/*
* QEMU USB packet combining code (for input pipelining)
*
* Copyright(c) 2012 Red Hat, Inc.
*
* Red Hat Authors:
* Hans de Goede <hdegoede@redhat.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "qemu/units.h"
#include "hw/usb.h"
#include "qemu/iov.h"
#include "trace.h"
static void usb_combined_packet_add(USBCombinedPacket *combined, USBPacket *p)
{
qemu_iovec_concat(&combined->iov, &p->iov, 0, p->iov.size);
QTAILQ_INSERT_TAIL(&combined->packets, p, combined_entry);
p->combined = combined;
}
/* Note will free combined when the last packet gets removed */
static void usb_combined_packet_remove(USBCombinedPacket *combined,
USBPacket *p)
{
assert(p->combined == combined);
p->combined = NULL;
QTAILQ_REMOVE(&combined->packets, p, combined_entry);
if (QTAILQ_EMPTY(&combined->packets)) {
qemu_iovec_destroy(&combined->iov);
g_free(combined);
}
}
/* Also handles completion of non combined packets for pipelined input eps */
void usb_combined_input_packet_complete(USBDevice *dev, USBPacket *p)
{
USBCombinedPacket *combined = p->combined;
USBEndpoint *ep = p->ep;
USBPacket *next;
int status, actual_length;
bool short_not_ok, done = false;
if (combined == NULL) {
usb_packet_complete_one(dev, p);
goto leave;
}
assert(combined->first == p && p == QTAILQ_FIRST(&combined->packets));
status = combined->first->status;
actual_length = combined->first->actual_length;
short_not_ok = QTAILQ_LAST(&combined->packets)->short_not_ok;
QTAILQ_FOREACH_SAFE(p, &combined->packets, combined_entry, next) {
if (!done) {
/* Distribute data over uncombined packets */
if (actual_length >= p->iov.size) {
p->actual_length = p->iov.size;
} else {
/* Send short or error packet to complete the transfer */
p->actual_length = actual_length;
done = true;
}
/* Report status on the last packet */
if (done || next == NULL) {
p->status = status;
} else {
p->status = USB_RET_SUCCESS;
}
p->short_not_ok = short_not_ok;
/* Note will free combined when the last packet gets removed! */
usb_combined_packet_remove(combined, p);
usb_packet_complete_one(dev, p);
actual_length -= p->actual_length;
} else {
/* Remove any leftover packets from the queue */
p->status = USB_RET_REMOVE_FROM_QUEUE;
/* Note will free combined on the last packet! */
dev->port->ops->complete(dev->port, p);
}
}
/* Do not use combined here, it has been freed! */
leave:
/* Check if there are packets in the queue waiting for our completion */
usb_ep_combine_input_packets(ep);
}
/* May only be called for combined packets! */
void usb_combined_packet_cancel(USBDevice *dev, USBPacket *p)
{
USBCombinedPacket *combined = p->combined;
assert(combined != NULL);
USBPacket *first = p->combined->first;
/* Note will free combined on the last packet! */
usb_combined_packet_remove(combined, p);
if (p == first) {
usb_device_cancel_packet(dev, p);
}
}
/*
* Large input transfers can get split into multiple input packets, this
* function recombines them, removing the short_not_ok checks which all but
* the last packet of such splits transfers have, thereby allowing input
* transfer pipelining (which we cannot do on short_not_ok transfers)
*/
void usb_ep_combine_input_packets(USBEndpoint *ep)
{
USBPacket *p, *u, *next, *prev = NULL, *first = NULL;
USBPort *port = ep->dev->port;
int totalsize;
assert(ep->pipeline);
assert(ep->pid == USB_TOKEN_IN);
QTAILQ_FOREACH_SAFE(p, &ep->queue, queue, next) {
/* Empty the queue on a halt */
if (ep->halted) {
p->status = USB_RET_REMOVE_FROM_QUEUE;
port->ops->complete(port, p);
continue;
}
/* Skip packets already submitted to the device */
if (p->state == USB_PACKET_ASYNC) {
prev = p;
continue;
}
usb_packet_check_state(p, USB_PACKET_QUEUED);
/*
* If the previous (combined) packet has the short_not_ok flag set
* stop, as we must not submit packets to the device after a transfer
* ending with short_not_ok packet.
*/
if (prev && prev->short_not_ok) {
break;
}
if (first) {
if (first->combined == NULL) {
USBCombinedPacket *combined = g_new0(USBCombinedPacket, 1);
combined->first = first;
QTAILQ_INIT(&combined->packets);
qemu_iovec_init(&combined->iov, 2);
usb_combined_packet_add(combined, first);
}
usb_combined_packet_add(first->combined, p);
} else {
first = p;
}
/* Is this packet the last one of a (combined) transfer? */
totalsize = (p->combined) ? p->combined->iov.size : p->iov.size;
if ((p->iov.size % ep->max_packet_size) != 0 || !p->short_not_ok ||
next == NULL ||
/* Work around for Linux usbfs bulk splitting + migration */
(totalsize == (16 * KiB - 36) && p->int_req)) {
usb_device_handle_data(ep->dev, first);
assert(first->status == USB_RET_ASYNC);
if (first->combined) {
QTAILQ_FOREACH(u, &first->combined->packets, combined_entry) {
usb_packet_set_state(u, USB_PACKET_ASYNC);
}
} else {
usb_packet_set_state(first, USB_PACKET_ASYNC);
}
first = NULL;
prev = p;
}
}
}
