diff options
Diffstat (limited to 'drivers/usb/gadget/function/storage_common.c')
| -rw-r--r-- | drivers/usb/gadget/function/storage_common.c | 504 |
1 files changed, 504 insertions, 0 deletions
diff --git a/drivers/usb/gadget/function/storage_common.c b/drivers/usb/gadget/function/storage_common.c new file mode 100644 index 000000000000..648f9e489b39 --- /dev/null +++ b/drivers/usb/gadget/function/storage_common.c @@ -0,0 +1,504 @@ +/* + * storage_common.c -- Common definitions for mass storage functionality + * + * Copyright (C) 2003-2008 Alan Stern + * Copyeight (C) 2009 Samsung Electronics + * Author: Michal Nazarewicz ([email protected]) + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +/* + * This file requires the following identifiers used in USB strings to + * be defined (each of type pointer to char): + * - fsg_string_interface -- name of the interface + */ + +/* + * When USB_GADGET_DEBUG_FILES is defined the module param num_buffers + * sets the number of pipeline buffers (length of the fsg_buffhd array). + * The valid range of num_buffers is: num >= 2 && num <= 4. + */ + +#include <linux/module.h> +#include <linux/blkdev.h> +#include <linux/file.h> +#include <linux/fs.h> +#include <linux/usb/composite.h> + +#include "storage_common.h" + +/* There is only one interface. */ + +struct usb_interface_descriptor fsg_intf_desc = { + .bLength = sizeof fsg_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 = FSG_STRING_INTERFACE, +}; +EXPORT_SYMBOL_GPL(fsg_intf_desc); + +/* + * Three full-speed endpoint descriptors: bulk-in, bulk-out, and + * interrupt-in. + */ + +struct usb_endpoint_descriptor fsg_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 */ +}; +EXPORT_SYMBOL_GPL(fsg_fs_bulk_in_desc); + +struct usb_endpoint_descriptor fsg_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 */ +}; +EXPORT_SYMBOL_GPL(fsg_fs_bulk_out_desc); + +struct usb_descriptor_header *fsg_fs_function[] = { + (struct usb_descriptor_header *) &fsg_intf_desc, + (struct usb_descriptor_header *) &fsg_fs_bulk_in_desc, + (struct usb_descriptor_header *) &fsg_fs_bulk_out_desc, + NULL, +}; +EXPORT_SYMBOL_GPL(fsg_fs_function); + + +/* + * 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 configuration descriptor. + */ +struct usb_endpoint_descriptor fsg_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 = cpu_to_le16(512), +}; +EXPORT_SYMBOL_GPL(fsg_hs_bulk_in_desc); + +struct usb_endpoint_descriptor fsg_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 = cpu_to_le16(512), + .bInterval = 1, /* NAK every 1 uframe */ +}; +EXPORT_SYMBOL_GPL(fsg_hs_bulk_out_desc); + + +struct usb_descriptor_header *fsg_hs_function[] = { + (struct usb_descriptor_header *) &fsg_intf_desc, + (struct usb_descriptor_header *) &fsg_hs_bulk_in_desc, + (struct usb_descriptor_header *) &fsg_hs_bulk_out_desc, + NULL, +}; +EXPORT_SYMBOL_GPL(fsg_hs_function); + +struct usb_endpoint_descriptor fsg_ss_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 = cpu_to_le16(1024), +}; +EXPORT_SYMBOL_GPL(fsg_ss_bulk_in_desc); + +struct usb_ss_ep_comp_descriptor fsg_ss_bulk_in_comp_desc = { + .bLength = sizeof(fsg_ss_bulk_in_comp_desc), + .bDescriptorType = USB_DT_SS_ENDPOINT_COMP, + + /*.bMaxBurst = DYNAMIC, */ +}; +EXPORT_SYMBOL_GPL(fsg_ss_bulk_in_comp_desc); + +struct usb_endpoint_descriptor fsg_ss_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 = cpu_to_le16(1024), +}; +EXPORT_SYMBOL_GPL(fsg_ss_bulk_out_desc); + +struct usb_ss_ep_comp_descriptor fsg_ss_bulk_out_comp_desc = { + .bLength = sizeof(fsg_ss_bulk_in_comp_desc), + .bDescriptorType = USB_DT_SS_ENDPOINT_COMP, + + /*.bMaxBurst = DYNAMIC, */ +}; +EXPORT_SYMBOL_GPL(fsg_ss_bulk_out_comp_desc); + +struct usb_descriptor_header *fsg_ss_function[] = { + (struct usb_descriptor_header *) &fsg_intf_desc, + (struct usb_descriptor_header *) &fsg_ss_bulk_in_desc, + (struct usb_descriptor_header *) &fsg_ss_bulk_in_comp_desc, + (struct usb_descriptor_header *) &fsg_ss_bulk_out_desc, + (struct usb_descriptor_header *) &fsg_ss_bulk_out_comp_desc, + NULL, +}; +EXPORT_SYMBOL_GPL(fsg_ss_function); + + + /*-------------------------------------------------------------------------*/ + +/* + * If the next two routines are called while the gadget is registered, + * the caller must own fsg->filesem for writing. + */ + +void fsg_lun_close(struct fsg_lun *curlun) +{ + if (curlun->filp) { + LDBG(curlun, "close backing file\n"); + fput(curlun->filp); + curlun->filp = NULL; + } +} +EXPORT_SYMBOL_GPL(fsg_lun_close); + +int fsg_lun_open(struct fsg_lun *curlun, const char *filename) +{ + int ro; + struct file *filp = NULL; + int rc = -EINVAL; + struct inode *inode = NULL; + loff_t size; + loff_t num_sectors; + loff_t min_sectors; + unsigned int blkbits; + unsigned int blksize; + + /* R/W if we can, R/O if we must */ + ro = curlun->initially_ro; + if (!ro) { + filp = filp_open(filename, O_RDWR | O_LARGEFILE, 0); + if (PTR_ERR(filp) == -EROFS || PTR_ERR(filp) == -EACCES) + ro = 1; + } + if (ro) + filp = filp_open(filename, O_RDONLY | O_LARGEFILE, 0); + if (IS_ERR(filp)) { + LINFO(curlun, "unable to open backing file: %s\n", filename); + return PTR_ERR(filp); + } + + if (!(filp->f_mode & FMODE_WRITE)) + ro = 1; + + inode = file_inode(filp); + if ((!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode))) { + LINFO(curlun, "invalid file type: %s\n", filename); + goto out; + } + + /* + * If we can't read the file, it's no good. + * If we can't write the file, use it read-only. + */ + if (!(filp->f_mode & FMODE_CAN_READ)) { + LINFO(curlun, "file not readable: %s\n", filename); + goto out; + } + if (!(filp->f_mode & FMODE_CAN_WRITE)) + ro = 1; + + size = i_size_read(inode->i_mapping->host); + if (size < 0) { + LINFO(curlun, "unable to find file size: %s\n", filename); + rc = (int) size; + goto out; + } + + if (curlun->cdrom) { + blksize = 2048; + blkbits = 11; + } else if (inode->i_bdev) { + blksize = bdev_logical_block_size(inode->i_bdev); + blkbits = blksize_bits(blksize); + } else { + blksize = 512; + blkbits = 9; + } + + num_sectors = size >> blkbits; /* File size in logic-block-size blocks */ + min_sectors = 1; + if (curlun->cdrom) { + min_sectors = 300; /* Smallest track is 300 frames */ + if (num_sectors >= 256*60*75) { + num_sectors = 256*60*75 - 1; + LINFO(curlun, "file too big: %s\n", filename); + LINFO(curlun, "using only first %d blocks\n", + (int) num_sectors); + } + } + if (num_sectors < min_sectors) { + LINFO(curlun, "file too small: %s\n", filename); + rc = -ETOOSMALL; + goto out; + } + + if (fsg_lun_is_open(curlun)) + fsg_lun_close(curlun); + + curlun->blksize = blksize; + curlun->blkbits = blkbits; + curlun->ro = ro; + curlun->filp = filp; + curlun->file_length = size; + curlun->num_sectors = num_sectors; + LDBG(curlun, "open backing file: %s\n", filename); + return 0; + +out: + fput(filp); + return rc; +} +EXPORT_SYMBOL_GPL(fsg_lun_open); + + +/*-------------------------------------------------------------------------*/ + +/* + * Sync the file data, don't bother with the metadata. + * This code was copied from fs/buffer.c:sys_fdatasync(). + */ +int fsg_lun_fsync_sub(struct fsg_lun *curlun) +{ + struct file *filp = curlun->filp; + + if (curlun->ro || !filp) + return 0; + return vfs_fsync(filp, 1); +} +EXPORT_SYMBOL_GPL(fsg_lun_fsync_sub); + +void store_cdrom_address(u8 *dest, int msf, u32 addr) +{ + if (msf) { + /* Convert to Minutes-Seconds-Frames */ + addr >>= 2; /* Convert to 2048-byte frames */ + addr += 2*75; /* Lead-in occupies 2 seconds */ + dest[3] = addr % 75; /* Frames */ + addr /= 75; + dest[2] = addr % 60; /* Seconds */ + addr /= 60; + dest[1] = addr; /* Minutes */ + dest[0] = 0; /* Reserved */ + } else { + /* Absolute sector */ + put_unaligned_be32(addr, dest); + } +} +EXPORT_SYMBOL_GPL(store_cdrom_address); + +/*-------------------------------------------------------------------------*/ + + +ssize_t fsg_show_ro(struct fsg_lun *curlun, char *buf) +{ + return sprintf(buf, "%d\n", fsg_lun_is_open(curlun) + ? curlun->ro + : curlun->initially_ro); +} +EXPORT_SYMBOL_GPL(fsg_show_ro); + +ssize_t fsg_show_nofua(struct fsg_lun *curlun, char *buf) +{ + return sprintf(buf, "%u\n", curlun->nofua); +} +EXPORT_SYMBOL_GPL(fsg_show_nofua); + +ssize_t fsg_show_file(struct fsg_lun *curlun, struct rw_semaphore *filesem, + char *buf) +{ + char *p; + ssize_t rc; + + down_read(filesem); + if (fsg_lun_is_open(curlun)) { /* Get the complete pathname */ + p = d_path(&curlun->filp->f_path, buf, PAGE_SIZE - 1); + if (IS_ERR(p)) + rc = PTR_ERR(p); + else { + rc = strlen(p); + memmove(buf, p, rc); + buf[rc] = '\n'; /* Add a newline */ + buf[++rc] = 0; + } + } else { /* No file, return 0 bytes */ + *buf = 0; + rc = 0; + } + up_read(filesem); + return rc; +} +EXPORT_SYMBOL_GPL(fsg_show_file); + +ssize_t fsg_show_cdrom(struct fsg_lun *curlun, char *buf) +{ + return sprintf(buf, "%u\n", curlun->cdrom); +} +EXPORT_SYMBOL_GPL(fsg_show_cdrom); + +ssize_t fsg_show_removable(struct fsg_lun *curlun, char *buf) +{ + return sprintf(buf, "%u\n", curlun->removable); +} +EXPORT_SYMBOL_GPL(fsg_show_removable); + +/* + * The caller must hold fsg->filesem for reading when calling this function. + */ +static ssize_t _fsg_store_ro(struct fsg_lun *curlun, bool ro) +{ + if (fsg_lun_is_open(curlun)) { + LDBG(curlun, "read-only status change prevented\n"); + return -EBUSY; + } + + curlun->ro = ro; + curlun->initially_ro = ro; + LDBG(curlun, "read-only status set to %d\n", curlun->ro); + + return 0; +} + +ssize_t fsg_store_ro(struct fsg_lun *curlun, struct rw_semaphore *filesem, + const char *buf, size_t count) +{ + ssize_t rc; + bool ro; + + rc = strtobool(buf, &ro); + if (rc) + return rc; + + /* + * Allow the write-enable status to change only while the + * backing file is closed. + */ + down_read(filesem); + rc = _fsg_store_ro(curlun, ro); + if (!rc) + rc = count; + up_read(filesem); + + return rc; +} +EXPORT_SYMBOL_GPL(fsg_store_ro); + +ssize_t fsg_store_nofua(struct fsg_lun *curlun, const char *buf, size_t count) +{ + bool nofua; + int ret; + + ret = strtobool(buf, &nofua); + if (ret) + return ret; + + /* Sync data when switching from async mode to sync */ + if (!nofua && curlun->nofua) + fsg_lun_fsync_sub(curlun); + + curlun->nofua = nofua; + + return count; +} +EXPORT_SYMBOL_GPL(fsg_store_nofua); + +ssize_t fsg_store_file(struct fsg_lun *curlun, struct rw_semaphore *filesem, + const char *buf, size_t count) +{ + int rc = 0; + + if (curlun->prevent_medium_removal && fsg_lun_is_open(curlun)) { + LDBG(curlun, "eject attempt prevented\n"); + return -EBUSY; /* "Door is locked" */ + } + + /* Remove a trailing newline */ + if (count > 0 && buf[count-1] == '\n') + ((char *) buf)[count-1] = 0; /* Ugh! */ + + /* Load new medium */ + down_write(filesem); + if (count > 0 && buf[0]) { + /* fsg_lun_open() will close existing file if any. */ + rc = fsg_lun_open(curlun, buf); + if (rc == 0) + curlun->unit_attention_data = + SS_NOT_READY_TO_READY_TRANSITION; + } else if (fsg_lun_is_open(curlun)) { + fsg_lun_close(curlun); + curlun->unit_attention_data = SS_MEDIUM_NOT_PRESENT; + } + up_write(filesem); + return (rc < 0 ? rc : count); +} +EXPORT_SYMBOL_GPL(fsg_store_file); + +ssize_t fsg_store_cdrom(struct fsg_lun *curlun, struct rw_semaphore *filesem, + const char *buf, size_t count) +{ + bool cdrom; + int ret; + + ret = strtobool(buf, &cdrom); + if (ret) + return ret; + + down_read(filesem); + ret = cdrom ? _fsg_store_ro(curlun, true) : 0; + + if (!ret) { + curlun->cdrom = cdrom; + ret = count; + } + up_read(filesem); + + return ret; +} +EXPORT_SYMBOL_GPL(fsg_store_cdrom); + +ssize_t fsg_store_removable(struct fsg_lun *curlun, const char *buf, + size_t count) +{ + bool removable; + int ret; + + ret = strtobool(buf, &removable); + if (ret) + return ret; + + curlun->removable = removable; + + return count; +} +EXPORT_SYMBOL_GPL(fsg_store_removable); + +MODULE_LICENSE("GPL"); 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