| /* Driver for USB Mass Storage compliant devices |
| * SCSI layer glue code |
| * |
| * $Id: scsiglue.c,v 1.26 2002/04/22 03:39:43 mdharm Exp $ |
| * |
| * Current development and maintenance by: |
| * (c) 1999-2002 Matthew Dharm (mdharm-usb@one-eyed-alien.net) |
| * |
| * Developed with the assistance of: |
| * (c) 2000 David L. Brown, Jr. (usb-storage@davidb.org) |
| * (c) 2000 Stephen J. Gowdy (SGowdy@lbl.gov) |
| * |
| * Initial work by: |
| * (c) 1999 Michael Gee (michael@linuxspecific.com) |
| * |
| * This driver is based on the 'USB Mass Storage Class' document. This |
| * describes in detail the protocol used to communicate with such |
| * devices. Clearly, the designers had SCSI and ATAPI commands in |
| * mind when they created this document. The commands are all very |
| * similar to commands in the SCSI-II and ATAPI specifications. |
| * |
| * It is important to note that in a number of cases this class |
| * exhibits class-specific exemptions from the USB specification. |
| * Notably the usage of NAK, STALL and ACK differs from the norm, in |
| * that they are used to communicate wait, failed and OK on commands. |
| * |
| * Also, for certain devices, the interrupt endpoint is used to convey |
| * status of a command. |
| * |
| * Please see http://www.one-eyed-alien.net/~mdharm/linux-usb for more |
| * information about this driver. |
| * |
| * 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, or (at your option) any |
| * later version. |
| * |
| * This program is distributed in the hope that it will be useful, but |
| * WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License along |
| * with this program; if not, write to the Free Software Foundation, Inc., |
| * 675 Mass Ave, Cambridge, MA 02139, USA. |
| */ |
| |
| #include <linux/slab.h> |
| #include <linux/module.h> |
| |
| #include <scsi/scsi.h> |
| #include <scsi/scsi_cmnd.h> |
| #include <scsi/scsi_devinfo.h> |
| #include <scsi/scsi_device.h> |
| #include <scsi/scsi_eh.h> |
| |
| #include "usb.h" |
| #include "scsiglue.h" |
| #include "debug.h" |
| #include "transport.h" |
| #include "protocol.h" |
| |
| /*********************************************************************** |
| * Host functions |
| ***********************************************************************/ |
| |
| static const char* host_info(struct Scsi_Host *host) |
| { |
| return "SCSI emulation for USB Mass Storage devices"; |
| } |
| |
| static int slave_alloc (struct scsi_device *sdev) |
| { |
| /* |
| * Set the INQUIRY transfer length to 36. We don't use any of |
| * the extra data and many devices choke if asked for more or |
| * less than 36 bytes. |
| */ |
| sdev->inquiry_len = 36; |
| return 0; |
| } |
| |
| static int slave_configure(struct scsi_device *sdev) |
| { |
| struct us_data *us = host_to_us(sdev->host); |
| |
| /* Scatter-gather buffers (all but the last) must have a length |
| * divisible by the bulk maxpacket size. Otherwise a data packet |
| * would end up being short, causing a premature end to the data |
| * transfer. Since high-speed bulk pipes have a maxpacket size |
| * of 512, we'll use that as the scsi device queue's DMA alignment |
| * mask. Guaranteeing proper alignment of the first buffer will |
| * have the desired effect because, except at the beginning and |
| * the end, scatter-gather buffers follow page boundaries. */ |
| blk_queue_dma_alignment(sdev->request_queue, (512 - 1)); |
| |
| /* Set the SCSI level to at least 2. We'll leave it at 3 if that's |
| * what is originally reported. We need this to avoid confusing |
| * the SCSI layer with devices that report 0 or 1, but need 10-byte |
| * commands (ala ATAPI devices behind certain bridges, or devices |
| * which simply have broken INQUIRY data). |
| * |
| * NOTE: This means /dev/sg programs (ala cdrecord) will get the |
| * actual information. This seems to be the preference for |
| * programs like that. |
| * |
| * NOTE: This also means that /proc/scsi/scsi and sysfs may report |
| * the actual value or the modified one, depending on where the |
| * data comes from. |
| */ |
| if (sdev->scsi_level < SCSI_2) |
| sdev->scsi_level = SCSI_2; |
| |
| /* According to the technical support people at Genesys Logic, |
| * devices using their chips have problems transferring more than |
| * 32 KB at a time. In practice people have found that 64 KB |
| * works okay and that's what Windows does. But we'll be |
| * conservative; people can always use the sysfs interface to |
| * increase max_sectors. */ |
| if (le16_to_cpu(us->pusb_dev->descriptor.idVendor) == USB_VENDOR_ID_GENESYS && |
| sdev->request_queue->max_sectors > 64) |
| blk_queue_max_sectors(sdev->request_queue, 64); |
| |
| /* We can't put these settings in slave_alloc() because that gets |
| * called before the device type is known. Consequently these |
| * settings can't be overridden via the scsi devinfo mechanism. */ |
| if (sdev->type == TYPE_DISK) { |
| |
| /* Disk-type devices use MODE SENSE(6) if the protocol |
| * (SubClass) is Transparent SCSI, otherwise they use |
| * MODE SENSE(10). */ |
| if (us->subclass != US_SC_SCSI) |
| sdev->use_10_for_ms = 1; |
| |
| /* Many disks only accept MODE SENSE transfer lengths of |
| * 192 bytes (that's what Windows uses). */ |
| sdev->use_192_bytes_for_3f = 1; |
| |
| /* Some devices don't like MODE SENSE with page=0x3f, |
| * which is the command used for checking if a device |
| * is write-protected. Now that we tell the sd driver |
| * to do a 192-byte transfer with this command the |
| * majority of devices work fine, but a few still can't |
| * handle it. The sd driver will simply assume those |
| * devices are write-enabled. */ |
| if (us->flags & US_FL_NO_WP_DETECT) |
| sdev->skip_ms_page_3f = 1; |
| |
| /* A number of devices have problems with MODE SENSE for |
| * page x08, so we will skip it. */ |
| sdev->skip_ms_page_8 = 1; |
| |
| /* Some disks return the total number of blocks in response |
| * to READ CAPACITY rather than the highest block number. |
| * If this device makes that mistake, tell the sd driver. */ |
| if (us->flags & US_FL_FIX_CAPACITY) |
| sdev->fix_capacity = 1; |
| } else { |
| |
| /* Non-disk-type devices don't need to blacklist any pages |
| * or to force 192-byte transfer lengths for MODE SENSE. |
| * But they do need to use MODE SENSE(10). */ |
| sdev->use_10_for_ms = 1; |
| } |
| |
| /* Some devices choke when they receive a PREVENT-ALLOW MEDIUM |
| * REMOVAL command, so suppress those commands. */ |
| if (us->flags & US_FL_NOT_LOCKABLE) |
| sdev->lockable = 0; |
| |
| /* this is to satisfy the compiler, tho I don't think the |
| * return code is ever checked anywhere. */ |
| return 0; |
| } |
| |
| /* queue a command */ |
| /* This is always called with scsi_lock(host) held */ |
| static int queuecommand(struct scsi_cmnd *srb, |
| void (*done)(struct scsi_cmnd *)) |
| { |
| struct us_data *us = host_to_us(srb->device->host); |
| |
| US_DEBUGP("%s called\n", __FUNCTION__); |
| |
| /* check for state-transition errors */ |
| if (us->srb != NULL) { |
| printk(KERN_ERR USB_STORAGE "Error in %s: us->srb = %p\n", |
| __FUNCTION__, us->srb); |
| return SCSI_MLQUEUE_HOST_BUSY; |
| } |
| |
| /* fail the command if we are disconnecting */ |
| if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) { |
| US_DEBUGP("Fail command during disconnect\n"); |
| srb->result = DID_NO_CONNECT << 16; |
| done(srb); |
| return 0; |
| } |
| |
| /* enqueue the command and wake up the control thread */ |
| srb->scsi_done = done; |
| us->srb = srb; |
| up(&(us->sema)); |
| |
| return 0; |
| } |
| |
| /*********************************************************************** |
| * Error handling functions |
| ***********************************************************************/ |
| |
| /* Command timeout and abort */ |
| /* This is always called with scsi_lock(host) held */ |
| static int command_abort(struct scsi_cmnd *srb) |
| { |
| struct us_data *us = host_to_us(srb->device->host); |
| |
| US_DEBUGP("%s called\n", __FUNCTION__); |
| |
| /* Is this command still active? */ |
| if (us->srb != srb) { |
| US_DEBUGP ("-- nothing to abort\n"); |
| return FAILED; |
| } |
| |
| /* Set the TIMED_OUT bit. Also set the ABORTING bit, but only if |
| * a device reset isn't already in progress (to avoid interfering |
| * with the reset). To prevent races with auto-reset, we must |
| * stop any ongoing USB transfers while still holding the host |
| * lock. */ |
| set_bit(US_FLIDX_TIMED_OUT, &us->flags); |
| if (!test_bit(US_FLIDX_RESETTING, &us->flags)) { |
| set_bit(US_FLIDX_ABORTING, &us->flags); |
| usb_stor_stop_transport(us); |
| } |
| |
| /* Wait for the aborted command to finish */ |
| wait_for_completion(&us->notify); |
| |
| /* Reacquire the lock and allow USB transfers to resume */ |
| clear_bit(US_FLIDX_ABORTING, &us->flags); |
| clear_bit(US_FLIDX_TIMED_OUT, &us->flags); |
| return SUCCESS; |
| } |
| |
| /* This invokes the transport reset mechanism to reset the state of the |
| * device */ |
| /* This is always called with scsi_lock(host) held */ |
| static int device_reset(struct scsi_cmnd *srb) |
| { |
| struct us_data *us = host_to_us(srb->device->host); |
| int result; |
| |
| US_DEBUGP("%s called\n", __FUNCTION__); |
| |
| /* lock the device pointers and do the reset */ |
| down(&(us->dev_semaphore)); |
| if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) { |
| result = FAILED; |
| US_DEBUGP("No reset during disconnect\n"); |
| } else |
| result = us->transport_reset(us); |
| up(&(us->dev_semaphore)); |
| |
| return result; |
| } |
| |
| /* This resets the device's USB port. */ |
| /* It refuses to work if there's more than one interface in |
| * the device, so that other users are not affected. */ |
| /* This is always called with scsi_lock(host) held */ |
| static int bus_reset(struct scsi_cmnd *srb) |
| { |
| struct us_data *us = host_to_us(srb->device->host); |
| int result, rc; |
| |
| US_DEBUGP("%s called\n", __FUNCTION__); |
| |
| /* The USB subsystem doesn't handle synchronisation between |
| * a device's several drivers. Therefore we reset only devices |
| * with just one interface, which we of course own. */ |
| |
| down(&(us->dev_semaphore)); |
| if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) { |
| result = -EIO; |
| US_DEBUGP("No reset during disconnect\n"); |
| } else if (us->pusb_dev->actconfig->desc.bNumInterfaces != 1) { |
| result = -EBUSY; |
| US_DEBUGP("Refusing to reset a multi-interface device\n"); |
| } else { |
| rc = usb_lock_device_for_reset(us->pusb_dev, us->pusb_intf); |
| if (rc < 0) { |
| US_DEBUGP("unable to lock device for reset: %d\n", rc); |
| result = rc; |
| } else { |
| result = usb_reset_device(us->pusb_dev); |
| if (rc) |
| usb_unlock_device(us->pusb_dev); |
| US_DEBUGP("usb_reset_device returns %d\n", result); |
| } |
| } |
| up(&(us->dev_semaphore)); |
| |
| /* lock the host for the return */ |
| return result < 0 ? FAILED : SUCCESS; |
| } |
| |
| /* Report a driver-initiated device reset to the SCSI layer. |
| * Calling this for a SCSI-initiated reset is unnecessary but harmless. |
| * The caller must own the SCSI host lock. */ |
| void usb_stor_report_device_reset(struct us_data *us) |
| { |
| int i; |
| struct Scsi_Host *host = us_to_host(us); |
| |
| scsi_report_device_reset(host, 0, 0); |
| if (us->flags & US_FL_SCM_MULT_TARG) { |
| for (i = 1; i < host->max_id; ++i) |
| scsi_report_device_reset(host, 0, i); |
| } |
| } |
| |
| /*********************************************************************** |
| * /proc/scsi/ functions |
| ***********************************************************************/ |
| |
| /* we use this macro to help us write into the buffer */ |
| #undef SPRINTF |
| #define SPRINTF(args...) \ |
| do { if (pos < buffer+length) pos += sprintf(pos, ## args); } while (0) |
| |
| static int proc_info (struct Scsi_Host *host, char *buffer, |
| char **start, off_t offset, int length, int inout) |
| { |
| struct us_data *us = host_to_us(host); |
| char *pos = buffer; |
| const char *string; |
| |
| /* if someone is sending us data, just throw it away */ |
| if (inout) |
| return length; |
| |
| /* print the controller name */ |
| SPRINTF(" Host scsi%d: usb-storage\n", host->host_no); |
| |
| /* print product, vendor, and serial number strings */ |
| if (us->pusb_dev->manufacturer) |
| string = us->pusb_dev->manufacturer; |
| else if (us->unusual_dev->vendorName) |
| string = us->unusual_dev->vendorName; |
| else |
| string = "Unknown"; |
| SPRINTF(" Vendor: %s\n", string); |
| if (us->pusb_dev->product) |
| string = us->pusb_dev->product; |
| else if (us->unusual_dev->productName) |
| string = us->unusual_dev->productName; |
| else |
| string = "Unknown"; |
| SPRINTF(" Product: %s\n", string); |
| if (us->pusb_dev->serial) |
| string = us->pusb_dev->serial; |
| else |
| string = "None"; |
| SPRINTF("Serial Number: %s\n", string); |
| |
| /* show the protocol and transport */ |
| SPRINTF(" Protocol: %s\n", us->protocol_name); |
| SPRINTF(" Transport: %s\n", us->transport_name); |
| |
| /* show the device flags */ |
| if (pos < buffer + length) { |
| pos += sprintf(pos, " Quirks:"); |
| |
| #define US_FLAG(name, value) \ |
| if (us->flags & value) pos += sprintf(pos, " " #name); |
| US_DO_ALL_FLAGS |
| #undef US_FLAG |
| |
| *(pos++) = '\n'; |
| } |
| |
| /* |
| * Calculate start of next buffer, and return value. |
| */ |
| *start = buffer + offset; |
| |
| if ((pos - buffer) < offset) |
| return (0); |
| else if ((pos - buffer - offset) < length) |
| return (pos - buffer - offset); |
| else |
| return (length); |
| } |
| |
| /*********************************************************************** |
| * Sysfs interface |
| ***********************************************************************/ |
| |
| /* Output routine for the sysfs max_sectors file */ |
| static ssize_t show_max_sectors(struct device *dev, char *buf) |
| { |
| struct scsi_device *sdev = to_scsi_device(dev); |
| |
| return sprintf(buf, "%u\n", sdev->request_queue->max_sectors); |
| } |
| |
| /* Input routine for the sysfs max_sectors file */ |
| static ssize_t store_max_sectors(struct device *dev, const char *buf, |
| size_t count) |
| { |
| struct scsi_device *sdev = to_scsi_device(dev); |
| unsigned short ms; |
| |
| if (sscanf(buf, "%hu", &ms) > 0 && ms <= SCSI_DEFAULT_MAX_SECTORS) { |
| blk_queue_max_sectors(sdev->request_queue, ms); |
| return strlen(buf); |
| } |
| return -EINVAL; |
| } |
| |
| static DEVICE_ATTR(max_sectors, S_IRUGO | S_IWUSR, show_max_sectors, |
| store_max_sectors); |
| |
| static struct device_attribute *sysfs_device_attr_list[] = { |
| &dev_attr_max_sectors, |
| NULL, |
| }; |
| |
| /* |
| * this defines our host template, with which we'll allocate hosts |
| */ |
| |
| struct scsi_host_template usb_stor_host_template = { |
| /* basic userland interface stuff */ |
| .name = "usb-storage", |
| .proc_name = "usb-storage", |
| .proc_info = proc_info, |
| .info = host_info, |
| |
| /* command interface -- queued only */ |
| .queuecommand = queuecommand, |
| |
| /* error and abort handlers */ |
| .eh_abort_handler = command_abort, |
| .eh_device_reset_handler = device_reset, |
| .eh_bus_reset_handler = bus_reset, |
| |
| /* queue commands only, only one command per LUN */ |
| .can_queue = 1, |
| .cmd_per_lun = 1, |
| |
| /* unknown initiator id */ |
| .this_id = -1, |
| |
| .slave_alloc = slave_alloc, |
| .slave_configure = slave_configure, |
| |
| /* lots of sg segments can be handled */ |
| .sg_tablesize = SG_ALL, |
| |
| /* limit the total size of a transfer to 120 KB */ |
| .max_sectors = 240, |
| |
| /* merge commands... this seems to help performance, but |
| * periodically someone should test to see which setting is more |
| * optimal. |
| */ |
| .use_clustering = 1, |
| |
| /* emulated HBA */ |
| .emulated = 1, |
| |
| /* we do our own delay after a device or bus reset */ |
| .skip_settle_delay = 1, |
| |
| /* sysfs device attributes */ |
| .sdev_attrs = sysfs_device_attr_list, |
| |
| /* module management */ |
| .module = THIS_MODULE |
| }; |
| |
| /* To Report "Illegal Request: Invalid Field in CDB */ |
| unsigned char usb_stor_sense_invalidCDB[18] = { |
| [0] = 0x70, /* current error */ |
| [2] = ILLEGAL_REQUEST, /* Illegal Request = 0x05 */ |
| [7] = 0x0a, /* additional length */ |
| [12] = 0x24 /* Invalid Field in CDB */ |
| }; |
| |