/* * file_storage.c -- File-backed USB Storage Gadget, for USB development * * Copyright (C) 2003-2008 Alan Stern * 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 File-backed Storage Gadget 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 gadget driver for a USB * device, it also illustrates a technique of double-buffering for increased * throughput. Last but not least, it gives an easy way to probe the * behavior of the Mass Storage drivers in a USB host. * * Backing storage is provided by a regular file or a block device, specified * by the "file" module parameter. Access can be limited to read-only by * setting the optional "ro" module parameter. (For CD-ROM emulation, * access is always read-only.) The gadget will indicate that it has * removable media if the optional "removable" module parameter is set. * * There is support for multiple logical units (LUNs), each of which has * its own backing file. The number of LUNs can be set using the optional * "luns" module parameter (anywhere from 1 to 8), and the corresponding * files are specified using comma-separated lists for "file" and "ro". * The default number of LUNs is taken from the number of "file" elements; * it is 1 if "file" is not given. If "removable" is not set then a backing * file must be specified for each LUN. If it is set, then an unspecified * or empty backing filename means the LUN's medium is not loaded. Ideally * each LUN would be settable independently as a disk drive or a CD-ROM * drive, but currently all LUNs have to be the same type. 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. * * Requirements are modest; only a bulk-in and a bulk-out endpoint are * needed (an interrupt-out endpoint is also needed for CBI). 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. * * Module options: * * file=filename[,filename...] * Required if "removable" is not set, names of * the files or block devices used for * backing storage * ro=b[,b...] Default false, booleans for read-only access * removable Default false, boolean for removable media * 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 * cdrom Default false, boolean for whether to emulate * a CD-ROM drive * * The pathnames of the backing files and the ro settings are available in * the attribute files "file" and "ro" in the lun 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. * * This gadget driver 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 * . 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 * . */ /* * Driver Design * * The FSG driver 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. So just before the thread * exits, it deregisters the gadget driver. This makes things a little * tricky: The driver is deregistered at two places, and the exiting * thread can indirectly call fsg_unbind() which in turn can tell the * thread to exit. The first problem is resolved through the use of the * REGISTERED atomic bitflag; the driver will only be deregistered once. * The second problem is resolved by having fsg_unbind() check * fsg->state; it won't try to stop the thread if the state is already * FSG_STATE_TERMINATED. * * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "gadget_chips.h" /*-------------------------------------------------------------------------*/ #define FSG_DRIVER_DESC "Mass Storage Function" #define FSG_DRIVER_VERSION "20 November 2008" static const char fsg_string_interface[] = "Mass Storage"; #define FSG_NO_INTR_EP 1 #define FSG_BUFFHD_STATIC_BUFFER 1 #define FSG_NO_DEVICE_STRINGS 1 #define FSG_NO_OTG 1 #define FSG_NO_INTR_EP 1 #include "storage_common.c" /*-------------------------------------------------------------------------*/ /* Data shared by all the FSG instances. */ struct fsg_common { struct usb_gadget *gadget; /* filesem protects: backing files in use */ struct rw_semaphore filesem; 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 can_stall:1; unsigned int free_storage_on_release:1; /* 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 *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_composite_dev*cdev; struct usb_gadget *gadget; /* Copy of cdev->gadget */ struct fsg_common *common; u16 interface_number; /* 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; unsigned int bulk_out_maxpacket; enum fsg_state state; // For exception handling unsigned int exception_req_tag; u8 config, new_config; unsigned int running : 1; unsigned int bulk_in_enabled : 1; unsigned int bulk_out_enabled : 1; unsigned int phase_error : 1; unsigned int short_packet_received : 1; unsigned int bad_lun_okay : 1; unsigned int can_stall : 1; unsigned long atomic_bitflags; #define REGISTERED 0 #define IGNORE_BULK_OUT 1 struct usb_ep *bulk_in; struct usb_ep *bulk_out; int thread_wakeup_needed; struct completion thread_notifier; struct task_struct *thread_task; enum data_direction data_dir; u32 data_size; u32 data_size_from_cmnd; u32 tag; u32 residue; u32 usb_amount_left; }; 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_dev *fsg) { return (fsg->state > FSG_STATE_IDLE); } /* Make bulk-out requests be divisible by the maxpacket size */ static void set_bulk_out_req_length(struct fsg_dev *fsg, struct fsg_buffhd *bh, unsigned int length) { unsigned int rem; bh->bulk_out_intended_length = length; rem = length % fsg->bulk_out_maxpacket; if (rem > 0) length += fsg->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_dev *fsg) { /* Tell the main thread that something has happened */ fsg->thread_wakeup_needed = 1; if (fsg->thread_task) wake_up_process(fsg->thread_task); } static void raise_exception(struct fsg_dev *fsg, 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(&fsg->lock, flags); if (fsg->state <= new_state) { fsg->exception_req_tag = fsg->ep0_req_tag; fsg->state = new_state; if (fsg->thread_task) send_sig_info(SIGUSR1, SEND_SIG_FORCED, fsg->thread_task); } spin_unlock_irqrestore(&fsg->lock, flags); } /*-------------------------------------------------------------------------*/ static int ep0_queue(struct fsg_dev *fsg) { int rc; rc = usb_ep_queue(fsg->ep0, fsg->ep0req, GFP_ATOMIC); fsg->ep0->driver_data = fsg; if (rc != 0 && rc != -ESHUTDOWN) { /* We can't do much more than wait for a reset */ WARNING(fsg, "error in submission: %s --> %d\n", fsg->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_dev *fsg = ep->driver_data; struct fsg_buffhd *bh = req->context; if (req->status || req->actual != req->length) DBG(fsg, "%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(&fsg->lock); bh->inreq_busy = 0; bh->state = BUF_STATE_EMPTY; wakeup_thread(fsg); spin_unlock(&fsg->lock); } static void bulk_out_complete(struct usb_ep *ep, struct usb_request *req) { struct fsg_dev *fsg = ep->driver_data; struct fsg_buffhd *bh = req->context; dump_msg(fsg, "bulk-out", req->buf, req->actual); if (req->status || req->actual != bh->bulk_out_intended_length) DBG(fsg, "%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(&fsg->lock); bh->outreq_busy = 0; bh->state = BUF_STATE_FULL; wakeup_thread(fsg); spin_unlock(&fsg->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->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->config) 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, 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; return 1; } 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->lock); *pbusy = 1; *state = BUF_STATE_BUSY; spin_unlock_irq(&fsg->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); } } static int sleep_thread(struct fsg_dev *fsg) { 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 (fsg->thread_wakeup_needed) break; schedule(); } __set_current_state(TASK_RUNNING); fsg->thread_wakeup_needed = 0; return rc; } /*-------------------------------------------------------------------------*/ static int do_read(struct fsg_dev *fsg) { struct fsg_lun *curlun = fsg->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 (fsg->common->cmnd[0] == SC_READ_6) lba = get_unaligned_be24(&fsg->common->cmnd[1]); else { lba = get_unaligned_be32(&fsg->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 ((fsg->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 = fsg->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 = fsg->common->next_buffhd_to_fill; while (bh->state != BUF_STATE_EMPTY) { rc = sleep_thread(fsg); 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; fsg->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(fsg, fsg->bulk_in, bh->inreq, &bh->inreq_busy, &bh->state); fsg->common->next_buffhd_to_fill = bh->next; } return -EIO; // No default reply } /*-------------------------------------------------------------------------*/ static int do_write(struct fsg_dev *fsg) { struct fsg_lun *curlun = fsg->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 (fsg->common->cmnd[0] == SC_WRITE_6) lba = get_unaligned_be24(&fsg->common->cmnd[1]); else { lba = get_unaligned_be32(&fsg->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 ((fsg->common->cmnd[1] & ~0x18) != 0) { curlun->sense_data = SS_INVALID_FIELD_IN_CDB; return -EINVAL; } if (fsg->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 = amount_left_to_write = fsg->data_size_from_cmnd; while (amount_left_to_write > 0) { /* Queue a request for more data from the host */ bh = fsg->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; fsg->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 = bh->bulk_out_intended_length = amount; bh->outreq->short_not_ok = 1; start_transfer(fsg, fsg->bulk_out, bh->outreq, &bh->outreq_busy, &bh->state); fsg->common->next_buffhd_to_fill = bh->next; continue; } /* Write the received data to the backing file */ bh = fsg->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(); fsg->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; fsg->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) { fsg->short_packet_received = 1; break; } continue; } /* Wait for something to happen */ rc = sleep_thread(fsg); if (rc) return rc; } return -EIO; // No default reply } /*-------------------------------------------------------------------------*/ static int do_synchronize_cache(struct fsg_dev *fsg) { struct fsg_lun *curlun = fsg->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_inode_pages -> %ld\n", rc); } static int do_verify(struct fsg_dev *fsg) { struct fsg_lun *curlun = fsg->common->curlun; u32 lba; u32 verification_length; struct fsg_buffhd *bh = fsg->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(&fsg->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 ((fsg->common->cmnd[1] & ~0x10) != 0) { curlun->sense_data = SS_INVALID_FIELD_IN_CDB; return -EINVAL; } verification_length = get_unaligned_be16(&fsg->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_dev *fsg, struct fsg_buffhd *bh) { struct fsg_lun *curlun = fsg->common->curlun; u8 *buf = (u8 *) bh->buf; if (!curlun) { /* Unsupported LUNs are okay */ fsg->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, fsg->common->inquiry_string, sizeof fsg->common->inquiry_string); return 36; } static int do_request_sense(struct fsg_dev *fsg, struct fsg_buffhd *bh) { struct fsg_lun *curlun = fsg->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 fsg->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_dev *fsg, struct fsg_buffhd *bh) { struct fsg_lun *curlun = fsg->common->curlun; u32 lba = get_unaligned_be32(&fsg->common->cmnd[2]); int pmi = fsg->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_dev *fsg, struct fsg_buffhd *bh) { struct fsg_lun *curlun = fsg->common->curlun; int msf = fsg->common->cmnd[1] & 0x02; u32 lba = get_unaligned_be32(&fsg->common->cmnd[2]); u8 *buf = (u8 *) bh->buf; if ((fsg->common->cmnd[1] & ~0x02) != 0) { /* 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_dev *fsg, struct fsg_buffhd *bh) { struct fsg_lun *curlun = fsg->common->curlun; int msf = fsg->common->cmnd[1] & 0x02; int start_track = fsg->common->cmnd[6]; u8 *buf = (u8 *) bh->buf; if ((fsg->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_dev *fsg, struct fsg_buffhd *bh) { struct fsg_lun *curlun = fsg->common->curlun; int mscmnd = fsg->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 ((fsg->common->cmnd[1] & ~0x08) != 0) { // Mask away DBD curlun->sense_data = SS_INVALID_FIELD_IN_CDB; return -EINVAL; } pc = fsg->common->cmnd[2] >> 6; page_code = fsg->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_dev *fsg) { if (!fsg->common->curlun) { return -EINVAL; } else if (!fsg->common->curlun->removable) { fsg->common->curlun->sense_data = SS_INVALID_COMMAND; return -EINVAL; } return 0; } static int do_prevent_allow(struct fsg_dev *fsg) { struct fsg_lun *curlun = fsg->common->curlun; int prevent; if (!fsg->common->curlun) { return -EINVAL; } else if (!fsg->common->curlun->removable) { fsg->common->curlun->sense_data = SS_INVALID_COMMAND; return -EINVAL; } prevent = fsg->common->cmnd[4] & 0x01; if ((fsg->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_dev *fsg, struct fsg_buffhd *bh) { struct fsg_lun *curlun = fsg->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_dev *fsg, struct fsg_buffhd *bh) { struct fsg_lun *curlun = fsg->common->curlun; /* We don't support MODE SELECT */ 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->usb_amount_left = nkeep + fsg->residue; while (fsg->usb_amount_left > 0) { /* Wait for the next buffer to be free */ while (bh->state != BUF_STATE_EMPTY) { rc = sleep_thread(fsg); if (rc) return rc; } nsend = min(fsg->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->usb_amount_left -= nsend; nkeep = 0; } return 0; } static int throw_away_data(struct fsg_dev *fsg) { struct fsg_buffhd *bh; u32 amount; int rc; for (bh = fsg->common->next_buffhd_to_drain; bh->state != BUF_STATE_EMPTY || fsg->usb_amount_left > 0; bh = fsg->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; fsg->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(fsg, FSG_STATE_ABORT_BULK_OUT); return -EINTR; } continue; } /* Try to submit another request if we need one */ bh = fsg->common->next_buffhd_to_fill; if (bh->state == BUF_STATE_EMPTY && fsg->usb_amount_left > 0) { amount = min(fsg->usb_amount_left, FSG_BUFLEN); /* amount is always divisible by 512, hence by * the bulk-out maxpacket size */ bh->outreq->length = bh->bulk_out_intended_length = amount; bh->outreq->short_not_ok = 1; start_transfer(fsg, fsg->bulk_out, bh->outreq, &bh->outreq_busy, &bh->state); fsg->common->next_buffhd_to_fill = bh->next; fsg->usb_amount_left -= amount; continue; } /* Otherwise wait for something to happen */ rc = sleep_thread(fsg); if (rc) return rc; } return 0; } static int finish_reply(struct fsg_dev *fsg) { struct fsg_buffhd *bh = fsg->common->next_buffhd_to_fill; int rc = 0; switch (fsg->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 (fsg->can_stall) { fsg_set_halt(fsg, fsg->bulk_out); rc = halt_bulk_in_endpoint(fsg); } break; /* All but the last buffer of data must have already been sent */ case DATA_DIR_TO_HOST: if (fsg->data_size == 0) { /* Nothing to send */ /* If there's no residue, simply send the last buffer */ } else if (fsg->residue == 0) { bh->inreq->zero = 0; start_transfer(fsg, fsg->bulk_in, bh->inreq, &bh->inreq_busy, &bh->state); fsg->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 (fsg->can_stall) { bh->inreq->zero = 1; start_transfer(fsg, fsg->bulk_in, bh->inreq, &bh->inreq_busy, &bh->state); fsg->common->next_buffhd_to_fill = bh->next; rc = halt_bulk_in_endpoint(fsg); } else { rc = pad_with_zeros(fsg); } 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 (fsg->residue == 0) ; // Nothing to receive /* Did the host stop sending unexpectedly early? */ else if (fsg->short_packet_received) { raise_exception(fsg, 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 (fsg->can_stall) { fsg_set_halt(fsg, fsg->bulk_out); raise_exception(fsg, 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(fsg); break; } return rc; } static int send_status(struct fsg_dev *fsg) { struct fsg_lun *curlun = fsg->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 = fsg->common->next_buffhd_to_fill; while (bh->state != BUF_STATE_EMPTY) { rc = sleep_thread(fsg); if (rc) return rc; } if (curlun) { sd = curlun->sense_data; sdinfo = curlun->sense_data_info; } else if (fsg->bad_lun_okay) sd = SS_NO_SENSE; else sd = SS_LOGICAL_UNIT_NOT_SUPPORTED; if (fsg->phase_error) { DBG(fsg, "sending phase-error status\n"); status = USB_STATUS_PHASE_ERROR; sd = SS_INVALID_COMMAND; } else if (sd != SS_NO_SENSE) { DBG(fsg, "sending command-failure status\n"); status = USB_STATUS_FAIL; VDBG(fsg, " 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 = fsg->tag; csw->Residue = cpu_to_le32(fsg->residue); csw->Status = status; bh->inreq->length = USB_BULK_CS_WRAP_LEN; bh->inreq->zero = 0; start_transfer(fsg, fsg->bulk_in, bh->inreq, &bh->inreq_busy, &bh->state); fsg->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_dev *fsg, int cmnd_size, enum data_direction data_dir, unsigned int mask, int needs_medium, const char *name) { int i; int lun = fsg->common->cmnd[1] >> 5; static const char dirletter[4] = {'u', 'o', 'i', 'n'}; char hdlen[20]; struct fsg_lun *curlun; hdlen[0] = 0; if (fsg->data_dir != DATA_DIR_UNKNOWN) sprintf(hdlen, ", H%c=%u", dirletter[(int) fsg->data_dir], fsg->data_size); VDBG(fsg, "SCSI command: %s; Dc=%d, D%c=%u; Hc=%d%s\n", name, cmnd_size, dirletter[(int) data_dir], fsg->data_size_from_cmnd, fsg->common->cmnd_size, hdlen); /* We can't reply at all until we know the correct data direction * and size. */ if (fsg->data_size_from_cmnd == 0) data_dir = DATA_DIR_NONE; if (fsg->data_dir == DATA_DIR_UNKNOWN) { // CB or CBI fsg->data_dir = data_dir; fsg->data_size = fsg->data_size_from_cmnd; } else { // Bulk-only if (fsg->data_size < fsg->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. */ fsg->data_size_from_cmnd = fsg->data_size; fsg->phase_error = 1; } } fsg->residue = fsg->usb_amount_left = fsg->data_size; /* Conflicting data directions is a phase error */ if (fsg->data_dir != data_dir && fsg->data_size_from_cmnd > 0) { fsg->phase_error = 1; return -EINVAL; } /* Verify the length of the command itself */ if (cmnd_size != fsg->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 <= fsg->common->cmnd_size) { DBG(fsg, "%s is buggy! Expected length %d " "but we got %d\n", name, cmnd_size, fsg->common->cmnd_size); cmnd_size = fsg->common->cmnd_size; } else { fsg->phase_error = 1; return -EINVAL; } } /* Check that the LUN values are consistent */ if (fsg->common->lun != lun) DBG(fsg, "using LUN %d from CBW, not LUN %d from CDB\n", fsg->common->lun, lun); /* Check the LUN */ if (fsg->common->lun >= 0 && fsg->common->lun < fsg->common->nluns) { fsg->common->curlun = curlun = &fsg->common->luns[fsg->common->lun]; if (fsg->common->cmnd[0] != SC_REQUEST_SENSE) { curlun->sense_data = SS_NO_SENSE; curlun->sense_data_info = 0; curlun->info_valid = 0; } } else { fsg->common->curlun = curlun = NULL; fsg->bad_lun_okay = 0; /* INQUIRY and REQUEST SENSE commands are explicitly allowed * to use unsupported LUNs; all others may not. */ if (fsg->common->cmnd[0] != SC_INQUIRY && fsg->common->cmnd[0] != SC_REQUEST_SENSE) { DBG(fsg, "unsupported LUN %d\n", fsg->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 && fsg->common->cmnd[0] != SC_INQUIRY && fsg->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 */ fsg->common->cmnd[1] &= 0x1f; // Mask away the LUN for (i = 1; i < cmnd_size; ++i) { if (fsg->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_dev *fsg) { struct fsg_buffhd *bh; int rc; int reply = -EINVAL; int i; static char unknown[16]; dump_cdb(fsg->common); /* Wait for the next buffer to become available for data or status */ bh = fsg->common->next_buffhd_to_drain = fsg->common->next_buffhd_to_fill; while (bh->state != BUF_STATE_EMPTY) { rc = sleep_thread(fsg); if (rc) return rc; } fsg->phase_error = 0; fsg->short_packet_received = 0; down_read(&fsg->common->filesem); // We're using the backing file switch (fsg->common->cmnd[0]) { case SC_INQUIRY: fsg->data_size_from_cmnd = fsg->common->cmnd[4]; if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST, (1<<4), 0, "INQUIRY")) == 0) reply = do_inquiry(fsg, bh); break; case SC_MODE_SELECT_6: fsg->data_size_from_cmnd = fsg->common->cmnd[4]; if ((reply = check_command(fsg, 6, DATA_DIR_FROM_HOST, (1<<1) | (1<<4), 0, "MODE SELECT(6)")) == 0) reply = do_mode_select(fsg, bh); break; case SC_MODE_SELECT_10: fsg->data_size_from_cmnd = get_unaligned_be16(&fsg->common->cmnd[7]); if ((reply = check_command(fsg, 10, DATA_DIR_FROM_HOST, (1<<1) | (3<<7), 0, "MODE SELECT(10)")) == 0) reply = do_mode_select(fsg, bh); break; case SC_MODE_SENSE_6: fsg->data_size_from_cmnd = fsg->common->cmnd[4]; if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST, (1<<1) | (1<<2) | (1<<4), 0, "MODE SENSE(6)")) == 0) reply = do_mode_sense(fsg, bh); break; case SC_MODE_SENSE_10: fsg->data_size_from_cmnd = get_unaligned_be16(&fsg->common->cmnd[7]); if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST, (1<<1) | (1<<2) | (3<<7), 0, "MODE SENSE(10)")) == 0) reply = do_mode_sense(fsg, bh); break; case SC_PREVENT_ALLOW_MEDIUM_REMOVAL: fsg->data_size_from_cmnd = 0; if ((reply = check_command(fsg, 6, DATA_DIR_NONE, (1<<4), 0, "PREVENT-ALLOW MEDIUM REMOVAL")) == 0) reply = do_prevent_allow(fsg); break; case SC_READ_6: i = fsg->common->cmnd[4]; fsg->data_size_from_cmnd = (i == 0 ? 256 : i) << 9; if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST, (7<<1) | (1<<4), 1, "READ(6)")) == 0) reply = do_read(fsg); break; case SC_READ_10: fsg->data_size_from_cmnd = get_unaligned_be16(&fsg->common->cmnd[7]) << 9; if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST, (1<<1) | (0xf<<2) | (3<<7), 1, "READ(10)")) == 0) reply = do_read(fsg); break; case SC_READ_12: fsg->data_size_from_cmnd = get_unaligned_be32(&fsg->common->cmnd[6]) << 9; if ((reply = check_command(fsg, 12, DATA_DIR_TO_HOST, (1<<1) | (0xf<<2) | (0xf<<6), 1, "READ(12)")) == 0) reply = do_read(fsg); break; case SC_READ_CAPACITY: fsg->data_size_from_cmnd = 8; if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST, (0xf<<2) | (1<<8), 1, "READ CAPACITY")) == 0) reply = do_read_capacity(fsg, bh); break; case SC_READ_HEADER: if (!fsg->common->curlun || !fsg->common->curlun->cdrom) goto unknown_cmnd; fsg->data_size_from_cmnd = get_unaligned_be16(&fsg->common->cmnd[7]); if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST, (3<<7) | (0x1f<<1), 1, "READ HEADER")) == 0) reply = do_read_header(fsg, bh); break; case SC_READ_TOC: if (!fsg->common->curlun || !fsg->common->curlun->cdrom) goto unknown_cmnd; fsg->data_size_from_cmnd = get_unaligned_be16(&fsg->common->cmnd[7]); if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST, (7<<6) | (1<<1), 1, "READ TOC")) == 0) reply = do_read_toc(fsg, bh); break; case SC_READ_FORMAT_CAPACITIES: fsg->data_size_from_cmnd = get_unaligned_be16(&fsg->common->cmnd[7]); if ((reply = check_command(fsg, 10, DATA_DIR_TO_HOST, (3<<7), 1, "READ FORMAT CAPACITIES")) == 0) reply = do_read_format_capacities(fsg, bh); break; case SC_REQUEST_SENSE: fsg->data_size_from_cmnd = fsg->common->cmnd[4]; if ((reply = check_command(fsg, 6, DATA_DIR_TO_HOST, (1<<4), 0, "REQUEST SENSE")) == 0) reply = do_request_sense(fsg, bh); break; case SC_START_STOP_UNIT: fsg->data_size_from_cmnd = 0; if ((reply = check_command(fsg, 6, DATA_DIR_NONE, (1<<1) | (1<<4), 0, "START-STOP UNIT")) == 0) reply = do_start_stop(fsg); break; case SC_SYNCHRONIZE_CACHE: fsg->data_size_from_cmnd = 0; if ((reply = check_command(fsg, 10, DATA_DIR_NONE, (0xf<<2) | (3<<7), 1, "SYNCHRONIZE CACHE")) == 0) reply = do_synchronize_cache(fsg); break; case SC_TEST_UNIT_READY: fsg->data_size_from_cmnd = 0; reply = check_command(fsg, 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: fsg->data_size_from_cmnd = 0; if ((reply = check_command(fsg, 10, DATA_DIR_NONE, (1<<1) | (0xf<<2) | (3<<7), 1, "VERIFY")) == 0) reply = do_verify(fsg); break; case SC_WRITE_6: i = fsg->common->cmnd[4]; fsg->data_size_from_cmnd = (i == 0 ? 256 : i) << 9; if ((reply = check_command(fsg, 6, DATA_DIR_FROM_HOST, (7<<1) | (1<<4), 1, "WRITE(6)")) == 0) reply = do_write(fsg); break; case SC_WRITE_10: fsg->data_size_from_cmnd = get_unaligned_be16(&fsg->common->cmnd[7]) << 9; if ((reply = check_command(fsg, 10, DATA_DIR_FROM_HOST, (1<<1) | (0xf<<2) | (3<<7), 1, "WRITE(10)")) == 0) reply = do_write(fsg); break; case SC_WRITE_12: fsg->data_size_from_cmnd = get_unaligned_be32(&fsg->common->cmnd[6]) << 9; if ((reply = check_command(fsg, 12, DATA_DIR_FROM_HOST, (1<<1) | (0xf<<2) | (0xf<<6), 1, "WRITE(12)")) == 0) reply = do_write(fsg); 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: fsg->data_size_from_cmnd = 0; sprintf(unknown, "Unknown x%02x", fsg->common->cmnd[0]); if ((reply = check_command(fsg, fsg->common->cmnd_size, DATA_DIR_UNKNOWN, 0xff, 0, unknown)) == 0) { fsg->common->curlun->sense_data = SS_INVALID_COMMAND; reply = -EINVAL; } break; } up_read(&fsg->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 && fsg->data_dir == DATA_DIR_TO_HOST) { reply = min((u32) reply, fsg->data_size_from_cmnd); bh->inreq->length = reply; bh->state = BUF_STATE_FULL; fsg->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; /* 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 (fsg->can_stall) { fsg_set_halt(fsg, fsg->bulk_out); halt_bulk_in_endpoint(fsg); } return -EINVAL; } /* Save the command for later */ fsg->common->cmnd_size = cbw->Length; memcpy(fsg->common->cmnd, cbw->CDB, fsg->common->cmnd_size); if (cbw->Flags & USB_BULK_IN_FLAG) fsg->data_dir = DATA_DIR_TO_HOST; else fsg->data_dir = DATA_DIR_FROM_HOST; fsg->data_size = le32_to_cpu(cbw->DataTransferLength); if (fsg->data_size == 0) fsg->data_dir = DATA_DIR_NONE; fsg->common->lun = cbw->Lun; fsg->tag = cbw->Tag; return 0; } static int get_next_command(struct fsg_dev *fsg) { struct fsg_buffhd *bh; int rc = 0; /* Wait for the next buffer to become available */ bh = fsg->common->next_buffhd_to_fill; while (bh->state != BUF_STATE_EMPTY) { rc = sleep_thread(fsg); if (rc) return rc; } /* Queue a request to read a Bulk-only CBW */ set_bulk_out_req_length(fsg, bh, USB_BULK_CB_WRAP_LEN); bh->outreq->short_not_ok = 1; start_transfer(fsg, fsg->bulk_out, bh->outreq, &bh->outreq_busy, &bh->state); /* 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(fsg); if (rc) return rc; } smp_rmb(); rc = received_cbw(fsg, bh); bh->state = BUF_STATE_EMPTY; return rc; } /*-------------------------------------------------------------------------*/ static int enable_endpoint(struct fsg_dev *fsg, struct usb_ep *ep, const struct usb_endpoint_descriptor *d) { int rc; ep->driver_data = fsg; rc = usb_ep_enable(ep, d); if (rc) ERROR(fsg, "can't enable %s, result %d\n", ep->name, rc); return rc; } static int alloc_request(struct fsg_dev *fsg, struct usb_ep *ep, struct usb_request **preq) { *preq = usb_ep_alloc_request(ep, GFP_ATOMIC); if (*preq) return 0; ERROR(fsg, "can't allocate request for %s\n", ep->name); return -ENOMEM; } /* * Reset interface setting and re-init endpoint state (toggle etc). * Call with altsetting < 0 to disable the interface. The only other * available altsetting is 0, which enables the interface. */ static int do_set_interface(struct fsg_dev *fsg, int altsetting) { int rc = 0; int i; const struct usb_endpoint_descriptor *d; if (fsg->running) DBG(fsg, "reset interface\n"); reset: /* Deallocate the requests */ for (i = 0; i < FSG_NUM_BUFFERS; ++i) { struct fsg_buffhd *bh = &fsg->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; } fsg->running = 0; if (altsetting < 0 || rc != 0) return rc; DBG(fsg, "set interface %d\n", altsetting); /* Enable the endpoints */ d = fsg_ep_desc(fsg->gadget, &fsg_fs_bulk_in_desc, &fsg_hs_bulk_in_desc); if ((rc = enable_endpoint(fsg, fsg->bulk_in, d)) != 0) goto reset; fsg->bulk_in_enabled = 1; d = fsg_ep_desc(fsg->gadget, &fsg_fs_bulk_out_desc, &fsg_hs_bulk_out_desc); if ((rc = enable_endpoint(fsg, fsg->bulk_out, d)) != 0) goto reset; fsg->bulk_out_enabled = 1; fsg->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 = &fsg->common->buffhds[i]; if ((rc = alloc_request(fsg, fsg->bulk_in, &bh->inreq)) != 0) goto reset; if ((rc = alloc_request(fsg, fsg->bulk_out, &bh->outreq)) != 0) 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; } fsg->running = 1; for (i = 0; i < fsg->common->nluns; ++i) fsg->common->luns[i].unit_attention_data = SS_RESET_OCCURRED; return rc; } /* * Change our operational configuration. This code must agree with the code * that returns config descriptors, and with interface altsetting code. * * It's also responsible for power management interactions. Some * configurations might not work with our current power sources. * For now we just assume the gadget is always self-powered. */ static int do_set_config(struct fsg_dev *fsg, u8 new_config) { int rc = 0; /* Disable the single interface */ if (fsg->config != 0) { DBG(fsg, "reset config\n"); fsg->config = 0; rc = do_set_interface(fsg, -1); } /* Enable the interface */ if (new_config != 0) { fsg->config = new_config; rc = do_set_interface(fsg, 0); if (rc != 0) fsg->config = 0; /* Reset on errors */ } 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->new_config = 1; raise_exception(fsg, FSG_STATE_CONFIG_CHANGE); return 0; } static void fsg_disable(struct usb_function *f) { struct fsg_dev *fsg = fsg_from_func(f); fsg->new_config = 0; raise_exception(fsg, FSG_STATE_CONFIG_CHANGE); } /*-------------------------------------------------------------------------*/ static void handle_exception(struct fsg_dev *fsg) { siginfo_t info; int sig; int i; struct fsg_buffhd *bh; enum fsg_state old_state; u8 new_config; struct fsg_lun *curlun; unsigned int exception_req_tag; int rc; /* Clear the existing signals. Anything but SIGUSR1 is converted * into a high-priority EXIT exception. */ for (;;) { sig = dequeue_signal_lock(current, ¤t->blocked, &info); if (!sig) break; if (sig != SIGUSR1) { if (fsg->state < FSG_STATE_EXIT) DBG(fsg, "Main thread exiting on signal\n"); raise_exception(fsg, FSG_STATE_EXIT); } } /* Cancel all the pending transfers */ for (i = 0; i < FSG_NUM_BUFFERS; ++i) { bh = &fsg->common->buffhds[i]; if (bh->inreq_busy) usb_ep_dequeue(fsg->bulk_in, bh->inreq); if (bh->outreq_busy) usb_ep_dequeue(fsg->bulk_out, bh->outreq); } /* Wait until everything is idle */ for (;;) { int num_active = 0; for (i = 0; i < FSG_NUM_BUFFERS; ++i) { bh = &fsg->common->buffhds[i]; num_active += bh->inreq_busy + bh->outreq_busy; } if (num_active == 0) break; if (sleep_thread(fsg)) return; } /* Clear out the controller's fifos */ if (fsg->bulk_in_enabled) usb_ep_fifo_flush(fsg->bulk_in); if (fsg->bulk_out_enabled) usb_ep_fifo_flush(fsg->bulk_out); /* Reset the I/O buffer states and pointers, the SCSI * state, and the exception. Then invoke the handler. */ spin_lock_irq(&fsg->lock); for (i = 0; i < FSG_NUM_BUFFERS; ++i) { bh = &fsg->common->buffhds[i]; bh->state = BUF_STATE_EMPTY; } fsg->common->next_buffhd_to_fill = fsg->common->next_buffhd_to_drain = &fsg->common->buffhds[0]; exception_req_tag = fsg->exception_req_tag; new_config = fsg->new_config; old_state = fsg->state; if (old_state == FSG_STATE_ABORT_BULK_OUT) fsg->state = FSG_STATE_STATUS_PHASE; else { for (i = 0; i < fsg->common->nluns; ++i) { curlun = &fsg->common->luns[i]; curlun->prevent_medium_removal = 0; curlun->sense_data = curlun->unit_attention_data = SS_NO_SENSE; curlun->sense_data_info = 0; curlun->info_valid = 0; } fsg->state = FSG_STATE_IDLE; } spin_unlock_irq(&fsg->lock); /* Carry out any extra actions required for the exception */ switch (old_state) { case FSG_STATE_ABORT_BULK_OUT: send_status(fsg); spin_lock_irq(&fsg->lock); if (fsg->state == FSG_STATE_STATUS_PHASE) fsg->state = FSG_STATE_IDLE; spin_unlock_irq(&fsg->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 (test_and_clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags)) usb_ep_clear_halt(fsg->bulk_in); if (fsg->ep0_req_tag == exception_req_tag) ep0_queue(fsg); // 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 < fsg->common->nluns; ++i) // fsg->common->luns[i].unit_attention_data = SS_RESET_OCCURRED; break; case FSG_STATE_CONFIG_CHANGE: rc = do_set_config(fsg, new_config); if (fsg->ep0_req_tag != exception_req_tag) break; if (rc != 0) // STALL on errors fsg_set_halt(fsg, fsg->ep0); else // Complete the status stage ep0_queue(fsg); break; case FSG_STATE_EXIT: case FSG_STATE_TERMINATED: do_set_config(fsg, 0); // Free resources spin_lock_irq(&fsg->lock); fsg->state = FSG_STATE_TERMINATED; // Stop the thread spin_unlock_irq(&fsg->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 *fsg_) { struct fsg_dev *fsg = fsg_; /* 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 (fsg->state != FSG_STATE_TERMINATED) { if (exception_in_progress(fsg) || signal_pending(current)) { handle_exception(fsg); continue; } if (!fsg->running) { sleep_thread(fsg); continue; } if (get_next_command(fsg)) continue; spin_lock_irq(&fsg->lock); if (!exception_in_progress(fsg)) fsg->state = FSG_STATE_DATA_PHASE; spin_unlock_irq(&fsg->lock); if (do_scsi_command(fsg) || finish_reply(fsg)) continue; spin_lock_irq(&fsg->lock); if (!exception_in_progress(fsg)) fsg->state = FSG_STATE_STATUS_PHASE; spin_unlock_irq(&fsg->lock); if (send_status(fsg)) continue; spin_lock_irq(&fsg->lock); if (!exception_in_progress(fsg)) fsg->state = FSG_STATE_IDLE; spin_unlock_irq(&fsg->lock); } spin_lock_irq(&fsg->lock); fsg->thread_task = NULL; spin_unlock_irq(&fsg->lock); /* XXX */ /* If we are exiting because of a signal, unregister the * gadget driver. */ /* if (test_and_clear_bit(REGISTERED, &fsg->atomic_bitflags)) */ /* usb_gadget_unregister_driver(&fsg_driver); */ /* Let the unbind and cleanup routines know the thread has exited */ complete_and_exit(&fsg->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->gadget = gadget; /* Create the LUNs, open their backing files, and register the * LUN devices in sysfs. */ curlun = kzalloc(nluns * sizeof *curlun, GFP_KERNEL); if (!curlun) { kfree(common); return ERR_PTR(-ENOMEM); } 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,"%s-lun%d", dev_name(&gadget->dev), 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 */ /* Buffers in buffhds are static -- no need for additional * allocation. */ bh = common->buffhds; i = FSG_NUM_BUFFERS - 1; do { bh->next = bh + 1; } while (++bh, --i); bh->next = common->buffhds; /* Prepare inquiryString */ if (cfg->release != 0xffff) { i = cfg->release; } else { /* The sa1100 controller is not supported */ i = gadget_is_sa1100(gadget) ? -1 : 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); #undef OR /* 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_sh(fsg->gadget) || gadget_is_at91(fsg->gadget)); kref_init(&common->ref); /* 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); return common; error_luns: common->nluns = i + 1; error_release: /* Call fsg_common_release() directly, ref is 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); unsigned i = common->nluns; struct fsg_lun *lun = common->luns; /* Beware tempting for -> do-while optimization: when in error * recovery 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); 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); DBG(fsg, "unbind\n"); clear_bit(REGISTERED, &fsg->atomic_bitflags); /* If the thread isn't already dead, tell it to exit now */ if (fsg->state != FSG_STATE_TERMINATED) { raise_exception(fsg, FSG_STATE_EXIT); wait_for_completion(&fsg->thread_notifier); /* The cleanup routine waits for this completion also */ complete(&fsg->thread_notifier); } fsg_common_put(fsg->common); 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 rc; int i; struct usb_ep *ep; fsg->gadget = gadget; fsg->ep0 = gadget->ep0; fsg->ep0req = c->cdev->req; /* 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; // 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; // claim the endpoint fsg->bulk_out = ep; 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 = fsg_hs_function; } /* maybe allocate device-global string IDs, and patch descriptors */ if (fsg_strings[FSG_STRING_INTERFACE].id == 0) { i = usb_string_id(c->cdev); if (i < 0) return i; fsg_strings[FSG_STRING_INTERFACE].id = i; fsg_intf_desc.iInterface = i; } fsg->thread_task = kthread_create(fsg_main_thread, fsg, "file-storage-gadget"); if (IS_ERR(fsg->thread_task)) { rc = PTR_ERR(fsg->thread_task); goto out; } DBG(fsg, "I/O thread pid: %d\n", task_pid_nr(fsg->thread_task)); set_bit(REGISTERED, &fsg->atomic_bitflags); /* Tell the thread to start working */ wake_up_process(fsg->thread_task); return 0; autoconf_fail: ERROR(fsg, "unable to autoconfigure all endpoints\n"); rc = -ENOTSUPP; out: fsg->state = FSG_STATE_TERMINATED; // The thread is dead fsg_unbind(c, f); complete(&fsg->thread_notifier); return rc; } /****************************** 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; spin_lock_init(&fsg->lock); init_completion(&fsg->thread_notifier); fsg->cdev = cdev; fsg->function.name = FSG_DRIVER_DESC; fsg->function.strings = fsg_strings_array; fsg->function.descriptors = fsg_fs_function; 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. */ fsg->can_stall = common->can_stall; rc = usb_add_function(c, &fsg->function); if (likely(rc == 0)) fsg_common_get(fsg->common); else kfree(fsg); 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, nluns; /* Configure LUNs */ nluns = cfg->nluns = !params->luns ? params->file_count ? params->file_count : 1 : params->luns; for (i = 0, lun = cfg->luns; i < FSG_MAX_LUNS && i < nluns; ++i, ++lun) { lun->ro = !!params->ro[i]; lun->cdrom = !!params->cdrom[i]; lun->removable = params->removable_count <= i || params->removable[i]; lun->filename = params->file_count > i && params->file[i][0] ? params->file[i] : 0; } /* Let FSG use defaults */ cfg->vendor_name = 0; cfg->product_name = 0; cfg->release = 0xffff; /* 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); }