diff options
Diffstat (limited to 'drivers/usb/gadget')
| -rw-r--r-- | drivers/usb/gadget/f_mass_storage.c | 2793 |
1 files changed, 2793 insertions, 0 deletions
diff --git a/drivers/usb/gadget/f_mass_storage.c b/drivers/usb/gadget/f_mass_storage.c new file mode 100644 index 0000000..c28866f --- /dev/null +++ b/drivers/usb/gadget/f_mass_storage.c @@ -0,0 +1,2793 @@ +/* + * 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 <config.h> +#include <malloc.h> +#include <common.h> + +#include <linux/err.h> +#include <linux/usb/ch9.h> +#include <linux/usb/gadget.h> +#include <usb_mass_storage.h> + +#include <asm/unaligned.h> +#include <linux/usb/gadget.h> +#include <linux/usb/gadget.h> +#include <linux/usb/composite.h> +#include <usb/lin_gadget_compat.h> + +/*------------------------------------------------------------------------*/ + +#define FSG_DRIVER_DESC "Mass Storage Function" +#define FSG_DRIVER_VERSION "2012/06/5" + +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" + +/*-------------------------------------------------------------------------*/ + +#define GFP_ATOMIC ((gfp_t) 0) +#define PAGE_CACHE_SHIFT 12 +#define PAGE_CACHE_SIZE (1 << PAGE_CACHE_SHIFT) +#define kthread_create(...) __builtin_return_address(0) +#define wait_for_completion(...) do {} while (0) + +struct kref {int x; }; +struct completion {int x; }; + +inline void set_bit(int nr, volatile void *addr) +{ + int mask; + unsigned int *a = (unsigned int *) addr; + + a += nr >> 5; + mask = 1 << (nr & 0x1f); + *a |= mask; +} + +inline void clear_bit(int nr, volatile void *addr) +{ + int mask; + unsigned int *a = (unsigned int *) addr; + + a += nr >> 5; + mask = 1 << (nr & 0x1f); + *a &= ~mask; +} + +struct fsg_dev; +struct fsg_common; + +/* Data shared by all the FSG instances. */ +struct fsg_common { + struct usb_gadget *gadget; + struct fsg_dev *fsg, *new_fsg; + + struct usb_ep *ep0; /* Copy of gadget->ep0 */ + struct usb_request *ep0req; /* Copy of cdev->req */ + unsigned int ep0_req_tag; + + 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[FSG_MAX_LUNS]; + + 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 functions. */ + const struct fsg_operations *ops; + /* 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; + + /* 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; + char nofua; + } luns[FSG_MAX_LUNS]; + + /* Callback functions. */ + const struct fsg_operations *ops; + /* Gadget's private data. */ + void *private_data; + + const char *vendor_name; /* 8 characters or less */ + const char *product_name; /* 16 characters or less */ + + 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); + WARN_ON(1); + 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; +} + +/*-------------------------------------------------------------------------*/ + +struct ums_board_info *ums_info; +struct fsg_common *the_fsg_common; + +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) +{ + common->thread_wakeup_needed = 1; +} + +static void raise_exception(struct fsg_common *common, enum fsg_state new_state) +{ + /* 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. */ + if (common->state <= new_state) { + common->exception_req_tag = common->ep0_req_tag; + common->state = new_state; + common->thread_wakeup_needed = 1; + } +} + +/*-------------------------------------------------------------------------*/ + +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 */ + bh->inreq_busy = 0; + bh->state = BUF_STATE_EMPTY; + wakeup_thread(common); +} + +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 */ + bh->outreq_busy = 0; + bh->state = BUF_STATE_FULL; + wakeup_thread(common); +} + +/*-------------------------------------------------------------------------*/ + +/* 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); + 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); + + *pbusy = 1; + *state = BUF_STATE_BUSY; + 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 void busy_indicator(void) +{ + static int state; + + switch (state) { + case 0: + puts("\r|"); break; + case 1: + puts("\r/"); break; + case 2: + puts("\r-"); break; + case 3: + puts("\r\\"); break; + case 4: + puts("\r|"); break; + case 5: + puts("\r/"); break; + case 6: + puts("\r-"); break; + case 7: + puts("\r\\"); break; + default: + state = 0; + } + if (state++ == 8) + state = 0; +} + +static int sleep_thread(struct fsg_common *common) +{ + int rc = 0; + int i = 0, k = 0; + + /* Wait until a signal arrives or we are woken up */ + for (;;) { + if (common->thread_wakeup_needed) + break; + + if (++i == 50000) { + busy_indicator(); + i = 0; + k++; + } + + usb_gadget_handle_interrupts(); + } + common->thread_wakeup_needed = 0; + return rc; +} + +/*-------------------------------------------------------------------------*/ + +static int do_read(struct fsg_common *common) +{ + struct fsg_lun *curlun = &common->luns[common->lun]; + u32 lba; + struct fsg_buffhd *bh; + int rc; + u32 amount_left; + loff_t file_offset; + 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); + 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->info_valid = 1; + bh->inreq->length = 0; + bh->state = BUF_STATE_FULL; + break; + } + + /* Perform the read */ + nread = 0; + rc = ums_info->read_sector(&(ums_info->ums_dev), + file_offset / SECTOR_SIZE, + amount / SECTOR_SIZE, + (char __user *)bh->buf); + if (rc) + return -EIO; + nread = amount; + + VLDBG(curlun, "file read %u @ %llu -> %d\n", amount, + (unsigned long long) file_offset, + (int) nread); + + 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->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->luns[common->lun]; + 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; + unsigned int amount; + unsigned int partial_page; + ssize_t nwritten; + int rc; + + if (curlun->ro) { + curlun->sense_data = SS_WRITE_PROTECTED; + return -EINVAL; + } + + /* 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 (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); + 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->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) { + 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->info_valid = 1; + break; + } + + amount = bh->outreq->actual; + + /* Perform the write */ + rc = ums_info->write_sector(&(ums_info->ums_dev), + file_offset / SECTOR_SIZE, + amount / SECTOR_SIZE, + (char __user *)bh->buf); + if (rc) + return -EIO; + nwritten = amount; + + VLDBG(curlun, "file write %u @ %llu -> %d\n", amount, + (unsigned long long) file_offset, + (int) nwritten); + + 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->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) +{ + return 0; +} + +/*-------------------------------------------------------------------------*/ + +static int do_verify(struct fsg_common *common) +{ + struct fsg_lun *curlun = &common->luns[common->lun]; + u32 lba; + u32 verification_length; + struct fsg_buffhd *bh = common->next_buffhd_to_fill; + loff_t file_offset; + u32 amount_left; + unsigned int amount; + ssize_t nread; + int rc; + + /* 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 */ + + /* 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); + if (amount == 0) { + curlun->sense_data = + SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE; + curlun->info_valid = 1; + break; + } + + /* Perform the read */ + nread = 0; + rc = ums_info->read_sector(&(ums_info->ums_dev), + file_offset / SECTOR_SIZE, + amount / SECTOR_SIZE, + (char __user *)bh->buf); + if (rc) + return -EIO; + nread = amount; + + VLDBG(curlun, "file read %u @ %llu -> %d\n", amount, + (unsigned long long) file_offset, + (int) nread); + 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->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->luns[common->lun]; + static const char vendor_id[] = "Linux "; + 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; + } + + memset(buf, 0, 8); + buf[0] = TYPE_DISK; + buf[2] = 2; /* ANSI SCSI level 2 */ + buf[3] = 2; /* SCSI-2 INQUIRY data format */ + buf[4] = 31; /* Additional length */ + /* No special options */ + sprintf((char *) (buf + 8), "%-8s%-16s%04x", (char*) vendor_id , + ums_info->name, (u16) 0xffff); + + return 36; +} + + +static int do_request_sense(struct fsg_common *common, struct fsg_buffhd *bh) +{ + struct fsg_lun *curlun = &common->luns[common->lun]; + 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; + valid = curlun->info_valid << 7; + curlun->sense_data = SS_NO_SENSE; + 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->luns[common->lun]; + 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->luns[common->lun]; + 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->luns[common->lun]; + 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->luns[common->lun]; + 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->luns[common->lun]; + + if (!curlun) { + return -EINVAL; + } else if (!curlun->removable) { + curlun->sense_data = SS_INVALID_COMMAND; + return -EINVAL; + } + + return 0; +} + +static int do_prevent_allow(struct fsg_common *common) +{ + struct fsg_lun *curlun = &common->luns[common->lun]; + int prevent; + + if (!curlun->removable) { + 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->luns[common->lun]; + 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->luns[common->lun]; + + /* 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; + } + + 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 = 0; /* 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; + } + } + 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) { + 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->luns[common->lun]; + 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; + 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]; + if (common->cmnd[0] != SC_REQUEST_SENSE) { + curlun->sense_data = SS_NO_SENSE; + curlun->info_valid = 0; + } + } else { + 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 0 + /* 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; + } +#endif + /* 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; + } + } + + 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]; + struct fsg_lun *curlun = &common->luns[common->lun]; + + 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->luns[common->lun].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->luns[common->lun].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) { + curlun->sense_data = SS_INVALID_COMMAND; + reply = -EINVAL; + } + break; + } + up_read(&common->filesem); + + if (reply == -EINTR) + 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; + } + + 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; + + 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) +{ + int i; + struct fsg_buffhd *bh; + enum fsg_state old_state; + struct fsg_lun *curlun; + unsigned int exception_req_tag; + + /* Cancel all the pending transfers */ + if (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. */ + + 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->sense_data = SS_NO_SENSE; + curlun->info_valid = 0; + } + common->state = FSG_STATE_IDLE; + } + + /* Carry out any extra actions required for the exception */ + switch (old_state) { + case FSG_STATE_ABORT_BULK_OUT: + send_status(common); + + if (common->state == FSG_STATE_STATUS_PHASE) + common->state = FSG_STATE_IDLE; + 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 */ + + 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 */ + common->state = FSG_STATE_TERMINATED; /* Stop the thread */ + 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; + } +} + +/*-------------------------------------------------------------------------*/ + +int fsg_main_thread(void *common_) +{ + struct fsg_common *common = the_fsg_common; + /* The main loop */ + do { + if (exception_in_progress(common)) { + handle_exception(common); + continue; + } + + if (!common->running) { + sleep_thread(common); + continue; + } + + if (get_next_command(common)) + continue; + + if (!exception_in_progress(common)) + common->state = FSG_STATE_DATA_PHASE; + + if (do_scsi_command(common) || finish_reply(common)) + continue; + + if (!exception_in_progress(common)) + common->state = FSG_STATE_STATUS_PHASE; + + if (send_status(common)) + continue; + + if (!exception_in_progress(common)) + common->state = FSG_STATE_IDLE; + } while (0); + + common->thread_task = NULL; + + return 0; +} + +static void fsg_common_release(struct kref *ref); + +static struct fsg_common *fsg_common_init(struct fsg_common *common, + struct usb_composite_dev *cdev) +{ + struct usb_gadget *gadget = cdev->gadget; + struct fsg_buffhd *bh; + struct fsg_lun *curlun; + int nluns, i, rc; + + /* Find out how many LUNs there should be */ + nluns = 1; + if (nluns < 1 || nluns > FSG_MAX_LUNS) { + printf("invalid number of LUNs: %u\n", nluns); + return ERR_PTR(-EINVAL); + } + + /* Allocate? */ + if (!common) { + common = calloc(sizeof *common, 1); + 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->ops = NULL; + common->private_data = NULL; + + 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 = calloc(nluns, sizeof *curlun); + if (!curlun) { + rc = -ENOMEM; + goto error_release; + } + common->nluns = nluns; + + for (i = 0; i < nluns; i++) { + common->luns[i].removable = 1; + + rc = fsg_lun_open(&common->luns[i], ""); + if (rc) + goto error_luns; + } + common->lun = 0; + + /* 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->inreq_busy = 0; + bh->outreq_busy = 0; + bh->buf = kmalloc(FSG_BUFLEN, GFP_KERNEL); + if (unlikely(!bh->buf)) { + rc = -ENOMEM; + goto error_release; + } + } while (--i); + bh->next = common->buffhds; + + snprintf(common->inquiry_string, sizeof common->inquiry_string, + "%-8s%-16s%04x", + "Linux ", + "File-Store Gadget", + 0xffff); + + /* Some peripheral controllers are known not to be able to + * halt bulk endpoints correctly. If one of them is present, + * disable stalls. + */ + + /* Tell the thread to start working */ + 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; + } + +#undef OR + /* Information */ + INFO(common, FSG_DRIVER_DESC ", version: " FSG_DRIVER_VERSION "\n"); + INFO(common, "Number of LUNs=%d\n", common->nluns); + + 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); + } + + 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) + fsg_lun_close(lun); + + 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); +} + + +/*-------------------------------------------------------------------------*/ + +/** + * usb_copy_descriptors - copy a vector of USB descriptors + * @src: null-terminated vector to copy + * Context: initialization code, which may sleep + * + * This makes a copy of a vector of USB descriptors. Its primary use + * is to support usb_function objects which can have multiple copies, + * each needing different descriptors. Functions may have static + * tables of descriptors, which are used as templates and customized + * with identifiers (for interfaces, strings, endpoints, and more) + * as needed by a given function instance. + */ +struct usb_descriptor_header ** +usb_copy_descriptors(struct usb_descriptor_header **src) +{ + struct usb_descriptor_header **tmp; + unsigned bytes; + unsigned n_desc; + void *mem; + struct usb_descriptor_header **ret; + + /* count descriptors and their sizes; then add vector size */ + for (bytes = 0, n_desc = 0, tmp = src; *tmp; tmp++, n_desc++) + bytes += (*tmp)->bLength; + bytes += (n_desc + 1) * sizeof(*tmp); + + mem = kmalloc(bytes, GFP_KERNEL); + if (!mem) + return NULL; + + /* fill in pointers starting at "tmp", + * to descriptors copied starting at "mem"; + * and return "ret" + */ + tmp = mem; + ret = mem; + mem += (n_desc + 1) * sizeof(*tmp); + while (*src) { + memcpy(mem, *src, (*src)->bLength); + *tmp = mem; + tmp++; + mem += (*src)->bLength; + src++; + } + *tmp = NULL; + + return ret; +} + + + +static void fsg_unbind(struct usb_configuration *c, struct usb_function *f) +{ + struct fsg_dev *fsg = fsg_from_func(f); + + DBG(fsg, "unbind\n"); + if (fsg->common->fsg == fsg) { + fsg->common->new_fsg = NULL; + raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE); + } + + free(fsg->function.descriptors); + free(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)) { + free(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_bind_config(struct usb_composite_dev *cdev, + struct usb_configuration *c, + struct fsg_common *common) +{ + struct fsg_dev *fsg; + int rc; + + fsg = calloc(1, sizeof *fsg); + if (!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; + common->fsg = fsg; + /* 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 (rc) + kfree(fsg); + + return rc; +} + +int fsg_add(struct usb_configuration *c) +{ + struct fsg_common *fsg_common; + + fsg_common = fsg_common_init(NULL, c->cdev); + + fsg_common->vendor_name = 0; + fsg_common->product_name = 0; + fsg_common->release = 0xffff; + + fsg_common->ops = NULL; + fsg_common->private_data = NULL; + + the_fsg_common = fsg_common; + + return fsg_bind_config(c->cdev, c, fsg_common); +} + +int fsg_init(struct ums_board_info *ums) +{ + ums_info = ums; + + return 0; +} |