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 | |