xref: /freebsd/sys/dev/usb/usb_mbuf.h (revision 0b57cec536236d46e3dba9bd041533462f33dbb7)
1 /* $FreeBSD$ */
2 /*-
3  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4  *
5  * Copyright (c) 2008 Hans Petter Selasky. All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #ifndef _USB_MBUF_H_
30 #define	_USB_MBUF_H_
31 
32 /*
33  * The following structure defines a minimum re-implementation of the
34  * mbuf system in the kernel.
35  */
36 struct usb_mbuf {
37 	uint8_t *cur_data_ptr;
38 	uint8_t *min_data_ptr;
39 	struct usb_mbuf *usb_nextpkt;
40 	struct usb_mbuf *usb_next;
41 
42 	usb_size_t cur_data_len;
43 	usb_size_t max_data_len;
44 	uint8_t last_packet:1;
45 	uint8_t unused:7;
46 };
47 
48 #define	USB_IF_ENQUEUE(ifq, m) do {		\
49     (m)->usb_nextpkt = NULL;			\
50     if ((ifq)->ifq_tail == NULL)		\
51         (ifq)->ifq_head = (m);			\
52     else					\
53         (ifq)->ifq_tail->usb_nextpkt = (m);	\
54     (ifq)->ifq_tail = (m);			\
55     (ifq)->ifq_len++;				\
56   } while (0)
57 
58 #define	USB_IF_DEQUEUE(ifq, m) do {				\
59     (m) = (ifq)->ifq_head;					\
60     if (m) {							\
61         if (((ifq)->ifq_head = (m)->usb_nextpkt) == NULL) {	\
62 	     (ifq)->ifq_tail = NULL;				\
63 	}							\
64 	(m)->usb_nextpkt = NULL;				\
65 	(ifq)->ifq_len--;					\
66     }								\
67   } while (0)
68 
69 #define	USB_IF_PREPEND(ifq, m) do {		\
70       (m)->usb_nextpkt = (ifq)->ifq_head;	\
71       if ((ifq)->ifq_tail == NULL) {		\
72 	  (ifq)->ifq_tail = (m);		\
73       }						\
74       (ifq)->ifq_head = (m);			\
75       (ifq)->ifq_len++;				\
76   } while (0)
77 
78 #define	USB_IF_QFULL(ifq)   ((ifq)->ifq_len >= (ifq)->ifq_maxlen)
79 #define	USB_IF_QLEN(ifq)    ((ifq)->ifq_len)
80 #define	USB_IF_POLL(ifq, m) ((m) = (ifq)->ifq_head)
81 
82 #define	USB_MBUF_RESET(m) do {			\
83     (m)->cur_data_ptr = (m)->min_data_ptr;	\
84     (m)->cur_data_len = (m)->max_data_len;	\
85     (m)->last_packet = 0;			\
86   } while (0)
87 
88 /* prototypes */
89 void   *usb_alloc_mbufs(struct malloc_type *type, struct usb_ifqueue *ifq,
90 	    usb_size_t block_size, uint16_t nblocks);
91 
92 #endif					/* _USB_MBUF_H_ */
93