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linux/drivers/usb/gadget/f_mass_storage.c
Michal Nazarewicz b894f60a23 USB: gadget: f_mass_storage: stale common->fsg value bug fix 
On fsg_unbind the common->fsg pointer was not NULLed if the
unbound fsg_dev instance was the current one.  As an effect,
the incorrect pointer was preserved in all further operations
which caused do_set_interface to reference an invalid region.

This commit fixes this by raising an exception in fsg_bind
which will change the common->fsg pointer.  This also requires
an wait queue so that the thread in fsg_bind can wait till the
worker thread handles the exception.

This commit removes also a config and new_config fields of
fsg_common as they are no longer needed since fsg can be
used to determine whether function is active or not.

Moreover, this commit removes possible race condition where
the fsg field was modified in both the worker thread and
form various other contexts.  This is fixed by replacing
prev_fsg with new_fsg.  At this point, fsg is assigned only
in worker thread.

Signed-off-by: Michal Nazarewicz <m.nazarewicz@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-06-30 08:16:07 -07:00

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/*
* f_mass_storage.c -- Mass Storage USB Composite Function
*
* Copyright (C) 2003-2008 Alan Stern
* Copyright (C) 2009 Samsung Electronics
* Author: Michal Nazarewicz <m.nazarewicz@samsung.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions, and the following disclaimer,
* without modification.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The names of the above-listed copyright holders may not be used
* to endorse or promote products derived from this software without
* specific prior written permission.
*
* ALTERNATIVELY, this software may be distributed under the terms of the
* GNU General Public License ("GPL") as published by the Free Software
* Foundation, either version 2 of that License or (at your option) any
* later version.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* The Mass Storage Function acts as a USB Mass Storage device,
* appearing to the host as a disk drive or as a CD-ROM drive. In
* addition to providing an example of a genuinely useful composite
* function for a USB device, it also illustrates a technique of
* double-buffering for increased throughput.
*
* Function supports multiple logical units (LUNs). Backing storage
* for each LUN is provided by a regular file or a block device.
* Access for each LUN can be limited to read-only. Moreover, the
* function can indicate that LUN is removable and/or CD-ROM. (The
* later implies read-only access.)
*
* MSF is configured by specifying a fsg_config structure. It has the
* following fields:
*
* nluns Number of LUNs function have (anywhere from 1
* to FSG_MAX_LUNS which is 8).
* luns An array of LUN configuration values. This
* should be filled for each LUN that
* function will include (ie. for "nluns"
* LUNs). Each element of the array has
* the following fields:
* ->filename The path to the backing file for the LUN.
* Required if LUN is not marked as
* removable.
* ->ro Flag specifying access to the LUN shall be
* read-only. This is implied if CD-ROM
* emulation is enabled as well as when
* it was impossible to open "filename"
* in R/W mode.
* ->removable Flag specifying that LUN shall be indicated as
* being removable.
* ->cdrom Flag specifying that LUN shall be reported as
* being a CD-ROM.
*
* lun_name_format A printf-like format for names of the LUN
* devices. This determines how the
* directory in sysfs will be named.
* Unless you are using several MSFs in
* a single gadget (as opposed to single
* MSF in many configurations) you may
* leave it as NULL (in which case
* "lun%d" will be used). In the format
* you can use "%d" to index LUNs for
* MSF's with more than one LUN. (Beware
* that there is only one integer given
* as an argument for the format and
* specifying invalid format may cause
* unspecified behaviour.)
* thread_name Name of the kernel thread process used by the
* MSF. You can safely set it to NULL
* (in which case default "file-storage"
* will be used).
*
* vendor_name
* product_name
* release Information used as a reply to INQUIRY
* request. To use default set to NULL,
* NULL, 0xffff respectively. The first
* field should be 8 and the second 16
* characters or less.
*
* can_stall Set to permit function to halt bulk endpoints.
* Disabled on some USB devices known not
* to work correctly. You should set it
* to true.
*
* If "removable" is not set for a LUN then a backing file must be
* specified. If it is set, then NULL filename means the LUN's medium
* is not loaded (an empty string as "filename" in the fsg_config
* structure causes error). The CD-ROM emulation includes a single
* data track and no audio tracks; hence there need be only one
* backing file per LUN. Note also that the CD-ROM block length is
* set to 512 rather than the more common value 2048.
*
*
* MSF includes support for module parameters. If gadget using it
* decides to use it, the following module parameters will be
* available:
*
* file=filename[,filename...]
* Names of the files or block devices used for
* backing storage.
* ro=b[,b...] Default false, boolean for read-only access.
* removable=b[,b...]
* Default true, boolean for removable media.
* cdrom=b[,b...] Default false, boolean for whether to emulate
* a CD-ROM drive.
* luns=N Default N = number of filenames, number of
* LUNs to support.
* stall Default determined according to the type of
* USB device controller (usually true),
* boolean to permit the driver to halt
* bulk endpoints.
*
* The module parameters may be prefixed with some string. You need
* to consult gadget's documentation or source to verify whether it is
* using those module parameters and if it does what are the prefixes
* (look for FSG_MODULE_PARAMETERS() macro usage, what's inside it is
* the prefix).
*
*
* Requirements are modest; only a bulk-in and a bulk-out endpoint are
* needed. The memory requirement amounts to two 16K buffers, size
* configurable by a parameter. Support is included for both
* full-speed and high-speed operation.
*
* Note that the driver is slightly non-portable in that it assumes a
* single memory/DMA buffer will be useable for bulk-in, bulk-out, and
* interrupt-in endpoints. With most device controllers this isn't an
* issue, but there may be some with hardware restrictions that prevent
* a buffer from being used by more than one endpoint.
*
*
* The pathnames of the backing files and the ro settings are
* available in the attribute files "file" and "ro" in the lun<n> (or
* to be more precise in a directory which name comes from
* "lun_name_format" option!) subdirectory of the gadget's sysfs
* directory. If the "removable" option is set, writing to these
* files will simulate ejecting/loading the medium (writing an empty
* line means eject) and adjusting a write-enable tab. Changes to the
* ro setting are not allowed when the medium is loaded or if CD-ROM
* emulation is being used.
*
* When a LUN receive an "eject" SCSI request (Start/Stop Unit),
* if the LUN is removable, the backing file is released to simulate
* ejection.
*
*
* This function is heavily based on "File-backed Storage Gadget" by
* Alan Stern which in turn is heavily based on "Gadget Zero" by David
* Brownell. The driver's SCSI command interface was based on the
* "Information technology - Small Computer System Interface - 2"
* document from X3T9.2 Project 375D, Revision 10L, 7-SEP-93,
* available at <http://www.t10.org/ftp/t10/drafts/s2/s2-r10l.pdf>.
* The single exception is opcode 0x23 (READ FORMAT CAPACITIES), which
* was based on the "Universal Serial Bus Mass Storage Class UFI
* Command Specification" document, Revision 1.0, December 14, 1998,
* available at
* <http://www.usb.org/developers/devclass_docs/usbmass-ufi10.pdf>.
*/
/*
* Driver Design
*
* The MSF is fairly straightforward. There is a main kernel
* thread that handles most of the work. Interrupt routines field
* callbacks from the controller driver: bulk- and interrupt-request
* completion notifications, endpoint-0 events, and disconnect events.
* Completion events are passed to the main thread by wakeup calls. Many
* ep0 requests are handled at interrupt time, but SetInterface,
* SetConfiguration, and device reset requests are forwarded to the
* thread in the form of "exceptions" using SIGUSR1 signals (since they
* should interrupt any ongoing file I/O operations).
*
* The thread's main routine implements the standard command/data/status
* parts of a SCSI interaction. It and its subroutines are full of tests
* for pending signals/exceptions -- all this polling is necessary since
* the kernel has no setjmp/longjmp equivalents. (Maybe this is an
* indication that the driver really wants to be running in userspace.)
* An important point is that so long as the thread is alive it keeps an
* open reference to the backing file. This will prevent unmounting
* the backing file's underlying filesystem and could cause problems
* during system shutdown, for example. To prevent such problems, the
* thread catches INT, TERM, and KILL signals and converts them into
* an EXIT exception.
*
* In normal operation the main thread is started during the gadget's
* fsg_bind() callback and stopped during fsg_unbind(). But it can
* also exit when it receives a signal, and there's no point leaving
* the gadget running when the thread is dead. At of this moment, MSF
* provides no way to deregister the gadget when thread dies -- maybe
* a callback functions is needed.
*
* To provide maximum throughput, the driver uses a circular pipeline of
* buffer heads (struct fsg_buffhd). In principle the pipeline can be
* arbitrarily long; in practice the benefits don't justify having more
* than 2 stages (i.e., double buffering). But it helps to think of the
* pipeline as being a long one. Each buffer head contains a bulk-in and
* a bulk-out request pointer (since the buffer can be used for both
* output and input -- directions always are given from the host's
* point of view) as well as a pointer to the buffer and various state
* variables.
*
* Use of the pipeline follows a simple protocol. There is a variable
* (fsg->next_buffhd_to_fill) that points to the next buffer head to use.
* At any time that buffer head may still be in use from an earlier
* request, so each buffer head has a state variable indicating whether
* it is EMPTY, FULL, or BUSY. Typical use involves waiting for the
* buffer head to be EMPTY, filling the buffer either by file I/O or by
* USB I/O (during which the buffer head is BUSY), and marking the buffer
* head FULL when the I/O is complete. Then the buffer will be emptied
* (again possibly by USB I/O, during which it is marked BUSY) and
* finally marked EMPTY again (possibly by a completion routine).
*
* A module parameter tells the driver to avoid stalling the bulk
* endpoints wherever the transport specification allows. This is
* necessary for some UDCs like the SuperH, which cannot reliably clear a
* halt on a bulk endpoint. However, under certain circumstances the
* Bulk-only specification requires a stall. In such cases the driver
* will halt the endpoint and set a flag indicating that it should clear
* the halt in software during the next device reset. Hopefully this
* will permit everything to work correctly. Furthermore, although the
* specification allows the bulk-out endpoint to halt when the host sends
* too much data, implementing this would cause an unavoidable race.
* The driver will always use the "no-stall" approach for OUT transfers.
*
* One subtle point concerns sending status-stage responses for ep0
* requests. Some of these requests, such as device reset, can involve
* interrupting an ongoing file I/O operation, which might take an
* arbitrarily long time. During that delay the host might give up on
* the original ep0 request and issue a new one. When that happens the
* driver should not notify the host about completion of the original
* request, as the host will no longer be waiting for it. So the driver
* assigns to each ep0 request a unique tag, and it keeps track of the
* tag value of the request associated with a long-running exception
* (device-reset, interface-change, or configuration-change). When the
* exception handler is finished, the status-stage response is submitted
* only if the current ep0 request tag is equal to the exception request
* tag. Thus only the most recently received ep0 request will get a
* status-stage response.
*
* Warning: This driver source file is too long. It ought to be split up
* into a header file plus about 3 separate .c files, to handle the details
* of the Gadget, USB Mass Storage, and SCSI protocols.
*/
/* #define VERBOSE_DEBUG */
/* #define DUMP_MSGS */
#include <linux/blkdev.h>
#include <linux/completion.h>
#include <linux/dcache.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/fcntl.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/kref.h>
#include <linux/kthread.h>
#include <linux/limits.h>
#include <linux/rwsem.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/freezer.h>
#include <linux/utsname.h>
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>
#include "gadget_chips.h"
/*------------------------------------------------------------------------*/
#define FSG_DRIVER_DESC "Mass Storage Function"
#define FSG_DRIVER_VERSION "2009/09/11"
static const char fsg_string_interface[] = "Mass Storage";
#define FSG_NO_INTR_EP 1
#define FSG_NO_DEVICE_STRINGS 1
#define FSG_NO_OTG 1
#define FSG_NO_INTR_EP 1
#include "storage_common.c"
/*-------------------------------------------------------------------------*/
struct fsg_dev;
/* Data shared by all the FSG instances. */
struct fsg_common {
struct usb_gadget *gadget;
struct fsg_dev *fsg, *new_fsg;
wait_queue_head_t fsg_wait;
/* filesem protects: backing files in use */
struct rw_semaphore filesem;
/* lock protects: state, all the req_busy's */
spinlock_t lock;
struct usb_ep *ep0; /* Copy of gadget->ep0 */
struct usb_request *ep0req; /* Copy of cdev->req */
unsigned int ep0_req_tag;
const char *ep0req_name;
struct fsg_buffhd *next_buffhd_to_fill;
struct fsg_buffhd *next_buffhd_to_drain;
struct fsg_buffhd buffhds[FSG_NUM_BUFFERS];
int cmnd_size;
u8 cmnd[MAX_COMMAND_SIZE];
unsigned int nluns;
unsigned int lun;
struct fsg_lun *luns;
struct fsg_lun *curlun;
unsigned int bulk_out_maxpacket;
enum fsg_state state; /* For exception handling */
unsigned int exception_req_tag;
enum data_direction data_dir;
u32 data_size;
u32 data_size_from_cmnd;
u32 tag;
u32 residue;
u32 usb_amount_left;
unsigned int can_stall:1;
unsigned int free_storage_on_release:1;
unsigned int phase_error:1;
unsigned int short_packet_received:1;
unsigned int bad_lun_okay:1;
unsigned int running:1;
int thread_wakeup_needed;
struct completion thread_notifier;
struct task_struct *thread_task;
/* Callback function to call when thread exits. */
int (*thread_exits)(struct fsg_common *common);
/* Gadget's private data. */
void *private_data;
/* Vendor (8 chars), product (16 chars), release (4
* hexadecimal digits) and NUL byte */
char inquiry_string[8 + 16 + 4 + 1];
struct kref ref;
};
struct fsg_config {
unsigned nluns;
struct fsg_lun_config {
const char *filename;
char ro;
char removable;
char cdrom;
} luns[FSG_MAX_LUNS];
const char *lun_name_format;
const char *thread_name;
/* Callback function to call when thread exits. If no
* callback is set or it returns value lower then zero MSF
* will force eject all LUNs it operates on (including those
* marked as non-removable or with prevent_medium_removal flag
* set). */
int (*thread_exits)(struct fsg_common *common);
/* Gadget's private data. */
void *private_data;
const char *vendor_name; /* 8 characters or less */
const char *product_name; /* 16 characters or less */
u16 release;
char can_stall;
};
struct fsg_dev {
struct usb_function function;
struct usb_gadget *gadget; /* Copy of cdev->gadget */
struct fsg_common *common;
u16 interface_number;
unsigned int bulk_in_enabled:1;
unsigned int bulk_out_enabled:1;
unsigned long atomic_bitflags;
#define IGNORE_BULK_OUT 0
struct usb_ep *bulk_in;
struct usb_ep *bulk_out;
};
static inline int __fsg_is_set(struct fsg_common *common,
const char *func, unsigned line)
{
if (common->fsg)
return 1;
ERROR(common, "common->fsg is NULL in %s at %u\n", func, line);
return 0;
}
#define fsg_is_set(common) likely(__fsg_is_set(common, __func__, __LINE__))
static inline struct fsg_dev *fsg_from_func(struct usb_function *f)
{
return container_of(f, struct fsg_dev, function);
}
typedef void (*fsg_routine_t)(struct fsg_dev *);
static int exception_in_progress(struct fsg_common *common)
{
return common->state > FSG_STATE_IDLE;
}
/* Make bulk-out requests be divisible by the maxpacket size */
static void set_bulk_out_req_length(struct fsg_common *common,
struct fsg_buffhd *bh, unsigned int length)
{
unsigned int rem;
bh->bulk_out_intended_length = length;
rem = length % common->bulk_out_maxpacket;
if (rem > 0)
length += common->bulk_out_maxpacket - rem;
bh->outreq->length = length;
}
/*-------------------------------------------------------------------------*/
static int fsg_set_halt(struct fsg_dev *fsg, struct usb_ep *ep)
{
const char *name;
if (ep == fsg->bulk_in)
name = "bulk-in";
else if (ep == fsg->bulk_out)
name = "bulk-out";
else
name = ep->name;
DBG(fsg, "%s set halt\n", name);
return usb_ep_set_halt(ep);
}
/*-------------------------------------------------------------------------*/
/* These routines may be called in process context or in_irq */
/* Caller must hold fsg->lock */
static void wakeup_thread(struct fsg_common *common)
{
/* Tell the main thread that something has happened */
common->thread_wakeup_needed = 1;
if (common->thread_task)
wake_up_process(common->thread_task);
}
static void raise_exception(struct fsg_common *common, enum fsg_state new_state)
{
unsigned long flags;
/* Do nothing if a higher-priority exception is already in progress.
* If a lower-or-equal priority exception is in progress, preempt it
* and notify the main thread by sending it a signal. */
spin_lock_irqsave(&common->lock, flags);
if (common->state <= new_state) {
common->exception_req_tag = common->ep0_req_tag;
common->state = new_state;
if (common->thread_task)
send_sig_info(SIGUSR1, SEND_SIG_FORCED,
common->thread_task);
}
spin_unlock_irqrestore(&common->lock, flags);
}
/*-------------------------------------------------------------------------*/
static int ep0_queue(struct fsg_common *common)
{
int rc;
rc = usb_ep_queue(common->ep0, common->ep0req, GFP_ATOMIC);
common->ep0->driver_data = common;
if (rc != 0 && rc != -ESHUTDOWN) {
/* We can't do much more than wait for a reset */
WARNING(common, "error in submission: %s --> %d\n",
common->ep0->name, rc);
}
return rc;
}
/*-------------------------------------------------------------------------*/
/* Bulk and interrupt endpoint completion handlers.
* These always run in_irq. */
static void bulk_in_complete(struct usb_ep *ep, struct usb_request *req)
{
struct fsg_common *common = ep->driver_data;
struct fsg_buffhd *bh = req->context;
if (req->status || req->actual != req->length)
DBG(common, "%s --> %d, %u/%u\n", __func__,
req->status, req->actual, req->length);
if (req->status == -ECONNRESET) /* Request was cancelled */
usb_ep_fifo_flush(ep);
/* Hold the lock while we update the request and buffer states */
smp_wmb();
spin_lock(&common->lock);
bh->inreq_busy = 0;
bh->state = BUF_STATE_EMPTY;
wakeup_thread(common);
spin_unlock(&common->lock);
}
static void bulk_out_complete(struct usb_ep *ep, struct usb_request *req)
{
struct fsg_common *common = ep->driver_data;
struct fsg_buffhd *bh = req->context;
dump_msg(common, "bulk-out", req->buf, req->actual);
if (req->status || req->actual != bh->bulk_out_intended_length)
DBG(common, "%s --> %d, %u/%u\n", __func__,
req->status, req->actual,
bh->bulk_out_intended_length);
if (req->status == -ECONNRESET) /* Request was cancelled */
usb_ep_fifo_flush(ep);
/* Hold the lock while we update the request and buffer states */
smp_wmb();
spin_lock(&common->lock);
bh->outreq_busy = 0;
bh->state = BUF_STATE_FULL;
wakeup_thread(common);
spin_unlock(&common->lock);
}
/*-------------------------------------------------------------------------*/
/* Ep0 class-specific handlers. These always run in_irq. */
static int fsg_setup(struct usb_function *f,
const struct usb_ctrlrequest *ctrl)
{
struct fsg_dev *fsg = fsg_from_func(f);
struct usb_request *req = fsg->common->ep0req;
u16 w_index = le16_to_cpu(ctrl->wIndex);
u16 w_value = le16_to_cpu(ctrl->wValue);
u16 w_length = le16_to_cpu(ctrl->wLength);
if (!fsg_is_set(fsg->common))
return -EOPNOTSUPP;
switch (ctrl->bRequest) {
case USB_BULK_RESET_REQUEST:
if (ctrl->bRequestType !=
(USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE))
break;
if (w_index != fsg->interface_number || w_value != 0)
return -EDOM;
/* Raise an exception to stop the current operation
* and reinitialize our state. */
DBG(fsg, "bulk reset request\n");
raise_exception(fsg->common, FSG_STATE_RESET);
return DELAYED_STATUS;
case USB_BULK_GET_MAX_LUN_REQUEST:
if (ctrl->bRequestType !=
(USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE))
break;
if (w_index != fsg->interface_number || w_value != 0)
return -EDOM;
VDBG(fsg, "get max LUN\n");
*(u8 *) req->buf = fsg->common->nluns - 1;
/* Respond with data/status */
req->length = min((u16)1, w_length);
fsg->common->ep0req_name =
ctrl->bRequestType & USB_DIR_IN ? "ep0-in" : "ep0-out";
return ep0_queue(fsg->common);
}
VDBG(fsg,
"unknown class-specific control req "
"%02x.%02x v%04x i%04x l%u\n",
ctrl->bRequestType, ctrl->bRequest,
le16_to_cpu(ctrl->wValue), w_index, w_length);
return -EOPNOTSUPP;
}
/*-------------------------------------------------------------------------*/
/* All the following routines run in process context */
/* Use this for bulk or interrupt transfers, not ep0 */
static void start_transfer(struct fsg_dev *fsg, struct usb_ep *ep,
struct usb_request *req, int *pbusy,
enum fsg_buffer_state *state)
{
int rc;
if (ep == fsg->bulk_in)
dump_msg(fsg, "bulk-in", req->buf, req->length);
spin_lock_irq(&fsg->common->lock);
*pbusy = 1;
*state = BUF_STATE_BUSY;
spin_unlock_irq(&fsg->common->lock);
rc = usb_ep_queue(ep, req, GFP_KERNEL);
if (rc != 0) {
*pbusy = 0;
*state = BUF_STATE_EMPTY;
/* We can't do much more than wait for a reset */
/* Note: currently the net2280 driver fails zero-length
* submissions if DMA is enabled. */
if (rc != -ESHUTDOWN && !(rc == -EOPNOTSUPP &&
req->length == 0))
WARNING(fsg, "error in submission: %s --> %d\n",
ep->name, rc);
}
}
#define START_TRANSFER_OR(common, ep_name, req, pbusy, state) \
if (fsg_is_set(common)) \
start_transfer((common)->fsg, (common)->fsg->ep_name, \
req, pbusy, state); \
else
#define START_TRANSFER(common, ep_name, req, pbusy, state) \
START_TRANSFER_OR(common, ep_name, req, pbusy, state) (void)0
static int sleep_thread(struct fsg_common *common)
{
int rc = 0;
/* Wait until a signal arrives or we are woken up */
for (;;) {
try_to_freeze();
set_current_state(TASK_INTERRUPTIBLE);
if (signal_pending(current)) {
rc = -EINTR;
break;
}
if (common->thread_wakeup_needed)
break;
schedule();
}
__set_current_state(TASK_RUNNING);
common->thread_wakeup_needed = 0;
return rc;
}
/*-------------------------------------------------------------------------*/
static int do_read(struct fsg_common *common)
{
struct fsg_lun *curlun = common->curlun;
u32 lba;
struct fsg_buffhd *bh;
int rc;
u32 amount_left;
loff_t file_offset, file_offset_tmp;
unsigned int amount;
unsigned int partial_page;
ssize_t nread;
/* Get the starting Logical Block Address and check that it's
* not too big */
if (common->cmnd[0] == SC_READ_6)
lba = get_unaligned_be24(&common->cmnd[1]);
else {
lba = get_unaligned_be32(&common->cmnd[2]);
/* We allow DPO (Disable Page Out = don't save data in the
* cache) and FUA (Force Unit Access = don't read from the
* cache), but we don't implement them. */
if ((common->cmnd[1] & ~0x18) != 0) {
curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
return -EINVAL;
}
}
if (lba >= curlun->num_sectors) {
curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
return -EINVAL;
}
file_offset = ((loff_t) lba) << 9;
/* Carry out the file reads */
amount_left = common->data_size_from_cmnd;
if (unlikely(amount_left == 0))
return -EIO; /* No default reply */
for (;;) {
/* Figure out how much we need to read:
* Try to read the remaining amount.
* But don't read more than the buffer size.
* And don't try to read past the end of the file.
* Finally, if we're not at a page boundary, don't read past
* the next page.
* If this means reading 0 then we were asked to read past
* the end of file. */
amount = min(amount_left, FSG_BUFLEN);
amount = min((loff_t) amount,
curlun->file_length - file_offset);
partial_page = file_offset & (PAGE_CACHE_SIZE - 1);
if (partial_page > 0)
amount = min(amount, (unsigned int) PAGE_CACHE_SIZE -
partial_page);
/* Wait for the next buffer to become available */
bh = common->next_buffhd_to_fill;
while (bh->state != BUF_STATE_EMPTY) {
rc = sleep_thread(common);
if (rc)
return rc;
}
/* If we were asked to read past the end of file,
* end with an empty buffer. */
if (amount == 0) {
curlun->sense_data =
SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
curlun->sense_data_info = file_offset >> 9;
curlun->info_valid = 1;
bh->inreq->length = 0;
bh->state = BUF_STATE_FULL;
break;
}
/* Perform the read */
file_offset_tmp = file_offset;
nread = vfs_read(curlun->filp,
(char __user *) bh->buf,
amount, &file_offset_tmp);
VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
(unsigned long long) file_offset,
(int) nread);
if (signal_pending(current))
return -EINTR;
if (nread < 0) {
LDBG(curlun, "error in file read: %d\n",
(int) nread);
nread = 0;
} else if (nread < amount) {
LDBG(curlun, "partial file read: %d/%u\n",
(int) nread, amount);
nread -= (nread & 511); /* Round down to a block */
}
file_offset += nread;
amount_left -= nread;
common->residue -= nread;
bh->inreq->length = nread;
bh->state = BUF_STATE_FULL;
/* If an error occurred, report it and its position */
if (nread < amount) {
curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
curlun->sense_data_info = file_offset >> 9;
curlun->info_valid = 1;
break;
}
if (amount_left == 0)
break; /* No more left to read */
/* Send this buffer and go read some more */
bh->inreq->zero = 0;
START_TRANSFER_OR(common, bulk_in, bh->inreq,
&bh->inreq_busy, &bh->state)
/* Don't know what to do if
* common->fsg is NULL */
return -EIO;
common->next_buffhd_to_fill = bh->next;
}
return -EIO; /* No default reply */
}
/*-------------------------------------------------------------------------*/
static int do_write(struct fsg_common *common)
{
struct fsg_lun *curlun = common->curlun;
u32 lba;
struct fsg_buffhd *bh;
int get_some_more;
u32 amount_left_to_req, amount_left_to_write;
loff_t usb_offset, file_offset, file_offset_tmp;
unsigned int amount;
unsigned int partial_page;
ssize_t nwritten;
int rc;
if (curlun->ro) {
curlun->sense_data = SS_WRITE_PROTECTED;
return -EINVAL;
}
spin_lock(&curlun->filp->f_lock);
curlun->filp->f_flags &= ~O_SYNC; /* Default is not to wait */
spin_unlock(&curlun->filp->f_lock);
/* Get the starting Logical Block Address and check that it's
* not too big */
if (common->cmnd[0] == SC_WRITE_6)
lba = get_unaligned_be24(&common->cmnd[1]);
else {
lba = get_unaligned_be32(&common->cmnd[2]);
/* We allow DPO (Disable Page Out = don't save data in the
* cache) and FUA (Force Unit Access = write directly to the
* medium). We don't implement DPO; we implement FUA by
* performing synchronous output. */
if (common->cmnd[1] & ~0x18) {
curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
return -EINVAL;
}
if (common->cmnd[1] & 0x08) { /* FUA */
spin_lock(&curlun->filp->f_lock);
curlun->filp->f_flags |= O_SYNC;
spin_unlock(&curlun->filp->f_lock);
}
}
if (lba >= curlun->num_sectors) {
curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
return -EINVAL;
}
/* Carry out the file writes */
get_some_more = 1;
file_offset = usb_offset = ((loff_t) lba) << 9;
amount_left_to_req = common->data_size_from_cmnd;
amount_left_to_write = common->data_size_from_cmnd;
while (amount_left_to_write > 0) {
/* Queue a request for more data from the host */
bh = common->next_buffhd_to_fill;
if (bh->state == BUF_STATE_EMPTY && get_some_more) {
/* Figure out how much we want to get:
* Try to get the remaining amount.
* But don't get more than the buffer size.
* And don't try to go past the end of the file.
* If we're not at a page boundary,
* don't go past the next page.
* If this means getting 0, then we were asked
* to write past the end of file.
* Finally, round down to a block boundary. */
amount = min(amount_left_to_req, FSG_BUFLEN);
amount = min((loff_t) amount, curlun->file_length -
usb_offset);
partial_page = usb_offset & (PAGE_CACHE_SIZE - 1);
if (partial_page > 0)
amount = min(amount,
(unsigned int) PAGE_CACHE_SIZE - partial_page);
if (amount == 0) {
get_some_more = 0;
curlun->sense_data =
SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
curlun->sense_data_info = usb_offset >> 9;
curlun->info_valid = 1;
continue;
}
amount -= (amount & 511);
if (amount == 0) {
/* Why were we were asked to transfer a
* partial block? */
get_some_more = 0;
continue;
}
/* Get the next buffer */
usb_offset += amount;
common->usb_amount_left -= amount;
amount_left_to_req -= amount;
if (amount_left_to_req == 0)
get_some_more = 0;
/* amount is always divisible by 512, hence by
* the bulk-out maxpacket size */
bh->outreq->length = amount;
bh->bulk_out_intended_length = amount;
bh->outreq->short_not_ok = 1;
START_TRANSFER_OR(common, bulk_out, bh->outreq,
&bh->outreq_busy, &bh->state)
/* Don't know what to do if
* common->fsg is NULL */
return -EIO;
common->next_buffhd_to_fill = bh->next;
continue;
}
/* Write the received data to the backing file */
bh = common->next_buffhd_to_drain;
if (bh->state == BUF_STATE_EMPTY && !get_some_more)
break; /* We stopped early */
if (bh->state == BUF_STATE_FULL) {
smp_rmb();
common->next_buffhd_to_drain = bh->next;
bh->state = BUF_STATE_EMPTY;
/* Did something go wrong with the transfer? */
if (bh->outreq->status != 0) {
curlun->sense_data = SS_COMMUNICATION_FAILURE;
curlun->sense_data_info = file_offset >> 9;
curlun->info_valid = 1;
break;
}
amount = bh->outreq->actual;
if (curlun->file_length - file_offset < amount) {
LERROR(curlun,
"write %u @ %llu beyond end %llu\n",
amount, (unsigned long long) file_offset,
(unsigned long long) curlun->file_length);
amount = curlun->file_length - file_offset;
}
/* Perform the write */
file_offset_tmp = file_offset;
nwritten = vfs_write(curlun->filp,
(char __user *) bh->buf,
amount, &file_offset_tmp);
VLDBG(curlun, "file write %u @ %llu -> %d\n", amount,
(unsigned long long) file_offset,
(int) nwritten);
if (signal_pending(current))
return -EINTR; /* Interrupted! */
if (nwritten < 0) {
LDBG(curlun, "error in file write: %d\n",
(int) nwritten);
nwritten = 0;
} else if (nwritten < amount) {
LDBG(curlun, "partial file write: %d/%u\n",
(int) nwritten, amount);
nwritten -= (nwritten & 511);
/* Round down to a block */
}
file_offset += nwritten;
amount_left_to_write -= nwritten;
common->residue -= nwritten;
/* If an error occurred, report it and its position */
if (nwritten < amount) {
curlun->sense_data = SS_WRITE_ERROR;
curlun->sense_data_info = file_offset >> 9;
curlun->info_valid = 1;
break;
}
/* Did the host decide to stop early? */
if (bh->outreq->actual != bh->outreq->length) {
common->short_packet_received = 1;
break;
}
continue;
}
/* Wait for something to happen */
rc = sleep_thread(common);
if (rc)
return rc;
}
return -EIO; /* No default reply */
}
/*-------------------------------------------------------------------------*/
static int do_synchronize_cache(struct fsg_common *common)
{
struct fsg_lun *curlun = common->curlun;
int rc;
/* We ignore the requested LBA and write out all file's
* dirty data buffers. */
rc = fsg_lun_fsync_sub(curlun);
if (rc)
curlun->sense_data = SS_WRITE_ERROR;
return 0;
}
/*-------------------------------------------------------------------------*/
static void invalidate_sub(struct fsg_lun *curlun)
{
struct file *filp = curlun->filp;
struct inode *inode = filp->f_path.dentry->d_inode;
unsigned long rc;
rc = invalidate_mapping_pages(inode->i_mapping, 0, -1);
VLDBG(curlun, "invalidate_mapping_pages -> %ld\n", rc);
}
static int do_verify(struct fsg_common *common)
{
struct fsg_lun *curlun = common->curlun;
u32 lba;
u32 verification_length;
struct fsg_buffhd *bh = common->next_buffhd_to_fill;
loff_t file_offset, file_offset_tmp;
u32 amount_left;
unsigned int amount;
ssize_t nread;
/* Get the starting Logical Block Address and check that it's
* not too big */
lba = get_unaligned_be32(&common->cmnd[2]);
if (lba >= curlun->num_sectors) {
curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
return -EINVAL;
}
/* We allow DPO (Disable Page Out = don't save data in the
* cache) but we don't implement it. */
if (common->cmnd[1] & ~0x10) {
curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
return -EINVAL;
}
verification_length = get_unaligned_be16(&common->cmnd[7]);
if (unlikely(verification_length == 0))
return -EIO; /* No default reply */
/* Prepare to carry out the file verify */
amount_left = verification_length << 9;
file_offset = ((loff_t) lba) << 9;
/* Write out all the dirty buffers before invalidating them */
fsg_lun_fsync_sub(curlun);
if (signal_pending(current))
return -EINTR;
invalidate_sub(curlun);
if (signal_pending(current))
return -EINTR;
/* Just try to read the requested blocks */
while (amount_left > 0) {
/* Figure out how much we need to read:
* Try to read the remaining amount, but not more than
* the buffer size.
* And don't try to read past the end of the file.
* If this means reading 0 then we were asked to read
* past the end of file. */
amount = min(amount_left, FSG_BUFLEN);
amount = min((loff_t) amount,
curlun->file_length - file_offset);
if (amount == 0) {
curlun->sense_data =
SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
curlun->sense_data_info = file_offset >> 9;
curlun->info_valid = 1;
break;
}
/* Perform the read */
file_offset_tmp = file_offset;
nread = vfs_read(curlun->filp,
(char __user *) bh->buf,
amount, &file_offset_tmp);
VLDBG(curlun, "file read %u @ %llu -> %d\n", amount,
(unsigned long long) file_offset,
(int) nread);
if (signal_pending(current))
return -EINTR;
if (nread < 0) {
LDBG(curlun, "error in file verify: %d\n",
(int) nread);
nread = 0;
} else if (nread < amount) {
LDBG(curlun, "partial file verify: %d/%u\n",
(int) nread, amount);
nread -= (nread & 511); /* Round down to a sector */
}
if (nread == 0) {
curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
curlun->sense_data_info = file_offset >> 9;
curlun->info_valid = 1;
break;
}
file_offset += nread;
amount_left -= nread;
}
return 0;
}
/*-------------------------------------------------------------------------*/
static int do_inquiry(struct fsg_common *common, struct fsg_buffhd *bh)
{
struct fsg_lun *curlun = common->curlun;
u8 *buf = (u8 *) bh->buf;
if (!curlun) { /* Unsupported LUNs are okay */
common->bad_lun_okay = 1;
memset(buf, 0, 36);
buf[0] = 0x7f; /* Unsupported, no device-type */
buf[4] = 31; /* Additional length */
return 36;
}
buf[0] = curlun->cdrom ? TYPE_CDROM : TYPE_DISK;
buf[1] = curlun->removable ? 0x80 : 0;
buf[2] = 2; /* ANSI SCSI level 2 */
buf[3] = 2; /* SCSI-2 INQUIRY data format */
buf[4] = 31; /* Additional length */
buf[5] = 0; /* No special options */
buf[6] = 0;
buf[7] = 0;
memcpy(buf + 8, common->inquiry_string, sizeof common->inquiry_string);
return 36;
}
static int do_request_sense(struct fsg_common *common, struct fsg_buffhd *bh)
{
struct fsg_lun *curlun = common->curlun;
u8 *buf = (u8 *) bh->buf;
u32 sd, sdinfo;
int valid;
/*
* From the SCSI-2 spec., section 7.9 (Unit attention condition):
*
* If a REQUEST SENSE command is received from an initiator
* with a pending unit attention condition (before the target
* generates the contingent allegiance condition), then the
* target shall either:
* a) report any pending sense data and preserve the unit
* attention condition on the logical unit, or,
* b) report the unit attention condition, may discard any
* pending sense data, and clear the unit attention
* condition on the logical unit for that initiator.
*
* FSG normally uses option a); enable this code to use option b).
*/
#if 0
if (curlun && curlun->unit_attention_data != SS_NO_SENSE) {
curlun->sense_data = curlun->unit_attention_data;
curlun->unit_attention_data = SS_NO_SENSE;
}
#endif
if (!curlun) { /* Unsupported LUNs are okay */
common->bad_lun_okay = 1;
sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
sdinfo = 0;
valid = 0;
} else {
sd = curlun->sense_data;
sdinfo = curlun->sense_data_info;
valid = curlun->info_valid << 7;
curlun->sense_data = SS_NO_SENSE;
curlun->sense_data_info = 0;
curlun->info_valid = 0;
}
memset(buf, 0, 18);
buf[0] = valid | 0x70; /* Valid, current error */
buf[2] = SK(sd);
put_unaligned_be32(sdinfo, &buf[3]); /* Sense information */
buf[7] = 18 - 8; /* Additional sense length */
buf[12] = ASC(sd);
buf[13] = ASCQ(sd);
return 18;
}
static int do_read_capacity(struct fsg_common *common, struct fsg_buffhd *bh)
{
struct fsg_lun *curlun = common->curlun;
u32 lba = get_unaligned_be32(&common->cmnd[2]);
int pmi = common->cmnd[8];
u8 *buf = (u8 *) bh->buf;
/* Check the PMI and LBA fields */
if (pmi > 1 || (pmi == 0 && lba != 0)) {
curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
return -EINVAL;
}
put_unaligned_be32(curlun->num_sectors - 1, &buf[0]);
/* Max logical block */
put_unaligned_be32(512, &buf[4]); /* Block length */
return 8;
}
static int do_read_header(struct fsg_common *common, struct fsg_buffhd *bh)
{
struct fsg_lun *curlun = common->curlun;
int msf = common->cmnd[1] & 0x02;
u32 lba = get_unaligned_be32(&common->cmnd[2]);
u8 *buf = (u8 *) bh->buf;
if (common->cmnd[1] & ~0x02) { /* Mask away MSF */
curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
return -EINVAL;
}
if (lba >= curlun->num_sectors) {
curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
return -EINVAL;
}
memset(buf, 0, 8);
buf[0] = 0x01; /* 2048 bytes of user data, rest is EC */
store_cdrom_address(&buf[4], msf, lba);
return 8;
}
static int do_read_toc(struct fsg_common *common, struct fsg_buffhd *bh)
{
struct fsg_lun *curlun = common->curlun;
int msf = common->cmnd[1] & 0x02;
int start_track = common->cmnd[6];
u8 *buf = (u8 *) bh->buf;
if ((common->cmnd[1] & ~0x02) != 0 || /* Mask away MSF */
start_track > 1) {
curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
return -EINVAL;
}
memset(buf, 0, 20);
buf[1] = (20-2); /* TOC data length */
buf[2] = 1; /* First track number */
buf[3] = 1; /* Last track number */
buf[5] = 0x16; /* Data track, copying allowed */
buf[6] = 0x01; /* Only track is number 1 */
store_cdrom_address(&buf[8], msf, 0);
buf[13] = 0x16; /* Lead-out track is data */
buf[14] = 0xAA; /* Lead-out track number */
store_cdrom_address(&buf[16], msf, curlun->num_sectors);
return 20;
}
static int do_mode_sense(struct fsg_common *common, struct fsg_buffhd *bh)
{
struct fsg_lun *curlun = common->curlun;
int mscmnd = common->cmnd[0];
u8 *buf = (u8 *) bh->buf;
u8 *buf0 = buf;
int pc, page_code;
int changeable_values, all_pages;
int valid_page = 0;
int len, limit;
if ((common->cmnd[1] & ~0x08) != 0) { /* Mask away DBD */
curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
return -EINVAL;
}
pc = common->cmnd[2] >> 6;
page_code = common->cmnd[2] & 0x3f;
if (pc == 3) {
curlun->sense_data = SS_SAVING_PARAMETERS_NOT_SUPPORTED;
return -EINVAL;
}
changeable_values = (pc == 1);
all_pages = (page_code == 0x3f);
/* Write the mode parameter header. Fixed values are: default
* medium type, no cache control (DPOFUA), and no block descriptors.
* The only variable value is the WriteProtect bit. We will fill in
* the mode data length later. */
memset(buf, 0, 8);
if (mscmnd == SC_MODE_SENSE_6) {
buf[2] = (curlun->ro ? 0x80 : 0x00); /* WP, DPOFUA */
buf += 4;
limit = 255;
} else { /* SC_MODE_SENSE_10 */
buf[3] = (curlun->ro ? 0x80 : 0x00); /* WP, DPOFUA */
buf += 8;
limit = 65535; /* Should really be FSG_BUFLEN */
}
/* No block descriptors */
/* The mode pages, in numerical order. The only page we support
* is the Caching page. */
if (page_code == 0x08 || all_pages) {
valid_page = 1;
buf[0] = 0x08; /* Page code */
buf[1] = 10; /* Page length */
memset(buf+2, 0, 10); /* None of the fields are changeable */
if (!changeable_values) {
buf[2] = 0x04; /* Write cache enable, */
/* Read cache not disabled */
/* No cache retention priorities */
put_unaligned_be16(0xffff, &buf[4]);
/* Don't disable prefetch */
/* Minimum prefetch = 0 */
put_unaligned_be16(0xffff, &buf[8]);
/* Maximum prefetch */
put_unaligned_be16(0xffff, &buf[10]);
/* Maximum prefetch ceiling */
}
buf += 12;
}
/* Check that a valid page was requested and the mode data length
* isn't too long. */
len = buf - buf0;
if (!valid_page || len > limit) {
curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
return -EINVAL;
}
/* Store the mode data length */
if (mscmnd == SC_MODE_SENSE_6)
buf0[0] = len - 1;
else
put_unaligned_be16(len - 2, buf0);
return len;
}
static int do_start_stop(struct fsg_common *common)
{
struct fsg_lun *curlun = common->curlun;
int loej, start;
if (!curlun) {
return -EINVAL;
} else if (!curlun->removable) {
curlun->sense_data = SS_INVALID_COMMAND;
return -EINVAL;
}
loej = common->cmnd[4] & 0x02;
start = common->cmnd[4] & 0x01;
/* eject code from file_storage.c:do_start_stop() */
if ((common->cmnd[1] & ~0x01) != 0 || /* Mask away Immed */
(common->cmnd[4] & ~0x03) != 0) { /* Mask LoEj, Start */
curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
return -EINVAL;
}
if (!start) {
/* Are we allowed to unload the media? */
if (curlun->prevent_medium_removal) {
LDBG(curlun, "unload attempt prevented\n");
curlun->sense_data = SS_MEDIUM_REMOVAL_PREVENTED;
return -EINVAL;
}
if (loej) { /* Simulate an unload/eject */
up_read(&common->filesem);
down_write(&common->filesem);
fsg_lun_close(curlun);
up_write(&common->filesem);
down_read(&common->filesem);
}
} else {
/* Our emulation doesn't support mounting; the medium is
* available for use as soon as it is loaded. */
if (!fsg_lun_is_open(curlun)) {
curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
return -EINVAL;
}
}
return 0;
}
static int do_prevent_allow(struct fsg_common *common)
{
struct fsg_lun *curlun = common->curlun;
int prevent;
if (!common->curlun) {
return -EINVAL;
} else if (!common->curlun->removable) {
common->curlun->sense_data = SS_INVALID_COMMAND;
return -EINVAL;
}
prevent = common->cmnd[4] & 0x01;
if ((common->cmnd[4] & ~0x01) != 0) { /* Mask away Prevent */
curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
return -EINVAL;
}
if (curlun->prevent_medium_removal && !prevent)
fsg_lun_fsync_sub(curlun);
curlun->prevent_medium_removal = prevent;
return 0;
}
static int do_read_format_capacities(struct fsg_common *common,
struct fsg_buffhd *bh)
{
struct fsg_lun *curlun = common->curlun;
u8 *buf = (u8 *) bh->buf;
buf[0] = buf[1] = buf[2] = 0;
buf[3] = 8; /* Only the Current/Maximum Capacity Descriptor */
buf += 4;
put_unaligned_be32(curlun->num_sectors, &buf[0]);
/* Number of blocks */
put_unaligned_be32(512, &buf[4]); /* Block length */
buf[4] = 0x02; /* Current capacity */
return 12;
}
static int do_mode_select(struct fsg_common *common, struct fsg_buffhd *bh)
{
struct fsg_lun *curlun = common->curlun;
/* We don't support MODE SELECT */
if (curlun)
curlun->sense_data = SS_INVALID_COMMAND;
return -EINVAL;
}
/*-------------------------------------------------------------------------*/
static int halt_bulk_in_endpoint(struct fsg_dev *fsg)
{
int rc;
rc = fsg_set_halt(fsg, fsg->bulk_in);
if (rc == -EAGAIN)
VDBG(fsg, "delayed bulk-in endpoint halt\n");
while (rc != 0) {
if (rc != -EAGAIN) {
WARNING(fsg, "usb_ep_set_halt -> %d\n", rc);
rc = 0;
break;
}
/* Wait for a short time and then try again */
if (msleep_interruptible(100) != 0)
return -EINTR;
rc = usb_ep_set_halt(fsg->bulk_in);
}
return rc;
}
static int wedge_bulk_in_endpoint(struct fsg_dev *fsg)
{
int rc;
DBG(fsg, "bulk-in set wedge\n");
rc = usb_ep_set_wedge(fsg->bulk_in);
if (rc == -EAGAIN)
VDBG(fsg, "delayed bulk-in endpoint wedge\n");
while (rc != 0) {
if (rc != -EAGAIN) {
WARNING(fsg, "usb_ep_set_wedge -> %d\n", rc);
rc = 0;
break;
}
/* Wait for a short time and then try again */
if (msleep_interruptible(100) != 0)
return -EINTR;
rc = usb_ep_set_wedge(fsg->bulk_in);
}
return rc;
}
static int pad_with_zeros(struct fsg_dev *fsg)
{
struct fsg_buffhd *bh = fsg->common->next_buffhd_to_fill;
u32 nkeep = bh->inreq->length;
u32 nsend;
int rc;
bh->state = BUF_STATE_EMPTY; /* For the first iteration */
fsg->common->usb_amount_left = nkeep + fsg->common->residue;
while (fsg->common->usb_amount_left > 0) {
/* Wait for the next buffer to be free */
while (bh->state != BUF_STATE_EMPTY) {
rc = sleep_thread(fsg->common);
if (rc)
return rc;
}
nsend = min(fsg->common->usb_amount_left, FSG_BUFLEN);
memset(bh->buf + nkeep, 0, nsend - nkeep);
bh->inreq->length = nsend;
bh->inreq->zero = 0;
start_transfer(fsg, fsg->bulk_in, bh->inreq,
&bh->inreq_busy, &bh->state);
bh = fsg->common->next_buffhd_to_fill = bh->next;
fsg->common->usb_amount_left -= nsend;
nkeep = 0;
}
return 0;
}
static int throw_away_data(struct fsg_common *common)
{
struct fsg_buffhd *bh;
u32 amount;
int rc;
for (bh = common->next_buffhd_to_drain;
bh->state != BUF_STATE_EMPTY || common->usb_amount_left > 0;
bh = common->next_buffhd_to_drain) {
/* Throw away the data in a filled buffer */
if (bh->state == BUF_STATE_FULL) {
smp_rmb();
bh->state = BUF_STATE_EMPTY;
common->next_buffhd_to_drain = bh->next;
/* A short packet or an error ends everything */
if (bh->outreq->actual != bh->outreq->length ||
bh->outreq->status != 0) {
raise_exception(common,
FSG_STATE_ABORT_BULK_OUT);
return -EINTR;
}
continue;
}
/* Try to submit another request if we need one */
bh = common->next_buffhd_to_fill;
if (bh->state == BUF_STATE_EMPTY
&& common->usb_amount_left > 0) {
amount = min(common->usb_amount_left, FSG_BUFLEN);
/* amount is always divisible by 512, hence by
* the bulk-out maxpacket size */
bh->outreq->length = amount;
bh->bulk_out_intended_length = amount;
bh->outreq->short_not_ok = 1;
START_TRANSFER_OR(common, bulk_out, bh->outreq,
&bh->outreq_busy, &bh->state)
/* Don't know what to do if
* common->fsg is NULL */
return -EIO;
common->next_buffhd_to_fill = bh->next;
common->usb_amount_left -= amount;
continue;
}
/* Otherwise wait for something to happen */
rc = sleep_thread(common);
if (rc)
return rc;
}
return 0;
}
static int finish_reply(struct fsg_common *common)
{
struct fsg_buffhd *bh = common->next_buffhd_to_fill;
int rc = 0;
switch (common->data_dir) {
case DATA_DIR_NONE:
break; /* Nothing to send */
/* If we don't know whether the host wants to read or write,
* this must be CB or CBI with an unknown command. We mustn't
* try to send or receive any data. So stall both bulk pipes
* if we can and wait for a reset. */
case DATA_DIR_UNKNOWN:
if (!common->can_stall) {
/* Nothing */
} else if (fsg_is_set(common)) {
fsg_set_halt(common->fsg, common->fsg->bulk_out);
rc = halt_bulk_in_endpoint(common->fsg);
} else {
/* Don't know what to do if common->fsg is NULL */
rc = -EIO;
}
break;
/* All but the last buffer of data must have already been sent */
case DATA_DIR_TO_HOST:
if (common->data_size == 0) {
/* Nothing to send */
/* If there's no residue, simply send the last buffer */
} else if (common->residue == 0) {
bh->inreq->zero = 0;
START_TRANSFER_OR(common, bulk_in, bh->inreq,
&bh->inreq_busy, &bh->state)
return -EIO;
common->next_buffhd_to_fill = bh->next;
/* For Bulk-only, if we're allowed to stall then send the
* short packet and halt the bulk-in endpoint. If we can't
* stall, pad out the remaining data with 0's. */
} else if (common->can_stall) {
bh->inreq->zero = 1;
START_TRANSFER_OR(common, bulk_in, bh->inreq,
&bh->inreq_busy, &bh->state)
/* Don't know what to do if
* common->fsg is NULL */
rc = -EIO;
common->next_buffhd_to_fill = bh->next;
if (common->fsg)
rc = halt_bulk_in_endpoint(common->fsg);
} else if (fsg_is_set(common)) {
rc = pad_with_zeros(common->fsg);
} else {
/* Don't know what to do if common->fsg is NULL */
rc = -EIO;
}
break;
/* We have processed all we want from the data the host has sent.
* There may still be outstanding bulk-out requests. */
case DATA_DIR_FROM_HOST:
if (common->residue == 0) {
/* Nothing to receive */
/* Did the host stop sending unexpectedly early? */
} else if (common->short_packet_received) {
raise_exception(common, FSG_STATE_ABORT_BULK_OUT);
rc = -EINTR;
/* We haven't processed all the incoming data. Even though
* we may be allowed to stall, doing so would cause a race.
* The controller may already have ACK'ed all the remaining
* bulk-out packets, in which case the host wouldn't see a
* STALL. Not realizing the endpoint was halted, it wouldn't
* clear the halt -- leading to problems later on. */
#if 0
} else if (common->can_stall) {
if (fsg_is_set(common))
fsg_set_halt(common->fsg,
common->fsg->bulk_out);
raise_exception(common, FSG_STATE_ABORT_BULK_OUT);
rc = -EINTR;
#endif
/* We can't stall. Read in the excess data and throw it
* all away. */
} else {
rc = throw_away_data(common);
}
break;
}
return rc;
}
static int send_status(struct fsg_common *common)
{
struct fsg_lun *curlun = common->curlun;
struct fsg_buffhd *bh;
struct bulk_cs_wrap *csw;
int rc;
u8 status = USB_STATUS_PASS;
u32 sd, sdinfo = 0;
/* Wait for the next buffer to become available */
bh = common->next_buffhd_to_fill;
while (bh->state != BUF_STATE_EMPTY) {
rc = sleep_thread(common);
if (rc)
return rc;
}
if (curlun) {
sd = curlun->sense_data;
sdinfo = curlun->sense_data_info;
} else if (common->bad_lun_okay)
sd = SS_NO_SENSE;
else
sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
if (common->phase_error) {
DBG(common, "sending phase-error status\n");
status = USB_STATUS_PHASE_ERROR;
sd = SS_INVALID_COMMAND;
} else if (sd != SS_NO_SENSE) {
DBG(common, "sending command-failure status\n");
status = USB_STATUS_FAIL;
VDBG(common, " sense data: SK x%02x, ASC x%02x, ASCQ x%02x;"
" info x%x\n",
SK(sd), ASC(sd), ASCQ(sd), sdinfo);
}
/* Store and send the Bulk-only CSW */
csw = (void *)bh->buf;
csw->Signature = cpu_to_le32(USB_BULK_CS_SIG);
csw->Tag = common->tag;
csw->Residue = cpu_to_le32(common->residue);
csw->Status = status;
bh->inreq->length = USB_BULK_CS_WRAP_LEN;
bh->inreq->zero = 0;
START_TRANSFER_OR(common, bulk_in, bh->inreq,
&bh->inreq_busy, &bh->state)
/* Don't know what to do if common->fsg is NULL */
return -EIO;
common->next_buffhd_to_fill = bh->next;
return 0;
}
/*-------------------------------------------------------------------------*/
/* Check whether the command is properly formed and whether its data size
* and direction agree with the values we already have. */
static int check_command(struct fsg_common *common, int cmnd_size,
enum data_direction data_dir, unsigned int mask,
int needs_medium, const char *name)
{
int i;
int lun = common->cmnd[1] >> 5;
static const char dirletter[4] = {'u', 'o', 'i', 'n'};
char hdlen[20];
struct fsg_lun *curlun;
hdlen[0] = 0;
if (common->data_dir != DATA_DIR_UNKNOWN)
sprintf(hdlen, ", H%c=%u", dirletter[(int) common->data_dir],
common->data_size);
VDBG(common, "SCSI command: %s; Dc=%d, D%c=%u; Hc=%d%s\n",
name, cmnd_size, dirletter[(int) data_dir],
common->data_size_from_cmnd, common->cmnd_size, hdlen);
/* We can't reply at all until we know the correct data direction
* and size. */
if (common->data_size_from_cmnd == 0)
data_dir = DATA_DIR_NONE;
if (common->data_size < common->data_size_from_cmnd) {
/* Host data size < Device data size is a phase error.
* Carry out the command, but only transfer as much as
* we are allowed. */
common->data_size_from_cmnd = common->data_size;
common->phase_error = 1;
}
common->residue = common->data_size;
common->usb_amount_left = common->data_size;
/* Conflicting data directions is a phase error */
if (common->data_dir != data_dir
&& common->data_size_from_cmnd > 0) {
common->phase_error = 1;
return -EINVAL;
}
/* Verify the length of the command itself */
if (cmnd_size != common->cmnd_size) {
/* Special case workaround: There are plenty of buggy SCSI
* implementations. Many have issues with cbw->Length
* field passing a wrong command size. For those cases we
* always try to work around the problem by using the length
* sent by the host side provided it is at least as large
* as the correct command length.
* Examples of such cases would be MS-Windows, which issues
* REQUEST SENSE with cbw->Length == 12 where it should
* be 6, and xbox360 issuing INQUIRY, TEST UNIT READY and
* REQUEST SENSE with cbw->Length == 10 where it should
* be 6 as well.
*/
if (cmnd_size <= common->cmnd_size) {
DBG(common, "%s is buggy! Expected length %d "
"but we got %d\n", name,
cmnd_size, common->cmnd_size);
cmnd_size = common->cmnd_size;
} else {
common->phase_error = 1;
return -EINVAL;
}
}
/* Check that the LUN values are consistent */
if (common->lun != lun)
DBG(common, "using LUN %d from CBW, not LUN %d from CDB\n",
common->lun, lun);
/* Check the LUN */
if (common->lun >= 0 && common->lun < common->nluns) {
curlun = &common->luns[common->lun];
common->curlun = curlun;
if (common->cmnd[0] != SC_REQUEST_SENSE) {
curlun->sense_data = SS_NO_SENSE;
curlun->sense_data_info = 0;
curlun->info_valid = 0;
}
} else {
common->curlun = NULL;
curlun = NULL;
common->bad_lun_okay = 0;
/* INQUIRY and REQUEST SENSE commands are explicitly allowed
* to use unsupported LUNs; all others may not. */
if (common->cmnd[0] != SC_INQUIRY &&
common->cmnd[0] != SC_REQUEST_SENSE) {
DBG(common, "unsupported LUN %d\n", common->lun);
return -EINVAL;
}
}
/* If a unit attention condition exists, only INQUIRY and
* REQUEST SENSE commands are allowed; anything else must fail. */
if (curlun && curlun->unit_attention_data != SS_NO_SENSE &&
common->cmnd[0] != SC_INQUIRY &&
common->cmnd[0] != SC_REQUEST_SENSE) {
curlun->sense_data = curlun->unit_attention_data;
curlun->unit_attention_data = SS_NO_SENSE;
return -EINVAL;
}
/* Check that only command bytes listed in the mask are non-zero */
common->cmnd[1] &= 0x1f; /* Mask away the LUN */
for (i = 1; i < cmnd_size; ++i) {
if (common->cmnd[i] && !(mask & (1 << i))) {
if (curlun)
curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
return -EINVAL;
}
}
/* If the medium isn't mounted and the command needs to access
* it, return an error. */
if (curlun && !fsg_lun_is_open(curlun) && needs_medium) {
curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
return -EINVAL;
}
return 0;
}
static int do_scsi_command(struct fsg_common *common)
{
struct fsg_buffhd *bh;
int rc;
int reply = -EINVAL;
int i;
static char unknown[16];
dump_cdb(common);
/* Wait for the next buffer to become available for data or status */
bh = common->next_buffhd_to_fill;
common->next_buffhd_to_drain = bh;
while (bh->state != BUF_STATE_EMPTY) {
rc = sleep_thread(common);
if (rc)
return rc;
}
common->phase_error = 0;
common->short_packet_received = 0;
down_read(&common->filesem); /* We're using the backing file */
switch (common->cmnd[0]) {
case SC_INQUIRY:
common->data_size_from_cmnd = common->cmnd[4];
reply = check_command(common, 6, DATA_DIR_TO_HOST,
(1<<4), 0,
"INQUIRY");
if (reply == 0)
reply = do_inquiry(common, bh);
break;
case SC_MODE_SELECT_6:
common->data_size_from_cmnd = common->cmnd[4];
reply = check_command(common, 6, DATA_DIR_FROM_HOST,
(1<<1) | (1<<4), 0,
"MODE SELECT(6)");
if (reply == 0)
reply = do_mode_select(common, bh);
break;
case SC_MODE_SELECT_10:
common->data_size_from_cmnd =
get_unaligned_be16(&common->cmnd[7]);
reply = check_command(common, 10, DATA_DIR_FROM_HOST,
(1<<1) | (3<<7), 0,
"MODE SELECT(10)");
if (reply == 0)
reply = do_mode_select(common, bh);
break;
case SC_MODE_SENSE_6:
common->data_size_from_cmnd = common->cmnd[4];
reply = check_command(common, 6, DATA_DIR_TO_HOST,
(1<<1) | (1<<2) | (1<<4), 0,
"MODE SENSE(6)");
if (reply == 0)
reply = do_mode_sense(common, bh);
break;
case SC_MODE_SENSE_10:
common->data_size_from_cmnd =
get_unaligned_be16(&common->cmnd[7]);
reply = check_command(common, 10, DATA_DIR_TO_HOST,
(1<<1) | (1<<2) | (3<<7), 0,
"MODE SENSE(10)");
if (reply == 0)
reply = do_mode_sense(common, bh);
break;
case SC_PREVENT_ALLOW_MEDIUM_REMOVAL:
common->data_size_from_cmnd = 0;
reply = check_command(common, 6, DATA_DIR_NONE,
(1<<4), 0,
"PREVENT-ALLOW MEDIUM REMOVAL");
if (reply == 0)
reply = do_prevent_allow(common);
break;
case SC_READ_6:
i = common->cmnd[4];
common->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
reply = check_command(common, 6, DATA_DIR_TO_HOST,
(7<<1) | (1<<4), 1,
"READ(6)");
if (reply == 0)
reply = do_read(common);
break;
case SC_READ_10:
common->data_size_from_cmnd =
get_unaligned_be16(&common->cmnd[7]) << 9;
reply = check_command(common, 10, DATA_DIR_TO_HOST,
(1<<1) | (0xf<<2) | (3<<7), 1,
"READ(10)");
if (reply == 0)
reply = do_read(common);
break;
case SC_READ_12:
common->data_size_from_cmnd =
get_unaligned_be32(&common->cmnd[6]) << 9;
reply = check_command(common, 12, DATA_DIR_TO_HOST,
(1<<1) | (0xf<<2) | (0xf<<6), 1,
"READ(12)");
if (reply == 0)
reply = do_read(common);
break;
case SC_READ_CAPACITY:
common->data_size_from_cmnd = 8;
reply = check_command(common, 10, DATA_DIR_TO_HOST,
(0xf<<2) | (1<<8), 1,
"READ CAPACITY");
if (reply == 0)
reply = do_read_capacity(common, bh);
break;
case SC_READ_HEADER:
if (!common->curlun || !common->curlun->cdrom)
goto unknown_cmnd;
common->data_size_from_cmnd =
get_unaligned_be16(&common->cmnd[7]);
reply = check_command(common, 10, DATA_DIR_TO_HOST,
(3<<7) | (0x1f<<1), 1,
"READ HEADER");
if (reply == 0)
reply = do_read_header(common, bh);
break;
case SC_READ_TOC:
if (!common->curlun || !common->curlun->cdrom)
goto unknown_cmnd;
common->data_size_from_cmnd =
get_unaligned_be16(&common->cmnd[7]);
reply = check_command(common, 10, DATA_DIR_TO_HOST,
(7<<6) | (1<<1), 1,
"READ TOC");
if (reply == 0)
reply = do_read_toc(common, bh);
break;
case SC_READ_FORMAT_CAPACITIES:
common->data_size_from_cmnd =
get_unaligned_be16(&common->cmnd[7]);
reply = check_command(common, 10, DATA_DIR_TO_HOST,
(3<<7), 1,
"READ FORMAT CAPACITIES");
if (reply == 0)
reply = do_read_format_capacities(common, bh);
break;
case SC_REQUEST_SENSE:
common->data_size_from_cmnd = common->cmnd[4];
reply = check_command(common, 6, DATA_DIR_TO_HOST,
(1<<4), 0,
"REQUEST SENSE");
if (reply == 0)
reply = do_request_sense(common, bh);
break;
case SC_START_STOP_UNIT:
common->data_size_from_cmnd = 0;
reply = check_command(common, 6, DATA_DIR_NONE,
(1<<1) | (1<<4), 0,
"START-STOP UNIT");
if (reply == 0)
reply = do_start_stop(common);
break;
case SC_SYNCHRONIZE_CACHE:
common->data_size_from_cmnd = 0;
reply = check_command(common, 10, DATA_DIR_NONE,
(0xf<<2) | (3<<7), 1,
"SYNCHRONIZE CACHE");
if (reply == 0)
reply = do_synchronize_cache(common);
break;
case SC_TEST_UNIT_READY:
common->data_size_from_cmnd = 0;
reply = check_command(common, 6, DATA_DIR_NONE,
0, 1,
"TEST UNIT READY");
break;
/* Although optional, this command is used by MS-Windows. We
* support a minimal version: BytChk must be 0. */
case SC_VERIFY:
common->data_size_from_cmnd = 0;
reply = check_command(common, 10, DATA_DIR_NONE,
(1<<1) | (0xf<<2) | (3<<7), 1,
"VERIFY");
if (reply == 0)
reply = do_verify(common);
break;
case SC_WRITE_6:
i = common->cmnd[4];
common->data_size_from_cmnd = (i == 0 ? 256 : i) << 9;
reply = check_command(common, 6, DATA_DIR_FROM_HOST,
(7<<1) | (1<<4), 1,
"WRITE(6)");
if (reply == 0)
reply = do_write(common);
break;
case SC_WRITE_10:
common->data_size_from_cmnd =
get_unaligned_be16(&common->cmnd[7]) << 9;
reply = check_command(common, 10, DATA_DIR_FROM_HOST,
(1<<1) | (0xf<<2) | (3<<7), 1,
"WRITE(10)");
if (reply == 0)
reply = do_write(common);
break;
case SC_WRITE_12:
common->data_size_from_cmnd =
get_unaligned_be32(&common->cmnd[6]) << 9;
reply = check_command(common, 12, DATA_DIR_FROM_HOST,
(1<<1) | (0xf<<2) | (0xf<<6), 1,
"WRITE(12)");
if (reply == 0)
reply = do_write(common);
break;
/* Some mandatory commands that we recognize but don't implement.
* They don't mean much in this setting. It's left as an exercise
* for anyone interested to implement RESERVE and RELEASE in terms
* of Posix locks. */
case SC_FORMAT_UNIT:
case SC_RELEASE:
case SC_RESERVE:
case SC_SEND_DIAGNOSTIC:
/* Fall through */
default:
unknown_cmnd:
common->data_size_from_cmnd = 0;
sprintf(unknown, "Unknown x%02x", common->cmnd[0]);
reply = check_command(common, common->cmnd_size,
DATA_DIR_UNKNOWN, 0xff, 0, unknown);
if (reply == 0) {
common->curlun->sense_data = SS_INVALID_COMMAND;
reply = -EINVAL;
}
break;
}
up_read(&common->filesem);
if (reply == -EINTR || signal_pending(current))
return -EINTR;
/* Set up the single reply buffer for finish_reply() */
if (reply == -EINVAL)
reply = 0; /* Error reply length */
if (reply >= 0 && common->data_dir == DATA_DIR_TO_HOST) {
reply = min((u32) reply, common->data_size_from_cmnd);
bh->inreq->length = reply;
bh->state = BUF_STATE_FULL;
common->residue -= reply;
} /* Otherwise it's already set */
return 0;
}
/*-------------------------------------------------------------------------*/
static int received_cbw(struct fsg_dev *fsg, struct fsg_buffhd *bh)
{
struct usb_request *req = bh->outreq;
struct fsg_bulk_cb_wrap *cbw = req->buf;
struct fsg_common *common = fsg->common;
/* Was this a real packet? Should it be ignored? */
if (req->status || test_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags))
return -EINVAL;
/* Is the CBW valid? */
if (req->actual != USB_BULK_CB_WRAP_LEN ||
cbw->Signature != cpu_to_le32(
USB_BULK_CB_SIG)) {
DBG(fsg, "invalid CBW: len %u sig 0x%x\n",
req->actual,
le32_to_cpu(cbw->Signature));
/* The Bulk-only spec says we MUST stall the IN endpoint
* (6.6.1), so it's unavoidable. It also says we must
* retain this state until the next reset, but there's
* no way to tell the controller driver it should ignore
* Clear-Feature(HALT) requests.
*
* We aren't required to halt the OUT endpoint; instead
* we can simply accept and discard any data received
* until the next reset. */
wedge_bulk_in_endpoint(fsg);
set_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
return -EINVAL;
}
/* Is the CBW meaningful? */
if (cbw->Lun >= FSG_MAX_LUNS || cbw->Flags & ~USB_BULK_IN_FLAG ||
cbw->Length <= 0 || cbw->Length > MAX_COMMAND_SIZE) {
DBG(fsg, "non-meaningful CBW: lun = %u, flags = 0x%x, "
"cmdlen %u\n",
cbw->Lun, cbw->Flags, cbw->Length);
/* We can do anything we want here, so let's stall the
* bulk pipes if we are allowed to. */
if (common->can_stall) {
fsg_set_halt(fsg, fsg->bulk_out);
halt_bulk_in_endpoint(fsg);
}
return -EINVAL;
}
/* Save the command for later */
common->cmnd_size = cbw->Length;
memcpy(common->cmnd, cbw->CDB, common->cmnd_size);
if (cbw->Flags & USB_BULK_IN_FLAG)
common->data_dir = DATA_DIR_TO_HOST;
else
common->data_dir = DATA_DIR_FROM_HOST;
common->data_size = le32_to_cpu(cbw->DataTransferLength);
if (common->data_size == 0)
common->data_dir = DATA_DIR_NONE;
common->lun = cbw->Lun;
common->tag = cbw->Tag;
return 0;
}
static int get_next_command(struct fsg_common *common)
{
struct fsg_buffhd *bh;
int rc = 0;
/* Wait for the next buffer to become available */
bh = common->next_buffhd_to_fill;
while (bh->state != BUF_STATE_EMPTY) {
rc = sleep_thread(common);
if (rc)
return rc;
}
/* Queue a request to read a Bulk-only CBW */
set_bulk_out_req_length(common, bh, USB_BULK_CB_WRAP_LEN);
bh->outreq->short_not_ok = 1;
START_TRANSFER_OR(common, bulk_out, bh->outreq,
&bh->outreq_busy, &bh->state)
/* Don't know what to do if common->fsg is NULL */
return -EIO;
/* We will drain the buffer in software, which means we
* can reuse it for the next filling. No need to advance
* next_buffhd_to_fill. */
/* Wait for the CBW to arrive */
while (bh->state != BUF_STATE_FULL) {
rc = sleep_thread(common);
if (rc)
return rc;
}
smp_rmb();
rc = fsg_is_set(common) ? received_cbw(common->fsg, bh) : -EIO;
bh->state = BUF_STATE_EMPTY;
return rc;
}
/*-------------------------------------------------------------------------*/
static int enable_endpoint(struct fsg_common *common, struct usb_ep *ep,
const struct usb_endpoint_descriptor *d)
{
int rc;
ep->driver_data = common;
rc = usb_ep_enable(ep, d);
if (rc)
ERROR(common, "can't enable %s, result %d\n", ep->name, rc);
return rc;
}
static int alloc_request(struct fsg_common *common, struct usb_ep *ep,
struct usb_request **preq)
{
*preq = usb_ep_alloc_request(ep, GFP_ATOMIC);
if (*preq)
return 0;
ERROR(common, "can't allocate request for %s\n", ep->name);
return -ENOMEM;
}
/* Reset interface setting and re-init endpoint state (toggle etc). */
static int do_set_interface(struct fsg_common *common, struct fsg_dev *new_fsg)
{
const struct usb_endpoint_descriptor *d;
struct fsg_dev *fsg;
int i, rc = 0;
if (common->running)
DBG(common, "reset interface\n");
reset:
/* Deallocate the requests */
if (common->fsg) {
fsg = common->fsg;
for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
struct fsg_buffhd *bh = &common->buffhds[i];
if (bh->inreq) {
usb_ep_free_request(fsg->bulk_in, bh->inreq);
bh->inreq = NULL;
}
if (bh->outreq) {
usb_ep_free_request(fsg->bulk_out, bh->outreq);
bh->outreq = NULL;
}
}
/* Disable the endpoints */
if (fsg->bulk_in_enabled) {
usb_ep_disable(fsg->bulk_in);
fsg->bulk_in_enabled = 0;
}
if (fsg->bulk_out_enabled) {
usb_ep_disable(fsg->bulk_out);
fsg->bulk_out_enabled = 0;
}
common->fsg = NULL;
wake_up(&common->fsg_wait);
}
common->running = 0;
if (!new_fsg || rc)
return rc;
common->fsg = new_fsg;
fsg = common->fsg;
/* Enable the endpoints */
d = fsg_ep_desc(common->gadget,
&fsg_fs_bulk_in_desc, &fsg_hs_bulk_in_desc);
rc = enable_endpoint(common, fsg->bulk_in, d);
if (rc)
goto reset;
fsg->bulk_in_enabled = 1;
d = fsg_ep_desc(common->gadget,
&fsg_fs_bulk_out_desc, &fsg_hs_bulk_out_desc);
rc = enable_endpoint(common, fsg->bulk_out, d);
if (rc)
goto reset;
fsg->bulk_out_enabled = 1;
common->bulk_out_maxpacket = le16_to_cpu(d->wMaxPacketSize);
clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
/* Allocate the requests */
for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
struct fsg_buffhd *bh = &common->buffhds[i];
rc = alloc_request(common, fsg->bulk_in, &bh->inreq);
if (rc)
goto reset;
rc = alloc_request(common, fsg->bulk_out, &bh->outreq);
if (rc)
goto reset;
bh->inreq->buf = bh->outreq->buf = bh->buf;
bh->inreq->context = bh->outreq->context = bh;
bh->inreq->complete = bulk_in_complete;
bh->outreq->complete = bulk_out_complete;
}
common->running = 1;
for (i = 0; i < common->nluns; ++i)
common->luns[i].unit_attention_data = SS_RESET_OCCURRED;
return rc;
}
/****************************** ALT CONFIGS ******************************/
static int fsg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
{
struct fsg_dev *fsg = fsg_from_func(f);
fsg->common->new_fsg = fsg;
raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
return 0;
}
static void fsg_disable(struct usb_function *f)
{
struct fsg_dev *fsg = fsg_from_func(f);
fsg->common->new_fsg = NULL;
raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
}
/*-------------------------------------------------------------------------*/
static void handle_exception(struct fsg_common *common)
{
siginfo_t info;
int i;
struct fsg_buffhd *bh;
enum fsg_state old_state;
struct fsg_lun *curlun;
unsigned int exception_req_tag;
/* Clear the existing signals. Anything but SIGUSR1 is converted
* into a high-priority EXIT exception. */
for (;;) {
int sig =
dequeue_signal_lock(current, &current->blocked, &info);
if (!sig)
break;
if (sig != SIGUSR1) {
if (common->state < FSG_STATE_EXIT)
DBG(common, "Main thread exiting on signal\n");
raise_exception(common, FSG_STATE_EXIT);
}
}
/* Cancel all the pending transfers */
if (likely(common->fsg)) {
for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
bh = &common->buffhds[i];
if (bh->inreq_busy)
usb_ep_dequeue(common->fsg->bulk_in, bh->inreq);
if (bh->outreq_busy)
usb_ep_dequeue(common->fsg->bulk_out,
bh->outreq);
}
/* Wait until everything is idle */
for (;;) {
int num_active = 0;
for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
bh = &common->buffhds[i];
num_active += bh->inreq_busy + bh->outreq_busy;
}
if (num_active == 0)
break;
if (sleep_thread(common))
return;
}
/* Clear out the controller's fifos */
if (common->fsg->bulk_in_enabled)
usb_ep_fifo_flush(common->fsg->bulk_in);
if (common->fsg->bulk_out_enabled)
usb_ep_fifo_flush(common->fsg->bulk_out);
}
/* Reset the I/O buffer states and pointers, the SCSI
* state, and the exception. Then invoke the handler. */
spin_lock_irq(&common->lock);
for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
bh = &common->buffhds[i];
bh->state = BUF_STATE_EMPTY;
}
common->next_buffhd_to_fill = &common->buffhds[0];
common->next_buffhd_to_drain = &common->buffhds[0];
exception_req_tag = common->exception_req_tag;
old_state = common->state;
if (old_state == FSG_STATE_ABORT_BULK_OUT)
common->state = FSG_STATE_STATUS_PHASE;
else {
for (i = 0; i < common->nluns; ++i) {
curlun = &common->luns[i];
curlun->prevent_medium_removal = 0;
curlun->sense_data = SS_NO_SENSE;
curlun->unit_attention_data = SS_NO_SENSE;
curlun->sense_data_info = 0;
curlun->info_valid = 0;
}
common->state = FSG_STATE_IDLE;
}
spin_unlock_irq(&common->lock);
/* Carry out any extra actions required for the exception */
switch (old_state) {
case FSG_STATE_ABORT_BULK_OUT:
send_status(common);
spin_lock_irq(&common->lock);
if (common->state == FSG_STATE_STATUS_PHASE)
common->state = FSG_STATE_IDLE;
spin_unlock_irq(&common->lock);
break;
case FSG_STATE_RESET:
/* In case we were forced against our will to halt a
* bulk endpoint, clear the halt now. (The SuperH UDC
* requires this.) */
if (!fsg_is_set(common))
break;
if (test_and_clear_bit(IGNORE_BULK_OUT,
&common->fsg->atomic_bitflags))
usb_ep_clear_halt(common->fsg->bulk_in);
if (common->ep0_req_tag == exception_req_tag)
ep0_queue(common); /* Complete the status stage */
/* Technically this should go here, but it would only be
* a waste of time. Ditto for the INTERFACE_CHANGE and
* CONFIG_CHANGE cases. */
/* for (i = 0; i < common->nluns; ++i) */
/* common->luns[i].unit_attention_data = */
/* SS_RESET_OCCURRED; */
break;
case FSG_STATE_CONFIG_CHANGE:
do_set_interface(common, common->new_fsg);
break;
case FSG_STATE_EXIT:
case FSG_STATE_TERMINATED:
do_set_interface(common, NULL); /* Free resources */
spin_lock_irq(&common->lock);
common->state = FSG_STATE_TERMINATED; /* Stop the thread */
spin_unlock_irq(&common->lock);
break;
case FSG_STATE_INTERFACE_CHANGE:
case FSG_STATE_DISCONNECT:
case FSG_STATE_COMMAND_PHASE:
case FSG_STATE_DATA_PHASE:
case FSG_STATE_STATUS_PHASE:
case FSG_STATE_IDLE:
break;
}
}
/*-------------------------------------------------------------------------*/
static int fsg_main_thread(void *common_)
{
struct fsg_common *common = common_;
/* Allow the thread to be killed by a signal, but set the signal mask
* to block everything but INT, TERM, KILL, and USR1. */
allow_signal(SIGINT);
allow_signal(SIGTERM);
allow_signal(SIGKILL);
allow_signal(SIGUSR1);
/* Allow the thread to be frozen */
set_freezable();
/* Arrange for userspace references to be interpreted as kernel
* pointers. That way we can pass a kernel pointer to a routine
* that expects a __user pointer and it will work okay. */
set_fs(get_ds());
/* The main loop */
while (common->state != FSG_STATE_TERMINATED) {
if (exception_in_progress(common) || signal_pending(current)) {
handle_exception(common);
continue;
}
if (!common->running) {
sleep_thread(common);
continue;
}
if (get_next_command(common))
continue;
spin_lock_irq(&common->lock);
if (!exception_in_progress(common))
common->state = FSG_STATE_DATA_PHASE;
spin_unlock_irq(&common->lock);
if (do_scsi_command(common) || finish_reply(common))
continue;
spin_lock_irq(&common->lock);
if (!exception_in_progress(common))
common->state = FSG_STATE_STATUS_PHASE;
spin_unlock_irq(&common->lock);
if (send_status(common))
continue;
spin_lock_irq(&common->lock);
if (!exception_in_progress(common))
common->state = FSG_STATE_IDLE;
spin_unlock_irq(&common->lock);
}
spin_lock_irq(&common->lock);
common->thread_task = NULL;
spin_unlock_irq(&common->lock);
if (!common->thread_exits || common->thread_exits(common) < 0) {
struct fsg_lun *curlun = common->luns;
unsigned i = common->nluns;
down_write(&common->filesem);
for (; i--; ++curlun) {
if (!fsg_lun_is_open(curlun))
continue;
fsg_lun_close(curlun);
curlun->unit_attention_data = SS_MEDIUM_NOT_PRESENT;
}
up_write(&common->filesem);
}
/* Let the unbind and cleanup routines know the thread has exited */
complete_and_exit(&common->thread_notifier, 0);
}
/*************************** DEVICE ATTRIBUTES ***************************/
/* Write permission is checked per LUN in store_*() functions. */
static DEVICE_ATTR(ro, 0644, fsg_show_ro, fsg_store_ro);
static DEVICE_ATTR(file, 0644, fsg_show_file, fsg_store_file);
/****************************** FSG COMMON ******************************/
static void fsg_common_release(struct kref *ref);
static void fsg_lun_release(struct device *dev)
{
/* Nothing needs to be done */
}
static inline void fsg_common_get(struct fsg_common *common)
{
kref_get(&common->ref);
}
static inline void fsg_common_put(struct fsg_common *common)
{
kref_put(&common->ref, fsg_common_release);
}
static struct fsg_common *fsg_common_init(struct fsg_common *common,
struct usb_composite_dev *cdev,
struct fsg_config *cfg)
{
struct usb_gadget *gadget = cdev->gadget;
struct fsg_buffhd *bh;
struct fsg_lun *curlun;
struct fsg_lun_config *lcfg;
int nluns, i, rc;
char *pathbuf;
/* Find out how many LUNs there should be */
nluns = cfg->nluns;
if (nluns < 1 || nluns > FSG_MAX_LUNS) {
dev_err(&gadget->dev, "invalid number of LUNs: %u\n", nluns);
return ERR_PTR(-EINVAL);
}
/* Allocate? */
if (!common) {
common = kzalloc(sizeof *common, GFP_KERNEL);
if (!common)
return ERR_PTR(-ENOMEM);
common->free_storage_on_release = 1;
} else {
memset(common, 0, sizeof common);
common->free_storage_on_release = 0;
}
common->private_data = cfg->private_data;
common->gadget = gadget;
common->ep0 = gadget->ep0;
common->ep0req = cdev->req;
/* Maybe allocate device-global string IDs, and patch descriptors */
if (fsg_strings[FSG_STRING_INTERFACE].id == 0) {
rc = usb_string_id(cdev);
if (unlikely(rc < 0))
goto error_release;
fsg_strings[FSG_STRING_INTERFACE].id = rc;
fsg_intf_desc.iInterface = rc;
}
/* Create the LUNs, open their backing files, and register the
* LUN devices in sysfs. */
curlun = kzalloc(nluns * sizeof *curlun, GFP_KERNEL);
if (unlikely(!curlun)) {
rc = -ENOMEM;
goto error_release;
}
common->luns = curlun;
init_rwsem(&common->filesem);
for (i = 0, lcfg = cfg->luns; i < nluns; ++i, ++curlun, ++lcfg) {
curlun->cdrom = !!lcfg->cdrom;
curlun->ro = lcfg->cdrom || lcfg->ro;
curlun->removable = lcfg->removable;
curlun->dev.release = fsg_lun_release;
curlun->dev.parent = &gadget->dev;
/* curlun->dev.driver = &fsg_driver.driver; XXX */
dev_set_drvdata(&curlun->dev, &common->filesem);
dev_set_name(&curlun->dev,
cfg->lun_name_format
? cfg->lun_name_format
: "lun%d",
i);
rc = device_register(&curlun->dev);
if (rc) {
INFO(common, "failed to register LUN%d: %d\n", i, rc);
common->nluns = i;
goto error_release;
}
rc = device_create_file(&curlun->dev, &dev_attr_ro);
if (rc)
goto error_luns;
rc = device_create_file(&curlun->dev, &dev_attr_file);
if (rc)
goto error_luns;
if (lcfg->filename) {
rc = fsg_lun_open(curlun, lcfg->filename);
if (rc)
goto error_luns;
} else if (!curlun->removable) {
ERROR(common, "no file given for LUN%d\n", i);
rc = -EINVAL;
goto error_luns;
}
}
common->nluns = nluns;
/* Data buffers cyclic list */
bh = common->buffhds;
i = FSG_NUM_BUFFERS;
goto buffhds_first_it;
do {
bh->next = bh + 1;
++bh;
buffhds_first_it:
bh->buf = kmalloc(FSG_BUFLEN, GFP_KERNEL);
if (unlikely(!bh->buf)) {
rc = -ENOMEM;
goto error_release;
}
} while (--i);
bh->next = common->buffhds;
/* Prepare inquiryString */
if (cfg->release != 0xffff) {
i = cfg->release;
} else {
i = usb_gadget_controller_number(gadget);
if (i >= 0) {
i = 0x0300 + i;
} else {
WARNING(common, "controller '%s' not recognized\n",
gadget->name);
i = 0x0399;
}
}
#define OR(x, y) ((x) ? (x) : (y))
snprintf(common->inquiry_string, sizeof common->inquiry_string,
"%-8s%-16s%04x",
OR(cfg->vendor_name, "Linux "),
/* Assume product name dependent on the first LUN */
OR(cfg->product_name, common->luns->cdrom
? "File-Stor Gadget"
: "File-CD Gadget "),
i);
/* Some peripheral controllers are known not to be able to
* halt bulk endpoints correctly. If one of them is present,
* disable stalls.
*/
common->can_stall = cfg->can_stall &&
!(gadget_is_at91(common->gadget));
spin_lock_init(&common->lock);
kref_init(&common->ref);
/* Tell the thread to start working */
common->thread_exits = cfg->thread_exits;
common->thread_task =
kthread_create(fsg_main_thread, common,
OR(cfg->thread_name, "file-storage"));
if (IS_ERR(common->thread_task)) {
rc = PTR_ERR(common->thread_task);
goto error_release;
}
init_completion(&common->thread_notifier);
init_waitqueue_head(&common->fsg_wait);
#undef OR
/* Information */
INFO(common, FSG_DRIVER_DESC ", version: " FSG_DRIVER_VERSION "\n");
INFO(common, "Number of LUNs=%d\n", common->nluns);
pathbuf = kmalloc(PATH_MAX, GFP_KERNEL);
for (i = 0, nluns = common->nluns, curlun = common->luns;
i < nluns;
++curlun, ++i) {
char *p = "(no medium)";
if (fsg_lun_is_open(curlun)) {
p = "(error)";
if (pathbuf) {
p = d_path(&curlun->filp->f_path,
pathbuf, PATH_MAX);
if (IS_ERR(p))
p = "(error)";
}
}
LINFO(curlun, "LUN: %s%s%sfile: %s\n",
curlun->removable ? "removable " : "",
curlun->ro ? "read only " : "",
curlun->cdrom ? "CD-ROM " : "",
p);
}
kfree(pathbuf);
DBG(common, "I/O thread pid: %d\n", task_pid_nr(common->thread_task));
wake_up_process(common->thread_task);
return common;
error_luns:
common->nluns = i + 1;
error_release:
common->state = FSG_STATE_TERMINATED; /* The thread is dead */
/* Call fsg_common_release() directly, ref might be not
* initialised */
fsg_common_release(&common->ref);
return ERR_PTR(rc);
}
static void fsg_common_release(struct kref *ref)
{
struct fsg_common *common = container_of(ref, struct fsg_common, ref);
/* If the thread isn't already dead, tell it to exit now */
if (common->state != FSG_STATE_TERMINATED) {
raise_exception(common, FSG_STATE_EXIT);
wait_for_completion(&common->thread_notifier);
/* The cleanup routine waits for this completion also */
complete(&common->thread_notifier);
}
if (likely(common->luns)) {
struct fsg_lun *lun = common->luns;
unsigned i = common->nluns;
/* In error recovery common->nluns may be zero. */
for (; i; --i, ++lun) {
device_remove_file(&lun->dev, &dev_attr_ro);
device_remove_file(&lun->dev, &dev_attr_file);
fsg_lun_close(lun);
device_unregister(&lun->dev);
}
kfree(common->luns);
}
{
struct fsg_buffhd *bh = common->buffhds;
unsigned i = FSG_NUM_BUFFERS;
do {
kfree(bh->buf);
} while (++bh, --i);
}
if (common->free_storage_on_release)
kfree(common);
}
/*-------------------------------------------------------------------------*/
static void fsg_unbind(struct usb_configuration *c, struct usb_function *f)
{
struct fsg_dev *fsg = fsg_from_func(f);
struct fsg_common *common = fsg->common;
DBG(fsg, "unbind\n");
if (fsg->common->fsg == fsg) {
fsg->common->new_fsg = NULL;
raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
/* FIXME: make interruptible or killable somehow? */
wait_event(common->fsg_wait, common->fsg != fsg);
}
fsg_common_put(common);
usb_free_descriptors(fsg->function.descriptors);
usb_free_descriptors(fsg->function.hs_descriptors);
kfree(fsg);
}
static int fsg_bind(struct usb_configuration *c, struct usb_function *f)
{
struct fsg_dev *fsg = fsg_from_func(f);
struct usb_gadget *gadget = c->cdev->gadget;
int i;
struct usb_ep *ep;
fsg->gadget = gadget;
/* New interface */
i = usb_interface_id(c, f);
if (i < 0)
return i;
fsg_intf_desc.bInterfaceNumber = i;
fsg->interface_number = i;
/* Find all the endpoints we will use */
ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_in_desc);
if (!ep)
goto autoconf_fail;
ep->driver_data = fsg->common; /* claim the endpoint */
fsg->bulk_in = ep;
ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_out_desc);
if (!ep)
goto autoconf_fail;
ep->driver_data = fsg->common; /* claim the endpoint */
fsg->bulk_out = ep;
/* Copy descriptors */
f->descriptors = usb_copy_descriptors(fsg_fs_function);
if (unlikely(!f->descriptors))
return -ENOMEM;
if (gadget_is_dualspeed(gadget)) {
/* Assume endpoint addresses are the same for both speeds */
fsg_hs_bulk_in_desc.bEndpointAddress =
fsg_fs_bulk_in_desc.bEndpointAddress;
fsg_hs_bulk_out_desc.bEndpointAddress =
fsg_fs_bulk_out_desc.bEndpointAddress;
f->hs_descriptors = usb_copy_descriptors(fsg_hs_function);
if (unlikely(!f->hs_descriptors)) {
usb_free_descriptors(f->descriptors);
return -ENOMEM;
}
}
return 0;
autoconf_fail:
ERROR(fsg, "unable to autoconfigure all endpoints\n");
return -ENOTSUPP;
}
/****************************** ADD FUNCTION ******************************/
static struct usb_gadget_strings *fsg_strings_array[] = {
&fsg_stringtab,
NULL,
};
static int fsg_add(struct usb_composite_dev *cdev,
struct usb_configuration *c,
struct fsg_common *common)
{
struct fsg_dev *fsg;
int rc;
fsg = kzalloc(sizeof *fsg, GFP_KERNEL);
if (unlikely(!fsg))
return -ENOMEM;
fsg->function.name = FSG_DRIVER_DESC;
fsg->function.strings = fsg_strings_array;
fsg->function.bind = fsg_bind;
fsg->function.unbind = fsg_unbind;
fsg->function.setup = fsg_setup;
fsg->function.set_alt = fsg_set_alt;
fsg->function.disable = fsg_disable;
fsg->common = common;
/* Our caller holds a reference to common structure so we
* don't have to be worry about it being freed until we return
* from this function. So instead of incrementing counter now
* and decrement in error recovery we increment it only when
* call to usb_add_function() was successful. */
rc = usb_add_function(c, &fsg->function);
if (unlikely(rc))
kfree(fsg);
else
fsg_common_get(fsg->common);
return rc;
}
/************************* Module parameters *************************/
struct fsg_module_parameters {
char *file[FSG_MAX_LUNS];
int ro[FSG_MAX_LUNS];
int removable[FSG_MAX_LUNS];
int cdrom[FSG_MAX_LUNS];
unsigned int file_count, ro_count, removable_count, cdrom_count;
unsigned int luns; /* nluns */
int stall; /* can_stall */
};
#define _FSG_MODULE_PARAM_ARRAY(prefix, params, name, type, desc) \
module_param_array_named(prefix ## name, params.name, type, \
&prefix ## params.name ## _count, \
S_IRUGO); \
MODULE_PARM_DESC(prefix ## name, desc)
#define _FSG_MODULE_PARAM(prefix, params, name, type, desc) \
module_param_named(prefix ## name, params.name, type, \
S_IRUGO); \
MODULE_PARM_DESC(prefix ## name, desc)
#define FSG_MODULE_PARAMETERS(prefix, params) \
_FSG_MODULE_PARAM_ARRAY(prefix, params, file, charp, \
"names of backing files or devices"); \
_FSG_MODULE_PARAM_ARRAY(prefix, params, ro, bool, \
"true to force read-only"); \
_FSG_MODULE_PARAM_ARRAY(prefix, params, removable, bool, \
"true to simulate removable media"); \
_FSG_MODULE_PARAM_ARRAY(prefix, params, cdrom, bool, \
"true to simulate CD-ROM instead of disk"); \
_FSG_MODULE_PARAM(prefix, params, luns, uint, \
"number of LUNs"); \
_FSG_MODULE_PARAM(prefix, params, stall, bool, \
"false to prevent bulk stalls")
static void
fsg_config_from_params(struct fsg_config *cfg,
const struct fsg_module_parameters *params)
{
struct fsg_lun_config *lun;
unsigned i;
/* Configure LUNs */
cfg->nluns =
min(params->luns ?: (params->file_count ?: 1u),
(unsigned)FSG_MAX_LUNS);
for (i = 0, lun = cfg->luns; i < cfg->nluns; ++i, ++lun) {
lun->ro = !!params->ro[i];
lun->cdrom = !!params->cdrom[i];
lun->removable = /* Removable by default */
params->removable_count <= i || params->removable[i];
lun->filename =
params->file_count > i && params->file[i][0]
? params->file[i]
: 0;
}
/* Let MSF use defaults */
cfg->lun_name_format = 0;
cfg->thread_name = 0;
cfg->vendor_name = 0;
cfg->product_name = 0;
cfg->release = 0xffff;
cfg->thread_exits = 0;
cfg->private_data = 0;
/* Finalise */
cfg->can_stall = params->stall;
}
static inline struct fsg_common *
fsg_common_from_params(struct fsg_common *common,
struct usb_composite_dev *cdev,
const struct fsg_module_parameters *params)
__attribute__((unused));
static inline struct fsg_common *
fsg_common_from_params(struct fsg_common *common,
struct usb_composite_dev *cdev,
const struct fsg_module_parameters *params)
{
struct fsg_config cfg;
fsg_config_from_params(&cfg, params);
return fsg_common_init(common, cdev, &cfg);
}
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