File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/drivers/usb/usbip/vhci_tx.c b/drivers/usb/usbip/vhci_tx.c
new file mode 100644
index 0000000..409fd99
--- /dev/null
+++ b/drivers/usb/usbip/vhci_tx.c
@@ -0,0 +1,224 @@
+/*
+ * Copyright (C) 2003-2008 Takahiro Hirofuchi
+ *
+ * This is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
+ * USA.
+ */
+
+#include <linux/kthread.h>
+#include <linux/slab.h>
+
+#include "usbip_common.h"
+#include "vhci.h"
+
+static void setup_cmd_submit_pdu(struct usbip_header *pdup,  struct urb *urb)
+{
+	struct vhci_priv *priv = ((struct vhci_priv *)urb->hcpriv);
+	struct vhci_device *vdev = priv->vdev;
+
+	usbip_dbg_vhci_tx("URB, local devnum %u, remote devid %u\n",
+			  usb_pipedevice(urb->pipe), vdev->devid);
+
+	pdup->base.command   = USBIP_CMD_SUBMIT;
+	pdup->base.seqnum    = priv->seqnum;
+	pdup->base.devid     = vdev->devid;
+	pdup->base.direction = usb_pipein(urb->pipe) ?
+		USBIP_DIR_IN : USBIP_DIR_OUT;
+	pdup->base.ep	     = usb_pipeendpoint(urb->pipe);
+
+	usbip_pack_pdu(pdup, urb, USBIP_CMD_SUBMIT, 1);
+
+	if (urb->setup_packet)
+		memcpy(pdup->u.cmd_submit.setup, urb->setup_packet, 8);
+}
+
+static struct vhci_priv *dequeue_from_priv_tx(struct vhci_device *vdev)
+{
+	struct vhci_priv *priv, *tmp;
+
+	spin_lock(&vdev->priv_lock);
+
+	list_for_each_entry_safe(priv, tmp, &vdev->priv_tx, list) {
+		list_move_tail(&priv->list, &vdev->priv_rx);
+		spin_unlock(&vdev->priv_lock);
+		return priv;
+	}
+
+	spin_unlock(&vdev->priv_lock);
+
+	return NULL;
+}
+
+static int vhci_send_cmd_submit(struct vhci_device *vdev)
+{
+	struct vhci_priv *priv = NULL;
+
+	struct msghdr msg;
+	struct kvec iov[3];
+	size_t txsize;
+
+	size_t total_size = 0;
+
+	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));
+		memset(&msg, 0, sizeof(msg));
+		memset(&iov, 0, sizeof(iov));
+
+		usbip_dbg_vhci_tx("setup txdata urb %p\n", urb);
+
+		/* 1. setup usbip_header */
+		setup_cmd_submit_pdu(&pdu_header, urb);
+		usbip_header_correct_endian(&pdu_header, 1);
+
+		iov[0].iov_base = &pdu_header;
+		iov[0].iov_len  = sizeof(pdu_header);
+		txsize += sizeof(pdu_header);
+
+		/* 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;
+			txsize += urb->transfer_buffer_length;
+		}
+
+		/* 3. setup iso_packet_descriptor */
+		if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
+			ssize_t len = 0;
+
+			iso_buffer = usbip_alloc_iso_desc_pdu(urb, &len);
+			if (!iso_buffer) {
+				usbip_event_add(&vdev->ud,
+						SDEV_EVENT_ERROR_MALLOC);
+				return -1;
+			}
+
+			iov[2].iov_base = iso_buffer;
+			iov[2].iov_len  = len;
+			txsize += len;
+		}
+
+		ret = kernel_sendmsg(vdev->ud.tcp_socket, &msg, iov, 3, 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;
+		}
+
+		kfree(iso_buffer);
+		usbip_dbg_vhci_tx("send txdata\n");
+
+		total_size += txsize;
+	}
+
+	return total_size;
+}
+
+static struct vhci_unlink *dequeue_from_unlink_tx(struct vhci_device *vdev)
+{
+	struct vhci_unlink *unlink, *tmp;
+
+	spin_lock(&vdev->priv_lock);
+
+	list_for_each_entry_safe(unlink, tmp, &vdev->unlink_tx, list) {
+		list_move_tail(&unlink->list, &vdev->unlink_rx);
+		spin_unlock(&vdev->priv_lock);
+		return unlink;
+	}
+
+	spin_unlock(&vdev->priv_lock);
+
+	return NULL;
+}
+
+static int vhci_send_cmd_unlink(struct vhci_device *vdev)
+{
+	struct vhci_unlink *unlink = NULL;
+
+	struct msghdr msg;
+	struct kvec iov[3];
+	size_t txsize;
+
+	size_t total_size = 0;
+
+	while ((unlink = dequeue_from_unlink_tx(vdev)) != NULL) {
+		int ret;
+		struct usbip_header pdu_header;
+
+		txsize = 0;
+		memset(&pdu_header, 0, sizeof(pdu_header));
+		memset(&msg, 0, sizeof(msg));
+		memset(&iov, 0, sizeof(iov));
+
+		usbip_dbg_vhci_tx("setup cmd unlink, %lu\n", unlink->seqnum);
+
+		/* 1. setup usbip_header */
+		pdu_header.base.command = USBIP_CMD_UNLINK;
+		pdu_header.base.seqnum  = unlink->seqnum;
+		pdu_header.base.devid	= vdev->devid;
+		pdu_header.base.ep	= 0;
+		pdu_header.u.cmd_unlink.seqnum = unlink->unlink_seqnum;
+
+		usbip_header_correct_endian(&pdu_header, 1);
+
+		iov[0].iov_base = &pdu_header;
+		iov[0].iov_len  = sizeof(pdu_header);
+		txsize += sizeof(pdu_header);
+
+		ret = kernel_sendmsg(vdev->ud.tcp_socket, &msg, iov, 1, txsize);
+		if (ret != txsize) {
+			pr_err("sendmsg failed!, ret=%d for %zd\n", ret,
+			       txsize);
+			usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_TCP);
+			return -1;
+		}
+
+		usbip_dbg_vhci_tx("send txdata\n");
+
+		total_size += txsize;
+	}
+
+	return total_size;
+}
+
+int vhci_tx_loop(void *data)
+{
+	struct usbip_device *ud = data;
+	struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
+
+	while (!kthread_should_stop()) {
+		if (vhci_send_cmd_submit(vdev) < 0)
+			break;
+
+		if (vhci_send_cmd_unlink(vdev) < 0)
+			break;
+
+		wait_event_interruptible(vdev->waitq_tx,
+					 (!list_empty(&vdev->priv_tx) ||
+					  !list_empty(&vdev->unlink_tx) ||
+					  kthread_should_stop()));
+
+		usbip_dbg_vhci_tx("pending urbs ?, now wake up\n");
+	}
+
+	return 0;
+}