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 "qemu/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 qemu_iovec_destroy(&combined->iov); 43 g_free(combined); 44 } 45 } 46 47 /* Also handles completion of non combined packets for pipelined input eps */ 48 void usb_combined_input_packet_complete(USBDevice *dev, USBPacket *p) 49 { 50 USBCombinedPacket *combined = p->combined; 51 USBEndpoint *ep = p->ep; 52 USBPacket *next; 53 int status, actual_length; 54 bool short_not_ok, done = false; 55 56 if (combined == NULL) { 57 usb_packet_complete_one(dev, p); 58 goto leave; 59 } 60 61 assert(combined->first == p && p == QTAILQ_FIRST(&combined->packets)); 62 63 status = combined->first->status; 64 actual_length = combined->first->actual_length; 65 short_not_ok = QTAILQ_LAST(&combined->packets, packets_head)->short_not_ok; 66 67 QTAILQ_FOREACH_SAFE(p, &combined->packets, combined_entry, next) { 68 if (!done) { 69 /* Distribute data over uncombined packets */ 70 if (actual_length >= p->iov.size) { 71 p->actual_length = p->iov.size; 72 } else { 73 /* Send short or error packet to complete the transfer */ 74 p->actual_length = actual_length; 75 done = true; 76 } 77 /* Report status on the last packet */ 78 if (done || next == NULL) { 79 p->status = status; 80 } else { 81 p->status = USB_RET_SUCCESS; 82 } 83 p->short_not_ok = short_not_ok; 84 /* Note will free combined when the last packet gets removed! */ 85 usb_combined_packet_remove(combined, p); 86 usb_packet_complete_one(dev, p); 87 actual_length -= p->actual_length; 88 } else { 89 /* Remove any leftover packets from the queue */ 90 p->status = USB_RET_REMOVE_FROM_QUEUE; 91 /* Note will free combined on the last packet! */ 92 dev->port->ops->complete(dev->port, p); 93 } 94 } 95 /* Do not use combined here, it has been freed! */ 96 leave: 97 /* Check if there are packets in the queue waiting for our completion */ 98 usb_ep_combine_input_packets(ep); 99 } 100 101 /* May only be called for combined packets! */ 102 void usb_combined_packet_cancel(USBDevice *dev, USBPacket *p) 103 { 104 USBCombinedPacket *combined = p->combined; 105 assert(combined != NULL); 106 USBPacket *first = p->combined->first; 107 108 /* Note will free combined on the last packet! */ 109 usb_combined_packet_remove(combined, p); 110 if (p == first) { 111 usb_device_cancel_packet(dev, p); 112 } 113 } 114 115 /* 116 * Large input transfers can get split into multiple input packets, this 117 * function recombines them, removing the short_not_ok checks which all but 118 * the last packet of such splits transfers have, thereby allowing input 119 * transfer pipelining (which we cannot do on short_not_ok transfers) 120 */ 121 void usb_ep_combine_input_packets(USBEndpoint *ep) 122 { 123 USBPacket *p, *u, *next, *prev = NULL, *first = NULL; 124 USBPort *port = ep->dev->port; 125 int totalsize; 126 127 assert(ep->pipeline); 128 assert(ep->pid == USB_TOKEN_IN); 129 130 QTAILQ_FOREACH_SAFE(p, &ep->queue, queue, next) { 131 /* Empty the queue on a halt */ 132 if (ep->halted) { 133 p->status = USB_RET_REMOVE_FROM_QUEUE; 134 port->ops->complete(port, p); 135 continue; 136 } 137 138 /* Skip packets already submitted to the device */ 139 if (p->state == USB_PACKET_ASYNC) { 140 prev = p; 141 continue; 142 } 143 usb_packet_check_state(p, USB_PACKET_QUEUED); 144 145 /* 146 * If the previous (combined) packet has the short_not_ok flag set 147 * stop, as we must not submit packets to the device after a transfer 148 * ending with short_not_ok packet. 149 */ 150 if (prev && prev->short_not_ok) { 151 break; 152 } 153 154 if (first) { 155 if (first->combined == NULL) { 156 USBCombinedPacket *combined = g_new0(USBCombinedPacket, 1); 157 158 combined->first = first; 159 QTAILQ_INIT(&combined->packets); 160 qemu_iovec_init(&combined->iov, 2); 161 usb_combined_packet_add(combined, first); 162 } 163 usb_combined_packet_add(first->combined, p); 164 } else { 165 first = p; 166 } 167 168 /* Is this packet the last one of a (combined) transfer? */ 169 totalsize = (p->combined) ? p->combined->iov.size : p->iov.size; 170 if ((p->iov.size % ep->max_packet_size) != 0 || !p->short_not_ok || 171 next == NULL || 172 /* Work around for Linux usbfs bulk splitting + migration */ 173 (totalsize == 16348 && p->int_req)) { 174 usb_device_handle_data(ep->dev, first); 175 assert(first->status == USB_RET_ASYNC); 176 if (first->combined) { 177 QTAILQ_FOREACH(u, &first->combined->packets, combined_entry) { 178 usb_packet_set_state(u, USB_PACKET_ASYNC); 179 } 180 } else { 181 usb_packet_set_state(first, USB_PACKET_ASYNC); 182 } 183 first = NULL; 184 prev = p; 185 } 186 } 187 } 188