = usb_interface_id(c, f);
3039         if (i < 0)
3040                 goto fail;
3041         fsg_intf_desc.bInterfaceNumber = i;
3042         fsg->interface_number = i;
3043
3044         /* Find all the endpoints we will use */
3045         ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_in_desc);
3046         if (!ep)
3047                 goto autoconf_fail;
3048         fsg->bulk_in = ep;
3049
3050         ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_out_desc);
3051         if (!ep)
3052                 goto autoconf_fail;
3053         fsg->bulk_out = ep;
3054
3055         /* Assume endpoint addresses are the same for both speeds */
3056         fsg_hs_bulk_in_desc.bEndpointAddress =
3057                 fsg_fs_bulk_in_desc.bEndpointAddress;
3058         fsg_hs_bulk_out_desc.bEndpointAddress =
3059                 fsg_fs_bulk_out_desc.bEndpointAddress;
3060
3061         /* Calculate bMaxBurst, we know packet size is 1024 */
3062         max_burst = min_t(unsigned, FSG_BUFLEN / 1024, 15);
3063
3064         fsg_ss_bulk_in_desc.bEndpointAddress =
3065                 fsg_fs_bulk_in_desc.bEndpointAddress;
3066         fsg_ss_bulk_in_comp_desc.bMaxBurst = max_burst;
3067
3068         fsg_ss_bulk_out_desc.bEndpointAddress =
3069                 fsg_fs_bulk_out_desc.bEndpointAddress;
3070         fsg_ss_bulk_out_comp_desc.bMaxBurst = max_burst;
3071
3072         ret = usb_assign_descriptors(f, fsg_fs_function, fsg_hs_function,
3073                         fsg_ss_function, fsg_ss_function);
3074         if (ret)
3075                 goto autoconf_fail;
3076
3077         return 0;
3078
3079 autoconf_fail:
3080         ERROR(fsg, "unable to autoconfigure all endpoints\n");
3081         i = -ENOTSUPP;
3082 fail:
3083         /* terminate the thread */
3084         if (fsg->common->state != FSG_STATE_TERMINATED) {
3085                 raise_exception(fsg->common, FSG_STATE_EXIT);
3086                 wait_for_completion(&fsg->common->thread_notifier);
3087         }
3088         return i;
3089 }
3090
3091 /****************************** ALLOCATE FUNCTION *************************/
3092
3093 static void fsg_unbind(struct usb_configuration *c, struct usb_function *f)
3094 {
3095         struct fsg_dev          *fsg = fsg_from_func(f);
3096         struct fsg_common       *common = fsg->common;
3097
3098         DBG(fsg, "unbind\n");
3099         if (fsg->common->fsg == fsg) {
3100                 fsg->common->new_fsg = NULL;
3101                 raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
3102                 /* FIXME: make interruptible or killable somehow? */
3103                 wait_event(common->fsg_wait, common->fsg != fsg);
3104         }
3105
3106         usb_free_all_descriptors(&fsg->function);
3107 }
3108
3109 static inline struct fsg_lun_opts *to_fsg_lun_opts(struct config_item *item)
3110 {
3111         return container_of(to_config_group(item), struct fsg_lun_opts, group);
3112 }
3113
3114 static inline struct fsg_opts *to_fsg_opts(struct config_item *item)
3115 {
3116         return container_of(to_config_group(item), struct fsg_opts,
3117                             func_inst.group);
3118 }
3119
3120 static void fsg_lun_attr_release(struct config_item *item)
3121 {
3122         struct fsg_lun_opts *lun_opts;
3123
3124         lun_opts = to_fsg_lun_opts(item);
3125         kfree(lun_opts);
3126 }
3127
3128 static struct configfs_item_operations fsg_lun_item_ops = {
3129         .release                = fsg_lun_attr_release,
3130 };
3131
3132 static ssize_t fsg_lun_opts_file_show(struct config_item *item, char *page)
3133 {
3134         struct fsg_lun_opts *opts = to_fsg_lun_opts(item);
3135         struct fsg_opts *fsg_opts = to_fsg_opts(opts->group.cg_item.ci_parent);
3136
3137         return fsg_show_file(opts->lun, &fsg_opts->common->filesem, page);
3138 }
3139
3140 static ssize_t fsg_lun_opts_file_store(struct config_item *item,
3141                                        const char *page, size_t len)
3142 {
3143         struct fsg_lun_opts *opts = to_fsg_lun_opts(item);
3144         struct fsg_opts *fsg_opts = to_fsg_opts(opts->group.cg_item.ci_parent);
3145
3146         return fsg_store_file(opts->lun, &fsg_opts->common->filesem, page, len);
3147 }
3148
3149 CONFIGFS_ATTR(fsg_lun_opts_, file);
3150
3151 static ssize_t fsg_lun_opts_ro_show(struct config_item *item, char *page)
3152 {
3153         return fsg_show_ro(to_fsg_lun_opts(item)->lun, page);
3154 }
3155
3156 static ssize_t fsg_lun_opts_ro_store(struct config_item *item,
3157                                        const char *page, size_t len)
3158 {
3159         struct fsg_lun_opts *opts = to_fsg_lun_opts(item);
3160         struct fsg_opts *fsg_opts = to_fsg_opts(opts->group.cg_item.ci_parent);
3161
3162         return fsg_store_ro(opts->lun, &fsg_opts->common->filesem, page, len);
3163 }
3164
3165 CONFIGFS_ATTR(fsg_lun_opts_, ro);
3166
3167 static ssize_t fsg_lun_opts_removable_show(struct config_item *item,
3168                                            char *page)
3169 {
3170         return fsg_show_removable(to_fsg_lun_opts(item)->lun, page);
3171 }
3172
3173 static ssize_t fsg_lun_opts_removable_store(struct config_item *item,
3174                                        const char *page, size_t len)
3175 {
3176         return fsg_store_removable(to_fsg_lun_opts(item)->lun, page, len);
3177 }
3178
3179 CONFIGFS_ATTR(fsg_lun_opts_, removable);
3180
3181 static ssize_t fsg_lun_opts_cdrom_show(struct config_item *item, char *page)
3182 {
3183         return fsg_show_cdrom(to_fsg_lun_opts(item)->lun, page);
3184 }
3185
3186 static ssize_t fsg_lun_opts_cdrom_store(struct config_item *item,
3187                                        const char *page, size_t len)
3188 {
3189         struct fsg_lun_opts *opts = to_fsg_lun_opts(item);
3190         struct fsg_opts *fsg_opts = to_fsg_opts(opts->group.cg_item.ci_parent);
3191
3192         return fsg_store_cdrom(opts->lun, &fsg_opts->common->filesem, page,
3193                                len);
3194 }
3195
3196 CONFIGFS_ATTR(fsg_lun_opts_, cdrom);
3197
3198 static ssize_t fsg_lun_opts_nofua_show(struct config_item *item, char *page)
3199 {
3200         return fsg_show_nofua(to_fsg_lun_opts(item)->lun, page);
3201 }
3202
3203 static ssize_t fsg_lun_opts_nofua_store(struct config_item *item,
3204                                        const char *page, size_t len)
3205 {
3206         return fsg_store_nofua(to_fsg_lun_opts(item)->lun, page, len);
3207 }
3208
3209 CONFIGFS_ATTR(fsg_lun_opts_, nofua);
3210
3211 static ssize_t fsg_lun_opts_inquiry_string_show(struct config_item *item,
3212                                                 char *page)
3213 {
3214         return fsg_show_inquiry_string(to_fsg_lun_opts(item)->lun, page);
3215 }
3216
3217 static ssize_t fsg_lun_opts_inquiry_string_store(struct config_item *item,
3218                                                  const char *page, size_t len)
3219 {
3220         return fsg_store_inquiry_string(to_fsg_lun_opts(item)->lun, page, len);
3221 }
3222
3223 CONFIGFS_ATTR(fsg_lun_opts_, inquiry_string);
3224
3225 static struct configfs_attribute *fsg_lun_attrs[] = {
3226         &fsg_lun_opts_attr_file,
3227         &fsg_lun_opts_attr_ro,
3228         &fsg_lun_opts_attr_removable,
3229         &fsg_lun_opts_attr_cdrom,
3230         &fsg_lun_opts_attr_nofua,
3231         &fsg_lun_opts_attr_inquiry_string,
3232         NULL,
3233 };
3234
3235 static struct config_item_type fsg_lun_type = {
3236         .ct_item_ops    = &fsg_lun_item_ops,
3237         .ct_attrs       = fsg_lun_attrs,
3238         .ct_owner       = THIS_MODULE,
3239 };
3240
3241 static struct config_group *fsg_lun_make(struct config_group *group,
3242                                          const char *name)
3243 {
3244         struct fsg_lun_opts *opts;
3245         struct fsg_opts *fsg_opts;
3246         struct fsg_lun_config config;
3247         char *num_str;
3248         u8 num;
3249         int ret;
3250
3251         num_str = strchr(name, '.');
3252         if (!num_str) {
3253                 pr_err("Unable to locate . in LUN.NUMBER\n");
3254                 return ERR_PTR(-EINVAL);
3255         }
3256         num_str++;
3257
3258         ret = kstrtou8(num_str, 0, &num);
3259         if (ret)
3260                 return ERR_PTR(ret);
3261
3262         fsg_opts = to_fsg_opts(&group->cg_item);
3263         if (num >= FSG_MAX_LUNS)
3264                 return ERR_PTR(-ERANGE);
3265         num = array_index_nospec(num, FSG_MAX_LUNS);
3266
3267         mutex_lock(&fsg_opts->lock);
3268         if (fsg_opts->refcnt || fsg_opts->common->luns[num]) {
3269                 ret = -EBUSY;
3270                 goto out;
3271         }
3272
3273         opts = kzalloc(sizeof(*opts), GFP_KERNEL);
3274         if (!opts) {
3275                 ret = -ENOMEM;
3276                 goto out;
3277         }
3278
3279         memset(&config, 0, sizeof(config));
3280         config.removable = true;
3281
3282         ret = fsg_common_create_lun(fsg_opts->common, &config, num, name,
3283                                     (const char **)&group->cg_item.ci_name);
3284         if (ret) {
3285                 kfree(opts);
3286                 goto out;
3287         }
3288         opts->lun = fsg_opts->common->luns[num];
3289         opts->lun_id = num;
3290         mutex_unlock(&fsg_opts->lock);
3291
3292         config_group_init_type_name(&opts->group, name, &fsg_lun_type);
3293
3294         return &opts->group;
3295 out:
3296         mutex_unlock(&fsg_opts->lock);
3297         return ERR_PTR(ret);
3298 }
3299
3300 static void fsg_lun_drop(struct config_group *group, struct config_item *item)
3301 {
3302         struct fsg_lun_opts *lun_opts;
3303         struct fsg_opts *fsg_opts;
3304
3305         lun_opts = to_fsg_lun_opts(item);
3306         fsg_opts = to_fsg_opts(&group->cg_item);
3307
3308         mutex_lock(&fsg_opts->lock);
3309         if (fsg_opts->refcnt) {
3310                 struct config_item *gadget;
3311
3312                 gadget = group->cg_item.ci_parent->ci_parent;
3313                 unregister_gadget_item(gadget);
3314         }
3315
3316         fsg_common_remove_lun(lun_opts->lun);
3317         fsg_opts->common->luns[lun_opts->lun_id] = NULL;
3318         lun_opts->lun_id = 0;
3319         mutex_unlock(&fsg_opts->lock);
3320
3321         config_item_put(item);
3322 }
3323
3324 static void fsg_attr_release(struct config_item *item)
3325 {
3326         struct fsg_opts *opts = to_fsg_opts(item);
3327
3328         usb_put_function_instance(&opts->func_inst);
3329 }
3330
3331 static struct configfs_item_operations fsg_item_ops = {
3332         .release                = fsg_attr_release,
3333 };
3334
3335 static ssize_t fsg_opts_stall_show(struct config_item *item, char *page)
3336 {
3337         struct fsg_opts *opts = to_fsg_opts(item);
3338         int result;
3339
3340         mutex_lock(&opts->lock);
3341         result = sprintf(page, "%d", opts->common->can_stall);
3342         mutex_unlock(&opts->lock);
3343
3344         return result;
3345 }
3346
3347 static ssize_t fsg_opts_stall_store(struct config_item *item, const char *page,
3348                                     size_t len)
3349 {
3350         struct fsg_opts *opts = to_fsg_opts(item);
3351         int ret;
3352         bool stall;
3353
3354         mutex_lock(&opts->lock);
3355
3356         if (opts->refcnt) {
3357                 mutex_unlock(&opts->lock);
3358                 return -EBUSY;
3359         }
3360
3361         ret = strtobool(page, &stall);
3362         if (!ret) {
3363                 opts->common->can_stall = stall;
3364                 ret = len;
3365         }
3366
3367         mutex_unlock(&opts->lock);
3368
3369         return ret;
3370 }
3371
3372 CONFIGFS_ATTR(fsg_opts_, stall);
3373
3374 #ifdef CONFIG_USB_GADGET_DEBUG_FILES
3375 static ssize_t fsg_opts_num_buffers_show(struct config_item *item, char *page)
3376 {
3377         struct fsg_opts *opts = to_fsg_opts(item);
3378         int result;
3379
3380         mutex_lock(&opts->lock);
3381         result = sprintf(page, "%d", opts->common->fsg_num_buffers);
3382         mutex_unlock(&opts->lock);
3383
3384         return result;
3385 }
3386
3387 static ssize_t fsg_opts_num_buffers_store(struct config_item *item,
3388                                           const char *page, size_t len)
3389 {
3390         struct fsg_opts *opts = to_fsg_opts(item);
3391         int ret;
3392         u8 num;
3393
3394         mutex_lock(&opts->lock);
3395         if (opts->refcnt) {
3396                 ret = -EBUSY;
3397                 goto end;
3398         }
3399         ret = kstrtou8(page, 0, &num);
3400         if (ret)
3401                 goto end;
3402
3403         fsg_common_set_num_buffers(opts->common, num);
3404         ret = len;
3405
3406 end:
3407         mutex_unlock(&opts->lock);
3408         return ret;
3409 }
3410
3411 CONFIGFS_ATTR(fsg_opts_, num_buffers);
3412 #endif
3413
3414 static struct configfs_attribute *fsg_attrs[] = {
3415         &fsg_opts_attr_stall,
3416 #ifdef CONFIG_USB_GADGET_DEBUG_FILES
3417         &fsg_opts_attr_num_buffers,
3418 #endif
3419         NULL,
3420 };
3421
3422 static struct configfs_group_operations fsg_group_ops = {
3423         .make_group     = fsg_lun_make,
3424         .drop_item      = fsg_lun_drop,
3425 };
3426
3427 static struct config_item_type fsg_func_type = {
3428         .ct_item_ops    = &fsg_item_ops,
3429         .ct_group_ops   = &fsg_group_ops,
3430         .ct_attrs       = fsg_attrs,
3431         .ct_owner       = THIS_MODULE,
3432 };
3433
3434 static void fsg_free_inst(struct usb_function_instance *fi)
3435 {
3436         struct fsg_opts *opts;
3437
3438         opts = fsg_opts_from_func_inst(fi);
3439         fsg_common_put(opts->common);
3440         kfree(opts);
3441 }
3442
3443 static struct usb_function_instance *fsg_alloc_inst(void)
3444 {
3445         struct fsg_opts *opts;
3446         struct fsg_lun_config config;
3447         int rc;
3448
3449         opts = kzalloc(sizeof(*opts), GFP_KERNEL);
3450         if (!opts)
3451                 return ERR_PTR(-ENOMEM);
3452         mutex_init(&opts->lock);
3453         opts->func_inst.free_func_inst = fsg_free_inst;
3454         opts->common = fsg_common_setup(opts->common);
3455         if (IS_ERR(opts->common)) {
3456                 rc = PTR_ERR(opts->common);
3457                 goto release_opts;
3458         }
3459
3460         rc = fsg_common_set_num_buffers(opts->common,
3461                                         CONFIG_USB_GADGET_STORAGE_NUM_BUFFERS);
3462         if (rc)
3463                 goto release_opts;
3464
3465         pr_info(FSG_DRIVER_DESC ", version: " FSG_DRIVER_VERSION "\n");
3466
3467         memset(&config, 0, sizeof(config));
3468         config.removable = true;
3469         rc = fsg_common_create_lun(opts->common, &config, 0, "lun.0",
3470                         (const char **)&opts->func_inst.group.cg_item.ci_name);
3471         if (rc)
3472                 goto release_buffers;
3473
3474         opts->lun0.lun = opts->common->luns[0];
3475         opts->lun0.lun_id = 0;
3476
3477         config_group_init_type_name(&opts->func_inst.group, "", &fsg_func_type);
3478
3479         config_group_init_type_name(&opts->lun0.group, "lun.0", &fsg_lun_type);
3480         configfs_add_default_group(&opts->lun0.group, &opts->func_inst.group);
3481
3482         return &opts->func_inst;
3483
3484 release_buffers:
3485         fsg_common_free_buffers(opts->common);
3486 release_opts:
3487         kfree(opts);
3488         return ERR_PTR(rc);
3489 }
3490
3491 static void fsg_free(struct usb_function *f)
3492 {
3493         struct fsg_dev *fsg;
3494         struct fsg_opts *opts;
3495
3496         fsg = container_of(f, struct fsg_dev, function);
3497         opts = container_of(f->fi, struct fsg_opts, func_inst);
3498
3499         mutex_lock(&opts->lock);
3500         opts->refcnt--;
3501         mutex_unlock(&opts->lock);
3502
3503         kfree(fsg);
3504 }
3505
3506 static struct usb_function *fsg_alloc(struct usb_function_instance *fi)
3507 {
3508         struct fsg_opts *opts = fsg_opts_from_func_inst(fi);
3509         struct fsg_common *common = opts->common;
3510         struct fsg_dev *fsg;
3511
3512         fsg = kzalloc(sizeof(*fsg), GFP_KERNEL);
3513         if (unlikely(!fsg))
3514                 return ERR_PTR(-ENOMEM);
3515
3516         mutex_lock(&opts->lock);
3517         opts->refcnt++;
3518         mutex_unlock(&opts->lock);
3519
3520         fsg->function.name      = FSG_DRIVER_DESC;
3521         fsg->function.bind      = fsg_bind;
3522         fsg->function.unbind    = fsg_unbind;
3523         fsg->function.setup     = fsg_setup;
3524         fsg->function.set_alt   = fsg_set_alt;
3525         fsg->function.disable   = fsg_disable;
3526         fsg->function.free_func = fsg_free;
3527
3528         fsg->common               = common;
3529
3530         return &fsg->function;
3531 }
3532
3533 DECLARE_USB_FUNCTION_INIT(mass_storage, fsg_alloc_inst, fsg_alloc);
3534 MODULE_LICENSE("GPL");
3535 MODULE_AUTHOR("Michal Nazarewicz");
3536
3537 /************************* Module parameters *************************/
3538
3539
3540 void fsg_config_from_params(struct fsg_config *cfg,
3541                        const struct fsg_module_parameters *params,
3542                        unsigned int fsg_num_buffers)
3543 {
3544         struct fsg_lun_config *lun;
3545         unsigned i;
3546
3547         /* Configure LUNs */
3548         cfg->nluns =
3549                 min(params->luns ?: (params->file_count ?: 1u),
3550                     (unsigned)FSG_MAX_LUNS);
3551         for (i = 0, lun = cfg->luns; i < cfg->nluns; ++i, ++lun) {
3552                 lun->ro = !!params->ro[i];
3553                 lun->cdrom = !!params->cdrom[i];
3554                 lun->removable = !!params->removable[i];
3555                 lun->filename =
3556                         params->file_count > i && params->file[i][0]
3557                         ? params->file[i]
3558                         : NULL;
3559         }
3560
3561         /* Let MSF use defaults */
3562         cfg->vendor_name = NULL;
3563         cfg->product_name = NULL;
3564
3565         cfg->ops = NULL;
3566         cfg->private_data = NULL;
3567
3568         /* Finalise */
3569         cfg->can_stall = params->stall;
3570         cfg->fsg_num_buffers = fsg_num_buffers;
3571 }
3572 EXPORT_SYMBOL_GPL(fsg_config_from_params);