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path: root/drivers/usb/storage/scsiglue.c
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diff --git a/drivers/usb/storage/scsiglue.c b/drivers/usb/storage/scsiglue.c
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+/* 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);
+ }
+ scsi_unlock(us_to_host(us));
+
+ /* Wait for the aborted command to finish */
+ wait_for_completion(&us->notify);
+
+ /* Reacquire the lock and allow USB transfers to resume */
+ scsi_lock(us_to_host(us));
+ 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__);
+
+ scsi_unlock(us_to_host(us));
+
+ /* 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));
+
+ /* lock the host for the return */
+ scsi_lock(us_to_host(us));
+ 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__);
+
+ scsi_unlock(us_to_host(us));
+
+ /* 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 */
+ scsi_lock(us_to_host(us));
+ 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 */
+};
+