vhci_tx.c

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/*
 * 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)
{
    unsigned long flags;
    struct vhci_priv *priv, *tmp;

    spin_lock_irqsave(&vdev->priv_lock, flags);

    list_for_each_entry_safe(priv, tmp, &vdev->priv_tx, list) {
        list_move_tail(&priv->list, &vdev->priv_rx);
        spin_unlock_irqrestore(&vdev->priv_lock, flags);
        return priv;
    }

    spin_unlock_irqrestore(&vdev->priv_lock, flags);

    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;
        void *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)
{
    unsigned long flags;
    struct vhci_unlink *unlink, *tmp;

    spin_lock_irqsave(&vdev->priv_lock, flags);

    list_for_each_entry_safe(unlink, tmp, &vdev->unlink_tx, list) {
        list_move_tail(&unlink->list, &vdev->unlink_rx);
        spin_unlock_irqrestore(&vdev->priv_lock, flags);
        return unlink;
    }

    spin_unlock_irqrestore(&vdev->priv_lock, flags);

    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;
}