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 static void usb_combined_packet_remove(USBCombinedPacket *combined, 35 USBPacket *p) 36 { 37 assert(p->combined == combined); 38 p->combined = NULL; 39 QTAILQ_REMOVE(&combined->packets, p, combined_entry); 40 } 41 42 /* Also handles completion of non combined packets for pipelined input eps */ 43 void usb_combined_input_packet_complete(USBDevice *dev, USBPacket *p) 44 { 45 USBCombinedPacket *combined = p->combined; 46 USBEndpoint *ep = p->ep; 47 USBPacket *next; 48 enum { completing, complete, leftover }; 49 int result, state = completing; 50 bool short_not_ok; 51 52 if (combined == NULL) { 53 usb_packet_complete_one(dev, p); 54 goto leave; 55 } 56 57 assert(combined->first == p && p == QTAILQ_FIRST(&combined->packets)); 58 59 result = combined->first->result; 60 short_not_ok = QTAILQ_LAST(&combined->packets, packets_head)->short_not_ok; 61 62 QTAILQ_FOREACH_SAFE(p, &combined->packets, combined_entry, next) { 63 if (state == completing) { 64 /* Distribute data over uncombined packets */ 65 if (result >= p->iov.size) { 66 p->result = p->iov.size; 67 } else { 68 /* Send short or error packet to complete the transfer */ 69 p->result = result; 70 state = complete; 71 } 72 p->short_not_ok = short_not_ok; 73 usb_combined_packet_remove(combined, p); 74 usb_packet_complete_one(dev, p); 75 result -= p->result; 76 } else { 77 /* Remove any leftover packets from the queue */ 78 state = leftover; 79 p->result = USB_RET_REMOVE_FROM_QUEUE; 80 dev->port->ops->complete(dev->port, p); 81 } 82 } 83 /* 84 * If we had leftover packets the hcd driver will have cancelled them 85 * and usb_combined_packet_cancel has already freed combined! 86 */ 87 if (state != leftover) { 88 g_free(combined); 89 } 90 leave: 91 /* Check if there are packets in the queue waiting for our completion */ 92 usb_ep_combine_input_packets(ep); 93 } 94 95 /* May only be called for combined packets! */ 96 void usb_combined_packet_cancel(USBDevice *dev, USBPacket *p) 97 { 98 USBCombinedPacket *combined = p->combined; 99 assert(combined != NULL); 100 101 usb_combined_packet_remove(combined, p); 102 if (p == combined->first) { 103 usb_device_cancel_packet(dev, p); 104 } 105 if (QTAILQ_EMPTY(&combined->packets)) { 106 g_free(combined); 107 } 108 } 109 110 /* 111 * Large input transfers can get split into multiple input packets, this 112 * function recombines them, removing the short_not_ok checks which all but 113 * the last packet of such splits transfers have, thereby allowing input 114 * transfer pipelining (which we cannot do on short_not_ok transfers) 115 */ 116 void usb_ep_combine_input_packets(USBEndpoint *ep) 117 { 118 USBPacket *p, *u, *next, *prev = NULL, *first = NULL; 119 USBPort *port = ep->dev->port; 120 int ret, totalsize; 121 122 assert(ep->pipeline); 123 assert(ep->pid == USB_TOKEN_IN); 124 125 QTAILQ_FOREACH_SAFE(p, &ep->queue, queue, next) { 126 /* Empty the queue on a halt */ 127 if (ep->halted) { 128 p->result = USB_RET_REMOVE_FROM_QUEUE; 129 port->ops->complete(port, p); 130 continue; 131 } 132 133 /* Skip packets already submitted to the device */ 134 if (p->state == USB_PACKET_ASYNC) { 135 prev = p; 136 continue; 137 } 138 usb_packet_check_state(p, USB_PACKET_QUEUED); 139 140 /* 141 * If the previous (combined) packet has the short_not_ok flag set 142 * stop, as we must not submit packets to the device after a transfer 143 * ending with short_not_ok packet. 144 */ 145 if (prev && prev->short_not_ok) { 146 break; 147 } 148 149 if (first) { 150 if (first->combined == NULL) { 151 USBCombinedPacket *combined = g_new0(USBCombinedPacket, 1); 152 153 combined->first = first; 154 QTAILQ_INIT(&combined->packets); 155 qemu_iovec_init(&combined->iov, 2); 156 usb_combined_packet_add(combined, first); 157 } 158 usb_combined_packet_add(first->combined, p); 159 } else { 160 first = p; 161 } 162 163 /* Is this packet the last one of a (combined) transfer? */ 164 totalsize = (p->combined) ? p->combined->iov.size : p->iov.size; 165 if ((p->iov.size % ep->max_packet_size) != 0 || !p->short_not_ok || 166 next == NULL || 167 /* Work around for Linux usbfs bulk splitting + migration */ 168 (totalsize == 16348 && p->int_req)) { 169 ret = usb_device_handle_data(ep->dev, first); 170 assert(ret == USB_RET_ASYNC); 171 if (first->combined) { 172 QTAILQ_FOREACH(u, &first->combined->packets, combined_entry) { 173 usb_packet_set_state(u, USB_PACKET_ASYNC); 174 } 175 } else { 176 usb_packet_set_state(first, USB_PACKET_ASYNC); 177 } 178 first = NULL; 179 prev = p; 180 } 181 } 182 } 183