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/osdep.h" 23 #include "qemu/units.h" 24 #include "qemu-common.h" 25 #include "hw/usb.h" 26 #include "qemu/iov.h" 27 #include "trace.h" 28 29 static void usb_combined_packet_add(USBCombinedPacket *combined, USBPacket *p) 30 { 31 qemu_iovec_concat(&combined->iov, &p->iov, 0, p->iov.size); 32 QTAILQ_INSERT_TAIL(&combined->packets, p, combined_entry); 33 p->combined = combined; 34 } 35 36 /* Note will free combined when the last packet gets removed */ 37 static void usb_combined_packet_remove(USBCombinedPacket *combined, 38 USBPacket *p) 39 { 40 assert(p->combined == combined); 41 p->combined = NULL; 42 QTAILQ_REMOVE(&combined->packets, p, combined_entry); 43 if (QTAILQ_EMPTY(&combined->packets)) { 44 qemu_iovec_destroy(&combined->iov); 45 g_free(combined); 46 } 47 } 48 49 /* Also handles completion of non combined packets for pipelined input eps */ 50 void usb_combined_input_packet_complete(USBDevice *dev, USBPacket *p) 51 { 52 USBCombinedPacket *combined = p->combined; 53 USBEndpoint *ep = p->ep; 54 USBPacket *next; 55 int status, actual_length; 56 bool short_not_ok, done = false; 57 58 if (combined == NULL) { 59 usb_packet_complete_one(dev, p); 60 goto leave; 61 } 62 63 assert(combined->first == p && p == QTAILQ_FIRST(&combined->packets)); 64 65 status = combined->first->status; 66 actual_length = combined->first->actual_length; 67 short_not_ok = QTAILQ_LAST(&combined->packets, packets_head)->short_not_ok; 68 69 QTAILQ_FOREACH_SAFE(p, &combined->packets, combined_entry, next) { 70 if (!done) { 71 /* Distribute data over uncombined packets */ 72 if (actual_length >= p->iov.size) { 73 p->actual_length = p->iov.size; 74 } else { 75 /* Send short or error packet to complete the transfer */ 76 p->actual_length = actual_length; 77 done = true; 78 } 79 /* Report status on the last packet */ 80 if (done || next == NULL) { 81 p->status = status; 82 } else { 83 p->status = USB_RET_SUCCESS; 84 } 85 p->short_not_ok = short_not_ok; 86 /* Note will free combined when the last packet gets removed! */ 87 usb_combined_packet_remove(combined, p); 88 usb_packet_complete_one(dev, p); 89 actual_length -= p->actual_length; 90 } else { 91 /* Remove any leftover packets from the queue */ 92 p->status = USB_RET_REMOVE_FROM_QUEUE; 93 /* Note will free combined on the last packet! */ 94 dev->port->ops->complete(dev->port, p); 95 } 96 } 97 /* Do not use combined here, it has been freed! */ 98 leave: 99 /* Check if there are packets in the queue waiting for our completion */ 100 usb_ep_combine_input_packets(ep); 101 } 102 103 /* May only be called for combined packets! */ 104 void usb_combined_packet_cancel(USBDevice *dev, USBPacket *p) 105 { 106 USBCombinedPacket *combined = p->combined; 107 assert(combined != NULL); 108 USBPacket *first = p->combined->first; 109 110 /* Note will free combined on the last packet! */ 111 usb_combined_packet_remove(combined, p); 112 if (p == first) { 113 usb_device_cancel_packet(dev, p); 114 } 115 } 116 117 /* 118 * Large input transfers can get split into multiple input packets, this 119 * function recombines them, removing the short_not_ok checks which all but 120 * the last packet of such splits transfers have, thereby allowing input 121 * transfer pipelining (which we cannot do on short_not_ok transfers) 122 */ 123 void usb_ep_combine_input_packets(USBEndpoint *ep) 124 { 125 USBPacket *p, *u, *next, *prev = NULL, *first = NULL; 126 USBPort *port = ep->dev->port; 127 int totalsize; 128 129 assert(ep->pipeline); 130 assert(ep->pid == USB_TOKEN_IN); 131 132 QTAILQ_FOREACH_SAFE(p, &ep->queue, queue, next) { 133 /* Empty the queue on a halt */ 134 if (ep->halted) { 135 p->status = USB_RET_REMOVE_FROM_QUEUE; 136 port->ops->complete(port, p); 137 continue; 138 } 139 140 /* Skip packets already submitted to the device */ 141 if (p->state == USB_PACKET_ASYNC) { 142 prev = p; 143 continue; 144 } 145 usb_packet_check_state(p, USB_PACKET_QUEUED); 146 147 /* 148 * If the previous (combined) packet has the short_not_ok flag set 149 * stop, as we must not submit packets to the device after a transfer 150 * ending with short_not_ok packet. 151 */ 152 if (prev && prev->short_not_ok) { 153 break; 154 } 155 156 if (first) { 157 if (first->combined == NULL) { 158 USBCombinedPacket *combined = g_new0(USBCombinedPacket, 1); 159 160 combined->first = first; 161 QTAILQ_INIT(&combined->packets); 162 qemu_iovec_init(&combined->iov, 2); 163 usb_combined_packet_add(combined, first); 164 } 165 usb_combined_packet_add(first->combined, p); 166 } else { 167 first = p; 168 } 169 170 /* Is this packet the last one of a (combined) transfer? */ 171 totalsize = (p->combined) ? p->combined->iov.size : p->iov.size; 172 if ((p->iov.size % ep->max_packet_size) != 0 || !p->short_not_ok || 173 next == NULL || 174 /* Work around for Linux usbfs bulk splitting + migration */ 175 (totalsize == (16 * KiB - 36) && p->int_req)) { 176 usb_device_handle_data(ep->dev, first); 177 assert(first->status == USB_RET_ASYNC); 178 if (first->combined) { 179 QTAILQ_FOREACH(u, &first->combined->packets, combined_entry) { 180 usb_packet_set_state(u, USB_PACKET_ASYNC); 181 } 182 } else { 183 usb_packet_set_state(first, USB_PACKET_ASYNC); 184 } 185 first = NULL; 186 prev = p; 187 } 188 } 189 } 190