Merge tag 'usb-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb

Pull USB updates from Greg KH:
 "Here is the big set of USB patches for 5.4-rc1.

  Two major chunks of code are moving out of the tree and into the
  staging directory, uwb and wusb (wireless USB support), because there
  are no devices that actually use this protocol anymore, and what we
  have today probably doesn't work at all given that the maintainers
  left many many years ago. So move it to staging where it will be
  removed in a few releases if no one screams.

  Other than that, lots of little things. The usual gadget and xhci and
  usb serial driver updates, along with a bunch of sysfs file cleanups
  due to the driver core changes to support that. Nothing really major,
  just constant forward progress.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'usb-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (159 commits)
  USB: usbcore: Fix slab-out-of-bounds bug during device reset
  usb: cdns3: Remove redundant dev_err call in cdns3_probe()
  USB: rio500: Fix lockdep violation
  USB: rio500: simplify locking
  usb: mtu3: register a USB Role Switch for dual role mode
  usb: common: add USB GPIO based connection detection driver
  usb: common: create Kconfig file
  usb: roles: get usb-role-switch from parent
  usb: roles: Add fwnode_usb_role_switch_get() function
  device connection: Add fwnode_connection_find_match()
  usb: roles: Introduce stubs for the exiting functions in role.h
  dt-bindings: usb: mtu3: add properties about USB Role Switch
  dt-bindings: usb: add binding for USB GPIO based connection detection driver
  dt-bindings: connector: add optional properties for Type-B
  dt-binding: usb: add usb-role-switch property
  usbip: Implement SG support to vhci-hcd and stub driver
  usb: roles: intel: Enable static DRD mode for role switch
  xhci-ext-caps.c: Add property to disable Intel SW switch
  usb: dwc3: remove generic PHY calibrate() calls
  usb: core: phy: add support for PHY calibration
  ...

13 files changed, 396 insertions, 180 deletions

diff --git a/drivers/usb/usbip/stub.h b/drivers/usb/usbip/stub.h
index 35618ceb2791..d11270560c24 100644
--- a/drivers/usb/usbip/stub.h
+++ b/drivers/usb/usbip/stub.h
@@ -52,7 +52,11 @@ struct stub_priv {
 	unsigned long seqnum;
 	struct list_head list;
 	struct stub_device *sdev;
-	struct urb *urb;
+	struct urb **urbs;
+	struct scatterlist *sgl;
+	int num_urbs;
+	int completed_urbs;
+	int urb_status;
 
 	int unlinking;
 };
@@ -86,6 +90,7 @@ extern struct usb_device_driver stub_driver;
 struct bus_id_priv *get_busid_priv(const char *busid);
 void put_busid_priv(struct bus_id_priv *bid);
 int del_match_busid(char *busid);
+void stub_free_priv_and_urb(struct stub_priv *priv);
 void stub_device_cleanup_urbs(struct stub_device *sdev);
 
 /* stub_rx.c */
diff --git a/drivers/usb/usbip/stub_dev.c b/drivers/usb/usbip/stub_dev.c
index 7931e6cecc70..2305d425e6c9 100644
--- a/drivers/usb/usbip/stub_dev.c
+++ b/drivers/usb/usbip/stub_dev.c
@@ -106,38 +106,13 @@ err:
 }
 static DEVICE_ATTR_WO(usbip_sockfd);
 
-static int stub_add_files(struct device *dev)
-{
-	int err = 0;
-
-	err = device_create_file(dev, &dev_attr_usbip_status);
-	if (err)
-		goto err_status;
-
-	err = device_create_file(dev, &dev_attr_usbip_sockfd);
-	if (err)
-		goto err_sockfd;
-
-	err = device_create_file(dev, &dev_attr_usbip_debug);
-	if (err)
-		goto err_debug;
-
-	return 0;
-
-err_debug:
-	device_remove_file(dev, &dev_attr_usbip_sockfd);
-err_sockfd:
-	device_remove_file(dev, &dev_attr_usbip_status);
-err_status:
-	return err;
-}
-
-static void stub_remove_files(struct device *dev)
-{
-	device_remove_file(dev, &dev_attr_usbip_status);
-	device_remove_file(dev, &dev_attr_usbip_sockfd);
-	device_remove_file(dev, &dev_attr_usbip_debug);
-}
+static struct attribute *usbip_attrs[] = {
+	&dev_attr_usbip_status.attr,
+	&dev_attr_usbip_sockfd.attr,
+	&dev_attr_usbip_debug.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(usbip);
 
 static void stub_shutdown_connection(struct usbip_device *ud)
 {
@@ -379,17 +354,8 @@ static int stub_probe(struct usb_device *udev)
 		goto err_port;
 	}
 
-	rc = stub_add_files(&udev->dev);
-	if (rc) {
-		dev_err(&udev->dev, "stub_add_files for %s\n", udev_busid);
-		goto err_files;
-	}
-
 	return 0;
 
-err_files:
-	usb_hub_release_port(udev->parent, udev->portnum,
-			     (struct usb_dev_state *) udev);
 err_port:
 	dev_set_drvdata(&udev->dev, NULL);
 	usb_put_dev(udev);
@@ -457,7 +423,6 @@ static void stub_disconnect(struct usb_device *udev)
 	/*
 	 * NOTE: rx/tx threads are invoked for each usb_device.
 	 */
-	stub_remove_files(&udev->dev);
 
 	/* release port */
 	rc = usb_hub_release_port(udev->parent, udev->portnum,
@@ -526,4 +491,5 @@ struct usb_device_driver stub_driver = {
 	.resume		= stub_resume,
 #endif
 	.supports_autosuspend	=	0,
+	.dev_groups	= usbip_groups,
 };
diff --git a/drivers/usb/usbip/stub_main.c b/drivers/usb/usbip/stub_main.c
index 2e4bfccd4bfc..c1c0bbc9f8b1 100644
--- a/drivers/usb/usbip/stub_main.c
+++ b/drivers/usb/usbip/stub_main.c
@@ -6,6 +6,7 @@
 #include <linux/string.h>
 #include <linux/module.h>
 #include <linux/device.h>
+#include <linux/scatterlist.h>
 
 #include "usbip_common.h"
 #include "stub.h"
@@ -281,13 +282,49 @@ static struct stub_priv *stub_priv_pop_from_listhead(struct list_head *listhead)
 	struct stub_priv *priv, *tmp;
 
 	list_for_each_entry_safe(priv, tmp, listhead, list) {
-		list_del(&priv->list);
+		list_del_init(&priv->list);
 		return priv;
 	}
 
 	return NULL;
 }
 
+void stub_free_priv_and_urb(struct stub_priv *priv)
+{
+	struct urb *urb;
+	int i;
+
+	for (i = 0; i < priv->num_urbs; i++) {
+		urb = priv->urbs[i];
+
+		if (!urb)
+			return;
+
+		kfree(urb->setup_packet);
+		urb->setup_packet = NULL;
+
+
+		if (urb->transfer_buffer && !priv->sgl) {
+			kfree(urb->transfer_buffer);
+			urb->transfer_buffer = NULL;
+		}
+
+		if (urb->num_sgs) {
+			sgl_free(urb->sg);
+			urb->sg = NULL;
+			urb->num_sgs = 0;
+		}
+
+		usb_free_urb(urb);
+	}
+	if (!list_empty(&priv->list))
+		list_del(&priv->list);
+	if (priv->sgl)
+		sgl_free(priv->sgl);
+	kfree(priv->urbs);
+	kmem_cache_free(stub_priv_cache, priv);
+}
+
 static struct stub_priv *stub_priv_pop(struct stub_device *sdev)
 {
 	unsigned long flags;
@@ -314,25 +351,15 @@ done:
 void stub_device_cleanup_urbs(struct stub_device *sdev)
 {
 	struct stub_priv *priv;
-	struct urb *urb;
+	int i;
 
 	dev_dbg(&sdev->udev->dev, "Stub device cleaning up urbs\n");
 
 	while ((priv = stub_priv_pop(sdev))) {
-		urb = priv->urb;
-		dev_dbg(&sdev->udev->dev, "free urb seqnum %lu\n",
-			priv->seqnum);
-		usb_kill_urb(urb);
-
-		kmem_cache_free(stub_priv_cache, priv);
+		for (i = 0; i < priv->num_urbs; i++)
+			usb_kill_urb(priv->urbs[i]);
 
-		kfree(urb->transfer_buffer);
-		urb->transfer_buffer = NULL;
-
-		kfree(urb->setup_packet);
-		urb->setup_packet = NULL;
-
-		usb_free_urb(urb);
+		stub_free_priv_and_urb(priv);
 	}
 }
 
diff --git a/drivers/usb/usbip/stub_rx.c b/drivers/usb/usbip/stub_rx.c
index b0a855acafa3..66edfeea68fe 100644
--- a/drivers/usb/usbip/stub_rx.c
+++ b/drivers/usb/usbip/stub_rx.c
@@ -7,6 +7,7 @@
 #include <linux/kthread.h>
 #include <linux/usb.h>
 #include <linux/usb/hcd.h>
+#include <linux/scatterlist.h>
 
 #include "usbip_common.h"
 #include "stub.h"
@@ -201,7 +202,7 @@ static void tweak_special_requests(struct urb *urb)
 static int stub_recv_cmd_unlink(struct stub_device *sdev,
 				struct usbip_header *pdu)
 {
-	int ret;
+	int ret, i;
 	unsigned long flags;
 	struct stub_priv *priv;
 
@@ -246,12 +247,14 @@ static int stub_recv_cmd_unlink(struct stub_device *sdev,
 		 * so a driver in a client host will know the failure
 		 * of the unlink request ?
 		 */
-		ret = usb_unlink_urb(priv->urb);
-		if (ret != -EINPROGRESS)
-			dev_err(&priv->urb->dev->dev,
-				"failed to unlink a urb # %lu, ret %d\n",
-				priv->seqnum, ret);
-
+		for (i = priv->completed_urbs; i < priv->num_urbs; i++) {
+			ret = usb_unlink_urb(priv->urbs[i]);
+			if (ret != -EINPROGRESS)
+				dev_err(&priv->urbs[i]->dev->dev,
+					"failed to unlink %d/%d urb of seqnum %lu, ret %d\n",
+					i + 1, priv->num_urbs,
+					priv->seqnum, ret);
+		}
 		return 0;
 	}
 
@@ -433,14 +436,36 @@ static void masking_bogus_flags(struct urb *urb)
 	urb->transfer_flags &= allowed;
 }
 
+static int stub_recv_xbuff(struct usbip_device *ud, struct stub_priv *priv)
+{
+	int ret;
+	int i;
+
+	for (i = 0; i < priv->num_urbs; i++) {
+		ret = usbip_recv_xbuff(ud, priv->urbs[i]);
+		if (ret < 0)
+			break;
+	}
+
+	return ret;
+}
+
 static void stub_recv_cmd_submit(struct stub_device *sdev,
 				 struct usbip_header *pdu)
 {
-	int ret;
 	struct stub_priv *priv;
 	struct usbip_device *ud = &sdev->ud;
 	struct usb_device *udev = sdev->udev;
+	struct scatterlist *sgl = NULL, *sg;
+	void *buffer = NULL;
+	unsigned long long buf_len;
+	int nents;
+	int num_urbs = 1;
 	int pipe = get_pipe(sdev, pdu);
+	int use_sg = pdu->u.cmd_submit.transfer_flags & URB_DMA_MAP_SG;
+	int support_sg = 1;
+	int np = 0;
+	int ret, i;
 
 	if (pipe == -1)
 		return;
@@ -449,76 +474,139 @@ static void stub_recv_cmd_submit(struct stub_device *sdev,
 	if (!priv)
 		return;
 
-	/* setup a urb */
-	if (usb_pipeisoc(pipe))
-		priv->urb = usb_alloc_urb(pdu->u.cmd_submit.number_of_packets,
-					  GFP_KERNEL);
-	else
-		priv->urb = usb_alloc_urb(0, GFP_KERNEL);
+	buf_len = (unsigned long long)pdu->u.cmd_submit.transfer_buffer_length;
 
-	if (!priv->urb) {
-		usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
-		return;
+	/* allocate urb transfer buffer, if needed */
+	if (buf_len) {
+		if (use_sg) {
+			sgl = sgl_alloc(buf_len, GFP_KERNEL, &nents);
+			if (!sgl)
+				goto err_malloc;
+		} else {
+			buffer = kzalloc(buf_len, GFP_KERNEL);
+			if (!buffer)
+				goto err_malloc;
+		}
 	}
 
-	/* allocate urb transfer buffer, if needed */
-	if (pdu->u.cmd_submit.transfer_buffer_length > 0) {
-		priv->urb->transfer_buffer =
-			kzalloc(pdu->u.cmd_submit.transfer_buffer_length,
-				GFP_KERNEL);
-		if (!priv->urb->transfer_buffer) {
+	/* Check if the server's HCD supports SG */
+	if (use_sg && !udev->bus->sg_tablesize) {
+		/*
+		 * If the server's HCD doesn't support SG, break a single SG
+		 * request into several URBs and map each SG list entry to
+		 * corresponding URB buffer. The previously allocated SG
+		 * list is stored in priv->sgl (If the server's HCD support SG,
+		 * SG list is stored only in urb->sg) and it is used as an
+		 * indicator that the server split single SG request into
+		 * several URBs. Later, priv->sgl is used by stub_complete() and
+		 * stub_send_ret_submit() to reassemble the divied URBs.
+		 */
+		support_sg = 0;
+		num_urbs = nents;
+		priv->completed_urbs = 0;
+		pdu->u.cmd_submit.transfer_flags &= ~URB_DMA_MAP_SG;
+	}
+
+	/* allocate urb array */
+	priv->num_urbs = num_urbs;
+	priv->urbs = kmalloc_array(num_urbs, sizeof(*priv->urbs), GFP_KERNEL);
+	if (!priv->urbs)
+		goto err_urbs;
+
+	/* setup a urb */
+	if (support_sg) {
+		if (usb_pipeisoc(pipe))
+			np = pdu->u.cmd_submit.number_of_packets;
+
+		priv->urbs[0] = usb_alloc_urb(np, GFP_KERNEL);
+		if (!priv->urbs[0])
+			goto err_urb;
+
+		if (buf_len) {
+			if (use_sg) {
+				priv->urbs[0]->sg = sgl;
+				priv->urbs[0]->num_sgs = nents;
+				priv->urbs[0]->transfer_buffer = NULL;
+			} else {
+				priv->urbs[0]->transfer_buffer = buffer;
+			}
+		}
+
+		/* copy urb setup packet */
+		priv->urbs[0]->setup_packet = kmemdup(&pdu->u.cmd_submit.setup,
+					8, GFP_KERNEL);
+		if (!priv->urbs[0]->setup_packet) {
 			usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 			return;
 		}
-	}
 
-	/* copy urb setup packet */
-	priv->urb->setup_packet = kmemdup(&pdu->u.cmd_submit.setup, 8,
-					  GFP_KERNEL);
-	if (!priv->urb->setup_packet) {
-		dev_err(&udev->dev, "allocate setup_packet\n");
-		usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
-		return;
+		usbip_pack_pdu(pdu, priv->urbs[0], USBIP_CMD_SUBMIT, 0);
+	} else {
+		for_each_sg(sgl, sg, nents, i) {
+			priv->urbs[i] = usb_alloc_urb(0, GFP_KERNEL);
+			/* The URBs which is previously allocated will be freed
+			 * in stub_device_cleanup_urbs() if error occurs.
+			 */
+			if (!priv->urbs[i])
+				goto err_urb;
+
+			usbip_pack_pdu(pdu, priv->urbs[i], USBIP_CMD_SUBMIT, 0);
+			priv->urbs[i]->transfer_buffer = sg_virt(sg);
+			priv->urbs[i]->transfer_buffer_length = sg->length;
+		}
+		priv->sgl = sgl;
 	}
 
-	/* set other members from the base header of pdu */
-	priv->urb->context                = (void *) priv;
-	priv->urb->dev                    = udev;
-	priv->urb->pipe                   = pipe;
-	priv->urb->complete               = stub_complete;
+	for (i = 0; i < num_urbs; i++) {
+		/* set other members from the base header of pdu */
+		priv->urbs[i]->context = (void *) priv;
+		priv->urbs[i]->dev = udev;
+		priv->urbs[i]->pipe = pipe;
+		priv->urbs[i]->complete = stub_complete;
 
-	usbip_pack_pdu(pdu, priv->urb, USBIP_CMD_SUBMIT, 0);
+		/* no need to submit an intercepted request, but harmless? */
+		tweak_special_requests(priv->urbs[i]);
 
+		masking_bogus_flags(priv->urbs[i]);
+	}
 
-	if (usbip_recv_xbuff(ud, priv->urb) < 0)
+	if (stub_recv_xbuff(ud, priv) < 0)
 		return;
 
-	if (usbip_recv_iso(ud, priv->urb) < 0)
+	if (usbip_recv_iso(ud, priv->urbs[0]) < 0)
 		return;
 
-	/* no need to submit an intercepted request, but harmless? */
-	tweak_special_requests(priv->urb);
-
-	masking_bogus_flags(priv->urb);
 	/* urb is now ready to submit */
-	ret = usb_submit_urb(priv->urb, GFP_KERNEL);
-
-	if (ret == 0)
-		usbip_dbg_stub_rx("submit urb ok, seqnum %u\n",
-				  pdu->base.seqnum);
-	else {
-		dev_err(&udev->dev, "submit_urb error, %d\n", ret);
-		usbip_dump_header(pdu);
-		usbip_dump_urb(priv->urb);
-
-		/*
-		 * Pessimistic.
-		 * This connection will be discarded.
-		 */
-		usbip_event_add(ud, SDEV_EVENT_ERROR_SUBMIT);
+	for (i = 0; i < priv->num_urbs; i++) {
+		ret = usb_submit_urb(priv->urbs[i], GFP_KERNEL);
+
+		if (ret == 0)
+			usbip_dbg_stub_rx("submit urb ok, seqnum %u\n",
+					pdu->base.seqnum);
+		else {
+			dev_err(&udev->dev, "submit_urb error, %d\n", ret);
+			usbip_dump_header(pdu);
+			usbip_dump_urb(priv->urbs[i]);
+
+			/*
+			 * Pessimistic.
+			 * This connection will be discarded.
+			 */
+			usbip_event_add(ud, SDEV_EVENT_ERROR_SUBMIT);
+			break;
+		}
 	}
 
 	usbip_dbg_stub_rx("Leave\n");
+	return;
+
+err_urb:
+	kfree(priv->urbs);
+err_urbs:
+	kfree(buffer);
+	sgl_free(sgl);
+err_malloc:
+	usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
 }
 
 /* recv a pdu */
diff --git a/drivers/usb/usbip/stub_tx.c b/drivers/usb/usbip/stub_tx.c
index f0ec41a50cbc..36010a82b359 100644
--- a/drivers/usb/usbip/stub_tx.c
+++ b/drivers/usb/usbip/stub_tx.c
@@ -5,25 +5,11 @@
 
 #include <linux/kthread.h>
 #include <linux/socket.h>
+#include <linux/scatterlist.h>
 
 #include "usbip_common.h"
 #include "stub.h"
 
-static void stub_free_priv_and_urb(struct stub_priv *priv)
-{
-	struct urb *urb = priv->urb;
-
-	kfree(urb->setup_packet);
-	urb->setup_packet = NULL;
-
-	kfree(urb->transfer_buffer);
-	urb->transfer_buffer = NULL;
-
-	list_del(&priv->list);
-	kmem_cache_free(stub_priv_cache, priv);
-	usb_free_urb(urb);
-}
-
 /* be in spin_lock_irqsave(&sdev->priv_lock, flags) */
 void stub_enqueue_ret_unlink(struct stub_device *sdev, __u32 seqnum,
 			     __u32 status)
@@ -85,6 +71,22 @@ void stub_complete(struct urb *urb)
 		break;
 	}
 
+	/*
+	 * If the server breaks single SG request into the several URBs, the
+	 * URBs must be reassembled before sending completed URB to the vhci.
+	 * Don't wake up the tx thread until all the URBs are completed.
+	 */
+	if (priv->sgl) {
+		priv->completed_urbs++;
+
+		/* Only save the first error status */
+		if (urb->status && !priv->urb_status)
+			priv->urb_status = urb->status;
+
+		if (priv->completed_urbs < priv->num_urbs)
+			return;
+	}
+
 	/* link a urb to the queue of tx. */
 	spin_lock_irqsave(&sdev->priv_lock, flags);
 	if (sdev->ud.tcp_socket == NULL) {
@@ -156,18 +158,22 @@ static int stub_send_ret_submit(struct stub_device *sdev)
 	size_t total_size = 0;
 
 	while ((priv = dequeue_from_priv_tx(sdev)) != NULL) {
-		int ret;
-		struct urb *urb = priv->urb;
+		struct urb *urb = priv->urbs[0];
 		struct usbip_header pdu_header;
 		struct usbip_iso_packet_descriptor *iso_buffer = NULL;
 		struct kvec *iov = NULL;
+		struct scatterlist *sg;
+		u32 actual_length = 0;
 		int iovnum = 0;
+		int ret;
+		int i;
 
 		txsize = 0;
 		memset(&pdu_header, 0, sizeof(pdu_header));
 		memset(&msg, 0, sizeof(msg));
 
-		if (urb->actual_length > 0 && !urb->transfer_buffer) {
+		if (urb->actual_length > 0 && !urb->transfer_buffer &&
+		   !urb->num_sgs) {
 			dev_err(&sdev->udev->dev,
 				"urb: actual_length %d transfer_buffer null\n",
 				urb->actual_length);
@@ -176,6 +182,11 @@ static int stub_send_ret_submit(struct stub_device *sdev)
 
 		if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS)
 			iovnum = 2 + urb->number_of_packets;
+		else if (usb_pipein(urb->pipe) && urb->actual_length > 0 &&
+			urb->num_sgs)
+			iovnum = 1 + urb->num_sgs;
+		else if (usb_pipein(urb->pipe) && priv->sgl)
+			iovnum = 1 + priv->num_urbs;
 		else
 			iovnum = 2;
 
@@ -192,6 +203,15 @@ static int stub_send_ret_submit(struct stub_device *sdev)
 		setup_ret_submit_pdu(&pdu_header, urb);
 		usbip_dbg_stub_tx("setup txdata seqnum: %d\n",
 				  pdu_header.base.seqnum);
+
+		if (priv->sgl) {
+			for (i = 0; i < priv->num_urbs; i++)
+				actual_length += priv->urbs[i]->actual_length;
+
+			pdu_header.u.ret_submit.status = priv->urb_status;
+			pdu_header.u.ret_submit.actual_length = actual_length;
+		}
+
 		usbip_header_correct_endian(&pdu_header, 1);
 
 		iov[iovnum].iov_base = &pdu_header;
@@ -200,12 +220,47 @@ static int stub_send_ret_submit(struct stub_device *sdev)
 		txsize += sizeof(pdu_header);
 
 		/* 2. setup transfer buffer */
-		if (usb_pipein(urb->pipe) &&
+		if (usb_pipein(urb->pipe) && priv->sgl) {
+			/* If the server split a single SG request into several
+			 * URBs because the server's HCD doesn't support SG,
+			 * reassemble the split URB buffers into a single
+			 * return command.
+			 */
+			for (i = 0; i < priv->num_urbs; i++) {
+				iov[iovnum].iov_base =
+					priv->urbs[i]->transfer_buffer;
+				iov[iovnum].iov_len =
+					priv->urbs[i]->actual_length;
+				iovnum++;
+			}
+			txsize += actual_length;
+		} else if (usb_pipein(urb->pipe) &&
 		    usb_pipetype(urb->pipe) != PIPE_ISOCHRONOUS &&
 		    urb->actual_length > 0) {
-			iov[iovnum].iov_base = urb->transfer_buffer;
-			iov[iovnum].iov_len  = urb->actual_length;
-			iovnum++;
+			if (urb->num_sgs) {
+				unsigned int copy = urb->actual_length;
+				int size;
+
+				for_each_sg(urb->sg, sg, urb->num_sgs, i) {
+					if (copy == 0)
+						break;
+
+					if (copy < sg->length)
+						size = copy;
+					else
+						size = sg->length;
+
+					iov[iovnum].iov_base = sg_virt(sg);
+					iov[iovnum].iov_len = size;
+
+					iovnum++;
+					copy -= size;
+				}
+			} else {
+				iov[iovnum].iov_base = urb->transfer_buffer;
+				iov[iovnum].iov_len  = urb->actual_length;
+				iovnum++;
+			}
 			txsize += urb->actual_length;
 		} else if (usb_pipein(urb->pipe) &&
 			   usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
diff --git a/drivers/usb/usbip/usbip_common.c b/drivers/usb/usbip/usbip_common.c
index 45da3e01c7b0..6532d68e8808 100644
--- a/drivers/usb/usbip/usbip_common.c
+++ b/drivers/usb/usbip/usbip_common.c
@@ -680,8 +680,12 @@ EXPORT_SYMBOL_GPL(usbip_pad_iso);
 /* some members of urb must be substituted before. */
 int usbip_recv_xbuff(struct usbip_device *ud, struct urb *urb)
 {
-	int ret;
+	struct scatterlist *sg;
+	int ret = 0;
+	int recv;
 	int size;
+	int copy;
+	int i;
 
 	if (ud->side == USBIP_STUB || ud->side == USBIP_VUDC) {
 		/* the direction of urb must be OUT. */
@@ -701,29 +705,48 @@ int usbip_recv_xbuff(struct usbip_device *ud, struct urb *urb)
 	if (!(size > 0))
 		return 0;
 
-	if (size > urb->transfer_buffer_length) {
+	if (size > urb->transfer_buffer_length)
 		/* should not happen, probably malicious packet */
-		if (ud->side == USBIP_STUB) {
-			usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
-			return 0;
-		} else {
-			usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
-			return -EPIPE;
-		}
-	}
+		goto error;
 
-	ret = usbip_recv(ud->tcp_socket, urb->transfer_buffer, size);
-	if (ret != size) {
-		dev_err(&urb->dev->dev, "recv xbuf, %d\n", ret);
-		if (ud->side == USBIP_STUB || ud->side == USBIP_VUDC) {
-			usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
-		} else {
-			usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
-			return -EPIPE;
+	if (urb->num_sgs) {
+		copy = size;
+		for_each_sg(urb->sg, sg, urb->num_sgs, i) {
+			int recv_size;
+
+			if (copy < sg->length)
+				recv_size = copy;
+			else
+				recv_size = sg->length;
+
+			recv = usbip_recv(ud->tcp_socket, sg_virt(sg),
+						recv_size);
+
+			if (recv != recv_size)
+				goto error;
+
+			copy -= recv;
+			ret += recv;
 		}
+
+		if (ret != size)
+			goto error;
+	} else {
+		ret = usbip_recv(ud->tcp_socket, urb->transfer_buffer, size);
+		if (ret != size)
+			goto error;
 	}
 
 	return ret;
+
+error:
+	dev_err(&urb->dev->dev, "recv xbuf, %d\n", ret);
+	if (ud->side == USBIP_STUB || ud->side == USBIP_VUDC)
+		usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
+	else
+		usbip_event_add(ud, VDEV_EVENT_ERROR_TCP);
+
+	return -EPIPE;
 }
 EXPORT_SYMBOL_GPL(usbip_recv_xbuff);
 
diff --git a/drivers/usb/usbip/vhci_hcd.c b/drivers/usb/usbip/vhci_hcd.c
index 000ab7225717..585a84d319bd 100644
--- a/drivers/usb/usbip/vhci_hcd.c
+++ b/drivers/usb/usbip/vhci_hcd.c
@@ -697,7 +697,8 @@ static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flag
 	}
 	vdev = &vhci_hcd->vdev[portnum-1];
 
-	if (!urb->transfer_buffer && urb->transfer_buffer_length) {
+	if (!urb->transfer_buffer && !urb->num_sgs &&
+	     urb->transfer_buffer_length) {
 		dev_dbg(dev, "Null URB transfer buffer\n");
 		return -EINVAL;
 	}
@@ -1143,6 +1144,15 @@ static int vhci_setup(struct usb_hcd *hcd)
 		hcd->speed = HCD_USB3;
 		hcd->self.root_hub->speed = USB_SPEED_SUPER;
 	}
+
+	/*
+	 * Support SG.
+	 * sg_tablesize is an arbitrary value to alleviate memory pressure
+	 * on the host.
+	 */
+	hcd->self.sg_tablesize = 32;
+	hcd->self.no_sg_constraint = 1;
+
 	return 0;
 }
 
diff --git a/drivers/usb/usbip/vhci_rx.c b/drivers/usb/usbip/vhci_rx.c
index 44cd64518925..33f8972ba842 100644
--- a/drivers/usb/usbip/vhci_rx.c
+++ b/drivers/usb/usbip/vhci_rx.c
@@ -90,6 +90,9 @@ static void vhci_recv_ret_submit(struct vhci_device *vdev,
 	if (usbip_dbg_flag_vhci_rx)
 		usbip_dump_urb(urb);
 
+	if (urb->num_sgs)
+		urb->transfer_flags &= ~URB_DMA_MAP_SG;
+
 	usbip_dbg_vhci_rx("now giveback urb %u\n", pdu->base.seqnum);
 
 	spin_lock_irqsave(&vhci->lock, flags);
diff --git a/drivers/usb/usbip/vhci_tx.c b/drivers/usb/usbip/vhci_tx.c
index 2fa26d0578d7..c3803785f6ef 100644
--- a/drivers/usb/usbip/vhci_tx.c
+++ b/drivers/usb/usbip/vhci_tx.c
@@ -5,6 +5,7 @@
 
 #include <linux/kthread.h>
 #include <linux/slab.h>
+#include <linux/scatterlist.h>
 
 #include "usbip_common.h"
 #include "vhci.h"
@@ -50,19 +51,23 @@ static struct vhci_priv *dequeue_from_priv_tx(struct vhci_device *vdev)
 
 static int vhci_send_cmd_submit(struct vhci_device *vdev)
 {
+	struct usbip_iso_packet_descriptor *iso_buffer = NULL;
 	struct vhci_priv *priv = NULL;
+	struct scatterlist *sg;
 
 	struct msghdr msg;
-	struct kvec iov[3];
+	struct kvec *iov;
 	size_t txsize;
 
 	size_t total_size = 0;
+	int iovnum;
+	int err = -ENOMEM;
+	int i;
 
 	while ((priv = dequeue_from_priv_tx(vdev)) != NULL) {
 		int ret;
 		struct urb *urb = priv->urb;
 		struct usbip_header pdu_header;
-		struct usbip_iso_packet_descriptor *iso_buffer = NULL;
 
 		txsize = 0;
 		memset(&pdu_header, 0, sizeof(pdu_header));
@@ -72,18 +77,45 @@ static int vhci_send_cmd_submit(struct vhci_device *vdev)
 		usbip_dbg_vhci_tx("setup txdata urb seqnum %lu\n",
 				  priv->seqnum);
 
+		if (urb->num_sgs && usb_pipeout(urb->pipe))
+			iovnum = 2 + urb->num_sgs;
+		else
+			iovnum = 3;
+
+		iov = kcalloc(iovnum, sizeof(*iov), GFP_KERNEL);
+		if (!iov) {
+			usbip_event_add(&vdev->ud, SDEV_EVENT_ERROR_MALLOC);
+			return -ENOMEM;
+		}
+
+		if (urb->num_sgs)
+			urb->transfer_flags |= URB_DMA_MAP_SG;
+
 		/* 1. setup usbip_header */
 		setup_cmd_submit_pdu(&pdu_header, urb);
 		usbip_header_correct_endian(&pdu_header, 1);
+		iovnum = 0;
 
-		iov[0].iov_base = &pdu_header;
-		iov[0].iov_len  = sizeof(pdu_header);
+		iov[iovnum].iov_base = &pdu_header;
+		iov[iovnum].iov_len  = sizeof(pdu_header);
 		txsize += sizeof(pdu_header);
+		iovnum++;
 
 		/* 2. setup transfer buffer */
 		if (!usb_pipein(urb->pipe) && urb->transfer_buffer_length > 0) {
-			iov[1].iov_base = urb->transfer_buffer;
-			iov[1].iov_len  = urb->transfer_buffer_length;
+			if (urb->num_sgs &&
+				      !usb_endpoint_xfer_isoc(&urb->ep->desc)) {
+				for_each_sg(urb->sg, sg, urb->num_sgs, i) {
+					iov[iovnum].iov_base = sg_virt(sg);
+					iov[iovnum].iov_len = sg->length;
+					iovnum++;
+				}
+			} else {
+				iov[iovnum].iov_base = urb->transfer_buffer;
+				iov[iovnum].iov_len  =
+						urb->transfer_buffer_length;
+				iovnum++;
+			}
 			txsize += urb->transfer_buffer_length;
 		}
 
@@ -95,23 +127,26 @@ static int vhci_send_cmd_submit(struct vhci_device *vdev)
 			if (!iso_buffer) {
 				usbip_event_add(&vdev->ud,
 						SDEV_EVENT_ERROR_MALLOC);
-				return -1;
+				goto err_iso_buffer;
 			}
 
-			iov[2].iov_base = iso_buffer;
-			iov[2].iov_len  = len;
+			iov[iovnum].iov_base = iso_buffer;
+			iov[iovnum].iov_len  = len;
+			iovnum++;
 			txsize += len;
 		}
 
-		ret = kernel_sendmsg(vdev->ud.tcp_socket, &msg, iov, 3, txsize);
+		ret = kernel_sendmsg(vdev->ud.tcp_socket, &msg, iov, iovnum,
+				     txsize);
 		if (ret != txsize) {
 			pr_err("sendmsg failed!, ret=%d for %zd\n", ret,
 			       txsize);
-			kfree(iso_buffer);
 			usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_TCP);
-			return -1;
+			err = -EPIPE;
+			goto err_tx;
 		}
 
+		kfree(iov);
 		kfree(iso_buffer);
 		usbip_dbg_vhci_tx("send txdata\n");
 
@@ -119,6 +154,13 @@ static int vhci_send_cmd_submit(struct vhci_device *vdev)
 	}
 
 	return total_size;
+
+err_tx:
+	kfree(iso_buffer);
+err_iso_buffer:
+	kfree(iov);
+
+	return err;
 }
 
 static struct vhci_unlink *dequeue_from_unlink_tx(struct vhci_device *vdev)
diff --git a/drivers/usb/usbip/vudc.h b/drivers/usb/usbip/vudc.h
index cf968192e59f..1bd4bc005829 100644
--- a/drivers/usb/usbip/vudc.h
+++ b/drivers/usb/usbip/vudc.h
@@ -115,7 +115,7 @@ struct vudc_device {
 	struct list_head dev_entry;
 };
 
-extern const struct attribute_group vudc_attr_group;
+extern const struct attribute_group *vudc_groups[];
 
 /* visible everywhere */
 
diff --git a/drivers/usb/usbip/vudc_dev.c b/drivers/usb/usbip/vudc_dev.c
index a72c17ff1c6a..c8eeabdd9b56 100644
--- a/drivers/usb/usbip/vudc_dev.c
+++ b/drivers/usb/usbip/vudc_dev.c
@@ -616,18 +616,10 @@ int vudc_probe(struct platform_device *pdev)
 	if (ret < 0)
 		goto err_add_udc;
 
-	ret = sysfs_create_group(&pdev->dev.kobj, &vudc_attr_group);
-	if (ret) {
-		dev_err(&udc->pdev->dev, "create sysfs files\n");
-		goto err_sysfs;
-	}
-
 	platform_set_drvdata(pdev, udc);
 
 	return ret;
 
-err_sysfs:
-	usb_del_gadget_udc(&udc->gadget);
 err_add_udc:
 	cleanup_vudc_hw(udc);
 err_init_vudc_hw:
@@ -640,7 +632,6 @@ int vudc_remove(struct platform_device *pdev)
 {
 	struct vudc *udc = platform_get_drvdata(pdev);
 
-	sysfs_remove_group(&pdev->dev.kobj, &vudc_attr_group);
 	usb_del_gadget_udc(&udc->gadget);
 	cleanup_vudc_hw(udc);
 	kfree(udc);
diff --git a/drivers/usb/usbip/vudc_main.c b/drivers/usb/usbip/vudc_main.c
index 390733e6937e..678faa82598c 100644
--- a/drivers/usb/usbip/vudc_main.c
+++ b/drivers/usb/usbip/vudc_main.c
@@ -22,6 +22,7 @@ static struct platform_driver vudc_driver = {
 	.remove		= vudc_remove,
 	.driver		= {
 		.name	= GADGET_NAME,
+		.dev_groups = vudc_groups,
 	},
 };
 
diff --git a/drivers/usb/usbip/vudc_sysfs.c b/drivers/usb/usbip/vudc_sysfs.c
index 6dcd3ff655c3..100f680c572a 100644
--- a/drivers/usb/usbip/vudc_sysfs.c
+++ b/drivers/usb/usbip/vudc_sysfs.c
@@ -215,7 +215,12 @@ static struct bin_attribute *dev_bin_attrs[] = {
 	NULL,
 };
 
-const struct attribute_group vudc_attr_group = {
+static const struct attribute_group vudc_attr_group = {
 	.attrs = dev_attrs,
 	.bin_attrs = dev_bin_attrs,
 };
+
+const struct attribute_group *vudc_groups[] = {
+	&vudc_attr_group,
+	NULL,
+};