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 2.1 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 Lesser General Public License 20 * along with this program; if not, see <http://www.gnu.org/licenses/>. 21 */ 22 #include "qemu/osdep.h" 23 #include "qemu/units.h" 24 #include "hw/usb.h" 25 #include "qemu/iov.h" 26 #include "trace.h" 27 28 static void usb_combined_packet_add(USBCombinedPacket *combined, USBPacket *p) 29 { 30 qemu_iovec_concat(&combined->iov, &p->iov, 0, p->iov.size); 31 QTAILQ_INSERT_TAIL(&combined->packets, p, combined_entry); 32 p->combined = combined; 33 } 34 35 /* Note will free combined when the last packet gets removed */ 36 static void usb_combined_packet_remove(USBCombinedPacket *combined, 37 USBPacket *p) 38 { 39 assert(p->combined == combined); 40 p->combined = NULL; 41 QTAILQ_REMOVE(&combined->packets, p, combined_entry); 42 if (QTAILQ_EMPTY(&combined->packets)) { 43 qemu_iovec_destroy(&combined->iov); 44 g_free(combined); 45 } 46 } 47 48 /* Also handles completion of non combined packets for pipelined input eps */ 49 void usb_combined_input_packet_complete(USBDevice *dev, USBPacket *p) 50 { 51 USBCombinedPacket *combined = p->combined; 52 USBEndpoint *ep = p->ep; 53 USBPacket *next; 54 int status, actual_length; 55 bool short_not_ok, done = false; 56 57 if (combined == NULL) { 58 usb_packet_complete_one(dev, p); 59 goto leave; 60 } 61 62 assert(combined->first == p && p == QTAILQ_FIRST(&combined->packets)); 63 64 status = combined->first->status; 65 actual_length = combined->first->actual_length; 66 short_not_ok = QTAILQ_LAST(&combined->packets)->short_not_ok; 67 68 QTAILQ_FOREACH_SAFE(p, &combined->packets, combined_entry, next) { 69 if (!done) { 70 /* Distribute data over uncombined packets */ 71 if (actual_length >= p->iov.size) { 72 p->actual_length = p->iov.size; 73 } else { 74 /* Send short or error packet to complete the transfer */ 75 p->actual_length = actual_length; 76 done = true; 77 } 78 /* Report status on the last packet */ 79 if (done || next == NULL) { 80 p->status = status; 81 } else { 82 p->status = USB_RET_SUCCESS; 83 } 84 p->short_not_ok = short_not_ok; 85 /* Note will free combined when the last packet gets removed! */ 86 usb_combined_packet_remove(combined, p); 87 usb_packet_complete_one(dev, p); 88 actual_length -= p->actual_length; 89 } else { 90 /* Remove any leftover packets from the queue */ 91 p->status = USB_RET_REMOVE_FROM_QUEUE; 92 /* Note will free combined on the last packet! */ 93 dev->port->ops->complete(dev->port, p); 94 } 95 } 96 /* Do not use combined here, it has been freed! */ 97 leave: 98 /* Check if there are packets in the queue waiting for our completion */ 99 usb_ep_combine_input_packets(ep); 100 } 101 102 /* May only be called for combined packets! */ 103 void usb_combined_packet_cancel(USBDevice *dev, USBPacket *p) 104 { 105 USBCombinedPacket *combined = p->combined; 106 assert(combined != NULL); 107 USBPacket *first = p->combined->first; 108 109 /* Note will free combined on the last packet! */ 110 usb_combined_packet_remove(combined, p); 111 if (p == first) { 112 usb_device_cancel_packet(dev, p); 113 } 114 } 115 116 /* 117 * Large input transfers can get split into multiple input packets, this 118 * function recombines them, removing the short_not_ok checks which all but 119 * the last packet of such splits transfers have, thereby allowing input 120 * transfer pipelining (which we cannot do on short_not_ok transfers) 121 */ 122 void usb_ep_combine_input_packets(USBEndpoint *ep) 123 { 124 USBPacket *p, *u, *next, *prev = NULL, *first = NULL; 125 USBPort *port = ep->dev->port; 126 int totalsize; 127 128 assert(ep->pipeline); 129 assert(ep->pid == USB_TOKEN_IN); 130 131 QTAILQ_FOREACH_SAFE(p, &ep->queue, queue, next) { 132 /* Empty the queue on a halt */ 133 if (ep->halted) { 134 p->status = USB_RET_REMOVE_FROM_QUEUE; 135 port->ops->complete(port, p); 136 continue; 137 } 138 139 /* Skip packets already submitted to the device */ 140 if (p->state == USB_PACKET_ASYNC) { 141 prev = p; 142 continue; 143 } 144 usb_packet_check_state(p, USB_PACKET_QUEUED); 145 146 /* 147 * If the previous (combined) packet has the short_not_ok flag set 148 * stop, as we must not submit packets to the device after a transfer 149 * ending with short_not_ok packet. 150 */ 151 if (prev && prev->short_not_ok) { 152 break; 153 } 154 155 if (first) { 156 if (first->combined == NULL) { 157 USBCombinedPacket *combined = g_new0(USBCombinedPacket, 1); 158 159 combined->first = first; 160 QTAILQ_INIT(&combined->packets); 161 qemu_iovec_init(&combined->iov, 2); 162 usb_combined_packet_add(combined, first); 163 } 164 usb_combined_packet_add(first->combined, p); 165 } else { 166 first = p; 167 } 168 169 /* Is this packet the last one of a (combined) transfer? */ 170 totalsize = (p->combined) ? p->combined->iov.size : p->iov.size; 171 if ((p->iov.size % ep->max_packet_size) != 0 || !p->short_not_ok || 172 next == NULL || 173 /* Work around for Linux usbfs bulk splitting + migration */ 174 (totalsize == (16 * KiB - 36) && p->int_req)) { 175 usb_device_handle_data(ep->dev, first); 176 assert(first->status == USB_RET_ASYNC); 177 if (first->combined) { 178 QTAILQ_FOREACH(u, &first->combined->packets, combined_entry) { 179 usb_packet_set_state(u, USB_PACKET_ASYNC); 180 } 181 } else { 182 usb_packet_set_state(first, USB_PACKET_ASYNC); 183 } 184 first = NULL; 185 prev = p; 186 } 187 } 188 } 189