xref: /freebsd/sys/dev/usb/usb_mbuf.h (revision f126890ac5386406dadf7c4cfa9566cbb56537c5)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2008 Hans Petter Selasky. All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #ifndef _USB_MBUF_H_
29 #define	_USB_MBUF_H_
30 
31 /*
32  * The following structure defines a minimum re-implementation of the
33  * mbuf system in the kernel.
34  */
35 struct usb_mbuf {
36 	uint8_t *cur_data_ptr;
37 	uint8_t *min_data_ptr;
38 	struct usb_mbuf *usb_nextpkt;
39 	struct usb_mbuf *usb_next;
40 
41 	usb_size_t cur_data_len;
42 	usb_size_t max_data_len;
43 	uint8_t last_packet:1;
44 	uint8_t unused:7;
45 };
46 
47 #define	USB_IF_ENQUEUE(ifq, m) do {		\
48     (m)->usb_nextpkt = NULL;			\
49     if ((ifq)->ifq_tail == NULL)		\
50         (ifq)->ifq_head = (m);			\
51     else					\
52         (ifq)->ifq_tail->usb_nextpkt = (m);	\
53     (ifq)->ifq_tail = (m);			\
54     (ifq)->ifq_len++;				\
55   } while (0)
56 
57 #define	USB_IF_DEQUEUE(ifq, m) do {				\
58     (m) = (ifq)->ifq_head;					\
59     if (m) {							\
60         if (((ifq)->ifq_head = (m)->usb_nextpkt) == NULL) {	\
61 	     (ifq)->ifq_tail = NULL;				\
62 	}							\
63 	(m)->usb_nextpkt = NULL;				\
64 	(ifq)->ifq_len--;					\
65     }								\
66   } while (0)
67 
68 #define	USB_IF_PREPEND(ifq, m) do {		\
69       (m)->usb_nextpkt = (ifq)->ifq_head;	\
70       if ((ifq)->ifq_tail == NULL) {		\
71 	  (ifq)->ifq_tail = (m);		\
72       }						\
73       (ifq)->ifq_head = (m);			\
74       (ifq)->ifq_len++;				\
75   } while (0)
76 
77 #define	USB_IF_QFULL(ifq)   ((ifq)->ifq_len >= (ifq)->ifq_maxlen)
78 #define	USB_IF_QLEN(ifq)    ((ifq)->ifq_len)
79 #define	USB_IF_POLL(ifq, m) ((m) = (ifq)->ifq_head)
80 
81 #define	USB_MBUF_RESET(m) do {			\
82     (m)->cur_data_ptr = (m)->min_data_ptr;	\
83     (m)->cur_data_len = (m)->max_data_len;	\
84     (m)->last_packet = 0;			\
85   } while (0)
86 
87 /* prototypes */
88 void   *usb_alloc_mbufs(struct malloc_type *type, struct usb_ifqueue *ifq,
89 	    usb_size_t block_size, uint16_t nblocks);
90 
91 #endif					/* _USB_MBUF_H_ */
92