Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1293 insertions, 0 deletions

diff --git a/drivers/usb/storage/uas.c b/drivers/usb/storage/uas.c
new file mode 100644
index 000000000..1fc7143c3
--- /dev/null
+++ b/drivers/usb/storage/uas.c
@@ -0,0 +1,1293 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * USB Attached SCSI
+ * Note that this is not the same as the USB Mass Storage driver
+ *
+ * Copyright Hans de Goede <hdegoede@redhat.com> for Red Hat, Inc. 2013 - 2016
+ * Copyright Matthew Wilcox for Intel Corp, 2010
+ * Copyright Sarah Sharp for Intel Corp, 2010
+ */
+
+#include <linux/blkdev.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/usb.h>
+#include <linux/usb_usual.h>
+#include <linux/usb/hcd.h>
+#include <linux/usb/storage.h>
+#include <linux/usb/uas.h>
+
+#include <scsi/scsi.h>
+#include <scsi/scsi_eh.h>
+#include <scsi/scsi_dbg.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi_tcq.h>
+
+#include "uas-detect.h"
+#include "scsiglue.h"
+
+#define MAX_CMNDS 256
+
+struct uas_dev_info {
+	struct usb_interface *intf;
+	struct usb_device *udev;
+	struct usb_anchor cmd_urbs;
+	struct usb_anchor sense_urbs;
+	struct usb_anchor data_urbs;
+	unsigned long flags;
+	int qdepth, resetting;
+	unsigned cmd_pipe, status_pipe, data_in_pipe, data_out_pipe;
+	unsigned use_streams:1;
+	unsigned shutdown:1;
+	struct scsi_cmnd *cmnd[MAX_CMNDS];
+	spinlock_t lock;
+	struct work_struct work;
+	struct work_struct scan_work;      /* for async scanning */
+};
+
+enum {
+	SUBMIT_STATUS_URB	= BIT(1),
+	ALLOC_DATA_IN_URB	= BIT(2),
+	SUBMIT_DATA_IN_URB	= BIT(3),
+	ALLOC_DATA_OUT_URB	= BIT(4),
+	SUBMIT_DATA_OUT_URB	= BIT(5),
+	ALLOC_CMD_URB		= BIT(6),
+	SUBMIT_CMD_URB		= BIT(7),
+	COMMAND_INFLIGHT        = BIT(8),
+	DATA_IN_URB_INFLIGHT    = BIT(9),
+	DATA_OUT_URB_INFLIGHT   = BIT(10),
+	COMMAND_ABORTED         = BIT(11),
+	IS_IN_WORK_LIST         = BIT(12),
+};
+
+/* Overrides scsi_pointer */
+struct uas_cmd_info {
+	unsigned int state;
+	unsigned int uas_tag;
+	struct urb *cmd_urb;
+	struct urb *data_in_urb;
+	struct urb *data_out_urb;
+};
+
+/* I hate forward declarations, but I actually have a loop */
+static int uas_submit_urbs(struct scsi_cmnd *cmnd,
+				struct uas_dev_info *devinfo);
+static void uas_do_work(struct work_struct *work);
+static int uas_try_complete(struct scsi_cmnd *cmnd, const char *caller);
+static void uas_free_streams(struct uas_dev_info *devinfo);
+static void uas_log_cmd_state(struct scsi_cmnd *cmnd, const char *prefix,
+				int status);
+
+/*
+ * This driver needs its own workqueue, as we need to control memory allocation.
+ *
+ * In the course of error handling and power management uas_wait_for_pending_cmnds()
+ * needs to flush pending work items. In these contexts we cannot allocate memory
+ * by doing block IO as we would deadlock. For the same reason we cannot wait
+ * for anything allocating memory not heeding these constraints.
+ *
+ * So we have to control all work items that can be on the workqueue we flush.
+ * Hence we cannot share a queue and need our own.
+ */
+static struct workqueue_struct *workqueue;
+
+static void uas_do_work(struct work_struct *work)
+{
+	struct uas_dev_info *devinfo =
+		container_of(work, struct uas_dev_info, work);
+	struct uas_cmd_info *cmdinfo;
+	struct scsi_cmnd *cmnd;
+	unsigned long flags;
+	int i, err;
+
+	spin_lock_irqsave(&devinfo->lock, flags);
+
+	if (devinfo->resetting)
+		goto out;
+
+	for (i = 0; i < devinfo->qdepth; i++) {
+		if (!devinfo->cmnd[i])
+			continue;
+
+		cmnd = devinfo->cmnd[i];
+		cmdinfo = (void *)&cmnd->SCp;
+
+		if (!(cmdinfo->state & IS_IN_WORK_LIST))
+			continue;
+
+		err = uas_submit_urbs(cmnd, cmnd->device->hostdata);
+		if (!err)
+			cmdinfo->state &= ~IS_IN_WORK_LIST;
+		else
+			queue_work(workqueue, &devinfo->work);
+	}
+out:
+	spin_unlock_irqrestore(&devinfo->lock, flags);
+}
+
+static void uas_scan_work(struct work_struct *work)
+{
+	struct uas_dev_info *devinfo =
+		container_of(work, struct uas_dev_info, scan_work);
+	struct Scsi_Host *shost = usb_get_intfdata(devinfo->intf);
+
+	dev_dbg(&devinfo->intf->dev, "starting scan\n");
+	scsi_scan_host(shost);
+	dev_dbg(&devinfo->intf->dev, "scan complete\n");
+}
+
+static void uas_add_work(struct uas_cmd_info *cmdinfo)
+{
+	struct scsi_pointer *scp = (void *)cmdinfo;
+	struct scsi_cmnd *cmnd = container_of(scp, struct scsi_cmnd, SCp);
+	struct uas_dev_info *devinfo = cmnd->device->hostdata;
+
+	lockdep_assert_held(&devinfo->lock);
+	cmdinfo->state |= IS_IN_WORK_LIST;
+	queue_work(workqueue, &devinfo->work);
+}
+
+static void uas_zap_pending(struct uas_dev_info *devinfo, int result)
+{
+	struct uas_cmd_info *cmdinfo;
+	struct scsi_cmnd *cmnd;
+	unsigned long flags;
+	int i, err;
+
+	spin_lock_irqsave(&devinfo->lock, flags);
+	for (i = 0; i < devinfo->qdepth; i++) {
+		if (!devinfo->cmnd[i])
+			continue;
+
+		cmnd = devinfo->cmnd[i];
+		cmdinfo = (void *)&cmnd->SCp;
+		uas_log_cmd_state(cmnd, __func__, 0);
+		/* Sense urbs were killed, clear COMMAND_INFLIGHT manually */
+		cmdinfo->state &= ~COMMAND_INFLIGHT;
+		cmnd->result = result << 16;
+		err = uas_try_complete(cmnd, __func__);
+		WARN_ON(err != 0);
+	}
+	spin_unlock_irqrestore(&devinfo->lock, flags);
+}
+
+static void uas_sense(struct urb *urb, struct scsi_cmnd *cmnd)
+{
+	struct sense_iu *sense_iu = urb->transfer_buffer;
+	struct scsi_device *sdev = cmnd->device;
+
+	if (urb->actual_length > 16) {
+		unsigned len = be16_to_cpup(&sense_iu->len);
+		if (len + 16 != urb->actual_length) {
+			int newlen = min(len + 16, urb->actual_length) - 16;
+			if (newlen < 0)
+				newlen = 0;
+			sdev_printk(KERN_INFO, sdev, "%s: urb length %d "
+				"disagrees with IU sense data length %d, "
+				"using %d bytes of sense data\n", __func__,
+					urb->actual_length, len, newlen);
+			len = newlen;
+		}
+		memcpy(cmnd->sense_buffer, sense_iu->sense, len);
+	}
+
+	cmnd->result = sense_iu->status;
+}
+
+static void uas_log_cmd_state(struct scsi_cmnd *cmnd, const char *prefix,
+			      int status)
+{
+	struct uas_cmd_info *ci = (void *)&cmnd->SCp;
+	struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
+
+	if (status == -ENODEV) /* too late */
+		return;
+
+	scmd_printk(KERN_INFO, cmnd,
+		    "%s %d uas-tag %d inflight:%s%s%s%s%s%s%s%s%s%s%s%s ",
+		    prefix, status, cmdinfo->uas_tag,
+		    (ci->state & SUBMIT_STATUS_URB)     ? " s-st"  : "",
+		    (ci->state & ALLOC_DATA_IN_URB)     ? " a-in"  : "",
+		    (ci->state & SUBMIT_DATA_IN_URB)    ? " s-in"  : "",
+		    (ci->state & ALLOC_DATA_OUT_URB)    ? " a-out" : "",
+		    (ci->state & SUBMIT_DATA_OUT_URB)   ? " s-out" : "",
+		    (ci->state & ALLOC_CMD_URB)         ? " a-cmd" : "",
+		    (ci->state & SUBMIT_CMD_URB)        ? " s-cmd" : "",
+		    (ci->state & COMMAND_INFLIGHT)      ? " CMD"   : "",
+		    (ci->state & DATA_IN_URB_INFLIGHT)  ? " IN"    : "",
+		    (ci->state & DATA_OUT_URB_INFLIGHT) ? " OUT"   : "",
+		    (ci->state & COMMAND_ABORTED)       ? " abort" : "",
+		    (ci->state & IS_IN_WORK_LIST)       ? " work"  : "");
+	scsi_print_command(cmnd);
+}
+
+static void uas_free_unsubmitted_urbs(struct scsi_cmnd *cmnd)
+{
+	struct uas_cmd_info *cmdinfo;
+
+	if (!cmnd)
+		return;
+
+	cmdinfo = (void *)&cmnd->SCp;
+
+	if (cmdinfo->state & SUBMIT_CMD_URB)
+		usb_free_urb(cmdinfo->cmd_urb);
+
+	/* data urbs may have never gotten their submit flag set */
+	if (!(cmdinfo->state & DATA_IN_URB_INFLIGHT))
+		usb_free_urb(cmdinfo->data_in_urb);
+	if (!(cmdinfo->state & DATA_OUT_URB_INFLIGHT))
+		usb_free_urb(cmdinfo->data_out_urb);
+}
+
+static int uas_try_complete(struct scsi_cmnd *cmnd, const char *caller)
+{
+	struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
+	struct uas_dev_info *devinfo = (void *)cmnd->device->hostdata;
+
+	lockdep_assert_held(&devinfo->lock);
+	if (cmdinfo->state & (COMMAND_INFLIGHT |
+			      DATA_IN_URB_INFLIGHT |
+			      DATA_OUT_URB_INFLIGHT |
+			      COMMAND_ABORTED))
+		return -EBUSY;
+	devinfo->cmnd[cmdinfo->uas_tag - 1] = NULL;
+	uas_free_unsubmitted_urbs(cmnd);
+	cmnd->scsi_done(cmnd);
+	return 0;
+}
+
+static void uas_xfer_data(struct urb *urb, struct scsi_cmnd *cmnd,
+			  unsigned direction)
+{
+	struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
+	int err;
+
+	cmdinfo->state |= direction | SUBMIT_STATUS_URB;
+	err = uas_submit_urbs(cmnd, cmnd->device->hostdata);
+	if (err) {
+		uas_add_work(cmdinfo);
+	}
+}
+
+static bool uas_evaluate_response_iu(struct response_iu *riu, struct scsi_cmnd *cmnd)
+{
+	u8 response_code = riu->response_code;
+
+	switch (response_code) {
+	case RC_INCORRECT_LUN:
+		cmnd->result = DID_BAD_TARGET << 16;
+		break;
+	case RC_TMF_SUCCEEDED:
+		cmnd->result = DID_OK << 16;
+		break;
+	case RC_TMF_NOT_SUPPORTED:
+		cmnd->result = DID_TARGET_FAILURE << 16;
+		break;
+	default:
+		uas_log_cmd_state(cmnd, "response iu", response_code);
+		cmnd->result = DID_ERROR << 16;
+		break;
+	}
+
+	return response_code == RC_TMF_SUCCEEDED;
+}
+
+static void uas_stat_cmplt(struct urb *urb)
+{
+	struct iu *iu = urb->transfer_buffer;
+	struct Scsi_Host *shost = urb->context;
+	struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
+	struct urb *data_in_urb = NULL;
+	struct urb *data_out_urb = NULL;
+	struct scsi_cmnd *cmnd;
+	struct uas_cmd_info *cmdinfo;
+	unsigned long flags;
+	unsigned int idx;
+	int status = urb->status;
+	bool success;
+
+	spin_lock_irqsave(&devinfo->lock, flags);
+
+	if (devinfo->resetting)
+		goto out;
+
+	if (status) {
+		if (status != -ENOENT && status != -ECONNRESET && status != -ESHUTDOWN)
+			dev_err(&urb->dev->dev, "stat urb: status %d\n", status);
+		goto out;
+	}
+
+	idx = be16_to_cpup(&iu->tag) - 1;
+	if (idx >= MAX_CMNDS || !devinfo->cmnd[idx]) {
+		dev_err(&urb->dev->dev,
+			"stat urb: no pending cmd for uas-tag %d\n", idx + 1);
+		goto out;
+	}
+
+	cmnd = devinfo->cmnd[idx];
+	cmdinfo = (void *)&cmnd->SCp;
+
+	if (!(cmdinfo->state & COMMAND_INFLIGHT)) {
+		uas_log_cmd_state(cmnd, "unexpected status cmplt", 0);
+		goto out;
+	}
+
+	switch (iu->iu_id) {
+	case IU_ID_STATUS:
+		uas_sense(urb, cmnd);
+		if (cmnd->result != 0) {
+			/* cancel data transfers on error */
+			data_in_urb = usb_get_urb(cmdinfo->data_in_urb);
+			data_out_urb = usb_get_urb(cmdinfo->data_out_urb);
+		}
+		cmdinfo->state &= ~COMMAND_INFLIGHT;
+		uas_try_complete(cmnd, __func__);
+		break;
+	case IU_ID_READ_READY:
+		if (!cmdinfo->data_in_urb ||
+				(cmdinfo->state & DATA_IN_URB_INFLIGHT)) {
+			uas_log_cmd_state(cmnd, "unexpected read rdy", 0);
+			break;
+		}
+		uas_xfer_data(urb, cmnd, SUBMIT_DATA_IN_URB);
+		break;
+	case IU_ID_WRITE_READY:
+		if (!cmdinfo->data_out_urb ||
+				(cmdinfo->state & DATA_OUT_URB_INFLIGHT)) {
+			uas_log_cmd_state(cmnd, "unexpected write rdy", 0);
+			break;
+		}
+		uas_xfer_data(urb, cmnd, SUBMIT_DATA_OUT_URB);
+		break;
+	case IU_ID_RESPONSE:
+		cmdinfo->state &= ~COMMAND_INFLIGHT;
+		success = uas_evaluate_response_iu((struct response_iu *)iu, cmnd);
+		if (!success) {
+			/* Error, cancel data transfers */
+			data_in_urb = usb_get_urb(cmdinfo->data_in_urb);
+			data_out_urb = usb_get_urb(cmdinfo->data_out_urb);
+		}
+		uas_try_complete(cmnd, __func__);
+		break;
+	default:
+		uas_log_cmd_state(cmnd, "bogus IU", iu->iu_id);
+	}
+out:
+	usb_free_urb(urb);
+	spin_unlock_irqrestore(&devinfo->lock, flags);
+
+	/* Unlinking of data urbs must be done without holding the lock */
+	if (data_in_urb) {
+		usb_unlink_urb(data_in_urb);
+		usb_put_urb(data_in_urb);
+	}
+	if (data_out_urb) {
+		usb_unlink_urb(data_out_urb);
+		usb_put_urb(data_out_urb);
+	}
+}
+
+static void uas_data_cmplt(struct urb *urb)
+{
+	struct scsi_cmnd *cmnd = urb->context;
+	struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
+	struct uas_dev_info *devinfo = (void *)cmnd->device->hostdata;
+	struct scsi_data_buffer *sdb = NULL;
+	unsigned long flags;
+	int status = urb->status;
+
+	spin_lock_irqsave(&devinfo->lock, flags);
+
+	if (cmdinfo->data_in_urb == urb) {
+		sdb = scsi_in(cmnd);
+		cmdinfo->state &= ~DATA_IN_URB_INFLIGHT;
+		cmdinfo->data_in_urb = NULL;
+	} else if (cmdinfo->data_out_urb == urb) {
+		sdb = scsi_out(cmnd);
+		cmdinfo->state &= ~DATA_OUT_URB_INFLIGHT;
+		cmdinfo->data_out_urb = NULL;
+	}
+	if (sdb == NULL) {
+		WARN_ON_ONCE(1);
+		goto out;
+	}
+
+	if (devinfo->resetting)
+		goto out;
+
+	/* Data urbs should not complete before the cmd urb is submitted */
+	if (cmdinfo->state & SUBMIT_CMD_URB) {
+		uas_log_cmd_state(cmnd, "unexpected data cmplt", 0);
+		goto out;
+	}
+
+	if (status) {
+		if (status != -ENOENT && status != -ECONNRESET && status != -ESHUTDOWN)
+			uas_log_cmd_state(cmnd, "data cmplt err", status);
+		/* error: no data transfered */
+		sdb->resid = sdb->length;
+	} else {
+		sdb->resid = sdb->length - urb->actual_length;
+	}
+	uas_try_complete(cmnd, __func__);
+out:
+	usb_free_urb(urb);
+	spin_unlock_irqrestore(&devinfo->lock, flags);
+}
+
+static void uas_cmd_cmplt(struct urb *urb)
+{
+	if (urb->status)
+		dev_err(&urb->dev->dev, "cmd cmplt err %d\n", urb->status);
+
+	usb_free_urb(urb);
+}
+
+static struct urb *uas_alloc_data_urb(struct uas_dev_info *devinfo, gfp_t gfp,
+				      struct scsi_cmnd *cmnd,
+				      enum dma_data_direction dir)
+{
+	struct usb_device *udev = devinfo->udev;
+	struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
+	struct urb *urb = usb_alloc_urb(0, gfp);
+	struct scsi_data_buffer *sdb = (dir == DMA_FROM_DEVICE)
+		? scsi_in(cmnd) : scsi_out(cmnd);
+	unsigned int pipe = (dir == DMA_FROM_DEVICE)
+		? devinfo->data_in_pipe : devinfo->data_out_pipe;
+
+	if (!urb)
+		goto out;
+	usb_fill_bulk_urb(urb, udev, pipe, NULL, sdb->length,
+			  uas_data_cmplt, cmnd);
+	if (devinfo->use_streams)
+		urb->stream_id = cmdinfo->uas_tag;
+	urb->num_sgs = udev->bus->sg_tablesize ? sdb->table.nents : 0;
+	urb->sg = sdb->table.sgl;
+ out:
+	return urb;
+}
+
+static struct urb *uas_alloc_sense_urb(struct uas_dev_info *devinfo, gfp_t gfp,
+				       struct scsi_cmnd *cmnd)
+{
+	struct usb_device *udev = devinfo->udev;
+	struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
+	struct urb *urb = usb_alloc_urb(0, gfp);
+	struct sense_iu *iu;
+
+	if (!urb)
+		goto out;
+
+	iu = kzalloc(sizeof(*iu), gfp);
+	if (!iu)
+		goto free;
+
+	usb_fill_bulk_urb(urb, udev, devinfo->status_pipe, iu, sizeof(*iu),
+			  uas_stat_cmplt, cmnd->device->host);
+	if (devinfo->use_streams)
+		urb->stream_id = cmdinfo->uas_tag;
+	urb->transfer_flags |= URB_FREE_BUFFER;
+ out:
+	return urb;
+ free:
+	usb_free_urb(urb);
+	return NULL;
+}
+
+static struct urb *uas_alloc_cmd_urb(struct uas_dev_info *devinfo, gfp_t gfp,
+					struct scsi_cmnd *cmnd)
+{
+	struct usb_device *udev = devinfo->udev;
+	struct scsi_device *sdev = cmnd->device;
+	struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
+	struct urb *urb = usb_alloc_urb(0, gfp);
+	struct command_iu *iu;
+	int len;
+
+	if (!urb)
+		goto out;
+
+	len = cmnd->cmd_len - 16;
+	if (len < 0)
+		len = 0;
+	len = ALIGN(len, 4);
+	iu = kzalloc(sizeof(*iu) + len, gfp);
+	if (!iu)
+		goto free;
+
+	iu->iu_id = IU_ID_COMMAND;
+	iu->tag = cpu_to_be16(cmdinfo->uas_tag);
+	iu->prio_attr = UAS_SIMPLE_TAG;
+	iu->len = len;
+	int_to_scsilun(sdev->lun, &iu->lun);
+	memcpy(iu->cdb, cmnd->cmnd, cmnd->cmd_len);
+
+	usb_fill_bulk_urb(urb, udev, devinfo->cmd_pipe, iu, sizeof(*iu) + len,
+							uas_cmd_cmplt, NULL);
+	urb->transfer_flags |= URB_FREE_BUFFER;
+ out:
+	return urb;
+ free:
+	usb_free_urb(urb);
+	return NULL;
+}
+
+/*
+ * Why should I request the Status IU before sending the Command IU?  Spec
+ * says to, but also says the device may receive them in any order.  Seems
+ * daft to me.
+ */
+
+static struct urb *uas_submit_sense_urb(struct scsi_cmnd *cmnd, gfp_t gfp)
+{
+	struct uas_dev_info *devinfo = cmnd->device->hostdata;
+	struct urb *urb;
+	int err;
+
+	urb = uas_alloc_sense_urb(devinfo, gfp, cmnd);
+	if (!urb)
+		return NULL;
+	usb_anchor_urb(urb, &devinfo->sense_urbs);
+	err = usb_submit_urb(urb, gfp);
+	if (err) {
+		usb_unanchor_urb(urb);
+		uas_log_cmd_state(cmnd, "sense submit err", err);
+		usb_free_urb(urb);
+		return NULL;
+	}
+	return urb;
+}
+
+static int uas_submit_urbs(struct scsi_cmnd *cmnd,
+			   struct uas_dev_info *devinfo)
+{
+	struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
+	struct urb *urb;
+	int err;
+
+	lockdep_assert_held(&devinfo->lock);
+	if (cmdinfo->state & SUBMIT_STATUS_URB) {
+		urb = uas_submit_sense_urb(cmnd, GFP_ATOMIC);
+		if (!urb)
+			return SCSI_MLQUEUE_DEVICE_BUSY;
+		cmdinfo->state &= ~SUBMIT_STATUS_URB;
+	}
+
+	if (cmdinfo->state & ALLOC_DATA_IN_URB) {
+		cmdinfo->data_in_urb = uas_alloc_data_urb(devinfo, GFP_ATOMIC,
+							cmnd, DMA_FROM_DEVICE);
+		if (!cmdinfo->data_in_urb)
+			return SCSI_MLQUEUE_DEVICE_BUSY;
+		cmdinfo->state &= ~ALLOC_DATA_IN_URB;
+	}
+
+	if (cmdinfo->state & SUBMIT_DATA_IN_URB) {
+		usb_anchor_urb(cmdinfo->data_in_urb, &devinfo->data_urbs);
+		err = usb_submit_urb(cmdinfo->data_in_urb, GFP_ATOMIC);
+		if (err) {
+			usb_unanchor_urb(cmdinfo->data_in_urb);
+			uas_log_cmd_state(cmnd, "data in submit err", err);
+			return SCSI_MLQUEUE_DEVICE_BUSY;
+		}
+		cmdinfo->state &= ~SUBMIT_DATA_IN_URB;
+		cmdinfo->state |= DATA_IN_URB_INFLIGHT;
+	}
+
+	if (cmdinfo->state & ALLOC_DATA_OUT_URB) {
+		cmdinfo->data_out_urb = uas_alloc_data_urb(devinfo, GFP_ATOMIC,
+							cmnd, DMA_TO_DEVICE);
+		if (!cmdinfo->data_out_urb)
+			return SCSI_MLQUEUE_DEVICE_BUSY;
+		cmdinfo->state &= ~ALLOC_DATA_OUT_URB;
+	}
+
+	if (cmdinfo->state & SUBMIT_DATA_OUT_URB) {
+		usb_anchor_urb(cmdinfo->data_out_urb, &devinfo->data_urbs);
+		err = usb_submit_urb(cmdinfo->data_out_urb, GFP_ATOMIC);
+		if (err) {
+			usb_unanchor_urb(cmdinfo->data_out_urb);
+			uas_log_cmd_state(cmnd, "data out submit err", err);
+			return SCSI_MLQUEUE_DEVICE_BUSY;
+		}
+		cmdinfo->state &= ~SUBMIT_DATA_OUT_URB;
+		cmdinfo->state |= DATA_OUT_URB_INFLIGHT;
+	}
+
+	if (cmdinfo->state & ALLOC_CMD_URB) {
+		cmdinfo->cmd_urb = uas_alloc_cmd_urb(devinfo, GFP_ATOMIC, cmnd);
+		if (!cmdinfo->cmd_urb)
+			return SCSI_MLQUEUE_DEVICE_BUSY;
+		cmdinfo->state &= ~ALLOC_CMD_URB;
+	}
+
+	if (cmdinfo->state & SUBMIT_CMD_URB) {
+		usb_anchor_urb(cmdinfo->cmd_urb, &devinfo->cmd_urbs);
+		err = usb_submit_urb(cmdinfo->cmd_urb, GFP_ATOMIC);
+		if (err) {
+			usb_unanchor_urb(cmdinfo->cmd_urb);
+			uas_log_cmd_state(cmnd, "cmd submit err", err);
+			return SCSI_MLQUEUE_DEVICE_BUSY;
+		}
+		cmdinfo->cmd_urb = NULL;
+		cmdinfo->state &= ~SUBMIT_CMD_URB;
+		cmdinfo->state |= COMMAND_INFLIGHT;
+	}
+
+	return 0;
+}
+
+static int uas_queuecommand_lck(struct scsi_cmnd *cmnd,
+					void (*done)(struct scsi_cmnd *))
+{
+	struct scsi_device *sdev = cmnd->device;
+	struct uas_dev_info *devinfo = sdev->hostdata;
+	struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
+	unsigned long flags;
+	int idx, err;
+
+	BUILD_BUG_ON(sizeof(struct uas_cmd_info) > sizeof(struct scsi_pointer));
+
+	/* Re-check scsi_block_requests now that we've the host-lock */
+	if (cmnd->device->host->host_self_blocked)
+		return SCSI_MLQUEUE_DEVICE_BUSY;
+
+	if ((devinfo->flags & US_FL_NO_ATA_1X) &&
+			(cmnd->cmnd[0] == ATA_12 || cmnd->cmnd[0] == ATA_16)) {
+		memcpy(cmnd->sense_buffer, usb_stor_sense_invalidCDB,
+		       sizeof(usb_stor_sense_invalidCDB));
+		cmnd->result = SAM_STAT_CHECK_CONDITION;
+		cmnd->scsi_done(cmnd);
+		return 0;
+	}
+
+	spin_lock_irqsave(&devinfo->lock, flags);
+
+	if (devinfo->resetting) {
+		cmnd->result = DID_ERROR << 16;
+		cmnd->scsi_done(cmnd);
+		goto zombie;
+	}
+
+	/* Find a free uas-tag */
+	for (idx = 0; idx < devinfo->qdepth; idx++) {
+		if (!devinfo->cmnd[idx])
+			break;
+	}
+	if (idx == devinfo->qdepth) {
+		spin_unlock_irqrestore(&devinfo->lock, flags);
+		return SCSI_MLQUEUE_DEVICE_BUSY;
+	}
+
+	cmnd->scsi_done = done;
+
+	memset(cmdinfo, 0, sizeof(*cmdinfo));
+	cmdinfo->uas_tag = idx + 1; /* uas-tag == usb-stream-id, so 1 based */
+	cmdinfo->state = SUBMIT_STATUS_URB | ALLOC_CMD_URB | SUBMIT_CMD_URB;
+
+	switch (cmnd->sc_data_direction) {
+	case DMA_FROM_DEVICE:
+		cmdinfo->state |= ALLOC_DATA_IN_URB | SUBMIT_DATA_IN_URB;
+		break;
+	case DMA_BIDIRECTIONAL:
+		cmdinfo->state |= ALLOC_DATA_IN_URB | SUBMIT_DATA_IN_URB;
+		/* fall through */
+	case DMA_TO_DEVICE:
+		cmdinfo->state |= ALLOC_DATA_OUT_URB | SUBMIT_DATA_OUT_URB;
+	case DMA_NONE:
+		break;
+	}
+
+	if (!devinfo->use_streams)
+		cmdinfo->state &= ~(SUBMIT_DATA_IN_URB | SUBMIT_DATA_OUT_URB);
+
+	err = uas_submit_urbs(cmnd, devinfo);
+	/*
+	 * in case of fatal errors the SCSI layer is peculiar
+	 * a command that has finished is a success for the purpose
+	 * of queueing, no matter how fatal the error
+	 */
+	if (err == -ENODEV) {
+		cmnd->result = DID_ERROR << 16;
+		cmnd->scsi_done(cmnd);
+		goto zombie;
+	}
+	if (err) {
+		/* If we did nothing, give up now */
+		if (cmdinfo->state & SUBMIT_STATUS_URB) {
+			spin_unlock_irqrestore(&devinfo->lock, flags);
+			return SCSI_MLQUEUE_DEVICE_BUSY;
+		}
+		uas_add_work(cmdinfo);
+	}
+
+	devinfo->cmnd[idx] = cmnd;
+zombie:
+	spin_unlock_irqrestore(&devinfo->lock, flags);
+	return 0;
+}
+
+static DEF_SCSI_QCMD(uas_queuecommand)
+
+/*
+ * For now we do not support actually sending an abort to the device, so
+ * this eh always fails. Still we must define it to make sure that we've
+ * dropped all references to the cmnd in question once this function exits.
+ */
+static int uas_eh_abort_handler(struct scsi_cmnd *cmnd)
+{
+	struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
+	struct uas_dev_info *devinfo = (void *)cmnd->device->hostdata;
+	struct urb *data_in_urb = NULL;
+	struct urb *data_out_urb = NULL;
+	unsigned long flags;
+
+	spin_lock_irqsave(&devinfo->lock, flags);
+
+	uas_log_cmd_state(cmnd, __func__, 0);
+
+	/* Ensure that try_complete does not call scsi_done */
+	cmdinfo->state |= COMMAND_ABORTED;
+
+	/* Drop all refs to this cmnd, kill data urbs to break their ref */
+	devinfo->cmnd[cmdinfo->uas_tag - 1] = NULL;
+	if (cmdinfo->state & DATA_IN_URB_INFLIGHT)
+		data_in_urb = usb_get_urb(cmdinfo->data_in_urb);
+	if (cmdinfo->state & DATA_OUT_URB_INFLIGHT)
+		data_out_urb = usb_get_urb(cmdinfo->data_out_urb);
+
+	uas_free_unsubmitted_urbs(cmnd);
+
+	spin_unlock_irqrestore(&devinfo->lock, flags);
+
+	if (data_in_urb) {
+		usb_kill_urb(data_in_urb);
+		usb_put_urb(data_in_urb);
+	}
+	if (data_out_urb) {
+		usb_kill_urb(data_out_urb);
+		usb_put_urb(data_out_urb);
+	}
+
+	return FAILED;
+}
+
+static int uas_eh_device_reset_handler(struct scsi_cmnd *cmnd)
+{
+	struct scsi_device *sdev = cmnd->device;
+	struct uas_dev_info *devinfo = sdev->hostdata;
+	struct usb_device *udev = devinfo->udev;
+	unsigned long flags;
+	int err;
+
+	err = usb_lock_device_for_reset(udev, devinfo->intf);
+	if (err) {
+		shost_printk(KERN_ERR, sdev->host,
+			     "%s FAILED to get lock err %d\n", __func__, err);
+		return FAILED;
+	}
+
+	shost_printk(KERN_INFO, sdev->host, "%s start\n", __func__);
+
+	spin_lock_irqsave(&devinfo->lock, flags);
+	devinfo->resetting = 1;
+	spin_unlock_irqrestore(&devinfo->lock, flags);
+
+	usb_kill_anchored_urbs(&devinfo->cmd_urbs);
+	usb_kill_anchored_urbs(&devinfo->sense_urbs);
+	usb_kill_anchored_urbs(&devinfo->data_urbs);
+	uas_zap_pending(devinfo, DID_RESET);
+
+	err = usb_reset_device(udev);
+
+	spin_lock_irqsave(&devinfo->lock, flags);
+	devinfo->resetting = 0;
+	spin_unlock_irqrestore(&devinfo->lock, flags);
+
+	usb_unlock_device(udev);
+
+	if (err) {
+		shost_printk(KERN_INFO, sdev->host, "%s FAILED err %d\n",
+			     __func__, err);
+		return FAILED;
+	}
+
+	shost_printk(KERN_INFO, sdev->host, "%s success\n", __func__);
+	return SUCCESS;
+}
+
+static int uas_target_alloc(struct scsi_target *starget)
+{
+	struct uas_dev_info *devinfo = (struct uas_dev_info *)
+			dev_to_shost(starget->dev.parent)->hostdata;
+
+	if (devinfo->flags & US_FL_NO_REPORT_LUNS)
+		starget->no_report_luns = 1;
+
+	return 0;
+}
+
+static int uas_slave_alloc(struct scsi_device *sdev)
+{
+	struct uas_dev_info *devinfo =
+		(struct uas_dev_info *)sdev->host->hostdata;
+
+	sdev->hostdata = devinfo;
+
+	/*
+	 * The protocol has no requirements on alignment in the strict sense.
+	 * Controllers may or may not have alignment restrictions.
+	 * As this is not exported, we use an extremely conservative guess.
+	 */
+	blk_queue_update_dma_alignment(sdev->request_queue, (512 - 1));
+
+	if (devinfo->flags & US_FL_MAX_SECTORS_64)
+		blk_queue_max_hw_sectors(sdev->request_queue, 64);
+	else if (devinfo->flags & US_FL_MAX_SECTORS_240)
+		blk_queue_max_hw_sectors(sdev->request_queue, 240);
+
+	return 0;
+}
+
+static int uas_slave_configure(struct scsi_device *sdev)
+{
+	struct uas_dev_info *devinfo = sdev->hostdata;
+
+	if (devinfo->flags & US_FL_NO_REPORT_OPCODES)
+		sdev->no_report_opcodes = 1;
+
+	/* A few buggy USB-ATA bridges don't understand FUA */
+	if (devinfo->flags & US_FL_BROKEN_FUA)
+		sdev->broken_fua = 1;
+
+	/* UAS also needs to support FL_ALWAYS_SYNC */
+	if (devinfo->flags & US_FL_ALWAYS_SYNC) {
+		sdev->skip_ms_page_3f = 1;
+		sdev->skip_ms_page_8 = 1;
+		sdev->wce_default_on = 1;
+	}
+
+	/* Some disks cannot handle READ_CAPACITY_16 */
+	if (devinfo->flags & US_FL_NO_READ_CAPACITY_16)
+		sdev->no_read_capacity_16 = 1;
+
+	/* Some disks cannot handle WRITE_SAME */
+	if (devinfo->flags & US_FL_NO_SAME)
+		sdev->no_write_same = 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 (devinfo->flags & US_FL_FIX_CAPACITY)
+		sdev->fix_capacity = 1;
+
+	/*
+	 * in some cases we have to guess
+	 */
+	if (devinfo->flags & US_FL_CAPACITY_HEURISTICS)
+		sdev->guess_capacity = 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 (devinfo->flags & US_FL_NO_WP_DETECT)
+		sdev->skip_ms_page_3f = 1;
+
+	scsi_change_queue_depth(sdev, devinfo->qdepth - 2);
+	return 0;
+}
+
+static struct scsi_host_template uas_host_template = {
+	.module = THIS_MODULE,
+	.name = "uas",
+	.queuecommand = uas_queuecommand,
+	.target_alloc = uas_target_alloc,
+	.slave_alloc = uas_slave_alloc,
+	.slave_configure = uas_slave_configure,
+	.eh_abort_handler = uas_eh_abort_handler,
+	.eh_device_reset_handler = uas_eh_device_reset_handler,
+	.this_id = -1,
+	.sg_tablesize = SG_NONE,
+	.skip_settle_delay = 1,
+};
+
+#define UNUSUAL_DEV(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax, \
+		    vendorName, productName, useProtocol, useTransport, \
+		    initFunction, flags) \
+{ USB_DEVICE_VER(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax), \
+	.driver_info = (flags) }
+
+static struct usb_device_id uas_usb_ids[] = {
+#	include "unusual_uas.h"
+	{ USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, USB_SC_SCSI, USB_PR_BULK) },
+	{ USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, USB_SC_SCSI, USB_PR_UAS) },
+	{ }
+};
+MODULE_DEVICE_TABLE(usb, uas_usb_ids);
+
+#undef UNUSUAL_DEV
+
+static int uas_switch_interface(struct usb_device *udev,
+				struct usb_interface *intf)
+{
+	struct usb_host_interface *alt;
+
+	alt = uas_find_uas_alt_setting(intf);
+	if (!alt)
+		return -ENODEV;
+
+	return usb_set_interface(udev, alt->desc.bInterfaceNumber,
+			alt->desc.bAlternateSetting);
+}
+
+static int uas_configure_endpoints(struct uas_dev_info *devinfo)
+{
+	struct usb_host_endpoint *eps[4] = { };
+	struct usb_device *udev = devinfo->udev;
+	int r;
+
+	r = uas_find_endpoints(devinfo->intf->cur_altsetting, eps);
+	if (r)
+		return r;
+
+	devinfo->cmd_pipe = usb_sndbulkpipe(udev,
+					    usb_endpoint_num(&eps[0]->desc));
+	devinfo->status_pipe = usb_rcvbulkpipe(udev,
+					    usb_endpoint_num(&eps[1]->desc));
+	devinfo->data_in_pipe = usb_rcvbulkpipe(udev,
+					    usb_endpoint_num(&eps[2]->desc));
+	devinfo->data_out_pipe = usb_sndbulkpipe(udev,
+					    usb_endpoint_num(&eps[3]->desc));
+
+	if (udev->speed < USB_SPEED_SUPER) {
+		devinfo->qdepth = 32;
+		devinfo->use_streams = 0;
+	} else {
+		devinfo->qdepth = usb_alloc_streams(devinfo->intf, eps + 1,
+						    3, MAX_CMNDS, GFP_NOIO);
+		if (devinfo->qdepth < 0)
+			return devinfo->qdepth;
+		devinfo->use_streams = 1;
+	}
+
+	return 0;
+}
+
+static void uas_free_streams(struct uas_dev_info *devinfo)
+{
+	struct usb_device *udev = devinfo->udev;
+	struct usb_host_endpoint *eps[3];
+
+	eps[0] = usb_pipe_endpoint(udev, devinfo->status_pipe);
+	eps[1] = usb_pipe_endpoint(udev, devinfo->data_in_pipe);
+	eps[2] = usb_pipe_endpoint(udev, devinfo->data_out_pipe);
+	usb_free_streams(devinfo->intf, eps, 3, GFP_NOIO);
+}
+
+static int uas_probe(struct usb_interface *intf, const struct usb_device_id *id)
+{
+	int result = -ENOMEM;
+	struct Scsi_Host *shost = NULL;
+	struct uas_dev_info *devinfo;
+	struct usb_device *udev = interface_to_usbdev(intf);
+	unsigned long dev_flags;
+
+	if (!uas_use_uas_driver(intf, id, &dev_flags))
+		return -ENODEV;
+
+	if (uas_switch_interface(udev, intf))
+		return -ENODEV;
+
+	shost = scsi_host_alloc(&uas_host_template,
+				sizeof(struct uas_dev_info));
+	if (!shost)
+		goto set_alt0;
+
+	shost->max_cmd_len = 16 + 252;
+	shost->max_id = 1;
+	shost->max_lun = 256;
+	shost->max_channel = 0;
+	shost->sg_tablesize = udev->bus->sg_tablesize;
+
+	devinfo = (struct uas_dev_info *)shost->hostdata;
+	devinfo->intf = intf;
+	devinfo->udev = udev;
+	devinfo->resetting = 0;
+	devinfo->shutdown = 0;
+	devinfo->flags = dev_flags;
+	init_usb_anchor(&devinfo->cmd_urbs);
+	init_usb_anchor(&devinfo->sense_urbs);
+	init_usb_anchor(&devinfo->data_urbs);
+	spin_lock_init(&devinfo->lock);
+	INIT_WORK(&devinfo->work, uas_do_work);
+	INIT_WORK(&devinfo->scan_work, uas_scan_work);
+
+	result = uas_configure_endpoints(devinfo);
+	if (result)
+		goto set_alt0;
+
+	/*
+	 * 1 tag is reserved for untagged commands +
+	 * 1 tag to avoid off by one errors in some bridge firmwares
+	 */
+	shost->can_queue = devinfo->qdepth - 2;
+
+	usb_set_intfdata(intf, shost);
+	result = scsi_add_host(shost, &intf->dev);
+	if (result)
+		goto free_streams;
+
+	/* Submit the delayed_work for SCSI-device scanning */
+	schedule_work(&devinfo->scan_work);
+
+	return result;
+
+free_streams:
+	uas_free_streams(devinfo);
+	usb_set_intfdata(intf, NULL);
+set_alt0:
+	usb_set_interface(udev, intf->altsetting[0].desc.bInterfaceNumber, 0);
+	if (shost)
+		scsi_host_put(shost);
+	return result;
+}
+
+static int uas_cmnd_list_empty(struct uas_dev_info *devinfo)
+{
+	unsigned long flags;
+	int i, r = 1;
+
+	spin_lock_irqsave(&devinfo->lock, flags);
+
+	for (i = 0; i < devinfo->qdepth; i++) {
+		if (devinfo->cmnd[i]) {
+			r = 0; /* Not empty */
+			break;
+		}
+	}
+
+	spin_unlock_irqrestore(&devinfo->lock, flags);
+
+	return r;
+}
+
+/*
+ * Wait for any pending cmnds to complete, on usb-2 sense_urbs may temporarily
+ * get empty while there still is more work to do due to sense-urbs completing
+ * with a READ/WRITE_READY iu code, so keep waiting until the list gets empty.
+ */
+static int uas_wait_for_pending_cmnds(struct uas_dev_info *devinfo)
+{
+	unsigned long start_time;
+	int r;
+
+	start_time = jiffies;
+	do {
+		flush_work(&devinfo->work);
+
+		r = usb_wait_anchor_empty_timeout(&devinfo->sense_urbs, 5000);
+		if (r == 0)
+			return -ETIME;
+
+		r = usb_wait_anchor_empty_timeout(&devinfo->data_urbs, 500);
+		if (r == 0)
+			return -ETIME;
+
+		if (time_after(jiffies, start_time + 5 * HZ))
+			return -ETIME;
+	} while (!uas_cmnd_list_empty(devinfo));
+
+	return 0;
+}
+
+static int uas_pre_reset(struct usb_interface *intf)
+{
+	struct Scsi_Host *shost = usb_get_intfdata(intf);
+	struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
+	unsigned long flags;
+
+	if (devinfo->shutdown)
+		return 0;
+
+	/* Block new requests */
+	spin_lock_irqsave(shost->host_lock, flags);
+	scsi_block_requests(shost);
+	spin_unlock_irqrestore(shost->host_lock, flags);
+
+	if (uas_wait_for_pending_cmnds(devinfo) != 0) {
+		shost_printk(KERN_ERR, shost, "%s: timed out\n", __func__);
+		scsi_unblock_requests(shost);
+		return 1;
+	}
+
+	uas_free_streams(devinfo);
+
+	return 0;
+}
+
+static int uas_post_reset(struct usb_interface *intf)
+{
+	struct Scsi_Host *shost = usb_get_intfdata(intf);
+	struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
+	unsigned long flags;
+	int err;
+
+	if (devinfo->shutdown)
+		return 0;
+
+	err = uas_configure_endpoints(devinfo);
+	if (err && err != -ENODEV)
+		shost_printk(KERN_ERR, shost,
+			     "%s: alloc streams error %d after reset",
+			     __func__, err);
+
+	/* we must unblock the host in every case lest we deadlock */
+	spin_lock_irqsave(shost->host_lock, flags);
+	scsi_report_bus_reset(shost, 0);
+	spin_unlock_irqrestore(shost->host_lock, flags);
+
+	scsi_unblock_requests(shost);
+
+	return err ? 1 : 0;
+}
+
+static int uas_suspend(struct usb_interface *intf, pm_message_t message)
+{
+	struct Scsi_Host *shost = usb_get_intfdata(intf);
+	struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
+
+	if (uas_wait_for_pending_cmnds(devinfo) != 0) {
+		shost_printk(KERN_ERR, shost, "%s: timed out\n", __func__);
+		return -ETIME;
+	}
+
+	return 0;
+}
+
+static int uas_resume(struct usb_interface *intf)
+{
+	return 0;
+}
+
+static int uas_reset_resume(struct usb_interface *intf)
+{
+	struct Scsi_Host *shost = usb_get_intfdata(intf);
+	struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
+	unsigned long flags;
+	int err;
+
+	err = uas_configure_endpoints(devinfo);
+	if (err) {
+		shost_printk(KERN_ERR, shost,
+			     "%s: alloc streams error %d after reset",
+			     __func__, err);
+		return -EIO;
+	}
+
+	spin_lock_irqsave(shost->host_lock, flags);
+	scsi_report_bus_reset(shost, 0);
+	spin_unlock_irqrestore(shost->host_lock, flags);
+
+	return 0;
+}
+
+static void uas_disconnect(struct usb_interface *intf)
+{
+	struct Scsi_Host *shost = usb_get_intfdata(intf);
+	struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
+	unsigned long flags;
+
+	spin_lock_irqsave(&devinfo->lock, flags);
+	devinfo->resetting = 1;
+	spin_unlock_irqrestore(&devinfo->lock, flags);
+
+	cancel_work_sync(&devinfo->work);
+	usb_kill_anchored_urbs(&devinfo->cmd_urbs);
+	usb_kill_anchored_urbs(&devinfo->sense_urbs);
+	usb_kill_anchored_urbs(&devinfo->data_urbs);
+	uas_zap_pending(devinfo, DID_NO_CONNECT);
+
+	/*
+	 * Prevent SCSI scanning (if it hasn't started yet)
+	 * or wait for the SCSI-scanning routine to stop.
+	 */
+	cancel_work_sync(&devinfo->scan_work);
+
+	scsi_remove_host(shost);
+	uas_free_streams(devinfo);
+	scsi_host_put(shost);
+}
+
+/*
+ * Put the device back in usb-storage mode on shutdown, as some BIOS-es
+ * hang on reboot when the device is still in uas mode. Note the reset is
+ * necessary as some devices won't revert to usb-storage mode without it.
+ */
+static void uas_shutdown(struct device *dev)
+{
+	struct usb_interface *intf = to_usb_interface(dev);
+	struct usb_device *udev = interface_to_usbdev(intf);
+	struct Scsi_Host *shost = usb_get_intfdata(intf);
+	struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
+
+	if (system_state != SYSTEM_RESTART)
+		return;
+
+	devinfo->shutdown = 1;
+	uas_free_streams(devinfo);
+	usb_set_interface(udev, intf->altsetting[0].desc.bInterfaceNumber, 0);
+	usb_reset_device(udev);
+}
+
+static struct usb_driver uas_driver = {
+	.name = "uas",
+	.probe = uas_probe,
+	.disconnect = uas_disconnect,
+	.pre_reset = uas_pre_reset,
+	.post_reset = uas_post_reset,
+	.suspend = uas_suspend,
+	.resume = uas_resume,
+	.reset_resume = uas_reset_resume,
+	.drvwrap.driver.shutdown = uas_shutdown,
+	.id_table = uas_usb_ids,
+};
+
+static int __init uas_init(void)
+{
+	int rv;
+
+	workqueue = alloc_workqueue("uas", WQ_MEM_RECLAIM, 0);
+	if (!workqueue)
+		return -ENOMEM;
+
+	rv = usb_register(&uas_driver);
+	if (rv) {
+		destroy_workqueue(workqueue);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static void __exit uas_exit(void)
+{
+	usb_deregister(&uas_driver);
+	destroy_workqueue(workqueue);
+}
+
+module_init(uas_init);
+module_exit(uas_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR(
+	"Hans de Goede <hdegoede@redhat.com>, Matthew Wilcox and Sarah Sharp");