/* * file_storage.c -- File-backed USB Storage Gadget, for USB development * * Copyright (C) 2003-2005 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. 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. The gadget will indicate that * it has removable media if the optional "removable" module parameter is set. * * The gadget supports the Control-Bulk (CB), Control-Bulk-Interrupt (CBI), * and Bulk-Only (also known as Bulk-Bulk-Bulk or BBB) transports, selected * by the optional "transport" module parameter. It also supports the * following protocols: RBC (0x01), ATAPI or SFF-8020i (0x02), QIC-157 (0c03), * UFI (0x04), SFF-8070i (0x05), and transparent SCSI (0x06), selected by * the optional "protocol" module parameter. In addition, the default * Vendor ID, Product ID, and release number can be overridden. * * 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. * * 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 * transport=XXX Default BBB, transport name (CB, CBI, or BBB) * protocol=YYY Default SCSI, protocol name (RBC, 8020 or * ATAPI, QIC, UFI, 8070, or SCSI; * also 1 - 6) * vendor=0xVVVV Default 0x0525 (NetChip), USB Vendor ID * product=0xPPPP Default 0xa4a5 (FSG), USB Product ID * release=0xRRRR Override the USB release number (bcdDevice) * buflen=N Default N=16384, buffer size used (will be * rounded down to a multiple of * PAGE_CACHE_SIZE) * * If CONFIG_USB_FILE_STORAGE_TEST is not set, only the "file", "ro", * "removable", "luns", and "stall" options are available; default values * are used for everything else. * * 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. * * 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. */ #undef DEBUG #undef VERBOSE #undef DUMP_MSGS #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "gadget_chips.h" /*-------------------------------------------------------------------------*/ #define DRIVER_DESC "File-backed Storage Gadget" #define DRIVER_NAME "g_file_storage" #define DRIVER_VERSION "28 November 2005" static const char longname[] = DRIVER_DESC; static const char shortname[] = DRIVER_NAME; MODULE_DESCRIPTION(DRIVER_DESC); MODULE_AUTHOR("Alan Stern"); MODULE_LICENSE("Dual BSD/GPL"); /* Thanks to NetChip Technologies for donating this product ID. * * DO NOT REUSE THESE IDs with any other driver!! Ever!! * Instead: allocate your own, using normal USB-IF procedures. */ #define DRIVER_VENDOR_ID 0x0525 // NetChip #define DRIVER_PRODUCT_ID 0xa4a5 // Linux-USB File-backed Storage Gadget /* * This driver assumes self-powered hardware and has no way for users to * trigger remote wakeup. It uses autoconfiguration to select endpoints * and endpoint addresses. */ /*-------------------------------------------------------------------------*/ #define xprintk(f,level,fmt,args...) \ dev_printk(level , &(f)->gadget->dev , fmt , ## args) #define yprintk(l,level,fmt,args...) \ dev_printk(level , &(l)->dev , fmt , ## args) #ifdef DEBUG #define DBG(fsg,fmt,args...) \ xprintk(fsg , KERN_DEBUG , fmt , ## args) #define LDBG(lun,fmt,args...) \ yprintk(lun , KERN_DEBUG , fmt , ## args) #define MDBG(fmt,args...) \ printk(KERN_DEBUG DRIVER_NAME ": " fmt , ## args) #else #define DBG(fsg,fmt,args...) \ do { } while (0) #define LDBG(lun,fmt,args...) \ do { } while (0) #define MDBG(fmt,args...) \ do { } while (0) #undef VERBOSE #undef DUMP_MSGS #endif /* DEBUG */ #ifdef VERBOSE #define VDBG DBG #define VLDBG LDBG #else #define VDBG(fsg,fmt,args...) \ do { } while (0) #define VLDBG(lun,fmt,args...) \ do { } while (0) #endif /* VERBOSE */ #define ERROR(fsg,fmt,args...) \ xprintk(fsg , KERN_ERR , fmt , ## args) #define LERROR(lun,fmt,args...) \ yprintk(lun , KERN_ERR , fmt , ## args) #define WARN(fsg,fmt,args...) \ xprintk(fsg , KERN_WARNING , fmt , ## args) #define LWARN(lun,fmt,args...) \ yprintk(lun , KERN_WARNING , fmt , ## args) #define INFO(fsg,fmt,args...) \ xprintk(fsg , KERN_INFO , fmt , ## args) #define LINFO(lun,fmt,args...) \ yprintk(lun , KERN_INFO , fmt , ## args) #define MINFO(fmt,args...) \ printk(KERN_INFO DRIVER_NAME ": " fmt , ## args) /*-------------------------------------------------------------------------*/ /* Encapsulate the module parameter settings */ #define MAX_LUNS 8 static struct { char *file[MAX_LUNS]; int ro[MAX_LUNS]; int num_filenames; int num_ros; unsigned int nluns; int removable; int can_stall; char *transport_parm; char *protocol_parm; unsigned short vendor; unsigned short product; unsigned short release; unsigned int buflen; int transport_type; char *transport_name; int protocol_type; char *protocol_name; } mod_data = { // Default values .transport_parm = "BBB", .protocol_parm = "SCSI", .removable = 0, .can_stall = 1, .vendor = DRIVER_VENDOR_ID, .product = DRIVER_PRODUCT_ID, .release = 0xffff, // Use controller chip type .buflen = 16384, }; module_param_array_named(file, mod_data.file, charp, &mod_data.num_filenames, S_IRUGO); MODULE_PARM_DESC(file, "names of backing files or devices"); module_param_array_named(ro, mod_data.ro, bool, &mod_data.num_ros, S_IRUGO); MODULE_PARM_DESC(ro, "true to force read-only"); module_param_named(luns, mod_data.nluns, uint, S_IRUGO); MODULE_PARM_DESC(luns, "number of LUNs"); module_param_named(removable, mod_data.removable, bool, S_IRUGO); MODULE_PARM_DESC(removable, "true to simulate removable media"); module_param_named(stall, mod_data.can_stall, bool, S_IRUGO); MODULE_PARM_DESC(stall, "false to prevent bulk stalls"); /* In the non-TEST version, only the module parameters listed above * are available. */ #ifdef CONFIG_USB_FILE_STORAGE_TEST module_param_named(transport, mod_data.transport_parm, charp, S_IRUGO); MODULE_PARM_DESC(transport, "type of transport (BBB, CBI, or CB)"); module_param_named(protocol, mod_data.protocol_parm, charp, S_IRUGO); MODULE_PARM_DESC(protocol, "type of protocol (RBC, 8020, QIC, UFI, " "8070, or SCSI)"); module_param_named(vendor, mod_data.vendor, ushort, S_IRUGO); MODULE_PARM_DESC(vendor, "USB Vendor ID"); module_param_named(product, mod_data.product, ushort, S_IRUGO); MODULE_PARM_DESC(product, "USB Product ID"); module_param_named(release, mod_data.release, ushort, S_IRUGO); MODULE_PARM_DESC(release, "USB release number"); module_param_named(buflen, mod_data.buflen, uint, S_IRUGO); MODULE_PARM_DESC(buflen, "I/O buffer size"); #endif /* CONFIG_USB_FILE_STORAGE_TEST */ /*-------------------------------------------------------------------------*/ /* USB protocol value = the transport method */ #define USB_PR_CBI 0x00 // Control/Bulk/Interrupt #define USB_PR_CB 0x01 // Control/Bulk w/o interrupt #define USB_PR_BULK 0x50 // Bulk-only /* USB subclass value = the protocol encapsulation */ #define USB_SC_RBC 0x01 // Reduced Block Commands (flash) #define USB_SC_8020 0x02 // SFF-8020i, MMC-2, ATAPI (CD-ROM) #define USB_SC_QIC 0x03 // QIC-157 (tape) #define USB_SC_UFI 0x04 // UFI (floppy) #define USB_SC_8070 0x05 // SFF-8070i (removable) #define USB_SC_SCSI 0x06 // Transparent SCSI /* Bulk-only data structures */ /* Command Block Wrapper */ struct bulk_cb_wrap { __le32 Signature; // Contains 'USBC' u32 Tag; // Unique per command id __le32 DataTransferLength; // Size of the data u8 Flags; // Direction in bit 7 u8 Lun; // LUN (normally 0) u8 Length; // Of the CDB, <= MAX_COMMAND_SIZE u8 CDB[16]; // Command Data Block }; #define USB_BULK_CB_WRAP_LEN 31 #define USB_BULK_CB_SIG 0x43425355 // Spells out USBC #define USB_BULK_IN_FLAG 0x80 /* Command Status Wrapper */ struct bulk_cs_wrap { __le32 Signature; // Should = 'USBS' u32 Tag; // Same as original command __le32 Residue; // Amount not transferred u8 Status; // See below }; #define USB_BULK_CS_WRAP_LEN 13 #define USB_BULK_CS_SIG 0x53425355 // Spells out 'USBS' #define USB_STATUS_PASS 0 #define USB_STATUS_FAIL 1 #define USB_STATUS_PHASE_ERROR 2 /* Bulk-only class specific requests */ #define USB_BULK_RESET_REQUEST 0xff #define USB_BULK_GET_MAX_LUN_REQUEST 0xfe /* CBI Interrupt data structure */ struct interrupt_data { u8 bType; u8 bValue; }; #define CBI_INTERRUPT_DATA_LEN 2 /* CBI Accept Device-Specific Command request */ #define USB_CBI_ADSC_REQUEST 0x00 #define MAX_COMMAND_SIZE 16 // Length of a SCSI Command Data Block /* SCSI commands that we recognize */ #define SC_FORMAT_UNIT 0x04 #define SC_INQUIRY 0x12 #define SC_MODE_SELECT_6 0x15 #define SC_MODE_SELECT_10 0x55 #define SC_MODE_SENSE_6 0x1a #define SC_MODE_SENSE_10 0x5a #define SC_PREVENT_ALLOW_MEDIUM_REMOVAL 0x1e #define SC_READ_6 0x08 #define SC_READ_10 0x28 #define SC_READ_12 0xa8 #define SC_READ_CAPACITY 0x25 #define SC_READ_FORMAT_CAPACITIES 0x23 #define SC_RELEASE 0x17 #define SC_REQUEST_SENSE 0x03 #define SC_RESERVE 0x16 #define SC_SEND_DIAGNOSTIC 0x1d #define SC_START_STOP_UNIT 0x1b #define SC_SYNCHRONIZE_CACHE 0x35 #define SC_TEST_UNIT_READY 0x00 #define SC_VERIFY 0x2f #define SC_WRITE_6 0x0a #define SC_WRITE_10 0x2a #define SC_WRITE_12 0xaa /* SCSI Sense Key/Additional Sense Code/ASC Qualifier values */ #define SS_NO_SENSE 0 #define SS_COMMUNICATION_FAILURE 0x040800 #define SS_INVALID_COMMAND 0x052000 #define SS_INVALID_FIELD_IN_CDB 0x052400 #define SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE 0x052100 #define SS_LOGICAL_UNIT_NOT_SUPPORTED 0x052500 #define SS_MEDIUM_NOT_PRESENT 0x023a00 #define SS_MEDIUM_REMOVAL_PREVENTED 0x055302 #define SS_NOT_READY_TO_READY_TRANSITION 0x062800 #define SS_RESET_OCCURRED 0x062900 #define SS_SAVING_PARAMETERS_NOT_SUPPORTED 0x053900 #define SS_UNRECOVERED_READ_ERROR 0x031100 #define SS_WRITE_ERROR 0x030c02 #define SS_WRITE_PROTECTED 0x072700 #define SK(x) ((u8) ((x) >> 16)) // Sense Key byte, etc. #define ASC(x) ((u8) ((x) >> 8)) #define ASCQ(x) ((u8) (x)) /*-------------------------------------------------------------------------*/ /* * These definitions will permit the compiler to avoid generating code for * parts of the driver that aren't used in the non-TEST version. Even gcc * can recognize when a test of a constant expression yields a dead code * path. */ #ifdef CONFIG_USB_FILE_STORAGE_TEST #define transport_is_bbb() (mod_data.transport_type == USB_PR_BULK) #define transport_is_cbi() (mod_data.transport_type == USB_PR_CBI) #define protocol_is_scsi() (mod_data.protocol_type == USB_SC_SCSI) #else #define transport_is_bbb() 1 #define transport_is_cbi() 0 #define protocol_is_scsi() 1 #endif /* CONFIG_USB_FILE_STORAGE_TEST */ struct lun { struct file *filp; loff_t file_length; loff_t num_sectors; unsigned int ro : 1; unsigned int prevent_medium_removal : 1; unsigned int registered : 1; u32 sense_data; u32 sense_data_info; u32 unit_attention_data; struct device dev; }; #define backing_file_is_open(curlun) ((curlun)->filp != NULL) static inline struct lun *dev_to_lun(struct device *dev) { return container_of(dev, struct lun, dev); } /* Big enough to hold our biggest descriptor */ #define EP0_BUFSIZE 256 #define DELAYED_STATUS (EP0_BUFSIZE + 999) // An impossibly large value /* Number of buffers we will use. 2 is enough for double-buffering */ #define NUM_BUFFERS 2 enum fsg_buffer_state { BUF_STATE_EMPTY = 0, BUF_STATE_FULL, BUF_STATE_BUSY }; struct fsg_buffhd { void *buf; dma_addr_t dma; enum fsg_buffer_state state; struct fsg_buffhd *next; /* The NetChip 2280 is faster, and handles some protocol faults * better, if we don't submit any short bulk-out read requests. * So we will record the intended request length here. */ unsigned int bulk_out_intended_length; struct usb_request *inreq; int inreq_busy; struct usb_request *outreq; int outreq_busy; }; enum fsg_state { FSG_STATE_COMMAND_PHASE = -10, // This one isn't used anywhere FSG_STATE_DATA_PHASE, FSG_STATE_STATUS_PHASE, FSG_STATE_IDLE = 0, FSG_STATE_ABORT_BULK_OUT, FSG_STATE_RESET, FSG_STATE_INTERFACE_CHANGE, FSG_STATE_CONFIG_CHANGE, FSG_STATE_DISCONNECT, FSG_STATE_EXIT, FSG_STATE_TERMINATED }; enum data_direction { DATA_DIR_UNKNOWN = 0, DATA_DIR_FROM_HOST, DATA_DIR_TO_HOST, DATA_DIR_NONE }; struct fsg_dev { /* lock protects: state, all the req_busy's, and cbbuf_cmnd */ spinlock_t lock; struct usb_gadget *gadget; /* filesem protects: backing files in use */ struct rw_semaphore filesem; /* reference counting: wait until all LUNs are released */ struct kref ref; struct usb_ep *ep0; // Handy copy of gadget->ep0 struct usb_request *ep0req; // For control responses unsigned int ep0_req_tag; const char *ep0req_name; struct usb_request *intreq; // For interrupt responses int intreq_busy; struct fsg_buffhd *intr_buffhd; 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 intr_in_enabled : 1; unsigned int phase_error : 1; unsigned int short_packet_received : 1; unsigned int bad_lun_okay : 1; unsigned long atomic_bitflags; #define REGISTERED 0 #define CLEAR_BULK_HALTS 1 #define SUSPENDED 2 struct usb_ep *bulk_in; struct usb_ep *bulk_out; struct usb_ep *intr_in; struct fsg_buffhd *next_buffhd_to_fill; struct fsg_buffhd *next_buffhd_to_drain; struct fsg_buffhd buffhds[NUM_BUFFERS]; int thread_wakeup_needed; struct completion thread_notifier; struct task_struct *thread_task; sigset_t thread_signal_mask; int cmnd_size; u8 cmnd[MAX_COMMAND_SIZE]; enum data_direction data_dir; u32 data_size; u32 data_size_from_cmnd; u32 tag; unsigned int lun; u32 residue; u32 usb_amount_left; /* The CB protocol offers no way for a host to know when a command * has completed. As a result the next command may arrive early, * and we will still have to handle it. For that reason we need * a buffer to store new commands when using CB (or CBI, which * does not oblige a host to wait for command completion either). */ int cbbuf_cmnd_size; u8 cbbuf_cmnd[MAX_COMMAND_SIZE]; unsigned int nluns; struct lun *luns; struct lun *curlun; }; typedef void (*fsg_routine_t)(struct fsg_dev *); static int inline 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 inline 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 struct fsg_dev *the_fsg; static struct usb_gadget_driver fsg_driver; static void close_backing_file(struct lun *curlun); static void close_all_backing_files(struct fsg_dev *fsg); /*-------------------------------------------------------------------------*/ #ifdef DUMP_MSGS static void dump_msg(struct fsg_dev *fsg, const char *label, const u8 *buf, unsigned int length) { unsigned int start, num, i; char line[52], *p; if (length >= 512) return; DBG(fsg, "%s, length %u:\n", label, length); start = 0; while (length > 0) { num = min(length, 16u); p = line; for (i = 0; i < num; ++i) { if (i == 8) *p++ = ' '; sprintf(p, " %02x", buf[i]); p += 3; } *p = 0; printk(KERN_DEBUG "%6x: %s\n", start, line); buf += num; start += num; length -= num; } } static void inline dump_cdb(struct fsg_dev *fsg) {} #else static void inline dump_msg(struct fsg_dev *fsg, const char *label, const u8 *buf, unsigned int length) {} static void inline dump_cdb(struct fsg_dev *fsg) { int i; char cmdbuf[3*MAX_COMMAND_SIZE + 1]; for (i = 0; i < fsg->cmnd_size; ++i) sprintf(cmdbuf + i*3, " %02x", fsg->cmnd[i]); VDBG(fsg, "SCSI CDB: %s\n", cmdbuf); } #endif /* DUMP_MSGS */ 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); } /*-------------------------------------------------------------------------*/ /* Routines for unaligned data access */ static u16 inline get_be16(u8 *buf) { return ((u16) buf[0] << 8) | ((u16) buf[1]); } static u32 inline get_be32(u8 *buf) { return ((u32) buf[0] << 24) | ((u32) buf[1] << 16) | ((u32) buf[2] << 8) | ((u32) buf[3]); } static void inline put_be16(u8 *buf, u16 val) { buf[0] = val >> 8; buf[1] = val; } static void inline put_be32(u8 *buf, u32 val) { buf[0] = val >> 24; buf[1] = val >> 16; buf[2] = val >> 8; buf[3] = val & 0xff; } /*-------------------------------------------------------------------------*/ /* * DESCRIPTORS ... most are static, but strings and (full) configuration * descriptors are built on demand. Also the (static) config and interface * descriptors are adjusted during fsg_bind(). */ #define STRING_MANUFACTURER 1 #define STRING_PRODUCT 2 #define STRING_SERIAL 3 #define STRING_CONFIG 4 #define STRING_INTERFACE 5 /* There is only one configuration. */ #define CONFIG_VALUE 1 static struct usb_device_descriptor device_desc = { .bLength = sizeof device_desc, .bDescriptorType = USB_DT_DEVICE, .bcdUSB = __constant_cpu_to_le16(0x0200), .bDeviceClass = USB_CLASS_PER_INTERFACE, /* The next three values can be overridden by module parameters */ .idVendor = __constant_cpu_to_le16(DRIVER_VENDOR_ID), .idProduct = __constant_cpu_to_le16(DRIVER_PRODUCT_ID), .bcdDevice = __constant_cpu_to_le16(0xffff), .iManufacturer = STRING_MANUFACTURER, .iProduct = STRING_PRODUCT, .iSerialNumber = STRING_SERIAL, .bNumConfigurations = 1, }; static struct usb_config_descriptor config_desc = { .bLength = sizeof config_desc, .bDescriptorType = USB_DT_CONFIG, /* wTotalLength computed by usb_gadget_config_buf() */ .bNumInterfaces = 1, .bConfigurationValue = CONFIG_VALUE, .iConfiguration = STRING_CONFIG, .bmAttributes = USB_CONFIG_ATT_ONE | USB_CONFIG_ATT_SELFPOWER, .bMaxPower = 1, // self-powered }; static struct usb_otg_descriptor otg_desc = { .bLength = sizeof(otg_desc), .bDescriptorType = USB_DT_OTG, .bmAttributes = USB_OTG_SRP, }; /* There is only one interface. */ static struct usb_interface_descriptor intf_desc = { .bLength = sizeof intf_desc, .bDescriptorType = USB_DT_INTERFACE, .bNumEndpoints = 2, // Adjusted during fsg_bind() .bInterfaceClass = USB_CLASS_MASS_STORAGE, .bInterfaceSubClass = USB_SC_SCSI, // Adjusted during fsg_bind() .bInterfaceProtocol = USB_PR_BULK, // Adjusted during fsg_bind() .iInterface = STRING_INTERFACE, }; /* Three full-speed endpoint descriptors: bulk-in, bulk-out, * and interrupt-in. */ static struct usb_endpoint_descriptor fs_bulk_in_desc = { .bLength = USB_DT_ENDPOINT_SIZE, .bDescriptorType = USB_DT_ENDPOINT, .bEndpointAddress = USB_DIR_IN, .bmAttributes = USB_ENDPOINT_XFER_BULK, /* wMaxPacketSize set by autoconfiguration */ }; static struct usb_endpoint_descriptor fs_bulk_out_desc = { .bLength = USB_DT_ENDPOINT_SIZE, .bDescriptorType = USB_DT_ENDPOINT, .bEndpointAddress = USB_DIR_OUT, .bmAttributes = USB_ENDPOINT_XFER_BULK, /* wMaxPacketSize set by autoconfiguration */ }; static struct usb_endpoint_descriptor fs_intr_in_desc = { .bLength = USB_DT_ENDPOINT_SIZE, .bDescriptorType = USB_DT_ENDPOINT, .bEndpointAddress = USB_DIR_IN, .bmAttributes = USB_ENDPOINT_XFER_INT, .wMaxPacketSize = __constant_cpu_to_le16(2), .bInterval = 32, // frames -> 32 ms }; static const struct usb_descriptor_header *fs_function[] = { (struct usb_descriptor_header *) &otg_desc, (struct usb_descriptor_header *) &intf_desc, (struct usb_descriptor_header *) &fs_bulk_in_desc, (struct usb_descriptor_header *) &fs_bulk_out_desc, (struct usb_descriptor_header *) &fs_intr_in_desc, NULL, }; #define FS_FUNCTION_PRE_EP_ENTRIES 2 #ifdef CONFIG_USB_GADGET_DUALSPEED /* * USB 2.0 devices need to expose both high speed and full speed * descriptors, unless they only run at full speed. * * That means alternate endpoint descriptors (bigger packets) * and a "device qualifier" ... plus more construction options * for the config descriptor. */ static struct usb_qualifier_descriptor dev_qualifier = { .bLength = sizeof dev_qualifier, .bDescriptorType = USB_DT_DEVICE_QUALIFIER, .bcdUSB = __constant_cpu_to_le16(0x0200), .bDeviceClass = USB_CLASS_PER_INTERFACE, .bNumConfigurations = 1, }; static struct usb_endpoint_descriptor hs_bulk_in_desc = { .bLength = USB_DT_ENDPOINT_SIZE, .bDescriptorType = USB_DT_ENDPOINT, /* bEndpointAddress copied from fs_bulk_in_desc during fsg_bind() */ .bmAttributes = USB_ENDPOINT_XFER_BULK, .wMaxPacketSize = __constant_cpu_to_le16(512), }; static struct usb_endpoint_descriptor hs_bulk_out_desc = { .bLength = USB_DT_ENDPOINT_SIZE, .bDescriptorType = USB_DT_ENDPOINT, /* bEndpointAddress copied from fs_bulk_out_desc during fsg_bind() */ .bmAttributes = USB_ENDPOINT_XFER_BULK, .wMaxPacketSize = __constant_cpu_to_le16(512), .bInterval = 1, // NAK every 1 uframe }; static struct usb_endpoint_descriptor hs_intr_in_desc = { .bLength = USB_DT_ENDPOINT_SIZE, .bDescriptorType = USB_DT_ENDPOINT, /* bEndpointAddress copied from fs_intr_in_desc during fsg_bind() */ .bmAttributes = USB_ENDPOINT_XFER_INT, .wMaxPacketSize = __constant_cpu_to_le16(2), .bInterval = 9, // 2**(9-1) = 256 uframes -> 32 ms }; static const struct usb_descriptor_header *hs_function[] = { (struct usb_descriptor_header *) &otg_desc, (struct usb_descriptor_header *) &intf_desc, (struct usb_descriptor_header *) &hs_bulk_in_desc, (struct usb_descriptor_header *) &hs_bulk_out_desc, (struct usb_descriptor_header *) &hs_intr_in_desc, NULL, }; #define HS_FUNCTION_PRE_EP_ENTRIES 2 /* Maxpacket and other transfer characteristics vary by speed. */ #define ep_desc(g,fs,hs) (((g)->speed==USB_SPEED_HIGH) ? (hs) : (fs)) #else /* If there's no high speed support, always use the full-speed descriptor. */ #define ep_desc(g,fs,hs) fs #endif /* !CONFIG_USB_GADGET_DUALSPEED */ /* The CBI specification limits the serial string to 12 uppercase hexadecimal * characters. */ static char manufacturer[64]; static char serial[13]; /* Static strings, in UTF-8 (for simplicity we use only ASCII characters) */ static struct usb_string strings[] = { {STRING_MANUFACTURER, manufacturer}, {STRING_PRODUCT, longname}, {STRING_SERIAL, serial}, {STRING_CONFIG, "Self-powered"}, {STRING_INTERFACE, "Mass Storage"}, {} }; static struct usb_gadget_strings stringtab = { .language = 0x0409, // en-us .strings = strings, }; /* * Config descriptors must agree with the code that sets configurations * and with code managing interfaces and their altsettings. They must * also handle different speeds and other-speed requests. */ static int populate_config_buf(struct usb_gadget *gadget, u8 *buf, u8 type, unsigned index) { #ifdef CONFIG_USB_GADGET_DUALSPEED enum usb_device_speed speed = gadget->speed; #endif int len; const struct usb_descriptor_header **function; if (index > 0) return -EINVAL; #ifdef CONFIG_USB_GADGET_DUALSPEED if (type == USB_DT_OTHER_SPEED_CONFIG) speed = (USB_SPEED_FULL + USB_SPEED_HIGH) - speed; if (speed == USB_SPEED_HIGH) function = hs_function; else #endif function = fs_function; /* for now, don't advertise srp-only devices */ if (!gadget->is_otg) function++; len = usb_gadget_config_buf(&config_desc, buf, EP0_BUFSIZE, function); ((struct usb_config_descriptor *) buf)->bDescriptorType = type; return len; } /*-------------------------------------------------------------------------*/ /* 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); } /*-------------------------------------------------------------------------*/ /* The disconnect callback and ep0 routines. These always run in_irq, * except that ep0_queue() is called in the main thread to acknowledge * completion of various requests: set config, set interface, and * Bulk-only device reset. */ static void fsg_disconnect(struct usb_gadget *gadget) { struct fsg_dev *fsg = get_gadget_data(gadget); DBG(fsg, "disconnect or port reset\n"); raise_exception(fsg, FSG_STATE_DISCONNECT); } static int ep0_queue(struct fsg_dev *fsg) { int rc; rc = usb_ep_queue(fsg->ep0, fsg->ep0req, GFP_ATOMIC); if (rc != 0 && rc != -ESHUTDOWN) { /* We can't do much more than wait for a reset */ WARN(fsg, "error in submission: %s --> %d\n", fsg->ep0->name, rc); } return rc; } static void ep0_complete(struct usb_ep *ep, struct usb_request *req) { struct fsg_dev *fsg = (struct fsg_dev *) ep->driver_data; if (req->actual > 0) dump_msg(fsg, fsg->ep0req_name, req->buf, req->actual); if (req->status || req->actual != req->length) DBG(fsg, "%s --> %d, %u/%u\n", __FUNCTION__, req->status, req->actual, req->length); if (req->status == -ECONNRESET) // Request was cancelled usb_ep_fifo_flush(ep); if (req->status == 0 && req->context) ((fsg_routine_t) (req->context))(fsg); } /*-------------------------------------------------------------------------*/ /* 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 = (struct fsg_dev *) ep->driver_data; struct fsg_buffhd *bh = (struct fsg_buffhd *) req->context; if (req->status || req->actual != req->length) DBG(fsg, "%s --> %d, %u/%u\n", __FUNCTION__, 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 = (struct fsg_dev *) ep->driver_data; struct fsg_buffhd *bh = (struct fsg_buffhd *) 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", __FUNCTION__, 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); } #ifdef CONFIG_USB_FILE_STORAGE_TEST static void intr_in_complete(struct usb_ep *ep, struct usb_request *req) { struct fsg_dev *fsg = (struct fsg_dev *) ep->driver_data; struct fsg_buffhd *bh = (struct fsg_buffhd *) req->context; if (req->status || req->actual != req->length) DBG(fsg, "%s --> %d, %u/%u\n", __FUNCTION__, 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); fsg->intreq_busy = 0; bh->state = BUF_STATE_EMPTY; wakeup_thread(fsg); spin_unlock(&fsg->lock); } #else static void intr_in_complete(struct usb_ep *ep, struct usb_request *req) {} #endif /* CONFIG_USB_FILE_STORAGE_TEST */ /*-------------------------------------------------------------------------*/ /* Ep0 class-specific handlers. These always run in_irq. */ #ifdef CONFIG_USB_FILE_STORAGE_TEST static void received_cbi_adsc(struct fsg_dev *fsg, struct fsg_buffhd *bh) { struct usb_request *req = fsg->ep0req; static u8 cbi_reset_cmnd[6] = { SC_SEND_DIAGNOSTIC, 4, 0xff, 0xff, 0xff, 0xff}; /* Error in command transfer? */ if (req->status || req->length != req->actual || req->actual < 6 || req->actual > MAX_COMMAND_SIZE) { /* Not all controllers allow a protocol stall after * receiving control-out data, but we'll try anyway. */ fsg_set_halt(fsg, fsg->ep0); return; // Wait for reset } /* Is it the special reset command? */ if (req->actual >= sizeof cbi_reset_cmnd && memcmp(req->buf, cbi_reset_cmnd, sizeof cbi_reset_cmnd) == 0) { /* Raise an exception to stop the current operation * and reinitialize our state. */ DBG(fsg, "cbi reset request\n"); raise_exception(fsg, FSG_STATE_RESET); return; } VDBG(fsg, "CB[I] accept device-specific command\n"); spin_lock(&fsg->lock); /* Save the command for later */ if (fsg->cbbuf_cmnd_size) WARN(fsg, "CB[I] overwriting previous command\n"); fsg->cbbuf_cmnd_size = req->actual; memcpy(fsg->cbbuf_cmnd, req->buf, fsg->cbbuf_cmnd_size); wakeup_thread(fsg); spin_unlock(&fsg->lock); } #else static void received_cbi_adsc(struct fsg_dev *fsg, struct fsg_buffhd *bh) {} #endif /* CONFIG_USB_FILE_STORAGE_TEST */ static int class_setup_req(struct fsg_dev *fsg, const struct usb_ctrlrequest *ctrl) { struct usb_request *req = fsg->ep0req; int value = -EOPNOTSUPP; u16 w_index = le16_to_cpu(ctrl->wIndex); u16 w_length = le16_to_cpu(ctrl->wLength); if (!fsg->config) return value; /* Handle Bulk-only class-specific requests */ if (transport_is_bbb()) { switch (ctrl->bRequest) { case USB_BULK_RESET_REQUEST: if (ctrl->bRequestType != (USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE)) break; if (w_index != 0) { value = -EDOM; break; } /* Raise an exception to stop the current operation * and reinitialize our state. */ DBG(fsg, "bulk reset request\n"); raise_exception(fsg, FSG_STATE_RESET); value = DELAYED_STATUS; break; case USB_BULK_GET_MAX_LUN_REQUEST: if (ctrl->bRequestType != (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE)) break; if (w_index != 0) { value = -EDOM; break; } VDBG(fsg, "get max LUN\n"); *(u8 *) req->buf = fsg->nluns - 1; value = 1; break; } } /* Handle CBI class-specific requests */ else { switch (ctrl->bRequest) { case USB_CBI_ADSC_REQUEST: if (ctrl->bRequestType != (USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE)) break; if (w_index != 0) { value = -EDOM; break; } if (w_length > MAX_COMMAND_SIZE) { value = -EOVERFLOW; break; } value = w_length; fsg->ep0req->context = received_cbi_adsc; break; } } if (value == -EOPNOTSUPP) 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 value; } /*-------------------------------------------------------------------------*/ /* Ep0 standard request handlers. These always run in_irq. */ static int standard_setup_req(struct fsg_dev *fsg, const struct usb_ctrlrequest *ctrl) { struct usb_request *req = fsg->ep0req; int value = -EOPNOTSUPP; u16 w_index = le16_to_cpu(ctrl->wIndex); u16 w_value = le16_to_cpu(ctrl->wValue); /* Usually this just stores reply data in the pre-allocated ep0 buffer, * but config change events will also reconfigure hardware. */ switch (ctrl->bRequest) { case USB_REQ_GET_DESCRIPTOR: if (ctrl->bRequestType != (USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_DEVICE)) break; switch (w_value >> 8) { case USB_DT_DEVICE: VDBG(fsg, "get device descriptor\n"); value = sizeof device_desc; memcpy(req->buf, &device_desc, value); break; #ifdef CONFIG_USB_GADGET_DUALSPEED case USB_DT_DEVICE_QUALIFIER: VDBG(fsg, "get device qualifier\n"); if (!fsg->gadget->is_dualspeed) break; value = sizeof dev_qualifier; memcpy(req->buf, &dev_qualifier, value); break; case USB_DT_OTHER_SPEED_CONFIG: VDBG(fsg, "get other-speed config descriptor\n"); if (!fsg->gadget->is_dualspeed) break; goto get_config; #endif case USB_DT_CONFIG: VDBG(fsg, "get configuration descriptor\n"); #ifdef CONFIG_USB_GADGET_DUALSPEED get_config: #endif value = populate_config_buf(fsg->gadget, req->buf, w_value >> 8, w_value & 0xff); break; case USB_DT_STRING: VDBG(fsg, "get string descriptor\n"); /* wIndex == language code */ value = usb_gadget_get_string(&stringtab, w_value & 0xff, req->buf); break; } break; /* One config, two speeds */ case USB_REQ_SET_CONFIGURATION: if (ctrl->bRequestType != (USB_DIR_OUT | USB_TYPE_STANDARD | USB_RECIP_DEVICE)) break; VDBG(fsg, "set configuration\n"); if (w_value == CONFIG_VALUE || w_value == 0) { fsg->new_config = w_value; /* Raise an exception to wipe out previous transaction * state (queued bufs, etc) and set the new config. */ raise_exception(fsg, FSG_STATE_CONFIG_CHANGE); value = DELAYED_STATUS; } break; case USB_REQ_GET_CONFIGURATION: if (ctrl->bRequestType != (USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_DEVICE)) break; VDBG(fsg, "get configuration\n"); *(u8 *) req->buf = fsg->config; value = 1; break; case USB_REQ_SET_INTERFACE: if (ctrl->bRequestType != (USB_DIR_OUT| USB_TYPE_STANDARD | USB_RECIP_INTERFACE)) break; if (fsg->config && w_index == 0) { /* Raise an exception to wipe out previous transaction * state (queued bufs, etc) and install the new * interface altsetting. */ raise_exception(fsg, FSG_STATE_INTERFACE_CHANGE); value = DELAYED_STATUS; } break; case USB_REQ_GET_INTERFACE: if (ctrl->bRequestType != (USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_INTERFACE)) break; if (!fsg->config) break; if (w_index != 0) { value = -EDOM; break; } VDBG(fsg, "get interface\n"); *(u8 *) req->buf = 0; value = 1; break; default: VDBG(fsg, "unknown control req %02x.%02x v%04x i%04x l%u\n", ctrl->bRequestType, ctrl->bRequest, w_value, w_index, le16_to_cpu(ctrl->wLength)); } return value; } static int fsg_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl) { struct fsg_dev *fsg = get_gadget_data(gadget); int rc; int w_length = le16_to_cpu(ctrl->wLength); ++fsg->ep0_req_tag; // Record arrival of a new request fsg->ep0req->context = NULL; fsg->ep0req->length = 0; dump_msg(fsg, "ep0-setup", (u8 *) ctrl, sizeof(*ctrl)); if ((ctrl->bRequestType & USB_TYPE_MASK) == USB_TYPE_CLASS) rc = class_setup_req(fsg, ctrl); else rc = standard_setup_req(fsg, ctrl); /* Respond with data/status or defer until later? */ if (rc >= 0 && rc != DELAYED_STATUS) { rc = min(rc, w_length); fsg->ep0req->length = rc; fsg->ep0req->zero = rc < w_length; fsg->ep0req_name = (ctrl->bRequestType & USB_DIR_IN ? "ep0-in" : "ep0-out"); rc = ep0_queue(fsg); } /* Device either stalls (rc < 0) or reports success */ return rc; } /*-------------------------------------------------------------------------*/ /* 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); else if (ep == fsg->intr_in) dump_msg(fsg, "intr-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)) WARN(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 lun *curlun = fsg->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->cmnd[0] == SC_READ_6) lba = (fsg->cmnd[1] << 16) | get_be16(&fsg->cmnd[2]); else { lba = get_be32(&fsg->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->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((unsigned int) amount_left, mod_data.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->next_buffhd_to_fill; while (bh->state != BUF_STATE_EMPTY) { if ((rc = sleep_thread(fsg)) != 0) 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; 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; 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->next_buffhd_to_fill = bh->next; } return -EIO; // No default reply } /*-------------------------------------------------------------------------*/ static int do_write(struct fsg_dev *fsg) { struct lun *curlun = fsg->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; } curlun->filp->f_flags &= ~O_SYNC; // Default is not to wait /* Get the starting Logical Block Address and check that it's * not too big */ if (fsg->cmnd[0] == SC_WRITE_6) lba = (fsg->cmnd[1] << 16) | get_be16(&fsg->cmnd[2]); else { lba = get_be32(&fsg->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->cmnd[1] & ~0x18) != 0) { curlun->sense_data = SS_INVALID_FIELD_IN_CDB; return -EINVAL; } if (fsg->cmnd[1] & 0x08) // FUA curlun->filp->f_flags |= O_SYNC; } 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->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, mod_data.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; 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->next_buffhd_to_fill = bh->next; continue; } /* Write the received data to the backing file */ bh = fsg->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->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; 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; 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 */ if ((rc = sleep_thread(fsg)) != 0) return rc; } return -EIO; // No default reply } /*-------------------------------------------------------------------------*/ /* Sync the file data, don't bother with the metadata. * This code was copied from fs/buffer.c:sys_fdatasync(). */ static int fsync_sub(struct lun *curlun) { struct file *filp = curlun->filp; struct inode *inode; int rc, err; if (curlun->ro || !filp) return 0; if (!filp->f_op->fsync) return -EINVAL; inode = filp->f_dentry->d_inode; mutex_lock(&inode->i_mutex); current->flags |= PF_SYNCWRITE; rc = filemap_fdatawrite(inode->i_mapping); err = filp->f_op->fsync(filp, filp->f_dentry, 1); if (!rc) rc = err; err = filemap_fdatawait(inode->i_mapping); if (!rc) rc = err; current->flags &= ~PF_SYNCWRITE; mutex_unlock(&inode->i_mutex); VLDBG(curlun, "fdatasync -> %d\n", rc); return rc; } static void fsync_all(struct fsg_dev *fsg) { int i; for (i = 0; i < fsg->nluns; ++i) fsync_sub(&fsg->luns[i]); } static int do_synchronize_cache(struct fsg_dev *fsg) { struct lun *curlun = fsg->curlun; int rc; /* We ignore the requested LBA and write out all file's * dirty data buffers. */ rc = fsync_sub(curlun); if (rc) curlun->sense_data = SS_WRITE_ERROR; return 0; } /*-------------------------------------------------------------------------*/ static void invalidate_sub(struct lun *curlun) { struct file *filp = curlun->filp; struct inode *inode = filp->f_dentry->d_inode; unsigned long rc; rc = invalidate_inode_pages(inode->i_mapping); VLDBG(curlun, "invalidate_inode_pages -> %ld\n", rc); } static int do_verify(struct fsg_dev *fsg) { struct lun *curlun = fsg->curlun; u32 lba; u32 verification_length; struct fsg_buffhd *bh = fsg->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_be32(&fsg->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->cmnd[1] & ~0x10) != 0) { curlun->sense_data = SS_INVALID_FIELD_IN_CDB; return -EINVAL; } verification_length = get_be16(&fsg->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 */ 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((unsigned int) amount_left, mod_data.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; 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; break; } file_offset += nread; amount_left -= nread; } return 0; } /*-------------------------------------------------------------------------*/ static int do_inquiry(struct fsg_dev *fsg, struct fsg_buffhd *bh) { u8 *buf = (u8 *) bh->buf; static char vendor_id[] = "Linux "; static char product_id[] = "File-Stor Gadget"; if (!fsg->curlun) { // Unsupported LUNs are okay fsg->bad_lun_okay = 1; memset(buf, 0, 36); buf[0] = 0x7f; // Unsupported, no device-type return 36; } memset(buf, 0, 8); // Non-removable, direct-access device if (mod_data.removable) buf[1] = 0x80; buf[2] = 2; // ANSI SCSI level 2 buf[3] = 2; // SCSI-2 INQUIRY data format buf[4] = 31; // Additional length // No special options sprintf(buf + 8, "%-8s%-16s%04x", vendor_id, product_id, mod_data.release); return 36; } static int do_request_sense(struct fsg_dev *fsg, struct fsg_buffhd *bh) { struct lun *curlun = fsg->curlun; u8 *buf = (u8 *) bh->buf; u32 sd, sdinfo; /* * 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; } else { sd = curlun->sense_data; sdinfo = curlun->sense_data_info; curlun->sense_data = SS_NO_SENSE; curlun->sense_data_info = 0; } memset(buf, 0, 18); buf[0] = 0x80 | 0x70; // Valid, current error buf[2] = SK(sd); put_be32(&buf[3], sdinfo); // 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 lun *curlun = fsg->curlun; u32 lba = get_be32(&fsg->cmnd[2]); int pmi = fsg->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_be32(&buf[0], curlun->num_sectors - 1); // Max logical block put_be32(&buf[4], 512); // Block length return 8; } static int do_mode_sense(struct fsg_dev *fsg, struct fsg_buffhd *bh) { struct lun *curlun = fsg->curlun; int mscmnd = fsg->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->cmnd[1] & ~0x08) != 0) { // Mask away DBD curlun->sense_data = SS_INVALID_FIELD_IN_CDB; return -EINVAL; } pc = fsg->cmnd[2] >> 6; page_code = fsg->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 mod_data.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