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1/* SPDX-License-Identifier: MIT */
2
3/*
4 * usbif.h
5 *
6 * USB I/O interface for Xen guest OSes.
7 *
8 * Copyright (C) 2009, FUJITSU LABORATORIES LTD.
9 * Author: Noboru Iwamatsu <n_iwamatsu@jp.fujitsu.com>
10 */
11
12#ifndef __XEN_PUBLIC_IO_USBIF_H__
13#define __XEN_PUBLIC_IO_USBIF_H__
14
15#include "ring.h"
16#include "../grant_table.h"
17
18/*
19 * Detailed Interface Description
20 * ==============================
21 * The pvUSB interface is using a split driver design: a frontend driver in
22 * the guest and a backend driver in a driver domain (normally dom0) having
23 * access to the physical USB device(s) being passed to the guest.
24 *
25 * The frontend and backend drivers use XenStore to initiate the connection
26 * between them, the I/O activity is handled via two shared ring pages and an
27 * event channel. As the interface between frontend and backend is at the USB
28 * host connector level, multiple (up to 31) physical USB devices can be
29 * handled by a single connection.
30 *
31 * The Xen pvUSB device name is "qusb", so the frontend's XenStore entries are
32 * to be found under "device/qusb", while the backend's XenStore entries are
33 * under "backend/<guest-dom-id>/qusb".
34 *
35 * When a new pvUSB connection is established, the frontend needs to setup the
36 * two shared ring pages for communication and the event channel. The ring
37 * pages need to be made available to the backend via the grant table
38 * interface.
39 *
40 * One of the shared ring pages is used by the backend to inform the frontend
41 * about USB device plug events (device to be added or removed). This is the
42 * "conn-ring".
43 *
44 * The other ring page is used for USB I/O communication (requests and
45 * responses). This is the "urb-ring".
46 *
47 * Feature and Parameter Negotiation
48 * =================================
49 * The two halves of a Xen pvUSB driver utilize nodes within the XenStore to
50 * communicate capabilities and to negotiate operating parameters. This
51 * section enumerates these nodes which reside in the respective front and
52 * backend portions of the XenStore, following the XenBus convention.
53 *
54 * Any specified default value is in effect if the corresponding XenBus node
55 * is not present in the XenStore.
56 *
57 * XenStore nodes in sections marked "PRIVATE" are solely for use by the
58 * driver side whose XenBus tree contains them.
59 *
60 *****************************************************************************
61 * Backend XenBus Nodes
62 *****************************************************************************
63 *
64 *------------------ Backend Device Identification (PRIVATE) ------------------
65 *
66 * num-ports
67 * Values: unsigned [1...31]
68 *
69 * Number of ports for this (virtual) USB host connector.
70 *
71 * usb-ver
72 * Values: unsigned [1...2]
73 *
74 * USB version of this host connector: 1 = USB 1.1, 2 = USB 2.0.
75 *
76 * port/[1...31]
77 * Values: string
78 *
79 * Physical USB device connected to the given port, e.g. "3-1.5".
80 *
81 *****************************************************************************
82 * Frontend XenBus Nodes
83 *****************************************************************************
84 *
85 *----------------------- Request Transport Parameters -----------------------
86 *
87 * event-channel
88 * Values: unsigned
89 *
90 * The identifier of the Xen event channel used to signal activity
91 * in the ring buffer.
92 *
93 * urb-ring-ref
94 * Values: unsigned
95 *
96 * The Xen grant reference granting permission for the backend to map
97 * the sole page in a single page sized ring buffer. This is the ring
98 * buffer for urb requests.
99 *
100 * conn-ring-ref
101 * Values: unsigned
102 *
103 * The Xen grant reference granting permission for the backend to map
104 * the sole page in a single page sized ring buffer. This is the ring
105 * buffer for connection/disconnection requests.
106 *
107 * protocol
108 * Values: string (XEN_IO_PROTO_ABI_*)
109 * Default Value: XEN_IO_PROTO_ABI_NATIVE
110 *
111 * The machine ABI rules governing the format of all ring request and
112 * response structures.
113 *
114 * Protocol Description
115 * ====================
116 *
117 *-------------------------- USB device plug events --------------------------
118 *
119 * USB device plug events are send via the "conn-ring" shared page. As only
120 * events are being sent, the respective requests from the frontend to the
121 * backend are just dummy ones.
122 * The events sent to the frontend have the following layout:
123 * 0 1 2 3 octet
124 * +----------------+----------------+----------------+----------------+
125 * | id | portnum | speed | 4
126 * +----------------+----------------+----------------+----------------+
127 * id - uint16_t, event id (taken from the actual frontend dummy request)
128 * portnum - uint8_t, port number (1 ... 31)
129 * speed - uint8_t, device XENUSB_SPEED_*, XENUSB_SPEED_NONE == unplug
130 *
131 * The dummy request:
132 * 0 1 octet
133 * +----------------+----------------+
134 * | id | 2
135 * +----------------+----------------+
136 * id - uint16_t, guest supplied value (no need for being unique)
137 *
138 *-------------------------- USB I/O request ---------------------------------
139 *
140 * A single USB I/O request on the "urb-ring" has the following layout:
141 * 0 1 2 3 octet
142 * +----------------+----------------+----------------+----------------+
143 * | id | nr_buffer_segs | 4
144 * +----------------+----------------+----------------+----------------+
145 * | pipe | 8
146 * +----------------+----------------+----------------+----------------+
147 * | transfer_flags | buffer_length | 12
148 * +----------------+----------------+----------------+----------------+
149 * | request type specific | 16
150 * | data | 20
151 * +----------------+----------------+----------------+----------------+
152 * | seg[0] | 24
153 * | data | 28
154 * +----------------+----------------+----------------+----------------+
155 * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
156 * +----------------+----------------+----------------+----------------+
157 * | seg[XENUSB_MAX_SEGMENTS_PER_REQUEST - 1] | 144
158 * | data | 148
159 * +----------------+----------------+----------------+----------------+
160 * Bit field bit number 0 is always least significant bit, undefined bits must
161 * be zero.
162 * id - uint16_t, guest supplied value
163 * nr_buffer_segs - uint16_t, number of segment entries in seg[] array
164 * pipe - uint32_t, bit field with multiple information:
165 * bits 0-4: port request to send to
166 * bit 5: unlink request with specified id (cancel I/O) if set (see below)
167 * bit 7: direction (1 = read from device)
168 * bits 8-14: device number on port
169 * bits 15-18: endpoint of device
170 * bits 30-31: request type: 00 = isochronous, 01 = interrupt,
171 * 10 = control, 11 = bulk
172 * transfer_flags - uint16_t, bit field with processing flags:
173 * bit 0: less data than specified allowed
174 * buffer_length - uint16_t, total length of data
175 * request type specific data - 8 bytes, see below
176 * seg[] - array with 8 byte elements, see below
177 *
178 * Request type specific data for isochronous request:
179 * 0 1 2 3 octet
180 * +----------------+----------------+----------------+----------------+
181 * | interval | start_frame | 4
182 * +----------------+----------------+----------------+----------------+
183 * | number_of_packets | nr_frame_desc_segs | 8
184 * +----------------+----------------+----------------+----------------+
185 * interval - uint16_t, time interval in msecs between frames
186 * start_frame - uint16_t, start frame number
187 * number_of_packets - uint16_t, number of packets to transfer
188 * nr_frame_desc_segs - uint16_t number of seg[] frame descriptors elements
189 *
190 * Request type specific data for interrupt request:
191 * 0 1 2 3 octet
192 * +----------------+----------------+----------------+----------------+
193 * | interval | 0 | 4
194 * +----------------+----------------+----------------+----------------+
195 * | 0 | 8
196 * +----------------+----------------+----------------+----------------+
197 * interval - uint16_t, time in msecs until interruption
198 *
199 * Request type specific data for control request:
200 * 0 1 2 3 octet
201 * +----------------+----------------+----------------+----------------+
202 * | data of setup packet | 4
203 * | | 8
204 * +----------------+----------------+----------------+----------------+
205 *
206 * Request type specific data for bulk request:
207 * 0 1 2 3 octet
208 * +----------------+----------------+----------------+----------------+
209 * | 0 | 4
210 * | 0 | 8
211 * +----------------+----------------+----------------+----------------+
212 *
213 * Request type specific data for unlink request:
214 * 0 1 2 3 octet
215 * +----------------+----------------+----------------+----------------+
216 * | unlink_id | 0 | 4
217 * +----------------+----------------+----------------+----------------+
218 * | 0 | 8
219 * +----------------+----------------+----------------+----------------+
220 * unlink_id - uint16_t, request id of request to terminate
221 *
222 * seg[] array element layout:
223 * 0 1 2 3 octet
224 * +----------------+----------------+----------------+----------------+
225 * | gref | 4
226 * +----------------+----------------+----------------+----------------+
227 * | offset | length | 8
228 * +----------------+----------------+----------------+----------------+
229 * gref - uint32_t, grant reference of buffer page
230 * offset - uint16_t, offset of buffer start in page
231 * length - uint16_t, length of buffer in page
232 *
233 *-------------------------- USB I/O response --------------------------------
234 *
235 * 0 1 2 3 octet
236 * +----------------+----------------+----------------+----------------+
237 * | id | start_frame | 4
238 * +----------------+----------------+----------------+----------------+
239 * | status | 8
240 * +----------------+----------------+----------------+----------------+
241 * | actual_length | 12
242 * +----------------+----------------+----------------+----------------+
243 * | error_count | 16
244 * +----------------+----------------+----------------+----------------+
245 * id - uint16_t, id of the request this response belongs to
246 * start_frame - uint16_t, start_frame this response (iso requests only)
247 * status - int32_t, XENUSB_STATUS_* (non-iso requests)
248 * actual_length - uint32_t, actual size of data transferred
249 * error_count - uint32_t, number of errors (iso requests)
250 */
251
252enum xenusb_spec_version {
253 XENUSB_VER_UNKNOWN = 0,
254 XENUSB_VER_USB11,
255 XENUSB_VER_USB20,
256 XENUSB_VER_USB30, /* not supported yet */
257};
258
259/*
260 * USB pipe in xenusb_request
261 *
262 * - port number: bits 0-4
263 * (USB_MAXCHILDREN is 31)
264 *
265 * - operation flag: bit 5
266 * (0 = submit urb,
267 * 1 = unlink urb)
268 *
269 * - direction: bit 7
270 * (0 = Host-to-Device [Out]
271 * 1 = Device-to-Host [In])
272 *
273 * - device address: bits 8-14
274 *
275 * - endpoint: bits 15-18
276 *
277 * - pipe type: bits 30-31
278 * (00 = isochronous, 01 = interrupt,
279 * 10 = control, 11 = bulk)
280 */
281
282#define XENUSB_PIPE_PORT_MASK 0x0000001f
283#define XENUSB_PIPE_UNLINK 0x00000020
284#define XENUSB_PIPE_DIR 0x00000080
285#define XENUSB_PIPE_DEV_MASK 0x0000007f
286#define XENUSB_PIPE_DEV_SHIFT 8
287#define XENUSB_PIPE_EP_MASK 0x0000000f
288#define XENUSB_PIPE_EP_SHIFT 15
289#define XENUSB_PIPE_TYPE_MASK 0x00000003
290#define XENUSB_PIPE_TYPE_SHIFT 30
291#define XENUSB_PIPE_TYPE_ISOC 0
292#define XENUSB_PIPE_TYPE_INT 1
293#define XENUSB_PIPE_TYPE_CTRL 2
294#define XENUSB_PIPE_TYPE_BULK 3
295
296#define xenusb_pipeportnum(pipe) ((pipe) & XENUSB_PIPE_PORT_MASK)
297#define xenusb_setportnum_pipe(pipe, portnum) ((pipe) | (portnum))
298
299#define xenusb_pipeunlink(pipe) ((pipe) & XENUSB_PIPE_UNLINK)
300#define xenusb_pipesubmit(pipe) (!xenusb_pipeunlink(pipe))
301#define xenusb_setunlink_pipe(pipe) ((pipe) | XENUSB_PIPE_UNLINK)
302
303#define xenusb_pipein(pipe) ((pipe) & XENUSB_PIPE_DIR)
304#define xenusb_pipeout(pipe) (!xenusb_pipein(pipe))
305
306#define xenusb_pipedevice(pipe) \
307 (((pipe) >> XENUSB_PIPE_DEV_SHIFT) & XENUSB_PIPE_DEV_MASK)
308
309#define xenusb_pipeendpoint(pipe) \
310 (((pipe) >> XENUSB_PIPE_EP_SHIFT) & XENUSB_PIPE_EP_MASK)
311
312#define xenusb_pipetype(pipe) \
313 (((pipe) >> XENUSB_PIPE_TYPE_SHIFT) & XENUSB_PIPE_TYPE_MASK)
314#define xenusb_pipeisoc(pipe) (xenusb_pipetype(pipe) == XENUSB_PIPE_TYPE_ISOC)
315#define xenusb_pipeint(pipe) (xenusb_pipetype(pipe) == XENUSB_PIPE_TYPE_INT)
316#define xenusb_pipectrl(pipe) (xenusb_pipetype(pipe) == XENUSB_PIPE_TYPE_CTRL)
317#define xenusb_pipebulk(pipe) (xenusb_pipetype(pipe) == XENUSB_PIPE_TYPE_BULK)
318
319#define XENUSB_MAX_SEGMENTS_PER_REQUEST (16)
320#define XENUSB_MAX_PORTNR 31
321#define XENUSB_RING_SIZE 4096
322
323/*
324 * RING for transferring urbs.
325 */
326struct xenusb_request_segment {
327 grant_ref_t gref;
328 uint16_t offset;
329 uint16_t length;
330};
331
332struct xenusb_urb_request {
333 uint16_t id; /* request id */
334 uint16_t nr_buffer_segs; /* number of urb->transfer_buffer segments */
335
336 /* basic urb parameter */
337 uint32_t pipe;
338 uint16_t transfer_flags;
339#define XENUSB_SHORT_NOT_OK 0x0001
340 uint16_t buffer_length;
341 union {
342 uint8_t ctrl[8]; /* setup_packet (Ctrl) */
343
344 struct {
345 uint16_t interval; /* maximum (1024*8) in usb core */
346 uint16_t start_frame; /* start frame */
347 uint16_t number_of_packets; /* number of ISO packet */
348 uint16_t nr_frame_desc_segs; /* number of iso_frame_desc segments */
349 } isoc;
350
351 struct {
352 uint16_t interval; /* maximum (1024*8) in usb core */
353 uint16_t pad[3];
354 } intr;
355
356 struct {
357 uint16_t unlink_id; /* unlink request id */
358 uint16_t pad[3];
359 } unlink;
360
361 } u;
362
363 /* urb data segments */
364 struct xenusb_request_segment seg[XENUSB_MAX_SEGMENTS_PER_REQUEST];
365};
366
367struct xenusb_urb_response {
368 uint16_t id; /* request id */
369 uint16_t start_frame; /* start frame (ISO) */
370 int32_t status; /* status (non-ISO) */
371#define XENUSB_STATUS_OK 0
372#define XENUSB_STATUS_NODEV (-19)
373#define XENUSB_STATUS_INVAL (-22)
374#define XENUSB_STATUS_STALL (-32)
375#define XENUSB_STATUS_IOERROR (-71)
376#define XENUSB_STATUS_BABBLE (-75)
377#define XENUSB_STATUS_SHUTDOWN (-108)
378 int32_t actual_length; /* actual transfer length */
379 int32_t error_count; /* number of ISO errors */
380};
381
382DEFINE_RING_TYPES(xenusb_urb, struct xenusb_urb_request, struct xenusb_urb_response);
383#define XENUSB_URB_RING_SIZE __CONST_RING_SIZE(xenusb_urb, XENUSB_RING_SIZE)
384
385/*
386 * RING for notifying connect/disconnect events to frontend
387 */
388struct xenusb_conn_request {
389 uint16_t id;
390};
391
392struct xenusb_conn_response {
393 uint16_t id; /* request id */
394 uint8_t portnum; /* port number */
395 uint8_t speed; /* usb_device_speed */
396#define XENUSB_SPEED_NONE 0
397#define XENUSB_SPEED_LOW 1
398#define XENUSB_SPEED_FULL 2
399#define XENUSB_SPEED_HIGH 3
400};
401
402DEFINE_RING_TYPES(xenusb_conn, struct xenusb_conn_request, struct xenusb_conn_response);
403#define XENUSB_CONN_RING_SIZE __CONST_RING_SIZE(xenusb_conn, XENUSB_RING_SIZE)
404
405#endif /* __XEN_PUBLIC_IO_USBIF_H__ */