1 /* 2 * QEMU USB packet combining code (for input pipelining) 3 * 4 * Copyright(c) 2012 Red Hat, Inc. 5 * 6 * Red Hat Authors: 7 * Hans de Goede <hdegoede@redhat.com> 8 * 9 * This library is free software; you can redistribute it and/or 10 * modify it under the terms of the GNU Lesser General Public 11 * License as published by the Free Software Foundation; either 12 * version 2 of the License, or(at your option) any later version. 13 * 14 * This library is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 17 * Lesser General Public License for more details. 18 * 19 * You should have received a copy of the GNU General Public License 20 * along with this program; if not, see <http://www.gnu.org/licenses/>. 21 */ 22 #include "qemu-common.h" 23 #include "hw/usb.h" 24 #include "iov.h" 25 #include "trace.h" 26 27 static void usb_combined_packet_add(USBCombinedPacket *combined, USBPacket *p) 28 { 29 qemu_iovec_concat(&combined->iov, &p->iov, 0, p->iov.size); 30 QTAILQ_INSERT_TAIL(&combined->packets, p, combined_entry); 31 p->combined = combined; 32 } 33 34 /* Note will free combined when the last packet gets removed */ 35 static void usb_combined_packet_remove(USBCombinedPacket *combined, 36 USBPacket *p) 37 { 38 assert(p->combined == combined); 39 p->combined = NULL; 40 QTAILQ_REMOVE(&combined->packets, p, combined_entry); 41 if (QTAILQ_EMPTY(&combined->packets)) { 42 g_free(combined); 43 } 44 } 45 46 /* Also handles completion of non combined packets for pipelined input eps */ 47 void usb_combined_input_packet_complete(USBDevice *dev, USBPacket *p) 48 { 49 USBCombinedPacket *combined = p->combined; 50 USBEndpoint *ep = p->ep; 51 USBPacket *next; 52 int status, actual_length; 53 bool short_not_ok, done = false; 54 55 if (combined == NULL) { 56 usb_packet_complete_one(dev, p); 57 goto leave; 58 } 59 60 assert(combined->first == p && p == QTAILQ_FIRST(&combined->packets)); 61 62 status = combined->first->status; 63 actual_length = combined->first->actual_length; 64 short_not_ok = QTAILQ_LAST(&combined->packets, packets_head)->short_not_ok; 65 66 QTAILQ_FOREACH_SAFE(p, &combined->packets, combined_entry, next) { 67 if (!done) { 68 /* Distribute data over uncombined packets */ 69 if (actual_length >= p->iov.size) { 70 p->actual_length = p->iov.size; 71 } else { 72 /* Send short or error packet to complete the transfer */ 73 p->actual_length = actual_length; 74 done = true; 75 } 76 /* Report status on the last packet */ 77 if (done || next == NULL) { 78 p->status = status; 79 } else { 80 p->status = USB_RET_SUCCESS; 81 } 82 p->short_not_ok = short_not_ok; 83 /* Note will free combined when the last packet gets removed! */ 84 usb_combined_packet_remove(combined, p); 85 usb_packet_complete_one(dev, p); 86 actual_length -= p->actual_length; 87 } else { 88 /* Remove any leftover packets from the queue */ 89 p->status = USB_RET_REMOVE_FROM_QUEUE; 90 /* Note will free combined on the last packet! */ 91 dev->port->ops->complete(dev->port, p); 92 } 93 } 94 /* Do not use combined here, it has been freed! */ 95 leave: 96 /* Check if there are packets in the queue waiting for our completion */ 97 usb_ep_combine_input_packets(ep); 98 } 99 100 /* May only be called for combined packets! */ 101 void usb_combined_packet_cancel(USBDevice *dev, USBPacket *p) 102 { 103 USBCombinedPacket *combined = p->combined; 104 assert(combined != NULL); 105 USBPacket *first = p->combined->first; 106 107 /* Note will free combined on the last packet! */ 108 usb_combined_packet_remove(combined, p); 109 if (p == first) { 110 usb_device_cancel_packet(dev, p); 111 } 112 } 113 114 /* 115 * Large input transfers can get split into multiple input packets, this 116 * function recombines them, removing the short_not_ok checks which all but 117 * the last packet of such splits transfers have, thereby allowing input 118 * transfer pipelining (which we cannot do on short_not_ok transfers) 119 */ 120 void usb_ep_combine_input_packets(USBEndpoint *ep) 121 { 122 USBPacket *p, *u, *next, *prev = NULL, *first = NULL; 123 USBPort *port = ep->dev->port; 124 int totalsize; 125 126 assert(ep->pipeline); 127 assert(ep->pid == USB_TOKEN_IN); 128 129 QTAILQ_FOREACH_SAFE(p, &ep->queue, queue, next) { 130 /* Empty the queue on a halt */ 131 if (ep->halted) { 132 p->status = USB_RET_REMOVE_FROM_QUEUE; 133 port->ops->complete(port, p); 134 continue; 135 } 136 137 /* Skip packets already submitted to the device */ 138 if (p->state == USB_PACKET_ASYNC) { 139 prev = p; 140 continue; 141 } 142 usb_packet_check_state(p, USB_PACKET_QUEUED); 143 144 /* 145 * If the previous (combined) packet has the short_not_ok flag set 146 * stop, as we must not submit packets to the device after a transfer 147 * ending with short_not_ok packet. 148 */ 149 if (prev && prev->short_not_ok) { 150 break; 151 } 152 153 if (first) { 154 if (first->combined == NULL) { 155 USBCombinedPacket *combined = g_new0(USBCombinedPacket, 1); 156 157 combined->first = first; 158 QTAILQ_INIT(&combined->packets); 159 qemu_iovec_init(&combined->iov, 2); 160 usb_combined_packet_add(combined, first); 161 } 162 usb_combined_packet_add(first->combined, p); 163 } else { 164 first = p; 165 } 166 167 /* Is this packet the last one of a (combined) transfer? */ 168 totalsize = (p->combined) ? p->combined->iov.size : p->iov.size; 169 if ((p->iov.size % ep->max_packet_size) != 0 || !p->short_not_ok || 170 next == NULL || 171 /* Work around for Linux usbfs bulk splitting + migration */ 172 (totalsize == 16348 && p->int_req)) { 173 usb_device_handle_data(ep->dev, first); 174 assert(first->status == USB_RET_ASYNC); 175 if (first->combined) { 176 QTAILQ_FOREACH(u, &first->combined->packets, combined_entry) { 177 usb_packet_set_state(u, USB_PACKET_ASYNC); 178 } 179 } else { 180 usb_packet_set_state(first, USB_PACKET_ASYNC); 181 } 182 first = NULL; 183 prev = p; 184 } 185 } 186 } 187