1 files changed, 371 insertions, 0 deletions
diff --git a/drivers/staging/usbip/stub_tx.c b/drivers/staging/usbip/stub_tx.c
new file mode 100644
index 000000000000..d5563cd980be
--- /dev/null
+++ b/drivers/staging/usbip/stub_tx.c
@@ -0,0 +1,371 @@
+/*
+ * 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 "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);
+	kfree(urb->transfer_buffer);
+	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)
+{
+	struct stub_unlink *unlink;
+
+	unlink = kzalloc(sizeof(struct stub_unlink), GFP_ATOMIC);
+	if (!unlink) {
+		dev_err(&sdev->interface->dev, "alloc stub_unlink\n");
+		usbip_event_add(&sdev->ud, VDEV_EVENT_ERROR_MALLOC);
+		return;
+	}
+
+	unlink->seqnum = seqnum;
+	unlink->status = status;
+
+	list_add_tail(&unlink->list, &sdev->unlink_tx);
+}
+
+/**
+ * stub_complete - completion handler of a usbip urb
+ * @urb: pointer to the urb completed
+ * @regs:
+ *
+ * When a urb has completed, the USB core driver calls this function mostly in
+ * the interrupt context. To return the result of a urb, the completed urb is
+ * linked to the pending list of returning.
+ *
+ */
+void stub_complete(struct urb *urb)
+{
+	struct stub_priv *priv = (struct stub_priv *) urb->context;
+	struct stub_device *sdev = priv->sdev;
+	unsigned long flags;
+
+	dbg_stub_tx("complete! status %d\n", urb->status);
+
+
+	switch (urb->status) {
+	case 0:
+		/* OK */
+		break;
+	case -ENOENT:
+		uinfo("stopped by a call of usb_kill_urb() because of"
+					"cleaning up a virtual connection\n");
+		return;
+	case -ECONNRESET:
+		uinfo("unlinked by a call of usb_unlink_urb()\n");
+		break;
+	case -EPIPE:
+		uinfo("endpoint %d is stalled\n", usb_pipeendpoint(urb->pipe));
+		break;
+	case -ESHUTDOWN:
+		uinfo("device removed?\n");
+		break;
+	default:
+		uinfo("urb completion with non-zero status %d\n", urb->status);
+	}
+
+	/* link a urb to the queue of tx. */
+	spin_lock_irqsave(&sdev->priv_lock, flags);
+
+	if (priv->unlinking) {
+		stub_enqueue_ret_unlink(sdev, priv->seqnum, urb->status);
+		stub_free_priv_and_urb(priv);
+	} else
+		list_move_tail(&priv->list, &sdev->priv_tx);
+
+
+	spin_unlock_irqrestore(&sdev->priv_lock, flags);
+
+	/* wake up tx_thread */
+	wake_up(&sdev->tx_waitq);
+}
+
+
+/*-------------------------------------------------------------------------*/
+/* fill PDU */
+
+static inline void setup_base_pdu(struct usbip_header_basic *base,
+		__u32 command, __u32 seqnum)
+{
+	base->command = command;
+	base->seqnum  = seqnum;
+	base->devid   = 0;
+	base->ep      = 0;
+	base->direction   = 0;
+}
+
+static void setup_ret_submit_pdu(struct usbip_header *rpdu, struct urb *urb)
+{
+	struct stub_priv *priv = (struct stub_priv *) urb->context;
+
+	setup_base_pdu(&rpdu->base, USBIP_RET_SUBMIT, priv->seqnum);
+
+	usbip_pack_pdu(rpdu, urb, USBIP_RET_SUBMIT, 1);
+}
+
+static void setup_ret_unlink_pdu(struct usbip_header *rpdu,
+		struct stub_unlink *unlink)
+{
+	setup_base_pdu(&rpdu->base, USBIP_RET_UNLINK, unlink->seqnum);
+
+	rpdu->u.ret_unlink.status = unlink->status;
+}
+
+
+/*-------------------------------------------------------------------------*/
+/* send RET_SUBMIT */
+
+static struct stub_priv *dequeue_from_priv_tx(struct stub_device *sdev)
+{
+	unsigned long flags;
+	struct stub_priv *priv, *tmp;
+
+	spin_lock_irqsave(&sdev->priv_lock, flags);
+
+	list_for_each_entry_safe(priv, tmp, &sdev->priv_tx, list) {
+		list_move_tail(&priv->list, &sdev->priv_free);
+		spin_unlock_irqrestore(&sdev->priv_lock, flags);
+		return priv;
+	}
+
+	spin_unlock_irqrestore(&sdev->priv_lock, flags);
+
+	return NULL;
+}
+
+static int stub_send_ret_submit(struct stub_device *sdev)
+{
+	unsigned long flags;
+	struct stub_priv *priv, *tmp;
+
+	struct msghdr msg;
+	struct kvec iov[3];
+	size_t txsize;
+
+	size_t total_size = 0;
+
+	while ((priv = dequeue_from_priv_tx(sdev)) != NULL) {
+		int ret;
+		struct urb *urb = priv->urb;
+		struct usbip_header pdu_header;
+		void *iso_buffer = NULL;
+
+		txsize = 0;
+		memset(&pdu_header, 0, sizeof(pdu_header));
+		memset(&msg, 0, sizeof(msg));
+		memset(&iov, 0, sizeof(iov));
+
+		dbg_stub_tx("setup txdata urb %p\n", urb);
+
+
+		/* 1. setup usbip_header */
+		setup_ret_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->actual_length > 0) {
+			iov[1].iov_base = urb->transfer_buffer;
+			iov[1].iov_len  = urb->actual_length;
+			txsize += urb->actual_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(&sdev->ud,
+						SDEV_EVENT_ERROR_MALLOC);
+				return -1;
+			}
+
+			iov[2].iov_base = iso_buffer;
+			iov[2].iov_len  = len;
+			txsize += len;
+		}
+
+		ret = kernel_sendmsg(sdev->ud.tcp_socket, &msg, iov,
+				     3, txsize);
+		if (ret != txsize) {
+			dev_err(&sdev->interface->dev,
+				"sendmsg failed!, retval %d for %zd\n",
+				ret, txsize);
+			kfree(iso_buffer);
+			usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
+			return -1;
+		}
+
+		kfree(iso_buffer);
+		dbg_stub_tx("send txdata\n");
+
+		total_size += txsize;
+	}
+
+
+	spin_lock_irqsave(&sdev->priv_lock, flags);
+
+	list_for_each_entry_safe(priv, tmp, &sdev->priv_free, list) {
+		stub_free_priv_and_urb(priv);
+	}
+
+	spin_unlock_irqrestore(&sdev->priv_lock, flags);
+
+	return total_size;
+}
+
+
+/*-------------------------------------------------------------------------*/
+/* send RET_UNLINK */
+
+static struct stub_unlink *dequeue_from_unlink_tx(struct stub_device *sdev)
+{
+	unsigned long flags;
+	struct stub_unlink *unlink, *tmp;
+
+	spin_lock_irqsave(&sdev->priv_lock, flags);
+
+	list_for_each_entry_safe(unlink, tmp, &sdev->unlink_tx, list) {
+		list_move_tail(&unlink->list, &sdev->unlink_free);
+		spin_unlock_irqrestore(&sdev->priv_lock, flags);
+		return unlink;
+	}
+
+	spin_unlock_irqrestore(&sdev->priv_lock, flags);
+
+	return NULL;
+}
+
+
+static int stub_send_ret_unlink(struct stub_device *sdev)
+{
+	unsigned long flags;
+	struct stub_unlink *unlink, *tmp;
+
+	struct msghdr msg;
+	struct kvec iov[1];
+	size_t txsize;
+
+	size_t total_size = 0;
+
+	while ((unlink = dequeue_from_unlink_tx(sdev)) != 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));
+
+		dbg_stub_tx("setup ret unlink %lu\n", unlink->seqnum);
+
+		/* 1. setup usbip_header */
+		setup_ret_unlink_pdu(&pdu_header, unlink);
+		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(sdev->ud.tcp_socket, &msg, iov,
+				     1, txsize);
+		if (ret != txsize) {
+			dev_err(&sdev->interface->dev,
+				"sendmsg failed!, retval %d for %zd\n",
+				ret, txsize);
+			usbip_event_add(&sdev->ud, SDEV_EVENT_ERROR_TCP);
+			return -1;
+		}
+
+
+		dbg_stub_tx("send txdata\n");
+
+		total_size += txsize;
+	}
+
+
+	spin_lock_irqsave(&sdev->priv_lock, flags);
+
+	list_for_each_entry_safe(unlink, tmp, &sdev->unlink_free, list) {
+		list_del(&unlink->list);
+		kfree(unlink);
+	}
+
+	spin_unlock_irqrestore(&sdev->priv_lock, flags);
+
+	return total_size;
+}
+
+
+/*-------------------------------------------------------------------------*/
+
+void stub_tx_loop(struct usbip_task *ut)
+{
+	struct usbip_device *ud = container_of(ut, struct usbip_device, tcp_tx);
+	struct stub_device *sdev = container_of(ud, struct stub_device, ud);
+
+	while (1) {
+		if (signal_pending(current)) {
+			dbg_stub_tx("signal catched\n");
+			break;
+		}
+
+		if (usbip_event_happend(ud))
+			break;
+
+		/*
+		 * send_ret_submit comes earlier than send_ret_unlink.  stub_rx
+		 * looks at only priv_init queue. If the completion of a URB is
+		 * earlier than the receive of CMD_UNLINK, priv is moved to
+		 * priv_tx queue and stub_rx does not find the target priv. In
+		 * this case, vhci_rx receives the result of the submit request
+		 * and then receives the result of the unlink request. The
+		 * result of the submit is given back to the usbcore as the
+		 * completion of the unlink request. The request of the
+		 * unlink is ignored. This is ok because a driver who calls
+		 * usb_unlink_urb() understands the unlink was too late by
+		 * getting the status of the given-backed URB which has the
+		 * status of usb_submit_urb().
+		 */
+		if (stub_send_ret_submit(sdev) < 0)
+			break;
+
+		if (stub_send_ret_unlink(sdev) < 0)
+			break;
+
+		wait_event_interruptible(sdev->tx_waitq,
+				(!list_empty(&sdev->priv_tx) ||
+				 !list_empty(&sdev->unlink_tx)));
+	}
+}